Method and device for hydrogen production by thermochemical decomposition of water using cobalt oxide and hydroxide
The method of producing hydrogen by thermochemical cycle decomposition of water using cobalt oxide and hydroxide employs a multi-step reaction, which solves the problems of high reaction temperature, difficulty in separating hydrogen and oxygen, and high energy consumption in traditional pyrolysis methods. It achieves the stepwise production of high-purity hydrogen and oxygen, extends reactor life, reduces energy consumption, and realizes the preparation of clean fuel with zero carbon emissions.
Patent Information
- Application Number
- CN202310890544.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-19
- Publication Date
- 2026-02-13
- Estimated Expiration
- 2043-07-19
AI Technical Summary
Existing methods for producing hydrogen from water pyrolysis have problems such as excessively high reaction temperatures, difficulty in separating hydrogen and oxygen mixtures, high energy consumption, and short reactor lifespan. The service life and operational stability of the circulating oxygen carrier in the traditional two-step high-temperature water pyrolysis method are insufficient.
A thermochemical cycle method for water decomposition using cobalt oxide and hydroxide is employed. This method involves a multi-step reaction, including the pyrolysis of high-valence cobalt oxide to generate low-valence cobalt oxide and oxygen, the reaction of low-valence cobalt oxide and hydroxide to generate cobaltate intermediates and hydrogen, and finally the reaction of the cobaltate intermediates with water to generate high-valence cobalt oxide and hydroxide. This method reduces the reaction temperature and achieves the stepwise production of high-purity hydrogen and oxygen.
It achieves stepwise production of hydrogen and oxygen with low energy consumption and high purity, extends the service life of the reactor, reduces the energy consumption of gas separation and purification, improves atom utilization, and realizes the preparation of clean fuel with zero carbon emissions.
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Figure CN116969418B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of clean energy production and hydrogen energy technology, and in particular to a method and device for thermally decomposing water into hydrogen by using cobalt oxide and hydroxide in a thermochemical cycle. BACKGROUND
[0002] The progress of society cannot be separated from the development of energy. Compared with fossil energy, which currently occupies a dominant position in China's energy structure, hydrogen energy has attracted much attention as a new type of energy due to its high energy density, simple composition, and clean and pollution-free combustion products.
[0003] However, in existing hydrogen production processes, the purity of hydrogen is often low. For example, in the case of methane wet reforming and methanol reforming, which are relatively well-developed technologies, the hydrogen produced in these processes is often in the form of syngas, making it difficult to produce high-purity hydrogen. Therefore, how to achieve efficient and clean continuous production of high-purity hydrogen has become a major problem limiting the large-scale application of hydrogen.
[0004] Thermal decomposition of water is an important part of hydrogen production technology. However, conventional methods of directly decomposing water have many problems, such as extremely high reaction temperatures (> 3000℃), difficulty in separating the produced hydrogen and oxygen, and high overall energy consumption. Therefore, the thermochemical cycle hydrogen production method, which uses a circulating oxygen carrier as a medium, has become a research hotspot. The thermochemical cycle hydrogen production method divides the conventional single-step thermal decomposition reaction into two or more steps, and through the oxidation and reduction reactions of the oxygen carrier, the reaction temperature is reduced, thereby solving many problems existing in conventional direct thermal decomposition.
[0005] However, the highest reaction temperature of the two-step high-temperature thermal decomposition of water currently in common use is close to 1500℃, and the service life and operational stability of the reactor and the circulating oxygen carrier are greatly tested during the cycle. The low oxygen partial pressure environment required for the reaction further increases the power consumption of the system. Therefore, a multi-step water decomposition method for hydrogen production with lower energy consumption, better technical and economic performance, and better cycle performance is urgently needed. SUMMARY
[0006] In view of the above problems, the present application provides a method and device for thermally decomposing water into hydrogen by using cobalt oxide and hydroxide in a thermochemical cycle, to solve the above technical problems.
[0007] One aspect of the present application provides a method for hydrogen production by thermal-chemical cycle decomposition of water using cobalt oxide and hydroxide, comprising: pyrolyzing high-valence cobalt oxide to generate low-valence cobalt oxide and oxygen under a first temperature condition; mixing the low-valence cobalt oxide with a hydroxide to generate a cobaltate intermediate and hydrogen under a second temperature condition; introducing water into a reaction system of the cobaltate intermediate and the hydrogen to make the cobaltate intermediate, the hydrogen and the water react, and generate the high-valence cobalt oxide and the hydroxide under a third temperature condition.
