Grain is the primary feedstock used in ethanol production in the United States. Other feedstocks will vary by region. Any type of grain containing starch can be used to produce ethanol. Biomass materials vary considerably in potential ethanol yield and should be carefully evaluated.
Corn is the predominant grain processed in U.S. ethanol plants. In some areas of the country other grains including wheat, barley and grain sorghum are used as feedstocks for ethanol. Some process technologies allow multiple grain feedstocks to be used in the same plant. Grain fractions, out of condition grain and off-spec grain can also be used for ethanol production in some cases. However, most process technologies are designed to use a single type of grain that meets specific grading parameters.
Careful attention should be given to the cost and availability of the primary feedstock. In many grain ethanol plants, the feedstock cost can account for 50-70 percent of the ethanol input cost depending on the price range. Feedstock price volatility should be examined and strategies should be employed for managing this cost.
In some instances, a plant may be sited to take advantage of other materials that can be used as feedstocks. Starch or sugar containing materials such as food processing waste have been used for ethanol production. The production of ethanol has historically been limited to using sources of soluble sugar or starch. However, new technologies are being developed to allow production from cellulosic biomass. Biomass materials demonstrating potential as ethanol feedstocks include wood, waste, paper, leafy crop materials, rice or wheat straw and other renewable matter. Several process technologies are currently available for conversion of biomass materials into ethanol. Extensive information about cellulose feedstocks, process technology and economics of ethanol production from cellulosic materials, and biofuels from other renewable resources will be evaluated and their price history will be factored in.