Process for producing a synthesis gas product containing hydrogen

Abstract

1. A process for producing a synthesis gas product by an endothermic reaction of a feed stream, the process comprising the steps of: providing an ammonia fuel stream; conducting a first combustion in which the ammonia fuel stream is partially calcined to generate a flue gas stream comprising heat and an uncalcined portion of the ammonia fuel stream; providing heat from the first combustion and from the flue gas stream to an endothermic reaction, thereby obtaining a cooled flue gas stream; conducting a second combustion of the cooled flue gas stream in which the uncalcined portion of the ammonia fuel stream is calcined; and providing heat from the second combustion to the endothermic reaction.

Description

[Technical Field]

[0001] The field of the invention is that of processes for producing a synthesis gas product. The invention particularly relates to a process for producing a synthesis gas product comprising hydrogen by endothermic reaction of a feed stream. The invention also relates to a furnace for producing a synthesis gas product comprising hydrogen by endothermic reaction of a feed stream. [Background technology]

[0002] The endothermic reaction of the feed stream to produce a synthesis gas product containing hydrogen can be carried out in a catalytic unit at high temperatures, e.g., 400°C to 800°C. Such units typically include a metal shell, a catalyst, and an external heat source. To keep the CO2 emissions of the process as low as possible, the external heat source is provided by the simple combustion of an ammonia fuel stream in a furnace. The process requires large amounts of heat and energy.

[0003] A drawback of such a process is that ammonia fuel has poor combustion characteristics, such as low flame speed, small explosion window, and high ignition temperature, which lead to flame instability and undesirable emissions such as unconverted ammonia and nitrogen oxides (NOx). Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention proposes a process for producing a synthesis gas product containing hydrogen from a feedstock that improves the combustion of ammonia fuel.

[0005] In this disclosure, the ammonia fuel stream is also referred to as ammonia fuel. [Means for solving the problem]

[0006] To this end, the present invention proposes a process for producing a synthesis gas product, in particular a synthesis gas product comprising hydrogen, by endothermic reaction of a feed stream, said process comprising the following steps: providing an ammonia fuel stream; conducting a first combustion, wherein the ammonia fuel stream is partially combusted to generate heat and a flue gas stream comprising an uncombusted portion of the uncombusted ammonia fuel stream; providing heat from the first combustion and from the flue gas stream to an endothermic reaction, thereby obtaining a cooled flue gas stream; conducting a second combustion of the cooled exhaust gas stream, wherein an uncalcined portion of the ammonia fuel stream is combusted; providing heat from the second combustion to the endothermic reaction; Includes.

[0007] The first combustion occurs during a first combustion step and the second combustion occurs during a second combustion step.

[0008] The secondary combustion of the uncalcined portion of the ammonia fuel stream allows for complete combustion of the ammonia fuel stream, improving heat and minimizing emissions of NOx and unconverted ammonia.

[0009] According to one aspect of the invention, the feed stream is an ammonia feed stream and the endothermic reaction is an endothermic decomposition reaction of the ammonia feed stream.

[0010] According to one aspect of the invention, the endothermic reaction is carried out catalytically over a catalyst that promotes the endothermic reaction.

[0011] According to one aspect of the invention, the process includes conditioning the ammonia fuel stream, such as vaporizing the ammonia fuel stream, said conditioning the ammonia fuel stream following the step of providing the ammonia fuel stream.

[0012] According to one aspect of the invention, the second combustion is carried out non-catalytically, in other words, in the absence of any catalyst to promote the oxidation of ammonia.

[0013] According to one aspect of the invention, the first combustion is carried out non-catalytically.

[0014] According to one aspect of the invention, the primary combustion is carried out in at least one baking device, the term baking device indicating that the secondary combustion is carried out from the formation of a flame.

[0015] According to one aspect of the invention, the first and second combustions are carried out in a calcination chamber in which heat from the first and second combustions is provided to an endothermic reaction, and specifically, the ammonia fuel stream and the flue gas stream circulate within a circulation channel of the calcination chamber.

[0016] Non-catalytic combustion of ammonia converts ammonia to nitrogen (N2) and water (H2O) with small amounts of nitrogen oxides.

[0017] According to one aspect of the invention, the first combustion is achieved by delivering a first oxidant stream to an ammonia fuel stream, and the second combustion is achieved by delivering a second oxidant stream to a non-combusting portion of the ammonia fuel stream.

