Ammonia cracking device, ammonia catalytic cracking method and gas turbine system

Abstract

The invention provides an ammonia cracking device, an ammonia catalytic cracking method and a gas turbine system, and can be applied to the technical field of ammonia catalytic cracking. The ammonia cracking device comprises one or more ammonia cracking units, wherein each ammonia cracking unit comprises a main shell and a plurality of ammonia cracking units; the heat source channels are arranged in the main shell in parallel; a plurality of cracking reaction channels; the first ventilation opening is formed in the third surface; the second ventilation opening is formed in the fourth surface; wherein one of the first air vent and the second air vent is configured to introduce reaction gas containing ammonia gas into the cracking reaction channel, so that at least part of ammonia gas in the reaction gas is subjected to catalytic cracking reaction under the action of the catalyst; the other one of the first air vent and the second air vent is configured to discharge cracked gas generated after the catalytic cracking reaction; the heat source channel is configured to introduce heat source gas.

Description

Technical Field

[0001] This disclosure relates to the field of ammonia catalytic cracking technology, specifically to an ammonia cracking apparatus, a method for ammonia catalytic cracking, and a gas turbine system. Background Technology

[0002] Currently, there are several problems in the efficient and clean utilization of ammonia fuel. For example, in terms of high-temperature heat source supply, electric heating has low energy efficiency and high operating costs, while solar heating is significantly affected by fluctuations in natural conditions and is difficult to provide continuous and stable heating. Existing technologies have not yet formed an efficient, low-carbon, and stable heat source supply solution. Heat exchange structure; for example, in terms of cracking reaction efficiency, due to limitations in process residence time, equipment pressure drop, and thermodynamic balance, existing cracking devices cannot achieve complete decomposition of ammonia and require complex gas separation devices to improve ammonia conversion rate. Summary of the Invention

[0003] In view of the above problems, this disclosure provides an ammonia cracking device, a method for ammonia catalytic cracking, and a gas turbine system.

[0004] According to a first aspect of this disclosure, an ammonia cracking apparatus is provided, comprising one or more ammonia cracking units, said ammonia cracking unit comprising:

[0005] The main housing includes opposing first and second surfaces, as well as opposing third and fourth surfaces;

[0006] Multiple heat source channels are arranged side by side inside the main housing. Each heat source channel includes a channel inlet and a channel outlet, and the channel inlet and the channel outlet respectively penetrate the first surface and the second surface.

[0007] Multiple pyrolysis reaction channels, wherein each pyrolysis reaction channel is formed by a gap between two adjacent heat source channels, and each pyrolysis reaction channel is filled with a catalyst;

[0008] The first vent is located on the third side;

[0009] The second vent is located on the fourth side;

[0010] Wherein, one of the first vent and the second vent is configured to introduce a reaction gas containing ammonia into the cracking reaction channel, so that at least a portion of the ammonia in the reaction gas undergoes a catalytic cracking reaction under the action of the catalyst; the other of the first vent and the second vent is configured to discharge the cracked gas generated after the catalytic cracking reaction.

[0011] The heat source channel is configured to introduce heat source gas to heat the pyrolysis reaction channel, thereby enhancing the activity of the catalytic pyrolysis reaction.

[0012] A second aspect of this disclosure provides a method for catalytic cracking using the aforementioned ammonia cracking apparatus, comprising:

[0013] The first ammonia cracking unit, the second ammonia cracking unit, the third ammonia cracking unit, and the fourth ammonia cracking unit are used in parallel.

[0014] A third aspect of this disclosure provides a method for catalytic cracking using the aforementioned ammonia cracking apparatus, comprising:

[0015] The first ammonia cracking unit and the second ammonia cracking unit are connected in series to form a first series group, the third ammonia cracking unit and the fourth ammonia cracking unit are connected in series to form a second series group, and the first series group and the second series group are connected in parallel.

[0016] A fourth aspect of this disclosure provides a method for catalytic cracking using the aforementioned ammonia cracking apparatus, comprising:

[0017] The first ammonia cracking unit, the second ammonia cracking unit, the third ammonia cracking unit, and the fourth ammonia cracking unit are used in series.

[0018] The fifth aspect of this disclosure provides a method for catalytic cracking using the above-described ammonia cracking apparatus, comprising:

[0019] The first ammonia cracking unit and the second ammonia cracking unit are used in parallel to form a first parallel group, and the third ammonia cracking unit and the fourth ammonia cracking unit are used in parallel to form a second parallel group. The first parallel group and the second parallel group are then used in series.

[0020] A sixth aspect of this disclosure provides a gas turbine system for the aforementioned ammonia cracking unit, comprising:

[0021] The burner is configured to burn at least a portion of the hydrogen in the cracked gas output from the ammonia cracking unit as fuel to obtain heat source gas;

[0022] A turbine is configured to convert the thermal energy of the heat source gas output from a burner into mechanical energy for power generation.

[0023] At least a portion of the heat source gas output from the burner is fed into the heat source channel in the ammonia cracking unit.

[0024] According to embodiments of this disclosure, the system further includes:

[0025] The load regulation module is configured to adjust the number of multiple ammonia cracking units in use according to the electrical load, so as to regulate the hydrogen production and thus regulate the temperature of the heat source gas output by the burner.

[0026] According to embodiments of this disclosure, a multi-mode compact ammonia catalytic cracking reactor is provided, particularly suitable for low-pollution fuel utilization in gas turbine systems. Addressing technical problems such as low ammonia cracking conversion rate, unstable heating, large equipment size, and low system efficiency, this device integrates two major functions: catalytic cracking and high-efficiency heat exchange. Utilizing multi-stage catalytic cracking units, enhanced serpentine heat exchange, and multi-mode combined operation, and through precise control of the operating status of each catalytic unit, it achieves efficient and clean utilization of ammonia fuel and closed-loop energy recovery. It can provide stable, high-quality fuel gas and high-temperature heat sources even under fluctuating renewable energy conditions such as wind power and photovoltaic power, providing a supporting solution for next-generation low-carbon gas turbine systems.

[0027] The design incorporates multiple heat source channels and pyrolysis reaction channels, arranged in an alternating pattern. The heat source channels surround the pyrolysis reaction channels, providing continuous heat for the pyrolysis reaction and forming a self-sustaining energy cycle. This structural design not only enhances the heat exchange area but also strengthens the heat exchange uniformity, achieving complete ammonia decomposition and improving decomposition efficiency and sufficiency.

[0028] Furthermore, in the multiple heat source channels, the channel inlet and outlet of each heat source channel pass through the first and second opposite sides of the main shell, respectively. This structural design facilitates the arrangement of multiple ammonia cracking units along the flow direction of the heat source channels. The heat source channels of multiple ammonia cracking units can be connected to form an integral channel. Connecting an external heat source only requires one inlet and one outlet, which reduces the difficulty of connecting and installing external heat sources.

[0029] The high-temperature flue gas discharged from the combustion chamber of a gas turbine system is relatively hot, for example, between 800-1000℃. Using this high-temperature flue gas as a heat source gas in the heat source channel meets the requirements of high-temperature catalytic cracking, improving the reaction performance, catalytic efficiency, and reaction saturation. At 800-1000℃, the catalytic reaction starts rapidly, avoiding catalyst deactivation. Staged cracking reduces residual NH3. By providing a high-temperature environment to promote the complete cracking of ammonia, the cracked gas can serve as the fuel source for the combustion chamber, achieving a closed-loop combustion heat generation system.

[0030] It is evident that the aforementioned device solves the problems in related technologies, such as low efficiency and high energy consumption of electric heating; intermittent and unstable heating from renewable energy sources; insufficient ammonia cracking conversion rate; and excessive residual ammonia. Attached Figure Description

[0031] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0032] Figure 1 A schematic diagram of an ammonia cracking apparatus according to an embodiment of the present disclosure is shown.

[0033] Figure 2 A schematic diagram of the structure of an ammonia cracking unit according to an embodiment of the present disclosure is shown.

[0034] Figure 3 A schematic diagram of the structure of a cover plate according to an embodiment of the present disclosure is shown.

[0035] Figure 4 A schematic diagram of the structure of a baffle according to an embodiment of the present disclosure is shown.

[0036] Figure 5 This schematically illustrates the assembly orientation of the cover plate and baffle in an ammonia cracking unit according to an embodiment of the present disclosure;

[0037] Figure 6 A schematic diagram of the structure of a first connecting end cap according to an embodiment of the present disclosure is shown.

[0038] Figure 7 The diagram illustrates the assembly configuration of the first ammonia cracking unit and the second ammonia cracking unit according to embodiments of the present disclosure.

[0039] Figure 8 A schematic diagram of the structure of a first pyrolysis gas collection channel according to an embodiment of the present disclosure is shown.

[0040] Figure 9 The diagram illustrates the gas flow direction in a first series group formed by combining a first ammonia cracking unit and a second ammonia cracking unit according to an embodiment of the present disclosure.

[0041] Explanation of reference numerals in the attached figures:

[0042] 100, First ammonia cracking unit; 200, Second ammonia cracking unit; 300, Third ammonia cracking unit; 400, Fourth ammonia cracking unit; 500, First connecting end cap; 600, Second connecting end cap; 700, First cracked gas collection channel;

[0043] 101. Main shell; 102. Heat source channel; 103. Pyrolysis reaction channel; 104. Channel inlet; 105. Cover plate; 106. Baffle; 107. First vent; 108. Second vent; 109. Flange; 110. First gap channel. Detailed Implementation

[0044] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0045] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0046] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0047] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0048] Guided by the "dual-carbon" strategic goal, the exploration and development of low-carbon and clean fuels has become an important direction for promoting the green transformation and sustainable development of the energy sector. Among them, hydrogen and ammonia, as two typical zero-carbon fuels, emit no carbon dioxide during combustion, possessing significant advantages in replacing fossil fuels, reducing carbon emissions, and mitigating environmental pollution. In recent years, with the large-scale development of renewable energy sources such as wind and solar power, the production cost of green electricity has continued to decline, providing broad development space for green fuels such as green hydrogen and green ammonia produced based on renewable energy. Due to its high hydrogen content (up to 17.6% by mass) and ease of liquefaction and storage at room temperature and high pressure, ammonia has become an ideal hydrogen carrier, showing broad application potential in multiple fields such as industrial energy, power generation, and transportation. At present, ammonia storage and transportation technologies are relatively mature, and low-cost, safe, and reliable large-scale storage and transportation can be achieved relying on existing industrial facilities, possessing a good industrialization foundation.

