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Breakdown of Cell Wall Nanostructure in Dilute Acid Pretreated Biomass
Science Conference Proceedings (OSTI)
The generation of bioethanol from lignocellulosic biomass holds great promise for renewable and clean energy production. A better understanding of the complex mechanisms of lignocellulose breakdown during various pretreatment methods is needed to realize this potential in a cost and energy efficient way. Here, we use small-angle neutron scattering (SANS) to characterize morphological changes in switchgrass lignocellulose across molecular to sub-micron length scales resulting from the industrially-relevant dilute acid pretreatment method. Our results demonstrate that dilute acid pretreatment increases the cross-sectional radius of the crystalline cellulose fibril. This change is accompanied by removal of hemicellulose and the formation of Rg ~ 135 lignin aggregates. The structural signature of smooth cell wall surfaces is observed at length scales larger than 1000 , and it remains remarkably invariable during pretreatment. This study elucidates the interplay of the different biomolecular components in the break down process of switchgrass by dilute acid pretreatment. The results are important for the development of efficient strategies of biomass to biofuel conversion.
Pingali, Sai Venkatesh [ORNL; Urban, Volker S [ORNL; Heller, William T [ORNL; McGaughey, Joseph [ORNL; O'Neill, Hugh Michael [ORNL; Foston, Marcus B [ORNL; Myles, Dean A A [ORNL; Ragauskas, Arthur J [ORNL; Evans, Barbara R [ORNL
Cellulase Accessibility of Dilute-Acid Pretreated Corn Stover
SciTech Connect
The conclusions of this presentation are: (1) The dilute-acid pretreatment reduces xylan content in corn stover. This reduction in xylan content appears to render the substrate less recalcitrant. Below {approx}8%, xylan content is no longer the dominant factor in biomass recalcitrance. (2) Decreasing xylan content of corn stover also created more binding sites for Cel7A, but no strong correlation with actual xylan content. (3) We found no correlation between bound Cel7A concentration and lignin content. Maybe lignin is blocking the way for Cel7A? The contribution of lignin to biomass recalcitrance requires further investigation.
Jeoh, T.; Johnson, D. K.; Adney, W. S.; Himmel, M. E.
Changes in lignocellulosic supramolecular and ultrastructure during dilute acid pretreatment of Populus and switchgrass
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lignocellulosic lignocellulosic supramolecular and ultrastructure during dilute acid pretreatment of Populus and switchgrass Marcus Foston, Art J. Ragauskas* BioEnergy Science Center, School of Chemistry and Biochemistry, Institute of Paper Science and Technology, Georgia Institute of Technology, 500 10th St., Atlanta, GA 30332, USA a r t i c l e i n f o Article history: Received 23 March 2009 Received in revised form 17 July 2010 Accepted 23 July 2010 Available online xxx Keywords: Dilute acid pretreatment Cellulose Supramolecular structure Populus Switchgrass a b s t r a c t Dilute acid pretreatment (DAP) is commonly employed prior to enzymatic deconstruction of cellulose to increase overall sugar and subsequent ethanol yields from downstream bioconversion processes. Typically optimization of pretreatment is evaluated by deter- mining hemicellulose removal, subsequent reactivity towards
High Xylose Yields from Dilute Acid Pretreatment of Corn Stover Under Process-Relevant Conditions
Pretreatment experiments were carried out to demonstrate high xylose yields at high solids loadings in two different batch pretreatment reactors under process-relevant conditions. Corn stover was pretreated with dilute sulfuric acid using a 4-l Steam Digester and a 4-l stirred ZipperClave{reg_sign} reactor. Solids were loaded at 45% dry matter (wt/wt) after sulfuric acid catalyst impregnation using nominal particle sizes of either 6 or 18 mm. Pretreatment was carried out at temperatures between 180 and 200 C at residence times of either 90 or 105 s. Results demonstrate an ability to achieve high xylose yields (>80%) over a range of pretreatment conditions, with performance showing little dependence on particle size or pretreatment reactor type. The high xylose yields are attributed to effective catalyst impregnation and rapid rates of heat transfer during pretreatment.
Weiss, N. D.; Nagle, N. J.; Tucker, M. P.; Elander, R. T.
Impact of Corn Stover Composition on Hemicellulose Conversion during Dilute Acid Pretreatment and Enzymatic Cellulose Digestibility of the Pretreated Solids
This study assessed the impact of corn stover compositional variability on xylose conversion yields during dilute acid pretreatment and on enzymatic cellulose digestibility of the resulting pretreated solids. Seven compositionally-different stovers obtained from various locations throughout the United States were pretreated at three different conditions in triplicate in a pilot-scale continuous reactor. At the same pretreatment severity, a 2-fold increase in monomeric xylose yield and a 1.5-fold increase in enzymatic cellulose digestibility from their lowest values were found. Similar results were observed at the other pretreatment conditions. It was found that xylose conversion yields decreased with increasing acid neutralization capacity or soil content of the corn stover. Xylose yields also increased with increasing xylan content. No other significant correlations between corn stover's component concentrations and conversion yields were found.
Weiss, N. D.; Farmer, J. D.; Schell, D. J.
Redistribution of Lignin Caused by Dilute Acid Pretreatment of Biomass
Research conducted at NREL has shown that lignin undergoes a phase transition during thermochemical pretreatments conducted above its glass transition temperature. The lignin coalesces within the plant cell wall and appears as microscopic droplets on cell surfaces. It is clear that pretreatment causes significant changes in lignin distribution in pretreatments at all scales from small laboratory reactors to pilot scale reactors. A method for selectively extracting lignin droplets from the surfaces of pretreated cell walls has allowed us to characterize the chemical nature and molecular weight distribution of this fraction. The effect of lignin redistribution on the digestibility of pretreated solids has also been tested. It is clear that removal of the droplets increases the digestibility of pretreated corn stover. The improved digestibility could be due to decreased non-specific binding of enzymes to lignin in the droplets, or because the droplets no longer block access to cellulose.
Johnson, D. K.; Donohoe, B. S.; Katahira, R.; Tucker, M. P.; Vinzant, T. B.; Himmel, M. E.
Measurement of Porosity in Dilute Acid Pretreated Corn Stover
The conclusions of this report are: (1) pretreated corn stover appeared to have more accessible pore volume than raw corn stover; (2) solute exclusion method--differences in the pore volume were not detectable due to the high variability of the measurements; (3) thermoporosimetry--differences in pore volume between pretreated samples were not observed despite the low variability of the measurement and a good correction was found between unfrozen water at 240K and xylan content; and (4) porosity measurements showed no correlation between ethanol yields and the volume accessible to an enzyme size probe, for this sample set.
Ishizawa, C.; Davis, M. F.; Johnson, D. K.
Impacts of Deacetylation Prior to Dilute Acid Pretreatment on the Bioethanol Process
Dilute acid pretreatment is a promising pretreatment technology for the biochemical production of ethanol from lignocellulosic biomass. During dilute acid pretreatment, xylan depolymerizes to form soluble xylose monomers and oligomers. Because the xylan found in nature is highly acetylated, the formation of xylose monomers requires two steps: (1) cleavage of the xylosidic bonds, and (2) cleavage of covalently bonded acetyl ester groups. Results: In this study, we show that the latter may be the rate limiting step for xylose monomer formation. Furthermore, acetyl groups are also found to be a cause of biomass recalcitrance and hydrolyzate toxicity. While the removal of acetyl groups from native corn stover by alkaline de-esterification prior to pretreatment improves overall process yields, the exact impact is highly dependent on the corn stover variety in use. Xylose monomer yields in pretreatment generally increases by greater than 10%. Compared to pretreated corn stover controls, the deacetylated corn stover feedstock is approximately 20% more digestible after pretreatment. Finally, by lowering hydrolyzate toxicity, xylose utilization and ethanol yields are further improved during fermentation by roughly 10% and 7%, respectively. In this study, several varieties of corn stover lots were investigated to test the robustness of the deacetylation-pretreatment-saccharification-fermentation process. Conclusions: Deacetylation shows significant improvement on glucose and xylose yields during pretreatment and enzymatic hydrolysis, but it also reduces hydrolyzate toxicity during fermentation, thereby improving ethanol yields and titer. The magnitude of effect is dependent on the selected corn stover variety, with several varieties achieving improvements of greater than 10% xylose yield in pretreatment, 20% glucose yield in low solids enzymatic hydrolysis and 7% overall ethanol yield.
Chen, X.; Shekiro, J.; Franden, M. A.; Wang, W.; Johnson, D. K.; Zhang, M.; Kuhn, E.; Tucker, M. P.
Improved Multivariate Calibration Models for Corn Stover Feedstock and Dilute-Acid Pretreated Corn Stover
We have studied rapid calibration models to predict the composition of a variety of biomass feedstocks by correlating near-infrared (NIR) spectroscopic data to compositional data produced using traditional wet chemical analysis techniques. The rapid calibration models are developed using multivariate statistical analysis of the spectroscopic and wet chemical data. This work discusses the latest versions of the NIR calibration models for corn stover feedstock and dilute-acid pretreated corn stover. Measures of the calibration precision and uncertainty are presented. No statistically significant differences (p = 0.05) are seen between NIR calibration models built using different mathematical pretreatments. Finally, two common algorithms for building NIR calibration models are compared; no statistically significant differences (p = 0.05) are seen for the major constituents glucan, xylan, and lignin, but the algorithms did produce different predictions for total extractives. A single calibration model combining the corn stover feedstock and dilute-acid pretreated corn stover samples gave less satisfactory predictions than the separate models.
Wolfrum, E. J.; Sluiter, A. D.
Effects of Dilute Acid Pretreatment on Cellulose DP and the Relationship Between DP Reduction and Cellulose Digestibility
The degree of polymerization(DP) of cellulose is considered to be one of the most important properties affecting the enzymatic hydrolysis of cellulose. Various pure cellulosic and biomass materials have been used in a study of the effect of dilute acid treatment on cellulose DP. A substantial reduction in DP was found for all pure cellulosic materials studied even at conditions that would be considered relatively mild for pretreatment. The effect of dilute acid pretreatment on cellulose DP in biomass samples was also investigated. Corn stover pretreated with dilute acid under the most optimal conditions contained cellulose with a DPw in the range of 1600{approx}3500, which is much higher than the level-off DP(DPw 150{approx}300) obtained with pure celluloses. The effect of DP reduction on the saccharification of celluloses was also studied. From this study it does not appear that cellulose DP is a main factor affecting cellulose saccharification.
Wang, W.; Chen, X.; Tucker, M.; Himmel, M. E.; Johnson, D. K.
Combined Dilute Acid and Solvent Based Pretreatment of Agricultural Wastes for Efficient Lignocellulosic Fractionation and Biofuels Production
A true biorefinery for processing lignocellulosic biomass should achieve maximum utilization of all major constituents (cellulose, hemicellulose, & lignin) within the feedstock. In this work a combined pretreatment process of dilute acid (DA) and N-methyl morpholine N-oxide (NMMO) is described that allows for both fractionation and subsequent complete hydrolysis of the feedstocks (corn stover and sugarcane bagasse). During this multi-step processing, the dilute acid pretreatment solubilizes the majority (>90%) of the hemicellulosic fraction, while the NMMO treatment yields a cellulosic fraction that is completely digestible within 48 hours at low enzyme loadings. With both the cellulosic and hemicellulosic fractions being converted into separate, dissolved sugar fractions, the remaining portion is nearly pure lignin. When used independently, DA and NMMO pretreatments are only able to achieve ~80% and ~45% cellulosic conversion, respectively. Mass balance calculations along with experimental results are used to illustrate the feasibility of separation and recycling of NMMO.
Brodeur, G.; Ramakrishnan, S.; Wilson, C.; Telotte, J.; Collier, J.; Stickel, J.
Effect of pelleting on the recalcitrance and bioconversion of dilute-acid pretreated corn stover
Background: Knowledge regarding the performance of densified biomass in biochemical processes is limited. The effects of densification on biochemical conversion are explored here. Methods: Pelleted corn stover samples were generated from bales that were milled to 6.35 mm. Low-solids acid pretreatment and simultaneous saccharification and fermentation were performed to evaluate pretreatment efficacy and ethanol yields achieved for pelleted and ground stover (6.35 mm and 2 mm) samples. Both pelleted and 6.35-mm ground stover were evaluated using a ZipperClave� reactor under high-solids, process-relevant conditions for multiple pretreatment severities (Ro), followed by enzymatic hydrolysis of the washed, pretreated solids. Results: Monomeric xylose yields were significantly higher for pellets (approximately 60%) than for ground formats (approximately 38%). Pellets achieved approximately 84% of theoretical ethanol yield (TEY); ground stover formats had similar profiles, reaching approximately 68% TEY. Pelleting corn stover was not detrimental to pretreatment efficacy for both low- and high-solids conditions, and even enhanced ethanol yields.
Allison E Ray; Amber Hoover; Gary Gresham
Comparative Study of Corn Stover Pretreated by Dilute Acid and Cellulose Solvent-Based Lignocellulose Fractionation: Enzymatic Hydrolysis, Supramolecular Structure, and Substrate Accessibility
Liberation of fermentable sugars from recalcitrant biomass is among the most costly steps for emerging cellulosic ethanol production. Here we compared two pretreatment methods (dilute acid, DA, and cellulose solvent and organic solvent lignocellulose fractionation, COSLIF) for corn stover. At a high cellulase loading [15 filter paper units (FPUs) or 12.3 mg cellulase per gram of glucan], glucan digestibilities of the corn stover pretreated by DA and COSLIF were 84% at hour 72 and 97% at hour 24, respectively. At a low cellulase loading (5 FPUs per gram of glucan), digestibility remained as high as 93% at hour 24 for the COSLIF-pretreated corn stover but reached only {approx}60% for the DA-pretreated biomass. Quantitative determinations of total substrate accessibility to cellulase (TSAC), cellulose accessibility to cellulase (CAC), and non-cellulose accessibility to cellulase (NCAC) based on adsorption of a non-hydrolytic recombinant protein TGC were measured for the first time. The COSLIF-pretreated corn stover had a CAC of 11.57 m{sup 2}/g, nearly twice that of the DA-pretreated biomass (5.89 m{sup 2}/g). These results, along with scanning electron microscopy images showing dramatic structural differences between the DA- and COSLIF-pretreated samples, suggest that COSLIF treatment disrupts microfibrillar structures within biomass while DA treatment mainly removes hemicellulose. Under the tested conditions COSLIF treatment breaks down lignocellulose structure more extensively than DA treatment, producing a more enzymatically reactive material with a higher CAC accompanied by faster hydrolysis rates and higher enzymatic digestibility.
Zhu, Z.; Sathitsuksanoh, N.; Vinzant, T.; Schell, D. J.; McMillian, J. D.; Zhang, Y. H. P.
Process Design and Economics for Biochemical Conversion of Lignocellulosic Biomass to Ethanol: Dilute-Acid Pretreatment and Enzymatic Hydrolysis of Corn Stover
Biochemical Conversion of Biochemical Conversion of Lignocellulosic Biomass to Ethanol Dilute-Acid Pretreatment and Enzymatic Hydrolysis of Corn Stover D. Humbird, R. Davis, L. Tao, C. Kinchin, D. Hsu, and A. Aden National Renewable Energy Laboratory Golden, Colorado P. Schoen, J. Lukas, B. Olthof, M. Worley, D. Sexton, and D. Dudgeon Harris Group Inc. Seattle, Washington and Atlanta, Georgia Technical Report NREL/TP-5100-47764 May 2011 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401 303-275-3000 * www.nrel.gov Contract No. DE-AC36-08GO28308
This report describes one potential biochemical ethanol conversion process, conceptually based upon core conversion and process integration research at NREL. The overarching process design converts corn stover to ethanol by dilute-acid pretreatment, enzymatic saccharification, and co-fermentation. Building on design reports published in 2002 and 1999, NREL, together with the subcontractor Harris Group Inc., performed a complete review of the process design and economic model for the biomass-to-ethanol process. This update reflects NREL's current vision of the biochemical ethanol process and includes the latest research in the conversion areas (pretreatment, conditioning, saccharification, and fermentation), optimizations in product recovery, and our latest understanding of the ethanol plant's back end (wastewater and utilities). The conceptual design presented here reports ethanol production economics as determined by 2012 conversion targets and 'nth-plant' project costs and financing. For the biorefinery described here, processing 2,205 dry ton/day at 76% theoretical ethanol yield (79 gal/dry ton), the ethanol selling price is $2.15/gal in 2007$.
Humbird, D.; Davis, R.; Tao, L.; Kinchin, C.; Hsu, D.; Aden, A.; Schoen, P.; Lukas, J.; Olthof, B.; Worley, M.; Sexton, D.; Dudgeon, D.
Carbonic Acid Pretreatment of Biomass
This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. 1) Solidify the theoretical understanding of the binary CO2/H2O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. 2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. 3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. 4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. 5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic acid compared to water alone. 6) Determine optimal conditions for carbonic acid pretreatment of aspen wood. Optimal severities appeared to be in the mid range tested. ASPEN-Plus modeling and economic analysis of the process indicate that the process could be cost competitive with sulfuric acid if the concentration of solids in the pretreatment is maintained very high (~50%). Lower solids concentrations result in larger reactors that become expensive to construct for high pressure applications.
G. Peter van Walsum; Kemantha Jayawardhana; Damon Yourchisin; Robert McWilliams; Vanessa Castleberry
Can Delignification Decrease Cellulose Digestibility in Acid Pretreated Corn Stover?
It has previously been shown that the improved digestibility of dilute acid pretreated corn stover is at least partially due to the removal of xylan and the consequent increase in accessibility of the cellulose to cellobiohydrolase enzymes. We now report on the impact that lignin removal has on the accessibility and digestibility of dilute acid pretreated corn stover. Samples of corn stover were subjected to dilute sulfuric acid pretreatment with and without simultaneous (partial) lignin removal. In addition, some samples were completely delignified after the pretreatment step using acidified sodium chlorite. The accessibility and digestibility of the samples were tested using a fluorescence-labeled cellobiohydrolase (Trichoderma reesei Cel7A) purified from a commercial cellulase preparation. Partial delignification of corn stover during dilute acid pretreatment was shown to improve cellulose digestibility by T. reesei Cel7A; however, decreasing the lignin content below 5% (g g{sup -1}) by treatment with acidified sodium chlorite resulted in a dramatic reduction in cellulose digestibility. Importantly, this effect was found to be enhanced in samples with lower xylan contents suggesting that the near complete removal of xylan and lignin may cause aggregation of the cellulose microfibrils resulting in decreased cellulase accessibility.
Ishizawa, C. I.; Jeoh, T.; Adney, W. S.; Himmel, M. E.; Johnson, D. K.; Davis, M. F.
Two-stage dilute acid prehydrolysis of biomass
DOE Patents (OSTI)
The invention relates to a two stage dilute acid prehydrolysis of biomass for solubilization of hemicellulosic sugars and a pretreatment for enzymatic hydrolysis of cellulose. In particular, the invention pertains to a two stage dilute acid prehydrolysis treatment of a feedstock of hemicellulosic material comprising xylan that is slow hydrolyzable and xylan that is fast hydrolyzable under low temperature conditions to hydrolyze said fast hydrolyzable xylan to xylose; removing said xylose and leaving a feedstock residue containing said slow hydrolyzable xylan; treating said residue containing said slow hydrolyzable xylan with a dilute organic or inorganic acid under temperature conditions higher than said low temperature conditions to hydrolyze said slow hydrolyzable xylan to xylose, and removing said xylose.
Grohmann, K.; Torget, R.W.
Dilute acid/metal salt hydrolysis of lignocellulosics
A modified dilute acid method of hydrolyzing the cellulose and hemicellulose in lignocellulosic material under conditions to obtain higher overall fermentable sugar yields than is obtainable using dilute acid alone, comprising: impregnating a lignocellulosic feedstock with a mixture of an amount of aqueous solution of a dilute acid catalyst and a metal salt catalyst sufficient to provide higher overall fermentable sugar yields than is obtainable when hydrolyzing with dilute acid alone; loading the impregnated lignocellulosic feedstock into a reactor and heating for a sufficient period of time to hydrolyze substantially all of the hemicellulose and greater than 45% of the cellulose to water soluble sugars; and recovering the water soluble sugars.
Nguyen, Quang A. (Golden, CO); Tucker, Melvin P. (Lakewood, CO)
A two-stage dilute acid prehydrolysis process on xylan containing hemicellulose in biomass is effected by: treating feedstock of hemicellulosic material comprising xylan that is slow hydrolyzable and xylan that is fast hydrolyzable under predetermined low temperature conditions with a dilute acid for a residence time sufficient to hydrolyze the fast hydrolyzable xylan to xylose; removing said xylose from said fast hydrolyzable xylan and leaving a residue; and treating said residue having a slow hydrolyzable xylan with a dilute acid under predetermined high temperature conditions for a residence time required to hydrolyze said slow hydrolyzable xylan to xylose.
Grohmann, Karel (Winter Haven, FL); Torget, Robert W. (Littleton, CO)
Ethanol production with dilute acid hydrolysis using partially dried lignocellulosics
A process of converting lignocellulosic biomass to ethanol, comprising hydrolyzing lignocellulosic materials by subjecting dried lignocellulosic material in a reactor to a catalyst comprised of a dilute solution of a strong acid and a metal salt to lower the activation energy (i.e., the temperature) of cellulose hydrolysis and ultimately obtain higher sugar yields.
Nguyen, Quang A. (Chesterfield, MO); Keller, Fred A. (Lakewood, CO); Tucker, Melvin P. (Lakewood, CO)
Sulfuric Acid Pretreatment and Enzymatic Hydrolysis of Photoperiod Sensitvie Sorghum for Ethanol Production
Photoperiod sensitive (PS) sorghum, with high soluble sugar content, high mass yield and high drought tolerance in dryland environments, has great potential for bioethanol production. The effect of diluted sulfuric acid pretreatment on enzymatic hydrolysis was investigated. Hydrolysis efficiency increased from 78.9 to 94.4% as the acid concentration increased from 0.5 to 1.5%. However, the highest total glucose yield (80.3%) occurred at the 1.0% acid condition because of the significant cellulose degradation at the 1.5% concentration. Synchrotron wide-angle X-ray diffraction was used to study changes of the degree of crystallinity. With comparison of cellulosic crystallinity and adjusted cellulosic crystallinity, the crystalline cellulose decreased after low acidic concentration (0.5%) applied, but did not change significantly, as the acid concentration increased. Scanning electron microscopy was also employed to understand how the morphological structure of PS sorghum changed after pretreatment. Under current processing conditions, the total ethanol yield is 74.5% (about 0.2 g ethanol from 1 g PS sorghum). A detail mass balance was also provided.
F Xu; Y Shi; X Wu
Pretreatment and Fermentation of Sugarcane Trash to Carboxylic Acids
E-Print Network (OSTI)
The rising price of oil is hurting consumers all over the world. There is growing interest in producing biofuels from non-food crops, such as sugarcane trash. Lignocellulosic biomass (e.g., sugarcane trash) is an abundant, inexpensive, and renewable resource. The patented MixAlco process is a cost-effective solution, which does not require sterility or the addition of expensive enzymes to convert lignocellulosic biomass to transportation fuels and valuable chemicals. In this study, the MixAlco process was used to convert sugarcane trash to carboxylic acids under thermophilic conditions. Lime-treated sugarcane trash (80%) and chicken manure (20%) was used as the feedstock in rotary 1-L fermentors. Ammonium bicarbonate buffer was used to mitigate the effects of product (carboxylic acid) inhibition. Marine inoculum was used because of the high adaptability of the mixed culture of microorganisms present. Iodoform solution was added to inhibit methanogenesis. Preliminary batch studies over a 20-day period produced 19.7 g/L of carboxylic acids. Sugarcane trash had the highest average yield (0.31 g total acid/g VS fed) and highest average conversion (0.70 g VS digested/g VS fed) among the three substrates compared. Countercurrent fermentations were performed at various volatile solid loading rates (VSLR) and liquid residence times (LRT). The highest acid productivity of 1.40 g/(L?d) was at a total acid concentration of 29.9 g/L. The highest conversion and yield were 0.64 g VS digested/g VS fed and 0.36 g total acid/g VS fed, respectively. The continuum particle distribution model (CPDM) was used to predict acid concentration at various VSLR and LRT. The average error in between the predicted and experimental acid concentration and conversion were 4.62% and 1.42%, respectively. The effectiveness of several pretreatment methods was evaluated using the CPDM method. The best-performing method was short-term, no-wash, oxidative lime pretreatment with ball milling. At an industrial-scale solids loading of 300 g VS/L liquid, the CPDM ?map? predicts a total acid concentration of 64.0 g/L at LRT of 30 days, VSLR of 7 g/(L?d), and conversion of 57%. Also high conversion of 76% and high acid concentration of 52 g/L are achieved at a VSLR of 4 g/(L?d) and LRT of 30 days.
Nachiappan, Balasubraman
Pretreatment of solid carbonaceous material with dicarboxylic aromatic acids to prevent scale formation
Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by pretreatment with a pretreating agent selected from the group consisting of phthalic acid, phthalic anhydride, pyromellitic acid and pyromellitic anhydride. The pretreatment is believed to convert the scale-forming components to the corresponding phthalate and/or pyromellitate prior to liquefaction. The pretreatment is accomplished at a total pressure within the range from about 1 to about 2 atmospheres. Temperature during pretreatment will generally be within the range from about 5.degree. to about 80.degree. C.
Brunson, Roy J. (Buffalo Grove, IL)
Practical Guide to Vegetable Oil ProcessingChapter 3 Crude Oil De-gumming and Acid Pre-treatment
Practical Guide to Vegetable Oil Processing Chapter 3 Crude Oil De-gumming and Acid Pre-treatment Processing eChapters Processing Press Downloadable pdf of Chapter 3 Crude Oil De-gumming and Acid Pre-treatment fro
Due to concerns with biomass collection systems and soil sustainability there are opportunities to investigate the optimal plant fractions to collect for conversion. An ideal feedstock would require low severity pretreatment to release a maximum amount of sugar during enzymatic hydrolysis. Corn stover fractions were separated by hand and analyzed for glucan, xylan, acid soluble lignin, acid insoluble lignin, and ash composition. The stover fractions were also pretreated with either 0, 0.4, or 0.8% NaOH for 2 hours at room temperature, washed, autoclaved and saccharified. In addition, acid pretreated samples underwent simultaneous saccharification and fermentation (SSF) to ethanol. In general, the two pretreatments produced similar trends with cobs, husks, and leaves responding best to the pretreatments, the tops of stalks responding slightly less, and the bottom of the stalks responding the least. For example, corn husks pretreated with 0.8% NaOH released over 90% (standard error of 3.8%) of the available glucan, while only 45% (standard error of 1.1%) of the glucan was produced from identically treated stalk bottoms. Estimates of the theoretical ethanol yield using acid pretreatment followed by SSF were 65% (standard error of 15.9%) for husks and 29% (standard error of 1.8%) for stalk bottoms. This suggests that integration of biomass collection systems to remove sustainable feedstocks could be integrated with the processes within a biorefinery to minimize overall ethanol production costs.
K. B. Duguid; M. D. Montross; C. W. Radtke; C. L. Crofcheck; L. M. Wendt; S. A. Shearer
Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons: Dilute-Acid and Enzymatic Deconstruction of Biomass to Sugars and Biological Conversion of Sugars to Hydrocarbons
DOE Green Energy (OSTI)
This report describes one potential conversion process to hydrocarbon products by way of biological conversion of lingnocellulosic-dervied sugars. The process design converts biomass to a hydrocarbon intermediate, a free fatty acid, using dilute-acid pretreatement, enzymatic saccharification, and bioconversion. Ancillary areas--feed handling, hydrolysate conditioning, product recovery and upgrading (hydrotreating) to a final blendstock material, wastewater treatment, lignin combusion, and utilities--are also included in the design.
Davis, R.; Tao, L.; Tan, E. C. D.; Biddy, M. J.; Beckham, G. T.; Scarlata, C.; Jacobson, J.; Cafferty, K.; Ross, J.; Lukas, J.; Knorr, D.; Schoen, P.
Fundamental study on kinetics and transport phenomena in low water dilute acid total hydrolysis of cellulosic biomass
The overall objective of this research is to delineate the process of the dilute-acid hydrolysis of biomass and seek better understanding of the reactions involving dilute-acid treatment of lignocellulosic biomass. Specifically the scope of the work entails the following two primary technical elements: Verification of the heterogeneous nature of the reaction mechanism in dilute-acid hydrolysis of cellulosic component of the biomass. Experimental investigation to identify the overall reaction pattern and the kinetic constants associated with dilute-acid hydrolysis of the cellulosic component of the agricultural residues.
Auburn University
Summary of Findings from the Biomass Refining Consortium for Applied Fundamentals and Innovation (CAFI): Corn Stover Pretreatment
The Biomass Refining Consortium for Applied Fundamentals and Innovation, with members from Auburn University, Dartmouth College, Michigan State University, the National Renewable Energy Laboratory, Purdue University, Texas A&M University, the University of British Columbia, and the University of California at Riverside, has developed comparative data on the conversion of corn stover to sugars by several leading pretreatment technologies. These technologies include ammonia fiber expansion pretreatment, ammonia recycle percolation pretreatment, dilute sulfuric acid pretreatment, flowthrough pretreatment (hot water or dilute acid), lime pretreatment, controlled pH hot water pretreatment, and sulfur dioxide steam explosion pretreatment. Over the course of two separate USDA- and DOE-funded projects, these pretreatment technologies were applied to two different corn stover batches, followed by enzymatic hydrolysis of the remaining solids from each pretreatment technology using identical enzyme preparations, enzyme loadings, and enzymatic hydrolysis assays. Identical analytical methods and a consistent material balance methodology were employed to develop comparative sugar yield data for each pretreatment and subsequent enzymatic hydrolysis. Although there were differences in the profiles of sugar release, with the more acidic pretreatments releasing more xylose directly in the pretreatment step than the alkaline pretreatments, the overall glucose and xylose yields (monomers + oligomers) from combined pretreatment and enzymatic hydrolysis process steps were very similar for all of these leading pretreatment technologies. Some of the water-only and alkaline pretreatment technologies resulted in significant amounts of residual xylose oligomers still remaining after enzymatic hydrolysis that may require specialized enzyme preparations to fully convert xylose oligomers to monomers.
Elander, R. T.; Dale, B. E.; Holtzapple, M.; Ladisch, M. R.; Lee, Y. Y.; Mitchinson, C.; Saddler, J. N.; Wyman, C. E.
Dilute Acid Hydrolysis of Oligomers in Hydrothermal Pretreatment Hydrolyzate into Monomers with High Yields
heat and electricity used by conversion process or exported to the grid.heat and power to the production facility with excess left to export to the power grid.
Tsai, Yueh-Du
578. Hsu T. 1996. Bioethanol: Production and Utilization.design and costing of bioethanol technology: a tool for9 Bioethanol
Impact of Recycling Stillage on Conversion of Dilute Sulfuric Acid Pretreated Corn Stover to Ethanol (Poster)
A description of methods and results from an experiment designed to assess the impact of process water recycle on corn stover-to-ethanol conversion process performance.
Mohagheghi, A.; Schell, D. J.
cellulosic biomass to ethanol __________________ 3 Hemicellulose hydrolysis ________________________________________ 5 Thesis objectives _______________________________________________ 6 References ____________________________________________________ 7 Chapter 2 - Literature Review _____________________________________________ 9 Bioethanol Feedstock ___________________________________________feedstock that are inexpensive and abundant(Wyman 1999). In addition, as illustrated in Figure 1.1, cellulosic
of fossil fuels and carbon dioxide emission. Ethanol95 ix List of Figures Figure 1.1 Biofuels and carbon dioxideGoldemberg 2007).Carbon dioxide is the major greenhouse gas
sugar cane or corn starch, making ethanol from cellulosicdesigned to convert corn stover to ethanol by a series of77 NREL biochemical ethanol conversion process of corn
Breakdown of Cell Wall Nanostructure in Dilute Acid Pretreated Sai Venkatesh Pingali,*,
Weave Composite ~ 1 dpa, HFIR irradiation ORNL / Kyoto U. A science-based program involving tailored
Lignocellulosic biomass offers lower price, lower chemicalby food price fluctuations. Lignocellulosic biomass such as
via traditional biomass that generates heat by combustion.biomass handing, ethanol recovery, wastewater treatment, solid waste combustion,
Separation of glycols from dilute aqueous solutions via complexation with boronic acids
This work examines methods of separating low molecular weight glycols from dilute aqueous solution. Extraction into conventional solvents is generally not economical, since, in the literature reviewed, distribution ratios for the two- to four-carbon glycols are all less than one. Distribution ratios can be increased, however, by incorporating into the organic phase an extracting agent that will complex with the solute of interest. The extracting agent investigated in this work is 3-nitrophenylboronic acid (NPBA). NPBA, a boric acid derivative, reversibly complexes with many glycols. The literature on complexation of borate and related compounds with glycols, including mechanistic data, measurement techniques, and applications to separation processes, provides information valuable for designing experiments with NPBA and is reviewed herein. 88 refs., 15 figs., 24 tabs.
Randel, L.A.; King, C.J.
UC-61 PRETREATMENT OF BIOMASS PRIOR TO LIQUEFACTION Larry L.10093 PRETREATMENT OF BIOMASS PRIOR TO LIQUEFACTION Larry L.hydrolytic pretreatment to biomass feedstocks, higher acid
Schaleger, Larry L.
Co-hydrolysis of hydrothermal and dilute acid pretreated Populus slurries to support development of a high-throughput pretreatment system
Abstract Background: The BioEnergy Science Center (BESC)production. Background The BioEnergy Science Center (BESC)abbreviations used BESC: BioEnergy Science Center; HT: high-
Studer, Michael H; Brethauer, Simone; DeMartini, Jaclyn D; McKenzie, Heather L; Wyman, Charles E
system. Biotechnology for Biofuels 2011 Submit your nextStuder et al. Biotechnology for Biofuels 2011, 4:19 http://Studer et al. Biotechnology for Biofuels 2011, 4:19 http://
Biomass pretreatment
A method is provided for producing an improved pretreated biomass product for use in saccharification followed by fermentation to produce a target chemical that includes removal of saccharification and or fermentation inhibitors from the pretreated biomass product. Specifically, the pretreated biomass product derived from using the present method has fewer inhibitors of saccharification and/or fermentation without a loss in sugar content.
Hennessey, Susan Marie; Friend, Julie; Elander, Richard T; Tucker, III, Melvin P
Ultrastructure and Sugar Yields from Three Different Pretreatments of Corn Stover
and the Joint BioEnergy Institute ( JBEI) are collaborating to understand how biomass pretreatments with much different deconstruction patterns impact the chemical and ultrastructural features of biomass and its biological conversion to sugars. Dilute sulfuric acid (DA), ammonia fiber expansion (AFEX), and ionic liquid (IL) pretreatments are applied to the same source of corn stover by the BESC, GLBRC, and JBEI, respectively. Common sources of cellulase and other accessory enzymes are then employed to release sugars from the solids left after each pretreatment. The GLBRC applies material balances to each overall pretreatment-hydrolysis system to determine the fates of key biomass constituents and also optimizes enzyme formulations for each substrate using their microplate saccharification system. The BESC
Genomic Science Awardee; Usda-doe Plant; Feedstock Genomics; Charles E. Wyman; Xiadi Gao; Leonardo Da; Costa Sousa; Shishir P. S. Chundawat; Bruce E. Dale
A method is presented for pretreating a thorium surface prior to electroplating the surface. The pretreatment steps of the invention comprise cleaning by vapor blasting the surface, anodically pickling in a 5 to 15% by volume aqueous hydrochloric acid bath with a current of 125 to 250 amp/sq ft for 3 to 5 min at room temperature, chemically pickling the surface in a 5 to 15% by volume of aqueous sulfuric acid for 3 to 5 min at room temperature, and rinsing the surface with water.
Beach, J.G.; Schaer, G.R.
Lignocellulosic Biomass to Ethanol Process Design and Economics Utilizing Co-Current Dilute Acid Prehydrolysis and Enzymatic Hydrolysis for Corn Stover
This report is an update of NREL's ongoing process design and economic analyses of processes related to developing ethanol from lignocellulosic feedstocks. The U.S. Department of Energy (DOE) is promoting the development of ethanol from lignocellulosic feedstocks as an alternative to conventional petroleum-based transportation fuels. DOE funds both fundamental and applied research in this area and needs a method for predicting cost benefits of many research proposals. To that end, the National Renewable Energy Laboratory (NREL) has modeled many potential process designs and estimated the economics of each process during the last 20 years. This report is an update of the ongoing process design and economic analyses at NREL. We envision updating this process design report at regular intervals; the purpose being to ensure that the process design incorporates all new data from NREL research, DOE funded research and other sources, and that the equipment costs are reasonable and consistent with good engineering practice for plants of this type. For the non-research areas this means using equipment and process approaches as they are currently used in industrial applications. For the last report, published in 1999, NREL performed a complete review and update of the process design and economic model for the biomass-to-ethanol process utilizing co-current dilute acid prehydrolysis with simultaneous saccharification (enzymatic) and co-fermentation. The process design included the core technologies being researched by the DOE: prehydrolysis, simultaneous saccharification and co-fermentation, and cellulase enzyme production. In addition, all ancillary areas--feed handling, product recovery and purification, wastewater treatment (WWT), lignin combustor and boiler-turbogenerator, and utilities--were included. NREL engaged Delta-T Corporation (Delta-T) to assist in the process design evaluation, the process equipment costing, and overall plant integration. The process design and costing for the lignin combustor and boiler turbogenerator was reviewed by Reaction Engineering Inc. (REI) and Merrick & Company reviewed the wastewater treatment. Since then, NREL has engaged Harris Group (Harris) to perform vendor testing, process design, and costing of critical equipment identified during earlier work. This included solid/liquid separation and pretreatment reactor design and costing. Corn stover handling was also investigated to support DOE's decision to focus on corn stover as a feedstock for lignocellulosic ethanol. Working with Harris, process design and costing for these areas were improved through vendor designs, costing, and vendor testing in some cases. In addition to this work, enzyme costs were adjusted to reflect collaborative work between NREL and enzyme manufacturers (Genencor International and Novozymes Biotech) to provide a delivered enzyme for lignocellulosic feedstocks. This report is the culmination of our work and represents an updated process design and cost basis for the process using a corn stover feedstock. The process design and economic model are useful for predicting the cost benefits of proposed research. Proposed research results can be translated into modifications of the process design, and the economic impact can be assessed. This allows DOE, NREL, and other researchers to set priorities on future research with an understanding of potential reductions to the ethanol production cost. To be economically viable, ethanol production costs must be below market values for ethanol. DOE has chosen a target ethanol selling price of $1.07 per gallon as a goal for 2010. The conceptual design and costs presented here are based on a 2010 plant start-up date. The key research targets required to achieve this design and the $1.07 value are discussed in the report.
Aden, A.; Ruth, M.; Ibsen, K.; Jechura, J.; Neeves, K.; Sheehan, J.; Wallace, B.; Montague, L.; Slayton, A.; Lukas, J.
Comparative Sugar Recovery and Fermentation Data Following Pretreatment of Poplar Wood by Leading Technologies
Through a Biomass Refining Consortium for Applied Fundamentals and Innovation among Auburn University, Dartmouth College, Michigan State University, the National Renewable Energy Laboratory, Purdue University, Texas A&M University, the University of British Columbia, and the University of California at Riverside, leading pretreatment technologies based on ammonia fiber expansion, aqueous ammonia recycle, dilute sulfuric acid, lime, neutral pH, and sulfur dioxide were applied to a single source of poplar wood, and the remaining solids from each technology were hydrolyzed to sugars using the same enzymes. Identical analytical methods and a consistent material balance methodology were employed to develop comparative performance data for each combination of pretreatment and enzymes. Overall, compared to data with corn stover employed previously, the results showed that poplar was more recalcitrant to conversion to sugars and that sugar yields from the combined operations of pretreatment and enzymatic hydrolysis varied more among pretreatments. However, application of more severe pretreatment conditions gave good yields from sulfur dioxide and lime, and a recombinant yeast strain fermented the mixed stream of glucose and xylose sugars released by enzymatic hydrolysis of water washed solids from all pretreatments to ethanol with similarly high yields. An Agricultural and Industrial Advisory Board followed progress and helped steer the research to meet scientific and commercial needs.
Wyman, C. E.; Dale, B. E.; Elander, R. T.; Holtzapple, M.; Ladisch, M. R.; Lee, Y. Y.; Mitchinson, C.; Saddler, J. N.
Pretreatment Technology Plan
This technology plan presents a strategy for the identification, evaluation, and development of technologies for the pretreatment of radioactive wastes stored in underground storage tanks at the Hanford Site. This strategy includes deployment of facilities and process development schedules to support the other program elements. This document also presents schedule information for alternative pretreatment systems: (1) the reference pretreatment technology development system, (2) an enhanced pretreatment technology development system, and (3) alternative pretreatment technology development systems.
Barker, S.A. [Westinghouse Hanford Co., Richland, WA (US); Thornhill, C.K.; Holton, L.K. Jr. [Pacific Northwest Lab., Richland, WA (US)
Summary - WTP Pretreatment Facility
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
Block Block D DOE is Immob site's t facilitie purpos techno Facility to be i The as CTEs, Readin * C * C * W * Tr * U * Pu * W * H * Pl The as require The Ele Site: H roject: W Report Date: M ited States Wast Why DOE Diagram of Cesiu s constructing bilization Plant tank wastes. T es including a P se of this asses ology elements y and determin ncorporated in What th ssessment team along with eac ness Level (TR s Nitric Acid Re s Ion Exchang Waste Feed Eva reated LAW Ev ltrafiltration Pro ulse Jet Mixer Waste Feed Rec LW Lag Storag lant Wash and ssessment team ed maturity prio To view the full T http://www.em.doe. objective of a Tech ements (CTEs), usin Hanford/ORP Waste Treatme March 2007 Departmen te Treatm E-EM Did This um Nitric Acid R a Waste Treat (WTP) at Hanf The WTP is com Pretreatment F ssment was to s (CTEs) in the
Pretreatment of microbial sludges
Methods are described for pretreating microbial sludges to break cells and disrupt organic matter. One method involves the use of sonication, and another method involves the use of shear forces. The pretreatment of sludge enhances bioconversion of the organic fraction. This allows for efficient dewatering of the sludge and reduces the cost for final disposal of the waste.
Rivard, C.J.; Nagle, N.J.
Rivard, Christopher J. (Lakewood, CO); Nagle, Nicholas J. (Louisville, CO)
Mild coal pretreatment to improve liquefaction reactivity
This report describes work completed during the fourth quarter of a three year project to study the effects of mild chemical pretreatment on coal dissolution reactivity during low severity liquefaction or coal/oil coprocessing. The overall objective of this research is to elucidate changes in the chemical and physical structure of coal by pretreating with methanol or other simple organic solvent and a trace amount of hydrochloric acid and measure the influence of these changes on coal dissolution reactivity. This work is part of a larger effort to develop a new coal liquefaction or coal/oil coprocessing scheme consisting of three main process steps: (1) mile pretreatment of the feed coal to enhance dissolution reactivity and dry the coal, (2) low severity thermal dissolution of the pretreated coal to obtain a very reactive coal-derived residual material amenable to upgrading, and (3) catalytic upgrading of the residual products to distillate liquids.
Miller, R.L.
Methods of pretreating comminuted cellulosic material with carbonate-containing solutions
Methods of pretreating comminuted cellulosic material with an acidic solution and then a carbonate-containing solution to produce a pretreated cellulosic material are provided. The pretreated material may then be further treated in a pulping process, for example, a soda-anthraquinone pulping process, to produce a cellulose pulp. The pretreatment solutions may be extracted from the pretreated cellulose material and selectively re-used, for example, with acid or alkali addition, for the pretreatment solutions. The resulting cellulose pulp is characterized by having reduced lignin content and increased yield compared to prior art treatment processes.
Francis, Raymond
Process Design and Economics Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons: Dilute-Acid and Enzymatic Deconstruction of Biomass to Sugars and Biological Conversion of Sugars to Hydrocarbons R. Davis, L. Tao, E.C.D. Tan, M.J. Biddy, G.T. Beckham, and C. Scarlata National Renewable Energy Laboratory J. Jacobson and K. Cafferty Idaho National Laboratory J. Ross, J. Lukas, D. Knorr, and P. Schoen Harris Group Inc. Technical Report NREL/TP-5100-60223 October 2013 NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy Operated by the Alliance for Sustainable Energy, LLC. This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.
Thermochemical Pretreatment for Anaerobic Digestion of Sorted Waste
The effect of alkaline hydrothermal pre?treatment for anaerobic digestion of mechanically?sorted municipal solid waste (MSW) and source?sorted waste was studied. Waste was hydrothermally pre?treated in dilute alkali solution. Hydrolysis product was incubated in 500 ml saline bottle to determine methane potential (MP) under mesospheric anaerobic conditions. Optimum reaction condition obtained in the study is 170?�C at the dose of 4 g NaOH/100 g solid for one hour. Soluble COD was 13936 mg/L and methane yield was 164 ml/g VS for 6 days incubation at optimum conditions. More than 50% biogas increase was achieved over the control
W. Hao; W. Hongtao
Understanding Substrate Features Influenced by Pretreatments that Limit Biomass Deconstruction by Enzymes
and enzymatic hydrolysis for corn stover. In BookEnzymatic Hydrolysis for Corn Stover (Editor ed. ^eds. ).acid pretreatment of corn stover followed by enzymatic
Gao, Xiadi
How Wood Chip Size Affects Pretreatment Effectiveness of Woody Biomass for Biological Processing
acid pretreatment of biomass. Biotechnol. Bioeng. Symp. 15,that limit enzymatic hydrolysis of biomass. Appl. Biochem.hydrolysis of cellulosic biomass. Biofuels 2(4):421-450.
Tam, Jerry
A Comparison of Chemical Pretreatment Methods for Converting Cotton Stalks to Ethanol.
??The objective of this study was to investigate the effectiveness of sulfuric acid, sodium hydroxide, hydrogen peroxide, and ozone pretreatments for conversion of cotton stalks� (more)
Silverstein, Rebecca Anne
explosion pretreatment of wood: effect of chip size, acid,In: Soltes, E.J. (Ed. ), Wood and Agriculture Residues �D. , Wegener, G. , 1984. Wood: Chemistry, Ultrastructure,
Dilution physics modeling: Dissolution/precipitation chemistry
This report documents progress made to date on integrating dilution/precipitation chemistry and new physical models into the TEMPEST thermal-hydraulics computer code. Implementation of dissolution/precipitation chemistry models is necessary for predicting nonhomogeneous, time-dependent, physical/chemical behavior of tank wastes with and without a variety of possible engineered remediation and mitigation activities. Such behavior includes chemical reactions, gas retention, solids resuspension, solids dissolution and generation, solids settling/rising, and convective motion of physical and chemical species. Thus this model development is important from the standpoint of predicting the consequences of various engineered activities, such as mitigation by dilution, retrieval, or pretreatment, that can affect safe operations. The integration of a dissolution/precipitation chemistry module allows the various phase species concentrations to enter into the physical calculations that affect the TEMPEST hydrodynamic flow calculations. The yield strength model of non-Newtonian sludge correlates yield to a power function of solids concentration. Likewise, shear stress is concentration-dependent, and the dissolution/precipitation chemistry calculations develop the species concentration evolution that produces fluid flow resistance changes. Dilution of waste with pure water, molar concentrations of sodium hydroxide, and other chemical streams can be analyzed for the reactive species changes and hydrodynamic flow characteristics.
Onishi, Y.; Reid, H.C.; Trent, D.S.
Helium dilution refrigeration system
A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation is disclosed. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains [sup 3]He and [sup 4]He liquids which are precooled by a coupled container containing [sup 3]He liquid, enabling the phase separation of a [sup 3]He rich liquid phase from a dilute [sup 3]He-[sup 4]He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the [sup 3]He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute [sup 3]He-[sup 4]He liquid phase. 2 figs.
Roach, P.R.; Gray, K.E.
