Potential of group contribution methods for the prediction of phase equilibria and excess properties of complex mixtures
Potential of group contribution methods for the prediction of phase equilibria and excess properties of complex mixtures
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DOI：
10.1351/pac200375070875
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发表时间：
2003-07-01
影响因子：
1.8
通讯作者：
Gmehling, J
中科院分区：
文献类型：
--
作者：
Gmehling, J
对纯化合物及其混合物在整个组成和宽温度和压力范围内的热物理性质的可靠了解是计算机辅助合成、设计和优化化学过程的重要先决条件。各种相平衡的知识对于热分离过程的开发是最重要的（但也对于其他应用，例如多相反应器的设计，预测环境中化学品的命运等）。而25年前，主要的兴趣是针对类似大小的亚临界化合物的汽液平衡的预测工具（ASOG，CABAC）的发展，15年后的温度依赖性（过量的水），在无限稀释的活度系数，和固液平衡的低共熔混合物（包括强不对称系统）的适当描述实现。在与立方型状态方程[Soave-Redlich-Kwong（SRK），Peng-Robinson（PR）]相结合后，将基团贡献概念推广到超临界化合物[预测SRK（PSRK）]。随着适当电解质模型（LIFAC）的发展，状态方程方法甚至可以用于具有强电解质的系统。通过基团相互作用参数的修正、参数矩阵的扩展（引入新的结构基团、填补参数空白）以及大型数据库（多特蒙德数据库）的帮助，基团贡献法的预测结果得到了显著改善，适用范围大大扩展。此外，仍然存在的问题与基团贡献的方法（邻近效应，等）。在体积转换PR状态方程的帮助下，应用温度依赖性和改进的混合规则，最大限度地减少了基团贡献状态方程的剩余弱点（如液体密度的差结果，过量的非对称性和不对称系统的问题）。
Reliable knowledge of the thermophysical properties of pure compounds and their mixtures in the whole composition and a wide temperature and pressure range is a vital prerequisite for computer-aided synthesis, design, and optimization of chemical processes. Knowledge of the various phase equilibria is most important for the development of thermal separation processes (but also for other applications, such as the design of multiphase reactors, the prediction of the fate of a chemical in the environment, etc.).Whereas 25 years ago, the main interest was directed to the development of predictive tools for vapor-liquid equilibria of subcritical compounds of similar size (ASOG, UNIFAC), 15 years later a proper description of the temperature dependence (excess enthalpies), the activity coefficients at infinite dilution, and solid-liquid equilibria of eutectic mixtures (including strong asymmetric systems) was achieved. After the combination with cubic equations of state [Soave-Redlich-Kwong (SRK), Peng-Robinson (PR)], the group contribution concept was extended to supercritical compounds [predictive SRK (PSRK)]. With the development of an adequate electrolyte model (LIFAC), the equation-of-state approach can even be used for systems with strong electrolytes. With the revision of the group interaction parameters, the extension of the parameter matrix (introduction of new structural groups, filling of parameter gaps), and the help of a large database (Dortmund Data Bank), the predicted results of group contribution methods were significantly improved and the range of applicability greatly extended. Furthermore, still-existing problems with the group contribution approach (proximity effects, etc.) were reduced.With the help of a volume-tran slated PR equation of state and application of temperature-dependent and improved mixing rules, the remaining weaknesses of group contribution equations of state (such as poor results for liquid densities, excess enthalpies, and the problems with asymmetric systems) were minimized.