In one exemplary embodiment, a unit for regenerating a hydrocarbon conversion catalyst for a hydrocarbon conversion zone can generally include passing the hydrocarbon conversion catalyst through, sequentially, a catalyst-disengaging zone having a first atmosphere, an adsorption zone having a second atmosphere, and a regeneration zone including a combustion zone; introducing an inert gas between the first atmosphere and the second atmosphere; and passing a flue gas from the combustion zone to the adsorption zone.