Methane production equipment system and methane production method using ocean energy and resources

Abstract

The invention relates to a methane production equipment system and a methane production method using ocean energy and resources. The methane production equipment system comprises an offshore power generation device, an electrolytic hydrogen production device, a seawater carbon capture device and a methane synthesis device. The electrolytic hydrogen production device, the seawater carbon capture device and the methane synthesis device are electrically connected with the offshore power generation device respectively. The offshore power generation device supplies power to the electrolytic hydrogen production device, the seawater carbon capture device and the methane synthesis device; the electrolytic hydrogen production device is used for producing hydrogen and supplying the hydrogen to the methane synthesis device; the seawater carbon capture device is used for producing carbon dioxide and supplying the carbon dioxide to the methane synthesis device; the methane synthesis device uses hydrogen and carbon dioxide to produce methane. According to the methane production equipment system, offshore power generation, offshore hydrogen production, seawater carbon capture, green methane and the like are organically combined, and a technical path is provided for high-quality and large-scale development of offshore wind power resources.

Description

Technical Field

[0001] The present invention relates to the field of new energy technology, and in particular to a methane production equipment system and a methane production method utilizing marine energy and resources. Background Art

[0002] As an important part of clean energy, marine new energy such as offshore wind power has attracted widespread attention due to its rich resources and huge development potential. However, the development and utilization of marine new energy faces multiple challenges, including strong fluctuations in power generation, long offshore distances, and high power transmission costs, which make it difficult to utilize. Summary of the invention

[0003] Based on this, it is necessary to provide a methane production equipment system and a methane production method that utilizes marine energy and resources to solve the problem of difficulties in utilizing offshore wind power.

[0004] One of the purposes of the present invention is to provide a methane production equipment system utilizing marine energy and resources, the scheme is as follows:

[0005] A methane production equipment system utilizing marine energy and resources, including an offshore power generation device, an electrolytic hydrogen production device, a seawater carbon capture device, and a methane synthesis device;

[0006] The electrolysis hydrogen production device, the seawater carbon capture device and the methane synthesis device are electrically connected to the offshore power generation device respectively, and the offshore power generation device is used to supply power to the electrolysis hydrogen production device, the seawater carbon capture device and the methane synthesis device;

[0007] The electrolytic hydrogen production device is used to produce hydrogen and supply hydrogen to the methane synthesis device; the seawater carbon capture device is used to produce carbon dioxide and supply carbon dioxide to the methane synthesis device; the methane synthesis device is used to produce methane using the hydrogen and the carbon dioxide.

[0008] In one embodiment, the offshore power generation device includes a wind turbine.

[0009] In one embodiment, the offshore power generation device also includes an AC-DC rectifier, one end of the AC-DC rectifier is connected to the wind turbine, and the other end is connected to the electrolysis hydrogen production device. The AC-DC rectifier is used to convert the alternating current generated by the wind turbine into direct current, and supply it to the electrolysis hydrogen production device after rectification and filtering.

[0010] In one embodiment, the offshore power generation device further includes an electrochemical energy storage system, which is connected to the wind turbine generator and is used to store surplus electrical energy.

[0011] In one embodiment, the electrolytic hydrogen production device includes a pure water storage tank, an electrolyzer, a first compressor and a hydrogen storage tank connected in sequence.

[0012] In one embodiment, the electrolyzer includes an alkaline electrolyzer and a proton exchange membrane electrolyzer.

[0013] In one embodiment, the seawater carbon capture device includes an electrochemical reactor, a second compressor and a carbon dioxide storage tank connected in sequence.

[0014] In one embodiment, the methane synthesis device includes a methane fixed bed reactor, a methane cooler, a methane separator and a methane storage tank connected in sequence. In one embodiment, the methane production equipment system also includes a seawater desalination device, and the offshore power generation device is also used to supply power to the seawater desalination device, and the seawater desalination device is used to produce desalinated water and supply desalinated water to the electrolytic hydrogen production device.

[0015] In one embodiment, the seawater desalination device includes a seawater pretreatment component, an ultrafiltration and reverse osmosis component, and an ultrapure water production component which are connected in sequence.

