Modeling solubility of refrigerants in ionic liquids using Peng Robinson-Two State equation of state

In recent years ionic liquids (ILs) are introduced as new absorbents for refrigerants in the refrigeration processes. In this paper, we investigate the phase equilibrium behavior of refrigerants and ILs binary solutions as novel potential systems in refrigeration industries. A simple association model namely Peng Robinson-Two State equation of state (PR-TS EoS), is used to model the phase equilibrium data (P-T-x) of 37 various imidazolium-based ionic liquids and refrigerants binary systems at different temperatures and pressures with a total of 969 data points. In the first step, the PR-TS EoS is applied on pure components and the parameters of the model are determined. The percent of average absolute relative deviation (AARD%) between the calculated results and the experimental data of vapor pressures and liquid densities of the refrigerants are 0.58% and 1.59%, respectively. The similar AARD% for the liquid density of the ionic liquids is 0.20%. In the following, the present model is applied to calculate the vapor-liquid equilibrium of refrigerant + IL binary systems. The results of the current model show a deviation as AARD = 3.54%. Also, the performance of the PR-TS EoS is compared with the Peng-Robinson (PR) EoS and Peng Robinson-Kwak Mansoori (PR-KM) EoS. In summary, the results of the PR TS EoS represent a good agreement with the experiments and the present model shows superiority with respect to PR and PR-KM EoSs. (C) 2019 Elsevier B.V. All rights reserved.