Mathematical modeling of diesel autothermal reformer geometry modifications

The earlier proposed mathematical model provides a reliable description of n-hexadecane (diesel surrogate) reforming over the Rh/Ce(0.75)Zr(0.25)O2-delta-n-Al2O3/FeCrAl structured catalyst. This work is devoted to the optimi-zation of geometric parameters of the catalytic block , the reactor. The process simulation was carried out using commercial software COMSOL Multiphysics in 2D axisymmetric geometry. Variations in the ratio of the radius to the length of the cylindrical module were considered. To improve heat distribution from the front to the outlet block part, module modification with a steel rod located inside the catalyst was modeled. Truncated cone modules of different shape were also considered. It has been shown that at angles between generatrix and base plane less than 60, a part of the cartridge remains inactive, despite the high temperatures (800 - 850 C) in the module. Finally, a modification of the catalytic cartridge with circumferential steel walls installed along the module, forming several vertical sections from the periphery of the cartridge to the center or vice versa was studied. This modification allowed increasing hydrogen yield from 21.7 to 23.4 vol% and may be used for the development and optimization of catalytic reformers for diesel autothermal reforming.