Burner for burning a combustible
Patent Information
- Application Number
- PCT/EP2026/056705
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-11
- Filing Date
- 2026-03-11
- Publication Date
- 2026-09-17
Smart Images
Figure EP2026056705_17092026_PF_FP_ABST
Abstract
Description
[0001] Hydrogen Onsite S.L.
[0002] H34628WO
[0003] Burner for burning a combustible
[0004] FIELD OF THE INVENTION
[0005] The present disclosure relates to a system and method for burning a combustible. Specifically, the present disclosure relates to a burner and a vessel system designed for efficient combustion usable for any process requiring an input of heat, such as endothermic reactions, for example ammonia cracking as well as to related methods.
[0006] BACKGROUND OF THE INVENTION
[0007] In the field of industrial combustion systems, it is common to utilize burners to generate heat for various applications, including driving endothermic reactions. Endothermic reactions require an input of energy to proceed, and burners are often employed to provide the necessary thermal energy.
[0008] Known burners typically involve the combustion of various fuels, such as natural gas, oil, or coal, to produce the required heat. These burners are designed aiming at efficiently mixing the fuel with an oxidizer, usually air, to achieve complete combustion and maximize heat output.
[0009] One specific application of industrial burners is in the process of ammonia cracking, where ammonia is decomposed into nitrogen and hydrogen gas. Ammonia cracking is an endothermic reaction that requires a significant amount of heat to proceed. Traditional burners used for this purpose often face challenges related to efficiency, control, and restriction of unwanted emissions. For instance, the combustion of ammonia can produce nitrogen oxides (NOx), which are harmful pollutants. Additionally, achieving a uniform temperature distribution within the combustion chamber is crucial for the efficient cracking of ammonia, but this can be difficult with conventional burner designs.
[0010] Despite the substantial advances in the field of industrial combustion systems, there remains a need for improved burner designs that can more efficiently provide heat for endothermic reactions, such as ammonia cracking, while minimizing emissions and ensuring uniform temperature distribution within the combustion chamber.
[0011] ON 110 986 059 A discloses a waste water incinerator comprising a multi-stage burner and a plurality of fuel injectors and air lines arranged downstream from the burner.SUMMARY OF THE INVENTION
[0012] It is an object of this invention to provide systems that overcomes one or more of the disadvantages of known systems.
[0013] A first aspect of the invention provides a burner for burning a combustible according to claim i. The combustible may be a combustible liquid or a combustible gas, preferably a combustible gas comprising ammonia.
[0014] The burner comprises a multi-section combustion chamber comprising a first section, a second section and a third section. The first section, the second section, and the third section may correspond to fluidly interconnected regions of the combustion chamber with differences in shape, orientation, and / or cross-section with respect to each other.
[0015] The burner may comprise a burner body that surrounds the combustion chamber. The burner body may be made of a refractory material, for example any material known to provide thermal insulation and to withstand very high temperatures of up to more than i.ooo°C, more than i.500°C, like silicon carbide, or even more than 2.ooo°C. The refractory material may be chosen to resist corrosion from ammonia combustion. The refractory material may for example comprise one or more of alumina, zirconia, magnesium oxide, mullite and chromia.
[0016] The burner further comprises a main combustible inlet for feeding the combustible into the combustion chamber, in particular in the first section thereof, and a main comburent inlet for feeding a comburent into the combustion chamber, in particular in the first section thereof. At least one of the main combustible inlet and the main comburent inlet is configured for feeding the combustible or the comburent, respectively, at a first longitudinal position along the combustion chamber. The first longitudinal position is a position along the combustion chamber at which at least one of the combustible and the comburent, possibly both, is / are fed into the combustion chamber for combustion. The first longitudinal position may correspond to a longitudinal end of the combustion chamber but this needs not be the case. The combustible can for example be or comprise ammonia. The comburent can be air and / or comprise oxygen. The "inlets" referred to herein may refer to open ends of conduits for feeding a fluid, preferably a gas, into the combustion chamber.Also arranged in the first section of the combustion chamber at and / or near the first longitudinal position may be an igniting device for igniting the combustible to initiate combustion thereof with the comburent and an optional ignition sensor to detect ignition in the combustion chamber.
[0017] The first section may have a circular cross-section with a diameter decreasing from a first longitudinal end distal from the second section, at which the main combustible inlet and the main comburent inlet may be located, to a second longitudinal end proximal to the second section. Thus, the first section may have a tronco-conical shape, expanding towards the second section.
[0018] The third section comprises a main outlet for outputting a combustion exhaust gas. The third section may have a rectangular cross-section.
[0019] The second section is arranged between the first section and the third section. An input flow of combustible and an input flow of comburent enter the combustion chamber in the first section and the combustion takes place while the mixture of combustion and comburent advances through the second section and on to the third section, where the combustion exhaust gas resulting from the combustion can be output from the combustion chamber through the main outlet. The second section may have a circular cross-section with substantially constant diameter. Thus, the second section may have a substantially cylindrical shape.
[0020] A longitudinal direction of the third section is angled, preferably perpendicular, with respect to a longitudinal direction of the second section. Thus, the combustion chamber may define at least one turn of its longitudinal direction between the second section and the third section. An angle between the longitudinal direction of the third section and the longitudinal direction of the second section may be 90° but may also be smaller or greater than 90° in other configurations.
[0021] A longitudinal direction of the first section may be equal to or different from the longitudinal direction of the second section. Thus a longitudinal direction of the first section may be aligned (with a o° angle) with a longitudinal direction of the second section or maybe angled with respect thereto.In embodiments with more than three sections of the combustion chamber, sections other than the first, second and third section may have a longitudinal direction equal to or different from any of the longitudinal directions of the first, second and third sections.
