Ionic liquid-mediated selective extraction of lignin from wood leading to enhanced enzymatic cellulose hydrolysis.
Lignocellulose represents a key sustainable source of biomass for transformation into biofuels and bio-based products. Unfortunately, lignocellulosic biomass is highly recalcitrant to biotransformation, both microbial and enzymatic, which limits its use and prevents economically viable conversion into value-added products. As a result, effective pretreatment strategies are necessary, which invariably involves high energy processing or results in the degradation of key components of lignocellulose. In this work, the ionic liquid, 1-ethyl-3-methylimidazolium acetate ([Emim][CH3COO]), was used as a pretreatment solvent to extract lignin from wood flour. The cellulose in the pretreated wood flour becomes far less crystalline without undergoing solubilization. When 40% of the lignin was removed, the cellulose crystallinity index dropped below 45, resulting in > 90% of the cellulose in wood flour to be hydrolyzed by Trichoderma viride cellulase. [Emim] [CH3COO] was easily reused, thereby resulting in a highly concentrated solution of chemically unmodified lignin, which may serve as a valuable source of a polyaromatic material as a value-added product.
Lee
Sang Hyun
SH
Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
Doherty
Thomas V
TV
Linhardt
Robert J
RJ
Dordick
Jonathan S
JS
D001709:Biotechnology / Q000379:methods*; D002482:Cellulose / Q000378:metabolism*; D019652:Extraction and Processing Industry / Q000379:methods*; D006868:Hydrolysis; D007093:Imidazoles / Q000737:chemistry; D008031:Lignin / Q000302:isolation & purification*; D012997:Solvents / Q000737:chemistry; D014242:Trichoderma / Q000378:metabolism*; D014934:Wood / Q000737:chemistry*
D007093:Imidazoles; D012997:Solvents; D002482:Cellulose; D008031:Lignin; C518739:1-ethyl-3-methylimidazolium