Modeling Hydrofluoroolefins with the Cubic Plus Association and Perturbed-Chain Statistical Associating Fluid Theory Equations of State

Hydrofluoroolefins (HFOs) have been proposed as promising candidates for alternative refrigerants. In this work, a comprehensive comparison of the performance of the Cubic Plus Association (CPA) and (perturbed-chain statistical associating fluid theory) (PC-SAFT) equations of state for six thermodynamic properties of HFOs is presented, in which 11 parameter estimation methods are considered and analyzed. On the basis of the comparison with experimental data and a theoretical analysis, a method meeting both satisfactory results and simplicity is recommended for parameter estimation for this type of compounds. The results show that both CPA and PCSAFT perform equally well for the prediction of vapor pressure, liquid density, and speed of sound in the gas phase. CPA provides better isobaric heat capacity predictions compared to PC-SAFT irrespectively of the estimation method used, but PCSAFT presents the best overall performance when all properties are considered.