Review of alternative technologies for acetone-butanol-ethanol separation: Principles, state-of-the-art, and development trends

n-Butanol is an advanced next-generation drop-in biofuel, which can be produced by anaerobic acetone-butanol-ethanol (ABE) fermentation using biomass derived carbohydrates as substate by Clostridia sp. Nevertheless, even though there are plenty of breakthroughs for continuous improving the competitiveness of biological n-butanol production towards the petrol-chemical ones, a series technical barrier still limited the commercialization of ABE industry. As one of the major bottlenecks, the complex constitution of solvent product with extremely low concentrations always resulted in the energy-intensive downstream separation of the ABE production from fermentation broth, which further challenged the economic viability of the whole n-butanol process. To over-come the obstacle, in recent years, great effort has been taken to seek for an energy-saving and cost-effective technique for ABE separation from fermentation broth. This review aims to highlight the mechanisms of the arisen alternative n-butanol separation techniques and covered along with the limitations and advantages of these techniques. A comprehensive discussion of the current emerged trends in multi-stages separation inte-gration processes are also made for the prospective separation techniques involved in n-butanol production.

Automated summary

n-Butanol is an advanced biofuel produced through ABE fermentation, but technical barriers such as complex solvent product composition and energy-intensive downstream separation have hindered commercialization. Efforts have been made to seek energy-efficient techniques for ABE separation and discuss emerging trends in multi-stages separation integration processes for n-butanol production.