摘要
A reactive benzyl alcohol/5-SSA system enabled efficient corn stover component fractionation. • The fractionation removed 86.52% lignin and 90.51% hemicellulose while retaining 88.45% cellulose. • Low-condensation lignin was recovered through benzyl alcohol-mediated structural protection. • HSQC and DFT revealed that benzyl alcohol suppressed lignin condensation via reactive grafting. • Pretreated residue is converted into high-surface-area porous biochar. Efficient fractionation of lignocellulosic biomass under mild conditions while preserving lignin structural integrity remains a major challenge for biomass valorization. In this work, we developed a binary pretreatment system composed of benzyl alcohol and 5-sulfosalicylic acid (5-SSA) for the mild fractionation and component utilization of corn stover. The results showed that under the optimal conditions (100 °C, 60 min, and 4 wt% 5-SSA), 86.52% of lignin and 90.51% of hemicellulose were removed, while 88.45% of cellulose was retained. The recovered lignin showed high purity, a light color, a low condensation degree, and a relatively uniform molecular-weight distribution. 2D-HSQC NMR combined with DFT calculations suggested that benzyl alcohol may suppress lignin condensation through stabilization of benzylic intermediates and interaction with reactive nucleophilic sites on lignin aromatic rings. In addition, benzyl glycosides were identified as important hemicellulose-derived products in the aqueous phase, suggesting a solvent participated alcoholysis/glycosylation pathway. The cellulose-rich solid residue was upgraded into porous biochar with a specific surface area of up to 1388.13 m 2 g −1 via KHCO 3 -assisted pyrolysis. This work provides an effective strategy for the mild fractionation of corn stover, recovery of high-quality lignin, and integrated valorization of biomass components. Download: Download high-res image (114KB) Download: Download full-size image
危险品化学品经营许可证（带存储）