System and method for co-production of green hydrogen and green ammonia

Abstract

The application discloses a system and method for jointly preparing green hydrogen and green ammonia, and relates to the technical field of jointly preparing green hydrogen and green ammonia. When an oxygen carrier reaction cavity is heated to a first reaction temperature, the oxygen carrier generates intermediate oxygen products and oxygen. The nitrogen carrier reaction cavity is heated by the heated oxygen carrier reaction cavity to a second reaction temperature, and the nitrogen carrier and nitrogen gas react to generate intermediate nitrogen products. When the oxygen carrier reaction cavity is no longer heated and gradually cools down to a third reaction temperature, the intermediate oxygen products and water react to generate the oxygen carrier and hydrogen. The nitrogen carrier reaction cavity is heated by the oxygen carrier reaction cavity which is no longer heated to a fourth reaction temperature, and the intermediate nitrogen products and hydrogen react to generate the nitrogen carrier and ammonia. The system is designed to use water and nitrogen as raw materials and high-temperature heat energy provided by renewable energy to simultaneously prepare hydrogen and ammonia without by-products.

Description

Technical Field

[0001] This invention relates to the field of combined preparation technology of green hydrogen and green ammonia, and in particular to a system and method for the combined preparation of green hydrogen and green ammonia based on thermochemical chaining driven by concentrated solar energy. Background Technology

[0002] Green hydrogen refers to hydrogen produced using renewable energy sources (such as solar, wind, and hydropower), while green ammonia refers to ammonia produced using renewable energy sources (such as solar, wind, and hydropower). Both green hydrogen and green ammonia are expected to become important components of the future energy system, possessing characteristics such as high energy density, cleanliness, and renewability. In recent years, green ammonia has shown significant advantages in terms of unit energy storage, fuel calorific value, and energy storage density, and its storage and transportation costs are low, leading to its expansion from the traditional fertilizer sector to the new energy sector. Traditional hydrogen production methods mainly rely on fossil fuels, such as natural gas and coal, generating significant greenhouse gas emissions while producing hydrogen. Traditional ammonia synthesis methods mainly employ the Haber-Bosch process, requiring high-temperature and high-pressure reaction conditions and using fossil fuels such as natural gas as raw materials, resulting in significant carbon dioxide emissions while producing ammonia.

[0003] Therefore, there is an urgent need for a technology that can jointly produce green hydrogen and green ammonia without greenhouse gas emissions. Summary of the Invention

[0004] The purpose of this invention is to provide a system and method for the joint preparation of green hydrogen and green ammonia, using water and nitrogen as raw materials and utilizing high-temperature thermal energy provided by renewable energy sources to simultaneously prepare hydrogen and ammonia without generating byproducts.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] In a first aspect, the present invention provides a system for the joint preparation of green hydrogen and green ammonia, the system comprising a reactor and a heat supply component;

[0007] The reactor includes an oxygen carrier reaction chamber and a nitrogen carrier reaction chamber, with a thermal insulation material between the two chambers. An oxygen carrier is disposed within the oxygen carrier reaction chamber, and a nitrogen carrier is disposed within the nitrogen carrier reaction chamber. The heat supply component generates heat energy based on renewable energy sources and supplies this heat energy to the oxygen carrier reaction chamber.

[0008] When the oxygen carrier reaction chamber is heated to a first reaction temperature, the oxygen carrier is used to react at the first reaction temperature to generate intermediate oxygen products and oxygen; the nitrogen carrier reaction chamber is used to receive the heat energy transferred by the heated oxygen carrier reaction chamber through the thermal insulation material to a second reaction temperature, and the nitrogen carrier is used to react with nitrogen gas at the second reaction temperature to generate intermediate nitrogen products; the second reaction temperature is lower than the first reaction temperature;

[0009] When the oxygen carrier reaction chamber is no longer heated and gradually cools down to the third reaction temperature, the intermediate oxygen product is used to react with water at the third reaction temperature to generate the oxygen carrier and hydrogen. The nitrogen carrier reaction chamber is used to receive the heat energy transferred by the heat-insulating material from the oxygen carrier reaction chamber, which is no longer heated, to reach the fourth reaction temperature. The intermediate nitrogen product is used to react with hydrogen at the fourth reaction temperature to generate the nitrogen carrier and ammonia. The fourth reaction temperature is lower than the third reaction temperature.

[0010] In some embodiments, the heat supply component is a concentrating solar collector; the concentrating solar collector is used to convert solar energy into heat energy.