Horizontal Pretreatment Reactor System (Poster), NREL (National Renewable Energy Laboratory)
Diff Diff erent pretreatment chemistry/ residence time combinations are possible using these multiple horizontal-tube reactors * Each tube is indirectly and directly steam heated to temperatures of 150 0 C to 210 0 C * Residence time is varied by changing the speed of the auger that moves the biomass through each tube reactor * Tubes are used individually or in combination to achieve diff erent pretreatment residence times * Smaller tubes made from Hastelloy, an acid-resistant material, are used with more corrosive chemicals and residence times from 3 to 20 minutes * Larger tubes made from 316 stainless steel are used for residence times from 20 to 120 minutes Horizontal Pretreatment Reactor System Versatile pretreatment system for a wide range of pretreatment chemistries
This report describes work completed during the fifth quarter of a three year project to study the effects of mild chemical pretreatment on coal dissolution reactivity during low severity liquefaction or coal/oil coprocessing. The overall objective of this research is to elucidate changes in the chemical and physical structure of coal by pretreating with methanol or other simple organic solvent and a trace amount of hydrochloric acid and measure the influence of these changes on coal dissolution reactivity. Work this quarter focused on analytical characterization of untreated and treated Wyodak subbituminous coal and Illinois {number sign}6 bituminous coal. Mossbauer spectroscopy and x-ray diffraction techniques were used to study the effect of methanol/HCl pretreatment on the composition of each coal's inorganic phase. Results from these studies indicated that calcite is largely removed during pretreatment, but that other mineral species such as pyrite are unaffected. This finding is significant, since calcite removal appears to directly correlate with low severity liquefaction enhancement. Further work will be performed to study this phenomenon in more detail.
Biomass Pretreatment for Integrated Steelmaking
Presentation Title, Biomass Pretreatment for Integrated Steelmaking. Author(s), Shiju Thomas, Paul Cha, Steven J McKnight, Vincent A Bouma, Andrew L Petrik,
Vertical Pretreatment Reactor System (Poster)
IBRF poster developed for the IBRF showcase. Describes the two-vessel system for primary and secondary pretreatment of biomass solids at different temperatures.
Not Available
Double-shell tank waste pretreatment
Double-shell tanks contain most of the transuranic/high-level chemical processing waste generated at the Hanford Site in recent years. A small mass fraction of this waste is responsible for its characterization as transuranic/high-level waste. Pretreatment will partition the waste into a small fraction containing most of the transuranic/high-level components and a large fraction that is a low-level waste. The operations for achieving this objective include dissolution of water-soluble salts, dissolution of precipitated metal oxides in acid, clarification of the resulting dissolver liquors, transuranium element removal by solvent extraction and cesium removal by ion exchange. The primary benefit of pretreatment is a reduction in the overall cost of waste disposal.
Orme, R.M.; Appel, J.N.
Investigations of Biomass Pretreatment and Submerged Fixed-bed Fermentation
To improve the MixAlco process and biomass pretreatment, five studies were conducted. Three studies related to fermentation, whereas the other two investigated the effectiveness of shock tube pretreatment (STP) coupled with oxidative lime pretreatment (OLP). In the first study, the constant-selectivity assumption used in the continuum particle distribution model (CPDM) was determined to be invalid. During a 32-day batch fermentation, selectivity increased from 0.10 to 0.40 g acid/g non-acid volatile solid (NAVS) digested. Future revisions to CPDM should incorporate a non-constant selectivity term. In the second study, a revised procedure was developed to provide a more accurate determination of moisture content. Conventional drying at 105 degrees C allowed product acids to vaporize with water, which introduced errors. Using the revised procedure, calcium hydroxide or sodium hydroxide was added to samples at a concentration of 0.01 g base/g sample, which retained acids in the sample. The mass of additional retained material closely matched that of the additional retained acid. Three related studies involving biomass pretreatment were performed. In the first, recommended parameters for pretreating sugarcane bagasse with OLP and STP were determined. Recommended OLP parameters were 130 degrees C, 6.9-bar O2, and 2-h duration. The effects of solids concentration, liquid fill volume, particle size, type of shotgun shell, number of shocks, and pretreatment order were investigated. Liquid fill volume, particle size, type of shotgun shell, and pretreatment order were significant variables, whereas solids concentration and number of shocks were not. Recommended OLP parameters were used as a basis for an additional experiment. To simulate industrial-scale pile fermentation, fixed-bed batch fermentation of OLP + STP sugarcane bagasse was performed in 1-L PVC fermentors. Rubber mulch was used as a structural support material to prevent filter plugging, which had been reported in previous work. After 42 d, acid concentration reached 8 g/L with yield approximately 0.1 g acid/g NAVS fed. Poor fermentation performance was caused by short solid-liquid contact time and poor pH control. A third biomass pretreatment experiment investigated the potential of pretreated corn stover as a potential ruminant feed. Five samples (raw, OLP, STP, OLP + STP, and STP + OLP) were analyzed for composition and in vitro digestibility. STP followed by OLP increased neutral detergent fiber (NDF) digestibility from 49.3 to 79.0 g NDF digested/100 g NDF fed. On an organic matter basis, STP + OLP corn stover plus water-soluble extractives had a total digestible nutrients (TDN) of 74.9, nearly reaching corn grain at 88.1.
Meysing, Daniel
Impact of thermal pretreatment on the fast pyrolysis conversion of Southern Pine
Background: Thermal pretreatment of biomass ranges from simple (nondestructive) drying to more severe treatments that cause devolatization, depolymerization and carbonization. These pretreatments have demonstrated promise for transforming raw biomass into feedstock material that has improved milling, handling, storage and conversion properties. In this work, southern pine material was pretreated at 120, 180, 230 and 270 degrees C, and then subjected to pyrolysis tests in a continuous-feed bubbling-fluid bed pyrolysis system. Results: High pretreatment temperatures were associated with lower specific grinding energies, higher grinding rates and lower hydrogen and oxygen contents. Higher pretreatment temperatures were also correlated with increased char production, decreased total acid number and slight decrease in the oxygen content of the pyrolysis liquid fraction. Conclusion: Thermal pretreatment has both beneficial and detrimental impacts on fast pyrolysis conversion of pine material to bio-oil, and the effect of thermal pretreatment on upgrading of pyrolysis bio-oil requires further attention.
Tyler L. Westover; Manunya Phanphanich; Micael L. Clark; Sharna R. Rowe; Steven E. Egan; Christopher T Wright; Richard D. Boardman; Alan H. Zacher
Effects of physical and chemical pretreatments on the crystallinity of bagasse
Biomass conversion technologies are receiving increasing attention due to global climate change and most recently plans from the President of the United States to reduce fossil fuel consumption. The MixAlco process converts a variety of feedstocks, such as agricultural residues, municipal solid waste, and sewage sludge, into mixed alcohols via microbial fermentation, which can then be used as fuel additives or independently as an alternative fuel. Optimizing the pretreatment step of this process is critical to improving product yields. The process uses lime pretreatment, which can be enhanced using new decrystallization pretreatment methods, namely hydrodynamic cavitation and shock tube pretreatment.Previous studies on biomass decrystallization showed an increase in biomass digestibility when hydrodynamic cavitation was utilized as a pretreatment step. This previous work was expanded by studying both acoustic and hydrodynamic cavitation. Computational fluid dynamics (CFD) was used to model the cavitator to improve its efficiency. The crystallinity before and after pretreatment was analyzed. A new laboratory-scale MixAlco lime-pretreatment system was developed to produce greater quantities of lime-pretreated biomass that could be subjected to decrystallization experiments. The length of pretreatment, water loading, and bagasse loadings were varied for the shock tube experiments. After each pretreatment, enzymatic hydrolysis was performed, and the equivalent glucose yield was measured by the DNS (dinitrosalicylic acid) assay. Additionally, mixed-acid fermentation was performed to show the benefits of reduced crystallinity on the MixAlco fermentation. The acoustic and hydrodynamic cavitation pretreatments had a modest effect on crystallinity. In contrast, the shock tube pretreatment shows greater promise as an effective decrystallization pretreatment, even for lime-treated bagasse. Repeated shocks had little effect on digestibility and the crystallinity; however, the water temperature used in shock tube pretreatment played an important role in bagasse digestibility and crystallinity.
Jones, Maxine Janette
Down-regulation of the Caffeic acid O-methyltransferase Gene in Switchgrass Reveals a Novel Monolignol Analog
Down-regulation of the caffeic acid 3-O-methyltransferase (COMT) gene in the lignin biosynthetic pathway of switchgrass (Panicum virgatum) resulted in cell walls of transgenic plants releasing more constituent sugars after pretreatment by dilute acid and treatment with glycosyl hydrolases from an added enzyme preparation and from Clostridium thermocellum. Fermentation of both wild-type and transgenic switchgrass after milder hot water pretreatment with no water washing showed that only the transgenic switchgrass inhibited C. thermocellum. Gas chromatography-mass spectrometry-based metabolomics were undertaken on cell wall aqueous extracts to determine the nature of the microbial inhibitors, confirming the increased concentration of a number of phenolic acids and aldehydes that are known inhibitors of fermentation. Metabolomic analyses of the transgenic biomass additionally revealed the presence of a novel monolignol-like metabolite, identified as trans-3, 4-dimethoxy-5-hydroxycinnamyl alcohol (iso-sinapyl alcohol) in both non-pretreated, as well as hot water pretreated samples. Although there was no indication that iso-sinapyl alcohol was integrated into the cell wall, diversion of substrates from sinapyl alcohol to free iso-sinapyl alcohol, its glucoside, and associated upstream lignin pathway changes, including increased phenolic aldehydes and acids, are associated with more facile cell wall deconstruction, and to the observed inhibitory effect on microbial growth.
Tschaplinski, Timothy J [ORNL; Standaert, Robert F [ORNL; Engle, Nancy L [ORNL; Martin, Madhavi Z [ORNL; Sangha, Amandeep K [ORNL; Parks, Jerry M [ORNL; Smith, Jeremy C [ORNL; Samuel, Reichel [ORNL; Pu, Yunqiao [ORNL; Ragauskas, A J [Georgia Institute of Technology; Hamilton, Choo Yieng [ORNL; Fu, Chunxiang [Noble Foundation; Wang, Zeng-Yu [Noble Foundation; Davison, Brian H [ORNL; Dixon, Richard A [Noble Foundation; Mielenz, Jonathan R [ORNL
Steam pretreatment for coal liquefaction
Steam pretreatment is the reaction of coal with steam at temperatures well below those usually used for solubilization. The objective of the proposed work is to test the application of steam pretreatment to coal liquefaction. This quarter, a 300 ml stirred autoclave for liquefaction tests were specified and ordered, procedures for extraction tests were reestablished, and the synthesis of four model compounds was completed. Two of these compounds remain to be purified.
Graff, R.A.; Balogh-Nair, V.
The fate of lignin during hydrothermal pretreatment
straw pretreated for bioethanol production. Biotechnologyof woody biomass for bioethanol production. Bioresources
Trajano, Heather L; Engle, Nancy L; Foston, Marcus; Ragauskas, Arthur J; Tschaplinski, Timothy J; Wyman, Charles E
Processes for pretreating lignocellulosic biomass: A review
This paper reviews existing and proposed pretreatment processes for biomass. The focus is on the mechanisms by which the various pretreatments act and the influence of biomass structure and composition on the efficacy of particular pretreatment techniques. This analysis is used to identify pretreatment technologies and issues that warrant further research.
McMillan, J.D.
Infiltration as ventilation: Weather-induced dilution
Infiltration as ventilation: Weather-induced dilution Title Infiltration as ventilation: Weather-induced dilution Publication Type Report LBNL Report Number LBNL-5795E Year of...
Office of Legacy Management (LM)
Acid/Pueblo Canyon, New Mexico, Site is Acid/Pueblo Canyon, New Mexico, Site is located near the town of Los Alamos, New Mexico, approximately 25 miles northwest of Santa Fe and 60 miles north-northeast of Albuquerque. The site is accessible from Canyon Road, which runs just south of the former waste treatment plant. The plant was situated on a mesa that forms the south rim of Acid Canyon. Acid Canyon is a small tributary near the head
Caloramator sp. Tolerance of Pretreatment Inhibitors from ...
Biomass and Biofuels Caloramator sp. Tolerance of Pretreatment Inhibitors from Lignocellulosics Oak Ridge National Laboratory. Contact ORNL About This ...
Method to Produce Highly Digestible, Pretreated ...
Method to Produce Highly Digestible, Pretreated Lignocellulosic Biomass Using Anhydrous Liquid Ammonia Inventors: Shishir Chundawat, Leonardo Sousa, ...
Acid/Pueblo Canyon, New Mexico, Site. Acid/Pueblo Canyon, New Mexico, Site. This site is managed by the U.S. Department of Energy Office of Legacy Management. Site Description and History The Acid/Pueblo Canyon, New Mexico, Site is located near the town of Los Alamos, New Mexico, approximately 25 miles northwest of Santa Fe and 60 miles north-northeast of Albuquerque. The site is accessible from Canyon Road, which runs just south
Comminution employing liquid nitrogen pretreatments
The goal of this project is to develop a methodology that will lead to the establishment of an effective, efficient technique for ultrafine grinding of coal. We believe that the key to successful coal grinding is strongly dependent upon the change of the brittleness of coal under a freezing temperature pretreatment. Furthermore, a cryogenic grinding process may provide the basis for the development of advanced technologies involving the separation of the pyritic minerals from coal. Specific objectives of the program are to: determine the effect of low temperature pretreatments on the microfracture development along the coal/pyrite interface and on the fracture resistance (brittleness) of coal. Specifically, we intend to examine the effect of direct contact of coal with liquid nitrogen, dry ice, and dry-iced acetone. Also, we intend to study pyrite liberation as a result of these treatments; determine the fracture resistance of coal under different low temperature pretreatments; determine the relationships between the fracture resistance of coal and the effectiveness of a grinding process; determine the effect of the frozen coal grinding on the pyrite liberation; evaluate factors which might effect process design, scale-up, and economics; and make a first pass economic assessment of the process. 15 refs., 13 figs., 3 tabs.
Yen, S.C. (Southern Illinois Univ., Carbondale, IL (USA). Dept. of Civil Engineering and Mechanics); Hippo, E.J. (Southern Illinois Univ., Carbondale, IL (USA). Dept. of Mechanical Engineering and Energy Processes)
The effect of pretreatments on surfactin production from potato process effluent by Bacillus subtilis
Pretreatment of low-solids (LS) potato process effluent was tested for potential to increase surfactin yield. Pretreatments included heat, removal of starch particulates, and acid hydrolysis. Elimination of contaminating vegetative cells was necessary for surfactin production. After autoclaving, 0.40 g/L of surfactin was produced from the effluent in 72 h, versus 0.24 g/L in the purified potato starch control. However, surfactin yields per carbon consumed were 76% lower from process effluent. Removal of starch particulates had little effect on the culture. Acid hydrolysis decreased growth and surfactant production, except 0.5 wt% acid, which increased the yield by 25% over untreated effluent.
D. N. Thompson; S. L. Fox; G. A. Bala
Application of high throughput pretreatment and cohydrolysis...
1 Biofuels and Environmental Biotechnology Biotechnology and Bioengineering DOI 10.1002bit.24951 Application of High Throughput Pretreatment and Co-Hydrolysis System to...
Rhode Island Pretreatment Regulations (Rhode Island)
Energy.gov (U.S. Department of Energy (DOE))
These regulations set standards for water pretreatment prior to release to Publicly Owned Treatment Works (POTWs), and require effluent data including the identity, amount, frequency, concentration...
The Effects of Surfactant Pretreatment and Xylooligomers on Enzymatic Hydrolysis of Cellulose and Pretreated Biomass
rich solution was produced by water-only pretreatment ofDP of xylooligomers produced by water-only pretreatment ofXylooligomer mixtures were produced by water-only hydrolysis
Qing, Qing
Pretreatment of neutralized cladding removal waste sludge: Status Report
This report describes the status of process development for pretreating Hanford neutralized cladding removal waste (NCRW) sludge, of which [approximately] 3.3 [times] 10[sup 6] L is stored in Tanks 103-AW and 105-AW at the Hanford Site. The initial baseline process chosen for pretreating NCRW sludge is to dissolve the sludge in nitric acid and extract the -transuranic (MU) elements from the dissolved sludge solution with octyl(phenyl)-N,N-diisobutylcarbamoyl methyl phosphine oxide (CNWO). This process converts the NCRW sludge into a relatively large volume of low-level waste (LLW) to be disposed of as grout, leaving only a small volume of high-level waste (HLW) requiring vitrification in the Hanford Waste Vitrification Plant (HWVP).
Lumetta, G J; Swanson, J L
A process is given for anodically treating the surface of uranium articles, prior to metal plating. The metal is electrolyzed in an aqueous solution of about 10% polycarboxylic acid, preferably oxalic acid, from 1 to 5% by weight of glycerine and from 1 to 5% by weight of hydrochloric acid at from 20 to 75 deg C for from 30 seconds to 15 minutes. A current density of from 60 to 100 amperes per square foot is used.
Wehrmann, R.F.
A compact rotating dilution refrigerator
We describe the design and performance of a new rotating dilution refrigerator that will primarily be used for investigating the dynamics of quantized vortices in superfluid 4He. All equipment required to operate the refrigerator and perform experimental measurements is mounted on two synchronously driven, but mechanically decoupled, rotating carousels. The design allows for relative simplicity of operation and maintenance and occupies a minimal amount of space in the laboratory. Only two connections between the laboratory and rotating frames are required for the transmission of electrical power and helium gas recovery. Measurements on the stability of rotation show that rotation is smooth to around 0.001 rad/s up to angular velocities in excess of 2.5 rad/s. The behavior of a high-Q mechanical resonator during rapid changes in rotation has also been investigated.
Fear, M J; Chorlton, D A; Zmeev, D E; Gillott, S J; Sellers, M C; Richardson, P P; Agrawal, H; Batey, G; Golov, A I
Mild coal pretreatment to improve liquefaction reactivity. Quarterly technical progress report, June--August 1991
Pretreatment of high solid microbial sludges
A process and apparatus for pretreating microbial sludges in order to enhance secondary anaerobic digestion. The pretreatment process involves disrupting the cellular integrity of municipal sewage sludge through a combination of thermal, explosive decompression and shear forces. The sludge is pressurized and pumped to a pretreatment reactor where it is mixed with steam to heat and soften the sludge. The pressure of the sludge is suddenly reduced and explosive decompression forces are imparted which partially disrupt the cellular integrity of the sludge. Shear forces are then applied to the sludge to further disrupt the cellular integrity of the sludge. Disrupting cellular integrity releases both soluble and insoluble organic constituents and thereby renders municipal sewage sludge more amenable to secondary anaerobic digestion.
Rivard, Christopher J. (Lakewood, CO); Nagle, Nicholas J. (Broomfield, CO)
A process and apparatus are disclosed for pretreating microbial sludges in order to enhance secondary anaerobic digestion. The pretreatment process involves disrupting the cellular integrity of municipal sewage sludge through a combination of thermal, explosive decompression and shear forces. The sludge is pressurized and pumped to a pretreatment reactor where it is mixed with steam to heat and soften the sludge. The pressure of the sludge is suddenly reduced and explosive decompression forces are imparted which partially disrupt the cellular integrity of the sludge. Shear forces are then applied to the sludge to further disrupt the cellular integrity of the sludge. Disrupting cellular integrity releases both soluble and insoluble organic constituents and thereby renders municipal sewage sludge more amenable to secondary anaerobic digestion. 1 fig.
Pretreatment Rules (Ohio) | Department of Energy
Pretreatment Rules (Ohio) Pretreatment Rules (Ohio) Pretreatment Rules (Ohio) < Back Eligibility Agricultural Industrial Investor-Owned Utility Municipal/Public Utility Rural Electric Cooperative Utility Program Info State Ohio Program Type Environmental Regulations Provider Ohio Environmental Protection Agency This law lists state requirements and standards regulating the introduction of pollutants into Publicly Owned Treatment Works (POTWs) by industrial users. The following substances shall not be introduced into a POTW: (1) Pollutants that create a fire or explosion hazard in the POTW including, but not limited to, wastestreams with a closed cup flashpoint of less than 140 degrees Fahrenheit or 60 degrees; (2) Pollutants that will cause corrosive structural damage to the POTW, but in no case discharges with pH lower than 5.0, unless the POTW is
Dilute acid/metal salt hydrolysis of lignocellulosics - Energy ...
Building Energy Efficiency ... Solar Thermal; ... loading the impregnated lignocellulosic feedstock into a reactor and heating for a sufficient period of time to ...
Ethanol production with dilute acid hydrolysis using partially ...
Patent Number: 6,660,506: Issued: December 9, 2003: Official Filing: View the Complete Patent at the US Patent & Trademark Office: Lab: National Renewable Energy ...
Nanoporous Membranes for Pretreatment of Lignocellulose and Other Applications
Researchers at ORNL have developed an inorganic membrane element and a flowthrough recycle (FTR) process for pretreating lignocellulosic biomass to ...
Pre-treatment of Dye Wastewater by Electrolysis Technology
Presentation Title, Pre-treatment of Dye Wastewater by Electrolysis Technology .... Application in High Temperature Thermochemical Hydrogen Production.
Carbonic Acid Retreatment of Biomass
This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. (1) Solidify the theoretical understanding of the binary CO{sub 2}/H{sub 2}O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. (2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. (3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. (4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. (5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic acid compared to water alone. (6) Determine optimal conditions for carbonic acid pretreatment of aspen wood. Optimal severities appeared to be in the mid range tested. ASPEN-Plus modeling and economic analysis of the process indicate that the process could be cost competitive with sulfuric acid if the concentration of solids in the pretreatment is maintained very high ({approx}50%). Lower solids concentrations result in larger reactors that become expensive to construct for high pressure applications.
Baylor university
Waste Treatment and Immobilation Plant Pretreatment Facility
7 7 Technology Readiness Assessment for the Waste Treatment and Immobilization Plant (WTP) Pretreatment Facility L. Holton D. Alexander M. Johnson H. Sutter August 2007 Prepared by the U.S. Department of Energy Office of River Protection Richland, Washington, 99352 07-DESIGN-047 Technology Readiness Assessment for the Waste Treatment and Immobilization Plant (WTP) Pretreatment Facilities L. Holton D. Alexander M. Johnson H. Sutter August 2007 Prepared by the U.S. Department of Energy Office of River Protection under Contract DE-AC05-76RL01830 07-DESIGN-047 iii Summary The U.S. Department of Energy (DOE), Office of River Protection (ORP) and the DOE Office of Environmental Management (EM), Office of Project Recovery has completed a Technology Readiness
We examine the linear stability analysis of a hot, dilute, and differentially rotating plasma by considering anisotropic transport effects. In dilute plasmas, the ion Larmor radius is small compared with its collisional mean free path. In this case, the transport of heat and momentum along the magnetic field lines becomes important. This paper presents a novel linear instability that may be more powerful and greater than ideal magnetothermal instability and ideal magnetorotational instability in the dilute astrophysical plasmas. This type of plasma is believed to be found in the intracluster medium (ICM) of galaxy clusters and radiatively ineffective accretion flows around black holes. We derive the dispersion relation of this instability and obtain the instability condition. There is at least one unstable mode that is independent of the temperature gradient direction for a helical magnetic field geometry. This novel instability is driven by the gyroviscosity coupled with differential rotation. Therefore, we call it gyroviscous-modified magnetorotational instability (GvMRI). We examine how the instability depends on signs of the temperature gradient and the gyroviscosity and also on the magnitude of the thermal frequency and on the values of the pitch angle. We provide a detailed physical interpretation of the obtained results. The GvMRI is applicable not only to the accretion flows and ICM but also to the transition region between cool dense gas and the hot low-density plasma in stellar coronae, accretion disks, and the multiphase interstellar medium because it is independent of the temperature gradient direction.
Devlen, Ebru, E-mail: email@example.com [Department of Astronomy and Space Sciences, Faculty of Science, University of Ege, Bornova 35100, Izmir (Turkey)
A process is described for the preparation of trifluoroacetic acid. Acetone vapor diluted wlth nitrogen and fluorine also diluted with nltrogen are fed separately at a temperature of about 210 deg C into a reaction vessel containing a catalyst mass selected from-the group consisting of silver and gold. The temperature in the reaction vessel is maintained in the range of 200 deg to 250 deg C. The reaction product, trifluoroacetyl fluoride, is absorbed in aqueous alkali solution. Trifluoroacetic acid is recovered from the solution by acidification wlth an acid such as sulfuric followed by steam distillation.
Haworth, W.N.; Stacey, M.
Kinetic Modeling and Assessment of Lime Pretreatment of Poplar Wood
Because of widespread availability, low cost, sustainability, and potential supply far greater than that of food crops, lignocellulosic biomass is one of the most promising feedstocks for producing biofuels through fermentation processes. Among lignocellulose choices, poplar wood is appealing because of high energy potential, above-average carbon mitigation potential, fast growth, and high yields. Lignocellulose structural features limit accessibility of enzymes or microorganisms. To overcome these limitations, pretreatment is required. Among several choices of pretreatment, lime pretreatment is preferred because lime is the cheapest alkali, safest to handle, easy to recover, and compatible with oxidants. The main effect of lime pretreatment is to degrade lignin, which occurs with good carbohydrate preservation and is enhanced with oxidants. Among several choices of oxidant, oxygen and air are preferred because of low cost and widespread availability. This study systematically assesses the effects of lime pretreatment on poplar wood using four different modes: long-term oxidative, long-term non-oxidative, short-term constant pressure, and short-term varying pressure. Long-term pretreatments use temperatures between 25 and 65� C, air if oxidant is used, and last several weeks. Short-term pretreatments use temperatures between 110 and 180� C, pressurized oxygen, and last several minutes to hours. Pretreatment was assessed on the basis of 3-day enzymatic digestibility using enzyme loadings of 15 FPU/g glucan in raw biomass. The results were used to recommend pretreatment conditions based on highest overall yield of glucan (after combined pretreatment and enzymatic hydrolysis) for each pretreatment mode. For each pretreatment mode, kinetic models for delignification and carbohydrates degradation were obtained and used to determine the conditions (temperature, pressure, and time) that maximize glucan preservation subjected to a target lignin yield. This study led to conclude that the most robust, and selective mode of lime pretreatment is varying pressure.
Sierra Ramirez, Rocio
CO.sub.2 Pretreatment prevents calcium carbonate formation
Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by pretreatment with carbon dioxide. The carbon dioxide pretreatment is believed to convert the scale-forming components to the corresponding carbonate prior to liquefaction. The pretreatment is accomplished at a total pressure within the range from about 14 to about 68 atmospheres and a carbon dioxide partial pressure within the range from about 14 to about 34 atmospheres. Temperature during pretreatment will generally be within the range from about 100.degree. to about 200.degree. C.
Neavel, Richard C. (Baytown, TX); Brunson, Roy J. (Buffalo Grove, IL); Chaback, Joseph J. (Worthington, OH)
Biodiesel Impact on Engine Lubricant Dilution During Active Regeneration of Aftertreatment Systems
Experiments were conducted with ultra low sulfur diesel (ULSD) and 20% biodiesel blends (B20) to compare lube oil dilution levels and lubricant properties for systems using late in-cylinder fuel injection for aftertreatment regeneration. Lube oil dilution was measured by gas chromatography (GC) following ASTM method D3524 to measure diesel content, by Fourier transform infrared (FTIR) spectrometry following a modified ASTM method D7371 to measure biodiesel content, and by a newly developed back-flush GC method that simultaneously measures both diesel and biodiesel. Heavy-duty (HD) engine testing was conducted on a 2008 6.7L Cummins ISB equipped with a diesel oxidation catalyst (DOC) and diesel particle filter (DPF). Stage one of engine testing consisted of 10 consecutive repeats of a forced DPF regeneration event. This continuous operation with late in-cylinder fuel injection served as a method to accelerate lube-oil dilution. Stage two consisted of 16 hours of normal engine operation over a transient test cycle, which created an opportunity for any accumulated fuel in the oil sump to evaporate. Light duty (LD) vehicle testing was conducted on a 2010 VW Jetta equipped with DOC, DPF and a NOx storage catalyst (NSC). Vehicle testing comprised approximately 4,000 miles of operation on a mileage-accumulation dynamometer (MAD) using the U.S. Environmental Protection Agency's Highway Fuel Economy Cycle because of the relatively low engine oil and exhaust temperatures, and high DPF regeneration frequency of this cycle relative to other cycles examined. Comparison of the lube oil dilution analysis methods suggests that D3524 does not measure dilution by biodiesel. The new back-flush GC method provided analysis for both diesel and biodiesel, in a shorter time and with lower detection limit. Thus all lube oil dilution results in this paper are based on this method. Analysis of the HD lube-oil samples showed only 1.5% to 1.6% fuel dilution for both fuels during continuous operation under DPF regeneration events. During the second stage of HD testing, the ULSD lube-oil dilution levels fell from 1.5% to 0.8%, while for B20, lube-oil dilution levels fell from 1.6% to 1.0%, but the fuel in the oil was 36% biodiesel. For the LD vehicle tests, the frequency of DPF regeneration events was observed to be the same for both ULSD and B20. No significant difference between the two fuels' estimated soot loading was detected by the engine control unit (ECU), although a 23% slower rate of increase in differential pressure across DPF was observed with B20. It appears that the ECU estimated soot loading is based on the engine map, not taking advantage of the lower engine-out particulate matter from the use of biodiesel. After 4,000 miles of LD vehicle operation with ULSD, fuel dilution in the lube-oil samples showed total dilution levels of 4.1% diesel. After 4,000 miles of operation with B20, total fuel in oil dilution levels were 6.7% consisting of 3.6% diesel fuel and 3.1% biodiesel. Extrapolation to the 10,000-mile oil drain interval with B20 suggests that the total fuel content in the oil could reach 12%, compared to 5% for operation on ULSD. Analysis of the oil samples also included measurement of total acid number, total base number, viscosity, soot, metals and wear scar; however, little difference in these parameters was noted.
He, X.; Williams, A.; Christensen, E.; Burton, J.; McCormick, R.
Pretreatment Methods for Biomass Conversion into Biofuels ...
Technology Marketing Summary Hydrolysis of lignocellulosic biomass using an acid catalyst to produce sugars has been known for decades but can be ...
Fundamentals of Biomass Pretreatment by Fractionation
Fundamentals of Biomass Pretreatment by Fractionation Poulomi Sannigrahi 1,2 and Arthur J. Ragauskas 1,2,3 1 BioEnergy Science Center, Oak Ridge, USA 2 Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, USA 3 School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, USA 10.1 Introduction With the rise in global energy demand and environmental concerns about the use of fossil fuels, the need for rapid development of alternative fuels from sustainable, non-food sources is now well acknowledged. The effective utilization of low-cost high-volume agricultural and forest biomass for the production of transporta- tion fuels and bio-based materials will play a vital role in addressing this concern [1]. The processing of lignocellulosic biomass, especially from mixed agricultural and forest sources with varying composition,
Cellulosic Biofuels: Importance, Recalcitrance, and Pretreatment
Cellulosic Cellulosic Biofuels: Importance, Recalcitrance, and Pretreatment Lee Lynd 1,2 and Mark Laser 1 1 Thayer School of Engineering, Dartmouth College, Hanover, USA 2 BioEnergy Science Center, Oak Ridge, USA 2.1 Our Place in History The two most profound societal transformations in history have been spawned by radical shifts in human- kind's use of natural resources. The agricultural revolution, which spanned about two millennia beginning around 4000 BC, saw hunter-gatherer societies subsisting on wild plants and animals being largely dis- placed by those cultivating the land to produce crops and domesticated livestock. The industrial revolution followed, beginning around 1700 and lasting roughly two hundred years, during which time preindustrial agricultural societies gave way to those harnessing precious metals and fossil energy to develop sophisti- cated economies centered
Optimization of steam explosion pretreatment. Final report
Different operating conditions are required to optimize the yield from each of the various fractions in the substrate. Xylose recovery is maximized at short cooking times whereas maximum lignin recovery requires much longer cooking times. Peak glucose yield and rumen digestibility occur at intermediate times. If process conditions are set for maximum glucose yield we have achieved a yield of 68% of the theoretical, based on an average of a dozen substrates tested. Individual results ranged from 46 to 87%. If the process is optimized for maximum total sugars (i.e. glucose plus xylose) we have obtained an average yield of 60%, with a range of 31 to 75%. With rumen microflora, the average value of the in-vitro cellulose digestibility was 82%, with a range of 41 to 90%. The optimum operating conditions for total sugars are a pressure of 500 to 550 psig with a cooking time of 40 to 50 seconds and 35% starting moisture content. Particle size is not a significant factor, nor is pre-steaming or use of a constricting die in the gun nozzle. High quality lignin can be extracted with 80% yield. The Iotech lignin is very soluble, has a low molecular weight and is reactive. The unique properties of the lignin derive from the explosion at the end of the pretreatment. A lignin formaldehyde resin has been successfully formulated and tested. It represents a high value utilization of the lignin byproduct with immediate market potential. A detailed engineering design of the process gives an estimated operating cost of $7.50/OD ton of biomass. At this low cost, the Iotech process achieves many important pretreatment goals in a single step. The substrate has been sterilized; it has been pulverized into a powder; the cellulose has been accessible; and a highly reactive lignin fraction can be recovered and utilized.
Foody, P.
Long-term lime pretreatment of poplar wood
Lignocellulosic biomass (e.g., poplar wood) provides a unique and sustainable resource for environmentally safe organic fuels and chemicals. The core of this study is the pretreatment step involved in bioconversion processes. Pretreatment is required to realize high yields vital to commercial success. The focus of the pretreatment step is to methodically change key features of the biomass to favor enzymatic hydrolysis. This work assesses the compositional changes due to oxidative and non-oxidative longterm lime pretreatment of poplar wood (up to 4 weeks of pretreatment) at mild temperatures (25�C to 65�C), and their effect on the enzymatic yield of glucan and xylan. The most important pretreatment yield of lignin was 54 g lignin remaining/100 g lignin in raw biomass, and was accomplished for 4-week lime pretreatment at 65�C in oxidative conditions. The corresponding pretreatment yields of glucan and xylan were 85.9 g glucan recovered/100 g glucan in raw biomass and 80.2 g xylan recovered/100 g xylan in raw biomass respectively. For poplar wood oxidatively pretreated with lime for 4 weeks at 65�C and enzymatically hydrolyzed with an enzyme loading of 15 FPU/g glucan in raw biomass during a 3-day period, the best overall yields of glucan and xylan, were 80.7 g glucan hydrolyzed/100 g glucan in raw biomass and 66.9 g xylan hydrolyzed/100 g xylan in raw biomass respectively. The corresponding hydrolysis yields were 94.0 g glucan hydrolyzed/100 g glucan in treated biomass and 83.5 g xylan hydrolyzed/100 g xylan in treated biomass respectively. Because there is a previous study of long-term lime pretreatment of corn stover (Kim, 2004), the data obtained in this work show the effect of using woody lignocellulose as substrate. From the comparison, resulted that in the case of poplar wood oxidatively pretreated at 65�C for 4 weeks, less lignin was removed and more carbohydrates were solubilized, however the hydrolysis yield of glucan was almost equal and the hydrolysis yield of xylan was higher than the reported by Kim for corn stover oxidatively pretreated at 55�C for 4 weeks. The overall yield of glucan resulted lower in the case of poplar wood because of the lower pretreatment yield of glucan. Thus, it is important to complete the mass balances including an analysis on the pretreatment liquor to determine if the solubilized glucan was degraded.
Silver Uptake from Dilute Cyanide Solution Using Activated Charcoal
About this Abstract. Meeting, 2012 TMS Annual Meeting & Exhibition. Symposium , General Poster Session. Presentation Title, W-95: Silver Uptake from Dilute�...
Process chemistry for the pretreatment of Hanford tank wastes
Current guidelines for disposing radioactive wastes stored in underground tanks at the US Department of Energy`s Hanford Site call for the vitrification of high-level waste in borosilicate glass and disposal of the glass canisters in a deep geologic repository. Low-level waste is to be cast in grout and disposed of on site in shallow burial vaults. Because of the high cost of vitrification and geologic disposal, methods are currently being developed to minimize the volume of high-level waste requiring disposal. Two approaches are being considered for pretreating radioactive tank sludges: (1) leaching of selected components from the sludge and (2) acid dissolution of the sludge followed by separation of key radionuclides. The leaching approach offers the advantage of simplicity, but the acid dissolution/radionuclide extraction approach has the potential to produce the least number of glass canisters. Four critical components (Cr, P, S, and Al) were leached from an actual Hanford tank waste-Plutonium Finishing Plant sludge. The Al, P, and S were removed from the sludge by digestion of the sludge with 0.1 M NaOH at 100{degrees}C. The Cr was leached by treating the sludge with alkaline KMnO{sub 4} at 100{degrees}C. Removing these four components from the sludge will dramatically lower the number of glass canisters required to dispose of this waste. The transuranic extraction (TRUEX) solvent extraction process has been demonstrated at a bench scale using an actual Hanford tank waste. The process, which involves extraction of the transuranic elements with octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO), separated 99.9% of the transuranic elements from the bulk components of the waste. Several problems associated with the TRUEX processing of this waste have been addressed and solved.
Lumetta, G.J.; Swanson, J.L. [Pacific Northwest Lab., Richland, WA (United States); Barker, S.A. [Westinghouse Hanford Co., Richland, WA (United States)
Dilute Oxygen Combustion - Phase 3 Report
Dilute Oxygen Combustion (DOC) burners have been successfully installed and operated in the reheat furnace at Auburn Steel Co., Inc., Auburn, NY, under Phase 3 of the Dilute Oxygen Combustion project. Two new preheat zones were created employing a total of eight 6.5 MMBtu/hr capacity burners. The preheat zones provide a 30 percent increase in maximum furnace production rate, from 75 tph to 100 tph. The fuel rate is essentially unchanged, with the fuel savings expected from oxy-fuel combustion being offset by higher flue gas temperatures. When allowance is made for the high nitrogen level and high gas phase temperature in the furnace, measured NOx emissions are in line with laboratory data on DOC burners developed in Phase 1 of the project. Burner performance has been good, and there have been no operating or maintenance problems. The DOC system continues to be used as part of Auburn Steel's standard reheat furnace practice. High gas phase temperature is a result of the high firing density needed to achieve high production rates, and little opportunity exists for improvement in that area. However, fuel and NOx performance can be improved by further conversion on furnace zones to DOC burners, which will lower furnace nitrogen levels. Major obstacles are cost and concern about increased formation of oxide scale on the steel. Oxide scale formation may be enhanced by exposure of the steel to higher concentrations of oxidizing gas components (primarily products of combustion) in the higher temperature zones of the furnace. Phase 4 of the DOC project will examine the rate of oxide scale formation in these higher temperature zones and develop countermeasures that will allow DOC burners to be used successfully in these furnace zones.
Riley, Michael F.
Dilute Oxygen Combustion Phase 3 Final Report
Dilute Oxygen Combustion (DOC) burners have been successfully installed and operated in the reheat furnace at Auburn Steel Co., Inc., Auburn, NY, under Phase 3 of the Dilute Oxygen Combustion project. Two new preheat zones were created employing a total of eight 6.5 MMBtu/hr capacity burners. The preheat zones provide a 30 percent increase in maximum furnace production rate, from 75 tph to 100 tph. The fuel rate is essentially unchanged, with the fuel savings expected from oxy-fuel combustion being offset by higher flue gas temperatures. When allowance is made for the high nitrogen level and high gas phase temperature in the furnace, measured NOx emissions are in line with laboratory data on DOC burners developed in Phase 1 of the project. Burner performance has been good and there have been no operating or maintenance problems. The DOC system continues to be used as part of Auburn Steel?s standard reheat furnace practice. High gas phase temperature is a result of the high firing density needed to achieve high production rates, and little opportunity exists for improvement in that area. However, fuel and NOx performance can be improved by further conversion of furnace zones to DOC burners, which will lower furnace nitrogen levels. Major obstacles are cost and concern about increased formation of oxide scale on the steel. Oxide scale formation may be enhanced by exposure of the steel to higher concentrations of oxidizing gas components (primarily products of combustion) in the higher temperature zones of the furnace. Phase 4 of the DOC project will examine the rate of oxide scale formation in these higher temperature zones and develop countermeasures that will allow DOC burners to be used successfully in these furnace zones.
Riley, M.F.; Ryan, H.M.
Bioethanol Production Based on Simultaneous Saccharification and Fermentation of Wheat Straw
The potential of wheat straw as raw materials for ethanol production was investigated. Ethanol cooking at 190 ? for 60 min was adopted as pretreatment method for dilute sulfuric acid impregnated wheat straw. The pretreated wheat straw was used ... Keywords: dilute sulfuric acid catalysis, ethanol cooking pretreatment, wheat straw, simultaneous saccharification and fermentation, ethanol
Peng Luo; Zhong Liu
The Office of River Protection (ORP) has authorized a study to recommend and select options for interim pretreatment of tank waste and support Waste Treatment Plant (WTP) low activity waste (LAW) operations prior to startup of all the WTP facilities. The Interim Pretreatment System (IPS) is to be a moderately sized system which separates entrained solids and 137Cs from tank waste for an interim time period while WTP high level waste vitrification and pretreatment facilities are completed. This study's objective is to prepare pre-conceptual technology descriptions that expand the technical detail for selected solid and cesium separation technologies. This revision includes information on additional feed tanks.
Low Temperature Photoluminescence from Dilute Bismides
We report on photoluminescence measurements of GaAs{sub (1?x)}Bi{sub x} thin films containing dilute concentration (x {le} 0.045%) of isoelectronic impurity Bi. At a temperature of 4 K, we observed a sharp emission line at {approx}1.510 eV and a series of undulations in an energy range of {approx}20 meV below it. We attribute the sharp line at {approx}1.510 eV to the recombination of excitons bound to a complex formed by unintentionally incorporated acceptor or donor atoms in the samples. Undulations observed below the sharp line at 1.510 eV are assigned to the vibronic levels of the acceptors, generated by the dynamic Jahn-Teller effect due to the coupling between the holes bound to Bi and acceptors. The sharp line at {approx}1.510 eV and the undulation peaks show a redshift with increasing Bi concentration due to the decrease in band gap as a result of the strong perturbation to the GaAs band structure induced by isoelectronic Bi impurities. No spectral evidence for isolated Bi forming a bound state in GaAs was seen and similar to the case of Bi in GaP, no Bi-Bi pair states were observed.
Kini, R. N.; Mascarenhas, A.; France, R.; Ptak, A. J.
There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have conducted adsorption, phase behavior and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases IFT with a minimum at about 0.2 M. Addition of surfactant decreases IFT further. In the absence of surfactant the minerals are oil wet after aging with crude oil. Addition of surfactant solution decreases the contact angle to intermediate wettability. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Plans for the next quarter include conducting adsorption, phase behavior and wettability studies.
Kishore K. Mohanty
There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have conducted adsorption, phase behavior, interfacial tension (IFT) and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases IFT with a minimum at about 0.2 M. Addition of surfactant decreases IFT further. In the absence of surfactant the minerals are oil-wet after aging with crude oil. Addition of surfactant solution decreases the contact angle to intermediate-wet for many surfactants and water-wet for one surfactant. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Plans for the next quarter include conducting core adsorption, phase behavior, wettability and mobilization studies.
There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have conducted adsorption, phase behavior, interfacial tension (IFT) and wettability studies. Alfoterra-38 (0.05 wt%), Alfoterra-35 (0.05 wt%), SS-6656 (0.05 wt%), and DTAB (1 wt%) altered the wettability of the initially oil-wet calcite plate to an intermediate/water-wet state. Low IFT ({approx}10{sup -3} dynes/cm) is obtained with surfactants 5-166, Alfoterra-33 and Alfoterra-38. Plans for the next quarter include conducting wettability and mobilization studies.
Dilute Surfactant Methods for Carbonate Formations
There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the best hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. Laboratory-scale surfactant brine imbibition experiments give high oil recovery (35-62% OOIP) for initially oil-wet cores through wettability alteration and IFT reduction. Core-scale simulation results match those of the experiments. Initial capillarity-driven imbibition gives way to a final gravity-driven process. As the matrix block height increases, surfactant alters wettability to a lesser degree, or permeability decreases, oil production rate decreases. The scale-up to field scale will be further studied in the next quarter.
Vertical Pretreatment Reactor System (Poster), NREL (National Renewable Energy Laboratory)
Vertical Pretreatment Reactor System Vertical Pretreatment Reactor System Two-vessel system for primary and secondary pretreatment at diff erent temperatures * Biomass is heated by steam injection to temperatures of 120°C to 210°C in the pressurized mixing tube * Preheated, premixed biomass is retained for specified residence time in vertical holding vessel; material continuously moves by gravity from top to bottom of reactor in plug-fl ow fashion * Residence time is adjusted by changing amount of material held in vertical vessel relative to continuous fl ow of material entering and exiting vessel * Optional additional reactor vessel allows for secondary pretreatment at lower temperatures-120°C to 180°C-with potential to add other chemical catalysts * First vessel can operate at residence
Physical and Chemical Features of Pretreated Biomass that Influence...
Physical and Chemical Features of Pretreated Biomass that Influence Macro-Micro-accessibility and Biological Processing Rajeev Kumar 1,3 and Charles E. Wyman 1,2,3 1 Center for...
Use of Chemical Pretreatment to Enhance Liquid Waste of Processing
This report details unique chemical pretreatment and processing techniques presently used by utilities in their nuclear plant liquid radwaste treatment programs. It presents specific utility experience from a number of plants employing these processing alternatives.
Pretreatment of industrial discharges to publicly owned treatment works (POTW)
A discussion covers a brief survey of federal regulations establishing standards for the pretreatment of pollutants discharged into POTW's; the experience of the Municipality of Metropolitan Seattle (Metro) in dealing with the pretreatment of heavy metals in industrial and commercial discharges; a study and analysis by Seattle Metro of organic priority pollutants in wastewater including identification sources; and POTW treatment control technology for organic priority pollutants in Seattle Metro.
Ongerth, J.E.; Dewalle, F.B.
Sugar-Based Ethanol Biorefinery: Ethanol, Succinic Acid and By-Product Production
Lignin from pretreatment seemed to offer a potential source of valuable by-products. Although a wide range of phenolic compounds were present in the effluent from dilute ammonia pretreatment, the concentrations of each (except for benzoic acid) were too low to consider for extraction. The cellulosic hydrolysis system was modified to produce commercially recoverable quantities of cellobiose, which has a small but growing market in the food process industries. A spin-off of this led to the production of a specific oligosaccharide which appears to have both medical and commercial implications as a fungal growth inhibitor. An alternate use of sugars produced from biomass hydrolysis would be to produce succinic acid as a chemical feedstock for other conversions. An organism was developed which can do this bioconversion, but the economics of succinic acid production were such that it could not compete with current commercial practice. To allow recovery of commercial amounts of ethanol from bagasse fermentation, research was conducted on high solids loading fermentations (using S. cerevisiae) with commercial cellulase on pretreated material. A combination of SHF/SSF treatment with fed-batch operation allowed fermentation at 30% solids loading. Supplementation of the fermentation with a small amount of black-strap molasses had results beyond expectation. There was an enhancement of conversion as well as production of ethanol levels above 6.0% w/w, which is required both for efficient distillation as well as contaminant repression. The focus of fermentation development was only on converting the cellulose to ethanol, as this yeast is not capable of fermenting both glucose and xylose (from hemicellulose). In anticipation of the future development of such an organism, we screened the commercially available xylanases to find the optimum mix for conversion of both cellulose and hemicellulose. A different mixture than the spezyme/novozyme mix used in our fermentation research was found to be more efficient at converting both cellulose and hemicellulose. Efforts were made to select a mutant of Pichia stipitis for ability to co-ferment glucose and xylose to ethanol. New mutation technology was developed, but an appropriate mutant has not yet been isolated. The ability to convert to stillage from biomass fermentations were determined to be suitable for anaerobic degradation and methane production. An economic model of a current sugar factory was developed in order to provide a baseline for the cost/benefit analysis of adding cellulosic ethanol production.
