Research reinforces economic, environmental benefits of corn cobs as source for cellulosic ethanol

ISU study, EPA analysis indicate vast potential for POET's cellulosic process
Sioux Falls, S.D.

Corn cobs are both economical and environmentally friendly as a feedstock for cellulosic ethanol, university and government reports indicate, reaffirming POET's strategy for commercializing its new technology.

Removing corn cobs from fields for use in cellulosic ethanol production appears to have no substantial impact on soil nutrient content, based on results from the first year of a multi-year study by Iowa State University (ISU).

POET’s process for producing cellulosic ethanol uses corn cobs as the feedstock. POET’s pilot-scale plant in Scotland, S.D. is already producing cellulosic ethanol at a rate of approximately 20,000 gallons per year, and plans are on schedule for 25 million gallons per year of commercial production in Emmetsburg, Iowa in 2011.

The ISU research was funded by POET as part of the company’s ongoing internal study into the sustainability of using corn cobs as a cellulosic feedstock.

Results from the first year of the study, conducted on a test field near the Emmetsburg site, indicate that fertilizer treatment for a field in which cobs have been removed would be almost identical to treatment of a field in which cobs were not removed. ISU researchers will continue their work this year on the test plots, compiling more data to help farmers manage their land well while taking advantage of an additional revenue source from their fields.

“This information reinforces previous research showing that corn cobs are a sustainable, environmentally friendly feedstock for producing cellulosic ethanol, and removing them from the field will not alter soil quality,” said Scott Weishaar, POET Vice President of Commercial Development. “We are committed to thoroughly evaluating our process to ensure the benefits of cellulosic ethanol are fully realized.”

Previous research by the U.S. Department of Agriculture showed that cobs contain only 2-3 percent of the measured nutrients of the above-ground corn plant. The collaboration between POET and ISU takes a closer look at data regarding soil quality and nutrient levels, the impact of cob and stover removal on future plant growth and recommended levels of fertilizer applications, if any, for cob or stover removal. In addition, POET is investigating the impact of cob piles on future plant growth on the pile site.

Additionally, the Draft Regulatory Impact Analysis released this month by the U.S. Environmental Protection Agency touts the economic benefit of using corn stover, which includes corn cobs, in making cellulosic ethanol.

“… corn stover was chosen as the most economical agricultural feedstock to be used to produce ethanol in order to meet the 16 [billion gallon] EISA (Energy Independence and Security Act) cellulosic biofuel requirement. We estimate that by 2022 greater than 400 million tons of corn stover could be produced. Approximately 82 million tons would be needed to produce 7.8 billion gallons of cellulosic biofuel that our modeling projects to come from corn stover by 2022.” (Draft Regulatory Impact Analysis: Changes to Renewable Fuel Standard Program, page 17 http://www.epa.gov/oms/renewablefuels/420d09001.pdf)