The analysis of radiative transfer in photoreactors is often crucial for operating efficient photoreactions. This article aims to present a complete experimental and theoretical coupled approach allowing radiative transfer analysis of photoreactors containing particulate media. TiO 2 powder, widely used in photocatalysis, was selected as a case study material for this work. First, Mie theory was used and adapted to assess the effective properties of heterogenous powders. A home-made experimental bench allowing normal-hemispheric transmittance measurement was settled. Theoretical and experimental evaluations of the radiative properties were compared and appear to match each other. The second part of the work consisted in both transmittance and local radiant energy modeling through Monte Carlo and Two Flux models using the previously defined radiative properties as entry parameters. The comparison of experimental and modeled transmittance highlighted the consistence of these models which were then used to describe the radiant energy evolution inside a parallelplane photoreactor.