Catalyst assembly technology in FCC. Part II: The influence of fresh and contaminant-affected catalyst structure on FCC performance

Historically, great emphasis has been placed on the influence of catalyst c omponents (zeolite, matrix, contaminant traps) on the performance of FCC. A lthough physical qualities such as mesoporosity have been recognized as imp ortant, no significant attention has been paid to the influence of mass tra nsfer barriers caused by various manufacturing processes and those induced by certain contaminants on the performance of FCC catalysts. Such barriers will become increasingly important in short contact time FCC. This paper provides examples of both manufacturing and contaminant induced mass transfer barriers and their influence on process performance. Results from a mathematical model illustrating the influence of such barriers are p resented. Finally, catalyst architectures that better tolerate the effects of contaminant induced barriers are discussed.