Monday, March 8, 2010

Converting cellulose into ethanol

llustration of sugar molecules in corn biomass.

Researchers have developed a method of processing cellulose from plants and other non-edible natural products into individual sugar molecules that then can be fermented by bacteria to produce ethanol. Plant cellulose contains long chains of useful sugars that store plenty of energy, but it is largely inaccessible due to the difficulty of breaking down cellulose. Joseph Binder and Ronald Raines converted cellulose to simple sugars with a combination of an ionic liquid, acid, and chromatography and suggest that their technique could be developed into a largescale industrial process to produce biofuel or other products. After the completion of the short (approximately 2–4 hours) chemical reaction, Binder and Raines report that bacteria and yeast could easily ferment the extracted sugars into ethanol. Compared to other industrial processes, the technique does not require as much dangerous, concentrated acid. The authors say the reaction can be used on many sources of lignocellulose, including non-food feedstocks such as switchgrass, wood, crop residues, and paper wastes. The technique is currently constrained by the expense of the ionic liquid, and must remain efficient if it is to be scaled up to a fullsize biorefinery, according to the authors. 

"Fermentable sugars by chemical hydrolysis of biomass" 
by Joseph B. Binder and Ronald T. Raines