A thermochemical cycle hydrogen production device and a hydrogen production method

Abstract

The present invention provides a thermochemical cycle hydrogen production device and a hydrogen production method. The thermochemical cycle hydrogen production device of the invention can heat the system with inexpensive biomass and the like as fuel by setting a heating chamber, which can significantly reduce the heating cost of the process (the heating temperature is below 900 °C) and expand the application range. The thermochemical cycle hydrogen production method of the present invention introduces biomass pyrolysis gas and uses an oxygen carrier in combination, further reducing the temperature of the thermochemical cycle reaction process, which helps to extend the service life of the reaction device. Compared with the conventional thermochemical cycle hydrogen production process, the fuel-assisted thermochemical cycle hydrogen production process requires a relatively low reaction temperature. In addition, compared with the conventional thermochemical cycle hydrogen production process, the fuel-assisted thermochemical cycle hydrogen production process has the advantages of low investment and operation costs and high stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen production, and particularly relates to a thermochemical cycle hydrogen production device and a hydrogen production method. Background Art

[0002] Hydrogen energy is an important part of the future national energy system, and the hydrogen energy industry is a key development direction. Developing green hydrogen production technology is of great significance for building a hydrogen energy industrial chain. The thermochemical cycle direct water splitting hydrogen production technology, as a green and renewable hydrogen production technology, has received extensive attention. Thermochemical cycle hydrogen production is realized by a two-step cycle based on a metal oxide redox pair (oxygen carrier) to decompose water for hydrogen production. However, due to the relatively stable thermodynamic properties of water, the conventional thermochemical cycle water splitting reaction needs to be carried out at a relatively high temperature (greater than 1500 °C). Since the temperature of the conventional thermochemical cycle hydrogen production process is relatively high (about 1500 °C), the conventional heating method has high energy consumption and poor economy. Therefore, its reactor mainly adopts the method of solar concentrator heating, and mainly faces problems such as high reactor cost, solar heat supply being affected by weather, climate, etc., poor stability, and difficulty in large-scale production.

[0003] Based on the defects of the current thermochemical cycle hydrogen production process and reactor, it is necessary to improve it. Summary of the Invention

[0004] In view of this, the present invention provides a thermochemical cycle hydrogen production device and a hydrogen production method to solve or at least partially solve the defects existing in the prior art.

[0005] In a first aspect, the present invention provides a thermochemical cycle hydrogen production device, comprising:

[0006] A housing with a hollow interior, one end of the interior of the housing forms a combustion chamber, the other end forms a heating chamber, the combustion chamber is communicated with the heating chamber, and a fuel inlet pipe is provided on the housing corresponding to the combustion chamber;

[0007] An intake air ring pipe sleeved on the outer periphery of the housing corresponding to the combustion chamber;

[0008] A plurality of reaction tubes located in the heating chamber, one end of the reaction tube extends downward and passes through the housing to communicate with the intake air ring pipe;

[0009] An exhaust gas ring pipe located outside the housing, the other end of the reaction tube extends upward and passes through the housing to communicate with the exhaust gas ring pipe.

[0010] Preferably, a flue gas discharge pipe is provided on the housing corresponding to the heating chamber, and the exhaust gas ring pipe is sleeved on the outer periphery of the flue gas discharge pipe.

[0011] Preferably, an intake pipe is provided at the end of the intake ring pipe, the reaction tube is connected to the intake pipe, and a first valve is provided in the intake pipe.

[0012] Preferably, an air outlet pipe is provided at the end of the air outlet ring pipe, the reaction tube is connected to the air outlet pipe, and a second valve is provided in the air outlet pipe.

[0013] Preferably, a porous distribution plate is provided in the reaction tube for carrying the oxygen carrier.

[0014] Preferably, a temperature and pressure detector is provided on the top of the reaction tube to monitor the temperature and pressure in the reaction tube.

[0015] Preferably, a heat-insulating layer is further provided outside the shell, and an oxygen carrier adding port is provided at the portion of the reaction tube outside the shell.

[0016] In a second aspect, the present invention further provides a thermochemical cycle method for producing hydrogen, comprising the following steps:

[0017] Providing the thermochemical cycle hydrogen production device;

[0018] placing an oxygen carrier in a reaction tube;

[0019] Add fuel into the combustion chamber through the fuel inlet pipe, and introduce air to enable the fuel to be fully burned in the combustion chamber;

[0020] The pyrolysis gas is introduced into the air inlet ring pipe, and the heat generated by the combustion of the fuel heats the reaction tube, so that the pyrolysis gas reacts with the oxygen carrier, and the lattice oxygen in the oxygen carrier is captured, and the oxygen carrier is reduced, and the pyrolysis gas undergoes a reforming reaction to produce synthesis gas, which is discharged from the air outlet ring pipe;

[0021] After the reduction of the oxygen carrier is completed, the introduction of pyrolysis gas is stopped, and steam is introduced into the air inlet ring pipe. The steam reacts with the reduced oxygen carrier to produce hydrogen, which is discharged from the air outlet ring pipe. The oxygen carrier oxidized by steam obtains lattice oxygen and is regenerated.

