小麦秸秆半纤维素丙酸法预处理降解动力学

Degradation Kinetics of Hemicellulose of Wheat Straw Pretreated by Propionic Acid

研究了小麦秸秆丙酸法预处理过程中半纤维素的降解动力学。结果表明,半纤维素降解过程可分为0～60 min的快速降解和60～180 min的缓慢降解2个阶段。通过建立反应动力学方程,获得了小麦秸秆丙酸法预处理的化学反应速率常数和反应级数。当温度为60、70、80和90℃时,速率常数分别为1.98×10-4、1.67×10-3、1.79×10-2和4.42×10-2,反应级数分别为1.99、1.40、0.61和0.46。在一定温度和时间条件范围内的动力学研究表明,小麦秸秆的丙酸法预处理的平均反应活化能为180.16 kJ/mol,频率因子为5.27×1024L/(mol.min)。

Degradation kinetics of hemicellulose of wheat straw pretreated by propionic acid was studied. The results showed that two distinct phases occurred during the degradation process of hemicellulose of wheat straw, the fast degradation stage from the beginning to 60 min and the mild degradation stage from 60 min to 180 min. The rate constant and the order of reaction were determined through the establishment of kinetic equation. Under the temperature of 60°C , 70°C, 80°C and 90°C , the rate constants were 1.98 x 10^-4, 1.67 x 10^-3, 1.79 x 10^-2 and 4.42 x10^-2, respectively. At the same time, the order of reactions were 1.99, 1.40, 0.61, 0. 46, respectively. The experiment was carried out in a certain range of temperature and time, the average active energy was 180. 16 kJ/mol, and the frequency constant was 5.27 x 10^24 L/（mol.min）.