Abstract: A cogeneration system which produces electrical power through the use of an augmented Brayton cycle is disclosed. A pressurized air stream from an industrial source, such as a petroleum refinery, is heated by indirect heat exchange against a turbine effluent stream and is then depressurized in a turbine which drives an electrical generator. Preferably, a high temperature gas stream which also is simultaneously depressurized in the same turbine is admixed into the heated air stream before the air stream enters the turbine. A portion of the air stream may be heated in a supplemental combustion zone rather than by heat exchange.

Abstract: A process is disclosed for recovering mechanical energy from a particle-containing pressurized high temperature gas stream such as the flue gas stream of an FCC regenerator. Heat is removed from the gas stream in two different indirect heat exchangers in series flow and the gas stream is then scrubbed by contact with a liquid to remove entrained particles. The gas stream is then reheated by exchange against itself in the second heat exchanger and depressurized in a power recovery expander which produces useful mechanical energy. The scrubbed gas stream may be further heated in the FCC regenerator or some other high temperature location prior to being depressurized in the power recovery expander.

Abstract: An air supply system for the catalyst regeneration zone of a fluidized catalytic cracking unit also supplies a pressurized air stream to the turbine of an electrical generating plant. The compressor which produces the pressurized air stream is driven by passing the flue gas of the regeneration zone through a power recovery expander. Preferably, the pressurized air stream is first heated by heat exchange against the turbine effluent and then admixed with hot gas from separate turbin-type gas generators prior to being passed into the turbine. This provides a very practical and relatively low-cost cogeneration process.