Ammonia hydrogen production fuel cell-storage battery hybrid power supply system

Abstract

The utility model discloses an ammonia hydrogen production fuel cell-storage battery hybrid power supply system which comprises a liquid ammonia source, a gasifier, a first heat exchanger, an ammonia decomposition reactor, a membrane separation purifier, a pure hydrogen collector, a fuel cell and a power supply unit. The system preheats ammonia gas through the first heat exchanger, and the energy efficiency is improved; ammonia gas in the ammonia decomposition reactor is decomposed into hydrogen and nitrogen, high-temperature product mixed gas serves as a heat source of the first heat exchanger, and energy is recycled; the membrane separation purifier adopts a selective hydrogen permeation membrane to efficiently separate hydrogen, so that the hydrogen purity is improved; the power supply unit comprises a storage battery and a super capacitor which are arranged in parallel, the fuel cell can charge the storage battery and the super capacitor, and the storage battery can charge the super capacitor, so that the stability and the reliability of power supply are improved, and complementary utilization of energy is realized; and stable power output can be provided under various working conditions.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen energy, and in particular to an ammonia-hydrogen fuel cell-battery hybrid power supply system. Background Art

[0002] As a clean and efficient energy carrier, hydrogen boasts advantages such as high energy density and zero pollution, and is considered a crucial component of the future energy system. However, traditional hydrogen production methods, such as steam reforming, suffer from high energy consumption and high carbon emissions, limiting their large-scale application.

[0003] Against this backdrop, ammonia-to-hydrogen technology has become a research hotspot due to its advantages, including a wide range of raw material sources (industrial waste gas, agricultural waste, etc. can be converted into ammonia), convenient storage and transportation (liquid ammonia is easy to store and transport), and flexible and controllable hydrogen production processes. Ammonia can be converted into hydrogen and nitrogen through thermal decomposition, and this reaction is reversible, making it easy to adjust reaction conditions for efficient hydrogen production.

[0004] Among renewable liquid fuels, ammonia has a high hydrogen density by mass and volume, far higher than liquid hydrogen systems, and has mild storage conditions. Fuel cells have the advantages of high efficiency and high power. Therefore, using an ammonia-to-hydrogen system as a hydrogen source to drive a hydrogen-oxygen fuel cell has high technical value, especially for large electric-powered mobile vehicles. However, mobile vehicles such as trucks and ships require a faster start-up and shutdown response, but the ammonia-to-hydrogen system requires a long startup time. Therefore, a single ammonia-to-hydrogen system seriously affects the smooth operation of downstream loads. Therefore, how to couple the characteristics of the ammonia-to-hydrogen system with the fuel cell and the necessary auxiliary power supply to shorten the start-up and shutdown time and increase the smooth operation of the downstream load unit is a technical demand that needs to be broken through in the field of hydrogen energy applications. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides an ammonia-to-hydrogen fuel cell-battery hybrid power supply system. By integrating key components such as ammonia decomposition hydrogen production, fuel cells, batteries, and supercapacitors, this system achieves stable hydrogen production, efficient utilization, and flexible energy storage. The ammonia decomposition hydrogen production subsystem optimizes ammonia gasification, heat exchange, decomposition, and purification processes, improving system startup speed, hydrogen yield, and purity. The fuel cell utilizes hydrogen produced by the ammonia-to-hydrogen system as fuel, reacting with air to generate electricity. Batteries and supercapacitors, serving as energy storage elements with distinct characteristics, complement each other, balancing the energy supply and demand of the power supply system and improving system stability and reliability.

[0006] The utility model adopts the following technical solutions:

[0007] An ammonia-hydrogen fuel cell-battery hybrid power supply system, comprising a liquid ammonia source, a vaporizer, a first heat exchanger, an ammonia decomposition reactor, a membrane separation purifier, a pure hydrogen collector, a fuel cell and a power supply unit; the liquid ammonia source is connected to the vaporizer for gasifying liquid ammonia into ammonia; the first heat exchanger comprises a first heat exchange ammonia channel and a first heat exchange product gas channel, the ammonia decomposition reactor comprises an ammonia decomposition reaction ammonia channel and an ammonia decomposition reaction flue gas channel, the membrane separation purifier comprises a purified hydrogen channel and an unpurified hydrogen channel, the outlet of the vaporizer is connected to the inlet of the first heat exchange ammonia channel, the outlet of the first heat exchange ammonia channel is connected to the inlet of the ammonia decomposition reaction ammonia channel, and the ammonia after heat exchange by the first heat exchanger is passed into the An ammonia decomposition reactor decomposes ammonia; the outlet of the ammonia decomposition reaction ammonia channel is connected to the inlet of the first heat exchange product gas channel, and the outlet of the first heat exchange product gas channel is connected to the inlet of the purified hydrogen channel. The product mixed gas after decomposition by the ammonia decomposition reactor serves as the heat exchange medium of the first heat exchanger and exchanges heat with the ammonia passing through the first heat exchange ammonia channel, and then enters the membrane separation purifier for hydrogen purification; the outlet of the purified hydrogen channel is connected to the inlet of the pure hydrogen collector, and the purified hydrogen is cooled and collected and stored. The outlet of the pure hydrogen collector is connected to the negative electrode of the fuel cell to provide fuel hydrogen for the fuel cell. The fuel cell and the power supply unit are arranged in parallel to jointly constitute a hybrid power supply system.

