Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

(Liquid + liquid) equilibrium data for ternary and quaternary systems containing n-hexane (C6H14), toluene (C7H8), m-xylene (C8H10), propanol (C3H8O), sulfolane (C4H8SO2), and water (H2O) were measured at T = 303.15 K. Phase diagrams of {w1C4H8SO2 + w2C7H8 + (1 - w1 - w2)C6H14}, {w1C4H8SO2 + w2C8H10 + (1 - w1 - w2)C6H14}, {w1C4H8SO2 + w2C3H8O + w3C7H8 + (1 - w1 - w2 - w3)C6H14} and also systems containing water: {w1C4H8SO2 + w2H2O + w3C7H8 + (1 - w1 - w2 - w3)C6H14} and {w1C4H8SO2 + w2H2O + w3C8H10 + (1 - w1 - w2 - w3)C6H14} (w = mass fraction) were obtained at T = 303.15 K. The (liquid + liquid) equilibrium data of the systems were used to obtain interaction parameters in non-random two-liquid (NRTL) and universal quasi-chemical theory (UNIQUAC) activity coefficient models. These parameters can be used to predict equilibrium data of ternary and quaternary systems. The root mean square deviations (RMSDs) using these models were calculated and reported. The partition coefficients and the selectivity factors of solvents for extraction of toluene or m-xylene from n-hexane at T = 303.15 K are calculated and presented. The experimental selectivity factors of sulfolane for the system {w1C4H8SO2 + w2C7H8 + (1 - w1 - w2)C6H14} at T = 298.15 K and T = 323.15 K were taken from the literature and the influence of temperature on the extraction of toluene was also investigated. The phase diagrams for the ternary and quaternary systems including both the experimental and correlated tie lines are presented. The tie-line data of the studied systems were also correlated using the Hand equation and the correlation parameters are calculated and reported.