棉秆与麦草蒸煮反应的动力学比较

比较了棉秆和麦草蒸煮反应的脱木质素速率常数,提出一种研究蒸煮反应动力学的实验和计算新方法。通过对不同恒温条件下的反应速率常数计算,采用与实际蒸煮反应相同的液比,用较短时间周期的有效碱浓度变化值和木质素含量变化值计算得出了两种原料烧碱-蒽醌法蒸煮反应的活化能。棉秆烧碱-蒽醌法蒸煮反应的活化能和麦草烧碱-蒽醌法蒸煮反应的活化能在整个脱木质素阶段基本是不变的。麦草烧碱-蒽醌蒸煮反应的活化能为51.0 kJ/mol。棉秆烧碱-蒽醌法蒸煮反应的活化能是138.1 kJ/mol,高于麦草蒸煮反应活化能,说明麦草蒸煮脱木质素反应比棉秆更容易。

Comparison of Cooking Kinetics between Wheat Straw and Cotton Stalk

Comparison of cooking kinetics between cotton stalk and wheat straw was studied in this paper.A novel experimental and calculating method for the study of cooking kinetics was established.By application of identical liquor ratio as used in actual cooking conditions,activation energies of soda-AQ cooking of cotton and wheat pulps were obtained from determinations of effective alkali concentration and residual lignin content,as well as from calculation of reaction rate constant.Activation energies of soda-AQ cooking of cotton stalk and wheat straw were basically unchanged during the whole cooking period.Activation energy of soda-AQ cooking of wheat straw was 51.0 kJ/mol which was lower than that of soda-AQ cooking of cotton stalk at 138.1 kJ/mol,which indicated that delignification of wheat straw was easier than that of cotton stalk during soda-AQ cooking.