Estimation of thermodynamic properties of Light process gases in oil and gas industry using a new and applicable equation of state

In this study various empirical، theoritical and semi-theoritical equations of state for different optional fluids، have been investigated and the accuracy of these equations for thermodynamic properties estimation of these fluids in comparison with experimental data، was evaluated. Also a new equation of state has been derived from Mohammadikhah-Abolqasemi-Mohebbi semi-theoretical equation and has been introduced. The results of this research have showed that assumed equations of state have good accuracy in predicting the enthalpy and entropy for pure fluids in atmospheric pressures and slightly higher، except for n-butane which the error was high. Also، results of this research have showed good agreement between calculated data from these equations for compressibility factor prediction of optional fluids with experimental data. Also soave-redlich-kwong equation of state has been recommended for calculating thermodynamic properties including enthalpy and entropy at low pressures، because it has showed minimum errors.