Modeling Photocatalytic Reactions Reaction parameters

The main difference between photochemical and thermal reaction is the presence of a radiation-activated step. The rate of reaction of this step is proportional to the local volumetric rate of energy absorption (LVREA). For any emission model, the LVREA is a function of the spatial variables, of the physical properties and geometrical characteristics of the lamp-reactor system, and some physicochemical properties of the reacting mixture. The most important design parameter that is pertinent in photochemical and photocatalytic reactions is the effective attenuation coefficient. 

Three-dimensional CFD-coupled with radiation field modeling and photocatalytic reaction dynamics was employed by Salvado-Estivill et al. (2007b) to model the decomposition of TCE in a flat-plate, single-pass photocatalytic reactor containing immobilized P25. The outcome was pollutant-specific kinetic rate parameters, which were independent of the reactor geometry, radiation field, and fluid dynamics. This was followed by... 

This paper is concerned with an attractive possibility involving both zeolite and semiconductor in photocatalytic oxidation. We study here the heterogeneous photocatalytic oxidation of various alkylbenzenes and unsaturated model compounds using Ti02 and zeolite-added Ti02 as catalyst. The influence of reaction parameters and the effect of zeolite addition are analysed. 

The consideration of equations (1-12) and/or (1-13) leads to the advancement of photocatalytic conversion rate models, such as the series-parallel model proposed by Salaices et al. (2004) where the derived kinetic parameters are based on the iiradiated weight of catalyst. As such, these can be considered as intrinsic parameters with phenomenological meaning pertinent to the photocatalytic reaction. 

The influence of various physical parameters was studied in the case of the oxidation of cyclohexane selected as a model reaction. Since the main product is cyclohexanone, its rate of formation was chosen as representative of the photocatalytic activity of the system. 

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