GM taps Coskata as cellulosic ethanol provider

By Sarah Smith
General Motors has partnered with Coskata Inc. to run its fleet of vehicles on ethanol made from nonfood sources. The feedstock-flexible process will convert garbage, old tires, plastic and agricultural waste into ethanol through bacterial fermentation.

The partnership was unveiled at the North American International Auto Show in Detroit in January. GM, the world's largest automaker, will receive cellulosic ethanol from Illinois-based Coskata in late 2008 and begin testing it. Coskata, founded in 2006, plans to open a 40,000-gallon facility at the end of 2008, according to Wes Bolsen, vice president of business development. "We will go from that facility to a 100 MMgy ethanol facility that we will break ground on this year," he added. "We look to put as much as 10 billion gallons of ethanol on the market by 2022."

Coskata will use proprietary microorganisms to extract nearly all of the energy value from a biomass-based synthesis gas stream. The process will also recycle wastewater and reduce carbon dioxide emissions. Coskata claims it can produce ethanol for under $1 per gallon, or as Bolson put it, "We are commercially viable [at half the cost of traditional ethanol production]." The process will lower production costs by using local waste materials and avoid the drawbacks of interfering with food supplies, he added. Bolsen envisions locating Coskata's plants next to traditional corn-based ethanol plants, "taking in additional agricultural waste to make those plants more efficient," he said.

The microorganisms are the key, Bolson stressed. The gasification system "allows the feedstock flexibility," he said. "You can put pretty much anything in it. The microorganisms are very, very efficient at converting it, and then we have some patented processes on the back end to separate the ethanol from the water."

Having the clout and funding of GM behind the technology is definitely a plus. "They want the rapid commercialization of this next generation of ethanol, as well," Bolson said.
Although Coskata's gasification-to-ethanol technology is still in the embryonic stage, the company said it is ready to proceed and delayed unveiling the breakthrough because GM wanted to open the auto show with a bombshell announcement.

In another auto show announcement, Toyota said it is conducting in-house research on the feasibility of producing wood-based ethanol.