A Rational Approach to the Design of Photocatalytic Reactors

A model to assess the performances of an annular photocatalytic reactor has been developed by investigating different operational conditions through an analysis based on the proper dimensionless parameters (namely, the optical thickness, the Thiele modulus and two among the well-known Damkohler and Peclet numbers, which are properly redefined). Different dependences of the reaction kinetics on the local rate of radiant energy absorption are also considered. Because the progress of the reaction is affected by the radiation field, all these parameters are dependent on the catalyst concentration and then indirectly on the catalyst load. The conditions under which an optimal value for the catalyst concentration may exist are determined, thus contributing to provide insight to one aspect that is quite controversial in the literature.