CO_2二元体系临界性质计算方法的研究

Methods for calculation of the critical properties of binary systems with supercritical CO 2

建立了计算二元混合物临界温度Tcm的公式和温度的二元相互作用参数kTij的表达式 ,用这两个表达式计算了超临界CO2 分别与甲苯、环己烷、乙醇、甲醇、正丁醛、异丁醛等组分六对二元复合体系的临界温度 ,并与其他方法的计算结果进行了对比。结果表明文中所建立的表达式能够较好地对实验数据进行拟合 ,证明了公式的可靠性 ;同时还根据混合规则am 中kaij的表达式 ,确定了表达式系数并结合RK EOS对六组超临界CO2 的二元复合体系的临界压力数据进行了拟合 ,结果令人满意。

An equation for calculation of the critical temperature of six binary systems with supercritical carbon dioxide was proposed. The expression of interaction parameter, k T ij, in the equation was also suggested. The calculated results obtained from this and other methods were compared with the experimental data. It shows that the equation proposed in this paper is in good agreement with the experimental data. The expression of interaction parameter, k a ij, in the mixing rules of a m, was described and the coefficients of k a ij expression were obtained from the experimental data. The RK-EOS was used to calculate the critical pressure of the six binary systems with supercritical CO 2 and the calculated results were well coincident with the experimental data.