Liquid phase equilibria of the system (water + phosphoric acid + 1-octanol) at T = (298.2, 308.2, and 318.2) K

Experimental solubility and tie-line data for the ternary system of (water + phosphoric acid + 1-octanol) were measured at T = (298.2, 308.2, and 318.2) K and atmospheric pressure. Data for the binodal curves were determined by cloud-point titration method. The concentration of each phase was determined by acidimetric titration, the Karl–Fischer technique, and refractive index measurements. A type-1 LLE phase diagram was obtained for this ternary system. The experimental tie-line data were correlated using the UNIQUAC and NRTL models. The reliability of the experimental data was determined through the Othmer–Tobias and Hand plots. Distribution coefficients and separation factors were evaluated over the immiscibility regions. The effect of temperature on the biphasic region of the ternary system and separation factor was found to be small at the temperatures studied. The Katritzky LSER model was applied to correlate distribution coefficients and separation factors in this ternary system.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Liquid phase equilibria of (water + PA + 1-octanol) system were measured. ► Experimental LLE data were correlated with NRTL and UNIQUAC models. ► Distribution coefficients and separation factors were evaluated.