[0049] Ammonia fuel gas turbines are considered a crucial component in future large-scale, long-cycle, cross-seasonal energy storage systems, playing a key role in new power systems primarily based on wind power, photovoltaics, and other new energy sources. The efficient and clean utilization of ammonia fuel generally requires the decomposition of ammonia into nitrogen and hydrogen before combustion to drive power generation. However, the ammonia fuel decomposition process still faces a series of key technical challenges, mainly concentrated in the following two aspects:

[0050] Regarding heat source supply, existing technologies generally rely on electric heating or solar heating to provide the necessary high-temperature conditions for ammonia cracking reactions. For example, some technologies use solar-driven ammonia decomposition, converting solar radiation into heat energy through a heat collection device to drive the cracking reaction. However, this approach is significantly affected by day-night cycles and weather conditions, requiring complex energy or heat storage systems to ensure process continuity and stability, increasing system complexity and cost. Another example is a three-layer nested structure: an inner shell for the combustion chamber, a middle layer for the ammonia cracking reactor, and an outer layer for exhaust gas insulation. This decomposition device has an annular cylindrical structure, and the combustion chamber has a single axial temperature distribution. The ammonia decomposition reaction spirals upwards, resulting in high resistance. While electric heating offers the advantage of flexible adjustment, it relies on high-grade electricity, has low energy utilization efficiency, and suffers from high power consumption in large-scale applications. Furthermore, using traditional fossil fuels for heating contradicts the goal of zero-carbon utilization of ammonia fuel and fails to meet the requirements of low-carbon development.

[0051] Regarding ammonia cracking efficiency, related technologies mainly employ single-stage direct-flow reactors for cracking. However, due to the limited residence time of ammonia within the reactor, the ammonia conversion rate is generally low, typically not exceeding 90%. To improve the conversion rate, conventional methods primarily rely on extending the reactor length or increasing the operating temperature. However, lengthening the reactor significantly increases the gas flow pressure drop, reducing the overall system efficiency. Furthermore, the ammonia cracking reaction is constrained by thermodynamic equilibrium, requiring high-temperature conditions (such as above 800°C) for the ammonia decomposition rate to fully exceed the 99% upper limit. In addition, the mixed gas (H2, N2, and a small amount of NH3) generated after intermediate-temperature cracking requires further purification of hydrogen, which adds complex gas separation and purification processes, further increasing costs and process difficulty.

[0052] In summary, the main technical problems currently existing in the efficient and clean utilization of ammonia fuel are as follows:

[0053] (1) In terms of high-temperature heat source supply, electric heating has low energy efficiency and high operating costs, while solar heating is significantly affected by fluctuations in natural conditions and is difficult to provide continuous and stable heating. Existing technologies have not yet formed an efficient, low-carbon, and stable heat source supply solution; heat exchange structure;

[0054] (2) In terms of pyrolysis reaction efficiency, due to limitations in process residence time, equipment pressure drop and thermodynamic balance, existing pyrolysis units are unable to achieve complete decomposition of ammonia under medium and low temperature conditions, and need to rely on complex gas separation devices to improve ammonia conversion rate.

[0055] Therefore, technological breakthroughs are urgently needed in heat source supply and pyrolysis reactor design. On the one hand, it is necessary to study how to stably provide a high-temperature environment to promote the full pyrolysis of ammonia through innovative heat source supply methods, without being limited by thermodynamic equilibrium in terms of temperature; on the other hand, it is necessary to optimize the reactor structure and operating conditions to improve the pyrolysis conversion rate and reduce the content of undecomposed ammonia.

[0056] To address the aforementioned issues, embodiments of this disclosure provide a multi-mode compact ammonia catalytic cracking reactor, particularly suitable for low-pollution fuel utilization in gas turbine systems. Addressing technical problems such as low ammonia cracking conversion rate, unstable heating, large equipment size, and low system efficiency, this device integrates two major functions: catalytic cracking and high-efficiency heat exchange.

[0057] Figure 1 A schematic diagram of an ammonia cracking apparatus according to an embodiment of the present disclosure is shown. Figure 2 A schematic diagram of the structure of an ammonia cracking unit according to an embodiment of the present disclosure is shown.

[0058] like Figure 1 As shown, the ammonia cracking device includes one or more ammonia cracking units, such as the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400 in the figure.

[0059] Among them, such as Figure 1 , 2 As shown, each ammonia cracking unit includes a main shell 101, multiple heat source channels 102, multiple cracking reaction channels 103, a first vent 107, and a second vent (not shown in the figure).

[0060] The main shell 101 includes a first and a second face facing each other, as well as a third and a fourth face facing each other (the fourth face is opposite to the third face, not shown in the figure). The main shell 101 can be a cube or a cuboid structure, with the first and second faces facing each other, the third and fourth faces facing each other, the third face intersecting with the first and second faces, and the fourth face intersecting with the first and second faces.

[0061] Multiple heat source channels 102 are arranged in parallel within the main housing 101. Each heat source channel 102 includes a channel inlet 104 and a channel outlet. The channel inlet 104 and the channel outlet pass through the first surface and the second surface, respectively. The channel outlet is another outlet of the heat source channel 102 opposite to the channel inlet 104, which is not shown in the figure.

[0062] In the multiple pyrolysis reaction channels 103, each pyrolysis reaction channel 103 is formed by the gap between two adjacent heat source channels 102, and each pyrolysis reaction channel 103 is filled with a catalyst.

[0063] The first vent 107 is located on the third side (not shown in the figure); the second vent 108 is located on the fourth side (not shown in the figure).

[0064] One of the first vent 107 and the second vent is configured to introduce a reaction gas containing ammonia into the cracking reaction channel 103, so that at least part of the ammonia in the reaction gas undergoes a catalytic cracking reaction under the action of a catalyst; the other of the first vent 107 and the second vent is configured to discharge the cracked gas generated after the catalytic cracking reaction.

[0065] For example, the first vent 107 is configured to introduce ammonia-containing reaction gas into the cracking reaction channel 103; the second vent is configured to discharge the cracked gas generated after the catalytic cracking reaction. Alternatively, the second vent is configured to introduce ammonia-containing reaction gas into the cracking reaction channel 103, and the first vent 107 is configured to discharge the cracked gas generated after the catalytic cracking reaction.

[0066] It should be noted that multiple ammonia cracking units, such as the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400 in the figure, can be used in parallel or in series, or in various other scenarios, including both series and partial parallel connections. Therefore, the reaction gas introduced into the ammonia cracking unit can be pure ammonia or an intermediate product gas containing ammonia obtained after incomplete cracking of ammonia.

[0067] For example, such as Figure 1 In the scenario shown, where the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are used in series, in the first ammonia cracking unit 100, the first vent 107 is configured to introduce ammonia-containing reaction gas into the cracking reaction channel 103; the second vent is configured to discharge the cracked gas generated after the catalytic cracking reaction; in the second ammonia cracking unit 200, the second vent is configured to introduce ammonia-containing reaction gas into the cracking reaction channel 103, and the first vent 107 is configured to discharge the cracked gas generated after the catalytic cracking reaction.

[0068] When ammonia gas is introduced, the initial ammonia gas (purity ≥99.9%) can be adjusted to 0.5-1 MPa by a pressure reducing valve before entering the preheater, where it is preheated to above 150°C. The preheated ammonia gas then enters the ammonia cracking unit.

[0069] In the above-mentioned device, the heat source channel 102 is configured to introduce heat source gas to heat the cracking reaction channel 103 to improve the activity of the catalytic cracking reaction.

[0070] Each cracking reaction channel 103 is filled with a catalyst, which can be any type of catalyst, such as one or a mixture of Ru, Ni, Co, and Fe-based catalysts. The catalyst can be made in the form of granules, honeycomb, foam ceramics, or coated catalyst layers. Comparison of different forms: granular packed beds – easy to replace, but with higher pressure drop; honeycomb catalysts – lower pressure drop, more uniform channels; foam ceramics – better heat transfer; coated layers – suitable for small, compact devices. A flexible trade-off can be made between cost, activity, and lifespan based on the actual application scenario, adapting to different application scenarios while ensuring an ammonia conversion rate of ≥99.9%.

[0071] In the cracking reaction channel, ammonia undergoes an endothermic cracking reaction under the action of a catalyst. Ammonia catalytic cracking is a process that utilizes transition metal catalysts (such as Ru, Ni, Co, and Fe) to decompose ammonia into hydrogen and nitrogen under high-temperature conditions. This process follows the chemical reaction equations below: .

[0072] The heat source gas can be high-temperature flue gas discharged from the combustion chamber of the gas turbine system. Furthermore, part or all of the fuel in the combustion chamber can come from the cracked gas (a mixture of hydrogen and nitrogen) produced by the aforementioned ammonia cracking unit. The high-temperature flue gas discharged from the combustion chamber has a high temperature, for example, between 800-1000℃, which meets the requirements of high-temperature catalytic cracking, improves the reaction performance of catalytic cracking, and increases catalytic efficiency and reaction saturation.

[0073] If limited by operating conditions or gas supply, the following alternative fuels can be used in the combustion chamber: 1) Natural gas, whose combustion products have extremely low nitrogen content, can serve as a stable high-temperature heat source. Temperature range: 800-1000℃, with good adjustability. 2) Coal gas or methane recombination gas can provide a high-temperature heat source, but attention must be paid to system desulfurization and decarbonization treatment. 3) Renewable fuel biomethane, which meets the requirements for carbon neutrality. 4) When external power is abundant, electric heating can be used to rapidly raise the flue gas temperature or provide auxiliary insulation. Through fuel substitution, the unit has fuel diversity and flexibility, ensuring the required heat input under various operating conditions.

[0074] like Figure 1 , 2As shown, heat source channel 102 and pyrolysis reaction channel 103 are arranged alternately. High-temperature flue gas is input into heat source channel 102 to provide stable and uniform heat for the pyrolysis reaction. The channels are staggered on both sides of pyrolysis reaction channel 103, forming a double-sided high-temperature enclosure. The channel inlet 104 of heat source channel 102 is connected to the combustion chamber outlet to receive high-temperature flue gas; the channel outlet of heat source channel 102 is the flue gas outlet, where heat energy is discharged or recovered.

[0075] The wall materials of the heat source channel 102 and the pyrolysis reaction channel 103 need to have high temperature strength, oxidation resistance and corrosion resistance to work at high temperature of 800-1000℃ for a long time.

[0076] The heat source channel 102 and the pyrolysis reaction channel 103 can be made of a variety of materials. For example, a nickel-based alloy can be selected, and a coating can be applied to the outer layer of the nickel-based alloy to improve its resistance to oxidation, nitriding, and carburization. Alternatively, a ceramic matrix composite material can be selected, which is more suitable for extreme high-temperature applications (≥1100℃). Through the selection of a variety of high-temperature resistant materials, flexible configuration can be made according to cost, operating conditions, and lifespan to meet different long-term operating conditions.

[0077] The heat from the high-temperature flue gas is transferred to the pyrolysis reaction channel 103 through the channel wall. This increases the ambient temperature within the channel, transferring heat to the ammonia catalyst bed, stabilizing the high temperature at 800-1000℃, effectively overcoming thermodynamic equilibrium limitations and improving the ammonia decomposition rate. The pyrolysis reaction channel 103 provides space for the ammonia catalytic pyrolysis reaction, decomposing ammonia into hydrogen and nitrogen. The internal catalyst exchanges heat with the high-temperature flue gas. Ammonia flows along the channel from the inlet side to the outlet side, undergoing gradual pyrolysis. At the high temperature of 800-1000℃, the catalytic reaction starts rapidly, preventing catalyst deactivation, and staged pyrolysis reduces residual NH3.

