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The present invention relates to a novel method for conducting phase transfer catalysis in a multiphase reaction system wherein the different phases are separated by a membrane permeable to the phase transfer catalyst and its various reaction complexes. The invention also relates to membranes and a membrane-containing apparatus useful in carrying out phase transfer catalysis.
1. A process for conducting heterogeneous reactions in a liquid-liquid two phase reaction system containing an organic phase and an aqueous phase, said reaction being carried out in the presence of reactants and a phase transfer catalyst, the improvement comprising:
(a) separating said organic phase and aqueous phase with a membrane, which membrane is substantially wet by one of the phases and wherein one of the phases contains a phase transfer catalyst
whereby said aqueous phase and organic phase remain substantially separated by said membrane during and after completion of said reaction.
2. The process of claim 1 wherein said membrane is of a hydrophilic material.
3. The process of claim 1 wherein the membrane is of a hydrophobic material.
4. The process of claim 2 wherein said hydrophilic membrane is one selected from the group consisting of regenerated cellulose, hydrophilic polyacrylonitrile-based copolymer, and polyethersulfone/polyethylene oxide polymer blend.
5. The process of claim 3 wherein said membrane is one selected from the group consisting of polytetrafluoroethylene, polysulfone, polyethersulfone, poly-(2,6-dimethyl) phenylene oxide, polypropylene, polypropylene/polybutadiene polymer blends, and polyvinylidene fluoride.
6. The process of claim 1 wherein the two-phase reaction is selected from the group consisting of a displacement reaction, an alkylation reaction, an oxidation reaction, or an esterification reaction.
7. The process of claim 1 wherein the membrane separates a reaction chamber into two reaction chambers.
8. The process of claim 7 wherein the aqueous phase and organic phase are located in opposite chambers.
9. The process of claim 1 wherein the membrane is in the form of a hollow fiber.
10. The process of claim 9 wherein multiple hollow fibers are placed together in a membrane reactor, the bulk aqueous phase is located within the bores of the hollow fibers, the organic phase is located outside of the fibers, and one of said phases wets said membrane.
11. The process of claim 9 wherein multiple hollow fibers are placed together in a membrane reactor, the organic phase is located within the bores of the hollow fibers, the bulk aqueous phase is located outside of the fibers, and one of said liquid phases wets said membrane.
12. The process of claim 1 wherein the membrane is in the form of a flat sheet.
13. The process of claim 1 wherein the phase transfer catalyst is one selected from the group consisting of quaternary ammonium cations, quaternary phosphonium cations, and cyclic polyethers.
14. The process of claim 1 wherein the phase transfer catalyst is tricaprylmethylammonium chloride.
15. The process of claim 1 wherein at least one of said phases is continuously flowing along the surface of said membrane.
16. The process of claim 15 wherein one of said reactants is present in said aqueous phase said reactant being contacted with one surface of said membrane and the other of said reactants is present in said organic phase said reactant being contacted with the opposite surface of said membrane.
17. The process of claim 15 wherein at least one reaction product is removed from one of said phases.
18. The process of claim 1 wherein said aqueous and organic phases are flowing in opposite directions along the opposite surfaces of said membrane.
19. The process of claim 1 wherein the phase transfer catalyst is tri-n-butylmethylammonium chloride.
20. The process of claim 1 wherein the phase transfer catalyst is an organophosphine.
21. The process of claim 1 wherein the phase transfer catalyst is a benzylalkylammonium salt.
22. The process of claim 1 wherein the phase transfer catalyst is one selected from the group consisting of a cyclic polyether, a polyethlene glycol, and a silacrown ether.
23. The process of claim 1 wherein the membrane is substantially wet by the aqueous phase and the organic phase is maintained at a pressure in excess of the pressure on the aqueous phase.
24. The process of claim 23 wherein the organic-phase pressure is maintained from 0.1 psi to 100 psi higher than that of the aqueous phase.
25. The process of claim 24 wherein the organic-phase pressure exceeds that of the aqueous phase by 1 to 20 psi.
26. The process of claim 1 wherein the membrane is substantially wet by the organic phase and the aqueous phase is maintained at a pressure in excess of the pressure on the organic phase.
27. The process of claim 26 wherein the membrane is substantially wet by the organic phase and the aqueous phase is maintained at a pressure in excess of the pressure on the organic phase.
28. The process of claim 27 wherein the aqueous-phase pressure exceeds that of the organic phase by a 1 to 20 psi.
29. The process of claim 1 wherein the membrane is substantially non-porous and swollen by one of said phases.
30. The process of claim 1 wherein the membrane is porous and wet by one of said phases.
31. The procless of claim 1 wherein the volumetric flow rates of the two liquid phases differ by a factor ranging from two to fifty.
32. The process of claim 1 wherein the phase transfer catalyst is selected from the group consisting of a tetrabutyl phosphonium salt and a alkylphosphonium salt.
33. The process of claim 1 wherein the phase transfer catalyst is triethylene diamine.
34. The process of claim 1 wherein at least one of said reactants is dissolved in the organic phase and another of said reactants is an anionic reactant which is dissolved in the aqueous phase.
35. The process of claim 34 wherein said membrane is substantially wet by one of the phases and is substantially permeable to said phase transfer catalyst, the complex formed between said phase transfer catalyst and the anionic reactant, and the complex formed between said phase transfer catalyst and a product of said heterogeneous reaction.
36. The process of claim 1 wherein said phase transfer catalyst is soluble in said organic phase and substantially insoluble in said aqueous phase.
37. The process of claim 36 wherein said membrane is wet by the aqueous phase.
38. The process of claim 37 wherein said phase transfer catalyst complexes at the interface between said aqueous and organic phases with one of said reactants which is present in said aqueous phase.
