ESTIMATION OF CATALYST ACTIVITY PROFILES IN FIXED-BED REACTORS WITH DECAYING CATALYSTS

A new scheme is developed to estimate temperature, composition and catalyst activity profiles within a fixed-bed catalytic reactor in which catalyst deactivation may be occurring. As a case study, the partial oxidation of o-xylene to phthalic anhydride is examined. Two coupled estimators are employed, one for the spatially distributed quasi-steady state temperature and composition profiles and the other for the spatially varying dynamic catalyst activity profile. Their efficacy is tested by computer simulation using typical experimental temperature measurements corrupted by noise. Simulation results indicate that the overall scheme is efficient and usable for on-line implementation in full-scale reactors.