Sorption‐assisted thermopervaporation method for organics recovery from ABE fermentation broth

BACKGROUND: Fermentation broth is a complex mixture which contains target and other organic compounds which must be continuously recovered to maintain microorganism activity. To overcome this problem, a sorption‐assisted thermopervaporation (SA‐TPV) method has been proposed, which enables the removal of volatile organics by means of evaporation, and low and nonvolatile compounds by membrane adsorption. RESULTS: A dense membrane made of polymer of intrinsic microporosity in the SA‐TPV process demonstrated stable performance (butanol flux 57.7 g m⁻² h⁻¹; separation factor butanol/water 30.4) within five months of operation with cell‐free ABE fermentation broth. Scanning electron microscopy/energy dispersive X‐ray spectroscopy analysis revealed that the proposed SA‐TPV method reduced ‘external’ membrane fouling by a factor of three. Fourier transform infrared and gas chromatography/ mass spectrometry analysis confirmed that it was possible to extract ‘external’ and ‘internal’ foulants by membrane adsorption followed by in situ regeneration. CONCLUSION: The SA‐TPV approach can be effective for recovery of both volatile and nonvolatile compounds from fermentation broth, whilst maintaining stable long‐term membrane performance. © 2019 Society of Chemical Industry