Use of γ-valerolactone solvent to extract carbohydrates from cellulosic materials for use in creating biofuels

Related to obtaining biofuels from cellulosic sources, work from the University of Wisconsin discusses use of a γ-valerolactone solvent.

The Abstract from the paper published on January 17, 2014:



Widespread production of biomass-derived fuels and chemicals will require cost-effective processes for breaking down cellulose and hemicellulose into their constituent sugars. Here, we report laboratory-scale production of soluble carbohydrates from corn stover, hardwood, and softwood at high yields (70 to 90%) in a solvent mixture of biomass-derived γ-valerolactone (GVL), water, and dilute acid (0.05 weight percent H2SO4). GVL promotes thermocatalytic saccharification through complete solubilization of the biomass, including the lignin fraction. The carbohydrates can be recovered and concentrated (up to 127 grams per liter) by extraction from GVL into an aqueous phase by addition of NaCl or liquid CO2. This strategy is well suited for catalytic upgrading to furans or fermentative upgrading to ethanol at high titers and near theoretical yield. We estimate through preliminary techno-economic modeling that the overall process could be cost-competitive for ethanol production, with biomass pretreatment followed by enzymatic hydrolysis.



Citation

Science 17 January 2014:
Vol. 343 no. 6168 pp. 277-280



Separately, note published US 20120302767 titled PRODUCTION OF LEVULINIC ACID, FURFURAL, AND GAMMA VALEROLACTONE FROM C5 and C6 CARBOHYDRATES IN MONO- AND BIPHASIC SYSTEMS USING GAMMA-VALEROLACTONE AS A SOLVENT .

from the specification

Significant advances have been made in recent years with respect to using heterogeneous catalysts for converting biomass-derived compounds to fuels and chemicals. Conventional approaches deconstruct solid lignocellulose into smaller molecules that are soluble in various solvents (e.g., water, ionic liquids), thereby allowing transport of these reactants to the active sites on the heterogeneous catalyst, the majority of which are located within the pores of a high-surface area material. A difficulty in implementing this strategy is that chemical components used to deconstruct solid cellulose (e.g., sulfuric acid) may alter the performance of heterogeneous catalysts used subsequently to convert the soluble biomass-derived reactants to the desired fuels and/or chemicals. As a result, costly purification steps are required to implement a cascade catalytic process. Thus, the present method addresses a long-felt and unmet need by providing a route to levulinic acid, gamma-valerolactone, furfural, and downstream value-added chemicals that uses gamma-valerolactone itself as a reaction solvent in a monophasic reacti