Co‐solvent Pretreatment Reduces Costly Enzyme Requirements for High Sugar and Ethanol Yields from Lignocellulosic Biomass. Issue 10 (11th February 2015)

• Record Type: Journal Article
• Authors: Nguyen, Thanh Yen; Cai, Charles M.; Kumar, Rajeev; Wyman, Charles E.
• Is Part Of: ChemSusChem. Volume 8:Issue 10(2015:May)
• Page Start: 1716
• Page End: 1725
• Publication Date: 2015-02-11
• Subjects: biomass -- enzymes -- hydrolysis -- renewable resources -- solvent effects; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201403045
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: We introduce a new pretreatment called co‐solvent‐enhanced lignocellulosic fractionation (CELF) to reduce enzyme costs dramatically for high sugar yields from hemicellulose and cellulose, which is essential for the low‐cost conversion of biomass to fuels. CELF employs THF miscible with aqueous dilute acid to obtain up to 95 % theoretical yield of glucose, xylose, and arabinose from corn stover even if coupled with enzymatic hydrolysis at only 2 mgenzyme gglucan −1 . The unusually high saccharification with such low enzyme loadings can be attributed to a very high lignin removal, which is supported by compositional analysis, fractal kinetic modeling, and SEM imaging. Subsequently, nearly pure lignin product can be precipitated by the evaporation of volatile THF for recovery and recycling. Simultaneous saccharification and fermentation of CELF‐pretreated solids with low enzyme loadings and Saccharomyces cerevisiae produced twice as much ethanol as that from dilute‐acid‐pretreated solids if both were optimized for corn stover. Abstract : Break it down! We describe a new pretreatment approach, co‐solvent‐enhanced lignocellulosic fractionation (CELF), that reduces plant recalcitrance by solvating biomass lignin using acidified aqueous THF solutions to improve sugar yields and reduce enzyme requirements for saccharification. Our results provide important insights into promising biomass pretreatment strategies.