Method and system for solar-driven chemical-looping-reinforced wet reforming hydrogen production and source CO2 separation

Abstract

The invention discloses a method and a system for hydrogen production through solar-driven chemical-looping-enhanced wet reforming and CO2 separation from a source. The method comprises a concentrating solar-driven chemical-looping-enhanced wet reforming reaction, an oxygen carrier reduction reaction and an air oxidation reaction. The method comprises the following steps: providing 500-650 DEG C heat energy by concentrating solar energy to drive hydrocarbon fuel and water vapor to be subjected to chemical chain enhanced wet reforming reaction under the action of an oxygen carrier in an under-oxidation state and a catalyst to obtain a first mixed gas of CO2 and H2 and a reduction state oxygen carrier, and separating H2 in the first mixed gas to obtain purge gas; the reduction-state oxygen carrier is oxidized into an initial oxidation-state oxygen carrier by air, the initial oxidation-state oxygen carrier completely oxidizes the purge gas to obtain CO2 and H2O, and CO2 source separation and capture are realized, the solar energy is utilized to drive chemical looping to reinforce wet reforming hydrogen production, the reaction temperature is reduced, the energy efficiency of hydrogen production by hydrocarbon fuel is greatly improved, and low-energy-consumption source separation and capture of CO2 are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of multi-energy complementary hydrogen production, and relates to a method and system for solar-driven chemical chain enhanced wet reforming hydrogen production and source separation of CO2. Background Art

[0002] As a clean and renewable energy, hydrogen energy has the advantages of high calorific value, high energy efficiency, energy storage and wide application, and is an important part of the future energy structure. At present, the steam reforming hydrogen production technology of hydrocarbon fuels represented by natural gas occupies an important position in the global hydrogen preparation, accounting for nearly 50% of the global hydrogen production. Its process flow includes methane pretreatment, high temperature reforming, water vapor shift, separation and purification. However, limited by the thermodynamic equilibrium of natural gas wet reforming reaction, the traditional natural gas steam reforming process has the disadvantages of high reaction temperature (>800℃), low raw material single-pass conversion rate, and high CO concentration. In addition, the reforming reaction is a strongly endothermic process that consumes part of the natural gas raw material and the purge gas to generate heat energy to meet the heat demand of the high temperature reforming process, which makes the natural gas steam reforming process have bottlenecks such as high reaction temperature, high hydrogen production energy consumption, high CO2 emissions, and low natural gas raw material conversion rate, and brings unbearable separation energy consumption to CO2 separation and capture.

[0003] At present, although concentrated solar energy can be used to drive the wet reforming reaction process of hydrocarbon fuels to replace the combustion of hydrocarbon fuels and purge gas to achieve the purpose of reducing the raw material consumption of hydrogen production and improving the conversion rate of hydrocarbon fuels. However, the high reaction temperature of wet reforming of hydrocarbon fuels such as natural gas will lead to high temperature of concentrated solar energy collection, making the structure of solar energy collection system complex and significantly increasing heat loss. At the same time, the low one-way conversion rate of hydrocarbon fuels makes the utilization efficiency of solar energy low. In addition, the use of concentrated solar energy to drive the wet reforming reaction process of hydrocarbon fuels still cannot solve the problem of high CO2 emissions and high separation and capture energy consumption in the hydrogen production system of hydrocarbon fuel wet reforming. Summary of the invention

[0004] In order to solve the technical problems in the prior art of using concentrated solar energy to drive the wet reforming reaction of hydrocarbon fuels such as natural gas to produce hydrogen and capture carbon dioxide, such as low hydrocarbon fuel conversion rate, low solar energy utilization efficiency, high CO2 emissions and high energy consumption for separation and capture, the present invention discloses a method for solar energy driven chemical chain enhanced wet reforming to produce hydrogen and separate CO2 at the source, the method comprising concentrated solar energy driven chemical chain enhanced wet reforming reaction, oxygen carrier reduction reaction and air oxidation reaction.