[0011] In some embodiments, the thermal insulation material is a ceramic material, including alumina ceramics, silicon carbide ceramics, boron nitride ceramics, and zirconium oxide ceramics;

[0012] The oxygen carrier is made of cerium oxide, doped cerium-based materials, perovskite, or ferrite materials.

[0013] The nitrogen support material is magnesium nitride, iron nitride, manganese nitride, or cerium nitride.

[0014] In some embodiments, the oxygen carrier reaction chamber is provided with a first nitrogen inlet, a first mixed gas outlet, a water inlet, and a gas-water mixed outlet;

[0015] The first nitrogen inlet is used to input nitrogen into the oxygen carrier reaction chamber to carry the oxygen generated in the oxygen carrier reaction chamber to the first mixed gas outlet; the first mixed gas outlet is used to discharge the mixture of nitrogen and oxygen from the oxygen carrier reaction chamber.

[0016] The water inlet is used to input water into the oxygen carrier reaction chamber; the gas-water mixture outlet is used to discharge the mixture of unreacted water and hydrogen generated in the oxygen carrier reaction chamber from the oxygen carrier reaction chamber.

[0017] In some embodiments, the nitrogen carrier reaction chamber is provided with a second nitrogen inlet, a hydrogen inlet, and a second mixed gas outlet.

[0018] The second nitrogen inlet is used to input nitrogen into the nitrogen carrier reaction chamber;

[0019] The hydrogen inlet is used to input hydrogen into the nitrogen carrier reaction chamber; the second mixed gas outlet is used to discharge the mixture of unreacted hydrogen and ammonia generated in the nitrogen carrier reaction chamber from the nitrogen carrier reaction chamber.

[0020] In some embodiments, the system further includes a first heat exchanger; the first heat exchanger is connected to the first nitrogen inlet, the second nitrogen inlet and the first mixed gas outlet respectively; the first heat exchanger is used to exchange heat between the nitrogen input to the first nitrogen inlet and the second nitrogen inlet and the nitrogen and oxygen mixture output from the first mixed gas outlet.

[0021] The system further includes a second heat exchanger; the second heat exchanger is connected to the water inlet and the gas-water mixture outlet respectively; the second heat exchanger is used to exchange heat between the water input to the water inlet and the mixture of water and hydrogen output from the gas-water mixture outlet.

[0022] In some embodiments, the system further includes a first gas separation device; the first gas separation device is connected to the first heat exchanger; the first gas separation device is used to separate the mixture of nitrogen and oxygen to obtain nitrogen and oxygen.

[0023] The system also includes a gas-water separation device; the gas-water separation device is connected to the second heat exchanger; the gas-water separation device is used to separate the mixture of water and hydrogen to obtain water and hydrogen.

[0024] The system further includes a second gas separation device; the second gas separation device is connected to the second mixed gas outlet; the second gas separation device is used to separate the mixed gas of hydrogen and ammonia to obtain hydrogen and ammonia.

[0025] In some embodiments, the gas-water separator is also connected to the hydrogen inlet; the gas-water separator is used to input a portion of the separated hydrogen into the hydrogen inlet.

[0026] In some embodiments, the first reaction temperature is 1200-1600℃, the second reaction temperature is 600-1000℃, the third reaction temperature is 700-1100℃, and the fourth reaction temperature is 200-600℃.

[0027] Secondly, the present invention also provides a method for the combined preparation of green hydrogen and green ammonia, the method comprising:

[0028] When the oxygen carrier reaction chamber is heated to the first reaction temperature, the oxygen carrier reacts at the first reaction temperature to generate intermediate oxygen products and oxygen; the nitrogen carrier reaction chamber receives the heat energy transferred by the heated oxygen carrier reaction chamber through the thermal insulation material to reach the second reaction temperature, and the nitrogen carrier reacts with nitrogen gas at the second reaction temperature to generate intermediate nitrogen products; the second reaction temperature is lower than the first reaction temperature;

[0029] When the oxygen carrier reaction chamber is no longer heated and gradually cools down to the third reaction temperature, the intermediate oxygen product reacts with water at the third reaction temperature to generate the oxygen carrier and hydrogen. The nitrogen carrier reaction chamber receives the heat energy transferred by the thermal insulation material from the oxygen carrier reaction chamber, which is no longer heated, to reach the fourth reaction temperature. The intermediate nitrogen product reacts with hydrogen at the fourth reaction temperature to generate the nitrogen carrier and ammonia. The fourth reaction temperature is lower than the third reaction temperature.

