Particle-resolved lattice Boltzmann simulations for sedimentation of catalyst particles involving coke deposition

Catalyst deactivation by coke deposition in heterogeneous catalysis critically impacts reaction kinetics, yet its effects on particulate flows remain poorly understood. This work employs a particle-resolved immersed boundary-lattice Boltzmann method to analyze coke-influenced particle motion and particle–fluid interaction during sedimentation. The results reveal that for single/multiple particles, coke deposition on the catalyst particles gradually increases the particle density and accelerates the settling velocity of particles. When the reaction rate increases to certain extent, there exists a critical particle Reynolds number beyond which the vortex shedding around the catalyst appears, leading to a significant change in the flow pattern and particles motion. For settling of multiple particles, the initial release positions affect the movement of particles. Moreover, by analyzing the change of coke deposition rate during sedimentation, it is proved that the deactivation of catalyst is heterogeneous, which is caused by the uneven concentration distribution.