A cogeneration process is provided for a regenerator in a fluidized catalytic cracking system having a reactor and a regenerator. The process includes introducing flue gas from the regenerator into a heating unit to produce heated flue gas at a temperature of at least about 900° C. The heated flue gas is introduced into an expander. Steam is heated with the heated flue gas to produce heated steam. The heated steam is introduced into a turbine to extract energy from the steam.