Donal F. Day
Dilute Oxygen Combustion Phase I Final Report
A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NOx) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NOx through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NOx production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature (~1366 K) oxidant (7-27% O2 vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d+ scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d+ scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW (~0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric arrangement, firing rate, and fuel injection velocity. NOx emissions increased with increasing furnace nitrogen content and furnace temperature, but remained relatively insensitive to variations in fuel injection velocity and firing rate. NOx emissions below 5-10-3 g/MJ (10 ppm-air equivalent at 3% O2 dry) were obtained for furnace temperatures below 1533 K (2300°F) and furnace nitrogen levels between 1 and 40%. CO emissions were typically low (DOC burner arrangements were ascertained through furnace pressure measurements, wit6h increased stability occurring as furnace temperature increased and as the separation distance between fuel and oxidant inputs decreased. Based on current market conditions, oxy-fuel conversion of batch steel reheat furnaces with a DOC burner is justified on the basis of lower utility costs alone. However, conversion of continuous steel reheat furnaces, which are responsible for most steel production, required additional economic incentives, such as further fuel savings, increased furnace productivity, or emission credits.
Ryan, H.M.; Riley, M.F.; Kobayashi, H.
A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NOx) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NOx through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NOx production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature (~1366 K) oxidant (7-27% O2 vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d+ scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d+ scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW (~0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric arrangement, firing rate, and fuel injection velocity. NOx emissions increased with increasing furnace nitrogen content and furnace temperature, but remained relatively insensitive to variations in fuel injection velocity and firing rate. NOx emissions below 5-10-3 g/MJ (10 ppm-air equivalent at 3% O2 dry) were obtained for furnace temperatures below 1533 K (2300°F) and furnace nitrogen levels between 1 and 40%. CO emissions were typically low (<35 ppm). Detailed in-furnace species measurements revealed the importance of the interior furnace circulation patterns, as influenced by fuel and oxidant injection schemes, on pollutant emissions. The combustion stability traits of several DOC burner arrangements were ascertained through furnace pressure measurements, wit6h increased stability occurring as furnace temperature increased and as the separation distance between fuel and oxidant inputs decreased. Based on current market conditions, oxy-fuel conversion of batch steel reheat furnaces with a DOC burner is justified on the basis of lower utility costs alone. However, conversion of continuous steel reheat furnaces, which are responsible for most steel production, required additional economic incentives, such as further fuel savings, increased furnace productivity, or emission credits.
Dilute Oxygen Combustion Phase 2 Final Report
A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NOx) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NOx through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NOx production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature (~1366 K) oxidant (7-27% O2 vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d+ scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d+ scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW (~0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric arrangement, firing rate, and fuel injection velocity. NOx emissions increased with increasing furnace nitrogen content and furnace temperature, but remained relatively insensitive to variations in fuel injection velocity and firing rate. NOx emissions below 5-10-3 g/MJ (10 ppm-air equivalent at 3% O2 dry) were obtained for furnace temperatures below 1533 K (2300?F) and furnace nitrogen levels between 1 and 40%. CO emissions were typically low (<35 ppm). Detailed in-furnace species measurements revealed the importance of the interior furnace circulation patterns, as influenced by fuel and oxidant injection schemes, on pollutant emissions. The combustion stability traits of several DOC burner arrangements were ascertained through furnace pressure measurements, wit6h increased stability occurring as furnace temperature increased and as the separation distance between fuel and oxidant inputs decreased. Based on current market conditions, oxy-fuel conversion of batch steel reheat furnaces with a DOC burner is justified on the basis of lower utility costs alone. However, conversion of continuous steel reheat furnaces, which are responsible for most steel production, required additional economic incentives, such as further fuel savings, increased furnace productivity, or emission credits.
A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NOx) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NOx through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NOx production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature (~1366 K) oxidant (7-27% O2 vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d+ scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d+ scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW (~0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric arrangement, firing rate, and fuel injection velocity. NOx emissions increased with increasing furnace nitrogen content and furnace temperature, but remained relatively insensitive to variations in fuel injection velocity and firing rate. NOx emissions below 5-10-3 g/MJ (10 ppm-air equivalent at 3% O2 dry) were obtained for furnace temperatures below 1533 K (2300?F) and furnace nitrogen levels between 1 and 40%. CO emissions were typically low (DOC burner arrangements were ascertained through furnace pressure measurements, wit6h increased stability occurring as furnace temperature increased and as the separation distance between fuel and oxidant inputs decreased. Based on current market conditions, oxy-fuel conversion of batch steel reheat furnaces with a DOC burner is justified on the basis of lower utility costs alone. However, conversion of continuous steel reheat furnaces, which are responsible for most steel production, required additional economic incentives, such as further fuel savings, increased furnace productivity, or emission credits.
Effect of alkaline pretreatment on anaerobic digestion of solid wastes
The introduction of the anaerobic digestion for the treatment of the organic fraction of municipal solid waste (OFMSW) is currently of special interest. The main difficulty in the treatment of this waste fraction is its biotransformation, due to the complexity of organic material. Therefore, the first step must be its physical, chemical and biological pretreatment for breaking complex molecules into simple monomers, to increase solubilization of organic material and improve the efficiency of the anaerobic treatment in the second step. This paper describes chemical pretreatment based on lime addition (Ca(OH){sub 2}), in order to enhance chemical oxygen demand (COD) solubilization, followed by anaerobic digestion of the OFMSW. Laboratory-scale experiments were carried out in completely mixed reactors, 1 L capacity. Optimal conditions for COD solubilization in the first step of pretreatment were 62.0 mEq Ca(OH){sub 2}/L for 6.0 h. Under these conditions, 11.5% of the COD was solubilized. The anaerobic digestion efficiency of the OFMSW, with and without pretreatment, was evaluated. The highest methane yield under anaerobic digestion of the pretreated waste was 0.15 m{sup 3} CH{sub 4}/kg volatile solids (VS), 172.0% of the control. Under that condition the soluble COD and VS removal were 93.0% and 94.0%, respectively. The results have shown that chemical pretreatment with lime, followed by anaerobic digestion, provides the best results for stabilizing the OFMSW.
Lopez Torres, M. [National Center for Scientific Researcher (CNIC), Environmental Pollution Department (DECA), Ave. 25 y 158, Cubanacan, Playa, Havana City (Cuba)], E-mail: email@example.com; Espinosa Llorens, Ma. del C. [National Center for Scientific Researcher (CNIC), Environmental Pollution Department (DECA), Ave. 25 y 158, Cubanacan, Playa, Havana City (Cuba)
Evaluation of coal pretreatment prior to co-processing
The Western Research Institute is currently developing a mild gasification process for the recovery of a stabilized char product for use as a fuel. A liquid product of limited value is produced during the mild gasification process that may be suited as a co-processing vehicle for coal-oil co-processing. Research was conducted to evaluate co-processing of this mild gasification liquid with coal. The two major areas of research discussed in this report are: (1) coal pretreatment with a coal-derived liquid to induce coal swelling and promote catalyst dispersion and (2) co-processing coal that has been thermally pretreated in the presence of the mild gasification liquid. The results of the investigation to evaluate co-processing of coal that has been thermally pretreated in the presence of the mild gasification liquid indicate that the thermal pretreatment adversely affected the coal-oil co-processing under hydrogen pressure. Thermally pretreated coals co-processed under a hydrogen atmosphere and without benefit of catalyst exhibited about 86 wt % conversion as compared to 96 wt % for coal that was only thermally dried. The addition of the iron pentacarbonyl catalyst precursor to the thermally pretreated coals did improve the conversion to near that of the dried coal. Results from analysis of the product obtained from co-processing the Illinois No. 6 coal showed it was upgraded in terms of oxygen content and hydrogen to carbon atomic ratio when compared to the mild gasification liquid.
Guffey, F.D.; Barbour, F.A.; Blake, R.F.
Research Highlights | ORNL Neutron Sciences
of Biomass Components at Nanoscale To Dilute Acid Pretreatment The generation of bioethanol from lignocellulosic biomass holds great promise for renewable and clean energy...
The work conducted in this project is an extension of the developments itemized in DE-FG-36-04GO14236. This program is designed to help the development of a biorefinery based around a raw sugar mill, which in Louisiana is an underutilized asset. Some technical questions were answered regarding the addition of a biomass to ethanol facility to existing sugar mills. The focus of this work is on developing technology to produce ethanol and valuable by-products from bagasse. Three major areas are addressed, feedstock storage, potential by-products and the technology for producing ethanol from dilute ammonia pre-treated bagasse. Sugar mills normally store bagasse in a simple pile. During the off season there is a natural degradation of the bagasse, due to the composting action of microorganisms in the pile. This has serious implications if bagasse must be stored to operate a bagasse/biorefinery for a 300+ day operating cycle. Deterioration of the fermentables in bagasse was found to be 6.5% per month, on pile storage. This indicates that long term storage of adequate amounts of bagasse for year-round operation is probably not feasible. Lignin from pretreatment seemed to offer a potential source of valuable by-products. Although a wide range of phenolic compounds were present in the effluent from dilute ammonia pretreatment, the concentrations of each (except for benzoic acid) were too low to consider for extraction. The cellulosic hydrolysis system was modified to produce commercially recoverable quantities of cellobiose, which has a small but growing market in the food process industries. A spin-off of this led to the production of a specific oligosaccharide which appears to have both medical and commercial implications as a fungal growth inhibitor. An alternate use of sugars produced from biomass hydrolysis would be to produce succinic acid as a chemical feedstock for other conversions. An organism was developed which can do this bioconversion, but the economics of succinic acid production were such that it could not compete with current commercial practice. To allow recovery of commercial amounts of ethanol from bagasse fermentation, research was conducted on high solids loading fermentations (using S. cerevisiae) with commercial cellulase on pretreated material. A combination of SHF/SSF treatment with fed-batch operation allowed fermentation at 30% solids loading. Supplementation of the fermentation with a small amount of black-strap molasses had results beyond expectation. There was an enhancement of conversion as well as production of ethanol levels above 6.0% w/w, which is required both for efficient distillation as well as contaminant repression. The focus of fermentation development was only on converting the cellulose to ethanol, as this yeast is not capable of fermenting both glucose and xylose (from hemicellulose). In anticipation of the future development of such an organism, we screened the commercially available xylanases to find the optimum mix for conversion of both cellulose and hemicellulose. A different mixture than the spezyme/novozyme mix used in our fermentation research was found to be more efficient at converting both cellulose and hemicellulose. Efforts were made to select a mutant of Pichia stipitis for ability to co-ferment glucose and xylose to ethanol. New mutation technology was developed, but an appropriate mutant has not yet been isolated. The ability to convert to stillage from biomass fermentations were determined to be suitable for anaerobic degradation and methane production. An economic model of a current sugar factory was developed in order to provide a baseline for the cost/benefit analysis of adding cellulosic ethanol production.
Method and apparatus for gasifying with a fluidized bed gasifier having integrated pretreating facilities
An integral gasifier including a pretreater section and a gasifier section separated by a distribution grid is defined by a single vessel. The pretreater section pretreats coal or other carbon-containing material to be gasified to prevent caking and agglomeration of the coal in the gasifier. The level of the coal bed of the pretreater section and thus the holding or residence time in said bed is selectively regulated by the amount of pretreated coal which is lifted up a lift pipe into the gasifier section. Thus, the holding time in the pretreater section can be varied according to the amount of pretreat necessary for the particular coal to be gasified.
Rice, Louis F. (Arcadia, CA)
Dilute Oxygen Combustion Phase IV Final Report
Novel furnace designs based on Dilute Oxygen Combustion (DOC) technology were developed under subcontract by Techint Technologies, Coraopolis, PA, to fully exploit the energy and environmental capabilities of DOC technology and to provide a competitive offering for new furnace construction opportunities. Capital cost, fuel, oxygen and utility costs, NOx emissions, oxide scaling performance, and maintenance requirements were compared for five DOC-based designs and three conventional air5-fired designs using a 10-year net present value calculation. A furnace direct completely with DOC burners offers low capital cost, low fuel rate, and minimal NOx emissions. However, these benefits do not offset the cost of oxygen and a full DOC-fired furnace is projected to cost $1.30 per ton more to operate than a conventional air-fired furnace. The incremental cost of the improved NOx performance is roughly $6/lb NOx, compared with an estimated $3/lb. NOx for equ8pping a conventional furnace with selective catalytic reduction (SCCR) technology. A furnace fired with DOC burners in the heating zone and ambient temperature (cold) air-fired burners in the soak zone offers low capital cost with less oxygen consumption. However, the improvement in fuel rate is not as great as the full DOC-fired design, and the DOC-cold soak design is also projected to cost $1.30 per ton more to operate than a conventional air-fired furnace. The NOx improvement with the DOC-cold soak design is also not as great as the full DOC fired design, and the incremental cost of the improved NOx performance is nearly $9/lb NOx. These results indicate that a DOC-based furnace design will not be generally competitive with conventional technology for new furnace construction under current market conditions. Fuel prices of $7/MMBtu or oxygen prices of $23/ton are needed to make the DOC furnace economics favorable. Niche applications may exist, particularly where access to capital is limited or floor space limitations are critical. DOC technology will continue to have a highly competitive role in retrofit applications requiring increases in furnace productivity.
Riley, M.F.
Addressing Complexity In Laboratory Experiments- The Scaling Of Dilute
Open Energy Info (EERE)
source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Addressing Complexity In Laboratory Experiments- The Scaling Of Dilute Multiphase Flows In Magmatic Systems Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Addressing Complexity In Laboratory Experiments- The Scaling Of Dilute Multiphase Flows In Magmatic Systems Details Activities (0) Areas (0) Regions (0) Abstract: The kinematic and dynamic scaling of dilute multiphase mixtures in magmatic systems is the only guarantee for the geological verisimilitude of laboratory experiments. We present scaling relations that can provide a more complete framework to scale dilute magmatic systems because they
Separation processes using expulsion from dilute supercritical solutions
A process for separating isotopes as well as other mixtures by utilizing the behavior of dilute repulsive or weakly attractive elements of the mixtures as the critical point of the solvent is approached.
Cochran, Jr., Henry D. (Oak Ridge, TN)
Translation of dilution tolerance for gasoline SI engine
There are a variety of fuel improvement strategies being developed for spark ignition engines which use dilution. Many of these technologies use a combination of different diluents. It is impractical in optimizing these ...
Niekamp, Troy S. (Troy Steven)
A process is described for separating isotopes as well as other mixtures by utilizing the behavior of dilute repulsive or weakly attractive elements of the mixtures as the critical point of the solvent is approached.
Cochran, H.D. Jr.
Quantitation of Glycidyl Esters via Stable Isotope Dilution Analysis
Quantitation of Glycidyl Esters via Stable Isotope Dilution Analysis Michael Granvogl and Peter Schieberle Technical University of Munich, Chair for Food Chemistry and German Research Centre for Food Chemistry, Lise-Meitner-Str. 34, Freising, Germ
Anatomy of symmetry energy of dilute nuclear matter
The symmetry energy coefficients of dilute clusterized nuclear matter are evaluated in the $S$-matrix framework. Employing a few different definitions commonly used in the literature for uniform nuclear matter, it is seen that the different definitions lead to perceptibly different results for the symmetry coefficients for dilute nuclear matter. They are found to be higher compared to those obtained for uniform matter in the low density domain. The calculated results are in reasonable consonance with those extracted recently from experimental data.
J. N. De; S. K. Samaddar; B. K. Agrawal
The Propagation of Photons in the Dilute Ionized Gas
The dilute ionized gas is very popular in the Universe. Usually only the Compton interactions, the "Sunyaev-Zel'dovich" effect, were considered while photons propagated in this medium. In this paper the "soft-photon process" is considered. Due to the soft photons emitted during the propagation of a photon in the dilute ionized gas, the main photon (propagating in the original direction) will be redshifted. The formula to calculate this redshift is derived.
Zheng, Yijia
Yijia Zheng
Dilution Refrigeration of Multi-Ton Cold Masses
Dilution refrigeration is the only means to provide continuous cooling at temperatures below 250 mK. Future experiments featuring multi-ton cold masses require a new generation of dilution refrigeration systems, capable of providing a heat sink below 10 mK at cooling powers which exceed the performance of present systems considerably. This thesis presents some advances towards dilution refrigeration of multi-ton masses in this temperature range. A new method using numerical simulation to predict the cooling power of a dilution refrigerator of a given design has been developed in the framework of this thesis project. This method does not only allow to take into account the differences between an actual and an ideal continuous heat exchanger, but also to quantify the impact of an additional heat load on an intermediate section of the dilute stream. In addition, transient behavior can be simulated. The numerical model has been experimentally verified with a dilution refrigeration system which has been designed, ...
Wikus, P; CERN. Geneva
Effect of pretreating of host oil on coprocessing. Final report
A petroleum vacuum resid (1,000 F+) was pretreated by catalytic hydrogenation and hydrocracking reactions and the pretreated resids (host oils) were then coprocessed with coal. The fraction of coal converted to soluble products and the yield of pentane-soluble oils were determined after coprocessing. The phenolic oxygen concentration of the oil product provided a means for estimating the fraction of coal liquids in the products; oils originating from coal had much higher concentrations of phenolic oxygen than those originating from petroleum. Resids that were pretreated by mild temperature hydrogenation reactions, where cracking was suppressed, became better host oils; when these pretreated resids were coprocessed with coal, more of the mixture was converted to tetrahydrofuran-soluble products. Depending on the pretreatment, the pentane-soluble oil yields following thermal coprocessing were either significantly lower or slightly higher than the oil yields obtained with untreated resid. The yield of oils was strongly affected by the concentration of coal in the feed. The presence of small amounts, less than 33% of coal, enhanced the conversion of petroleum resid to oils during coprocessing, although the increases were small. 91 refs.
Wender, I.; Tierney, J.W.
New lignocellulose pretreatments using cellulose solvents: a review
Received: Received: 7 September 2012 Accepted: 13 September 2012 Published online in Wiley Online Library: (wileyonlinelibrary.com) DOI 10.1002/jctb.3959 New lignocellulose pretreatments using cellulose solvents: a review Noppadon Sathitsuksanoh, a† Anthe George b,c and Y-H Percival Zhang a,d,e∗ Abstract Non-food lignocellulosic biomass is the most abundant renewable bioresource as a collectable, transportable, and storable chemical energy that is far from fully utilized. The goal of biomass pretreatment is to improve the enzymatic digestibility of pretreated lignocellulosic biomass. Many substrate factors, such as substrate accessibility, lignin content, particle size and so on, contribute to its recalcitrance. Cellulose accessibility to hydrolytic enzymes is believed to be the most important substrate characteristic limiting enzymatic hydrolysis. Cellulose
Hazard Analysis for the Pretreatment Engineering Platform (PEP)
The Pretreatment Engineering Platform (PEP) is designed to perform a demonstration on an engineering scale to confirm the Hanford Waste Treatment Plant Pretreatment Facility (PTF) leaching and filtration process equipment design and sludge treatment process. The system will use scaled prototypic equipment to demonstrate sludge water wash, caustic leaching, oxidative leaching, and filtration. Unit operations to be tested include pumping, solids washing, chemical reagent addition and blending, heating, cooling, leaching, filtration, and filter cleaning. In addition, the PEP will evaluate potential design changes to the ultrafiltration process system equipment to potentially enhance leaching and filtration performance as well as overall pretreatment throughput. The skid-mounted system will be installed and operated in the Processing Development Laboratory-West at Pacific Northwest National Laboratory (PNNL) in Richland, Washington.
Sullivan, Robin S.; Geeting, John GH; Lawrence, Wesley E.; Young, Jonathan
Pre-treating Seed to Enhance Germination of Desert Shrubs
Creosotebush [Larrea tridentata (D.C.) Cav.] and white bursage [Ambrosia dumosa (A. Gray) W.W. Payne] seeds were subjected to pre-treatments of rinsing and soaking in water and thiourea to enhance germination in laboratory experiments. The effects of darkness, temperature, seed source, and soil moisture were also evaluated in the laboratory. The best pre-treatment from the laboratory experiments, rinsing with water for 36 hours followed by drying, was field-tested at Fort Irwin, California. Two sites and two seeding dates (early March and mid April) were determined for each site. Five mulch treatments (no mulch, straw, gravel, chemical stabilizer, and plastic) were evaluated in combination with the seed pre-treatments. Field emergence was greatly enhanced with the seed pre-treatment for white bursage during the March (18-42% increase in germination) and April seedings (16-23% increase in germination). Creosotebush showed poor germination during March (2-5%) when soil temperatures averaged 15 C, but germination increased during the April trials (6-43%) when soil temperatures averaged 23 C. The seed pre-treatment during the April trials increased germination from 16-23%. The plastic mulch treatment increased germination dramatically during both the March and April trials. The plastic mulch increased soil temperatures (8-10 C)and maintained high humidity during germination. Both the chemical stabilizer and the gravel mulches improved germination over the control while the straw mulch decreased germination. These results suggest that seed pre-treatments combined with irrigation and mulch are effective techniques to establish these two dominant Mojave Desert species from seed.
W. K. Ostler; D. C. Anderson; D. J. Hansen
High-Throughput Pretreatment and Hydrolysis Systems for Screening Biomass Species in Aqueous Pretreatment of Plant Biomass
High-throughput High-throughput Pretreatment and Hydrolysis Systems for Screening Biomass Species in Aqueous Pretreatment of Plant Biomass Jaclyn D. DeMartini 1,2,3,Ã and Charles E. Wyman 1,2,3 1 Department of Chemical and Environmental Engineering, University of California, Riverside, USA 2 Center for Environmental Research and Technology, University of California, Riverside, USA 3 BioEnergy Science Center, Oak Ridge, USA 22.1 Introduction: The Need for High-throughput Technologies The primary barrier to low-cost biological conversion of lignocellulosic biomass to renewable fuels and chemicals is plant recalcitrance, that is to say, resistance of cell walls to deconstruction by enzymes or microbes [1,2]. However, the discovery and use of biomass species with reduced recalcitrance, when com- bined with optimized pretreatment processes and enzyme mixtures, could potentially
Polarized target with dilution refrigerator: why and how
Polarized targets using dilution refrigerators have several advantages over targets of He/sup 3/ cryostats for some polarization experiments. One of the advantages is in the long nuclear spin lattice relaxation time in quite low temperatures. It permits holding the target polarization in a magnetic field different from the polarizing field. Another merit is in the fact that one can obtain higher polarization in a dilution refrigerator than in a He/sup 3/ cryostat, especially in the case of deuterons. These facts suggest various applications of the target with a dilution refrigerator, such as a spin-frozen target for spin-rotation parameter measurements, a target for spin effects in inelastic scattering, high polarized deuteron target, and so on. Furthermore, one can hopefully make a highly polarized HD target with further improvements of the dilution refrigerator. The possibility of the solid hydrogen polarization is also discussed. Finally, the principle of the dilution refrigerator and the special features of the refrigerator for the polarized target are briefly described. 7 figures.
Masaike, A.
Isotope dilution study of exchangeable oxygen in premium coal samples
A difficulty with improving the ability to quantitate water in coal is that truly independent methods do not always exist. The true value of any analytical parameter is always easier to determine if totally independent methods exist to determine that parameter. This paper describes the possibility of using a simple isotope dilution technique to determine the water content of coal and presents a comparison of these isotope dilution measurements with classical results for the set of Argonne coals from the premium coal sample program. Isotope dilution is a widely used analytical method and has been applied to the analysis of water in matrices as diverse as chicken fat, living humans, and coal. Virtually all of these applications involved the use of deuterium as the diluted isotope. This poses some problems if the sample contains a significant amount of exchangeable organic hydrogen and one is interested in discriminating exchangeable organic hydrogen from water. This is a potential problem in the coal system. To avoid this potential problem /sup 18/O was used as the diluted isotope in this work.
Finseth, D.
Process of concentrating ethanol from dilute aqueous solutions thereof
Relatively dilute aqueous solutions of ethanol are concentrated by passage through a bed of a crystalline silica polymorph, such as silicalite, to adsorb the ethanol with residual dilute feed in contact with the bed, which is displaced by passing concentrated aqueous ethanol through the bed without displacing the adsorbed ethanol. A product concentrate is then obtained by removing the adsorbed ethanol from the bed together with at least a portion of the concentrated aqueous ethanol used as the displacer liquid. This process permits ethanol to be concentrated from dilute fermentation beers, which may contain from 6 to 10% ethanol, to obtain a concentrate product at very low energy cost having an ethanol concentration in excess of 95%, such as a concentration of from 98 to 99.5%. 5 figs.
Oulman, C.S.; Chriswell, C.D.
Relatively dilute aqueous solutions of ethanol are concentrated by passage through a bed of a crystalline silica polymorph, such as silicalite, to adsorb the ethanol with residual dilute feed in contact with the bed, which is displaced by passing concentrated aqueous ethanol through the bed without displacing the adsorbed ethanol. A product concentrate is then obtained by removing the adsorbed ethanol from the bed together with at least a portion of the concentrated aqueous ethanol used as the displacer liquid. This process permits ethanol to be concentrated from dilute fermentation beers, which may contain from 6 to 10% ethanol, to obtain a concentrate product at very low energy cost having an ethanol concentration in excess of 95%, such as a concentration of from 98 to 99.5%.
Oulman, Charles S. (Ames, IA); Chriswell, Colin D. (Slater, IA)
Application of Cryocoolers to a Vintage Dilution Refrigerator
A dilution refrigerator is required for 50mK detector operation of CDMS (Cryogenic Dark Matter Search). Besides shielding the dilution refrigerator itself, the liquid nitrogen shield and liquid helium bath in the refrigerator cool the detector cryostat heat shields and cool electronics, resulting in significant external heat loads at 80K and at 4K. An Oxford Instruments Kelvinox 400 has served this role for ten years but required daily transfers of liquid nitrogen and liquid helium. Complicating the cryogen supply is the location 800 meters below ground in an RF shielded, class 10000 clean room at Soudan, MN. Nitrogen and helium re-liquefiers using cryocoolers were installed outside the clean room and continuously condense room temperature gas and return the liquids to the dilution refrigerator through a transfer line. This paper will describe the design, installation, controls and performance of liquefaction systems.
Schmitt, Richard; Smith, Gary; Ruschman, Mark; /Fermilab; Beaty, Jim; /Minnesota U.
Dilution cycle control for an absorption refrigeration system
A dilution cycle control system for an absorption refrigeration system is disclosed. The control system includes a time delay relay for sensing shutdown of the absorption refrigeration system and for generating a control signal only after expiration of a preselected time period measured from the sensed shutdown of the absorption refrigeration system, during which the absorption refrigeration system is not restarted. A dilution cycle for the absorption refrigeration system is initiated in response to generation of a control signal by the time delay relay. This control system is particularly suitable for use with an absorption refrigeration system which is frequently cycled on and off since the time delay provided by the control system prevents needless dilution of the absorption refrigeration system when the system is turned off for only a short period of time and then is turned back on.
Reimann, Robert C. (Lafayette, NY)
Effects of catalyst pretreatment for carbon nanotube growth
The effects of pretreatment of iron catalyst for carbon nanotube (CNT) growth was studied. CNTs were grown on Fe/A1203 (1/10 nm) thin-film catalyst deposited on silicon substrates via exposure to C2H4 in a thermal chemical ...
Morgan, Caitlin D
Separations/pretreatment considerations for Hanford privatization phase 2
The Tank Focus Area is funded to develop, demonstrate, and deploy technologies that will assist in the treatment and closure of its nuclear waste tanks. Pretreatment technologies developed to support the privatization effort by the Department of Energy are reviewed. Advancements in evaporation, solid-liquid separation, sludge treatment, solids controls, sodium management, and radionuclide removal are considered.
Hunt, R.D.; McGinnis, C.P.; Welch, T.D.
Coal liquefaction process using pretreatment with a binary solvent mixture
An improved process for thermal solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a hydrogen donor solvent comprises pretreating the coal with a binary mixture of an aromatic hydrocarbon and an aliphatic alcohol at a temperature below 300.degree. C. before the hydroliquefaction step. This treatment generally increases both conversion of coal and yields of oil.
Miller, Robert N. (Allentown, PA)
Savannah River Remediation, LLC (SRR) operates the Defense Waste Processing Facility for the U.S. Department of Energy at the Savannah River Site. This facility immobilizes high-level radioactive waste through vitrification following chemical pretreatment. Catalytic destruction of formate and oxalate ions to carbon dioxide has been observed during qualification testing of non-radioactive analog systems. Carbon dioxide production greatly exceeded hydrogen production, indicating the occurrence of a process other than the catalytic decomposition of formic acid. Statistical modeling was used to relate the new reaction chemistry to partial catalytic wet air oxidation of both formate and oxalate ions driven by the low concentrations of palladium, rhodium, and/or ruthenium in the waste. Variations in process conditions led to increases or decreases in the total oxidative destruction, as well as partially shifting the preferred species undergoing destruction from oxalate ion to formate ion.
Koopman, D.; Herman, C.; Pareizs, J.; Bannochie, C.; Best, D.; Bibler, N.; Fellinger, T.
Hydrothermal pretreatment to prevent scale during liquefaction of certain solid carbonaceous materials
Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by hydrothermal pretreatment. The said pretreatment is believed to convert the scale-forming components to the corresponding carbonate prior to liquefaction. The said pretreatment is accomplished at a total pressure within the range from about 1000 to about 4400 psia. Temperature during said pretreatment will generally be within the range from about 500.degree. to about 700.degree. F.
Stone, John B. (Houston, TX); Floyd, Frank M. (Baytown, TX)
NREL Breaks New Ground in Plant Pretreatment for Biofuels (Fact Sheet)
NREL researchers use imaging technologies to broaden knowledge of plant cell wall structures and identify ideal pretreatment of plant material.
Electrical resistivity imaging of conductive plume dilution in fractured rock
was injected into an injection well for 34 days to dilute a pre-existing potassium chloride (KCl) plume was conducted between the injection well and each of seven surrounding monitoring wells. Polar plots of the injection-well resistivity data in the direction of each monitoring well delineate specific locations where
Binley, Andrew
Lime pretreatment and enzymatic hydrolysis of corn stover
Renewable energy sources, such as lignocellulosic biomass, are environmentally friendly because they emit less pollution without contributing net carbon dioxide to the atmosphere. Among lignocellulosic biomass, corn stover is a very useful feedstock to economically produce environmentally friendly biofuels. Corn stover was pretreated with an excess of calcium hydroxide (0.5 g Ca(OH)2/g raw biomass) in non-oxidative and oxidative conditions at 25, 35, 45, and 55oC. The optimal condition is 55oC for 4 weeks with aeration, determined by yields of glucan and xylan. The overall yields of glucose (g glucan hydrolyzed/100 g original glucan) and xylose (g xylan hydrolyzed/100 g original xylan) were 91.3 and 51.8 at 15 FPU/g cellulose, respectively. Furthermore, when considering the dissolved fragments of glucan and xylan in the pretreatment liquors, the overall yields of glucose and xylose were 93.2 and 79.5 at 15 FPU/g cellulose, respectively. The pretreatment liquor has no inhibitory effect on ethanol fermentation using Saccharomyces cerevisiae D5A. At the recommended condition, only 0.073 g Ca(OH)2 was consumed per g of raw corn stover. Under extensive delignification conditions, 87.5% of the initial lignin was removed. Extensive delignfication required oxidative treatment and additional lime consumption. Deacetylation quickly reached a plateau within 1 week. Delignification highly depended on temperature and the presence of oxygen. Lignin and hemicellulose were selectively removed, but cellulose was not affected by lime pretreatment in mild temperatures (25 ?? 55oC). The delignification kinetic models of corn stover were empirically determined by three simultaneous first-order reactions. The activation energies for the oxidative delignification were estimated as 50.15 and 54.21 kJ/mol in the bulk and residual phases, respectively. Crystallinity slightly increased with delignification because amorphous components (lignin, hemicellulose) were removed. However, the increased crystallinity did not negatively affect the 3-d sugar yield of enzyme hydrolysis. Oxidative lime pretreatment lowered the acetyl and lignin contents to obtain high digestibility, regardless of crystallinity. The enzymatic digestibility of lime-treated biomass was affected by the change of structural features (acetylation, lignification, and crystallization) resulting from the treatment. The non-linear models for 3-d hydrolysis yields of glucan and xylan were empirically established as a function of the residual lignin fraction for the corn stover pretreated with lime and air.
Kim, Se Hoon
Enzymatic Digestibility of Corn Stover Fractions in Response to Fungal Pretreatment
Corn stover fractions (leaves, cobs, and stalks) were studied for enzymatic digestibility after pretreatment with a white rot fungus, Ceriporiopsis subvermispora. Among the three fractions, leaves had the least recalcitrance to fungal pretreatment and the lignin degradation reached 45% after 30 days of pretreatment. The lignin degradation of stalks and cobs was similar but was significantly lower than that of leaves (p corn cobs.
Cui, Z. F.; Wan, C. X.; Shi, J.; Sykes, R. W.; Li, Y. B.
Pretreatment Engineering Platform Phase 1 Final Test Report
Pacific Northwest National Laboratory (PNNL) was tasked by Bechtel National Inc. (BNI) on the River Protection Project, Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to conduct testing to demonstrate the performance of the WTP Pretreatment Facility (PTF) leaching and ultrafiltration processes at an engineering-scale. In addition to the demonstration, the testing was to address specific technical issues identified in Issue Response Plan for Implementation of External Flowsheet Review Team (EFRT) Recommendations - M12, Undemonstrated Leaching Processes.( ) Testing was conducted in a 1/4.5-scale mock-up of the PTF ultrafiltration system, the Pretreatment Engineering Platform (PEP). Parallel laboratory testing was conducted in various PNNL laboratories to allow direct comparison of process performance at an engineering-scale and a laboratory-scale. This report presents and discusses the results of those tests.
Kurath, Dean E.; Hanson, Brady D.; Minette, Michael J.; Baldwin, David L.; Rapko, Brian M.; Mahoney, Lenna A.; Schonewill, Philip P.; Daniel, Richard C.; Eslinger, Paul W.; Huckaby, James L.; Billing, Justin M.; Sundar, Parameshwaran S.; Josephson, Gary B.; Toth, James J.; Yokuda, Satoru T.; Baer, Ellen BK; Barnes, Steven M.; Golovich, Elizabeth C.; Rassat, Scot D.; Brown, Christopher F.; Geeting, John GH; Sevigny, Gary J.; Casella, Amanda J.; Bontha, Jagannadha R.; Aaberg, Rosanne L.; Aker, Pamela M.; Guzman-Leong, Consuelo E.; Kimura, Marcia L.; Sundaram, S. K.; Pires, Richard P.; Wells, Beric E.; Bredt, Ofelia P.
An improved process for thermal solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a hydrogen donor solvent comprises pretreating the coal with a binary mixture of an aromatic hydrocarbon and an aliphatic alcohol at a temperature below 300 C before the hydroliquefaction step. This treatment generally increases both conversion of coal and yields of oil. 1 fig.
Miller, R.N.
Separation and concentration of lower alcohols from dilute aqueous solutions
A process for producing, from a dilute aqueous solution of a lower (C.sub.1 -C.sub.5) alcohol, a concentrated liquid solution of the alcohol in an aromatic organic solvent is disclosed. Most of the water is removed from the dilute aqueous solution of alcohol by chilling sufficiently to form ice crystals. Simultaneously, the remaining liquid is extracted at substantially the same low temperature with a liquid organic solvent that is substantially immiscible in aqueous liquids and has an affinity for the alcohol at that temperature, causing the alcohol to transfer to the organic phase. After separating the organic liquid from the ice crystals, the organic liquid can be distilled to enrich the concentration of alcohol therein. Ethanol so separated from water and concentrated in an organic solvent such as toluene is useful as an anti-knock additive for gasoline.
Moore, Raymond H. (Richland, WA); Eakin, David E. (Kennewick, WA); Baker, Eddie G. (Richland, WA); Hallen, Richard T. (Richland, WA)
The Defense Waste Processing Facility at the Savannah River Site processes high-level radioactive waste from the processing of nuclear materials that contains dissolved and precipitated metals and radionuclides. Vitrification of this waste into borosilicate glass for ultimate disposal at a geologic repository involves chemically modifying the waste to make it compatible with the glass melter system. Pretreatment steps include removal of excess aluminum by dissolution and washing, and processing with formic and nitric acids to: (1) adjust the reduction-oxidation (redox) potential in the glass melter to reduce radionuclide volatility and improve melt rate; (2) adjust feed rheology; and (3) reduce by steam stripping the amount of mercury that must be processed in the melter. Elimination of formic acid pretreatment has been proposed to eliminate the production of hydrogen in the pretreatment systems; alternative reductants would be used to control redox. However, elimination of formic acid would result in significantly more mercury in the melter feed; the current specification is no more than 0.45 wt%, while the maximum expected prior to pretreatment is about 2.5 wt%. An engineering study has been undertaken to estimate the effects of eliminating mercury removal on the melter offgas system performance. A homogeneous gas-phase oxidation model and an aqueous phase model were developed to study the speciation of mercury in the DWPF melter offgas system. The model was calibrated against available experimental data and then applied to DWPF conditions. The gas-phase model predicted the Hg{sub 2}{sup 2-}/Hg{sup 2+} ratio accurately, but some un-oxidized Hg{sup 0} remained. The aqueous model, with the addition of less than 1 mM Cl{sub 2} showed that this remaining Hg{sup 0} would be oxidized such that the final Hg{sub 2}{sup 2+}/Hg{sup 2+} ratios matched the experimental data. The results of applying the model to DWPF show that due to excessive shortage of chloride, only 6% of the mercury fed is expected to be chlorinated, mostly as Hg{sub 2}Cl{sub 2}, while the remaining mercury would exist either as elemental mercury (90%) or HgO (4%).
Zamecnik, J; Alexander Choi, A
Measurement of dissolved neon by isotope dilution using a quadrupole mass spectrometer
and finally air. A special technique for sealing in whichsealing end. ple times by reverse isotope dilution with air.
Hamme, Roberta C; Emerson, Steven R
Electronic Structure and Magnetism in Diluted Magnetic Semiconductors
Electronic Structure and Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print Wednesday, 29 November 2006 00:00 The possibility of using electrons' spins in addition to their charge in information technology has created much enthusiasm for a new field of electronics popularly known as "spintronics." An intensely studied approach to obtaining spin-polarized carriers for data-storage devices is the use of diluted magnetic semiconductors created by doping ions like Mn, Fe, or Co having a net spin into a semiconducting host such as GaAs, ZnO, or GaN. The interaction among these spins leads to ferromagnetic order at low temperatures, which is necessary to create spin-polarized carriers. A research team working at ALS Beamline 4.0.2 and European Synchrotron Radiation Facility Beamline ID8 made a big leap forward in clarifying the microscopic picture of magnetism and anisotropy in Mn-doped GaAs by resolving localized and hybridized d states using angle-dependent x-ray magnetic circular dichroism (XMCD) measurements.
Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print The possibility of using electrons' spins in addition to their charge in information technology has created much enthusiasm for a new field of electronics popularly known as "spintronics." An intensely studied approach to obtaining spin-polarized carriers for data-storage devices is the use of diluted magnetic semiconductors created by doping ions like Mn, Fe, or Co having a net spin into a semiconducting host such as GaAs, ZnO, or GaN. The interaction among these spins leads to ferromagnetic order at low temperatures, which is necessary to create spin-polarized carriers. A research team working at ALS Beamline 4.0.2 and European Synchrotron Radiation Facility Beamline ID8 made a big leap forward in clarifying the microscopic picture of magnetism and anisotropy in Mn-doped GaAs by resolving localized and hybridized d states using angle-dependent x-ray magnetic circular dichroism (XMCD) measurements.
transformations transformations of Populus trichocarpa during dilute acid pretreatment Shilin Cao,{ ae Yunqiao Pu,* be Michael Studer,{ ce Charles Wyman cde and Arthur J. Ragauskas* abe Received 4th September 2012, Accepted 4th September 2012 DOI: 10.1039/c2ra22045h In this study, Populus trichocarpa was subjected to dilute acid pretreatment at varying pretreatment times. The three major components of lignocellulosic biomass, namely cellulose, hemicellulose and lignin, were isolated from the starting and dilute acid pretreated poplar. Gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) techniques were utilized to elucidate structural transformations of poplar during dilute acid pretreatment. The results demonstrated that the pretreatment dissolved hemicelluloses and disrupted structural features of lignin and polysaccharides. As revealed by NMR, the
Electrical conductivity of dispersions: from dry foams to dilute suspensions
We present new data for the electrical conductivity of foams in which the liquid fraction ranges from two to eighty percent. We compare with a comprehensive collection of prior data, and we model all results with simple empirical formul\\ae. We achieve a unified description that applies equally to dry foams and emulsions, where the droplets are highly compressed, as well as to dilute suspensions of spherical particles, where the particle separation is large. In the former limit, Lemlich's result is recovered; in the latter limit, Maxwell's result is recovered.
K. Feitosa; S. Marze; A. Saint-Jalmes; D. J. Durian
Chemical Pretreatment And Enzymatic Hydrolysis Of Mixed Source-Separated Organic (SSO) And Wood Waste.
??This paper examines the effectiveness of two pretreatments on Source-Separated Organic waste (SSO) mixed with wood wastes: long term lime for SSO mixed with forestry� (more)
Faye, Michael
145. Wyman C, Huber G: Biomass and America's energy futuredevelopment of leading biomass pretreatment technologies.U.S. Billion-Ton Update: Biomass Supply for a Bioenergy and
Evaluation of Cellruptor pre-treatment on biogas yield from various substrates.
?? In this thesis work, Cellruptor pre-treatment was evaluated in order to increase biogas yield. Initially, the effects of residence time (30, 60, 90, 120� (more)
Thiruvenkadam, Selvakumar
High Throughput Pretreatment and Enzyme Hydrolysis of Biomass: Screening Recalcitrance in Large Sample Populations (Presentation)
Presentation on the execution of the first high-throughput thermochemical pretreatment/enzyme digestion pipeline for screening biomass for recalcitrance.
Decker, S. R.
Effect of Pretreatment on the Strength and Formability of Vehicle Hot ...
Comparing with the traditional hot-forming HSS, the microstructure obtained in the pretreated samples ... Multi-Scale Design of Open-Cell Aluminum Alloy Foam.
Dilute magnetic semiconductors in spin-polarized electronics (invited)
Dilute magnetic semiconductors have proven to be very useful in building an all-semiconductor platform for spintronics{emdash}so far they provide the only viable route to establish spin-polarized current injection into a nonmagnetic semiconductor. The reasons for this become apparent from a simple spin-channel model, which predicts that spin injection into a semiconductor can, within linear response, only readily be achieved from a ferromagnetic injector that has: (i) a resistivity that is comparable to the semiconductor and (ii) preferably is 100% spin polarized. Both of these criteria can be met in magnetic semiconductors, but (so far) are hard to achieve using other materials. Experimentally, we demonstrate how dilute magnetic II{endash}VI semiconductors can be used to inject a strongly (up to 90%) spin-polarized current into a light emitting diode. In addition, we discuss the implications of the spin-channel model for the observation of giant magnetoresistance-like effects in the magnetoresistance of an all-semiconductor device. {copyright} 2001 American Institute of Physics.
Schmidt, Georg; Molenkamp, Laurens W.
Stability Regimes of Turbulent Nitrogen-Diluted Hydrogen Jet Flames
One option for combustion in zero-emission Integrated Gasification Combined Cycle (IGCC) power plants is non-premixed combustion of nitrogen-diluted hydrogen in air. An important aspect to non-premixed combustion is flame stability or anchoring, though only a few fundamental stability studies of these flames have taken place to date. The following paper presents the results of experiments investigating the effects of nitrogen diluent fraction, jet diameter, and exit velocity on the static stability limits of a turbulent hydrogen jet flame issuing from a thin-lipped tube into a quiescent atmosphere. Four different stability limits are observed: detachment from the burner lip, reattachment to the burner lip, transition from a laminar lifted flame base to blowout or to a turbulent lifted flame, and transition from a turbulent lifted flame to blowout. The applicability of existing theories and correlations to the stability results is discussed. These results are an important step in assessing the viability of a non-premixed combustion approach using hydrogen diluted with nitrogen as a fuel.
Weiland, N.T.; Strakey, P.A.
Technical Basis of Scaling Relationships for the Pretreatment Engineering Platform
Pacific Northwest National Laboratory has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Waste Treatment Plant (RPP-WTP) project to perform research and development activities. The Pretreatment Engineering Platform (PEP) is being designed and constructed as part of a plan to respond to an issue raised by the WTP External Flowsheet Review Team (EFRT) entitled �Undemonstrated Leaching Processes� and numbered M12. The PEP replicates the WTP leaching process using prototypic equipment and control strategies. The approach for scaling PEP performance data to predict WTP performance is critical to the successful resolution of the EFRT issue. This report describes the recommended PEP scaling approach, PEP data interpretation and provides recommendations on test conduct and data requirements.
Kuhn, William L.; Arm, Stuart T.; Huckaby, James L.; Kurath, Dean E.; Rassat, Scot D.
Synergistic Enhancement of Cellobiohydrolase Performance on Pretreated Corn Stover by Addition of Xylanase and Esterase Activities
Significant increases in the depolymerization of corn stover cellulose by cellobiohydrolase I (Cel7A) from Trichoderma reesei were observed using small quantities of non-cellulolytic cell wall-degrading enzymes. Purified endoxylanase (XynA), ferulic acid esterase (FaeA), and acetyl xylan esterase (Axe1) all enhanced Cel7A performance on corn stover subjected to hot water pretreatment. In all cases, the addition of these activities improved the effectiveness of the enzymatic hydrolysis in terms of the quantity of cellulose converted per milligram of total protein. Improvement in cellobiose release by the addition of the non-cellulolytic enzymes ranged from a 13-84% increase over Cel7A alone. The most effective combinations included the addition of both XynA and Axe1, which synergistically enhance xylan conversions resulting in additional synergistic improvements in glucan conversion. Additionally, we note a direct relationship between enzymatic xylan removal in the presence of XynA and the enhancement of cellulose hydrolysis by Cel7A.
Selig, M. J.; Knoshaug E. P.; Adney, W. S.; Himmel, M. E.; Decker, S. R.
This report provides the conclusions of the tank farm interim pretreatment technology decision process. It documents the methodology, data, and results of the selection of cross-flow filtration and ion exchange technologies for implementation in project W-551, Interim Pretreatment System. This selection resulted from the evaluation of specific scope criteria using quantitative and qualitative analyses, group workshops, and technical expert personnel.
Critical masses of uranium diluted with matrix material
Critical masses of square-prisms of highly enriched uranium diluted in various X/235U ratios with matrix material and polyethylene were measured. The Configuration cores were 22.86-cm and 45.72-cm square and were reflected with 8.1 3-cm and 10.1 6-cm thick side polyethylene reflectors, respectively. The configurations had 10.1 6-cm thick top and bottom polyethylene reflectors. For some configurations, the Rossi-a, which is an eigenvalue value characteristic for a particular configuration, was measured to establish a reactivity scale based on the degree of subcriticality . Finally, the critical mass experiments are compared with values calculated with MCNP and ENDF/B-VI cross-sections.
Sanchez, R. G. (Rene G.); Loaiza, D. J. (David J.); Kimpland, R. H. (Robert H.)
Dilution and resonance-enhanced repulsion in nonequilibrium fluctuation forces
In equilibrium, forces induced by fluctuations of the electromagnetic field between electrically polarizable objects (microscopic or macroscopic) in vacuum are generically attractive. The force may, however, become repulsive for microscopic particles coupled to thermal baths with different temperatures. We demonstrate that this nonequilibrium repulsion can be realized also between macroscopic objects, as planar slabs, if they are kept at different temperatures. It is shown that repulsion can be enhanced by (i) tuning of material resonances in the thermal region and by (ii) reducing the dielectric contrast due to ''dilution''. This can lead to stable equilibrium positions. We discuss the realization of these effects for aerogels, yielding repulsion down to submicron distances at realistic porosities.
