Ethanol is an alcohol (C₂H₅OH) that can be produced either by a petrochemical process or through the fermentation of sugar by yeast. It is the type of alcohol found in alcoholic beverages.  It is also viewed as a renewal energy source to be used as a substitute for gasoline in motor vehicles.

The sugars needed for the fermentation process can come from a number of sources. In the United States the predominant source is corn, in Brazil it is sugarcane. With the Energy Policy Act of 2005, (EPAC-2005) there is a stated U.S. production goal of 7.5 billion gallons of renewable fuels by the year 2012 and a major portion this will come from the production of ethanol.  When corn is used in the production of ethanol and using the more common dry milling process, each bushel of corn typically produces 2.8 gallons of ethanol and 17-18 pounds of the co-product, dry distiller’s grains with solubles (DDGS).

With the push for the production of renewable fuels, it has had a major impact on US agriculture. It has reduced the amount of corn available for export, tightening supplies of corn available for feeding livestock and has increased the supply of DDGS, a high-protein feed.  There are several articles that provide details on how the US agriculture has been impacted by the growth of the ethanol industry.

Traditionally corn and sugar have been the most viable ethanol producers, however, important research with other crops such as switchgrass as well as cellulosic technology give a great deal of optimism for future production and efficiency.