Patent ID: 8968523
Filing Date: 2015-03-03
Classification: B01D,C07C

Abstract:
1. A process comprising the steps: a) introducing a feed comprising: 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 b) condensing the first vaporous overhead stream to produce an optional gas phase and recover a first mixed condensate, wherein the first mixed condensate comprises c) introducing at least a portion of the aqueous phase to the first distillation column; d) introducing a first portion of the butanol phase into a second distillation column having at least a stripping section; e) operating the second distillation column to produce a second bottoms stream comprising the at least one isomer of butanol and being substantially free of water, and a second vaporous overhead stream comprising the at least one isomer of butanol and water; and f) introducing at least a portion of the aqueous phase into a fermentation vessel, wherein the extractant is selected such that it (A) preferentially extracts the at least one isomer of butanol over water and (B) is separable from the at least one isomer of butanol by distillation.