in a market economy , corporations aim to maximize profit . governments or society in general product quality , operational safety , and respect for the environment all have to be fulfilled . to maximize profit , the chemical industry always seeks the most competitive feedstock . when competitive feedstock is available , opportunities for new processes and technologies arise . technology for converting carbon dioxide into a feedstock source has been developed and used in brazil since the inception of pro - lcool , the brazilian national alcohol program , in the 1970s . given the legislation , the market demand for sustainable products , and the progress being made in biotechnology and catalysis , developers are working on new processes , which are giving rise to a wide range of biobased products . the old sugar mills ( engenhos ) have become efficient industrial facilities ( usinas ) that produce sweeteners , ethanol , and bioenergy . recent developments involve transforming sugar mills into biorefineries . besides sweeteners , biofuel , and bioenergy , the biorefineries will be able to produce bioplastics and other chemicals by using the whole cane via alcohol chemistry and fermentative routes . this essay analyzes the industry 's historical response to new developments stemming from the rise of competitive feedstock and the opportunities that it creates . it focuses on sugar cane , its availability as a feedstock source , and the technologies that can turn sugar cane into an important starting point for chemistry of the future . based on recent examples of processes and market developments , a new arrangement of integrated agroindustry , processing sugar cane and yielding higher value products , is foreseen  a sugar cane biorefinery . the history of the chemical industry is one of developing new processes for using the most competitive feedstock . competitive feedstocks make it possible to reach the lowest process cost and are available in quantities compatible with world - scale production . in early times discoveries made new natural feedstocks available , thus giving rise to new products . in the 19th century , during the industrial revolution , demand was high for coal , which was used to fire the steam engine . as a result , coal exploration was widespread , making coal abundant at low prices . it was not by chance that the chemical industry was established in regions where demand for industrial coal was high , such as germany . however , production scale still reflected only regional demand and transformation was expensive , not to mention the expensive mining operations . coal - based chemistry dominated until world war ii . in the second half of the 20th century , large - scale automobile consumption led to a high demand for fossil - based fuels . as a consequence , crude oil production improved enormously and huge refineries went on stream in order to provide fuel for individual mobility . using by - products from the refineries made it possible to use inexpensive production processes . moved by the awareness that it is consuming finite resources and climate change , society is searching for alternative feedstocks . improvements in agricultural technology , precision agriculture and plant biotechnology enable high - scale production of carbohydrate at lower cost . as an example , brazilian grain production increased at the same time as bioethanol production [ 57 ] .   besides their wide availability , carbohydrates are also renewable , in contrast to finite fossil feedstock . , carbon dioxide and water are transformed into biomass and oxygen , consuming light energy . if a biorenewable feedstock is used as the source of carbon , fossil carbon is not released into the atmosphere . the first relevant information is the comparative availability of petrochemicals and sugar cane - based products . this is important in view of the impact of a new process on the price of the feedstock . the second information is the comparative price for carbon in petrochemicals and biorenewables . to analyze the opportunity for the chemical industry , one needs a comparison based on the price for carbon , since this is the actual base of chemistry . not only the present price is important in evaluating prices , but also the long - term perspective . crude oil reached a record - high price of us$ 140 in the second half of 2008 , and prices are increasing again after the economical crisis . then , production irreversibly declines at the same rate at which it grew [ 9 , 10 ] . a projection by the international energy agency ( iea ) suggests that the production of conventional crude oil reached its peak in 2006 , at about 70 million barrels a day . the energy information agency ( eia ) estimates that the crude oil barrel price will lie between us$80 and us$100 on the next years . every time , however , the price is high , there is a trend to overproduction , limiting the price peak to some ranges . figure 1 shows price evolution of sugar and crude oil from 1990 until 2009 . not only the abundance and the price make a feedstock competitive . it is also necessary to have the technology to transform it to the desired product under economic conditions . sugar cane can be converted into chemicals via biotechnological ( fermentative ) or chemical ( alcohol - based catalysis ) processes . perhaps we are reaching the time when expenses are overcompensated by the better economic performance of biorenewables . competitive feedstock and transformation technology are necessary , but not sufficient for a product to be successful . nevertheless , a biobased product must perform comparably to other products of the same price . thus , brazilian cars are filled with ethanol if it does not exceed 70% of gasoline price [ 15 , 16 ] .   