杨木水热预处理过程中水解反应动力学研究

探讨了预处理温度和预处理时间对杨木水热预处理液中各组分含量的影响,同时采用改良的Saeman双相动力学模型建立了预处理液中木糖和葡萄糖的反应动力学方程,通过非线性拟合确定了不同条件下木糖和葡萄糖生成及分解的反应速率常数,由阿伦尼乌斯公式线性拟合得出木质纤维原料水解反应活化能.杨木预处理过程中木聚糖易降解部分活化能(Ef...

Hydrolysis Kinetics of Poplar During Thermal Hydrolysis

The effects of pretreatment temperature and time on the content of the hydrolysate of poplar during thermal hydrolysis were investigated.The reaction kinetic models of xylose and glucose in the hydrolysis solution were established by using the modified Saeman biphasic kinetic model.The reaction rate constants of monosaccharides generation and degradation under different conditions were determined by nonlinear fitting curve.The activation energy of lignocellulosic hydrolysis reaction was obtained by linear fitting of Arrhenius formula.The results showed that xylan was divided into an easy-to-hydrolyse fraction and a difficult-to-hydrolyse fraction during the pretreatment of poplar.The activation energies of easy-to-hydrolyse(E_f)and difficult-to-hydrolyse(E_s)xylan were 78.35 kJ/mol and 88.97 kJ/mol,respectively.The activation energy of xylose degradation(E₂)was 80.17 kJ/mol.Furthermore,the activation energy of glucan degradation(E₃=48.06 kJ/mol)was significantly lower than that of glucose degradation(E₄=90.18 kJ/mol).These results indicated that glucose was more stable than xylose,and the mild treatment conditions of hydrothermal pretreatment could realize the dissolution of hemicellulose accompanied by reducing the degradation of cellulose and monosaccharide.