Bimonte, Giuseppe [Dipartimento di Scienze Fisiche, Universita di Napoli Federico II, Complesso Universitario MSA, Via Cintia, I-80126 Napoli (Italy); INFN Sezione di Napoli, I-80126 Napoli (Italy); Emig, Thorsten [Laboratoire de Physique Theorique et Modeles Statistiques, CNRS UMR 8626, Bat. 100, Universite Paris-Sud, F-91405 Orsay cedex (France); Krueger, Matthias; Kardar, Mehran [Massachusetts Institute of Technology, Department of Physics, Cambridge, Massachusetts 02139 (United States)
GRR/Section 18-ID-c - Wastewater Pretreatment Permit | Open Energy
8-ID-c - Wastewater Pretreatment Permit 8-ID-c - Wastewater Pretreatment Permit < GRR Jump to: navigation, search GRR-logo.png GEOTHERMAL REGULATORY ROADMAP Roadmap Home Roadmap Help List of Sections Section 18-ID-c - Wastewater Pretreatment Permit 18IDCWastewaterPretreatmentPermit.pdf Click to View Fullscreen Triggers None specified Click "Edit With Form" above to add content 18IDCWastewaterPretreatmentPermit.pdf Error creating thumbnail: Page number not in range. Error creating thumbnail: Page number not in range. Error creating thumbnail: Page number not in range. Flowchart Narrative Industrial wastewater permits are issued at the local level. If wastewater is not discharged into a municipal sewer system, the nonpoint source and NPDES permit inquiries are sufficient. A common approach to wastewater treatment is to treat on-site. See Idaho's
Radiotracer Dilution Method for Mercury Inventory Study in Electrolytic Cells
Purpose of the experiment is to demonstrate feasibility the use of radiotracer to measure weight of mercury in electrolytic cells of soda industry. The weight of mercury in each cell of the plant is designed approximately 1700 kg. Radiotracer is prepared by mixing {sup 203}Hg radioactive mercury with 2400 g of inactive mercury in a bath. The respective precisely weighted mercury aliquots to be injected into the cells are prepared by pouring approximately 130 g of radioactive mercury taken from the bath into 13 standard vials, in accordance with the number of the cells tested. Four standard references prepared by further dilution of {+-}2 g active mercury taken from the bath to obtain the dilution factors range of 12,000 to 20,000 from which the calibration graph is constructed. The injection process is conducting by pouring the radioactive mercury from aliquots into the flowing mercury at the inlet side of the cell and allows them to mix thoroughly. It is assumed that the mass of the radiotracer injected into a closed system remains constant, at least during the period of the test. From this experiment it was observed that the mixing time is two days after injection of radioactive mercury. The inactive mercury in each electrolytic cell calculated by the radiotracer method is of the range 1351.529 kg to 1966.354 kg with maximum error (95% confidence) is 1.52 %. The accuracy of measurement of the present method is better than gravimetric one which accounts 4 % of error on average.
Sugiharto [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia); Centre for Application of Isotopes and Radiation Technology, National Nuclear Energy Agency, Jl. Lebak Bulus Raya No 49, Jakarta 12440 (Indonesia); Su'ud, Zaki; Kurniadi, Rizal; Waris, Abdul [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia); Santoso, Sigit Budi; Abidin, Zainal [Centre for Application of Isotopes and Radiation Technology, National Nuclear Energy Agency, Jl. Lebak Bulus Raya No 49, Jakarta 12440 (Indonesia); Santoso, Gatot Budi [PT. Industri Soda Indonesia, Jl. Raya Waru 31, Sidoarjo 61256 (Indonesia)
Influence of Physico-Chemical Changes on Enzymatic Digestibility of Ionic Liquid and AFEX pretreated Corn Stover
Ionic liquid (IL) and ammonia fiber expansion (AFEX) pretreatments were studied to develop the first direct side-by-side comparative assessment on their respective impacts on biomass structure, composition, process mass balance, and enzymatic saccharification efficiency. AFEX pretreatment completely preserves plant carbohydrates, whereas IL pretreatment extracts 76% of hemicellulose. In contrast to AFEX, the native crystal structure of the recovered corn stover from IL pretreatment was significantly disrupted. For both techniques, more than 70% of the theoretical sugar yield was attained after 48 h of hydrolysis using commercial enzyme cocktails. IL pretreatment requires less enzyme loading and a shorter hydrolysis time to reach 90% yields. Hemicellulase addition led to significant improvements in the yields of glucose and xylose for AFEX pretreated corn stover, but not for IL pretreated stover. These results provide new insights into the mechanisms of IL and AFEX pretreatment, as well as the advantages and disadvantages of each.
Li, Chenlin [Joint Bioenergy Institute; Cheng, Gang [Joint Bioenergy Institute; Kent, Michael S [ORNL; Ong, Markus [Sandia National Laboratories (SNL); Balan, Venkatesh [Michigan State University, East Lansing; Dale, Bruce E. [Michigan State University, East Lansing; Melnichenko, Yuri B [ORNL; Simmons, Blake [Sandia National Laboratories (SNL)
Geochemistry of Hydrofluoric Acid in Kaolinitic Soils
This document explores the geochemical reactions likely to occur when hydrofluoric acid is spilled on Savannah River Site (SRS) soil. In particular, we evaluate the potential of environmental damage from a one-time release of concentrated hydrofluoric acid into a trench. According to interviews with personnel involved, sometime between 1955 and 1960 drums of 50-60 per cent hydrofluoric acid were disposed in a trench in the Central Shops area. The method of disposal suggests that most of the acid would have been released at the time of burial. No evidence of drum disposal or acidic pH values was found. Therefore, the Soil and Groundwater Closure Projects group requested that we evaluate potential risk by examining the major geochemical interactions expected between hydrofluoric acid and soil. The geochemical calculations in this report were done with The Geochemist's Workbench (Registered). This program uses an extended Debye-Huckel method for calculating activity coefficients. The conclusions of this report are accurate, but some of the intermediate steps may have higher uncertainty. Hydrofluoric acid disposed in a trench in the area would have reacted with soil kaolinite to neutralize the pH to a value of about 4.2. Based on conservative assumptions, this would have occurred within the top 500 cm of soil. This analysis considers only the reaction of the acid with kaolinite. Other processes such as dilution, dispersion, and clogging of permeability would contribute to neutralization of the acid within a shorter distance. When the acid solution reached the water table, dilution would have driven the solution to saturation with gibbsite. A resulting layer enriched in aluminum may be the only remnant of the acid disposal identifiable today. However, any such layer would be difficult to identify because of the normally high aluminum concentrations in the soil. Subtle textural evidence of shallow soil dissolution may be present, but 40 years of rainfall infiltration may well have erased such evidence.
Critical masses of highly enriched uranium diluted with matrix material.
Radioactive waste containing fissile material is frequently encountered in decontamination and decommissioning activities. For the most part, this waste is placed in containers or drums and stored in storage facilities. The amount of fissile material in each drum is generally small because of criticality safety limits that have been calculated with computer transport codes such as MCNP,1 KENO,2 or ONEDANT.3 To the best of our knowledge, no experimental critical mass data are available to verify the accuracy of these calculations or any calculations for systems containing fissile material (U-235, Pu-239, U-233) in contact with matrix material such as Al2O3, CaO, SiO2, Al, MgO, etc. The experiments presented in this paper establish the critical masses of highly enriched uranium foils diluted to various X/235U ratios with polyethylene and SiO2, polyethylene and aluminum, polyethylene and MgO, polyethylene and Gd, polyethylene and Fe, and moderated and reflected with polyethylene. In addition, these critical mass experimental data will be used to validate cross section data.
Transverse emittance dilution due to coupler kicks in linear accelerators
One of the main concerns in the design of low emittance linear accelerators (linacs) is the preservation of beam emittance. Here we discuss one possible source of emittance dilution due to transverse electromagnetic fields in the accelerating cavities of the linac caused by the power coupler geometry. It is common wisdom that emittance growth from coupler kicks can be strongly reduced by having the coupler location alternate from above to below the beam pipe so that the coupler kick from one cavity is compensated by that of the next. While this is correct, alternating the coupler location requires large technical changes in superconducting cryomodules where cryogenic pipes are arranged parallel to a string of several cavities. We show here that cavities with high external $Q$ have coupler kicks that change the sign of their phase when the coupler is moved from before to after the cavity, as long as one accelerates on crest. This implies that the emittance growth from one cavity can be canceled by the next, pr...
Buckley, Brandon
An assessment of the dilution required to mitigate Hanford tank 241-SY-101
A group of experts from PNL and WHC convened November 2 and 3, 1994, to screen the current state of knowledge about dilution and reach a consensus on the minimum dilution ratio that will achieve passive mitigation of Tank 241-SY-101 wastes and the dilution ratio that would satisfy the given cross-site transfer criteria with reasonable assurance. The panel evaluated the effects of dilution on the parameters important in gas generation, retention, and release and reached the following conclusions, which are deduced from the existing body of data, experience, and analyses: (1) Dissolution of solids is the single most important aspect of mitigation by dilution. We are confident that diluting until nitrates, nitrites, and aluminum salts are dissolved will mitigate Hanford flammable gas tanks; (2) Sufficient solids dissolution can be achieved in Tank 241-SY-101 at a dilution ratio of 1:1, which will result in a average specific gravity of approximately 1.35. It is likely that a 0.5:1 dilution will also mitigate 241-SY-101, but the current uncertainty is too high to recommend this dilution ratio; (3) The recommended dilution requires a diluent with at least 2 molar free hydroxide, because aluminum probably precipitates at lower hydroxide concentrations. The transfer criteria for Tank 241-SY-101 waste were also evaluated. These criteria have been specified as solids content {<=}30% (volume), viscosity {<=}30% cP and density <1.5 g/mL. (1) Solids content is the limiting criterion if it is defined as volume fraction of settled solids. A 1:1 dilution will satisfy this criterion at nominal premixing conditions in Tank 241-SY-101; however, analysis of Window E core samples suggests that up to 1.5:1 might be required. If the solids content is interpreted simply as solids volume fraction no further dilution is necessary, because Tank 241-SY-101 waste (excluding the crust) is already below 30%; (2) Bulk density is the next limiting criterion and is met at 0.4:1 dilution.
Hudson, J.D.; Bredt, P.R.; Felmy, A.R.; Stewart, C.W.; Tingey, J.M.; Trent, D.S. [Pacific Northwest Lab., Richland, WA (United States); Barney, G.S.; Herting, D.L.; Larrick, A.P.; Reynolds, D.A. [Westinghouse Hanford Co., Richland, WA (United States)
Growth and Properties of the Dilute Bismide Semiconductor GaAs1-xBix a Complementary Alloy to the Dilute Nitrides
In this review we describe the growth and properties of the dilute bismide semiconductor alloy GaAs{sub 1-x}Bi{sub x} and show how its properties are in certain respects complementary to the dilute nitride alloy, GaN{sub y}As{sub 1-y}. Like the dilute nitrides the dilute bismides show a giant band gap bowing effect in which a small concentration of the alloying element has a disproportionate effect on the band gap, however in the case of the bismide the band gap reduction is associated with an increase in the energy of the valence band maximum (VBM) rather than a reduction in the energy of the conduction band minimum (CBM). Under standard GaAs growth conditions Bi acts as a surfactant with associated improvements in surface quality. In order to incorporate Bi, growth temperatures below 400 C are used with As{sub 2}/Ga flux ratios close to unity. The electron mobility of GaAs is only weakly affected by Bi alloying, in contrast to the dilute nitrides where the electron mobility decreases rapidly with N alloying. Bi alloying also produces a giant bowing effect in the spin orbit splitting in the valence band. Strong room temperature photoluminescence is observed. Prospects for future device applications of this new compound semiconductor alloy are discussed.
Tiedje, T.; Young, E. C.; Mascarenhas, A.
Effect of Pretreatment on the Properties of Agricultural Waste
Agricultural waste disposal is becoming a problem due to its increasing production and potential pollution. As a kind of biomass, agricultural waste can be used as a sustainable and renewable source of energy. Agricultural waste disposal is of great ... Keywords: agricultural waste, animal manure, acid washing, pyrolysis
Zhang Shouyu; Wang Jian; Wang Xiu-Jun; Peng Dingmao; Takayuki Takarada
Sulfuric acid-sulfur heat storage cycle
A method of storing heat is provided utilizing a chemical cycle which interconverts sulfuric acid and sulfur. The method can be used to levelize the energy obtained from intermittent heat sources, such as solar collectors. Dilute sulfuric acid is concentrated by evaporation of water, and the concentrated sulfuric acid is boiled and decomposed using intense heat from the heat source, forming sulfur dioxide and oxygen. The sulfur dioxide is reacted with water in a disproportionation reaction yielding dilute sulfuric acid, which is recycled, and elemental sulfur. The sulfur has substantial potential chemical energy and represents the storage of a significant portion of the energy obtained from the heat source. The sulfur is burned whenever required to release the stored energy. A particularly advantageous use of the heat storage method is in conjunction with a solar-powered facility which uses the Bunsen reaction in a water-splitting process. The energy storage method is used to levelize the availability of solar energy while some of the sulfur dioxide produced in the heat storage reactions is converted to sulfuric acid in the Bunsen reaction.
Norman, John H. (LaJolla, CA)
Charge and Spin Transport in Dilute Magnetic Semiconductors
This proposal to the DOE outlines a three-year plan of research in theoretical and computational condensed-matter physics, with the aim of developing a microscopic theory for charge and spin dynamics in disordered materials with magnetic impurities. Important representatives of this class of materials are the dilute magnetic semiconductors (DMS), which have attracted great attention as a promising basis for spintronics devices. There is an intense experimental effort underway to study the transport properties of ferromagnetic DMS such as (Ga,Mn)As, and a number of interesting features have emerged: negative magnetoresistance, anomalous Hall effect, non-Drude dynamical conductivity, and resistivity maxima at the Curie temperature. Available theories have been able to account for some of these features, but at present we are still far away from a systematic microscopic understanding of transport in DMS. We propose to address this challenge by developing a theory of charge and spin dynamics based on a combination of the memory-function formalism and time-dependent density functional theory. This approach will be capable of dealing with two important issues: (a) the strong degree of correlated disorder in DMS, close to the localization transition (which invalidates the usual relaxation-time approximation to the Boltzmann equation), (b) the essentially unknown role of dynamical many-body effects such as spin Coulomb drag. We will calculate static and dynamical conductivities in DMS as functions of magnetic order and carrier density, which will advance our understanding of recent transport and infrared absorption measurements. Furthermore, we will study collective plasmon excitations in DMS (3D, 2D and quantum wells), whose linewidths could constitute a new experimental probe of the correlation of disorder, many-body effects and charge and spin dynamics in these materials.
Ullrich, Carsten A.
Retention behavior of dilute polymers in oil sands
Adequate mobility control between fluid banks is a pertinent factor in the successful application of secondary and tertiary oil recovery processes. Favorable mobilities can be obtained by increasing the viscosity or reducing the permeability to the displacing fluid phase. Polyacrylamide and oio-polymers have proved to be useful for these purposes. These polymers increase the water viscosity substantially at low concentrations. The resulting reduced mobility of the displacing phase suppresses the fingering phenomenon and improves piston-like displacement. However, the structural complexity of these polymers coupled with the complexity of the flow channels in the porous medium cause part of these polymers to be retained in the reservoir as the displacing fluid from advances, thereby causing a reduction in the concentration of the polymer solution and consequently a loss of mobility control. In addition to the mechanical filtering, adsorption on the grain surfaces reduce the polymer concentration in the displacing fluid. Behavior of polyacrylamide polymers has been studied extensively. Susceptibility of these polymers to salinity, pH, shear, temperature, etc., is well documented. Mechanical entrapment, retention, degradation and adsorption behavior on porous media, including fired Berea sandstone, bead packs and Ottawa sand have been reported. The present study investigates the adsorption and trapping of polymers in flow experiments through unconsolidated oil field sands. Effects of particle size and mineral content have been studied. Effect of a surfactant slug on polymer-rock interaction is also reported. Corroborative studies have been conducted to study the pressure behavior and high tertiary oil recovery in surfactant dilute-polymer systems.
Kikani, J.; Somerton, W.H.
Diluted magnetic semiconductor effects in Mn-implanted silicon carbide
Light transmission and Faraday rotation spectra measured at the temperature of 2 K were compared for silicon carbide single crystals of 4H polytype (4H-SiC), implanted with 3.8 x 10{sup 16} cm{sup -2} of Mn ions at the beam energy of 190 keV, and a control 4H-SiC single crystal sample, which was not implanted. Mn ion implantation led to the creation of a Mn-doped surface layer with the average Mn concentration of 10{sup 21} cm{sup -3} and a thickness of approximately 0.2 {mu}m. Transmission of light through the implanted crystal changed only slightly in comparison with the control sample, which however, corresponded to a relatively strong attenuation in the implanted layer. This was interpreted as a result of scattering, which emerges in the surface layer due to optical nonuniformities, created by the high energy ion irradiation. The presence of a thin Mn-ion-containing surface layer led, despite its small thickness, to noticeable changes in the sample Faraday rotation spectra. The estimated values of the Verdet constant for this layer were about three orders of magnitude larger and of opposite sign compared to the Verdet constant values of the undoped sample. Magnetic field dependencies of the Faraday rotation contribution from the implanted layer were found to be saturating functions, which points to a proportionality of the Faraday rotation to the magnetization of the paramagnetic Mn ion subsystem. Based on these findings we conclude that the Mn-implanted SiC layer exhibits magneto-optical properties typical of a diluted magnetic semiconductor. At the same time, no ferromagnetic ordering was observed in the studied (Si, Mn)C sample.
Komarov, A. V.; Ryabchenko, S. M. [Institute of Physics of the National Academy of Sciences of Ukraine, 46 Nauki Ave., Kiev 03028 (Ukraine); Los, A. V. [ISS Ltd., Semiconductors and Circuits Lab, 15 Bozhenko Street, Kiev 03680 (Ukraine); Freescale Semiconductor Ukraine LLC., 15 Bozhenko Street, Kiev 03680 (Ukraine); Romanenko, S. M. [ISS Ltd., Semiconductors and Circuits Lab, 15 Bozhenko Street, Kiev 03680 (Ukraine)
Welding and Repair Technology Center: Development of Improved Weld Heat Input and Dilution Equations for Consumable Welding Processes
Predicting heat input into the substrate and weld dilution for consumable welding processes is a challenge due to the number of variables associated with these processes. Proper heat input and power ratio controls are critical to control weld dilution, particularly in dissimilar metal welds where low weld dilution is necessary to prevent solidification cracking or for cladding where weld dilution is minimized to maintain corrosion resistance of the clad material. This report discusses the ...
The Defense Waste Processing Facility (DWPF) at the Savannah River Site vitrifies radioactive High Level Waste (HLW) for repository internment. The process consists of three major steps: waste pretreatment, vitrification, and canister decontamination/sealing. HLW consists of insoluble metal hydroxides (primarily iron, aluminum, calcium, magnesium, manganese, and uranium) and soluble sodium salts (carbonate, hydroxide, nitrite, nitrate, and sulfate). The pretreatment process in the Chemical Processing Cell (CPC) consists of two process tanks, the Sludge Receipt and Adjustment Tank (SRAT) and the Slurry Mix Evaporator (SME) as well as a melter feed tank. During SRAT processing, nitric and formic acids are added to the sludge to lower pH, destroy nitrite and carbonate ions, and reduce mercury and manganese. During the SME cycle, glass formers are added, and the batch is concentrated to the final solids target prior to vitrification. During these processes, hydrogen can be produced by catalytic decomposition of excess formic acid. The waste contains silver, palladium, rhodium, ruthenium, and mercury, but silver and palladium have been shown to be insignificant factors in catalytic hydrogen generation during the DWPF process. A full factorial experimental design was developed to ensure that the existence of statistically significant two-way interactions could be determined without confounding of the main effects with the two-way interaction effects. Rh ranged from 0.0026-0.013% and Ru ranged from 0.010-0.050% in the dried sludge solids, while initial Hg ranged from 0.5-2.5 wt%, as shown in Table 1. The nominal matrix design consisted of twelve SRAT cycles. Testing included: a three factor (Rh, Ru, and Hg) study at two levels per factor (eight runs), three duplicate midpoint runs, and one additional replicate run to assess reproducibility away from the midpoint. Midpoint testing was used to identify potential quadratic effects from the three factors. A single sludge simulant was used for all tests and was spiked with the required amount of noble metals immediately prior to performing the test. Acid addition was kept effectively constant except to compensate for variations in the starting mercury concentration. SME cycles were also performed during six of the tests.
Stone, M; Tommy Edwards, T; David Koopman, D
Impacts of Biodiesel Fuel Blends Oil Dilution on Light-Duty Diesel Engine Operation
Assesses oil dilution impacts on a diesel engine operating with a diesel particle filter, NOx storage, a selective catalytic reduction emission control system, and a soy-based 20% biodiesel fuel blend.
Thornton, M. J.; Alleman, T. L.; Luecke, J.; McCormick, R. L.
Dilute magnetic semiconductor Cu2FeSnS4 nanocrystals with a novel zincblende structure
Diluted magnetic semiconductor Cu2FeSnS4 nanocrystals with a novel zincblende structure have been successfully synthesized by a hot-injection approach. Cu+, Fe2+, and Sn4+ ions occupy the same position in the ...
Xiaolu Liang; Xianhua Wei; Daocheng Pan
Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction
Low-temperature catalytic pretreatment is a promising approach to the development of an improved liquefaction process- This work is a fundamental study on effects of pretreatments on coal structure and reactivity in liquefaction. The main objectives of this project are to study the coal structural changes induced by low-temperature catalytic and thermal pretreatments by using spectroscopic techniques; and to clarify the pretreatment-induced changes in reactivity or convertibility of coals in the subsequent liquefaction. This report describes the recent progress of our work. Substantial progress has been made in the spectroscopic characterization of structure and pretreatment-liquefaction reactions of a Montana subbituminous Coal (DECS-9), and thermochemical analysis of three mw and reacted bituminous coals. Temperature programmed liquefaction has been performed on three low-rank coals both in the presence and absence of dispersed molybdenum sulfide catalyst. We also performed a detailed study of the effects of mild thermal pretreatment -- drying in air and in vacuum -- on thermal and catalytic liquefaction of a Wyodak subbituminous coal. Important information on structure and structure transformation during thermal pretreatment and liquefaction reactions of low-rank coals has been derived by applying solid-state CPMAS [sup 13]C NMR and flash pyrolysis-GC-MS (Py-GC-MS) for characterization of the macromolecular network of a Montana subbituminous coal and its residues from temperature-programmed and nonprogrammed liquefaction (TPL and N-PL) at final temperatures ranging from 300 to 425[degree]C in H-donor and non-donor solvents. The results revealed that this coal contains significant quantities of oxygen-bearing structures, corresponding to about 18 O-bound C per 100 C atoms and one O-bound C per every 5 to 6 aromatic C.
Song, C.; Saini, A.K.; Huang, L.; Wenzel, K.; Hou, L.; Hatcher, P.G.; Schobert, H.H.
Global convergence of diluted iterations in maximum-likelihood quantum tomography
In this paper we present an inexact stepsize selection for the Diluted R\\rho R algorithm, used to obtain the maximum likelihood estimate to the density matrix in quantum state tomography. We give a new interpretation for the diluted R\\rho R iterations that allows us to prove the global convergence under weaker assumptions. Thus, we propose a new algorithm which is globally convergent and suitable for practical implementation.
D. S. Gon�alves; M. A. Gomes-Ruggiero; C. Lavor
Remote Handling Devices for Disposition of Enriched Uranium Reactor Fuel Using Melt-Dilute Process
Remote handling equipment is required to achieve the processing of highly radioactive, post reactor, fuel for the melt-dilute process, which will convert high enrichment uranium fuel elements into lower enrichment forms for subsequent disposal. The melt-dilute process combines highly radioactive enriched uranium fuel elements with deleted uranium and aluminum for inductive melting and inductive stirring steps that produce a stable aluminum/uranium ingot of low enrichment.
Heckendorn, F.M.
Isotopic dilution of {sup 233}U with depleted uranium for criticality safety in processing and disposal
The disposal of excess {sup 233}U as waste is being considered. Because {sup 233}U is a fissile material, a key requirement for processing {sup 233}U to a final waste form and disposing of it is the avoidance of nuclear criticality. For many processing and disposal options, isotopic dilution is the most feasible and preferred option to avoid nuclear criticality. Isotopic dilution is dilution of fissile {sup 233}U with nonfissile {sup 238}U. The use of isotopic dilution removes any need to control nuclear criticality in process or disposal facilities through geometry or chemical composition. Isotopic dilution allows the use of existing waste management facilities that are not designed for significant quantities of fissile materials to be used for processing and disposing of {sup 233}U. The amount of isotopic dilution required to reduce criticality concerns to reasonable levels was determined in this study to be approximately 0.53 wt % {sup 233}U. The numerical calculations used to define this limit consisted of a homogeneous system of silicon dioxide (SiO{sub 2}), water (H{sub 2}O), {sup 233}U and depleted uranium (DU) in which the ratio of each component was varied to learn the conditions of maximum nuclear reactivity. About 188 parts of DU (0.2 wt % {sup 235}U) are required to dilute 1 part of {sup 233}U to this limit in a water-moderated system with no SiO{sub 2} present. Thus for the U.S. inventory of {sup 233}U, several hundred metric tons of DU would be required for isotopic dilution.
Hopper, C.M.; Wright, R.Q.; Elam, K.R.; Forsberg, C.W.
Two-Stage Fungal Pre-Treatment for Improved Biogas Production from Sisal Leaf Decortication Residues
Abstract: Sisal leaf decortications residue (SLDR) is amongst the most abundant agroindustrial residues in Tanzania and is a good feedstock for biogas production. Pretreatment of the residue prior to its anaerobic digestion (AD) was investigated using a twostage pre-treatment approach with two fungal strains, CCHT-1 and Trichoderma reesei in succession in anaerobic batch bioreactors. AD of the pre-treated residue with CCTH-1 at 10 % (wet weight inoculum/SLDR) inoculum concentration incubated for four days followed by incubation for eight days with 25 % (wet weight inoculum/SLDR) of T. reesei gave a methane yield of 0.292 � 0.04 m 3 CH4/kg volatile solids (VS)added. On reversing the pre-treatment succession of the fungal inocula using the same parameters followed by AD, methane yield decreased by about 55%. Generally, an increment in the range of 30�101% in methane yield in comparison to the un-treated SLDR was obtained. The results confirmed the potential of CCHT-1 followed by Trichoderma reesei fungi pre-treatment prior to AD to achieve significant improvement in biogas production from SLDR.
Mutemi Muthangya; Anthony Manoni Msh; Amelia Kajumulo Kivaisi
Fischer-Tropsch synthesis: Moessbauer studies of pretreated ultrafine iron oxide catalysts
Moessbauer spectroscopy indicates that a 24 hour-pretreatment in CO at 260{degrees}C and 8 atm. in a tetralin solvent almost completely converts uftrafine iron oxide (about 3 nm) to iron carbide. However, pretreatment in hydrogen under the same conditions resulted in reduction of about 33% of the iron to metallic Fe; the remainder was Fe{sub 3}O{sub 4}. Exposure of the CO pretreated catalyst to a 1:1 HDCO synthesis gas resulted in the gradual reoxidation of the carbides to Fe{sub 3}O{sub 4}. During the first 2 hours of exposure of the H{sub 2} pretreated sample to synthesis gas,.the metallic Fe was converted to iron carbides. Further exposure of the H{sub 2} pretreatment sample to synthesis gas did not result in a composition change of the catalyst. Therefore, it is concluded that iron carbides with different oxidation characteristics were formed in these two cases.
Chenshi Huang; Davis, B.H. (Kentucky Univ., Lexington, KY (United States). Center for Applied Energy Research); Rao, K.R.P.M.; Huffman, G.P.; Huggins, F.E. (Kentucky Univ., Lexington, KY (United States). Inst. for Mining and Minerals Research)
A new solvent system is being evaluated for use in the Modular Caustic-Side Solvent Extraction Unit (MCU) and in the Salt Waste Processing Facility (SWPF). The new system replaces the current dilute nitric acid strip solution with 0.01 M boric acid. This literature study is performed to determine if there is a potential for boric acid to crystallize in the lines with emphasis on the transfer lines to the Defense Waste Processing Facility. This report focuses on the aqueous phase chemistry of boric acid under conditions relevant to MCU and SWPF. Operating and transfer conditions examined for the purpose of this review include temperatures between 13 C (McLeskey, 2008) and 45 C (Fondeur, 2007) and concentrations from 0 to 3M in nitric acid as well as exposure of small amounts of entrained boric acid in the organic phase to the sodium hydroxide caustic wash stream. Experiments were also conducted to observe any chemical reactions and off-gas generation that could occur when 0.01 M boric acid solution mixes with 3 M nitric acid solution and vice versa. Based on the low concentration (0.01M) of boric acid in the MCU/SWPF strip acid and the moderate operating temperatures (13 C to 45 C), it is unlikely that crystallization of boric acid will occur in the acid strip solution under process or transfer conditions. Mixing experiments of boric and nitric acid show no measurable gas generation (< 1 cc of gas per liter of solution) under similar process conditions.
Crapse, K.; Kyser, E.
Bioethanol production from lignocellulosic feedstock using aqueous ammonia pretreatment and simultaneous saccharification and fermentation (SSF): process development and optimization.
??An integrated bioconversion process, which incorporated soaking in aqueous ammonia (SAA) pretreatment and two-phase simultaneous saccharification and fermentation (TPSSF), was investigated. The TPSSF process consists� (more)
Li, Xuan
This report provides summary data for use by the decision board to assess and select the final technology for project W-551, Interim Pretreatment System. This project will provide early pretreated low activity waste feed to the Waste Treatment Plant to allow Waste Treatment Plan Low Activity Waste facility operation prior to construction completion of the Pretreatment and High Level Waste facilities. The candidate solids separations technologies are rotary microfiltration and crossflow filtration, and the candidate cesium separation technologies are fractional crystallization, caustic-side solvent extraction, and ion-exchange using spherical resorcinol-fonnaldebyde resin. This document provides a summary of comparative data against prior weighted criteria to support technology selection. Supporting details and background for this summary are documented in the separate report, RPP-RPT-37741.
Statement of work for architect-engineer services, initial pretreatment module
This Statement of Work describes the Architect-Engineer services to be provided by Raytheon/BNFL in providing a conceptual design (Contract TGW-SVV-063869) for the Initial Pretreatment Module (IPM), Project W-236B, at the Hanford site, Richland, Washington. The IPM Project, a radiochemical process facility, will be designed and constructed for an initial phase of waste pretreatment, which will be for the removal of cesium from supernatant wastes to produce a Low-level waste (LLW) stream to a vitrification facility. The design shall also accommodate side streams of High-Level Waste (HLW) fractions that will be directed to suitable, existing storage tanks where they will be recombined with an additional high-activity waste fraction generated from pretreatment of the tank waste sludges and solids. This combined high-activity waste fraction will be immobilized as glass and disposed in a geological repository.
Sowa, K.B.
This report provides the detailed assessment forms and data for selection of the solids separation and cesium separation technology for project W-551, Interim Pretreatment System. This project will provide early pretreated low activity waste feed to the Waste Treatment Plant to allow Waste Treatment Plan Low Activity Waste facility operation prior to construction completion of the Pretreatment and High Level Waste facilities. The candidate solids separations technologies are rotary microfiltration and crossflow filtration, and the candidate cesium separation technologies are fractional crystallization, caustic-side solvent extraction, and ion-exchange using spherical resorcinol-formaldehyde resin. This data was used to prepare a cross-cutting technology summary, reported in RPP-RPT-37740.
Conversion for Avicel and AFEX pretreated corn stover by Clostridium thermocellum and simultaneous saccharification and fermentation: Insights into microbial conversion of pretreated cellulosic biomass
for for Avicel and AFEX pretreated corn stover by Clostridium thermocellum and simultaneous saccharification and fermentation: Insights into microbial conversion of pretreated cellulosic biomass Xiongjun Shao a , Mingjie Jin b,c , Anna Guseva a , Chaogang Liu d , Venkatesh Balan b,c , David Hogsett d , Bruce E. Dale b,c , Lee Lynd a,d,⇑ a Thayer School of Engineering at Dartmouth College, 8000 Cummings Hall, Hanover, NH 03755, USA b Biomass Conversion Research Laboratory (BCRL), Department of Chemical Engineering and Materials Science, Michigan State University, MBI Building, 3900 Collins Road, Lansing, MI 48910, USA c Great Lakes Bioenergy Research Center (GLBRC), Michigan State University, East Lansing, MI 48824, USA d Mascoma Corporation, 67 Etna Road, Suite 300, Lebanon, NH 03766, USA a r t i c l e i n f o Article history: Received 8 March 2011 Received in revised form 6 May 2011 Accepted
The objective of this report is to describe the pretreatment solutions that allow treatment to be tailored to specific wastes, processing ahead of the completion schedules for the main treatment facilities, and reduction of technical risks associated with future processing schedules. Wastes stored at Hanford and Savannah River offer challenging scientific and engineering tasks. At both sites, space limitations confound the ability to effectively retrieve and treat the wastes. Additionally, the radiation dose to the worker operating and maintaining the radiochemical plants has a large role in establishing the desired radioactivity removal. However, the regulatory requirements to treat supernatant and saltcake tank wastes differ at the two sites. Hanford must treat and remove radioactivity from the tanks based on the TriParty Agreement and Waste Incidental to Reprocessing (WIR) documentation. These authorizing documents do not specify treatment technologies; rather, they specify endstate conditions. Dissimilarly, Waste Determinations prepared at SRS in accordance with Section 3116 of the 2005 National Defense Authorization Act along with state operating permits establish the methodology and amounts of radioactivity that must be removed and may be disposed of in South Carolina. After removal of entrained solids and site-specific radionuclides, supernatant and saltcake wastes are considered to be low activity waste (LAW) and are immobilized in glass and disposed of at the Hanford Site Integrated Disposal Facility (IDF) or formulated into a grout for disposal at the Savannah River Site Saltstone Disposal Facility. Wastes stored at the Hanford Site or SRS comprise saltcake, supernate, and sludges. The supernatant and saltcake waste fractions contain primarily sodium salts, metals (e.g., Al, Cr), cesium-137 (Cs-137), technetium-99 (Tc-99) and entrained solids containing radionuclides such as strontium-90 (Sr-90) and transuranic elements. The sludges contain many of the transition metal hydroxides that precipitate when the spent acidic process solutions are rendered alkaline with sodium hydroxide. The sludges contain Sr-90 and transuranic elements. The wastes stored at each site have been generated and stored for over fifty years. Although the majority of the wastes were generated to support nuclear weapons production and reprocessing, the wastes differ substantially between the sites. Table 5 shows the volumes and total radioactivity (including decay daughters) of the waste phases stored in tanks at each site. At Hanford, there are 177 tanks that contain 56.5 Mgal of waste. SRS has 51 larger tanks, of which 2 are closed, that contain 36.5 Mgal. Mainly due to recovery operations, the waste stored at Hanford has less total curies than that stored at Savannah River. The total radioactivity of the Hanford wastes contains approximately 190 MCi, and the total radioactivity of the Savannah River wastes contains 400 MCi.
Wilmarth, B; Sheryl Bush, S
Caustic-Side Solvent-Extraction Modeling for Hanford Interim Pretreatment System
The purpose of this work is to examine the applicability of the Caustic-Side Solvent Extraction (CSSX) process for the removal of cesium from Hanford tank-waste supernatant solutions in support of the Hanford Interim Pretreatment System (IPS). The Hanford waste types are more challenging than those at the Savannah River Site (SRS) in that they contain significantly higher levels of potassium, the chief competing ion in the extraction of cesium. It was confirmed by use of the CSSX model that the higher levels of potassium depress the cesium distribution ratio (DCs), as validated by measurement of DCs values for four of eight specified Hanford waste-simulant compositions. The model predictions were good to an apparent standard error of �11%. It is concluded from batch distribution experiments, physical-property measurements, equilibrium modeling, flowsheet calculations, and contactor sizing that the CSSX process as currently employed for cesium removal from alkaline salt waste at the SRS is capable of treating similar Hanford tank feeds. For the most challenging waste composition, 41 stages would be required to provide a cesium decontamination factor (DF) of 5000 and a concentration factor (CF) of 5. Commercial contacting equipment with rotor diameters of 10 in. for extraction and 5 in. for stripping should have the capacity to meet throughput requirements, but testing will be required to confirm that the needed efficiency and hydraulic performance are actually obtainable. Markedly improved flowsheet performance was calculated for a new solvent formulation employing the more soluble cesium extractant BEHBCalixC6 used with alternative scrub and strip solutions, respectively 0.1 M NaOH and 10 mM boric acid. The improved system can meet minimum requirements (DF = 5000 and CF = 5) with 17 stages or more ambitious goals (DF = 40,000 and CF = 15) with 19 stages. Potential benefits of further research and development are identified that would lead to reduced costs, greater adaptability of the process to DOE alkaline salt wastes, and greater readiness for implementation. Such benefits accrue from optimal sizing of centrifugal contactors for application of the CSSX process for the IPS; more accurate modeling of cesium extraction with greater flexibility and applicability to a variety of feeds and flowsheet conditions; and further improving and optimizing the alternative CSSX solvent and scrub/strip system.
Moyer, B.A.; Birdwell, J.F.; Delmau, L. H.; McFarlane, J.
Pretreatment process for forming a smooth surface diamond film on a carbon-coated substrate
A process is disclosed for the pretreatment of a carbon-coated substrate to provide a uniform high density of nucleation sites thereon for the subsequent deposition of a continuous diamond film without the application of a bias voltage to the substrate. The process comprises exposing the carbon-coated substrate, in a microwave plasma enhanced chemical vapor deposition system, to a mixture of hydrogen-methane gases, having a methane gas concentration of at least about 4% (as measured by partial pressure), while maintaining the substrate at a pressure of about 10 to about 30 Torr during the pretreatment.
Feng, Zhu (Albany, CA); Brewer, Marilee (Goleta, CA); Brown, Ian (Berkeley, CA); Komvopoulos, Kyriakos (Orinda, CA)
Selection of Pretreatment Processes for Removal of Radionuclides from Hanford Tank Waste
The U.S. Department of Energy's (DOE's), Office of River Protection (ORP) located at Hanford Washington has established a contract (1) to design, construct, and commission a new Waste Treatment and Immobilization Plant (WTP) that will treat and immobilize the Hanford tank wastes for ultimate disposal. The WTP is comprised of four major elements, pretreatment, LAW immobilization, HLW immobilization, and balance of plant facilities. This paper describes the technologies selected for pretreatment of the LAW and HLW tank wastes, how these technologies were selected, and identifies the major technology testing activities being conducted to finalize the design of the WTP.
Carreon, R.; Mauss, B. M.; Johnson, M. E.; Holton, L. K.; Wright, G. T.; Peterson, R. A.; Rueter, K. J.
Measurement of Fuel Dilution of Oil in a Diesel Engine using Laser-Induced Fluorescence Spectroscopy
A technique for measuring the fuel dilution of oil in a diesel engine is presented. Fuel dilution can occur when advanced in-cylinder fuel injection techniques are employed for the purpose of producing rich exhaust for lean NOx trap catalyst regeneration. Laser-induced fluorescence (LIF) spectroscopy is used to monitor the oil in a Mercedes 1.7-liter engine operated on a dynamometer platform. A fluorescent dye suitable for use in diesel fuel and oil systems is added to the engine fuel. The LIF spectra are monitored to detect the growth of the dye signal relative to the background fluorescence of the oil; fuel mass concentration is quantified based on a known sample set. The technique was implemented with fiber optic probes which can be inserted at various points in the oil system of the engine. A low cost 532-nm laser diode was used for excitation of the fluorescence. Measurements of fuel dilution of oil are presented for various in-cylinder injection strategies for rich operation of the diesel engine. Rates of fuel dilution increase for all strategies relative to normal lean operation, and higher fuel dilution rates are observed when extra fuel injection occurs later in the combustion cycle when fuel penetration into the cylinder wall oil film is more likely.
Parks, II, James E [ORNL; Partridge Jr, William P [ORNL
A mobile melt-dilute (MMD) module for the treatment of aluminum research reactor spent fuel is being developed. The process utilizes a closed system approach to retain fission products/gases inside a sealed canister after treatment. The MMD process melts and dilutes spent fuel with depleted uranium to obtain a fissile fraction of less than 0.2. The final ingot is solidified inside the sealed canister and can be stored safely either wet or dry until final disposition or reprocessing. The MMD module can be staged at or near the research reactor fuel storage sites to facilitate the melt-dilute treatment of the spent fuel into a stable non-proliferable form.
Adams, T
Patterns and intrinsic fluctuations in semi-dilute motor-filament systems.
We perform Brownian dynamics simulations of molecular motor-induced ordering and structure formations in semi-dilute cytoskeletal filament solutions. In contrast to the previously studied dilute case where binary filament interactions prevail, the semi-dilute regime is characterized by multiple motor-mediated interactions. Moreover, the forces and torques exerted by motors on filaments are intrinsically fluctuating quantities. We incorporate the influences of thermal and motor fluctuations into our model as additive and multiplicative noises, respectively. Numerical simulations reveal that filament bundles and vortices emerge from a disordered initial state. Subsequent analysis of motor noise effects reveals: (i) Pattern formation is very robust against fluctuations in motor force; (ii) bundle formation is associated with a significant reduction of the motor fluctuation contributions; (iii) the time scale of vortex formation and coalescence decreases with increases in motor noise amplitude.
Swaminathan, S.; Ziebert, F.; Aranson, I. S.; Karpeev, D.; Northwestern Univ.; UMR CNRS Gulliver
Evaluation of feeds for melt and dilute process using an analytical hierarchy process
Westinghouse Savannah River Company was requested to evaluate whether nuclear materials other than aluminum-clad spent nuclear fuel should be considered for treatment to prepare them for disposal in the melt and dilute facility as part of the Treatment and Storage Facility currently projected for construction in the L-Reactor process area. The decision analysis process used to develop this analysis considered many variables and uncertainties, including repository requirements that are not yet finalized. The Analytical Hierarchy Process using a ratings methodology was used to rank potential feed candidates for disposition through the Melt and Dilute facility proposed for disposition of Savannah River Site aluminum-clad spent nuclear fuel. Because of the scoping nature of this analysis, the expert team convened for this purpose concentrated on technical feasibility and potential cost impacts associated with using melt and dilute versus the current disposition option. This report documents results of the decision analysis.
Krupa, J.F.
Persistence of magnons in a site-diluted dimerized frustrated antiferromagnet
Persistence of magnons in a site-diluted dimerized frustrated antiferromagnet Persistence of magnons in a site-diluted dimerized frustrated antiferromagnet This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2011 J. Phys.: Condens. Matter 23 416003 (http://iopscience.iop.org/0953-8984/23/41/416003) Download details: IP Address: 184.108.40.206 The article was downloaded on 17/10/2011 at 17:07 Please note that terms and conditions apply. View the table of contents for this issue, or go to the journal homepage for more Home Search Collections Journals About Contact us My IOPscience IOP PUBLISHING JOURNAL OF PHYSICS: CONDENSED MATTER J. Phys.: Condens. Matter 23 (2011) 416003 (9pp) doi:10.1088/0953-8984/23/41/416003 Persistence of magnons in a site-diluted dimerized frustrated antiferromagnet M B Stone 1 , A Podlesnyak 1 , G Ehlers
Laboratory Demonstration of the Pretreatment Process with Caustic and Oxidative Leaching Using Actual Hanford Tank Waste
This report describes the bench-scale pretreatment processing of actual tank waste materials through the entire baseline WTP pretreatment flowsheet in an effort to demonstrate the efficacy of the defined leaching processes on actual Hanford tank waste sludge and the potential impacts on downstream pretreatment processing. The test material was a combination of reduction oxidation (REDOX) tank waste composited materials containing aluminum primarily in the form of boehmite and dissolved S saltcake containing Cr(III)-rich entrained solids. The pretreatment processing steps tested included � caustic leaching for Al removal � solids crossflow filtration through the cell unit filter (CUF) � stepwise solids washing using decreasing concentrations of sodium hydroxide with filtration through the CUF � oxidative leaching using sodium permanganate for removing Cr � solids filtration with the CUF � follow-on solids washing and filtration through the CUF � ion exchange processing for Cs removal � evaporation processing of waste stream recycle for volume reduction � combination of the evaporated product with dissolved saltcake. The effectiveness of each process step was evaluated by following the mass balance of key components (such as Al, B, Cd, Cr, Pu, Ni, Mn, and Fe), demonstrating component (Al, Cr, Cs) removal, demonstrating filterability by evaluating filter flux rates under various processing conditions (transmembrane pressure, crossflow velocities, wt% undissolved solids, and PSD) and filter fouling, and identifying potential issues for WTP. The filterability was reported separately (Shimskey et al. 2008) and is not repeated herein.
Fiskum, Sandra K.; Billing, Justin M.; Buck, Edgar C.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Jenson, Evan D.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Shimskey, Rick W.; Snow, Lanee A.
Underground storage tank integrated demonstration: Evaluation of pretreatment options for Hanford tank wastes
Separation science plays a central role inn the pretreatment and disposal of nuclear wastes. The potential benefits of applying chemical separations in the pretreatment of the radioactive wastes stored at the various US Department of Energy sites cover both economic and environmental incentives. This is especially true at the Hanford Site, where the huge volume (>60 Mgal) of radioactive wastes stored in underground tanks could be partitioned into a very small volume of high-level waste (HLW) and a relatively large volume of low-level waste (LLW). The cost associated with vitrifying and disposing of just the HLW fraction in a geologic repository would be much less than those associated with vitrifying and disposing of all the wastes directly. Futhermore, the quality of the LLW form (e.g., grout) would be improved due to the lower inventory of radionuclides present in the LLW stream. In this report, we present the results of an evaluation of the pretreatment options for sludge taken from two different single-shell tanks at the Hanford Site-Tanks 241-B-110 and 241-U-110 (referred to as B-110 and U-110, respectively). The pretreatment options examined for these wastes included (1) leaching of transuranic (TRU) elements from the sludge, and (2) dissolution of the sludge followed by extraction of TRUs and {sup 90}Sr. In addition, the TRU leaching approach was examined for a third tank waste type, neutralized cladding removal waste.
Lumetta, G.J.; Wagner, M.J.; Colton, N.G.; Jones, E.O.
Research on Turbidity Removal and Byproduct Magnesium Hydroxide in Alkalify Flocculation Desalination Pretreatment
The reverse osmosis desalination is becoming an effective approach in seawater desalination to solve the shortage of freshwater resource. Since reverse osmosis desalination plants depend on high quality feed water to ensure. Turbidity is the most important ... Keywords: Alkalify Flocculation, Desalination Pretreatment
Liuhe Yishouzhi; Wuyan Wujiaquan
Residence Time Distribution Measurement and Analysis of Pilot-Scale Pretreatment Reactors for Biofuels Production: Preprint
Measurement and analysis of residence time distribution (RTD) data is the focus of this study where data collection methods were developed specifically for the pretreatment reactor environment. Augmented physical sampling and automated online detection methods were developed and applied. Both the measurement techniques themselves and the produced RTD data are presented and discussed.
Sievers, D.; Kuhn, E.; Tucker, M.; Stickel, J.; Wolfrum, E.
BIOETHANOL PRODUCTION FROM WET OXIDSED CORN STOVER USING PRE-TREATED MANURE AS A NUTRIENT SOURCE E (sugar-, and starch-containing) raw materials represent the major part of the total production cost- linked, rigid lignocellulose complex. This structure severely limits the biological conversion; therefore
Effect of a surface pre-treatment on graphene growth using a SiC substrate
This study reports surface pre-treatment techniques for the formation of a high-quality graphene layer on a SiC surface. It is demonstrated that silicon passivation of SiC surface using a silane flow and subsequent sacrificial oxidation can significantly ... Keywords: Graphene, Sacrificial oxidation, Silane treatment, Sulfur hexafluoride (SF6), Surface passivation
Jun-Ho Seo; Byung-Jin Kang; Jeong Hun Mun; Sung-Kyu Lim; Byung Jin Cho
Dry Blending to Achieve Isotopic Dilution of Highly Enriched Uranium Oxide Materials
The end of the cold war produced large amounts of excess fissile materials in the United States and Russia. The Department of Energy has initiated numerous activities to focus on identifying material management strategies for disposition of these excess materials. To date, many of these planning strategies have included isotopic dilution of highly enriched uranium as a means of reducing the proliferation and safety risks. Isotopic dilution by dry blending highly enriched uranium with natural and/or depleted uranium has been identified as one non-aqueous method to achieve these risk (proliferation and criticality safety) reductions. This paper reviews the technology of dry blending as applied to free flowing oxide materials.
