Heat, electricity and mechanical energy combined supply system of two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling

Abstract

The invention relates to a heat, electricity and mechanical energy combined supply system of a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling, and belongs to the technical field of ammonia decomposition hydrogen production energy comprehensive utilization. Comprising an ammonia gas supply unit, a water vapor supply unit, an air supply unit, a first heat exchanger, a second heat exchanger, a front-section reactor, a rear-section reactor, a gas-liquid separator, a hydrogen storage unit, a proton exchange membrane battery, an ammonia-hydrogen burner, a hydrogen-air burner and a third heat exchanger. The system has the characteristics of complete and compact structure and multiple functions; the system energy utilization rate is high, and energy self-sufficiency can be achieved; energy utilization is achieved, output flexibility is high, regulation and control modes are diversified, and the capacity of outputting heat, electricity, mechanical energy and hydrogen outwards is achieved; the system is low in cost, high in safety and strong in adaptability.

Description

Technical Field

[0001] The present invention relates to a heat, electricity and mechanical energy co-supply system of a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling, belonging to the technical field of comprehensive utilization of energy for ammonia decomposition hydrogen production. Background Art

[0002] At present, human society's energy system faces two major problems: environmental pollution and sustainable development. The development and utilization of new energy is an effective way to solve the above problems. Hydrogen energy, as the main type of new energy, has significant advantages such as high energy density, cleanliness, and sustainability. However, it has limitations such as high production costs and many storage and transportation problems, which slow down its large-scale promotion and application. Hydrogen itself has low volume density, difficulty in liquefaction, flammability and explosiveness, which lead to high costs, high energy consumption, low efficiency, and prominent safety issues in the direct storage and transportation of hydrogen. The on-site production of hydrogen using hydrogen storage materials can avoid various problems of direct storage and transportation of hydrogen, and is suitable for hydrogen energy applications where it is difficult to directly obtain hydrogen or where safety issues are of high concern.

[0003] Ammonia is a suitable hydrogen storage material. Compared to direct hydrogen storage, ammonia storage offers advantages such as high volumetric energy density, ease of liquefaction, low storage and transportation costs, and improved safety. At hydrogen-using sites, ammonia can be decomposed into N2 and H2 products, which provide hydrogen for hydrogen-using equipment. Currently, NH3 production technology is mature, scalable, and low-cost. Furthermore, NH3 storage and transportation technology is mature, the system is comprehensive, and the infrastructure is widely established. The "ammonia-hydrogen" energy system established on this basis is a key approach to hydrogen energy application.

[0004] In addition, the development of ammonia as a hydrogen storage medium can connect renewable energy, hydrogen energy and traditional industries, and develop a full-chain "ammonia-hydrogen" green circular economy route of "clean and efficient ammonia synthesis - safe and low-cost storage and transportation of ammonia - carbon-free and efficient "ammonia-hydrogen" utilization", such as on-site ammonia hydrogen production and refueling integrated stations, vehicle / marine power and "ammonia-hydrogen" combustion internal combustion engines, etc., which are of great significance to ensuring national energy and environmental security and sustainable social and economic development.

[0005] Ammonia decomposition to produce hydrogen is applicable to a variety of hydrogen energy application fields and is easy to scale up in engineering. It is an efficient, clean, portable in-situ hydrogen production technology. Energy production and utilization systems based on ammonia decomposition to produce hydrogen have become a hot topic in the current field of hydrogen energy applications. Various types of hydrogen energy utilization systems based on ammonia decomposition to produce hydrogen have been developed, such as: CN 117125671A discloses an ammonia decomposition to produce hydrogen system and its application, which generates a hydrogen source that can be used by proton membrane fuel cells by coupling the ammonia decomposition hydrogen production process and ammonia adsorption deamination; CN101538010B introduces an ammonia decomposition to produce hydrogen system based on the waste heat of heat engine exhaust, which uses the high-temperature exhaust gas discharged by the heat engine (such as an internal combustion engine) to provide heat for the ammonia decomposition reaction, and the generated hydrogen is used for combustion in the power unit, aiming to improve energy utilization efficiency and reduce environmental pollution. However, at present, the ammonia decomposition to produce hydrogen system still has problems such as low operational flexibility, single output energy form, and low comprehensive energy utilization. The system still has room for improvement.

[0006] The design and application of efficient ammonia decomposition reactors is another technical difficulty in the research of ammonia decomposition and hydrogen production. Various types of ammonia decomposers with novel structures have been reported, such as: CN115106049B introduces an ammonia decomposition reactor with an ammonia preheating function, which is used to improve the efficiency of ammonia decomposition and meet the requirements of compact system integration. The reactor includes a heat exchanger body and a reactor body, wherein the heat exchanger is coated on the outside of the reactor. The heat medium of the heat exchanger is the high-temperature hydrogen-nitrogen mixture after decomposition, which preheats the ammonia entering the reactor, thereby increasing the ammonia temperature in the reactor and making the decomposition reaction more complete. However, the structural design of low-temperature, high-throughput ammonia decomposers is still a key issue in this research field.

[0007] In the development of efficient ammonia decomposition catalysts, to overcome the high reaction temperature of ammonia decomposition hydrogen production catalysts, Tsinghua University and Hong Kong Baptist University, in patent CN1528657A, used transition metals and metal nitrides as active components, and alkali metals, alkaline earth metals, and rare earth metal compounds as additives, to prepare a low-temperature ammonia decomposition hydrogen production catalyst via an impregnation method. Fuzhou University, in CN113058595A, used a colloidal precipitation method to prepare a supported Ru catalyst. These studies have significantly advanced the development of ammonia decomposition hydrogen production catalysts. However, overall, the low-temperature activity and stability of ammonia decomposition hydrogen production catalysts need to be further improved. Summary of the Invention

[0008] The purpose of the present invention is to provide a heat, electricity, and mechanical energy co-supply system for a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling, so as to solve the problems in the prior art of complex ammonia hydrogen production devices, low system energy utilization, single output energy form, and the need for external energy supply.

[0009] To achieve the above objectives, the technical solutions of the present invention are as follows.

[0010] A heat, electricity, and mechanical energy co-supply system for a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling, comprising an ammonia supply unit, a steam supply unit, an air supply unit, a first heat exchanger, a second heat exchanger, a front-end reactor, a back-end reactor, a gas-liquid separator, a hydrogen storage unit, a proton exchange membrane battery, an ammonia-hydrogen burner, a hydrogen-air burner, and a third heat exchanger;

[0011] One path of the ammonia supply unit is sequentially connected to the first heat exchanger, the second heat exchanger and the front-end reactor, and the other path is sequentially connected to the third heat exchanger and the ammonia-hydrogen burner;

[0012] One line of the air supply unit is connected to the ammonia-hydrogen burner, and the other line is connected to the hydrogen-air burner;

[0013] Both the front-end reactor and the back-end low-temperature reactor are tubular fixed-bed reactors. The diameter of the front-end reactor is larger than that of the back-end reactor. The front-end reactor is provided with an ammonia inlet and a mixed gas outlet, and is filled with a nickel-based catalyst. The back-end reactor is provided with a mixed gas inlet, a water vapor inlet, a nitrogen outlet, and a hydrogen outlet. The back-end reactor is filled with a ruthenium-based catalyst and has a tubular composite palladium separation membrane on its inner wall. A gap is left between the tubular composite palladium separation membrane and the back-end reactor.

