Ethanol

Ethanol is a clean-burning, clear, colorless liquid that is produced from renewable sources and typically used as a gasoline additive. However, questions have been raised about whether production of ethanol and other biofuels consume more energy than is saved through the use of these fuels.

What is 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. It is a clear, colorless liquid and typically used as a gasoline additive.

How ethanol is formed

Ethanol is made by fermenting and then distilling starch or sugar crops such as sugarcane, barley, rice, maize, potatoes, sorghum, sunflower, sugar beets, wheat and other grains, or even cornstalks, fruit and vegetable waste. It can also be produced from cellulosic biomass, such as trees and grasses, and is called bioethanol. Read more.

History of ethanol

Ethanol is not a new fuel. It was used as far back as the 1860s to light homes and businesses. In 1908, Henry Ford's Model T was built to run on mixture of gasoline and alcohol, which he called the "fuel of the future." Read more.

Uses for ethanol

Ethanol is most commonly used to increase octane and improve the emissions quality of gasoline. It is also used as a solvent in the manufacturing of varnishes and perfumes, a preservative for biological specimens,in the preparation of essences and flavorings, in medicines and drugs, and as a disinfectant.

Demand for ethanol

In the transportation sector, ethanol is the most widely used liquid biofuel in the world. Roughly one quarter of corn grown in the United States is used to produce ethanol, and overall consumption of ethanol in the country hit a record high last year, exceeding 9 billion gallons, according to the U.S. Congressional Budget Office. Nearly 3 billion bushels of corn were used to produce ethanol in the United States last year -- an increase of almost a billion bushels over 2007.

Renewable energy represents 46 percent of Brazil’s total annual energy supply, one-third of which is ethanol.

Ethanol pros and cons

Pros

• Easily manufactured
• Fewer emissions than fossil fuel sources
• Carbon-neutral (C02 emissions offset by photosynthesis in plants)

Cons

• Source must be near usage to cut transportation costs
• Extensive use of cropland
• Less energy in a gallon of ethanol than in a gallon of gasoline/diesel fuel
• Costs more than gasoline to produce
• Currently requires government subsidy to be affordable to consumers
• Requires engine conversion to be used as fuel

More ethanol resources

American Coalition for Ethanol - Provides an introduction to ethanol, how it is made, and several brochures and publications covering ethanol-related topics.

Ethanol Promotion and Information Council - Offers facts about ethanol and how it is made.