Determining apparent kinetics for catalyst pellets using particle‐resolved computational fluid dynamics

Abstract Conventional methods for determining apparent kinetics for fixed‐bed reactor design require experiments under ideal flow conditions and with negligible external diffusion limitation, which are costly and inconvenient. This study proposes a new method for determining the apparent kinetics based on particle‐resolved computational fluid dynamics (PRCFD) that can resolve the influence of inter‐particle transfer. Using PRCFD allows kinetic measurements in fixed‐bed reactors with minimal catalyst (down to a single pellet) loading and small gas velocity. Au/TS‐1 catalyst pellets for propylene epoxidation are used to evaluate this method. The results show that this method can yield reliable apparent kinetics. PRCFD‐based quantification confirms that non‐ideal flow and transport limitations are significant, necessitating PRCFD for accurate determination of apparent kinetics. A comparison reveals that the material cost of this method can be three orders of magnitude lower than that of a conventional method at the expense of an increased but acceptable computational cost.