Ethanol production in the United States is based almost entirely on corn as a feedstock. Corn‑based ethanol production is projected to fall over the next 10 years.
This reflects declining overall gasoline consumption in the United States (which is mostly a 10‑percent ethanol blend, E10), infrastructural and other constraints on growth for E15 (15‑percent ethanol blend), and the small size of the market for E85 (85‑percent ethanol blend), with less-than-offsetting increases in U.S. ethanol exports.
Even with the U.S. ethanol production decline, demand for corn to produce ethanol continues to be strong. While the share of U.S. corn expected to go to U.S. ethanol production falls, it accounts for over a third of total U.S. corn use throughout the projection period.
Source:usda.gov