Thesimulation and full predictive design of large-scale photocatalytic reactors canbe carried out by solving the conservation equations of momentum, energy andmass on the system, similarly to conventional chemical reactors. The momentumand mass balance equations take the same expressions as those corresponding tothermal reactors, as they depend on the fluid dynamic behavior of the reactor(well-mixed, plug-flow, axial dispersion, etc.), the relevant mass transfermechanism (diffusion and/or convection) and the expression corresponding to thereaction rate taking into consideration the stoichiometry of the chemicalreactions. In contrast, the classic enthalpy balance that describes the heatflows and temperature profiles in thermal chemical reactors is substituted inphotochemical reactors by the radiative energy balance. Fil: Marugan, Javier. Universidad Rey Juan Carlos; España Fil: Van Grieken, Rafael. Universidad Rey Juan Carlos; España Fil: Cassano, Alberto Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Alfano, Orlando Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina