Abstract: A process and apparatus for achieving turbulent or fast fluidized bed regeneration of spent FCC catalyst in a bubbling bed regenerator having a stripper mounted over the regenerator and a stripped catalyst standpipe within the regenerator. A closed coke combustor vessel is added to the existing regenerator vessel, and spent catalyst is discharged into the coke combustor and regenerated in a turbulent or fast fluidized bed, and discharged up into a dilute phase transport which preferably encompasses, and is in a countercurrent heat exchange relationship with, the spent catalyst standpipe. Regenerated catalyst is discharged from the dilute phase transport riser, and collected in the bubbling dense bed surrounding the coke combustor. Catalyst may be recycled from the dense bed to the coke combustor for direct contact heat exchange. Catalyst coolers may be used on catalyst recycle lines to the coke combustor, or on the line returning regenerated catalyst to the cracking reactor.