热水预水解过程杨木及水解液中组分的变化

Changes of Components in Poplar and Its Hydrolyzate during Hot Water Pre-hydrolysis

关键词:  杨木  热水预水解  组分变化  水解产物

Key Words:poplar  autohydrolysis  component change  hydrolyzate

摘要:探究了热水预水解对杨木组分、微观结构的影响及预水解液中降解产物含量变化的规律。结果表明，在保温时间60 min、保温温度155~175℃以及在保温时间0～120 min、保温温度170℃的条件下，随保温温度的升高或时间的延长，杨木热水预水解后的得率、聚戊糖和Klason木素的相对含量整体减少，纤维素的相对含量和结晶度有所增加；杨木热水预水解后的纤维形貌发生变化，出现不规则碎片和孔洞；预水解液中的酸溶木素含量增加，甲酸、乙酸、糠醛和5-羟甲基糠醛的浓度增加，糖含量随保温温度的升高不断增加，但随保温时间的延长呈先增加后减少的趋势。

Abstract:The effect of hot water pre-hydrolysis on the composition and microstructure of poplar wood and its relationship with the contents of degradation products in hydrolyzate were investigated. Experiments showed that pre-hydrolysisat a temperature of 155～175℃ for 60 min and at 170℃ for 0～120 min, the yield of poplar wood chips after hydrolysis， the relative content of pentosan and Klason lignin in hydrolysate decreased as a whole， and the relative content and crystallinity of cellulose increased with the increase of temperature or the prolongation of time.Hydrolyzed fiber morphology was changed， appearing irregular fragments and holes.The content of acid soluble lignin in the hydrolyzate increased， the concentration of formic acid， acetic acid， furfural and 5-hydroxymethylfurfural(5-hmf)increased. The content of sugar increased with the increase of temperature， but it increased first and then decreased with the increase of the time keeping at the maximum temperature．