[0016] Another object of the present invention is to provide a method for producing methane using marine energy and resources, the scheme is as follows:

[0017] A methane production method using marine energy and resources, using the methane production equipment system described in any of the above embodiments, the methane production method comprises the following steps:

[0018] Using the offshore power generation device to supply power to the electrolysis hydrogen production device, the seawater carbon capture device and the methane synthesis device;

[0019] Producing hydrogen by utilizing the electrolytic hydrogen production device and supplying hydrogen to the methane synthesis device;

[0020] utilizing the seawater carbon capture device to produce carbon dioxide and supplying the carbon dioxide to the methane synthesis device;

[0021] The methane synthesis device is used to produce methane using the hydrogen and the carbon dioxide as raw materials.

[0022] Compared with the traditional scheme, the above-mentioned methane production equipment system and methane production method using marine energy and resources have the following beneficial effects:

[0023] The above-mentioned methane production equipment system and methane production method generate electricity through offshore power generation equipment, and supply electricity to electrolytic hydrogen production equipment, seawater carbon capture equipment and methane synthesis equipment. Electrolytic hydrogen production technology can better cope with the volatility, intermittency and cross-temporal and spatial storage needs of offshore wind power and other electricity. Seawater carbon capture technology can achieve efficient recycling of carbon dioxide. Combined with carbon dioxide hydrogenation to synthesize methane technology, it can effectively solve the storage and transportation problems of hydrogen in the process of offshore wind power hydrogen production, and can achieve large-scale production of green methane, thereby promoting near-zero emissions in the entire cycle of energy utilization. The above-mentioned methane production equipment system provides a technical path for the high-quality and large-scale development of offshore wind power resources by organically combining offshore power generation, offshore hydrogen production, seawater carbon capture and green methane. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic structural diagram of a methane production equipment system utilizing ocean energy and resources according to an embodiment of the present invention.

[0025] Description of reference numerals:

[0026] 1. Methane production equipment system; 10. Offshore power generation device; 11. Wind turbine; 12. AC-DC rectifier; 13. Electrochemical energy storage system; 20. Seawater desalination device; 21. Seawater pretreatment components; 22. Ultrafiltration and reverse osmosis components; 23. Ultrapure water production components; 30. Electrolysis hydrogen production device; 31. Power supply components; 32. Pure water storage tank; 33. Alkaline electrolyzer; 34. Proton exchange membrane electrolyzer; 35. First compressor; 36. Hydrogen storage tank; 40. Seawater carbon capture device; 41. Electrochemical reactor; 42. Second compressor; 43. Carbon dioxide storage tank; 50. Methane synthesis device; 51. Methane fixed bed reactor; 52. Methane cooler; 53. Methane separator; 54. Methane storage tank. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like 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 present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0031] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] The present invention provides a methane production equipment system utilizing ocean energy and resources.

[0033] The methane production equipment system of one embodiment includes an offshore power generation device 10 , an electrolytic hydrogen production device 30 , a seawater carbon capture device 40 and a methane synthesis device 50 .

[0034] The electrolytic hydrogen production device 30, the seawater carbon capture device 40 and the methane synthesis device 50 are respectively electrically connected to the offshore power generation device 10. The offshore power generation device 10 supplies power to the electrolytic hydrogen production device 30, the seawater carbon capture device 40 and the methane synthesis device 50;

[0035] The electrolytic hydrogen production device 30 produces hydrogen and supplies hydrogen to the methane synthesis device 50;

[0036] The seawater carbon capture device 40 produces carbon dioxide and supplies the carbon dioxide to the methane synthesis device 50;

[0037] The methane synthesis unit 50 produces methane using hydrogen and carbon dioxide.

[0038] The above-mentioned methane production equipment system generates electricity through the offshore power generation device 10, and supplies electricity to the electrolytic hydrogen production device 30, the seawater carbon capture device 40 and the methane synthesis device 50. The electrolytic hydrogen production technology can better cope with the volatility, intermittency and cross-temporal and spatial storage requirements of offshore wind power and other electricity. The seawater carbon capture technology can achieve efficient recycling of carbon dioxide. Combined with the carbon dioxide hydrogenation to methane technology, it can effectively solve the storage and transportation problems of hydrogen in the process of offshore wind power hydrogen production, and can achieve large-scale production of green methane, thereby promoting near-zero emissions in the entire cycle of energy utilization. The above-mentioned methane production equipment system provides a technical path for the high-quality and large-scale development of offshore wind power resources by organically combining offshore power generation, offshore hydrogen production, seawater carbon capture and green methane.

