Particle-Resolved CFD Simulations of Isobutane and 2‑Butene Alkylation over Complex-Shaped Zeolite Catalysts in Fixed Bed Reactors

Liquid alkylation of isobutane and 2-butene in zeolite catalysts is impeded by severe internal diffusion influences, which are reduced by optimizing the catalyst shape in this paper. We simulate this reaction in fixed beds filled with catalyst shapes of sphere, cylinder, quadrilobe, trilobe, and ring using the particle-resolved computational fluid dynamics (CFD) approach to address the effects of catalyst shape on voidage, bulk flow, pressure drop, heat transfer, reaction, and internal diffusion effectiveness factor. Among them, trilobes in beds have the highest 2-butene conversion under the same volumetric space velocity because of their advantages such as more even velocity profile, larger external surface area compared with cylinders, spheres, and quadrilobes, and larger catalyst volume compared with rings, which show the highest conversion under the same weight hourly space velocity (WHSV) due to their highest external surface area per volume. The 2-butene conversion indicator increases with the increase of the catalyst porosity. Our research will benefit the catalyst design for this reaction.