Henry, Roger Neil; Chipman, Nathan Alan; Rajamani, R. K.
Ionic liquid pretreatment of poplar wood at room temperature: swelling and incorporation of nanoparticles
Lignocellulosic biomass represents a potentially sustainable source of liquid fuels and commodity chemicals. It could satisfy the energy needs for transportation and electricity generation, while contributing substantially to carbon sequestration and limiting the accumulation of greenhouse gases in the atmosphere. Potential feedstocks are abundant and include crops, agricultural wastes, forest products, grasses, and algae. Among those feedstocks, wood is mainly constituted of three components: cellulose, hemicellulose, and lignin. The conversion process of lignocellulosic biomass typically consists of three steps: (1) pretreatment; (2) hydrolysis of cellulose and hemicellulose into fermentable sugars; and (3) fermentation of the sugars into liquid fuels (ethanol) and other commodity chemicals. The pretreatment step is necessary due to the complex structure of the plant cell wall and the chemical resistance of lignin. Most current pretreatments are energy-intensive and/or polluting. So it is imperative to develop new pretreatments that are economically viable and environmentally friendly. Recently, ionic liquids have attracted considerable interest, due to their ability to dissolve biopolymers, such as cellulose, lignin, native switchgrass, and others. Ionic liquids are also considered green solvents, since they have been successfully recycled at high yields for further use with limited efficiency loss. Also, a few microbial cellulases remain active at high ionic liquid concentration. However, all studies on the dissolution of wood in ionic liquids have been conducted so far at high temperatures, typically above 90 C. Development of alternative pretreatments at room temperature is desirable to eliminate the additional energy cost. In this study, thin sections of poplar wood were swollen at room temperature by a 3 h ionic liquid (1-ethyl-3-methylimidazolium acetate or EMIMAc) pretreatment. The pretreated sample was then exposed to an aqueous suspension of nanoparticles that resulted in the sample contraction and the deposition of nanoparticles onto the surface and embedded into the cell wall. To date, both silver and gold particles ranging in size from 40-100 nm have been incorporated into wood. Penetration of gold nanoparticles of 100 nm diameter in the cell walls was best confirmed by near-infrared confocal Raman microscopy, since the deposition of gold nanoparticles induces a significant enhancement of the Raman signal from the wood in their close proximity, an enhancement attributed to the surface-enhanced Raman effect (SERS). After rinsing with water, scanning electron microscopy (SEM) and Raman images of the same areas show that most nanoparticles remained on the pretreated sample. Raman images at different depths reveal that a significant number of nanoparticles were incorporated into the wood sample, at depths up to 4 {micro}m, or 40 times the diameter of the nanoparticles. Control experiments on an untreated wood sample resulted in the deposition of nanoparticles only at the surface and most nanoparticles were removed upon rinsing. This particle incorporation process enables the development of new pretreatments, since the nanoparticles have a high surface-to-volume ratio and could be chemically functionalized. Other potential applications for the incorporated nanoparticles include isotope tracing, catalysis, imaging agents, drug-delivery systems, energy-storage devices, and chemical sensors.
Lucas, Marcel [Los Alamos National Laboratory; Macdonald, Brian A [Los Alamos National Laboratory; Wagner, Gregory L [Los Alamos National Laboratory; Joyce, Steven A [Los Alamos National Laboratory; Rector, Kirk D [Los Alamos National Laboratory
Spin-polarized current oscillations in diluted magnetic semiconductor multiple quantum wells Manuel Bejar,1
Spin-polarized current oscillations in diluted magnetic semiconductor multiple quantum wells Manuel and charge dynamics of electrons in n-doped II-VI semiconductor multiple quantum wells when one or more quantum wells are doped with Mn. The interplay between strongly nonlinear interwell charge transport
Sánchez, David
Compartmental anaerobic baffled reactor kinetic model for treatment of dilute aircraft deicing fluid
A four-compartment, anaerobic baffled reactor (ABR) incorporating granular sludge biomass (GSB) was operated at different hydraulic retention times (HRTs) in the range of 3 to 24 hours using dilute aircraft deicing fluid (ADF) with different chemical ... Keywords: anaerobic, baffled reactor, deicing fluid
Juan Marin; Kevin J. Kennedy; Cigdem Eskicioglu; Mohamed F. Hamoda
Solvation Phenomena in Dilute Solutions: Formal, Experimental Evidence, and Modeling Implications
We review the fundamentals underlying a general molecular-based formalism for the microscopic interpretation of the solvation phenomena involving sparingly soluble solutes in compressible media, an approach that hinges around the unambiguous splitting of the species correlation function integrals into short-(finite) and long-ranged (diverging) contributions at infinite dilution, where this condition is taken as the reference system for the derivation of composition expansions. Then, we invoke the formalism (a) to illustrate the well-behaved nature of the solvation contributions to the mechanical partial molecular properties of solutes at infinite dilution, (b) to guide the development of, and provide molecular-based support to, the macroscopic modeling of high-temperature dilute aqueous-electrolyte solutions, (c) to study solvation effects on the kinetic rate constants of reactions in near-critical solvents in an attempt to understand from a microscopic perspective the macroscopic evidence regarding the thermodynamic pressure effects, and (d) to interpret the microscopic mechanism behind synergistic solvation effects involving either co-solutes or co-solvents, and provide a molecular argument on the unsuitability of the van der Waals one-fluid (vdW-1f) mixing rules for the 2 description of weakly attractive solutes in compressible solvents. Finally, we develop thermodynamically consistent perturbation expansions, around the infinite dilution reference, for the species residual properties in binary and ternary mixtures, and discuss the theoretical and modeling implications behind ad hoc first-order truncated expansions.
Chialvo, Ariel A [ORNL
Determination of Mercury in Coal by Isotope Dilution Cold-Vapor Generation Inductively
Articles Determination of Mercury in Coal by Isotope Dilution Cold-Vapor Generation Inductively developed for high-accuracy determinations of mer- cury in bituminous and sub-bituminous coals. A closed- system digestion process employing a Carius tube is used to completely oxidize the coal matrix
A quadrature-based third-order moment method for dilute gas-particle flows
Dilute gas-particle flows can be described by a kinetic equation containing terms for spatial transport, gravity, fluid drag, and particle-particle collisions. However, the direct numerical solution of the kinetic equation is intractable for most applications ... Keywords: Boltzmann equation, Gas-particle flows, Kinetic equation, Quadrature method of moments, Velocity distribution function
R. O. Fox
Global NOx Measurements in Turbulent Nitrogen-Diluted Hydrogen Jet Flames
Turbulent hydrogen diffusion flames diluted with nitrogen are currently being studied to assess their ability to achieve the DOE Turbine Program�s aggressive emissions goal of 2 ppm NOx in a hydrogen-fueled IGCC gas turbine combustor. Since the unstrained adiabatic flame temperatures of these diluted flames are not low enough to eliminate thermal NOx formation the focus of the current work is to study how the effects of flame residence time and global flame strain can be used to help achieve the stated NOx emissions goal. Dry NOx measurements are presented as a function of jet diameter nitrogen dilution and jet velocity for a turbulent hydrogen/nitrogen jet issuing from a thin-lipped tube in an atmospheric pressure combustor. The NOx emission indices from these experiments are normalized by the flame residence time to ascertain the effects of global flame strain and fuel Lewis Number on the NOx emissions. In addition dilute hydrogen diffusion flame experiments were performed in a high-pressure combustor at 2 4 and 8 atm. The NOx emission data from these experiments are discussed as well as the results from a Computational Fluid Dynamics modeling effort currently underway to help explain the experimental data.
Analysis of several hazardous conditions for large transfer and back-dilution sequences in Tank 241-SY-101
The first transfer of 89 kgal of waste and back-dilution of 61 kgal of water in Hanford Tank 241-SY-101 was accomplished December 18--20, 1999. Limits were placed on the transfer and back-dilution volumes because of concerns about potential gas release, crust sinking, and degradation of mixer pump performance. Additional transfers and back-dilutions are being planned that will bring the total to 500 kgal, which should dissolve a large fraction of the solids in the tank and dilute it well beyond the point where significant gas retention can occur. This report provides the technical bases for removing the limits on transfer and back-dilution volume by evaluating the potential consequences of several postulated hazardous conditions in view of the results of the first campaign and results of additional analyses of waste behavior.
CW Stewart; LA Mahoney; WB Barton
At-tank supplemental pretreatment including both filtration and small column ion exchange is currently under evaluation to facilitate salt waste retrieval and processing in the Hanford tank farms. Spherical resorcinol formaldehyde (sRF) resin is the baseline ion exchange resin for use in the Waste Treatment and Immobilization Plant (WTP). This document provides background and technical rationale to assist in determining whether spherical resorcinol formaldehyde (sRF) is also the appropriate ion exchange resin for supplemental LAW pretreatment processes and compares sRF with crystalline silicotitanate (CST) as potential supplemental pretreatment ion exchange media.
Approaches for regeneration of amine-carboxylic acid extracts
Extraction processes based on reversible chemical complexation can be useful for separation of polar organics from dilute solution. Tertiary amines are effective extractants for the recovery of carboxylic acids from aqueous solution. The regeneration of aminecarboxylic acid extracts is an important step which strongly influences the economic viability of the separation process. Several regeneration methods are critically reviewed, and the factors that affect swing regeneration processes, including temperature-swing, diluent composition-swing and pH-swing with a volatile base are discussed. Interest in this area comes from interest in treatment of waste streams, particularly in petrochemical and fermentation manufacture.
Dai, Y.; King, C.J.
Role of Liquid Waste Pretreatment Technologies in Solving the DOE Clean-up Mission
Role of Liquid Waste Pretreatment Technologies in Role of Liquid Waste Pretreatment Technologies in Solving the DOE Clean-up Mission W. R. Wilmarth March 5 2009 March 5, 2009 HLW Corporate Board Phoenix AZ HLW Corporate Board, Phoenix, AZ Co-authors M. E. Johnson, CH2M Hill Plateau Remediation Company G. Lumetta, Pacific Northwest National Laboratory N Machara DOE Office of Engineering and Technology N. Machara, DOE Office of Engineering and Technology M. R. Poirier, Savannah River National Laboratory P C S DOE S h Ri P. C. Suggs, DOE Savannah River M. C. Thompson, Savannah River National Laboratory, Retired Retired 2 Background Separations is a fundamental business within DOE. The role of separations today is to expedite waste retrieval The role of separations today is to expedite waste retrieval, processing and closure. Recognized as part of E&T Roadmap
Structural changes in switchgrass lignin and hemicelluloses during pretreatments by NMR analysis
changes changes in switchgrass lignin and hemicelluloses during pretreatments by NMR analysis Reichel Samuel a, c , Marcus Foston a, c , Nan Jiang a, c , Lenong Allison a, c , Arthur J. Ragauskas a, b, c, * a School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA b Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA, USA c BioEnergy Science Center, USA a r t i c l e i n f o Article history: Received 14 May 2011 Received in revised form 13 August 2011 Accepted 25 August 2011 Available online xxx Keywords: Switchgrass Pretreatment HSQC NMR analysis Lignin a b s t r a c t Switchgrass is currently being developed as a sustainable bio-energy crop due to its broad adaptability, high mass yield and low agricultural input. Its current conversion to biofuels is detrimentally impacted by its native recalcitrance which is typically addressed using
Activation of catalyst for gas-phase combustion by electrochemical pretreatment
The catalytic activity of an IrO{sub 2} catalyst used as an electrode on a YSZ solid electrolyte cell for the gas-phase combustion of ethylene can be increased by electrochemical pretreatment. Thus, the polarization of the IrO{sub 2} electrode during 90 min at 300 {micro}A, relative to a gold electrode, both deposited on YSZ, increases the activity of the IrO{sub 2} catalyst after current interruption by a factor of 3. In situ catalyst work function measurements showed that after the electrochemical pretreatment the IrO{sub 2} catalyst obtains higher work function. The activation of the catalyst is explained through the formation of a higher oxide, IrO{sub 2+{delta}}.
Nicole, J.; Wodiunig, S.; Comninellis, C. [Swiss Federal Inst. of Tech., Lausanne (Switzerland). Inst. of Chemical Engineering; Tsiplakides, D. [Univ. of Patras (Greece). Dept. of Chemical Engineering
A process is given for producing superior alkyl orthophosphoric acid extractants for use in solvent extraction methods to recover and purify various metals such as uranium and vanadium. The process comprises slurrying P/sub 2/O/ sub 5/ in a solvent diluent such as kerosene, benzene, isopropyl ether, and the like. An alipbatic alcohol having from nine to seventeen carbon atoms, and w- hcrein ihc OH group is situated inward of the terminal carbon atoms, is added to the slurry while the reaction temperature is mainiained below 60 deg C. The alcohol is added in the mole ratio of about 2 to l, alcohol to P/sub 2/O/sub 5/. A pyrophosphate reaotion product is formed in the slurry-alcohol mixture. Subsequently, the pyrophosphate reaction product is hydrolyzed with dilute mineral acid to produce the desired alkyl orthophosphoric aeid extractant. The extraetant may then be separated and utilized in metal-recovery, solvent- extraction processes. (AEC)
Grinstead, R.R.
Program on Technology Innovation: Gasification Testing of Various Biomasses in Untreated and Pretreated (Leached) Forms
Leaching of biomass to remove/eliminate troublesome constituents, such as alkali metals, chlorine, sulfur, and phosphorus, presents the opportunity to solve many of the problems found when firing and/or cofiring low-cost and low-grade agricultural biomasses, grasses, and waste materials for energy or production of biofuels. The Electric Power Research Institute (EPRI) has fostered projects for the development and testing of this potential game-changing biomass pretreatment technology since 2010. As part ...
Review of technologies for the pretreatment of retrieved single-shell tank waste at Hanford
The purpose of the study reported here was to identify and evaluate innovative processes that could be used to pretreat mixed waste retrieved from the 149 single-shell tanks (SSTs) on the US Department of Energy`s (DOE) Hanford site. The information was collected as part of the Single Shell Tank Waste Treatment project at Pacific Northwest Laboratory (PNL). The project is being conducted for Westinghouse Hanford Company under their SST Disposal Program.
Gerber, M.A.
The purpose of the study reported here was to identify and evaluate innovative processes that could be used to pretreat mixed waste retrieved from the 149 single-shell tanks (SSTs) on the US Department of Energy's (DOE) Hanford site. The information was collected as part of the Single Shell Tank Waste Treatment project at Pacific Northwest Laboratory (PNL). The project is being conducted for Westinghouse Hanford Company under their SST Disposal Program.
Method for aqueous gold thiosulfate extraction using copper-cyanide pretreated carbon adsorption
A gold thiosulfate leaching process uses carbon to remove gold from the leach liquor. The activated carbon is pretreated with copper cyanide. A copper (on the carbon) to gold (in solution) ratio of at least 1.5 optimizes gold recovery from solution. To recover the gold from the carbon, conventional elution technology works but is dependent on the copper to gold ratio on the carbon.
Young, Courtney; Melashvili, Mariam; Gow, Nicholas V
Alternatives generation and analysis for the phase 1 high-level waste pretreatment process selection
This report evaluates the effects of enhanced sludge washing and sludge washing without caustic leaching during the preparation of the Phase 1 high-level waste feeds. The pretreatment processing alternatives are evaluated against their ability to satisfy contractual, cost minimization, and other criteria. The information contained in this report is consistent with, and supplemental to, the Tank Waste Remediation System Operation and Utilization Plan (Kirkbride et al. 1997).
Manuel, A.F.
This work is a fundamental study of catalytic pretreatments as a potential preconversion step to low-severity liquefaction. The ultimate goal of this work is to provide the basis for the design of an improved liquefaction process and to facilitate our understanding of those processes that occur when coals are initially dissolved. The main objectives of this project are to study the effects of low-temperature pretreatments on coal structure and their impacts on the subsequent liquefaction. The effects of pretreatment temperatures, catalyst type, coal rank and influence of solvent will be examined. We have made significant progress in the following four aspects during this quarterly period: (1) influence of drying and oxidation of coal on the conversion and product distribution in catalytic liquefaction of Wyodak subbituminous coal using a dispersed catalyst; (2) spectroscopic characterization of dried and oxidized Wyodak coal and the insoluble residues from catalytic and thermal liquefaction; (3) the structural alteration of low-rank coal in low-severity liquefaction with the emphasis on the oxygen-containing functional groups; and (4) effects of solvents and catalyst dispersion methods in temperature-programmed and non-programmed liquefaction of three low-rank coals.
Song, C.; Saini, A.K.; Wenzel, K.; Huang, L.; Hatcher, P.G.; Schobert, H.H.
Radioactive waste tank Initial Pretreatment Module (IPM) technology development and selection
The processing of nuclear materials at the Hanford Site has resulted in the accumulation of radioactive wastes stored in 177 single- and double-shell tanks (SSTs and DSTs). Fifty-four of the 177 tanks are currently on a tank watch list because organic chemicals and ferrocyanide compounds in the tanks present a potential fire or explosion hazard. In addition, one additional SST is under consideration for placement on the watch list because of high organic concentration. Seventeen of the watch list tanks require pretreatment, and two DST complexant concentrate waste tanks not on the watch list may also need pretreatment. The proposed Initial Pretreatment Module (IPM) is expected to resolve the safety concerns by destroying the organics and ferrocyanide compounds in the tank wastes. The primary objective of the IPM is to destroy or modify constituents that cause safety concerns in the watch list tanks. A secondary objective is to enhance the cost effectiveness of processing the wastes by performing additional processing. Overall, IPM will achieve organic/ferrocyanide destruction (the primary goal) and will assist in the separation of cesium, strontium, and technetium from the tank wastes.
Beeman, G.H. [Pacific Northwest Lab., Richland, WA (United States); Hansrote, G. [Westinghouse Hanford Co., Richland, WA (United States)
Tank Waste Remediation System tank waste pretreatment and vitrification process development testing requirements assessment
A multi-faceted study was initiated in November 1993 to provide assurance that needed testing capabilities, facilities, and support infrastructure (sampling systems, casks, transportation systems, permits, etc.) would be available when needed for process and equipment development to support pretreatment and vitrification facility design and construction schedules. This first major report provides a snapshot of the known testing needs for pretreatment, low-level waste (LLW) and high-level waste (HLW) vitrification, and documents the results of a series of preliminary studies and workshops to define the issues needing resolution by cold or hot testing. Identified in this report are more than 140 Hanford Site tank waste pretreatment and LLW/HLW vitrification technology issues that can only be resolved by testing. The report also broadly characterizes the level of testing needed to resolve each issue. A second report will provide a strategy(ies) for ensuring timely test capability. Later reports will assess the capabilities of existing facilities to support needed testing and will recommend siting of the tests together with needed facility and infrastructure upgrades or additions.
Howden, G.F.
Pretreatment status report on the identification and evaluation of alternative processes. Milestone Report No. C064
The purpose of this report is to support the development and demonstration of a pretreatment system that will (1) destroy organic materials and ferrocyanide in tank wastes so that the wastes can be stored safely, (2) separate the high-activity and low-activity fractions, (3) remove radionuclides and remove or destroy hazardous chemicals in LLW as necessary to meet waste form feed requirements, (4) support development and demonstration of vitrification technology by providing representative feeds to the bench-scale glass melter, (5) support full-scale HLW vitrification operations, including near-term operation, by providing feed that meets specifications, and (6) design and develop pretreatment processes that accomplish the above objectives and ensure compliance with environmental regulations. This report is a presentation of candidate technologies for pretreatment of Hanford Site tank waste. Included are descriptions of studies by the Pacific Northwest Laboratory of Battelle Memorial Institute; Science Applications International Corporation, an independent consultant; BNFL, Inc. representing British technologies; Numatec, representing French technologies; and brief accounts of other relevant activities.
Sutherland, D.G. [Westinghouse Hanford Co., Richland, WA (United States); Brothers, A.J. [Pacific Northwest Lab., Richland, WA (United States); Beary, M.M.; Nicholson, G.A. [Science Applications International Corp., San Diego, CA (United States)
Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction. Final technical report, Volume 2 - hydrogenative and hydrothermal pretreatments and spectroscopic characterization using pyrolysis-GC-MS, CPMAS {sup 13}C NMR and FT-IR
It has been indicated by DOE COLIRN panel that low-temperature catalytic pretreatment is a promising approach to the development of an improved liquefaction process. This work is a fundamental study on effects of pretreatments on coal structure and reactivity in liquefaction. The main objectives of this project are to study the coal structural changes induced by low-temperature catalytic and thermal pretreatments by using spectroscopic techniques; and to clarify the pretreatment-induced changes in reactivity or convertibility of coals. As the second volume of the final report, here we summarize our work on spectroscopic characterization of four raw coals including two subbituminous coals and two bituminous coals, tetrahydrofuran (THF)-extracted but unreacted coals, the coals (THF-insoluble parts) that have been thermally pretreated. in the absence of any solvents and in the presence of either a hydrogen-donor solvent or a non-donor solvent, and the coals (THF-insoluble parts) that have been catalytically pretreated in the presence of a dispersed Mo sulfide catalyst in the absence of any solvents and in the presence of either a hydrogen-donor solvent or a non-donor solvent.
Chunshan Song; Hatcher, P.G.; Saini, A.K.; Wenzel, K.A.
Asymptotically optimal purification and dilution of mixed qubit and Gaussian states
Given an ensemble of mixed qubit states, it is possible to increase the purity of the constituent states using a procedure known as state purification. The reverse operation, which we refer to as dilution, reduces the level of purity present in the constituent states. In this paper we find asymptotically optimal procedures for purification and dilution of an ensemble of i.i.d. mixed qubit states, for some given input and output purities and an asymptotic output rate. Our solution involves using the statistical tool of local asymptotic normality, which recasts the qubit problem in terms of attenuation and amplification of a single displaced Gaussian state. Therefore, to obtain the qubit solutions, we must first solve the analogous problems in the Gaussian setup. We provide full solutions to all of the above, for the (global) trace norm figure of merit.
Peter Bowles; Madalin Guta; Gerardo Adesso
Stability and instability of a hot and dilute nuclear droplet. II. Dissipative isoscalar modes
Results on dissipative isoscalar modes of a hot and dilute nuclear droplet are presented. As compared to the adiabatic limit (part I), realistic dissipation yields a substantial reduction of the growth rates for all unstable modes, while the area of spinodal instability in the ($\\varrho$,T)-plane remains unchanged. The qualitative features of multifragmentation through spinodal decomposition as obtained in the adiabatic limit are not significantly affected by dissipation.
W. N�renberg; G. Papp; P. Rozmej
A Laboratory Study of Hydrated Lime Properties in Dilute Phase Conveyance
Recent regulatory actions are reducing allowable emissions of sulfur trioxide (SO3) from coal-fired power plants. Therefore, the need to economically and reliably remove SO3 from flue gas streams is taking on additional urgency. Three sorbents are commonly used for SO3 removal151hydrated lime, trisodium hydrogendicarbonate dihydrate (trona), and sodium bisulfate. Hydrated lime has been shown to be an economical choice; however, dilute phase conveyance from storage hoppers to duct injection lances has bee...
Understanding the Potential and Limitations of Dilute Nitride Alloys for Solar Cells
Dilute nitride alloys provide a powerful tool for engineering the band gap and lattice constant of III-V alloys. However, nitrogen degrades the performance of GaAs solar cells. This project seeks to understand and demonstrate the limits of performance of GaInNAs alloys by (a) correlating deep-level transient spectroscopy (DLTS) data with device performance and (b) using molecular beam epitaxy (MBE) to reduce background impurity concentrations.
Kurtz, S.; Ptak, A.; Johnston, S.; Kramer, C.; Young, M.; Friedman, D.; Geisz, J.; McMahon, W.; Kibbler, A.; Olson, J.; Crandall, R.; Branz, H.
Magnetite and magnetite/silver core/shell nanoparticles with diluted magnet-like behavior
In the present work is reported the use of the biopolymer chitosan as template for the preparation of magnetite and magnetite/silver core/shell nanoparticles systems, following a two step procedure of magnetite nanoparticles in situ precipitation and subsequent silver ions reduction. The crystalline and morphological characteristics of both magnetite and magnetite/silver core/shell nanoparticles systems were analyzed by high resolution transmission electron microscopy (HRTEM) and nanobeam diffraction patterns (NBD). The results of these studies corroborate the core/shell morphology and the crystalline structure of the magnetite core and the silver shell. Moreover, magnetization temperature dependent, M(T), measurements show an unusual diluted magnetic behavior attributed to the dilution of the magnetic ordering in the magnetite and magnetite/silver core/shell nanoparticles systems. - Graphical abstract: Biopolymer chitosan was used as stabilization media to synthesize both magnetite and magnetite/silver core/shell nanoparticles. Results of HRTEM and NBD patterns confirm core/shell morphology of the obtained nanoparticles. It was found that the composites show diluted magnet-like behavior.
Garza-Navarro, Marco [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Universidad s/n, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Torres-Castro, Alejandro, E-mail: email@example.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Universidad s/n, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon 66600 (Mexico); Gonzalez, Virgilio; Ortiz, Ubaldo [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Universidad s/n, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon 66600 (Mexico); De la Rosa, Elder [Centro de Investigaciones en Optica, A.P. 1-948, Leon Gto. 37160 (Mexico)
Waterflood and Enhanced Oil Recovery Studies using Saline Water and Dilute Surfactants in Carbonate Reservoirs
Water injection has been practiced to displace the hydrocarbons towards adjacent wells and to support the reservoir pressure at or above the bubble point. Recently, waterflooding in sandstone reservoirs, as secondary and tertiary modes, proved to decrease the residual oil saturation. In calcareous rocks, water from various resources (deep formation, seawater, shallow beds, lakes and rivers) is generally injected in different oil fields. The ions interactions between water molecules, salts ions, oil components, and carbonate minerals are still ambiguous. Various substances are usually added before or during water injection to enhance oil recovery such as dilute surfactant. Various methods were used including surface charge (zeta potential), static and dynamic contact angle, core flooding, inductively coupled plasma spectrometry, CAT scan, and geochemical simulation. Limestone and dolomite particles were prepared at different wettability conditions to mimic the actual carbonate reservoirs. In addition to seawater and dilute seawater (50, 20, 10, and 1 vol%), formation brine, shallow aquifer water, deionized water and different crude oil samples were used throughout this study. The crude oil/water/carbonates interactions were also investigated using short and long (50 cm) limestone and dolomite rocks at different wettability and temperature conditions. The aqueous ion interactions were extensively monitored via measuring their concentrations using advanced analytical techniques. The activity of the free ions, complexes, and ion pairs in aqueous solutions were simulated at high temperatures and pressures using OLI electrolyte simulation software. Dilute seawater decreased the residual oil saturation in some of the coreflood tests. Hydration and dehydration processes through decreasing and increasing salinity showed no impact on calcite wettability. Effect of individual ions (Ca, Mg, and Na) and dilute seawater injection on oil recovery was insignificant in compare to the dilute surfactant solutions (0.1 wt%). The reaction mechanisms were confirmed to be adsorption of hydroxide ions, complexes and ion pairs at the interface which subsequently altered the surface potential from positive to negative. Results in this study indicate multistage waterflooding can enhance oil recovery in the field under certain conditions. Mixed streams simulation results suggest unexpected ions interactions (NaCO3-1, HSO4-1, NaSO4-1 and SO4-2) with various activities trends especially at high temperatures.
Alotaibi, Mohammed
Chemical pre-treatment of radioactive waste at the Savannah River Site is performed to prepare the waste for vitrification into a stable waste glass form. During pre-treatment, compounds in the waste become catalytically active. Mercury, rhodium, and palladium become active for nitrite destruction by formic acid, while rhodium and ruthenium become active for catalytic conversion of formic acid into hydrogen and carbon dioxide. Nitrite ion is present during the maximum activity of rhodium, but is consumed prior to the activation of ruthenium. Catalytic hydrogen generation during pre-treatment can exceed radiolytic hydrogen generation by several orders of magnitude. Palladium and mercury impact the maximum catalytic hydrogen generation rates of rhodium and ruthenium by altering the kinetics of nitrite ion decomposition. New data are presented that illustrate the interactions of these various species.
Koopman, D.; Pickenheim, B.; Lambert, D.; Newell, J; Stone, M.
Pretreatment of neutralized cladding removal waste sludge: Results of the second design basis experiment
For several years, the Pacific Northwest Laboratory (PNL) has been investigating methods to pretreat Hanford neutralized cladding removal waste (NCRW) sludge. In the past, Zircaloy-clad metallic U fuel was chemically decladded using the Zirflex process; NCRW sludge was formed when the decladding solution was neutralized for storage in carbon-steel tanks. This sludge, which is currently stored in Tanks 103-AW and 105-AW on the Hanford Site, primarily consists of insoluble Zr hydroxides and/or oxides and NaF. Significant quantities of Al, La, U, as well as other insoluble minor constituents are present in the sludge, along with sodium and potassium nitrates, nitrites, and hydroxides in the interstitial liquid. The sludge contains about 2,000 nCi of transuranic (TRU) material per gram of dry sludge, and mixed fission products. Therefore, the sludge must be handled as high-level waste (HLW). The NCRW sludge must be pretreated before treatment (e.g., vitrification) and disposal, so that the overall cost of disposal can be minimized. The NCRW pretreatment flowsheet was designed to achieve the following objectives: (a) to separate Am and Pu from the major sludge constituents (Na, Zr). (b) to separate Am and Pu from U. (c) to concentrate Am and Pu in a small volume for immobilization in borosilicate glass, based on Hanford Waste Vitrification Plant (HWVP). The flowsheet involves: (1) sludge washing, (2) sludge dissolution, (3) extraction of U with tributyl phosphate (TBP), and (4) extraction of TRUs with octyl(phenyl)-N,N-diisobutlycarbamoylmethyl-phosphine oxide (CMPO). As presented in the flowsheet, the NCRW sludge is first washed with 0.I M NaOH to remove interstitial liquid and soluble salts from the sludge including sodium and potassium fluorides, carbonates, hydroxides, nitrates, and nitrites. The washed sludge is then subjected to two dissolution steps to achieve near complete dissolution of Zr.
Lumetta, G.J.
A review on biomass classification and composition, cofiring issues and pretreatment methods
Presently around the globe there is a significant interest in using biomass for power generation as power generation from coal continues to raise environmental concerns. Biomass alone can be used for generation of power which can bring lot of environmental benefits. However the constraints of using biomass alone can include high investments costs for biomass feed systems and also uncertainty in the security of the feedstock supply due to seasonal variations and in most of the countries biomass is dispersed and the infrastructure for biomass supply is not well established. Alternatively cofiring biomass along with coal offer advantages like (a) reducing the issues related to biomass quality and buffers the system when there is insufficient feedstock quantity and (b) costs of adapting the existing coal power plants will be lower than building new systems dedicated only to biomass. However with the above said advantages there exists some technical constrains including low heating and energy density values, low bulk density, lower grindability index, higher moisture and ash content to successfully cofire biomass with coal. In order to successfully cofire biomass with coal, biomass feedstock specifications need to be established to direct pretreatment options that may include increasing the energy density, bulk density, stability during storage and grindability. Impacts on particle transport systems, flame stability, pollutant formation and boiler tube fouling/corrosion must also be minimized by setting feedstock specifications including composition and blend ratios if necessary. Some of these limitations can be overcome by using pretreatment methods. This paper discusses the impact of feedstock pretreatment methods like sizing, baling, pelletizing, briquetting, washing/leaching, torrefaction, torrefaction and pelletization and steam explosion in attainment of optimum feedstock characteristics to successfully cofire biomass with coal.
Jaya Shankar Tumuluru; Shahab Sokhansanj; Christopher T. Wright; Richard D. Boardman
Assessment of effective parameters on dilution using approximate reasoning methods in longwall mining method, Iran coal mines
Approximately more than 90% of all coal production in Iranian underground mines is derived directly longwall mining method. Out of seam dilution is one of the essential problems in these mines. Therefore the dilution can impose the additional cost of mining and milling. As a result, recognition of the effective parameters on the dilution has a remarkable role in industry. In this way, this paper has analyzed the influence of 13 parameters (attributed variables) versus the decision attribute (dilution value), so that using two approximate reasoning methods, namely Rough Set Theory (RST) and Self Organizing Neuro- Fuzzy Inference System (SONFIS) the best rules on our collected data sets has been extracted. The other benefit of later methods is to predict new unknown cases. So, the reduced sets (reducts) by RST have been obtained. Therefore the emerged results by utilizing mentioned methods shows that the high sensitive variables are thickness of layer, length of stope, rate of advance, number of miners, type of...
Owladeghaffari, H; Saeedi, G H R
Results of Waste Transfer and Back-Dilution in Tanks 241-SY-101 and 241-SY-102
This report chronicles the process of remediation of the flammable gas hazard in Tank 241-SY-101 (SY-101) by waste transfer and back-dilution from December 18, 1999 through April 2, 2000. A brief history is given of the development of the flammable gas retention and release hazard in this tank, and the transfer and dilution systems are outlined. A detailed narrative of each of the three transfer and dilution campaigns is given to provide structure for the balance of the report. Details of the behavior of specific data are then described, including the effect of transfer and dilution on the waste levels in Tanks SY-101 and SY-102, data from strain gauges on equipment suspended from the tank dome, changes in waste configuration as inferred from neutron and gamma logs, headspace gas concentrations, waste temperatures, and the mixerpump operating performance. Operating data and performance of the transfer pump in SY-101 are also discussed.
LA Mahoney; ZI Antoniak; WB Barton; JM Conner; NW Kirch; CW Stewart; BE Wells
Net alkalinity and net acidity 2: Practical considerations Carl S. Kirby a,*, Charles A. Cravotta III b,1
. Both surfaces were cleaned prior to braz- ing with nitric acid and/ or acetone. When used, flux oxidation of a powdered dilute cop- per-aluminum alloy. The oxidized alloy is then placed in a pure copper one, the interlayer melts. Stage two in- volves erosion and dissolution of part of the base metal
Kirby, Carl S.
Phytic acid plus calcium, but not phytic acid alone, decreases fluoride bioavailability in the rat
Results of in vitro studies have suggested that fluoride becomes insoluble when some soy-based infant formulas are diluted with fluoridated water because of the presence of phytate, added calcium or a combination of these factors. The present study was designed to test this hypothesis in vivo. Male albino rats were fed a purified diet containing phytic acid, calcium and fluoride for 4 weeks in a factorial design of treatments. Phytic acid was added to the diet by chemically reacting a phytic acid concentrate with casein prior to diet preparation to mimic a soy-protein. Food intake, weight gain and femur P were unaffected by dietary treatments. Both phytic acid and supplemental calcium alone had little or no effect upon fluoride uptake into either bone or teeth. The combination of phytic acid plus supplemental calcium, however, significantly increased % of fluoride intake found in the feces which was reflected in a significant decrease in fluoride concentration of femur, 2nd molar teeth and vertebrate bone. These results provide evidence that insoluble complex formation produced by a calcium and phytate interaction can explain reduced fluoride solubility in some soy-based infant formulas as well as decreased fluoride absorbability in vivo.
Cerklewski, F.L. (Oregon State Univ., Corvallis (United States))
Effect of Lignin Removal by Alkaline Peroxide Pretreatment on the Susceptibility of Corn Stover to Purified Cellulolytic and Xylanolytic Enzymes
Pretreatment of corn stover with alkaline peroxide (AP) at pH 11.5 resulted in reduction of lignin content in the residual solids as a function of increasing batch temperature. Scanning electron microscopy of these materials revealed notably more textured surfaces on the plant cell walls as a result of the delignifying pretreatment. As expected, digestion of the delignified samples with commercial cellulase preparations showed an inverse relationship between the content of lignin present in the residual solids after pretreatment and the extent of both glucan and xylan conversion achievable. Digestions with purified enzymes revealed that decreased lignin content in the pretreated solids did not significantly impact the extent of glucan conversion achievable by cellulases alone. Not until purified xylanolytic activities were included with the cellulases were significant improvements in glucan conversion realized. In addition, an inverse relationship was observed between lignin content after pretreatment and the extent of xylan conversion achievable in a 24-h period with the xylanolytic enzymes in the absence of the cellulases. This observation, coupled with the direct relationship between enzymatic xylan and glucan conversion observed in a number of cases, suggests that the presence of lignins may not directly occlude cellulose present in lignocelluloses but rather impact cellulase action indirectly by its association with xylan.
Selig, M. J.; Vinzant, T. B.; Himmel, M. E.; Decker, S. R.
Fischer-Tropsch synthesis: Moessbauer studies of pretreated ultrafine iron oxide catalysts. Partial quarterly progress report, April--June 1992
Chenshi Huang; Davis, B.H. [Kentucky Univ., Lexington, KY (United States). Center for Applied Energy Research; Rao, K.R.P.M.; Huffman, G.P.; Huggins, F.E. [Kentucky Univ., Lexington, KY (United States). Inst. for Mining and Minerals Research
Biological treatment of concentrated hazardous, toxic, andradionuclide mixed wastes without dilution
Approximately 10 percent of all radioactive wastes produced in the U. S. are mixed with hazardous or toxic chemicals and therefore can not be placed in secure land disposal facilities. Mixed wastes containing hazardous organic chemicals are often incinerated, but volatile radioactive elements are released directly into the biosphere. Some mixed wastes do not currently have any identified disposal option and are stored locally awaiting new developments. Biological treatment has been proposed as a potentially safer alternative to incineration for the treatment of hazardous organic mixed wastes, since biological treatment would not release volatile radioisotopes and the residual low-level radioactive waste would no longer be restricted from land disposal. Prior studies have shown that toxicity associated with acetonitrile is a significant limiting factor for the application of biotreatment to mixed wastes and excessive dilution was required to avoid inhibition of biological treatment. In this study, we demonstrate that a novel reactor configuration, where the concentrated toxic waste is drip-fed into a complete-mix bioreactor containing a pre-concentrated active microbial population, can be used to treat a surrogate acetonitrile mixed waste stream without excessive dilution. Using a drip-feed bioreactor, we were able to treat a 90,000 mg/L acetonitrile solution to less than 0.1 mg/L final concentration using a dilution factor of only 3.4. It was determined that the acetonitrile degradation reaction was inhibited at a pH above 7.2 and that the reactor could be modeled using conventional kinetic and mass balance approaches. Using a drip-feed reactor configuration addresses a major limiting factor (toxic inhibition) for the biological treatment of toxic, hazardous, or radioactive mixed wastes and suggests that drip-feed bioreactors could be used to treat other concentrated toxic waste streams, such as chemical warfare materiel.
Stringfellow, William T.; Komada, Tatsuyuki; Chang, Li-Yang
CRITICAL STUDIES OF DILUTE CARBIDE FAST REACTOR CORE. ZPR-III Assembly 34
Critical studies were made with a simulated, large, dilute power reactor having uranium carbide as fuel. The uranium in the core was 30.7% enriched, and the atomic ratio of uranium to carbon was 0.946. The critical mass was 503.01 kg U/sup 235/ and the critical volume 574.47 liters. Central reactivity coefficients, effective fission crosssection ratios, heterogeneity effects, reactivity worth of distributed materials, foil irradiations, and the average prompt neutron lifetime were measured. Multigroup calculations using the Yiftah, Okrent, and Moldauer crosssection set overestimated k for the critical configuration by 4.7%. (auth)
Hubert, R.J.; Long, J.K.; McVean, R.L.; Gasidlo, J.M.
Melt-Dilute Form of AI-Based Spent Nuclear Fuel Disposal Criticality Summary Report
Criticality analysis of the proposed melt-dilute (MD) form of aluminum-based spent nuclear fuel (SNF), under geologic repository conditions, was performed [1] following the methodology documented in the Disposal Criticality Analysis Methodology Topical Report [2]. This methodology evaluates the potential for nuclear criticality for a waste form in a waste package. Criticality calculations show that even with waste package failure, followed by degradation of material within the waste package and potential loss of neutron absorber materials, sub-critical conditions can be readily demonstrated for the MD form of aluminum-based SNF.
D. Vinson; A. Serika
Interaction of manganese(II) with the surface of calcite in dilute solutions and seawater
The interaction of Mn/sup 2 +/ with the surface of calcite in aqueous solutions is complex. In dilute solutions the Mn/sup 2 +/ is rapidly adsorbed, MnCO/sub 3/ nucleates on the calcite surface and then grows by a first order reaction with respect to the initial Mn/sup 2 +/ concentration. At higher ionic strengths, in NaCl solutions, the rate of these processes is slower, but the same general pattern persists. In solutions containing Mg/sup 2 +/, at the concentration of seawater and in seawater, the nucleation phase of the uptake process does not appear to occur. The long term uptake rate of Mn/sup 2 +/ on the surface of calcite in seawater is first order with respect to the disolved Mn/sup 2 +/ concentration. The rate constant is over 3 orders of magnitude smaller than that found in dilute Mg/sup 2 +/-free solutions. A probable explanation for the slower growith rate in seawater is that MnCO/sub 3/ is not nucleated on the calcite surface due to the presence of high Mg/sup 2 +/ concentrations. These, through site competition, prevent enough Mn/sup 2 +/ from being adsorbed to reach a critical concentration for MnCO/sub 3/ nucleation. This behavior is similar to that found for orthophosphate with calcite surfaces in dilute solutions and seawater. Measurements of the solubility of rhodochrosite in seawater gave results from an undersaturation approach to equilibrium in excellent agreement with those found in previous studies in dilute solutions. When equilibrium was approached from supersaturation, approximately 50 times more calcium was precipitated than Mn/sup 2 +/. The measured solubility was over twice that determined from undersaturation. It is possible that a Mn-calcite containing 25 to 30 mole percent MnCO/sub 3/ formed on the rhodochrosite from the supersaturated solutions. Consequently, it is doubtful that rhodochrosite controls the concentration of Mn/sup 2 +/ in calcium carbonate rich marine environments.
Franklin, M. L.; Morse, J. W.
Potential for Waste Stratification from Back-Dilution in Tank 241-SY-101
Since late 1997, the floating crust layer in Hanford Tank 241-SY-101 (SY-101) has grown about two meters by gas accumulation. To reverse crust growth and reduce its retained gas volume, the waste in SY-101 will be diluted by transferring at least 300,000 gal of waste out of the tank and replacing it with water. In the fall of 1999, approximately 100,000 gal of this waste will be transferred into Tank SY-102; within a few days of that initial transfer, approximately 100,000 gal of water will be added to SY-101. This initial back-dilution is being planned to ensure that the base of the floating crust layer will be lifted away from the mixer pump inlet with minimal effect on the crust itself. The concern is that the added water will pool under the crust, so the resulting fluid mixture will be too light to lift the crust away from the mixer pump and dissolution at the crust base could cause unwanted gas release. To ensure sufficient mixing to prevent such stratification, water will be added near the tank bottom either through an existing sparge ring on the base of the mixer pump or through the dilution line at the inlet of the transfer pump. A number of simulations using the TEMPEST code showed that the mixing of the water and waste by this method is rapid, and the water does not pool under the crust. Although a density gradient is present, its magnitude is small compared with the difference between the slurry and water density. The result is essentially the same whether water is introduced at the base of the mixer pump or at the transfer pump. There is little effect of water flowrate up to the 500 gpm studied. In all cases, the minimum density remained above that required to float the crust and well above the density of saturated liquid. This indicates that the base of the crust will rise during back-dilution and there will be little or no dissolution of the crust base because the water will be close to saturation from the dissolution of solids in the mixed slurry.
Antoniak, Z.I.; Meyer, P.A.
Time-dependent gas phase kinetics in a hydrogen diluted silane plasma
The gas phase kinetics in a high-pressure hydrogen diluted silane plasma has been studied at time scales of 10{sup -2}-6x10{sup 2} s. The time-resolved gas phase composition shows the following kinetics at different time scales: silane decomposition and polysilane generation in < or approx. 2x10{sup -1} s, nanoparticle formation and plasma density reduction in 10{sup -1}-10{sup 0} s, polysilane accumulation in 10{sup 0}-10{sup 2} s, and silane depletion and electrode heating in > or approx. 10{sup 1} s. Disilane radicals are implied to be the dominant film precursors in addition to silyl radicals.
Nunomura, S.; Kondo, M. [Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Yoshida, I. [Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Advanced Photovoltaics Development Center, Advanced Energy Research Center, Sanyo Electric Co., Ltd., 108 Ohmori, Anpachi-cho, Anpachi-gun, Gifu 503-0195 (Japan)
Design of a scanning gate microscope in a cryogen-free dilution refrigerator
We report on our design of a scanning gate microscope housed in a cryogen-free dilution refrigerator with a base temperature of 15 mK. The recent increase in efficiency of pulse tube cryocoolers has made cryogen-free systems popular in recent years. However, this new style of cryostat presents challenges for performing scanning probe measurements, mainly as a result of the vibrations introduced by the cryocooler. We demonstrate scanning with root-mean-square vibrations of 0.8 nm at 3 K and 2.1 nm at 15 mK in a 1 kHz bandwidth with our design.
Pelliccione, Matthew; Bartel, John; Keller, Andrew; Goldhaber-Gordon, David
Mapping out the structural changes of natural and pretreated plant cell wall surfaces by atomic force microscopy single molecular recognition imaging
and fractionation of corn stover by ammonia recyclethe enzymic hydrolysis of corn stover. Biomass Bioenergyafter steam pretreatment of corn stover with or without the
Zhang, Mengmeng; Chen, Guojun; Kumar, Rajeev; Xu, Bingqian
Supplementation with xylanase and beta-xylosidase to reduce xylo-oligomer and xylan inhibition of enzymatic hydrolysis of cellulose and pretreated corn stover
pretreatment technologies to corn stover. Bioresourcerelationship to features of corn stover solids produced byexplosion treatment of corn stover. Appl Biochem Biotech
Qing, Qing; Wyman, Charles E
Anaerobic fermentation of rice straw and chicken manure to carboxylic acids
In this work, 80% lime-treated rice straw and 20% lime-treated chicken manure were used as substrates in rotary fermentors. Countercurrent fermentation was performed at various volatile solid loading rates (VSLR) and liquid residence times (LRT). The highest acid productivity of 1.69 g/(L�?·d) was at a total acid concentration of 32.4 g/L. The highest conversion and yield were 0.692 g VS digested/g VS fed and 0.29 g total acids/g VS fed, respectively. The continuum particle distribution model (CPDM) was used to predict product concentrations at various VSLR and LRT. CPDM predicted the experimental total acid concentration and conversion at an average error of 6.41% and 6.55%, respectively. A fixed-bed fermentation system was designed to perform pretreatment and fermentation in the same unit. High product concentrations (~48 g/L) as well as high conversions (0.741 g VS digested/g VS fed, F4, Train B) were obtained from the same fermentor. CPDM was extended to predict product concentrations in the fixed-bed fermentation system. The model gave a good estimate of the product concentrations and retention time. After biomass fermentation, the residue can be combusted to generate heat. For pretreatment purposes, the use of ash can replace lime. A study was performed using ash as a potential pretreatment agent. Ash from raw poplar wood was effective in pretreating poplar wood; however, ash from bagasse fermentation residues was not useful in pretreating bagasse. Previous modeling studies indicate that a conversion of 95% could be achieved with bagasse using countercurrent fermentation. Because lignin constitutes 13% of the dry weight of bagasse, this means lignin would have to be digested to obtain a conversion of 95%. Experiments on the fermentation of enzymatically liberated lignin from both poplar wood and bagasse do not show that solubilized lignin was fermented to organic acids by using a mixed culture of marine microorganisms. Two buffer systems (ammonium bicarbonate and calcium carbonate) were used to compare product concentrations of carboxylic acid fermentations using office paper and chicken manure. It has been demonstrated that the total product concentration using ammonium bicarbonate is almost double the product concentration using calcium carbonate.
