(Liquid+ liquid) equilibria of ternary and quaternary systems containing n-hexane, toluene, m-xylene, propanol, sulfolane, and water at T= 303.15 K

Abstract

(Liquid + liquid) equilibrium data for ternary and quaternary systems containing n-hexane (C6H14 ), toluene (C 7H8 ), m-xylene (C8 H10 ), propanol (C 3H8 O), sulfolane (C 4H8 SO2), and water (H 2O) were measured at T = 303.15 K. Phase diagrams of {w1 C4 H8SO 2 + w2 C7 H8 + (1 w1 w2)C 6H14 }, {w1C 4H8 SO2 + w2 C 8H10 + (1 w1 w2)C6 H14 }, {w1 C4 H8SO2 + w2C 3H 8O + w3C 7H 8 + (1 w1 w2 w3)C 6H14 } and also systems containing water: {w1C 4H 8SO2 + w2H2 O + w3C 7H8 + (1 w1 w2 w3 )C6H14 } and {w1 C4 H8SO2 + w2 H2O + w3 C8 H10 + (1 w1 w2 w3 )C6H 14} (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 {w1C 4H8 SO2 + w2 C7 H8 + (1 w1 w2)C 6H14 } 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. Ó 2006 Elsevier Ltd. All rights reserved