[0014] The ammonia inlet is connected to the second heat exchanger, the mixed gas outlet is connected to the mixed gas outlet, the water vapor inlet is connected to the water vapor supply unit, and the hydrogen outlet is connected to the gas-liquid separator;

[0015] The top of the gas-liquid separator is connected to the hydrogen storage unit, and the bottom is provided with a drain port connected to the front end of the water vapor supply unit. A condenser is provided inside the gas-liquid separator.

[0016] The rear end of the hydrogen storage unit is connected to the proton exchange membrane battery, the ammonia hydrogen burner and the hydrogen air burner respectively;

[0017] The ammonia supply unit gasifies liquid ammonia into ammonia and splits it into two paths, one of which enters the front-end reactor after preheating; the other enters the ammonia-hydrogen burner; the front-end reactor decomposes most of the ammonia into nitrogen and hydrogen at 550-650°C, and transports the mixed gas to the back-end reactor; the back-end reactor completely decomposes the remaining ammonia at 450-500°C, and separates the hydrogen through a composite palladium separation membrane; the water vapor supply unit is used to gasify water into water vapor and then transport it to the back-end reactor and purge the hydrogen to the gas-liquid separator; the gas-liquid separator liquefies the water vapor input to the back-end reactor and separates it from the hydrogen; the air supply unit transports air to the ammonia-hydrogen burner and the hydrogen-air burner respectively; the hydrogen storage unit transports hydrogen to the proton exchange membrane battery, the ammonia-hydrogen burner and the hydrogen-air burner, and the heat generated by the reaction in the hydrogen-air burner is used to provide energy for the system.

[0018] Furthermore, the rear ends of the ammonia supply unit, the water vapor supply unit, and the air supply unit are all provided with tail gas outlets; the nitrogen outlet on the rear reactor is sequentially connected to the first heat exchanger and the tail gas outlet of the ammonia supply unit; the ammonia-hydrogen burner is provided with a high-temperature tail gas outlet, which is sequentially connected to the front reactor, the third heat exchanger, and the tail gas outlet of the rear end of the air supply unit; the hydrogen-air burner is provided with a high-temperature tail gas outlet, which is sequentially connected to the second heat exchanger and the tail gas outlet of the rear end of the water vapor supply unit;

[0019] The high-temperature nitrogen gas flow in the rear-stage reactor enters the ammonia supply unit from the nitrogen outlet to preheat the raw ammonia and gasify the liquid ammonia;

[0020] The liquefied water in the gas-liquid separator circulates from the drain port to the front end of the water vapor supply unit, and the hydrogen enters the front end of the hydrogen storage unit;

[0021] After the hydrogen storage unit transports the hydrogen to the proton exchange membrane battery, it supplies energy to the power-demanding equipment in the form of electrical energy; and / or, after the hydrogen storage unit transports the hydrogen to the ammonia-hydrogen burner, the ammonia, hydrogen and air are mixed and burned to supply energy to the heat-demanding equipment in the form of thermal energy; and / or, after the hydrogen storage unit transports the hydrogen to the hydrogen-air burner, the heat generated by the mixed combustion of hydrogen and air is first input into the second heat exchanger to preheat the low-temperature ammonia from the first heat exchanger, and then input into the fourth heat exchanger to preheat the air from the air tank, and then discharged;

[0022] After the high-temperature tail gas of the ammonia-hydrogen burner exchanges heat with the front-stage reactor, it is first input into the third heat exchanger to preheat the ammonia entering the ammonia-hydrogen burner, and then input into the fourth heat exchanger to preheat the air from the air tank, and then discharged.

[0023] Furthermore, the ammonia supply unit includes an ammonia storage tank, a first evaporator and a first splitter connected in sequence; a pressure reducing valve is provided on the connecting pipeline between the ammonia storage tank and the first evaporator, the first evaporator is provided with an exhaust gas outlet connected to the first heat exchanger, and the first splitter is respectively connected to the first heat exchanger and the third heat exchanger.

[0024] Furthermore, the water vapor supply unit includes a water tank, a water pump and a second evaporator connected in sequence; the water tank is also connected to the drain outlet of the gas-liquid separator; the second evaporator is provided with an exhaust gas outlet connected to the second heat exchanger, and the second evaporator is also connected to the water vapor inlet on the rear reactor.

[0025] Furthermore, the air supply unit includes an air tank, a fourth heat exchanger and a third diverter connected in sequence; the fourth heat exchanger is provided with an exhaust gas outlet connected to the third heat exchanger, and the third diverter is respectively connected to the ammonia hydrogen burner and the hydrogen-air burner.

[0026] Furthermore, the hydrogen storage unit includes a hydrogen storage tank, a compressor and a second diverter connected in sequence, and the second diverter is connected to the proton exchange membrane battery, the ammonia hydrogen burner and the hydrogen-air burner respectively.

[0027] Furthermore, the ratio of the diameter of the front-end reactor, the catalyst bed height in the front-end reactor, the diameter of the back-end reactor, and the catalyst bed height in the back-end reactor is 50-60:300-400:20-30:100-200.

[0028] Furthermore, the front-end reactor and the back-end reactor are connected via a metal partition with a through hole, the diameter of the through hole matches the diameter of the back-end reactor, and a metal mesh is provided on the through hole.

[0029] Furthermore, the nickel-based catalyst has a core-shell structure, with the core being nanoparticles of catalytically active nickel or a nickel-based composite material, and the shell being a porous, high-temperature-resistant inert material. The ruthenium-based catalyst is a Ru / Al2O3-CeO2 catalyst, with a Ru loading of 1% to 7%. Furthermore, the shell thickness of the nickel-based catalyst is 5 to 100 nanometers, and the high-temperature-resistant inert material comprises at least one of SiO2, Al2O3, CeO2, molecular sieves, and MgO.

[0030] Furthermore, the power output of the proton membrane fuel cell, the thermal output of the ammonia-hydrogen burner, and the thermal output of the hydrogen-air burner are adjusted based on the energy requirements of each component of the system by adjusting the flow ratio of hydrogen, ammonia, and air. For example, the flow rate of process liquid ammonia is 1-2 kmol / h, the flow rate of water is 0.1-0.3 kmol / h, the flow rate of ammonia for ammonia-hydrogen combustion is 0.1-1 kmol / h, the flow rate of hydrogen for hydrogen-air combustion is 0.2-1 kmol / h, and the air is supplied at a 10% excess, for a total air flow rate of 1-5 kmol / h. The optimized comprehensive energy efficiency for single power output is 57-64%, the optimized energy efficiency for single ammonia-hydrogen burner thermal output is 70-72%, and the optimized efficiency for single hydrogen-air burner thermal output is 65-68%. The optimal comprehensive energy utilization rate for the combined supply of heat, electricity, and mechanical energy reaches 81%.