Agbogbo, Frank Kwesi
Anaerobic digestion of organic fraction of municipal solid waste combining two pretreatment modalities, high temperature microwave and hydrogen peroxide
Highlights: Black-Right-Pointing-Pointer Microwave and H{sub 2}O{sub 2} pretreatment were studied to enhance anaerobic digestion of organic waste. Black-Right-Pointing-Pointer The whole waste pretreated at 115 Degree-Sign C or 145 Degree-Sign C had the highest biogas production. Black-Right-Pointing-Pointer Biogas production of the whole waste decreased at 175 Degree-Sign C due to formation of refractory compounds. Black-Right-Pointing-Pointer Pretreatment to 145 Degree-Sign C and 175 Degree-Sign C were the best when considering only the free liquid fraction. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} pretreatment had a lag phase and the biogas production was not higher than MW pretreated samples. - Abstract: In order to enhance anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW), pretreatment combining two modalities, microwave (MW) heating in presence or absence of hydrogen peroxide (H{sub 2}O{sub 2}) were investigated. The main pretreatment variables affecting the characteristics of the OFMSW were temperature (T) via MW irradiation and supplemental water additions of 20% and 30% (SWA20 and SW30). Subsequently, the focus of this study was to evaluate mesophilic batch AD performance in terms of biogas production, as well as changes in the characteristics of the OFMSW post digestion. A high MW induced temperature range (115-175 Degree-Sign C) was applied, using sealed vessels and a bench scale MW unit equipped with temperature and pressure controls. Biochemical methane potential (BMP) tests were conducted on the whole OFMSW as well as the liquid fractions. The whole OFMSW pretreated at 115 Degree-Sign C and 145 Degree-Sign C showed 4-7% improvement in biogas production over untreated OFMSW (control). When pretreated at 175 Degree-Sign C, biogas production decreased due to formation of refractory compounds, inhibiting the digestion. For the liquid fraction of OFMSW, the effect of pretreatment on the cumulative biogas production (CBP) was more pronounced for SWA20 at 145 Degree-Sign C, with a 26% increase in biogas production after 8 days of digestion, compared to the control. When considering the increased substrate availability in the liquid fraction after MW pretreatment, a 78% improvement in biogas production vs. the control was achieved. Combining MW and H{sub 2}O{sub 2} modalities did not have a positive impact on OFMSW stabilization and enhanced biogas production. In general, all samples pretreated with H{sub 2}O{sub 2} displayed a long lag phase and the CBP was usually lower than MW irradiated only samples. First order rate constant was calculated.
Shahriari, Haleh, E-mail: firstname.lastname@example.com [Department of Civil Engineering, University of Ottawa, 161 Louis Pasteur St., P.O. Box 450, Stn. A, Ottawa, ON, K1N 6N5 (Canada); Warith, Mostafa [Department of Civil Engineering, University of Ottawa, 161 Louis Pasteur St., P.O. Box 450, Stn. A, Ottawa, ON, K1N 6N5 (Canada); Hamoda, Mohamed [Department of Environmental Technology and Management, Kuwait University, P.O. Box 5969, Safat 13060 (Kuwait); Kennedy, Kevin J. [Department of Civil Engineering, University of Ottawa, 161 Louis Pasteur St., P.O. Box 450, Stn. A, Ottawa, ON, K1N 6N5 (Canada)
L�vy Fluctuations and Tracer Diffusion in Dilute Suspensions of Algae and Bacteria
Swimming microorganisms rely on effective mixing strategies to achieve efficient nutrient influx. Recent experiments, probing the mixing capability of unicellular biflagellates, revealed that passive tracer particles exhibit anomalous non-Gaussian diffusion when immersed in a dilute suspension of self-motile Chlamydomonas reinhardtii algae. Qualitatively, this observation can be explained by the fact that the algae induce a fluid flow that may occasionally accelerate the colloidal tracers to relatively large velocities. A satisfactory quantitative theory of enhanced mixing in dilute active suspensions, however, is lacking at present. In particular, it is unclear how non-Gaussian signatures in the tracers' position distribution are linked to the self-propulsion mechanism of a microorganism. Here, we develop a systematic theoretical description of anomalous tracer diffusion in active suspensions, based on a simplified tracer-swimmer interaction model that captures the typical distance scaling of a microswimmer's flow field. We show that the experimentally observed non-Gaussian tails are generic and arise due to a combination of truncated L\\'evy statistics for the velocity field and algebraically decaying time correlations in the fluid. Our analytical considerations are illustrated through extensive simulations, implemented on graphics processing units to achieve the large sample sizes required for analyzing the tails of the tracer distributions.
Irwin M. Zaid; J�rn Dunkel; Julia M. Yeomans
Effects of Coaxial Air on Nitrogen-Diluted Hydrogen Jet Diffusion Flame Length and NOx Emission
Turbulent nitrogen-diluted hydrogen jet diffusion flames with high velocity coaxial air flows are investigated for their NOx emission levels. This study is motivated by the DOE turbine program�s goal of achieving 2 ppm dry low NOx from turbine combustors running on nitrogen-diluted high-hydrogen fuels. In this study, effects of coaxial air velocity and momentum are varied while maintaining low overall equivalence ratios to eliminate the effects of recirculation of combustion products on flame lengths, flame temperatures, and resulting NOx emission levels. The nature of flame length and NOx emission scaling relationships are found to vary, depending on whether the combined fuel and coaxial air jet is fuel-rich or fuel-lean. In the absence of differential diffusion effects, flame lengths agree well with predicted trends, and NOx emissions levels are shown to decrease with increasing coaxial air velocity, as expected. Normalizing the NOx emission index with a flame residence time reveals some interesting trends, and indicates that a global flame strain based on the difference between the fuel and coaxial air velocities, as is traditionally used, is not a viable parameter for scaling the normalized NOx emissions of coaxial air jet diffusion flames.
Weiland, N.T.; Chen, R.-H.; Strakey, P.A.
Investigation of CTBT OSI Radionuclide Techniques at the DILUTED WATERS Nuclear Test Site
Under the Comprehensive Nuclear-Test-Ban Treaty (CTBT), a verification regime that includes the ability to conduct an On-Site Inspection (OSI) will be established. The Treaty allows for an OSI to include many techniques, including the radionuclide techniques of gamma radiation surveying and spectrometry and environmental sampling and analysis. Such radioactivity detection techniques can provide the �smoking gun� evidence that a nuclear test has occurred through the detection and quantification of indicative recent fission products. An OSI faces restrictions in time and manpower, as dictated by the Treaty; not to mention possible logistics difficulties due to the location and climate of the suspected explosion site. It is thus necessary to have a good understanding of the possible source term an OSI will encounter and the proper techniques that will be necessary for an effective OSI regime. One of the challenges during an OSI is to locate radioactive debris that has escaped an underground nuclear explosion (UNE) and settled on the surface near and downwind of ground zero. To support the understanding and selection of sampling and survey techniques for use in an OSI, we are currently designing an experiment, the Particulate Release Experiment (PRex), to simulate a small-scale vent from an underground nuclear explosion. PRex will occur at the Nevada National Security Site (NNSS). The project is conducted under the National Center for Nuclear Security (NCNS) funded by the National Nuclear Security Agency (NNSA). Prior to the release experiment, scheduled for Spring of 2013, the project scheduled a number of activities at the NNSS to prepare for the release experiment as well as to utilize the nuclear testing past of the NNSS for the development of OSI techniques for CTBT. One such activity�the focus of this report�was a survey and sampling campaign at the site of an old UNE that vented: DILUTED WATERS. Activities at DILUTED WATERS included vehicle-based survey, in situ measurements with high-purity germanium (HPGe) and hand-held LaBr3 systems, soil sampling with a variety of tools, and laboratory gamma spectrometric analysis of those samples. A further benefit of the measurement campaign was to gain familiarity with the many logistical aspects of performing radiological field work at NNSS ahead of the PRex. Many practical lessons concerning the proper methodologies and logistics of using the surveying and sampling equipment were noted. These Lessons Learned are compiled together in Appendix A. The vehicle-based survey was successful in that it found a previously unknown hotspot (determined to be 232Th) while it demonstrated that a better method for keeping a serpentine track without staking was needed. Some of the soil sampling equipment was found to be impractical for the application, though core sampling would not be the correct way to take soil samples for a fresh vent deposit (as opposed to an old site like DILUTED WATERS). Due to the site�s age, 137Cs was the only fission radioisotope identified, though others were searched for. While not enough samples were taken and analyzed to definitively link the 137Cs to DILUTED WATERS as opposed to other NNSS activities, results were consistent with the historical DILUTED WATERS plume. MDAs were compared for soil sampling and in situ measurements.
Baciak, James E.; Milbrath, Brian D.; Detwiler, Rebecca S.; Kirkham, Randy R.; Keillor, Martin E.; Lepel, Elwood A.; Seifert, Allen; Emer, Dudley; Floyd, Michael
Silicon-Germanium Films Deposited by Low Frequency PE CVD: Effect of H2 and Ar Dilution
We have studied structure and electrical properties of Si{sub 1-Y}Ge{sub Y}:H films deposited by low frequency PE CVD over the entire composition range from Y=0 to Y=1. The deposition rate of the films and their structural and electrical properties were measured for various ratios of the germane/silane feed gases and with and without dilution by Ar and by H{sub 2}. Structure and composition was studied by Auger electron spectroscopy (AES), secondary ion mass spectroscopy (SIMS) and Fourier transform infrared (FTIR) spectroscopy. Surface morphology was characterized by atomic force microscopy (AFM). We found: (1) The deposition rate increased with Y maximizing at Y=1 without dilution. (2) The relative rate of Ge and Si incorporation is affected by dilution. (3) Hydrogen preferentially bonds to silicon. (4) Hydrogen content decreases for increasing Y. In addition, optical measurements showed that as Y goes for 0 to 1, the Fermi level moves from mid gap to the conduction band edge, i.e. the films become more n-type. No correlation was found between the pre-exponential and the activation energy of conductivity. The behavior of the conductivity {gamma}-factor suggests a local minimum in the density of states at E {approx} 0.33 eV for the films grown with or without H-dilution and E {approx} 0.25 eV for the films with Ar dilution.
Kosarev, A; Torres, A; Hernandez, Y; Ambrosio, R; Zuniga, C; Felter, T E; Asomoza, R R; Kudriavtsev, Y; Silva-Gonzalez, R; Gomez-Barojas, E; Ilinski, A; Abramov, A S
Buoyancy and Dissolution of the Floating Crust Layer in Tank 241-SY-101 During Transfer and Back-Dilution
To remediate gas retention in the floating crust layer and the potential for buoyant displacement gas releases from below the crust, waste will be transferred out of Hanford Tank 241-SY-101 (SY-101) in the fall of 1999 and back-diluted with water in several steps of about 100,000 gallons each. To evaluate the effects of back-dilution on the crust a static buoyancy model is derived that predicts crust and liquid surface elevations as a function of mixing efficiency and volume of water added during transfer and back-dilution. Experimental results are presented that demonstrate the basic physics involved and verify the operation of the models. A dissolution model is also developed to evaluate the effects of dissolution of solids on crust flotation. The model includes dissolution of solids suspended in the slurry as well as in the crust layers. The inventory and location of insoluble solids after dissolution of the soluble fraction are also tracked. The buoyancy model is applied to predict the crust behavior for the first back-dilution step in SY-101. Specific concerns addressed include conditions that could cause the crust to sink and back-dilution requirements that keep the base of the crust well above the mixer pump inlet.
CW Stewart; JH Sukamto; JM Cuta; SD Rassat
Cellulose solventbased biomass pretreatment breaks highly ordered hydrogen bonds in cellulose fibers of switchgrass
Solvent-Based Solvent-Based Biomass Pretreatment Breaks Highly Ordered Hydrogen Bonds in Cellulose Fibers of Switchgrass Noppadon Sathitsuksanoh, 1,2 Zhiguang Zhu, 1 Sungsool Wi, 3 Y.-H. Percival Zhang 1,2,4 1 Biological Systems Engineering Department, Virginia Polytechnic Institute and State University (Virginia Tech), 210-A Seitz Hall, Blacksburg, Virginia 24061; telephone: 540-231-7414, fax: 540-231-3199; e-mail: email@example.com 2 Institute for Critical Technology and Applied Science (ICTAS), Virginia Polytechnic Institute and State University, Blacksburg, Virginia 3 Chemistry Department, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 4 DOE BioEnergy Science Center (BESC), Oak Ridge, Tennessee Received 25 June 2010; revision received 23 August 2010; accepted 4 October 2010 Published online 21 October 2010 in Wiley Online Library (wileyonlinelibrary.com).
The Zymomonas mobilis regulator hfq contributes to tolerance against multiple lignocellulosic pretreatment inhibitors
Yang et al. BMC Microbiology 2010, 10:135 Yang et al. BMC Microbiology 2010, 10:135 http://www.biomedcentral.com/1471-2180/10/135 Open Access R E S E A R C H A R T I C L E BioMed Central © 2010 Yang et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Research article The Zymomonas mobilis regulator hfq contributes to tolerance against multiple lignocellulosic pretreatment inhibitors Shihui Yang 1,2 , Dale A Pelletier 1 , Tse-Yuan S Lu 1 and Steven D Brown* 1,2 Abstract Background: Zymomonas mobilis produces near theoretical yields of ethanol and recombinant strains are candidate
The Role of Pretreatment FDG-PET in Nasopharyngeal Carcinoma Treated With Intensity-Modulated Radiotherapy
Purpose: Pretreatment with 2- [{sup 18}F] fluorodeoxyglucose positron emission tomography ({sup 18}F-FDG-PET) was evaluated as a predictor of local failure-free survival (LFFS), disease-free survival (DFS), and overall survival (OS) in patients with nonkeratinizing nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT) alone or concurrently with chemotherapy (CCRT). Patients and Methods: Seventy-five M0 NPC patients who received FDG-PET before treatment were analyzed. The primary tumor FDG uptake was measured as the maximum standardized uptake value (SUVmax). The LFFS, DFS, and OS were calculated by the Kaplan-Meier method, and the differences were evaluated on log-rank test. The prognostic significance was assessed by univariate and multivariate analyses. Results: Eighteen patients received IMRT alone and 57 received CCRT. The mean SUVmax was significantly higher in 12 patients with locoregional or distant failure than in those without failure (p 5) indicates poor outcome in patients with NPC.
Liu, Wen-Shan [School of Medicine, Chung Shan Medical University and Department of Radiation Oncology, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Wu, Ming-Fang [School of Medicine, Chung Shan Medical University and Division of Medical Oncology, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Tseng, Hsien-Chun [School of Medicine, Chung Shan Medical University and Department of Radiation Oncology, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Liu, Jung-Tung [School of Medicine, Chung Shan Medical University and Department of Surgery, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Weng, Jui-Hung [Department of Nuclear Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Li, Yueh-Chun [School of Medicine, Chung Shan Medical University and Department of Radiation Oncology, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Lee, Jong-Kang, E-mail: email@example.com [School of Medicine, Chung Shan Medical University and Department of Nuclear Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan (China)
Preliminary design requirements document (DRD) for Project W-236B, ``Initial Pretreatment Module``
The scope of this Design Requirements Document (DRD) is to identify and define the functions, with associated requirements, which must be performed to separate Hanford Site tank waste supernatants into low-level and high-level fractions. This documents sets forth function requirements, performance requirements, and design constraints necessary to begin conceptual design for the Initial Pretreatment Module (IPM). System and physical interfaces between the IPM project and the Tank Waste Remediation System (TWRS) are identified. The constraints, performance requirements, and transfer of information and data across a technical interface will be documented in an Interface Control Document. Supplemental DRDs will be prepared to provide more detailed requirements specific to systems described in the DRD.
Swanson, L.M.
A method is described for separating lignin from liquid solutions resulting from the pretreatment of lignocellulosic materials such as switchgrass with ammonium hydroxide. The method involves a sequence of steps including acidification, evaporation, and precipitation or centrifugation that are performed under defined conditions, and results in a relatively pure, solid lignin product. The method is tested on ammonium hydroxide solutions containing lignin extracted from switchgrass. Experimental results show that the method is capable of recovering between 66-95% of dissolved lignin as a precipitated solid. Cost estimates of pilot-scale and industrial-scale expressions of the process indicate that breakeven lignin prices of $2.36/kg and $0.78/kg, respectively, may be obtainable with this recovery method.
Sherman, S.; Gorensek, M.; Milliken, C.
Evaluation of solid-based separation materials for the pretreatment of radioactive wastes
Separation science will play an important role in pretreating nuclear wastes stored at various US Department of Energy Sites. The application of separation processes offers potential economic and environmental benefits with regards to remediating these sites. For example, at the Hanford Site, the sizeable volume of radioactive wastes stored in underground tanks could be partitioned into a small volume of high-level waste (HLW) and a relatively large volume of low-level waste (LLW). After waste separation, only the smaller volume of HLW would require costly vitrification and geologic disposal. Furthermore, the quality of the remaining LLW form (e.g., grout) would be improved due to the lower inventory of radionuclides present in the LLW stream. This report investigates extraction chromatography as a possible separation process for Hanford wastes.
Lumetta, G.J.; Wagner, M.J.; Wester, D.W.; Morrey, J.R.
Impact of Mixed Feedstocks and Feedstock Densification on Ionic Liquid Pretreatment Efficiency
Background: Lignocellulosic biorefineries must be able to efficiently process the regional feedstocks that are available at cost-competitive prices year round. These feedstocks typically have low energy densities and vary significantly in composition. One potential solution to these issues is blending and/or densifying the feedstocks in order to create a uniform feedstock. Results/discussion: We have mixed four feedstocks - switchgrass, lodgepole pine, corn stover, and eucalyptus - in flour and pellet form and processed them using the ionic liquid 1-ethyl-3-methylimidazolium acetate. Sugar yields from both the mixed flour and pelletized feedstocks reach 90% within 24 hours of saccharification. Conclusions: Mixed feedstocks, in either flour or pellet form, are efficiently processed using this pretreatment process, and demonstrate that this approach has significant potential.
Jian Shi; Vicki S. Thompson; Neal A. Yancey; Vitalie Stavila; Blake A. Simmons; Seema Singh
Candidate processes for diluting the {sup 235}U isotope in weapons-capable highly enriched uranium
The United States Department of Energy (DOE) is evaluating options for rendering its surplus inventories of highly enriched uranium (HEU) incapable of being used to produce nuclear weapons. Weapons-capable HEU was earlier produced by enriching uranium in the fissile {sup 235}U isotope from its natural occurring 0.71 percent isotopic concentration to at least 20 percent isotopic concentration. Now, by diluting its concentration of the fissile {sup 235}U isotope in a uranium blending process, the weapons capability of HEU can be eliminated in a manner that is reversible only through isotope enrichment, and therefore, highly resistant to proliferation. To the extent that can be economically and technically justified, the down-blended uranium product will be made suitable for use as commercial reactor fuel. Such down-blended uranium product can also be disposed of as waste if chemical or isotopic impurities preclude its use as reactor fuel.
Snider, J.D.
Room-temperature diluted magnetic semiconductors p-(Ga,Ni)N
High concentration (5 at. %) Ni was incorporated into a chemical vapor deposition-grown GaN film by using a thin protecting Ni layer on top of the GaN film during ion implantation. After etching off the protecting layer, subsequent annealing up to 800 deg. C under flowing N{sub 2} resulted in a p-type GaN with apparent ferromagnetic behavior up to {approx}320 K. In addition, the ferromagnetic behavior became more manifest with increasing annealing temperature that increases hole concentration. No presence of any other second phases nor clusters in the Ni-implanted region was identifiable, at least to the 0.2 nm point-to-point resolution of high resolution transmission electron microscopy. This novel indirect implantation process that being easy to implement appears promising for attaining room-temperature diluted magnetic semiconductors which are applicable to magnetotransport, magneto-optical and spintronics devices, among others.
Huang, R.-T.; Hsu, C.-F.; Kai, J.-J.; Chen, F.-R.; Chin, T.-S. [Department of Engineering and System Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 300, Taiwan (China)
Can conduction induce convection? The non-linear saturation of buoyancy instabilities in dilute plasmas
We study the effects of anisotropic thermal conduction on low-collisionality, astrophysical plasmas using two and three-dimensional magnetohydrodynamic simulations. For weak magnetic fields, dilute plasmas are buoyantly unstable for either sign of the temperature gradient: the heat-flux-driven buoyancy instability (HBI) operates when the temperature increases with radius while the magnetothermal instability (MTI) operates in the opposite limit. In contrast to previous results, we show that, in the presence of a sustained temperature gradient, the MTI drives strong turbulence and operates as an efficient magnetic dynamo (akin to standard, adiabatic convection). Together, the turbulent and magnetic energies contribute up to ~10% of the pressure support in the plasma. In addition, the MTI drives a large convective heat flux, ~1.5% of rho c_s^3. These findings are robust even in the presence of an external source of strong turbulence. Our results on the nonlinear saturation of the HBI are consistent with previous...
McCourt, Michael; Sharma, Prateek; Quataert, Eliot
The Lyapunov spectrum of the many-dimensional dilute random Lorentz gas
For a better understanding of the chaotic behavior of systems of many moving particles it is useful to look at other systems with many degrees of freedom. An interesting example is the high-dimensional Lorentz gas, which, just like a system of moving hard spheres, may be interpreted as a dynamical system consisting of a point particle in a high-dimensional phase space, moving among fixed scatterers. In this paper, we calculate the full spectrum of Lyapunov exponents for the dilute random Lorentz gas in an arbitrary number of dimensions. We find that the spectrum becomes flatter with increasing dimensionality. Furthermore, for fixed collision frequency the separation between the largest Lyapunov exponent and the second largest one increases logarithmically with dimensionality, whereas the separations between Lyapunov exponents of given indices not involving the largest one, go to fixed limits.
Astrid S. de Wijn; Henk van Beijeren
Universal phase structure of dilute Bose gases with Rashba spin-orbit coupling
A Bose gas subject to a light-induced Rashba spin-orbit coupling possesses a dispersion minimum on a circle in momentum space; we show that kinematic constraints due to this dispersion cause interactions to renormalize to universal, angle-dependent values that govern the phase structure in the dilute-gas limit. We find that, regardless of microscopic interactions, (a) the ground state involves condensation at two opposite momenta and is, in finite systems, a fragmented condensate and and (b) there is a nonzero-temperature instability toward the condensation of pairs of bosons. We discuss how our results can be reconciled with the qualitatively different mean-field phase diagram, which is appropriate for dense gases.
Gopalakrishnan, Sarang [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States); Lamacraft, Austen [Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States); Department of Physics, University of Virginia, Charlottesville, Virginia 22904 (United States); Goldbart, Paul M. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)
Dilute Group III-V nitride intermediate band solar cells with contact blocking layers
An intermediate band solar cell (IBSC) is provided including a p-n junction based on dilute III-V nitride materials and a pair of contact blocking layers positioned on opposite surfaces of the p-n junction for electrically isolating the intermediate band of the p-n junction by blocking the charge transport in the intermediate band without affecting the electron and hole collection efficiency of the p-n junction, thereby increasing open circuit voltage (V.sub.OC) of the IBSC and increasing the photocurrent by utilizing the intermediate band to absorb photons with energy below the band gap of the absorber layers of the IBSC. Hence, the overall power conversion efficiency of a IBSC will be much higher than an conventional single junction solar cell. The p-n junction absorber layers of the IBSC may further have compositionally graded nitrogen concentrations to provide an electric field for more efficient charge collection.
Walukiewicz, Wladyslaw (Kensington, CA); Yu, Kin Man (Lafayette, CA)
A hybrid 2-zone/WAVE engine combustion model for simulating combustion instabilities during dilute operation
Internal combustion engines are operated under conditions of high exhaust gas recirculation (EGR) to reduce NO x emissions and promote enhanced combustion modes such as HCCI. However, high EGR under certain conditions also promotes nonlinear feedback between cycles, leading to the development of combustion instabilities and cyclic variability. We employ a two-zone phenomenological combustion model to simulate the onset of combustion instabilities under highly dilute conditions and to illustrate the impact of these instabilities on emissions and fuel efficiency. The two-zone in-cylinder combustion model is coupled to a WAVE engine-simulation code through a Simulink interface, allowing rapid simulation of several hundred successive engine cycles with many external engine parametric effects included. We demonstrate how this hybrid model can be used to study strategies for adaptive feedback control to reduce cyclic combustion instabilities and, thus, preserve fuel efficiency and reduce emissions.
Edwards, Kevin Dean [ORNL; Wagner, Robert M [ORNL; Chakravarthy, Veerathu K [ORNL; Daw, C Stuart [ORNL; Green Jr, Johney Boyd [ORNL
Proceedings of the OECD/CSNI specialists meeting on boron dilution reactivity transients
The purpose of the meeting was to bring together experts involved in the different activities related to boron dilution transients. The experts came from all involved parties, including research organizations, regulatory authorities, vendors and utilities. Information was openly shared and discussed on the experimental results, plant and systems analysis, numerical analysis of mixing and probability and consequences of these transients. Regulatory background and licensing implications were also included to provide the proper frame work for the technical discussion. Each of these areas corresponded to a separate session. The meeting focused on the thermal-hydraulic aspects because of the current interest in that subject and the significant amount of new technical information being generated.
Effects of oxygen cover gas and NaOH dilution on gas generation in tank 241-SY-101 waste
Laboratory studies are reported of gas generation in heated waste from tank 241-SY-101. The rates of gas generation and the compositions of product gas were measured. Three types of tests are compared. The tests use: undiluted waste, waste diluted by a 54% addition of 2.5 M NaOH, and undiluted waste with a reactive cover gas of 30% Oxygen in He. The gas generation rate is reduced by dilution, increased by higher temperatures (which determines activation energies), and increased by reactions of Oxygen (these primarily produce H{sub 2}). Gases are generated as reduction products oxidation of organic carbon species by nitrite and oxygen.
Person, J.C.
In spring 2011, the Technology Maturation Plan (TMP) for the Supplemental Treatment Project (RPP-PLAN-49827, Rev. 0), Technology Maturation Plan for the Treatment Project (T4S01) was developed. This plan contains all identified actions required to reach technical maturity for a field-deployable waste feed pretreatment system. The supplemental pretreatment system has a filtration and a Cs-removal component. Subsequent to issuance of the TMP, rotary microfiltration (RMF) has been identified as the prime filtration technology for this application. The prime Cs-removal technology is small column ion exchange (ScIX) using spherical resorcinol formaldehyde (sRF) as the exchange resin. During fiscal year 2011 (FY2011) some of the tasks identified in the TMP have been completed. As of September 2011, the conceptual design package has been submitted to DOE as part of the critical decision (CD-1) process. This document describes the remaining tasks identified in the TMP to reach technical maturity and evaluates the validity of the proposed tests to fill the gaps as previously identified in the TMP. The potential vulnerabilities are presented and the completed list of criteria for the DOE guide DOE G 413.3-4 different technology readiness levels are added in an attachment. This evaluation has been conducted from a technology development perspective - all programmatic and manufacturing aspects were excluded from this exercise. Compliance with the DOE G 413.3-4 programmatic and manufacturing requirements will be addressed directly by the Treatment Project during the course of engineering design. The results of this evaluation show that completion of the proposed development tasks in the TMP are sufficient to reach TRL 6 from a technological point of view. The tasks involve actual waste tests using the current baseline configuration (2nd generation disks, 40 psi differential pressure, 30 C feed temperature) and three different simulants - the PEP, an AP-Farm and an S-saltcake. Based on FY2011 dollars used in the TMP, these tests will have ROM costs of $950K and require up to 10 months to complete. Completion of the simulant testing will satisfy the TRL 5 and TRL 6 criteria that are related to system testing with materials that represent the full range of properties in a relevant environment.
Sugarcane juice extraction and preservation, and long-term lime pretreatment of bagasse
New technologies, such as an efficient vapor-compression evaporator, a stationary lime kiln (SLK), and the MixAlco process, compelled us to re-evaluate methods for producing sugar from cane. These technologies allow more water and lime to be used, and they add more value to bagasse. Extracting and preserving the sugars, and lime pretreating the bagasse to enhance biodigestibility, all at the same time in a pile, was demonstrated to be unfeasible; therefore, sugar extraction must occur before lime treating the bagasse. Sugar extraction should occur countercurrently by lixiviation, where liquid moves in stages opposite to the soaked bagasse (megasse), which is conveyed by screw-press conveyors that gently squeeze the fiber in each stage, improving extraction. The performance of a pilot-scale screw-press conveyor was tested for dewatering capabilities and power consumption. The unoptimized equipment decreased megasse moisture from 96 to 89%. Simulation of the process suggested that eight stages are necessary to achieve 98% recovery from typical sugarcane. The cumulative power for the screw-press conveyor system was 17.0�2.1 hp?h/ton dry fiber. Thin raw juice preserved with lime for several months showed no sucrose degradation and no quality deterioration, except for reducing sugar destruction. The lime loading needed for 1-year preservation is 0.20 g Ca(OH)2/g sucrose. Shorter times require less lime. After preservation, the juice was carbonated and filtered, and the resulting sludge pelletized. Due to their high organic content, the pellets were too weak for calcination temperatures used in the SLK. The organics must be decreased prior to pelletization and sodium must be supplemented as a binding agent. Long-term lime pretreatment of bagasse showed two delignification phases: bulk (rapid) and residual (slow). These were modeled by two simultaneous first-order reactions. Treatments with air purging and higher temperatures (50 ? 57oC) delignified more effectively, especially during the residual phase, thus yielding higher cellulase-enzyme digestibilities after 2 ? 8 weeks of treatment. At temperatures > 60oC, pure oxygen purging is preferred. Fresh bagasse was of better quality than old bagasse. Treatment with NaOH yielded a larger bulk delignification phase than Ca(OH)2. Long-term lime pulping of bagasse was unsuitable for copy-quality paper, but it was appropriate for strawboard and other filler applications.
Granda Cotlear, Cesar Benigno
The Melt-Dilute Treatment of Al-Base Highly Enriched DOE Spent Nuclear Fuels: Principles and Practices
The melt-dilute treatment technology program is focused on the development and implementation of a treatment technology for diluting highly enriched (>20 percent 235U) aluminum spent nuclear fuel to low enriched levels (<20 percent 235U) and qualifying the LEU Al-SNF form for geologic repository storage. In order to reduce the enrichment of these assemblies prior to ultimate geologic repository disposal, the melt-dilute technology proposes to melt these SNF assemblies and then dilute with additions of depleted uranium. The benefits accrued from this treatment process include the potential for significant volume reduction, reduced criticality potential, and the potential for enhanced SNF form characteristics. The emphasis within the development program to date has been on determining the process metallurgy and off-gas system design for the treatment of all types of Al SNF (UAlx, Al-U3O8, and Al-U3Si2). In determining the process metallurgy a wide range of alloys, representative of those expected in the Al-SNF form, have been fabricated and their product characteristics, namely microstructure, homogeneity, phase composition, and "ternary" constituent effects have been analyzed. As a result of the presence of species within the melt which will possess significant vapor pressures in the desired operating temperature range an off-gas system is necessary. Of the volitile species the one of greatest concern is 137Cs.
Adams, T.M.
High concentration caustic solutions are known to cause stress corrosion cracking in carbon steel at elevated temperature. This calculation establishes the conditions where heat of dilution will not cause the solution temperature--concentration to exceed the boundary for stress corrosion cracking as established by NACE International.
chemical vapor deposition (PECVD) with a fixed germane to disilane ratio of 0.72 and a wide range], cathode deposition [2], and using disilane- germane mixture without H dilution [3] in PECVD process. A gas mixture of disilane, germane and hydrogen was used with a fixed germane to disilane ratio of 0
Deng, Xunming
272 JOURNAL OF DISPLAY TECHNOLOGY, VOL. 9, NO. 4, APRIL 2013 First-Principle Electronic Properties of Dilute-As
structure, dilute-As GaNAs, First-Principle, lasers, light-emitting diodes. I. INTRODUCTION GROUP III-Nitride compound plays a critical role in the optoelectronic applications such as light-emitting diodes (LEDs for the laser and light emitting diode applications. Due to the technological importance that is potentially
Gilchrist, James F.
NMR and SR study of magnetic dilution in the triangular Heisenberg antiferromagnet This article has been downloaded from IOPscience. Please scroll down to see the full text article.
NMR and SR study of magnetic dilution in the triangular Heisenberg antiferromagnet NaCrO 2 Collections Journals About Contact us My IOPscience #12;NMR and µSR study of magnetic dilution with isotropic interactions [1]. We examine by NMR and µSR the effect of substitution of non magnetic Ga3+ ions
Paris-Sud 11, Université de
Completing Pre-Pilot Tasks To Scale Up Biomass Fractionation Pretreatment Apparatus From Batch To Continuous
PureVision Technology, Inc. (PureVision) was the recipient of a $200,000 Invention and Innovations (I&I) grant from the U. S. Department of Energy (DOE) to complete prepilot tasks in order to scale up its patented biomass fractionation pretreatment apparatus from batch to continuous processing. The initial goal of the I&I program, as detailed in PureVision's original application to the DOE, was to develop the design criteria to build a small continuous biomass fractionation pilot apparatus utilizing a retrofitted extruder with a novel screw configuration to create multiple reaction zones, separated by dynamic plugs within the reaction chamber that support the continuous counter-flow of liquids and solids at elevated temperature and pressure. Although the ultimate results of this 27-month I&I program exceeded the initial expectations, some of the originally planned tasks were not completed due to a modification of direction in the program. PureVision achieved its primary milestone by establishing the design criteria for a continuous process development unit (PDU). In addition, PureVision was able to complete the procurement, assembly, and initiate shake down of the PDU at Western Research Institute (WRI) in Laramie, WY during August 2003 to February 2004. During the month of March 2004, PureVision and WRI performed initial testing of the continuous PDU at WRI.
Dick Wingerson
Field Demonstration of Acetone Pretreatment and Composting of Particulate-TNT-Contaminated Soil
Solid fragments of explosives in soil are common in explosives testing and training areas. In this study we initially sieved the upper 6 in of contaminated soil through a 3-mm mesh, and found 2, 4, 6-trinitrotoluene (TNT) fragments. These contributed to an estimated concentration of 1.7 kg per cubic yard soil, or for 2000 ppm TNT in the soil. Most of the fragments ranged 4 mm to 10 mm diameter in size, but explosives particles weighing up to 56 g (about 4 cm diameter) were frequently observed. An acetone pretreatment/composting system was then demonstrated at field scale. The amount of acetone required for a TNT-dissolving slurry process was controlled by the viscosity of the soil/acetone mix rather than the TNT dissolution rate. The amount needed was estimated at about 55 gallons acetone per cubic yard soil. Smaller, 5- to 10-mm-diameter fragments went into solution in less than 15 min at a mixer speed of 36 rpm, with a minimum of 2 g TNT going into solution per 30 min for the larger chunks. The slurries were than mixed with compost starting materials and composted in a vented 1 yd3 container. After 34 days incubation time TNT was below the site-specific regulatory threshold of 44 ppm. TNT metabolites and acetone were also below their regulatory thresholds established for the site.
Radtke, Corey William; Smith, D.; Owen, S.; Roberto, Francisco Figueroa
Lignocellulose Recalcitrance Screening by Integrated High Throughput Hydrothermal Pretreatment and Enzymatic Saccharification
We report a novel 96-well multiplate reactor system for comparative analysis of lignocellulose recalcitrance via integrated hydrothermal pretreatment and enzymatic saccharification. The system utilizes stackable nickel/gold-plated 96-well aluminum reactor plates, a clamping device fit to a standard Parr reactor, and robotics for efficient liquids and solids handling. A capacity of 20 plates allows up to 1,920 separate hydrothermal reactions per run. Direct and rapid analysis of key end-products, glucose and xylose, is facilitated by the use of glucose oxidase/peroxidase and xylose dehydrogenase-linked assays. To demonstrate efficacy, a set of 755 poplar core samples from the US Department of Energy's BioEnergy Science Center was tested. Total sugar release ranged from 0.17 to 0.64 g/g of biomass and correlated strongly with the ratio of syringyl to guaiacyl lignins in the samples. Variance among sample replicates was sufficiently minimal to permit clear assignment of differences in recalcitrance throughout this large sample set.
Selig, M. J.; Tucker, M. P.; Sykes, R. W.; Reichel, K. L.; Brunecky, R.; Himmel, M. E.; Davis, M. F.; Decker, S. R.
Computer simulation and economic analysis for ammonia fiber explosion (AFEX) pretreatment process
The ammonia fiber explosion (AFFECT) process is a promising new pretreatment for enhancing the reactivity of lignocerulose materials with many advantages over existing processes. The material is soaked in high-pressure liquid ammonia for a few minutes then the pressure is explosively released. A combined chemical (cellulose decrystamution) and physical (increased surface area) effect increases the enzymatic digestibility of lignocelmose. The laboratory phase of AFEX development is nearing completion, and a brief preliminary economic analysis (without detailed sizing) was finished. However, a commercial size plant has not been developed. This study was undertaken in an effort to support and assist AFEX commercialization through process simulation and cost analysis. In this study, a steady state computer simulation package was developed for the AFEX process. Corn fiber was used as the representative biomass treated by AFEX. Different ammonia loadings, water loadings, temperatures and pressures were used as operational parameters. Mass balances and energy balances are the major determinants of the equipments selected and sized. 'nermodynamic models or kinetic models are also included. A preliminary cost estimate includes total purchased-equipment cost using the equipment cost ratio method. The process computer simulation model was programmed in FORTRAN. FORTRAN subroutine libraries from IMSL (International Mathematical and Statistics Library), Inc. were used as needed. To increase the portability of the program, the programming was done on an EBM compatible PC.
Wang, Lin
Detecting Cellulase Penetration Into Corn Stover Cell Walls by Immuno-Electron Microscopy
In general, pretreatments are designed to enhance the accessibility of cellulose to enzymes, allowing for more efficient conversion. In this study, we have detected the penetration of major cellulases present in a commercial enzyme preparation (Spezyme CP) into corn stem cell walls following mild-, moderate- and high-severity dilute sulfuric acid pretreatments. The Trichoderma reesei enzymes, Cel7A (CBH I) and Cel7B (EG I), as well as the cell wall matrix components xylan and lignin were visualized within digested corn stover cell walls by immuno transmission electron microscopy (TEM) using enzyme- and polymer-specific antibodies. Low severity dilute-acid pretreatment (20 min at 100 C) enabled <1% of the thickness of secondary cell walls to be penetrated by enzyme, moderate severity pretreatment at (20 min at 120 C) allowed the enzymes to penetrate {approx}20% of the cell wall, and the high severity (20 min pretreatment at 150 C) allowed 100% penetration of even the thickest cell walls. These data allow direct visualization of the dramatic effect dilute-acid pretreatment has on altering the condensed ultrastructure of biomass cell walls. Loosening of plant cell wall structure due to pretreatment and the subsequently improved access by cellulases has been hypothesized by the biomass conversion community for over two decades, and for the first time, this study provides direct visual evidence to verify this hypothesis. Further, the high-resolution enzyme penetration studies presented here provide insight into the mechanisms of cell wall deconstruction by cellulolytic enzymes.
Donohoe, B. S.; Selig, M. J.; Viamajala, S.; Vinzant, T. B.; Adney, W. S.; Himmel, M. E.
Determination of porosity of lignocellulosic biomass before and after pretreatment by using Simonsâ stain and NMR techniques
porosity porosity of lignocellulosic biomass before and after pretreatment by using Simons' stain and NMR techniques Xianzhi Meng a , Marcus Foston a,1 , Johannes Leisen b , Jaclyn DeMartini c , Charles E. Wyman c , Arthur J. Ragauskas a,⇑ a BioEnergy Science Center, School of Chemistry and Biochemistry, Institute of Paper Science and Technology, Georgia Institute of Technology, 500 10th Street, Atlanta, GA 30332, USA b School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA c Department of Chemical & Environmental Engineering, Center for Environmental Research and Technology, University of California, Riverside, BioEnergy Science Center, Riverside, CA 92507, USA h i g h l i g h t s Cellulose accessibility was tested by Simons' stain and multiple NMR techniques. Pretreatment increases the pore size and overall surface area of the
Laboratory Report on Performance Evaluation of Key Constituents during Pre-Treatment of High Level Waste Direct Feed
The analytical capabilities of the 222-S Laboratory are tested against the requirements for an optional start up scenario of the Waste Treatment and Immobilization Plant on the Hanford Site. In this case, washed and in-tank leached sludge would be sent directly to the High Level Melter, bypassing Pretreatment. The sludge samples would need to be analyzed for certain key constituents in terms identifying melter-related issues and adjustment needs. The analyses on original tank waste as well as on washed and leached material were performed using five sludge samples from tanks 241-AY-102, 241-AZ-102, 241-AN-106, 241-AW-105, and 241-SY-102. Additionally, solid phase characterization was applied to determine the changes in mineralogy throughout the pre-treatment steps.
Huber, Heinz J.
Oxidation pretreatment to reduce corrosion of 20%Cr-25%Ni-Nb stainless steel. II. Surface morphology and oxide characterization
Improved corrosion behavior of 20%Cr-25%Ni-Nb steel resulting from a low pressure oxidation pretreatment in CO/sub 2/ has been related to changes in elemental composition and distribution in the oxide scale. Auger electron spectroscopy, secondary ion mass spectroscopy, electron microprobe, and X-ray diffraction techniques have been used to investigate the properties of the oxide scale formed on both untreated and pretreated specimens when oxidized at 823 K and 923 K in a CO/sub 2/-1%CO atmosphere. A sputter ion plating technique has been used to separate the oxide from the metal and the incorporation of chromium and silicon at the metal-oxide interface has been investigated at grain centers and grain boundaries by depth profiling. The improvement in oxide adhesion and oxidation rates, using data from Parts I and II of this study, is assessed in terms of oxide formation by solid-state displacement reactions.
Tempest, P.A.; Wild, R.K.
Acrylic Acid from 3-Hydroxypropionic Acid - Energy Innovation ...
Technology Marketing Summary. 3-hydroxypropionic acid is readily converted to acrylic acid by conversion to the acid salt followed by treatment with a solid oxide ...
Conversion of legacy radioactive high-level waste at the Savannah River Site into a stable glass waste form involves a chemical pretreatment process to prepare the waste for vitrification. Waste slurry is treated with nitric and formic acids to achieve certain goals. The total quantity of acid added to a batch of waste slurry is constrained by the catalytic activity of trace noble metal fission products in the waste that can convert formic acid into hydrogen gas at many hundreds of times the radiolytic hydrogen generation rate. A large block of experimental process simulations were performed to characterize the chemical reactions that consume acid prior to hydrogen generation. The analysis led to a new equation for predicting the quantity of acid required to process a given volume of waste slurry.
Koopman, D.; Pickenheim, B.; Lambert, D.; Newell, J.; Stone, M.
Benchmark calculations for the diluted highly enriched uranium (HEU) and aluminum experiment
The HEU-Al experiment was performed using the Planet universal critical assembly at Los Alamos Critical Experiment Facility (LACEF) in Los Alamos National Laboratory. This experiment consisted of placing HEU foils interspersed with aluminum plates in a column stack. These uranium foils were moderated and reflected by polyethylene square plates. This experiment was performed to measure the prompt neutron decay constants in uranium systems diluted by matrix materials. This experimental set-up yielded a Al/235U ratio of 60:1.1 The experimental keff was 1.001 and the modeled MCNP keff was 1.0016{+-}0.0004. This report summarizes the benchmark calculations performed to validate the experiment. The experimental arrangement is depicted in Figure 1. As Figure 1 illustrates the stack is divided into two parts. The bottom half of the stack rest on an aluminum support plate which is 1 inch thick. The top half of the experiment rest on 0.75 inch thick polyethylene plate. Criticality is achieved by decreasing the gap between the top and bottom portions of the stack. To disassemble the configuration the bottom stack is dropped to its initial position. There are no other control or safety rods inside the assembly.
Loaiza, D. J. (David J.); Sanchez, R. G. (Rene G.)
HB-Line Dissolver Dilution Flows and Dissolution Capability with Dissolver Charge Chute Cover Off
A flow test was performed in Scrap Recovery of HB-Line to document the flow available for hydrogen dilution in the dissolvers when the charge chute covers are removed. Air flow through the dissolver charge chutes, with the covers off, was measured. A conservative estimate of experimental uncertainty was subtracted from the results. After subtraction, the test showed that there is 20 cubic feet per minute (cfm) air flow through the dissolvers during dissolution with a glovebox exhaust fan operating, even with the scrubber not operating. This test also showed there is 6.6 cfm air flow through the dissolvers, after subtraction of experimental uncertainty if the scrubber and the glovebox exhaust fans are not operating. Three H-Canyon exhaust fans provide sufficient motive force to give this 6.6 cfm flow. Material charged to the dissolver will be limited to chemical hydrogen generation rates that will be greater than or equal to 25 percent of the Lower Flammability Limit (LFL) during normal operations. The H-Canyon fans will maintain hydrogen below LFL if electrical power is lost. No modifications are needed in HB-Line Scrap Recovery to ensure hydrogen is maintained less that LFL if the scrubber and glovebox exhaust fans are not operating.
Hallman, D.F.
Carriers-mediated ferromagnetic enhancement in Al-doped ZnMnO dilute magnetic semiconductors
Nano-crystalline Zn{sub 0.95-x}Mn{sub 0.05}Al{sub x}O (x = 0, 0.05, 0.10) dilute magnetic semiconductors (DMS) were synthesized by sol-gel derived auto-combustion. X-ray diffraction (XRD) analysis shows that the samples have pure wurtzite structure typical of ZnO without the formation of secondary phases or impurity. Crystallite sizes were approximated by Scherrer formula while surface morphology and grain sizes were measured by field emission scanning electron microscopy. Incorporation of Mn and Al into the ZnO structure was confirmed by energy-dispersive X-ray analysis. Temperature dependent electrical resistivity measurements showed a decreasing trend with the doping of Al in ZnMnO, which is attributable to the enhancement of free carriers. Vibrating sample magnetometer studies confirmed the presence of ferromagnetic behavior at room temperature. The results indicate that Al doping results in significant variation in the concentration of free carriers and correspondingly the carrier-mediated magnetization and room temperature ferromagnetic behavior, showing promise for practical applications. We attribute the enhanced saturation magnetization and electrical conductivity to the exchange interaction mediated by free electrons.
Saleem, Murtaza [Centre of Excellence in Solid State Physics, University of the Punjab, Lahore-54590 (Pakistan); Siddiqi, Saadat A. [Centre of Excellence in Solid State Physics, University of the Punjab, Lahore-54590 (Pakistan); Interdisciplinary Research Centre in Biomedical Materials (IRCBM), COMSATS Institute of Information Technology, Defence Road, Off Raiwind Road, Lahore (Pakistan); Atiq, Shahid, E-mail: firstname.lastname@example.com [Centre of Excellence in Solid State Physics, University of the Punjab, Lahore-54590 (Pakistan); Anwar, M. Sabieh; Hussain, Irshad [School of Science and Engineering (SSE), Lahore University of Management Sciences (LUMS), Opposite Sector U, D.H.A. Lahore Cantt-54792 (Pakistan); Alam, Shahzad [Pakistan Council for Scientific and Industrial Research (PCSIR) Laboratories Complex, Lahore (Pakistan)
Laser Doppler Anemometry Measurements of Dilute Pneumatic Transport in a Vertical Lifter
Vertical pneumatic transport in a lab-scale vertical lifter has been studied using Laser Doppler Anemometry (LDA). The experimental system consists of a lower fluidized silo, an upper receiving tank and a connecting vertical transport pipe made of clear glass. The experimental study has been performed in order to get detailed information of the complex gas-particle flow behavior in a dilute vertical conveying system. Axial and tangential particle velocities, as well as root mean square velocities are measured simultanously for different flow conditions. The particulate material transported is Zirconium Oxide (ZrO2) solids. Measurements is obtained using transport air flow rate of 24, 36, 48 and 60 m3/h. The air is feeded into the tranport air through a nozzle. The length this nozzle is sticking into the transport pipe is varied in order to study the nozzle position influence on the flow behavior. The receiving tank is equipped with weighing cells, so that solids mass fluxes also can be measured for different flow conditions.
Telemark Technological R; D Centre (tel-tek; Vidar Mathiesen; Vidar Mathiesen; Tron Solberg; Tron Solberg
A method is given for the production of improved yields of trifluoroacetic acid. The compound is prepared by oxidizing m-aminobenzotrifluoride with an alkali metal or alkaline earth metal permanganate at a temperature in the range of 80 deg C to 100 deg C while dissolved ln a mixture of water with glacial acetic acid and/or trifluoroacetic acid. Preferably a mixture of water and trifluoroacetic acid ls used as the solvent.
