采用热重分析法研究了硬脂酸甲酯、油酸甲酯和亚油酸甲酯在氮气气氛中的热分解特性,并采用Coats-Redfern积分法对硬脂酸甲酯、油酸甲酯和亚油酸甲酯的热分解过程进行动力学分析,建立热分解模型。结果表明:硬脂酸甲酯和油酸甲酯的热分解过程表现为简单的一步分解,而亚油酸甲酯则呈现出较复杂的两步分解过程;随着升温速率提高,热分解区间向高温区移动,热分解活化能和指前因子呈现出较好的动力学补偿效应,且在不同升温速率下具有不同的热分解反应机理函数;模拟计算的热分解率与实验数据误差基本在10%左右。动力学模型能够很好地预测各脂肪酸甲酯热分解过程,为进一步扩大试验和生物柴油应用中的高温热分解衰变模型提供理论依据。
The pyrolysis characteristics of methyl stearate, methyl oleate and methyl linoleate were studied by thermo - gravimetric analysis method in nitrogen atmosphere. The kinetics analysises of pyrolysis processes of methyl stearate, methyl oleate and methyl linoleate were carried out by Coats - Redfern inte- gral method to set thermal decomposition models. The results showed that pyrolysis processes of methyl stearate and methyl oleate were simple one step decomposition, while the pyrolysis process of methyl lino- leate was relatively complicated two step decomposition; the pyrolysis region shifted toward the higher temperature region when heating rate increased. Moreover, the pyrolysis activation energy and pre - expo- nential factor presented a good kinetics compensation effect, and the pyrolysis reaction mechanism func- tions were different at different heating rates. The error of pyrolysis rates between analog calculation data and experimental data was about 10%. The kinetics models were able to accurately predict the pyrolysis processes of the mentioned fatty acid methyl esters, which could provide theoretical foundation for further bench -scale research and high temperature thermal decomposition decay model in biodiesel application.