A simple model for temperature-independent kij of the PR-vdW model for mixtures containing HCs, HFCs, PFCs, HFOs, CO2, RE170 and R13I1

• A simple predictive model for temperature-independent binary interaction parameter kij of the PR-vdW model was presented.
• The proposed model exhibited better performance than the available models on vapor-liquid equilibria (VLE) description.
• kij were predicted and used to evaluate the VLE data for binary and ternary mixtures, and good agreements were found.

The purpose of this paper is to establish a simple model for temperature-independent binary interaction parameter kij of the PR-vdW model (Peng-Robinson equation of state with van der Waals one-parameter mixing rules). The model was proposed as kij = wjki + wikj (i ≠ j). In the present model, every pure component was considered to have a constant contribution ki to kij, constant wi is the contribution coefficient of component j mixing with component i. kij can be determined by summing the contribution coefficient of each pure component times its contribution. By regressing the vapor-liquid equilibrium (VLE) data of binary mixtures, 119 kij were obtained and used to optimize the constant contribution ki and contribution coefficient wi. kij of 351 binary systems were predicted and used to describe the VLE data of binary and ternary mixtures. Better performs could be found in the present model than the available models on VLE description of the mixtures.