Tuesday, November 6, 2007

A Critical Comparison of Nrhb with Saft and Simplified Pc-Saft

Ioannis Tsivintzelis1, Andreas Grenner2, Ioannis Economou2, Georgios M. Kontogeorgis2, and Costas Panayiotou1. (1) Department of Chemical Engineering, University of Thessaloniki, 54124 Thessaloniki, Greece, Thessaloniki, Greece, (2) Department of Chemical Engineering, Technical University of Denmark, Lyngby, D2800, Denmark

Two types of statistical thermodynamic models are critically compared in this work: The Non-Random Hydrogen-Bonding (NRHB) Theory, which is a compressible lattice model, represents the first type, while the Statistical Associating Fluid Theory (SAFT) and the Simplified Perturbed-Chain-Statistical Associating Fluid Theory (sPC-SAFT), which are based on Wertheim's perturbation theory, represent the second type. A standard data base for the evaluation of vapor-liquid equilibrium (VLE) models proposed by Danner and Guess and liquid-liquid equilibrium data of carefully selected binary mixtures, such as water – hydrocarbons, alkanols – hydrocarbons, water – alkanols and glycols – hydrocarbons, were used to benchmark the accuracy of the models. The capacity of the models to, both, correlate and predict phase equilibria is discussed.