Study on Hydroxylated Modification of Industrial Solid Wastes-Alkali Lignin

摘要

Alkali lignin is one of the most abundant and renewable resources extracted from alkaline pulp black liquor in the paper industry. Its utilization rate is less than 10%, with a big waste and pollution in the process. We researched molecular structure of lignin to improve its properties by hydroxylated modification with hydrogen peroxide, by which, we can change the structure of alkali lignin, develop its new uses and can expand its applications. Hydroxylation of alkali lignin, which was catalyzed by ferric hydroxide with hydrogen peroxide was studied. Effects on hydroxylated modification were investigated such as reaction temperature, reaction time, weight ratio of hydrogen peroxide to lignin and weight ratio of ferric hydroxide to lignin. The results showed that the optimization conditions of hydroxylation were as follows: reaction temperature 60 °C, reaction time 60 min, weight ratio of hydrogen peroxide to lignin 1.2, weight ratio of ferric hydroxide to lignin 1-4%. At this time, hydroxyl value was almost double that of alkali lignin. It showed that hydroxylated modification of alkali lignin was very successful.