[0030] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0031] This invention provides a system and method for the joint preparation of green hydrogen and green ammonia, comprising a reactor and a heat supply component. The reactor includes an oxygen carrier reaction chamber, a nitrogen carrier reaction chamber, and a thermal insulation material disposed between the oxygen carrier reaction chamber and the nitrogen carrier reaction chamber. The heat supply component generates heat energy based on renewable energy and supplies heat energy to the oxygen carrier reaction chamber. When the oxygen carrier reaction chamber is heated to a first reaction temperature, the oxygen carrier reacts at the first reaction temperature to generate intermediate oxygen products and oxygen. The nitrogen carrier reaction chamber receives the heat energy transferred from the heated oxygen carrier reaction chamber through the thermal insulation material to reach a second reaction temperature. The oxygen carrier reaction chamber reacts with nitrogen at the reaction temperature to generate an intermediate nitrogen product. When the oxygen carrier reaction chamber is no longer heated and gradually cools down to the third reaction temperature, the intermediate oxygen product reacts with water at the third reaction temperature to generate an oxygen carrier and hydrogen. The nitrogen carrier reaction chamber receives the heat energy transferred by the no longer heated oxygen carrier reaction chamber through the thermal insulation material to reach the fourth reaction temperature. The intermediate nitrogen product reacts with hydrogen at the fourth reaction temperature to generate a nitrogen carrier and ammonia. This invention, by designing the above system, uses water and nitrogen as raw materials and utilizes the high-temperature thermal energy provided by renewable energy to simultaneously produce hydrogen and ammonia without generating byproducts. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the system provided in Embodiment 1 of the present invention.

[0034] Symbol explanation:

[0035] 1-Concentrating solar collector; 2-Reactor; 3-First heat exchanger; 4-First gas separation device; 5-Second heat exchanger; 6-Gas-water separation device; 7-Second gas separation device; 8-Oxygen storage tank; 9-Nitrogen storage tank; 10-Ammonia storage tank; 11-Hydrogen storage tank; 12-Water tank. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] The purpose of this invention is to provide a system and method for the joint preparation of green hydrogen and green ammonia, using water and nitrogen as raw materials and utilizing high-temperature thermal energy provided by renewable energy sources to simultaneously prepare hydrogen and ammonia without generating byproducts.

[0038] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Example 1:

[0040] This embodiment provides a system for the joint preparation of green hydrogen and green ammonia, such as... Figure 1 As shown, the system includes a reactor 2 and a heat supply component.

[0041] The reactor 2 in this embodiment can also be called a high-temperature reactor. It is a device that uses high-temperature thermal energy to carry out chemical reactions. The reactor 2 consists of two chambers, including an oxygen carrier reaction chamber (also called an oxygen carrier chamber) and a nitrogen carrier reaction chamber (also called a nitrogen carrier chamber). A thermal insulation material is provided between the oxygen carrier reaction chamber and the nitrogen carrier reaction chamber. An oxygen carrier is provided in the oxygen carrier reaction chamber and a nitrogen carrier is provided in the nitrogen carrier reaction chamber.

[0042] The heat supply component in this embodiment is used to generate heat energy based on renewable energy and provide heat energy to the oxygen carrier reaction chamber. Specifically, the heat supply component can be a concentrating solar collector 1. Concentrating solar energy is a solar energy utilization technology that uses a reflector or lens to focus sunlight onto a small point to generate high temperature or high pressure, thereby generating energy. In this embodiment, the concentrating solar collector 1 is used to collect and focus solar energy, converting it into heat energy to provide a high heat collection temperature for the reactor 2. The concentrating solar collector 1 can be a dish concentrator, a tower concentrator, or a secondary reflector concentrator. Of course, other types of heat supply components can also be used in this embodiment, as long as they can convert renewable energy into heat energy.

[0043] In this embodiment, two chemical reactions occur simultaneously in the two chambers of reactor 2. The first chemical reaction is a high-temperature chemical reaction, which is carried out on the basis of absorbing heat energy provided by the heat energy supply component. The second chemical reaction is a low-temperature chemical reaction, which is carried out on the basis of no longer absorbing heat energy provided by the heat energy supply component.

[0044] (1) High-temperature chemical reaction:

[0045] Figure 1 The solid line in the diagram represents the gas flow direction during the high-temperature chemical reaction. In the oxygen-carrier reaction chamber, the oxygen carrier releases O2 (oxygen) at high temperature; in the nitrogen-carrier reaction chamber, the nitrogen carrier undergoes a nitrogen fixation reaction. The reactions in both chambers occur simultaneously. The chemical equation for the high-temperature chemical reaction is as follows:

[0046] Oxygen carrier reaction chamber: M x O y →M x O y-δ +δ / 2O2 (Reaction temperature: 1200~1600℃).