[0031] Beneficial effects

[0032] The present invention provides a heat, electricity, mechanical energy, and co-supply system for a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling. Through the combined mechanism design, the use of two-stage ammonia decomposition can reduce the cost of catalyst use and the overall energy required for the ammonia decomposition reaction, and fully utilize the waste heat of the reaction tail gas to provide liquid ammonia vaporization and preheating. At the same time, part of the product hydrogen and raw ammonia are used for combustion to provide the heat demand for ammonia decomposition hydrogen production and external supply, and the waste heat of the tail gas after combustion is fully utilized to preheat the air and vaporize water. While reducing the demand for external energy, the effective hydrogen production rate is increased and the economic cost is reduced. The combination of ammonia decomposition hydrogen production and membrane separation and hydrogen purification technologies also reduces the pressure of later tail gas treatment and reduces the burden of environmental protection. The introduction of ammonia as the main fuel can further promote the replacement of fossil energy and improve the diversity of national energy.

[0033] The two-stage ammonia decomposition hydrogen production system in this system combines reaction and separation functions, effectively performing both the ammonia decomposition hydrogen production reaction and hydrogen separation. The system utilizes a single reactor with two stages connected in series. The first stage is an ammonia pre-decomposition reactor filled with a nickel-based catalyst, which decomposes the majority of ammonia (over 80%) into nitrogen and hydrogen at 550-650°C. The second stage is a tubular membrane separation reactor filled with a ruthenium-based catalyst, which completely decomposes the remaining ammonia at 450-500°C. High-purity hydrogen is then separated using a palladium membrane. The two-stage reactor design divides the reactor into two zones: a high-temperature zone and a low-temperature zone. This reduces the high-temperature zone, lowers heat demand, and conserves energy. The ruthenium-based catalyst and palladium membrane separation are used only in the second stage of the reactor, significantly reducing the use of precious metals palladium and ruthenium, and lowering catalyst costs. The inlet gas to the second stage reactor is a mixture of ammonia, hydrogen, and nitrogen, with a high hydrogen content, which improves the hydrogen separation efficiency of the palladium membrane. Keeping the palladium membrane in a low-temperature environment helps extend its service life. The two reactors are combined to achieve a final ammonia conversion rate exceeding 99%. Simultaneously, hydrogen is separated by the membrane and released into the annular gap within the tube. The hydrogen in the annular gap is then purged with steam and removed.

[0034] This system boasts high energy conversion and utilization efficiency. It uses the exhaust gas from ammonia-hydrogen combustion as the heat source for the ammonia decomposition reactor, and utilizes the waste heat from the exhaust gas from hydrogen-air combustion and the ammonia decomposition product gas as preheating for the feed gas. This fully utilizes the system's waste heat, improves overall energy utilization, and achieves energy self-sufficiency. The remaining exhaust gas after membrane separation is piped back to the first heat exchanger and the first evaporator for heat exchange. Due to the high reaction rate, the ammonia conversion rate approaches 100%. After heat exchange, it can be discharged directly if it meets regulatory requirements. This effectively utilizes the heat from the ammonia decomposition exhaust gas. The waste heat from the hydrogen-air burner exhaust is piped back to the second evaporator for heat exchange. The reaction products are clean and can be discharged directly if they meet regulatory requirements. The waste heat from the ammonia-hydrogen burner exhaust is piped back to the third heat exchanger and the third heat exchanger for heat exchange. The reaction products are clean and can be discharged directly if they meet regulatory requirements.

[0035] This system can flexibly adjust the flow ratios of hydrogen, ammonia, and air via flow dividers, depending on the energy requirements of each component within the system. This allows for adjustments to the electrical output of the proton membrane fuel cell, the thermal output of the ammonia-hydrogen burner, and the thermal output of the hydrogen-air burner. High-purity hydrogen can also be directly output, making the entire system highly flexible and adaptable. Furthermore, to ensure complete combustion of ammonia and hydrogen in the ammonia-hydrogen burner and hydrogen in the hydrogen-air burner, the air flow can be allowed to exceed 10%. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the structure of the system in an embodiment of the present invention.

[0037] In the figure: 1-hydrogen storage tank, 2-pressure reducing valve, 3-first evaporator, 4-first diverter, 5-first heat exchanger, 6-second heat exchanger, 7-front-end reactor, 8-gas-liquid separator, 9-hydrogen storage tank, 10-compressor, 11-second diverter, 12-proton membrane fuel cell, 13-ammonia-hydrogen burner, 14-hydrogen-air burner, 15-third heat exchanger, 16-fourth heat exchanger, 17-third diverter, 18-water tank, 19 water pump, 20-second evaporator, 21-air tank, 22-back-end reactor.

[0038] Figure 2 1 is a reaction flow chart of the system described in an embodiment of the present invention.

[0039] Figure 3 1 is a structural diagram of a two-stage ammonia decomposition reactor in an embodiment of the present invention.

[0040] Figure 4 (a) and (b) are HR-TEM images of Ni@SiO2-5, and (c) is the ammonia conversion rate diagram of Ni@SiO2-x (x=5, 10, 15, 20) catalysts.

[0041] Figure 5 (a) is the HR-TEM image of 5% Ru / γ-Al2O3-30% CeO2, and (b) is the ammonia conversion rate diagram of x% Ru / γ-Al2O3-30% CeO2 (x=1, 2, 3, 5, 7) catalysts.

[0042] Figure 6 1 is a production flow chart of the system described in the embodiment. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below with reference to specific embodiments.

[0044] The present invention provides a heat, electricity, mechanical energy, and hydrogen co-supply system for a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling, comprising a liquid ammonia storage tank, an ammonia evaporator, a multi-stage ammonia heat exchanger, an ammonia decomposition (separation) process device, a hydrogen buffer storage device, an ammonia-hydrogen combustion device, a hydrogen-air combustion device, a hydrogen fuel cell, and the like, which are sequentially connected by pipelines. The energy co-supply system can continuously and stably provide electrical energy, mechanical energy, thermal energy, and a portion of high-purity hydrogen to the external system. Specifically, the hydrogen generated by the ammonia decomposition hydrogen production device enters the proton membrane fuel cell through a gas diverter to supply electrical energy to the outside, enters the ammonia-hydrogen burner to supply mechanical energy and thermal energy to the outside, and enters the hydrogen burner to provide the heat required for the cold start of the ammonia decomposition hydrogen production device. The energy co-supply system has high energy conversion and utilization efficiency. The exhaust gas after the ammonia-hydrogen combustion is used as the heat source of the ammonia decomposition reactor, and the exhaust gas after the hydrogen-air combustion and the waste heat of the ammonia decomposition product gas are used as the preheating of the feed gas. This fully utilizes the waste heat of the system, improves the overall energy utilization rate, and realizes the energy self-supply of the system. The energy co-supply system has great operational flexibility. By adjusting the flow rate of raw ammonia and the relative ratio of hydrogen in each path in the gas diverter, the overall energy output of the system and the relative proportions of heat, electricity and mechanical energy can be quickly and conveniently regulated. The two-stage ammonia decomposition hydrogen production device has the function of reaction and separation coupling, that is, it can realize the reaction function of ammonia decomposition to produce hydrogen, and can also complete the function of hydrogen separation. The device adopts a structure of two sections in series of a single reactor. The front section is an ammonia pre-decomposition reactor, which is filled with a nickel-based catalyst. At 550-600°C, most of the ammonia (more than 80%) is decomposed into nitrogen and hydrogen; the rear section is a tubular membrane separation reactor, which is filled with a ruthenium-based catalyst. The remaining ammonia is completely decomposed at 450°C, and high-purity hydrogen is obtained by separation using a palladium membrane. Through the two-stage reactor structure design, the reactor is divided into two areas, a high-temperature section and a low-temperature section, which reduces the high-temperature area of ​​the reactor, reduces heat demand, and saves energy. In addition, the ruthenium-based catalyst and the palladium membrane separation are only used in the rear section of the reactor, which greatly reduces the amount of precious metals palladium and ruthenium, and reduces the cost of the catalyst. The inlet gas of the rear section reactor is a mixed gas of ammonia, hydrogen, and nitrogen, and the hydrogen content is relatively high, which is conducive to improving the hydrogen separation efficiency of the palladium membrane. The palladium membrane is in the low-temperature area, which is conducive to extending its service life. The nickel-based catalyst is a core-shell structure with a highly standardized size structure, with nanoparticles of catalytically active substances nickel-based or nickel-based composite materials inside, and a high-temperature resistant inert shell material with a porous structure outside. It has significant advantages such as high activity, high temperature resistance, and long life.