[0022] Configurations of the burner in which the first and second sections of the combustion chamber are aligned along the longitudinal direction of the second section and perpendicular to a longitudinal direction of the third section may be referred to as L-shaped configurations of the combustion chamber. However, other shapes are also covered by the present invention.
[0023] The second section may be arranged over one longitudinal end of the third section, for example in an L-shaped configuration, but this needs not be the case. Alternative configurations in which the second section is arranged over a middle portion of the third section, a so-called T-shaped configurations, are also encompassed by the present invention.
[0024] A “longitudinal direction” of a given section of the combustion chamber may refer herein to a direction along which reaction gases advance during the combustion. Additionally or alternatively, a “longitudinal direction” of a given section of the combustion chamber may refer herein to direction in which said section of the combustion chamber has a longest extension in space and / or with respect to which the combustion chamber displays a symmetry, such as a rotational symmetry or a mirror symmetry.
[0025] The main combustible inlet and / or the main comburent inlet may be configured for feeding a respective fluid into the combustion chamber in a direction parallel to a longitudinal direction of the first section and possibly of the second section. In other embodiments, the main combustible inlet and / or the main comburent inlet may be configured for feeding a respective fluid into the combustion chamber in a direction angled with respect to the longitudinal direction of the first section and possibly of the second section.
[0026] The second section comprises one or more secondary combustible inlets for feeding a flow of secondary combustible into the combustion chamber at a second longitudinal position along the combustion chamber and one or more secondary comburent inlets for feeding a flow of secondary comburent into the combustion chamber at the second longitudinal position along the combustion chamber.The secondary combustible may be the same as the first combustible or different. For example, if the first combustible is ammonia, the secondary combustible may be a gas comprising ammonia, for example a residual gas from a hydrogen separation process applied to the outcome of an ammonia cracking reaction.
[0027] Likewise, the secondary comburent may be the same as the first comburent or different. For example, the first comburent and the secondary comburent may both be or comprise air.
[0028] The second longitudinal position, at which the secondary flows of the secondary combustible and the secondary comburent are fed into the combustion chamber, is spaced apart and downstream along the longitudinal direction of the second section from the first longitudinal position, at which the flows of the (main) combustible and / or the (main) comburent are fed into the combustion chamber. Such separation between the first and second longitudinal positions was found by the present inventors to contribute to an improved temperature profile within the combustion chamber and to a significant reduction of NOx in the combustion chamber.
[0029] According to an embodiment, a longitudinal distance along the combustion chamber and / or along the longitudinal direction of the second section between the first longitudinal position and the second longitudinal position may be at least 6o%, preferably at least 70%, more preferably at least 80% of a longitudinal distance between the first longitudinal position and a longitudinal end of the second section distal from the first section, i.e. proximal to the third section. A longitudinal end of the second section distal from the first section is a longitudinal end of the second section adjacent to the third section, at which the second section opens into the third section.
[0030] Additionally or alternatively, a longitudinal distance along the combustion chamber and / or along the longitudinal direction of the second section between the first longitudinal position and the second longitudinal position may be at least 60%, preferably at least 70%, more preferably at least 80% of a longitudinal distance between the first longitudinal position and an initial position of a gas path along the longitudinal direction of the third section. Since the second section opens into the third section at a longitudinal end thereof mentioned above, gas flowing along the combustion chamber may flow along the longitudinal direction of the second section until it reaches theaforesaid longitudinal end of the second section. From that point on, the gas can flow in the longitudinal direction of the third section, i.e. along the third section.
[0031] Such distance ratios contribute to significantly reducing the generation of nitrogen oxides (NOx) in the combustion exhaust gas and to further homogenize the combustion exhaust gas, at least for some combinations of process parameters such as type and flow amount of combustible, temperatures of the comburent and the combustible at the respective inlets. By having a third section longer than the combination of the first and second sections, the distance between a first combustion zone in the first and second sections and further downstream combustion zones, for example in the third section, facilitates a more gradual and controlled combustion process, allowing for better mixing and homogenization of the combustion exhaust gas.
[0032] According to preferred embodiments, a longitudinal distance along the combustion chamber between the first longitudinal position and the second longitudinal position maybe at least 50 cm, preferably at least 75 cm, and more preferably at least 90 cm. This particular arrangement allows for a more controlled and gradual mixing of the combustible and comburent, which is crucial for achieving optimal combustion conditions and NOx reduction.
[0033] The combustion chamber may have a specific ratio between the longitudinal extensions of its sections. The longitudinal extension of a section of the combustion chamber may refer to an extension thereof in the main direction of the corresponding section of the chamber. According to preferred embodiments, a ratio of the longitudinal extension of the combustion chamber along the third direction, particularly in the third section, over a longitudinal extension of the combustion chamber along the second direction, comprising the second section and possibly the first section, is designed to be at least 1, and preferably higher, such as at least 5 / 4, more preferably at least 3 / 2 or at least 5 / 3.
[0034] Additionally or alternatively, a ratio of a longitudinal extension of the combustion chamber along the longitudinal direction of the third section over a distance along the longitudinal direction of the second section between the first longitudinal position and a longitudinal end of the second section distal from the first section and / or between the first longitudinal position and an initial position of a gas path along the longitudinal direction of the first section is greater than 1, with preferred values being at least 3 / 2, at least 7 / 4 or at least 2.Such dimensional ratios allow that the combustion exhaust gas has sufficient path to homogenize as it travels from the second section to the main outlet, which is beneficial for achieving efficient combustion conditions, reducing the presence of hotspots or areas with incomplete combustion. Further, such extension ratios allow creating sufficient space for receiving a vessel on the burner, over the third section of the combustion chamber. Such vessel can for example be a heat exchanger or a reactor usable for various purposes, such as further processing of the combustion exhaust gases or additional reactions that require a controlled environment. For example, the vessel may be or comprise an ammonia cracking reactor using the exhaust combustion gases from the combustion chamber for extracting heat for the endothermic ammonia cracking reaction hosted therein.
