关键词: 相平衡, 状态方程, 分子热力学, 网络平台, 传递性质

Abstract: Molecular thermodynamic models and the properties of fluid phase equilibria are necessary to the design, running, control and optimization of industrial process and furthermore its precision and reliability are directly related to the modeling and optimization results of process simulation. In this context, an equation of state with variable range for square⁃well potential (SWCF⁃VR) was developed based on the statistical association fluid theory and applied to represent the thermodynamic properties like vapor⁃liquid equilibria (VLE), liquid⁃liquid equilibria, solid⁃liquid equilibria, enthalpy of vaporization or mixing and so on for traditional fluids, associated fluids, electrolyte solutions, ionic liquids, polymers, etc. At the same time, the equation of sate combining with surface tension and viscosity can be used to predict and calculate the transfer properties of the mixture such as surface tension and viscosity successfully. The salient feature in our model was that transferable molecular parameters fitted from experimental phase equilibria data or predicted from group contribution method or solvation calculation were used. Meanwhile, the test of theoretical model and determination of molecular parameters in SWCF⁃VR were carried out always based on experimental thermodynamic data. Thus, an online platform for fluid phase equilibria (www.equilibria.cn) were developed, where the details about phase behavior conception, classification and applications were summarized, and data searching systems and some softwares for VLE calculation provided. The mentioned thermodynamic model and online platform in this work could be well used for process design, modeling and optimization.

Key words: Phase equilibria, Equation of state, Molecular thermodynamics, Online platform, Transport properties