Chemistry Structure of ethanol molecule. All bonds are single bonds Glucose(a simple sugar) is created in the plant by photosynthesis. 6 CO2 + 6 H2O +light C6H12O6 + 6 O2 During ethanol fermentation, glucose is decomposed intoethanol and carbon dioxide. C6H12O6 2 C2H5OH+ 2 CO2 + heat During combustionethanol reacts with oxygen to produce carbon dioxide, water, and heat: C2H5OH +3 O2 2 CO2 + 3 H2O + heat After doubling the combustion reaction because twomolecules of ethanol are produced for each glucose molecule, and adding allthree reactions together, there are equal numbers of each type of molecule oneach side of the equation, and the net reaction for the overall production andconsumption of ethanol is just: light heat The heat of the combustion ofethanol is used to drive the piston in the engine by expanding heated gases. Itcan be said that sunlight is used to run the engine. Glucose itself is not theonly substance in the plant that is fermented. The simple sugar fructose alsoundergoes fermentation. Three other compounds in the plant can be fermentedafter breaking them up by hydrolysis into the glucose or fructose moleculesthat compose them. Starch and cellulose are molecules that are strings ofglucose molecules, and sucrose (ordinary table sugar) is a molecule of glucosebonded to a molecule of fructose. The energy to create fructose in the plantultimately comes from the metabolism of glucose created by photosynthesis, andso sunlight also provides the energy generated by the fermentation of theseother molecules. Ethanol may also be produced industrially from ethene(ethylene). Addition of water to the double bond converts ethene to ethanol:CH2=CH2 + H2O CH3CH2OH This is done in the presence of an acid which catalyzesthe reaction, but is not consumed. The ethene is produced from petroleum bysteam cracking. When ethanol is burned in the atmosphere rather than in pureoxygen, other chemical reactions occur with different components of theatmosphere such as N2. This leads to the production of nitrous oxides NOx , amajor air pollutant. Sources Main article: Energy crop Sugar cane harvestCornfield in South Africa Switchgrass Ethanol is a renewable energy sourcebecause the energy is generated by using a resource, sunlight, which isnaturally replenished. Creation of ethanol starts with photosynthesis causing afeedstock, such as sugar cane or corn, to grow. These feedstocks are processedinto ethanol. About 5% of the ethanol produced in the world in 2003 wasactually a petroleum product. It is made by the catalytic hydration of ethylenewith sulfuric acid as the catalyst. It can also be obtained via ethylene oracetylene, from calcium carbide, coal, oil gas, and other sources. Two milliontons of petroleum-derived ethanol are produced annually. The principalsuppliers are plants in the United States, Europe, and South Africa. Petroleumderived ethanol (synthetic ethanol) is chemically identical to bio-ethanol andcan be differentiated only by radiocarbon dating. Bio-ethanol is usuallyobtained from the conversion of carbon based feedstock. Agricultural feedstocksare considered renewable because they get energy from the sun usingphotosynthesis, provided that all minerals required for growth (such asnitrogen and phosphorus) are returned to the land. Ethanol can be produced froma variety of feedstocks such as sugar cane, bagasse, miscanthus, sugar beet,sorghum, grain sorghum, switchgrass, barley, hemp, kenaf, potatoes, sweetpotatoes, cassava, sunflower, fruit, molasses, corn, stover, grain, wheat,straw, cotton, other biomass, as well as many types of cellulose waste andharvestings, whichever has the best well-to-wheel assessment. An alternativeprocess to produce bio-ethanol from algae is being developed by the companyAlgenol. Rather than grow algae and then harvest and ferment it the algae growin sunlight and produce ethanol directly which is removed without killing thealgae. It is claimed the process can produce 6000 gallons per acre per yearcompared with 400 gallons for corn production. Currently, the first generationprocesses for the production of ethanol from corn use only a small part of thecorn plant: the corn kernels are taken from the corn plant and only the starch,which represents about 50% of the dry kernel mass, is transformed into ethanol.Two types of second generation processes are under development. The first typeuses enzymes and yeast to convert the plant cellulose into ethanol while thesecond type uses pyrolysis to convert the whole plant to either a liquidbio-oil or a syngas. Second generation processes can also be used with plantssuch as grasses, wood or agricultural waste material such as straw. Productionprocess See also: problems associated with corn-derived ethanol The basic stepsfor large scale production of ethanol are: microbial (yeast) fermentation ofsugars, distillation, dehydration (requirements vary, see Ethanol fuelmixtures, below), and denaturing (optional). Prior to fermentation, some cropsrequire saccharification or hydrolysis of carbohydrates such as cellulose andstarch into sugars. Saccharification of cellulose is called cellulolysis (seecellulosic ethanol). Enzymes are used to convert starch into sugar.Fermentation Main article: Ethanol fermentation Ethanol is produced bymicrobial fermentation of the sugar. Microbial fermentation will currently onlywork directly with sugars. Two major components of plants, starch andcellulose, are both made up of sugars, and can in principle be converted tosugars for fermentation. Currently, only the sugar (e.g. sugar cane) and starch(e.g. corn) portions can be economically converted. However, there is muchactivity in the area of cellulosic ethanol, where the cellulose part of a plantis broken down to sugars and subsequently converted to ethanol. DistillationEthanol plant in West Burlington, Iowa Ethanol plant in Sertozinho, Brazil. Forthe ethanol to be usable as a fuel, water must be removed. Most of the water isremoved by distillation, but the purity is limited to 95-96% due to theformation of a low-boiling water-ethanol azeotrope. The 95.6% m/m (96.5% v/v)ethanol, 4.4% m/m (3.5% v/v) water mixture may be used as a fuel alone, butunlike anhydrous ethanol, is immiscible in gasoline, so the water fraction istypically removed in further treatment in order to burn in combination withgasoline in gasoline engines. Dehydration There are basically five dehydrationprocesses to remove the water from an azeotropic ethanol/water mixture. Thefirst process, used in many early fuel ethanol plants, is called azeotropicdistillation and consists of adding benzene or cyclohexane to the mixture. Whenthese components are added to the mixture, it forms a heterogeneous azeotropicmixture in vapor-liquid-liquid equilibrium, which when distilled producesanhydrous ethanol in the column bottom, and a vapor mixture of water andcyclohexane/benzene. When condensed, this becomes a two-phase liquid mixture.Another early method, called extractive distillation, consists of adding aternary component which will increase ethanol’s relative volatility. When theternary mixture is distilled, it will produce anhydrous ethanol on the topstream of the column. With increasing attention being paid to saving energy,many methods have been proposed that avoid distillation all together fordehydration. Of these methods, a third method has emerged and has been adoptedby the majority of modern ethanol plants. This new process uses molecularsieves to