[0047] Among them, M x O y As an oxygen carrier; M x O y-δ It is an intermediate oxygen product.

[0048] Nitrogen carrier reaction chamber: M x N y-1 +N2→M x N y (Reaction temperature: 600~1000℃).

[0049] Among them, M x N y-1 As a nitrogen carrier; M x N y It is an intermediate nitrogen product.

[0050] (2) Low-temperature chemical reactions:

[0051] Figure 1 The dashed lines in the diagram indicate the direction of mass flow during the low-temperature chemical reaction. In the oxygen-carrier reaction chamber, the intermediate oxygen product reacts with H₂O (water) to produce H₂ (hydrogen gas); in the nitrogen-carrier reaction chamber, the intermediate nitrogen product reacts with H₂ to produce NH₃ (ammonia gas). The reactions in both chambers occur simultaneously. The chemical equations for the low-temperature chemical reactions are as follows:

[0052] Oxygen carrier reaction chamber: M x O y-δ +H2O→M x O y +δH2 (Reaction temperature: 700~1100℃).

[0053] Nitrogen carrier reaction chamber: M x N y +3 / 2H2→M x O y-1 +NH3 (reaction temperature: 200~600℃).

[0054] Based on the above principles, the preparation process of the system for jointly preparing green hydrogen and green ammonia in this embodiment includes: Step 1: The oxygen carrier reaction chamber absorbs heat from concentrated solar energy to heat the oxygen carrier and release oxygen. This oxygen reaction product is carried out by the purge gas N2 (nitrogen). The nitrogen carrier reaction chamber is heated by the heat transferred from the oxygen carrier reaction chamber, and a nitrogen fixation reaction occurs at a high temperature. Step 2: Without the need for concentrated solar energy input, reactor 2 reacts at a lower temperature. The intermediate oxygen product in the oxygen carrier reaction chamber reacts with H2O to generate H2, and the intermediate nitrogen product in the nitrogen carrier reaction chamber reacts with H2 to generate NH3. After the second step reaction is completed, the first step reaction is repeated to enter the next cycle. The different temperatures of the two chambers are achieved through thermal insulation materials. The reactor 2 designed in this embodiment is a dual-chamber reactor that integrates hydrogen and ammonia production. It has a simple structure and low material cost, and the oxygen and nitrogen carriers in the two chambers undergo redox reactions during the cycle without mass loss.

[0055] Specifically, when the oxygen carrier reaction chamber is heated to the first reaction temperature, the oxygen carrier reacts at this temperature to generate intermediate oxygen products and oxygen gas. The nitrogen carrier reaction chamber receives heat energy transferred from the heated oxygen carrier reaction chamber through the thermal insulation material to reach the second reaction temperature. The nitrogen carrier reacts with nitrogen gas at this second reaction temperature to generate intermediate nitrogen products. The second reaction temperature is lower than the first reaction temperature. When the oxygen carrier reaction chamber is deheated and gradually cools to the third reaction temperature, the intermediate oxygen products react with water at this third reaction temperature to generate oxygen carrier and hydrogen gas. The nitrogen carrier reaction chamber receives heat energy transferred from the deheated oxygen carrier reaction chamber through the thermal insulation material to reach the fourth reaction temperature. The intermediate nitrogen products react with hydrogen gas at this fourth reaction temperature to generate nitrogen carrier and ammonia gas. The fourth reaction temperature is lower than the third reaction temperature. The first reaction temperature is 1200-1600℃, the second reaction temperature is 600-1000℃, the third reaction temperature is 700-1100℃, and the fourth reaction temperature is 200-600℃.

[0056] The thermal insulation material in this embodiment is used to transfer heat energy from the oxygen carrier reaction chamber to the nitrogen carrier reaction chamber, and to keep the temperature in the nitrogen carrier reaction chamber lower than that in the oxygen carrier reaction chamber. Therefore, different materials are selected for the thermal insulation material according to different reaction temperature requirements. In this embodiment, the thermal insulation material is a ceramic material, including alumina ceramics, silicon carbide ceramics, boron nitride ceramics, and zirconium oxide ceramics. That is, the thermal insulation material can be alumina, silicon carbide, boron nitride, zirconium oxide, and other ceramic materials. This embodiment can also achieve the required reaction temperature by adjusting the thickness and density of the thermal insulation material.

[0057] The oxygen carrier in this embodiment needs to meet the properties of high temperature resistance, structural stability, non-vaporization, non-sintering, stable crystal structure, and release of a large amount of oxygen during redox reactions. As an example, the oxygen carrier material can be cerium oxide, doped cerium-based materials, perovskite, or ferrite materials.

