Recovery of 2,3-butanediol from water by a solvent extraction and pervaporation separation scheme

An integrated separation scheme based on solvent extraction and pervaporation was proposed to recover 2,3-buthanediol from a synthetic fermentation broth. The selected extracting solvent 1-butanol was found to be more suitable than others. Polydimethylsiloxane membrane was employed to further enrich the 2,3-butanediol in the organic phase consisting of 2,3-butanediol, 1-butanol and water. Of the three species, water was found to be the most permeable in the membrane followed by 1-butanol, implying that concentration and purification of 2,3-butanediol as membrane retentate could be achieved by using the polydimethylsiloxane membrane alone. Two membrane batch operations, i.e., dehydration, and removal of 1-butanol using chitosan and polydimethylsiloxane composite membranes, respectively, were conducted to demonstrate the capability of the selected membranes for producing 2,3-butanediol with purities higher than 98 wt.%. And numerical simulation showed the viability of the membrane in continuous operation for the recovery of 2,3-buatendiol.