In this work, the degradation of tetrachloroethylene or perchloroethylene (PCE) in an air stream was studied for different values of PCE feed concentrations, relative humidity levels, and light intensities. The TiO 2 photocatalyst was deposited as a thin film on a borosilicate glass plate by means of a sol-gel technique. The reactor was operated under kinetic control regime. An expression of the intrinsic reaction kinetics was developed. This expression is based on a model of the absorption of radiant energy on the surface of the catalyst, followed by a detailed reaction mechanism based on a reaction scheme that involves Cl • as an active reaction intermediate. Experimental results from a differential photoreactor were used to validate the proposed kinetic model and to determine the kinetic parameters by nonlinear regression of experimental data. The obtained results show: (1) first-order kinetics with respect to the PCE concentration, (2) linear dependence with the photon absorption rate, and (3) site-competitive adsorption between PCE and water, resulting in a dependence of the kinetics on the relative humidity.

A model of radiant energy emission for tridimensional sources has been developed and used to predict radiation flux density profiles in an annular photochemical reactor. This paper presents results for a reactor without dispersion or absorption effects; that is, reflexions and refractions have been neglected and the energy has been assumed to propagate in a transparent medium.Computed radiation profiles agree well with published experimental data in a similar lamp‐reactor set up.Also, the formulation does not introduce, as it is the case with all line models, any form of singularities in the prediction of radiation flux density values.Finally, a parametric study of the effects of lamp dimensions on the shape of the radiation profiles was also made.

A three-dimensional radiation model coupled with two-dimensional mass balances for the intervening chemical species is solved for the photochemical chlorination of ethane. The analysis was carried out using the full mechanistic kinetic sequence and employing polychromatic radiation for a process conducted in a tubular reactor placed inside an elliptical reflector.Theoretical predictions were compared with bench-scale experiments and showed excellent agreement. Using the validated model, computational experiments were conducted to explore the influence of reactor design and operational parameters upon the degree of chlorination. Dichlorination reactions were also added to the kinetic model to analyze reactor behavior from the viewpoint of selectivity. The a priori design method described can be applied from first principles and requires no experimentally adjustable parameters.