[0058] The nitrogen support material in this embodiment can be a variable valence metal or transition metal material such as magnesium nitride, iron nitride, manganese nitride, and cerium nitride. As an example, the nitrogen support material is magnesium nitride, iron nitride, manganese nitride, or cerium nitride.

[0059] In this embodiment, the oxygen carrier reaction chamber is provided with a first nitrogen inlet, a first mixed gas outlet, a water inlet, and a gas-water mixture outlet. During high-temperature chemical reactions, the first nitrogen inlet is used to input nitrogen into the oxygen carrier reaction chamber, carrying the oxygen generated within the chamber to the first mixed gas outlet, which discharges the nitrogen and oxygen mixture from the oxygen carrier reaction chamber. During low-temperature chemical reactions, the water inlet is used to input water into the oxygen carrier reaction chamber, and the gas-water mixture outlet discharges a mixture of unreacted water and generated hydrogen from the oxygen carrier reaction chamber.

[0060] In this embodiment, the nitrogen carrier reaction chamber is equipped with a second nitrogen inlet, a hydrogen inlet, and a second mixed gas outlet. During high-temperature chemical reactions, the second nitrogen inlet is used to introduce nitrogen into the nitrogen carrier reaction chamber. During low-temperature chemical reactions, the hydrogen inlet is used to introduce hydrogen into the nitrogen carrier reaction chamber, and the second mixed gas outlet is used to discharge the mixture of unreacted hydrogen and ammonia generated within the nitrogen carrier reaction chamber.

[0061] Considering the large heat loss in thermochemical H2 synthesis and the difficulty in designing a regenerative heating system, this embodiment also considers a gas-phase regenerative heating design. Preferably, the system in this embodiment further includes a first heat exchanger 3, which is connected to a first nitrogen inlet, a second nitrogen inlet, and a first mixed gas outlet. The first heat exchanger 3 is used to exchange heat between the nitrogen input to the first and second nitrogen inlets and the nitrogen and oxygen mixture output from the first mixed gas outlet. The high temperature of the output mixed gas is used to preheat the nitrogen entering the oxygen carrier reaction chamber and the nitrogen carrier reaction chamber, enabling the recovery and utilization of thermal energy. The system in this embodiment also includes a second heat exchanger 5, which is connected to a water inlet and a gas-water mixture outlet. The second heat exchanger 5 is used to exchange heat between the water input to the water inlet and the water and hydrogen mixture output from the gas-water mixture outlet. The high temperature of the output mixture is used to preheat the water entering the oxygen carrier reaction chamber, enabling the recovery and utilization of thermal energy.

[0062] The system in this embodiment also includes a first gas separation device 4, which is connected to the first heat exchanger 3. The first gas separation device 4 is used to separate the mixture of nitrogen and oxygen to obtain nitrogen and oxygen.

[0063] The system in this embodiment also includes a gas-water separation device 6, which is connected to the second heat exchanger 5. The gas-water separation device 6 is used to separate the mixture of water and hydrogen to obtain water and hydrogen.

[0064] The system in this embodiment also includes a second gas separation device 7, which is connected to a second mixed gas outlet. The second gas separation device 7 is used to separate the mixed gas of hydrogen and ammonia to obtain hydrogen and ammonia.

[0065] In this embodiment, the gas-water separation device 6 is also connected to the hydrogen inlet. The gas-water separation device 6 is used to input a portion of the separated hydrogen into the hydrogen inlet, so that the hydrogen generated in the oxygen carrier reaction chamber can be directly supplied to the nitrogen carrier reaction chamber.

[0066] The system in this embodiment also includes an oxygen storage tank 8, a nitrogen storage tank 9, an ammonia storage tank 10, a hydrogen storage tank 11, and a water tank 12. The oxygen storage tank 8 is connected to the first gas separation device 4 and is used to store the oxygen separated by the first gas separation device 4. The nitrogen storage tank 9 is connected to both the first gas separation device 4 and the first heat exchanger 3, and is used to store the nitrogen separated by the first gas separation device 4. Nitrogen is also introduced into the oxygen carrier reaction chamber through the first nitrogen inlet of the first heat exchanger 3, and into the nitrogen carrier reaction chamber through the second nitrogen inlet of the first heat exchanger 3. The ammonia storage tank 10 is connected to the second gas separation device 7 and is used to store the ammonia separated by the second gas separation device 7. The hydrogen storage tank 11 is connected to both the gas-water separation device 6 and the second gas separation device 7, and is used to store the hydrogen separated by both the gas-water separation device 6 and the second gas separation device 7. Water tank 12 is connected to gas-water separator 6 and second heat exchanger 5 respectively. It is used to store the water separated by gas-water separator 6 and input water into oxygen carrier reaction chamber through water inlet of second heat exchanger 5.

