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

BACKGROUNDFermentation 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. RESULTSA dense membrane made of polymer of intrinsic microporosity in the SA-TPV process demonstrated stable performance (butanol flux 57.7 gm(-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. CONCLUSIONThe SA-TPV approach can be effective for recovery of both volatile and nonvolatile compounds from fermentation broth, whilst maintaining stable long-term membrane performance. (c) 2019 Society of Chemical Industry