Ethanol: What is it?
Ethanol is a grain alcohol that has many uses; transportation fuel, alcoholic beverages, antiseptics, cleaning products. We will focus on motor fuel throughout this page. Ethanol is blended with gasoline to be used in motor vehicles. Nearly all of the motor gasoline sold in the United States contains at least 10% ethanol. Any gasoline-powered vehicle in the United States can use a 10% ethanol blend in their gas with no modifications. Flex fuel vehicles, which do have modifications can use E15, a gasoline with 15% ethanol content and/or E85, a fuel that may contain up to 85% ethanol.
Where does Ethanol Come From?
Ethanol can be made from many sources of starch including corn, wheat, grain sorghum, barley, potatoes, sugar cane, and sweet sorghum. Because of a consistent surplus in corn crops, most ethanol is made from field corn, also called dent corn or #2 yellow corn. The majority of corn grown in Illinois is field corn, which is not the kind you eat. Less than 1% of corn grown in Illinois is sweet corn, the corn we eat. Therefore, even though ethanol is made from corn, it does not take away from feeding the population. In order to produce ethanol from the field corn it can be fermented from many sources of starch. Since there is an abundant supply of corn, most ethanol is produced in the Midwest where ethanol plants are close to a consistent supply of corn, water, and livestock production. A by-product of ethanol production is distillers grains, which can be fed to livestock. Illinois is ranked third in Ethanol production in the United States, with 13 ethanol plants producing approximately 42% of the gasoline produced in the state. The United States is the #1 producing country in the world of ethanol!
How is Ethanol Produced?
Ethanol in the United States is mostly produced from field corn. Once the field corn is harvested it is hauled to a nearby elevator. The elevator then sells the grain to various businesses for use. For ethanol, biorefineries purchase corn. A biorefinery is a facility that converts biomass, such as starch from corn, into biofuels, power and chemicals. The corn is finely ground with water and enzymes to convert the starch for fermentation. The liquid starch is turning into sugars. Yeast is added and the fermentation of corn, yeast and sugars creates ethanol and carbon dioxide. This process takes about two days. The mixture is heated for a final time allowing the ethanol to evaporate into a vapor that is collected. The vapor is cooled and condensed into a liquid suitable for blending with gasoline. What's left is the corn and yeast solids, distillers grain. One bushel of corn, approximately 56 pounds, can create approximately 2.8 gallons of ethanol and 17 pounds of distillers grain. Ethanol is then sold and transported across the United States to gas stations. At the gas pump a consumer may have multiple options of fuel to put into their vehicle. The three general categories of ethanol-gasoline blends are E10, E15, and E85.
Ethanol Use in Motor Vehicles
Illinois consumers can find ethanol blends at most gas stations in the state. Nearly 70% of all gasoline includes an ethanol blend. Ethanol is one of the most economical performance fuels on the market, which is why all NASCAR drivers choose to use it in their vehicles. Many teams have reported an increase in horsepower and no decrease in mileage when using ethanol-enhanced fuel. All gasoline engines in the United States can use E10. The use of ethanol in your gas tank reduces emissions by more than 50% and can reduce greenhouse gas emissions, on average by 42-52%!
E10 is the most common blend found at the gas pump today. This fuel is a blend of 10% ethanol to 90% unleaded gasoline. All gasoline powered vehicles in the United States can use this in their gas tank.
Consumers now have the ability to use a higher ethanol blend fuel, E85. This is a blend of 85% ethanol and 15% gasoline. In order to use E85 in your gas tank, you must use a flex fuel vehicle or have a vehicle modified to use E85.
Ferment Your Own Ethanol
Great Lakes Bioenergy Research Center has great, simple experiment that you can do in your classroom! "In this simple experiment, students investigate the process of fermentation in resealable bags with bakers yeast, warm water and various sources of plant sugar." There is an activity for all ages elementary through high school. This lesson can serve as an engaging activity to launch more in-depth into biofuels, practice charting, reading a ruler, telling time, and more! Check out some of the resources below that we made for our lesson and adapt it for your classroom!