Study On Enzymatic Beating Of Kraft Pulp

This paper is contributed to the research of enzymatic beating in softwood kraft pulp beating process and the subsequent results on pulp beating degree and property by using different kinds of enzymes - mono/multi-component cellulase, hemicellulase and xylanase. Also, some kinds of enzymes which are suitable for softwood kraft pulp beating efficiency improvement were sorted out. At the same time, the basic function of different enzyme components in enzymatic beating process was defined initially.The research shows that Pulpzyme HC can effectively improve the beating efficiency and strength properties for both bleached and unbleached softwood kraft pulp. Results show that cellulase, especially endoglucanase, is essential in enzymatic beating. Under the same operating conditions, mono-component endo-glucanase Novozym476 with cellulose binding domain (CBD) and mono-component endoglucanase DeniMax401 can increase the beating degree of softwood kraft pulp. Moreover, multi-component cellulases Novozym342 and DeniMax501 containing exoglucanase can promote beating more effectively. Again, Xylanase PulpzymeHC also has the capability of increasing beating degree. However, under the same lab conditions, the result shows that mono-component endoglucanase Novozyme613 can't improve the beating significantly, and has negative effect on pulp strength properties.The experimental results indicate that the pretreatment of softwood kraft pulp using cellulase and multi-component of cellulase and hemicellulase before beating can improve beating degree, and decrease the power consumption. On beating efficiency improvement, the synergetic effect of endoglucanase and exoglucanase on beating improvement has more advantages compared than mono-component endoglucanase. Mono-component xylanase can also improve the beating properties.