In a dehydrogenation process wherein catalyst is regenerated off-stream by use of heated air, at least two reactors are in the regeneration cycle, with regeneration air being heated to regeneration catalyst temperature for introduction into the first reactor, and thereafter being reheated to catalyst regeneration temperature and introduced into the second reactor. Such air may also be employed for preheating feed to the dehydrogenation reactor and/or for steam generation by heating such air to the temperature required for such procedure.