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US 12,203,705 B2Granted
Enhancement of thermochemical regeneration operation
AssigneePraxair Technology, Inc.
InventorsArthur W. Francis, Hisashi Kobayashi, Robert L. Bell, Kuang-Tsai Wu
Life of this patent
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Abstract
A combustion method in which heated flue gas heats a regenerator through which a mixture of fuel and flue gas is then passed to undergo endothermic reactions that produce syngas which is fed into a furnace together with a motive gas stream, wherein fuel is combusted with the motive gas stream to provide heat in alternate cycles.
Claims19
A method of carrying out combustion in a furnace, comprising
- (A) combusting fuel in a furnace to produce gaseous combustion products;
- and
- (B) carrying out the following sequence of steps (1) through (4):
- (1) (i) passing a portion of the gaseous combustion products into and through a cooled first regenerator to heat the first regenerator and cool said portion of the gaseous combustion products,
- (ii) passing at least part of said cooled portion of gaseous combustion products from said first regenerator, and gaseous fuel, into a heated second regenerator and, in the second regenerator, reacting the gaseous combustion products and the gaseous fuel in an endothermic reaction in the second regenerator to form syngas comprising hydrogen and CO,
- (iii) passing said syngas formed in the second regenerator at a velocity less than 50 feet per second into a first duct having an outlet that is connected to the interior of the furnace,
- (iv) injecting at least one stream of motive gas having a velocity of at least 100 feet per second from a first nozzle in the first duct into the syngas in the first duct upstream from the interior of the furnace, thereby entraining the syngas into the motive gas stream in the first duct and forming in the first duct a mixed stream comprising a mixture of the syngas and the motive gas and having a velocity greater than 50 feet per second, and
- (v) passing said mixed stream in the first duct at a velocity of greater than 50 feet per second from said first duct into said furnace and combusting the mixed stream with one or more oxidant streams injected into said furnace;
- and then
- (2) (i) discontinuing the passage of said gaseous fuel into the second regenerator, continuing to pass cooled gaseous combustion products into and through said second regenerator thereby removing said gaseous fuel and syngas from the second regenerator and lowering the concentration of said gaseous fuel and syngas in the second regenerator, feeding fuel and gaseous oxidant out of the first nozzle in the first duct and combusting them to generate heat of combustion which heats the interior of the furnace, and thereafter discontinuing the injection of said gaseous oxidant from said first nozzle in the first duct, so that only said fuel is being passed out of the first nozzle, and combusting said fuel with said one or more oxidant streams injected into said furnace;
- and thereafter
- (ii) discontinuing the flow of said fuel out of the first nozzle into the first duct, and discontinuing combustion of said fuel out of said first nozzle, and discontinuing passage of gaseous combustion products from the furnace through the first regenerator;
- and then
- (3) (i) passing a portion of the gaseous combustion products into and through a cooled second regenerator to heat the second regenerator and cool said portion of the gaseous combustion products,
- (ii) passing at least part of said cooled portion of gaseous combustion products from said second regenerator, and said gaseous fuel, into a heated first regenerator and, in the first regenerator, reacting the gaseous combustion products and the gaseous fuel in an endothermic reaction in the first regenerator to form syngas comprising hydrogen and CO,
- (iii) passing said syngas formed in the first regenerator at a velocity less than 50 feet per second into a second duct having an outlet that is connected to the interior of the furnace,
- (iv) injecting at least one stream of motive gas having a velocity of at least 100 feet per second from a second nozzle in the second duct into the syngas in the second duct upstream from the interior of the furnace, thereby entraining the syngas into the motive gas stream in the second duct and forming in the second duct a mixed stream comprising a mixture of the syngas and the motive gas and having a velocity greater than 50 feet per second, and
- (v) passing said mixed stream in the second duct at a velocity of greater than 50 feet per second from said second duct into said furnace and combusting the mixed stream with one or more oxidant streams injected into said furnace;
- and then
- (4) (i) discontinuing the passage of gaseous fuel into the first regenerator, continuing to pass cooled gaseous combustion products into and through said first regenerator thereby removing fuel and syngas from the first regenerator and lowering the concentration of fuel and syngas in the first regenerator, feeding fuel and gaseous oxidant out of the second nozzle in the second duct and combusting them to generate heat of combustion which heats the interior of the furnace, and thereafter discontinuing the injection of said gaseous oxidant from said second nozzle in the second duct, so that only said fuel is being passed out of the second nozzle, and combusting said fuel with said one or more oxidant streams injected into said furnace;
- and thereafter
- (ii) discontinuing the flow of said fuel out of the second nozzle into the second duct, and discontinuing combustion of said fuel out of said second nozzle, and discontinuing passage of gaseous combustion products from the furnace through the second regenerator;
- and then
- (C) repeating step (B) at least once.
21 more elements
Dependencies are inferred from the claim text.