Phase diagrams for the aqueous solutions of butyric acid with cyclohexane at different temperatures: Experimental and correlated data

Abstract

In this work, experimental tie-line data for the (water + butyric acid + cyclohexane) system were obtained at T = 298.2, 303.2, 308.2, and 313.2 K and atmospheric pressure. The investigated ternary system exhibits type-1 behavior of LLE. The experimental tie-line data were compared with those correlated by the UNIQUAC and NRTL models. The consistency of the experimental tie-line data was determined through the Othmer Tobias and Hand correlation equations. Distribution coefficients and separation factors were evaluated over the immiscibility regions. The influence of temperature on the equilibrium characteristics and separation factor was found to be considerable at the temperatures studied. A comparison of the extracting capability of the solvent at different temperatures was made with respect to separation factors. The Katritzky LSER model was applied to correlate distribution coefficients and separation factors in this ternary system. The LSER model values showed good regression fits to the experimental results.