Liquid-Liquid Equilibrium Studies on Extraction of Commercially Significant Carboxylic Acids

Abstract

Carboxylic acids are commercially very important organic acids and their extraction from fermentation broth can be one of the sources of recycling back these important organic acids.Here, we have worked on two systems: experimental tie-line results and solubility (binodal) curves were obtained for the ternary systems of water + acetic acid + hexanol and water + caproic acid + methyl isobutyl ketone at temperature of 308K and at atmospheric pressure. The concentrations of the components in the equilibrium phases were measured using gas chromatography for hexanol and methyl isobutyl ketone and acid concentration in each phase was determined by titration against NaOH solution. The water concentration was determined using mass balance. Using the equilibrium tie line phase compositions graph was plotted for the ternary systems. Solubility or binodal curves were obtained by joining these tie line phase compositions. The two phase and the one phase region were then determined for the ternary systems. Distribution coefficients and separation factors were calculated for the ternary systems to determine whether the solvents used were suitable for extraction of those specific organic acids from their aqueous phases.