[0022] Preferably, the oxygen carrier includes at least one of brownmillerite, Co-Fe metal oxide, and high entropy spinel oxide;

[0023] The high entropy spinel oxide comprises (Ni 0.2 Co 0.2 Ca 0.2 Cu 0.2 Mg 0.2 )Fe2O4、(Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Mg 0.2 ) at least one of Fe2O4;

[0024] The pyrolysis gas includes the following components by volume fraction: CO 23-33%, CH4 10-20%, C n H m 7-17%, H2 18-28%, CO2 17-27%, where m and n are both positive integers, 2≤n≤4, 4≤m≤10;

[0025] The fuel is biomass powder.

[0026] Preferably, the heat generated by the combustion of the fuel heats the reaction tube so that the temperature in the reaction tube is 600-900°C;

[0027] Steam is introduced into the intake annular pipe, where the steam temperature is 200-400°C;

[0028] The steam includes water vapor and / or toluene vapor.

[0029] A thermochemical cycle hydrogen production device and a test method thereof according to the present invention have the following

[0030] beneficial effects compared with the prior art:

[0031] 1. In the thermochemical cycle hydrogen production device of the present invention, by setting a heating chamber, inexpensive biomass and the like can be used as fuel to heat the system, which can significantly reduce the heating cost of this process (heating temperature below 900°C) and expand the application range.

[0032] 2. In the thermochemical cycle hydrogen production method of the present invention, by introducing biomass pyrolysis gas and using an oxygen carrier in combination, the temperature of the thermochemical cycle reaction process is further reduced, which helps to extend the service life of the reaction device. Specifically, by introducing reducing fuels such as toluene during the reduction process of metal oxides, and the fuel-assisted thermochemical cycle direct water splitting hydrogen production process, the reaction temperature can be significantly reduced to below 900°C; compared with the conventional thermochemical cycle hydrogen production process, the fuel-assisted thermochemical cycle hydrogen production process requires a relatively lower reaction temperature, and the heat required for the reaction process can be supplied by conventional heating methods, such as the combustion of fuels such as methane, biogas, and biomass powder. In addition, compared with the conventional thermochemical cycle hydrogen production process, the fuel-assisted thermochemical cycle hydrogen production process has the advantages of low investment and operation costs and high stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 This is a schematic structural diagram of the thermochemical cycle hydrogen production device of the present invention;

[0035] Figure 2 This is a top view of the thermochemical cycle hydrogen production device of the present invention. Specific Embodiments

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0037] For a better understanding of the present invention rather than limiting its scope, all numbers representing amounts, percentages, and other numerical values used in this application should be understood to be modified by the word "about" in all cases. Therefore, unless otherwise specified, the numerical parameters listed in the specification and the appended claims are approximate values, which may vary according to the different desired properties. Each numerical parameter should at least be regarded as obtained according to the reported significant figures and by the conventional rounding method.

[0038] It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments. Additionally, in the description of this application, the term "comprising" means "including but not limited to". The various embodiments of the present invention may exist in a range format; it should be understood that the description in a range format is only for convenience and brevity and should not be construed as a rigid limitation on the scope of the present invention; therefore, it should be considered that the described range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0039] The present invention provides a thermochemical cycle hydrogen production device, as Figures 1-2 shown, including:

[0040] A housing 1, which is hollow inside. One end inside the housing forms a combustion chamber 11, and the other end forms a heating chamber 12. The combustion chamber 11 communicates with the heating chamber 12. A fuel inlet pipe 10 is provided on the housing corresponding to the combustion chamber;

[0041] An intake air ring pipe 2, which is sleeved on the outer periphery of the housing corresponding to the combustion chamber 11;

[0042] A plurality of reaction tubes 3, which are located in the heating chamber 12. One end of the reaction tube 3 extends downward and passes through the housing to communicate with the intake air ring pipe 2;

[0043] An outlet air ring pipe 4, which is located outside the housing 1. The other end of the reaction tube 3 extends upward and passes through the housing to communicate with the outlet air ring pipe 4.

[0044] The thermochemical cycle hydrogen production device of the present invention includes a housing 1, an intake air ring pipe 2, a plurality of reaction tubes 3, and an outlet air ring pipe 4. The housing 1 is hollow inside, and an upper end inside the housing forms a heating chamber 12 and a lower end forms a combustion chamber 11. The intake air ring pipe 2 is circular and sleeved on the outer periphery of the housing corresponding to the combustion chamber 11. A plurality of reaction tubes 3 are provided in the heating chamber 12. Specifically, the number of reaction tubes 3 can be 1, 2, 3, 4, 5, 6... n. The upper end of each reaction tube 3 extends upward and passes through the housing to communicate with the outlet air ring pipe 4, and the lower end extends downward and passes through the housing to communicate with the intake air ring pipe 2.

[0045] The thermochemical cycle hydrogen production device of the present invention, by providing a heating chamber, can use inexpensive biomass and the like as fuel to heat the system, can significantly reduce the heating cost of this process (heating temperature is below 900 °C), and improves the application range.

