K/MgO-Al_2O_3催化大豆油酯交换制备生物柴油动力学研究

Kinetics of biodiesel preparation by transesterification of soybean oil catalyzed with K/MgO-Al_2O_3

以大豆油为原料,考察了固定床反应器内K/Mg O-Al_2O_3催化大豆油与甲醇酯交换制备生物柴油反应过程的宏观动力学。结果表明:大豆油与甲醇的固定床酯交换反应在甲醇过量时可当作单步反应处理,反应速率方程为rA=-d CA/dt=kAC0.4A,活化能E为28.081 4 k J/mol,指前因子A为5.933 6×103L/(mol·h)。采用动力学方程计算值与实验值的相对误差绝对值均在4%以内,进一步验证了动力学方程的可靠性和实用性。

With soybean oil as raw material, the macro - kinetics of preparing biodiesel by transesterifica- tion of soybean oil and methanol catalyzed by K/MgO - Al2O3 in fixed - bed reactor was investigated. The results showed that the transesterification in fixed -bed reactor could be approximately treated as a single step reaction when the methanol was excessive. The reaction rate equation, activation energy and the pre - exponential factor were rA = - dCA/dt = kACA^0.4, 28. 081 4 kJ/mol and 5. 933 6 × 10^3 L/（ mol · h） , respectively. The deviation between the calculated values according to the above kinetics e- quation and the experimental values was within 4% ,which further verified the reliability and practicality of the kinetic equation.