描述桉木硫酸盐浆氧脱木素过程动力学的新模型

A New Kinetics Model of Oxygen Delignification of Fast-growing Eucalyptus Kraft Pulp

关键词:  氧脱木素  残碱  卡伯值  动力学模型

Key Words:oxygen delignification  residual alkali  kappa number  kinetics model

摘要:以桉木硫酸盐浆为原料，考察了氧脱木素温度、氧压、NaOH用量及反应时间对木素脱除程度的影响及残碱的变化规律。研究发现，氧脱木素过程溶液的NaOH浓度与纸浆卡伯值（用于表征纸浆木素含量）的自然对数之间呈线性关系；结合这一关系，建立了引入碱浓动态变化的氧脱木素动力学模型。结果表明，该模型能很好地预测桉木硫酸盐浆在各种工艺条件下的纸浆卡伯值（R2=0.980）。与传统氧脱木素动力学模型相比，该模型在参数量的控制及参数设置的合理性方面更具优势；由于考虑了过程残碱的变化，动力学模型参数的拟合结果更接近理论值。

Abstract:The effects of temperature, oxygen pressure, sodium hydroxide charge and reaction time on oxygen delignification of the fast-growing eucalyptus kraft pulp were investigated. It was found that the concentration of sodium hydroxide during oxygen delignification had a linear relationship with the natural logarithm of kappa number that standing for the residual lignin content in the pulp. Based on the information from the above investigation and observation, a new kinetics model of oxygen delignification was developed. The results showed that the present model could provide a good description for the oxygen delignification of the eucalyptus kraft pulps at different process conditions (R2=0.980). Compared to the traditional kinetics models of oxygen delignification, the present model minimized the number of kinetics parameters in the mathematical equation, which made the model much simpler and reliable.