Reaping and Sewing From Corn – The entire plant is now usable

Could corn be the peanut of the 21st century?

Scientists are creating a new method of processing corn that could lower the cost of filling up your tank and make your tank tops more comfortable.

By John Gartner Wired.com

The National Renewable Energy Lab and chemical company DuPont have teamed to design a versatile bio-refinery that turns the entire corn plant into a source for materials and a petroleum alternate.

Right now, only corn grains are used extensively to produce ethanol. The corn "stover," or stalks and leaves, is usually discarded or used to a limited extent for biomass energy. Ethanol refineries process only the kernels to produce ethanol, which is combined with gasoline to extend the energy potential of fossil fuels.

The Integrated Corn-Based Bioproducts Refinery consortium — led by DuPont and including the NREL, Diversa, Michigan State and Deere & Company — is developing a processing plant that would use grains as source material to replace petroleum-based polymers, and would create ethanol from the less-expensive leftover cellulose materials. DuPont and NREL this week announced an additional $7.7 million has been invested in the project.

Earlier this year DuPont announced a new polymer called Sorona that is used to make clothing such as swimsuits, negligees, carpets and upholstery. Sorona products are based on petroleum, but DuPont has joined with Genencor to engineer a microorganism to ferment sugars from corn and corn biomass that would replace the petroleum.

Sorona is superior to other polymers because it "offers a combination of attributes not found in any other single polymer, including soft touch, comfort stretch or resiliency, built-in stain resistance, easy care and bright colors," said Raymond Miller, DuPont’s program director for the bio-refinery initiative. Miller said using biomass products could lower production costs for Sorona and reduce its environmental impact. DuPont has a pilot biomass-based production facility in Decatur, Illinois, and plans to start sending samples to the market in the near future.

Because corn grain is more valuable as the basis for a polymer, scientists at NREL and Diversa are working on a method of creating ethanol from the leftover maize materials.

Breaking down cellulose into simple sugars is much more difficult than converting grains because the coarser plant materials — such as corn stalks or trees — "don’t want to be easily eaten" by enzymes, said John Ashworth, team leader of partnership development for the National Biomass Coordination Office at the U.S. Department of Energy. "The good news is that the materials (cellulose) are much cheaper to obtain, but the bad news is, (the enzyme processing) is really hard to do."

NREL has developed a new two-step process that pre-treats the cellulose material so newly developed enzymes can break it down into sugars that can be fermented into ethanol. Ashworth said enzymes available today are too expensive and constitute about one-third to one-half the cost of ethanol products, but his team and researchers at Diversa are working to whittle that percentage down dramatically over the next few years.

Ashworth hopes cost decreases resulting from improving the enzymes and production process will make the first bio-refinery feasible in five years. He said an integrated bio-refinery would be a more flexible platform because a "variety of biomass materials, such as wood chips, sawdust or wheat straw" could theoretically be processed into ethanol. Ashworth expects that cellulose-based ethanol could be produced in sufficient quantities to become cost-competitive with grain-based production by 2010, and be competitive with gasoline within 10 to 15 years.

Congress is trying to grow demand for ethanol as part of its comprehensive energy legislation. The bill (currently being consolidated from House and Senate versions) would require increasing the use of ethanol to 5 billion gallons by early next decade, nearly double this year’s expected 2.7 billion gallons.

Ethanol is used as an additive to petroleum to reduce American dependence on foreign oil and to cut down on the production of carbon monoxide. But according to Jerry Martin, a spokesman for the California Air Resources Board, improvements in car engines in the last 10 years have negated the need for oxygenates like ethanol or MTBE.

From an environmental standpoint, "there’s no real need to have ethanol in gasoline for today’s cars," said Martin. He said that the board studied ethanol in the 1990s and found that it increases the production of harmful particulate matter in the air and also increases production of nitrogen oxide, which forms smog. Martin said because the environmental impact of ethanol isn’t severe, adding ethanol to gasoline "may not be a harm, but it’s certainly not advantageous."

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