Catalytic cracking process

A process for raising the temperature of a dense bed in the regenerator of a catalytic cracking unit to a predetermined level, said unit comprising a cracking section operating in the absence of added hydrogen and a regenerating section in which CO is combusted in the dilute phase, which unit contains a circulating inventory of solid acidic cracking catalyst;

• the improvement which comprises:
• a. circulating with said catalyst 0.01 to 50 ppm, based on total catalyst inventory, of at least one metal of the group consisting of platinum, palladium, iridium, osmium, rhodium, ruthenium, and rhenium;
• b. and causing CO to combust in said dense bed;
• c. thereby raising the dense bed temperature to said predetermined level;
• and
• d. maintaining the dense bed temperature at its predetermined level by monitoring the temperature thereof and adding more of said metal when the temperature falls below a set limit.