[0008] Optionally, the high-valence cobalt oxide is Co3O4, the low-valence cobalt oxide is CoO, and the cobaltate intermediate is XCoO2, wherein X is a metal cation in the hydroxide.
[0009] Optionally, the first temperature is 850-950℃, the second temperature is 750-850℃, and the third temperature is 500-700℃.
[0010] Optionally, the first temperature, the second temperature and the third temperature are provided by an external energy source.
[0011] Optionally, the method further comprises: cooling and collecting the oxygen under the first temperature condition; and cooling and collecting the hydrogen under the second temperature condition.
[0012] Optionally, the method further comprises: cooling the high-valence cobalt oxide and the hydroxide after generating the high-valence cobalt oxide and the hydroxide; and separating the high-valence cobalt oxide and the hydroxide.
[0013] Another aspect of the present application provides a device for hydrogen production by thermal-chemical cycle decomposition of water using cobalt oxide and hydroxide, comprising: a pyrolysis reactor for pyrolyzing high-valence cobalt oxide to generate low-valence cobalt oxide and oxygen under a first temperature condition; a hydrogen production reactor for mixing the low-valence cobalt oxide with a hydroxide to generate a cobaltate intermediate and hydrogen under a second temperature condition; and a cycle regeneration reactor for introducing water into a reaction system of the cobaltate intermediate and the hydrogen to make the cobaltate intermediate, the hydrogen and the water react, and generate the high-valence cobalt oxide and the hydroxide under a third temperature condition.
[0014] Optionally, a first cooler is used to cool and collect the oxygen; and a second cooler is used to cool and collect the hydrogen.
[0015] Optionally, further comprising: a third cooler, configured to cool the high-valence cobalt oxide and the hydroxide after the high-valence cobalt oxide and the hydroxide are generated; and a solid-phase separator, configured to separate the high-valence cobalt oxide and the hydroxide, and input the separated high-valence cobalt oxide into the pyrogenic oxydo-reduction reactor and input the separated hydroxide into the hydrogen production reactor.
[0016] The above-mentioned at least one technical solution adopted in the embodiments of the present application can achieve the following beneficial effects:
[0017] The cobalt oxide and hydroxide thermochemical cyclic water-splitting hydrogen production method disclosed by the present application can realize the step-by-step production of high-purity oxygen and hydrogen, and reduce the energy consumption required for gas separation and purification in the overall process.
[0018] The cobalt oxide and hydroxide thermochemical cyclic water-splitting hydrogen production method disclosed by the present application can realize the step-by-step production of high-purity oxygen and hydrogen, and reduce the energy consumption required for gas separation and purification in the overall process.
[0019] The cobalt oxide and hydroxide thermochemical cyclic water-splitting hydrogen production method disclosed by the present application has a lower overall reaction temperature, effectively alleviates or avoids the problems of short service life and poor stability of the reactor and the circulating carrier, and large energy loss caused by excessively high reaction temperature in the traditional thermochemical cycle.
[0020] The cobalt oxide and hydroxide thermochemical cyclic water-splitting hydrogen production method disclosed by the present application can realize water (H2O) as the only material input of the cyclic system, greatly improving the atomic utilization rate.
[0021] The cobalt oxide and hydroxide thermochemical cyclic water-splitting hydrogen production method disclosed by the present application has a lower overall reaction temperature, effectively alleviates or avoids the problems of short service life and poor stability of the reactor and the circulating carrier, and large energy loss caused by excessively high reaction temperature in the traditional thermochemical cycle. BRIEF DESCRIPTION OF DRAWINGS
[0022] For a more complete understanding of the present application and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings in which:
[0023] Figure 1 Fig. 1 schematically shows a cobalt oxide and hydroxide thermochemical cyclic water-splitting hydrogen production method provided by an embodiment of the present application;
[0024] Figure 2Fig. 1 schematically shows a first example of a method for producing hydrogen by thermally decomposing water using a cobalt oxide and a hydroxide according to an embodiment of the present application;
[0025] Figure 3 Fig. 2 schematically shows a second example of a method for producing hydrogen by thermally decomposing water using a cobalt oxide and a hydroxide according to an embodiment of the present application;
[0026] Figure 4 Fig. 3 schematically shows a third example of a method for producing hydrogen by thermally decomposing water using a cobalt oxide and a hydroxide according to an embodiment of the present application. DETAILED DESCRIPTION
[0027] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. It should be understood, however, that the description which follows is merely exemplary and is not intended to limit the scope of the application. In the following detailed description of the embodiments of the present application, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without these specific details. In other instances, well-known structures and functions have not been described in detail in order to avoid obscuring aspects of the present application.