remove water from fuel ethanol. In this process, ethanol vapor underpressure passes through a bed of molecular sieve beads. The bead’s pores aresized to allow absorption of water while excluding ethanol. After a period oftime, the bed is regenerated under vacuum to remove the absorbed water. Twobeds are used so that one is available to absorb water while the other is beingregenerated. This dehydration technology can account for energy saving of 3,000btus/gallon (840 kJ/l) compared to earlier azeotropic distillation. TechnologyEthanol-based engines Ethanol is most commonly used to power automobiles,though it may be used to power other vehicles, such as farm tractors, boats andairplanes. Ethanol (E100) consumption in an engine is approximately 51% higherthan for gasoline since the energy per unit volume of ethanol is 34% lower thanfor gasoline. However, the higher compression ratios in an ethanol-only engineallow for increased power output and better fuel economy than could be obtainedwith lower compression ratios. In general, ethanol-only engines are tuned togive slightly better power and torque output than gasoline-powered engines. Inflexible fuel vehicles, the lower compression ratio requires tunings that givethe same output when using either gasoline or hydrated ethanol. For maximum useof ethanol’s benefits, a much higher compression ratio should be used, whichwould render that engine unsuitable for gasoline use. When ethanol fuelavailability allows high-compression ethanol-only vehicles to be practical, thefuel efficiency of such engines should be equal to or greater than currentgasoline engines. Current high compression ethanol-only engine designs areapproximately 20-30% less fuel efficient than their gasoline-only counterparts.A 2004 MIT study and an earlier paper published by the Society of AutomotiveEngineers identify a method to exploit the characteristics of fuel ethanolsubstantially better than mixing it with gasoline. The method presents thepossibility of leveraging the use of alcohol to achieve definite improvementover the cost-effectiveness of hybrid electric. The improvement consists ofusing dual-fuel direct-injection of pure alcohol (or the azeotrope or E85) andgasoline, in any ratio up to 100% of either, in a turbocharged, highcompression-ratio, small-displacement engine having performance similar to anengine having twice the displacement. Each fuel is carried separately, with amuch smaller tank for alcohol. The high-compression (which increasesefficiency) engine will run on ordinary gasoline under low-power cruiseconditions. Alcohol is directly injected into the cylinders (and the gasolineinjection simultaneously reduced) only when necessary to suppress nock such aswhen significantly accelerating. Direct cylinder injection raises the alreadyhigh octane rating of ethanol up to an effective 130. The calculated over-allreduction of gasoline use and CO2 emission is 30%. The consumer cost paybacktime shows a 4:1 improvement over turbo-diesel and a 5:1 improvement overhybrid. In addition, the problems of water absorption into pre-mixed gasoline(causing phase separation), supply issues of multiple mix ratios andcold-weather starting are avoided. Ethanol’s higher octane rating allows anincrease of an engine’s compression ratio for increased thermal efficiency. Inone study, complex engine controls and increased exhaust gas recirculationallowed a compression ratio of 19.5 with fuels ranging from neat ethanol toE50. Thermal efficiency up to approximately that for a diesel was achieved.This would result in the MPG (miles per gallon) of a dedicated ethanol vehicleto be about the same as one burning gasoline. Since 1989 there have also beenethanol engines based on the diesel principle operating in Sweden. They areused primarily in city buses, but also in distribution trucks and wastecollectors. The engines, made by Scania, have a modified compression ratio, andthe fuel (known as ED95) used is a mix of 93.6 % ethanol and 3.6 %ignition improver, and 2.8% denaturants. The ignition improver makes itpossible for the fuel to ignite in the diesel combustion cycle. It is then alsopossible to use the energy efficiency of the diesel principle with ethanol.These engines have been used in the United Kingdom by Reading Transport but theuse of bioethanol fuel is now being phased out.why Engine cold start during thewinter The Brazilian 2008 Honda Civic flex-fuel has outside direct access tothe secondary reservoir gasoline tank in the front right side, thecorresponding fuel filler door is shown by the arrow. High ethanol blendspresent a problem to achieve enough vapor pressure for the fuel to evaporateand spark the ignition during cold weather (since ethanol tends to increasefuel enthalpy of vaporization). When vapor pressure is below 45 kPa starting acold engine becomes difficult. In order to avoid this problem at temperaturesbelow 11 Celsius (59 F), and to reduce ethanol higher emissions during coldweather, both the US and the European markets adopted E85 as the maximum blendto be used in their flexible fuel vehicles, and they are optimized to run atsuch a blend. At places with harsh cold weather, the ethanol blend in the UShas a seasonal reduction to E70 for these very cold regions, though it is stillsold as E85. At places where temperatures fall below -12 C (10 F) during thewinter, it is recommended to install an engine heater system, both for gasolineand E85 vehicles. Sweden has a similar seasonal reduction, but the ethanolcontent in the blend is reduced to E75 during the winter months. Brazilian flexfuel vehicles can operate with ethanol mixtures up to E100, which is hydrousethanol (with up to 4% water), which causes vapor pressure to drop faster ascompared to E85 vehicles. As a result, Brazilian flex vehicles are built with asmall secondary gasoline reservoir located near the engine. During a cold startpure gasoline is injected to avoid starting problems at low temperatures. Thisprovision is particularly necessary for users of Brazil’s southern and centralregions, where temperatures normally drop below 15 Celsius (59 F) during thewinter. An improved flex engine generation was launched in 2009 that eliminatesthe need for the secondary gas storage tank. In March 2009 Volkswagen do Brasillaunched the Polo E-Flex, the first Brazilian flex fuel model without anauxiliary tank for cold start. Ethanol fuel mixtures For more details on thistopic, see Common ethanol fuel mixtures. Hydrated ethanol gasoline type C pricetable for use in Brazil To avoid engine stall due to “slugs” of water in thefuel lines interrupting fuel flow, the fuel must exist as a single phase. Thefraction of water that an ethanol-gasoline fuel can contain without phaseseparation increases with the percentage of ethanol.. This shows, for example,that E30 can have up to about 2% water. If there is more than about 71%ethanol, the remainder can be any proportion of water or gasoline and phaseseparation will not occur. However, the fuel mileage declines with increasedwater content. The increased solubility of water with higher ethanol contentpermits E30 and hydrated ethanol to be put in the same tank since anycombination of them always results in a single phase. Somewhat less water istolerated at lower temperatures. For E10 it is about 0.5% v/v at 70 F anddecreases to about 0.23% v/v at -30 F. In many countries cars are mandated torun on mixtures of ethanol. Brazil requires cars be suitable for a 