By combining a dipole expression with an Soave–Redlich–Kister, SRK, equation of state,
a new SRK equation of state is developed. a0, ci, b and bp, the parameters of this equation, were optimized for pure compounds by using experimental data of vapor pressure
and saturated liquid density. Examining the modeling results for the dipolar compounds
shows that this equation correlates well with their behavior. The physical properties of
pure compounds, including the heat capacity, speed of sound, Joule–Thomson coefcient
and enthalpy of evaporation were calculated using this equation of state, and were in good
agreement with the experimental results. By combining a dipole expression with the SRK
equation, a good improvement in the prediction of the Joule–Thomson coefcient of the
liquid phase was made. Also, vapor–liquid equilibrium calculations were performed for
four binary systems by using this SRK equation, which shows that the prediction of the
system behavior by the revised SRK equation was improved.