Liquid-liquid equilibrium measurements and interaction explorations for separation of azeotrope n-butyl acetate and n-butanol using three ionic liquids

Abstract To separate the azeotropic mixture n-butyl acetate and n-butanol by liquid–liquid extraction, three ionic liquids (ILs) 1-ethyl-3-methylimidazolium dihydrogen phosphate ([Emim]H2PO4), 1-butyl-3-methylimidazolium ([Bmim]H2PO4) 1-hexyl-3-methylimidazolium ([Hmim]H2PO4) were adopted as extractants. The equilibrium data for ternary mixtures (n-butyl acetate + n-butanol + [Emim]H2PO4/[Bmim]H2PO4/[Hmim]H2PO4) was measured at 298.15 K 101.3 kPa. extraction capacity of evaluated partition coefficient selectivity. NRTL model applied to fit with root mean square deviation less than 0.009. hydrogen bond length interaction energy between acetate/n-butanol calculated effect liquid cations different carbon chain explored.