[0005] Wherein, in the concentrated solar energy driven chemical chain enhanced wet reforming reaction, the concentrated solar energy provides heat energy of 500-650°C to drive the hydrocarbon fuel to react with water vapor to undergo wet reforming to obtain CO and H2, CO and the hydrocarbon fuel are converted to H2 and CO2 by underoxidized oxygen carriers to obtain a first mixed gas including H2, CO2 and unreacted hydrocarbon fuel, the underoxidized oxygen carrier is reduced to a reduced oxygen carrier, and H2 in the first mixed gas is separated to obtain a purge gas, which includes unreacted hydrocarbon fuel, CO2 and residual H2;

[0006] In the air oxidation reaction, the reduced oxygen carrier is oxidized by air to an initial oxidized oxygen carrier carrying sensible heat;

[0007] In the oxygen carrier reduction reaction, the residual H2, CO and unreacted hydrocarbon fuel in the purge gas are oxidized into CO2 and H2O by the initial oxidation state oxygen carrier carrying sensible heat, and the initial oxidation state oxygen carrier is reduced to an under-oxidized state oxygen carrier.

[0008] In an optional embodiment, in the concentrated solar energy driven chemical chaining enhanced wet reforming reaction, a reforming hydrogen production catalyst structure is provided in the reactor or a hydrogen production catalyst is mixed in the under-oxidized oxygen carrier.

[0009] In an optional embodiment, the underoxidized oxygen carrier is represented by MeO 1-δ , the reduced oxygen carrier is represented by MeO 1-γ , the initial oxidized oxygen carrier is represented by MeO, wherein γ>δ, and the oxygen release degree of the reduced oxygen carrier is greater than the oxygen release degree of the under-oxidized oxygen carrier.

[0010] In an optional embodiment, the active components of the initial oxidation state oxygen carrier include one or more of Fe2O3, CoO, CuO, Mn2O3 and perovskite.

[0011] An embodiment of the present invention also provides a solar-driven chemical chaining enhanced wet reforming system for producing hydrogen and CO2, the system comprising a chemical chaining enhanced wet reforming reactor, an air oxidation reactor, an oxygen carrier reduction reactor, a concentrating solar energy system and a hydrogen separation and purification system, the chemical chaining enhanced wet reforming reactor, the oxygen carrier reduction reactor and the air oxidation reactor are all in the form of moving bed reactors, and the oxygen carrier solid particles inside them move downward by gravity.

[0012] The chemical looping enhanced wet reforming reactor is provided with a gas inlet and an oxygen carrier inlet at the top, a first mixed gas outlet at the bottom, and an oxygen carrier outlet at the bottom, the first mixed gas outlet is connected to the hydrogen separation and purification system, the chemical looping enhanced wet reforming reactor is connected to the concentrated solar energy system, and the concentrated solar energy system provides the required heat energy for the chemical looping enhanced wet reforming reaction between hydrocarbon fuel and water vapor under the action of underoxidized oxygen carrier and catalyst in the chemical looping enhanced wet reforming reactor;

[0013] The top of the air oxidation reactor is provided with a solid inlet and an air inlet, the solid inlet is connected to the oxygen carrier outlet, the lower part is provided with an oxygen-depleted air outlet, and the bottom is provided with a solid outlet;

[0014] The oxygen carrier reduction reactor is provided with an oxygen carrier solid inlet, a CO2 outlet, a purge gas inlet and an oxygen carrier solid outlet. The initial oxidized oxygen carrier input through the oxygen carrier solid inlet is in countercurrent contact with the purge gas input through the purge gas inlet. The purge gas inlet is connected to the outlet of the hydrogen separation and purification system, and the oxygen carrier solid outlet is connected to the oxygen carrier inlet.

[0015] In an optional embodiment, a reforming hydrogen production catalyst structure is provided in the chemical looping enhanced wet reforming reactor.

[0016] In an optional embodiment, the system further includes an under-oxidized oxygen carrier storage tank, in which an under-oxidized oxygen carrier containing a mixed reforming hydrogen production catalyst is stored, and an outlet of the under-oxidized oxygen carrier storage tank is connected to an oxygen carrier inlet of the chemical looping enhanced wet reforming reactor.

[0017] In an optional embodiment, the system further comprises a feeding unit, wherein the feeding unit is connected to the gas inlet, and the feeding unit is used for mixing hydrocarbon fuel and water vapor and outputting the mixed mixture to the chemical looping enhanced wet reforming reactor.

