Entrainer selection for separating tetrahydrofuran/water azeotropic mixture by extractive distillation

Abstract

The mixture of tetrahydrofuran (THF) and water is a minimum boiling azeotrope due to the strong hydrogen bond effect. Some entrainers with different molecular structures which can potentially disrupt hydrogen bonds have been used to improve the relative volatility of THF–water system. After cautiously screening, we find that dimethyl sulfoxide (DMSO) as a hydrogen bond breaker is more effective to break the azeotrope than 1, 2-propanediol proposed by Songlin Xu etc. To validate our viewpoint, the vapor–liquid equilibrium (VLE) data of the two ternary systems: THF (1)+water (2)+1, 2-propanediol (3) and THF (1)+water (2)+DMSO (3) were measured at 101.32kPa. And these data are also valuable for the design of extractive distillation process. The nonrandom two-liquid (NRTL) model was applied to correlate the binary and ternary VLE data.