微晶纤维素在盐酸、甲酸体系中的水解动力学

Hydrolysis Kinetics of Microcrystalline Cellulose in Formic Acid System

研究了微晶纤维素在盐酸、甲酸体系(4%盐酸,甲酸78.22%,水17.78%)中的水解动力学,以及反应温度在55～75℃、反应时间0～9h对葡萄糖得率的影响,并探讨了葡萄糖在该水解体系中的降解情况。研究结果表明,葡萄糖的降解反应和纤维素的水解反应相比是个快速反应。微晶纤维素在盐酸、甲酸体系中的水解速率表现在反应温度为55℃时,水解速率为6.34×10-3h-1;反应温度为65℃时,水解速率为2.94×10-2h-1;反应温度为75℃时,水解速率为6.84×10-2h-1。葡萄糖的降解速率表现为反应温度为55℃时,降解速率为0.01h-1;反应温度为65℃时,降解速率为0.14h-1;反应温度为75℃时,降解速率为0.34h-1。微晶纤维素水解的表观活化能为105.61kJ/mol,葡萄糖的降解表观活化能131.37kJ/mol。

An experiment was conducted to study the hydrolysis kinetics of mieroerystalline cellulose in the formic acid system with 4% hydrocldorie acid and 78.22% formic acid under mild conditions. The effects of temperature （from 55 to 75 degrees C） and retention time （0 - 9 h） on the glucose concentration were analyzed, and the degradation of glucose was also discussed. Result indicates that the degradation of glucose is a fast reaction compared with the hydrolysis reaction of cellulose. The hydrolysis velocities of mierocrystalline cellulose increase with temperature, which are 6.34 ×10^-3 per hour at 55 degrees C, 2, 94 × 10^ -2 per hour at 65 degrees C, 6.84 × 10^ -2 per hour at 75 degrees C. The velocities of glucose degradation are 0, 01 per hour at 55 degrees C, 0.14 per hour at 65 degrees C, 0.34 per hour at 75 degrees C. The activation energy of mierocrystalline cellulose hydrolysis is 105.61 kJ/mol, and that of glucose degradation is 131.37 kJ/mol.