[0039] In some examples, the offshore power generation device 10 includes a wind turbine 11 for generating electricity using offshore wind energy.

[0040] In some of the examples, the offshore power generation device 10 also includes an AC-DC rectifier 12, one end of the AC-DC rectifier 12 is connected to the wind turbine 11, and the other end is connected to the electrolysis hydrogen production device 30. The AC-DC rectifier 12 is used to convert the alternating current generated by the wind turbine 11 into direct current, and supply it to the electrolysis hydrogen production device 30 after rectification and filtering.

[0041] In some of the examples, the offshore power generation device 10 further includes an electrochemical energy storage system 13 , which is connected to the wind turbine 11 and is used to store surplus electrical energy.

[0042] The electrolytic hydrogen production device 30 utilizes offshore fluctuating wind power to electrolyze water to produce hydrogen to provide hydrogen required for the methane synthesis reaction. The electrolytic hydrogen production device 30 includes a power supply component 31, which is connected to the AC-DC rectifier 12 in the offshore power generation device 10 for distributing the wind power load. In some examples, the electrolytic hydrogen production device 30 includes a pure water storage tank 32, an electrolyzer, a compressor 35, and a hydrogen storage tank 36 connected in sequence.

[0043] In some of these examples, the electrolyzer includes an alkaline electrolyzer 33 and a proton exchange membrane electrolyzer 34. The alkaline electrolyzer 33 and the proton exchange membrane electrolyzer 34 can be connected in sequence, for example, the alkaline electrolyzer 33 is arranged between the pure water storage tank 32 and the proton exchange membrane electrolyzer 34. In addition, the alkaline electrolyzer 33 and the proton exchange membrane electrolyzer 34 can also be arranged in parallel. The power supply component 31 controls the output distribution of the offshore power generation device 10 according to the capacity configuration of the hydrogen production equipment, distributes the wind power load with lower volatility to the alkaline electrolyzer 33 for consumption and application, ensures the stability of the load power of the alkaline electrolyzer 33, and distributes the wind power load with higher volatility to the proton exchange membrane electrolyzer 34 for consumption and application, giving play to the rapid response characteristics of the proton exchange membrane electrolyzer 34. In this way, the maximization of wind energy utilization and the maximization of hydrogen production efficiency can be achieved.

[0044] The working power range of the proton exchange membrane electrolyzer 34 is wider than that of the alkaline electrolyzer 33, and the response speed of the proton exchange membrane 34 (seconds) is higher than that of the alkaline electrolyzer 33 (minutes). The alkaline electrolyzer 33 and the proton exchange membrane electrolyzer 34 are loaded with wind power loads with different fluctuation characteristics, so that the wind power output of the hydrogen production equipment is matched to maximize the hydrogen production efficiency. For example, the DC energy consumption of hydrogen production of the alkaline electrolyzer 33 is 4.0~4.3 kWh / Nm 3 , current density is 6000~7000 A / m 2 , the cell voltage is 1.8~2.0 V, and the hydrogen purity is above 99.7%. The DC energy consumption of hydrogen production in the proton exchange membrane electrolyzer 34 is 3.8~4.0 kWh / Nm 3 , current density is 7000~8000 A / m 2 , the cell voltage is 1.8~2.0 V, and the hydrogen purity is above 99.9%. The compressor 35 is used to pressurize the hydrogen to the pressure required by the methane synthesis section. The hydrogen storage tank 36 is used to charge and discharge the gas and adjust the hydrogen flow to meet the production requirements of methane synthesis.

[0045] The above-mentioned electrolytic hydrogen production device 30 can effectively solve the coupling problem between the offshore wind power fluctuation power source and the hydrogen production system, realize flexible hydrogen production, improve the efficiency of wind power consumption, and enhance the overall stability of the system.

