CATALYST SINTERING IN FIXED-BED REACTORS - DEACTIVATION RATE AND THERMAL HISTORY

An experimental study has been carried out of the in situ thermal degradation of a commercial dehydrogenation catalyst in a fixed-bed reactor. The activity of catalyst particles sampled at different reactor positions after several reaction-regeneration cycles has been related to their time-temperature history, according to the following kinetics: -da(o)/dt = 0.147 exp(-73,600/RT)a(o)2.2 The above equation represents the loss of activity under coke-free conditions, that is, activity loss due to sintering. The results of the study show that important differences in catalytic activity can be obtained for different positions of a fixed-bed catalytic reactor after several operation-regeneration cycles.