Ethanol—A Renewable Energy Source
What is ethanol?
Ethanol is a clear, colorless liquid alcohol, which is also called ethyl alcohol or grain alcohol. Ethanol is a renewable source of energy made by fermenting any biomass high in carbohydrates (starch, sugar, and cellulose) through a process similar to brewing beer. It can be produced from ethylene, or any material containing starch or sugar. It is most commonly produced from field corn, sugar cane, or wheat, but is also being made from other grains, cheese whey, and waste from the beverage, brewery, and wine industries. In the US, it is mainly produced from corn grown in the mid-west.
Ethanol contains hydrogen and carbon, just like gasoline, but it also contains oxygen. By putting the oxygen within the fuel, the combustion process is more complete. In other words, the oxygen helps the fuel burn better and more cleanly. New technologies may soon enable the production of ethanol from the cellulose of rice straw, forest residue, sawdust, pulp and paper sludge, and dedicated energy crops such as switch-grass, prairie grass, and fast-growing poplar trees. Ethanol is denatured or poisoned (e.g, blended with gasoline) to prevent human ingestion.
Ethanol has been used as a transportation fuel since Henry Ford and other transportation pioneers began developing automobiles. In the 1880s, Ford used ethanol to fuel one of his first automobiles, the quadricycle. In 1908, the Ford Model T was designed with a carburetor adjustment that could allow the vehicle to run on ethanol fuel produced by American farmers. Ford’s vision was to “build a vehicle affordable to the working family and powered by a fuel that would boost the rural farm economy.”
During the 1930s, more than 2,000 service stations in the Midwest sold ethanol made from corn, but the ethanol industry closed down in the ‘40s with the coming of low-priced middle-east petroleum. During World War I and II in both the United States and in Europe, alcohol fuels supplemented supplies of petroleum-based fuels.
The oil crisis in the 1970s raised the price of oil and gas and reignited the gasohol era, when gasoline was extended with the addition of 10 percent ethanol. (Gasohol is not considered an alternative fuel.) When gasoline became more plentiful, ethanol was blended with gasoline to increase the octane rating, and the name gasohol was replaced with names reflecting the increased octane. Unleaded plus or super unleaded are two examples of names used today.