Iowa State University Energy Economist Robert Wisner predicts that ethanol supply will match E-10 demand in the next two or three years, if not sooner. He warns that if the allowable blend is not increased, it is almost certain to not only halt construction of corn-starch ethanol plants but also to greatly curtail or halt investment in a cellulose ethanol industry. In an AgMRC Renewable Energy Newsletter article, Wisner wrote that calls for the U.S. Environmental Protection Agency to raise the allowed blend from E-10 to E-15 are running about 18 to 1.
But, Wisner says more research is needed to pin down firm answers to complex questions that must be answered before the EPA can grant an increase in the blend wall. EPA is required to base its decision on sound analysis, and the analysis is complex since higher ethanol blends may trigger unintended consequences.
Wisner offers a list of questions that require answers. They include: how much greater ethanol use will affect the livestock industry and food prices, to what extent corn-based ethanol production may lead to converting pasture or forests in other countries to cropland, whether higher ethanol blends will increase some emissions including nitrous oxide and acetaldehyde, whether a hotter-burning E-15 blend will shorten the life of your car's emissions equipment, and how E-15 will work with small engines like lawn mowers.