Ammonia decomposition product membrane separation and purification-fuel cell coupling system

Abstract

The utility model discloses a membrane separation and purification-fuel cell coupling system for ammonia decomposition products. Comprising a liquid ammonia storage device for storing liquid ammonia, a gasifier for gasifying the liquid ammonia into ammonia gas, an ammonia decomposition reactor for receiving the ammonia gas and performing decomposition reaction, a membrane separation purifier for receiving, separating and purifying hydrogen in product gas, a radiator for cooling the purified hydrogen and a fuel cell which are connected in series, and the cathode of the fuel cell receives the hydrogen cooled by the radiator as fuel. According to the system, ammonia is used as a carrier of hydrogen, the decomposition process is relatively clean, and the emission of byproducts is effectively reduced through a membrane separation technology, so that the whole system is more environment-friendly. And meanwhile, by using the fuel cell, pollutant emission in the traditional combustion process is reduced, and the aim of carbon neutralization is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen energy, in particular to an ammonia decomposition product membrane separation and purification-fuel cell coupling system. Background Art

[0002] As the global demand for renewable energy and clean energy continues to grow, hydrogen energy, as a clean and efficient energy carrier, has received widespread attention. However, the storage and transportation of hydrogen has always been one of the main bottlenecks restricting its large-scale application. Ammonia is regarded as a highly promising hydrogen storage and transportation medium due to its high hydrogen density, easy liquefaction and storage, and relatively safe transportation characteristics.

[0003] Ammonia decomposition hydrogen production technology, that is, decomposing ammonia into hydrogen and nitrogen, is a key step in achieving the conversion of ammonia to hydrogen. This technology can not only provide pure hydrogen as fuel for equipment such as fuel cells, but also maximize the utilization of resources through the recycling of by-product nitrogen. However, traditional ammonia decomposition hydrogen production systems often have problems such as low hydrogen purity, complex by-product treatment, and low system energy efficiency, making it difficult to meet the growing demand for hydrogen energy applications.

[0004] Fuel cells, the most common of which are hydrogen-oxygen fuel cells, are electrical energy output devices that use hydrogen as fuel. They can be used to drive mobile equipment such as ships and large trucks, and can also be used for energy storage. In these usage scenarios, usually due to space limitations, the miniaturization and modularization of equipment are very important. Hydrogen-oxygen fuel cells have very high requirements for hydrogen purity, usually requiring a hydrogen purity of at least 99.97%. Therefore, if hydrogen from the chemical hydrogen production process is to be used with fuel cells, a purification device is necessary. Compared with the commonly used commercial pressure swing adsorption purification device, the membrane separation device is small, lightweight, and has high separation efficiency, making it suitable for mobile equipment.

[0005] Directly coupling ammonia decomposition to produce hydrogen with hydrogen energy utilization equipment such as fuel cells to achieve instant preparation and efficient utilization of hydrogen is also one of the current research hotspots in the field of hydrogen energy. However, the commonly used membrane separation equipment is mainly palladium-based membrane separation equipment, which has high operating costs due to its precious metal properties. How to achieve efficient separation and purification of ammonia decomposition products, develop low-cost membrane separation equipment usage methods, and how to optimize the integration and energy efficiency of the entire system are still technical problems that need to be solved urgently. Utility Model Content

[0006] In view of the shortcomings of the existing technology, the utility model provides an ammonia decomposition product membrane separation and purification-fuel cell coupling system, which aims to improve the purity and output of hydrogen through innovative system design and efficient separation and purification technology, optimize the energy efficiency and integration of the system, and provide strong support for the large-scale application of hydrogen energy.

[0007] The utility model adopts the following technical solutions:

[0008] The utility model provides an ammonia decomposition product membrane separation and purification-fuel cell coupling system, comprising:

[0009] A liquid ammonia storage device, used for storing liquid ammonia;

[0010] a vaporizer connected to the liquid ammonia storage device and used for vaporizing the liquid ammonia into ammonia gas;

[0011] an ammonia decomposition reactor, which is disposed downstream of the gasifier, receives ammonia from the gasifier and performs a decomposition reaction to generate a product gas containing hydrogen;

[0012] a membrane separation purifier, which is arranged downstream of the ammonia decomposition reactor and is used to receive and separate and purify hydrogen in the product gas from the ammonia decomposition reactor;

[0013] a radiator, which is arranged downstream of the purified gas channel of the membrane separation purifier and is used to cool the purified hydrogen;

[0014] The fuel cell is arranged downstream of the radiator, and the negative electrode of the fuel cell receives the hydrogen gas cooled by the radiator as fuel.

