Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

Isobaric vapor-liquid equilibria (VLE) for the azeotropic system of methanol + methyl carbonate and the ternary systems of methanol + methyl carbonate + 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM][NTf2]) and methanol + methyl carbonate + 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([HMIM][NTf2]) have been obtained using an Othmer Still. Methyl carbonate could be separated from the azeotropic system with [BMIM][NTf2] and [HMIM][NTf2] due to the existence of cross-salt effect. The experimental data were in good agreement with the correlated data using the NRTL model. The model results indicated that the minimum mole fractions required for [BMIM][NTf2] and [HMIM][NTf2] to eliminate azeotropes were 0.048 and 0.043, respectively. The separation capacity of [HMIM][NTf2] was much higher than that of [BMIM][NTf2]. This work provided a general method to understand the effect of ionic liquids (ILs) on the isobaric VLE behavior of methanol + methyl carbonate, and a promising way to the industrial application of ILs in extractive distillation.