among the established carbohydrate sources , the first reason is attributable to the efficient biochemical photosynthesis pathway , the c4 route . secondly , it grows in a tropical environment with sun and water , which are abundant throughout the year . further , its soluble carbohydrate ( sucrose ) is ready to use . over the last 30 years , the development of biofuel technology for production enabled a mature technology for a sugar cane - based economy . another fundamental aspect is the use of the whole crop , which amounts to a very positive energy balance and the lowest carbon footprint . besides the sugar , the energy for the sugar mill is obtained from bagasse , the fiber residue from sugar cane after the milling process . on top of that , its energy efficiency is much higher than that of corn and wheat , as shown in figure 2 . for these reasons , sugar cane can be considered the green crude , and is capable of supplying the carbon needed by the market at competitive prices and with the sustainability demanded by the society . although a very significant development in sugar cane technology was noted with pro - lcool in 1975 , the beginning of the development dates back to the 16th century . in 1532 , martim afonso de souza introduced sugar cane in brazil . the portuguese conqueror brought the technology from madeira and azores islands . from the 16th century until 1930s , sugar cane agriculture focused on sweeteners production , although some spirits were also distilled for consumption in the colony . the sugar mills used man or animal power to extract sugar juice , and production was characterized by low technology . in 1930 , the sugar mills were transformed into usinas when brazilian president getlio vargas determined the addition of 5% ( v / v ) of ethanol to gasoline , leading to a mix of products : sugar and ethanol . from 1930s until 1990s the traditional usinas produced sugar , ethanol from molasses , and used the bagasse to produce steam . in the 1990s the brazilian energy market was liberalized , opening a new outlet opportunity for sugar cane processors . the bagasse surplus present in the usina could be converted into bioelectricity in high - pressure boilers . , at the same time , the sugar sector in brazil was deregulated . as a consequence , innovation turned to be the best way for usinas to increase profitability . since then , the modern usinas produce sweeteners , biofuel and bioenergy . the production of chemicals based on sugar cane is achieved by two different routes : alcohol chemistry and fermentative routes . both will be discussed in detail . alcohol fermentation has been known since 7,000 b.c . ; its efficiency suppressed the petrochemical route of ethanol production . high yields are possible at high temperatures and pressure and with expensive investment to drive reaction in the desired direction . a comparison of alcohol chemistry and petrochemical routes shows lower sensitivity to economy of scale for the former . salgema produced 100 kilotons per year ethylene based on alcohol in the 1980s for the dichloroethene / polyvinyl chloride ( dce / pvc ) production . the production was abandoned due to low crude oil prices in the 1980s , which inhibited the competitiveness of this technology . ethylene is a precursor of several plastics ( e.g. , pe , pvc , pva , polystyrene ) , and its world market was 128.0 million metric tons in 2008 . recently , braskem , dow and solvay indupa renewed the world 's attention to the production of bioethylene . braskem s.a . started production of biopolyethylene in triunfo - rs , brazil , in 2010 . dow brasil s.a . announced that it would continue its plan for fully integrated production of polyethylene starting from sugar cane in minas gerais , brazil , and solvay indupa s.a.i.c . is going to produce pvc from ethanol in its site in santo andr - sp , brazil [ 2628 ] . synthetic rubber for tire production is made from butadiene , which can be obtained through the catalytic conversion of alcohol . the lebedev process was modified by carbide and carbon chem corp ( usa ) in the 1940s . the butadiene production from ethanol was also carried out in brazil ( by coperbo ) from 1967 to 1986 with 27.5 kilotons per year capacity . the yield of the process  approximately 70%and the comparatively high ethanol price in the 1980s limited the process 's economic attractiveness [ 30 , 31 ] . currently there is favorable demand for biomaterials in the automotive industry ( market pull ) . at the same time , improvements in the catalytic reaction selectivity ( technology push ) can enhance economic attractiveness again . it yields acetaldehyde , which is an important chemical intermediate for the production of several chemicals , such as acetic acid , peroxiacetic acid , acetic anhydrid , butanol , keten - deketen , crotonaldehyde , pentaerythritol , chloral , pyridine , and acetic esters . this way , ethanol reaches through chemistry different markets in many applications : agricultural , food and