Dehydration of acetic acid-water mixtures with near critical and supercritical fluid solvents
Equilibrium tie lines and phase densities are presented for acetic acid-water mixtures with near critical propane at 361K and 52 bar. Experimental measurements were obtained with a static technique; the equilibrium phases were directly sampled with high-pressure liquid sample injection valves at the temperature and pressure of interest. The data obtained in this work indicate that near critical propane can be used to facilitate the production of glacial acetic acid from dilute acetic acid-water solutions. Both these experimental data and the authors earlier results for acetic acid-water mixtures with supercritical carbon dioxide have been used to test an equation of state which has recently been developed by Grenzheuser and Gmehling for systems which contain associating fluids. Results indicate that the equation's pure component parameters need to be refitted to represent the critical region more accurately.
McCully, M.A.; Mullins, J.C.; Thies, M.C.; Hartley, I.J.
Pretreatment Predictors of Adverse Radiation Effects After Radiosurgery for Arteriovenous Malformation
Purpose: To identify vascular and dosimetric predictors of symptomatic T2 signal change and adverse radiation effects after radiosurgery for arteriovenous malformation, in order to define and validate preexisting risk models. Methods and Materials: A total of 125 patients with arteriovenous malformations (AVM) were treated at our institution between 2005 and 2009. Eighty-five patients have at least 12 months of clinical and radiological follow-up. Any new-onset headaches, new or worsening seizures, or neurological deficit were considered adverse events. Follow-up magnetic resonance images were assessed for new onset T2 signal change and the volume calculated. Pretreatment characteristics and dosimetric variables were analyzed to identify predictors of adverse radiation effects. Results: There were 19 children and 66 adults in the study cohort, with a mean age of 34 (range 6-74). Twenty-three (27%) patients suffered adverse radiation effects (ARE), 9 patients with permanent neurological deficit (10.6%). Of these, 5 developed fixed visual field deficits. Target volume and 12 Gy volume were the most significant predictors of adverse radiation effects on univariate analysis (p < 0.001). Location and cortical eloquence were not significantly associated with the development of adverse events (p = 0.12). No additional vascular parameters were identified as predictive of ARE. There was a significant target volume threshold of 4 cm{sup 3}, above which the rate of ARE increased dramatically. Multivariate analysis target volume and the absence of prior hemorrhage are the only significant predictors of ARE. The volume of T2 signal change correlates to ARE, but only target volume is predictive of a higher volume of T2 signal change. Conclusions: Target volume and the absence of prior hemorrhage is the most accurate predictor of adverse radiation effects and complications after radiosurgery for AVMs. A high percentage of permanent visual field defects in this series suggest the optic radiation is a critical radiosensitive structure.
Hayhurst, Caroline; Monsalves, Eric [Gamma Knife Unit, Division of Neurosurgery, University Health Network, Toronto (Canada); Prooijen, Monique van [Physics Department, Princess Margaret Hospital, Toronto (Canada); Cusimano, Michael [Division of Neurosurgery, St Michael's Hospital, Toronto (Canada); Tsao, May [Radiation Oncology Program, Sunnybrook Hospital, University of Toronto (Canada); Menard, Cynthia [Radiation Oncology Program, Princess Margaret Hospital, University of Toronto (Canada); Kulkarni, Abhaya V. [Division of Neurosurgery, Hospital for Sick Children, University of Toronto (Canada); Schwartz, Michael [Division of Neurosurgery, Sunnybrook Hospital, University of Toronto (Canada); Zadeh, Gelareh, E-mail: firstname.lastname@example.com [Gamma Knife Unit, Division of Neurosurgery, University Health Network, Toronto (Canada)
Reducing volatilization of heavy metals in phosphate-pretreated municipal solid waste incineration fly ash by forming pyromorphite-like minerals
This research investigated the feasibility of reducing volatilization of heavy metals (lead, zinc and cadmium) in municipal solid waste incineration (MSWI) fly ash by forming pyromorphite-like minerals via phosphate pre-treatment. To evaluate the evaporation characteristics of three heavy metals from phosphate-pretreated MSWI fly ash, volatilization tests have been performed by means of a dedicated apparatus in the 100-1000 deg. C range. The toxicity characteristic leaching procedure (TCLP) test and BCR sequential extraction procedure were applied to assess phosphate stabilization process. The results showed that the volatilization behavior in phosphate-pretreated MSWI fly ash could be reduced effectively. Pyromorphite-like minerals formed in phosphate-pretreated MSWI fly ash were mainly responsible for the volatilization reduction of heavy metals in MSWI fly ash at higher temperature, due to their chemical fixation and thermal stabilization for heavy metals. The stabilization effects were encouraging for the potential reuse of MSWI fly ash.
Sun Ying; Zheng Jianchang [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Zou Luquan [Shanghai Center of Solid Waste Disposal, Shanghai (China); Liu Qiang; Zhu Ping [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Qian Guangren, E-mail: firstname.lastname@example.com [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China)
Nucleic acid detection compositions
The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.
Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann (Madison, WI); Dahlberg, James L. (Madison, WI)
Experimental and Numerical Investigation of Boron Dilution Transients in Pressurized Water Reactors
Within the pressurized water reactor (PWR) safety analyses, attention has increasingly focused in recent years on boron dilution events that could potentially lead to reactivity transients. Mixing of the low-boron water with the ambient coolant of higher boron content provides an important mitigation mechanism before the low-boron water enters the core.Experimental support is needed to validate the computational tools to be applied to analyze the mixing of the low-boron water. Experiments were performed in the three test facilities - the Upper Plenum Test Facility (UPTF), the Primaerkreislauf (PKL), and the Rossendorf coolant mixing model (ROCOM) - in Germany.The relevant PKL and UPTF tests were focused on small-break loss-of-coolant accident (SBLOCA) scenarios with reflux-condenser mode and restart of natural circulation. The two test facilities represent a typical western-type PWR and are/were operated by Siemens/KWU now Framatome ANP in Germany. While the restart of natural circulation was investigated in the PKL system test facility (volume 1:145, height 1:1), the UPTF experiments dealt with the mixing of water flows with different boron concentration in the cold legs, reactor pressure vessel (RPV) downcomer, and the lower plenum (all these components were full-scale models).The results from the PKL test facility demonstrate that in case of a postulated SBLOCA with reflux condensation phase, natural circulation does not start up simultaneously in all loops. This means that slugs of condensate, which might have accumulated in the pump seal during reflux-condenser mode of operation, would reach the RPV at different points in time. The UPTF tests showed an almost ideal mixing of water flows with different boron concentration in the RPV downcomer.The ROCOM test facility has been built in a linear scale of 1:5 for the investigation of coolant mixing phenomena in a wide range of flow conditions in the RPV of the German KONVOI-type PWR. The test results presented are focused on the mixing of a slug of deborated water during the startup of the first reactor coolant pump. Based on experimentally determined pulse responses, a semianalytical model for the description of coolant mixing inside the KONVOI RPV has been developed. Calculations for a presumed boron dilution event during the startup of the first reactor coolant pump have been carried out by means of the semianalytical model and independently by means of the computational fluid dynamics code CFX-4. The semianalytical model is able to describe the time dependent behavior of the deboration front at each fuel element position in a good agreement with the experiment. All main mixing effects, observed in the experiment, are also reproduced by the CFX calculation.
Hertlein, Roland J. [Framatome ANP GmbH (France); Umminger, Klaus [Framatome ANP GmbH (France); Kliem, Soeren [Forschungszentrum Rossendorf e.V. (Germany); Prasser, Horst-Michael [Forschungszentrum Rossendorf e.V. (Germany); Hoehne, Thomas [Forschungszentrum Rossendorf e.V. (Germany); Weiss, Frank-Peter [Forschungszentrum Rossendorf e.V. (Germany)
DOE has initiated numerous activities to focus on identifying material management strategies to disposition various excess fissile materials. In particular the INEEL has stored 1,700 Kg of offspec HEU at INTEC in CPP-651 vault facility. Currently, the proposed strategies for dispositioning are (a) aqueous dissolution and down blending to LEU via facilities at SRS followed by shipment of the liquid LEU to NFS for fabrication into LWR fuel for the TVA reactors and (b) dilution of the HEU to 0.9% for discard as a waste stream that would no longer have a criticality or proliferation risk without being processed through some type of enrichment system. Dispositioning this inventory as a waste stream via aqueous processing at SRS has been determined to be too costly. Thus, dry blending is the only proposed disposal process for the uranium oxide materials in the CPP-651 vault. Isotopic dilution of HEU to typically less than 20% by dry blending is the key to solving the dispositioning issue (i.e., proliferation) posed by HEU stored at INEEL. RM-2 mill is a technology developed and successfully tested for producing ultra-fine particles by dry grinding. Grinding action in RM-2 mill produces a two million-fold increase in the number of particles being blended in a centrifugal field. In a previous study, the concept of achieving complete and adequate blending and mixing (i.e., no methods were identified to easily separate and concentrate one titanium compound from the other) in remarkably short processing times was successfully tested with surrogate materials (titanium dioxide and titanium mono-oxide) with different particle sizes, hardness and densities. In the current project, the RM-2 milling technology was thoroughly tested with mixtures of natural uranium oxide (NU) and depleted uranium oxide (DU) stock to prove its performance. The effects of mill operating and design variables on the blending of NU/DU oxides were evaluated. First, NU and DU both made of the same oxide, UO{sub 3}, was used in the testing. Next, NU made up of UO{sub 3} and DU made up of UO{sub 2} was used in the test work. In every test, the blend achieved was characterized by spatial sampling of the ground product and analyzing for {sup 235}U concentration. The test work proved that these uranium oxide materials can be blended successfully. The spatial concentration was found to be uniform. Next, sintered thorium oxide pellets were used as surrogate for light water breeder reactor pellets (LWBR). To simulate LWBR pellet dispositioning, the thorium oxide pellets were first ground to a powder form and then the powder was blended with NU. In these tests also the concentration of {sup 235}U and {sup 232}Th in blended products fell within established limits proving the success of RM-2 milling technology. RM-2 milling technology is applicable to any dry radioactive waste, especially brittle solids that can be ground up and mixed with the non-radioactive stock.
Raj K. Rajamani; Sanjeeva Latchireddi; Vikas Devrani; Harappan Sethi; Roger Henry; Nate Chipman
Process for the preparation of lactic acid and glyceric acid
Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.
Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI
On April 21, 2009, the Energy Facilities Contractors Group (EFCOG) Waste Management Working Group (WMWG) provided a recommendation to the Department of Energy's Environmental Management program (DOE-EM) concerning supplemental guidance on blending methodologies to use to classify waste forms to determine if the waste form meets the definition of Transuranic (TRU) Waste or can be classified as Low-Level Waste (LLW). The guidance provides specific examples and methods to allow DOE and its Contractors to properly classify waste forms while reducing the generation of TRU wastes. TRU wastes are much more expensive to characterize at the generator's facilities, ship, and then dispose at the Waste Isolation Pilot Plant (WIPP) than Low-Level Radioactive Waste's disposal. Also the reduction of handling and packaging of LLW is inherently less hazardous to the nuclear workforce. Therefore, it is important to perform the characterization properly, but in a manner that minimizes the generation of TRU wastes if at all possible. In fact, the generation of additional volumes of radioactive wastes under the ARRA programs, this recommendation should improve the cost effective implementation of DOE requirements while properly protecting human health and the environment. This paper will describe how the message of appropriate, less expensive, less hazardous blending of radioactive waste is the 'right' thing to do in many cases, but can be confused with inappropriate 'dilution' that is frowned upon by regulators and stakeholders in the public. A proposal will be made in this paper on how to communicate this very complex and confusing technical issue to regulatory bodies and interested stakeholders to gain understanding and approval of the concept. The results of application of the proposed communication method and attempt to change the regulatory requirements in this area will be discussed including efforts by DOE and the NRC on this very complex subject.
Goldston, W.
Structural Characterization
Characterization Characterization and Comparison of Switchgrass Ball-milled Lignin Before and After Dilute Acid Pretreatment Reichel Samuel & Yunqiao Pu & Babu Raman & Arthur J. Ragauskas Received: 25 April 2009 / Accepted: 10 August 2009 # Humana Press 2009 Abstract To reduce the recalcitrance and enhance enzymatic activity, dilute H 2 SO 4 pretreatment was carried out on Alamo switchgrass (Panicum virgatum). Ball-milled lignin was isolated from switchgrass before and after pretreatment. Its structure was characterized by 13 C, HSQC, and 31 P NMR spectroscopy. It was confirmed that ball-milled switchgrass lignin is of HGS type with a considerable amount of p-coumarate and felurate esters of lignin. The major ball-milled lignin interunit was the β-O-4 linkage, and a minor amount of phenylcoumarin, resinol, and spirodienone units were also present. As a result of the acid pretreatment,
Nuclear Isotopic Dilution of Highly-Enriched Uranium-235 and Uranium-233 by Dry Blending via the RM-2 Mill Technology
The United States Department of Energy has initiated numerous activities to identify strategies to disposition various excess fissile materials. Two such materials are the off-specification highly enriched uranium-235 oxide powder and the uranium-233 contained in unirradiated nuclear fuel both currently stored at the Idaho National Engineering and Environmental Laboratory. This report describes the development of a technology that could dilute these materials to levels categorized as low-enriched uranium, or further dilute the materials to a level categorized as waste. This dilution technology opens additional pathways for the disposition of these excess fissile materials as existing processing infrastructure continues to be retired.
N. A. Chipman; R. N. Henry; R. K. Rajamani; S. Latchireddi; V. Devrani; H. Sethi; J. L. Malhotra
Mapping the acid stimulation in the Beowawe geothermal field using surface electrical potentials
A surface electrical potential system was fielded during the chemical stimulation of the Rossi 21-19 well in the Beowawe Geothermal Field. The technique, which measures variations in resistivity resulting from the flow of conductive fluid into the reservoir, was not only shown to be highly sensitive to the chemical treatment, but was also responsive to in situ conductive zones before any acid injection. A review of the experiment and a preliminary interpretation of the data are presented. The data provide convincing evidence that it should be possible to map the treated zone as well as the primary pretreatment in situ conductive zones.
Hart, C.M.; Engi, D.; Morris, H.E.
Mapping the Acid Stimulation in the Beowawe Geothermal Field Using Surface Electrical Potentials
A surface electrical potential system was fielded during the chemical stimulation of the Rossi 21-19 well in the Beowawe Geothermal Field. The technique, which measures variations in resistivity resulting from the flow of conductive fluid into the reservoir, was not only shown to be highly sensitive, not only to the chemical treatment, but also to the in situ conductive zones before any acid injection. A review of the experiment and a preliminary interpretation of the data are presented. The data provide convincing evidence that it should be possible to map the treated zone as well as the primary pretreatment in situ conductive zones.
Hart, Carolyne M.; Engi, Dennis; Morris, Harris E.
Effect of pretreatment and additives on boron release during pyrolysis and gasification of coal
Boron is one of the most toxic and highly volatile elements present in coal. As part of a series of studies carried out on coal cleaning to prevent environmental problems and to promote efficient coal utilization processes, the removal of boron by leaching with water and acetic acid has been investigated. The effects of the addition of ash components, that is, SiO{sub 2}, Al{sub 2}O{sub 3}, and CaO on the control of boron release during pyrolysis and gasification were investigated. Here, 20-70% of boron in coal was removed by leaching the coal with water and acetic acid. Boron leached by water and acetic acid was related to the volatiles released from coal in pyrolysis below 1173 K. The addition of ash components such as SiO{sub 2} and Al{sub 2}O{sub 3} was found to be effective in suppressing the release of boron during pyrolysis at temperatures below and above 1173 K, respectively. The addition of CaO to coal was effective in suppressing the release of boron during gasification at 1173 K. 26 refs., 7 figs., 3 tabs.
Yuuki Mochizuki; Katsuyasu Sugawara; Yukio Enda [Akita University, Akita (Japan). Faculty of Engineering and Resources Science
Attenuation of dilute aromatic hydrocarbon transport by a block copolymer in a compacted vertisol
Municipal solid waste landfills in the United States are built with a composite bottom liner consisting of a flexible membrane liner of high-density polyethylene overlying a compacted soil liner. Hydrocarbons have been shown to pass through the flexible membrane liner by diffusion. Flexible membrane liners often have flaws allowing direct contact between the leachate and the compacted soil liner. The transmission of hydrocarbons to the compacted soil liner presents a threat to groundwater supplies. The study was performed to determine if the modification of a compacted soil liner with a thermoplastic elastomer block copolymer could successfully sequester benzene, toluene, ethylbenzene, and xylenes and meet the United States Environmental Protection Agency's saturated hydraulic conductivity requirement of 1x10?? cm sec?�. Compacted Ships clay modified with 0, 1, 3, 5, and 10% weight of a thermoplastic elastomer block copolymer was tested for saturated hydraulic conductivity using 10.2 cm fixed wall permeameters. The compacted Ships clay met the United States Environmental Protection Agency's mandated saturated hydraulic conductivity of 10?? cm sec?� at polymer contents of 3% (wt) polymer or less. The presence of dissolved aromatic hydrocarbons had no effect on the saturated hydraulic conductivity. The ability of the polymer to attenuate the transport of dilute aromatic hydrocarbons was tested by permeating the compacted soil/polymer treatments with a 0.01N CaSO4 solution contaminated with benzene, toluene, ethylbenzene, and xylenes. Leachate from permeameters packed with soil containing more than 1% (wt) polymer had BTEX concentrations below the drinking water standard for 3 or more pore volumes. The findings of this research were applied to a hypothetical compacted soil liner constructed with Ships clay modified to include 3% (wt) polymer and having a saturated hydraulic conductivity of 4.23 x 10?? cm sec?�. It was assumed that the soil liner was in direct contact with landfill leachate. The hypothetical liner would protect the groundwater from contamination above the maximum contamination limit for drinking water by benzene for 350 years, toluene for 140 years, and ethylbenzene for 260 years.
Akin, James Browning
Formulation, Pretreatment, and Densification Options to Improve Biomass Specifications for Co-Firing High Percentages with Coal
There is a growing interest internationally to use more biomass for power generation, given the potential for significant environmental benefits and long-term fuel sustainability. However, the use of biomass alone for power generation is subject to serious challenges, such as feedstock supply reliability, quality, and stability, as well as comparative cost, except in situations in which biomass is locally sourced. In most countries, only a limited biomass supply infrastructure exists. Alternatively, co-firing biomass alongwith coal offers several advantages; these include reducing challenges related to biomass quality, buffering the system against insufficient feedstock quantity, and mitigating the costs of adapting existing coal power plants to feed biomass exclusively. There are some technical constraints, such as low heating values, low bulk density, and grindability or size-reduction challenges, as well as higher moisture, volatiles, and ash content, which limit the co-firing ratios in direct and indirect co-firing. To achieve successful co-firing of biomass with coal, biomass feedstock specifications must be established to direct pretreatment options in order to modify biomass materials into a format that is more compatible with coal co-firing. The impacts on particle transport systems, flame stability, pollutant formation, and boiler-tube fouling/corrosion must also be minimized by setting feedstock specifications, which may include developing new feedstock composition by formulation or blending. Some of the issues, like feeding, co-milling, and fouling, can be overcome by pretreatment methods including washing/leaching, steam explosion, hydrothermal carbonization, and torrefaction, and densification methods such as pelletizing and briquetting. Integrating formulation, pretreatment, and densification will help to overcome issues related to physical and chemical composition, storage, and logistics to successfully co-fire higher percentages of biomass ( > 40%) with coal.
Jaya Shankar Tumuluru; J Richard Hess; Richard D. Boardman; Shahab Sokhansanj; Christopher T. Wright; Tyler L. Westover
Adsorptive Membranes vs. Resins for Acetic Acid Removal from Biomass Hydrolysates
Acetic acid is a compound commonly found in hemicellulosic hydrolysates. This weak acid strongly influences the bioconversion of sugar containing hydrolysates. Previous investigators have used anion exchange resins for acetic acid removal from different hemicellulosic hydrolysates. In this study, the efficiency of an anion exchange membrane was compared to that of an anion exchange resin, for acetic acid removal from a DI water solution and an acidic hemicellulose hydrolysate pretreated using two different methods. Ion exchange membranes and resins have very different geometries. Here the performance of membranes and resins is compared using two dimensionless parameters, the relative mass throughput and chromatographic bed number. The relative mass throughput arises naturally from the Thomas solution for ion exchange. The results show that the membrane exhibit better performance in terms of capacity, and loss of the desired sugars. In addition acetic acid may be eluted at a higher concentration from the membrane thus leading to the possibility of recovery and re-use of the acetic acid.
Han, B.; Carvalho, W.; Canilha, L.; da Silva, S. S.; e Silva, J. B. A.; McMillan, J. D.; Wickramasinghe, S. R.
Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction. Technical progress report, August 1992--July 1992
Low-temperature catalytic pretreatment is a promising approach to the development of an improved liquefaction process- This work is a fundamental study on effects of pretreatments on coal structure and reactivity in liquefaction. The main objectives of this project are to study the coal structural changes induced by low-temperature catalytic and thermal pretreatments by using spectroscopic techniques; and to clarify the pretreatment-induced changes in reactivity or convertibility of coals in the subsequent liquefaction. This report describes the recent progress of our work. Substantial progress has been made in the spectroscopic characterization of structure and pretreatment-liquefaction reactions of a Montana subbituminous Coal (DECS-9), and thermochemical analysis of three mw and reacted bituminous coals. Temperature programmed liquefaction has been performed on three low-rank coals both in the presence and absence of dispersed molybdenum sulfide catalyst. We also performed a detailed study of the effects of mild thermal pretreatment -- drying in air and in vacuum -- on thermal and catalytic liquefaction of a Wyodak subbituminous coal. Important information on structure and structure transformation during thermal pretreatment and liquefaction reactions of low-rank coals has been derived by applying solid-state CPMAS {sup 13}C NMR and flash pyrolysis-GC-MS (Py-GC-MS) for characterization of the macromolecular network of a Montana subbituminous coal and its residues from temperature-programmed and nonprogrammed liquefaction (TPL and N-PL) at final temperatures ranging from 300 to 425{degree}C in H-donor and non-donor solvents. The results revealed that this coal contains significant quantities of oxygen-bearing structures, corresponding to about 18 O-bound C per 100 C atoms and one O-bound C per every 5 to 6 aromatic C.
Controlling acid rain
High concentrations of sulfuric and nitric acid in raTn fn the northeastern USA are caused by the large scale combustion of fossil fuels within this region. Average precipitation acidity is pH 4.2, but spatial and temporal ...
Fay, James A.
Lignocellulosic Biomass to Ethanol Process Design and Economics Utilizing Co-Current Dilute Acid Prehydrolysis and Enzymatic Hydrolysis Current and Futuristic Scenarios
The National Renewable Energy Laboratory (NREL) has undertaken a complete review and update of the process design and economic model for the biomass-to-ethanol enzymatic based process. The process design includes the core technologies being researched by the U.S. Department of Energy (DOE): prehydrolysis, simultaneous saccharification and co-fermentation, and cellulase enzyme production. In addition, all ancillary areasfeed handling, product recovery and purification, wastewater treatment lignin burner and boiler-turbogenerator, and utilitiesare included. NREL engaged Delta-T Corporation to assist in the process design evaluation, equipment costing, and overall plant integration. The process design and costing for the lignin burner and boiler turbogenerator has been reviewed by Reaction Engineering Inc. and the wastewater treatment by Merrick Company. An overview of both reviews is included here. The purpose of this update was to ensure that the process design and equipment costs were reasonable and consistent with good engineering practice for plants of this type using available technical data. This work has resulted in an economic model that can be used to predict the cost of producing ethanol from cellulosic biomass using this technology if a plant were to be built in the next few years. The model was also extended using technology improvements that are expected to be developed based on the current DOE research plan. Future process designs and cost estimates are given for the years 2005, 2010, and 2015.
Galvez, A.; Ibsen, K.; Majdeski, H.; Ruth, M.; Sheehan, J.; Wooley, R.
The National Renewable Energy Laboratory (NREL) has undertaken a complete review and update of the process design and economic model for the biomass-to-ethanol enzymatic based process. The process design includes the core technologies being researched by the U.S. Department of Energy (DOE): prehydrolysis, simultaneous saccharification and co-fermentation, and cellulase enzyme production. In addition, all ancillary areas--feed handling, product recovery and purification, wastewater treatment lignin burner and boiler--turbogenerator, and utilities--are included. NREL engaged Delta-T Corporation to assist in the process design evaluation, equipment costing, and overall plant integration. The process design and costing for the lignin burner and boiler turbogenerator has been reviewed by Reaction Engineering Inc. and the wastewater treatment by Merrick and Company. An overview of both reviews is included here. The purpose of this update was to ensure that the process design and equipment costs were reasonable and consistent with good engineering practice for plants of this type using available technical data. This work has resulted in an economic model that can be used to predict the cost of producing ethanol from cellulosic biomass using this technology if a plant were to be built in the next few years. The model was also extended using technology improvements that are expected to be developed based on the current DOE research plan. Future process designs and cost estimates are given for the years 2005, 2010, and 2015.
Wooley, R.; Ruth, M.; Sheehan, J.; Ibsen, K.; Majdeski, H.; Galvez, A.
Commercial Alloys for Sulfuric Acid Vaporization in Thermochemical Hydrogen Cycles
Most thermochemical cycles being considered for producing hydrogen include a processing stream in which dilute sulfuric acid is concentrated, vaporized and then decomposed over a catalyst. The sulfuric acid vaporizer is exposed to highly aggressive conditions. Liquid sulfuric acid will be present at a concentration of >96 wt% (>90 mol %) H2SO4 and temperatures exceeding 400oC [Brown, et. al, 2003]. The system will also be pressurized, 0.7-3.5 MPa, to keep the sulfuric acid in the liquid state at this temperature and acid concentration. These conditions far exceed those found in the commercial sulfuric acid generation, regeneration and handling industries. Exotic materials, e.g. ceramics, precious metals, clad materials, etc., have been proposed for this application [Wong, et. al., 2005]. However, development time, costs, reliability, safety concerns and/or certification issues plague such solutions and should be considered as relatively long-term, optimum solutions. A more cost-effective (and relatively near-term) solution would be to use commercially-available metallic alloys to demonstrate the cycle and study process variables. However, the corrosion behavior of commercial alloys in sulfuric acid is rarely characterized above the natural boiling point of concentrated sulfuric acid (~250oC at 1 atm). Therefore a screening study was undertaken to evaluate the suitability of various commercial alloys for concentration and vaporization of high-temperature sulfuric acid. Initially alloys were subjected to static corrosion tests in concentrated sulfuric acid (~95-97% H2SO4) at temperatures and exposure times up to 200oC and 480 hours, respectively. Alloys with a corrosion rate of less than 5 mm/year were then subjected to static corrosion tests at a pressure of 1.4 MPa and temperatures up to 375oC. Exposure times were shorter due to safety concerns and ranged from as short as 5 hours up to 144 hours. The materials evaluated included nickel-, iron- and cobalt-based commercial alloys. The corrosion rates in these tests are reported and how they may or may not relate to the corrosion behavior in an operating thermochemical cycle is discussed.
Thomas M. Lillo; Karen M. Delezene-Briggs
An Assessment of Ore Waste and Dilution Resulting From Buffer/Choke Blasting in Surface Gold Mines
A discrete element computer program named DMC{underscore}BLAST (Distinct Motion Code) has been under development since 1987 for modeling rock blasting (Preece {ampersand} Taylor, 1989). This program employs explicit time integration and uses spherical or cylindrical elements that are represented as circles in two dimensions (2-D). DMC{underscore}BLAST calculations compare favorably with data from actual bench blasts (Preece et al, 1993). Buffer Choke blasting is commonly used in surface gold mines to break the rock and dilate it sufficiently for ease of digging, with the assumption of insignificant horizontal movement. The blast designs usually call for relatively shallow holes benches ({lt} 11 m) with small blastholes (approx. 165 mm), small burdens and spacings ({lt}5 m), often with 50% or more of the hole stemmed. Control of blast-induced horizontal movement is desired because the ore is assayed in place from the blasthole drill cuttings and digging polygons of ore and waste are laid out before the blast. Horizontal movement at the ore waste boundary can result in dilution of the ore or loss of ore with the waste. The discrete element computer program DMC{underscore}BLAST has been employed to study spatial variation of horizontal rock motion during buffer choke blasting. Patterns of rock motion can be recognized from the discrete element simulations that would be difficult or impossible to recognize in the field (Preece, Tidman and Chung, 1997). Techniques have been developed to calculate ore waste and dilution from the horizontal movement predicted by DMC{underscore}BLAST. Four DMC{underscore}BLAST simulations of buffer blasting have been performed. The blasts are identical except that the burden and spacing are systematically varied which also changes the powder factor. Predictions of ore waste or dilution are made for each burden in the blast, assuming no horizontal movement, to illustrate the spatial variation observed.
Preece, D.S. [Sandia National Labs., Albuquerque, NM (United States); Chung, S.H.; Tidman, J.P. [ICI Explosives (Canada)
The Stability of Dilute Plasmas with Thermal and Composition Gradients. I. The Slow Conduction Limit: Overstable Gravity Modes
We analyze the stability of a dilute plasma with thermal and composition gradients in the limit where conduction is slow compared to the dynamical timescale. We find necessary and sufficient conditions for stability when the background magnetic field is either parallel or perpendicular to the thermal and composition gradients that are parallel to the gravitational field. We provide approximate solutions for all the relevant modes involved, which are driven by gravity, conduction, and diffusion. We discuss the astrophysical implications of our findings for a representative galaxy cluster where helium has sedimented.
Pessah, Martin E
Volatile fatty acid fermentation of lime-treated bagasse by rumen microorganisms
This thesis describes the design and operation of a batch, anaerobic, in vitro fermentation of sugarcane bagasse by a mixed culture of ruminal microflora. The bagasse was supplemented with a small amount of alfalfa (0.16 g alfalfa/g bagasse) to provide necessary nutrients. The volatile fatty acid (VFA) product concentrations, yields and proportions of each acid for six different bagasse concentrations (10, 20, 35, 50, 75, and 100 g/L) are reported. Bagasse was treated with calcium hydroxide to increase the digestibility of the cell wall carbohydrates. The treatment conditions were: Ca(OH)2 loading = 10 g/100 g dry bagasse, water loading = 8.5 g/g dry bagasse, temperature 100'C, and treatment time = 1 hour. Compared to untreated bagasse, the lime-treated bagasse gave higher total VFA concentrations, faster rates of acidogenesis, and more stable molar proportions of individual VFA'S. The highest total VFA concentration obtained from lime-treated bagasse was 690 mM (45 g/L). By applying the lime pretreatment, the total VFA concentrations increased over 80% for a 10 g dry bagasse/L loading fermentation (from 4.5g VFA/L to 8.5 g VFAAL) With lime pretreatment, approximately 71 to 96% of the final total VFA yields were accomplished within the initial three days of fermentation, whereas only 52 to 67% were achieved without pretreatment during the same time period. At all solid loadings, the VFA molar compositions resulting from lime-treated bagasse were quite constant: acetate, 64-70%; propionate, 21-28%; butyrate, 6.5-7.6%; and other acids were about 1% each. In this thesis, we examined the effect of higher substrate concentration up to 100 g dry bagasse/L. For untreated bagasse, the VFA yields were fairly constant regardless of substrate concentration (ca. 0.37 g VFA/g dry substrate). However, for lime-treated bagasse, the total VFA yields decreased as the substrate concentrations increased. The best total VFA yield obtained from 10 g/L lime-treated bagasse was 0.63 g VFA/g dry raw substrate (or 0.82 g VFA/g dry ash-free substrate or 0.94 g VFA/g dry ash-free, lignin- free substrate). This is greater than yields previously reported in the literature using lignocellulosic substrates, and hence demonstrates the superiority of this very effective lime pretreatment.
Lee, Chang-Ming
The analysis of species behavior involving dilute fluid environments has been crucial for the advance of modern solvation thermodynamics through molecular-based formalisms to guide the development of macroscopic regression tools in the description of fluid behavior and correlation of experimental data (Chialvo 2013). Dilute fluid environments involving geologic formations are of great theoretical and practical relevance regardless of the thermodynamic state conditions. The most challenging systems are those involving highly compressible and reactive confined environments, i.e., where small perturbations of pressure and/or temperature can trigger considerable density changes. This in turn can alter significantly the species solvation, their preferential solvation, and consequently, their reactivity with one another and with the surrounding mineral surfaces whose outcome is the modification of the substrate porosity and permeability, and ultimately, the integrity of the mineral substrates. Considering that changes in porosity and permeability resulting from dissolution and precipitation phenomena in confined environments are at the core of the aqueous CO2-mineral interactions, and that caprock integrity (e.g., sealing capacity) depends on these key parameters, it is imperative to gain fundamental understanding of the mineral-fluid interfacial phenomena and fluid-fluid equilibria under mineral confinement at subsurface conditions. In order to undertand the potential effects of acid gases as contaminants of supercritical CO2 streams, in the next section we will discuss the thermodynamic behavior of CO2 fluid systems by addressing two crucial issues in the context of carbon capture, utilization and sequestration (CCUS) technologies: (i) Why should we consider (acid gas) CO2 impurities? and (ii) Why are CO2 fluid - mineral interactions of paramount relevance?
Chialvo, Ariel A [ORNL] [ORNL; Vlcek, Lukas [ORNL] [ORNL; Cole, David [Ohio State University] [Ohio State University
Synthesis of acid addition salt of delta-aminolevulinic acid ...
A process of preparing an acid addition salt of delta-aminolevulinc acid comprising: a) dissolving a lower alkyl 5-bromolevulinate and hexamethylenetetramine in a ...
Recovery of Phosphoric Acid in Waste Acid Mixtures Discharged ...
Aug 1, 2003 ... In order to separate impurity acids from the phosphoric acid, trioctyl phosphate ( TOP) is used as an extractant. TOP can extract acetic and nitric�...
Pretreatment Engineering Platform (PEP) Integrated Test B Run Report--Caustic and Oxidative Leaching in UFP-VSL-T02A
Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed and operated as part of a plan to respond to issue M12, �Undemonstrated Leaching Processes� of the External Flowsheet Review Team (EFRT) issue response plan.( ) The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing.
Geeting, John GH; Bredt, Ofelia P.; Burns, Carolyn A.; Golovich, Elizabeth C.; Guzman-Leong, Consuelo E.; Josephson, Gary B.; Kurath, Dean E.; Sevigny, Gary J.; Aaberg, Rosanne L.
CURRICULUM VITAE Richard Meilan Tel: 765-496-2287
related to environmental impact and biomass production, and the conversion of biomass to biofuels and bio of dilute acid pretreatment of switchgrass shows changes in cellulose structure The generation of bioethanol is an essential step in cellulose extraction and is intended to facilitate the enzymatic hydrolysis and conversion
Partial flow of compressed-hot water through corn stover to enhance hemicellulose sugar recovery
in biological conversion of cellulosics to ethanol and other products; therefore, advanced pretreatment SSF conversion while applying extremely dilute sulfuric acid (0.07 wt %) in a counter- current. (2) Wyman, C. E., Ed. Handbook on Bioethanol: Production and Utilization, Applied Energy Technology
California at Riverside, University of
National Bioenergy Center - Biochemical Platform Integration Project: Quarterly Update, Winter 2010
Winter 2011 edition of the National Bioenergy Center's Biochemical Platform Integration Project quarterly newsletter. Issue topics: 33rd Symposium on Biotechnology for Fuels and Chemicals program topic areas; results from reactive membrane extraction of inhibitors from dilute-acid pretreated corn stover; list of 2010 task publications.
Schell, D.
Carbon supported Pt and Pt-Co electrocatalysts for the oxygen reduction reaction in low temperature fuel cells were prepared by the reduction of the metal salts with sodium borohydride and sodium formate. The effect of surface treatment with nitric acid on the carbon surface and Co on the surface of carbon prior to the deposition of Pt was studied. The catalysts where Pt was deposited on treated carbon the ORR reaction preceded more through the two electron pathway and favored peroxide production, while the fresh carbon catalysts proceeded more through the four electron pathway to complete the oxygen reduction reaction. NaCOOH reduced Pt/C catalysts showed higher activity that NaBH{sub 4} reduced Pt/C catalysts. It was determined that the Co addition has a higher impact on catalyst activity and active surface area when used with NaBH{sub 4} as reducing agent as compared to NaCOOH.
Fox, E.; Colon-Mercado, H.
Development and field application of a mathematical model for predicting the kinematic viscosity of crude oil/diluter mixture under continuous production conditions
Experience producing medium to heavy oil areas has demonstrated that most conventional artificial production systems are inefficient. This situation has been improved by mixing diluter fluids or light crude oil with medium to heavy crude oil downhole. The mixing increases production efficiency, crude oil selling value, and conditions crude to meet minimum selling conditions. An analytical model has been developed to analyze the behavior of crude oil/diluter mixtures under continuous production conditions. The model developed for this study has practical application in field operations. The most important applications are: to select the proper diluter fluid to be used in a specific area; to calculate the exact amount of diluter to be mixed with crude oil to obtain a specific viscosity; to forecast the amount of diluter fluid required for normal and continuous oilfield operations; to predict crude oil-diluter mixture kinematic viscosity under any proportion of the components for economic evaluation; and to calculate API gravities of the produced mixture under continuous operation. The crude oils used in this study have a gravity between 8.6/sup 0/API and 14.3/sup 0/API. The diluters used have a gravity between 31.4/sup 0/API and 63/sup 0/API. The paper presents the analytical model and one application to Venezuelan field in the Orinoco Petroleum Belt, one of the largest oil reserves in the world. Each well in the field has a different viscosity and different production rate. The production rate was considered continuous and under exponential decline.
Alcocer, C.F.; Menzie, D.E.
Pervaporation separation of ethanol-water mixtures using polyacrylic acid composite membranes
Synthetic, organic, polymeric membranes were prepared from polyacrylic acid salts for use with pervaporation apparatus in the separation of ehthanol-water mixtures. The polymeric material was prepared in dilute aqueous solution and coated onto a polysulfone support film, from which excess polymeric material was subsequently removed. Cross-links were then generated by limited exposure to toluene-2,4-diisocyanata solution, after which the prepared membrane was heat-cured. The resulting membrane structure showed selectivity in permeating water over a wide range of feed concentrations. 4 tabs.
Neidlinger, H.H.
Chlorophyll and acid rain
Chlorophyll and acid rain Chlorophyll and acid rain Name: beachbum Status: N/A Age: N/A Location: N/A Country: N/A Date: Around 1993 Question: A while ago I read an article that stated that after a plant received acid rain, there seemed to be less of chlorophyll a and b in the plant. I was wondering where does the chlorophyll go and what is the actual process (cell structure affected?). Replies: I think that less chlorophyll being present would be more likely a result of less being produced. Plant cell constantly turn over cell material, it will also constantly produce more. So if one compares a plant not exposed to acid rain (presumably producing a normal amount of chlorophyll and the exposed plant then one sees that the exposed plant has less chlorophyll than the unexposed plant. I do not think I can answer the rest of your question.
Nucleic Acid Softwars
Nucleic Acid Software Nucleic Acid Software FR3D, a software for finding local and composite recurrent structural motifs in RNA 3D structures. Sarver, M., Zirbel, C.L., Stombaugh, J., Mokdad, A. and Leontis, N.B. (2008) FR3D: finding local and composite recurrent structural motifs in RNA 3D structures. J Math Biol, 56, 215-252. RNAView, a program for quickly generating a display of RNA/DNA secondary structures with tertiary interactions. Yang, H., Jossinet, F., Leontis, N., Chen, L., Westbrook, J., Berman, H.M. and Westhof, E. (2003) Tools for the automatic identification and classification of RNA base pairs. Nucleic Acids Res, 31, 3450-3460. RNAMLview, a program to display and/or edit RNAView 2-dimensional diagrams. 3DNA, a software package for the analysis, rebuilding and visualization of three-dimensional nucleic acid structures.
Reactivity of Acid Generators
Reactivity of Acid Generators for Chemically Amplified Resists with Reactivity of Acid Generators for Chemically Amplified Resists with Low-Energy Electrons Atsuro Nakano, Takahiro Kozawa, Seiichi Tagawa, Tomasz Szreder, James F. Wishart, Toshiyuki Kai and Tsutomu Shimokawa Jpn. J. Appl. Phys., 45, L197-L200 (2006). [Find paper at the Japanese Journal of Applied Physics] Abstract: In chemically amplified resists for ionizing radiations such as electron beams and extreme ultraviolet (EUV), low-energy electrons play an important role in the pattern formation processes. The reactivity of acid generators with low-energy electrons was evaluated using solvated electrons in tetrahydrofuran, which were generated by a pulsed electron beam. The rate constants of acid generators with the solvated electrons ranged from 0.6 to 1.9 x 1011 M-1s-1
(Acid rain workshop)
The traveler presented a paper entitled Susceptibility of Asian Ecosystems to Soil-Mediated Acid Rain Damage'' at the Second Workshop on Acid Rain in Asia. The workshop was organized by the Asian Institute of Technology (Bangkok, Thailand), Argonne National Laboratory (Argonne, Illinois), and Resource Management Associates (Madison, Wisconsin) and was sponsored by the US Department of Energy, the United Nations Environment Program, the United Nations Economic and Social Commission for Asia and the Pacific, and the World Bank. Papers presented on the first day discussed how the experience gained with acid rain in North America and Europe might be applied to the Asian situation. Papers describing energy use projections, sulfur emissions, and effects of acid rain in several Asian countries were presented on the second day. The remaining time was allotted to discussion, planning, and writing plans for a future research program.
Turner, R.S.
Alternate processing flowsheets for treating NCAW waste slurry with formic acid
High-level waste stored at the US Department of Energy`s Hanford Site will be pretreated and fed to the Hanford Waste Virtrification Plant (HWVP). The reference flowsheet used to develop the pretreatment process calls for formic acid. However, the potential for generating H{sub 2} and NH{sub 3} during treatment of high-level waste (HLW) with HCOOH was identified at Pacific Northwest Laboratory by Wiemers. Work performed at PNL during FY 1991, FY 1992, and FY 1993 further documented the generation of H{sub 2} and NH{sub 3} in neutralized current acid waste (NCAW) slurries treated with HCOOH. Studies at the University of Georgia under contract with Savannah River Technology Center (SRTC) and PNL have verified the catalytic role of noble metals in the generation of H{sub 2} and NH{sub 3}. Both laboratory-scale and pilot-scale studies at SRTC have documented the H{sub 2} and NH{sub 3} generation phenomena. Since H{sub 2} and NH{sub 3} may create hazardous conditions in a waste slurry treatment plant, it is important to reduce the H{sub 2} generation rate and the amount of NH{sub 3} to the lowest levels.
Smith, H.D.; Merz, M.D.; Wiemers, K.D.; Bell, R.D.; Williford, R.E.; Larson, D.E.
Engineering of a high-throughput screening system to identify cellulosic biomass, pretreatments, and enzyme formulations that enhance sugar release
Engineering Engineering of a High-Throughput Screening System to Identify Cellulosic Biomass, Pretreatments, and Enzyme Formulations That Enhance Sugar Release Michael H. Studer, Jaclyn D. DeMartini, Simone Brethauer, Heather L. McKenzie, Charles E. Wyman Chemical and Environmental Engineering Department, Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, 1084 Columbia Avenue, Riverside, California 92507; telephone: þ951-781-5791; fax: þ951-781-5790; e-mail: firstname.lastname@example.com Received 7 April 2009; revision received 21 August 2009; accepted 31 August 2009 Published online 3 September 2009 in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/bit.22527 ABSTRACT: The recalcitrance of cellulosic biomass, the only abundant, sustainable feedstock for making liquid fuels, is a primary
NREL Breaks New Ground in Plant Pretreatment for Biofuels (Fact Sheet), Highlights in Science, NREL (National Renewable Energy Laboratory)
NREL researchers use imaging technologies to broaden NREL researchers use imaging technologies to broaden knowledge of plant cell wall structures and identify ideal pretreatment of plant material. Scientists at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) and BioEnergy Science Center combined different microscopic imaging methods to gain a greater understanding of the relationships between biomass cell wall structure and enzyme digestibility. This breakthrough could lead to optimizing sugar yields and lowering the costs of making biofuels. Using the new approach, NREL researchers discovered the localization of the enzymes responsible for deconstruction of the cell wall polymers and the effects of enzyme action on the cell wall. Unlike traditional composition analysis, the new methods allow access to
Bamboo saccharification through cellulose solvent-based biomass pretreatment followed by enzymatic hydrolysis at ultra-low cellulase loadings
Bamboo Bamboo saccharification through cellulose solvent-based biomass pretreatment followed by enzymatic hydrolysis at ultra-low cellulase loadings Noppadon Sathitsuksanoh a,b , Zhiguang Zhu a , Tsung-Jen Ho c,d , Ming-Der Bai e , Yi-Heng Percival Zhang a,b,f, * a Biological Systems Engineering Department, Virginia Polytechnic Institute and State University (Virginia Tech), 210-A Seitz Hall, Blacksburg, VA 24061, USA b Institute for Critical Technology and Applied Science (ICTAS), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA c Pilot Process and Applications Department of Chemical Engineering Division, Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu 30011, Taiwan d Department of Chemical and Materials Engineering, National Central University, Chungli 32001, Taiwan e BioFuel Department
Status Report: Pretreatment chemistry evaluation-Wash and leach factors for the single-shell tank waste inventory
This report discusses a methodology developed to depict overall wash and leach factors for the Hanford single-shell tank (SST) inventory. The factors derived from this methodology, which is based on available partitioning data, are applicable to a composite SST inventory rather than only an assumed insoluble portion. The purpose of considering the entire inventory is to provide a more representative picture of the partitioning behavior of the analytes during envisioned waste retrieval and processing activities. The work described in this report was conducted by the Pretreatment Chemistry Evaluation task of the Tank Waste Remediation System (TWRS). The leach factors will be used to estimate the further removal of analytes, such as sodium, aluminum, phosphate, and other minor components. Wash and leach factors are given for elements expected to drive the volume of material disposed of as high-level waste (HLW).
Colton, N.G.
Determination of saccharides and ethanol from biomass conversion using Raman spectroscopy: Effects of pretreatment and enzyme composition
This dissertation focuses on the development of facile and rapid quantitative Raman spectroscopy measurements for the determination of conversion products in producing bioethanol from corn stover. Raman spectroscopy was chosen to determine glucose, xylose and ethanol in complex hydrolysis and fermentation matrices. Chapter 1 describes the motives and main goals of this work, and includes an introduction to biomass, commonly used pretreatment methods, hydrolysis and fermentation reactions. The principles of Raman spectroscopy, its advantages and applications related to biomass analysis are also illustrated. Chapter 2 and 3 comprise two published or submitted manuscripts, and the thesis concludes with an appendix. In Chapter 2, a Raman spectroscopic protocol is described to study the efficiency of enzymatic hydrolysis of cellulose by measuring the main product in hydrolysate, glucose. Two commonly utilized pretreatment methods were investigated in order to understand their effect on glucose measurements by Raman spectroscopy. Second, a similar method was set up to determine the concentration of ethanol in fermentation broth. Both of these measurements are challenged by the presence of complex matrices. In Chapter 3, a quantitative comparison of pretreatment protocols and the effect of enzyme composition are studied using systematic methods. A multipeak fitting algorithm was developed to analyze spectra of hydrolysate containing two analytes: glucose and xylose. Chapter 4 concludes with a future perspective of this research area. An appendix describes a convenient, rapid spectrophotometric method developed to measure cadmium in water. This method requires relatively low cost instrumentation and can be used in microgravity, such as space shuttles or the International Space Station. This work was performed under the supervision of Professor Marc Porter while at Iowa State University. Research related to producing biofuel from bio-renewable resources, especially bioethanol from biomass, has grown significantly in the past decade due to the high demand and rising costs of fossil fuels. More than 3 percent of the energy consumption in the U.S. is derived from renewable biomass, mostly through industrial heat and steam production by the pulp and paper industry, and electricity generation from municipal solid waste (MSW) and forest industry residues. The utilization of food-based biomass to make fuels has been widely criticized because it may increase food shortages throughout the world and raise the cost of food. Thus, nonfood-based and plentiful lignocellulosic feedstocks, such as corn stover, perennial grass, bagasse, sorghum, wheat/rice straw, herbaceous and woody crops, have great potential to be new bio-renewable sources for energy production. Given that many varieties of biomass are available, there is need for a rapid, simple, high-throughput method to screen the conversion of many plant varieties. The most suitable species for each geographic region must be determined, as well as the optimal stage of harvest, impacts of environmental conditions (temperature, soil, pH, etc.). Various genetically modified plants should be studied in order to establish the desired biomass in bioethanol production. The main screening challenge, however, is the complexity of plant cell wall structures that make reliable and sensitive analysis difficult. To date, one of the most popular methods to produce lignocellulosic ethanol is to perform enzymatic hydrolysis followed by fermentation of the hydrolysate with yeast. There are several vital needs related to the field of chemistry that have been suggested as primary research foci needed to effectively improve lignocellulosic ethanol production. These topics include overcoming the recalcitrance of cellulosic biomass, the pervasiveness of pretreatment, advanced biological processing and better feedstocks. In this thesis, a novel approach using Raman spectroscopy has been developed to address important issues related to bioethanol generation, which will aid the research aimed to solve the topics m
Shih, Chien-Ju
Optical high acidity sensor
An apparatus and method for determining acid concentrations in solutions having acid concentrations of from about 0.1 Molar to about 16 Molar is disclosed. The apparatus includes a chamber for interrogation of the sample solution, a fiber optic light source for passing light transversely through the chamber, a fiber optic collector for receiving the collimated light after transmission through the chamber, a coating of an acid resistant polymeric composition upon at least one fiber end or lens, the polymeric composition in contact with the sample solution within the chamber and having a detectable response to acid concentrations within the range of from about 0.1 Molar to about 16 Molar, a measurer for the response of the polymeric composition in contact with the sample solution, and a comparer of the measured response to predetermined standards whereby the acid molarity of the sample solution within the chamber can be determined. Preferably, a first lens is attached to the end of the fiber optic light source, the first lens adapted to collimate light from the fiber optic light source, and a second lens is attached to the end of the fiber optic collector for focusing the collimated light after transmission through the chamber. 10 figs.
