Abstract: Biodiesel (FAME) is a biodegradable clean energetic resource comprised by a mixture of monoalkyl esters of long chain fatty acids that can be obtained from a wide variety of raw materials. The thermodynamics of transesterification reaction of triglyceride for production of biodiesel is simulated and evaluated using Gibbs energies method. The results obtained can be used to reacting systems to produce biodiesel, based on the transesterification. The thermodynamic calculation of the three consecutive reversible transesterification reactions of triolein with methanol was carried out by means of group-contribution methods and Zhao’s empirical formulas，ΔS? v = A s lgT b + B s . Factors affecting the conversion rate are studied in transesterification of triolein and methanol. From this analysis, it is concluded that the reaction enthalpy is -10.742 kJ?mol-1 at 298 K, showing a slightly exothermic reaction. The reactions are performed easily at lower temperature and higher pressure. The conversion rate of triolein in liquid methanol is smaller change at condition of temperature and pressure. Increase in molar ratios of methanol to triolein, results in increase in conversion of triolein. The equilibrium conversion of triolein reaches 98.8% at molar ratios of 20:1, methanol to triolein. Increase in pressure of methanol vapor, results in increase in triolein conversion, while an increase in temperature of methanol vapor results in a decrease in triolein conversion. Compare with results of experimental data from references, the group-contribution analysis method is feasible.

摘要： 采用基团贡献法和赵氏经验公式(ΔS? v = A s lgT b + B s )计算了三油酸甘油酯与甲醇之间发生的三步连续可逆酯交换反应的标准摩尔反应焓、标准摩尔熵、标准摩尔反应Gibbs函数和标准平衡常数，并分析了酯交换反应转化率的影响因素。结果表明，酯交换反应是放热反应，低温和高压有利于反应的进行。酯交换反应的转化率在甲醇液相时受温度和压力的影响较小，醇油比增大可以提高反应的转化率，当醇油比为20:1时转化率达到98.8%。酯交换反应的转化率在甲醇气相时，随着压力的增大而增大，随着温度的增大而减小。通过计算结果与实验数据进行比较，表明本文提出的分析方法是可行的。

关键词: 基团贡献法, 生物柴油, 酯交换反应, 热力学, Gibbs函数