packaging , construction , coatings and inks , cosmetics and pharmaceuticals . the oxidation of ethanol and the production of alcohol - based solvents are carried out by rhodia brasil ltda . in paulinia - sp , ethyl tert - butyl ether ( etbe ) is an oxygenate gasoline additive that can replace methyl tert - butyl ether ( mtbe ) . it can be a renewable portion of fuel , which conforms with european legislation and is preferred by the mineral oil industry to other biorenewable fuels , such as the direct addition of ethanol to gasoline . as its production requires isobutylene , it is unlikely to take place at the usina . produces in triunfo - rs , brazil , 212 kilotons per year of etbe for the export market . it is an important solvent for the chemical industry , used in the production of cellulose plastics , for example , cellulose acetate . the fermentative route is based on the conversion of carbohydrate ( sugar ) by a microorganism to the desired compound . the fermentative route is characterized by completely different conditions from the traditional chemical production , thus requiring a different equipment setup . for example , the fermentation is traditionally conducted between 30c and 37c and atmospheric pressure . although in many cases the equipment must be designed to support sterilization , these are mild conditions compared to petrochemical processes . a further important difference is related to the purification steps . in the fermentative route , many transformation steps are carried out by one single microorganism and in one single reaction vessel . the process setup is also flexible regarding biological improvement ; that is , continuous improvement of the microorganism is possible without any necessary modification to the equipment during production life time . on the other hand , the development of a microorganism exacts a high price for r&d before commercial production may start . the differences to the classical equipment setup allow a paradigm change as regards the economy of scale for fermentative processes . the fermentative route has profited from recent developments in biotechnology , such as metabolic engineering , proteomics , and metabolomics . these developments enable debottlenecking or even the construction of new pathways in microorganisms . as a consequence , process performance can be significantly enhanced . some examples of chemicals from fermentative production will be presented briefly . poly(hydroxy - butyrate ) ( phb ) is a biopolymer obtained from sugar cane through a fully renewable concept . sugar is the substrate for fermentation , a process that enables the microorganism to accumulate the polymer . the cells are harvested at the end of fermentation and the polymer is recovered from biomass . phb biodegradability enables special applications , for example , tubes for culture of seedlings , which degrade after the seedling is planted . phb industrial sa has a pilot plant of phb production fully integrated in a usina using the bagasse as energy . another example of fermentative production of chemicals is done on an industrial scale by dupont ( e. i. du pont de nemours and company ) . at this company , bio - pdo ( 1,3-propanediol ) is produced via a synthetic biochemical route . in a subsequent step , the diol undergoes a reaction for polyester formation , yielding a high performance polymer that performs in the same way as the polymer produced via the traditional chemical route . the production facility is located in the usa , where corn is used as source of carbohydrate . other amino acids have important applications in the food industry [ 38 , 39 ] . in brazil , 200 kilotons per year of the amino acid lysine were produced in 2008 for animal nutrition . the amino acid production is an example of how genetic engineering increases the competitiveness of the fermentative route . thus , evonik degussa gmbh succeeded in producing amino acids on a commercial scale by fermentation . in the past , the amino acids were obtained by the hydrolysis of protein containing animal products [ 41 , 42 ] . the fermentation of wild type clostridium yields a mixture of solvents containing acetone , butanol and ethanol ( abe ) . the abe fermentation process was used in eastern europe , south africa and china on an industrial scale until the 1990s . the process has natural limitations like the products mixture , the maximum final yield and concentration , combined with high energy demand for purifying the products . nevertheless , ongoing industrial development ( butamax advanced biofuels llc as joint - venture from dupont & bp ) is opening up new perspectives for this process . several patents have been applied for the exclusive production of butanol to be used as renewable fuel additive [ 44 , 45 ] . besides existing processes this fact is coherent , given the assumption that the competitiveness of biorenewable feedstock is increasing . amyris biotechnologies inc . developed a pathway to obtain renewable diesel and jet fuel from sugar cane by fermentation . a pilot - scale production facility is located in campinas - sp , brazil , while an industrial scale production usina is under construction in pradopolis - sp , brazil [ 46 , 47 ] . another new development is the gasification of bagasse and sugar cane trash ( includes cane tops and stalk leaves ) that yields biomass - to - liquid ( btl ) . bagasse and sugar cane trash are abundant at the usinas , and its gasification leads to syngas . from syngas it is possible to obtain liquid fuels , methanol , hydrogen and other substances via catalytic reactions . however , the industrial application is limited by the economics .   