A comprehensive analysis of organosilane surfactant-assisted hydrogen peroxide-p-toluenesulfonic acid pretreatment for enhancing saccharification efficiency of rapeseed straw

Abstract

Rapeseed straw, a low-cost agricultural byproduct, constitutes approximately 80% of rapeseed biomass. To efficiently utilize rapeseed straw, combination pretreatment can be attempted to develop for enhancing its enzymatic saccharification. Reducing sugars will be obtained in a high yield, which may be used to producing biofuels, biobased chemicals, additives, polymers, and pharmaceuticals. In this research, organosilane surfactant-assisted H₂O₂-p-toluenesulfonic acid pretreatment was built to be an efficient approach to alter the structure of lignocellulose and enhance the enzymatic hydrolysis efficiency of rapeseed straw. At 80 °C for 30 min, 87.1% of xylan and 99.4% of lignin in rapeseed straw were removed. After enzymatic saccharification, the yield of reducing sugars reached 87.3%. A series of characterizations demonstrated that this combination pretreatment increased cellulose accessibility from 498.4 to 1030.0 mg/g and decreased lignin hydrophobicity from 3.9 to 2.5 g/L. Computer simulations showed that an increase in electrostatic and van der Waals repulsion favored the dissolution of the pretreatment hindering fractions (lignin and hemicellulose). A comprehensive analysis of mass balance and energy flow was carried out to assess the full pretreatment process. This combination pretreatment was an efficient pretreatment strategy for enhancing enzymatic saccharification of lignocellulose.