水热处理对杨木微观结构和降解产物的影响

Effect of Hydrothermal Treatment on the Poplar Microstructure and Degradation Products

探讨了不同处理条件对杨木水热处理液中总木糖、乙酸、木质素含量及杨木微观结构的影响。利用单因素实验探索处理液中总木糖含量的变化规律,并以总木糖含量为指标,采用响应面法优化杨木水热处理条件。结果表明,随水热处理温度上升,木片微观孔洞增多或增大,同时表面不规则剥落和微球状沉积物不断增多,使木片比表面积先增大后减小。反应温度172.51℃,保温时间88.14 min,固液比1∶6.06时,处理液中总木糖含量达到最优值76.54 mg/g,木质素和乙酸含量分别为34.14 mg/g和11.28 mg/g。

The effects of different treatment conditions on the content of total xylose,acetic acid and lignin in the poplar hydrothermal treatment liquor and the microstructure of poplar wood chips were discussed.The single factor experiment was used to explore the changing law of the total xylose content in the hydrothermal treatment liquor.The total xylose content was used as an indicator to optimize the poplar hydrothermal treatment conditions via response surface method.The results showed that with the increase of the hydrothermal treatment temperature,the area and number of microscopic pores of the wood chips increased,whereas the number of irregular exfoliation and micro-spherical deposits on the surface of the wood chips also increased.Therefore,the specific surface area of wood chips increased first and then decreased.The total xylose content in the poplar hydrothermal treatment liquor reached the optimal value of 76.54 mg/g with the reaction temperature of 172.51℃,the holding time of 88.14 min,and the solid-liquid ratio of 1∶6.06.The content of lignin and acetic acid were 34.14 mg/g and 11.28 mg/g,respectively.