[0046] The seawater carbon capture device 40 is used to capture and provide carbon dioxide required for the methane synthesis reaction from seawater. In some examples, the seawater carbon capture device 40 includes an electrochemical reactor 41, a compressor 42, and a carbon dioxide storage tank 43 connected in sequence.

[0047] The electrochemical reactor 41 adjusts the pH value of seawater to convert dissolved carbon dioxide into gaseous components, thereby enriching, separating and capturing carbon dioxide. The carbon dioxide extraction rate of the electrochemical reactor 41 is 80% to 90%, and the energy consumption of carbon dioxide capture is 2 to 4 kWh / Nm 3 The purity of carbon dioxide is above 90%. The compressor 42 is used to pressurize carbon dioxide to the pressure required by the methane synthesis section. The carbon dioxide storage tank 43 is used to charge and discharge gas and adjust the carbon dioxide flow to meet the production requirements of methane synthesis.

[0048] The methane synthesis device 50 synthesizes methane using hydrogen provided by the electrolytic hydrogen production device 30 and carbon dioxide provided by the seawater carbon capture device 40. In some examples, the methane synthesis device 50 includes a methane fixed bed reactor 51, a methane cooler 52, a methane separator 53 and a methane storage tank 54 connected in sequence.

[0049] Among them, the methane fixed bed reactor 51 is connected to the hydrogen storage tank 36 and the carbon dioxide storage tank 43, the hydrogen storage tank 36 provides hydrogen, the carbon dioxide storage tank 43 provides carbon dioxide, hydrogen and carbon dioxide are introduced into the methane fixed bed reactor 51 to synthesize gaseous methane, the gaseous methane is introduced into the methane cooler 52 for cooling to obtain crude methane, the crude methane is purified by the methane separator 53 to obtain refined methane, and the refined methane is introduced into the methane storage tank 54 for storage. Preferably, the catalyst in the methane fixed bed reactor 51 uses Al2O3 as a carrier, Ni as a catalyst to improve the activity and methane selectivity, and CeO2 as an activator to improve the activity and methane selectivity of the catalyst system, the operating temperature is 350~500℃, the operating pressure is 1~10 MPa, and the volume ratio of hydrogen and carbon dioxide is maintained between 4.2:1 and 4.5:1. After passing through the methane cooler 52 and the methane separator 53, the selectivity of methane reaches 90%~96%. In some of the examples, the methane production equipment system further includes a seawater desalination device 20 , the offshore power generation device 10 supplies power to the seawater desalination device 20 , and the seawater desalination device 20 supplies desalinated water to the electrolytic hydrogen production device 30 .

[0050] In some of the examples, the seawater desalination device 20 includes a seawater pretreatment component 21, an ultrafiltration and reverse osmosis component 22, and an ultrapure water production component 23 which are sequentially connected.

[0051] Among them, the seawater pretreatment component 21 is used to remove large particle impurities such as suspended matter, microorganisms, and organic matter in the seawater. The ultrafiltration and reverse osmosis component 22 removes dissolved salts and other small molecular impurities from the seawater to produce desalinated water. The ultrapure water device 23 further removes residual ions, organic matter, bacteria and other impurities in the water on the basis of desalinated water to obtain ultrapure water. Preferably, in order to meet the water quality requirements of the electrolytic hydrogen production device 30, the conductivity of ultrapure water is controlled below 0.1 μs / cm (25°C). In some of the examples, the ultrapure water device 23 is connected to the pure water storage tank 32 in the electrolytic hydrogen production device 30 through a pipeline. The pure water storage tank 32 provides ultrapure water, which is passed into the alkaline electrolyzer 33 and the proton exchange membrane electrolyzer 34 to produce hydrogen by water electrolysis.

[0052] Furthermore, the present invention also provides a methane production method using any of the above-mentioned examples of methane production equipment systems.

[0053] A methane production method according to an embodiment of the present invention uses any of the above-mentioned methane production equipment systems, and the methane production method includes the following steps:

[0054] The offshore power generation device 10 is used to supply power to the electrolytic hydrogen production device 30, the seawater carbon capture device 40 and the methane synthesis device 50;

[0055] The electrolytic hydrogen production device 30 uses the electric energy supplied by the offshore power generation device 10 to produce hydrogen, and supplies the hydrogen to the methane synthesis device 50;

[0056] The seawater carbon capture device 40 uses the electric energy supplied by the offshore power generation device 10 to produce carbon dioxide, and supplies the carbon dioxide to the methane synthesis device 50;

[0057] The methane synthesis device 50 produces methane using the hydrogen supplied from the electrolytic hydrogen production device 30 and the carbon dioxide supplied from the seawater carbon capture device 40 as raw materials.

