A SAFT Equation of State Based on Triangular-Well Fluid Potential

In this works, the main objective is to develop the frame work for a Statistical Associated Fluid Theory based upon the Triangular-Well (TW) fluid potential proposed by Betancourt-Cárdenas et al. [Mol. Phys. 105 (2007) 2987 and Mol. Phys. 106 (2008) 113] based on the perturbation theory by Barker-Henderson. The TW potential is more realistic than the well-know square-well (SW) potential commonly used in the popular SAFT and PC-SAFT, besides the TW keep a significative analytical simplicity compared to others potentials. TW shows a great potential to be used for the molecular based equations of state as it can be observe in the followings works Zhou [J. Chem. Phys. 130 (2009), 014502], Koyuncu [Mol. Phys. 109 (2011), 565] y Rivera et al. [Mol. Phys. 110 (2012), 1317 ]. The formulation by Betancourt-Cardenas used a second order perturbation theory with a macroscopic compressibility approximation. We present vapour–liquid phase diagrams and thermodynamic properties such as the density as a function of the pressure at different temperatures and for several values of the potential range. The preliminary results are promising of good agreement with data reported in the literature.