Review of modeling and simulation strategies for unstructured packing bed photoreactors with CFD method

The structure of photoreactors plays a key role in the photocatalysis by affecting the catalyst loading, mass and light transport properties. Nowadays it has become increasingly important to investigate the hydrodynamic and photocatalytic performances of photoreactors by computational fluid dynamic (CFD) method, thanks to its less cost and more steerable conditions. However, only a limited number of reports about CFD modeling of the packing bed photoreactors were presented because the unstructured substrates are difficult to reconstruct. In this paper, the bed generation technology and relevant hydrodynamic model, reaction kinetic model, and irradiation transport model of packing bed photoreactors are systematically reviewed and analyzed. The deficiency and the required modification of different CFD coupling strategies with the simulations of packing bed photoreactors are presented. The effects of temperature and local light intensity on the kinetic models and modified kinetic equations are summarized. This work may bridge the knowledge gap between the unstructured geometry generation technologies and the CFD simulations of packing bed photoreactors to promote the development/commercialization of the photocatalysis radically.