[0035] In a preferred embodiment, a vertical separation of the main outlet from a lowest point or a lowest surface of the burner may be not more than i m, preferably not more than 90 centimeters, and more preferably not more than 70 centimeters. This particular vertical separation of the main outlet from a lowest point or lowest surface specification is intended to facilitate the accommodation of a vessel on the burner over the third section of the combustion chamber within the interior space of a standardized shippable container, which typically has a height of 2,89 m. By maintaining such vertical separation of the main outlet from a lowest point or lowest surface of the main outlet within the specified limits, the design ensures that there is sufficient overhead space above a vessel coupled to the main outlet and also for any necessary conduits, connections, or additional equipment that may be required for the vessel's operation.
[0036] According to a preferred embodiment, the burner may further comprise a gas distribution plate arranged at the main outlet. The main outlet may be in fluid communication with the combustion chamber through the gas distribution plate. The gas distribution plate may allow regulating and distributing the flow of combustion exhaust gas through the main outlet, to obtain a more homogeneous flow of combustion exhaust gas. The gas distribution plate may comprise a plate with a plurality of openings formed therethrough.
[0037] According to preferred embodiments, the one or more secondary combustible inlets and / or the one or more secondary comburent inlets may comprise at least two, preferably at least four, more preferably at least eight secondary combustible inletsand / or secondary comburent inlets, evenly arranged around a cross-sectional perimeter of the combustion chamber. This implies that the secondary inlets for combustible and / or comburent may all be arranged at the second longitudinal position, evenly surrounding the second section of the combustion chamber to maximize homogenization.
[0038] Each of the one or more secondary combustible inlets and / or of the one or more secondary comburent inlets may be arranged and / or connected to a ring-shaped conduit surrounding the combustion chamber.
[0039] Further, each of the one or more secondary combustible inlets and / or of the one or more secondary comburent inlets may be configured for feeding the corresponding fluid into the combustion chamber perpendicularly, i.e. perpendicular to the longitudinal direction of the second section, or at an angle with respect to such direction different from 90°C, for example between 450and 1350.
[0040] In preferred embodiments, the burner may comprise one or more optional further inlets for feeding a flow of secondary fluid into the combustion chamber downstream from the second longitudinal position, in particular in the third section. The one or more further inlets can for example comprise a further combustible inlet and / or a further comburent inlet. Such additional inlets are preferably arranged outside of a projection of the second section upon the third section.
[0041] According to preferred embodiments, the main combustible inlet and the main comburent inlet may be coaxial, the main combustible inlet and the main comburent inlet may correspond to the ends of coaxially arranged conduits, for example an interior conduit for the combustible surrounded by an exterior conduit for the comburent and coaxial with it.
[0042] Additionally or alternatively, each of the secondary combustible inlets may likewise be coaxial with a corresponding one of the secondary comburent inlets. Such coaxial configurations may facilitate a more efficient mixing of the combustible with the comburent within the combustion chamber while being space-saving, as it allows for a more compact design of the burner. This is especially beneficial in applications where space is limited, such as onboard applications or placement of the burner in a shippablecontainer, as it minimizes the footprint of the burner while maintaining optimal performance.
[0043] The burner may further comprise a swirling device fluidly connected to the main combustible inlet and / or the main comburent inlet for feeding the combustible and / or the comburent into the combustion chamber as a turbulent rotational flow around a longitudinal axis of the combustion chamber. The swirling device may be configured for feeding the comburent and the combustible into the combustion chamber such that a flow of comburent surrounds a flow of combustible.
[0044] The burner may further comprise, preferably over the third section of the combustion chamber, a coupling flange for coupling the burner to a vessel such that the is vessel is thermal connection with the combustion chamber. “Thermal connection” may refer herein to an arrangement of the vessel with respect to the combustion chamber allowing the vessel to effectively receive thermal energy (heat) from the combustion chamber. The coupling flange may be arranged around the main outlet. For the same considerations outlined above with respect to a vertical distance from the main inlet to a lowest point or a lowest surface of the burner, a vertical distance of the coupling flange to a bottom lowest point or a lowest surface of the burner may be not more than i m, preferably not more than 90 cm, more preferably not more than 70 cm.
[0045] A second aspect of the invention refers to a vessel system comprising a burner for burning a combustible, preferably ammonia, according to any of the preceding embodiments of the first aspect of the invention, and a vessel, wherein the vessel is in thermal connection with the combustion chamber of the burner. The vessel may for example comprise a heat exchanger and / or a reactor, for instance an ammonia cracking reactor. The vessel system may be a reactor system configured to produce hydrogen through the process of ammonia cracking. This system may comprise a burner for burning a combustible, with may preferably be or comprise ammonia. The burner may operate in accordance with any of the previously described embodiments of the first aspect of the invention.
[0046] A third aspect of the invention refers to a shippable container containing a vessel system according to the second aspect of the invention and / or a burner for burning a combustible according to any embodiment of the first aspect of the invention. Ashippable container may refer herein to a container of standard dimensions and size that is usable for maritime and / or terrestrial transport.
[0047] The container may be a so-called intermodal container or shipping container, which may be designed and built for intermodal freight transport and may be specifically adapted (skidized) for containing and transporting a vessel system according to the second aspect of the invention and / or a burner for burning a combustible according to any embodiment of the first aspect of the invention. Accordingly, the vessel system according to the second aspect of the invention and / or the burner according to the first aspect of the invention can be used as an easily transportable plug-and-play solution.
[0048] Such containers typically have a height, i.e. a distance from a bottom surface of the container to a top surface of the container when the container is resting on the ground from 2,5 m to 3,5 m, preferably from 2,75 m to 3 m.
