Experimental isobaric vapour–liquid–liquid equilibrium data for the quaternary systems water (1)–ethanol (2)–acetone (3)–n-butyl acetate (4) and water (1)–ethanol (2)–acetone (3)–methyl ethyl ketone (4) and their partially miscible-constituent ternaries

Experimental vapour–liquid–liquid equilibrium data for the (type B) quaternary systems water (1)–ethanol (2)–acetone (3)–n-butyl acetate (4) and water (1)–ethanol (2)–acetone (3)–methyl ethyl ketone (4) were measured using a circulation equilibrium still employing vigorous mechanical mixing in the boiling chamber. The first quaternary system was measured isobarically at pressures of 760, 600 and 360 mm Hg, and the other system measured isobarically at atmospheric pressure. The partially miscible constituent ternaries of both quaternary systems, water (1)–acetone (2)–n-butyl acetate (3), water (1)–ethanol (2)–n-butyl acetate (3), water (1)–acetone (2)–methyl ethyl ketone (3) and water (1)–ethanol (2)–methyl ethyl ketone (3) were also measured at the same conditions. The measured experimental data were found to be thermodynamically consistent according to the isobaric point-by-point thermodynamic consistency criterion of Wisniak.