Effect of diameter distribution of particles on methane steam reforming in multi-channel grille-sphere composite packed bed

Methane steam reforming with using packed bed reactor is one of vital alternatives to produce the hydrogen in industry. The diameter distribution of particles in packed bed reactor greatly affects the efficiency of packed bed reactor, however, there are few studies in this field. In this paper, the equivalent medium method was used to study the effect of different diameter distribution of particles on methane steam reforming in multi-channel grille-sphere composite packed bed. It was found that, the hydrogen mass flow rate is related to the overall heat transfer coefficient and represents efficiency of methane steam reforming. To weaken uneven velocity and temperature distributions in multi-channels grille-sphere composited packed bed, the heat transfer coefficient and pressure drop per unit length are optimized in the local region by optimized diameter distribution of variable particles in radial and axial direction. As a result, by utilizing specific diameter of particles in different assigned regions, the efficiency of diameter distribution of variable particles can be increased by about 5% compared with that in traditional structure with uniform diameter particles. The optimization guidance of diameter distribution of variable particles in multi-channel grille-sphere composite packed bed is summarized.