HRX-SAFT Equation of State for Fluid Mixtures: New Analytical Formulation

In this work, we incorporate the new analytical sine model (ANS) crossover function (Kiselev and Ely, Chem. Eng. Sci. 2006, 61, 5107.) into the previously developed crossover statistical associating fluid theory (HRX-SAFT) equation of state (EOS) (Kiselev et al. Ind. Eng. Chem. Res . 2006, 45, 3981.). Similar to the original HRX-SAFT EOS, the new crossover HRX/ANS EOS incorporates non-analytic scaling laws in the critical region and is transformed into the analytical, classical HR-SAFT EOS far away from the critical point. The new HRX/ANS EOS does not, however, require a numerical solution for the crossover function, making it much simpler and more convenient for practical calculations. In this work, the HRX/ANS-SAFT mixture model is developed and tested against extensive experimental data for VLE, PVTx, and excess properties in carbon dioxide + methanol and water + methanol mixtures.