39. The process of claim 1 wherein the membrane is substantially permeable to said phase transfer catalyst, the complex formed between said phase transfer catalyst and one of said reactants and the complex formed between said phase transfer catalyst and the product of said heterogeneous reaction.
40. The process of claim 1 wherein said phase transfer catalyst permeates said membrane.
Phase-transfer catalysis is a technique for facilitating reactions between aqueous and organic phase reactants that normally do not proceed rapidly because neither reactant is soluble in the phase containing the other reactant. Often, the aqueous phase reactant is insoluble in the organic phase.
Typically, in phase transfer catalysis a phase transfer agent is added to a two-phase mixture to extract an aqueous-phase reactant into the organic phase so that a reaction can proceed. This technique has been exploited routinely by chemists for about ten to fifteen years as a tool for laboratory synthesis and, recently, the advantages of phase-transfer catalysts for industrial-scale production have been recognized. As a result, phase-transfer catalysis is now employed in the manufacture of many agricultural chemicals, pharmaceuticals, and other specialty chemicals and intermediates.
Phase-transfer catalysis may also be used where one of the coreactants has low water solubility. Often, phase-transfer catalysis will be used in reactions that occur in an organic media where two or more reactants are involved and all but one of these is soluble in the organic phase. The one insoluble reactant is usually an anion dissolved in an aqueous phase. In the absence of the phase transfer catalyst (otherwise known as "PTC"), the solubility of the anion in the organic phase is generally so small that negligible reaction rates are observed. However, the presence of a PTC in the reaction mixture promotes the transfer of the reacting anion into the organic phase, thus allowing the reaction to proceed at a significantly higher rate. Such organic reactants frequently will be structurally complex and are costly to manufacture. As an example, a number of the pyrethroid alpha-cyano esters are prepared by a phase-transfer-catalyzed coupling reaction between a substituted benzaldehyde moiety and a water-soluble cyanide salt, accompanied by reaction of the cyanohydrin so produced with a chrysanthemic acid derivative (typically an acyl halide). Baum, U.S. Pat. Nos. 4,254,050; 4,254,051; and 4,254,052.
Examples of general reaction classes amenable to phase transfer catalysis include nucleophilic substitution reactions, carbene formation, alkylations and alkoxylations, oxidations and reductions, and condensation, elimination, and addition reactions. More specifically, phase transfer catalysis can be used to catalyze the formation of ring compounds from straight-chain halocarbons, esters from acids, and ethers from alcohols; the synthesis of alkylchlorides and other alkyl halides by anion displacement; the alkylation of carbanions; and the oxidation of olefins to carboxylic acids. Freedman, H. H. (Pure and Appl Chem., 58 (1986) 857-868) sets forth a compilation of reaction types and industrial applications of phase transfer catalysis.
Conventionally, phase transfer catalysis is conducted in dispersed-phase systems wherein a two-phase mixture containing a phase transfer catalyst or PTC is stirred vigorously in a tank or other vessel to form an agitated interface or a dispersion (FIG. 3). Typically, the overall rate of conversion initially increases with stirring speed, since increasing the stirring speed causes the formation of greater numbers of smaller drops with higher interfacial areas. Ultimately, however, the conversion rate plateaus with increased stirring speed, as the heterogeneous reaction system undergoes a transition from mass-transfer control to bulk organic-phase kinetic control.
Unfortunately, a number of problems are associated with the small drop sizes required to maximize phase transfer catalysis reaction rates. In particular, some PTCs are surface-active by their very nature and act as effective emulsification agents. This is an advantage where dispersion and the creation of high interfacial areas are the objectives, but a disadvantage when it comes time for the phases to coalesce and be separated from one another. In addition to the practical difficulties associated with the continual making and breaking of dispersions and emulsions, and recovery of products therefrom, incomplete phase separation and entrainment of one phase into the other can result in loss of expensive product and phase transfer agent or PTC, as well as reduced product purity.
Other disadvantages of conducting phase transfer catalysis in dispersed-phase systems is its irreproducibility and relative inflexibility. For example, in conventional phase transfer catalysis, one is constrained to operate over relatively narrow ranges of volumetric phase ratios, and the relative mass transfer resistances of the aqueous and organic boundary layers cannot be readily and independently controlled. Scale-up of biphasic systems is often unreliable as well. With conventional dispersed-phase PTC processing there is relatively little way of independently manipulating boundary layer to bulk phase volume ratios, interfacial area to bulk phase volume ratios, and absolute and relative aqueous-phase and organic-phase mass transfer resistances in order to improve the efficiency of phase transfer catalysis.
Phase transfer catalysis has also been carried out with the use of ion exchange membranes serving as partitions in electrochemical diaphragm cells. U.S. Pat. No. 4,414,079 to Yamataka et al. and 4,277,318 to Matlock et al. Phase Transfer Catalysts have been covalently attached to capsule membranes which separate an aqueous phase outside of the capsule from an organic phase inside of the capsule. Once these capsules are formed, however, there is no way to provide fresh organic phase material to the inner portion of the capsule or continuously remove any product or reactant from that phase. Okahata et al., J. Chem. Soc., Chem. Comm., No. 13, pp. 920-922 (1985).
The different phases of biphasic (i.e. aqueous/organic) systems have been separated with membranes, for instance, in the conduct of solvent extraction operations. (FIG. 4) U.S. Pat. Nos. 3,956,112 to Lee et al. and 3,957,504 to Ho et al. However, catalysis reactions are not disclosed as taking place during membrane solvent extractions.
Therefore, it is an object of the present invention to provide a method for carrying out phase transfer catalysis without the problems associated with mixing of dispersed phase systems and phase transfer catalysts.
It is a further object of this invention to enhance the separability of the phase components and reaction products after phase transfer catalysis.
It is an additional object of this invention to provide reliable, reproducible and controllable phase transfer catalysis which is capable of meeting the requirements of high-level industrial production.
