FORMIC ACID PULPING OF WHEAT STRAW AND PRELIMINARY ANALYSIS OF LIGNIN STRUCTURE
To find the important parameters that affect the cooking process and to predict the properties of the produced lignin and pulp, the impact of concentration of formic acid, cooking temperature, and cooking time as well as the pre-treatment time on the pulp yield and kappa number was investigated and the lignin structure in raw material, unbleached pulp and that in the black liquor was analyzed with FTIR. The result shows that pulp yield is mostly influenced by cooking time while the kappa number is significantly affected by cooking temperature. Factors can be listed in the order of importance as follows: those affecting pulp yield are acid concentration > cooking time > cooking temperature > pre-treating time, and those affecting the Kappa number are: cooking temperature > acid Concentration > cooking time > pre-treating time. The FTIR spectra show that, during the cooking process, ether bond C-O-C in the lignin of unbleached pulp reduced and conjugated C=O increased. The content of lignin with S-unit and H-unit structure is fairly high in the black liquor. The results are in favor of the optimization of formic acid pulping process and helpful for the application in the production of lignin based by-products.
formic acid pulping wheat straw lignin
Xie Xiaohong Fan Yongming Li Mingfei Ma Ruijie Wu Ruiping
College of Materials Science and Technology, Beijing Forestry University, Beijing, 100083, China
国际会议
广州
英文
1045-1048
2010-11-08（万方平台首次上网日期，不代表论文的发表时间）