A Kinetic Model of the Photocatalytic Oxidation of Tetrachloroethylene in Gas Phase

IMOBERDORF, G.E.; IRAZOQUI, H.A.; ALFANO, O.M.; CASSANO, A.E.

Buenos Aires, Argentina

Conferencia; International Conference: Monitoring Systems and Novel Technologies for Detection/Removal of Pollutants in/from Ecosystems; 2004

UNIND-LAM, Ac. Nacional de Ciencias Exactas, Físicas y Naturales

Many volatile chlorinated organic compounds have a widespread industrial application, as it happens with tetrachloroethylene (perchloroethylene or PCE). In addition to being toxic and carcinogenic, these compounds are also highly persistent in the environment. An effective option for its elimination is by means of photocatalytic reactions that uses TiO2 catalyst. For the design of photoreactors, it is necessary to know the kinetics of the reaction. In this work, the intrinsic kinetics of the reaction was derived from the proposed reaction mechanism and the parameters of the kinetic expression were determined by non-linear regression of experimental data. A reactor was built following a design that makes it easily operable outside the region where diffusive control phenomena are detectable. A thin film of TiO2 catalyst was deposited on borosilicate glass plates by means of a sol-gel(1) technique. The reactor feed consists of mixtures of PCE and chromatographic quality air with controlled humidity and temperature. Within the range of operating variables: PCE (5-20 ppm), relative humidity (0-100%) and irradiation level (0-100%), the mineralización of the PCE was practically complete, without any by-product detected.