beyond the described activities , many other companies and partnerships participate in this technological development , for example , dsm / roquette , novozymes / cargill , shell / virent , genencor / dupont and perstorp [ 4953 ] . as confidentiality is necessary to enable advantages , the announcements represent only a small fraction of research activities , so much more has not been disclosed . one of the major drivers for the market acceptance of biobased products is consumers ' awareness of climate change . therefore , it is fundamental for biobased products to feature their ability to reduce the carbon footprint . the biobased production , when integrated in a usina to form a biorefinery , enables highly sustainable processes . on one hand , sugar cane agriculture has been deemed more sustainable than other comparable feedstock sources such as corn . on the other hand , the use of bagasse and sugar cane trash as source of energy for the process , which avoids the use of fossil fuels , has a further positive impact on the carbon footprint . the industry average carbon dioxide emission is 1.8  kg of co2 eq . per kg of polyethylene produced from conventional resources , while for polyethylene from sugar cane it is 2.1  kg of co2 eq . per kg of polyethylene , because when sugar cane grows , it captures carbon dioxide . this way , the total avoided emission is 3.9  kg of co2 eq . per kg of polyethylene . we can see the production of chemicals based on carbohydrates , especially on sugar cane , accelerating . old processes are being operated anew , new processes are going on - stream and r&d is taking on an impressive dimension . thus , we can assume that in the future , sugar cane will be used to produce a wide range of products : sweeteners , biofuel , bioenergy , bioplastics and other chemicals . at the same time , the vision of the usinas being established at sites where many sugar cane - based processes are integrated is becoming a reality . this is possible , as the production integration into a biorefinery enhances the competitiveness of bioprocesses . the possibilities of inclusion in a biorefinery flowchart are shown in figure 5 . as there is a wide range of processes and products , the combination of routes is possible , which allows the biorefinery to be very flexible . an important question to be answered is : who are going to be the players able to manage all the relevant issues ? according to a study published by mckinsey , successful players will be companies with a strategic fit to the biobased chemical business , with a competitive advantage through intellectual property , fermentation know - how , market intelligence , with competence in access to feedstock , metabolic and genetic engineering , fermentation stream know - how , downstream processing , processing capacity , product integration , marketing and distribution , and with conditions for high r&d investments . we should remember that the development may take 10 years to reach the market . to cope with all challenges , partnering along the value chain is an option that should be used frequently .   at present , we can observe that r&d centers are often located in the usa and europe , but there are increasing activities in brazil , too . for production , brazil is the most economically attractive choice due to its superior sugar cane economics , well - developed infrastructure , timing and availability of greenfield opportunities , but there are also opportunities in china , some countries of southeast asia and of africa . usina production integration allows its transformation into a biorefinery that can use all the sugar cane potential . alcohol chemistry products , amino acids , bioplastics , solvents and many other products are enjoying growing market demand , favored by the growing number of  green thinker consumers , who are willing to consume biobased products made , for example , from sugar cane . new options regarding the economy of scale and new technologies make biobased products economically attractive , as proved by many investments on the sugar cane value chain in recent time . brazil has an outstanding position , where the development of the technology and processes for sugar cane - based products is already taking place .
carbohydrates are nowadays a very competitive feedstock for the chemical industry because their availability is compatible with world - scale chemical production and their price , based on the carbon content , is comparable to that of petrochemicals . at the same time , demand is rising for biobased products . 
 brazilian sugar cane is a competitive feedstock source that is opening the door to a wide range of bio - based products . 
 this essay begins with the importance of the feedstock for the chemical industry and discusses developments in sugar cane processing that lead to low cost feedstocks . 
 thus , sugar cane enables a new chemical industry , as it delivers a competitive raw material and a source of energy . as a result 
 , sugar mills are being transformed into sustainable biorefineries that fully exploit the potential of sugar cane .