Measurement and Correlation of LLE Data for the Ternary System Water + Phosphoric Acid + 1-Undecanol at 303.2 K

Experimental solubility curve and tie-line data were obtained for the ternary system (water + phosphoric acid + 1-undecanol) at T = 303.2 K and ambient pressure. The cloud point method was employed to determine the binodal curve data. The mass fraction compositions of each layer were explored by acid-base and the Karl Fisher titration methods accompanied by mass balance calculations. For above mentioned ternary system, a type-1 LLE behavior was observed. The reliability of the experimental compositions was proved by using the Othmer–Tobias and Hand plots. The UNIQUAC and NRTL thermodynamic models were applied to correlate the equilibrium tie-line points. The experimental points were adequately regressed using the thermodynamic models. Distribution coefficients and separation factors were computed over the non-miscible region. For the separation process, separation factor should be greater than one and for the investigated system, this factor was suitable to apply separation treatment in all concentrations of phosphoric acid at the studied temperature. The Katritzky parameters were utilized for LSER modeling of distribution coefficients of the studied mixtures. The ternary system showed good fittings with the LSER model.