2,3-Butanediol recovery from fermentation broth using membrane pertraction

2,3-Butanediol (BDO) has gained immense interest for use as a platform chemical in the production of many important chemicals such as synthetic rubber, plasticizer, and octane boosters. Using BDO as a precursor for sustainable aviation fuel production may significantly reduce the carbon footprint of the airline industry. However, recovery of BDO is challenging due to its relatively low concentration (∼10 wt %) in fermentation broth and its high affinity for water. In this work, we developed a membrane pertraction process for BDO recovery from biomass derived fermentation broth. Different organic solvents such as hexanol and oleyl alcohol were investigated. With traditional solvent extraction, hexanol required a solvent to feed ratio of 10 to recover >90 % BDO, and oleyl alcohol could recover 35 % of BDO at the same ratio. BDO recovery of >90 % was demonstrated with pertraction; a BDO extraction rate of 15 g¹m⁻²h⁻¹ was achieved using hexanol, and an extraction rate of 10 g¹m⁻²h⁻¹ was achieved using oleyl alcohol. Impurities commonly found in fermentation broth did not affect the separation performance of the pertraction process. This work demonstrates pertraction as a low-footprint, scalable method for recovery of high-purity BDO from fermentation broth.