Adiabatic reactors stability

Activation energy, stability in trickle-bed reactors, 76 Activation overpotential, cross-flow monolith fuel cell reactor, 182 Activity balance, deactivation of non-adiabatic packed-bed reactors, 394 Adiabatic reactors stability, 337-58 trickle-bed, safe operation, 61-81 Adsorption equilibrium, countercurrent moving-bed catalytic reactor, 273 Adsorption isotherms, countercurrent moving-bed catalytic reactor, 278,279f... 

As a consequence of this explanation the reaction runaway to total methanation is not a necessary condition for the observed phenomenon. Any simple exothermic two phase reaction in an adiabatic reactor ought to show the same behaviour provided that one phase with a high throughput is used to carry the heat out of the reactor and the flow is suddenly reduced. This will be shown in the following simulation results. Due to problems with the numerical stability of the solution (see Apendix) only a moderate reaction rate will be considered. Reaction parameters are chosen in such a way that in steady state the liquid concentration Cf drops from 4.42 to 3.11 kmol/m3 but the temperature rise is only 3°C (hydrogen in great excess). At t = 0 the uniform flow profile... 

An individual reactor in a train can, of course, run away because of its own internal disturbances, but it can also send disturbances ahead to affect the stability of downstream reactors. If there is no intermediate heat exchange, the train acts like a single adiabatic reactor, subject only to disturbances in its feed. Within the stages there is backmixing, but there is none otherwise. A reactor series can also serve as a model for packed-bed reactors, if the upstream propagation implied by Equation (12) is not realistic. 

Backmixing by axial diffusion, and stability of adiabatic reactors, 344... 

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