Second-generation biofuels produced from switchgrass or corn stover have a lower carbon footprint than corn-based ethanol, said the Environmental Working Group in advocating a wholesale overhaul of federal biofuel policy. In a report, EWG said Congress should eliminate the requirement to blend corn ethanol into gasoline and to extend the mandate for biofuels derived from cellulosic sources, such as grasses, woody plants and crop debris. If lawmakers do not act promptly, the green group said the EPA should, on its own authority, begin in 2016 to gradually eliminate the corn ethanol mandate.
The EPA says it will announce the biofuels requirements for 2015 and 2016 by the end of this month. Its proposed rule is under review at the White House. The agency says the gasoline market is saturated with biofuels, mostly corn ethanol, at the traditional blend rate of 10 percent, so it proposed in May to lower the ethanol target and the mandate for “advanced” biofuels, such as cellulosic ethanol. The next-generation biofuels are years later than expected in coming into commercial production.
DuPont opened a 30-million-gallon-a-year cellulosic ethanol plant in Iowa last week. It is the largest-volume plant in the world, the company says, with fuel that reduces greenhouse gas emissions by 90 percent compared to gasoline. Feedstock for the plant is corn stover, “the stalks, leaves and cobslef in a field after harvest.”
In its report, EWG said “elimination of the corn ethanol mandate will create a powerful incentive for greater investment in cellulosic ethanol.” To protect against soil erosion, there should be limits on the amount of corn stover that can be removed from fields, it said.