During the batch fermentation with PV, permeate samples were pooled to measure ABE concentration at different time intervals, while the fluxes and separation factors of various solvents were calculated according to Eqs. (4) and (5), respectively. The results are presented in Fig. 2. Fig. 2a shows that the butanol and ABE concentrations in the permeate solution could be up to 118.70 and 203.76 g/L at the early stage of PV operation, respectively. As operation went on, the butanol and ABE concentrations in the permeate solution declined slowly with decreasing ABE concentration in the
broth. Fig. 2b shows the performance of the silicalite-1 filled PDMS/PAN composite membrane in batch fermentation with PV. Butanol separation factor ranged from 29 to 32, while the total flux varied from 520 to 573 g/m2 h due to the variation of solvent concentration in the broth. The variation of separation factor and total fluxes were similar to those found with model ABE solution (see Supplementary material, Fig. 1S), indicating that the silicalite-1 filled PDMS/PAN composite membrane was not fouled by the fermentation broth