Isobaric Vapor−Liquid Equilibrium for (Propan-2-ol + Water + 1-Butyl-3-methylimidazolium Tetrafluoroborate)†

Isobaric vapor−liquid equilibrium (VLE) data for {propan-2-ol (1) + water (2) + 1-butyl-3-methylimidazolium tetrafluoroborate(3)} where 3 is an ionic liquid ([BMIM]+[BF4]−) at atmospheric pressure (101.32 kPa) were measured with a modified Othmer still. The results showed that the ionic liquid studied can transfer the azeotropic point and eliminate the azeotropic phenomena when its concentration is up to x3 = 0.20. This means that [BMIM]+[BF4]− can be used as a promising entrainer in the application of extractive distillation. However, the comparison of the salting-out effect of [BMIM]+[BF4]− with that of 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM]+[BF4]−) was conducted. The measured ternary data were correlated using the NRTL equation.