[0067] Based on the specific structure of the above system, the working process of the system in this embodiment includes:

[0068] (1) Turn on the concentrating solar collector 1, collect solar energy through the concentrating solar collector 1, and convert it into the heat energy required for the oxygen carrier reaction chamber, and heat the oxygen carrier reaction chamber to the first reaction temperature.

[0069] (2) The nitrogen gas supplied by the nitrogen storage tank 9 is first heated by the first heat exchanger 3, and then enters the oxygen carrier reaction chamber through the first nitrogen inlet and the nitrogen carrier reaction chamber through the second nitrogen inlet, respectively, so that the nitrogen storage tank 9 provides purge nitrogen and reactant nitrogen to the oxygen carrier reaction chamber and the nitrogen carrier reaction chamber, respectively. In the oxygen carrier reaction chamber, the oxygen carrier generates intermediate oxygen products and releases oxygen at the first reaction temperature. The purge nitrogen carries the released oxygen to the first mixed gas outlet. The nitrogen and oxygen mixture output from the first mixed gas outlet is heated by the first heat exchanger 3, and then separated into nitrogen and oxygen by the first gas separation device 4. The separated nitrogen enters the nitrogen storage tank 9, and the separated oxygen enters the oxygen storage tank 8. At this time, in the nitrogen carrier reaction chamber, the nitrogen carrier reaction chamber receives the heat energy transferred by the oxygen carrier reaction chamber through the thermal insulation material to reach the second reaction temperature. The nitrogen carrier undergoes a nitrogen fixation reaction, that is, the nitrogen carrier and reactant nitrogen generate intermediate nitrogen products at the second reaction temperature. After the reaction is completed, the concentrating solar collector 1 is turned off.

[0070] (3) In the oxygen carrier reaction chamber, when the oxygen carrier reaction chamber is no longer heated and gradually cooled to the third reaction temperature, the water provided by the water tank 12 is heated by the second heat exchanger 5 and then enters the oxygen carrier reaction chamber through the water inlet to provide water vapor to the oxygen carrier reaction chamber. The oxygen carrier reaction chamber undergoes a hydrogen evolution reaction, that is, the intermediate oxygen product reacts with water at the third reaction temperature to generate oxygen carrier and hydrogen. The unreacted water and the reaction product hydrogen in the oxygen carrier reaction chamber are sent to the second heat exchanger 5 through the gas-water mixing outlet. After heat exchange by the second heat exchanger 5, water and hydrogen are separated by the gas-water separation device 6. The separated water directly enters the water tank 12, and part of the separated hydrogen enters the hydrogen storage tank 11, while the other part enters the nitrogen carrier reaction chamber through the hydrogen inlet. At this time, in the nitrogen carrier reaction chamber, the nitrogen carrier reaction chamber receives the heat energy transferred from the oxygen carrier reaction chamber through the thermal insulation material to reach the fourth reaction temperature. The ammonia synthesis reaction occurs in the nitrogen carrier reaction chamber, that is, the intermediate nitrogen product reacts with hydrogen at the fourth reaction temperature to generate nitrogen carrier and ammonia. The unreacted hydrogen and the reaction product ammonia in the nitrogen carrier reaction chamber enter the second gas separation device 7 through the second mixed gas outlet. Hydrogen and ammonia are separated by the second gas separation device 7. The separated hydrogen enters the hydrogen storage tank 11, and the separated ammonia enters the ammonia storage tank 10.

[0071] (4) After the reaction is complete, repeat (1) to enter the next cycle.

[0072] Existing technologies require fossil fuel input or high-temperature electrical energy, resulting in significant heat loss, complex system design, and poor operational stability. Therefore, this embodiment utilizes renewable energy to produce hydrogen and ammonia through a high-temperature thermochemical loop, achieving sustainable development of clean energy. This process requires only high-temperature thermal energy from renewable energy sources, using H2O and N2 as raw materials, with H2 and NH3 as products, and no byproducts generated. The system provided in this embodiment is a system for the combined production of green hydrogen and green ammonia through a high-temperature thermochemical loop. It only requires high-temperature thermal energy from renewable energy sources to drive the process, integrating hydrogen production and ammonia synthesis technologies into a single reactor. This means that hydrogen production and ammonia synthesis technologies utilizing renewable energy are integrated into one reactor. The system design is simple and efficient, and the raw materials are clean, abundant, and readily available H2O and N2, with no byproducts generated. This solves the problems of complex processes, high operating pressure, and high carbon dioxide emissions associated with traditional hydrogen production and ammonia synthesis technologies.

