Reactor Diameter Impact on Hot Zone Dynamics in an Adiabatic Packed Bed Reactor.

Recent analysis revealed that a pseudohomogeneous model of a uniformly active, adiabatic packed bed reactor can predict formation of stable hot zones in the cross-section of the reactor if the kinetic rate expression can lead to isothermal rate oscillations. This prediction was confirmed by simulations of CO oxidation. We show that hot zone formation in a shallow reactor can be predicted also for C₂H₄ hydrogenation, the kinetic model of which is structurally different from that of CO oxidation. Qualitatively different spatiotemporal temperature patterns may form under the same operating conditions. Their number increases as the reactor diameter is increased. An increase in the reactor diameter increases the time constant of the transversal heat dispersion and decreases the temperature synchronization among points on the same reactor cross-section. The interaction and conjugation among qualitatively different moving temperature patterns can lead to formation of complex motions. [ABSTRACT FROM AUTHOR]