Abstract: An improved process and regenerator suited for the regeneration of coke contaminated catalysts. Such coke contaminated catalysts are formed during the fluidized bed cracking of crude oil derived feed stocks into motor fuels and other distillates. The improved regenerator is equipped with an upper combustion zone for oxidizing carbon present on the catalyst to carbon dioxide and water and a lower cooling zone wherein hot catalyst is transported from the upper combustion zone to the lower cooling zone through a substantially vertical conduit for indirect heat exchange contact with a coolant for reducing the temperature thereof. The cooled catalyst is returned to the upper combustion zone. Air is used to fluidize the cracking catalyst in the lower cooling zone and is vented to the upper combustion zone and used as a source of oxidizing gas.