月桂酸甲酯和月桂酸乙酯热力学性质研究

Investigation on the Thermodynamic Properties of Methyl Laurate and Ethyl Laurate

使用PC-SAFT状态方程对月桂酸甲酯和月桂酸乙酯的热力学性质(包括液相密度、比定压热容、液相声速和等温压缩系数等)进行了全面的理论研究。在回归模型参数时分别采用饱和蒸气压和0.1 MPa时液相密度数据作为原始数据(方法一)以及0.1~60 MPa内的高压液相密度作为原始数据(方法二),分别得到了PC-SAFT方程的参数,计算了相应的热力学性质并进行了比较分析。第一种方法准确地预测了目标工质的定压比热容。相较于第一种方法,方法二在等温压缩系数、液相声速等二阶偏导性质的描述上表现的更好。

A comprehensive theoretical research on thermodynamic properties(including liquid density,isobaric heat capacity,speed of sound in liquid phase and isothermal compressibility)for methyl laurate and ethyl laurate is presented with Perturbed-Chain Statistical Associating Fluid Theory(PC-SAFT equation of state).The parameters in the equation were regressed from two methods,one is used the vapor pressure and liquid density at 0.1 MPa of the substances as the primary data(called method 1),another is used the high-pressure liquid densities from 0.1~60 MPa as the primary data(called method 2).The corresponding thermodynamic properties were calculated and analyzed.Method 1 performs well for the prediction of isobaric heat capacity,and method 2 has the better performance on the prediction of second-order derivative properties,such as isothermal compressibility and speed of sound in liquid phase.