Briefly stated, the present invention pertains to a method of carrying out phase transfer catalysis in a multi-phase system, such as with aqueous and organic phases, wherein the phases are separated by a membrane which membrane is substantially wet by one of the phases and wherein one of the phases contains at least one phase transfer catalyst. The membrane may be permeable to the phase transfer catalyst, the reactants in the different phases and reaction complexes with the phase transfer catalyst. In phase transfer catalysis, the reaction of these two solutes, each of which is initially present in separate and immiscible phases, is facilitated by the use of a reactant-complexing agent, the phase transfer catalyst or PTC. This invention encompases the use of a phase transfer catalyst to accelerate, for instance, the rate of reaction of a water-soluble anionic reactant with organic-soluble reactants in a system containing two immiscible phases.
This invention is capable of being carried out using membranes having a variety of forms and configurations. For instance, the use of hollow-fiber and other types of membrane modules as two-phase contactors and reactors is particularly suited to and preferred in the conduct of phase-transfer-catalyzed reactions. (FIG. 6)
In particular, hollow-fiber membrane modules permit intimate, high-surface-area contact to be achieved between the immiscible phases on either side of the membrane, thereby obviating the need to disperse one phase in the other. As a result, entrainment and/or emulsification are minimized or eliminated, these problems otherwise being aggravated by the surface activity of certain phase transfer catalysts. Benefits accrue in terms of product recovery or yield, product purity, and, potentially, catalyst recovery and effectiveness. Additionally, membrane contacting equipment is simple, reliable, and relatively easily scaled-up as compared to other high-performance phase contacting/separating equipment such as centrifugal extractors. Finally, additional operating flexibility is gained in terms of the range of permissible organic:aqueous phase ratios or flow rate ratios.
The present invention may be more readily understood by reference to the following figures wherein:
FIG. 1 illustrates a typical phase-transfer catalyzed reaction system.
FIG. 2 illustrates the mechanism of phase transfer catalysis.
FIG. 3 schematically diagrams conventional phase transfer catalysis in a dispersed-phase system.
FIG. 4 illustrates the process of membrane solvent extraction.
FIG. 5 illustrates membrane solvent extraction in a hollow-fiber membrane reactor.
FIG. 6 illustrates a Phase Transfer Catalyst membrane reactor.
FIG. 7 graphically shows a semilog plot of reactant removal vs. time in a membrane reactor.
The present invention is based, in part, upon the fact that certain compounds, such as organic quaternary salts of the elements of Group VA of the Periodic Table of the Elements (as in Handbook of Chemistry and Physics, Chemical Rubber Company, 45th Edition. (1964) p B2), can effectively catalyze heterogeneous reactions in which the reactants are located in distinct liquid phases by transferring ions or other reactive species across the phase interface. Frequently, the reaction of interest takes place in organic media and involves two or more reactants, one of which is insoluble in the organic phase. The one insoluble reactant is usually an anion dissolved in an aqueous phase which is in intimate contact with the organic phase. In the absence of the PTC the solubility of the anion in the organic phase is generally so small that negligible reaction rates are observed. However, the presence of a PTC in the reaction mixture promotes the transfer of the reacting anion into the organic phase and by this mechanism, the reaction is allowed to proceed at a significantly higher rate.
In general, phase transfer catalysts are cationic in nature, i.e., they are positively charged, and when in the presence of anions (negatively charged species) the two will form a neutral complex which is generally organic soluble. The degree to which the complex is soluble in the organic phase will depend, among other things, on the nature of the anion, the PTC, and the complex (sometimes called ion-pair), concentration of each species, temperature, and the volume of both the aqueous and organic phases. Many phase transfer catalysts are both water and organic soluble, but others are water insoluble and exist (e.g., chloride or hydroxide complexes) in organic media only. With the latter type of PTC, the extraction of anions from an aqueous phase generally takes place by an anion exchange mechanism at the organic/aqueous interface. Certain other PTCs, e.g. the polyethylene-glycols and crown ethers, are electrically neutral.
It should be noted that the nature of the organic phases generally employed in phase transfer catalysis usually results in two immiscible liquid phases, one organic and the other aqueous, which are characterized by a small but finite solubility of each phase within the other. Since the small amount of either phase dissolved in the other phase has no influence on the overall catalytic reaction process, such solvent-or water-saturated phases will be referred to as being "substantially free" of the other phase, thus denoting the absence of significant quantities of one water phase being dispersed or entrained within the other.
Broadly stated, the reaction involved in this invention provides a catalyst capable of complexing with a first reactant which is substantially disposed in a first liquid phase and transferring such first reactant into a second liquid phase which is substantially immiscible in the first phase, and which by this invention is separated from said first phase by a membrane, and there yielding up the first reactant to a second reactant which is substantially entirely disposed in such second liquid phase. More particularly, the type of reactions involved in this invention are those in which one or more reactants, usually but not always dissolved in inert solvent, are reacted with an anion dissolved in a second immiscible phase in the presence of a phase transfer catalyst. The PTC promotes the transfer of such anion into the first liquid phase which by this invention is separated from the second phase by a membrane.
This invention can also be generally stated to be a process for conducting heterogeneous reactions in a liquid-liquid two phase reaction system containing an organic phase and an aqueous phase, said reaction being carried out in the presence of reactants and a phase transfer catalyst, the improvement comprising separating said organic phase and aqueous phase with a membrane, which membrane is substantially wet by one of the phases and wherein one of the phases contains a phase transfer catalyst whereby said aqueous phase and organic phase remain substantially separated by said membrane during and after completion of said reaction.