[0008] The fuel cell includes a battery positive electrode, a battery negative electrode, a battery air channel, a battery hydrogen channel and a battery ion exchange membrane. The battery positive electrode and the battery negative electrode are separated by the battery ion exchange membrane to form two independent reaction areas. The battery air channel is arranged on the outside of the battery positive electrode and is conductive to the battery positive electrode. External air enters the battery positive electrode area through the battery air channel. The battery hydrogen channel is arranged on the outside of the battery negative electrode and is conductive to the battery negative electrode. Hydrogen from the pure hydrogen collector enters the battery negative electrode area through the battery hydrogen channel.

[0009] The power supply unit includes a battery and a supercapacitor arranged in parallel, the positive electrode of the battery is connected to the positive electrode of the battery and the positive electrode of the supercapacitor, and the negative electrode of the battery is connected to the negative electrode of the battery and the negative electrode of the supercapacitor to form a parallel power supply system, and through a unidirectional power-conducting element (such as a diode), the fuel cell can charge the battery and the supercapacitor, and the battery can charge the supercapacitor, and reverse charging cannot be achieved.

[0010] The system also includes a second heat exchanger and a hydrogen burner. The second heat exchanger includes a second heat exchange air channel and a second heat exchange flue gas channel. The outlet of the hydrogen burner is connected to the inlet of the ammonia decomposition reaction flue gas channel to provide heat energy for the decomposition of ammonia in the ammonia decomposition reactor. The outlet of the ammonia decomposition reaction flue gas channel is connected to the inlet of the second heat exchange flue gas channel to preheat the air entering the second heat exchange air channel. The outlet of the second heat exchange flue gas channel is connected to the flue gas treatment and release unit to treat and release the flue gas after combustion and heat exchange.

[0011] The system further includes an air compressor, the outlet of the air compressor is divided into two paths, one path is connected to the inlet of the second heat exchange air channel, and the other path is connected to the positive electrode of the fuel cell.

[0012] The system also includes a gas mixer, and the hot air after heat exchange in the second heat exchanger and the unpurified hydrogen through the unpurified hydrogen channel enter the gas mixer; the outlet of the pure hydrogen collector is connected to the gas mixer, and the purified hydrogen in the pure hydrogen collector flows into the gas mixer as ignition hydrogen; the mixed gas flowing out after the gases are mixed in the gas mixer flows into the burner, and is ignited and burned in the burner to produce high-temperature flue gas.

[0013] Preferably, the battery comprises a lithium-ion battery or a sodium-ion battery.

[0014] The separation membrane used for purification in the membrane separation purifier is a selective hydrogen permeable membrane, which can efficiently separate hydrogen from other gases. After the gas flows out from the outlet of the product gas channel of the first heat exchanger, it enters the unpurified hydrogen channel of the purifier. Thereafter, the gas will be split into two directions. The hydrogen that passes through the selective hydrogen permeable membrane enters the purified hydrogen channel, while the unpurified gas that does not pass through the selective hydrogen permeable membrane, containing hydrogen, nitrogen and a small amount of unreacted ammonia, enters the gas mixer.

[0015] Preferably, the separation membrane in the membrane separation purifier is a metal vanadium or metal niobium alloy membrane, and the alloy material is represented by M1. x M2 y M3 z , where M1 represents one or two of metals V and Nb, M2 represents one or more of metals W, Mo, and Ta, and M1 and M2 form a solid solution. M3 is a deoxidizing alloying element and represents one of Cr, Mn, Ti, Al, Y, Ma, La, Sr, Ba, and Ce. The subscripts x, y, and z represent the molar fractions of the element atoms of M1, M2, and M3, respectively, where x is 0.87 to 0.96, y is 0.03 to 0.13, and z is 0.005 to 0.01, and x+y+z=1.00.