25% ethanolblend, and has required various mixtures between 22% and 25% ethanol, since ofJuly 2007 25% is required. The United States allows up to 10% blends, and somestates require this (or a smaller amount) in all gasoline sold. Other countrieshave adopted their own requirements. Beginning with the model year 1999, anincreasing number of vehicles in the world are manufactured with engines whichcan run on any fuel from 0% ethanol up to 100% ethanol without modification.Many cars and light trucks (a class containing minivans, SUVs and pickuptrucks) are designed to be flexible-fuel vehicles (also called dual-fuelvehicles). In older model years, their engine systems contained alcohol sensorsin the fuel and/or oxygen sensors in the exhaust that provide input to theengine control computer to adjust the fuel injection to achieve stochiometric(no residual fuel or free oxygen in the exhaust) air-to-fuel ratio for any fuelmix. In newer models, the alcohol sensors have been removed, with the computerusing only oxygen and airflow sensor feedback to estimate alcohol content. Theengine control computer can also adjust (advance) the ignition timing toachieve a higher output without pre-ignition when it predicts that higheralcohol percentages are present in the fuel being burned. This method is backedup by advanced knock sensors – used in most high performance gasoline enginesregardless of whether they’re designed to use ethanol or not – that detectpre-ignition and detonation. Fuel economy In theory, all fuel-driven vehicleshave a fuel economy (measured as miles per US gallon, or liters per100 km) that is directly proportional to the fuel’s energy content. Inreality, there are many other variables that come in to play that affect theperformance of a particular fuel in a particular engine. Ethanol containsapprox. 34% less energy per unit volume than gasoline, and therefore in theory,burning pure ethanol in a vehicle will result in a 34% reduction in miles perUS gallon, given the same fuel economy, compared to burning pure gasoline.Since ethanol has a higher octane rating, the engine can be made more efficientby raising its compression ratio. In fact using a variable turbocharger, thecompression ratio can be optimized for the fuel being used, making fuel economyalmost constant for any blend. . For E10 (10% ethanol and 90% gasoline), theeffect is small (~3%) when compared to conventional gasoline, and even smaller(1-2%) when compared to oxygenated and reformulated blends. However, for E85(85% ethanol), the effect becomes significant. E85 will produce lower mileagethan gasoline, and will require more frequent refueling. Actual performance mayvary depending on the vehicle. Based on EPA tests for all 2006 E85 models, theaverage fuel economy for E85 vehicles resulted 25.56% lower than unleadedgasoline. The EPA-rated mileage of current USA flex-fuel vehicles should beconsidered when making price comparisons, but it must be noted that E85 is ahigh performance fuel, with an octane rating of about 104, and should becompared to premium. In one estimate the US retail price for E85 ethanol is2.62 US dollar per gallon or 3.71 dollar corrected for energy equivalencycompared to a gallon of gasoline priced at 3.03 dollar. Brazilian cane ethanol(100%) is priced at 3.88 dollar against 4.91 dollar for E25 (as July 2007).Consumer production systems While biodiesel production systems have beenmarketed to home and business users for many years, commercialized ethanolproduction systems designed for end-consumer use have lagged in themarketplace. In 2008, two different companies announced home-scale ethanolproduction systems. The AFS125 Advanced Fuel System from Allard Research andDevelopment is capable of producing both ethanol and biodiesel in one machine,while the E-100 MicroFueler from E-Fuel Corporation is dedicated to ethanolonly. Experience by country The world’s top ethanol fuel producers in 2008 werethe United States with 9.0 billion U.S. liquid gallons (bg) and Brazil (6.47bg), accounting for 89% of world production of 17.33 billion US gallons (65.6million liters). Strong incentives, coupled with other industry developmentinitiatives, are giving rise to fledgling ethanol industries in countries suchas Canada, China, Thailand, Colombia, India, Australia, and some CentralAmerican countries. Nevertheless, ethanol has yet to make a dent in world oilconsumption of approximately 4000 million tonnes/yr (84 million barrels/day) in2006. Total Annual Ethanol Production (All Grades) by Country (2004-2006) Top15 countries (Millions of U.S. liquid gallons per year) Annual Fuel EthanolProduction by Country (2007-2008) Top 15 countries/blocks (Millions of U.S.liquid gallons per year) World rank Country 2006 2005 2004 World rankCountry/Region 2008 2007 1  United States 4,855 4,264 3,535 1  UnitedStates 9,000.0 6,498.6 2  Brazil 4,491 4,227 3,989 2  Brazil 6,472.25,019.2 3  China 1,017 1,004 964 3  European Union 733.6 570.3 4 India 502 449 462 4  China 501.9 486.0 5  France 251 240 219 5 Canada 237.7 211.3 6  Germany 202 114 71 6  Thailand 89.8 79.27  Russia 171 198 198 7  Colombia 79.3 74.9 8  Canada 153 61 618  India 66.0 52.8 9  Spain 122 93 79 9 Central America n/a 39.6 10 South Africa 102 103 110 10  Australia 26.4 26.4 11  Thailand93 79 74 11  Turkey n/a 15.8 12  United Kingdom 74 92 106 12 Pakistan n/a 9.2 13  Ukraine 71 65 66 13  Peru n/a 7.9 14 Poland 66 58 53 14  Argentina n/a 5.2 15  Saudi Arabia 52 32 7915  Paraguay n/a 4.7 World Total 13,489 12,150 10,770 World Total17,335.29 13,101.7 Brazil Main articles: Ethanol fuel in Brazil and History ofethanol fuel in Brazil Brazil has ethanol fuel available throughout thecountry. A typical Petrobras filling station at So Paulo with dual fuelservice, marked A for alcohol (ethanol) and G for gasoline. Typical Brazilian“flex” models from several carmakers, that run on any blend of ethanol andgasoline, from E20-E25 gasohol to E100 ethanol fuel. The Honda CG 150 Titan Mixwas launched in the Brazilian market in 2009 and became the first flex-fuelmotorcycle sold in the world. Brazil has the largest and most successfulbio-fuel programs in the world, involving production of ethanol fuel from sugarcane, and it is considered to have the world’s first sustainable biofuelseconomy. In 2006 Brazilian ethanol provided 18% of the country’s road transportsector fuel consumption needs, and by April 2008, more than 50% of fuelconsumption for the gasoline market. As a result of the increasing use ofethanol, together with the exploitation of domestic deep water oil sources,Brazil, which years ago had to import a large share of the petroleum needed fordomestic consumption, in 2006 reached complete self-sufficiency in oil supply.Together, Brazil and the United States lead the industrial world in globalethanol production, accounting together for 70% of the world’s production andnearly 90% of ethanol used for fuel. In 2006 Brazil produced 16.3 billionliters (4.3 billion U.S. liquid gallons), which represents 33.3% of the world’stotal ethanol production and 42% of the world’s ethanol used as fuel. Sugarcane plantations cover 3.6 million hectares of land for ethanol production,representing just 1% of Brazil’s arable land, with a productivity of 7,500liters of ethanol per hectare, as compared with the U.S. maize ethanolproductivity of 3,000 liters per hectare. The ethanol industry in Brazil ismore than 30 year-old and even though it is no longer subsidized, productionand