A typical PTC reaction of interest, a displacement reaction, is diagrammatically shown in FIG. 1. The mechanism of one type of phase-transfer reaction is shown in FIG. 2. As illustrated in FIG. 2, the catalyst "Q" extracts the aqueous phase reactant "Y" into the organic phase, where the reaction takes place between the complex "QY" and the reactant"RX". The products of this reaction are "RY" and the complex "QX". Reaction conditions are most favorable when extraction of "Y-" is highly favored over extraction of "X-" since this will cause the less soluble complex "QX" to be returned to the aqueous phase. This permits "Q+" to be regenerated and rendered capable of extracting more "Y-". Under these conditions, much less than stoichiometric quantities of catalyst can be used, because the catalyst can continually shuttle back and forth between phases, carrying fresh reactant into the organic phase with it. It is foreseeable in the practice of this invention that the phase transfer catalyst permeates, in both complexed and uncomplexed forms, into and within but not necessarily across the membranes on one side of the aqueous/organic interface. Certain phase transfer catalysts and complexes thereof used in the practice of this invention entirely cross the membrane from one bulk phase into the other, whereas other phase transfer catalysts and complexes will diffuse within but not completely cross the membrane. The term "permeate" as used herein is meant to describe and includes both of these modes of action, i.e., the phase transfer catalyst and its complexes both crossing the membrane and/or diffusing within it.
Typical and preferred phase-transfer catalysts utilized in carrying out this invention are quaternary ammonium or phosphonium cations, or cyclic polyethers complexed with small cations. It should be further pointed out that the terms catalytic activity and catalysis as they are here used are intended to mean that a finite increase in the rate at which the reactants in the two phases react with each other is caused to occur by the presence in the system of the phase transfer catalyst. Phase transfer catalysts may be obtained commercially from, for instance, the Henkel Corp. ("Aliquot 336-PTC" or tricaprylmethylammonium chloride, a water-insoluble quaternary ammonium salt); Ethyl Corp. ("TBMAC" or tri-n-butylmethylammonium chloride); American Cyanamid (organophosphine chemicals); Hexcel Specialty Chemicals (tetrabutylammonium and benzylalkylammonium salts); Petrarch Systems, Inc. (silacrown ethers) Bofors Nobel; and Air Products and Chemicals ("Dabco" or triethylene diamine). Still others include Union Carbide (PEG-600 or polyethyleneglycol); RSA Corp. (benzyltriethylammonium chloride and tetrabutylphosphonium chloride); and Sherex Chem. Corp. (Adogen-464 or tricaprylmethylammonium chloride).
In a preferred embodiment the phase transfer catalysis is carried out in a membrane reactor. In a further preferred embodiment, the membranes utilized in this reactor comprise hollow-fibers. In this embodiment hollow-fiber membrane modules permit intimate, high-surface-area contact to be achieved between the immiscible phases on either side of the membrane.
Additionally, this membrane contacting equipment is simple, passive, reliable, and relatively easily scaled-up as compared to other high-performance phase contacting/separating equipment such as centrifugal extractors. The use of this membrane contacting equipment in phase transfer catalysis should result in additional operating flexibility (e.g., organic: aqueous phase or flow rate ratios and continuous operation). Whereas in conventional phase transfer catalysis the interfacial area between the organic and aqueous phases depends on the relative volumes of the two liquid phases (as well as on other operating parameters such as the degree of agitation) in membrane phase transfer catalysis the area of the aqueous/organic interface is fixed and is equal to the membrane area. For this reason, membrane phase transfer catalysis reactors can efficiently be operated at more extreme volumetric phase or flow rate rations than is the case in the absence of a membrane. Indeed, it is forseeable within the scope of this invention that the volumetric flow rates of the two liquid-phases may differ by a factor of under 2 to more than 50 times the other.
Phase transfer catalysis "efficiency" criteria that are beneficially and positively effected by membrane reactor operation include reactor productivity (i.e., conversion rate per unit reactor volume), organic and aqueous phase stability (e.g., stability against emulsification), permissible organic-to-aqueous phase volume or flow rate ratios, product recovery and yield, product purity, catalyst recovery, and control over undesirable side reactions.
Membranes and membrane modules suited to the practice of the present invention are similar construction to those used in membrane solvent extraction. (FIG. 5) Two types of membrane may be employed in the practice of this invention in, for instance, a phase contactor/separator reactor. The preferred membrane may be either a:
(1) hydrophobic and microporous membrane, or
(2) hydrophilic membrane, either gel-type or microporous.
Depending on their morphologies and composition many membranes will become wet upon contact with an aqueous or organic liquid. Without intending to be bound by any theory or mechanism, the term "wet" as used herein means that the membrane has been impregnated with a solvent from one of the two phases. For example, a membrane made of a hydrophobic material characterized by pores will generally become wet upon contact with an organic solvent due to capillary action. The same wetting properties are observed for membranes made of hydrophilic materials when contacted with an aqueous phase. On the other hand, many other membranes are substantially non-porous in the sense of being free of discrete, well-defined pores, i.e., the polymer phase (whether hydrophilic or hydrophobic) is substantially continuous in these membranes. However, this type of membrane will generally become swollen or wet when contacted with an appropriate solvent whenever a strong affinity exists between the polymer/solvent pair. One example of this type of membrane (also called "gel-type" membranes) is provided by regenerated cellulose membranes of the type used in hemodialysis, which swell markedly when placed in contact with water. Either type of membrane morphology (gel-type or microporous), or a combination thereof, when wet with the appropriate solvent (by capillarity or by swelling) can be used in the present invention.
