Application to binary mixtures of a group contribution SAFT EOS (GC-SAFT)

Many authors have shown the ability of the statistical associating fluid theory (SAFT) equations of state (EOS) to model hydrocarbon systems. The parameter estimation in the absence of data strongly limits the use of these equations. As an answer to this problem, a group contribution (GC) method for pure compound parameters was proposed in a previous work [S. Tamouza, J.-P. Passarello, P. Tobaly, J.-C. de Hemptinne, Fluid Phase Equilib. 222–223 (2004) 67–76]. s paper, vapor liquid equilibria (VLE) of several binary mixtures are compared with experimental data, using the GC pure compounds parameters, and without any binary interaction parameter. The calculations have been performed with two versions of the SAFT equations (original SAFT and SAFT-VR). The mixtures that have been investigated are both non-associative (containing n-alkanes) and associative (containing 1-alcohols). sults show that the group contribution (GC) method provides pure compound parameters that allow a satisfactory prediction of the binary mixtures. In several cases, the GC parameters yield even better results for binary mixtures than those adjusted directly on the pure compounds (specific parameters). This rather unexpected observation may be due to the fact that these parameters take more information into account than the specific ones.