Process and apparatus for enhanced removal of contaminants in fluid catalytic cracking processes

Abstract

Systems for separating a contaminant trapping additive from a cracking catalyst may include a contaminant removal vessel having one or more fluid connections for receiving contaminated cracking catalyst, contaminated contaminant trapping additive, fresh contaminant trapping additive, and a fluidizing gas. In the contaminant removal vessel, the spent catalyst may be contacted with contaminant trapping additive, which may have an average particle size and/or density greater than the cracking catalyst. A separator may be provided for separating an overhead stream from the contaminant removal vessel into a first stream comprising cracking catalyst and lifting gas and a second stream comprising contaminant trapping additive. A recycle line may be used for transferring contaminant trapping additive recovered in the second separator to the contaminant removal vessel, allowing contaminant trapping additive to accumulate in the contaminant removal vessel. A bottoms product line may provide for recovering contaminant trapping additive from the contaminant removal vessel.