Phase equilibrium modeling for methane solubility in aqueous sodium chloride solutions using an association equation of state

A new formulation for the fraction of electron acceptor sites of methane (CH4) of cubic-plus-association couple with Huron-Vidal (CPA-HV) model is presented, and a combine rule is used to calculate the cross-associating strength of CH4-water (H2O) binary system. Meanwhile, the interaction parameters (E-ij, E-ji and F) of CPA-HV model are regressed for CH4-H2O binary and CH4-H2O-NaCl ternary systems. The predictions of CPA-HV model are consistent with a lot of binary and ternary experimental data of these systems. Compared with CPA-vdW and SRK-HV models, the accuracy of CPA-HV model is the best for vapor-liquid equilibria of CH4-H2O system. The average absolute relative deviations of the predicted CH4 solubility in H2O and aqueous sodium chloride solutions for CPA-HV model are respectively 5.84% and 6.91%. (C) 2019 Elsevier B.V. All rights reserved.