Modelling of catalytic reactors containing core–shell pellets with various morphologies for series reactions

Abstract

Modelling of series reactions was performed for core–shell catalysts. Mathematical solutions of concentrations inside the pellets were derived from reaction–diffusion equations considering inert‐core thickness (ξc) for first‐order kinetics. Transient behaviours of catalytic reactors containing core–shell pellets were predicted, assuming pseudo‐steady state approximation. In a batch reactor, the removal rate of reactants increased with increasing Thiele modulus and decreasing ξc in the order of sphere > cylinder > slab. The transient concentration of the intermediate product was maximum and affected by the distribution coefficient, diffusivity ratio, particle shape, and ξc. In a continuously stirred tank reactor, the concentration was affected by feed rate and catalyst loading, and conversion could be enhanced by a cascade connection. In a fixed‐bed reactor, the concentration increased with increasing ξc due to an insufficient catalyst volume. Péclet number and particle shape also affected the concentration, implying that axial dispersion and interfacial area are important design parameters.