Stepwise processing strategy for efficient and comprehensive utilization of sugarcane bagasse via enzymatic hydrolysis and catalytic conversion to produce 5-hydroxymethylfurfural

Abstract

To achieve the goal of “no waste” in circular bioeconomy on the basis of waste-to-energy conversion, the development of efficient technology for sustainable treatment and utilization of lignocellulosic biomass is significant yet challenging. In this study, a stepwise processing strategy based on enzymatic hydrolysis and catalytic conversion was proposed for comprehensive utilization of sugarcane bagasse (SCB) to produce value-added products. Mechanical activation (MA) pretreatment was adopted to disrupt the recalcitrant structure of SCB for improving enzymatic hydrolysis of polysaccharides to produce reducing sugars, obtaining a high yield (392 mg/g SCB) of target sugars (TS; i.e., cellobiose and glucose). The enzymolysis residue and Al(NO3)3·9 H2O were treated by MA and then calcinated to construct the biochar (BC)-based catalyst (denoted as MA-Al/BC) with Brønsted–Lewis dual-acidic sites, which effectively catalyzed the conversion of TS to produce 5-hydroxymethylfurfural (5-HMF). A TS conversion of 94.5% and a 5-HMF yield of 77.6% were achieved at 190 °C for 4 h in the biphasic system. MA-Al/BC exhibited excellent universality for efficient catalytic conversion of various carbohydrates. This study offers a promising approach for value-added exploitation of agricultural wastes within circular bioeconomy principles.