桉木热水预水解固相中组分变化规律

Variation of solid residues components of eucalyptus by hot water pre-hydrolysis

基于热水预抽提工艺,研究了预水解过程中固相组分的变化规律。以桉木片为原料,固定液比1∶6,设定预水解温度150、160、170和180℃,分别保温0、30、60、90和120min后,考察固相得率、纤维素保留率、半纤维素抽出率、酸溶木素和酸不溶木素脱除率的变化。结果表明,随着预水解温度和时间的延长,固相得率和纤维素保留率呈下降趋势,半纤维素抽出率和木素(酸不溶木素和酸溶木素)脱除率呈上升趋势。保温时间为90min时,纤维素保留率上升,酸不溶木素脱除率下降,其原因有待进一步探讨。

The variation of solid residues components in the hydrolysis process was studied based on the process of hot water extraction.The changes of solid-phase yield,cellulose retention rate,hemicellulose extraction rate and lignin removal rate were investigated using eucalyptus wood chip as raw material,in the conditions of fixed solid to liquid ratio of 1∶6,pre-hydrolysis temperature at 150,160,170 and 180 ℃,and holding time of 0,30,60,90 and 120 min,respectively.The results showed that the yield of solid phase and cellulose retention rate decreased with the increasing of pre-hydrolysis temperature and extending of time,while the hemicellulose extraction rate and the lignin（including acid insoluble lignin and acid soluble lignin）removal rate increased.But the cellulose retention rate increased and the acid insoluble lignin removal rate decreased when the holding time was90 min,and the reason need further investigation.