[0015] The membrane separation purifier comprises a purified gas channel and a residual gas channel, wherein the purified gas channel comprises an air inlet and an air outlet, the air inlet is used to receive the product gas from the ammonia decomposition reactor, and the hydrogen purified by the purified gas channel is output through the air outlet and enters the negative electrode of the fuel cell; the residual gas channel has at least one residual gas outlet for discharging unpurified gas.

[0016] The system further comprises a residual gas collector, which is connected to the gas outlet of the residual gas channel in the membrane separation purifier and is used for collecting and processing unpurified gas.

[0017] 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.

[0018] The system further comprises a control device, which is electrically connected to the ammonia decomposition reactor and the fuel cell respectively, and can be used to automatically adjust the decomposition rate of the ammonia decomposition reactor according to the hydrogen demand of the fuel cell and the system operation state.

[0019] The technical solution of the utility model has the following advantages:

[0020] A. Efficient hydrogen production and purification: The utility model system effectively converts liquid ammonia into ammonia gas through an ammonia decomposition reactor, and further decomposes it into hydrogen. Subsequently, a membrane separation purifier is used to efficiently separate and purify the product gas, which significantly improves the purity and output of hydrogen, and provides high-quality hydrogen fuel for subsequent fuel cells.

[0021] B. Maximization of energy utilization: The utility model realizes the immediate utilization of hydrogen by directly coupling the ammonia decomposition hydrogen production system with the fuel cell, avoids energy loss and safety hazards during hydrogen storage and transportation, and improves the energy utilization efficiency of the entire system.

[0022] C. Environmentally friendly: In the utility model, ammonia is used as a hydrogen carrier, and its decomposition process is relatively clean. In addition, the system effectively reduces the emission of by-products through membrane separation technology, making the entire system more environmentally friendly. At the same time, the use of fuel cells also reduces the emission of pollutants in the traditional combustion process, which is conducive to achieving the goal of carbon neutrality.

[0023] D. High system integration: The utility model system integrates multiple links such as ammonia decomposition, gas purification, heat dissipation and fuel cells into a compact system, which reduces the equipment footprint, reduces system complexity and maintenance costs, and improves the overall performance and reliability of the system.

[0024] E. Flexibility and scalability: The system of the utility model can adjust the scale and quantity of the ammonia decomposition reactor, membrane separation purifier and fuel cell according to actual needs to adapt to hydrogen energy application scenarios of different scales, and has good flexibility and scalability.

[0025] F. Residual gas recycling: The unpurified gas separated by the membrane separation purifier of the utility model is collected in the residual gas collector. This part of the gas can be further processed or recycled according to the specific situation, realizing the maximum utilization of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the present utility model, the drawings required for use in the specific implementation methods will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 The overall structure diagram of the ammonia decomposition product membrane separation and purification-fuel cell coupling system (I);

[0028] Figure 2 Schematic diagram of the overall structure of the ammonia decomposition product membrane separation and purification-fuel cell coupling system (II).

[0029] The following are marked in the figure:

[0030] 1-liquid ammonia storage device; 2-gasifier; 3-ammonia decomposition reactor; 4-membrane separation purifier, 4a-purified gas channel, 4b-residual gas channel; 5-radiator; 6-fuel cell; 7-residual gas collector; 8-control device. DETAILED DESCRIPTION

