NRDC urges sustainable practices for ethanol from corn stalks

Source: Tiffany Stecker, E&E reporter • Posted: Wednesday, November 18, 2015

As the United States sits on the cusp of a potential ethanol boom from corn stalks and leaves, a conservation group is calling on producers to increase oversight to ensure the fuel leaves a small environmental footprint.

The Natural Resources Defense Council released a report yesterday with recommendations on how such corn stover ethanol producers can implement and improve sustainability practices at their plants.

“Now is the time to ensure that the sourcing of crop residues and the production of new energy crops avoid negative environmental impacts,” Sasha Stashwick, a policy analyst with NRDC, wrote in a blog post.

Corn stover includes the dried stalks, leaves and husks of corn left over after harvest. U.S. EPA considers the fuel to be an effective tool in combating climate change, reducing greenhouse gas emissions 90 percent or more compared with gasoline.

But scientists have raised concerns about environmental consequences if too much stover is collected from the soils of neighboring farms. Stover plays an important role in controlling erosion and building carbon in the soil, another step to keeping carbon in the ground and out of the atmosphere. A 2014 study by the University of Nebraska found that removing too much stover could cancel out the benefits from using cellulosic ethanol as a low-carbon ingredient (ClimateWire, April 21, 2014).

The NRDC report calls on companies to institute and enforce sustainability requirements in their operations; adopt independent, third-party sustainability audits; and work with conservation groups and farmers to develop best practices. The report also requests that federal loan- and grant-giving agencies require that plants be certified for sustainability before they are able to accept funding.

Last month, the world’s largest corn stover cellulosic ethanol plant opened in Iowa. Dupont Industrial Biosciences’ Nevada, Iowa, facility will produce up to 30 million gallons of ethanol per year, joining Poet-DSM Advanced Biofuels LLC and Abengoa Bioenergy SA as major corn stover biofuel producers in the Midwest (Greenwire, Oct. 30).

The cellulosic ethanol industry has said plants like DuPont collect only about 25 percent of the corn stover on the soil, not enough to cause a disturbance.

The production of cellulosic ethanol has fallen far behind Congress’ intended schedule when it updated the renewable fuel standard in the 2007 Energy Independence and Security Act. By 2011, the country was set to produce 1 billion gallons of the fuel per year. The industry was slow to ramp up, producing only 33 million gallons last year.