Fluid catalyst regeneration process and apparatus

A process for regenerating a coke contaminated fluid catalyst, said process including the steps of:

• (a) introducing oxygen containing regeneration gas, coke contaminated fluid catalyst, and cooled recycled regenerated catalyst from a source hereinafter described, into a lower locus of combustion zone maintained at a temperature sufficient for coke oxidation and therein oxidizing coke to produce hot regenerated catalyst and hot flue gas;
• (b) transporting said hot flue gas and said hot regenerated catalyst from an upper locus of said combustion zone into a regenerated catalyst disengaging zone, wherein said hot regenerated catalyst is separated from said flue gas and collected in a first collection zone at a lower locus of said disengaging zone as a fluidized bed the surface of which is at a first level;
• (c) transporting a portion of said hot regenerated catalyst from said first collection zone by means of downward gravity flow to the lower locus of a cooling zone separate from and below said disengaging zone wherein said cooling zone heat is withdrawn from said hot regenerated catalyst by indirect heat exchange with a cooling fluid enclosed in a heat exchange means inserted into said cooling zone to produce cool regenerated catalyst, said catalyst being maintained in said cooling zone as a dense phase fluidized bed by passing a fluidizing gas upwardly through such bed;
• (d) withdrawing said cool regenerated catalyst from said cooling zone by means of said catalyst overflowing from said cooling zone into a second collection zone at a lower locus of said disengaging zone, said catalyst being collected in said second collection zone as a dense phase fluidized bed the surface of which is at a second level, said first level being of sufficient height above said second level to provide the driving force required to circulate said catalyst through said cooling zone and;
• (e) transporting said catalyst by means of downward gravity flow from said second collection zone to said lower locus of said combustion zone as said cooled recycled regenerated catalyst.