[0078] According to embodiments of this disclosure, a multi-mode compact ammonia catalytic cracking reactor is provided, particularly suitable for low-pollution fuel utilization in gas turbine systems. Addressing technical problems such as low ammonia cracking conversion rate, unstable heating, large equipment size, and low system efficiency, this device integrates two major functions: catalytic cracking and high-efficiency heat exchange. Utilizing multi-stage catalytic cracking units, enhanced serpentine heat exchange, and multi-mode combined operation, and through precise control of the operating status of each catalytic unit, it achieves efficient and clean utilization of ammonia fuel and closed-loop energy recovery. It can provide stable, high-quality fuel gas and high-temperature heat sources even under fluctuating renewable energy conditions such as wind power and photovoltaic power, providing a supporting solution for next-generation low-carbon gas turbine systems.

[0079] The system incorporates multiple heat source channels 102 and pyrolysis reaction channels 103, arranged in an alternating pattern. The heat source channels 102 surround the pyrolysis reaction channels 103, providing continuous heat for the pyrolysis reaction and forming a self-sustaining energy cycle. This structural design not only enhances the heat exchange area but also strengthens the heat exchange uniformity, achieving complete ammonia decomposition and improving decomposition efficiency and sufficiency.

[0080] Furthermore, in the multiple heat source channels 102, the channel inlet 104 and channel outlet of each heat source channel 102 respectively penetrate the first and second opposite sides of the main shell 101. This structural design facilitates the arrangement of multiple ammonia cracking units along the flow direction of the heat source channel 102. The heat source channels 102 of multiple ammonia cracking units can be connected to form an integral channel. Connecting an external heat source only requires one inlet and one outlet, which reduces the difficulty of connecting and installing external heat sources.

[0081] The high-temperature flue gas discharged from the combustion chamber of the gas turbine system is relatively hot, for example, between 800-1000℃. Introducing this high-temperature flue gas as a heat source into heat source channel 102 meets the requirements of high-temperature catalytic cracking, improving the reaction performance, catalytic efficiency, and reaction saturation. At the high temperature of 800-1000℃, the catalytic reaction starts rapidly, avoiding catalyst deactivation. Staged cracking reduces residual NH3. By providing a high-temperature environment to promote the complete cracking of ammonia, the cracked gas serves as the fuel source for the combustion chamber, achieving a closed-loop combustion heat generation system.

[0082] It is evident that the aforementioned device solves the problems in related technologies, such as low efficiency and high energy consumption of electric heating; intermittent and unstable heating from renewable energy sources; insufficient ammonia cracking conversion rate; and excessive residual ammonia.

[0083] According to embodiments of this disclosure, further, as Figure 2 As shown, the heat source channel and the pyrolysis reaction channel are serpentine channels.

[0084] During the process of transferring the heat of the high-temperature flue gas to the cracking reaction channel 103 through the channel wall, each cracking reaction channel 103 is surrounded on both sides by serpentine heat source channels 102. The two types of channels are arranged alternately to achieve the maximum heat transfer area and uniform heat flow distribution, so that the temperature distribution of the catalyst bed is uniform, avoiding local hot spots and cold spots, improving the catalyst utilization rate. The high temperature surrounding on both sides and the serpentine structure can effectively increase the heat transfer area, ensure the uniform temperature of the catalyst bed, avoid local overcooling or overheating, and keep the ambient temperature inside the cracking reaction channel 103 stable at 800-1000℃, effectively breaking through the thermodynamic equilibrium limit and improving the ammonia decomposition rate.

[0085] Furthermore, a combination of straight-through and serpentine channels can also be used, with some heat source channels using straight-through rapid heating and others using serpentine insulation and heat exchange.

[0086] According to an embodiment of this disclosure, the third and fourth sides of the main housing 101 are respectively provided with a first opening and a second opening.

[0087] The aforementioned device also includes a cover plate and a baffle.

[0088] A cover plate is installed at the first opening, and the cover plate has a first vent. A baffle plate is installed at the second opening, and the baffle plate has a second vent.

[0089] Figure 3 A schematic diagram of the structure of a cover plate according to an embodiment of the present disclosure is shown. Figure 4 A schematic diagram of the structure of a baffle according to an embodiment of the present disclosure is shown.

[0090] like Figure 1 As shown, the third and fourth sides of the main housing 101 are respectively provided with a first opening and a second opening (the second opening has the same structure as the first opening, and is not shown in the figure).

[0091] The cover plate 105 is installed to seal the first opening; the cover plate 105 is provided with a first vent 107. The baffle plate 106 is installed to seal the second opening; the baffle plate 106 is provided with a second vent 108.

[0092] According to embodiments of this disclosure, such as Figure 4 Multiple second vents 108 are provided on the baffle 106, and the multiple second vents 108 are evenly distributed on the baffle 106. The size of the second vents 108 in the baffle 106 is smaller than the particle size of the catalyst particles, which plays a role in preventing the catalyst from scattering. Multiple second vents 108 facilitate the smooth discharge of cracked gas.

[0093] Figure 5 The schematic diagram illustrates the assembly orientation of the cover plate 105 and the baffle plate 106 in an ammonia cracking unit according to an embodiment of the present disclosure.

[0094] As shown in Figure 5, the cover plate 105 and the baffle plate 106 are respectively installed on both sides of the main housing 101.

[0095] In this configuration, one of the first vent 107 and the second vent 108 is configured to introduce ammonia-containing reaction gas into the cracking reaction channel 103; the other of the first vent 107 and the second vent 108 is configured to discharge the cracked gas generated after the catalytic cracking reaction. For example, the first vent 107 is configured to introduce ammonia-containing reaction gas into the cracking reaction channel 103, and the second vent 108 is configured to discharge the cracked gas generated after the catalytic cracking reaction. Alternatively, the second vent 108 can be configured to introduce ammonia-containing reaction gas into the cracking reaction channel 103, and the first vent 107 can be configured to discharge the cracked gas generated after the catalytic cracking reaction, thus accommodating various scenarios.

[0096] For example, the heat source airflow passes through heat source channel 102 ( Figure 5 In the process, the heat source gas enters from the direction perpendicular to the paper surface; ammonia (or ammonia-containing reaction gas) enters the cracking reaction channel 103 from the first vent 107 on the cover plate 105, and the cracked gas obtained from the cracking is discharged through the second vent 108 on the baffle plate 106.

[0097] For example, the heat source airflow can also pass through heat source channel 102 ( Figure 5 In the process, the heat source gas enters from the direction perpendicular to the paper plane; ammonia (or ammonia-containing reaction gas) enters the cracking reaction channel 103 from the second vent 108 on the baffle 106, and the cracked gas obtained from the cracking is discharged through the first vent 107 on the cover plate 105.

[0098] According to embodiments of this disclosure, the ammonia cracking unit includes four cracking units, such as... Figure 1 As shown, the ammonia cracking unit includes a first ammonia cracking unit 100, a second ammonia cracking unit 200, a third ammonia cracking unit 300, and a fourth ammonia cracking unit 400. The four cracking units are as follows: Figure 1 The method shown is to assemble in two stacked layers.

[0099] Specifically, the first ammonia cracking unit 100 and the third ammonia cracking unit 300 are arranged and assembled along a first direction, which indicates the direction from the channel inlet 104 of the heat source channel 102 to the channel outlet; the second ammonia cracking unit 200 and the fourth ammonia cracking unit 400 are arranged and assembled along the first direction.

[0100] The first ammonia cracking unit 100 and the second ammonia cracking unit 200 are arranged and assembled along the second direction, which is perpendicular to the first direction; the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are arranged and assembled along the second direction.

[0101] The inlet 104 and outlet of each heat source channel 102 pass through the first and second opposite sides of the main shell 101, respectively. This structural design facilitates the arrangement of multiple ammonia cracking units along the flow direction of the heat source channel 102. The heat source channels 102 of multiple ammonia cracking units can be connected to form an integral channel. Connecting an external heat source only requires one inlet and one outlet, which reduces the difficulty of connecting and installing external heat sources.

[0102] like Figure 1 Assembled in this manner, the heat source channel 102 of the first ammonia cracking unit 100 is aligned with the heat source channel 102 of the third ammonia cracking unit 300, such that the channel outlet of the heat source channel 102 of the first ammonia cracking unit 100 is connected to the channel inlet 104 of the heat source channel 102 of the third ammonia cracking unit 300; similarly, the heat source channel 102 of the second ammonia cracking unit 200 is aligned with the heat source channel 102 of the fourth ammonia cracking unit 400, such that the channel outlet of the heat source channel 102 of the second ammonia cracking unit 200 is connected to the channel inlet 104 of the heat source channel 102 of the fourth ammonia cracking unit 400.

[0103] Furthermore, along the second direction, the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are arranged and assembled in the second direction with interconnected channels; the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are arranged and assembled in the second direction with interconnected channels. If the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are symmetrically assembled, the second vent 108 on the baffle 106 of the first ammonia cracking unit 100 is connected to the second vent 108 on the baffle 106 of the second ammonia cracking unit 200.

[0104] According to embodiments of this disclosure, such as Figure 1 As shown, the above-mentioned device also includes a first connecting end cover 500 and a second connecting end cover 600.

[0105] Figure 6 A schematic diagram of the structure of a first connecting end cap 500 according to an embodiment of the present disclosure is shown. The structure of the second connecting end cap 600 is the same as that of the first connecting end cap 500, and is not shown separately.

[0106] A first connecting end cap 500 is installed on the channel inlet 104 side of the heat source channel 102 of the first ammonia cracking unit 100 and the second ammonia cracking unit 200, and is configured to connect the channel inlet 104 of the heat source channel 102 of the first ammonia cracking unit 100 and the second ammonia cracking unit 200 to a gas source device that generates heat source gas. For example, the inlet of the first connecting end cap 500 is connected to the combustion chamber outlet of a gas turbine system.

[0107] The second connecting end cap 600 is installed on the outlet side of the heat source channel 102 of the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400, and is configured to connect the outlet of the heat source channel 102 of the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 to the waste heat collection device. In this way, the heat source gas enters through the inlet of the first connecting end cap 500, passes through the heat source channels 102 of the four ammonia cracking units, and exits through the outlet of the second connecting end cap 600, entering the waste heat collection device, where the waste heat from the high-temperature heat source is further utilized.

[0108] Figure 7 The diagram illustrates the assembly of the first ammonia cracking unit and the second ammonia cracking unit according to embodiments of the present disclosure.

[0109] According to embodiments of this disclosure, such as Figure 7 As shown, the edge portions of the fourth surfaces of the first ammonia cracking unit 100 and the second ammonia cracking unit 200 extend outward along the second direction to form flange portions 109. Similarly, the edge portions of the fourth surfaces of the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 also extend outward along the second direction to form flange portions 109, as shown in the diagram. Figure 7 No illustration provided.

[0110] The first ammonia cracking unit 100 and the second ammonia cracking unit 200 are arranged symmetrically, and the flange portion 109 of the fourth side of the main shell 101 of the first ammonia cracking unit 100 and the second ammonia cracking unit 200 respectively enclose to form a first gap channel 110.

[0111] The flange portions 109 of the first ammonia cracking unit 100 and the second ammonia cracking unit 200 surround each other to form a first gap channel 110. The first gap channel 110 can be formed by the first ammonia cracking unit 100 and the second ammonia cracking unit 200 as an integral part, or it can be formed as a separate first gap channel 110.

[0112] The first ammonia cracking unit 100 and the second ammonia cracking unit 200 can be used in series or in parallel.

