| abstract |
A process for recovering butanol from a mixture comprising a water-immiscible organic extractant, water, butanol, and optionally a non-condensable gas, is provided. The butanol is selected from 1-butanol, isobutanol, and mixtures thereof. An overhead stream from a first distillation column is decanted into two liquid phases. The wet butanol phase is refined in a second distillation column; the aqueous phase is returned to the first distillation column. A portion of the wet butanol phase from the decanter is also returned to the first distillation column. The extractant comprises at least one solvent selected from the group consisting of C 7 to C 22 fatty alcohols, C 7 to C 22 fatty acids, esters of C 7 to C 22 fatty acids, C 7 to C 22 fatty aldehydes, and mixtures thereof. |