Biphasic 2-methyltetrahydrofuran/oxalic acid/water pretreatment to enhance cellulose enzymatic hydrolysis and lignin valorization

A biphasic pretreatment was adopted to disturb the recalcitrant structure of bamboo for further enzymatic hydrolysis and to obtain easily valorized lignin by-product. The biphasic system consisted of biomass-derived chemicals-2-methyltetrahydrofuran and oxalic acid as well as water, and the reactions were conducted at 120-180 degrees C for 20 min. The treatment resulted in notable removal of hemicelluloses and lignin. After the pretreatment, the cellulose conversion rate during enzymatic hydrolysis was enhanced by 6.7-fold as compared to the unpretreated raw material. Comprehensive analysis of the lignin product indicated that it exhibited representative structure (such as beta-O-4, beta-beta linkages) as compared to native lignin, contained a very low amount of contaminated sugars (0.67-2.39%), and had a relatively medium molecular weight (Mw 2240-3730 g/mol) and good solubility in many organic solvents. This indicated that the lignin showed great potential application in conversion into materials and liquid fuels. (C) 2017 Elsevier Ltd. All rights reserved.