[0018] According to one aspect of the invention, the first oxidant comprises first combustion air and the second oxidant comprises second combustion air.

[0019] According to one aspect of the invention, a first combustion occurs in a first combustion zone of a calcination chamber, a second combustion occurs in a second combustion zone of the calcination chamber, and an exhaust gas stream generated by the first combustion of the ammonia fuel in the first combustion zone flows to the second combustion zone for the second combustion step.

[0020] According to one aspect of the invention, a first combustion zone is located within a first combustion chamber of a calcination chamber and a second combustion zone is located within a second combustion chamber of the calcination chamber, the combustion chambers being fluidly connected by a portion of a circulation channel.

[0021] According to one aspect of the invention, a common oxidant stream is provided by a common distribution manifold, which is then split into a first oxidant stream and a second oxidant stream.

[0022] According to one aspect of the invention, a common oxidant stream is divided into a first oxidant stream and a second oxidant stream by a flow separator, such as a valve, plate, orifice, or opening.

[0023] According to one aspect of the invention, a first oxidant stream is supplied to a first combustion zone by a dedicated first distribution manifold, and a second oxidant stream is supplied to a second combustion zone by a dedicated second distribution manifold.

[0024] According to one aspect of the invention, a common oxidant stream is split into a first oxidant stream and a second oxidant stream upstream of the first and second distribution manifolds in the direction of circulation of the oxidant stream.

[0025] According to one aspect of the invention, a second oxidant stream is fed downstream of a first oxidant stream in the direction of circulation of the ammonia fuel or exhaust gas stream. The exhaust gas stream is generated by a first combustion of the ammonia fuel. The exhaust gas stream comprises the uncombusted portion of the ammonia fuel gas stream after the first combustion and combustion products of the first combustion, i.e., nitrogen and water.

[0026] According to one aspect of the invention, a first oxidant flow is dispensed into a circulation channel and a second oxidant flow is dispensed into said circulation channel downstream of the first oxidant flow in the direction of circulation of the ammonia fuel flow.

[0027] According to one aspect of the invention, the second oxidant stream and the first oxidant stream have the same composition.

[0028] According to one aspect of the invention, the second oxidant stream and the first oxidant stream have different compositions.

[0029] According to one aspect of the invention, the process includes controlling a first oxidant flow to reach a near stochiometric value for the first combustion.

[0030] According to one aspect of the invention, the first combustion is carried out at a lambda value comprised between 0.9 and 1.1, preferably between 0.95 and 1.03, the lambda value being the mass ratio between oxidizer and fuel during combustion.

[0031] According to one aspect of the invention, the process includes controlling the second oxidant flow.

[0032] According to one aspect of the invention, the second combustion is carried out at a lambda value of at least one.

[0033] According to one aspect of the invention, the process includes the step of controlling the second oxidant flow to combust all of the uncalcined portion of the ammonia.

[0034] According to one aspect of the invention, the second combustion step results in combustion of at least 90% of the exhaust gas stream, preferably 100% of the exhaust gas stream.

[0035] According to one aspect of the invention, the second distribution manifold includes a plurality of conduits, all of which are centrally controlled, i.e., the conduits are not individually controlled.

[0036] According to one aspect of the invention, a process includes providing a feed stream.

[0037] According to one aspect of the invention, the process includes conditioning the feed stream, said conditioning step following the step of providing the feed stream, thus obtaining a conditioned feed stream.

[0038] According to one aspect of the present invention, an endothermic reaction converts the conditioned feed stream into a synthesis gas product, specifically a synthesis gas product comprising hydrogen.

[0039] According to one aspect of the invention, the synthesis gas product comprises hydrogen and nitrogen. Specifically, the synthesis gas product also comprises an unconverted portion of the ammonia feed stream. In other words, the synthesis gas product comprises hydrogen, nitrogen, and an unconverted portion of the ammonia feed stream that is not converted by the endothermic decomposition reaction of the ammonia feed stream.

[0040] According to one aspect of the invention, the process includes releasing the synthesis gas product.

[0041] According to one aspect of the invention, the process includes, following the step of releasing said synthesis gas product, a step of treating the synthesis gas product. The treating step can be, for example, a purification step.

[0042] According to one aspect of the invention, the step of processing the synthesis gas product is a purification step, said purification step using methods such as pressure swing adsorption (acronym PSA), cryogenic separation, membrane, temperature swing adsorption (acronym TSA).