[0016] Preferably, the operating temperature of the separation membrane is 240-640° C., and the pressure of the gas entering the membrane separation purifier is >0.2 MPa.

[0017] More preferably, the operating temperature of the separation membrane is 300-400° C., and the pressure of the gas entering the membrane separation purifier is 0.4-1.2 MPa.

[0018] Preferably, the ammonia decomposition reactor is a fixed bed reactor, and an ammonia decomposition catalyst is filled in the ammonia channel of the ammonia decomposition reactor. The reactant ammonia gas flow flows out of the first heat exchanger and enters the ammonia channel of the ammonia decomposition reactor, flows through the ammonia decomposition catalyst, and is converted into decomposition products to obtain hydrogen and nitrogen.

[0019] Preferably, the ammonia decomposition catalyst is one or a mixture of an iron-based catalyst and a ruthenium-based catalyst; after the device is running smoothly, the reaction conditions of the ammonia decomposition reactor are as follows: the operating temperature is 340-840°C, the gas pressure in the reactor is controlled at 0.2-3 MPa, and the ammonia gas space velocity is 100-10000h -1 .

[0020] More preferably, the reaction conditions of the ammonia decomposition reactor are as follows: the operating temperature is 440-580°C, the gas pressure in the reactor is controlled at 0.5-1.5 MPa, and the ammonia gas space velocity is 1400-6000 h -1 .

[0021] The burner contains an ignition device. Under appropriate fuel flow rate and air flow rate, after successful ignition and stable operation of the device, the air flow rate is 4 to 30 times the ammonia flow rate flowing into the ammonia decomposition reactor; whether the fuel combustion state is normal is judged by whether the burner outlet temperature is not less than 640°C.

[0022] The purity of the purified hydrogen flowing out of the membrane separation purifier is not less than 99.99%.

[0023] The technical solution of this utility model has the following advantages:

[0024] A. This utility model integrates key components such as ammonia decomposition hydrogen production, fuel cells, batteries, and supercapacitors to achieve stable hydrogen production, efficient utilization, and flexible energy storage. The ammonia decomposition hydrogen production subsystem improves hydrogen yield and purity by optimizing ammonia gasification, heat exchange, decomposition, and purification processes. The fuel cell uses the generated hydrogen as fuel, reacting with air to generate electricity. The batteries and supercapacitors serve as energy storage elements, balancing system energy supply and demand and improving system stability and reliability.

[0025] B. This utility model combines a fuel cell with a battery and supercapacitor to create a hybrid power supply system. This not only improves power supply stability and reliability, but also achieves complementary energy utilization, ensuring stable power output under various operating conditions. The design of a unidirectional energizing element enables the fuel cell to charge the battery and supercapacitor, and vice versa, while reverse charging is prohibited, ensuring the safety of the charging process and the rationality of energy flow.

[0026] C. The present system combines the advantages of ammonia's high hydrogen density with the appropriate storage capacity, high power density, and instantaneous operation of batteries and supercapacitors. The overall system boasts high energy storage density, a short startup time, and high power output. Capacitors, batteries, and fuel cells work in relays, optimizing the storage energy values ​​of ammonia and electricity to ensure smooth system operation. Through system optimization, the present hydrogen production system can achieve a smooth hydrogen supply from a cold start at room temperature in less than 20 minutes. This significantly reduces the time required for conventional ammonia decomposition hydrogen production systems, significantly reducing the battery storage capacity requirements.

[0027] D. In terms of temperature and pressure compatibility, the preferred operating temperature of the metal separation membrane of the present invention is 300-400°C, and the temperature within the reactor is preferably 440-580°C. This indicates that the temperature and pressure range of the product gas after passing through the first heat exchanger is well matched to the operating temperature range of the metal separation membrane. In particular, the preferred reaction temperature and pressure ranges are well matched to the temperature and pressure ranges where the alloy membrane achieves excellent separation performance. This eliminates the need for further process changes such as heating and pressurizing the product gas during gas separation and purification using the alloy membrane, simplifying the process and saving overall energy consumption.

[0028] E. This utility model fully utilizes the operating temperature and pressure characteristics of the ammonia decomposition hydrogen production reaction, making it suitable for hydrogen purification using non-precious metal alloy membranes. The use of non-precious metal alloy membranes significantly reduces the cost of separation membranes compared to palladium-based membranes. Furthermore, compared to commonly used pressure swing adsorption separation methods, the alloy membranes in this utility model significantly reduce weight and volume for equivalent hydrogen separation flux, which is of great significance for the miniaturization, modularization, and portability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present invention, the following will briefly introduce the drawings required for use in the specific implementation methods. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1This is a schematic diagram of the overall structure of the ammonia-hydrogen fuel cell-battery hybrid power supply system.

