相思木水预水解过程中半纤维素的溶出和解聚

Dissolution and Depolymerization of Hemicelluloses of Acacia Wood during Autohydrolysis

在不同的水解温度和时间下对相思木进行水预水解处理,采用离子色谱分析了水解液中单糖和低聚糖含量以及水解物料中葡萄糖和木糖保留率,以研究水预水解温度和时间对相思木半纤维素水解溶出和解聚行为的影响。结果表明,水预水解温度170℃、水解60 min时,水解液中总低聚糖含量达到最大值17.29 g/L,其中低聚木糖含量为12.45 g/L;水预水解温度170℃、水解80 min时,水解液中总糖含量达到最大值25.86 g/L。水解液中总低聚糖和总糖含量达到最大值后,再提高水解温度和延长水解时间,虽然可提高原料中半纤维素溶出量,但水解液中总低聚糖和总糖含量降低。

Acacia wood was pre-hydrolyzed under various temperatures and time, the content of monomeric sugar and oligomeric sugar in prehydrolysate, and also the retention rate of glucose and xylose in the hydrolyzed residues were analyzed by using ion chromatography, the influence of hydrolysis temperature and time on the dissolution and depolymerization of hemicelluloses were investigated. The results showed that the content of oligomeric sugar in the hydrolyzate reached the maximum of 17.29 g/L, among which xylo oligomer was 12.45 g/L when hydrolysis temperature and time were 170℃ and 60 min respectively. The content of total sugars （ including monomeric and oligomeric sugar） reached the maximum of 25.86 g/L at 170℃ and 80 min reaction time. A maximun total contents of oligomeric sugar and monomeric sugar were found in prehydrolysate. After this maximun value appearing, by further increasing pre-hydrolysis temperature and reaction time, the dissolution of hemicellulose was improved, but the content of oligomeric sugar and total sugars were decreased.