[0043] According to one aspect of the invention, the step of conditioning the feed stream includes vaporizing the feed stream (thereby obtaining a gaseous feed stream), preheating and / or superheating the feed stream.

[0044] According to one aspect of the invention, heat for vaporizing, preheating and / or heating during the step of conditioning the feed stream is provided by a combustion step carried out in a calcination chamber.

[0045] The present invention also relates to a furnace for producing a synthesis gas product, particularly a synthesis gas product comprising hydrogen, by endothermic reaction of a feed stream, said furnace comprising: a firing chamber including at least one burner arranged to combust an ammonia fuel stream; at least one reactor configured to produce a synthesis gas product, particularly a synthesis gas product comprising hydrogen, by endothermic reaction of a feed stream, said reactor being positioned to be heated by a calcination chamber; a first distribution manifold configured to deliver a first oxidant stream to the calcination chamber for calcining a portion of the ammonia fuel stream and to generate an exhaust gas stream including an uncalcined portion of the ammonia; a second distribution manifold configured to deliver a second oxidant stream to the calcination chamber for combusting the uncalcined ammonia; Includes.

[0046] Such furnaces can improve combustion of the ammonia fuel stream and reduce emissions of NOx and uncalcined ammonia.

[0047] According to one aspect of the invention, the first oxidant comprises first combustion air and the second oxidant comprises second combustion air.

[0048] In one aspect of the invention, the calcination chamber includes a first combustion zone and a second combustion zone, said combustion zones being fluidly connected to one another.

[0049] In one aspect of the invention, a first combustion zone is configured to calcine an ammonia fuel stream in a first combustion, thereby generating heat and a flue gas stream, and a second combustion zone is configured to calcine an uncalcined portion of the ammonia fuel stream in a second combustion, the first and second combustion zones being fluidly connected to one another.

[0050] In one aspect of the invention, the second combustion zone is located within the calcination chamber downstream of the first combustion zone in the direction of circulation of the fuel and flue gas flows.

[0051] In one aspect of the invention, the calcination chamber includes a circulation channel, the circulation channel being arranged to circulate an ammonia fuel stream and a flue gas stream.

[0052] In one aspect of the invention, a first distribution manifold is positioned to dispense a first oxidant into the circulation channel, and a second distribution manifold is positioned to dispense a second oxidant into the circulation channel downstream of the dispensing of the first oxidant flow in the direction of circulation of the ammonia fuel flow.

[0053] In one aspect of the invention, the furnace includes at least one flue gas exhaust conduit, such as a flue gas exhaust tunnel having a flue gas inlet, for collecting a flue gas stream from a first combustion of an ammonia fuel stream, the flue gas exhaust conduit configured to exhaust the flue gas from the furnace. Specifically, a portion of the flue gas exhaust conduit extends inside the calcination chamber in the second combustion zone, and the flue gas inlet is disposed on the portion of the flue gas exhaust conduit.

[0054] In one aspect of the invention, a second manifold is positioned to distribute a second oxidant flow to the exhaust gas exhaust conduit upstream of the flue gas intake.

[0055] In one aspect of the invention, the furnace includes a stream separator configured to divide a common oxidant stream into a first oxidant stream and a second oxidant stream.

[0056] In one aspect of the invention, the flow separator is configured to control the second oxidant flow circulating through the second distribution manifold.

[0057] In one aspect of the invention, the first distribution manifold and the second distribution manifold are both fluidly connected to a flow separator.

[0058] In one aspect of the invention, the first distribution manifold and the second distribution manifold are fluidly connected together only by a flow separator.

[0059] According to one aspect of the invention, a flow separator is located upstream of the first and second distribution manifolds.

[0060] In one aspect of the invention, the flow separator is a valve, for example a manual valve or an automatic valve.

[0061] In one aspect of the invention, the second distribution manifold includes a plurality of conduits, all of which are arranged for centralized control.

[0062] According to one aspect of the invention, a furnace includes a plurality of reactors and a plurality of burners arranged for an endothermic reaction.

[0063] According to one aspect of the invention, the reactors are fluidly arranged parallel to one another.

