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/m01),在水解过程中必须严格控制反应时间,减少糖的降解。
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 office 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.