In the preferred operation of the inventive method, an organic stream containing at least one of the reactants would be directed past one side of the membrane. Simultaneously, an aqueous stream containing at least one reactant (or coreactant e.g., an anionic reactant) would be directed across the opposite membrane surface. The phase in which the phase transfer catalyst is present in or will be introduced into the reactor will depend on the type of PTC employed (i.e., aqueous or organic soluble). For the case of water soluble PTCs, complex formation with the reactant anion will take place, followed by extraction of the complex into the organic phase. In the organic phase, the complex and organic soluble reactant(s) will react to form the desired products. Following the organic-phase reaction, the phase transfer catalyst complexed with one of the reaction products returns to the aqueous phase, dissociates, and, hence, is regenerated for participation in another reaction cycle.
When hydrophobic membranes are employed, either microporous or solvent swollen, the pressure difference across the membrane, defined here as the aqueous phase pressure minus the organic phase pressure, must be greater than zero throughout the reactor in order to prevent the organic phase from flowing through the membrane into the aqueous phase. On the other hand, when hydrophilic membranes are used, either gel-type or microporous, the pressure in the organic phase must be greater than the pressure in the aqueous phase throughout the reactor in order to prevent an ultrafiltrative flow of the aqueous phase into the organic phase. Typically, the pressure difference should be between 0.1 and 100 psi and usually between 1 and 10 psi. In any event, the transmembrane pressure difference should not exceed the value which would cause intrusion of the pressurized liquid phase into the membrane wet by the other liquid phase. In the case of microporous membranes, this intrusion pressure ΔP may be estimated from the Young-LaPlace equation as: ##EQU1## Where γ is the liquid-liquid interfacial tension, r is the pore radius, and θ is the three-phase contact angle.
Typically, reactant conversions will depend on process stream flow rates or times of reaction, in addition to the particular phase transfer catalyst and membrane used in the process. Knowledge of PTC-catalyzed reaction kinetics and membrane permabilities will assist in optimizing such reactor operating conditions as process stream flow rates and reaction times. In the practice of this invention, phase-transfer-catalyzed reaction rates will typically increase with temperature, as they do in the absence of a membrane, with absolute operating pressure levels having an insignificant effect. However, one of the significant advantages of this invention is the ability to operate over a wide range of flow rates, temperature, volumetric phase or flow rate ratios, reactant compositions, and with differing membranes and phase transfer agents.
Generally speaking, either hydrophobic or hydrophilic membrane materials may be used in the practice of the present invention. Similarly, both microporous and solvent-swollen (e.g., gel-type) membrane morphologies will exhibit significant permeability to many PTCs and their complexes with reactants and products, and so will be suitable for the practice of this invention. However, whereas most of the alkyl and benzylammonium salts are small species with molecular weights (MWs) ranging from about 200 to 400 (e.g., "BTEAC" or benzyltriethylammonium chloride, MW 228; Aliquot-336/Adogen-464 or tricaprylmethyl-ammonium chloride, MW 400), certain of the polyethylene glycols (PEGs) employed as phase transfer catalysts have molecular weights ranging from about 350-600 to as much as several thousand. With large or bulky PTCs (e.g., the higher-molecular-weight PEGs), microporous membranes may be preferred to solvent-swollen gel-type membranes for reasons of the generally higher permeability of the microporous membranes large species.
When hydrophobic membranes are employed, either microporous or solvent swollen, the aqueous/organic interface will be located at the surface of the membrane adjacent to the aqueous stream. The membrane itself will be substantially wet by and will therefore contain organic solvent, and the PTC-catalyzed reaction will occur in part within the membrane proper, as well as within the bulk organic phase on one side of the membrane. In contrast, when the membrane is hydrophilic, whether gel-type or microporous, the aqueous/organic interface will reside at the surface of the membrane adjacent to the organic stream, and the reaction will take place primarily in the organic phase on one side of the water-wet membrane. In either case, the membrane will be apprecially permeable to at least one of the reactants and to the phase transfer catalyst.
Examples of the method according to this invention are given hereafter. These examples are meant to be illustrative and not to be considered as limiting the scope of the invention.
A flat sheet membrane reactor was fashioned from an alumimum block (FIG. 6). A flow channel 0.05 cm deep, 10 cm wide, and 20 cm long was cut into each block. Inlet and outlet flow distribution manifolds were also machined into the blocks. The flowing streams were isolated by bolting the two blocks together with a hydrophobic membrane sandwiched in between. The aqueous stream was run at a higher pressure than the organic stream in order to maintain a stable aqueous/organic interface at the surface of the hydrphobic membrane adjacent to the aqueous stream. Because of this pressure drop, the membrane was supported separately. A highly porous stainles steel screen 0.05 cm thick was fastened to the bottom of the organic stream flow channel to provide this support.
A reaction using the above reactor was conducted using the following chemistry. Bromooctane in the organic solvent chlorobenzene was reacted with aqueous iodide to form iodoctane in chlorobenzene and aqueous bromide ion. To ensure that this reaction required the use of a phase transfer catalyst, a brief dispersed-phase study was conducted. A solution 0.5 M in bromooctane and 0.1 M in tetradecane (as a gas chromatograph standard) in chlorobenzene was stirred with an equal volume of 2.0 M potassium iodide at 40 degrees C. for 4 hours. After this period, no iodooctane could be detected by gas chromatography. All analyses were conducted with a Perkin-Elmer 3920 gas chromatograph equipped with a flame ionization detector and a 10' by 1/8" OV-101 column at 200 degrees C. When this experiment was repeated using 0.05 M tetrabutylammonium bromide in the organic feed as a phase transfer catalyst, 50% conversion of bromooctane to iodoctane was observed after 4 hours. Because the organic-phase concentration of tetrabutylammonium iodide, the active form of the catalyst, remains constant with time under these reaction conditions, first-order kinetics with respect to the disappearance of bromooctane is predicted by the phase transfer catalysis mechanism. This effect was observed in these experiments.