[0018] In an optional embodiment, the system further comprises a gas-liquid separator, which is connected to the CO2 gas outlet and is used for performing gas-liquid separation on the water-containing CO2 output from the oxygen carrier reduction reactor to obtain dry CO2.

[0019] In an optional embodiment, the system further includes a temperature control unit, which is connected to the chemical chain enhanced wet reforming reactor and the concentrated solar energy system, and is used to collect the temperature inside the chemical chain enhanced wet reforming reactor, and control the concentrated solar energy system based on the collected temperature, so that the temperature inside the chemical chain enhanced wet reforming reactor is within the range of 500 to 650°C.

[0020] Compared with the prior art, the at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects:

[0021] (1) By introducing chemical chain circulation oxygen carriers, the wet reforming hydrogen production reaction process is strengthened, which greatly improves the conversion rate of hydrocarbon fuels (such as natural gas, methane, etc.) and the hydrogen production per unit of hydrocarbon fuel. Compared with the traditional wet reforming process, it significantly improves the hydrogen production efficiency of the reforming process and eliminates the CO water vapor shift device. Furthermore, while strengthening the chemical chain, the chemical chain conversion technology is used to achieve efficient enrichment of CO2 with nearly zero energy consumption in the hydrogen production process, which not only overcomes the high energy consumption problem caused by decarbonization in the traditional hydrogen production process, but also greatly improves the environmental protection and economic benefits of the entire reaction system, providing a breakthrough solution for greenhouse gas emission reduction in hydrogen production.

[0022] (2) By using concentrated solar energy to provide thermal energy to drive the wet reforming reaction, the carbon dioxide emissions and energy losses caused by the combustion of hydrocarbon fuels are avoided. By using the low-grade thermal energy in concentrated solar energy as a heat source, the reaction can be effectively driven, improving the efficiency of solar energy utilization, so that the unstable, low-energy-density energy form of solar energy is converted into stable, high-energy-density chemical energy, improving the energy grade of solar energy, not only reducing the consumption of high-grade hydrocarbon fuels, but also reducing the irreversible losses in the high-temperature reaction process of ordinary wet reforming hydrogen production, thereby improving the energy efficiency and economy of the overall reaction.

[0023] (3) By introducing underoxidized oxygen carriers (i.e., intermediate oxidized oxygen carriers), the hydrogen selectivity in the chemical chain hydrogen production reaction is improved, and the methane wet reforming hydrogen production process is strengthened, so that the reaction temperature is reduced to 500-650°C, which is significantly lower than the high temperature conditions required for traditional wet reforming reactions. This provides convenient conditions for solar energy concentration and heat collection, improves the utilization efficiency of solar energy, thereby reducing energy consumption, increasing hydrogen yield and reducing overall operating costs.

[0024] (4) The chemical chain enhanced wet reforming reaction process of the present invention improves the fuel utilization rate and the actual reaction heat absorption during the reforming reaction, simultaneously increases the input energy and utilization efficiency of solar energy, and improves the overall energy efficiency of the system.

[0025] (5) During the air oxidation process and the reduction reaction process, the heat released can be absorbed by the oxygen carrier, which can provide part of the heat to the wet reforming reactor, thus achieving effective heat recovery and utilization and improving the overall energy efficiency of the system.

[0026] (6) The method of the present invention combines the advantages of renewable energy quality improvement, wet reforming hydrogen production and chemical chain low-energy carbon dioxide capture through multi-energy complementarity, ensuring the sustainability and more efficient utilization of energy, and providing a more economically and environmentally beneficial technical path for future clean energy production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 The schematic diagram of the method for producing hydrogen and CO2 by solar-driven chemical chaining enhanced wet reforming disclosed in an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of a solar-driven chemical chaining enhanced wet reforming system for producing hydrogen and CO2 according to an embodiment of the present invention;

[0030] Figure 3 The gas product concentration distribution experimental test results of the chemical looping enhanced methane wet reforming reaction under typical working conditions disclosed in the embodiments of the present invention;