[0031] The following are marked in the figure:

[0032] 1-Liquid ammonia source; 2-Gasifier; 3-First heat exchanger, 31-First heat exchange ammonia channel, 32-First heat exchange product gas channel; 4-Ammonia decomposition reactor, 41-Ammonia decomposition reaction ammonia channel, 42-Ammonia decomposition reaction flue gas channel; 5-Second heat exchanger, 51-Second heat exchange air channel, 52-Second heat exchange flue gas channel; 6-Membrane separation purifier, 61-Unpurified hydrogen channel, 62-Purified hydrogen channel; 7-Fuel cell, 71-Battery positive electrode, 72-Battery negative electrode, 73-Battery air channel, 74-Battery hydrogen channel, 75-Battery ion exchange membrane; 8-Gas mixer; 9-Hydrogen burner; 10-Pure hydrogen collector; 20-Air compressor; 30-Flue gas treatment and release unit; 40-Power supply unit, 401-Battery, 402-Supercapacitor, 403-Current unidirectional element, 404-Positive and negative output terminals of the power supply unit. DETAILED DESCRIPTION

[0033] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0034] like Figure 1As shown, this embodiment provides an ammonia-hydrogen fuel cell-battery hybrid power supply system, including a liquid ammonia source 1, a vaporizer 2, a first heat exchanger 3, an ammonia decomposition reactor 4, a membrane separation purifier 6, a pure hydrogen collector 10, a fuel cell 7 and a power supply unit 40; the liquid ammonia source 1 is connected to the vaporizer 2 for gasifying the liquid ammonia into ammonia; the first heat exchanger 3 includes a first heat exchange ammonia channel 31 and a first heat exchange product gas channel 32, the ammonia decomposition reactor 4 includes an ammonia decomposition reaction ammonia channel 41 and an ammonia decomposition reaction flue gas channel 42, the membrane separation purifier 6 includes an unpurified hydrogen channel 61 and a purified hydrogen channel 62, the outlet of the vaporizer 2 is connected to the inlet of the first heat exchange ammonia channel 31, and the outlet of the first heat exchange ammonia channel 31 is connected to the inlet of the ammonia decomposition reaction ammonia channel 41, The ammonia gas after heat exchange in the first heat exchanger 3 is passed into the ammonia decomposition reactor 4 for ammonia decomposition; the outlet of the ammonia decomposition reaction ammonia channel 41 is connected to the inlet of the first heat exchange product gas channel 32, and the outlet of the first heat exchange product gas channel 32 is connected to the inlet of the purified hydrogen channel 62. The product mixed gas after decomposition in the ammonia decomposition reactor 4 serves as the heat exchange medium of the first heat exchanger 3 and exchanges heat with the ammonia gas passing through the first heat exchange ammonia channel 31, and then passes into the membrane separation purifier 6 for hydrogen purification; the outlet of the purified hydrogen channel 62 is connected to the inlet of the pure hydrogen collector 10, and the purified hydrogen is cooled and collected for storage. The outlet of the pure hydrogen collector 10 is connected to the negative electrode of the fuel cell 7 to provide fuel hydrogen for the fuel cell 7. The fuel cell 7 and the power supply unit 40 are arranged in parallel to form a hybrid power supply system. The present invention realizes the stable preparation, efficient utilization and flexible energy storage of hydrogen by integrating key components such as ammonia decomposition hydrogen production, fuel cell and power supply unit. Among them, the ammonia decomposition hydrogen production subsystem improves the yield and purity of hydrogen by optimizing the ammonia gasification, heat exchange, decomposition, and purification processes; the fuel cell uses the generated hydrogen as fuel to react with air to generate electricity; the power supply unit serves as an energy storage element to balance the system's energy supply and demand, thereby improving system stability and reliability.

[0035] Furthermore, the fuel cell 7 includes a battery positive electrode 71, a battery negative electrode 72, a battery air channel 73, a battery hydrogen channel 74 and a battery ion exchange membrane 75. The battery positive electrode 71 and the battery negative electrode 72 are separated by the battery ion exchange membrane 75 to form two independent reaction areas. The battery air channel 73 is arranged on the outside of the battery positive electrode 71 and is connected to the battery positive electrode 71. External air enters the battery positive electrode 71 area through the battery air channel 73. The battery hydrogen channel 74 is arranged on the outside of the battery negative electrode 72 and is connected to the battery negative electrode 72. Hydrogen from the pure hydrogen collector 10 enters the battery negative electrode 72 area through the battery hydrogen channel 74.

