Stability of adiabatic packed bed reactors. Effect of flow variations and coupling between the particles

A simple cell model is used for the determination of necessary and sufficient conditions for the stability of an adiabatic fixed bed reactor. These conditions are stronger than those obtained by considering only a perturbation of a single particle. Because of the nonuniqueness of the steady state profiles certain pathological effects can occur when the flow rate of the reactant is changed. Geometric coupling between the particles and heat transfer by radiation give rise to further complexities. Examples are given in which the trends predicted by the models have been observed experimentally by Wicke and Frank-Kamenetskii.