January 21, 2008

Volume 86, Number 03

p. 11

Biofuels

GM Backs Ethanol Start-Up Coskata

Company claims its technology can significantly lower the price of the fuel

Michael McCoy

General Motors is investing in Coskata, a start-up biofuels company that says it can produce ethanol from a wide range of feedstocks for less than $1.00 per gal, compared with a wholesale selling price of more than $2.00 per gal today.

A partnership between the two companies was revealed last week at the North American International Auto Show in Detroit. "We are very excited about what this breakthrough will mean to the viability of biofuels and, more important, to our ability to reduce dependence on petroleum," said GM CEO Rick Wagoner.

Warrenville, Ill.-based Coskata was founded in 2006 by Todd Kimmel, a former venture capitalist, and Rathin Datta, a Ph.D. chemical engineer who previously founded Vertec Biosolvents, a marketer of biologically derived solvents. Coskata's initial funders were Advanced Technology Ventures, GreatPoint Ventures, and Khosla Ventures.

Although most ethanol made in the U.S. today comes from corn kernels, the Bush Administration is promoting the use of cellulosic feedstocks such as corn stalks and wood waste that don't cut into the food supply. Coskata says its process can consume virtually any carbon-based feedstock, including municipal waste, old tires, and agricultural waste.

To date, much of the focus in cellulosic biofuels has been on biochemical processes. These approaches use enzymes to break down cellulose into sugars, which are then fermented into ethanol.

In Coskata's process, feedstock is gasified into syngas—a mixture of carbon monoxide and hydrogen—using conventional technology. In the next step, the syngas is sent to a special bioreactor where microorganisms consume the two gases, excreting ethanol as a waste product. In a third step, membranes separate the ethanol from water.

According to Coskata, an Argonne National Laboratory analysis of its process found that it generates up to 7.7 times more energy than it consumes, compared with just 1.3 times for corn ethanol.

Ron Cascone, director of biofuels development for the consulting firm Nexant Chem Systems, says Coskata seems to combine the best of chemical and fermentation technologies. Preparing a clean syngas feedstock through gasification, he points out, avoids the "messy soups" that can plague cellulosic biomass fermentation.

Coskata is drawing on the chemical industry for its management team. Its CEO is William Roe, who joined the company last September after 29 years with the water treatment chemicals firm Nalco. Coskata's vice president for R&D and engineering is Richard E. Tobey, a 28-year veteran of Dow Chemical.

"We will have our first commercial-scale plant making 50 million to 100 million gal of ethanol running in 2011, and that includes the two years it will take to build the plant," Roe said at the auto show. He added that Coskata could account for a "significant portion" of the 21 billion gal of biomass ethanol called for by 2022 under the Energy Independence & Security Act, which President George W. Bush signed last month.

Chemical & Engineering News

ISSN 0009-2347

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