期刊
CURRENT ORGANIC CHEMISTRY
卷 17, 期 15, 页码 1589-1595出版社
BENTHAM SCIENCE PUBL LTD
DOI: 10.2174/13852728113179990068
关键词
PHL lignin; Dissolving pulp; Kraft pulping; Characteristics; Phenolic hydroxyl group; Molecular weight; Methoxyl group
资金
- National Science Foundation of China [31070525]
- Prior Special Study of 973 Program [2011CB211705]
- NSERC CRD grant
The kraft-based dissolving pulp production process can be a model for the forest biorefinery concept. The objective of this study is to characterize the dissolved lignin present in the pre-hydrolysis liquor (PHL) to facilitate its subsequent use following the forest biorefinery concept. In this work, lignin was isolated from PHL by acidification using dilute H2SO4, followed by purification through dissolution in a dioxane solution (9: 1) and re-precipitation with diethyl ether. The characteristics of PHL lignin were compared with those of the dioxane lignin, acetic acid (AA) lignin and ethanosolv (EL) lignin isolated from the same mixed hardwood (maple, poplar and birch wood chips, in a ratio of 7:2:1), which is the raw material used for dissolving pulp production. The obtained lignin samples were characterized by UV, FTIR, H-1-NMR spectroscopy, molecular weight determination, elemental and methoxyl analyses. The results showed that the absorptivity of dioxane lignin at 276 nm was 10.0 l g(-1) cm(-1), while that of PHL lignin was 17.2 l g(-1) cm(-1). The presence of condensed structures in the PHL lignin was also observed in the FTIR spectrum (strong bands at 870 and 890 cm(-1)), which was also present in the AA and EL lignins. The lignin isolated from PHL had a lower molecular weight and methoxyl group per C-9 unit, in comparison with other lignin samples. H-1-NMR analysis indicated a significant increase in the phenolic hydroxyl content in the PHL lignin, caused by cleavage of aryl-ether bonds during the prehydrolysis.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据