[0036] The power supply unit 40 includes a battery 401 and a supercapacitor 402 arranged in parallel. The positive electrode 71 of the battery is connected to the positive electrode of the battery 401 and the positive electrode of the supercapacitor 402, and the negative electrode 72 of the battery is connected to the negative electrode of the battery 401 and the negative electrode of the supercapacitor 402, forming a parallel power supply system. And through a unidirectional power supply element 403 (such as a diode, etc.), the fuel cell 7 can charge the battery 401 and the supercapacitor 402, and the battery 401 can charge the supercapacitor 402, while the reverse charging of the above charging cannot be achieved. The positive and negative electrodes 404 of the total power supply system can, in principle, be connected to any downstream power load. The utility model combines a fuel cell with a battery and a supercapacitor into a hybrid power supply system, which not only improves the stability and reliability of the power supply, but also realizes the complementary utilization of energy, ensuring that stable power output can be provided under various working conditions. The battery 401 can be selected from one of a lithium-ion battery or a sodium-ion battery or other, and is not specifically limited here.

[0037] The system also includes a second heat exchanger 5 and a hydrogen burner 9. The second heat exchanger 5 includes a second heat exchange air channel 51 and a second heat exchange flue gas channel 52. The outlet of the hydrogen burner 9 is connected to the inlet of the ammonia decomposition reaction flue gas channel 42, providing heat energy for the decomposition of ammonia in the ammonia decomposition reactor 4. The outlet of the ammonia decomposition reaction flue gas channel 42 is connected to the inlet of the second heat exchange flue gas channel 52, used to preheat the air entering the second heat exchange air channel 51. The outlet of the second heat exchange flue gas channel 52 is connected to the flue gas treatment and release unit 30, used to treat and release the flue gas after combustion and heat exchange. The utility model realizes efficient energy recovery and utilization by performing multi-stage heat exchange between the heat generated during the ammonia decomposition process and the heat generated during the combustion process. In particular, the high-temperature flue gas generated by combustion is used to preheat the ammonia entering the ammonia decomposition reactor, reducing energy consumption and improving the overall thermal efficiency of the system.

[0038] The purification membrane in membrane separation purifier 6 is a selective hydrogen-permeable membrane, capable of efficiently separating hydrogen from other gases. After exiting the outlet of product gas channel 32 of first heat exchanger 3, the gas enters unpurified hydrogen channel 61 of purifier 6. Thereafter, the gas is split in two directions: hydrogen that has passed through the separation membrane enters purified hydrogen channel 62, while unpurified gas that has not passed through the separation membrane, containing hydrogen, nitrogen, and a small amount of unreacted ammonia, enters gas mixer 8.

[0039] Specifically, the separation membrane of the membrane separation purifier 6 is made of metal vanadium or metal niobium alloy membrane, and the alloy material can be expressed as: M1 x M2 y M3 z; Wherein M1 represents metal V or Nb, or both, M2 represents one or more of metals W, Mo, Ta, and M3 represents one of Cr, Mn, Ti, Al, Y, Ma, La, Sr, Ba, and Ce; subscripts x, y, and z represent the molar fractions of the atoms of M1, M2, and M3, respectively, where x is 0.87 to 0.96, y is 0.03 to 0.13, and z is 0.005 to 0.01, and x+y+z=1.00; the two metals M1 and M2 form a solid solution, and M3 acts as a deoxidizing alloying element. In this embodiment, the separation membrane in the membrane separation purifier 6 adopts a metal vanadium-niobium alloy membrane, and the specific material can be expressed as V 0.80 Nb 0.12 Mo 0.05 Cr 0.03 The operating temperature of the separation membrane is 240-640°C, preferably 300-400°C; the operating pressure, i.e., the pressure of the gas entering the membrane separator, is >0.2 MPa, preferably 0.4-1.2 MPa. It is worth noting that if the separation process parameters are outside the above operating temperature and pressure, it does not mean that the hydrogen separation and purification will be completely ineffective, but may lead to one or more of the following situations: reduced purification efficiency, reduced hydrogen purity, and rapid damage to the separation membrane.