use of ethanol was stimulated through: Low-interest loans for theconstruction of ethanol distilleries Guaranteed purchase of ethanol by thestate-owned oil company at a reasonable price Retail pricing of neat ethanol soit is competitive if not slightly favorable to the gasoline-ethanol blend Taxincentives provided during the 1980s to stimulate the purchase of neat ethanolvehicles. Guaranteed purchase and price regulation were ended some years ago,with relatively positive results. In addition to these other policies, ethanolproducers in the state of So Paulo established a research and technologytransfer center that has been effective in improving sugar cane and ethanolyields. There are no longer light vehicles in Brazil running on pure gasoline.Since 1977 the government made mandatory to blend 20% of ethanol (E20) withgasoline (gasohol), requiring just a minor adjustment on regular gasolinemotors. Today the mandatory blend is allowed to vary nationwide between 20% to25% ethanol (E25) and it is used by all regular gasoline vehicles andflexible-fuel vehicles. The Brazilian car manufacturing industry developedflexible-fuel vehicles that can run on any proportion of gasoline and ethanol.Introduced in the market in 2003, these vehicles became a commercial success.By December 2009 the fleet of “flex” cars and light commercial vehicles hadreached 9.35 million vehicles, and 183.3 thousand flex-fuel motorcycles. Theethanol-powered and “flex” vehicles, as they are popularly known, aremanufactured to tolerate hydrated ethanol (E100), an azeotrope composed of95.6% ethanol and 4.4% water. The latest innovation within the Brazilianflexible-fuel technology is the development of flex-fuel motorcycles. The firstflex motorcycle was launched to the market by Honda in March 2009. Produced byits Brazilian subsidiary Moto Honda da Amaznia, the CG 150 Titan Mix is soldfor around US$2,700. During the first eight months after its market launch theCG 150 Titan Mix has sold 139,059 motorcycles, capturing a 10.6% market share,and ranking second in sales of new motorcycles in the Brazilian market byOctober 2009. United States  United States fuel ethanol production andimports (2001-2008) (Millions of U.S. liquid gallons) Year Production ImportsDemand 2001 1,770 n/a n/a 2002 2,130 46 2,085 2003 2,800 61 2,900 2004 3,400161 3,530 2005 3,904 135 4,049 2006 4,855 653 5,377 2007 6,500 450 6,847 20089,000 556 9,637 Note: Demand figures includes stocks change and small exportsin 2005 Main article: Ethanol fuel in the United States The United Statesproduces and consumes more ethanol fuel than any other country in the world.Ethanol use as fuel dates back to Henry Ford, who in 1896 designed his firstcar, the “Quadricycle” to run on pure ethanol. Then in 1908, he produced thefamous Ford Model T capable of running on gasoline, ethanol or a combination ofboth. Ford continued to advocate for ethanol as fuel even during theprohibition. Most cars on the road today in the U.S. can run on blends of up to10% ethanol, and motor vehicle manufacturers already produce vehicles designedto run on much higher ethanol blends. In 2007 Portland, Oregon, became thefirst city in the United States to require all gasoline sold within city limitsto contain at least 10% ethanol. As of January 2008, three states Missouri,Minnesota, and Hawaii require ethanol to be blended with gasoline motor fuel.Many cities also require ethanol blends due to non-attainment of federal airquality goals. E85 FlexFuel Chevrolet Impala LT 2009, Miami, Florida. Severalmotor vehicle manufacturers, including Ford, Chrysler, and GM, sellflexible-fuel vehicles that can use gasoline and ethanol blends ranging frompure gasoline all the way up to 85% ethanol (E85). By mid-2006, there wereapproximately six million E85-compatible vehicles on U.S. roads. In the USAthere are currently about 1,900 stations distributing ethanol, although moststations are in the corn belt area. One of the debated methods for distributionin the US is using existing oil pipelines, which raises concerns overcorrosion. In any case, some companies proposed building a 1,700-mile pipelineto carry ethanol from the Midwest through Central Pennsylvania to New York. Theproduction of fuel ethanol from corn in the United States is controversial fora few reasons. Production of ethanol from corn is 5 to 6 times less efficientthan producing it from sugarcane. Ethanol production from corn is highlydependent upon subsidies and it consumes a food crop to produce fuel. Thesubsidies paid to fuel blenders and ethanol refineries have often been cited asthe reason for driving up the price of corn, and in farmers planting more cornand the conversion of considerable land to corn (maize) production whichgenerally consumes more fertilizers and pesticides than many other land uses.This is at odds with the subsidies actually paid directly to farmers that aredesigned to take corn land out of production and pay farmers to plant grass andidle the land, often in conjunction with soil conservation programs, in anattempt to boost corn prices. Recent developments with cellulosic ethanolproduction and commercialization may allay some of these concerns. Atheoretically much more efficient way of ethanol production has been suggestedto use sugar beets which make about the same amount of ethanol as corn withoutusing the corn food crop especially since sugar beets can grow in less tropicalconditions than sugar cane. Most of the ethanol consumed in the US is in theform of low blends with gasoline up to 10%. Shown a fuel pump in Marylandselling mandatory E10. On October 2008 the first “biofuels corridor” wasofficially opened along I-65, a major interstate highway in the central UnitedStates. Stretching from northern Indiana to southern Alabama, this corridorconsisting of more than 200 individual fueling stations makes it possible todrive a flex-fueled vehicle from Lake Michigan to the Gulf of Mexico withoutbeing further than a quarter tank worth of fuel from an E85 pump. On April 23,2009, the California Air Resources Board approved the specific rules and carbonintensity reference values for the California Low-Carbon Fuel Standard (LCFS)that will go into effect in January 1, 2011. During the consultation processthere was controversy regarding the inclusion and modeling of indirect land usechange effects. After the CARB’s ruling, among other criticisms,representatives of the US ethanol industry complained that this standardoverstates the environmental effects of corn ethanol, and also criticized theinclusion of indirect effects of land-use changes as an unfair penalty todomestically produced corn ethanol because deforestation in the developingworld is being tied to US ethanol production. The initial reference value setfor 2011 for LCFS means that Mid-west corn ethanol will not meet the Californiastandard unless current carbon intensity is reduced. A similar controversyarose after the U.S. Environmental Protection Agency (EPA) published on May 5,2009, its notice of proposed rulemaking for the new Renewable Fuel Standard(RFS). The draft of the regulations was released for public comment during a60-day period. EPA’s proposed regulations also included the carbon footprintfrom indirect land-use changes. On the same day, President Barack Obama signeda Presidential Directive with the aim to advance biofuels research and improvetheir commercialization. The Directive established a Biofuels InteragencyWorking Group comprise