Ethanol

Ethanol is an alcohol-based alternative fuel produced by fermenting and distilling starch crops that have been converted into simple sugars. Corn, barley, wheat, and sugarcane are all examples of renewable resources that can be converted into ethanol. Ethanol can also be produced from cellulosic biomass, such as trees and grasses, and is called bioethanol. Ethanol is most commonly used to increase octane and improve the emissions quality of gasoline. It is a clear, colorless liquid and typically used as a gasoline additive. However, questions have been raised about whether production of ethanol and other biofuels consumes more energy than is saved through the use of these fuels.