Liquid–liquid equilibria of ionic liquid N-ethylpyridinium tetrafluoroborate + trisodium citrate/ammonium citrate tribasic/sodium succinate/sodium tartrate aqueous two-phase systems at 298.15 K

Binodal curves of the aqueous N-ethylpyridinium tetrafluoroborate ([EPy]BF4) + trisodium citrate (Na3C6H5O7), [EPy]BF4 + ammonium citrate tribasic ((NH4)3C6H5O7), [EPy]BF4 + sodium succinate (Na2C4H4O4) and [EPy]BF4 + sodium tartrate (Na2C4H4O6) systems have been determined experimentally at T = 298.15 K. The Merchuk equation and two other equations were used to correlate the binodal data. The effective excluded volume (EEV) values obtained from the binodal model for these four systems were determined. The Othmer–Tobias, Bancroft, two-parameter and Setschenow-type equations were used for the correlation of the tie-line data. The results show that good agreement was obtained with the experimental data with the two-parameter and the Setschenow-type equations.

► [EPy]BF4 ionic liquid–organic salt aqueous two-phase systems were discussed.
► The binodal curves data and tie-line data were determined experimentally.
► Experimental equations were satisfactorily used to correlate the data.
► The salting-out effect were obtained from the effective excluded volume values.