[0045] This invention proposes a two-stage ammonia decomposition hydrogen production system for heat, electricity, mechanical energy, and hydrogen cogeneration based on a coupled reaction and separation process. The system boasts a complete, compact structure and diverse functions. The system boasts high energy utilization, enabling energy self-sufficiency. It also offers flexibility in energy utilization and output, diverse control methods, and the ability to output heat, electricity, mechanical energy, and hydrogen. The system also boasts low cost, high safety, and strong adaptability.

[0046] like Figure 1 As shown, a heat, electricity, mechanical energy, and hydrogen co-supply system of a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling includes: an ammonia storage tank 1, a pressure reducing valve 2, a first evaporator 3, a first flow splitter 4, a first heat exchanger 5, a second heat exchanger 6, a front-end reactor 7, a back-end reactor 22, a gas-liquid separator 8, a hydrogen storage tank 9, a compressor 10, a second flow splitter 11, a proton membrane fuel cell 12, an ammonia-hydrogen burner 13, a hydrogen-air burner 14, a third heat exchanger 15, a fourth heat exchanger 16, a third flow splitter 17, a water tank 18, a water pump 19, a second evaporator 20, and an air tank 21;

[0047] The ammonia decomposition process group includes: liquid ammonia is output from the ammonia storage tank 1, vaporized through the pressure reducing valve 2 and the first evaporator 3, and then input into the first splitter 4; one stream outlet of the first splitter 4 is connected to the first heat exchanger 5 through a pipeline, and the other stream outlet of the first splitter 4 is connected to the ammonia-hydrogen burner 13 through a pipeline; ammonia gas is input into the first heat exchanger 5 through a pipeline for primary heat exchange, and then into the second heat exchanger 6 for secondary heat exchange, and finally input into the first reactor 7. After pre-reaction in the front-end reactor, it enters the second reactor 22 for complete reaction. The nitrogen generated by ammonia decomposition is output from the back-end reactor 22 and connected to the first heat exchanger and the first evaporator in sequence through pipelines;

[0048] Air is output from the air tank 21, preheated by the fourth heat exchanger 16, and then input into the third splitter 17; one stream outlet of the third splitter 17 is connected to the ammonia-hydrogen burner 13 through a pipeline, and the other stream outlet of the third splitter 17 is connected to the hydrogen-air combustion chamber 14 through a pipeline;

[0049] The hydrogen buffer storage device includes: water is output from the water tank 18, input into the second evaporator 20 through the water pump 19, and then passed into the second reactor 22 after being vaporized; the water vapor purges and carries high-purity hydrogen into the gas-liquid separation tank 8, and the liquefied water is discharged from the bottom of the pipe and circulated to the water tank 18, and the hydrogen is stored in the hydrogen storage tank 9;

[0050] Hydrogen is output from the hydrogen storage tank 9 and input into the second diverter 11 through the compressor 10; the second diverter 11 is divided into three streams for output, the first stream inputs part of the hydrogen into the ammonia hydrogen burner 13 through a pipeline, the second stream inputs part of the hydrogen into the proton membrane fuel cell 12 through a pipeline, and the third stream inputs part of the hydrogen into the hydrogen-air burner 14 through a pipeline.

[0051] The front-end reactor 7 is an ammonia pre-decomposition reactor, which is filled with a nickel-based catalyst and performs an ammonia decomposition reaction at a high temperature (550-650°C) until the ammonia is decomposed to more than 80%. The back-end reactor is an ammonia decomposition-separation tubular membrane reactor, which is filled with a ruthenium-based catalyst and performs an ammonia decomposition reaction at a low temperature (450-500°C) until the ammonia is decomposed to more than 99%. At the same time, high-purity hydrogen is separated by a palladium membrane. In the back-end reactor, hydrogen enters the annular gap in the tube through membrane separation, and the hydrogen in the annular gap is carried out by water vapor purge. After the high-temperature nitrogen in the inner tube flows out of the reactor, it is first input into the second heat exchanger 5 for preheating the raw ammonia, and then input into the first evaporator 3 for liquid ammonia gasification, and is discharged into the air after the heat exchange is completed. The reactions in the front-end reactor and the back-end reactor include: 2NH3=N2+3H2.