[0049] For the same reasons explained above with respect to a vertical distance from the main outlet and / or from a coupling flange over a lowest point or a lowest surface of the burner, a height of the main outlet and / or of sauch coupling flange of the burner over a bottom surface of the shippable container may be not more than 1 m, preferably not more than 90 cm, more preferably not more than 70 cm.
[0050] A fourth aspect of the invention refers to a method of burning a combustible using a burner, preferably a burner according to any embodiment of the first aspect of the invention, wherein the method comprises: injecting a first combustible input stream of a first combustible and a first comburent input stream of a first comburent, wherein wherein at least one the first combustible input stream and the first comburent input stream is injected at a first longitudinal position of a combustion chamber of the burner, igniting the combustible, and injecting, at a second longitudinal position of a combustion chamber of the burner downstream and spaced apart from the first longitudinal position, a second combustible input stream of a second combustible and a second comburent input stream of a second comburent.
[0051] A distance between the first longitudinal position and the second longitudinal position may be as discussed above for a burner according to embodiments of the first aspect of the invention.The first combustible may be or comprise ammonia. The first comburent may be air and / or comprise oxygen. Additionally or alternatively, the second comburent may be air and / or comprise oxygen and the second combustible may comprise ammonia, for example ammonia obtained from an ammonia cracking reaction and comprising residual ammonia, hydrogen and nitrogen.
[0052] For example, if the first combustible is ammonia, the second combustible may be a gas comprising ammonia, for example a residual gas from a hydrogen separation process applied to the outcome of an ammonia cracking reaction. Further, the first comburent and the secondary comburent may both be or comprise air.
[0053] Preferably, the first comburent is injected into the combustion chamber in substechiometric conditions with respect to the first combustible. This implies that the amount of comburent is not sufficient for the combustible to be entirely combusted in the combustion chamber, for which some remnants of combustible may be present in the combustion exhaust gas. This proves beneficial for reducing NOx in the combustion chamber.
[0054] The method may further comprise injecting a third combustible input stream of a third combustible and / or a third comburent input stream of a third comburent at a third longitudinal position downstream from the second longitudinal position. The third combustible may be the same as the first and / or second combustible. The third comburent may be the same as the first and / or second comburent.
[0055] A temperature of the combustible and / or of the combustion exhaust gas at the main outlet of the burner may be at least 8oo°C, preferably at least iooo°C. Such temperatures are usable for driving endothermic reactions, such as for example an ammonia cracking reaction.
[0056] A fifth aspect of the invention refers to a method of producing hydrogen from ammonia cracking comprising a method according to the fourth aspect of burning a combustible using a burner, possibly a burner according to the first aspect of the invention, wherein heat produced by burning the combustible in the burner is used for feeding an endothermic ammonia cracking reaction.BRIEF DESCRIPTION OF THE DRAWINGS
[0057] Fig. 1 Shows a schematic side view of a burner according to the invention with a multi-section combustion chamber.
[0058] Fig. 2 Shows a schematic view of a cross-section of the second section of the burner of Fig. 1 along cross-sectional plane A-A’.
[0059] Fig. 3 Shows a schematic top view of the gas distribution plate of the burner of Fig.
[0060] 1.
[0061] Fig. 4 Shows a schematic cross-sectional view of the gas distribution plate of Fig. 3 along cross-sectional plane B-B’.
[0062] Fig. 5 Shows a schematic top view of the burner of Fig. 1.
[0063] Fig. 6 Shows a schematic view of a vessel system including a burner and a vessel, arranged within a shippable container.
[0064] Fig. 7 Shows a schematic side view of another burner according to the invention with a multi-section combustion chamber.
[0065] Fig. 8 Shows a schematic top view of the burner of Fig. 7.
[0066] The same reference numerals are used in all Figures for indicating the same elements.
[0067] DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0068] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to a preferred embodiment illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated apparatus and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur now or in the future to one skilled in the art to which the invention relates.Fig. i shows a schematic view of a burner io for burning a combustible, for example ammonia. The burner io comprises a burner body 9 that encloses a combustion chamber 12 formed therein. The combustion chamber 12 is enclosed by the burner body 9 made of refractory material, providing thermal insulation and structural integrity.
[0069] The combustion chamber 12 is a multi-section combustion chamber having, in this exemplary embodiment, three distinguishable sections: A first section 12-1, a second section 12-2 and a third section 12-3. The first section 12-1 and the second section 12-2 have the same longitudinal direction L2, which in the exemplary embodiment shown corresponds to a vertical downward direction.
[0070] The first section 12-1 is a frustoconical section having a rotational symmetry around a central axis of the first section 12-1 and a circular cross-section with a diameter that increases from a first end, distal from the second section 12-2, to a second end adjacent to the second section 12-2.
[0071] The first section 12-1 comprises a main combustible inlet 13 and a main comburent inlet 15. The main combustible inlet 13 and the main comburent inlet 15 are coaxially arranged, with the main comburent inlet 15 surrounding and enclosing the main combustible inlet 13. In the exemplary embodiment shown in Fig. 1, the main comburent inlet 15 is coupled to a swirling device 7 that is fluidly connected thereto and configured for feeding a comburent received from the main comburent inlet 15 into the combustion chamber 12, thereby and a first comburent input stream IBi of a first comburent into the first section 12-1 of the combustion chamber 12. Further, the main combustible inlet 13 is configured for injecting a first combustible input stream IA1 of the first combustible into the first section 12-1 of the combustion chamber 12, possibly through a corresponding injector (not-shown). The swirling device 7 is configured for generating a turbulent rotational flow of the first comburent around a longitudinal axis of the combustion chamber 12, with the flow of the first comburent surrounding the flow of the first combustible. In preferred embodiments, the first combustible may be gaseous ammonia (NH3) and the first comburent may be air.