[0028] The terms used herein are merely used to describe specific embodiments and are not intended to limit the present application. The terms "include", "comprise" and the like as used herein specify the presence of stated features, steps, operations, elements, and / or components but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.
[0029] All terms used herein, including technical and scientific terms, have the same meanings as those generally understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having meanings consistent with the context of the present specification, and should not be interpreted in an idealized or overly formal way.
[0030] As shown in Fig. 1, the present application provides a method for producing hydrogen by thermally decomposing water using a cobalt oxide and a hydroxide, which includes S1 to S3. Figure 1
[0031] S1, pyrolyzing a high-valence cobalt oxide at a first temperature condition to produce a low-valence cobalt oxide and oxygen.
[0032] S2, mixing the low-valence cobalt oxide and a hydroxide at a second temperature condition to produce a cobaltate intermediate and hydrogen.
[0033] S3, introducing water into a reaction system of the cobaltate intermediate and the hydrogen at a third temperature condition to produce a high-valence cobalt oxide and a hydroxide by reacting the cobaltate intermediate, the hydrogen, and the water in the reaction system.
[0034] The method for preparing H2 by using cobalt oxide and hydroxide to realize multi-step thermochemical decomposition of H2O, mainly includes three steps of releasing oxygen by decomposition of high-valence cobalt oxide, releasing hydrogen by reaction of low-valence cobalt oxide and hydroxide, and realizing regeneration of hydroxide and high-valence cobalt oxide by introducing water, and the total reaction is the reaction of H2O decomposition to generate H2 and O2.
[0035] In the embodiment, the high-valence cobalt oxide is Co3O4, the low-valence cobalt oxide is CoO, and the cobaltate intermediate product is XCoO2, wherein X is a metal cation in the hydroxide.
[0036] Alternatively, the hydroxide is a metal hydroxide represented by sodium hydroxide or potassium hydroxide.
[0037] In the embodiment, the first temperature is 850-950℃, the second temperature is 750-850℃, and the third temperature is 500-700℃. The first temperature, the second temperature and the third temperature are provided by an external energy source.
[0038] On the basis of the above conditions, the method for preparing H2 by using cobalt oxide and hydroxide to realize thermochemical cyclic decomposition of water of the embodiment of the application specifically includes the following steps.
[0039] In the first step, cobalt trioxide (Co3O4) is heated to 850-950℃, and at the temperature range, the reactants are pyrolyzed to generate cobalt monoxide (CoO) and oxygen (O2), and the reaction equation involved in the step is as follows:
[0040] 2Co3O4→6CoO+O2
[0041] In the reaction process of the first step, oxygen can be cooled and collected.
[0042] In the second step, the generated cobalt monoxide (CoO) is mixed with hydroxide (XOH), and at the temperature condition of 750-850℃, the two react to generate cobaltate (XCoO2, X is a metal cation in the hydroxide) and release hydrogen (H2). The reaction equation involved in the step is as follows:
[0043] 2CoO+2XOH→2XCOO2+H2
[0044] In the reaction process of the second step, hydrogen can be cooled and collected.
[0045] In the third step, water (H2O) is introduced into the hydrogen (H2) atmosphere generated in the second step to react with the cobaltate (XCoO2) generated in the second step. The reaction temperature is 500-700℃, and cobalt trioxide (Co3O4) and hydroxide (XOH) are generated to realize regeneration of the circulating material. The reaction equation involved in the step is as follows:
[0046] H2+2H2O+6XCoO2→2Co3O4+6XOH
[0047] The hydrogen involved in the third step reaction can come from the residual system in the second step or the gas not separated from the system in time in the second step, so that no additional gas needs to be introduced into the system during the reaction. After the generation of the high-valence cobalt oxide and the hydroxide, the high-valence cobalt oxide and the hydroxide are cooled; and the high-valence cobalt oxide and the hydroxide are separated to participate in the respective reactions of the next cycle.
[0048] In the above method, the heat source required for the first step and the second step reaction is widely available, which can be provided by combustion of fossil energy (natural gas, coal, petroleum, etc.), or renewable energy (geothermal energy, biomass energy combustion, concentrated solar energy, etc.) can be used to drive the reaction. The total reaction of the above three-step reaction is the decomposition of water, and the reaction equation is: 2H2O→2H2+O2.
