E85 automobile fuel

The production of ethanol by fermentation of grains and sugars is one of the oldest known organic reactions, going back at least 8()()0 years in the Middle East and perhaps as many as 9000 years in China. Fermentation is carried out by adding yeast to an aqueous sugar solution, wlicic cnz.yines break down carbohydrates into ethanol and CO2. As noted in the chapter introduction, approximately 4 billion gallons of ethanol is produced each year in the United States by fermentation, with essentially the entire amount used to make E85 automobile fuel. 

The ethanol concentration in gasoline can vary from 10% (called E10) to 70% and up to 85% (called E85). All automobiles can use E10 fuel, but only the flex-fuel vehicles (6 million cars in the United States, which is 2.4% of the automobile fleet) can run on E85. The flex-fuel car gas tanks are... 

While most automotive fuel sold in the United States contains 10% ethanol, it is also possible to power the vehicle on a blend that is primarily ethanol. The optimum blend sold in both the U.S. and European markets for flexible-fuel vehicles is E85 (mixture of gasoline containing 85% of ethanol). In Brazil, flex-fuel vehicles can operate with ethanol mixtures up to ElOO. The Brazihan 2008 Honda Civic flex-fuel car is built with a secondary reservoir gasoline tank. In March 2009 the first Polo E-Hex was launched in Brazil without the auxiliary gasoline tank. Ethanol-based engines can be used to power automobiles, tractors, city buses, distribution trucks, and waste collectors. 

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