MATHEMATICAL-MODELING OF MONOLITH REACTORS FOR PHOTOCATALYTIC OXIDATION OF AIR CONTAMINANTS

A distributed parameter model for photocatalytic oxidation of air cont aminants in monolith reactors is presented. Heat and mass balance equa tions for monolith structure are combined with a model of irradiation from a light source and a kinetic model for photon adsorption and chem ical reaction to describe the processes of heat, mass and photon trans fer within the system and the heterogeneous chemistry at the catalyst surface. The model accounts for interaction between light and matter a t the catalyst surface, convective and interphase gas-solid heat and m ass transfer, reaction at the catalyst surface and heat conduction wit hin the solid structure. Together with detailed axial profile of tempe rature and conversion in the gas phase and at the catalyst surface und er different operating conditions (inlet gas temperature, composition and flow rate, light source power, monolith geometry), the model provi des the distribution of photon flux along the channels and allows the discrimination between thermal and pure photonic effect on the overall rate of conversion. (C) 1998 Elsevier Science S.A. All rights reserve d.