Experimental and Correlational Study of Phase Equilibria in Aqueous Solutions of Formic and Butyric Acids with Isoamyl Acetate and Methyl Isoamyl Ketone at T = 298.15 K

Abstract

This study demonstrates the experimental solubility and tie-line data for {water + formic acid or butyric acid + solvents} ternary systems at T = 298.15 K and p = 101.32 kPa for the first time. The selected organic solvents were isoamyl acetate and methyl isoamyl ketone. Despite structural similarity, however, they belong to two different C7 chemical classifications. The phase diagrams for all of the studied ternary systems are of type-1. Solubility curves were experimentally determined using the cloud point method. The experimental tie-line data were determined by acidimetric titration, the Karl–Fischer technique, and refractive index measurements. The experimental tie-line data were correlated using the UNIQUAC and NRTL models. The quality of the experimental tie-line data was determined through the Othmer–Tobias and Hand correlation plots. From the experimental equilibrium data, distribution coefficients and separation factors were obtained through the regions of immiscibility.