In the membrane reactor experiments, the feed compositions were the same as in the above dispersed-phase experiments. The membrane material used was Goretex 10-mil tape supplied by W.L. Gore Associates, Elkton, Md. Goretex is a microporous polytetrafluoroethylene membrane. The porosity and tortuosity were measured at 61% and 1.7, respectively. Flow rates were set using constant head tanks. The requisite membrane pressure drop was maintained by elevating the aqueous stream tube outlet several inches above the organic tube outlet.
The aluminum reactor was maintained at 40 degrees C. in a constant temperature bath. The flowrates, always equal to each other, were varied in the range of 3 to 8 ml/hr. After each adjustment, a period of at least 5 hours and usually overnight was allowed for the system to reach steady state. Several measurements of conversion were taken during a period of 2 to 3 hours to ensure that steady state had been achieved. The steady state experimental results were as follows: 33% conversion at 3.1 ml/hr., 22% conversion at 4.4 ml/hr, and 16% conversion at 7.1 ml/hr. No entrainment of chlorobenzene in the aqueous effluent could be detected visually, and only a slight trace was found by GC analysis. No water was observed in the chlorobenzene effluent. The reactor operated for 72 hours without interruption.
In the example set forth below, the initial organic-and aqueous-phase feed compositions were the same as used in Example 1. The membrane employed was gel-type regenerated cellulose in a hollow-fiber geometry, with the organic phase fed to the lumen side of the fibers and the aqueous phase fed to the shell side of the module. The hollow-fiber module contained 1.5m2 of active membrane area characterized by an ultrafiltration rate of 6.4 ml/hr-mmHg and by urea, creatinine, and vitamin B12 clearances of 183, 165 and 59 ml/min, respectively, as measured at blood (QB) and dialysate (QD) flow rates of QB =200 ml/min and QD =500 ml/min. The hollow-fiber membrane module, designated AM-300M, was obtained from Asahi Medical Co. via Mediflex International, Inc. In order to impart some limited degree of solvent resistance to the modules, the dialyzer end caps were first coated with Devcon 5-minute epoxy, and the original O-rings were replaced with more solvent-resistant Viton O-rings.
The initial volumes of organic and aqueous phases charged to the system were both 250 ml, and both phases were recirculated between the membrane module and their respective reservoirs at flow rates of 5 ml/min. The reaction temperature was maintained at about 38� C. by immersing the module in a thermostated water bath, and bromooctane conversion was followed as a function of time by gas chromatography.
Conversion vs. time data are summarized in Table I. These data are also plotted in conventional fashion on semi-logarithmic coordinates in 7. From the slope of the solid line through the data, a first-order rate constant k1 of 0.09 hr-1 can be calculated. Also shown for comparison (as the dashed line) is the conversion vs. time prediction of an analytical model for the case of ion-exchange equilibrium where the mass transfer resistances on both sides of the membrane are assumed negligible.
TABLE I______________________________________Bromooctane Conversion vs. Time in aPhase-Transfer-Catalyzed Membrane ReactorTime (hrs) Reactant Conversion______________________________________0.001.5 0.112.0 0.152.5 0.173.0 0.193.5 0.244.0 0.295.0 0.326.0 0.368.5 0.439.5 0.4820.0 0.7020.5 0.6921.0 0.7221.5 0.7321.5 0.72______________________________________
The present invention is not intended to be limited in scope by the above experiments or by the membranes or phase transfer catalysts used since each is intended merely as an illustration of the invention. In addition, any membrane or phase transfer catalyst which is functionally equivalent to those set forth herein is intended to be within the scope of this invention. Indeed, various modifications of the invention, in addition to those shown and described herein, will become apparent to those skilled in the art from the foregoing description and accompanying s. Such modifications are intended to fall within the scope of the appended claims.
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National Guard Bureau
WASHINGTON, May 13, 2002 On Armed Forces Day 1962, President John F. Kennedy advised the people of the United States to "guard zealously (the) right to serve in the Armed Forces, for without them, there will be no other rights to guard." Today, the citizens of our Nation pause to honor those of you who have exercised that right and volunteered to defend our country. It is my privilege to join them in recognizing the dedication of every soldier, sailor, airman, Marine, and Coast Guardsman who serves in our Armed Forces.
This past year has shown once again the depths of your courage and commitment, and your willingness to endure hardship. Whether National Guard, Reserve or active duty; whether serving on land, at sea, or in the air; whether deployed for combat operations, participating in multinational exercises, or training for future missions, you have performed magnificently. All the citizens of our country know they can depend on you to get the job done.
Many of you will be unable to attend the ceremonies acknowledging your service - - because you are on duty around the Nation and the world, defending America's interests and fighting the terrorists who threaten to destroy our way of life. Be assured that the people of the United States recognize and appreciate your sacrifice. You continue to demonstrate the very best our Nation has to offer. The Joint Chiefs of Staff and I join all Americans in paying tribute to you and your families. May God bless our country and all of you who serve her.
Gen. Richard B. Myers, USAF

subset: commoncrawl


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Full detailed profile on Jessica Bennett Played by Danica Stewart on Passions Daytime Soap Opera.
Danica Stewart
Birthday: 1983-08-02
Tabitha looks into her bowl while Endora watches Jessica in her toy screen. She thinks that all Jessica needs is a good dose of courage, like the cowardly lion. Spike tracks Jessica down sitting in Tabitha's yard. He accuses her of hiding from him and tries to feed her drugs when she refuses to go out hooking. Inside, Tabitha and Endora aren't impressed with Spike's evil. 'Maybe it's time he met the real deal,' they laugh. Tabitha is going to teach Spike a lesson he will never forget. Going into the backyard, she asks Jessica and Spike to come in and give her a hand. After Jessica convinces him to go along, Endora takes Jessica up to the attic and Tabitha sends Spike into the basement with a twist of the arm. Opening the basement door, she shoves him down as flames shoot out. As she holds the door shut, a terrified Spike slowly goes down the stairs before being attacked.
