Fluidized catalytic cracking regeneration process

A process is described herein for regeneration of spent, coke contaminated fluidized cracking catalyst by burning coke therefrom with a molecular oxygen containing regeneration gas in a fluidized dense phase bed, and for burning substantially all carbon monoxide formed to carbon dioxide. A method is provided for establishing a homogeneous dense phase fluidized bed of catalyst undergoing regeneration. Additionally, a method is provided for transferring heat from a dilute phase back to the fluidized dense phase catalyst bed.