of three agencies, the Department of Agriculture, theEnvironmental Protection Agency, and the Department of Energy. This group willdeveloped a plan to increase flexible fuel vehicle use and assist in retailmarketing efforts. Also they will coordinate infrastructure policies impactingthe supply, secure transport, and distribution of biofuels. The group will alsocome up with policy ideas for increasing investment in next-generation fuels,such as cellulosic ethanol, and for reducing the environmental footprint ofgrowing biofuels crops, particularly corn-based ethanol. Europe Production ofBioethanol in the  European Union (GWh) No Country 2005 2006 1 Germany 978 2,554 2  Spain 1,796 2,382 3  France 853 1,482 4 Sweden 907 830 5  Italy 47 759 6  Poland 379 711 7 Hungary 207 201 8  Lithuania 47 107 9  Netherlands 47 89 10 Czech Republic 0 89 11  Latvia 71 71 12  Finland 77 0 27 Total5,411 9,274 n.a. = not available Consumption of Bioethanol in the European Union (GWh) No Country 2005 2006 2007 1  Germany 1,6823,544 3,408 2  France 871 1,719 3,174 3  Sweden 1,681 1,894 2,113 4 Spain 1,314 1,332 1,310 5  Poland 329 611 991 6  United Kingdom502 563 907 7  Bulgaria - 0 769 8  Austria 0 0 254 9  Slovakia 04 154 10  Lithuania 10 64 135 11  Hungary 28 136 107 12 Netherlands 0 179 101 13  Denmark - 42 70 14  Ireland 0 13 5415  Latvia 5 12 20 16  Luxembourg 0 0 10 17  Slovenia 0 2 9 18 Czech Republic 0 13 2 19  Italy 59 0 0 20  Finland 0 10 n.a. 27EU 6,481 10,138 13,563 The consumption of bioethanol is largest in Europe inGermany, Sweden, France and Spain. Europe produces equivalent to 90% of itsconsumption (2006). Germany produced ca 70% of its consumption, Spain 60% andSweden 50% (2006). In Sweden there are 792 E85 filling stations and in France131 E85 service stations with 550 more under construction. On Monday, September17, 2007 the first ethanol fuel pump was opened in Reykjavik, Iceland. Thispump is the only one of its kind in Iceland. The fuel is imported by Brimborg,a Volvo dealer, as a pilot to see how ethanol fueled cars work in Iceland. InThe Netherlands regular petrol with no bio-additives is slowly being outphased,since EU-legislation has been passed that requires the fraction of nonmineralorigin to become minimum 5.75% of the total fuel consumption volume in 2010.This can be realised by substitutions in diesel or in petrol of any biologicalsource; or fuel sold in the form of pure biofuel. (2007) There are only a fewgas stations where E85 is sold, which is an 85% ethanol, 15% petrol mix.Directly neighbouring country Germany is reported to have a much better biofuelinfrastructure and offers both E85 and E50. Biofuel is taxed equally as regularfuel. However, fuel tanked abroad cannot be taxed and a recent payment receiptwill in most cases suffice to prevent fines if customs check tank contents.(Authorities are aware of high taxation on fuels and cross-border fuelrefilling is a well-known practice.) An example of an ethanol powered bus. Thisis a Scania OmniCity which has been touring the United Kingdom, which does notuse the fuel widely. A larger fleet of similar buses will enter service inStockholm in 2008. Sweden Main article: Ethanol fuel in Sweden Sweden is theleading country in Europe regarding the use of ethanol as fuel, though it hasto import most of the ethanol. All Swedish gas stations are required by an actof parliament to offer at least one alternative fuel, and every fifth car inStockholm now drives at least partially on alternative fuels, mostly ethanol.The number of bioethanol stations in Europe is highest in Sweden, with 1,200stations and a fleet of 116 thousand flexi-fuel vehicles as of July 2008.Stockholm will introduce a fleet of Swedish-made electric hybrid buses in itspublic transport system on a trial basis in 2008. These buses will useethanol-powered internal-combustion engines and electric motors. The vehiclesdiesel engines will use ethanol. In order to achieve a broader use of biofuelsseveral government incentives were implemented. Ethanol, as the other biofuels,were exempted of both, the CO2 and energy taxes until 2009, resulting in a 30%price reduction at the pump of E85 fuel over gasoline. Furthermore, otherdemand side incentives for flexifuel vehicle owners include a USD 1,800 bonusto buyers of FFVs, exemption from the Stockholm congestion tax, up to 20%discount on auto insurance, free parking spaces in most of the largest cities,lower annual registration taxes, and a 20% tax reduction for flexifuel companycars. Also, a part of the program, the Swedish Government ruled that 25% oftheir vehicle purchases (excluding police, fire and ambulance vehicles) must bealternative fuel vehicles.; By the first months of 2008, this package ofincentives resulted in sales of flexible-fuel cars representing 25% of new carsales. Bioethanol stations  European Union Country Stations No/106 persons Sweden 1,200 131.26  France 211 3.27  Germany 193 2.35 Switzerland 40 5.27  Ireland 29 6.84  United Kingdom 22 0.36Asia China Main article: Bioenergy in China China is promoting ethanol-basedfuel on a pilot basis in five cities in its central and northeastern region, amove designed to create a new market for its surplus grain and reduceconsumption of petroleum. The cities include Zhengzhou, Luoyang and Nanyang incentral China’s Henan province, and Harbin and Zhaodong in Heilongjiangprovince, northeast China. Under the program, Henan will promote ethanol-basedfuel across the province by the end of this year. Officials say the move is ofgreat importance in helping to stabilize grain prices, raise farmers’ incomeand reducing petrol- induced air pollution. Thailand Thailand already use 10%ethanol (E10) widely on big scale on the local market. Beginning in 2008Thailand started with the sale of E20 and by late 2008 E85 flexible fuelvehicles were introduced with only two gas stations selling E85. Thailand isnow converting some of the cassava stock hold by the government into fuelethanol. Cassava-based ethanol productions are being ramped up to help managethe agricultural outputs of both cassava and sugar cane. With its abundantbiomass resources, it is believed that the fuel ethanol program will be a newmeans of job creation in the rural areas while enhancing the balance sheet offuel imports. Australia Main article: Ethanol fuel in Australia Legislation inAustralia imposes a 10% cap on the concentration of fuel ethanol blends. Blendsof 90% unleaded petrol and 10% fuel ethanol are commonly referred to as E10.E10 is available through service stations operating under the BP, Caltex, Shelland United brands as well as those of a number of smaller independents. Notsurprisingly, E10 is most widely available closer to the sources of productionin Queensland and New South Wales where Sugar Cane is grown. E10 is mostcommonly blended with 91 RON “regular unleaded” fuel. There is a requirementthat retailers label blends containing fuel ethanol on the dispenser. Due toethanol’s greater stability under pressure it is used by Shell in their 100octane fuel. Similarly IFS add 10% ethanol to their 91 octane fuel, label itpremium fuel and sell it more cheaply that regular unleaded. This is converseto the general practice of adding ethanol to a lesser quality fuel to bring itsoctane rating up to 91. Some concern was raised over the use of ethanol blendfuels in petrol vehicles in 2003, yet manufacturers widely claimed that theirvehicles were engined for such fuels. Since then there