For the past couple of years, General Motors had been touting its E85 ethanol-capable vehicles with the theme “Live Green, Go Yellow” campaign, with the “yellow” signifying corn. This has led to some problems, given that (1) corn is a food crop and (2) it takes on the order of four gallons of water to produce a gallon of ethanol. So the ear of corn has been replaced on the GM E85 logo with switch grass, which people don’t eat and few animals consume. But more notably, GM has made a financial investment in Coskata (Warrenville, IL; ,www.coskata.com), an ethanol producer that holds the proprietary rights to a special class of microorganisms and patented bioreactor designs capable of producing ethanol from multiple non-food sources, including switch grass. Coskata claims its process, which also utilizes intense heat to break down the materials, can produce ethanol for under $1 per gallon, utilizing less than one gallon of water per gallon of ethanol produced. Coskata and GM envision utilizing woodchips, landfill waste, and old tires as a base for ethanol production. They plan to have a 40,000-gallon commercial demonstration facility on line by the end of 2008, and develop facilities capable of producing 50-100 million gallons of ethanol by 2011.
GM chose to invest in because of its ability to produce ethanol at lower costs with higher yields, says Candice Wheeler, GM technical fellow for Chemistry and Environmental Sciences at the automaker’s Research and Development Group: “The level of water usage was significant, and stood out for us. Certainly, the fact that it was cost competitive didn’t hurt either,” Wheeler says. What’s next? GM will work directly with Coskata to make its process commercially viable while obtaining additional funding from the federal government.—KMK