Vapor–liquid equilibria of alternative refrigerants and their binaries by molecular simulations employing the reaction Gibbs ensemble Monte Carlo method

Alternative refrigerants HFC125 (CHF2CF3) and HFC 134a (CF3CH2F) are modeled as a dipolar two-center Lennard–Jones fluid and alternative refrigerant HFC32 (CH2F2) is modeled as a dipolar Lennard–Jones fluid. We calculate vapor–liquid equilibria of these refrigerants by Gibbs–Duhem integration and vapor–liquid equilibria of two binaries (HFC 125 + HFC 134a and HFC 134a + HFC 32) by the reaction Gibbs ensemble Monte Carlo method. Potential parameters of the model are fitted to the critical temperature and vapor–liquid equilibrium data. The predictions are very good, and of comparable accuracy to those obtained using the Wilson and the UNIFAC thermodynamic-based approaches, even though such approaches use experimental mixture information.