[0049] In the above method, water is input into the system as the only consumed raw material, and solid materials (such as hydroxide (XOH) and cobalt trioxide (Co3O4)) can be regenerated through the three-step reaction cycle.
[0050] Another aspect of the present application also provides a cobalt oxide and hydroxide thermochemical cycle water decomposition hydrogen production device, comprising: a pyrolysis oxygen release reactor 01, a first cooler 02, a hydrogen production reactor 03, a second cooler 04, a cycle regeneration reactor 05, a third cooler 06 and a solid phase separator 07.
[0051] The pyrolysis oxygen release reactor 01 is used to pyrolyze the high-valence cobalt oxide under the first temperature condition to generate low-valence cobalt oxide and oxygen.
[0052] The hydrogen production reactor 03 is used to mix the low-valence cobalt oxide and the hydroxide to generate cobalt salt intermediate products and hydrogen under the second temperature condition.
[0053] The cycle regeneration reactor 05 is used to introduce water into the reaction system of the cobalt salt intermediate products and hydrogen under the third temperature condition, so that the cobalt salt intermediate products, hydrogen and water in the reaction system react to generate high-valence cobalt oxide and hydroxide.
[0054] The first cooler 02 is used to cool and collect oxygen.
[0055] The second cooler 04 is used to cool and collect hydrogen.
[0056] The third cooler 06 is used to cool the high-valence cobalt oxide and the hydroxide after the generation of the high-valence cobalt oxide and the hydroxide.
[0057] The solid phase separator 07 is used to separate the high valence cobalt oxide and hydroxide, and the separated high valence cobalt oxide is input into the pyrogenic oxygen production reactor 01, and the separated hydroxide is input into the hydrogen production reactor 03.
[0058] The method and device for thermally decomposing water to produce hydrogen by using cobalt oxide and hydroxide provided by the present disclosure will be described in detail below in combination with specific examples.
[0059] Example 1
[0060] In this embodiment, sodium hydroxide (NaOH) and cobalt oxide are used as the working medium to realize three-step water (H2O) decomposition to produce hydrogen (H2). The reaction equations are as follows:
[0061] Pyrogenic oxygen production: 2Co3O4→6CoO+O2
[0062] Hydrogen production: 2CoO+2NaOH→2NaCoO2+H2
[0063] Regeneration: H2+2H2O+6NaCoO2→6NaOH+2Co3O4
[0064] Figure 2 The specific flow chart of this embodiment is shown.
[0065] (1) Cobalt oxide (Co3O4) is filled into the pyrogenic oxygen production reactor 01, and the reaction temperature is set to 850-950℃ under normal pressure, and oxygen (O2) and cobalt monoxide (CoO) are generated.
[0066] (2) The O2 generated in step (1) is separated from the system and collected after being treated by the first cooler 02.
[0067] (3) The CoO generated in step (1) and the sodium hydroxide (NaOH) separated by the solid phase separator 07 are introduced into the hydrogen production reactor 03, and the reaction temperature is set to 750-850℃, and sodium cobaltate (NaCoO2) and hydrogen (H2) are generated.
[0068] (4) The H2 obtained in step (3) is treated by the second cooler 04 and collected; part of the H2 is introduced into the regeneration reactor 05 after being cooled.
[0069] (5) The NaCoO2 obtained in step (3) and part of the H2 refluxed in the second cooler 04 are introduced into the regeneration reactor 05, and react with the water vapor (H2O) introduced from outside, and the reaction temperature is set to 500-700℃, and NaOH and Co3O4 are generated, realizing the regeneration of the reaction raw materials.
[0070] (6) The NaOH and Co3O4 generated in step (5) are treated by the third cooler 06 and the solid phase separator 07, so as to separate the two substances. The separated NaOH is recycled to the hydrogen production reactor 03, and the separated Co3O4 is recycled to the pyrogenic oxygen reactor 01, and participates in the respective reactions in the next cycle.
[0071] Example Two
[0072] In this example, potassium hydroxide (KOH) and cobalt oxide are used as the circulating working substance, and three-step water (H2O) decomposition is used to produce hydrogen (H2). The reaction equations are as follows:
[0073] Pyrogenic oxygen: 2Co3O4→6CoO+O2
[0074] Hydrogen production: 2CoO+2KOH→2KCoO2+H2
[0075] Circulating regeneration: H2+2H2O+6KCoO2→6KOH+2Co3O4
[0076] As shown in Figure 3 the specific flow chart of this example.
