A MODEL OF CATALYTIC CRACKING CONVERSION IN FIXED MOVING AND FLUID-BED REACTORS

The conversion of gas oils during catalytic cracking may be represented by a pseudo-second-order reaction coupled with a first-order decay of the catalyst activity. For plug flow in the gas phase and for vapor residence times small in relation to the catalyst decay times, it was possible to solve the defining partial differential equation to yield isothermal models for conversion in fixed, fluid, and moving bed reactors. Comparisons of these models and cracking results show that they successfully represent the experimental data over wide ranges of operating conditions. The models are presented in terms of two dimensionless groups: an extent of reaction group and an extent of catalyst decay group. Comparison of various reactor types simply becomes a comparison of the appropriate dimensionless groups. © 1968, American Chemical Society. All rights reserved.