[0064] Further features, details and advantages of the invention will become more apparent upon reading the description given below and with reference to the drawings. [Brief explanation of the drawings]

[0065] [Figure 1] FIG. 1 is a schematic diagram of the process of the present invention. [Figure 2] FIG. 2 is a schematic diagram of a furnace of the present invention. [Figure 3] FIG. 3 is a schematic diagram of a furnace reactor of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0066] It should first be noted that the drawings disclose the invention in detail as it is put into practice, and said drawings may of course serve to more clearly define the invention as needed.

[0067] 1 illustrates a process 100 for producing a synthesis gas product containing hydrogen by endothermic decomposition of an ammonia feed stream. However, it should be noted that the present invention encompasses all types of endothermic reactions, such as steam methane reforming. By "synthesis gas product" we mean a gas product synthesized by a chemical reaction carried out in any endothermic process, such as steam methane reforming, ammonia cracking, or methanol cracking.

[0068] The process includes the following steps:

[0069] The present invention comprises the following steps: providing an ammonia feed stream 101 comprising ammonia; providing an ammonia fuel containing ammonia; performing a first combustion 105 in which the ammonia fuel stream is partially calcined to generate heat and a flue gas stream comprising an uncalcined portion of the ammonia fuel stream; providing heat 112 from the first combustion 105 and from the flue gas stream to an endothermic decomposition reaction, thereby obtaining a cooled flue gas stream; performing a second combustion 106 of the cooled exhaust gas stream, in which the uncalcined portion of the ammonia fuel stream is calcined; providing heat 107 to the endothermic decomposition reaction 103 from the second combustion 106; We propose a process including:

[0070] The process also includes the following steps: conditioning the ammonia feed stream 102; Releasing the synthesis gas product 108; Processing of synthetic gas products 109 Includes.

[0071] Steps 101-108 and 110-112 are carried out in a furnace for producing a synthesis gas product containing hydrogen by endothermic decomposition of an ammonia feed stream (see FIG. 2).

[0072] Here, the conditioning step 102 is, for example but not limited to, a vaporization step of the ammonia feed stream.

[0073] Catalytic conversion 103 is the decomposition reaction of the ammonia feed stream, which is an endothermic reaction requiring heat. Catalytic conversion occurs in the presence of an active catalyst that promotes the endothermic decomposition reaction of the ammonia feed stream when heat is provided to the catalytic conversion.

[0074] The process includes two combustion steps 105 and 106. To accomplish these two combustions, an ammonia fuel stream is first provided to the combustion zone of furnace 104. The ammonia fuel stream is distributed to the combustion zone by ammonia fuel manifold 9.

[0075] A first oxidant stream, here a first combustion air stream, is provided 110 by a first distribution manifold. The provided first combustion air stream is fed to an ammonia fuel stream to achieve a first combustion 105. A portion of the ammonia fuel stream remains uncombusted; in other words, this first combustion 105 is the combustion of a portion of the ammonia fuel stream. Once the first combustion is achieved, an exhaust gas stream from the first combustion 105 is collected by an exhaust gas exhaust conduit, such as a tunnel, for discharge.

[0076] A second combustion 106 is achieved downstream of this first combustion 105. To effect the second combustion 106, a second oxidant stream, here a second combustion air stream 111, is provided by a second distribution manifold. The second combustion air stream is fed to a non-combustion portion of the ammonia fuel gas stream, which non-combustion portion is combusted during the second combustion 106. The second distribution manifold is positioned to distribute the second combustion air stream into the flue gas exhaust conduit upstream of the flue gas intake.

[0077] The lambda value is the ratio of the oxidizer, here the combustion air flow, divided by the stochiometric combustion air flow associated with the fuel composition and fuel flow. The first combustion is carried out at a lambda value comprised between 0.9 and 1.1, preferably between 0.95 and 1.03. The second combustion is carried out at a lambda value of at least 1. The second combustion is therefore carried out under superstochiometric conditions, resulting in a better combustion yield.

[0078] The heat from these two combustions is transferred from this combustion zone to the catalytic endothermic cracking reaction by conversion and induction.

[0079] Following the catalytic endothermic decomposition reaction, the synthesis gas product comprises hydrogen, nitrogen, and optionally a portion of the unconverted ammonia feedstock. In this particular embodiment, where the synthesis gas product is the product of the endothermic decomposition reaction of ammonia, "synthesis gas product" refers to the cracked gas product comprising hydrogen and nitrogen.

