Numerical Optimization of the Abies Ethanol Lignin Sulfation Process with Sulfamic Acid in 1,4-Dioxane Medium in the Presence of Urea

摘要

The process of abies ethanol lignin sulfation with sulfamic acid in 1,4-dioxane medium in the presence of urea was optimized by calculation methods. The influence of such factors, as the ratio of lignin/sulfating complex (L/SC), temperature and time of the sulfation process on the sulfur content in the resulting sulfated ethanol lignin and its yield, has been established. The variance analysis of the obtained mathematical models testifies their good predictive properties. The optimal conditions of abies ethanol lignin sulfation process, which provide the formation of water-soluble sulfated lignin with a high yield (to 100 % wt.) and sulfur content (up to 7.9 % wt.), have been established. They are: temperature of 95-100 degrees C, the ratio L/SC 1:2,3-1:2:9 and the time of the process 119-137 minutes.