3D modeling of a CPOX-reformer including detailed chemistry and radiation effects with DUO

•3D modeling of a honeycomb CPOX reformer for the conversion of methane on rhodium.•Calculation domain comprises the flow region and two monoliths (one of them coated) with 77 channels each.•Modeling includes detailed surface chemistry and solid body radiation.•Comparison of concentrations and fluid/solid temperatures with measured data.•Radiation influences heat distribution but the effect on the chemical conversion is weak.