Intensification of Acetone-Butanol-Ethanol Fermentation via Products Recovery: Thermopervaporation Assisted by Phase Separation

Abstract

Inexp the present work, we propose the techniques providing a way to enhance biobutanol production via the acetone-butanol-ethanol (ABE) fermentation process. The proposed techniques employ highly efficient butanol-producing strains and extended range of renewable substrates. Also, an efficient approach to butanol removal from the culture liquid is presented – the novel technique of membrane thermopervaporation with porous condenser, coupled with phase separation (TPV-PC), which uses the low-grade heat (50-80°?) only to create the driving force. In order to increase the butanol yield in the fermentation process, the reducing agent (glycerol) was introduced into the studied substrates based on grain crops flour and beet molasses. It was found that glycerol enhances the fermentation efficiency with almost all the clostridia strains used, providing an increase in butanol fraction in the total ABE content – from 60 to 80%. It was shown that the TPV-PC technique provides stable butanol removal from the fermentation broths up to concentration of 0.5% and lower, regardless on the microorganisms strain and the fermentation broth composition.