Jorgensen, B.S.; Nekimken, H.L.; Carey, W.P.; O`Rourke, P.E.
An apparatus and method for determining acid concentrations in solutions having acid concentrations of from about 0.1 Molar to about 16 Molar is disclosed. The apparatus includes a chamber for interrogation of the sample solution, a fiber optic light source for passing light transversely through the chamber, a fiber optic collector for receiving the collimated light after transmission through the chamber, a coating of an acid resistant polymeric composition upon at least one fiber end or lens, the polymeric composition in contact with the sample solution within the chamber and having a detectable response to acid concentrations within the range of from about 0.1 Molar to about 16 Molar, a measurer for the response of the polymeric composition in contact with the sample solution, and, a comparer of the measured response to predetermined standards whereby the acid molarity of the sample solution within the chamber can be determined. Preferably, a first lens is attached to the end of the fiber optic light source, the first lens adapted to collimate light from the fiber optic light source, and a second lens is attached to the end of the fiber optic collector for focusing the collimated light after transmission through the chamber.
Jorgensen, Betty S. (Jemez Springs, NM); Nekimken, Howard L. (Los Alamos, NM); Carey, W. Patrick (Lynnwood, WA); O' Rourke, Patrick E. (Martinez, GA)
An introduction to the special section on application of leading pretreatments to switchgrass by the Biomass Refining Consortium for Applied Fundamentals
- mochemical approaches in particular, did an effective job of mak- ing biomass susceptible to enzyme attack by the Biomass Refining Consortium for Applied Fundamentals and Innovation (CAFI) Pretreatment is among the most costly steps in the overall bio- logical conversion of cellulosic biomass to fuels and chemicals. Pre
Nucleic Acid Tools
Nucleic Acid Tools Nucleic Acid Tools RNA 3D Motif Atlas, a representative collection of RNA 3D internal and hairpin loop motifs. Petrov, A.I., Zirbel, C.L., Leontis, N.B. (2013) Automated classification of RNA 3D motifs and the RNA 3D motif atlas. RNA. Non-redundant List of RNA-containing 3D structures. Leontis, N.B., & Zirbel, C.L. (2012) In Leontis, N. B., Westhof. E. (ed.), RNA 3D structure analysis and prediction. Springer Berlin Heidelberg Vol. 27, pp. 281-298. RNA Base Triple Atlas, a collection of motifs consisting of two RNA basepairs. Abu Almakarem, A.S., Petrov, A.I., Stombaugh, J., Zirbel, C.L. and Leontis, N.B. (2012) Comprehensive survey and geometric classification of base triples in RNA structures. Nucleic Acids Res, 40, 1407-1423. R3D Align, an application for detailed nucleotide to nucleotide
Ground state energy of dilute neutron matter at next-to-leading order in lattice chiral effective field theory
We present lattice calculations for the ground state energy of dilute neutron matter at next-to-leading order in chiral effective field theory. This study follows a series of recent papers on low-energy nuclear physics using chiral effective field theory on the lattice. In this work we introduce an improved spin- and isospin-projected leading-order action which allows for a perturbative treatment of corrections at next-to-leading order and smaller estimated errors. Using auxiliary fields and Euclidean-time projection Monte Carlo, we compute the ground state of 8, 12, and 16 neutrons in a periodic cube, covering a density range from 2% to 10% of normal nuclear density.
Evgeny Epelbaum; Hermann Krebs; Dean Lee; Ulf-G. Mei�ner
1-D Cluster Array at the Three Phase Contact Line in Diluted Colloids Subjected to A.C. Electric Fields
Colloidal particles provide an efficient mean of building multiple scale structured materials from colloidal dispersions. In this Brief Report, we account for experimental evidence on the formation of a colloidal cluster array at a three-phase contact line. We study the influence of low frequency external alternating electric fields on a diluted colloidal dispersion opened to the air. We focus on the cluster formation and their evolution in the meniscus by measuring characteristic times and lengths. We observe that the clusters are separated by a well-defined length and that, in our experimental conditions, they survive between five a fifteen minutes. These new results could be of technological relevance in building tailored colloidal structures in non-patterned substrates.
M. Pichumani; M. Giuliani; W. Gonz�lez-Vi�as
Synthesis of acid addition salt of delta-aminolevulinic acid from 5-bromo levulinic acid esters
A process of preparing an acid addition salt of delta-aminolevulinc acid comprising: a) dissolving a lower alkyl 5-bromolevulinate and hexamethylenetetramine in a solvent selected from the group consisting of water, ethyl acetate, chloroform, acetone, ethanol, tetrahydrofuran and acetonitrile, to form a quaternary ammonium salt of the lower alkyl 5-bromolevulinate; and b) hydrolyzing the quaternary ammonium salt with an inorganic acid to form an acid addition salt of delta-aminolevulinic acid.
Moens, Luc (Lakewood, CO)
Development of Oxidative Lime Pretreatment and Shock Treatment to Produce Highly Digestible Lignocellulose for Biofuel and Ruminant Feed Applications
At present, the United States generates biofuels (ethanol) from corn grain. Unfortunately, low crop yields and limited growth regions result in limited availability. Furthermore, the use of staple food crops for ethanol production has generated a highly controversial food vs. fuel debate. Because of its high abundance and relatively low cost, lignocellulosic biomass is a promising alternative feedstock for biofuel production; however, structural features of lignocellulose limit accessibility of enzymes or microorganisms. These structural barriers include high lignin content, acetyl groups on hemicellulose, high cellulose crystallinity, cellulose degree of polymerization, and small pore volume. To overcome these barriers, a variety of pretreatment processes (chemical and mechanical) have been developed. Oxidative-lime pretreatment (OLP) is highly effective at reducing lignin content and removing acetyl groups from hemicellulose. Combining OLP with a mechanical treatment process greatly enhances the enzymatic digestibility of lignocellulose. Recommended OLP conditions were determined for Dacotah (120 �C, 6.89-bar O2, 240 min) and Alamo (110 �C, 6-89-bar O2, 240 min) switchgrass. Using recommended conditions, 72-h glucan digestibilities (g glucan hydrolyzed/100 g glucan in raw biomass; 15 filter paper units/g raw glucan) of 85.2 and 88.5 were achieved for Dacotah and Alamo, respectively. Adding ball milling to OLP further enhanced glucan digestibility to 91.1 (Dacotah) and 90.0 (Alamo). In previous studies, shock treatment achieved promising results, but was often inconsistent. This work refined shock treatment with a focus on using consistent procedures and performance analysis. The combination of OLP and shock treatment enhanced the 72-h glucan digestibility of several promising biomass feedstocks: bagasse (74.0), corn stover (92.0), poplar wood (94.0), sorghum (71.8), and switchgrass (89.0). Highly digestible lignocellulose can also be used as ruminant animal feed. Shock treatment plus OLP increased the total digestible nutrients (TDNN; g nutrients digested/100 g organic matter) of corn stover from 51.9 (untreated) to 72.6. Adding in pre-washed corn stover solubles to produce a combined feed (17.8 percent corn stover solubles and 82.2 percent shock OLP corn stover) increased TDNN to 74.9. Mixing in enough solubilized protein to match the crude protein content of corn grain further improved TDNN to 75.5, only 12.6 less than corn grain.
Falls, Matthew David
Pretreatment Staging Positron Emission Tomography/Computed Tomography in Patients With Inflammatory Breast Cancer Influences Radiation Treatment Field Designs
Purpose: Positron emission tomography/computed tomography (PET/CT) is increasingly being utilized for staging of inflammatory breast cancer (IBC). The purpose of this study was to define how pretreatment PET/CT studies affected postmastectomy radiation treatment (PMRT) planning decisions for IBC. Methods and Materials: We performed a retrospective analysis of 62 patients diagnosed with IBC between 2004 and 2009, who were treated with PMRT in our institution and who had a staging PET/CT within 3 months of diagnosis. Patients received a baseline physical examination, staging mammography, ultrasonographic examination of breast and draining lymphatics, and chest radiography; most patients also had a bone scan (55 patients), liver imaging (52 patients), breast MRI (46 patients), and chest CT (25 patients). We compared how PET/CT findings affected PMRT, assuming that standard PMRT would target the chest wall, level III axilla, supraclavicular fossa, and internal mammary chain (IMC). Any modification of target volumes, field borders, or dose prescriptions was considered a change. Results: PET/CT detected new areas of disease in 27 of the 62 patients (44%). The areas of additional disease included the breast (1 patient), ipsilateral axilla (1 patient), ipsilateral supraclavicular (4 patients), ipsilateral infraclavicular (1 patient), ipsilateral IMC (5 patients), ipsilateral subpectoral (3 patients), mediastinal (8 patients), other distant/contralateral lymph nodes (15 patients), or bone (6 patients). One patient was found to have a non-breast second primary tumor. The findings of the PET/CT led to changes in PMRT in 11 of 62 patients (17.7%). These changes included additional fields in 5 patients, adjustment of fields in 2 patients, and higher doses to the supraclavicular fossa (2 patients) and IMC (5 patients). Conclusions: For patients with newly diagnosed IBC, pretreatment PET/CT provides important information concerning involvement of locoregional lymph nodes, mediastinal lymph nodes, and unsuspected sites of distant metastasis. This information is important in the design of radiotherapy treatment fields and, therefore, we recommend that PET/CT be a component of initial staging for IBC.
Walker, Gary V. [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Niikura, Naoki [Department of Breast and Endocrine Surgery, Tokai University School of Medicine, Kanagawa (Japan)] [Department of Breast and Endocrine Surgery, Tokai University School of Medicine, Kanagawa (Japan); Yang Wei [Department of Diagnostic Radiology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Diagnostic Radiology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rohren, Eric [Department of Nuclear Medicine, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Nuclear Medicine, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Valero, Vicente [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Woodward, Wendy A. [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Alvarez, Ricardo H. [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Lucci, Anthony [Department of Surgical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Surgical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Ueno, Naoto T. [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Buchholz, Thomas A., E-mail: firstname.lastname@example.com [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)
Acid Placement in Acid Jetting Treatments in Long Horizontal Wells
In the Middle East, extended reach horizontal wells (on the order of 25,000 feet of horizontal displacement) are commonly acid stimulated by jetting acid out of drill pipe. The acid is jetted onto the face of the openhole wellbore as the drill pipe is withdrawn from the well. The jetting action helps to remove the drilling fluid filter cake and promote the acid to penetrate into the formation and form wormholes to stimulate the well. However, with very long sections of wellbore open to flow, the acid placement and subsequent wormhole distribution and penetration depths are uncertain. This study has modeled the acid jetting process using a comprehensive model of acid placement and wormhole propagation in a horizontal well. It is presumed that the acid jetting tool removes the drilling mud filter cake, so that no filter cake exists between the end of the drill pipe and the toe of the well. Correspondingly, the model also assumes that there is an intact, low-permeability filter cake on the borehole wall between the end of the drill pipe and the heel of the well. The drill pipe is modeled as being withdrawn from the well during the acid jetting treatment, as is done in practice. The acidizing simulator predicts the distribution of acid and the depths of wormholes formed as functions of time and position during the acid jetting treatment. The model shows that the acid jetting process as typically applied in these wells preferentially stimulates the toe region of the horizontal well. Comparisons of the simulation predictions with published data for acid jetting treatments in such wells showed good general agreement. Based on the simulation study, this study presents recommendations for improved acid jetting treatment procedures to improve the distribution of acid injected into the formation.
Sasongko, Hari
Self-organized GaAs patterns on misoriented GaAs (111)B substrates using dilute nitrides by molecular beam epitaxy
Recently, the growth of patterned surfaces is being used to demonstrate the site control of the three-dimensional nanostructures, and in particular quantum dots. Nevertheless the pre-patterning techniques show some disadvantages. In this work, we report ... Keywords: Dilute nitrides, InAs, Molecular beam epitaxy, Patterned surface, Quantum dots
R. Gargallo; J. Miguel-S�nchez; �. Guzm�n; U. Jahn; E. Mu�oz
Recovery of carboxylic acids at pH greater than pK{sub a}
Economics of producing carboxylic acids by fermentation is often dominated, not by the fermentation cost, but by the cost of recovering and purifying the acids from dilute aqueous solutions. Experiments were performed to measure uptakes of lactic and succinic acids as functions of pH by basic polymeric sorbents; sorbent regeneration was also tested. Performance at pH > pK{sub a} and regenerability depend on sorbent basicity; apparent pK{sub a} and monomer pK{sub a} can be used to predict sorbent performance. Two basic amine extractants, Alamine 336 and Amberlite LA-2, in were also studied; they are able to sustain capacity to higher pH in diluents that stabilize the acid-amine complex through H bonding. Secondary amines perform better than tert-amines in diluents that solvate the additional proton. Competitive sulfate and phosphate, an interference in fermentation, are taken up by sorbents more strongly than by extractants. The third step in the proposed fermentation process, the cracking of the trimethylammonium (TMA) carboxylate, was also examined. Because lactic acid is more soluble and tends to self-esterify, simple thermal cracking does not remove all TMA; a more promising approach is to esterify the TMA lactate by reaction with an alcohol.
Tung, L.A.
Inhibition of homologous recombination repair in irradiated tumor cells pretreated with Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin
In order to investigate the mechanism of radio-sensitization by an Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG), we studied repair of DNA double strand breaks (DSBs) in irradiated human cells pre-treated with 17-AAG. DSBs are thought to be the critical target for radiation-induced cell death. Two human tumor cell lines DU145 and SQ-5 which showed clear radio-sensitization by 17-AAG revealed a significant inhibition of DSB repair, while normal human cells which did not show radio-sensitization by the drug indicated no change in the DSB repair kinetics with 17-AAG. We further demonstrated that BRCA2 was a novel client protein for Hsp90, and 17-AAG caused the degradation of BRCA2 and in turn altered the behavior of Rad51, a critical protein for homologous recombination (HR) pathway of DSB repair. Our data demonstrate for the first time that 17-AAG inhibits the HR repair process and could provide a new therapeutic strategy to selectively result in higher tumor cell killing.
Noguchi, Miho [Graduate School of Science and Technology, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Heavy-Ion Radiobiology Research Group, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Yu, Dong [Heavy-Ion Radiobiology Research Group, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Hirayama, Ryoichi [Heavy-Ion Radiobiology Research Group, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Ninomiya, Yasuharu [Heavy-Ion Radiobiology Research Group, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Sekine, Emiko [Heavy-Ion Radiobiology Research Group, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kubota, Nobuo [Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ami-machi, Inashiki-gun, Ibaraki 300-0394 (Japan); Ando, Koichi [Graduate School of Science and Technology, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Heavy-Ion Radiobiology Research Group, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Okayasu, Ryuichi [Heavy-Ion Radiobiology Research Group, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan)]. E-mail: email@example.com
Lubrication with boric acid additives
Self-lubricating resin compositions including a boric acid additive and a synthetic polymer including those thermoset materials.
Erdemir, Ali (Naperville, IL)
Theoretical Study of the Thermal Decomposition of Carboxylic Acids at Pyrolysis Temperature
Carboxylic acids are important in the processing of biomass into renewable fuels and chemicals. They are formed from the pretreatment and pyrolysis of hemicellulose biopolymers and are released from the decomposition of sugars. They result from the deconstruction of polyhydroxyalkanoates (bacterial carbon storage polymers) from fatty acids derived from algae, bacteria, and oil crops. The thermal deoxygenation of carboxylic acids is an important step in the conversion of biomass into aliphatic hydrocarbons suitable for use in renewable biofuels and as petrochemical replacements. Decarboxylation, a primary decomposition pathway under pyrolysis conditions, represents an ideal conversion process, because it eliminates two atoms of oxygen for every carbon atom removed. Problematically, additional deoxygenation processes exist (e.g. dehydration) that are in direct competition with decarboxylation and result in the formation of reactive and more fragmented end products. To better understand the competition between decarboxylation and other deoxygenation processes and to gain insight into possible catalysts that would favor decarboxylation, we have investigated the mechanisms and thermochemistry of the various unimolecular and bimolecular deoxygenation pathways for a family of C1-C4 organic acids using electronic structure calculations at the M06-2X/6-311++G(2df,p) level of theory.
Clark, J. M.; Robichaud, D. J.; Nimlos, M. R.
Plant Cell Walls: Basics of Structure, Chemistry, Accessibility and the Influence on Conversion - Aqueous Pretreatment of Plant Biomass for Biological and Chemical Conversion to Fuels and Chemicals
This book is focused on the pretreatment of biomass, a necessary step for efficient conversion of the plant cell wall materials to fuels and other products. Pretreatment is required because it is difficult to access, separate, and release the monomeric sugars comprising the biopolymers within the biomass that can be further upgraded to products through chemical processes such as aqueous phase reforming or biological routes such as fermentation of the sugars to ethanol This resistance to degradation or difficulty to release the monomers (mostly sugars) is commonly referred to as recalcitrance. There are many methods to overcome plant recalcitrance, but the underlying cause of the recalcitrance lies in the complex combination of chemical and structural features of the plant cell walls.
Davison, Brian H [ORNL; Davis, Dr. Mark F. [National Renewable Energy Laboratory (NREL); Parks, Jerry M [ORNL; Donohoe, Bryan [National Renewable Energy Laboratory (NREL)
Effects of Feedstocks and Inoculum Sources on Mixed-Acid and Hydrogen Fermentations
With increasing energy demand, decreasing oil supply, and continuously accumulating waste in landfills, the interest in converting lignocellulosic biomass to liquid fuels has grown. The MixAlco� process requires no exogenous enzymes, no sterility, can be adapted to any biodegradable feedstock, and converts lignocellulosic biomass into valuable chemicals and transportation fuels. This work focuses on the effects different feedstocks and inocula have on mixed-acid/hydrogen fermentations. When volatile solids (VS) are digested, mixed-acid fermentations produce hydrogen gas as a secondary byproduct. Hydrogen is only produced when there is an excess of NADH within the cell and when the energy selectivity (gamma) of the system has not been met. Continuous fermentations of paper produced 16.7 g carboxylic acid/L and 15.7 mL H2/g VS digested. Continuous fermentations of pretreated bagasse produced 17.1 g carboxylic acid/L and 41.1 mL H2/g VS digested. Both fermentations produced a fraction of the theoretical amount of hydrogen. The paper fermentation had a hydrogen percent yield of 6.9 percent, whereas the bagasse fermentation had a hydrogen percent yield of 22.6 percent. Hydrogen production was capped at this level because gamma had been met for these systems. The Bioscreening Project, a joint project between three departments, sought to improve the MixAlco� process by finding natural cultures containing high biomass converters and high acid producers. A total of 505 inoculum samples were collected from 19 sites and screened using paper and yeast extract fermentations. The best converters were analyzed with Continuum Particle Distribution Modeling (CPDM). Nine inocula were run in paper and yeast extract countercurrent fermentations in which the overall performance varied less than 13 percent. Comparisons between six countercurrent train cultures showed an average culture similarity of 0.40 (Yue-Clayton similarity). With the dissimilar microbial cultures and the very similar fermentation performance, the performance of the MixAlco� process depends on fermentation conditions, not on the microorganisms. Batch fermentations of office paper wastes, pineapple residue, Aloe vera rinds, wood molasses, sugar molasses, extracted algae, non-extracted algae, crude glycerol, obtained from the biodiesel process, and pretreated water hyacinths produced sufficient carboxylic acids and had sufficiently high conversions to be viable substrates for the MixAlco� process.
Forrest, Andrea Kelly
Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction. Technical progress report, December 1992--March 1993
Guiding optimal biofuels : a comparative analysis of the biochemical production of ethanol and fatty acid ethyl esters from switchgrass.
In the current study, processes to produce either ethanol or a representative fatty acid ethyl ester (FAEE) via the fermentation of sugars liberated from lignocellulosic materials pretreated in acid or alkaline environments are analyzed in terms of economic and environmental metrics. Simplified process models are introduced and employed to estimate process performance, and Monte Carlo analyses were carried out to identify key sources of uncertainty and variability. We find that the near-term performance of processes to produce FAEE is significantly worse than that of ethanol production processes for all metrics considered, primarily due to poor fermentation yields and higher electricity demands for aerobic fermentation. In the longer term, the reduced cost and energy requirements of FAEE separation processes will be at least partially offset by inherent limitations in the relevant metabolic pathways that constrain the maximum yield potential of FAEE from biomass-derived sugars.
Paap, Scott M.; West, Todd H.; Manley, Dawn Kataoka; Dibble, Dean C.; Simmons, Blake Alexander; Steen, Eric J. [Joint BioEnergy Institute, Emeryville, CA; Beller, Harry R. [Lawrence Berkeley National Laboratory, Berkeley, CA; Keasling, Jay D. [Lawrence Berkeley National Laboratory, Berkeley, CA; Chang, Shiyan [Tsinghua University, Beijing, PR China
Non-Lead/Acid Battery Recyclers:
... in H2O solution such as Citric Acid, Acetic Acid, Acetates or ... MnO2 is soluble in sulfuric acid only at ... cells were treated by alkali followed by acids. ...
Synthesis of Silica Supported AuCu Nanoparticle Catalysts and the Effects of Pretreatment Conditions for the CO Oxidation Reaction
Supported gold nanoparticles have generated an immense interest in the field of catalysis due to their extremely high reactivity and selectivity. Recently, alloy nanoparticles of gold have received a lot of attention due to their enhanced catalytic properties. Here we report the synthesis of silica supported AuCu nanoparticles through the conversion of supported Au nanoparticles in a solution of Cu(C{sub 2}H{sub 3}O{sub 2}){sub 2} at 300 C. The AuCu alloy structure was confirmed through powder XRD (which indicated a weakly ordered alloy phase), XANES, and EXAFS. It was also shown that heating the AuCu/SiO{sub 2} in an O{sub 2} atmosphere segregated the catalyst into a Au-CuO{sub x} heterostructure between 150 C to 240 C. Heating the catalyst in H{sub 2} at 300 C reduced the CuO{sub x} back to Cu{sup 0} to reform the AuCu alloy phase. It was found that the AuCu/SiO{sub 2} catalysts were inactive for CO oxidation. However, various pretreatment conditions were required to form a highly active and stable Au-CuO{sub x}/SiO{sub 2} catalyst to achieve 100% CO conversion below room-temperature. This is explained by the in situ FTIR result, which shows that CO molecules can be chemisorbed and activated only on the Au-CuOx/SiO{sub 2} catalyst but not on the AuCu/SiO{sub 2} catalyst.
J Bauer; D Mullins; M Li; Z Wu; E Payzant; S Overbury; S Dai
Efficient degradation of lignocellulosic plant biomass without pretreatment by the 9 thermophilic anaerobe, Anaerocellum thermophilum DSM 6725
Very few cultivated microorganisms can degrade lignocellulosic biomass without chemical pretreatment. We show here that 'Anaerocellum thermophilum' DSM 6725, an anaerobic bacterium that grows optimally at 75 C, efficiently utilizes various types of untreated plant biomass, as well as crystalline cellulose and xylan. These include hardwoods such as poplar, low-lignin grasses such as napier and Bermuda grasses, and high-lignin grasses such as switchgrass. The organism did not utilize only the soluble fraction of the untreated biomass, since insoluble plant biomass (as well as cellulose and xylan) obtained after washing at 75 C for 18 h also served as a growth substrate. The predominant end products from all growth substrates were hydrogen, acetate, and lactate. Glucose and cellobiose (on crystalline cellulose) and xylose and xylobiose (on xylan) also accumulated in the growth media during growth on the defined substrates but not during growth on the plant biomass. A. thermophilum DSM 6725 grew well on first- and second-spent biomass derived from poplar and switchgrass, where spent biomass is defined as the insoluble growth substrate recovered after the organism has reached late stationary phase. No evidence was found for the direct attachment of A. thermophilum DSM 6725 to the plant biomass. This organism differs from the closely related strain A. thermophilum Z-1320 in its ability to grow on xylose and pectin. Caldicellulosiruptor saccharolyticus DSM 8903 (optimum growth temperature, 70 C), a close relative of A. thermophilum DSM 6725, grew well on switchgrass but not on poplar, indicating a significant difference in the biomass-degrading abilities of these two otherwise very similar organisms.
Yang, Sung-Jae [University of Georgia, Athens, GA; Kataeva, Irina [University of Georgia, Athens, GA; Hamilton-Brehm, Scott [ORNL; Engle, Nancy L [ORNL; Tschaplinski, Timothy J [ORNL; Doeppke, Crissa [National Renewable Energy Laboratory (NREL); Davis, Dr. Mark F. [National Renewable Energy Laboratory (NREL); Westpheling, Janet [University of Georgia, Athens, GA; Adams, Michael W. W. [University of Georgia, Athens, GA
Analysis of Pretreatment FDG-PET SUV Parameters in Head-and-Neck Cancer: Tumor SUV{sub mean} Has Superior Prognostic Value
Purpose: To evaluate the prognostic significance of different descriptive parameters in head-and-neck cancer patients undergoing pretreatment [F-18] fluoro-D-glucose-positron emission tomography (FDG-PET) imaging. Patients and Methods: Head-and-neck cancer patients who underwent FDG-PET before a course of curative intent radiotherapy were retrospectively analyzed. FDG-PET imaging parameters included maximum (SUV{sub max}), and mean (SUV{sub mean}) standard uptake values, and total lesion glycolysis (TLG). Tumors and lymph nodes were defined on co-registered axial computed tomography (CT) slices. SUV{sub max} and SUV{sub mean} were measured within these anatomic regions. The relationships between pretreatment SUV{sub max}, SUV{sub mean}, and TLG for the primary site and lymph nodes were assessed using a univariate analysis for disease-free survival (DFS), locoregional control (LRC), and distant metastasis-free survival (DMFS). Kaplan-Meier survival curves were generated and compared via the log-rank method. SUV data were analyzed as continuous variables. Results: A total of 88 patients was assessed. Two-year OS, LRC, DMFS, and DFS for the entire cohort were 85%, 78%, 81%, and 70%, respectively. Median SUV{sub max} for the primary tumor and lymph nodes was 15.4 and 12.2, respectively. Median SUV{sub mean} for the primary tumor and lymph nodes was 7 and 5.2, respectively. Median TLG was 770. Increasing pretreatment SUV{sub mean} of the primary tumor was associated with decreased disease-free survival (p = 0.01). Neither SUV{sub max} in the primary tumor or lymph nodes nor TLG was prognostic for any of the clinical endpoints. Patients with pretreatment tumor SUV{sub mean} that exceeded the median value (7) of the cohort demonstrated inferior 2-year DFS relative to patients with SUV{sub mean} {<=} the median value of the cohort, 58% vs. 82%, respectively, p = 0.03. Conclusion: Increasing SUV{sub mean} in the primary tumor was associated with inferior DFS. Although not routinely reported, pretreatment SUV{sub mean} may be a useful prognostic FDG-PET parameter and should be further evaluated prospectively.
Higgins, Kristin A., E-mail: firstname.lastname@example.com [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Hoang, Jenny K. [Department of Radiology, Division of Neuroradiology, Duke University Medical Center, Durham, NC (United States); Roach, Michael C.; Chino, Junzo; Yoo, David S. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Turkington, Timothy G. [Department of Radiology, Division of Nuclear Medicine, Duke University Medical Center, Durham, NC (United States); Department of Biomedical Engineering, Duke University Medical Center, Durham, NC (United States); Graduate Program in Medical Physics, Duke University Medical Center, Durham, NC (United States); Brizel, David M. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Department of Surgery, Division of Head and Neck Surgery, Duke University Medical Center, Durham, NC (United States)
Acid buffering a high pH soil for zinc diffusion
The effective use of an aqueous buffer solution of acetic acid and sodium acetate (1.0 M HOAc/1.4 M NaOAc, pH = 4.8) to lower the pH of a sand-attapulgite clay mixture from 9.4 to 4.8 is demonstrated. Soil buffering is necessary to prevent precipitation of Zn{sup 2+} as Zn(OH){sub 2(s)} during zinc diffusion tests. The choice of the acetic acid/sodium acetate buffer solution is based on results of batch-type tests and permeation tests performed to evaluate the soil-mixture pH lowering and buffering capacity of dilute solutions of HNO{sub 3} (a strong acid), 0.057 M HOAc (a weak acid), potassium hydrogen phthalate (a pH {approximately} 4 buffer), and the 1.0 M HOAc/1.4 MNaOAc buffer solution. Measured values of effective diffusion coefficients D* for zinc on unconfined, compacted test specimens of the buffered soil mixture ranged from 0.54 {times} 10{sup {minus}6} cm{sup 2}/s to 6.5 {times} 10{sup {minus}6} cm{sup 2}/s. This range of D*-values is within the range of D*-values reported for most reactive inorganic solutes in saturated clay soils and at the lower end of the range of D*-values for zinc in saturated clay soils.
Shackelford, C.D.; Cotten, T.E.; Rohal, K.M.; Strauss, S.H. [Colorado State Univ., Fort Collins, CO (United States)
Plutonium carbonate speciation changes as measured in dilute solutions with photoacoustic spectroscopy: Yucca Mountain Site Characterization Program Milestone report 3350
The stability fields for dilute Pu-carbonate species versus pH (8.4 to 12.0) and total carbonate concentrations (3 mM to 1.0 M) have been mapped-out using photoacoustic absorption spectroscopy (PAS). At least four different plutonium species, characterized by absorption peaks at 486, 492, 500, and 513 rim, have been found. A redox change to a Pu(VI) complex can not account for the speciation change associated with the first two spectra (486 and 492 nm peaks). Moreover, the data are consistent with what is predicted from a previous YMP milestone. This previous study was performed under very different conditions of plutonium concentration and carbonate/pH changes, and extension of these conditions to much lower Pu concentrations and to more neutral pHs was made possible with PAS spectroscopy. These new results reinforce the previous results by extending the range of direct observation and by eliminating other possibilities such as dimerization/polymerization reactions. As bicarbonate concentration is increased from .01 M to 1.0 M at pH=8.4 to 8.9, predominately [Pu(OH){sub x+1}(CO{sub 3}){sub y}]{sup 4-(x+2y)} (492 nm peak) is converted to [Pu(OH){sub x}(CO{sub 3}){sub y+l}]{sup 4-(x+2y+2)} (486 nm peak). The starting stoichiometry (x and y values) remain undetermined, but the effect of ionic strength and temperature indicate that the 486 nm species is highly charged, and therefore x+2y{ge}3. The temperature effect on the equilibrium between these two species was also investigated, with the species giving rise to the 486 nm peak reversibly losing importance at elevated (50 and 75{degrees}C temperatures).
Tait, C.D.; Ekberg, S.A.; Palmer, P.D.; Morris, D.E.
Pretreatment and Recycling Processes
Mar 13, 2012... such as shredder residue of automobile and scrapped appliance, was ... These criteria are best met by the Kumera steam dryer with best�...
Fatty Acid Methods and Measurements
... mixtures are analyzed by either gas chromatography with ... for fatty acids, including various oils and biodiesel ... Material 3276 Carrot Extract in Oil," Anal ...
Acidic gas capture by diamines
Compositions and methods related to the removal of acidic gas. In particular, the present disclosure relates to a composition and method for the removal of acidic gas from a gas mixture using a solvent comprising a diamine (e.g., piperazine) and carbon dioxide. One example of a method may involve a method for removing acidic gas comprising contacting a gas mixture having an acidic gas with a solvent, wherein the solvent comprises piperazine in an amount of from about 4 to about 20 moles/kg of water, and carbon dioxide in an amount of from about 0.3 to about 0.9 moles per mole of piperazine.
Rochelle, Gary (Austin, TX); Hilliard, Marcus (Missouri City, TX)
Volatility of Aqueous Acetic Acid, Formic Acid, and Sodium Acetate
The quality of water and steam is central to ensuring power plant component availability and reliability. A key part of developing operating cycle chemistry guidelines is an understanding of the impurity distribution between water and steam. This report examines the volatility of some of the principal cycle organic corrodents: acetic acid, formic acid, and sodium acetate.
Economic and kinetic studies of the production of chemicals and farm energy by fermentation of biomass
The farm energy system has been constructed in Drury, Missouri. The purpose of this unit is to demonstrate the feasibility of producing energy for farms (heat and electricity) from methane produced by anaerobic digestion of crop residues and other crop materials. The acid hydrolysis pre-treatment of corn stover studies utilize a two stage sulfuric acid contact. In the first stage, dilute sulfuric acid is used to hydrolyze the pentosan fraction of ground biomass. The second stage uses concentrated sulfuric acid for hexosan hydrolysis. The use of the two steps give high yields, possible with concentrated acid, without the problems of pentose decomposition.
Gaddy, J.L.
Upregulation of early growth response factor-1 by bile acids requires mitogen-activated protein kinase signaling
Cholestasis results when excretion of bile acids from the liver is interrupted. Liver injury occurs during cholestasis, and recent studies showed that inflammation is required for injury. Our previous studies demonstrated that early growth response factor-1 (Egr-1) is required for development of inflammation in liver during cholestasis, and that bile acids upregulate Egr-1 in hepatocytes. What remains unclear is the mechanism by which bile acids upregulate Egr-1. Bile acids modulate gene expression in hepatocytes by activating the farnesoid X receptor (FXR) and through activation of mitogen-activated protein kinase (MAPK) signaling. Accordingly, the hypothesis was tested that bile acids upregulate Egr-1 in hepatocytes by FXR and/or MAPK-dependent mechanisms. Deoxycholic acid (DCA) and chenodeoxycholic acid (CDCA) stimulated upregulation of Egr-1 to the same extent in hepatocytes isolated from wild-type mice and FXR knockout mice. Similarly, upregulation of Egr-1 in the livers of bile duct-ligated (BDL) wild-type and FXR knockout mice was not different. Upregulation of Egr-1 in hepatocytes by DCA and CDCA was prevented by the MEK inhibitors U0126 and SL-327. Furthermore, pretreatment of mice with U0126 prevented upregulation of Egr-1 in the liver after BDL. Results from these studies demonstrate that activation of MAPK signaling is required for upregulation of Egr-1 by bile acids in hepatocytes and for upregulation of Egr-1 in the liver during cholestasis. These studies suggest that inhibition of MAPK signaling may be a novel therapy to prevent upregulation of Egr-1 in liver during cholestasis.
Allen, Katryn [Department of Pharmacology, Toxicology, and Experimental Therapeutics, University of Kansas Medical Center, 4063 KLSIC, 3901 Rainbow Boulevard, Kansas City, KS 66160 (United States); Kim, Nam Deuk; Moon, Jeon-OK [Department of Pharmacology, Toxicology, and Experimental Therapeutics, University of Kansas Medical Center, 4063 KLSIC, 3901 Rainbow Boulevard, Kansas City, KS 66160 (United States); Department of Pharmacy, Pusan National University, Busan 609-735 (Korea, Republic of); Copple, Bryan L., E-mail: firstname.lastname@example.com [Department of Pharmacology, Toxicology, and Experimental Therapeutics, University of Kansas Medical Center, 4063 KLSIC, 3901 Rainbow Boulevard, Kansas City, KS 66160 (United States)
Metabolic regulation of the plant hormone indole-3-acetic acid
The phytohormone indole-3-acetic acid (IAA, auxin) is important for many aspects of plant growth, development and responses to the environment yet the routes to is biosynthesis and mechanisms for regulation of IAA levels remain important research questions. A critical issue concerning the biosynthesis if IAA in plants is that redundant pathways for IAA biosynthesis exist in plants. We showed that these redundant pathways and their relative contribution to net IAA production are under both developmental and environmental control. We worked on three fundamental problems related to how plants get their IAA: 1) An in vitro biochemical approach was used to define the tryptophan dependent pathway to IAA using maize endosperm, where relatively large amounts of IAA are produced over a short developmental period. Both a stable isotope dilution and a protein MS approach were used to identify intermediates and enzymes in the reactions. 2) We developed an in vitro system for analysis of tryptophan-independent IAA biosynthesis in maize seedlings and we used a metabolite profiling approach to isolate intermediates in this reaction. 3) Arabidopsis contains a small family of genes that encode potential indolepyruvate decarboxylase enzymes. We cloned these genes and studied plants that are mutant in these genes and that over-express each member in the family in terms of the level and route of IAA biosynthesis. Together, these allowed further development of a comprehensive picture of the pathways and regulatory components that are involved in IAA homeostasis in higher plants.
Jerry D. Cohen
A ACID RAIN Audrey Gibson
acid and nitric acid. Sunlight increases the rate of most of these reactions. Electric utility plants;Gas Natural Sources Concentration Carbon dioxide CO2 Decomposition 355 ppm Nitric oxide NO Electric, 2010 #12;Gas Non-Natural Sources Concentration Nitric oxide NO Internal Combustion (cars) 0.2 ppm
Toohey, Darin W.
A numerical study of transient ignition and flame characteristics of diluted hydrogen versus heated air in counterflow
Combined experimental and numerical studies of the transient response of ignition to strained flows require a well-characterized ignition trigger. Laser deposition of a small radical pool provides a reliable method for initiating ignition of mixtures that are near the ignition limit. Two-dimensional direct numerical simulations are used to quantify the sensitivity of ignition kernel formation and subsequent edge-flame propagation to the oxidizer temperature and the initial width and amplitude of O-atom deposition used to trigger ignition in an axisymmetric counterflow of heated air versus ambient hydrogen/nitrogen. The ignition delay and super-equilibrium OH concentration in the nascent ignition kernel are highly sensitive to variations in these initial conditions. The ignition delay decreases as the amplitude of the initial O-atom deposition increases. The spatial distribution and the magnitude of the OH overshoot are governed by multi-dimensional effects. The degree of OH overshoot near the burner centerline increases as the diameter of the initial O-atom deposition region decreases. This result is attributed to preferential diffusion of hydrogen in the highly curved leading portion of the edge flame that is established following thermal runaway. The edge-flame speed and OH overshoot at the leading edge of the edge flame are relatively insensitive to variations in the initial conditions of the ignition. The steady edge-flame speed is approximately twice the corresponding laminar flame speed. The rate at which the edge flame approaches its steady state is insensitive to the initial conditions and depends solely on the diffusion time scale at the edge flame. The edge flame is curved toward the heated oxidizer stream as a result of differences in the chemical kinetics between the leading edge and the trailing diffusion flame. The structure of the highly diluted diffusion flame considered in this study corresponds to Linan's 'premixed flame regime' in which only the oxidizer leaks through the reaction zone such that the flame is located at fuel lean rather than stoichiometric mixture fraction conditions. (author)
Yoo, Chun Sang; Chen, Jacqueline H. [Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551-0969 (United States); Frank, Jonathan H.
Yoo, Chun Sang; Chen, Jacqueline H.; Frank, Jonathan H. [Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551-0969 (United States)
A numerical study of transient ignition and flame characteristics of diluted hydrogen versus heated air in counterflow.
Combined experimental and numerical studies of the transient response of ignition to strained flows require a well-characterized ignition trigger. Laser deposition of a small radical pool provides a reliable method for initiating ignition of mixtures that are near the ignition limit. Two-dimensional direct numerical simulations are used to quantify the sensitivity of ignition kernel formation and subsequent edge-flame propagation to the oxidizer temperature and the initial width and amplitude of O-atom deposition used to trigger ignition in an axisymmetric counterflow of heated air versus ambient hydrogen/nitrogen. The ignition delay and super-equilibrium OH concentration in the nascent ignition kernel are highly sensitive to variations in these initial conditions. The ignition delay decreases as the amplitude of the initial O-atom deposition increases. The spatial distribution and the magnitude of the OH overshoot are governed by multi-dimensional effects. The degree of OH overshoot near the burner centerline increases as the diameter of the initial O-atom deposition region decreases. This result is attributed to preferential diffusion of hydrogen in the highly curved leading portion of the edge flame that is established following thermal runaway. The edge-flame speed and OH overshoot at the leading edge of the edge flame are relatively insensitive to variations in the initial conditions of the ignition. The steady edge-flame speed is approximately twice the corresponding laminar flame speed. The rate at which the edge flame approaches its steady state is insensitive to the initial conditions and depends solely on the diffusion time scale at the edge flame. The edge flame is curved toward the heated oxidizer stream as a result of differences in the chemical kinetics between the leading edge and the trailing diffusion flame. The structure of the highly diluted diffusion flame considered in this study corresponds to Linan's 'premixed flame regime' in which only the oxidizer leaks through the reaction zone such that the flame is located at fuel lean rather than stoichiometric mixture fraction conditions.
Yoo, Chun Sang; Chen, Jacqueline H.; Frank, Jonathan H.
Photochemical Studies on Xanthurenic Acid
Photochemical Studies on Xanthurenic Acid Photochemical Studies on Xanthurenic Acid J. E. Roberts, J. F. Wishart, L. Martinez, C. F. Chignell Photochem.Photobiol. 72, 467-471 (2000) Abstract: The tryptophan metabolite xanthurenic acid has been isolated from aged human cataractous lenses. The photophysical properties of xanthurenic acid were examined to determine if it is a potential chromophore for age-related cataractogenesis. We found that xanthurenic acid produces singlet oxygen (F*= 0.17; CD3OD) with the same efficiency as the lenticular chromophore N-formyl kynurenine and quenches singlet oxygen at a rate similar to other tryptophan metabolites (2.1 x 107 M-1 s-1; CD3OD) found in the eye. As the mechanisms of induction of cataracts may also involve redox reactions, the interactions of hydrated electrons (e-aq), the azide radical
Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria
Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263+-0.02 g cellulose L{sup -1} for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.
Aydin, Y. Andelib; Aksoy, Nuran Deveci [Chemical Engineering Department of Istanbul Technical University, Ayazaga, Maslak, Istanbul, 34469 (Turkey)
c0ee00378f 1..5
and and pretreatment chemistry Poulomi Sannigrahi, Dong Ho Kim, Seokwon Jung and Arthur Ragauskas * Received 22nd August 2010, Accepted 26th November 2010 DOI: 10.1039/c0ee00378f The formation of pseudo-lignin by the combination of carbohydrate and lignin degradation products has been proposed to be responsible for the increased Klason lignin content in biomass pretreated under acidic conditions. Direct evidence for the presence of pseudo-lignin has never been presented. The formation of additional lignin-like material may be detrimental to enzymatic hydrolysis due to the non-productive binding of enzymes with lignin. To investigate the chemistry of pseudo-lignin formation, dilute acid pretreatments were performed on delignified hybrid poplar biomass under conditions of varying severity. The results show a progressive increase in the Klason lignin content of the acid
Catalytic Hydrogenation of Glutamic Acid
Technology to convert biomass to chemical building blocks provides an opportunity to displace fossil fuels and increase the economic viability of bio-refineries. Coupling fermentation capability with aqueous phase catalysis provides novel routes to monomers and chemicals, including those not accessible from petrochemical routes. Glutamic acid provides a platform to numerous compounds through thermochemical approaches including, hydrogentation, cyclyization, decarboxylation and deamination. Hydrogenation of amino acids also provides access into chiral compounds with high enantio-purity. This paper details aqueous phase hydrogenation reactions we have developed that lead to valuable chemical intermediates from glutamic acid.
Holladay, John E.; Werpy, Todd A.; Muzatko, Danielle S.
Oxidation pretreatment to reduce corrosion of 20%Cr-25%Ni-Nb stainless steel. I. Weight gain and oxide thickness measurements
The improvement in corrosion resistance afforded by a low-pressure selective oxidation pretreatment on 20%Cr-25%Ni-Nb steel is assessed in terms of weight gain and oxide thickness measurements. Both can and sheet specimens were oxidized in a simulated CAGR CO/sub 2/ environment at 823, 923, and 1073 K, and gravimetric gross weight-gain measurements were supplemented by spinel and Cr/sub 2/O/sub 3/ oxide thickness measurements determined by X-ray diffractometry (XRD). The increased protection provided by the pretreatment resulted in a reduction in gross weigh gain of 3-4 times at 823 K, two and three times at 923 K, and a somewhat smaller improvement at higher temperatures. The improvement stemmed from the high proportion of Cr/sub 2/O/sub 3/ selectively formed in the preoxide layer itself. Thermally induced lattice strains in the oxide scale have been assessed from measurements of lattice expansion by XRD.
Metabolism of Thioctic Acid in Algae
METABOLISM OF THlOCTlC ACID IN ALGAE TWO-WEEK LOAN COPY ThisMETABOLISM OF THIOCTIC ACID IN ALGAE Hans Grisebach, R. , C.METABOLISM OF THIOCTIC ACID IN ALGAE Hans Grisebach, R. C.
Grisebach, Hans; Fuller, R.C.; Calvin, M.
An experimental and numerical investigation on the influence of external gas recirculation on the HCCI autoignition process in an engine: Thermal, diluting, and chemical effects
In order to contribute to the solution of controlling the autoignition in a homogeneous charge compression ignition (HCCI) engine, parameters linked to external gas recirculation (EGR) seem to be of particular interest. Experiments performed with EGR present some difficulties in interpreting results using only the diluting and thermal aspect of EGR. Lately, the chemical aspect of EGR is taken more into consideration, because this aspect causes a complex interaction with the dilution and thermal aspects of EGR. This paper studies the influence of EGR on the autoignition process and particularly the chemical aspect of EGR. The diluents present in EGR are simulated by N{sub 2} and CO{sub 2}, with dilution factors going from 0 to 46 vol%. For the chemically active species that could be present in EGR, the species CO, NO, and CH{sub 2}O are used. The initial concentration in the inlet mixture of CO and NO is varied between 0 and 170 ppm, while that of CH{sub 2}O alters between 0 and 1400 ppm. For the investigation of the effect of the chemical species on the autoignition, a fixed dilution factor of 23 vol% and a fixed EGR temperature of 70 C are maintained. The inlet temperature is held at 70 C, the equivalence ratios between 0.29 and 0.41, and the compression ratio at 10.2. The fuels used for the autoignition are n-heptane and PRF40. It appeared that CO, in the investigated domain, did not influence the ignition delays, while NO had two different effects. At concentrations up until 45 ppm, NO advanced the ignition delays for the PRF40 and at higher concentrations, the ignition delayed. The influence of NO on the autoignition of n-heptane seemed to be insignificant, probably due to the higher burn rate of n-heptane. CH{sub 2}O seemed to delay the ignition. The results suggested that especially the formation of OH radicals or their consumption by the chemical additives determines how the reactivity of the autoignition changed. (author)