[0046] In some embodiments, a flue gas discharge pipe 5 is provided on the housing 1 corresponding to the heating chamber 2, and the outlet air ring pipe 4 is sleeved on the outer periphery of the flue gas discharge pipe 5.

[0047] Specifically, a flue gas discharge pipe 5 is provided at the upper end of the housing 1 corresponding to the heating chamber 2. The flue gas discharge pipe 5 is used to discharge the flue gas generated by fuel combustion; the outlet air ring pipe 4 is circular and sleeved on the outer periphery of the flue gas discharge pipe 5.

[0048] In some embodiments, an intake pipe 21 is provided at the end of the intake air ring pipe 2. The end of the reaction tube 3 close to the intake air ring pipe 2 is communicated with the intake pipe 21, and a first valve 22 is provided in the intake pipe 21; after the first valve 22 is opened, the pyrolysis gas enters the reaction tube 3 through the intake pipe 21, and the pyrolysis gas reacts with the oxygen carrier in the reaction tube 3.

[0049] In some embodiments, an outlet pipe 41 is provided at the end of the outlet air ring pipe 4. The end of the reaction tube 3 close to the outlet air ring pipe 4 is communicated with the outlet pipe 41, and a second valve 42 is provided in the outlet pipe 41; after the second valve 42 is opened, the reaction gas generated by the reaction of the pyrolysis gas with the oxygen carrier in the reaction tube 3, or the steam reacts with the reduced oxygen carrier to produce hydrogen, which is discharged from the outlet pipe 41.

[0050] In some embodiments, a porous distribution plate 6 is provided inside the reaction tube 3 for carrying the oxygen carrier 7.

[0051] In some embodiments, a temperature and pressure detector 8 is provided at the top of the reaction tube 3 for monitoring the temperature and pressure inside the reaction tube 3.

[0052] Specifically, the upper end of the reaction tube 3 extends upward and passes through the outlet annular pipe 4, and the temperature and pressure detector 8 is arranged at the top of the reaction tube 3.

[0053] In some embodiments, a heat insulation layer is further provided outside the housing 1, and an oxygen carrier inlet is provided at the part of the reaction tube 3 outside the housing 1.

[0054] In some embodiments, the combustion chamber 11 is a cylindrical cavity body, which is arranged at the lower end of the housing 1. The fuel enters the combustion chamber through the fuel inlet pipe and burns to generate high-temperature flue gas. The high-temperature flue gas then enters the heating chamber. The temperature in the combustion chamber is not lower than 1000 °C; the reaction tubes are a series of vertical pipes uniformly distributed inside the heating chamber, and the high-temperature flue gas in the heating chamber heats them; a temperature and pressure detector is arranged at the top of the reaction tube, and a porous distribution plate is arranged inside the reaction tube, and the oxygen carrier is placed on the porous distribution plate; the functions of the reaction tube are different in different time periods. When the pyrolysis gas enters the reaction tube chamber, the reaction tube is a fuel reactor; when water vapor enters the inner chamber of the reaction tube, the reaction tube is a hydrogen production reactor at this time.

[0055] Specifically, the usage method of the thermochemical cycle hydrogen production device of the present invention includes the following steps:

[0056] 1. The fuel is fully pre-mixed with air and enters the combustion chamber through the fuel inlet pipe. After fully burning in the combustion chamber, high-temperature flue gas is generated. The high-temperature flue gas enters the heating chamber to heat the oxygen carrier in the reaction tube. After the heat exchange is completed, the high-temperature flue gas flows out from the flue gas outlet;

[0057] 2. The fuel uses biomass powder, the particle size of the biomass powder is not higher than 400 μm, and the temperature generated by the combustion chamber is not lower than 900 °C. The fuel inlet is sprayed along the tangential direction of the combustion chamber;

[0058] 2. The oxygen carrier in the reaction tube is placed on the porous distribution plate. The oxygen carrier can be calcium ferrite, Co-Fe metal oxide, high-entropy spinel oxide, etc.; keep all valves closed, and heat the oxygen carrier in the reaction tube to the required temperature of the reaction tube. The internal temperature range of the reaction tube is 600-900 °C;

[0059] 3. Open the first valve and the second valve, and introduce pyrolysis gas (the main components are CO, CH4, C n H m, H2, CO2), the pyrolysis gas reacts with the oxygen carrier to capture the lattice oxygen in the oxygen carrier, and the oxygen carrier is reduced, and the pyrolysis gas undergoes a reforming reaction to produce synthesis gas, which is discharged from the outlet pipe;

[0060] 4. After the oxygen carrier is reduced, water vapor is introduced from the air inlet pipe. The steam temperature is 200-400°C. The steam reacts with the reduced oxygen carrier to produce hydrogen, which is discharged from the air outlet pipe. The oxygen carrier oxidized by steam obtains lattice oxygen to achieve regeneration.

[0061] 5. Repeat steps 3 and 4 to obtain reaction gas and hydrogen intermittently.

[0062] 6. When there is only one reaction tube, intermittent hydrogen production can be achieved. When there are multiple reaction tubes, continuous hydrogen production can be achieved through valve control.

