Method and apparatus for the recovery of energy from the spent gases of a catalytic cracking unit

Claim 1

A METHOD FOR THE RECOVERY OF ENERGY FROM HOT EXIT GASES FROM THE REGENERATOR OF A CATALYTIC CRACKING UNIT WHICH COMPRISES: (A) MAINTAINING A BED OF FINELY DIVIDED CRACKING CATALYST BEARING CARBONACEOUS MATTER AS A FLUIDIZED BED WITHIN A CONFINED REGENERATOR BY PASSING REGENERATION AIR AT SUPERATMOSPHERIC PRESSURE UPWARDLY THROUGH THE BED AND BURNING SAID CARBONACEOUS MATTER, THEREBY PRODUCING HOT EXIT GAS WHICH CONTAINS A SMALL AMOUNT OF CARBON MONOXIDE, (B) SEPARATING THE CATALYST FROM SAID EXIT GAS WITHOUT SUBSTANTIAL REDUCTION IN TEMPERATURE OR PRESSURE, (C) FLOWING THE RESIDUAL EXIT GAS AT SUBSTANTIALLY SAID SUPERATMOSPHERIC PRESSURE TO A HIGH-PRESSURE STEAM BOILER, THEREIN BURNING THE SAID CARBON MONOXIDE BY ADDING SUPPLEMENTAL AIR AND AUXILIARY FUEL, TRANSFERRING HEAT FROM THE RESULTING HOT GAS TO HEATTRANSFER ELEMENTS OF THE BOILER, AND DISCHARGE SAID GAS AT SUBSTANTIALLY SAID SUPERATMOSPHERIC PRESSURE FROM THE BOILER, (D) CONTROLLING THE TEMPERATURE OF SAID DISCHARGED GAS INDEPENDENTLY OF THE COMBUSTION WITHIN SAID BOILER BY (1) MEASURING THE TEMPERATURE OF THE GAS CHARGED TO THE TURBINE-COMPRESSOR SET IN STEP (E) HEREOF, (2) BURNING ADDITIONAL FUEL AND THEREBY HEATING SAID GAS AFTER TRANSFERRING HEAT TO SAID HEATTRANSFER ELEMENTS, AND (3) CONTROLLING THE AMOUNT OF ADDITIONAL FUEL BURNT IN ACCORDANCE WITH SAID MEASURED TEMPERATURE, (E) EXPANDING THE GAS, AFTER SAID TEMPERATURE CONTROL, IN AT LEAST ONE GAS TURBINE-COMPRESSOR SET AND COMPRESSING AIR THEREBY, AND (F) SUPPLYING AT LEAST SOME OF THE COMPRESSED AIR TO SAID REGENERATOR AS REGENERATION AIR.

Claim 2

A METHOD FOR THE RECOVERY OF ENERGY FROM HOT EXIT GASES FROM THE REGENERATOR OF A CATALYTIC CRACKING UNIT WHICH COMPRISES: (A) MAINTAINING A BED OF FINELY DIVIDED CRACKING CATALYST BEARING CARBONACEOUS MATTER AS A FLUIDIZED BED WITHIN A CONFINED REGENERATOR BY PASSING REGENERATION AIR AT SUPERATMOSPHERIC PRESSURE UPWARDLY THROUGH THE BED AND BURNING SAID CARBONACEOUS MATTER, THEREBY PRODUCING HOT EXIT GAS WHICH CONTAINS A SMALL AMOUNT OF CARBON MONOXIDE, (B) SEPARATING THE CATALYST FROM SAID EXIT GAS WITHOUT SUBSTANTIAL REDUCTION IN TEMPERATURE OR PRESSURE, (C) FLOWING THE RESIDUAL EXIT GAS AT SUBSTANTIALLY SAID SUPERATMOSPHERIC PRESSURE TO A HIGH-PRESSURE STEAM BOILER, THEREIN BURNING THE SAID CARBON MONOXIDE BY ADDING SUPPLEMENTAL AIR AND AUXILIARY FUEL, TRANSFERRING HEAT FROM THE RESULTING HOT GAS TO HEATTRANSFER ELEMENTS OF THE BOILER, AND DISCHARGE SAID GAS AT SUBSTANTIALLY SAID SUPERATMOSPHERIC PRESSURE FROM THE BOILER, (D) CONTROLLING THE TEMPERATURE OF SAID DISCHARGED GAS INDEPENDENTLY OF THE COMBUSTION WITHIN SAID BOILER BY (1) MEASURING THE TEMPERATURE OF THE GAS CHARGED TO THE TURBINE-COMPRESSOR SET IN STEP (E) HEREOF, (2) BURNING ADDITIONAL FUEL AND THEREBY HEATING SAID GAS AFTER TRANSFERRING HEAT TO SAID HEATTRANSFER ELEMENTS, AND (3) CONTROLLING THE AMOUNT OF ADDITIONAL FUEL BURNT IN ACCORDANCE WITH SAID MEASURED TEMPERATURE, (E) EXPANDING THE GAS, AFTER SAID TEMPERATURE CONTROL, IN AT LEAST ONE GAS TURBINE-COMPRESSOR SET AND COMPRESSING AIR THEREBY, AND (F) SUPPLYING AT LEAST SOME OF THE COMPRESSED AIR TO SAID REGENERATOR AS REGENERATION AIR.