Cellulosic ethanol takes another step toward commercial processing

Bales of corn stover harvested near DuPont's new cellulosic ethanol plant site in Nevada, Iowa, represent the raw material that will be converted to ethanol. (Amy Mayer/Harvest Public Media)

The president of DuPont Industrial Biosciences conceded that the event billed as a “ground-breaking” actually followed the physical start of construction on the company’s new cellulosic ethanol plant in Nevada, Iowa. So Jim Collins re-dubbed the Nov. 30 event a “flag raising” and the Stars and Stripes were raised on a permanent flagpole outside the heated tent where he and others made their remarks.

Much of the ethanol used for fuel in the United States is made from corn, but cellulosic ethanol is a form of fuel made from non-edible parts of plants. DuPont, Collins said, has been working on cellulosic ethanol for 10 years, striving to overcome technological, logistical and economic hurdles in pursuit of a new non-food source for renewable fuel.

“Unlocking a new source of carbon is not your ordinary science project,” he said. While researchers delved into the scientific questions, agronomists and farmers worked on the logistics including how to harvest the waste plant material -- called stover -- leftover after the corn grain is gone and how to bale, transport and store it.

The idea behind cellulosic technology is that ultimately it can be customized to whatever source of cellulose is at hand—not necessarily corn. But for now, DuPont is working with corn and that’s one major reason they chose to build their first commercial-scale plant in Iowa. A Tennessee location served as the pilot plant and some Iowa corn stover even got shipped there for testing. But shipping stover long distances isn’t practical.

When the plant is fully operational—it’s expected to begin processing ethanol from the 2014 harvest and be at full capacity in 2015—it’s projected to produce 30 million gallons per year of ethanol from about 375,000 dry tons of stover. The plant matter will be harvested from some 190,000 acres within 30 miles of the plant. Farmers in the area will contract with DuPont to provide stover. For farmers, who have seen a big increase in residue as their corn yields have risen, removing about 20-30 percent of the stover will be a benefit to their soil, saving them on fertilizer they would have needed to manage the residue.

Iowa Gov. Terry Branstad thanked DuPont for its commitment to the state, which he considers a leader in biofuels.

“Cellulosic energy will help advance the ethanol industry and we want our state to be at the forefront of that. And that’s why we’re so proud to have been chosen as the location for this facility,” Branstad said.

He and Lt. Gov. Kim Reynolds applauded the new jobs the plant will bring—about 67 permanent, high-skill, well-paid jobs, the company predicts—and also committed to working with schools and colleges to prepare the workforce for the future.

“Our community colleges will provide training and re-training tools to ensure Iowa’s workforce is prepared for the next generation of biofuels,” Reynolds said.

Collins described partnerships with the existing ethanol processor Lincoln Way Energy, which is within sight of the new plant, and said DuPont has also worked closely with academic and government scientists.

“It’s not every day that you get a chance to create an entirely new industry,” Collins said. And though the first shovelful of dirt had long been turned over, he maintained this event marked a beginning.

“We’re breaking ground here not just on this new facility but on new jobs, new advances in sustainable agronomy and a new future for alternative energy,” Collins said.

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