Measurement and correlation of ternary (liquid–liquid) equilibrium data for n-heptane + p-xylene + (furfural or dimethyl sulfoxide) system at 303.15 K and 323.15 K

Liquid-liquid equilibrium (LLE) data for {n-heptane + p-xylene (PX) + furfural/dimethyl sulfoxide (DMSO)} ternary systems were measured at 303.15 K and 323.15 K and atmospheric pressure. Extraction performance of furfural and DMSO were evaluated using distribution coefficient (D) and selectivity (S) according to the measured tie-line data. And the results showed that DMSO had better extraction performance than furfural for separation of n-heptane and PX. Both UNIQUAC and NRTL models were used to correlate the experimental LLE data, and relevant interaction parameters were obtained. Consistency between the measured LLE data and the calculated by these two models was well evaluated by RMSD and maximum absolute deviation. Moreover, reliability of binary interaction parameters was confirmed by topological analysis related to the Gibbs tangent plane test.