Monte Carlo simulation of the radiation field in a reticulated foam photocatalytic reactor

The 3-D polychromatic radiation field for an annular packed-bed photocatalytic reactor using alumina reticulated foams as a monolithic catalyst support was simulated using Monte Carlo methodology. Two distinct methods were used for simulating photon transport: (1) a `spatial' approach that tracks the flight of a photon in a predetermined reticulate structure; (2) a `temporal' approach that generates the random porous structure of the reticulate as the photon flies into it. The two approaches yield almost identical results, although the temporal approach is far more efficient computationally. Simulations for the integral axially-averaged radial ultraviolet (UV) light profiles agree closely with experimental measurements for titania-coated 10, 20 and 30 PPI alumina reticulates and near UV lamps. The simulations reveal that the local volumetric rate of energy absorption (LVREA) in the reticulate and the magnitude of the LVREA gradient both increase with decreasing reticulate pore size.