prediction of retrograde condensation using the srk equation of state

the srk two-parameter cubic equation of state has been used for the calculation of the equilibrium constant using the liquid and vapor fugacity coefficients for three binary mixtures. dew and bubble points have been determined using the equilibrium constants and the phase envelope has been plotted showing dearly that retrograde condenstaion occurs. the following percent deviations have been obtained from the experimental values: 8.2% for carbon dioxide - monochloromethane binary system, 4% for the ethane heptane binary system, and 2% for the ethane - octane binary system. in view of the above comparisons, it seems that the srk equation of state is capable of predicting retrograde behavior with good accuracy.