[0052] The reactor design reduces the overall reaction temperature and the amount of precious metals used, thereby reducing energy consumption and economic costs. In addition, a Pd membrane separation structure is constructed in the rear reactor structure to achieve a combination of ammonia decomposition to produce hydrogen and membrane separation to purify hydrogen, thereby improving the reaction conversion rate and hydrogen separation efficiency and extending the life of the separation membrane. Specifically: (1) The reactor is a structure with two high and low temperature sections connected in series. The front section is an ammonia pre-decomposition reactor (high temperature section), which adopts a fixed bed reactor structure and is filled with a nickel-based catalyst. At 550-600°C, most of the ammonia (more than 80%) is decomposed into nitrogen and hydrogen; the rear section is a tubular fixed bed combined membrane separation reactor (low temperature section), which is filled with a ruthenium-based catalyst and has a composite palladium separation membrane structure on the outside. The remaining ammonia is completely decomposed at 450°C and is separated by a palladium membrane to obtain high-purity hydrogen. The two-stage reactor structure design allows the reactor to be divided into a high-temperature section and a low-temperature section, reducing the high-temperature section of the reactor, lowering heat demand and saving energy. In addition, the ruthenium-based catalyst and palladium membrane separation are only used in the rear section of the reactor, which greatly reduces the amount of precious metal palladium and ruthenium, reduces the catalyst cost, and the palladium membrane is in the low-temperature area, which is conducive to extending its service life; (2) The reactor is a two-stage variable diameter structure. The front section adopts a large diameter and large catalyst bed height structure to ensure the reactor volume and catalyst loading. Ammonia has sufficient residence time in the front section reactor, which is conducive to the decomposition and conversion of ammonia; the rear section adopts a small diameter and short catalyst bed height structure. The volume of the rear section reactor is reduced, which is conducive to further reducing the amount of ruthenium-based catalyst and palladium membrane and reducing equipment cost; in addition, the reactor volume is reduced and the gas pressure is increased, which is conducive to the membrane separation process of hydrogen and nitrogen; the inlet gas of the rear section reactor is a mixed gas of ammonia, hydrogen and nitrogen with a high hydrogen content (75%), which is conducive to improving the hydrogen separation of the palladium membrane Efficiency; (3) The front-end and back-end reactors are separated by a metal partition with a sealing function. In the middle of the metal partition is a circular hole that matches the size of the back-end reactor as a gas passage. The circular hole is covered with a 60-mesh metal mesh as a support for the catalyst particles and a gas distributor; (4) The back-end reactor 22 can use Al2O3 as the outer tube and the inner wall is covered with a Pd\Ag composite membrane. The gas generated by the reaction (hydrogen, nitrogen, and ammonia mixture) flows in the tube and is separated by the Pd membrane to separate nitrogen and hydrogen. The generated nitrogen (450°C) flows out of the reactor along the tube as a heat source for preheating the raw gas. After multi-stage heat exchange, it is emptied. The hydrogen enters the reactor cavity outside the membrane tube and flows out of the reactor under the purge of low-temperature water vapor (110°C) generated by the fuel cell. After passing through the condenser, it enters the hydrogen tank. The use of water vapor purge can reduce the hydrogen partial pressure on the outside of the membrane and increase the hydrogen pressure difference on both sides of the Pd membrane, which is beneficial to increase the separation rate. In addition, the hydrogen and water vapor are mixed to form a mixed gas that can directly enter the fuel cell. In the following embodiments, the structural schematic diagram of the front-end reactor 7 and the back-end reactor 22 used is as shown in FIG. Figure 3As shown, the front section adopts a structure with a large diameter (56 mm) and a large catalyst bed height (300 mm), and the rear section adopts a structure with a small diameter (28 mm) and a short catalyst bed height (100 mm). There is a 28 mm circular hole in the middle of the metal partition as a gas passage, and the circular hole is covered with a 60-mesh metal mesh as a support for the catalyst particles and a gas distributor.

[0053] The ammonia-hydrogen burner 13 is an energy supply device. After the mixture of ammonia, hydrogen and air is burned, it supplies energy to external heat-requiring equipment in the form of thermal energy. The high-temperature exhaust gas after combustion is connected to the front-end reactor 7 through a pipeline. After heat exchange with the front-end reactor 7, it is first input into the third heat exchanger 15 through a pipeline for heat exchange for preheating the ammonia entering the ammonia-hydrogen burner 13, and then input into the fourth heat exchanger 16 for preheating the air from the air tank 21, and then discharged. The reactions in the ammonia-hydrogen burner include: 2H2+O2=2H2O; 4NH3+3O2=2N2+6H2O.

[0054] The proton membrane fuel cell 12 is an energy supply device that supplies energy to external power-demanding equipment in the form of electrical energy, and when the heat supply of some devices in the system is insufficient, it can be supplemented in the form of electric heating;

[0055] The hydrogen-air burner 14 is an energy supply device. During the cold start phase of the system, the heat generated by it is mainly used to heat the ammonia before entering the front-end reactor 7. It is connected to the second heat exchanger 6 through a pipeline for heat exchange, and the low-temperature ammonia from the first heat exchanger 5 is heated to the high temperature required for the nickel-based catalytic ammonia decomposition reaction. The ammonia is then fed into the second evaporator 20 to vaporize liquid water into water vapor. After the heat is fully utilized, the tail gas is discharged. The reaction in the hydrogen-air burner includes: 2H2+O2=2H2O.

[0056] According to the energy required by each part of the system, the system can flexibly adjust the flow ratio of hydrogen, ammonia and air through a diverter to adjust the electrical output of the proton membrane fuel cell, the thermal output of the ammonia-hydrogen burner, and the thermal output of the hydrogen-air burner. It can also directly output high-purity hydrogen, making the entire system highly flexible and adaptable.

[0057] The nickel-based catalyst is a core-shell structure with a highly standardized size structure. The interior is a catalytically active material, nickel-based or nickel-based composite nanoparticles, and the exterior is a high-temperature resistant inert shell material with a porous structure and a thickness of 5-100 nanometers, including: SiO2, Al2O3, CeO2, molecular sieve, MgO. It can catalyze the decomposition of ammonia to a conversion rate of more than 80% at 550-650°C. The ruthenium-based catalyst is a Ru / Al2O3-CeO2 catalyst, wherein the Ru% is 1-7% and the molar ratio of Al2O3 to CeO2 is 30-1. It can catalyze the decomposition of ammonia to a conversion rate of more than 99% at 450-500°C. The relevant performance of the catalyst is as follows: Figure 4-5 shown.

[0058] like Figure 6 As shown, the system is used when:

[0059] Liquid ammonia is introduced from the ammonia storage tank 1 into the first evaporator 3 for vaporization, and then heated to 350°C through a multi-stage ammonia heat exchanger; the 350°C ammonia gas is introduced into the high-temperature zone of the front section of the reactor for ammonia decomposition reaction using a nickel-based catalyst, with a conversion rate of over 80%. The ammonia gas is then introduced into the low-temperature zone of the rear section of the reactor using a ruthenium-based catalyst to achieve a conversion rate of over 99%. After separation through a palladium membrane, the obtained high-purity hydrogen is purged out of the reactor using water vapor;

[0060] The water vapor-hydrogen mixture passes through the gas-liquid separation tank 8, the water enters the water tank 18, and the hydrogen enters the hydrogen storage tank 10 for subsequent use. The waste heat of the nitrogen tail gas generated by the decomposition of ammonia is used for the vaporization and preheating of the raw liquid ammonia;

[0061] Part of the produced high-purity hydrogen is mixed with air and burned to provide heat demand during the cold start of the system. Part of the hydrogen is used in the proton membrane fuel cell 12 to supply electricity to the outside. Part of the hydrogen is used as a combustion accelerator and mixed with ammonia to supply heat to the outside. It can also be directly supplied to the outside in the form of hydrogen.

[0062] The tail gases of the ammonia-hydrogen burner 13 and the hydrogen-air burner 14 are both preheated through heat exchangers for various gases used in the system.

[0063] This system can be used in scenarios where thermal power generation and hydrogen are needed, such as hydrogen refueling stations, large ships, and remote communities, to efficiently utilize liquid ammonia and reduce the impact of carbon dioxide on the environment. Furthermore, it provides a flexible, independent energy system for scenarios where thermal power generation and hydrogen are needed, such as hydrogen refueling stations, large ships, and remote communities.

[0064] The hydrogen produced by this system can be used as a chemical raw material to develop green chemical products, as a green energy to power fuel cell vehicles and provide fuel for boilers and stoves, and as a hydrogen source that is easy to transport, store, produce and use on site at hydrogen energy utilization sites; the heat and electricity produced can provide energy sources for the power systems and power systems of ships, and provide energy sources for heating, cooling, lighting and public facilities in the community.

