| 摘要 |
A method for passivating the adverse catalytic effects of metal contaminants, such as nickel, vanadium and iron, which become deposited on cracking catalyst is disclosed. A passivation promoter selected from the group consisting of cadmium, germanium, indium, tellurium and zinc is deposited on the catalyst and the catalyst is passed through a passivation zone having a reducing atmosphere maintained at an elevated temperature to decrease the adverse catalytic effects of the metal contaminants. The present method is of particular utility where the residence time of the cracking catalyst in the passivation zone is relatively short.
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