What is Ethanol?
Ethanol (ethyl alcohol, grain alcohol, EtOH) is a clear, colorless liquid. In dilute aqueous solution, it has a somewhat sweet flavor, but in more concentrated solutions it has a burning taste. Ethanol (CH3CH2OH) is made up of a group of chemical compounds whose molecules contain a hydroxyl group, -OH, bonded to a carbon atom. Ethanol made from cellulosic biomass materials instead of traditional feedstocks (starch crops) is called bioethanol.
The Clean Air Act Amendments of 1990 mandated the sale of oxygenated fuels in areas with unhealthy levels of carbon monoxide. Since that time, there has been strong demand for ethanol as an oxygenate blended with gasoline. In the United States each year, approximately 2 billion gallons are added to gasoline to increase octane and improve the emissions quality of gasoline.
Blends of at least 85% ethanol are considered alternative fuels under the Energy Policy Act of 1992 (EPAct). E85, a blend of 85% ethanol and 15% gasoline, is used in flexible fuel vehicles (FFVs) that are currently offered by most major auto manufacturers. FFVs can run on gasoline, E85, or any combination of the two and qualify as alternative fuel vehicles under EPAct regulations. For more information on flexible fuel vehicles, see our ethanol vehicles page.
In some areas, ethanol is blended with gasoline to form an E10 blend (10% ethanol and 90% gasoline).
How is Ethanol Made?
Ethanol can be produced from any biological feedstocks that contain appreciable amounts of sugar or materials that can be converted into sugar such as starch or cellulose. Sugar beets and sugar cane are examples of feedstocks that contain sugar. Corn contains starch that can relatively easily be converted into sugar. A significant percentage of trees and grasses are made up of cellulose, which can also be converted to sugar, although with more difficulty than required to convert starch.
The ethanol production process starts by grinding up the feedstock so it is more easily and quickly processed in the following steps. Once ground up, the sugar is either dissolved out of the material or the starch or cellulose is converted into sugar. The sugar is then fed to microbes that use it for food, producing ethanol and carbon dioxide in the process. A final step purifies the ethanol to the desired concentration.
Ethanol is also made from a wet-milling process. Many larger ethanol producers use this process, which also yields products such as high-fructose corn sweetener.
Ethanol Market
Many vehicles on the road today can run on blends of ethanol and gasoline—most on lower-level blends such as E10 (10% ethanol and 90% gasoline), and many on higher level blends such as E85 (85% ethanol and 15% gasoline). Because of the abundance of ethanol-compatible vehicles, the future is bright for ethanol as a fuel.
Most of today's commercially available vehicles can run on blends of E10, which is mandated in some areas of the country to act as a fuel oxygenate to improve air quality.
In addition, many newer vehicles can use E85, which qualifies as an alternative fuel under the Energy Policy Act of 1992. Vehicles that can run on E85, gasoline, or any mixture of the two are called flexible fuel vehicles (FFVs). FFVs are widely available and include sedans, minivans, sport utility vehicles, and pickup trucks. More than 5 million FFVs have already been sold in the United States, although many of the buyers remain unaware that they have the option to fuel with E85. See the ethanol vehicles page to learn more about FFVs. You can also identify an FFV by the vehicle identification number.
General Motors recently announced a new E85/FFV campaign, "Live Green, Go Yellow." Learn more about this marketing campaign by visiting their Web site.
Because of limited crude oil supplies and refining capacity, and rising concern over environmental degradation, there is a good market outlook for ethanol. Ethanol can be produced not only from corn, barley, and wheat, but also from cellulose feedstocks such as corn stalks, rice straw, sugar cane bagasse, pulpwood, switchgrass, and municipal solid waste. Because of the variety of feedstocks that can be used, ethanol offers tremendous opportunities for new jobs and economic growth outside the traditional "grain belt."
Currently, most E85 fueling stations are located in the Midwest, but infrastructure is growing nation wide. FFVs can fuel at these stations today. Check the AFDC's Alternative Fuels Station Locator to find E85 fueling in your area.
Looking into the future, the ethanol industry envisions a time when ethanol may be used as a fuel to produce hydrogen for fuel cell vehicle applications.
Ethanol Benefits
- E85 is easy to use and handle - E85 fueling equipment is slightly different and of similar cost to equipment used to store and dispense petroleum fuels. In some cases, it may be possible to convert your existing petroleum equipment to handle E85.
- Using E85 reduces petroleum consumption - Use of E85 will reduce a fleet's overall use of petroleum and replace it with a renewable-based fuel produced ("grown") in the United States.
- E85 is good for the environment - Beyond operational ease, E85 offers considerable environmental benefits.
- Flexible Fuel Vehicles (FFVs) are available and affordable - FFVs specifically designed to run on E85 are becoming more common each model year, and FFVs are typically available as standard equipment with little or no incremental cost.
- FFVs have flexible fueling options - FFVs may operate on gasoline, and, in fact, most of the 4 million FFVs on US roadways do today. Although that is not a positive from an E85-use standpoint, it does underscore the flexibility FFVs offer fleets. When E85 is not available, or an FFV travels outside the fueling network, a driver may simply fuel with either fuel as the situation dictates.