[0072] The burner 10 further comprises, arranged in the first section 12-1 of the combustion chamber 12, an igniting device 5 for igniting the mixture of the first combustible and the first comburent in the first section 12-1. Further, an ignition sensor 3 is provided in thefirst section 12-1 and is configured for detecting an ignition in the first section 12-1 to allow a human or machine supervisor of the burner io to receive information about the presence of an ongoing ignition activity within the combustion chamber 12.
[0073] As shown in the exemplary embodiment of Fig. 1, the ignition sensor 3 can be arranged inclined with respect to a longitudinal direction of the first section 12-1 so as to capture the interior of the first section with an improved angle of vision for monitoring ignition activity within the first section 12-1. Further the ignition device 5 can be aligned with a longitudinal direction of the first section 12-1, which in this case corresponds to direction L2 but in other embodiments may be a different direction.
[0074] The main combustible inlet 13 and the main comburent inlet 15 provide the ingoing flows IA1, IBi of the first combustible and the first comburent at the same longitudinal position Pi of the combustion chamber 12, which in the exemplary embodiment shown corresponds to the position of the optional swirling device 7 and of the main combustible inlet 13.
[0075] The skilled person understands that the position along the longitudinal direction of the combustion chamber 12 and / or along the longitudinal direction L2 at which the main combustible inlet 13 and the main comburent inlet 15 and / or the swirling device 7 open into the chamber needs not be precisely the same for both the injection of the combustible and of the comburent to be regarded as an injection “at the first longitudinal position”. Minor differences between the position of the main combustible inlet 13 and the main comburent inlet 15, for example in the order of up to 5 cm or up to to 1 cm, possibly in the millimetric range, may be negligible for the purposes of the present invention in configurations like in Fig. 1 in which both the main combustible inlet 13 and the main comburent inlet 15 are configured for feeding the corresponding fluid at the first longitudinal position Pi. In other words, the distances LD1, LD2 and / or LE-V may be measured from the main combustible inlet 13 and / or from the swirling device 7.
[0076] The first combustible and the first comburent are injected into the combustion chamber 12 through the main combustible inlet 13 and the main comburent inlet 15, respectively, and are then ignited by the ignition device 5, which thereby triggers a combustion reaction within the combustion chamber 12. The first comburent is preferably injectedinto the combustion chamber 12 in substechiometric conditions with respect to the first combustible.
[0077] The combustion reaction advances from the first section 12-1 to the second section 12-2, which in the exemplary embodiment shown in Fig. 1 corresponds to a downwards vertical flow.
[0078] The second section 12-2 has, in the exemplary embodiment shown in Fig. 1, a circular cross section with constant diameter greater than a maximal diameter of the first section 12-1 adjacent to the second section 12-2. Thus, the second section 12-2 of the combustion chamber 12 forms a cylindrical sub-volume of the combustion chamber 12.
[0079] At a second longitudinal position P2 along the combustion chamber 12, i.e. along the longitudinal direction L2, downstream from the first longitudinal position Pi with respect to the flow of gas and of the combustion reaction within the combustion chamber 12, a plurality of secondary combustible inlets 17 and secondary comburent inlets 19 are provided for feeding a flow of secondary combustible and / or of secondary comburent into the combustion chamber 12. Each of the secondary comburent inlets 19 is coaxially arranged with one of the secondary combustible inlet 17, with the secondary comburent inlet 19 surrounding the corresponding secondary combustible inlet 17.
[0080] As shown in the exemplary embodiment of Fig. 1, the secondary comburent inlets 19 and the secondary combustible inlets 17 need not be arranged perpendicular (at an angle of 90°) to the longitudinal direction L2 of the second section 12-2 and can be arranged with an angle with respect thereto, for example an angle from 20° to 160°, preferably from 70° to 110°.
[0081] By means of the secondary combustible inlet 17 and a corresponding secondary comburent inlet 19, a corresponding number of second combustible input streams IA2 and of second component input streams IB2, respectively, are injected into the combustion chamber 12 at the second longitudinal position P2.
[0082] The second combustible can comprise ammonia. For example, the second combustible may be a gas extracted from the permeate side of a hydrogen separator arrangeddownstream from an ammonia cracking reactor and may hence comprise rest ammonia together with nitrogen and hydrogen, with an exemplary molar composition of 2,2% NH3, 76,8% N2 and 21% H2. The second component can be air.
[0083] Fig. 2 shows a schematic top view of a cross-section of the combustion chamber 12 of the burner 10 of Fig. 1 corresponding to plain A-A' indicated in Fig. 1. In the exemplary embodiment shown, eight input positions IN1 to IN8 are evenly arranged around a cross-sectional perimeter of the second section 12-2 of the combustion chamber 12. Each of the each of the input positions IN1 to IN8 can correspond to the position of one of the secondary combustible inlets 17 and / or one of the secondary comburent inlets 19. For example, in some embodiments each of the input positions IN1 to IN8 can correspond to a secondary combustible inlet 17 and to a second comburent inlet 19 in coaxial arrangement, with the secondary combustible inlet 19 being interiorly arranged with respect to the coaxial second comburent inlet 19. In other related configurations, the secondary combustible inlet 17 and the secondary comburent inlets 19 may alternatingly occupy the input positions IN1 to IN8. In other configurations, the number of input positions needs not be eight and may be any number greater than 2, for example 3, 4, 5, 6, 7, 9 or 10.
[0084] The uniform distribution of the secondary combustible inlets 17 and the secondary comburent inlets 19 around the cross-sectional perimeter of the second section 12-2 of the combustion chamber 12 ensures an even mixing and combustion of the secondary combustible and the secondary comburent.
