草酸盐酸体系微晶纤维素水解动力学

Hydrolysis kinetics of microcrystalline cellulose in oxalic acid hydrochloric acid system

对微晶纤维素在草酸-盐酸体系中的水解情况进行了研究,并对不同条件下反应产物中葡萄糖的质量浓度进行了测定。依据纤维素酸水解反应特点,根据Seaman模型,对微晶纤维素在草酸盐酸体系中的水解动力学规律进行了研究。动力学结果:纤维素水解和葡萄糖降解的活化能分别是58.02 k J/mol和144.2 k J/mol。升高反应温度,使纤维素水解反应速度加快,也会使葡萄糖的降解速率加快。该模型的最佳反应条件是:固液比1∶20 g/m L,草酸的质量浓度25 g/L,盐酸的质量浓度1 g/L,温度90℃,时间9 h,在此条件下,葡萄糖质量浓度为1.657 g/L。

The hydrolysis of microcrystalline cellulose in the system of oxalic acid and hydrochloric acid was studied,and the mass concentration of glucose in different conditions was determined. According to the characteristics of cellulose acid hydrolysis,and according to the Seaman model,the kinetics of the hydrolysis of microcrystalline cellulose in the system of oxalic acid and hydrochloric acid was studied. Dynamics results： the activation energy of cellulose hydrolysis and glucose degradation was 58. 02 k J / mol and 144. 2 k J / mol. Raising the reaction temperature is advantageous to increase the reaction rate. Increasing reaction temperature can not only improve the reaction rate of cellulose hydrolysis,but also improve the degradation rate of glucose. The optimum reaction conditions of the model are a constant solidliquid ratio of 1 ∶ 20 g / m L,the concentration of oxalic acid is 25 g / L,the concentration of hydrochloric acid was 1 g / L,the temperature is 90 ℃,time is 9 h,and the glucose concentration is 1. 657 g / L.