[0058] The above methane production method generates electricity through an offshore power generation device and supplies electricity to an electrolytic hydrogen production device, a seawater carbon capture device and a methane synthesis device. The electrolytic hydrogen production technology can better cope with the volatility, intermittency and cross-temporal and spatial storage needs of offshore wind power and other electricity. The seawater carbon capture technology can achieve efficient recycling of carbon dioxide. Combined with the carbon dioxide hydrogenation to synthesize methane technology, it can effectively solve the storage and transportation problems of hydrogen in the process of offshore wind power hydrogen production, and can achieve large-scale production of green methane, thereby promoting near-zero emissions in the entire cycle of energy utilization. The above methane production equipment system provides a technical path for the high-quality and large-scale development of offshore wind power resources by organically combining offshore power generation, offshore hydrogen production, seawater carbon capture and green methane.

[0059] In the example where the electrolytic hydrogen production device 30 includes a pure water storage tank 32, an electrolyzer, a compressor 35 and a hydrogen storage tank 36 connected in sequence, the power supply component 31 controls the output distribution of the offshore power generation device 10 according to the capacity configuration of the hydrogen production equipment, and distributes the wind power load with lower volatility to the alkaline electrolyzer 33 for consumption and application, ensuring the stability of the load power of the alkaline electrolyzer 33, and distributes the wind power load with higher volatility to the proton exchange membrane electrolyzer 34 for consumption and application, giving play to the rapid response characteristics of the proton exchange membrane electrolyzer 34, so as to maximize the utilization of wind energy and maximize the efficiency of hydrogen production. The hydrogen is pressurized step by step to the pressure required for methane synthesis by the compressor 35, and the hydrogen is sent to the hydrogen storage tank 36 for storage. The flow rate of carbon dioxide entering the methane synthesis reaction tower 51 is adjusted by the hydrogen storage tank 36 to meet the production requirements of methane synthesis. In addition, the pure water flow entering the alkaline electrolyzer 33 and the proton exchange membrane electrolyzer 34 is adjusted by the pure water storage tank 32 to meet the production requirements of hydrogen production by electrolysis of water.

[0060] In the example where the seawater carbon capture device 40 includes an electrochemical reactor 41, a compressor 42, and a carbon dioxide storage tank 43 connected in sequence, the pH value of the seawater is adjusted by the electrochemical reactor 41, and the carbonates and bicarbonates in the seawater are converted into dissolved carbon dioxide, so that the carbon dioxide in the seawater is captured under vacuum conditions. The carbon dioxide is pressurized step by step to the pressure required for methane synthesis by the compressor 32 and sent to the carbon dioxide storage tank 43 for storage. The carbon dioxide flow entering the methane synthesis reaction tower 51 is adjusted by the carbon dioxide storage tank 43 to meet the production requirements of methane synthesis.

[0061] The methane synthesis device 50 is coupled with the electrolytic hydrogen production device 30 to flexibly adjust its operating state to match the output of the offshore power generation device 10. For example, in the example where the methane synthesis device 50 includes a methane fixed bed reactor 51, a methane cooler 52, a methane separator 53 and a methane storage tank 54 connected in sequence, when the output of the offshore power generation device 10 is high, the electrolytic hydrogen production device 30 and the methane synthesis device 50 are operated at a higher load, and the operating power of the alkaline electrolyzer 33 and the proton exchange membrane electrolyzer 34 is distributed through the power supply component 31 in the electrolytic hydrogen production device 30, and the excess hydrogen is stored in the hydrogen storage tank 35. When the output of the offshore power generation device 10 is low, the electrolytic hydrogen production device 30 is operated at a lower load, and the hydrogen in the storage tank is released to maintain the low-load operation of the methane synthesis device 30.

