Using Imidazolinium Salt to Separate an Azeotropic Acetone–Methanol System

So-called salt rectification, a selective way of separating liquid mixtures based on the use of salts, is discussed. Organic imidazolinium salt is used in this process for the first time. The separation of a model non-aqueous azeotropic acetone–methanol system is studied. 1,3-Bis(2,4,6-trimethylphenyl)imidazolinium chloride is chosen as the salt additive. The liquid–vapor equilibrium in the ternary imidazolinium salt–acetone–methanol system is studied in a modified Othmer still at a pressure of 101.3 kPa and salt concentrations of 0.1 to 0.5 mol kg −1 . The composition of the liquid and vapor phases is determined via gas chromatographic analysis. It is found that the azeotrope is broken at an imdazolinium salt concentration of 0.1 mol kg −1 . The NRTL electrolyte model is used to describe the vapor–liquid equilibrium.