PREDICTION MODEL FOR KAPPA NUMBER IN WHOLE STALK KENAF KRAFT PULPING

摘要

Kappa number of pulp in pulping process is generally considered to be an important parameter to characterize the degree of delignification. Reasonable Prediction Model of Kappa number of pulp is an important guarantee for effective on-line control. Kenaf, an annual herb, is an excellent raw material for pulp and paper making. And pulping from whole stalk kenaf is an effective way to protect forest resources. However, Prediction Model of Kappa number of pulping from whole stalk Kenaf has not been reported. Therefore, in view of improving the utilization rate of raw materials, energy-conservation and pollution-reduction in paper mills, the establishment of kappa number prediction model for whole stalk kenaf sulphate pulp will have important practical significance. In this paper, the effects of cooking temperature, cooking time, H-factor, initial concentration of effective alkali and sulfide on pulp Kappa number were examined. The results showed that Kappa number was linear with the logarithm of (H +200), the 0.7th power of the initial effective alkali concentration and the sulfidity. And then an empirical model of Kappa number was deduced, viz. K=108- 0.327 In(H+200)(EA)0.7In(S). Through the survey of the experiment sections, there was a good agreement (R2= 0.936) between the measured and predicted pulp Kappa number, indicating that the model was justifiable to be applied to predict pulp Kappa number during whole stalk kenaf kraft pulping.