Ethanol produced from corn stover is better for the climate than renewable fuel made from corn, underscoring the need for Congress to support production of next-generation fuels, a study released Tuesday concludes.
The report from the Environmental Working Group and the University of California found that ethanol produced from corn stover — the leaves and plants left once the grain has been harvested — offset about 96 percent of the emissions produced from gasoline.
Switch grass only offset about 47 percent, largely because the crops require some fertilizer to replace lost nutrients in the soil. The report said ethanol from corn is worse for the environment than even gasoline because of the water and fertilizer used to produce the grain — a fact vigorously disputed by the renewable fuel industry.
“Both of these fuels are clearly better for the climate than gasoline and corn ethanol, and both of these fuels have other environmental benefits that make them better for the environment than corn ethanol,” said Emily Cassidy, who authored the study for EWG. “What we really need to be thinking about the future of renewable fuels in this country is stimulating those that actually reduce emissions rather than corn ethanol … that has taken over the marketplace.”
The report said Congress, which has been under pressure by non-Midwest lawmakers, oil groups and others to overhaul the Renewable Fuel Standard, should eliminate the corn portion of the ethanol mandate and encourage more production of fuel that lower greenhouse gas emissions. The Renewable Fuel Standard requires a certain amount of biofuels to be included in gasoline.
With ethanol producers making almost as much of the fuel as the market can take — most of it made from corn kernel itself — there is little incentive to work on greener fuels coming from corn stover and other cellulosic material that are more costly to produce, Cassidy said. EWG said Congress should extended the cellulosic biofuels mandate that expires in 2022.
“The limited market for ethanol is saturated by corn ethanol, so elimination of the corn ethanol mandate will create a powerful incentive for greater investment in cellulosic ethanol,” the EWG report said.
Monte Shaw, executive director with the Iowa Renewable Fuels Association, disputed the fact that corn and the Renewable Fuel Standard are crowding out cellulosic ethanol. He noted that in many cases it is corn ethanol manufacturers who are opening up commercial cellulosic plants.
“Simply put, corn ethanol is a stepping-stone to cellulosic ethanol, not a barrier,” Shaw said. “Much like the vast majority of industries, first-generation products must pave the way for second-generation technology, and that’s what we’re seeing in biofuels today.”
Cellulosic production has taken longer to materialize on a commercial scale than many initially expected, but the next-generation fuel has shown signs of delivering on its promise. Iowa, the country’s largest ethanol producer, has opened up several plants in recent years.