An Investigation into Eucalyptus Hemicellulose Pre-extraction and its Influence on Alkaline Pulping
In this study,the eucalyptus chips were pretreated with alkaline liquor or hot water for extracting hemicellulose before pulping.The effects of pretreatment conditions on the extraction yield and subsequent pulping were discussed.Spectrophotometric analysis was adopted and a formula was introduced for calculating the relative yield of pentosan(or pentose).In the alkaline pre-extraction with different sodium hydroxide concentrations,the pentosan yield was quite low when the temperature was below 100℃.The relationship between the relative pentosan yield and the treatment time was established in the range of 0.5 to 13 hours at 90℃ with the NaOH concentration of 8％ or 10％.In the hot water pre-hydrolysis the relative yield of pentose went up with the temperature increasing.The yield of 33％ was obtained at the hydrolysis temperature of 170℃.In Comparison with the results from the regular wood chips under the same cooking conditions,pulping with pre-extracted chips resulted in a lower kappa number and higher pulp brightness.But the pulp yield and viscosity were decreased.Pulping with water pre-hydrolyzing showed better results than those from the alkaline pre-extraction.The higher pentose yield may induce the decline of pulp strength.
hemicellulose pre-extraction eucalyptus pentosan pulping
ZENG ZHANG CONGCONG CHI JIANREN YU XUAN LIU WEIWEI GE
State Key Laboratory of Pulp & Paper Engineering,South China University of Technology,Guangzhou,510640,P.R.China
国际会议
第二届国际造纸与环境学术会议(The Second International Papermaking & Environment Conference)
天津
英文
307-310
2008-05-14（万方平台首次上网日期，不代表论文的发表时间）