LAUSR

Abstract 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 (Eij, Eji 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%.