PROCESSO DE RESTAURACAO DA ACTIVIDADE DE UM CATALISADOR

This invention comprises improvements to processes for the catalytic cracking of hydrocarbon feedstocks. One such improvement to catalytic cracking processes provides compositions comprising metals passivating agents having an increased degree of stability. These compositions comprise aqueous suspensions of antimony by vinyl copolymers, aqueous suspensions of antimony oxide by diesters of phosphoric acid, or aqueous suspensions of antimony oxide by cellulose derivatives. Another improvement to catalytic cracking processes provides a process for reducing the viscosity of liquid suspensions of metals passivating agents without substantially reducing the stability of the liquid suspension by the utilization of at least two different particle ranges of metals passivating agents. A further improvement to catalytic cracking processes provides an efficient utilization of metals passivating agents by introducing the selected agent into the catalyst regeneration cycle of a catalytic cracking unit.