[0113] When the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are used in parallel, ammonia gas is simultaneously introduced into the first vent 107 on the cover plate 105 of the first ammonia cracking unit 100 and the second ammonia cracking unit 200. The cracked gas generated after the ammonia gas catalytic cracking reaction in the first ammonia cracking unit 100 and the second ammonia cracking unit 200 enters the first gap channel 110 through the second vent 108 on their respective baffles 106 and is collected.

[0114] When the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are used in series, ammonia gas is simultaneously introduced into the first vent 107 on the cover plate 105 of the first ammonia cracking unit 100. The cracked gas generated after the partial ammonia catalytic cracking reaction in the first ammonia cracking unit 100 enters the first gap channel 110 through the second vent 108 on the baffle 106 of the first ammonia cracking unit 100, and then enters the second ammonia cracking unit 200 through the second vent 108 on the baffle 106 of the second ammonia cracking unit 200. After the catalytic cracking reaction continues in the second ammonia cracking unit 200, cracked gas is generated. The cracked gas is output and collected through the first vent 107 on the cover plate 105 of the second ammonia cracking unit 200.

[0115] Furthermore, the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are also symmetrically arranged. After assembly, the flange portion 109 on the fourth side of the main housing 101 of each of the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 encloses and forms a second gap channel (not shown in the figure). The assembly structure and series / parallel connection method of the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are the same as those of the first ammonia cracking unit 100 and the second ammonia cracking unit 200, and will not be described again.

[0116] According to embodiments of this disclosure, the above-described assembly structure facilitates multi-condition adjustment by changing the gas flow direction or flow rate of the reaction gas and the cracked gas, thus forming a catalytic device adaptable to various scenarios.

[0117] For example, the system can adapt to load changes based on the gas turbine system's load conditions. Four catalytic cracking units are arranged symmetrically along the axis and radially. These units can be combined arbitrarily or operate individually. Gas flow is precisely controlled via an intake distribution regulating valve, enabling multi-mode operation (full load, half load, low load, etc.). For instance, all four ammonia cracking units operate simultaneously under high load; two units operate under medium load; and only one unit operates under low load. This provides highly flexible ammonia cracking capacity to adapt to different load fluctuations in the gas turbine; avoids large-volume single-channel structures, improving the unit's compactness; and reduces local temperature differences and extends catalyst life through unit combination switching. Compared to related technologies that only employ single-channel or parallel multi-channel straight-through structures, this system allows for multi-mode combined control.

[0118] For example, depending on the particle size of the catalyst packed in the ammonia cracking unit and / or the activity of the catalyst, various series and parallel operating conditions can be formed for the four catalytic cracking units. The first ammonia cracking unit, the second ammonia cracking unit, the third ammonia cracking unit, and the fourth ammonia cracking unit can be used in parallel or in series by changing the gas flow direction of the reaction gas and the cracking gas as needed.

[0119] For example, during the ammonia gas introduction process, the ammonia gas flow rate can be adjusted to balance the gas supply to the channels of the four catalytic cracking units, thereby achieving multi-mode control.

[0120] As can be seen, by adopting the above-mentioned assembly structure and combining the channel interconnection method of the four catalytic cracking units, without changing the structure of the device, multi-condition adjustment can be achieved by changing the gas flow direction or flow rate of the reaction gas and cracking gas, forming a catalytic device that can adapt to various scenarios, realizing modular and flexible adjustment of heat exchange capacity, and achieving rapid configuration, multi-scenario adaptation and long life cycle management.

[0121] According to embodiments of this disclosure, the above-mentioned apparatus further includes a first pyrolysis gas collection channel 700, which is connected to the first gap channel 110 and the second gap channel.

[0122] Figure 8 A schematic diagram of the structure of a first pyrolysis gas collection channel 700 according to an embodiment of the present disclosure is shown.

[0123] like Figure 1 As shown, the first cracked gas collection channel 700 is installed at the position of the first gap channel 110 formed by the first ammonia cracking unit 100 and the second ammonia cracking unit 200, and the second gap channel formed by the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400, for collecting the cracked gas flowing out of the first gap channel 110 and the second gap channel.

[0124] Based on this structure, the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400 can be used in parallel.

[0125] When these four units are used in parallel, the feed is divided into four parallel reactions before merging. If the feed is evenly distributed, the flow rate of each pyrolysis unit is Q / 4, and the spatial-temporal branching time of each pyrolysis unit is τ_branch = V / (Q / 4) = 4V / Q (where V represents the material velocity and Q represents the material flow rate). This results in a significantly reduced apparent gas velocity and a substantial decrease in pressure drop; a smoother heat load distribution and temperature profile; and ease of expansion and redundancy, facilitating maintenance without interrupting production. It is suitable for scenarios with limited pressure drop, requiring redundancy and high availability; and can achieve high and stable overall conversion under good distribution and temperature control conditions.

[0126] Specifically, using the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400 in parallel includes:

[0127] Ammonia gas is simultaneously introduced into the first vent 107 on the cover plate 105 of the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400, and the cracked gas output through the first gap channel 110 and the second gap channel is collected by the first cracked gas collection channel 700.

[0128] The cracked gas generated after the ammonia catalytic cracking reaction in the first ammonia cracking unit 100 and the second ammonia cracking unit 200 enters the first gap channel 110 through the second vent 108 on their respective baffles 106, and the cracked gas generated after the ammonia catalytic cracking reaction in the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 enters the second gap channel through the second vent 108 on their respective baffles 106.

[0129] According to an embodiment of this disclosure, the above-mentioned device further includes a docking pipe (not shown in the figure) for connecting the first vent 107 of the second ammonia cracking unit 200 and the first vent 107 of the third ammonia cracking unit 300.

[0130] The aforementioned device also includes a fourth cracked gas collection channel (not shown in the figure), which is connected to the first vent 107 of the fourth ammonia cracking unit 400.

[0131] Based on this structure, the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400 can be used in series.

[0132] According to embodiments of this disclosure, the use of the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400 in series includes:

[0133] Ammonia gas is introduced into the first vent 107 of the first ammonia cracking unit 100; the cracked gas output from the second ammonia cracking unit 200 via the first vent 107 is introduced into the third ammonia cracking unit 300 via the first vent 107 through the connecting pipe; the cracked gas output from the fourth ammonia cracking unit 400 via the first vent 107 is collected through the fourth cracked gas collection channel.

[0134] In this process, the cracked gas generated from the catalytic cracking reaction of a portion of the ammonia in the first ammonia cracking unit 100 sequentially enters the second ammonia cracking unit 200 through the second vent 108 and the first gap channel 110 of the first ammonia cracking unit 100, and the second vent 108 of the second ammonia cracking unit 200, where it continues to undergo catalytic cracking reaction to generate cracked gas. The cracked gas output from the second ammonia cracking unit 200 through the first vent 107 is introduced into the third ammonia cracking unit 300 through the first vent 107 of the third ammonia cracking unit 300 via a connecting pipe. The cracked gas generated from the catalytic cracking reaction of a portion of the ammonia in the third ammonia cracking unit 300 sequentially enters the fourth ammonia cracking unit 400 through the second vent 108 and the second gap channel of the third ammonia cracking unit 300, and the second vent 108 of the fourth ammonia cracking unit 400, where it continues to undergo catalytic cracking reaction to generate cracked gas.

[0135] Figure 9 The diagram illustrates the gas flow direction in a first series group formed by combining a first ammonia cracking unit 100 and a second ammonia cracking unit 200 according to an embodiment of the present disclosure. The gas flow directions in the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are the same as those in the first ammonia cracking unit 100 and the second ammonia cracking unit 200, and will not be described again here.

[0136] like Figure 9 As shown, in the first ammonia cracking unit 100, the heat source gas flows through the heat source channel 102 ( Figure 9 In the process, the heat source gas enters from the direction perpendicular to the paper plane); ammonia gas enters the cracking reaction channel 103 from the first vent 107 on the cover plate 105. The cracked gas generated after the partial ammonia catalytic cracking reaction in the first ammonia cracking unit 100 passes through the second vent 108 on the baffle 106 of the first ammonia cracking unit 100, the first gap channel 110, and the second vent 108 on the baffle 106 of the second ammonia cracking unit 200, and enters the second ammonia cracking unit 200. The cracked gas is generated after the catalytic cracking reaction continues in the second ammonia cracking unit 200.

[0137] Subsequently, the cracked gas output from the second ammonia cracking unit 200 via the first vent 107 is introduced into the third ammonia cracking unit 300 via the first vent 107 through the docking pipe. The cracked gas generated after the partial ammonia catalytic cracking reaction in the third ammonia cracking unit 300 enters the fourth ammonia cracking unit 400 via the second vent 108 on the baffle 106 of the third ammonia cracking unit 300, the second gap channel, and the second vent 108 on the baffle 106 of the fourth ammonia cracking unit 400. The cracked gas is then generated after the catalytic cracking reaction continues in the fourth ammonia cracking unit 400. Finally, the cracked gas output from the fourth ammonia cracking unit 400 via the first vent 107 is collected through the fourth cracked gas collection channel.

[0138] When these four units are used in series, the same stream of material passes through four bed segments sequentially. The equivalent bed lengths accumulate, and the corresponding equivalent bed volume increases. The total space-time τ_total = 4V / Q. This facilitates segmented heat compensation and temperature monitoring; it also provides stronger flow characteristics; and it approaches equilibrium segment by segment, making it suitable for achieving high conversion rates. It is suitable for scenarios that require the highest conversion rate, allow for larger pressure drops, and have segmented heating capabilities.

[0139] According to embodiments of this disclosure, the above-described apparatus further includes a second pyrolysis gas collection channel and a second pyrolysis gas collection channel (not shown in the figure).

[0140] The second cracked gas collection channel is connected to the first vent 107 of the second ammonia cracking unit 200, and the second cracked gas collection channel is connected to the first vent 107 of the fourth ammonia cracking unit 400.

[0141] Based on this structure, a series-parallel combination can be achieved between the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400. Specifically, the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are used in series to form a first series group, the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are used in series to form a second series group, and the first series group and the second series group are used in parallel.

[0142] In this combination of series and parallel connections, branch 1 is the first ammonia cracking unit 100. The second ammonia cracking unit is 200; branch 2 is the third ammonia cracking unit 300. The fourth ammonia cracking unit is 400 rpm; two "series trains" are connected in parallel, with their discharges converging. Each branch can provide inter-stage heat replenishment, possessing "segmented approximation" capability; the pressure drop is lower compared to a fully series system. Key operational points: Uniform distribution is crucial; otherwise, flow deviation will propagate between the two sections. ΔP (pressure difference), temperature, and conversion rate need to be monitored separately for each branch. Suitable for scenarios requiring a compromise between conversion rate, pressure drop, and operability, and where strong manifold distribution capabilities are desired.

[0143] According to embodiments of this disclosure, the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are used in series to form a first series group, the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are used in series to form a second series group, and the first series group and the second series group are used in parallel, including:

[0144] Ammonia gas is simultaneously introduced into the first vent 107 of the first ammonia cracking unit 100 and the third ammonia cracking unit 300; the cracked gas output from the second ammonia cracking unit 200 through the first vent 107 is collected by the second cracked gas collection channel, and the cracked gas output from the fourth ammonia cracking unit 400 through the first vent 107 is collected by the third cracked gas collection channel.

