【摘要】 以木聚糖、稻秆和棕榈壳为原料,采用间歇水解实验台,在压力4.0MPa、液固质量比20:1、搅拌转速500r/min的条件下,在温度160～220℃、时间0～60min范围内进行了水解动力学研究,经数据拟合得到水解反应动力学参数.研究表明,3种原料的水解行为大致遵循一级连续反应动力学模型,温度和时间是影响水解效果的主要因素.木聚糖水解反应活化能约为65.58kJ/mol,糖降解活化能达147.21kJ/mol,故水解产物中的还原糖能不断累积.稻杆和棕榈壳组分相对复杂,水解活化能分别为68.76和95.19kJ/mol,均高于相应的糖降解活化能(47.08和79.74kJ/mol),在水解过程中必须严格控制反应时间,减少糖的降解.更多还原

【Abstract】 Based on a self-designed batch reactor, xylan, rice straw and palm shell were pretreated by hot liquid water for hydrolysis kinetic study under 160～220℃, 4.0 MPa, 0～60 min, mass ratio of liquid to solid 20:1 and rotation speed of 500 r/min. All experimental data were fitted to the curves, and the kinetic parameters calculated. The results indicated that the hydrolysis obeyed a first-order sequential model. The temperature and time were the main influential factors. For xylan hydrolysis, the activation energy is 65.58 kJ/mol for hemicellulose hydrolysis and 147.21 kJ/mol for reducing sugars degradation. Thus the reducing sugars are enriched in the liquid products. However, the activation energy values of rice straw and palm shell are 68.76 and 95.19 kJ/mol for hemicellulose hydrolysis and 47.08, 79.74 kJ/mol for reducing sugars degradation respectively due to their complex composition compared with xylan. Consequently, the hydrolysis time should be controlled to decrease the degradation of reducing sugars.更多还原