Photochemical reactor design light source

Photochemical reactor design involves simultaneous solution of the mass, energy, and momentum balance equations (as in normal reactors) along with equations for the radiation field and energy source (which are specific to photochemical reactors). Two approaches are possible (1) the intensity of the incident light, irrespective of the source, is used as the inlet boundary condition incidence models)-, (2) the emission from the source itself is part of the mathematical description emission models). The first approach has been extensively used but suffers from the weakness that the incident light is a function of scale, and hence a priori design from laboratory scale data tends to be uncertain. The second approach is formally correct, and involves no such uncertainty. 

This geometry of irradiation makes the most efficient use of the light emitted by an extended light source. In fact, this geometry is used in all immersion-type photochemical reactors, and most industrial photochemical production units are based on this design. 

Within the general concept of the ESVE models, Alfano et al. conceived a model for the radiant power profile of a tubular light source located in the focal axis of a parabolic reflector in order to analyze the design of a cylindrical photochemical reactor irradiated from the bottom [118]. Differences between experimental and calculated (ESVE) results were always less than 15%. 

---