Experimental study of extraction behaviour of 2,3-butanediol from aqueous solution with 3-methyl-1-butanol in presence of KCl at 303.15 K

The influence of a solid salt on. liquid-liquid equilibrium cannot be ignored because it significantly changes the equilibrium composition. Liquid-liquid equilibrium is the result of intermolecular forces which can significantly change due to salt addition which introduces ionic forces affecting the thermodynamic equilibrium. Aqueous electrolyte liquid-liquid equilibrium is often related to extraction processes. In the present work the salt effect on the system namely water + 2,3-butanediol + 3-methyl-1-butanol has been studied at 303.15 K. The salt used in the above system is KCl with 10% and 15% and 20% concentration. The mutual solubility curve, tie-line data, distribution coefficient and selectivity were determined experimentally at different salt concentrations. The result obtained showed that the salt KCl significantly affect the solubility of 2,3-butanediol in organic solvent. KCl also changes the distribution coefficients and selectivity of 2,3-butanediol by changing the equilibrium composition. The heterogeneity region also increased as compared to the same system without salt. The thermodynamic consistency of the equilibrium tie-line data was ascertained by Othmer-Tobias plot, Setschenow equation and Hand equation.