Further Development of Modified UNIFAC (Dortmund): Revision and Extension 5

Abstract

For the estimation of thermodynamic properties of pure compounds and mixtures, often the group contribution concept is applied. A successful and well-known group contribution model for the prediction of phase equilibria is the group contribution method Modified UNIFAC (Dortmund). Since 1996, a company consortium has supported the further revision and extension of this method. The main objective of this consortium is the systematic revision and extension of the existing parameter matrix and the introduction of new main groups of industrial interest. In this paper, besides parameters for the new main group “formamides”, revised parameters for the already existing groups are given. Furthermore, an empirical expression for the prediction of alkane and cycloalkane solubilities in water is presented, because, as previously described in different articles [Wienke and Gmehling, Toxicol. Environ. Chem. 1998, 65, 57−86; Lohmann et al., Ind. Eng. Chem. Res. 2001, 40, 957−964; Skjold-Jørgensen et al., Ind. Eng. Process Des. Dev. 1979, 18, 714−722], poor solubilities of these compounds in water were accepted, to be able to predict the vapor−liquid equilibrium (VLE) behavior of alcohol−water systems with the desired accuracy. In addition, group interaction parameters of systems are presented, which were fitted to artificial data predicted using the COSMO−RS (Ol) model. This model basically can be used to fill gaps in the parameter matrix of reactive mixtures.