ISOLATON AND CHARACTERIZATION OF LIGNIN IN THE PRE-HYDROLYSIS LIQUOR OF KRAFT BASED DISSOLVING PULP PRODUCTION PROCESS
The separation of lignin from the pre-hydrolysis liquor (PHL) of dissolving pulp process will create new revenue for the dissolving pulp production process, and fits well with the integrated forest bio-refinery concept. Lignin will likely become a valuable source of renewable energy (e. g., biofuel,), and bio-materials (e. g. plastics, adhesives). In this study, lignin was isolated from the PHL by acidification with a weak H2SO4 solution, followed by purification through dissolving in a dioxane solution (9:1) and re-precipitation on diethyl ether. The characteristics of PHL lignin was compared with the dioxane lignin isolated from the hardwood (Maple, poplar and birch wood chips in the ratio of 7:2:1), which is the raw material for the dissolved pulp production. The thus obtained lignin samples were characterized by means of UV, FTIR, H-NMR spectroscopy, molecular weight determination, elemental and methoxyl analyses. The absorptivity of hardwood lignin was 10 L/(g·cm), while that of PHL lignin was 17.23 L/(g·cm). The presence of condensed structures in PHL lignin was observed as stronger band at 870 and 890cm(-1) in FTIR spectrum. The lignin isolated from the PHL has a low molecular weight, and a low methoxyl group per C- unit, in comparison with other lignin samples. H-NMR data indicates that a significant increase of phenolic hydroxyl content in the PHL lignin was observed as cleavage of aryl-ether bonds during the prehydrolysis process. Based on these results, it can be concluded that the isolated lignin from the PHL has potential value for the polymer industry.
PHL lignin dissolving pulp process, phenolic hydroxyl group molecular weight methoxyl group
M. Sarwar Jahan Z. Liu H. Wang A. Saeed Y Ni
Pulp and Paper Research Division, BCSIR Laboratories,Dhaka, Dr. Qudrat-i-Khuda Road, Dhaka 1205,Bang Limerick Pulp & Paper Centre, Univ. of New Brunswick,Fredericton, NB, Canada, E3B 5A3 Tianjin Key La Limerick Pulp & Paper Centre, Univ. of New Brunswick,Fredericton, NB, Canada, E3B 5A3 Key Lab. of Au Limerick Pulp & Paper Centre, Univ. Of New Brunswick,Fredericton, NB, Canada, E3B 5A3
国际会议
16th International Symposium on Wood,Fiber and Pulping Chemistry(第十六届木材、纤维及制浆化学国际会议)
天津
英文
178-183
2011-06-08（万方平台首次上网日期，不代表论文的发表时间）