Methods and apparatus for power recovery in fluid catalytic cracking systems

A co-generation apparatus for a regenerator in a fluidized catalytic cracking (FCC) system having a reactor and a regenerator, the apparatus comprising:

• a heating unit, in fluid communication with flue gas from the regenerator, that comprises first, second, and third locations, wherein the second and third locations are positioned apart from the first location, wherein the heating unit receives a flue gas from the regenerator at the first location, an oxygen/fuel gas mixture at the second location which, when combusted forms a hot combustion gas, and wherein the heating unit combines the flue gas and the hot combustion gas at the third location to form a heated flue gas;
• a water or steam source;
• a heat exchanger in fluid communication with the heating unit and the water or steam source that heats the water or steam source with the heated flue gas stream to form a heated steam;
• and
• a steam turbine in fluid communication with the heated steam from the heat exchanger, wherein the steam turbine is configured to generate energy upon entry of the heated steam therein.

A co-generation process for a regenerator in a fluidized catalytic cracking (FCC) system having a reactor and a regenerator, the process comprising the steps of:

• introducing flue gas from the regenerator into a combustion unit at a first location of the combustion unit, and introducing an air/fuel gas mixture into the combustion unit at a second location of the combustion unit apart from the first location;
• combusting the air/fuel gas mixture in the combustion unit at the second location to form a hot combustion gas;
• combining the hot combustion gas and the flue gas at a third location of the combustion unit apart from the first location to produce heated flue gas at a temperature of at least about 875° C. (about 1600° F.);
• expanding the heated flue gas in an expander to form an expanded, heated flue gas, wherein the expander generates electrical energy;
• heating water or steam with the expanded, heated flue gas to produce a heated steam at a pressure of at least about 2.75 MPa (about 27.5 bar);
• and
• introducing the heated steam into a turbine to extract energy in the form of mechanical or electrical energy from the heated steam.