[0063] Based on the same inventive concept, the present invention also provides a thermochemical cycle hydrogen production method, comprising the following steps:

[0064] S1. Provide the above-mentioned thermochemical cycle hydrogen production device;

[0065] S2, placing an oxygen carrier in a reaction tube;

[0066] S3, adding fuel into the combustion chamber through the fuel inlet pipe, and introducing air to allow the fuel to fully burn in the combustion chamber;

[0067] S4, introducing the pyrolysis gas into the air inlet ring pipe, and the heat generated by the fuel combustion heats the reaction tube, so that the pyrolysis gas reacts with the oxygen carrier, and the lattice oxygen in the oxygen carrier is captured, and the oxygen carrier is reduced, and the pyrolysis gas undergoes a reforming reaction to produce synthesis gas, which is discharged from the air outlet ring pipe;

[0068] S5. After the reduction of the oxygen carrier is completed, the introduction of pyrolysis gas is stopped, and steam is introduced into the air inlet ring pipe. The steam reacts with the reduced oxygen carrier to generate hydrogen, which is discharged from the air outlet ring pipe. The oxygen carrier oxidized by steam obtains lattice oxygen to achieve regeneration.

[0069] In some embodiments, the oxygen carrier comprises at least one of brownmillerite, Co—Fe metal oxide, and high entropy spinel oxide;

[0070] High entropy spinel oxides include (Ni 0.2 Co 0.2 Ca 0.2 Cu 0.2 Mg 0.2 )Fe2O4、(Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Mg 0.2)at least one of Fe2O4;

[0071] The pyrolysis gas comprises the following components by volume fraction: CO 23 - 33%, CH4 10 - 20%, C n H m 7 - 17%, H2 18 - 28%, CO2 17 - 27%, where m and n are both positive integers, 2 ≤ n ≤ 4, 4 ≤ m ≤ 10;

[0072] The fuel is biomass powder. Specifically, the biomass powder includes but is not limited to pine sawdust, plane tree leaves, plane tree branches, and straw.

[0073] Specifically, in the above embodiments, air is introduced to enable the fuel to burn fully in the combustion chamber; the introduction of air makes the excess air coefficient 1. The excess air coefficient represents the ratio of the actual supplied air to the theoretically supplied air when the fuel burns completely. That is to say, the supplied air may vary according to the different theoretical oxygen demands of the fuel. Defined by the excess air coefficient, it can ensure that each fuel biomass burns fully. When the fuel feed rate increases / decreases, the intake air volume also increases / decreases by the same multiple.

[0074] In some embodiments, the heat generated by the fuel combustion heats the reaction tube so that the temperature in the reaction tube is 600 - 900 °C;

[0075] Steam is introduced into the intake annular pipe, where the steam temperature is 200 - 400 °C;

[0076] The steam includes water vapor and / or toluene vapor.

[0077] In the thermochemical cycle hydrogen production method of the present invention, the introduction of biomass pyrolysis gas, combined with the use of an oxygen carrier, further reduces the temperature in the thermochemical cycle reaction process, which helps to extend the service life of the reaction device. Specifically, in the process of reducing metal oxides, reducing fuels such as methane are introduced, and the fuel-assisted thermochemical cycle direct water decomposition hydrogen production process can significantly reduce the reaction temperature to below 900 °C; compared with the conventional thermochemical cycle hydrogen production process, the fuel-assisted thermochemical cycle hydrogen production process requires a relatively lower reaction temperature, and the heat required for the reaction process can be supplied by conventional heating methods, such as the combustion of fuels such as methane, biogas, and biomass powder. In addition, compared with the conventional thermochemical cycle hydrogen production process, the fuel-assisted thermochemical cycle hydrogen production process has the advantages of low investment and operation costs and high stability.

[0078] The thermochemical cycle hydrogen production method of the present application is further described below with specific examples. This section further illustrates the content of the present invention in conjunction with specific examples, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0079] In the following examples, the hydrogen yield (Y H2 ,mmol / g OC) and purity (P syngas ,%) is calculated as follows:

[0080]

[0081] in, is the amount of H2 produced (molar amount), V total is the total volume of gas produced, is the volume of hydrogen produced, m OC is the mass of oxygen carrier used.

[0082] Example 1

[0083] This embodiment provides a thermochemical cycle hydrogen production method, comprising the following steps:

[0084] S1. Provide Figure 1 Thermochemical cycle hydrogen production device shown;

[0085] S2, 6 kg high entropy spinel oxygen carrier (Ni 0.2 Co 0.2 Ca 0.2 Cu 0.2 Mg 0.2 )Fe2O4 is placed on a porous distribution plate;

[0086] S3, biomass powder (specifically pine sawdust powder) with a particle size of 250 μm is used as fuel, the fuel is added to the combustion chamber through the fuel inlet pipe, and air is introduced to allow the fuel to be fully burned in the combustion chamber; the fuel feed rate is 1.5 kg / h, and the excess air coefficient is 1;

