The United States is producing nearly 15.2 billion gallons a year of ethanol a year at 214 plants, with a current capacity of 15.6 billion gallons a year, as of Oct. 6, 2016.
Five companies produced 45%t of that total.
ADM – This Decatur, Ill.-based grain and oilseed processor produces 1.76 billion gal./year at 8 plants in Illinois, Iowa, Nebraska and Minnesota. Visit www.adm.com .
POET – Headquartered in Sioux Falls, S.D., Poet produces 1.6 billion gal./year at 27 plants in Iowa, Minnesota, Missouri, Ohio, South Dakota and Indiana. Visit www.poet.com .
VALERO ENERGY CORPORATION – Based in San Antonio, Texas, Valero produces 1.2 billion gal./year at 11 plants in Iowa, Minnesota, Nebraska, Indiana, Ohio, South Dakota and Wisconsin. Visit www.valero.com 
GREEN PLAINS RENEWABLE ENERGY – With headquarters in Omaha, Neb., Green Plains produces 1.46 billion gal./year at 17 plants in Nebraska, Iowa, Illinois, Indiana, Michigan, Minnesota, Tennessee, Texas and Virginia. Visit www.gpreinc.com .
FLINT HILLS RESOURCES LP – This Wichita, Kan., company produces 820 million gal./year at seven plants in Iowa, Nebraska and Georgia. Visit www.fhr.com .
Source: Renewable Fuels Association