[0085] As shown in Fig. 1, the second longitudinal position P2 at which the second combustible and the second component are fed into the combustion chamber 12 is arranged downstream and spaced apart along the longitudinal direction L2 of the second section 12-2 with respect to the first longitudinal position Pi. This was found by the present inventors to significantly contribute to a reduction of NOx generation within the combustion chamber, while still ensuring a sufficient level of combustion.
[0086] The secondary combustible inlets 17 and the secondary comburent inlets 19 are strategically positioned at the second longitudinal position P2 to enhance the combustion process by providing additional combustible and additional comburent at adownstream location from the first longitudinal position Pi. This arrangement supports staged (stratified) combustion, which improves combustion efficiency and reduce undesired NOx emissions.
[0087] In particular, a longitudinal distance LD1 along the longitudinal direction L2 of the second section 12-2 between the first longitudinal position Pi and the second longitudinal position P2 corresponds to at least 60%, preferably at least 70%, more preferably at least 80% of a longitudinal distance LD2. The longitudinal distance LD2 is measured also along the longitudinal direction L2 between the first longitudinal position Pi and a longitudinal end i2-2e of the second section 12-2 that is distal from the first section 12-1, i.e. is adjacent to the third section 12-3. The longitudinal end i2-2e of the second section 12-2 corresponds to an initial position of a gas path along a longitudinal direction L3 of the third section 12-3 different from the longitudinal direction L2. At the longitudinal end i2-2e of the second section 12-2, a gas flowing along the second section 12-2 away from the first section 12-1 can start advancing in the longitudinal direction L3 of the third section 12-3, no longer being limited by the walls of the second section 12-2. According to some specific implementation examples, the longitudinal distance LD1 can be at least 50 cm, preferably at least 75 cm, more preferably at least 90 cm.
[0088] The third section 12-3 of the combustion chamber 12 extends along a longitudinal direction L3 that is angled with respect to the longitudinal direction L2 of the second section 12-2 and the first section 12-1. In the exemplary embodiment of Fig. 1, the longitudinal direction L3 is perpendicular to the longitudinal direction L2, such that the combustion chamber 12 is L-shaped. In other related embodiments, an angle between the longitudinal directions L3 and L2 needs not be 90 and may take different values, for example 20° or 450or 6o°, to explicitly name some examples.
[0089] The third section 12-3 is preferably longer than the rest of the combustion chamber. In particular, a ratio of a longitudinal extension LE-H of the third section 12-3 of the combustion chamber 12 along the first direction L3 over a longitudinal extension LE-V of the combustion chamber 12 along the longitudinal direction L2 of the second section 12-2 is at least 1, preferably at least 1.25, more preferably at least 1.5 or at least 1.67.
[0090] Additionally or alternatively, a ratio of the longitudinal extension LE-H of the third section 12-3 of the combustion chamber 12 along the first direction L3 over the distanceLD2 along the longitudinal direction L2 of the second section 12-2 between the first longitudinal position Pi and the longitudinal end i2-2e of the second section 12-2 may be greater than 1, preferably at least 1.5, preferably at least 1.75 or even at least 2.
[0091] The first section 12-3 comprises a main outlet 14 for outputting a combustion exhaust gas resulting from the combustion reaction within the combustion chamber 12. The main outlet 14 is arranged at a vertical distance Hi from a lowest surface 10b of the burner 10 of not more than 1 m, preferably not more than 90 cm, more preferably not more than 70 cm.
[0092] A coupling flange 16 is positioned around the main outlet 14 to enable fluid-tight communication between the burner and a vessel such as a heat exchanger and / or a reactor, facilitating integration into a vessel system.
[0093] At the main outlet 14, a gas distribution plate 18 is arranged, which is shown in further detail in Figs. 3 and 4. Fig. 3 shows a schematic top view of the gas distribution plate 18, whereas Fig. 4 shows an isolated cross-sectional view corresponding to the cross-sectional view of Fig. 1 and to cross-sectional plane B-B’ in Fig. 3. The gas distribution plate 18 comprises a plate i8p and a plurality of openings 180 formed through the plate i8p. The combustion exhaust gases resulting from the combustion reaction can leave the combustion chamber 12 through the main outlet 14, i.e. through the openings 180 of the gas distribution plate 18, which provides a distributed flow of such combustion exhaust gases.
[0094] The burner 10 further comprises a coupling flange 16 arranged around the main opening 14 that is configured for coupling a vessel to the burner 10, as will be explained in more detail below with respect to Fig. 5. The coupling flange can comprise a plurality of screw holes for receiving a corresponding plurality of screws. In some embodiments, a vertical distance H2 between the coupling flange 16 and the bottom surface 10b of the burner 10 is not more than 1 m, preferably not more than 90 cm, more preferably not more than 70 cm.
[0095] Fig. 5 shows a schematic top view of the burner 10 of Fig. 1, indicating the relative positions, in a top view, of the first section 12-1, the second section 12-2, the third section12-3, the main outlet 14, the optional gas distribution plate 18 and the optional coupling flange 16.
[0096] In the exemplary embodiment shown in Fig. 1, the burner 10 further comprises an optional further inlet 21 configured for feeding a flow of secondary fluid into the combustion chamber 12, for example air or the second combustible, downstream from the second longitudinal position P2, in the third section 12-3. As seen in Fig. 1, the further inlet 21 is arranged outside a vertical projection of the second section 12-2 upon the third section 12-3.