[0062] In the example where the methane production equipment system also includes a seawater desalination device 20, the offshore power generation device 10 supplies power to the seawater desalination device 20, and the offshore power generation device 10 uses the electric energy supplied by the offshore power generation device 10 to desalinate seawater, produce desalinated water, and supply the desalinated water to the electrolytic hydrogen production device 30. The methane synthesis device 50 also produces methane using the desalinated water supplied by the seawater desalination device 20 as a raw material.

[0063] In the example where the seawater desalination device 20 includes a seawater pretreatment component 21, an ultrafiltration and reverse osmosis component 22, and an ultrapure water production component 23 connected in sequence, the seawater pretreatment component 21 is used to remove large particle impurities such as suspended matter, microorganisms, and organic matter in the seawater. The ultrafiltration and reverse osmosis component 22 removes dissolved salts and other small molecular impurities from the seawater to produce desalinated water. The ultrapure water device 23 further removes residual ions, organic matter, bacteria, and other impurities in the water on the basis of the desalinated water to obtain ultrapure water.

[0064] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A methane production equipment system utilizing marine energy and resources, characterized in that: It includes offshore power generation equipment, electrolysis hydrogen production equipment, seawater carbon capture equipment and methane synthesis equipment; The electrolysis hydrogen production device, the seawater carbon capture device and the methane synthesis device are electrically connected to the offshore power generation device respectively, and the offshore power generation device is used to supply power to the electrolysis hydrogen production device, the seawater carbon capture device and the methane synthesis device; The electrolytic hydrogen production device is used to produce hydrogen and supply hydrogen to the methane synthesis device; the seawater carbon capture device is used to produce carbon dioxide and supply carbon dioxide to the methane synthesis device; the methane synthesis device is used to produce methane using the hydrogen and the carbon dioxide.

2. The methane production equipment system according to claim 1, characterized in that: The offshore power generation device comprises a wind turbine.

3. The methane production equipment system according to claim 2, characterized in that: The offshore power generation device further comprises an AC-DC rectifier, one end of the AC-DC rectifier is connected to the wind turbine generator, and the other end is connected to the electrolytic hydrogen production device, and the AC-DC rectifier is used to convert the alternating current generated by the wind turbine generator into direct current, and supply the direct current to the electrolytic hydrogen production device after rectification and filtering; and / or The offshore power generation device also includes an electrochemical energy storage system, which is connected to the wind turbine generator and is used to store surplus electrical energy.

4. The methane production equipment system according to claim 1, characterized in that: The electrolytic hydrogen production device comprises a pure water storage tank, an electrolyzer, a first compressor and a hydrogen storage tank which are connected in sequence.

5. The methane production equipment system according to claim 4, characterized in that: The electrolyzer includes an alkaline electrolyzer and a proton exchange membrane electrolyzer.

6. The methane production equipment system according to claim 1, characterized in that: The seawater carbon capture device comprises an electrochemical reactor, a second compressor and a carbon dioxide storage tank which are connected in sequence.

7. The methane production equipment system according to claim 1, characterized in that: The methane synthesis device comprises a methane fixed bed reactor, a methane cooler, a methane separator and a methane storage tank which are connected in sequence.

8. The methane production equipment system according to any one of claims 1 to 7, characterized in that: The methane production equipment system also includes a seawater desalination device, and the offshore power generation device is also used to supply power to the seawater desalination device. The seawater desalination device is used to produce desalinated water and supply desalinated water to the electrolytic hydrogen production device.

9. The methane production equipment system according to claim 8, characterized in that: The seawater desalination device comprises a seawater pretreatment component, an ultrafiltration and reverse osmosis component and an ultrapure water production component which are connected in sequence.

10. A method for producing methane using marine energy and resources, characterized in that: Utilizing the methane production equipment system according to any one of claims 1 to 9, the methane production method comprises the following steps: Using the offshore power generation device to supply power to the electrolysis hydrogen production device, the seawater carbon capture device and the methane synthesis device; Producing hydrogen by utilizing the electrolytic hydrogen production device and supplying hydrogen to the methane synthesis device; utilizing the seawater carbon capture device to produce carbon dioxide and supplying the carbon dioxide to the methane synthesis device; The methane synthesis device is used to produce methane using the hydrogen and the carbon dioxide as raw materials.

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