[0040] The ammonia decomposition reactor 4 uses a fixed bed reactor, and the ammonia decomposition catalyst is filled in the ammonia channel of the reactor. The reactant ammonia gas flow flows out of the first heat exchanger 3 and enters the ammonia channel 41 of the reactor, and flows through the ammonia decomposition catalyst to be converted into decomposition products to obtain hydrogen and nitrogen. In the ammonia decomposition reactor 4, when the device is running smoothly, the process conditions adopted are as follows: the ammonia decomposition catalyst is an iron-based catalyst, a ruthenium-based catalyst, or a mixture of the two types of catalysts; after the device is running smoothly, the reaction conditions of the reactor are as follows: the operating temperature is 340-840℃, preferably 440-580℃; the gas pressure in the reactor is controlled at 0.2-3MPa, preferably 0.5-1.5MPa; the ammonia gas space velocity is 100-10000h -1 , preferably 1400~6000h -1 .

[0041] The purity of the purified hydrogen flowing out of the membrane separation purifier 6 is not less than 99.99%; the hydrogen yield calculated based on this portion of hydrogen can reach 60-86%.

[0042] The system also includes an air compressor 20, the outlet of which is divided into two paths: one path communicates with the inlet of the second heat exchange air channel 51, and the other path communicates with the positive electrode 71 of the fuel cell 7. The system also includes a gas mixer 8, into which hot air after heat exchange in the second heat exchanger 5 and unpurified hydrogen from the unpurified hydrogen channel 61 enter. The outlet of the pure hydrogen collector 10 is connected to the gas mixer 8, and the purified hydrogen in the pure hydrogen collector 10 is fed into the gas mixer 8 as ignition hydrogen. After mixing the gases in the gas mixer 8, the mixed gas flows into the burner 9, where it ignites and burns to produce high-temperature flue gas.

[0043] In terms of temperature and pressure compatibility, the preferred operating temperature of the metal separation membrane of the present invention is 300-400°C, and the temperature within the reactor is preferably 440-580°C. This indicates that the temperature and pressure range of the product gas after passing through the first heat exchanger are well matched to the operating temperature range of the metal separation membrane. In particular, the preferred reaction temperature and pressure ranges are well matched to the temperature and pressure ranges where the alloy membrane achieves excellent separation performance. This eliminates the need for further process changes such as heating and pressurizing the product gas during gas separation and purification using the alloy membrane, simplifying the process and saving overall energy consumption.

[0044] Advantages of using non-precious metal membrane separators:

[0045] It's common knowledge in this field that hydrogen purity significantly impacts the quality and value of the resulting hydrogen product. For example, one of the hydrogen purity requirements for low-temperature hydrogen-oxygen fuel cells is a purity of at least 99.99%. Therefore, hydrogen produced through chemical reactions typically requires a purification process to significantly increase the value of the hydrogen product. Commonly used hydrogen purification methods include metal membrane separation and pressure swing adsorption (PSA) based on pressure swing adsorption technology.

[0046] The PSA method utilizes the varying adsorption capacities of porous materials, such as molecular sieves, for different gas molecules, as well as the varying adsorption and desorption capacities and rates under varying pressures. Through multiple pressure swings, some molecules (usually impurities) in the feed gas are adsorbed by the porous material, while more target gas molecules are desorbed, thereby purifying the target gas. While pressure swing adsorption technology is mature, and gases can be purified to high purity levels based on purity requirements, its drawback is that the devices are too large and heavy, making them unsuitable for factory installations and difficult to apply to mobile, skid-mounted, or modular equipment.

[0047] Metal membrane separation utilizes the sieving effect of the metal lattice at a certain temperature on substances of different sizes and their varying chemical affinities, allowing target gas molecules to pass through the membrane more quickly while impurity molecules are unable to, or only slowly, penetrate. Its advantages include high separation efficiency per unit mass, strong chemical selectivity, and ease of miniaturization and lightweighting. However, its main drawbacks are the limited selection of materials and high cost. Palladium membranes, the most widely used metal, are particularly expensive due to their precious metal properties and high processing costs.

[0048] This utility model fully utilizes the operating temperature and pressure characteristics of the ammonia decomposition hydrogen production reaction, making it suitable for hydrogen purification using non-precious metal alloy membranes. The use of non-precious metal alloy membranes significantly reduces the cost of separation membranes compared to palladium-based membranes. Furthermore, compared to commonly used pressure swing adsorption separation methods, the alloy membranes in this utility model significantly reduce weight and volume for equivalent hydrogen separation flux, which is of great significance for the miniaturization, modularization, and portability of the device.

[0049] The fixed-bed reactor described above is a common type of reactor used by those skilled in the art or chemical industry. Its key feature is that the catalyst is packed within the reactor, and the feed gas, under a specific temperature, pressure, and flow rate, passes through the catalyst bed to form reaction products. In this case, ammonia gas flowing from the first heat exchanger enters the reactor and passes through the catalyst to form nitrogen and hydrogen products.

