开发了一种由氯化胆碱(ChCl)基低共熔溶剂(DES)和甲基异丁基酮(MIBK)组成的简便两相体系,以实现糠醛的生产。一锅法从桉树中分离木质素并制备可发酵葡萄糖。结果表明,ChCl/1,2-丙二醇/MIBK体系具有将半纤维素转化为糠醛的最佳性能。在最佳条件下(MRChCl:1,2-丙二醇=1:2,原料:DES:MIBK比例=1:4:8g/g/mL,0.075mol/LAlCl3·6H2O,140°C,和90分钟),糠醛产率和葡萄糖产率分别达到65.0和92.2%,分别。同时,低分子量木质素(1250-1930g/mol),低多分散性(DM=1.25-1.53)和高纯度(碳水化合物含量仅为0.08-2.59%)从两相系统中再生。随着预处理温度的升高,再生木质素中的β-O-4、β-β和β-5键逐渐断裂,酚羟基的含量增加,但脂肪族羟基的含量下降。该研究为生物炼制过程中木质纤维素的综合利用提供了新的策略。
A facile biphasic system composed of choline chloride (ChCl)-based deep eutectic solvent (DES) and methyl isobutyl ketone (MIBK) was developed to realize the furfural production, lignin separation and preparation of fermentable glucose from Eucalyptus in one-pot. Results showed that the ChCl/1,2-propanediol/MIBK system owned the best property to convert hemicelluloses into furfural. Under the optimal conditions (MRChCl:1,2-propanediol = 1:2, raw materials:DES:MIBK ratio = 1:4:8 g/g/mL, 0.075 mol/L AlCl3·6H2O, 140 °C, and 90 min), the furfural yield and glucose yield reached 65.0 and 92.2 %, respectively. Meanwhile, the lignin with low molecular weight (1250-1930 g/mol), low polydispersity (DM = 1.25-1.53) and high purity (only 0.08-2.59 % carbohydrate content) was regenerated from the biphasic system. With the increase of pretreatment temperature, the β-O-4, β-β and β-5 linkages in the regenerated lignin were gradually broken, and the content of phenolic hydroxyl groups increased, but the content of aliphatic hydroxyl groups decreased. This research provides a new strategy for the comprehensive utilization of lignocellulose in biorefinery process.