Lewis acid-catalyzed biphasic 2-methyltetrahydrofuran/H2O pretreatment of lignocelluloses to enhance cellulose enzymatic hydrolysis and lignin valorization

Lewis acid-catalyzed pretreatment in a biphasic system consisting of bio-based solvent 2-methyltetrahydrofuran (2-MeTHF) and water for a highly integrated one-pot catalytic transformation of lignocelluloses have been achieved. The aim of this work was to study the effects of different Lewis acid catalysts and pretreatment temperatures on the structural characteristics of precipitated lignin and enzymatic hydrolysis of the pretreated substrates, as well as the quantitative analysis of precipitates, solid residues, soluble carbohydrates and inhibitors. After the AlCl3-catalyzed biphasic 2-MeTHF/H2O pretreatment at 180 °C, its maximum cellulose conversion rate was enhanced by 7.4-fold as compared to the raw material. The precipitated lignin exhibited the representative structure, relatively low molecular weight and high purity for preparing value-added aromatic chemicals or renewable polymers. Overall, AlCl3-catalyzed biphasic 2-MeTHF/H2O pretreatment may offer a promising approach for enhancing enzymatic hydrolysis and obtaining valorized lignin by-product.