LAUSR

Abstract In this study, the perturbed chain statistical associating fluid theory (PC-SAFT) equation of state (EoS) has been utilized for thermodynamic modeling of vapor–liquid and liquid–liquid equilibrium in mixtures containing glycol ether surfactant. Glycol ether surfactant molecules are modeled as associating components by considering two association sites per each molecule. The pure component parameters of the PC-SAFT EoS are adjusted to vapor pressure and liquid density experimental data with AARD of 0.861 and 0.379%, respectively. Using obtained parameters, the phase behavior of binary systems over wide range of thermodynamic conditions is studied. The average deviation between model calculations and experimental data for water + surfactant, alcohol + surfactant, hydrocarbon + surfactant and carbon dioxide + surfactant systems are about 2.18, 1.15, 2.67 and 14.55% respectively. Furthermore, the capability of the model has then been assessed by prediction of phase behavior for the ternary systems without any adjustable parameter. The results show that, the predicted and correlated results are in good agreement with experimental data.