Addition of Wood Model Components to Kraft Cooking to Better Understand the Improvement in Delignification Rate Caused by Dissolved Wood Components

In this study different dissolved wood components (DWC) in the industrial black liquor and their effect on the delignification during the kraft cook has been investigated. The cooking were performed on softwood as well as hardwood to see different effects on the delignification rates. Different wood model components as well as treated black liquor components were added to the kraft cooking liquor. The results show that the phenolic groups in the black liquor lignin has a positive effect on the delignifiacation rate. It was also shown that surfactant had a positive effect on the delignification rate in systems with low amount of DWC. Furthermore, it was shown that a black liquor with a low amount of lignin i.e. mostly carbohydrates had a positive effect on the delignification rate. Cellulose and hemicellulos, on the other hand, did not seem to have any effect on the delignification rate.