[0087] S4. The pyrolysis gas is introduced into the air inlet ring pipe. The heat generated by the combustion of the fuel heats the reaction tube, so that the pyrolysis gas reacts with the oxygen carrier, captures the lattice oxygen in the oxygen carrier, and the oxygen carrier is reduced. The pyrolysis gas undergoes a reforming reaction to produce synthesis gas, which is discharged from the air outlet ring pipe; the heat generated by the combustion of the fuel heats the reaction tube so that the temperature in the reaction tube is 700°C; the pyrolysis gas includes the following volume fraction components: CO 28%, CH4 15%, C3H8 12%, H2 23%, CO2 22%, and the pyrolysis gas flow rate is 1m 3 / h;

[0088] After the reduction of the oxygen carrier is completed, stop introducing the pyrolysis gas, introduce steam into the intake annular pipe, the steam reacts with the reduced oxygen carrier to produce hydrogen, and the hydrogen is discharged from the outlet annular pipe. The oxygen carrier after the oxidation of the steam obtains lattice oxygen and realizes regeneration; the steam flow rate is 3.6 kg / h, and the steam temperature is 400 °C;

[0089] Among them, the preparation method of the high-entropy spinel oxygen carrier (Ni 0.2 Co 0.2 Ca 0.2 Cu 0.2 Mg 0.2 )Fe2O4 includes the following steps:

[0090] S21. Mix Ni(NO3)2, Co(NO3)2, Ca(NO3)2, Cu(NO3)2, Mg(NO3)2, Fe(NO3)2 with citric acid, then add water and stir at 95 °C to obtain a gel;

[0091] S2. Place the gel in an oven at 105 °C until the sample is completely dry;

[0092] S3. Place the dried sample in a muffle furnace and calcine it at 1000 °C for 10 h. After cooling, grind and sieve it to a size range less than 212 μm (70 mesh), and the high-entropy spinel oxygen carrier (Ni 0.2 Co 0.2 Ca 0.2 Cu 0.2 Mg 0.2 )Fe2O4 is obtained;

[0093] Among them, the molar ratio of Ni(NO3)2, Co(NO3)2, Ca(NO3)2, Cu(NO3)2, Mg(NO3)2, Fe(NO3)2, and citric acid is 0.2:0.2:0.2:0.2:0.2:2:1.5;

[0094] The molar ratio of citric acid to water is 1:50.

[0095] According to the method in Example 1, the hydrogen production rate is 8 mmol / g, and the purity reaches 98%.

[0096] Example 2

[0097] This example provides a thermochemical cycle hydrogen production method, including the following steps:

[0098] S1. Provide Figure 1 the thermochemical cycle hydrogen production device shown;

[0099] S2, 6 kg high entropy spinel oxygen carrier (Ni 0.2 Co 0.2 Ca 0.2 Cu 0.2 Mg 0.2 )Fe2O4 (prepared by the same method as in Example 1) is placed on a porous distribution plate;

[0100] S3, using biomass powder (specifically pine sawdust powder) with a particle size of 250 μm as fuel, adding the fuel into the combustion chamber through the fuel inlet pipe, and introducing air to allow the fuel to be fully burned in the combustion chamber; the fuel feed rate is 2.5 kg / h, and the excess air coefficient is 1;

[0101] S4. The pyrolysis gas is introduced into the air inlet ring pipe. The heat generated by the combustion of the fuel heats the reaction tube, so that the pyrolysis gas reacts with the oxygen carrier, captures the lattice oxygen in the oxygen carrier, and the oxygen carrier is reduced. The pyrolysis gas undergoes a reforming reaction to produce synthesis gas, which is discharged from the air outlet ring pipe; the heat generated by the combustion of the fuel heats the reaction tube so that the temperature in the reaction tube is 800°C; the pyrolysis gas includes the following volume fraction components: CO 28%, CH4 15%, C3H8 12%, H2 23%, CO2 22%, and the pyrolysis gas flow rate is 1m 3 / h;

[0102] S5. After the reduction of the oxygen carrier is completed, the introduction of pyrolysis gas is stopped, and water vapor is introduced into the air inlet ring pipe. The water vapor reacts with the reduced oxygen carrier to generate hydrogen, which is discharged from the air outlet ring pipe. The oxygen carrier oxidized by water vapor obtains lattice oxygen to achieve regeneration; the water vapor flow rate is 3.6 kg / h, and the water vapor temperature is 400°C;

[0103] According to the method in Example 2, the hydrogen yield was 9.5 mmol / g and the purity was 94%.

