废弃植物油亚临界水解制取混合脂肪酸及其动力学研究

Study on preparation of fatty acid mixed from waste vegetable oil by hydrolysis in subcritical water and its kinetics

以废弃植物油为原料,用亚临界水解法制备混合脂肪酸,研究混合脂肪酸的制备条件及其反应动力学。结果表明,废弃植物油在亚临界水中的适宜反应条件为:反应温度280℃,反应时间30 min,油水体积比为1:3.5,转化率最高达98.1%。废弃植物油在亚临界水中的水解反应平均反应级数为n=1.123 89,活化能E_a=70.87 kJ/mol,频率因子A=1.770 6×10~5,动力学模型为-dc_A/dt=1.770 6×10~5e^(-70.87/RT)C_A^1.123.89。

Abstract ： The fatty acid mixed was prepared by hydrolysis from waste vegetable oil in subcritical water in order to study the conditions and its kinetics. The results showed that the optimal hydrolysis conditions of waste vegetable oil in subcritical water were obtained as follows ： reaction temperature 280℃, volume ratio of waste vegetable oil to water 1：3.5 and reaction time 30 min. Under these conditions, the conversion rate of the waste vegetable oil reached 98.1%. The kinetics analysis results indicated that the average reaction order n = 1. 123 89, the activation energy Ea =70.87 kJ/mol, frequency factor A = and the reaction kinetics model were -dcA/dt=1. 7706 ×10^5e^-70.87/RTcA^1.12389,respectively.