A photocatalytic impeller reactor for gas phase heterogeneous photocatalysis

A novel photocatalytic reactor based on a stirred tank configuration has been described. This reactor employs the use of photocatalytic impellers to aid the mass transport of gaseous organic compounds during photocatalytic reactions. Experiments involving toluene vapour photo-oxidation showed the reactor configuration is susceptible to catalyst deactivation even at low concentrations if treated for prolonged periods. For this reactor, the reactive time scale exceeds the diffusive time scale hence, toluene photo-oxidation was reaction limited. The dependency of photonic efficiency of the reaction on mass transfer and catalyst deactivation was observed when correlated with the Damköhler number and deactivation induced reduction reaction rates respectively. The results show an inverse variation with Damköhler number and proportionality to reaction rates.