[0065] Example 1

[0066] The heat, electricity, mechanical energy and hydrogen co-supply system of the two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling is specifically as follows:

[0067] S1. Liquid ammonia is output from the ammonia storage tank 1 at a pressure of 9.9 atm, reduced to 1.1 atm by the pressure reducing valve 2, and input into the first splitter 4 after being completely vaporized in the first evaporator 3; one stream outlet of the first splitter 4 is connected to the first heat exchanger 5 via a pipeline with a split ratio of 0.9; the other stream outlet of the first splitter 4 is connected to the ammonia-hydrogen burner 13 via a pipeline with a split ratio of 0.1; the ammonia gas is input into the heat exchanger through the pipeline, and the temperature after multi-stage heat exchange is 500°C.

[0068] S2. Ammonia gas at 550°C is fed into the front-end reactor 7, where it undergoes a preliminary reaction at 550°C with an ammonia conversion rate of 80% and a heat requirement of 11.4 kW for the ammonia decomposition reaction. The gas then enters the rear-end reactor 22 where it undergoes a complete reaction at 500°C with a conversion rate of 99.8% and a heat requirement of 1.93 kW. The reaction tail gas is then output for heat exchange with a heat exchanger, where its temperature drops to 119°C.

[0069] The reaction in the front-end reactor and the back-end reactor includes: 2NH3=N2+3H2.

[0070] Specifically, the gas composition output from the rear reactor 22 is (mol%): NH3: 0.02%, H2: 74.99%, N2: 24.99%;

[0071] S3. After separation, high-purity hydrogen is output from the hydrogen storage tank 9 and input into the second splitter 11; the second splitter 11 outputs in two streams, the first stream inputs the hydrogen required for partial combustion into the hydrogen-air burner 14 through a pipeline with a split ratio of 0.2; the second stream is input into the proton membrane fuel cell 12 through a pipeline with a split ratio of 0.8.

[0072] S4. The tail gas of the ammonia hydrogen burner is used to preheat the incoming ammonia, air and gasified liquid water until they are completely transformed into water vapor. After the heat is exchanged in sequence, the temperature drops to 65°C. The combustion reaction generates 7.55KW of heat that can be supplied to the outside world.

[0073] S5. The exhaust gas from the hydrogen-air burner is used to preheat the incoming air to 400°C and vaporize liquid ammonia. After heat exchange, the temperature drops to 33°C. The combustion reaction generates 16.21KW of heat that can be supplied to the outside world.

[0074] This method is provided with a hydrogen storage tank 9 for storing hydrogen, and its supply can be freely adjusted to burn for heat, battery power and direct hydrogen supply. It can also be used to reserve some hydrogen in the tank at each stop to meet the fuel and energy consumption required for the next start.

[0075] The method is provided with a water tank 6 for storing condensed water. The condensed water after gas-liquid separation can be stored in the water tank to provide a source of water vapor required for the next purge. This arrangement realizes water circulation and avoids wastewater outflow, which causes waste of resources.

[0076] In this embodiment, ammonia-hydrogen combustion is used to provide heat for gas preheating and liquid water vaporization, while hydrogen-air combustion is used to provide heat for gas preheating, liquid ammonia vaporization, and ammonia decomposition reactions. Of course, in other embodiments, the front-end reactor 7 and the back-end reactor 22 can be configured to use multi-energy synergistic heating, that is, the ammonia-hydrogen burner and the hydrogen-air burner can be used in coordination. Waste heat can also be used to provide some heat, and even electric heating can be used, with fuel cells used for energy supplementation to avoid energy waste. This is not a limitation here.

[0077] In this embodiment, the nickel-based catalyst used is Ni@SiO2-15 catalyst, and the ruthenium-based catalyst used is 5%Ru / γ-Al2O3-30%CeO2 catalyst.

[0078] In this embodiment, the flow rate of process liquid ammonia is 1 kmol / h, the flow rate of water is 0.135 kmol / h, the flow rate of ammonia used for ammonia-hydrogen combustion is 0.1 kmol / h, and the flow rate of hydrogen used for hydrogen-air combustion is 0.27 kmol / h. To ensure complete combustion reaction, air is supplied at an excess of 10%, and the total air flow rate is 1.107 kmol / h. In this embodiment, no external energy is required, and 1.1 kmol / h of high-purity hydrogen can be supplied to the outside, and 11 kW of heat energy can be supplied to the outside.

[0079] The heat, electricity, mechanical energy and hydrogen co-supply system of the two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling provided in this embodiment has low cost consumption and equipment investment, and does not emit CO x It does not emit greenhouse gases such as CO2, is environmentally friendly, and has low dependence on public works. It is conducive to the large-scale construction of small-scale liquid ammonia hydrogen production and refueling stations, laying the foundation for the construction and development of large-scale liquid ammonia hydrogen production industry.

[0080] Example 2

[0081] The structure, working principle and most parameters of this embodiment are the same as those of embodiment 1. The main differences are: in this embodiment, one stream outlet of the first splitter 4 is connected to the first heat exchanger 5 through a pipeline, and the split ratio is 0.8; the other stream outlet of the first splitter 4 is connected to the ammonia hydrogen burner 13 through a pipeline, and the split ratio is 0.2; the nickel-based catalyst used is Ni@SiO2-20 catalyst, and the ruthenium-based catalyst is 7%. The Ru / γ-Al2O3-30% CeO2 catalyst is used. Therefore, the pre-reaction in the front-stage reactor 7 at 550°C has an ammonia conversion rate of 85%, and the heat required for the ammonia decomposition reaction is 10.17 kW. The complete reaction in the back-stage reactor 22 at 500°C has a conversion rate of 99.5%, and the heat required for the reaction is 1.12 kW. The water flow rate is 0.12 kmol / h, the ammonia flow rate for ammonia-hydrogen combustion is 0.2 kmol / h, and the hydrogen flow rate for hydrogen-air combustion is 0.24 kmol / h. To ensure complete combustion, air is supplied at an excess of 10%, and the total air flow rate is 1.43 kmol / h. In this embodiment, no external energy is required, and 0.96 kmol / h of high-purity hydrogen can be supplied to the outside, while 18.13 kW of heat energy can be supplied to the outside.

[0082] Example 3

[0083] The structure, working principle and most parameters of this embodiment are the same as those of Example 1. The main differences are as follows: in this embodiment, one stream outlet of the first splitter 4 is connected to the first heat exchanger 5 via a pipeline, with a split ratio of 0.6; the other stream outlet of the first splitter 4 is connected to the ammonia-hydrogen burner 13 via a pipeline, with a split ratio of 0.4; the second splitter 11 outputs two streams, the first of which inputs the hydrogen required for partial combustion into the hydrogen-air burner 14 via a pipeline with a split ratio of 0.4; the second stream is input into the proton membrane fuel cell 12 via a pipeline with a split ratio of 0.6; the nickel-based catalyst used is Ni@SiO2-5 catalyst, and the ruthenium-based catalyst used is 1%. The Ru / γ-Al2O3-30% CeO2 catalyst is used. Therefore, the ammonia conversion rate of the preliminary reaction at 600°C in the front-stage reactor 7 is 92%, and the heat required for the ammonia decomposition reaction is 8.97KW. The conversion rate of the complete reaction at 525°C in the back-stage reactor 22 is 99.8%, and the heat required for the reaction is 0.13KW. The water flow rate is 0.09kmol / h, the ammonia flow rate for ammonia-hydrogen combustion is 0.4kmol / h, and the hydrogen flow rate for hydrogen-air combustion is 0.36kmol / h. To ensure complete combustion reaction, air is supplied at an excess of 10%, and the total air flow rate is 2.54kmol / h. In this embodiment, no external energy is required, and the amount of high-purity hydrogen that can be supplied to the outside is 0.54kmol / h. At the same time, 42.71KW of heat energy can be supplied to the outside.