[0080] The process includes a step 107 of releasing a synthesis gas product. During this step, the synthesis gas product is released from the reactor where the endothermic decomposition reaction occurs, where it is optionally treated in a treatment step 108. For example, this treatment step can be a purification step, which uses classical purification methods such as PSA, cryogenic separation, membrane, TSA, etc. Thus, purified hydrogen is obtained.

[0081] FIG. 2 is a schematic diagram of a furnace 1 for producing a synthesis gas product comprising hydrogen by endothermic decomposition of an ammonia feed stream in accordance with the present invention.

[0082] Furnace 1 includes a plurality of reactors 7 configured to produce a synthesis gas product, including hydrogen, here by endothermic decomposition of an ammonia feed stream. Reactors 7 are shown in Figure 3, where the reactors are fluidly arranged parallel to one another.

[0083] Reactor 7 is fed with an ammonia feed stream by ammonia feed stream manifold 6. The ammonia feed stream comes from ammonia feed source 15 exiting furnace 1.

[0084] The synthesis gas product, including hydrogen, is collected by collection conduit 10 .

[0085] Each reactor 7 is arranged inside a calcination chamber 8 contained within the furnace 1 .

[0086] The calcination chamber 8 includes a first combustion zone 16, here configured to perform a first combustion, and a second combustion zone 17, here configured to perform a second combustion. The first and second combustion zones 16, 17 are fluidly connected. The first and second combustion zones 16, 17 are fed by ammonia fuel streams via fuel channels 9. The ammonia fuel stream is derived from a source of ammonia fuel 14 stream.

[0087] A common oxidant stream, here a common combustion air stream, originates from an oxidant source, here a combustion air source 13. The combustion air stream is distributed from said combustion air source 13 through a common distribution manifold 18. The common combustion air stream is divided by a stream separator 2 into a first combustion air stream and a second combustion air stream.

[0088] The first distribution manifold 4 is configured to deliver the first combustion air stream to the ammonia fuel stream. The first distribution manifold 4 extends from the flow separator 2, configured to control the flow rate of the first combustion air stream, to a first combustion zone 16, where a first combustion of the ammonia fuel stream takes place. This first combustion is partial, so that a portion of the ammonia fuel stream remains unburned. From this first combustion, an exhaust gas stream 11 containing a portion of the unburned ammonia is collected by an exhaust gas exhaust conduit 3 and then discharged from the furnace via said exhaust gas exhaust conduit 3.

[0089] Furnace 1 includes a second combustion air stream distribution manifold 5 positioned to distribute the second combustion air stream upstream of the flue gas inlet into flue gas exhaust conduit 3. Second distribution manifold 5 extends from flow separator 2 to a second combustion zone 17 of calcination chamber 8, where the second combustion is performed to combust the uncalcined portion of the ammonia fuel gas stream from the first combustion.

[0090] The flow separator 2 is a valve arranged to divide a common combustion air stream, for example from a combustion air source 13, into a first combustion air stream and a second combustion air stream and to control the flow velocities of the first and second combustion air streams.

[0091] The reactor 7 shown in Figure 3 comprises an outer shell tube, which is pressurized. The outer shell tube contains a reaction chamber 75 in which catalytic conversion of an ammonia feed stream, here an endothermic decomposition reaction, is achieved. The reactor 7 comprises an ammonia feed inlet 71, which is configured to take fluid into the shell tube 72, more precisely the reaction chamber 75.

[0092] Reaction chamber 75 contains a bed of active solid catalyst 76 configured to promote the endothermic decomposition reaction of the ammonia feed stream into a synthesis gas product containing hydrogen. The catalyst may be, for example, a spent bed catalyst or a constructed catalyst. In a preferred embodiment, the catalyst comprises nickel. The ammonia feed stream circulates through the bed of active catalyst 76 where the endothermic decomposition reaction occurs. Because this reaction is only possible at elevated temperatures, heat 73 is provided to reaction chamber 75.

[0093] The catalyst bed 76 is configured to be heated by an external heat source, here heat from the first and second combustions described above.

[0094] The reactor includes an outlet 77 for a synthesis gas product comprising hydrogen.

Claims

1. A process (100) for producing a synthesis gas product by endothermic reaction of a feed stream, comprising the steps of: providing an ammonia fuel stream (101); conducting a first combustion (105) in which the ammonia fuel stream is partially calcined to generate heat and a flue gas stream comprising an uncalcined portion of the uncalcined ammonia fuel stream; providing heat (112) from said first combustion (105) and from said flue gas stream to said endothermic reaction, thereby obtaining a cooled flue gas stream; performing a second combustion (106) of the cooled exhaust gas stream, wherein an uncalcined portion of the ammonia fuel stream is calcined; providing heat (107) from said second combustion (106) to said endothermic reaction; Step (100).