have been no reports ofadverse affects to vehicles running on ethanol blended fuels. Caribbean Basin United States fuel ethanol imports by country (2002-2007) (Millions ofU.S. liquid gallons) Country 2007 2006 2005 2004 2003 2002  Brazil 188.8433.7 31.2 90.3 0 0  Jamaica 75.2 66.8 36.3 36.6 39.3 29.0  ElSalvador 73.3 38.5 23.7 5.7 6.9 4.5  Trinidad and Tobago 42.7 24.8 10.0 00 0  Costa Rica 39.3 35.9 33.4 25.4 14.7 12.0 All countries in CentralAmerica, northern South America and the Caribbean are located in a tropicalzone with suitable climate for growing sugar cane. In fact, most of thesecountries have a long tradition of growing sugar cane mainly for producingsugar and alcoholic beverages. As a result of the guerilla movements in CentralAmerica, in 1983 the United States unilateral and temporarily approved theCaribbean Basin Initiative, allowing most countries in the region to benefitfrom several tariff and trade benefits. These benefits were made permanent in1990 and more recently, these benefits were replaced by the Caribbean BasinTrade and Partnership Act, approved in 2000, and the Dominican RepublicentralAmerica Free Trade Agreement that went to effect in 2008. All these agreementshave allowed several countries in the region to export ethanol to the U.S freeof tariffs. Until 2004, the countries that benefited the most were Jamaica andCosta Rica, but as the U.S. began demanding more fuel ethanol, the twocountries increased their exports and two others began exporting. In 2007,Jamaica, El Salvador, Trinidad & Tobago and Costa Rica exported together tothe U.S. a total of 230.5 million gallons of ethanol, representing 54.1% ofU.S. fuel ethanol imports. Brasil began exporting ethanol to the U.S. in 2004and exported 188.8 million gallons representing 44.3% of U.S. ethanol importsin 2007. The remaining imports that year came from Canada and China. In March2007, “ethanol diplomacy” was the focus of President George W. Bush’s LatinAmerican tour, in which he and Brazil’s president, Luiz Inacio Lula da Silva,were seeking to promote the production and use of sugar cane based ethanolthroughout Latin America and the Caribbean. The two countries also agreed toshare technology and set international standards for biofuels. The Braziliansugar cane technology transfer would allow several Central American, Caribbeanand Andean countries to take advantage of their tariff-free trade agreements toincrease or become exporters to the United States in the short-term. Also, inAugust 2007, Brazil’s President toured Mexico and several countries in CentralAmerica and the Caribbean to promote Brazilian ethanol technology. The ethanolalliance between the U.S. and Brazil generated some negative reactions fromVenezuela’s President Hugo Chavez, and by then Cuba’s President, Fidel Castro,who wrote that “you will see how many people among the hungry masses of ourplanet will no longer consume corn.” “Or even worse,” he continued, “byoffering financing to poor countries to produce ethanol from corn or any otherkind of food, no tree will be left to defend humanity from climate change.”‘Daniel Ortega, Nicaragua’s President, and one of the preferencial recipients ofBrazilian technical aid also voiced critics to the Bush plan, but he vowedsupport for sugar cane based ethanol during Lula’s visit to Nicaragua. ColombiaColombia’s ethanol program began in 2002, based on a law approved in 2001mandating a mix of 10% ethanol with regular gasoline, and the plan is togradually reach a 25% blend in twenty-years. Sugar cane-based ethanolproduction began in 2005, when the law went into effect, and as localproduction was not enough to supply enough ethanol to the entire country’sfleet, the program was implemented only on cities with more than 500,000inhabitants, such as Cali, Pereira, and the capital city of Bogot. All of theethanol production comes from the Department of Valle del Cauca, Colombia’straditional sugar cane region. Cassava is the second source of ethanol, andpotatoes and castor oil are also being studied. On March 2009 the Colombiangovernment enacted a mandate to introduce E85 flexible-fuel cars. The executivedecree applies to all gasoline-powered vehicles with engines smaller than 2.0liters manufactured, imported, and commercialized in the country beginning in2012, mandating that 60% of such vehicles must have flex-fuel engines capableof running with gasoline or E85, or any blend of both. By 2014 the mandatoryquota is 80% and it will reach 100% by 2016. All vehicles with engines biggerthan 2.0 liters must be E85 capable starting in 2013. The decree also mandatesthat by 2011 all gasoline stations must provide infrastructure to guaranteeavailability of E85 throughout the country. The mandatory introduction of E85flex-fuels has been controversial. Costa Rica The government, based on theNational Biofuel Program, established the mandatory use of all gasoline sold inCosta Rica with a blend of around 7.5% ethanol, starting in October 2008. Theimplementation phase follows a two year trial that took place in the provincesof Guanacaste and Puntarenas. The government expects to increase the percent ofethanol mixed with gasoline to 12% in the next 4 to 5 years. The Costa Ricangovernment is pursuing this policy to lower the country’s dependency of foreignoil and to reduce the amount of greenhouse gases produced. The plan also callsfor an increase in ethanol producing crops and tax breaks for flex-fuelvehicles and other alternative fuel vehicles. However, the introduction of theblend of 7% ethanol was postponed in September 2008 until the beginning of2009. This delay was due to a request by the national association of fuelretailers to have more time available to adapt their fueling infrastructure.Additional delays caused another postponement, as fueling stations were notready yet for handling ethanol fuel, and now implementation is expected forNovember 2009. Despite the official postponement, during the months of Februaryand March 2009, ethanol in different blends was sold without warning toconsumers, which was cause for complains. The national distribution company,RECOPE, explained that it had already bought 50,000 barrels of ethanol storedand ready for distribution, so it decided to used as an oxygenate insubstitution of MTBE. Nevertheless, retail sales of E7 continue uninterruptedin the trial regions of Guanacaste and the Central Pacific for three years now.El Salvador As a result of the cooperation agreement between the United Statesand Brazil, El Salvador was chosen in 2007 to lead a pilot experience tointroduce state-of-the-art technology for growing sugar cane for production ofethanol fuel in Central America, as this technical bilateral cooperation islooking for helping Central American countries to reduce their dependence onforeign oil. Comparison of Brazil and the U.S. Evolution of the ethanolproductivity per hectare of sugarcane planted in Brazil between 1975 and 2004.Source: Goldemberg (2008). Brazil’s sugar cane-based industry is far moreefficient than the U.S. corn-based industry. Brazilian distillers are able toproduce ethanol for 22 cents per liter, compared with the 30 cents per literfor corn-based ethanol. Sugarcane cultivation requires a tropical orsubtropical climate, with a minimum of 600 mm (24 in) of annualrainfall. Sugarcane is one of the most efficient photosynthesizers in the plantkingdom, able to convert up to 2% of incident solar energy into biomass.Ethanol is produced by