Previous

Conventional Ethanol

Next

Ethanol is produced mainly by fermenting sugars. Simple sugars are the easiest to turn into ethanol, because they can be fed directly to microorganisms which will ferment them. Sugarcane is the most common of the sugar crops used for ethanol production. (Brazil makes ethanol from sugarcane.)

sugar → ethanol

Starch is the next easiest feedstock for ethanol production. However, starch needs to be converted to sugar first. This is a very simple process which uses enzymes to convert the starch to sugar. Once starch has been converted into sugar, the sugar can be fermented into ethanol. Most of the ethanol produced in the United States comes from corn kernels, which are a type of starch. There are several other sources of conventional ethanol.

starch → sugar → ethanol

USA RegionsIn order to produce enough ethanol from corn to drive all the cars in the U.S. for a year, you would need 500 million acres of corn, all for ethanol. (In 2007 U.S. farmers planted 100 million acres of corn total, 20 million acres of which were used for ethanol.)

Since U.S. ethanol is made from corn, most of the ethanol plants in the U.S. are located in major corn-farming areas. Do you know which area of the U.S. grows the most corn?

EXPLORE: To find the answer, visit "U.S. Ethanol Expansion Driving Changes Throughout the Agricultural Sector". Find the map entitled "U.S. ethanol capacity growing rapidly" and view the corn acres by county. Compare that map with this one.