从过量体积推算液相活度系数与汽液平衡数据

The Calculation of Liquid Activity Coefficient and Vapor Liquid Equilibrium Data from Excess Volume Data

本文运用统计热力学导出了一个直接由过量体积数据推算液相活度系数的新模型——EVLAC模型,本模型主要从“双液胞腔”与“局部组成”等概念出发,通过配分函数导出y-x表达式和V~E-x表达式,仅需要一个温度下的V~E-x数据即可推算出不同温度下盼恒温y-x,数据和不同压力下的恒压y-x数据,在不需要增加多元可调参数的情况下,可推广应用至多元体系。

A new model (EVLAC model) which can directly predict liquid activity coefficient from excess volume data are established by means of statistical thermodynamics. A new partition function equation is developed and then VE-x equation and γ-x equation can be derived mainly from the concepts of two liquid cell and local compositions. If VE-x data at only one temperature are available, the isothermal γ-x data and VLE. data at different temperatures and the isobaric VLE. data at different pressures can be calculated. This method can be extended to multi-component systems without increasing any multi-component parameters.About eighty sets isothermal activity coefficients of twenty five binary systems and fifteen sets isobaric activity coefficients and VLE. data are predicted by means of this new method. Good agreements between experimental data and predicted values are obtained.