The Role of Rare Earths in Fluid Catalytic Cracking (FCC) Catalyst

Rare earth oxides enhance catalyst activity and prevent the loss of acid sites during the FCC unit operation, especially when feed with high metal content is used. This chapter reviews the effects of rare earth elements on the structure, activity, and stability of FCC catalysts. It also looks into the mechanism of catalyst deactivation by vanadium and how rare earths are used to combat this. The objective is to elucidate the interaction of vanadium species with the zeolite component of the FCC catalysts and to show the role of rare earth elements in countering the deleterious effects of vanadium. The recycle of spent FCC catalyst with a focus on rare earth element recovery is also outlined.