In the attic, Jessica tells Endora that her family has always lived next door to them. Changing the subject, she tells her never to change who she is for a man; once you lose your soul, you can't get it back. 'Sure you can,' says Endora as she zaps herself into a young woman while Jessica's back is turned. Stunned when she sees the young woman standing before her, Jessica wonders what kind of drugs she was taking. Endora tells her that everything will be fine, but right now, she is going to show her the kind of life she could have. But first, they have to revisit her past.
Sam and Paloma find Jessica sadly standing and looking at flowers. She doesn't want another intervention; once the funeral is over, she's going home to her husband. After she stomps away, Sam vows to keep trying until they get her home where she belongs.
Spike and Jessica wander by. He reiterates that Noah and Paloma don't care about her and then drags her along to find a trick. She's cold and wants to go home. He tells her that work will warm her up. It doesn't feel like he's protecting her, she says, but he argues that he's only trying to provide for them. It tears him up to make her do this, but she's so good at it. After threatening to abandon her, he kisses her roughly and she pushes him off. A john comes by and Spike has to barter with him to sell her. Afterward, she walks by her old house and looks in at Noah and Paloma. She'll never have a love like that. 'I wish I'd never been born.'
In her room, Spike begs Jessica to come home with him. Offering her his hand, she is still unsure. Noah and Paloma come upstairs to check on Jessica. When they go into her room, they find that she is gone. Rushing to the window, they can see her leaving with Spike. They go out searching through the rat holes on the edge of town for them. Spike has brought Jessica home. It's worse than she remembered and there is a dead rat in the corner. He makes her some tea and tells her that he's the only one who has been there for her all along. Noah and Paloma begin knocking on the door. Spike tells Jessica to get them to leave. She lets them in and Spike tells them to go back to 'Leave it to Beaver land.' Noah puts his arms around Jessica and asks her to trust him, but she can only think of him making out with Paloma. 'I'm not leaving. My place is here with Spike,' she proclaims before asking them to go.
Jessica runs downstairs from Spike only to find Noah and Paloma making out on the couch. Spike tells her that they only act like they care about her because they have the hots for each other. Jessica and Spike go back up to her room. He tells her that she can't trust anyone and she believes him. 'Now you'll realize that I'm the only one who cares about you...forget about those losers downstairs,' he says as he kisses her neck. Jessica doesn't think that he loves her though; if he did, he wouldn't make her turn tricks and hit her. He says that those are only love taps and they should go some place where nobody will bother them.
Upstairs, Spike sits beside a sleeping Jessica. He thinks that he'll have her turning tricks by tomorrow night. He wakes her up with a kiss. Startled, he grabs a hold of her to stifle a scream. After a few threats, he takes his hand from her mouth . She tries to run, but he stops her and tells her that she can't walk away from him. 'You don't love me. All you do is hurt me,' she says. He tries to tell her that she's wrong and would be far worse off without him. Jessica refuses to turn tricks anymore; he has made her lose all self-confidence and hate herself. 'They've planted all kinds of crazy garbage in that empty head of yours,' he says before telling her that the intervention was just an excuse for Noah and Paloma to get together. He begins kissing her and she breaks away disgusted. She accuses him of always using her, but he argues that he is the only man that she can trust...and she murdered a string of johns. After threatening to expose her, she pushes him onto the bed and runs out of the room. When she gets downstairs, she sees Noah and Paloma making out on the couch. Things couldn't be turning out better for Spike if he planned them.
In her hospital bed, Jessica dreams of the 'thing' that she saw. Meanwhile, her friends Noah, Simone and Paloma try to figure out what her hallucinations of a man/woman amount to. Sam announces that this has to stop: They have to get rid of Spike. Paloma suggests another intervention, but Simone has Rae's funeral in the morning. They decide that they need to start right away. 'My ears are burning,' Spike declares as he breaks into the conversation. Sam lunges at his son-in-law, but Noah holds him back. Spike says that he has more right to be there than they do, but they stop him from going in to see Jessica and Sam threatens to arrest him for disturbing the peace. Spike tells him that he can't keep him away from his wife forever. 'She will never go back to you!' Paloma shouts as Spike snickers. He begins mocking Simone's funeral plans and wanders off. A nurse comes out to tell them that the tests prove that Jessica wasn't on any drugs. They wonder what she could have been seeing then. Jessica wakes up and everyone goes in to see her. Sam tells her that her brain is playing tricks on her, but she insists that what she saw was real. Sam and Noah help her out of bed to take her home, but Spike continues to lurk nearby. She knows too much about him now for him to let her go.
They take Jessica home, although Sam has to go to the station on an emergency call. She still insists that Spike loves her more than all of them and can change. Noah says that a man who really loves a woman would cherish her and not treat her like dirt. She becomes angry and moves away from them but they will not let her go. They throw all of the awful things that Spike does in her face and remind her of all of the good things in her life. She's confused, but she wants to believe them. Simone reminds her that the good girl she once was is still in her and she could be that way again if she lets them help her. Paloma decides that Jessica is too tired to go on and they need to put her to bed. They promise her that she will never have to see Spike again and they put her to bed. Simone is tired and needs to get her rest for the funeral. She's still angry at Luis, but Paloma promises her that she will be there for her. Tearfully, she leaves them alone and Noah tells Paloma how lucky Jessica is to have her as a friend. However, Spike is outside the house trying to figure out a way to get his wife out of there and shut her up. He sneaks into her room and sits beside her as she sleeps.
