Predictions of thermodynamic properties and phase equilibria of refrigerant systems with COSMO approaches

The knowledge of the phase equilibrium refrigerant mixtures is crucial for optimization production processes molecules, and design energetic systems (heat pumps, Organic Rankine Cycles, …). In this work, different predictive thermodynamic models (COSMO-RS COSMO-SAC-dsp) have been used to determine behavior refrigerants involving alkanes, fluorinated chlorinated compounds. COSMO-RS model leads rather satisfactory predictions vapor-liquid equilibria able capture azeotropic most systems. However, original COSMO-SAC as well 2010 version lead unsatisfactory VLE these systems, they are unable predict in alkane + refrigerants. By combining with a dispersion term (COSMO-SAC dsp model) readjusting universal parameter F atom, it possible get very similar accuracy COSMO-RS. order at high pressure, COSMO-SAC-dsp can be combined Peng-Robinson equation state MHV1 mixing rule. Excellent relative volatilities obtained approach over wide temperature pressure ranges. COSMO calculation also saturated liquid densities, vaporization enthalpy boiling points pure