[0073] This embodiment proposes for the first time a dual-chamber design for thermochemical chain hydrogen production and ammonia synthesis. The designed system includes components such as a concentrating solar thermal collector system, a dual-chamber reactor, heat exchange equipment, gas separation equipment, and storage equipment. Compared with existing technologies, the beneficial effects are as follows:

[0074] (1) Existing technologies require fossil energy input, which can lead to environmental pollution and greenhouse gas emissions. The raw materials in this embodiment are N2 and H2O, and the products are H2 and NH3, which can solve the above problems.

[0075] (2) Traditional ammonia synthesis or hydrogen production requires the introduction of electricity to provide driving force. In this embodiment, the driving force is only concentrated solar energy to heat the oxygen carrier, which does not require electricity.

[0076] (3) Existing thermochemical synthesis of H2 has large heat loss and difficult reheat design. This embodiment considers gas phase reheat design and energy gradient distribution utilization in the reaction chamber (i.e., providing heat energy to the nitrogen carrier reaction chamber through the oxygen carrier reaction chamber and thermal isolation material), which effectively reduces heat loss.

[0077] (4) Existing technologies have complex system designs, and thermochemical hydrogen production technology and traditional ammonia synthesis technology have a lot of equipment. They require the introduction of electrochemical oxygen pump equipment, solid oxide electrolysis cell device, desulfurization device and coal gasification device, etc. This embodiment introduces a dual-chamber reaction chamber design, which can effectively reduce equipment cost and management cost.

[0078] Example 2:

[0079] This embodiment provides a method for the combined preparation of green hydrogen and green ammonia based on the system described in Example 1, the method comprising:

[0080] When the oxygen carrier reaction chamber is heated to the first reaction temperature, the oxygen carrier reacts at the first reaction temperature to generate intermediate oxygen products and oxygen; the nitrogen carrier reaction chamber receives the heat energy transferred by the heated oxygen carrier reaction chamber through the thermal insulation material to reach the second reaction temperature, and the nitrogen carrier reacts with nitrogen gas at the second reaction temperature to generate intermediate nitrogen products; the second reaction temperature is lower than the first reaction temperature;

[0081] When the oxygen carrier reaction chamber is no longer heated and gradually cools down to the third reaction temperature, the intermediate oxygen product reacts with water at the third reaction temperature to generate the oxygen carrier and hydrogen. The nitrogen carrier reaction chamber receives the heat energy transferred by the thermal insulation material from the oxygen carrier reaction chamber, which is no longer heated, to reach the fourth reaction temperature. The intermediate nitrogen product reacts with hydrogen at the fourth reaction temperature to generate the nitrogen carrier and ammonia. The fourth reaction temperature is lower than the third reaction temperature.

[0082] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0083] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A system for the combined preparation of green hydrogen and green ammonia, characterized in that, The system includes a reactor and a heat supply component; The reactor includes an oxygen carrier reaction chamber and a nitrogen carrier reaction chamber, with a thermal insulation material between the two chambers. An oxygen carrier is disposed within the oxygen carrier reaction chamber, and a nitrogen carrier is disposed within the nitrogen carrier reaction chamber. The heat supply component generates heat energy based on renewable energy sources and supplies this heat energy to the oxygen carrier reaction chamber. When the oxygen carrier reaction chamber is heated to a first reaction temperature, the oxygen carrier is used to react at the first reaction temperature to generate intermediate oxygen products and oxygen; the nitrogen carrier reaction chamber is used to receive the heat energy transferred by the heated oxygen carrier reaction chamber through the thermal insulation material to a second reaction temperature, and the nitrogen carrier is used to react with nitrogen gas at the second reaction temperature to generate intermediate nitrogen products; the second reaction temperature is lower than the first reaction temperature; When the oxygen carrier reaction chamber is no longer heated and gradually cools down to the third reaction temperature, the intermediate oxygen product is used to react with water at the third reaction temperature to generate the oxygen carrier and hydrogen. The nitrogen carrier reaction chamber is used to receive the heat energy transferred by the heat-insulating material from the no-heated oxygen carrier reaction chamber to reach the fourth reaction temperature. The intermediate nitrogen product is used to react with hydrogen at the fourth reaction temperature to generate the nitrogen carrier and ammonia. The fourth reaction temperature is lower than the third reaction temperature. The first reaction temperature is 1200-1600℃, the second reaction temperature is 600-1000℃, the third reaction temperature is 700-1100℃, and the fourth reaction temperature is 200-600℃.