[0031] Figure 4 The experimental test results of the conversion rate of hydrocarbon fuel (methane) and the hydrogen production performance per unit methane in the chemical chaining enhanced methane wet reforming reaction process under typical working conditions disclosed in the embodiments of the present invention;

[0032] Figure 5 These are the experimental test results of the concentration of gas phase products in the oxygen reduction reaction under typical working conditions disclosed in the embodiments of the present invention. DETAILED DESCRIPTION

[0033] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0034] The following describes the implementation methods of the present application through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and the features of the embodiments can be combined with each other in the absence of conflict. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0035] In the description of this embodiment, it should be understood that the terms "top", "bottom", "lower", "rear", "left", "right", "vertical", "top", "bottom", "inside" and "outside" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the invention.

[0036] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present disclosure. The illustrations only show components related to the present disclosure rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0037] The embodiment of the present invention discloses a method for producing hydrogen by chemical chaining enhanced wet reforming and separating CO2 from the source driven by solar energy, see Figure 1 As shown, the method includes concentrated solar energy driven chemical chain enhanced wet reforming reaction, oxygen carrier reduction reaction and air oxidation reaction.

[0038] Wherein, in the concentrated solar energy driven chemical chain enhanced wet reforming reaction, the concentrated solar energy provides heat energy of 500-650°C to drive the hydrocarbon fuel to react with water vapor to undergo wet reforming to obtain CO and H2, CO and the hydrocarbon fuel are converted to H2 and CO2 by underoxidized oxygen carriers to obtain a first mixed gas including H2, CO2 and unreacted hydrocarbon fuel, the underoxidized oxygen carrier is reduced to a reduced oxygen carrier, and H2 in the first mixed gas is separated to obtain a purge gas, which includes unreacted hydrocarbon fuel, CO2 and residual H2;

[0039] In the air oxidation reaction, the reduced oxygen carrier is oxidized by air to an initial oxidized oxygen carrier carrying sensible heat. The air oxidation reaction is an exothermic reaction. The released heat can heat the initial oxidized oxygen carrier to increase its temperature. When it enters the reduction reactor, the sensible heat it carries will be released to meet the heat absorption requirement of the reduction reaction.

[0040] In the oxygen carrier reduction reaction, the residual H2, CO and unreacted hydrocarbon fuel in the purge gas are oxidized into CO2 and H2O by the initial oxidation state oxygen carrier carrying sensible heat, and the initial oxidation state oxygen carrier is reduced to an under-oxidized state oxygen carrier.

[0041] Specifically, in the concentrated solar energy driven chemical chain enhanced wet reforming reaction, hydrocarbon fuel and water vapor undergo reforming reaction to generate CO and H2, CO and unreacted hydrocarbon fuel undergo redox reaction with underoxidized oxygen carrier, and CO is continuously converted to CO2 to enhance the wet reforming reaction of hydrocarbon fuel and water vapor. In this reaction process, concentrated solar energy can provide the required heat energy of 500-650°C for the reaction. The use of concentrated solar energy can reduce the consumption of hydrocarbon fuel and improve the conversion rate of hydrocarbon fuel. After the whole reaction is completed, the first mixed gas is obtained, and the first mixed gas mainly contains CO2, H2 and a small amount of unreacted hydrocarbon fuel. High-purity hydrogen can be produced by gas-liquid separation and hydrogen purification of the first mixed gas, and a purge gas including unreacted hydrocarbon fuel, CO2, a small amount of CO and a small amount of H2 can be obtained. At the same time, the underoxidized oxygen carrier is reduced to a reduced oxygen carrier.

[0042] In the oxygen carrier reduction reaction, the unreacted hydrocarbon fuel, a small amount of CO and a small amount of H2 in the purge gas are converted into CO2 and H2O by the initial oxidized oxygen carrier to achieve CO2 enrichment, thus completing the source separation and capture of CO2.

