While corn-based ethanol continues to attract criticism, ethanol produced from cellulosic material such as switchgrass or corn stalks is viewed as a more palatable alternative, in part because it doesn't rely on food crops to be produced.

 

To get to the cellulose requires special enzymes to remove the lignin that holds the cellulose together. This lignin, however, can be used to fuel the process of turning the remaining material to ethanol, meaning the process relies less on fossil fuels than other methods of creating ethanol.

 

One issue with cellulosic ethanol, however, is the cost of the enzymes needed to break the cellulose down. The National Research Council of Canada said that while waste biomass is cheaper than corn, the current enzyme cost for biomass conversion is about 16 cents per gallon (or 3.78 litres) of fuel ethanol. The ideal economic target, they say, would be in the three-cent-per-gallon range.

 

Not everyone, however, is convinced that cellulosic ethanol is the answer. University of British Columbia ecologist Bill Rees, a longtime critic of ethanol as a fuel alternative, said cellulosic ethanol is no better. He said taking away corn stalks and other material that would normally return to the land would deplete the soil, requiring further fertilization later. Improving the fuel efficiency of cars on the road is a more cost-effective way to improve the environment, he said.