[0097] In an exemplary specific implementation of the burner 10, the first section 12-1 and the second section 12-2 can have an extension along the direction L2 of 300 mm and 889,4 mm, respectively. A diameter of the frustoconical first section 12-1 distal from the second section 12-2 can be 88,6 mm, and a diameter of the first section 12-1 adjacent to the second section 12-2 being 160,1 mm. A diameter of the second section 12-2 can be 400 mm. The third section may have an extension in the direction L3 of 2375 mm a height (parallel to the distances Hi and H2 in the drawings) of 150 mm and a width of 1000 mm. The main outlet 14 can have a circular shape with a diameter of 900 mm with the diffusion plate 18 fitted thereto. A thickness of the refractory material 9 can be in the range from 200 mm to 300 mm.
[0098] Fig. 6 shows a schematic view of a shippable container 90 that contains a vessel system 80 comprising the burner 10 of Fig. 1 and a vessel 20 attached thereto. The vessel 2ocan for example be a reactor, such as a tube-and-shell reactor, or a heat exchanger, and is coupled to the coupling flange 16 and arranged on the burner 10 over the third section 12-2 of the combustion chamber 12 such that the combustion chamber 12 of the burner 10 can transfer heat to the vessel 20..
[0099] For example, if the vessel 20 is an ammonia cracking reactor, an endothermic ammonia cracking reactor ammonia cracking reaction may take place in the interior of the vessel 20 while obtaining heat from the combustion exhaust gases from the combustion chamber 12.
[0100] The container 90 has a height HC between a container bottom CB and a container top CT of 2.896 m. The container 90 can be a standardized 20’ high cube container forterrestrial and maritime transport with dimensions 6.058 m x 2.438 m x 2.896 m (length x width x height). The container 90 can have one or more outlets and one or more inlets formed therethrough (not shown) as appropriate for plug-and-play operation of the vessel system 80 hosted within the container 90.
[0101] The vessel system 80 fits into the container 90 because it is specifically designed for this purpose, with a height H2 of the main outlet 14 and / or a height H3 of the coupling flange 16 of the reactor chamber 12 over the bottom surface CB of the container 90 being not more than 1 m, preferably not more than 90 cm and more preferably not more than 70 cm.
[0102] The vessel system 80 mounted within the container 90 can be used to perform a method of producing hydrogen from ammonia cracking. The vessel 20 can be a reactor for cracking ammonia and the heat required for the endothermic ammonia cracking reaction can be provided by burning a combustible, for example ammonia, in the burner 10. The temperature of the combustible and / or of the combustion exhaust gas at the main outlet 14 of the burner may be of iooo°C or more.
[0103] Fig. 7 and 8 respectively show a schematic side view and a top view of a modification of the burner 10 of Fig. 1 and 5. in which the second section 12-2 and the first section 12-1, rather than overlying a longitudinal end of the third section 12-3, overlie a middle portion of the third section 12-3, such that the third section 12-3 extends sideways left and right from a projection of the second section 12-2 thereon. This allows having a first main outlet 14a, a first optional diffusion plate 18a and a first optional coupling flange 16a for coupling a first vessel on one side of the second section 12-2 (right-hand side in Fig. 7 and 8) and having a second main outlet 14b, a second optional diffusion plate 18b and a second optional coupling flange 16b for coupling a second vessel on another side of the second section 12-2 (left-hand side in Fig. 7 and 8).
[0104] Thanks to the design configurations described herein, the burner 10 of Figs. 1 to 8 can generate NOx emissions when burning ammonia below 1.000 mg / Nm3, possibly below 200 mg / Nm3, on a dry basis, for a temperature of O,15°C and a pressure of 101,3 Pa and corrected to 3% of 02 corresponding to the administrative standard limits on NOx emissions valid in the European Union.Although preferred exemplary embodiments are shown and specified in detail in the drawings and the preceding specification, these should be viewed as purely exemplary and not as limiting the invention. It is noted in this regard that only the preferred exemplary embodiments are shown and specified, and all variations and modifications should be protected that presently or in the future lie within the scope of protection of the invention as defined in the claims.
Claims
Hydrogen Onsite S.L.H34628WOCLAIMS1. A burner (10) for burning a combustible, the burner (to) comprising:a multi-section combustion chamber (12) comprising a first section (12-1), a second section (12-2) and a third section (12-3),a main combustible inlet (13) for feeding the combustible into the combustion chamber (12) and a main comburent inlet (15) for feeding a comburent into the combustion chamber (12), wherein at least one of the main combustible inlet (13) and the main comburent inlet (15) is configured for feeding the combustible or the comburent, respectively, at a first longitudinal position (Pi) along the combustion chamber (12), wherein the third section (12-3) comprises a main outlet (14) for outputting a combustion exhaust gas, the second section (12-2) being arranged between the first section (12-1) and the third section (12-3), andwherein a longitudinal direction (L3) of the third section (12-3) is angled, preferably perpendicular, with respect to a longitudinal direction (L2) of the second section (12-2); wherein the second section (12-2) comprises one or more secondary combustible inlets (17) for feeding a flow of secondary combustible into the combustion chamber (12) at a second longitudinal position (P2) along the combustion chamber (12) and one or more secondaiy comburent inlets (19) for feeding a flow of secondary comburent into the combustion chamber (12) at the second longitudinal position (P2) along the combustion chamber (12),wherein the second longitudinal position (P2) is spaced apart and downstream from the first longitudinal position (Pi) along the longitudinal direction (L2) of the second section (12-2).
2. The burner of claim 1, wherein a longitudinal distance (LD1) along the combustion chamber (12) and / or along the longitudinal direction (L2) of the second section (12-2) between the first longitudinal position (Pi) and the second longitudinal position (P2) is at least 60%, preferably at least 70%, more preferably at least 80% of a longitudinal distance (LD2) between the first longitudinal position (Pi) and a longitudinal end (12- 2e) of the second section (12-2) distal from the first section (12-1) and / or of a longitudinal distance (LD2) between the first longitudinal position (Pi) and an initial position of a gas path along the longitudinal direction (L3) of the third section (12-3).
