![]() Agricultural feedstocks are considered renewable because they get energy from the sun using photosynthesis, provided that all minerals required for growth (such as nitrogen and phosphorus) are returned to the land. īio-ethanol is usually obtained from the conversion of carbon-based feedstock. Petroleum derived ethanol (synthetic ethanol) is chemically identical to bio-ethanol and can be differentiated only by radiocarbon dating. ![]() The principal suppliers are plants in the United States, Europe, and South Africa. Two million short tons (1,786,000 long tons 1,814,000 t) of petroleum-derived ethanol are produced annually. It can also be obtained via ethylene or acetylene, from calcium carbide, coal, oil gas, and other sources. ![]() It is made by the catalytic hydration of ethylene with sulfuric acid as the catalyst. Most ethanol is produced by fermentation.Ībout 5% of the ethanol produced in the world in 2003 was actually a petroleum product. The resulting product is called cellulosic ethanol, indicating its source.Įthanol is also produced industrially from ethylene by hydration of the double bond in the presence of a catalyst and high temperature. That, however, requires a pretreatment that splits the cellulose into glucose molecules and other sugars that subsequently can be fermented. It is also possible to generate ethanol out of cellulosic materials. Starch and cellulose molecules are strings of glucose molecules. Ethanol is subsequently isolated and purified by a combination of adsorption and distillation.ĭuring combustion, ethanol reacts with oxygen to produce carbon dioxide, water, and heat:Ĭ 2H 5OH + 3 O 2 → 2 CO 2 + 3 H 2O + heat The resulting solution has an ethanol content of around 15%. Fermentation takes place in an aqueous solution. They are mostly removed during ethanol purification. All bonds are single bonds.ĭuring ethanol fermentation, glucose and other sugars in the corn (or sugarcane or other crops) are converted into ethanol and carbon dioxide.Įthanol fermentation is not 100% selective with side products such as acetic acid and glycols. Concerns about its production and use relate to increased food prices due to the large amount of arable land required for crops, as well as the energy and pollution balance of the whole cycle of ethanol production, especially from corn. There has been considerable debate about how useful bioethanol is in replacing gasoline. It can be made from very common crops such as hemp, sugarcane, potato, cassava and corn. By December 2011 Brazil had a fleet of 14.8 million flex-fuel automobiles and light trucks and 1.5 million flex-fuel motorcycles that regularly use neat ethanol fuel (known as E100).īioethanol is a form of renewable energy that can be produced from agricultural feedstocks. Since 1976 the Brazilian government has made it mandatory to blend ethanol with gasoline, and since 2007 the legal blend is around 25% ethanol and 75% gasoline (E25). Some flexible-fuel vehicles are able to use up to 100% ethanol. gasoline fuel supply derived from domestic sources in 2011. can run on blends of up to 10% ethanol, and ethanol represented 10% of the U.S. Įthanol-blended fuel is widely used in Brazil, the United States, and Europe (see also Ethanol fuel by country). to replace the energy of 1 volume of gasoline, 1.5 times the volume of ethanol is needed. Įthanol fuel has a " gasoline gallon equivalency" (GGE) value of 1.5, i.e. In 2011 worldwide ethanol fuel production reached 8.46 ×10 10 liters (2.23 ×10 10 U.S. gal 1.86 ×10 10 imp gal) with the United States of America and Brazil being the top producers, accounting for 62.2% and 25% of global production, respectively. From 2007 to 2008, the share of ethanol in global gasoline type fuel use increased from 3.7% to 5.4%. Ethanol is commonly made from biomass such as corn or sugarcane. The first production car running entirely on ethanol was the Fiat 147, introduced in 1978 in Brazil by Fiat. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline. Ethanol fuel is ethyl alcohol, the same type of alcohol found in alcoholic beverages, used as fuel.
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