EFFECT OF DIFFERENT PRETREATMENT ON PREHYDROLYSATE AND WOOD RESIDUE FROM EUCALYPTUS CHIPS
Autohydrolysis and alkaline pretreatment was done on eucalyptus chips under different conditions. The effect on prehydrolysate and wood residue is investigated. For autohydrolysis pretreatment, higher decrease of pentosan content in wood is shown with elevated temperature and extended reaction time, which mainly accounts for the weight loss during pretreatment. Based on the GPC(Gel Permeation Chromatography) analytical results, the number-average molecular weight of hemicelluloses in alkaline pretreatment liquor and wood residues from different pretreatment decreases, and such decrease is greater for higher temperature. Compared with alkaline pretreatment, hemicelluloses in autohydrolyzed chips has much lower molecular weight, with similar dispersity to that in original wood. In the case of EMAL (Enzymatic/ Acidolysis Lignin) lignin, after autohydrolysis, the average molecular weight is increased while the polydispersity shows a little decrease compared to that from original wood. Based on the results from quantitative 31P-NMR analysis, after autohydrolysis, the total phenolic hydroxyl groups almost double and the S/G ratio is higher, but the amount of aliphatic hydroxyl and carboxyl groups shows a great decrease.
autohydrolysis alkaline pretreatment hemicelluloses EMAL lignin molecular weight distribution 31P-NMR
Zhang Zeng Chi Congcong Guo Wei
State Key Laboratory of Pulp and Paper Engineering,South China University of Technology, Guangzhou,510640, China
国际会议
广州
英文
277-280
2010-11-08（万方平台首次上网日期，不代表论文的发表时间）