OPTIMAL DISTRIBUTION OF MULTIFUNCTIONAL CATALYSTS IN A PACKED BED REACTOR

The problem of the optimal distribution of two multifunctional catalysts is analyzed. Two methods for obtaining optimal catalyst profiles, an analytic-numeric method and the method of steepest ascent, are compared. Though the analytic-numeric method yields a more accurate solution, the method of steepest ascent is usually easier to apply. Optimal catalyst loading profiles are determined for two cases of commercial interest: selective oxidation of butene and naphtha reforming with bimetallic catalysts- A sequential loading of the bismuth molybdate and the vanadium phosphate catalysis is recommended for low butene concentration levels, while at higher butene levels a mixed loading of the two catalysts may be desirable. For commonly encountered naphtha feedstocks a sequential loading of the Pt-Re and the Pt-Ir catalysts tends to be optimal. These compare well with experimental evidence in the literature.