2. 2. The process (100) of claim 1, wherein the first combustion (105) is effected by delivering a first oxidant stream to the ammonia fuel stream and the second combustion (106) is effected by delivering a second oxidant stream to a non-calcined portion of the ammonia fuel stream.

3. 3. The process (100) of claim 1 or 2, wherein the first combustion and the second combustion occur in a calcination chamber in which heat from the first combustion and the second combustion is provided to the endothermic reaction, the first combustion (105) occurring in a first combustion zone of the calcination chamber, the second combustion occurring in a second combustion zone of the calcination chamber, and the exhaust gas stream generated by the first combustion of the ammonia fuel in the first combustion zone flowing to the second combustion zone for the second combustion step.

4. The process (100) of any one of claims 1 to 3, comprising controlling the first oxidant flow to reach a near stochiometric value for the first combustion.

5. A process (100) according to any one of claims 1 to 4, wherein the first combustion (105) is carried out at a lambda value comprised between 0.9 and 1.1, preferably between 0.95 and 1.

03.

6. The process (100) of any one of claims 1 to 5, wherein the second combustion (106) is performed at a lambda value of at least 1.

7. The process (100) of any one of claims 3 and 1-6, wherein the second oxidant stream is supplied to the second combustion zone by a dedicated second distribution manifold, the second distribution manifold including a plurality of conduits, and all of the conduits are centrally controlled.

8. 1. A furnace (1) for producing a synthesis gas product by endothermic reaction of a feed stream, comprising: a calcination chamber (8) including at least one burner (12) arranged for combustion of an ammonia fuel stream; at least one reactor (7) configured to produce a synthesis gas product by endothermic reaction of a feed stream, said reactor (7) being arranged to be heated by said calcination chamber (8); a first distribution manifold (4) configured to deliver a first oxidant stream to the calcination chamber for calcining a portion of the ammonia feed stream and to generate an exhaust gas stream containing an uncalcined portion of the ammonia; a second distribution manifold (5) configured to deliver a second oxidant stream to the calcination chamber for combusting the uncalcined ammonia; a furnace (1) comprising:

9. 9. The furnace (1) of claim 8, wherein the calcination chamber (8) comprises a first combustion zone (16) and a second combustion zone (17), the combustion zones (16, 17) being fluidly connected to each other, the first combustion zone (16) being configured to combust the ammonia fuel stream in a first combustion, thereby generating heat and the flue gas stream, and the second combustion zone (17) being configured to calcinate an uncalcined portion of the ammonia fuel stream in a second combustion, the first and second combustion zones (16, 17) being fluidly connected to each other.

10. 10. The furnace (1) of claim 8 or 9, wherein the calcination chamber includes a circulation channel, the circulation channel being arranged to circulate the ammonia fuel flow and the flue gas flow, the first distribution manifold being arranged to dispense the first oxidant into the circulation channel, and the second distribution manifold being arranged to dispense the second oxidant into the circulation channel downstream of the first oxidant stream dispense in the direction of the ammonia fuel flow.

11. 11. The furnace (1) of claim 9 or 10, wherein the furnace comprises at least one flue gas exhaust conduit (3), such as a flue gas exhaust tunnel having a flue gas inlet, for collecting the flue gas stream from the first combustion of the ammonia fuel stream, the flue gas exhaust conduit being configured to exhaust the flue gas from the furnace.

12. 12. The furnace (1) according to claim 11, wherein a portion of the exhaust gas exhaust conduit (3) extends inside the firing chamber (8) within the second combustion zone (17), and the flue gas intake is arranged on the portion of the exhaust gas exhaust conduit (3).

13. The furnace (1) according to any one of claims 8 to 12, wherein the furnace comprises a stream separator (2) configured to split a common oxidant stream into the first oxidant stream and the second oxidant stream.

14. The furnace (1) according to any one of claims 8 to 13, wherein the first distribution manifold (4) and the second distribution manifold (5) are both fluidly connected to the flow separator (2).

15. A furnace according to any one of claims 8 to 14, wherein said second distribution manifold (5) comprises a plurality of conduits, all of said conduits being arranged to have centralized control.

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