热水预处理过程中P因子对杨木半纤维素溶出效果的影响

Effect of P Factor on Dissolution of Poplar Hemicellulose during the Hydrothermal Pretreatment Process

关键词:  杨木  热水预水解  P因子  低聚木糖

Key Words:poplar  prehydrolysis  P factor  xylo-oligosaccharides

摘要:制浆前对生物质原料进行热水预处理，可以有效地提取半纤维素，这对于生物质高值化利用具有重要意义。本实验研究了不同工艺条件下杨木热水预处理过程中半纤维素糖类组分的溶出规律以及酸溶木素、乙酸和醛类物质随预水解因子（P因子）的变化规律。结果表明，在热水预处理过程中，P因子较适宜的范围是685～1225，此范围内杨木中的半纤维素糖类能够较好地溶出，总木糖溶出率高达51.8%，预水解液中木糖、酸溶木素、乙酸、糠醛等含量与P因子的增加成正比，而低聚合度聚木糖（聚合度2～25）含量随P因子的增加先增加后降低。当P因子在717时，水解液中低聚合度聚木糖含量达最大值10.24 g/L，此P因子下原料中总木糖溶出率为44.2%，而且酸溶木素、乙酸、糠醛等非糖类物质含量较低，这有利于后续低聚合度聚木糖和木糖的分离提取生产功能性低聚木糖产品。

Abstract:Hydrothermal pretreatment of biomass before pulping can effectively extract hemicelluloses， and this is of great significance for high value utilization of biomass. In this work， in the process of hydrothermal pretreatment of poplar under different conditions， the dissolution of hemicelluloses， acid-soluble lignin， acetic acid and aldehydes change with the P factor were studied.The results indicated that the optimum range of P factor was from 685 to 1225， in this range， the hemicellulose in poplar could easily dissolve， and the total xylose dissolution rate was 51.8%. The contents of xylose， acid soluble lignin， acetic acid， furfural etc. in the hydrolysate were proportional to the increase of P factor， while the content of xylo-oligosaccharides was inversely proportional to the increase of P factor.When the P factor was 717， the content of xylo-oligosaccharides in hydrolysate reached a maximum of 10.24 g/L， the total xylose dissolution rate of the raw materials was 44.2%， and the contents of xylose， acetic acid， furfural and other non-carbohydrate substrates were low，this was benefit to the subsequent separation of xylose and xylo-oligosaccharides for producing functional products．