[0043] In the method of the present invention, the conversion rate of hydrocarbon raw materials can be improved and the concentration of product CO can be reduced by using chemical chain to strengthen the wet reforming reaction of hydrocarbon fuels. Compared with the traditional reforming hydrogen production process, it can save water vapor conversion, reduce the reaction temperature, reduce the energy loss in the solar energy concentration and heat collection process, and improve the utilization efficiency of solar energy. On the basis of strengthening the reforming reaction and reducing the reaction temperature, the oxygen carrier is cleverly used to completely oxidize the exhaust gas to complete the enrichment of CO2 source, and the source separation and low-energy capture of CO2 are achieved while the solar energy and hydrocarbon fuels complement each other to produce hydrogen efficiently.

[0044] The above-mentioned concentrated solar energy drives the chemical chain enhanced wet reforming reaction, oxygen carrier reduction reaction and air oxidation reaction to complete the entire chemical cycle. Compared with the traditional methane steam reforming hydrogen production process, the introduction of circulating oxygen carriers not only strengthens the wet reforming reaction, but also improves the overall reaction of hydrocarbon fuel conversion rate and hydrogen production, reduces the reaction temperature and CO yield, and also achieves carbon dioxide enrichment. While producing clean hydrogen, it can effectively reduce greenhouse gas emissions and has higher environmental benefits and economic value. Introducing concentrated solar energy in the chemical chain enhanced wet reforming reaction, by using concentrated solar energy to provide the necessary energy to drive the methane wet reforming hydrogen production reaction, this method avoids the carbon dioxide emissions and irreversible losses caused by the need to burn hydrocarbon fuels for heating in the traditional wet reforming reaction, and improves the overall reaction efficiency. In this process, the wet reforming hydrogen production reaction and the reduction reaction of hydrocarbon fuels and oxygen carriers are endothermic processes, which can significantly increase the solar energy input and utilization rate, and realize the upgrade from low-grade thermal energy to high-grade chemical energy. The utilization rate of renewable energy is improved through multi-energy complementarity, while the advantages of wet reforming hydrogen production and low-energy carbon dioxide capture in the chemical chain are integrated to achieve sustainable and more efficient energy utilization.

[0045] In an optional embodiment, the underoxidized oxygen carrier is represented by MeO 1-δ (such as Fe3O4), the reduced oxygen carrier is represented by MeO 1-γ (such as FeO), the initial oxidized oxygen carrier is represented by MeO (such as Fe2O3), wherein γ>δ, and the reduced oxygen carrier (MeO 1-γ ) releases more oxygen than the underoxidized oxygen carrier (MeO 1-δ )'s oxygen release level.

[0046] Specifically, the chemical equation for the concentrated solar energy driven chemical chain enhanced wet reforming reaction (hydrogen production) is: CH4+H2O=3H2+CO, CH4+H2O+MeO 1-δ →H2+CO2+MeO 1-γ 、CO+MeO 1-δ →CO2+MeO 1-γ ;

[0047] The chemical equation for the oxygen carrier reduction reaction (decarbonization) is: CO+MeO→CO2+MeO 1-δ 、CH4+MeO→CO2+H2O+MeO 1-δ ;

[0048] The chemical equation for the air oxidation reaction process (oxygen carrier regeneration) is: O2+MeO 1-γ →MeO.

[0049] In an optional embodiment, the main active components of the initial oxidation state oxygen carrier include one or more of Fe2O3, CoO, CuO, Mn2O3 and perovskite. For example, when Fe2O3 / Al2O3 (where Al2O3 is used as the skeleton material of Fe2O3) can be selected as the initial oxidation state oxygen carrier, the chemical equations of the above three reactions are as follows:

[0050] The chemical equations for the concentrated solar energy driven chemical chain enhanced wet reforming reaction (hydrogen production) are: CH4+H2O→3H2+CO, CH4+Fe3O4+H2O→3H2+3FeO+CO2, CO+Fe3O4→3FeO+CO2;

[0051] The chemical equation for the oxygen carrier reduction reaction (decarbonization) is: H2+CO+CH4+18Fe2O3→2CO2+12Fe3O4+3H2O;

[0052] The chemical equation for the air oxidation reaction process (oxygen carrier regeneration) is: O2+4FeO→2Fe2O3.