yeast fermentation of the sugar extracted from sugarcane. Sugarcane production in the United States occurs in Florida, Louisiana,Hawaii, and Texas. In prime growing regions, such as Hawaii, sugarcane canproduce 20 kg for each square meter exposed to the sun. The first threeplants to produce sugar cane-based ethanol are expected to go online inLouisiana by mid 2009. Sugar mill plants in Lacassine, St. James and Bunkiewere converted to sugar cane-based ethanol production using Colombiantechnology in order to make possible a profitable ethanol production. Thesethree plants will produce 100 million gallons of ethanol within five years.U.S. corn-derived ethanol costs 30% more because the corn starch must first beconverted to sugar before being distilled into alcohol. Despite this costdifferential in production, in contrast to Japan and Sweden, the U.S. does notimport much of Brazilian ethanol because of U.S. trade barriers correspondingto a tariff of 54-cent per gallon a levy designed to offset the 45-cent pergallon blender’s federal tax credit that is applied to ethanol no matter itscountry of origin. One advantage U.S. corn-derived ethanol offers is theability to return 1/3 of the feedstock back into the market as a replacementfor the corn used in the form of Distillers Dried Grain. Comparison of keycharacteristics between the ethanol industries in the United States and BrazilCharacteristic  Brazil  U.S. Units/comments Feedstock Sugar caneMaize Main cash crop for ethanol production, the US has less than 2% from othercrops. Total ethanol fuel production (2008) 6,472 9,000 Million U.S. liquidgallons Total arable land 355 270(1) Million hectares. Total area used forethanol crop (2006) 3.6 (1%) 10 (3.7%) Million hectares (% total arable)Productivity per hectare 6,800-8,000 3,800-4,000 Liters of ethanol per hectare.Brazil is 727 to 870 gal/acre (2006), US is 321 to 424 gal/acre (2003) Energybalance (input energy productivity) 8.3 to 10.2 1.3 to 1.6 Ratio of the energyobtained from ethanol/energy expended in its production Estimated GHG emissionsreduction 86-90%(2) 10-30%(2) % GHGs avoided by using ethanol instead ofgasoline, using existing crop land (No ILUC). Full life-cycle carbon intensity73.40 105.10(3) Grams of CO2 equivalent released per MJ of energy produced,includes indirect land use changes. Estimated payback time for GHG emissions 17years(4) 93 years(4) Brazilian cerrado for sugarcane and US grassland for corn.Land use change scenarios by Fargione Flexible-fuel vehicle fleet 9.3 million8.0 million Autos and light trucks only. Brazil as of December 2009 (E100FFVs). U.S. as of early 2009 (E85 FFVs). Ethanol fueling stations in thecountry 35,017 (100%) 2,113(1%) As % of total gas stations in the country.Brazil by December 2007. U.S. by January 2010. (170,000 total.) Ethanol’s sharein the gasoline market 50%(5) 4% As % of total consumption on a volumetricbasis. Brazil as of April 2008. US as of December 2006. Cost of production(USD/gallon) 0.83 1.14 2006/2007 for Brazil (22/liter), 2004 for U.S.(35/liter) Government subsidy (in USD) 0 (6) 0.45/gallon U.S. since 2009-01-01as a tax credit. Brazilian ethanol production is no longer subsidized.(6)Import tariffs (in USD) 20% (FOB) 0.54/gallon Brazil does not import ethanolfuel since 2002. The U.S. does in a regular basis. Notes: (1) Only contiguousU.S., excludes Alaska. (2) Assuming no land use change. (3) CARB estimate forMidwest corn ethanol. California’s gasoline carbon intensity is 95.86 blendedwith 10% ethanol. (4) Assuming direct land use change. (5) If diesel-poweredvehicles are included and due to ethanol’s lower energy content by volume,bioethanol represented 16.9% of the road sector energy consumption in 2007. (6)Brazilian ethanol production is no longer subsidized, but gasoline is heavilytaxed favoring ethanol fuel consumption (~54% tax). By the end of July 2008,when oil prices were close to its latest peak and the Brazilian Real exchangerate to the US dollar was close to its most recent minimum, the averagegasoline retail price at the pump in Brazil was USD 6.00 per gallon, while theaverage US price was USD 3.98 per gallon. The latest gas retail price increasein Brazil occurred in late 2005, when oil price was at USD 60 per barrel.Environment Energy balance Energy balance Country Type Energy balance United States Corn ethanol 1.3  Brazil Sugarcane ethanol 8 Germany Biodiesel 2.5  United States Cellulosic ethanol 236experimental, not in commercial production depending on production method Mainarticle: Ethanol fuel energy balance All biomass goes through at least some ofthese steps: it needs to be grown, collected, dried, fermented, and burned. Allof these steps require resources and an infrastructure. The total amount ofenergy input into the process compared to the energy released by burning theresulting ethanol fuel is known as the energy balance (or “Net energy gain”).Figures compiled in a 2007 by National Geographic Magazine point to modestresults for corn ethanol produced in the US: one unit of fossil-fuel energy isrequired to create 1.3 energy units from the resulting ethanol. The energybalance for sugarcane ethanol produced in Brazil is more favorable, 1:8. Energybalance estimates are not easily produced, thus numerous such reports have beengenerated that are contradictory. For instance, a separate survey reports thatproduction of ethanol from sugarcane, which requires a tropical climate to growproductively, returns from 8 to 9 units of energy for each unit expended, ascompared to corn which only returns about 1.34 units of fuel energy for eachunit of energy expended. Carbon dioxide, a greenhouse gas, is emitted duringfermentation and combustion. However, this is canceled out by the greateruptake of carbon dioxide by the plants as they grow to produce the biomass.When compared to gasoline, depending on the production method, ethanol releasesless greenhouse gases. Air pollution Compared with conventional unleadedgasoline, ethanol is a particulate-free burning fuel source that combusts withoxygen to form carbon dioxide, water and aldehydes. Gasoline produces 2.44 CO2equivalent kg/l and ethanol 1.94 (this is 21% less CO2)[citation needed]. TheClean Air Act requires the addition of oxygenates to reduce carbon monoxideemissions in the United States. The additive MTBE is currently being phased outdue to ground water contamination, hence ethanol becomes an attractivealternative additive. Current production methods include air pollution from themanufacturer of macronutrient fertilizers such as ammonia. A study byatmospheric scientists at Stanford University found that E85 fuel wouldincrease the risk of air pollution deaths relative to gasoline by 9% in LosAngeles, USA: a very large, urban, car-based metropolis that is a worst casescenario. Ozone levels are significantly increased, thereby increasingphotochemical smog and aggravating medical problems such as asthma. ManufactureIn 2002, monitoring the process of ethanol production from corn revealed thatthey released VOCs (volatile organic compounds) at a higher rate than hadpreviously been disclosed. The Environmental Protection Agency (EPA)subsequently reached settlement with Archer Daniels Midland and Cargill, two ofthe largest producers of ethanol, to reduce emission of these VOCs. VOCs areproduced when fermented corn mash is dried for sale as a supplement forlivestock feed. Devices known as thermal oxidizers or catalytic oxidizers canbe attached