Radiative Transfer in Photocatalytic Systems

Radiation absorption at the surjace of catalytic particles is the initial step of photocatalytic oxidation reactions currently considered for their potential effectiueness in the treatment of polluted water with traces of highly toxic organics. Owing to the presence of catalyst particles within the fluid phase, the radiation field within a photocatalytic reactor results from the absorption and scattering within the participating medium. An annular reactor with a coaxial central lamp was considered, and the resulting 2 0 radiation field was analyzed using a Monte Carlo technique to solve the radiatiw transfer equation. Results are discussed based on the relevant optical parameters, and a heuristic is deriued for the design and rating of a photocatalytic reactor. To exploit the reaction uolume effectiuely, the order of magnitude of the optical thickness should be close to unit): and for a giuen value of the ahsorption coefficient the catalyst with the lowest albedo should be selected; howeuer, a precise evaluation of the phase function is not crucial to a reliable representation of the radiation field.