2. The system according to claim 1, characterized in that, The heat supply component is a concentrating solar collector; the concentrating solar collector is used to convert solar energy into heat energy.

3. The system according to claim 1, characterized in that, The thermal insulation material is a ceramic material, including alumina ceramic, silicon carbide ceramic, boron nitride ceramic, and zirconium oxide ceramic. The oxygen carrier is made of cerium oxide, doped cerium-based materials, perovskite, or ferrite materials. The nitrogen support material is magnesium nitride, iron nitride, manganese nitride, or cerium nitride.

4. The system according to claim 1, characterized in that, The oxygen carrier reaction chamber is provided with a first nitrogen inlet, a first mixed gas outlet, a water inlet, and a gas-water mixed outlet; The first nitrogen inlet is used to input nitrogen into the oxygen carrier reaction chamber to carry the oxygen generated in the oxygen carrier reaction chamber to the first mixed gas outlet; the first mixed gas outlet is used to discharge the mixture of nitrogen and oxygen from the oxygen carrier reaction chamber. The water inlet is used to input water into the oxygen carrier reaction chamber; the gas-water mixture outlet is used to discharge the mixture of unreacted water and hydrogen generated in the oxygen carrier reaction chamber from the oxygen carrier reaction chamber.

5. The system according to claim 4, characterized in that, The nitrogen carrier reaction chamber is provided with a second nitrogen inlet, a hydrogen inlet, and a second mixed gas outlet. The second nitrogen inlet is used to input nitrogen into the nitrogen carrier reaction chamber; The hydrogen inlet is used to input hydrogen into the nitrogen carrier reaction chamber; the second mixed gas outlet is used to discharge the mixture of unreacted hydrogen and ammonia generated in the nitrogen carrier reaction chamber from the nitrogen carrier reaction chamber.

6. The system according to claim 5, characterized in that, The system further includes a first heat exchanger; the first heat exchanger is connected to the first nitrogen inlet, the second nitrogen inlet and the first mixed gas outlet respectively; the first heat exchanger is used to exchange heat between the nitrogen input to the first nitrogen inlet and the second nitrogen inlet and the nitrogen and oxygen mixture output from the first mixed gas outlet. The system further includes a second heat exchanger; the second heat exchanger is connected to the water inlet and the gas-water mixture outlet respectively; the second heat exchanger is used to exchange heat between the water input to the water inlet and the mixture of water and hydrogen output from the gas-water mixture outlet.

7. The system according to claim 6, characterized in that, The system further includes a first gas separation device; the first gas separation device is connected to the first heat exchanger; the first gas separation device is used to separate the mixture of nitrogen and oxygen to obtain nitrogen and oxygen. The system also includes a gas-water separation device; the gas-water separation device is connected to the second heat exchanger; the gas-water separation device is used to separate the mixture of water and hydrogen to obtain water and hydrogen. The system further includes a second gas separation device; the second gas separation device is connected to the second mixed gas outlet; the second gas separation device is used to separate the mixed gas of hydrogen and ammonia to obtain hydrogen and ammonia.

8. The system according to claim 7, characterized in that, The gas-water separator is also connected to the hydrogen inlet; the gas-water separator is used to input a portion of the separated hydrogen into the hydrogen inlet.

9. A method for the combined preparation of green hydrogen and green ammonia based on the system described in claim 1, characterized in that, The method includes: When the oxygen carrier reaction chamber is heated to the first reaction temperature, the oxygen carrier reacts at the first reaction temperature to generate intermediate oxygen products and oxygen; the nitrogen carrier reaction chamber receives the heat energy transferred by the heated oxygen carrier reaction chamber through the thermal insulation material to reach the second reaction temperature, and the nitrogen carrier reacts with nitrogen gas at the second reaction temperature to generate intermediate nitrogen products; the second reaction temperature is lower than the first reaction temperature; When the oxygen carrier reaction chamber is no longer heated and gradually cools down to the third reaction temperature, the intermediate oxygen product reacts with water at the third reaction temperature to generate the oxygen carrier and hydrogen. The nitrogen carrier reaction chamber receives the heat energy transferred by the thermal insulation material from the oxygen carrier reaction chamber, which is no longer heated, to reach the fourth reaction temperature. The intermediate nitrogen product reacts with hydrogen at the fourth reaction temperature to generate the nitrogen carrier and ammonia. The fourth reaction temperature is lower than the third reaction temperature.

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