Photos: Coskata's celluslosic ethanol conversion process

The announcement from General Motors at this year's Detroit auto show that it had invested in Coskata, a producer of cellulosic ethanol, created buzz across the automotive world. Coskata says its proprietary process, which relies on a combination of gasification and fermentation by microorganisms, is up to six times more efficient than the production of ethanol from corn. The process can handle everything from switchgrass to industrial waste to household garbage, produces fewer emissions and noxious byproducts than comparable systems, and will result in ethanol with a production cost of around one dollar per gallon.

The demand

While the world scrambles to prepare for alternatives to petroleum, concerns with corn-based ethanol--including its effect on rising food prices and its relative inefficiency--have become increasingly apparent. A promising alternative is cellulosic ethanol, which can be made from a variety of biomass feedstocks that place less demand on agricultural land and food-based crops. The amount of energy derived from cellulosic ethanol relative to the energy needed to harvest (known as the wells-to-wheels measurement) is also many times greater than that of corn-based ethanol. In December 2007, the Federal Government mandated the production of 36 billion gallons of ethanol annually by 2022, 21 billion of which is to come from cellulosic (non-corn-based) feedstock.

Photo Credit: Coskata

Text By: Kevin Massy