[0145] In this process, the cracked gas produced by the catalytic cracking reaction of a portion of the ammonia in the first ammonia cracking unit 100 sequentially enters the second ammonia cracking unit 200 through the second vent 108 of the first ammonia cracking unit 100, the first gap channel 110, and the second vent 108 of the second ammonia cracking unit 200, and continues to produce cracked gas after catalytic cracking reaction in the second ammonia cracking unit 200 (see...). Figure 9 ).

[0146] The cracked gas generated after the partial catalytic cracking reaction of ammonia in the third ammonia cracking unit 300 enters the fourth ammonia cracking unit 400 through the second vent 108 and the second gap channel of the third ammonia cracking unit 300, and the second vent 108 of the fourth ammonia cracking unit 400, and continues to generate cracked gas after catalytic cracking reaction in the fourth ammonia cracking unit 400.

[0147] According to embodiments of this disclosure, the above-described apparatus further includes a three-way pipe and a fourth pyrolysis gas collection channel (not shown in the figure).

[0148] The inlet of the three-way pipe is connected to the first gap channel 110, and the two outlets of the three-way pipe are connected to the first vent 107 of the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400, respectively; the fourth cracked gas collection channel is connected to the second gap channel.

[0149] Based on this structure, a series-parallel combination can be achieved between the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400. Specifically, the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are used in parallel to form a first parallel group, and the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are used in parallel to form a second parallel group. The first parallel group and the second parallel group are then used in series.

[0150] Specifically, the methods used in the above series-parallel connection include:

[0151] Ammonia gas is simultaneously introduced into the first vent of the first ammonia cracking unit 100 and the second ammonia cracking unit 200; the cracked gas output from the first gap channel 110 is distributed to the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 via the first vent 107 of the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 using a three-way pipe; the cracked gas output from the second gap channel is collected using a fourth cracked gas collection channel; wherein, the cracked gas generated after the catalytic cracking reaction of ammonia in the first ammonia cracking unit 100 and the second ammonia cracking unit 200 enters the first gap channel 110 through their respective second vent 108, and the cracked gas generated after the cracked gas in the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 continues to undergo catalytic cracking reaction enters the second gap channel through their respective second vent 108.

[0152] In the above-mentioned series-parallel configuration, the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are connected in parallel as the first stage, and the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are connected in parallel as the second stage. The first-stage outputs are combined and then distributed to the second stage, finally merging for final output. If evenly distributed, each parallel unit has different spatial and temporal characteristics at each stage. The total equivalent space-time of the two-stage cascaded circuit. The two-stage structure provides a "primary conversion + deep polishing" path, allowing for reheating and thorough mixing / redistribution between stages, which helps to bring the temperature back down and reduce NH3 escape. The parallel connection of two units per stage reduces the gas velocity of a single unit and decreases the pressure drop per stage; the total pressure drop after two stages in series is typically significantly lower than that of a four-stage fully series configuration. It is modular and scalable; any unit anomaly in any stage can be partially buffered by the parallel structure; online monitoring should be configured with flow / temperature / ΔP and interstage analysis.

[0153] Furthermore, the catalysts packed in the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400 are of different types; the method further includes: determining the types of catalysts packed in the plurality of ammonia cracking units according to predetermined conditions, wherein the predetermined conditions include at least one of the following: the material communication method between the plurality of ammonia cracking units, the reaction temperature inside each of the plurality of ammonia cracking units, and the particle size of the catalyst to be packed in the plurality of ammonia cracking units.

[0154] The following sections will explain each point.

[0155] (1) In one embodiment, the type of catalyst packed in the multiple ammonia cracking units is determined based on the material connection method (series or parallel connection) between the multiple ammonia cracking units and the reaction temperature inside each of the multiple ammonia cracking units.

[0156] (1.1) In the scenario where four cracking units are used in series, even if the catalyst is the same, the series connection will result in different partial pressures and temperature conditions faced by each segment; when the activity of each segment is different, this difference will be further amplified.

[0157] First ammonia cracking unit 100 (inlet section): Highest ammonia partial pressure, lowest hydrogen pressure, strongest kinetic driving force; strongest endothermic effect, prone to forming inlet cold point; if impurities are present, the inlet section acts more like a protective / sacrificial section. Second ammonia cracking unit 200 (front-middle section): Ammonia pressure has decreased but remains relatively high, typically undertaking the main conversion; if the temperature drop in the first ammonia cracking unit 100 is significant, the inlet temperature of the second ammonia cracking unit 200 may be too low, requiring heating compensation. Third ammonia cracking unit 300 (rear-middle section): Lower ammonia pressure, higher hydrogen pressure, significantly reduced reaction rate and more constrained by equilibrium; if the reaction temperatures of the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are lower than those of the first ammonia cracking unit 100 and the second ammonia cracking unit 200, both kinetics and equilibrium are more unfavorable. Fourth ammonia cracking unit 400 (tail-end polishing section): Lowest ammonia pressure, determining the final ammonia escape; most likely to become a system bottleneck, requiring sufficient "margin" (activity / temperature / bed density at least one of these).

[0158] When four cracking units are connected in series, ammonia gas decreases and hydrogen gas increases along the path, making the process slower as it progresses; moreover, the endothermic reaction is less likely to reach equilibrium at lower temperatures. A more robust approach for scenarios with decreasing temperatures is to increase catalyst activity along the flow direction (higher in the later stages). That is, along the tandem catalytic path of the first, second, third, and fourth ammonia cracking units, the activity of the catalyst increases sequentially; for example: a1 ≤ a2 < a3 ≤ a4 (or expressed in groups: (a1≈a2) < (a3≈a4)), where 'a' represents catalyst activity, and 1, 2, 3, and 4 represent different catalytic units. Specifically, a1, a2, a3, and a4 represent the catalyst activities of the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400, respectively.

[0159] The four ammonia cracking units can be divided according to their functions, and the activity should be configured / demonstrated accordingly:

[0160] First ammonia cracking unit 100: Inlet start-up + protection + controlled cooling point: The inlet driving force is already large; excessive activity can easily cause excessive local endothermy and form a cooling point; if there are impurities, the inlet section is more prone to poisoning / contamination. It is more suitable to choose a formulation with medium or low catalyst activity but with stability and stronger tolerance.

[0161] Second ammonia cracking unit 200: Main conversion section (consuming most of the ammonia): Still in the high ammonia partial pressure zone, it undertakes the main conversion; at the same temperature level as the first ammonia cracking unit 100, the main conversion can be ensured by appropriately increasing the activity. The catalyst activity is selected to be medium or slightly higher than that of the first ammonia cracking unit 100.

[0162] The third ammonia cracking unit 300: Post-compensation section (low ammonia + high hydrogen, suppressing environmental conditions): The post-compensation driving force is low and the temperature may be lower; higher intrinsic activity (and, if necessary, larger bed volume / stronger heating) is required to compensate for the rate decline. The downstream section can obtain some of the upstream thermal potential, which is beneficial for the high-activity catalyst to perform at a more stable temperature. A high catalyst activity (significantly higher than 1 / 2) is selected.

[0163] Fourth ammonia cracking unit 400: Final polishing section (determines ammonia escape): closest to equilibrium and with the lowest ammonia levels; the outlet performance is usually determined by the tail-end capacity; high activity in the latter section can also extend the system's usability after gradual deactivation in the former section. Select catalysts with the highest activity or those of the same class as the third ammonia cracking unit 300 but more "polishing-type".

[0164] (1.2) In the scenario where four pyrolysis units are used in parallel, if the conversion of a certain branch is significantly lower and it carries a large flow rate, it will significantly reduce the overall outlet index. Unlike series pyrolysis, parallel structures cannot rely on downstream reactors to "clean up" the unreacted ammonia in the upstream section. In parallel systems, the inlet composition of each branch is usually close to the same, but differences in temperature range and flow rate distribution can cause the outlet conversion to branch.

[0165] If the temperatures of the four pyrolysis units are similar, then the catalyst activity within the four pyrolysis units is consistent: a1 ≈ a2; a3 ≈ a4.

[0166] When the temperatures of the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are relatively higher or easier to maintain, while the temperatures of the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are relatively lower or more difficult to heat, in order to reduce the "weakest link effect" of the parallel system, the catalyst activity should be compensated according to the degree of temperature disadvantage (a3 ≈ a4) > (a1 ≈ a2).

[0167] If the four branches are structurally as symmetrical as possible, with identical catalyst volumes and evenly distributed flow rates (Qi≈Q / 4), the larger the temperature difference, the greater the required activity compensation ratio in order to make the "apparent rate capability" similar at different temperature levels. In practice, it is still necessary to verify this in conjunction with equilibrium constraints, bed heat transfer / heating capacity, and pressure drop.

[0168] If the flow distribution among the four branches is not completely uniform (Qi is not equal), the branch that carries a larger flow (higher space velocity, shorter residence time) needs higher reactivity (higher activity / higher temperature / larger bed volume) to avoid becoming a low-conversion branch.

[0169] (1.3) In the scenario where the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are connected in series to form a first series group, the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are connected in series to form a second series group, and the first series group and the second series group are connected in parallel: Branch 1 is the first ammonia cracking unit 100 The second ammonia cracking unit is 200; branch 2 is the third ammonia cracking unit 300. Fourth ammonia cracking unit 400;

[0170] Branch 1 (Temperature T12): Due to the high partial pressure of ammonia gas at the inlet of the series section, the large kinetic driving force, and the strong endothermic effect, the activity distribution within the branch should balance conversion and temperature control. A gradient of a1 ≤ a2 is recommended (or a1 ≈ a2, slightly lower, with a2 slightly higher for polishing / compensation). This avoids excessive activity in the first ammonia cracking unit 100, which could lead to an overly vigorous inlet reaction and the formation of a deep cryogenic point. Shifting a portion of the reaction load to the second ammonia cracking unit 200 helps to achieve uniform endothermic absorption and stable temperature.

[0171] Branch 2 (Temperature T34): Temperature conditions are generally more unfavorable (weaker thermal potential), and it still exhibits series characteristics. To achieve deep cracking and stable outlet parameters: a3 ≤ a4 (and the overall levels of a3 and a4 are higher than a1 and a2 of branch 1). To avoid excessive heat absorption at the inlet of the third ammonia cracking unit 300 leading to a cold spot; to reserve the "final polishing allowance" for the fourth ammonia cracking unit 400, which is beneficial for reducing the ammonia gas at the outlet of this branch.

[0172] In this series-parallel combination scenario, the catalyst activity distribution must simultaneously satisfy both the "series gradient within the branch" and the "capacity matching between branches". An increasing gradient of a1 ≤ a2 and a3 ≤ a4 is adopted within the branch to reduce the inlet cold point and retain polishing margin, while the overall distribution is a1 ≤ a2 < a3 ≤ a4 to compensate for unfavorable temperature conditions and avoid the bottleneck effect of parallel convergence.

[0173] (1.4) In the scenario where the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are used in parallel to form a first parallel group, and the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are used in parallel to form a second parallel group, and the first parallel group and the second parallel group are used in series, the first ammonia cracking unit 100 and the second ammonia cracking unit 200 in the first stage share the total flow rate. After the discharges are combined, mixing and temperature equalization can be achieved, and then the materials are distributed to the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 in the second stage in parallel. The "main conversion" is completed in the first stage and the inlet cold point is avoided to be too deep; the temperature is brought back to the target range through interstage reheating; and the "tail-end polishing" is achieved in the second stage to reduce the overall ammonia escape.