[0053] In an optional embodiment, in the concentrated solar energy driven chemical chaining enhanced wet reforming reaction, a reforming hydrogen production catalyst structure is provided in the reactor or a hydrogen production catalyst is mixed in the underoxidized oxygen carrier. Specifically, both the hydrogen production catalyst structure and the hydrogen production catalyst can use Ni-based catalysts, and other types of catalysts that can promote redox reactions between oxygen carriers with different oxygen release degrees in different reaction processes and gases can also be used.

[0054] In an optional embodiment, the above method can not only use hydrocarbon fuel as the hydrocarbon raw material, but also can be used for other hydrocarbons such as methane, ethane and propane.

[0055] The present invention also provides a solar-driven chemical chaining enhanced wet reforming system for producing hydrogen and CO2, see Figure 2 As shown, the system includes a chemical chain enhanced wet reforming reactor R1, an air oxidation reactor R2, an oxygen carrier reduction reactor R3, a concentrated solar energy system and a hydrogen separation and purification system. The chemical chain enhanced wet reforming reactor R1, the oxygen carrier reduction reactor R13 and the air oxidation reactor R2 are all in the form of moving bed reactors, and the solid particles of oxygen carriers inside them move downward by gravity. The various parts of the system are used to realize the above-mentioned method of solar-driven chemical chain enhanced wet reforming hydrogen production and source separation of CO2. Specifically, the chemical chain enhanced wet reforming reactor is used to carry out concentrated solar-driven chemical chain enhanced wet reforming reaction, the air oxidation reactor is used to carry out air oxidation reaction, and the oxygen carrier reduction reactor is used to carry out oxygen carrier reduction reaction. The oxygen carrier forms a cycle in the three reactors.

[0056] Among them, the chemical looping enhanced wet reforming reactor R1 is provided with a gas inlet and an oxygen carrier inlet at the top, a first mixed gas outlet at the bottom, and an oxygen carrier outlet at the bottom. The first mixed gas outlet is connected to the hydrogen separation and purification system. The concentrating solar energy system provides the required heat energy for the chemical looping enhanced wet reforming reaction of hydrocarbon fuel and water vapor in the chemical looping enhanced wet reforming reactor under the action of under-oxidized oxygen carrier and catalyst.

[0057] The top of the air oxidation reactor R2 is provided with a solid inlet and an air inlet, the solid inlet is connected to the oxygen carrier outlet, the lower part is provided with an oxygen-depleted air outlet, and the bottom is provided with a solid outlet.

[0058] The oxygen carrier reduction reactor R3 is provided with an oxygen carrier solid inlet, a CO2 outlet, a purge gas inlet and an oxygen carrier solid outlet. Specifically, the oxygen carrier solid inlet and the CO2 outlet can be arranged at the top of the oxygen carrier reduction reactor R3, and the purge gas inlet can be arranged at the bottom of the oxygen carrier reduction reactor R3. The initial oxidation state oxygen carrier input through the oxygen carrier solid inlet is in countercurrent contact with the purge gas input through the purge gas inlet. The oxygen carrier solid outlet is arranged at the bottom of the oxygen carrier reduction reactor R3, the purge gas inlet is connected to the outlet of the hydrogen separation and purification system, and the oxygen carrier solid outlet is connected to the oxygen carrier inlet.

[0059] In an optional embodiment not shown in the drawings, a reforming hydrogen production catalyst structure is provided in the chemical looping enhanced wet reforming reactor R1, wherein the hydrogen production catalyst structure can be arranged at the top of the oxygen carrier reduction reactor R3 near the oxygen carrier solid inlet, and can also be arranged along the oxygen carrier reduction reactor R3, and it can be arranged in the form of a grid or a tube.

[0060] In an optional embodiment, the system further includes an under-oxidized oxygen carrier storage tank, in which an under-oxidized oxygen carrier containing a mixed reforming hydrogen production catalyst is stored, and an outlet of the under-oxidized oxygen carrier storage tank is connected to an oxygen carrier inlet of the chemical looping enhanced wet reforming reactor.

[0061] In an optional embodiment, the system further comprises a feeding unit, wherein the feeding unit is connected to the gas inlet, and the feeding unit is used for mixing hydrocarbon fuel and water vapor and outputting the mixed mixture to the chemical looping enhanced wet reforming reactor.

