PSEUDOCOMPONENT TEST OF THE RELATIVE UTILIZATION OF FEED COMPONENTS IN FLUID CATALYTIC CRACKING

A pseudocomponent mixture is used to test the relative reactivity of hydrocarbon classes over a range of zeolite catalysts (USY, CREY, Beta, Omega, and ZSM-5) under industrial fluid catalytic cracking (FCC) conditions. The hydrocarbon mixture (32.7% n-hexadecane, 45.3% phenyloctane, 17.3% cyclohexyloctane, and 2.3% 2-methylhexadecane) was chosen to reflect the molecular distribution of n-paraffins, i-paraffins, naphthenes, and aromatics in a standard FCC gas oil feed. Analysis of the cracking results of the hydrocarbon mixture determines relative kinetic reaction rates which are decoupled from deactivation, volume expansion, and some adsorption terms. Each zeolite type cracks the hydrocarbons in the mixture at different relative rates, which reflects differences in competitive adsorption, relative diffusion rates, and acid site strength. The relative reaction rates of the hydrocarbon classes over a given zeolite are a strong determinant of the molecular distribution of the gasoline produced by that zeolite catalyst for both the pseudocomponent mixture and the full gas oil. © 1993 Academic Press, Inc.