03/01/2010
New Ionic Liquids Treatment for Converting Biomass to Sugars
Access to sugars is hindered by the recalcitrance of plant cell walls.
The Science
Digestion of cellulosic biomass to release fermentable sugars remains a major challenge: current biomass treatment approaches typically involve large volumes of hazardous concentrated acids, expensive secondary enzymatic digestion, and energy intensive heating. Researchers at the DOE Great Lakes Bioenergy Research Center have developed an improved chemical treatment method to liberate sugars from biomass. This approach uses a combination of ionic liquids, water, and dilute acid, resulting in the release of over 75% of the sugar molecules locked in corn stover. This approach produces fewer toxic byproducts that inhibit growth of the fermentative microbes used to convert released sugars to ethanol and other biofuels. Although the current experiments were performed at laboratory scale, potential avenues have been identified for scaling the approach for commercial development.
Summary
Researchers report a high-yielding chemical process for the hydrolysis of biomass into monosaccharides. Adding water gradually to a chloride ionic liquid-containing catalytic acid leads to a nearly 90% yield of glucose from cellulose and 70–80% yield of sugars from untreated corn stover. Ion-exclusion chromatography allows recovery of the ionic liquid and delivers sugar feedstocks that support the vigorous growth of ethanologenic microbes. This simple chemical process, which requires neither an edible plant nor a cellulase, could enable crude biomass to be the sole source of carbon for a scalable biorefinery.
BER Program Manager
Dawn Adin
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Biological Systems Science Division
[email protected]
References
Binder, J. B. and R. T. Raines. 2010. “Fermentable Sugars by Chemical Hydrolysis of Biomass,” Proceedings of the National Academy of Sciences 107, 4516–21. DOI:10.1073/pnas.0912073107.