[0104] Example 3

[0105] This embodiment provides a thermochemical cycle hydrogen production method, comprising the following steps:

[0106] S1. Provide Figure 1 Thermochemical cycle hydrogen production device shown;

[0107] S2, 6 kg high entropy spinel oxygen carrier (Ni 0.2 Co 0.2 Ca 0.2 Cu 0.2 Mg 0.2 )Fe2O4 (prepared by the same method as in Example 1) is placed on a porous distribution plate;

[0108] S3, using biomass powder (specifically pine sawdust powder) with a particle size of 250 μm as fuel, adding the fuel into the combustion chamber through the fuel inlet pipe, and introducing air to allow the fuel to be fully burned in the combustion chamber; the fuel feed rate is 5 kg / h, and the excess air coefficient is 1;

[0109] S4. The pyrolysis gas is introduced into the air inlet ring pipe. The heat generated by the combustion of the fuel heats the reaction tube, so that the pyrolysis gas reacts with the oxygen carrier, captures the lattice oxygen in the oxygen carrier, and the oxygen carrier is reduced. The pyrolysis gas undergoes a reforming reaction to produce synthesis gas, which is discharged from the air outlet ring pipe; the heat generated by the combustion of the fuel heats the reaction tube so that the temperature in the reaction tube is 900°C; the pyrolysis gas includes the following volume fraction components: CO 28%, CH4 15%, C3H8 12%, H2 23%, CO2 22%, and the pyrolysis gas flow rate is 1m 3 / h;

[0110] S5. After the reduction of the oxygen carrier is completed, the introduction of pyrolysis gas is stopped, and water vapor is introduced into the air inlet ring pipe. The water vapor reacts with the reduced oxygen carrier to generate hydrogen, which is discharged from the air outlet ring pipe. The oxygen carrier oxidized by water vapor obtains lattice oxygen to achieve regeneration; the water vapor flow rate is 3.6 kg / h, and the water vapor temperature is 400°C;

[0111] According to the method in Example 3, the hydrogen yield was 14.5 mmol / g and the purity was 85%.

[0112] Example 4

[0113] This embodiment provides a thermochemical cycle hydrogen production method, comprising the following steps:

[0114] S1. Provide Figure 1 Thermochemical cycle hydrogen production device shown;

[0115] S2, 6kg high entropy spinel oxygen carrier (Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Mg 0.2 )Fe2O4 is placed on a porous distribution plate;

[0116] S3, using biomass powder (specifically pine sawdust powder) with a particle size of 250 μm as fuel, adding the fuel into the combustion chamber through the fuel inlet pipe, and introducing air to allow the fuel to be fully burned in the combustion chamber; the fuel feed rate is 5 kg / h, and the excess air coefficient is 1;

[0117] S4. The pyrolysis gas is introduced into the air inlet ring pipe. The heat generated by the combustion of the fuel heats the reaction tube, so that the pyrolysis gas reacts with the oxygen carrier, captures the lattice oxygen in the oxygen carrier, and the oxygen carrier is reduced. The pyrolysis gas undergoes a reforming reaction to produce synthesis gas, which is discharged from the air outlet ring pipe; the heat generated by the combustion of the fuel heats the reaction tube so that the temperature in the reaction tube is 900°C; the pyrolysis gas includes the following volume fraction components: CO 28%, CH4 15%, C3H8 12%, H2 23%, CO2 22%, and the pyrolysis gas flow rate is 1m 3 / h;

[0118] S5. After the reduction of the oxygen carrier is completed, the introduction of pyrolysis gas is stopped, and water vapor is introduced into the air inlet ring pipe. The water vapor reacts with the reduced oxygen carrier to generate hydrogen, which is discharged from the air outlet ring pipe. The oxygen carrier oxidized by water vapor obtains lattice oxygen to achieve regeneration; the water vapor flow rate is 3.6 kg / h, and the water vapor temperature is 400°C;

[0119] Among them, the high entropy spinel oxygen carrier Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Mg 0.2 )The preparation method of Fe2O4 comprises the following steps:

[0120] S21, Cr(NO3)3, Mn(NO3)2, Co(NO3)2, Ni(NO3)2, Mg(NO3)2, Fe(NO3)2 and glycine were mixed, then water was added, and stirred at 105°C for 5h to obtain a gel;

[0121] S2. The gel was heated in a muffle furnace at 110°C for 4 hours, so that it continuously absorbed heat at low temperature and heated up to the ignition point, burned rapidly and released a large amount of smoke, and formed brittle loose powder in the self-propagating combustion. Then, it was cooled to room temperature, taken out, crushed, poured into a crucible, and placed in a muffle furnace again. The temperature was raised to 1200°C at a rate of 5°C / min, calcined for 400 minutes, and then cooled to room temperature at a rate of 10°C / min. It was taken out to obtain (Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Mg 0.2 )Fe2O4;

[0122] Among them, the molar ratio of Cr(NO3)3, Mn(NO3)2, Co(NO3)2, Ni(NO3)2, Mg(NO3)2, Fe(NO3)2, and glycine is 0.2:0.2:0.2:0.2:0.2:2:6;

[0123] The molar ratio of citric acid to water is 1:50.

[0124] According to the method in Example 4, the hydrogen yield was 18.5 mmol / g and the purity was 73%.

