Isobaric Vapor–Liquid Equilibrium Experiments\nof Methyl Propionate + Ethanol with Different Ionic Liquids at 101.3\nkPa

This\nstudy investigates the vapor–liquid phase equilibria\nfor the binary system of methyl propionate and ethanol as well as\nfor the ternary system with three ionic liquids, [BMIM][OAC], [EMIM][OAC],\nand [MMIM][DMP], as extractants. The nonrandom two-liquid (NRTL) model\nwas employed to correlate the vapor–liquid phase equilibrium\ndata. Results indicate that each ionic liquid increases the relative\nvolatility of methyl propionate to ethanol and effectively breaks\nthe azeotrope at a molar fraction of 0.08. The NRTL model exhibited\nan average relative deviation of 2.46% for binary systems and 3.73,\n4.05, and 3.60% for ternary systems. Of the ionic liquids tested,\n[BMIM][OAC] achieved the highest separation efficiency in the methyl\npropionate-ethanol azeotropic system.