麦草自水解过程中半纤维素和木质素的变化特性

Characterization of Hemicelluloses and Lignin Change of Wheat Straw in Autohydrolysis Process

自水解对木质纤维生物质转化利用具有重要意义,研究了自水解对麦草化学成分变化的特性。结果表明:温度和时间对麦草自水解化学成分变化有重要影响,温度170℃时,半纤维素与木质素的降解均呈现两个阶段,即保温60 min前的快速脱除阶段和60 min后的慢速脱除阶段,半纤维素脱除率分别为65.0%和16.7%,Klason木质素脱除率分别为33.0%和2.7%,酸溶木质素脱除率分别为66.1%和11.7%;自水解大大提高麦草苯醇抽出物含量,170℃保温210 min后苯醇抽出物含量达15.9%。麦草自水解具有生物炼制特点。

Autohydrolysis was significant for lignocelluloses bioxrtass bioconversion. The characterization of wheat straw chemical composition change in its autohydrolysis process was studied. The results showed that the temperature and time of autohydrolysis had obvious influence on the change of wheat straw chemical compositions. The hydrolysis process at 170℃ for hemicelluloses hydrolysis and delignification of wheat straw was divided to two stages, namely the fast stage before 60 min and the slow stage after 60 min. The hemicellulose hydrolysis ratio was 65.0% and 16.7%, the delignification of Klason lignin was 33.0% and 2.7%, and the delignification of acid soluble lignin was 66.1%and 16.7% in the two stages respectively. Alcohol-benzene extractives content was sharply increased in the process, in which reached 15.9% at 170℃ for 210 min. The wheat straw autohydrolysis had the characteristics of biorefinery.