Patent ID: 8373009

Claim:
A process comprising: a) introducing a feed comprising: (i) a water-immiscible organic extractant; (ii) water; (v) at least one isomer of butanol; and (vi) optionally a non-condensable gas into a first distillation column, wherein the first distillation column comprises a stripping section and optionally a rectifying section at an introduction point above the stripping section, the first distillation column having an operating temperature T 1 and an operating pressure P 1 in the stripping section; wherein T 1 and P 1 are selected to produce a first bottoms stream and a first vaporous overhead stream, the first bottoms stream comprising the water-immiscible organic extractant and water and being substantially free of butanol, and the first vaporous overhead stream comprising water, butanol, optionally the extractant, and optionally the non-condensable gas; b) introducing a water-immiscible organic entrainer to at least one process stream or vessel; c) condensing the first vaporous overhead stream to produce a gas phase and recover a first mixed condensate; wherein the first mixed condensate comprises: (i) an organic phase comprising butanol, entrainer, and water; and (ii) an aqueous phase comprising water and butanol; and wherein the first mixed condensate comprises sufficient entrainer to provide phase separation of the organic and the aqueous phases; d) introducing at least a portion of the aqueous phase to the first distillation column; e) introducing a first portion of the organic phase into a second distillation column having at least a stripping section; and f) operating the second distillation column to produce a second bottoms stream comprising butanol and wherein said bottoms stream is substantially free of water and entrainer, and a second vaporous overhead stream comprising butanol, entrainer, and water.