[0084] Example 4

[0085] The structure, working principle and most parameters of this embodiment are the same as those of Example 1. The main differences are as follows: in this embodiment, one stream outlet of the first splitter 4 is connected to the first heat exchanger 5 via a pipeline, with a split ratio of 0.75; the other stream outlet of the first splitter 4 is connected to the ammonia-hydrogen burner 13 via a pipeline, with a split ratio of 0.25; the second splitter 11 outputs two streams, the first of which inputs the hydrogen required for partial combustion into the hydrogen-air burner 14 via a pipeline with a split ratio of 0.3; the second stream is input into the proton membrane fuel cell 12 via a pipeline with a split ratio of 0.7; the nickel-based catalyst used is Ni@SiO2-10 catalyst, and the ruthenium-based catalyst used is 1%. The Ru / γ-Al2O3-30% CeO2 catalyst is used. Therefore, the pre-reaction in the front-stage reactor 7 at 550°C has an ammonia conversion rate of 78%, and the heat required for the ammonia decomposition reaction is 21.7 kW. The complete reaction in the back-stage reactor 22 at 500°C has a conversion rate of 99.6%, and the heat required for the reaction is 0.53 kW. The flow rate of process liquid ammonia is 2 kmol / h, the flow rate of water is 0.225 kmol / h, the flow rate of ammonia for ammonia-hydrogen combustion is 0.5 kmol / h, and the flow rate of hydrogen for hydrogen-air combustion is 0.675 kmol / h. To ensure complete combustion, air is supplied at a 10% excess, with a total air flow rate of 3.77 kmol / h. In this embodiment, no external energy is required, and 1.6 kmol / h of high-purity hydrogen can be supplied to the outside, while 56.04 kW of heat energy can be supplied to the outside.

[0086] Example 5

[0087] The structure, working principle and most parameters of this embodiment are the same as those of Example 1. The main differences are as follows: in this embodiment, one stream outlet of the first splitter 4 is connected to the first heat exchanger 5 via a pipeline, with a split ratio of 0.6; the other stream outlet of the first splitter 4 is connected to the ammonia-hydrogen burner 13 via a pipeline, with a split ratio of 0.4; the second splitter 11 outputs two streams, the first of which inputs the hydrogen required for partial combustion into the hydrogen-air burner 14 via a pipeline with a split ratio of 0.4; the second stream is input into the proton membrane fuel cell 12 via a pipeline with a split ratio of 0.6; the nickel-based catalyst used is Ni@SiO2-15 catalyst, and the ruthenium-based catalyst used is 2%. The Ru / γ-Al2O3-30% CeO2 catalyst is used. Therefore, the pre-reaction in the front-stage reactor 7 at 550°C has an ammonia conversion rate of 80%, and the heat required for the ammonia decomposition reaction is 14.35 kW. The complete reaction in the back-stage reactor 22 at 550°C has a conversion rate of 99.9%, and the heat required for the reaction is 3.58 kW. The flow rate of process liquid ammonia is 2 kmol / h, the flow rate of water is 0.18 kmol / h, the flow rate of ammonia for ammonia-hydrogen combustion is 0.8 kmol / h, and the flow rate of hydrogen for hydrogen-air combustion is 0.72 kmol / h. To ensure complete combustion, air is supplied at a 10% excess, for a total air flow rate of 2.61 kmol / h. In this embodiment, no external energy is required, and 1.09 kmol / h of high-purity hydrogen can be supplied to the outside, while 85.74 kW of heat energy can be supplied to the outside.

[0088] In summary, the present invention provides a heat, electricity, mechanical energy, and hydrogen co-supply system for an ammonia decomposition hydrogen production device based on reaction and separation coupling. By using part of the ammonia and hydrogen to burn and generate heat, the heat required for the ammonia decomposition reaction is provided, and no external energy is required, so that the device can operate continuously and stably; by performing step-by-step recovery and utilization of the waste heat in the reaction process, the energy utilization efficiency is significantly improved, and efficient energy utilization is achieved; by combining technologies such as ammonia decomposition hydrogen production and membrane separation and purification of hydrogen, the cost of the device is low, the pressure of the later tail gas treatment is reduced, and the burden of environmental protection is reduced; by adopting a two-stage ammonia decomposition reactor and two ammonia decomposition catalysts, the efficient utilization of the separation membrane is achieved, and the overall reaction temperature and the amount of precious metals used are reduced, thereby reducing energy consumption and economic costs, so that the single-pass conversion rate of ammonia exceeds 99.5% and the utilization rate of ammonia is close to 100%; at the same time, the steam water is condensed and recovered, reducing water consumption.

[0089] In summary, the invention includes but is not limited to the above embodiments. Any equivalent replacement or partial improvement made under the spirit and principle of the present invention shall be deemed to be within the scope of protection of the present invention.

Claims

1. A combined heat, electricity, and mechanical energy supply system for a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling, characterized by: The invention comprises an ammonia supply unit, a water vapor supply unit, an air supply unit, a first heat exchanger (5), a second heat exchanger (6), a front-end reactor (7), a back-end reactor (22), a gas-liquid separator (8), a hydrogen storage unit, a proton exchange membrane battery (12), an ammonia-hydrogen burner (13), a hydrogen-air burner (14) and a third heat exchanger (15); One path of the ammonia supply unit is sequentially connected to the first heat exchanger (5), the second heat exchanger (6) and the front-end reactor (7), and the other path is sequentially connected to the third heat exchanger (15) and the ammonia-hydrogen burner (13); One path of the air supply unit is connected to the ammonia hydrogen burner (13), and the other path is connected to the hydrogen air burner (14); The front-end reactor (7) and the rear-end low-temperature reactor (22) are both tubular fixed-bed reactors, and the diameter of the front-end reactor (7) is larger than that of the rear-end reactor (22); the front-end reactor (7) is provided with an ammonia inlet and a mixed gas outlet, and is filled with a nickel-based catalyst; the rear-end reactor (22) is provided with a mixed gas inlet, a water vapor inlet, a nitrogen outlet and a hydrogen outlet, and is filled with a ruthenium-based catalyst and has a tubular composite palladium separation membrane on its inner wall; a gap is left between the tubular composite palladium separation membrane and the rear-end reactor (22); The ammonia inlet is connected to the second heat exchanger (6), the mixed gas outlet is connected to the mixed gas outlet, the water vapor inlet is connected to the water vapor supply unit, and the hydrogen outlet is connected to the gas-liquid separator 8; The top of the gas-liquid separator (8) is connected to the hydrogen storage unit, and the bottom is provided with a drain port connected to the front end of the water vapor supply unit. A condenser is provided in the gas-liquid separator (8); The rear end of the hydrogen storage unit is connected to the proton exchange membrane battery (12), the ammonia hydrogen burner (13) and the hydrogen air burner (14) respectively; The ammonia supply unit gasifies the liquid ammonia into ammonia gas and splits it into two paths. One path enters the front-end reactor (7) after preheating; the other path enters the ammonia-hydrogen burner (13); the front-end reactor (7) decomposes most of the ammonia gas into nitrogen and hydrogen at 550-650°C, and transports the mixed gas to the back-end reactor (22); the back-end reactor (22) completely decomposes the remaining ammonia gas at 450-500°C, and separates the hydrogen through the composite palladium separation membrane; the water vapor supply unit gasifies the water into water vapor and transports it to the back-end reactor (22). The air is sent to the rear reactor (22) and the hydrogen is purged to the gas-liquid separator (8); the gas-liquid separator (8) liquefies the water vapor input from the rear reactor (22) and separates it from the hydrogen; the air supply unit transports the air to the ammonia-hydrogen burner (13) and the hydrogen-air burner (14) respectively; the hydrogen storage unit transports the hydrogen to the proton exchange membrane battery (12), the ammonia-hydrogen burner (13) and the hydrogen-air burner 14), and the heat generated by the reaction in the hydrogen-air burner (14) is used to provide energy for the system.