[0050] Due to the thermal effect of the reaction in the fixed bed reactor and the uneven heating of the heat source, the catalyst bed temperature in the reactor, usually called the reaction temperature, is often not uniform at different spatial points, usually within a temperature range. Typically, the temperature difference at different points can be in the range of 10 to 40°C.

[0051] “Gas space velocity” is a commonly used technical term in fixed bed reactor technology. It refers to the volume of gas flowing through a unit volume of catalyst per unit time under standard conditions. Its unit is usually h -1 .

[0052] Physical quantities such as reaction conversion rate, yield, gas purity, and the like are calculated using measurement and calculation methods recognized in the field.

[0053] The fuel cell described herein refers to a hydrogen-oxygen fuel cell, preferably one in which the negative electrode fuel is high-purity hydrogen and the positive electrode uses air as the oxygen source. Those skilled in the art will be aware that hydrogen-oxygen fuel cells require a high purity of hydrogen, which must be no less than 99.99% (v / v).

[0054] The ammonia hydrogen production system in the utility model (such as Figure 1Components 1 to 10) can achieve a time of no more than 20 minutes from starting from room temperature to the time when the pure hydrogen collector 10 smoothly supplies hydrogen to the fuel cell 7, and the quality of the hydrogen enables the fuel cell 7 to operate normally. It is worth noting that the short startup time will reduce the subsequent storage capacity requirements of the battery and supercapacitor. As long as the battery 401 and the supercapacitor 402 in the power supply unit can provide the downstream power load with a storage capacity of 20 minutes, the entire power supply system can achieve continuous and stable power supply. This storage capacity is relatively easy to achieve with the current technical level, so the specific selection of batteries and supercapacitors is not limited in this utility model.

[0055] The utility model has a compact system design and integrates multiple links such as liquid ammonia storage, gasification, heat exchange, ammonia decomposition to produce hydrogen, hydrogen purification, fuel cell power generation, and charging of batteries and supercapacitors, realizing continuous conversion from raw materials to electrical energy and improving the system's integration and automation level.

[0056] Any matters not described in this utility model are applicable to the prior art.

[0057] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. An ammonia-to-hydrogen fuel cell-battery hybrid power supply system, characterized in that: The invention comprises a liquid ammonia source (1), a vaporizer (2), a first heat exchanger (3), an ammonia decomposition reactor (4), a membrane separation purifier (6), a pure hydrogen collector (10), a fuel cell (7) and a power supply unit (40); the liquid ammonia source (1) is connected to the vaporizer (2) and is used to gasify the liquid ammonia into ammonia gas; the first heat exchanger (3) comprises a first heat exchange ammonia gas channel (31) and a first heat exchange product gas channel (32); the ammonia decomposition reactor (4) comprises an ammonia decomposition reaction channel (31) and a first heat exchange product gas channel (32); The ammonia channel (41) and the ammonia decomposition reaction flue gas channel (42) are connected. The membrane separation purifier (6) includes an unpurified hydrogen channel (61) and a purified hydrogen channel (62). The outlet of the gasifier (2) is connected to the inlet of the first heat exchange ammonia channel (31). The outlet of the first heat exchange ammonia channel (31) is connected to the inlet of the ammonia decomposition reaction ammonia channel (41). The ammonia after heat exchange in the first heat exchanger (3) is passed into the ammonia decomposition reactor (4 ) for ammonia decomposition; the outlet of the ammonia decomposition reaction ammonia channel (41) is connected to the inlet of the first heat exchange product gas channel (32), and the outlet of the first heat exchange product gas channel (32) is connected to the inlet of the unpurified hydrogen channel (61); the product mixed gas after decomposition by the ammonia decomposition reactor (4) is used as the heat exchange medium of the first heat exchanger (3) and is heat exchanged with the ammonia passing through the first heat exchange ammonia channel (31) and then passed into the membrane separation purifier (6) for hydrogen purification; the purified hydrogen enters the purified hydrogen channel (62), the outlet of the purified hydrogen channel (62) is connected to the inlet of the pure hydrogen collector (10), and the purified hydrogen is cooled and collected and stored; the outlet of the pure hydrogen collector (10) is connected to the negative electrode of the fuel cell (7) to provide fuel hydrogen for the fuel cell (7); the fuel cell (7) and the power supply unit (40) are arranged in parallel to form a hybrid power supply system.

