Baseri - M.S. Student of Chemical Engineering Department, Semnan University, Semnan, Iran
Lotfolahi - Chemical Engineering Department, Semnan University, Semnan, Iran
Haghighi Asl - Chemical Engineering Department, Semnan University, Semnan, Iran

A modification of Peng-Robinson equation of state (PR-EOS) is used to model the vapor-liquid equilibrium (VLE) in systems containing (water + Na2SO4 + supercritical_CO2). This EOS is used to predict the P-T diagram for the (water + Na2SO4 + CO2) system that moles of Na2SO4 in 1 Kg water are 0.25 and 1. The calculated results by the modified PR-EOS are compared with the correlation results by Anderko-Pitzer EOS. The average deviation of (ΔP/Pexp)2 % between the correlation results by Anderko-Pitzer EOS and experimental data is 0.7% while this value for modified PR-EOS is 0.37%.

vapor–liquid equilibrium; water-Na2SO4-CO2 system; supercritical; equation of state