Phase diagram of ionic liquid aqueous two-phase systems with N-butylpyridinium tetrafluoroborate, ammonium Citrate/Sodium acetate, and water from 308.15 K to 328.15 K

• We studied phase behavior of [BPy]BF4 + Salt + H2O systems at different temperatures.
• Some appropriate equations were used to correlate binodal curves.
• Salting-out ability is (NH4)3C6H5O7.
• CH3COONa.
• The effect of temperature on the studied system is consistent.

In this study, the phase diagrams and liquid–liquid equilibrium data for two-phase systems of N-butylpyridinium tetrafluoroborate ([BPy]BF4) + ammonium citrate ((NH4)3C6H5O7) have been experimentally determined at 308.15 K, 313.15 K, 318.15 K and 328.15 K. Sodium acetate (CH3COONa) + water had also been determined at 308.15 K, 318.15 K and 328.15 K. The binodal data were fit to the Merchuk equation and to two empirical equations with several parameters. Good agreement was obtained among these models.