College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; Jiangsu Co-Innovation Centre of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-forest Biomass, Nanjing Forestry University, Nanjing, Jiangsu 210042, China.
College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
Bioresour Technol. 2020 Nov;315:123776. doi: 10.1016/j.biortech.2020.123776. Epub 2020 Jul 4.
Integrated conversion and stepwise extraction of whole components in biomass with biphasic system are introduced for producing chemicals: levulinates and phenolics. When methanol/dimethoxymethane as biphasic solvent, 46.51% methyl levulinate and 18.78% phenolics were obtained with a conversion of 80.59 wt% per 4 g rice straw under the mild reaction conditions. Levulinates were collected with a 87.5 wt% high purity of methyl levulinate with stepwise precipitation and extraction from the cellulose and hemicellulose. The results of acid value, freezing point, induction period, kinematic viscosity, and flash point supposed that the extracted methyl levulinate could meet the requirements of fuel additives. Depolymerized lignin was consisted of many low-molecular phenolics. These results illustrated that the biphasic system can promote the conversion of cellulose and hemicellulose to the same product methyl levulinate through different intermediate transition compounds, and the catalyst can contribute to directly cleave the glycosidic bonds, β-O-4, and 4-O-5 with adequate protons.
采用双相体系对生物质中的全组分进行集成转化和分步提取，以生产化学品：乙酰丙酸酯和酚类。当甲醇/二甲氧基甲烷作为双相溶剂时，在温和的反应条件下，每 4 g 稻草可转化 80.59 wt%，得到 46.51%的甲基乙酰丙酸酯和 18.78%的酚类。通过分步沉淀和从纤维素和半纤维素中提取，乙酰丙酸酯的纯度高达 87.5 wt%，可以收集到高纯度的甲基乙酰丙酸酯。酸值、冰点、诱导期、运动粘度和闪点的结果表明，提取的甲基乙酰丙酸酯可以满足燃料添加剂的要求。解聚木质素由许多低分子量酚类组成。这些结果表明，双相体系可以通过不同的中间过渡化合物促进纤维素和半纤维素向同一产物甲基乙酰丙酸酯的转化，催化剂可以通过充足的质子直接裂解糖苷键、β-O-4 和 4-O-5。
