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Ethanol fuel is ethanol (ethyl alcohol), the same type of alcohol found in alcoholic beverages. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline. The first production car running entirely on ethanol was the Fiat 147, introduced in 1978 in Brazil by Fiat. Nowadays, cars are able to run using 100% ethanol fuel or a mix of Ethanol and gasoline (aka flex-fuel). It is commonly made from biomass such as corn or sugarcane. World ethanol production for transport fuel tripled between 2000 and 2007 from 17 billion to more than 52 billion liters. From 2007 to 2008, the share of ethanol in global gasoline type fuel use increased from 3.7% to 5.4%. In 2011 worldwide ethanol fuel production reached 22.36 billion U.S. liquid gallons (bg) (84.6 billion liters), with the United States as the top producer with 13.9 bg (52.6 billion liters), accounting for 62.2% of global production, followed by Brazil with 5.6 bg (21.1 billion liters).〔 Ethanol fuel has a "gasoline gallon equivalency" (GGE) value of , which means 1.5 gallons of ethanol produces the energy of one gallon of gasoline.〔(【引用サイトリンク】Gasoline Gallon Equivalent (GGE) Definition )〕 Ethanol fuel is widely used in Brazil and in the United States, and together both countries were responsible for 87.1% of the world's ethanol fuel production in 2011.〔 Most cars on the road today in the U.S. can run on blends of up to 10% ethanol, and ethanol represented 10% of the U.S. gasoline fuel supply derived from domestic sources in 2011.〔 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). By December 2011 Brazil had a fleet of 14.8 million flex-fuel automobiles and light trucks〔 pp. 62–63.〕〔 ''Carta de ANFAVEA 308'' pp. 4.〕 and 1.5 million flex-fuel motorcycles that regularly use neat ethanol fuel (known as E100). Bioethanol is a form of quasi-renewable energy that can be produced from agricultural feedstocks. It can be made from very common crops such as sugarcane, potato, cassava and corn. There has been considerable debate about how useful bioethanol is in replacing gasoline. Concerns about its production and use relate to increased food prices due to the large amount of arable land required for crops,〔(【引用サイトリンク】title=Deforestation diesel – the madness of biofuel )〕 as well as the energy and pollution balance of the whole cycle of ethanol production, especially from corn.〔Youngquist, W. ''Geodestinies'', National Book Company, Portland, Oregon, p.499〕 Recent developments with cellulosic ethanol production and commercialization may allay some of these concerns. Cellulosic ethanol offers promise because cellulose fibers, a major and universal component in plant cells walls, can be used to produce ethanol.〔(【引用サイトリンク】title=Industrial & Environmental )〕 According to the International Energy Agency, cellulosic ethanol could allow ethanol fuels to play a much bigger role in the future. ==Chemistry== During ethanol fermentation, glucose and other sugars in the corn (or sugarcane or other crops) are converted into ethanol and carbon dioxide. :C6H12O6 → 2 C2H5OH+ 2 CO2 + heat Ethanol fermentation is not 100% selective with other side products such acetic acid, glycols and many other products produced. They are mostly removed during ethanol purification. Fermentation takes place in an aqueous solution. The resulting solution has an ethanol content of around 15%. Ethanol is subsequently isolated and purified by a combination of adsorption and distillation. During combustion ethanol reacts with oxygen to produce carbon dioxide, water, and heat: :C2H5OH + 3 O2 → 2 CO2 + 3 H2O + heat Starch and cellulose molecules are strings of glucose molecules. It is also possible to generate ethanol out of cellulosic materials. That, however, requires a pretreatment that splits the cellulose into glycose molecules and other sugars that subsequently can be fermented. The resulting product is called cellulosic ethanol, indicating its source. Ethanol may also be produced industrially from ethylene by hydration of the double bond in the presence of catalysts and high temperature. :C2H4 + H2O → C2H5OH By far the largest fraction of the global ethanol production, however, is produced by fermentation. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ethanol fuel」の詳細全文を読む スポンサード リンク
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