Simultaneous isolation of cellulose and lignin from wheat straw and catalytic conversion to valuable chemical products
Bowei Yu, Guozhi Fan, Si‐Jiu Zhao, Yuchan Lu, Qiao He, Qunpeng Cheng, Juntao Yan, Bo Chai, Guangsen Song
Abstract
Abstract Convertible cellulose and lignin were simultaneously isolated from wheat straw using a two-stage process via simply varying temperature and H 2 SO 4 concentration. At the first-stage, cellulose was obtained by pretreating wheat straw at lower temperature and acid concentration using an organosolv process. The purity, yield and recovery rate of cellulose reached 86.8 wt%, 55.2 and 92.8% at 150 °C with 1 wt% H 2 SO 4 . At the second stage, the residual liquid was further treated at higher temperature and acid concentration, giving 17.4% lignin yield with 86.6% recovery rate and 93.2 wt% purity at 180 °C with 1.5 wt% H 2 SO 4 . The conversion of the as-isolated cellulose and lignin into chemicals was further investigated. The total yield of 5-hydroxymethylfurfural and glucose derived from wheat straw cellulose reached 82.5%, and 18.3% yield of monophenolic compounds from lignin were obtained, respectively. These results indicated that the two-stage process was effective for obtaining high-quality cellulose and lignin from wheat straw. Both of them displayed excellent convertible property.