Influence of the temperature on the liquid-liquid equilibria of heptane plus toluene plus sulfolane and heptane plus m-xylene plus sulfolane

摘要

Equilibrium tie line data have been determined at (298.15, 323.15, 348.15, and 373.15) K for the ternary liquid-liquid equilibria (LLE) of heptane + (toluene or m-xylene) + sulfolane systems. The relative mutual solubility of toluene is higher than that of m-xylene in heptane + sulfolane mixtures. The tie line data were correlated with the UNIQUAC and NRTL models. The calculated values based on the UNIQUAC model were found to be better than those based on the NRTL model; the average root-mean-square deviation between the phase composition obtained from experiment and that from calculation was 0.5111 for UNIQUAC compared to 0.6475 for NRTL. The values of selectivity and the distribution coefficient were derived from the equilibrium data at different temperatures.