Gibbs ensemble simulation of HCFC HFC mixtures by effective Stockmayer potential

Vapor-liquid equilibria for four HCFC/HFC binary mixtures, R22/R152a, R22/R 142b, R22/R134a, and R22/R32, were simulated by using the Gibbs ensemble Mo nte Carlo method. The effective Stockmayer potential proposed by the author s was used to represent molecular interactions. The potential parameters fo r the pure substances of interest were determined from their critical tempe ratures, the saturated liquid densities and the saturated vapor pressures a t a specific reduced temperature, T-r = 0.75. The Lorenz-Berthelot combinin g rules were adopted to calculate the LJ parameters for unlike molecules. P hase properties for the four systems, including compositions and densities of the coexisting vapor and liquid phases were simulated, and compared with experimental data. Good results show that our method is a predictive tool for the description of phase behavior for HCFC/HFC binary systems, which ar e possible alternatives for CFCs. (C) 1999 Elsevier Science B.V. All rights reserved.