Topology optimization of the catalyst distribution of planar methane steam reformers

Wall-coated nickel-based methane steam reformers are extensively used in hydrogen production. In such devices, nickel-based catalyst is coated on the walls and heat is supplied for the reforming process. Due to the existence of endothermic and exothermic characteristics, big temperature differences appear in the reformers, which is likely to cause serious mechanical degradation of the catalyst. This study conducts a topology optimization of the catalyst distribution to reduce the maximum temperature differences of the reformers. Nine cases with different inlet gas compositions and heating fluxes are optimized. For comparison, methane conversion rates are constrained to have the same values as the corresponding reference cases. Results show that optimized catalysts discretely distribute on the wall with different lengths. The narrow catalysts distribute upstream, while the wide catalysts distribute downstream. The optimized results not only largely reduce the maximum temperature differences (24%–82%) and improve temperature uniformity (40%–85%), but also maintain high methane conversion rates. The proposed approach could help to design the catalyst distribution of reformers.