a haghtalab - Department of Chemical Engineering, Tarbiat Modares University, Tehran, Iran
m zare - Department of Chemical Engineering, Tarbiat Modares University, Tehran, Iran
a.n ahmadi - Center of chemistry and petrochemical, Research Institute of Petroleum Industry, Tehran, Iran
k nazari - Center of chemistry and petrochemical, Research Institute of Petroleum Industry, Tehran, Iran

Electrolyte Cubic Square-Well Equation of State, eCSW EOS, [Haghtalab, A.; Mazloumi, S.H.;Fluid Phase Equilib. 2009, 285, 96-104] is based upon cubic-square-well equation of state. This equation of state is composed of the attractive term that is based on the square-well potential, thevan der Waals repulsive part and the mean spherical approximation theory (MSA) for electrostatic contribution. In this work, eCSW EOS is coupled with the van der Waals-Platteuw model andapplied to compute the conditions of gas hydrate formation. The H-L-V equilibrium calculation isperformed to optimize the Langmuir constants against temperature for N2, CH4, C2H6, C3H8, i- C4H10, n-C4H10 and CO2 hydrates using the experimental data in literature. Also, using eCSW EOS the interaction parameters of CO2-water and electrolyte-water are obtained. The equilibrium hydrate formation pressures of single gas hydrates are predicted and the results compared with the calculated values using SRK and PR EOSs. Also, predicting equilibrium hydrateformation pressures of various hydrate formers in the presence of electrolytes such as NaCl, KCland CaCl2 are performed. The results of prediction at the different cases are in good agreement with the experiments

hydrate, square well equation of state, electrolyte, vander Waals-Platteuw