[0062] In an optional embodiment, the system further comprises a gas-liquid separator, which is connected to the CO2 outlet and is used for performing gas-liquid separation on the aqueous CO2 output from the oxygen carrier reduction reactor to obtain dry high-purity / high-concentration CO2.

[0063] In an optional embodiment not shown in the drawings, the system also includes a temperature control unit, which is connected to the chemical chain enhanced wet reforming reactor and the concentrated solar energy system, and is used to collect the temperature inside the chemical chain enhanced wet reforming reactor, and control the concentrated solar energy system according to the collected temperature, so that the temperature inside the chemical chain enhanced wet reforming reactor is within the range of 500 to 650°C.

[0064] In this specific embodiment, methane is used as the hydrocarbon raw material, and the method of the present invention is used to produce hydrogen and separate and capture carbon dioxide from the source. The experimental results of the gas product concentration of the chemical chain enhanced wet reforming reaction driven by concentrated solar energy are as follows: Figure 3 The experimental results of methane conversion rate and unit methane hydrogen production performance are shown in Figure 4 The methane reformer shown is Figure 4 As shown, according to Figure 3 and Figure 4 It can be seen that at a reaction temperature of 600°C, the methane conversion rate reaches 90%, which is much higher than the traditional wet reforming conversion rate (about 40-50%), and the reaction temperature is greatly reduced. Figure 5 As shown in the figure, at 650℃, the initial oxidized oxygen carrier (i.e., completely oxidized oxygen carrier) reacts with the purge gas, the concentrations of residual H2, CO, and unreacted hydrocarbon fuels gradually decrease, and the concentration of CO2 gradually increases to nearly 99%. This reaction process continuously and stably achieves a good CO2 source decarbonization effect. At the same time, according to Figure 3 , Figure 4 and Figure 5 The results shown in the figure indicate that the method of the present invention significantly enhances the conversion rate and hydrogen production performance of the wet reforming reaction of hydrocarbon fuels, greatly reduces the reaction temperature, provides convenient conditions for concentrated solar energy heat collection, and is conducive to improving the efficiency of solar energy utilization. In addition, the CO concentration is much lower than the concentration of traditional wet reforming products, which has the conditions and advantages of eliminating the CO water vapor conversion device.

[0065] Obviously, those skilled in the art should understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0066] In addition, although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions of each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for producing hydrogen and separating CO2 from the source by solar-driven chemical chaining enhanced wet reforming, characterized in that: The method comprises concentrated solar energy driven chemical chaining enhanced wet reforming reaction, oxygen carrier reduction reaction and air oxidation reaction; In the concentrated solar energy driven chemical chain enhanced wet reforming reaction, the concentrated solar energy provides heat energy of 500 to 650° C. to drive the hydrocarbon fuel to react with water vapor to produce CO and H2. CO and the hydrocarbon fuel are oxidized by an underoxidized oxygen carrier to produce H2 and CO2 to produce a first mixed gas including H2, CO2 and unreacted hydrocarbon fuel. The underoxidized oxygen carrier is reduced to a reduced oxygen carrier. H2 in the first mixed gas is separated to produce a purge gas, which includes unreacted hydrocarbon fuel, CO2 and residual H2. In the air oxidation reaction, the reduced oxygen carrier is oxidized by air to an initial oxidized oxygen carrier carrying sensible heat; In the oxygen carrier reduction reaction, the residual H2, CO and unreacted hydrocarbon fuel in the purge gas are oxidized into CO2 and H2O by the initial oxidation state oxygen carrier carrying sensible heat, and the initial oxidation state oxygen carrier is reduced to an under-oxidized state oxygen carrier.

2. The method for producing hydrogen and separating CO2 from the source by solar-driven chemical chaining enhanced wet reforming according to claim 1, characterized in that: In the concentrated solar energy driven chemical chaining enhanced wet reforming reaction, a reforming hydrogen production catalyst structure is provided in the reactor or a hydrogen production catalyst is mixed in the underoxidized oxygen carrier.

