Salting-out effect on solvent extraction of ethanol and butanol

Low molecular weight alcohols have both Lewis-acid and Lewis-bass sites, and very strong hydrophilicities. Thus extraction from aqueous solutions with conventional solvents is comparatively difficult. This work studies solvent extraction of ethanol and butanol from aqueous solutions by adding salt. A series of extraction equilibrium experiments for ethanol and butanol was carried out using 1-octanol as solvent. The results show that the salting-out effect benefits the extraction of ethanol and butanol and higher distribution ratios are obtained. The salts with higher-electric-charge metal ions have stronger salting-out effect. Empirical formula are proposed for the salting-out effect on the extraction of ethanol and butanol.