纤维素在醇-水溶剂中水解及集总动力学研究

摘要

利用固定床式反应器研究了热压醇-水混合溶剂中处理木质纤维素制备还原糖的工艺条件及动力学.通过对不同反应温度、反应压力、不同溶剂等因素进行考察,发现在温度250℃、压力17 MPa、乙醇-水混合体积比1∶1时,还原糖的收率可达67.53％.以木质纤维素水解过程进行分段集总,提出了三集总动力学,拟合出了17 MPa下,乙醇加入前后,木质纤维素降解的表观活化能分别为119.497和56.784 kJ/mol.结果表明,乙醇-水作为溶剂时更有利于木质纤维素的降解,提高还原糖收率.%The process and kinetics of lignocellulose hydrolysis in hot - compressed alcohol-water mixtures for reducing sugar production in a fixed-bed reactor were investigated. It was found that the yield of reducing sugar could reach 67. 53% at a temperature of 250 t , a pressure of 17 Mpa and a volume ratio of ethanol/water 1: 1. By employing a 3-lump kinetic model, the apparent activation energies of lignocellulose hydrolyses without and with ethanol addition were estimated to be 119. 497 and 56. 784 kj/mol, respectively, at the pressure of 17 Mpa. The results showed that ethanol-water mixtures as solvent were beneficial to the hydrolysis of lignocellulose and improvement of reducing sugar production.