3. The method for producing hydrogen and separating CO2 from the source by solar-driven chemical chaining enhanced wet reforming according to claim 1, characterized in that: The underoxidized oxygen carrier is represented by MeO 1-δ , the reduced oxygen carrier is represented by MeO 1-γ , the initial oxidized oxygen carrier is represented by MeO, wherein γ>δ, and the oxygen release degree of the reduced oxygen carrier is greater than the oxygen release degree of the under-oxidized oxygen carrier.

4. The method for producing hydrogen and separating CO2 from the source by solar-driven chemical chaining enhanced wet reforming according to claim 1, characterized in that: The active components of the initial oxidation state oxygen carrier include one or more of Fe2O3, CoO, CuO, Mn2O3 and perovskite.

5. A solar-driven chemical chaining enhanced wet reforming system for hydrogen production and source separation of CO2, characterized in that: It includes a chemical chain enhanced wet reforming reactor, an air oxidation reactor, an oxygen carrier reduction reactor, a concentrated solar energy system and a hydrogen separation and purification system. The chemical chain enhanced wet reforming reactor, the oxygen carrier reduction reactor and the air oxidation reactor are all in the form of moving bed reactors, and the oxygen carrier solid particles inside them move downward by gravity. The chemical looping enhanced wet reforming reactor is provided with a gas inlet and an oxygen carrier inlet at the top, a first mixed gas outlet at the bottom, and an oxygen carrier outlet at the bottom, the first mixed gas outlet is connected to the hydrogen separation and purification system, the chemical looping enhanced wet reforming reactor is connected to the concentrated solar energy system, and the concentrated solar energy system provides the required heat energy for the chemical looping enhanced wet reforming reaction between hydrocarbon fuel and water vapor under the action of underoxidized oxygen carrier and catalyst in the chemical looping enhanced wet reforming reactor; The top of the air oxidation reactor is provided with a solid inlet and an air inlet, the solid inlet is connected to the oxygen carrier outlet, the lower part is provided with an oxygen-depleted air outlet, and the bottom is provided with a solid outlet; The oxygen carrier reduction reactor is provided with an oxygen carrier solid inlet, a CO2 outlet, a purge gas inlet and an oxygen carrier solid outlet. The initial oxidized oxygen carrier input through the oxygen carrier solid inlet is in countercurrent contact with the purge gas input through the purge gas inlet. The purge gas inlet is connected to the outlet of the hydrogen separation and purification system, and the oxygen carrier solid outlet is connected to the oxygen carrier inlet.

6. The solar-driven chemical chaining enhanced wet reforming hydrogen production and source separation of CO2 system according to claim 5 is characterized in that: A reforming hydrogen production catalyst structure is arranged in the chemical looping enhanced wet reforming reactor.

7. The solar-driven chemical chaining enhanced wet reforming hydrogen production and source separation of CO2 system according to claim 5 is characterized in that: It also includes an underoxidized oxygen carrier storage tank, in which an underoxidized oxygen carrier containing a mixed reforming hydrogen production catalyst is stored, and an outlet of the underoxidized oxygen carrier storage tank is connected to the oxygen carrier inlet of the chemical looping enhanced wet reforming reactor.

8. The solar-driven chemical chaining enhanced wet reforming hydrogen production and source separation of CO2 system according to claim 5 is characterized in that: It also includes a feeding unit, which is connected to the gas inlet and is used to mix hydrocarbon fuel and water vapor and output them to the chemical chaining enhanced wet reforming reactor.

9. The solar-driven chemical chaining enhanced wet reforming hydrogen production and source separation of CO2 system according to claim 5, characterized in that: It also includes a gas-liquid separator, which is connected to the CO2 gas outlet and is used to perform gas-liquid separation on the water-containing CO2 output from the oxygen carrier reduction reactor to obtain dry CO2.

10. The solar-driven chemical chaining enhanced wet reforming hydrogen production and source separation of CO2 system according to claim 5, characterized in that: It also includes a temperature control unit, which is connected to the chemical chain enhanced wet reforming reactor and the concentrated solar energy system, and is used to collect the temperature in the chemical chain enhanced wet reforming reactor, and control the concentrated solar energy system according to the collected temperature, so that the temperature in the chemical chain enhanced wet reforming reactor is within the range of 500 to 650°C.

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