The parameter domain of convective instability of the adiabatic packed‐bed reactor

Abstract

Packed‐bed reactors (PBR) can exhibit two types of convective instability: dynamic or differential‐flow instability (DIFI), and static instability, commonly referred to as parametric sensitivity (PS). DIFI and PS both amplify external perturbations and may result in reactor temperature excursions that can damage the product and the reactor itself. The convective character of DIFI and PS manifests itself physically in the return of the reactor to its initial stationary state after the external perturbation subsides. In this paper we describe a method of mapping the convective instability domain in the parameter space of a PBR and illustrate its application using a simple reactor model involving the standard exothermic reaction A → B + heat.

Transient Flow Rate Ramps for Methanation of Carbon Dioxide in an Adiabatic Fixed‐Bed Recycle Reactor

“…On contrary, fixed‐bed reactors—operated under nonisothermal conditions—can encounter dynamic (differential flow instability, DIFI) and static (parametric sensitivity, PS) instabilities. Both amplify external perturbations and may result in reactor temperatures causing product deterioration, selectivity loss, or a thermal runaway …”

“…Both amplify external perturbations and may result in reactor temperatures causing product deterioration, selectivity loss, or a thermal runaway. [18] The PS means that "small changes in one or more of the reactor input parameters lead to much larger changes in the output variables." [19] Multiple steady-states can be expected in the PS regime [20] known from the ignition and extinction behavior attributed to polytropic reactors.…”