2. The ammonia-to-hydrogen fuel cell-battery hybrid power supply system according to claim 1, characterized in that: The fuel cell (7) comprises a battery positive electrode (71), a battery negative electrode (72), a battery air channel (73), a battery hydrogen channel (74) and a battery ion exchange membrane (75). The battery positive electrode (71) and the battery negative electrode (72) are separated by the battery ion exchange membrane (75) to form two independent reaction areas. The battery air channel (73) is arranged outside the battery positive electrode (71) and is in conduction with the battery positive electrode (71). External air enters the battery positive electrode (71) area through the battery air channel (73). The battery hydrogen channel (74) is arranged outside the battery negative electrode (72) and is in conduction with the battery negative electrode (72). Hydrogen from the pure hydrogen collector (10) enters the battery negative electrode (72) area through the battery hydrogen channel (74).

3. The ammonia-to-hydrogen fuel cell-battery hybrid power supply system according to claim 2, characterized in that: The power supply unit (40) includes a battery (401) and a supercapacitor (402) arranged in parallel, the battery positive electrode (71) is connected to the positive electrode of the battery (401) and the positive electrode of the supercapacitor (402), and the battery negative electrode (72) is connected to the negative electrode of the battery (401) and the negative electrode of the supercapacitor (402), forming a parallel power supply system, so that the fuel cell (7) can charge the battery (401) and the supercapacitor (402), and the battery (401) can charge the supercapacitor (402).

4. The ammonia-to-hydrogen fuel cell-battery hybrid power supply system according to claim 3, characterized in that: The system further comprises a second heat exchanger (5) and a hydrogen burner (9), wherein the second heat exchanger (5) comprises a second heat exchange air channel (51) and a second heat exchange flue gas channel (52), wherein the outlet of the hydrogen burner (9) is connected to the inlet of the ammonia decomposition reaction flue gas channel (42) to provide heat energy for the decomposition of ammonia in the ammonia decomposition reactor (4), the outlet of the ammonia decomposition reaction flue gas channel (42) is connected to the inlet of the second heat exchange flue gas channel (52) to preheat the air entering the second heat exchange air channel (51), and the outlet of the second heat exchange flue gas channel (52) is connected to the flue gas treatment and release unit (30) to treat and release the flue gas after combustion and heat exchange.

5. The ammonia-to-hydrogen fuel cell-battery hybrid power supply system according to claim 4, characterized in that: The system further comprises an air compressor (20), the outlet of the air compressor (20) being divided into two paths, one path being connected to the inlet of the second heat exchange air channel (51), and the other path being connected to the positive electrode (71) of the fuel cell (7).

6. The ammonia-to-hydrogen fuel cell-battery hybrid power supply system according to claim 5, characterized in that: The system further comprises a gas mixer (8), wherein the hot air after heat exchange in the second heat exchanger (5) and the unpurified hydrogen passing through the unpurified hydrogen channel (61) enter the gas mixer (8); the outlet of the pure hydrogen collector (10) is connected to the gas mixer (8), and the purified hydrogen in the pure hydrogen collector (10) is used as ignition hydrogen to flow into the gas mixer (8); the mixed gas flowing out after mixing in the gas mixer (8) flows into the burner (9), and is ignited and burned in the burner (9) to generate high-temperature flue gas.

7. The ammonia-to-hydrogen fuel cell-battery hybrid power supply system according to claim 3, characterized in that: The storage battery (401) is a lithium ion battery or a sodium ion battery.

8. The ammonia-to-hydrogen fuel cell-battery hybrid power supply system according to claim 6, characterized in that: The separation membrane used for purification in the membrane separation purifier (6) is a selective hydrogen permeable membrane, which can efficiently separate hydrogen from other gases; after the gas flows out from the outlet of the product gas channel (32) of the first heat exchanger (3), it enters the unpurified hydrogen channel (61) of the purifier (6), and then the gas will be split into two directions, wherein the hydrogen that passes through the selective hydrogen permeable membrane enters the purified hydrogen channel (62), and the unpurified gas that does not pass through the selective hydrogen permeable membrane, containing hydrogen, nitrogen and a small amount of unreacted ammonia, enters the gas mixer (8).

9. The ammonia-to-hydrogen fuel cell-battery hybrid power supply system according to claim 1, characterized in that: The ammonia decomposition reactor (4) is a fixed bed reactor. An ammonia decomposition catalyst is filled in the ammonia channel of the ammonia decomposition reactor (4). The reactant ammonia gas flow flows out of the first heat exchanger (3) and enters the ammonia channel of the ammonia decomposition reactor (4). The reactant ammonia gas flows through the ammonia decomposition catalyst and is converted into decomposition products to obtain hydrogen and nitrogen.

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