Abstract
In binary systems of hydrogen and hydrocarbons, the fluid-phase thermodynamic behavior is unique in having the divergence of the critical curves to a high pressure region. The mixing parameter of a Peng-Robinson equation of state (PR EOS) for the binary systems including hydrogen with methane, ethane, propane, and carbon dioxide were determined. The mixing parameter of the present EOS has a functional form of temperature generalized by the critical temperatures of the hydrocarbons and carbon dioxide. Based on the corresponding state principle, the coefficients of the parameter were obtained with a non-linear least squares fitting to the experimental critical points of the mixtures. The developed PR EOS shows good agreement with the experimental data of not only the critical points but also the phase equilibria.