to the plants to burn off the hazardous gases. Carbon dioxide Seealso: Low-carbon fuel standard UK government calculation of carbon intensity ofcorn bioethanol grown in the US and burnt in the UK. Graph of UK figures forthe carbon intensity of bioethanol and fossil fuels. This graph assumes thatall bioethanols are burnt in their country of origin and that previouslyexisting cropland is used to grow the feedstock. The calculation of exactly howmuch carbon dioxide is produced in the manufacture of bioethanol is a complexand inexact process, and is highly dependent on the method by which the ethanolis produced and the assumptions made in the calculation. A calculation shouldinclude: The cost of growing the feedstock The cost of transporting thefeedstock to the factory The cost of processing the feedstock into bioethanolSuch a calculation may or may not consider the following effects: The cost ofthe change in land use of the area where the fuel feedstock is grown. The costof transportation of the bioethanol from the factory to its point of use Theefficiency of the bioethanol compared with standard gasoline The amount ofCarbon Dioxide produced at the tail pipe. The benefits due to the production ofuseful bi-products, such as cattle feed or electricity. The graph on the rightshows figures calculated by the UK government for the purposes of the Renewabletransport fuel obligation. The January 2006 Science article from UC Berkeley’sERG, estimated reduction from corn ethanol in GHG to be 13% after reviewing alarge number of studies. However, in a correction to that article releasedshortly after publication, they reduce the estimated value to 7.4%. A NationalGeographic Magazine overview article (2007) puts the figures at 22% less CO2emissions in production and use for corn ethanol compared to gasoline and a 56%reduction for cane ethanol. Carmaker Ford reports a 70% reduction in CO2emissions with bioethanol compared to petrol for one of their flexible-fuelvehicles. An additional complication is that production requires tilling newsoil which produces a one-off release of GHG that it can take decades orcenturies of production reductions in GHG emissions to equalize. As an example,converting grass lands to corn production for ethanol takes about a century ofannual savings to make up for the GHG released from the initial tilling. Changein land use See also: Indirect land use change impacts of biofuels Large-scalefarming is necessary to produce agricultural alcohol and this requiressubstantial amounts of cultivated land. University of Minnesota researchersreport that if all corn grown in the U.S. were used to make ethanol it woulddisplace 12% of current U.S. gasoline consumption. There are claims that landfor ethanol production is acquired through deforestation, while others haveobserved that areas currently supporting forests are usually not suitable forgrowing crops. In any case, farming may involve a decline in soil fertility dueto reduction of organic matter, a decrease in water availability and quality,an increase in the use of pesticides and fertilizers, and potential dislocationof local communities. However, new technology enables farmers and processors toincreasingly produce the same output using less inputs. Cellulosic ethanolproduction is a new approach which may alleviate land use and related concerns.Cellulosic ethanol can be produced from any plant material, potentiallydoubling yields, in an effort to minimize conflict between food needs vs. fuelneeds. Instead of utilizing only the starch by-products from grinding wheat andother crops, cellulosic ethanol production maximizes the use of all plantmaterials, including gluten. This approach would have a smaller carbonfootprint because the amount of energy-intensive fertilisers and fungicidesremain the same for higher output of usable material. The technology forproducing cellulosic ethanol is currently in the commercialization stage. Manyanalysts suggest that, whichever ethanol fuel production strategy is used, fuelconservation efforts are also needed to make a large impact on reducingpetroleum fuel use. Using Ethanol for Electricity Converting biomass toelectricity for charging electric vehicles may be a more “climate-friendly”transportation option than using biomass to produce ethanol fuel, according toan analysis published in Science in May. “You make more efficient use of theland and more efficient use of the plant biomass by making electricity ratherthan ethanol,” said Elliott Campbell, an environmental scientist at theUniversity of California at Merced, who led the research. “It’s another reasonthat, rather than race to liquid biofuels, we should consider other uses ofbio-resources.” For bioenergy to become a widespread climate solution, however,technological breakthroughs are necessary, analysts say. Researchers continueto search for more cost-effective developments in both cellulosic ethanol andadvanced vehicle batteries. Health Costs of Ethanol Emissions For each billionethanol-equivalent gallons of fuel produced and combusted in the US, thecombined climate-change and health costs are $469 million for gasoline, $472952million for corn ethanol depending on biorefinery heat source (natural gas,corn stover, or coal) and technology, but only $123208 million for cellulosicethanol depending on feedstock (prairie biomass, Miscanthus, corn stover, orswitchgrass). Efficiency of common crops As ethanol yields improve or differentfeedstocks are introduced, ethanol production may become more economicallyfeasible in the US. Currently, research on improving ethanol yields from eachunit of corn is underway using biotechnology. Also, as long as oil pricesremain high, the economical use of other feedstocks, such as cellulose, becomeviable. By-products such as straw or wood chips can be converted to ethanol.Fast growing species like switchgrass can be grown on land not suitable forother cash crops and yield high levels of ethanol per unit area. Crop Annualyield (Liters/hectare) Annual yield (US gal/acre) Greenhouse-gas savings (% vs.petrol)(1) Comments Miscanthus 7300 780 3773 Low-input perennial grass. Ethanolproduction depends on development of cellulosic technology. Switchgrass31007600 330810 3773 Low-input perennial grass. Ethanol production depends ondevelopment of cellulosic technology. Breeding efforts underway to increaseyields. Higher biomass production possible with mixed species of perennialgrasses. Poplar 37006000 400640 51100 Fast-growing tree. Ethanol productiondepends on development of cellulosic technology. Completion of genomicsequencing project will aid breeding efforts to increase yields. Sugar cane68008000 727870 8796 Long-season annual grass. Used as feedstock for mostbioethanol produced in Brazil. Newer processing plants burn residues not usedfor ethanol to generate electricity. Only grows in tropical and subtropicalclimates. Sweet sorghum 25007000 270750 No data Low-input annual grass. Ethanolproduction possible using existing technology. Grows in tropical and temperateclimates, but highest ethanol yield estimates assume multiple crops per year(only possible in tropical climates). Does not store well. Corn 31004000 3304241020 High-input annual grass. Used as feedstock for most bioethanol produced inUSA. Only kernels can be processed using available technology; development ofcommercial cellulosic technology would allow stover to be used and…

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