|The Coskata process can combine a variety of gasification technologies with Coskata proprietary microorganisms and bioreactors. Click to enlarge.|
Emphasizing on one hand the importance of ethanol as a shorter-term solution to reducing oil dependence and emissions, and on the other to coming up with alternatives to corn-based ethanol, GM Chairman and CEO Rick Wagoner announced a partnership with Coskata Inc., a second-generation ethanol startup, during his opening press conference at the North American International Auto Show.
Coskata uses a proprietary process that leverages patented microorganisms and bioreactor designs to produce ethanol from practically any carbon-based feedstock, including garbage, old tires and plant waste, for less than $1 a gallon—about half of today’s cost of producing gasoline. The partnership includes an undisclosed equity stake for GM, joint research and development into emissions technology and investigation into making ethanol from GM facilities’ waste and non-recyclable vehicle parts.
Coskata uses a three-step syngas-to-ethanol process:
Gasification. Carbon-based feedstock is converted into syngas using well-established gasification technologies.
Fermentation. Coskata’s proprietary microorganisms convert the resulting syngas into ethanol by consuming the carbon monoxide (CO) and hydrogen (H2) in the gas stream.
Separation. Pervaporation technology separates and recovers the ethanol.
Coskata’s process technology is ethanol-specific and enzyme independent, requiring no additional chemicals or pre-treatments.
Coskata’s process uses less than a gallon of water to make a gallon of ethanol compared to three gallons or more for other processes. According to Argonne National Laboratory, which analyzed Coskata’s process, for every unit of energy used, it generates up to 7.7 times that amount of energy, and it reduces CO2 emissions by up to 84% on a full well-to-wheels basis compared with gasoline.
A pilot plant will be in operation in the fourth quarter of 2008. GM will use the fuel in testing vehicles at GM’s Milford Proving Grounds. Coskata expects to have its first commercial-scale plant with a capacity of 50-100 million gallons of ethanol per year running in 2011.
Coskata was founded in 2006 by leading renewable energy investors and entrepreneurs, including Khosla Ventures, Advanced Technology Ventures, and GreatPoint Ventures. Vinod Khosla appeared at the press conference in Detroit.