[0174] Within the same temperature group (first ammonia cracking unit 100, second ammonia cracking unit 200 or third ammonia cracking unit 300, fourth ammonia cracking unit 400), the activity should be as close as possible (a1 ≈ a2; a3 ≈ a4) to reduce the amplification effect of parallel flow bias. The overall activity level of the second stage (third ammonia cracking unit 300, fourth ammonia cracking unit 400) is higher than that of the first stage (first ammonia cracking unit 100, second ammonia cracking unit 200), i.e. (a3, a4) > (a1, a2), to compensate for the lower temperature / weaker heating and to undertake polishing. The first stage has a more favorable temperature and driving force (higher T12, higher ammonia partial pressure), and the main conversion can be completed without the strongest activity; the second stage has a lower temperature and lower ammonia partial pressure, which is more unfavorable, and requires higher activity / stronger capacity to compensate.

[0175] In this series-parallel combination scenario, the catalyst activity distribution should adopt a strategy of "matching within the same stage and increasing between stages": the first stage a1 ≈ a2, with moderate activity to avoid inlet cold point and complete the main conversion; the second stage a3 ≈ a4, with overall higher activity than the first stage and retaining polishing margin at the end (which can be expressed as (a1 ≈ a2) < (a3 ≈ a4). This is complemented by interstage reheating and thorough mixing, ensuring even flow distribution and stable temperature control across all parallel stages, thereby achieving low ammonia escape and steady-state operation.

[0176] (2) In one embodiment, the type of catalyst packed in the multiple ammonia cracking units is determined based on the material connection method (series or parallel connection) between the multiple ammonia cracking units and the particle size of the catalyst in the multiple ammonia cracking units.

[0177] The influence of catalyst particle size is as follows:

[0178] Catalyst particle size affects the pressure drop (ΔP) inside the ammonia cracking unit: the pressure drop in the fixed bed increases significantly with decreasing particle size (viscous term in Ergun relation: 1 / dp², inertial term: 1 / dp). The smaller the particle size, the greater the pressure drop, the higher the energy consumption, and the easier it is to induce parallel flow deviation.

[0179] Catalyst particle size affects mass transfer / efficiency factor: the smaller the particle size, the shorter the external mass transfer resistance and internal diffusion path, and the higher the particle efficiency factor is usually; when the particle size is too large, internal diffusion restriction is likely to occur, and the apparent activity will decrease, especially in the low temperature / low driving force region.

[0180] Catalyst particle size affects thermal behavior: In endothermic reactions, the more concentrated the reaction, the easier it is to form a "cold spot". Larger particle size (or stronger diffusion restriction) may "passivate" the reaction intensity in the inlet section and reduce the depth of the cold spot; smaller particle size is more likely to release intrinsic activity, but if the heat supply is insufficient, it may lead to local temperature drop backlash.

[0181] Catalyst particle size affects anti-clogging and mechanical properties: If there is dust / entrainment upstream, larger particle sizes are less prone to clogging; too small a particle size may increase pressure drop and the risk of dust accumulation (this needs to be verified in conjunction with purification and filtration conditions).

[0182] (2.1) In the scenario where four pyrolysis units are used in series, the key constraints of series connection are: pressure drop accumulation, high driving force and strong heat absorption at the inlet, and low driving force at the tail end that is closer to equilibrium. Particle size distribution usually requires "controlling the cooling point and pressure drop at the front end and performing deep polishing at the rear end".

[0183] Therefore, the particle size gradient of the four pyrolysis units can be selected as follows: dp1 ≥ dp2 ≥ dp3 ≥ dp4 (particle size decreases along the flow direction, becoming finer downstream). dp represents the catalyst particle size, and 1, 2, 3, and 4 represent different catalytic units, i.e., dp1, dp2, dp3, and dp4 represent the particle sizes of the catalysts in the first ammonia pyrolysis unit 100, the second ammonia pyrolysis unit 200, the third ammonia pyrolysis unit 300, and the fourth ammonia pyrolysis unit 400, respectively.

[0184] First ammonia cracking unit 100 (inlet section): This section has the strongest driving force and the most vigorous reaction. Using larger particle sizes can reduce pressure drop and "passivate" the reaction concentration in the inlet section, mitigating the depth of the cold spot and the instantaneous impact on heating. It also provides better resistance to entrainment and blockage. Second ammonia cracking unit 200: Still in a high ammonia partial pressure region, a medium particle size can be used to strike a balance between pressure drop and effective factor, allowing for a more uniform distribution of the main conversion along the path from the first ammonia cracking unit 100 to the second ammonia cracking unit 200. Third ammonia cracking unit 300 and fourth ammonia cracking unit 400 (post-polishing): These sections have even lower ammonia partial pressures, and if T34 is relatively low, a higher effective factor is required to maintain the apparent rate. Using smaller particle sizes can reduce internal diffusion limitations, improve effective utilization, and help reduce ammonia escape.

[0185] It can be seen that along the reaction path of the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400, the thermal potential is transferred from the first ammonia cracking unit 100 and the second ammonia cracking unit 200 to the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400. Therefore, arranging smaller particle sizes in the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 can compensate for the unfavorable temperature to a certain extent.

[0186] (2.2) In the scenario where four pyrolysis units are used in parallel, the core of the parallel system is "flow distribution and the bottleneck effect". Different particle sizes will lead to different pressure drop resistances, thus causing flow deviation; and the parallel outlet is a flow-weighted average, so the branch with low conversion and high flow will dominate the overall index. The principle of particle size distribution: the parallel branches should achieve resistance matching and even distribution as much as possible, so it is recommended that the particle sizes within the same temperature group be similar.

[0187] Particle size gradient selection: dp1 ≈ dp2; dp3 ≈ dp4; and usually dp3, dp4 ≤ dp1, dp2 (the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are finer).

[0188] The particle sizes in the first ammonia cracking unit 100, the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400 are similar. If dp1 ≠ dp2, the different resistances will cause one branch to receive more flow, increasing outlet fluctuations. If T34 is relatively lower, using smaller particle sizes (finer dp3 and dp4) can improve the effective factor and enhance the conversion of this group to narrow the performance gap with the first ammonia cracking unit 100 and the second ammonia cracking unit 200; however, this will also increase the pressure drop of this group and tend to "take less flow," requiring hydraulic balancing through manifolds / orifice plates / valves to avoid pushing the flow to the branch with poorer conversion.

[0189] In parallel mode, particle size differences should be minimized, and throttling elements should be preferred over large particle size differences for flow regulation.

[0190] (2.3) In the scenario where the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are connected in series to form a first series group, the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are connected in series to form a second series group, and the first series group and the second series group are connected in parallel: Branch 1 is the first ammonia cracking unit 100 The second ammonia cracking unit is 200; branch 2 is the third ammonia cracking unit 300. The fourth ammonia cracking unit is 400. The particle size distribution needs to meet two objectives simultaneously: within the branch (in series), the main conversion, polishing, and controlled cooling point are achieved; between the branches (in parallel), the overall resistance of the two branches is matched with the outlet index, avoiding the weakest branch from dragging down the total outlet.

[0191] Particle size gradient selection: Branch 1: dp1 ≥ dp2; Branch 2: dp3 ≥ dp4; The particle size of Branch 2 should be finer or at least not coarser than that of Branch 1, i.e. (dp3, dp4) ≤ (dp1, dp2).

[0192] The inlet section (first ammonia cracking unit 100, and third ammonia cracking unit 300) uses a slightly larger particle size to buffer inlet heat absorption, reduce cold point risk, and control pressure drop; the second section (second ammonia cracking unit 200 or fourth ammonia cracking unit 400) uses a finer particle size for enhanced polishing. If the temperature / heating of branch 2 is lower, a finer particle size can be used to increase the effective factor to avoid excessively high ammonia levels at its outlet; however, a finer particle size will also increase the pressure drop of this branch, resulting in a smaller flow rate. If the goal is to reduce overall ammonia escape, it is often necessary to adjust the branch flow rate through valves / orifice plates: either direct more flow to a branch with better performance, or enhance the heating and bed capacity of branch 2.

[0193] (2.4) In a scenario where the first ammonia cracking unit 100 and the second ammonia cracking unit 200 are used in parallel to form the first parallel group, and the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are used in parallel to form the second parallel group, and the first parallel group and the second parallel group are used in series, this structure is a "two-stage parallel bed group in series". The first stage completes the main conversion, and the stages can be mixed / uniformed and reheated; the second stage is responsible for the tail-end polishing. The particle size distribution should be mainly "uniform within the same stage, progressively finer between stages (fineer in later stages)".

[0194] Particle size gradient selection: Within the same level: dp1 ≈ dp2; dp3 ≈ dp4; Between levels: (dp3, dp4) ≤ (dp1, dp2), indicating that the second level is finer.

[0195] The reason for equal distribution within the same stage is that if dp1 ≠ dp2, the first stage parallel connection will result in flow deviation, causing the first stage outlet composition / temperature to bifurcate between the two branches. Although interstage mixing is possible, the flow deviation will change the heat distribution and cold spot location, increasing the difficulty of control. The same applies to the second stage. The reason for progressive finer particle size between stages is that the second stage faces lower ammonia partial pressure, higher H2 inhibition, and potentially lower temperature (T34), requiring a higher efficiency factor and stronger polishing ability; smaller particle size helps reduce internal diffusion limitations and improve polishing effect. The heat potential is transferred from the first ammonia cracking unit 100, the second ammonia cracking unit 200 to the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400. The second stage is more likely to be "heat-deficient." Therefore, while using finer particle size to enhance polishing, interstage reheating and the second stage heating capacity should be checked as hard constraints to avoid the reaction being too pre-empted due to small particle size, resulting in a cold spot at the second stage inlet.

[0196] Another aspect of this disclosure provides a gas turbine system utilizing the aforementioned ammonia cracking unit, comprising:

[0197] The burner is configured to burn at least a portion of the hydrogen from the cracked gas output from the ammonia cracking unit as fuel to obtain heat source gas;

[0198] A turbine is configured to convert the thermal energy of the heat source gas output from a burner into mechanical energy for power generation.

[0199] At least a portion of the heat source gas output from the burner is fed into the heat source channel of the ammonia cracking unit. Specifically, the hydrogen-rich mixture (H2 / N2 = 3:1) produced by cracking enters the combustion chamber and is burned with premixed air in the burner to produce high-temperature flue gas of 800-1000°C.

[0200] According to embodiments of this disclosure, the high-temperature flue gas discharged from the combustion chamber of the gas turbine system has a high temperature, for example, between 800-1000°C. Using this high-temperature flue gas as a heat source gas in the heat source channel meets the requirements of high-temperature catalytic cracking, improving the reaction performance of catalytic cracking, increasing catalytic efficiency, and enhancing reaction sufficiency. At 800-1000°C, the catalytic reaction starts rapidly, avoiding catalyst deactivation. Staged cracking reduces residual NH3. While providing a high-temperature environment to promote complete ammonia cracking, the cracked gas serves as the fuel source for the combustion chamber, achieving a closed-loop combustion heat generation system. Based on this system, ammonia in the cracked gas is completely converted, eliminating fuel-type NOx generation. An advanced hydrogen burner further reduces thermal NOx generation (thermal NOx is mainly generated when ammonia is used as fuel), increasing the ammonia conversion rate from the traditional 90% to ≥99.9%, and reducing residual NH3 in the cracked tail gas to ≤0.1%, significantly reducing the source of fuel-type NOx.

