Abstract: The addition of distillation residues to the FCC feedstock leads to increased vanadiumloading on catalyst and the problems in catalyst deactivation.The deactivation process is related tothe destructive attack on the zeolite crystallite by V_2O_5.Formation of low melting pointV_2O_5-USY-Na_2O phases accelerates the diffusion of vanadium through the catalyst.A proposedmechanism,based on accelerated dealumination,is shown in the paper.Comparative vanadiumtrapping performances have been tested for FCC catalysts and the crystalline ABO_3 as an effectivevanadium trap is demonstrated in laboratory tests.

Key words: FCC catalyst, zeolite, vanadium trapping

摘要： The addition of distillation residues to the FCC feedstock leads to increased vanadiumloading on catalyst and the problems in catalyst deactivation.The deactivation process is related tothe destructive attack on the zeolite crystallite by V_2O_5.Formation of low melting pointV_2O_5-USY-Na_2O phases accelerates the diffusion of vanadium through the catalyst.A proposedmechanism,based on accelerated dealumination,is shown in the paper.Comparative vanadiumtrapping performances have been tested for FCC catalysts and the crystalline ABO_3 as an effectivevanadium trap is demonstrated in laboratory tests.

关键词: FCC catalyst;zeolite;vanadium trapping