US 11,674,090 B1
Energy optimization in fluid catalytic cracking and dehydrogenation units
Jan De Ren, Bracknell (GB); William J. Whyman, Collinsville, OK (US); Richard A. Johnson, II, Algonquin, IL (US); Jeffrey M. Knight, Downers Grove, IL (US); Anil Nivrutti Pachpande, Gurugram (IN); and Andrew J. Craig, Glen Ellyn, IL (US)
Assigned to Honeywell International Inc., Charlotte, NC (US)
Filed by Honeywell International Inc., Charlotte, NC (US)
Filed on Nov. 30, 2021, as Appl. No. 17/538,411.
Int. Cl. C10G 67/04 (2006.01); C10G 11/18 (2006.01); F01N 3/20 (2006.01)
CPC C10G 11/185 (2013.01) [F01N 3/2066 (2013.01); C10G 2300/207 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for treating flue gas from a fluid catalytic cracking (FCC) unit catalyst regenerator, an FCC unit catalyst regenerator CO-combustor, or a dehydrogenation unit catalyst regenerator comprising:
transferring heat from flue gas stream from the FCC unit catalyst regenerator, the FCC unit catalyst regenerator CO-combustor, or the dehydrogenation reactor to a boiler feed water stream in a heat recovery steam generator (HRSG) to form a cooled flue gas stream and a steam stream, wherein the flue gas stream comprises one or more of sulfur-containing compounds, nitrogen-containing compounds, and catalyst fines and wherein the flue gas stream has a temperature in a range of 200° C. to 290° C., the temperature being above a dew point of water and an acid comprising sulfuric acid and/or sulfur trioxide;
reacting one or more of the sulfur-containing compounds, the nitrogen-containing compounds, or both in the cooled flue gas stream from the HRSG with a reactant in a decontamination reactor, wherein the reactant comprises one or more of NaHCO3, NaOH, KOH to form a reactor effluent stream comprising one or more of Na2SO4, NaNO3, NaNO2, Na2CO3, K2SO4, and KNO3 while maintaining the reactor effluent stream at a temperature in a range of 200° C. to 290° C.;
filtering the reactor effluent stream to remove at least one of the Na2SO4, NaNO3, NaNO2, Na2CO3, K2SO4, KNO3 and the catalyst fines and form a filtered reactor effluent stream; and
pre-heating a combustion air stream or the boiler feed water stream with the filtered reactor effluent stream thereby reducing the temperature to 130° C. to 200° C. and staying above the dew point of water.