A silcone-silicalite-1 composite membrane was synthesized to recover acetone, butanol, and ethanol (ABE) from model solutions and the Clostridium acetobutylicum (ABE) fermentation broth. The adsorption capacity of the silicalite-1 in the presence of a mixture of acetone, butanol and ethanol were 8-12, 85-90 and <5mg/g, respectively. There was no apparent difference of absorption rate of butanol at 36°C and 79°C and desorption of butanol occurred efficiently at 78°C and 1-3Torr. The silicalite-1 was characterized by chemical analysis, NMR, electron micrographs, surface area and pore size determination and found to have identical properties to other silicalite-1 reported in the literature. The silicalite-1 was incorporated into a silicone membrane in an effort to enhance butanol flux and selectivity. A membrane with a silicalite-1 to polymer ratio of 1.5:1 (g:g) (306μm thick) had butanol selectivities of 100-108 and a flux of 89g/m2h at feed butanol concentrations ranging from 5 to 9g/l and a retentate temperature of 78°C. A 170μm silicone membrane under identical conditions had selectivity and flux of 30 and 84g/m2h, respectively. A thin silicalite membrane offered low selectivity and high flux, while a thick membrane offered high selectivity and low flux. The effect of butanol concentration (0.37-78g/l) on flux and selectivity was also studied. Copyright (C) 1999 Elsevier Science B.V.
- Silicone-silicalite membrane
ASJC Scopus subject areas
- Materials Science(all)
- Physical and Theoretical Chemistry
- Filtration and Separation