[0077] (1) Cobalt oxide (Co3O4) is filled into the pyrogenic oxygen reactor 01, and the reaction temperature is set to 850-950°C under normal pressure. Oxygen (O2) and cobalt monoxide (CoO) are generated by the reaction.
[0078] (2) The O2 generated in step (1) is separated from the system and collected after being treated by the first cooler 02.
[0079] (3) The CoO generated in step (1) and the potassium hydroxide (KOH) separated from the solid phase separator 07 are introduced into the hydrogen production reactor 03, and the reaction temperature is set to 750-850°C. Potassium cobaltate (KCoO2) and hydrogen (H2) are generated by the reaction.
[0080] (4) The H2 obtained in step (3) is treated by the second cooler 04 and collected. Part of the H2 is introduced into the circulating regeneration reactor 05 after being cooled.
[0081] (5) The KCoO2 obtained in step (3) and part of the H2 refluxed in the second cooler 04 are introduced into the circulating regeneration reactor 05, and react with the water vapor (H2O) introduced from outside. The reaction temperature is set to 500-700°C. KOH and Co3O4 are generated by the reaction, and the circulating regeneration of the reaction raw materials is realized.
[0082] (6) The KOH and Co3O4 generated in step (5) are treated by the third cooler 06 and the solid phase separator 07, so that the two substances are separated. The separated KOH is recycled to the hydrogen production reactor 03, and the separated Co3O4 is recycled to the pyrogenic oxygen production reactor 01, and participates in the respective reactions in the next cycle.
[0083] Example Three
[0084] The method for decomposing water into hydrogen by the three-step cycle of cobalt oxide and hydroxide according to the present application is composed of two endothermic reactions and one exothermic reaction, wherein the pyrogenic oxygen production reaction and the hydrogen production reaction are endothermic reactions, and the cycle regeneration reaction is an exothermic reaction. The driving of the endothermic reactions requires an external heat source to provide heat, which can come from conventional fuel combustion (coal combustion, natural gas combustion, biomass combustion, etc.), electric heating or renewable energy heating (solar energy, geothermal energy, etc.). Based on the method for producing fuel by the multi-step thermochemical cycle of cobalt oxide and hydroxide, and combined with the light concentration solar heat collection to provide heat for the cycle reaction, the present example gives an implementation scheme of the multi-step thermochemical cycle of cobalt oxide and hydroxide driven by light concentration solar energy.
[0085] In this example, the sunlight is concentrated by using a tower type light concentration solar energy device or a disc type light concentration solar energy device, heat energy is utilized, and the endothermic reactions in the cycle fuel production are driven. The specific process is as follows Figure 4 as shown.
[0086] (1) The light concentration solar energy device is used to concentrate heat energy, and drive the pyrogenic oxygen production reactor 01. The cobalt oxide (Co3O4) filled in the reactor 01 reacts at 850-950℃ to generate oxygen (O2) and cobalt monoxide (CoO).
[0087] (2) The O2 generated in step (1) is separated from the system, treated by the first cooler 02, and collected.
[0088] (3) The light concentration solar energy device is used to concentrate heat energy, and drive the hydrogen production reactor 03. The CoO generated in step (1) and the sodium hydroxide (NaOH) separated by the solid phase separator 07 are put into the hydrogen production reactor 03, and the reaction temperature is set to 750-850℃. Sodium cobaltate (NaCoO2) and hydrogen (H2) are generated by the reaction.
[0089] (4) The H2 obtained in step (3) is treated by the second cooler 04, and collected. Part of the H2 is collected after cooling and enters the cycle regeneration reactor 05.
[0090] (5) The NaCoO2 obtained in step (3) and part of the hydrogen gas flowing back in the second cooler 04 enter the circulating regeneration reactor 05, and react with the hydrogen gas (H2) introduced from outside, with the reaction temperature set at 500-700 DEG C, to generate NaOH and Co3O4, realizing the circulation regeneration of the reaction raw materials.
[0091] (6) The NaOH and Co3O4 generated in the circulating regeneration reactor 05 in step (5) are treated by the third cooler 06 and the solid-phase separator 07, realizing the separation of the two substances. The separated NaOH is circulated back to the hydrogen gas preparation reactor 03, and the separated Co3O4 is circulated back to the pyrogenic oxygen production reactor 01, and participates in the respective reactions in the next cycle.