[0201] According to embodiments of this disclosure, the system further includes a load regulation module configured to adjust the number of a plurality of ammonia cracking units in use according to the electrical load, so as to regulate the hydrogen production and thereby regulate the temperature of the heat source gas output by the burner.

[0202] For example, the four ammonia cracking units can be combined or operated individually in any configuration, with precise gas flow control via the intake distribution regulating valve, enabling multi-mode operation (full load, half load, low load, etc.). For instance, all four ammonia cracking units operate simultaneously under high load, two units operate under medium load, and only one unit operates under low load. This provides highly flexible ammonia cracking capacity to adapt to different load fluctuations in the gas turbine; avoids large-volume single-channel structures, improving unit compactness; and reduces local temperature differences and extends catalyst life through unit combination switching. Compared to related technologies that only employ single-channel or parallel multi-channel straight-through structures, this allows for multi-mode combined control.

[0203] When only one ammonia cracking unit is working, ammonia gas is only introduced into the first vent 107 of the first ammonia cracking unit 100, while the first vent 107 of the second ammonia cracking unit 200, the third ammonia cracking unit 300, and the fourth ammonia cracking unit 400 are closed.

[0204] The cracked gas generated in the first ammonia cracking unit 100 directly enters the first gap channel 110 through the second vent 108 of the baffle of the first ammonia cracking unit 100. The cracked gas output from the first gap channel 110 is collected through the first cracked gas collection channel 700 (since the internal resistance of the second ammonia cracking unit 200 is greater than the exhaust resistance of the first gap channel, the cracked gas will basically not enter the second ammonia cracking unit 200, and most of it will be discharged directly from the first gap channel 110).

[0205] When only two ammonia cracking units are operating, the first ammonia cracking unit 100 and the second ammonia cracking unit 200 can be used in parallel or in series, while the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 are shut down (ammonia gas supply is stopped). For the specific control of the gas flow direction of the reaction gas and the cracked gas in parallel or series operation scenarios, please refer to the aforementioned embodiments, which will not be repeated here.

[0206] Alternatively, only the third ammonia cracking unit 300 and the fourth ammonia cracking unit 400 can be used in parallel or in series, while the first ammonia cracking unit 100 and the second ammonia cracking unit 200 can be shut down (ammonia gas supply can be stopped).

[0207] The four ammonia cracking units can operate simultaneously. They can be all connected in parallel, all connected in series, or a combination of series and parallel connections. For specific control of the gas flow direction of the reaction gas and cracked gas, please refer to the aforementioned embodiments, which will not be repeated here.

[0208] According to embodiments of this disclosure, by switching between four-unit zones, it can support full-load operation, half-load partial unit operation, low-load maintenance operation, and rapid combustion chamber temperature adjustment. This responds to grid fluctuations, reduces frequent start-stop cycles, and adapts to fluctuations in hydrogen consumption. Traditional equipment typically only adapts to constant operating conditions.

[0209] According to embodiments of this disclosure, the entire ammonia cracking unit is designed in a modular fashion, and the gas turbine system may include one or more ammonia cracking units.

[0210] Each unit module has a processing capacity of approximately 100 kg-NH3 / h, and production capacity can be expanded by connecting multiple ammonia cracking units in parallel. The combustion chamber outlet flue gas temperature is controlled by adjusting the fuel supply and air flow through an ammonia flow valve, and the inlet temperature gradient of each catalytic cracking unit channel is adjusted through a flue gas diversion valve.

[0211] According to embodiments of this disclosure, if limited by operating conditions or gas supply conditions, the following alternative fuels can also be used for the combustion chamber: 1) Natural gas, whose combustion products have extremely low nitrogen content, can serve as a stable high-temperature heat source. Temperature range: 800-1000℃, with good adjustability. 2) Coal-to-gas or methane recombination gas can provide a high-temperature heat source, but attention must be paid to system desulfurization and decarbonization treatment. 3) Renewable fuel biomethane, which meets the requirements of carbon neutrality. 4) When external power is abundant, electric heating can be used to rapidly raise the flue gas temperature or provide auxiliary insulation. Through fuel substitution, the device has fuel diversity and flexibility, ensuring the required heat input under various operating conditions.

[0212] According to embodiments of this disclosure, the temperature of the heat source gas output from the burner can be controlled by adjusting the fuel supply, such as adjusting the flow rate of the fed cracked gas, to achieve recirculation control. Furthermore, various control methods can be employed, such as a PID automatic temperature control system—which automatically adjusts the temperature using temperature sensors, controllers, and actuators; or intelligent model predictive control (MPC)—which utilizes real-time modeling and prediction to achieve precise control under dynamic operating conditions; or electric auxiliary insulation—which uses an electric heater to further heat the flue gas temperature at the burner outlet to maintain the catalyst bed temperature during rapid load fluctuations.

[0213] Furthermore, in order to adapt to different emission requirements or coupled processes, various utilization methods can be adopted for the cracked gas output from the ammonia cracking unit.

[0214] For example, pyrolysis products can be directly fed into a burner for combustion, achieving closed-loop heating. Alternatively, pyrolysis products can be partially purified and used through membrane separation or pressure swing adsorption to obtain high-purity hydrogen for energy storage or chemical applications. Another example is low-NOx combustion of pyrolysis products combined with waste heat recovery, with the tail gas used in boilers or for waste heat power generation, improving energy efficiency. By modifying the system layout and distribution, it can flexibly adapt to various scenarios such as power generation, hydrogen storage, and combined heat and power (CHP).

[0215] It is evident that the above system possesses the following advantages: 1) Diverse fuel adaptability: adaptable to different regional fuel supply conditions; 2) Multi-scenario adaptability: flexible switching between power generation, heating, and hydrogen utilization; 3) Cost flexibility: multiple selections of high-temperature materials and catalysts; 4) Intelligent control: supporting different levels of automation and intelligence; 5) Scalable scale: flexible expansion from small-scale distributed to large-scale centralized systems.

[0216] According to embodiments of this disclosure, the above-described system provides an economical and environmentally friendly technical path for the large-scale commercialization of ammonia energy through the deep synergy of combustion-driven and catalytic cracking. Applicable to distributed hydrogen energy supply scenarios, its modular design can be flexibly adapted to 1-10MW energy systems, solving the three core problems of traditional ammonia cracking hydrogen production technology: unsustainable energy supply, insufficient cracking efficiency, and difficulty in controlling NOx emissions. Specifically, its technological breakthroughs are reflected in the following aspects:

[0217] Firstly, addressing the low energy efficiency issues caused by existing technologies relying on external high-grade electricity or unstable solar energy, this patent constructs a closed-loop energy cycle system. Traditional electrically heated pyrolysis devices consume a large amount of electricity, while this system utilizes the 800-1000℃ high-temperature flue gas generated by the combustion of pyrolysis products (a mixture of H2 and N2) as a heat source. Through a double-sided heat exchange design in the catalytic channel, it achieves cascaded utilization of thermal energy, thereby improving the system's thermal efficiency. This self-heating mode not only eliminates dependence on the power grid but also solves the industry problem of unstable pyrolysis reactions caused by the intermittent nature of solar heating.

[0218] Secondly, regarding the improvement of cracking efficiency, the multi-stage catalytic channel structure breaks through the conversion limit of traditional single-stage reactors. Compared with single-stage direct-flow cracking reactors, which are limited by short reaction paths and uneven heat exchange, the ammonia conversion rate is generally below 85%. The device of this embodiment adopts a multi-stage catalytic channel design to achieve a conversion rate of over 99.9%. The path is optimized: the serpentine structure extends the reaction path (single-stage channel length 1cm, total effective reaction path 5cm), or the reaction area of ​​the multi-channel catalytic cracking unit is increased to ensure sufficient contact time.

[0219] Staged catalysis: Each stage of catalytic cracking unit is independently filled with a high-efficiency catalyst, and the accumulation of intermediate products is avoided through progressive cracking; Uniform heat exchange: Intermittent heat exchange and a serpentine structure increase the heat exchange area, resulting in uniform catalyst bed temperature and improved ammonia decomposition rate.

[0220] The technical challenge of NOx control in ammonia fuel has been overcome through a "combustion heating-multi-stage pyrolysis-low-NOx combustion" technical route. In traditional ammonia combustion, the direct reaction of unpyrolyzed NH3 with O2 generates fuel-type NOx. However, the above system ensures that ammonia is completely pyrolyzed into H2 and N2 before combustion, eliminating free radical intermediates such as NH2 and NH at the source. Combined with advanced combustion technology, the amount of thermal NOx generated is reduced to below 25 ppm, two orders of magnitude lower than conventional ammonia combustion devices (NOx > 500 ppm). Precise temperature control in a high-temperature environment ensures the complete pyrolysis of ammonia into a mixture of H2 and N2, eliminating nitrogen-containing intermediates at the source. Advanced combustion chamber and combustion technology keep the combustion zone temperature below 1600℃, suppressing thermal NOx. The integrated design of the pyrolysis unit and combustion chamber results in unpyrolyzed ammonia residue of <0.1%, far lower than traditional systems.

[0221] Furthermore, considering system compactness and adaptability to multiple operating conditions, compared to electrically heated pyrolysis units which require a separate heating module, the aforementioned ammonia pyrolysis unit, through a nested design of multi-stage catalytic pyrolysis units and combustion chambers, reduces equipment volume by more than 50%. Simultaneously, by real-time monitoring of the NH3 concentration at the outlet of each catalytic pyrolysis unit and feedback adjustment of the flue gas flow distribution valve and pyrolysis unit mode, the pyrolysis rate fluctuation can be maintained within ±0.01% within a certain load range. Compared to electrically heated systems with fixed heat flux, this adaptive adjustment mechanism based on combustion heat exchange improves energy efficiency under partial load conditions, achieving stable operation within a 30-100% load range, adapting to the dynamic operating requirements of vehicles, ships, and other applications.

[0222] Compared to fossil fuel combustion heating solutions, the system emits only N2 and H2, achieving zero carbon emissions throughout its entire lifecycle. Compared to solar-powered systems, it does not require energy storage buffer devices, thus reducing the unit cost of hydrogen production.

[0223] In summary, based on the combination of "catalytic cracking—high-efficiency heat exchange" modules, and through synergistic innovation of "diverse heat sources—high-efficiency cracking," an ammonia energy utilization system and ammonia cracking unit can be constructed that simultaneously meets the requirements of "zero-carbon hydrogen production and high-efficiency stability." This solves the storage and transportation challenges of hydrogen production from renewable energy sources (using liquid ammonia as the hydrogen carrier) while avoiding the pollution problems of traditional ammonia utilization, providing a complete solution for the hydrogen energy industry chain from storage and transportation to end-use applications. It not only makes the ammonia fuel high-efficiency decomposition unit compact but also provides an effective technical path for the efficient utilization of ammonia fuel and low NOx emissions.