Jessica begins screaming as the man/woman/peeper/night stalker approaches her in the motel room. They've been waiting for her for a long time. They point a razor at her face when Noah, Paloma and Simone arrive at the door. Jessica lets them in and the client runs away before they can glimpse them. She tries to explain what 'the creature' looks like. They all think that she's stoned, but she swears it was real. Noah says that they are going to put her in detox and get her away from Spike for good. A noise comes from the bathroom and Jessica begs Noah to look. When he opens the door, a rat runs out and the girls scream. He shakes his head and goes in to find the bathroom empty. Jessica insists that a half man/half woman was really there. Noah takes his sister by the arm and tells her that she can tell the doctors all about it. After they leave, 'the creature' walks out of the bathroom. 'We'll meet again Jessica and soon...'
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|Dave Iliffe
|Wednesday, 06 June 2012 10:01
Dave Iliffe was born in Liverpool, England Aug. 25, 1951 and passed away April 22, 2012 in Bournemouth, England. Dave was raised Roman Catholic but had attended Bethel United Methodist Church in Glasgow. He loved with a passion the Liverpool Football Club and cheered them on every time they played. Dave was a quiet soul with a kind heart, always smiling and laughing. He loved landscaping, throwing huge parties and most of all he loved children. Children were always drawn to him and he loved being around them. He served in the British Military in Iraq.
Dave is survived by his loving wife of 9 years, Gail Greer-Iliffe of Glasgow; 2 step-daughters Stephanie Rigsby of Dayton, OH and Megan Rigsby (John) of Glasgow; a step-granddaughter on the way, Lily Cade Pedigo; 8 brothers, 3 sisters and 3 children and 6 grandchildren all in England. He is also survived by 3 best friends Marissa and Natalie Hughes and Gemma Cook all in England and several best friends here in America. He was preceded in death by his father, mother and one sister.
A memorial service will be held at Dave and Gail's home at 177 Patton Terrace Rd. in Glasgow on Saturday, June 9, 2012 at 3:00 PM with a celebration of Dave's life to follow the service at Bethel Methodist Church fellowship hall. A supper meal will be served by the church members and all are invited. If you are unable to attend the memorial service, please attend the celebration and meal.
In lieu of flowers the family requests memorial contributions to Bethel United Methodist Church.


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Governor Chris Christie's landslide victory in New Jersey–in which he won by more than 20 percentage points in a state where Democrats outnumber Republicans by 700,000; carried more than half of the Hispanic vote (51 percent) and 21 percent of the African-American vote; won 57 percent of the female vote and 63 percent of the male vote; won every education level and income group; and won nearly a third of the Democratic vote (32 percent) and more than 60 percent of independents (66 percent) and moderates (61 percent)–instantly makes him the early favorite for the 2016 Republican nomination.
With that in mind, it might be worth examining two aspects of his victory speech.
Right at the outset of his speech, Governor Christie framed things this way: "The people of New Jersey four years ago were downhearted and dispirited. They didn't believe that government could work for them anymore."
He went on to say this:
In fact, what they thought was that government was just there to take from them but not to give to them, not to work with them, not to work for them. Well, four years later, we stand here tonight showing that it is possible to put doing your job first, to put working together first, to fight for what you believe in, yet still stand by your principles and get something done for the people who elected you.
The New Jersey governor's message was not relentlessly anti-government; he is a man who speaks about limited and effective government. That's an important distinction–and one more Republicans and conservatives need to make.
Thirty years ago Irving Kristol wrote, "[The Republican Party] has failed to understand that the idea of limited government is not contradictory to the idea of energetic government or (what comes to the same thing) responsive government." As it was then, so it remains today.
Governor Christie also spoke in Kempian terms about outreach to non-traditional voters:
And while we may not always agree, we show up everywhere. We just don't show up in the places that vote for us a lot, we show up in the places that vote for us a little. We don't just show up in the places where we're comfortable, we show up in the places where we're uncomfortable.
Because when you lead, you need to be there. You need to show up, you need to listen and then you need to act. And you don't just show up six months before an election, you show up four years before one. And you just don't take no for an answer the first time no has happened. You keep going back and trying more. Because when I was elected four years ago, I wasn't elected just by the people who voted for me. I was the governor of all the people.
This is a useful corrective to those Republicans and conservatives who believe the success of the party lies in winning larger and larger percentages of a shrinking percentage of the electorate (white voters); who appear inclined to write off large swaths of voters; and who view more and more Americans as "takers," as dependent on the welfare state and therefore permanently in the camp of the Democratic Party.
Governor Christie showed that the Republican/conservative message, when framed the right way and backed up with genuine achievements, can do pretty well–and in some instances extremely well–in non-traditional demographic groups.
I'm certainly not ready at this stage to say who I believe ought to be the GOP nominee. For one thing, there are plenty of talented and intelligent people who might run. For another, you never know in advance how well, or how poorly, a person will do when running for president. It's a challenge unlike any other, and (as Rick Perry found out in 2012) being a successful governor doesn't mean you're suited to run for higher office.
That said, Governor Christie radiates confidence and competence. He is a commanding presence and possesses considerable skills, a record of achievement, and a smashing reelection victory (in a blue state) to his credit. Republicans would be fools not to look to him and learn from him, to take what worked for him in the Garden State and apply it elsewhere in America.


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ONU Wind Orchestra
Date and Time:
Saturday, December 14, 2013 - 7:30pm to 9:30pm
Event Location:
Freed Center for Performing Arts
The second annual "It's not quite Christmas yet" concert, titled Gaudete, will be presented by the ONU Wind Orchestra under the direction Dr. Thomas A. Hunt on Saturday, December 14 at 7:30pm in the Freed Center on the campus of Ohio Northern University. The program features works by David Maslanka, David Gillingham, W. Francis McBeth, and others. As a beautifully contrasting portion of the concert, the ONU Chamber Singers, directed by Dr. Ben Ayling, will present selections from its holiday repertoire. Ticket information may be obtained by calling the Freed Center Box Office at (419) 772-1900 between noon and 5:00pm Monday through Friday.