Sunday, May 4, 2008
2-53

Study on mass transfer of isopropylbenzene and oxygen in a two-phase partitioning bioreactor in the presence of silicone oil

Jean-Marc Aldric1, Jacqueline Destain2, Jean-Paul Lecomte3, and Philippe Thonart2. (1) Unité de bioindustries, Faculté des Sciences Agronomiques de Gembloux, 2 Passage des déportés, Gembloux, Belgium, (2) Bio-industries, Faculté Universitaire des Sciences Agronomiques de Gembloux, Passage des Déportés, 2, Gembloux, 5030, Belgium, (3) Antifoam development, Dow-Corning SA, Parc Industriel - Zone C, Seneffe, 7180, Belgium

A two-phase partitioning bioreactor (TPPB) to treat gas effluents polluted by volatile organic compound (VOC) has been developed. In this work, both the mass transfer of isopropylbenzene (IPB) and oxygen have been considered in relation to their influence on the hydrodynamics of the reactor and the type of silicone oils used as a second phase.
The synergistic effect of silicone oil and stirrer speed on the global oxygen mass transfer coefficient (KLa) and gas-hold-up (up to 12%) have been investigated. The addition of 10% of low viscosity silicone oil (10 centistokes) in the reactor does not significantly affect the  oxygen transfer rate. The very high solubility of IPB in the silicone oil leads to an  enhancement of driving force term, especially for high fraction of silicone oil. However, it does not seem useful to exceed a volume  fraction of 10% since KLaIPB   decreases sharply at higher proportions of silicone oil. KLaIPB and KLa O2 evolve in the same way with the proportion of silicone oil. These results confirm the potentialities of our bioreactor  to improve  both the oxygen and pollutant gas transfer in the field of the treatment of gaseous pollutants, even for highly concentrated effluents


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