[0224] Those skilled in the art will understand that the features described in the various embodiments of this disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments of this disclosure can be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0225] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. An ammonia cracking apparatus, comprising one or more ammonia cracking units, said ammonia cracking unit comprising: The main housing includes opposing first and second surfaces, as well as opposing third and fourth surfaces; Multiple heat source channels are arranged side by side inside the main housing. Each heat source channel includes a channel inlet and a channel outlet, and the channel inlet and the channel outlet respectively penetrate the first surface and the second surface. Multiple pyrolysis reaction channels, wherein each pyrolysis reaction channel is formed by a gap between two adjacent heat source channels, and each pyrolysis reaction channel is filled with a catalyst; The first vent is located on the third side; The second vent is located on the fourth side; Wherein, one of the first vent and the second vent is configured to introduce a reaction gas containing ammonia into the cracking reaction channel, so that at least a portion of the ammonia in the reaction gas undergoes a catalytic cracking reaction under the action of the catalyst; the other of the first vent and the second vent is configured to discharge the cracked gas generated after the catalytic cracking reaction. The heat source channel is configured to introduce heat source gas to heat the pyrolysis reaction channel, thereby enhancing the activity of the catalytic pyrolysis reaction.

2. The apparatus according to claim 1, wherein: The heat source channel and the pyrolysis reaction channel are serpentine channels.

3. The apparatus according to claim 1, wherein: The third and fourth surfaces are respectively provided with a first opening and a second opening; The device further includes: A cover plate is installed to seal the first opening, and the cover plate is provided with a first vent. A baffle is installed to seal the second opening, and the baffle is provided with a second vent.

4. The apparatus according to claim 3, wherein: The baffle has multiple second vents, which are evenly distributed on the baffle.

5. The apparatus according to claim 1, wherein: The ammonia cracking unit includes a first ammonia cracking unit, a second ammonia cracking unit, a third ammonia cracking unit, and a fourth ammonia cracking unit; The first ammonia cracking unit and the third ammonia cracking unit are arranged and assembled along the first direction, which represents the direction from the inlet of the heat source channel to the outlet of the channel; The second and fourth ammonia cracking units are arranged and assembled along the first direction; The first ammonia cracking unit and the second ammonia cracking unit are arranged and assembled along the second direction, which is perpendicular to the first direction. The third and fourth ammonia cracking units are arranged and assembled along the second direction.

6. The ammonia cracking apparatus according to claim 5, wherein: The outlet of the heat source channel of the first ammonia cracking unit is connected to the inlet of the heat source channel of the third ammonia cracking unit. The outlet of the heat source channel of the second ammonia cracking unit is connected to the inlet of the heat source channel of the fourth ammonia cracking unit.

7. The apparatus according to claim 6, further comprising: The first connecting end cap is installed on the channel inlet side of the heat source channel of the first ammonia cracking unit and the second ammonia cracking unit, and is configured to connect the channel inlet of the heat source channel of the first ammonia cracking unit and the second ammonia cracking unit to the gas source device that generates the heat source gas. The second connecting end cap is installed on the channel outlet side of the heat source channel of the third ammonia cracking unit and the fourth ammonia cracking unit, and is configured to connect the channel outlet of the heat source channel of the third ammonia cracking unit and the fourth ammonia cracking unit to the waste heat collection device.

8. The ammonia cracking apparatus according to claim 5, wherein: The edge portions of the fourth surfaces of the first ammonia cracking unit, the second ammonia cracking unit, the third ammonia cracking unit, and the fourth ammonia cracking unit extend outward along the second direction to form flange portions; The first ammonia cracking unit and the second ammonia cracking unit are arranged symmetrically, and the flange portion of the fourth side of each of the first ammonia cracking unit and the second ammonia cracking unit encloses and forms the first gap channel. The third and fourth ammonia cracking units are arranged symmetrically, and the flanges on the fourth surfaces of each unit enclose a second gap channel.

9. The ammonia cracking apparatus according to claim 8, further comprising: The first pyrolysis gas collection channel is connected to the first gap channel and the second gap channel.

10. The ammonia cracking apparatus according to claim 8, further comprising: The second cracked gas collection channel is connected to the first vent of the second ammonia cracking unit. The third cracked gas collection channel is connected to the first vent of the fourth ammonia cracking unit.

11. The ammonia cracking apparatus according to claim 8, further comprising: A connecting pipe is used to connect the first vent of the second ammonia cracking unit to the first vent of the third ammonia cracking unit. The fourth cracked gas collection channel is connected to the first vent of the fourth ammonia cracking unit.

12. The ammonia cracking apparatus according to claim 8, further comprising: The three-way pipe has an inlet connected to the first gap channel and two outlets connected to the first vents of the third ammonia cracking unit and the fourth ammonia cracking unit, respectively. The fourth pyrolysis gas collection channel is connected to the second gap channel.

13. A method for catalytic cracking using the ammonia cracking apparatus of claim 9, comprising: The first ammonia cracking unit, the second ammonia cracking unit, the third ammonia cracking unit, and the fourth ammonia cracking unit are used in parallel.

14. The method according to claim 13, wherein, Using the first ammonia cracking unit, the second ammonia cracking unit, the third ammonia cracking unit, and the fourth ammonia cracking unit in parallel includes: Ammonia gas is simultaneously introduced into the first vent of the first ammonia cracking unit, the second ammonia cracking unit, the third ammonia cracking unit, and the fourth ammonia cracking unit. The cracked gas output through the first gap channel and the second gap channel is collected using the first cracked gas collection channel. The cracked gas produced by the catalytic cracking reaction of ammonia in the first and second ammonia cracking units enters the first gap channel through their respective second vents, and the cracked gas produced by the catalytic cracking reaction of ammonia in the third and fourth ammonia cracking units enters the second gap channel through their respective second vents.

15. A method for catalytic cracking using the ammonia cracking apparatus of claim 10, comprising: The first ammonia cracking unit and the second ammonia cracking unit are connected in series to form a first series group, the third ammonia cracking unit and the fourth ammonia cracking unit are connected in series to form a second series group, and the first series group and the second series group are connected in parallel.

16. The method according to claim 15, wherein, Connecting the first ammonia cracking unit and the second ammonia cracking unit in series to form a first series group, connecting the third ammonia cracking unit and the fourth ammonia cracking unit in series to form a second series group, and connecting the first series group and the second series group in parallel includes: Ammonia gas is simultaneously introduced into the first vents of both the first and third ammonia cracking units; the cracked gas output from the second ammonia cracking unit via the first vent is collected using a second cracked gas collection channel, and the cracked gas output from the fourth ammonia cracking unit via the first vent is collected using a third cracked gas collection channel; wherein... The cracked gas produced by the catalytic cracking reaction of a portion of the ammonia in the first ammonia cracking unit enters the second ammonia cracking unit through the second vent of the first ammonia cracking unit, the first gap channel, and the second vent of the second ammonia cracking unit, and continues to produce cracked gas after catalytic cracking reaction in the second ammonia cracking unit. The cracked gas produced by the catalytic cracking reaction of a portion of the ammonia in the third ammonia cracking unit enters the fourth ammonia cracking unit through the second vent and the second gap channel of the third ammonia cracking unit, and then through the second vent of the fourth ammonia cracking unit. The cracked gas is then produced by the catalytic cracking reaction in the fourth ammonia cracking unit.

17. A method for catalytic cracking of ammonia using the ammonia cracking apparatus of claim 11, comprising: The first ammonia cracking unit, the second ammonia cracking unit, the third ammonia cracking unit, and the fourth ammonia cracking unit are used in series.

18. The method according to claim 17, wherein, Using the first ammonia cracking unit, the second ammonia cracking unit, the third ammonia cracking unit, and the fourth ammonia cracking unit in series includes: Ammonia gas is introduced into the first vent of the first ammonia cracking unit; the cracked gas output from the second ammonia cracking unit via the first vent is introduced into the third ammonia cracking unit via the first vent of the third ammonia cracking unit through a connecting pipe; the cracked gas output from the fourth ammonia cracking unit via the first vent is collected through a fourth cracked gas collection channel; wherein... The cracked gas produced by the catalytic cracking reaction of a portion of the ammonia in the first ammonia cracking unit enters the second ammonia cracking unit through the second vent of the first ammonia cracking unit, the first gap channel, and the second vent of the second ammonia cracking unit, and continues to produce cracked gas after catalytic cracking reaction in the second ammonia cracking unit. The cracked gas produced by the catalytic cracking reaction of a portion of the ammonia in the third ammonia cracking unit enters the fourth ammonia cracking unit through the second vent and the second gap channel of the third ammonia cracking unit, and then through the second vent of the fourth ammonia cracking unit. The cracked gas is then produced by the catalytic cracking reaction in the fourth ammonia cracking unit.

19. A method for catalytic cracking using the ammonia cracking apparatus of claim 12, comprising: The first ammonia cracking unit and the second ammonia cracking unit are used in parallel to form a first parallel group, and the third ammonia cracking unit and the fourth ammonia cracking unit are used in parallel to form a second parallel group. The first parallel group and the second parallel group are then used in series.

20. The method according to claim 19, wherein, The first ammonia cracking unit and the second ammonia cracking unit are used in parallel to form a first parallel group, and the third ammonia cracking unit and the fourth ammonia cracking unit are used in parallel to form a second parallel group. The first parallel group and the second parallel group are then used in series. Ammonia gas is simultaneously introduced into the first vents of the first and second ammonia cracking units; the cracked gas output from the first gap channel is distributed to the third and fourth ammonia cracking units via the first vents of the third and fourth ammonia cracking units using a three-way pipe; the cracked gas output from the second gap channel is collected using a fourth cracked gas collection channel; wherein... The cracked gas produced after the catalytic cracking reaction of ammonia in the first and second ammonia cracking units enters the first gap channel through their respective second vents, and the cracked gas produced after the catalytic cracking reaction of cracked gas in the third and fourth ammonia cracking units enters the second gap channel through their respective second vents.

21. The method according to any one of claims 13-20, wherein: The first ammonia cracking unit, the second ammonia cracking unit, the third ammonia cracking unit, and the fourth ammonia cracking unit are filled with different types of catalysts; The method further includes determining the type of catalyst to be packed in the plurality of ammonia cracking units according to predetermined conditions, wherein the predetermined conditions include at least one of the following: the material communication method between the plurality of ammonia cracking units, the reaction temperature inside each of the plurality of ammonia cracking units, and the particle size of the catalyst to be packed in the plurality of ammonia cracking units.

22. A gas turbine system comprising an ammonia cracking unit according to any one of claims 1-12, comprising: The burner is configured to burn at least a portion of the hydrogen in the cracked gas output from the ammonia cracking unit as fuel to obtain heat source gas; A turbine is configured to convert the thermal energy of the heat source gas output from a burner into mechanical energy for power generation. At least a portion of the heat source gas output from the burner is fed into the heat source channel in the ammonia cracking unit.

23. The system according to claim 22, further comprising: The load regulation module is configured to adjust the number of multiple ammonia cracking units in use according to the electrical load, so as to regulate the hydrogen production and thus regulate the temperature of the heat source gas output by the burner.

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