[0031] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] like Figure 1 As shown, this embodiment provides an ammonia decomposition product membrane separation purification-fuel cell coupling system, comprising a liquid ammonia storage device 1, a gasifier 2, an ammonia decomposition reactor 3, a membrane separation purifier 4, a radiator 5 and a fuel cell 6 arranged in series. The liquid ammonia storage device 1 is used to store liquid ammonia; the gasifier 2 is connected to the liquid ammonia storage device 1, and is used to gasify the liquid ammonia into ammonia gas; the ammonia decomposition reactor 3 is arranged downstream of the gasifier 2, receives the ammonia gas from the gasifier 2 and performs a decomposition reaction to generate a product gas containing hydrogen; the membrane separation purifier 4 is arranged downstream of the ammonia decomposition reactor 3, and is used to receive and separate and purify the hydrogen in the product gas from the ammonia decomposition reactor 3; the radiator 5 is arranged downstream of the purified gas channel of the membrane separation purifier 4, and is used to cool the purified hydrogen; the fuel cell 6 is arranged downstream of the radiator 5, and the negative electrode of the fuel cell 6 receives the hydrogen cooled by the radiator 5 as fuel.

[0033] Furthermore, the membrane separation purifier 4 comprises at least one air inlet, two air outlets and contains a metal alloy separation membrane; the gas channel through which the gas entering from the air inlet passes through the separation membrane and flows out from one of the air outlets is the purified gas channel 4a, and the gas channel that does not pass through the separation membrane and flows out from the other outlet is the residual gas channel 4b. In the utility model, the air inlet is used to receive the product gas from the ammonia decomposition reactor 3, and the hydrogen purified by the purified gas channel 4a passes through the outlet on the purified gas channel 4a, and then after being appropriately cooled by the radiator 5, it is output and enters the negative electrode of the fuel cell 6. The residual gas channel 4b has at least one residual gas outlet for discharging the unpurified gas. The system also includes a residual gas collector 7, which is connected to the outlet of the residual gas channel 4b in the membrane separation purifier 4, and is used to collect and process the unpurified gas.

[0034] The separation membrane used for purification in the membrane separation purifier 4 is a selective hydrogen permeable membrane, which is a metal alloy separation membrane in terms of material, and can efficiently separate hydrogen from other gases. Specifically, the separation membrane of the membrane separation purifier 6 is a 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; the subscripts x, y, and z represent the molar fractions of M1, M2, and M3 element atoms, respectively, where x is 0.87 to 0.96, y is 0.03 to 0.13, 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.

[0035] The working temperature of the separation membrane is 250-650°C, preferably 400-500°C; the working pressure, i.e. the gas pressure entering the membrane separator is >0.2MPa, preferably 0.4-1.2MPa; it is worth noting that the separation process parameters outside the above working temperature and pressure do not mean that the hydrogen separation and purification is completely ineffective, but may lead to one or more situations such as reduced purification efficiency, reduced hydrogen purity, and faster damage to the separation membrane.

[0036] The ammonia decomposition reactor 3 adopts a fixed bed reactor, and the reactor pipeline is filled with an ammonia decomposition catalyst. The reactant ammonia gas flow flows out of the gasifier 2 and enters the reactor pipeline, flows through the ammonia decomposition catalyst, and is converted into decomposition products to obtain hydrogen and nitrogen. The ammonia decomposition reactor 3 and the residual gas channel of the membrane separation purifier maintain a pressure in the range of 0.2 to 3 MPa, preferably 0.5-1.5 MPa when the device is in operation.

[0037] The purity of the purified hydrogen flowing out of the membrane separation purifier 4 is not less than 99.97%.

[0038] like Figure 2 As shown, the system further includes a control device 8, which is electrically connected to the ammonia decomposition reactor 3 and the fuel cell 6, respectively, and can be used to automatically adjust the decomposition rate of the ammonia decomposition reactor 3 according to the hydrogen demand of the fuel cell 6 and the system operating status.

[0039] The utility model has the advantages of efficient hydrogen production and purification, maximum energy utilization, environmental friendliness, high system integration, strong flexibility and scalability, and realization of waste gas recovery and utilization. The following is a specific analysis:

[0040] In terms of efficient hydrogen production and purification, the utility model system effectively converts liquid ammonia into ammonia gas through an ammonia decomposition reactor, and further decomposes it into hydrogen. Subsequently, a membrane separation purifier is used to efficiently separate and purify the product gas, which significantly improves the purity and yield of hydrogen and provides high-quality hydrogen fuel for subsequent fuel cells.