2. The heat, electricity, and mechanical energy co-supply system of a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling according to claim 1, characterized in that: The rear ends of the ammonia supply unit, the water vapor supply unit, and the air supply unit are all provided with tail gas outlets; the nitrogen outlet on the rear reactor (22) is sequentially connected to the first heat exchanger (5) and the tail gas outlet of the ammonia supply unit; the ammonia-hydrogen burner (13) is provided with a high-temperature tail gas outlet, which is sequentially connected to the front reactor (7), the third heat exchanger (15), and the tail gas outlet at the rear end of the air supply unit; the hydrogen-air burner (14) is provided with a high-temperature tail gas outlet, which is sequentially connected to the second heat exchanger (6) and the tail gas outlet at the rear end of the water vapor supply unit; The high-temperature nitrogen gas flow in the rear reactor (22) enters the ammonia supply unit through the nitrogen outlet, and is used to preheat the raw ammonia and gasify the liquid ammonia; the liquefied water in the gas-liquid separator (8) is circulated to the front end of the water vapor supply unit through the drain outlet, and the hydrogen enters the front end of the hydrogen storage unit; After the hydrogen storage unit transports the hydrogen to the proton exchange membrane battery (12), the hydrogen is supplied to the power-demanding equipment in the form of electrical energy; and / or, after the hydrogen storage unit transports the hydrogen to the ammonia-hydrogen burner (13), the ammonia, hydrogen and air are mixed and burned to supply the heat-demanding equipment in the form of thermal energy; and / or, after the hydrogen storage unit transports the hydrogen to the hydrogen-air burner (14), the heat generated by the mixed combustion of the hydrogen and air is first input to the second heat exchanger (6) to preheat the low-temperature ammonia from the first heat exchanger (5), and then input to the fourth heat exchanger (16) to preheat the air from the air tank (21), and then discharged; After the high-temperature tail gas of the ammonia-hydrogen burner (13) exchanges heat with the front-stage reactor (7), it is first input into the third heat exchanger (15) to preheat the ammonia gas entering the ammonia-hydrogen burner (13), and then input into the fourth heat exchanger (16) to preheat the air from the air tank (21), and then discharged.

3. A heat, electricity, and mechanical energy co-supply system for a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling according to claim 1 or 2, characterized in that: The ammonia supply unit comprises an ammonia storage tank (1), a first evaporator (3) and a first splitter (4) which are connected in sequence; a pressure reducing valve (2) is provided on the connecting pipeline between the ammonia storage tank (1) and the first evaporator (3); the first evaporator (3) is provided with an exhaust outlet connected to the first heat exchanger (5); and the first splitter (4) is connected to the first heat exchanger (5) and the third heat exchanger (15) respectively.

4. A combined heat, electricity, and mechanical energy supply system for a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling according to claim 1 or 2, characterized in that: The water vapor supply unit comprises a water tank (18), a water pump (19) and a second evaporator (20) connected in sequence; the water tank (18) is also connected to the drain outlet of the gas-liquid separator (18); the second evaporator (20) is provided with an exhaust gas outlet connected to the second heat exchanger (6), and the second evaporator (20) is also connected to the water vapor inlet on the rear reactor (22).

5. A combined heat, electricity, and mechanical energy supply system for a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling according to claim 1 or 2, characterized in that: The air supply unit comprises an air tank (21), a fourth heat exchanger (16) and a third diverter (17) which are connected in sequence; the fourth heat exchanger (16) is provided with an exhaust gas outlet connected to the third heat exchanger, and the third diverter (17) is connected to the ammonia-hydrogen burner (13) and the hydrogen-air burner (14) respectively.

6. A combined heat, electricity, and mechanical energy supply system for a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling according to claim 1 or 2, characterized in that: The hydrogen storage unit comprises a hydrogen storage tank (9), a compressor (10) and a second diverter (11) which are connected in sequence. The second diverter (11) is respectively connected to a proton exchange membrane battery (12), an ammonia hydrogen burner (13) and a hydrogen-air burner (14).

7. A combined heat, electricity, and mechanical energy supply system for a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling according to claim 1 or 2, characterized in that: The ratio of the diameter of the front-stage reactor (7), the height of the catalyst bed in the front-stage reactor (7), the diameter of the back-stage reactor (22), and the height of the catalyst bed in the back-stage reactor (22) is 50-60:300-400:20-30:100-200.

8. The heat, electricity, and mechanical energy co-supply system of a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling according to claim 1 or 2, characterized in that: The front-end reactor (7) and the back-end reactor (22) are connected via a metal partition with a through hole, the diameter of the through hole matches the diameter of the back-end reactor (22), and a 60-mesh metal mesh is provided on the through hole.

9. A combined heat, electricity, and mechanical energy supply system for a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling according to claim 1 or 2, characterized in that: The nickel-based catalyst has a core-shell structure, wherein the core is nanoparticles of the catalytically active substance nickel or a nickel-based composite material, and the shell is a high-temperature resistant inert material with a porous structure; the ruthenium-based catalyst is a Ru / Al2O3-CeO2 catalyst, wherein the Ru loading is 1% to 7%; furthermore, the shell thickness of the nickel-based catalyst is 5 to 100 nanometers, and the high-temperature resistant inert material includes one or more of SiO2, Al2O3, CeO2, molecular sieves and MgO.

10. A combined heat, electricity, and mechanical energy supply system for a two-stage ammonia decomposition hydrogen production device based on reaction and separation coupling according to claim 1 or 2, characterized in that: According to the energy required by each part of the system, the flow ratio of hydrogen, ammonia and air is adjusted to adjust the electrical energy output of the proton membrane fuel cell (12), the thermal energy output of the ammonia hydrogen burner (13) and the thermal energy output of the hydrogen air burner (14).

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