EFFECTS OF POISONING ON THE DYNAMICS OF FIXED-BED REACTORS .2. CONSTANT CONVERSION POLICY OF OPERATION

The dynamic behavior of a fixed bed reactor subject to strong, irreversible poisoning has been investigated. In this work, the nature of the reaction and reactor and deactivation characteristics have been incorporated into a study of fixed bed operation at constant conversion. Experiments and simulation results are presented, showing in a severe test that the variable capacity model for chemisorption of thiophene on Ni can explain the results. The constant conversion, temperature increased requirement (TIR) experiment is quite sensitive to the energetics of deactivation and, overall, provides a good measure of the worth of both the reactor simulation model and the approach to poisoning kinetics. Simulation of transients under TIR further illustrates the wavelike propagation of activity and concentration profiles through the bed. These resemble the cyclic operation of part 1 but differ importantly in end-of-bed behavior because of the constant-conversion requirement. Guard-bed behavior is observed but is modified by the constant conversion requirement and concomitant increase in bed temperature. © 1990, American Chemical Society. All rights reserved.