[0041] In terms of maximizing energy utilization, the utility model realizes the immediate utilization of hydrogen by directly coupling the ammonia decomposition hydrogen production system with the fuel cell, avoids energy loss and safety hazards during hydrogen storage and transportation, and improves the energy utilization efficiency of the entire system.

[0042] In terms of environmental friendliness, the ammonia used as a hydrogen carrier in the utility model has a relatively clean decomposition process, and the system effectively reduces the emission of byproducts through membrane separation technology, making the entire system more environmentally friendly. At the same time, the use of fuel cells also reduces pollutant emissions in traditional combustion processes, which is conducive to achieving carbon neutrality goals.

[0043] In terms of system integration, the utility model system integrates multiple links such as ammonia decomposition, gas purification, heat dissipation and fuel cells into a compact system, which reduces the equipment footprint, reduces system complexity and maintenance costs, and improves the overall performance and reliability of the system.

[0044] In terms of flexibility and scalability, the system of the utility model can adjust the scale and quantity of the ammonia decomposition reactor, membrane separation purifier and fuel cell according to actual needs to adapt to hydrogen energy application scenarios of different scales, and has good flexibility and scalability.

[0045] In terms of residual gas recovery and utilization, the unpurified gas separated by the membrane separation purifier of the utility model is collected in a residual gas collector. This part of the gas can be further processed or recycled according to the specific situation, thereby maximizing the utilization of resources.

[0046] Anything not described in the present invention is applicable to the prior art.

[0047] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present utility model.

Claims

1. An ammonia decomposition product membrane separation and purification-fuel cell coupling system, characterized in that: include: A liquid ammonia storage device (1), used for storing liquid ammonia; a vaporizer (2), connected to the liquid ammonia storage device (1), and used for vaporizing the liquid ammonia into ammonia gas; an ammonia decomposition reactor (3), which is arranged downstream of the gasifier (2), receives ammonia from the gasifier (2) and performs a decomposition reaction to generate a product gas containing hydrogen; a membrane separation purifier (4), which is arranged downstream of the ammonia decomposition reactor (3) and is used to receive and separate and purify hydrogen in the product gas from the ammonia decomposition reactor (3); a radiator (5), which is arranged downstream of the purified gas channel of the membrane separation purifier (4) and is used to cool the purified hydrogen; A fuel cell (6) is arranged downstream of the radiator (5), and a negative electrode of the fuel cell (6) receives hydrogen gas cooled by the radiator (5) as fuel.

2. The ammonia decomposition product membrane separation and purification-fuel cell coupling system according to claim 1, characterized in that: The membrane separation purifier (4) comprises a purified gas channel (4a) and a residual gas channel (4b), wherein the purified gas channel (4a) comprises an inlet and an outlet, the inlet being used to receive the product gas from the ammonia decomposition reactor (3), and the hydrogen purified by the purified gas channel (4a) is output through the outlet and enters the negative electrode of the fuel cell (6); the residual gas channel (4b) has at least one residual gas outlet for discharging unpurified gas.

3. The ammonia decomposition product membrane separation and purification-fuel cell coupling system according to claim 2, characterized in that: The system further comprises a residual gas collector (7), which is connected to the gas outlet of the residual gas channel (4b) in the membrane separation purifier (4) and is used for collecting and processing unpurified gas.

4. The ammonia decomposition product membrane separation and purification-fuel cell coupling system according to claim 3, characterized in that: The separation membrane used for purification in the membrane separation purifier (4) is a selective hydrogen permeable membrane, which can efficiently separate hydrogen from other gases.

5. The ammonia decomposition product membrane separation and purification-fuel cell coupling system according to any one of claims 1 to 4, characterized in that: The system further comprises a control device (8), wherein the control device (8) is electrically connected to the ammonia decomposition reactor (3) and the fuel cell (6) respectively, and can be used to automatically adjust the decomposition rate of the ammonia decomposition reactor (3) according to the hydrogen demand of the fuel cell (6) and the system operation state.

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