From the Wired article:
Besides cutting production costs to fire sale prices, the process avoids some key drawbacks of making ethanol from corn, company officials said. It wouldn't impact the food supply, and its net energy balance is high because the technique works almost anywhere using almost anything with great efficiency. The end result will be E85 sold at the pump for about a dollar cheaper per gallon than gasoline, according to the company...
Coskata uses existing gasification technology to convert almost any organic material into synthesis gas, which is a mix of carbon monoxide and hydrogen. Rather than fermenting that gas or using thermo-chemical catalysts to produce ethanol, Coskata pumps it into a reactor containing bacteria that consume the gas and excrete ethanol. Richard Tobey, Coskata's vice president of engineering, says the process yields 99.7 percent pure ethanol.
Gasification and bacterial conversion are common methods of producing ethanol, but biofuel experts said Coskata is the first to combine them. Doing so, they said, merges the feedstock flexibility of gasification with the relatively low cost of bacterial conversion.
Read the full article here.