초록
<P><B>Abstract</B></P> <P>Two-stage pervaporation for ABE recovery from fermentation broth was studied to reduce the energy cost. The permeate after the first stage <I>in situ</I> pervaporation system was further used as the feedstock in the second stage of pervaporation unit using the same PDMS/PVDF membrane. A total 782.5g/L of ABE (304.56g/L of acetone, 451.98g/L of butanol and 25.97g/L of ethanol) was achieved in the second stage permeate, while the overall acetone, butanol and ethanol separation factors were: 70.7–89.73, 70.48–84.74 and 9.05–13.58, respectively. Furthermore, the theoretical evaporation energy requirement for ABE separation in the consolidate fermentation, which containing two-stage pervaporation and the following distillation process, was estimated less than ∼13.2MJ/kg-butanol. The required evaporation energy was only 36.7% of the energy content of butanol. The novel two-stage pervaporation process was effective in increasing ABE production and reducing energy consumption of the solvents separation system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Two-stage pervaporation was integrated with continuous ABE fermentation. </LI> <LI> A total 782.5g/L of ABE was produced in the pervaporation based process. </LI> <LI> 70.48–84.74 of butanol separation factor was achieved by the two-stage pervaporation. </LI> <LI> Less than ∼13.2MJ/kg-butanol of theoretical evaporation energy was demand. </LI> </UL> </P>