Liquid-liquid equilibria for the ternary system containing water + phosphoric acid + organic entrainers at 308.15 and 328.15 K

Liquid-liquid equilibria data have been determined for the ternary system of water + phosphoric acid + organic entrainers (N-pentane, 2-methylpentane and N-hexane) at 308.15 and 328.15 K. Experiments were carried out at atmospheric pressure using stirred and thermo-regulated cells. Ternary phase diagrams were obtained by the experimental solubility and tie-line data. The reliability of the tie-line compositions was ascertained through the Othmer-Tobias equation. The measured liquid-liquid equilibrium data were compared with the non-random two liquid (NRTL) activity coefficient model. Root mean square deviations between experimental and calculated compositions were considered satisfactory. It was showed that the NRTL model of all ternary systems presented very good satisfactory results with root mean square deviations so it was concluded that this model was highly appropriate to calculate thermodynamic properties of the ternary solutions.