Fluid catalyst regeneration process and apparatus

Claim 1

A process for regenerating a coke-contaminated fluid catalyst in a fluid catalyst cracking reaction-regeneration unit, said process including the steps of: (a) introducing oxygen-containing regeneration gas, and coke-contaminated fluid catalyst, into a lower locus of a dilute phase combustion zone maintained at a temperature sufficient for coke oxidation and therein oxidizing coke to produce regenerated catalyst and flue gas; (b) transporting said flue gas and said regenerated catalyst from an upper locus of said combustion zone into a regenerated catalyst disengaging zone, wherein said regenerated catalyst is separated from said flue gas and is maintained at a specific maximum quantity of catalyst inventory regardless of the catalyst inventory in said regeneration unit in a dense phase after passage of a portion of said regenerated catalyst to said reaction unit; (c) transporting a required portion of said regenerated catalyst from said disengaging zone to a reaction zone; and (d) recycling within said regeneration unit via at least one internal recycle dipleg means substantially all of the remaining portion of said regenerated catalyst from said disengaging zone downwardly to said lower locus of said dilute phase combustion zone, and maintaining regenerated catalyst inventory in said disengagement zone to a specific maximum amount regardless of the catalyst inventory in said regeneration unit.