[0092] Compared with the traditional single-cycle system, the method for preparing hydrogen by thermally decomposing water through the chemical cycle of cobalt oxide and hydroxide innovatively proposes a new cycle system coupled by cobalt oxide and hydroxide. The reactants involved in the cycle reaction are stable in nature and low in corrosion, which can ensure the long-time operation of the system. The high-purity oxygen and hydrogen can be generated step by step, which reduces the energy consumption required for gas separation and purification in the overall process. The overall reaction temperature is low, which effectively alleviates and avoids the problems of short service life and poor stability of the reactor and circulating carrier and large energy loss caused by high reaction temperature in the traditional thermochemical cycle. The hydrogen (H2) consumed in the third step can come from part of the hydrogen product that does not timely separate from the system in the second step. In principle, the method can realize water (H2O) as the only material input of the cycle system, greatly improving the atomic utilization rate. The total reaction is a water pyrolysis reaction, realizing the preparation of clean fuel with zero carbon emission. By coupling other renewable energy as the energy input of the system, the overall energy saving of the system can be further improved.
[0093] Those skilled in the art can understand that the features described in various embodiments and / or claims of the present application can be combined or / and integrated, even if such combinations or integrations are not explicitly described in the present application. In particular, the features described in various embodiments and / or claims of the present application can be combined and / or integrated in various combinations, without departing from the spirit and teachings of the present application. All these combinations and / or integrations fall within the scope of the present application.
[0094] Although the present application has been shown and described with respect to certain exemplary embodiments thereof, it should be understood by those skilled in the art that various changes in form and detail can be made therein without departing from the spirit and scope of the application as defined by the appended claims and their equivalents. Therefore, the scope of the present application should not be limited to the above-described embodiments, but should be determined by the appended claims only, and their equivalents.
Claims
1. A method for the thermochemical decomposition of water into hydrogen by a cobalt oxide and hydroxide cycle, characterized in that, The method comprises: pyrolyzing cobalt oxide of high valence under a first temperature condition to generate cobalt oxide of low valence and oxygen; reacting the cobalt oxide of low valence with hydroxide under a second temperature condition to generate cobaltate intermediate and hydrogen; circulating water into the reaction system of the cobaltate intermediate and the hydrogen under a third temperature condition to make the cobaltate intermediate, the hydrogen and the water in the reaction system react to generate the cobalt oxide of high valence and the hydroxide; the cobalt oxide of high valence is Co3O4, the cobalt oxide of low valence is CoO, and the cobaltate intermediate is XCoO2, wherein X is metal cation in the hydroxide; the first temperature is 850-950℃, the second temperature is 750-850℃, and the third temperature is 500-700℃.
2. The method of claim 1, wherein, The first temperature, the second temperature and the third temperature are provided by external energy source.
3. The method of claim 1, wherein, The method comprises: cooling and collecting the oxygen under the first temperature condition; cooling and collecting the hydrogen under the second temperature condition.
4. The method of claim 1, wherein, The method further comprises: cooling the cobalt oxide of high valence and the hydroxide after the cobalt oxide of high valence and the hydroxide are generated; separating the cobalt oxide of high valence and the hydroxide.
5. A device for the thermochemical decomposition of water into hydrogen by a cobalt oxide and hydroxide cycle, characterized in that it comprises: The device comprises: a pyrolysis oxygen generation reactor (01) for pyrolyzing cobalt oxide of high valence under a first temperature condition to generate cobalt oxide of low valence and oxygen; a hydrogen generation reactor (03) for reacting the cobalt oxide of low valence with hydroxide under a second temperature condition to generate cobaltate intermediate and hydrogen; a circulating regeneration reactor (05) for circulating water into the reaction system of the cobaltate intermediate and the hydrogen under a third temperature condition to make the cobaltate intermediate, the hydrogen and the water in the reaction system react to generate the cobalt oxide of high valence and the hydroxide; the cobalt oxide of high valence is Co3O4, the cobalt oxide of low valence is CoO, and the cobaltate intermediate is XCoO2, wherein X is metal cation in the hydroxide; the first temperature is 850-950℃, the second temperature is 750-850℃, and the third temperature is 500-700℃.
6. The apparatus of claim 5, wherein, The device further comprises a first cooler (02) for cooling and collecting the oxygen; a second cooler (04) for cooling and collecting the hydrogen.
7. The apparatus of claim 5, wherein, The device further comprises: a third cooler (06) for cooling the cobalt oxide of high valence and the hydroxide after the cobalt oxide of high valence and the hydroxide are generated; a solid phase separator (07) for separating the cobalt oxide of high valence and the hydroxide, inputting the separated cobalt oxide of high valence into the pyrolysis oxygen generation reactor (01), and inputting the separated hydroxide into the hydrogen generation reactor (03).