Experimental and modelling of vapour–liquid equilibria of ternary systems {HCOOK + [Emim]Ac + H2O}, {HCOOK + [Emim]Br + H2O}, {HCOOK + [Emim]Cl + H2O}, and {HCOOK + [Emim]NO3 + H2O}

The vapour-liquid equilibrium (VLE) data of four ternary solutions HCOOK + [Emim]Ac /[Emim]Br / [Emim]Cl / [Emim]NO 3  + H 2 O were measured using the boiling method at the temperatures from 305.78 K to 387.08 K, at solute (HCOOK + IL) mass fractions ( w ) between 0.2 and 0.5. A total of 234 data points ( w  = 0 included) were obtained and correlated with empirical Antoine-type equations. The absolute average relative deviations (AARD %) between calculated and measured vapour pressures were 0.58%, 0.50%, 0.49%, 0.63%, respectively, which showed good agreement. The comparison of the experimental and standard data and combined uncertainties of the experimental data confirmed good reliability of the experimental method and apparatus. The four ternary solutions with ILs as additives have lower vapour pressure compared to the corresponding binary solutions without ILs. The results showed that the four ternary solutions of HCOOK + [Emim]Ac / [Emim]Br / [Emim]Cl / [Emim]NO 3  + H 2 O can be the alternatives for traditional dehumidification and absorption media. [Emim]Cl has the best ability to reduce the vapour pressure of HCOOK + H 2 O at the solute (HCOOK + IL) mass fraction of 0.4 and 0.5. The [Emim]Ac has the most effect reducing the vapour pressure of HCOOK + H 2 O at the solute (HCOOK + IL) mass fraction of 0.3.