Combination of ethanol and Fe3O4@C‐SO3H pretreatment of Eucalyptus for glucose release via enzymatic saccharification

Abstract

AbstractBACKGROUNDEnzymatic hydrolysis of lignocellulose is regarded as the most efficient route to producing fermentable sugars, one kind of promising future biofuel, while physiochemical pretreatment is the initial but most critical step for the efficient utilization of lignocellulose.RESULTSIn this study, a recoverable carbonaceous solid acid catalyst Fe3O4@C‐SO3H was used in combined organosolv pretreatment of Eucalyptus biomass at 140–180 °C with 50 vol% ethanol. The introduction of solid acid in ethanol pretreatment remarkably alleviated the requirement of smaller biomass size, but provided less influence on cellulosic degradation, which benefited the subsequent enzymatic hydrolysis to glucose. After the pretreatment using 50 vol% ethanol and 20% catalyst at 160 °C, 60.3% hemicellulose and 52.6% lignin were removed from Eucalyptus (75–250 μm) within 60 min, which resulted in a cellulose retention ratio of >90% and improved hydrolysis efficiency by nearly 20 and 2 folds, respectively, compared to untreated and ethanol pretreated materials.CONCLUSIONThis study explored a novel pretreatment technique to improve the efficiency of enzymatic saccharification. It also demonstrated that the hydrolysis yield of cellulose had significantly positive correlation with the removal of lignin and hemicellulose in Eucalyptus, but was less affected by cellulose crystallinity. © 2020 Society of Chemical Industry