Experimental determination and correlation of tie line data for the system (water + butyric acid + methylcyclohexane) at four temperatures

This study demonstrates the experimental solubility and tie line data for (water + butyric acid + methylcyclohexane) system at temperatures of 298.2, 308.2, 318.2, and 328.2 K and atmospheric pressure. The cloud-point titration method was used to determine solubility data (binodal curves). The tie line data were determined by acidimetric titration, the Karl–Fischer technique, and refractive index measurements. The investigated ternary system exhibits type-1 behavior of liquid–liquid equilibrium. The thermodynamic models UNIQUAC and NRTL were used to correlate the experimental tie-line data. The consistency of the tie-line data was determined through the Othmer Tobias and Hand correlation equations. Distribution coefficients and separation factors were calculated over the immiscibility regions. A comparison of the extracting capability of the solvent at different temperatures was made with respect to separation factors. The Katritzky multiparameter scale was applied to correlate distribution coefficients and separation factors in this ternary system.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Phase equilibria of water–BA–methylcyclohexane system were investigated. ► Experimental LLE data were correlated with NRTL and UNIQUAC models. ► Distribution coefficients and separation factors were evaluated.