Alireza Salemi - Faculty of Chemical Engineering, Babol (Noushirvani) University of Technolo gy
Kamyar Movagharnejad - Faculty of Chemical Engineering, Babol (Noushirvani) University of Technolo gy

Prediction of fluid properties is one of the main applications of all equations of state. However, all conventional equations of state lack accuracy near critical point. It is well known that all fluids show strange behaviors near critical point and so all of standard equations of state have to be modified to be able to describe the fluid behaviors in this region. In this study we have studied the validity of four conventional equations of state (RK, SRK, PR and Van der Waals) near critical point. It is shown that all of these equations give serious errors near critical region, so a modified version of SRK equation of state is introduced to improve the accuracy of the original EOS. It is shown that the modified EOS improves the accuracy of the original equation considerably for fluid properties such as vapor and liquid specific volumes.

equations of state, critical point, thermodynamic properties, SRK EOS