[0125] Example 5

[0126] This embodiment provides a thermochemical cycle hydrogen production method, comprising the following steps:

[0127] S1. Provide Figure 1 Thermochemical cycle hydrogen production device shown;

[0128] S2, 6kg high entropy spinel oxygen carrier (Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Mg 0.2 )Fe2O4 (prepared by the same method as in Example 4) is placed on a porous distribution plate;

[0129] S3, using biomass powder (specifically pine sawdust powder) with a particle size of 250 μm as fuel, adding the fuel into the combustion chamber through the fuel inlet pipe, and introducing air to allow the fuel to be fully burned in the combustion chamber; the fuel feed rate is 5 kg / h, and the excess air coefficient is 1;

[0130] S4. The pyrolysis gas is introduced into the air inlet ring pipe. The heat generated by the combustion of the fuel heats the reaction tube, so that the pyrolysis gas reacts with the oxygen carrier, captures the lattice oxygen in the oxygen carrier, and the oxygen carrier is reduced. The pyrolysis gas undergoes a reforming reaction to produce synthesis gas, which is discharged from the air outlet ring pipe; the heat generated by the combustion of the fuel heats the reaction tube so that the temperature in the reaction tube is 900°C; the pyrolysis gas includes the following volume components: CO 28%, CH4 15%, C3H8 12%, H2 23%, CO2 22%, and the pyrolysis gas flow rate is 1m 3 / h;

[0131] S5. After the reduction of the oxygen carrier is completed, the introduction of pyrolysis gas is stopped, and toluene vapor is introduced into the air inlet ring pipe. The toluene vapor reacts with the reduced oxygen carrier to produce hydrogen, which is discharged from the air outlet ring pipe. The oxygen carrier after oxidation of the toluene vapor obtains lattice oxygen to achieve regeneration; the toluene vapor flow rate is 3.6 kg / h, and the toluene vapor temperature is 400°C.

[0132] According to the method in Example 5, the hydrogen yield was 22.8 mmol / g and the purity was 63%.

[0133] Example 6

[0134] This embodiment provides a thermochemical cycle hydrogen production method, comprising the following steps:

[0135] S1. Provide Figure 1 Thermochemical cycle hydrogen production device shown;

[0136] S2, 6kg high entropy spinel oxygen carrier (Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Mg 0.2 )Fe2O4 (prepared by the same method as in Example 4) is placed on a porous distribution plate;

[0137] S3, using biomass powder (specifically pine sawdust powder) with a particle size of 250 μm as fuel, adding the fuel into the combustion chamber through the fuel inlet pipe, and introducing air to allow the fuel to be fully burned in the combustion chamber; the fuel feed rate is 2.5 kg / h, and the excess air coefficient is 1;

[0138] S4. The pyrolysis gas is introduced into the air inlet ring pipe. The heat generated by the combustion of the fuel heats the reaction tube, so that the pyrolysis gas reacts with the oxygen carrier, captures the lattice oxygen in the oxygen carrier, and the oxygen carrier is reduced. The pyrolysis gas undergoes a reforming reaction to produce synthesis gas, which is discharged from the air outlet ring pipe; the heat generated by the combustion of the fuel heats the reaction tube so that the temperature in the reaction tube is 800°C; the pyrolysis gas includes the following volume components: CO 28%, CH4 15%, C3H8 12%, H2 23%, CO2 22%, and the pyrolysis gas flow rate is 1m 3 / h;

[0139] S5. After the reduction of the oxygen carrier is completed, the introduction of pyrolysis gas is stopped, and toluene vapor is introduced into the air inlet ring pipe. The toluene vapor reacts with the reduced oxygen carrier to produce hydrogen, which is discharged from the air outlet ring pipe. The oxygen carrier after oxidation of the toluene vapor obtains lattice oxygen to achieve regeneration; the toluene vapor flow rate is 3.6 kg / h, and the toluene vapor temperature is 400°C.

[0140] According to the method in Example 6, the hydrogen yield was 16.8 mmol / g and the purity was 86%.

[0141] Example 7

[0142] This embodiment provides a thermochemical cycle hydrogen production method, comprising the following steps:

[0143] S1. Provide Figure 1 Thermochemical cycle hydrogen production device shown;

[0144] S2, 6kg high entropy spinel oxygen carrier (Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Mg 0.2 )Fe 2.0 O4 (prepared as in Example 4) is placed on a porous distribution plate;

[0145] S3, using biomass powder (specifically pine sawdust powder) with a particle size of 250 μm as fuel, adding the fuel into the combustion chamber through the fuel inlet pipe, and introducing air to allow the fuel to be fully burned in the combustion chamber; the fuel feed rate is 2.5 kg / h, and the excess air coefficient is 1;

[0146] S4. The pyrolysis gas is introduced into the air inlet ring pipe. The heat generated by the combustion of the fuel heats the reaction tube, so that the pyrolysis gas reacts with the oxygen carrier, captures the lattice oxygen in the oxygen carrier, and the oxygen carrier is reduced. The pyrolysis gas undergoes a reforming reaction to produce synthesis gas, which is discharged from the air outlet ring pipe; the heat generated by the combustion of the fuel heats the reaction tube so that the temperature in the reaction tube is 700°C; the pyrolysis gas includes the following volume components: CO 28%, CH4 15%, C3H8 12%, H2 23%, CO2 22%, and the pyrolysis gas flow rate is 1m 3 / h;

[0147] S5. After the reduction of the oxygen carrier is completed, the introduction of pyrolysis gas is stopped, and toluene vapor is introduced into the air inlet ring pipe. The toluene vapor reacts with the reduced oxygen carrier to produce hydrogen, which is discharged from the air outlet ring pipe. The oxygen carrier after oxidation of the toluene vapor obtains lattice oxygen to achieve regeneration; the toluene vapor flow rate is 3.6 kg / h, and the toluene vapor temperature is 400°C.

