G.M. Invests in Second Ethanol Process - New York Times →
“Ethanol made from non-grain materials, known as cellulose, is identical to corn ethanol, and the final steps ae usually the same: using yeast to ferment sugars into alcohol. But getting the sugar out of the cellulose is complicated. The process usually requires treating the cellulose with steam or acids to open up the material, and then letting enzymes — the digestive juices of bacteria or fungi — free the sugars. In addition, the cellulose includes both conventional six-carbon sugars as well as five-carbon sugars, but most industrial-grade yeast only likes the six-carbon variety.
Executives at Mascoma said they had developed a patented process, using heat and mechanical action, to treat the cellulose, avoiding the use of chemicals.”