3. The burner of claim 1 or 2, wherein a longitudinal distance (LD1) along the combustion chamber (12) between the first longitudinal position (Pi) and the second longitudinal position (P2) is at least 50 cm, preferably at least 75 cm, more preferably at least 90 cm.4- The burner of any of the preceding claims, wherein a ratio of a longitudinal extension (LE-H) of the third section (12-3) along the longitudinal direction (L3) of the third section (12-3), in particular in the third section (12-3), over a longitudinal extension (LEVI of the combustion chamber (12) along the longitudinal direction (L2) of the second section (12-2 ) is at least 1, preferably at least 5 / 4, more preferably at least 3 / 2 or at least 5 / 3-5. The burner of any of the preceding claims, wherein a ratio of a longitudinal extension (LE-H) of the third section (12-3) of the combustion chamber (12) along the longitudinal direction (L3) of the third section (12-3), in particular in the third section (12-3), over a distance (LD2) along the longitudinal direction (L2) of the second section (12-2) between the first longitudinal position (Pi) and a longitudinal end (i2-2e) of the second section (12-2) distal from the first section (12-1) and / or over a distance (LD2) along the longitudinal direction (L2) between the first longitudinal position (Pi) and an initial position of a gas path along the longitudinal direction (L3) of the section (12-3) is greater than 1, preferably at least 3 / 2, preferably at least 7 / 4, more preferably at least 2.
6. The burner of any of the preceding claims, wherein a vertical separation (Hi) of the main outlet (14) from a lowest point or lowest surface (10b) of the burner (10) is not more than 1 m, preferably not more than 90 cm, more preferably not more than 70 cm.
7. The burner of any of the preceding claims, further comprising a gas distribution plate (18) arranged at the main outlet (14), wherein the main outlet (14) is in fluid communication with the combustion chamber (12) through the gas distribution plate (18), wherein the gas distribution plate (18) preferably comprises a plate (i8p) with a plurality of openings (180) formed therethrough.
8. The burner of any of the preceding claims, wherein the one or more secondary combustible inlets (17) and / or the one or more secondary comburent inlets (19) comprise at least two, preferably at least four, more preferably at least eight secondary combustible inlets (17) and / or secondary comburent inlets (19), evenly arranged around a cross- sectional perimeter of the combustion chamber (12).
9. The burner of any of the preceding claims, further comprising one or more further inlets (21) for feeding a flow of secondary fluid into the combustion chamber (12) downstream from the second longitudinal position (P2).
10. The burner (10) of any of the preceding claims, wherein the main combustible inlet (13) and the main comburent inlet (15) are coaxial and / or wherein each of the secondary combustible inlets (17) is coaxial with a corresponding one of the secondary comburent inlets (19).
11. The burner (10) of any of the preceding claims, further comprising a swirling device (7) fluidly connected to the main combustible inlet (13) and / or the main comburent inlet (15) for feeding the combustible and / or the comburent, respectively, into the combustion chamber (12) as a turbulent rotational flow around a longitudinal axis of the combustion chamber (12), preferably such that a flow of comburent surrounds a flow of combustible.
12. The burner of any of the preceding claims, further comprising a coupling flange (16) for coupling the burner (10) to a vessel (20) such that the vessel (20) is in thermal connection with the combustion chamber (12) of the burner (10), the coupling flange (16) being arranged around the main outlet (14).
13. A vessel system (80) for producing hydrogen comprising a burner (10) for burning a combustible, preferably ammonia, according to any of the preceding claims and a vessel (20), wherein the vessel is in thermal connection with the combustion chamber (12) of the burner (10).
14. A shippable container (90) containing a vessel system (80) according to claim 13 and / or a burner (10) for burning a combustible according to any of claims 1 to 12.
15. The shippable container (90) of claim 14, wherein a height (H2) of the main outlet (14) of the burner over a bottom surface (CB) of the shipp able container (90) is not more than 1 m, preferably not more than 90 cm, more preferably not more than 70 cm.
16. A method of burning a combustible using a burner, preferably a burner (10) according to any of claims 1 to 12, wherein the method comprises:injecting a first combustible input stream (IA1) of a first combustible and a first comburent input stream (IB1) of a first comburent, wherein at least one the first combustible input stream (IA1) and the first comburent input stream (IBi) is injected at a first longitudinal position (Pi) of a combustion chamber (12) of the burner (10), igniting a mixture of the first combustible and the first comburent, andinjecting, at a second longitudinal position (P2) of a combustion chamber (12) of the burner (10) downstream and spaced apart from the first longitudinal position (Pi), oneor more second combustible input streams (IA2) of a second combustible and one or more second comburent input streams (IB2) of a second comburent.
17. The method of claim 16, wherein the first combustible is or comprises ammonia and / or wherein the first comburent is air and / or comprises oxygen.
18. The method of any of claims 16 or 17, wherein the first comburent is injected into the combustion chamber in substechiometric conditions with respect to the first combustible.
19. The method of claim 16 to 18, wherein the second combustible comprises ammonia obtained from an ammonia cracking reaction and comprises residual ammonia, hydrogen and nitrogen and / or wherein the second comburent is air and / or comprises oxygen.
20. The method of any of claims 16 to 19, further comprising injecting (106) a third combustible input stream (ICi) of a third combustible and / or a third comburent input stream (ICi) of a third comburent at a third longitudinal position (P3) downstream from the second longitudinal position (P2).
21. The method of any of claims 16 to 20, wherein a temperature of the combustible at the main outlet (14) of the burner (10) is at least 8oo°C, preferably at least iooo°C.
22. A method (200) of producing hydrogen from ammonia cracking comprising a method (too) according to any of claims 16 to 21 of burning a combustible using a burner, wherein heat produced by burning the combustible in the burner is used for driving an endothermic ammonia cracking reaction.