[0148] According to the method in Example 7, the hydrogen yield was 8.6 mmol / g and the purity was 98%.

[0149] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermochemical cycle hydrogen production method, characterized in that: The following steps are involved: Provide thermochemical cycle hydrogen production equipment; The thermochemical cycle hydrogen production device comprises: A shell body, which is hollow inside, a combustion chamber is formed at one end of the shell body, and a heating chamber is formed at the other end of the shell body, the combustion chamber is communicated with the heating chamber, and a fuel inlet pipe is opened on the shell body corresponding to the combustion chamber; An intake ring pipe is sleeved on the outer periphery of the shell corresponding to the combustion chamber; A plurality of reaction tubes are located in the heating chamber, one end of each reaction tube extends downward and passes through the shell to communicate with the air intake ring tube; An air outlet ring pipe is located outside the shell, and the other end of the reaction tube extends upward and passes through the shell to communicate with the air outlet ring pipe; A porous distribution plate is provided in the reaction tube for carrying oxygen carriers; placing an oxygen carrier in a reaction tube; Add fuel into the combustion chamber through the fuel inlet pipe, and introduce air to enable the fuel to be fully burned in the combustion chamber; The pyrolysis gas is introduced into the air inlet ring pipe, and the heat generated by the combustion of the fuel heats the reaction tube, so that the pyrolysis gas reacts with the oxygen carrier, and the lattice oxygen in the oxygen carrier is captured, and the oxygen carrier is reduced, and the pyrolysis gas undergoes a reforming reaction to produce synthesis gas, which is discharged from the air outlet ring pipe; After the oxygen carrier is reduced, the introduction of pyrolysis gas is stopped, and steam is introduced into the air inlet ring pipe. The steam reacts with the reduced oxygen carrier to generate hydrogen, which is discharged from the air outlet ring pipe. The oxygen carrier oxidized by steam obtains lattice oxygen to achieve regeneration. The oxygen carrier is a high entropy spinel oxide; The high entropy spinel oxide is (Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Mg 0.2 )Fe2O4; The pyrolysis gas includes the following components by volume: CO 23-33%, CH4 10-20%, C n H m 7~17%, H218~28%, CO217~27%, where m and n are both positive integers, 2≤n≤4, 4≤m≤10; The fuel is biomass powder; The heat generated by the combustion of the fuel heats the reaction tube so that the temperature inside the reaction tube reaches 800°C; The steam is introduced into the air inlet ring pipe, wherein the steam temperature is 400°C; The steam is toluene steam; The high entropy spinel oxygen carrier (Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Mg 0.2 )The preparation method of Fe2O4 comprises the following steps: S1. Mix Cr(NO3)3, Mn(NO3)2, Co(NO3)2, Ni(NO3)2, Mg(NO3)2, Fe(NO3)2 and glycine, then add water and stir at 105°C for 5h to obtain a gel; S2. The gel was heated in a muffle furnace at 110°C for 4 hours, so that it continuously absorbed heat at low temperature and heated up to the ignition point, burned rapidly and released a large amount of smoke, and formed brittle loose powder in the self-propagating combustion. Then, it was cooled to room temperature, taken out, crushed, poured into a crucible, and placed in a muffle furnace again. The temperature was raised to 1200°C at a rate of 5°C / min, calcined for 400 minutes, and then cooled to room temperature at a rate of 10°C / min. It was taken out to obtain (Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Mg 0.2 )Fe2O4; Among them, the molar ratio of Cr(NO3)3, Mn(NO3)2, Co(NO3)2, Ni(NO3)2, Mg(NO3)2, Fe(NO3)2, and glycine is 0.2:0.2:0.2:0.2:0.2:2:6; The molar ratio of glycine to water is 1:

50.

2. The thermochemical cycle hydrogen production method according to claim 1, characterized in that: A smoke exhaust pipe is arranged on the shell body corresponding to the heating chamber, and the air outlet ring pipe is sleeved on the outer periphery of the smoke exhaust pipe.

3. The thermochemical cycle hydrogen production method according to claim 1, characterized in that: An intake pipe is provided at the end of the intake ring pipe, the reaction tube is communicated with the intake pipe, and a first valve is provided in the intake pipe.

4. The thermochemical cycle hydrogen production method according to claim 1, characterized in that: An air outlet pipe is provided at the end of the air outlet ring pipe, the reaction tube is connected to the air outlet pipe, and a second valve is provided in the air outlet pipe.

5. The thermochemical cycle hydrogen production method according to claim 1, characterized in that: A temperature and pressure detector is provided on the top of the reaction tube to monitor the temperature and pressure in the reaction tube.

6. The thermochemical cycle hydrogen production method according to claim 1, characterized in that: A heat-insulating layer is also arranged outside the shell, and an oxygen carrier adding port is arranged on the part of the reaction tube outside the shell.

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