METHOD FOR SUPPRESSING THE POISONING EFFECTS OF CONTAMINANT METALS ON CRACKING CATALYSTS IN FLUID CATALYTIC CRACKING

摘要

ABSTRACT OF THE DISCLOSUREPoisoning of a cracking catalyst by contaminantmetals such as nickel, vanadium and iron during fluidcatalytic cracking of hydrocarbon charge stock containingthe contaminant metals is suppressed by depositing minoramounts of a bismuth-containing passivating agent on thecatalyst, desirably, a weight ratio of bismuth to nickelequivalents (nickel + 0.2 vanadium + 0.1 iron) of about0.01:1 to about 1:1. The passivating agent can alsocomprise mixtures of compounds of bismuth and antimony,bismuth and tin.