Device and method for producing hydrogen and chlorine alkali by using seawater

Abstract

This invention relates to the field of seawater hydrogen production, specifically to an apparatus and method for producing hydrogen and chlor-alkali from seawater. The apparatus includes: a sodium chloride crystallization platform, comprising a crystallization support plate and multiple black fine glass fiber tubes fixed to the crystallization support plate, with an inner diameter of less than 0.1 μm, the lower end opening into seawater, and the upper end opening upwards beyond the crystallization support plate; a freshwater production platform, used to produce freshwater using solar energy and supply freshwater to the crystallization support plate to dissolve sodium chloride crystals precipitated at the upper ends of the fine glass fiber tubes, forming brine; an electrolysis device for receiving and electrolyzing the brine, with an ion-exchange membrane between its anode and cathode plates to prevent OH⁻ from migrating from the cathode region to the anode region; a solar power generation platform connected to the electrolysis device for power supply; and a gas storage device, including a hydrogen storage space and a chlorine storage space. This invention can obtain completely green hydrogen, chlorine, and caustic soda from seawater without energy consumption.

Description

Technical Field

[0001] This invention relates to the field of seawater hydrogen production, specifically to an apparatus and method for producing hydrogen and chlor-alkali from seawater. Background Technology

[0002] With the overuse of fossil fuels, the energy crisis and environmental pollution problems are becoming increasingly severe. Hydrogen energy, due to its high calorific value and clean combustion products, is considered an important energy carrier for a future sustainable society. Among these technologies, water electrolysis for hydrogen production, which uses water as a raw material and produces green hydrogen through a clean reaction process, has received widespread attention.

[0003] However, hydrogen production technology through water electrolysis faces the bottleneck of freshwater scarcity, making the development of seawater electrolysis hydrogen production technology of significant strategic importance. However, during seawater electrolysis, chloride ions present in the seawater can trigger side reactions and corrode the catalyst, resulting in low selectivity and poor stability of the electrocatalyst. This problem has long constrained the practical application of seawater electrolysis technology.

[0004] To address the aforementioned issues, some research is currently focused on developing high-performance, corrosion-resistant seawater electrolysis catalysts. However, these electrodes are typically expensive and costly to manufacture, hindering large-scale application. Furthermore, in addition to corrosion resistance, it is crucial to prevent the deposition of calcium and magnesium ions on the electrode surface to form insoluble substances during seawater electrolysis. Excessive accumulation of these precipitates can cover the active sites of the electrode, leading to electrode failure and further complicating the implementation of seawater electrolysis technology. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a device for producing hydrogen and chlor-alkali using seawater. It can obtain completely green hydrogen, chlorine and caustic soda using seawater without energy consumption.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: an apparatus for producing hydrogen and chlor-alkali using seawater, comprising: A sodium chloride crystallization platform includes a crystallization support plate and multiple black fine glass fiber tubes. The fine glass fiber tubes are fixed on the crystallization support plate, have an inner diameter of less than 0.1 μm, have their lower ends open into seawater, and their upper ends open upwards beyond the crystallization support plate. A freshwater production platform is used to produce freshwater using solar energy and supply freshwater to the crystallization support plate to dissolve the sodium chloride crystals precipitated at the upper end of the fine glass fiber tube to form brine. An electrolysis device for receiving and electrolyzing the brine, wherein an ion-exchange membrane is provided between the anode plate and the cathode plate to prevent OH⁻ from migrating from the cathode region to the anode region; A solar power generation platform is connected to the electrolysis device to supply power; The gas storage device includes a hydrogen storage space connected to the gas outlet of the cathode plate and a chlorine storage space connected to the gas outlet of the anode plate.

[0007] Furthermore, the crystallization support plate is provided with a water flow channel; wherein, The inlet of the water flow channel is connected to the freshwater outlet of the freshwater production platform, and the outlet is connected to the liquid inlet of the electrolysis device. The upper end of each fine glass fiber tube is located in the flow area of ​​the water channel.

[0008] Furthermore, the water flow channel includes a groove formed between any two adjacent rows of fine glass fiber tubes.

[0009] Furthermore, the inner diameter of the fine glass fiber tube is 0.08~0.1μm.

[0010] Furthermore, the freshwater production platform includes a glass cavity with an inclined top. A gap is left between the inner surface of the top of the glass cavity and the seawater level below, which is used for the condensation of evaporated water vapor and its flow along the inclined top. A freshwater outlet for supplying freshwater to the crystallization support plate is provided at the lower part of the inclined top.

[0011] Furthermore, the freshwater production platform also includes a floating block made of hydrophilic material, which is positioned on the sea level inside the glass cavity.

[0012] Furthermore, the freshwater production platform also includes multiple black, coarse glass fiber tubes; wherein, The coarse glass fiber tube is located inside the glass cavity, with an inner diameter of 2.5~3mm. Its lower end is inserted into the seawater, and its upper end is opened beyond the seawater level, leaving a gap between it and the top inner surface of the glass cavity.

[0013] Furthermore, the outer side wall of the coarse glass fiber tube near the upper opening is provided with a photothermal catalyst.

[0014] Furthermore, the freshwater production platform also includes a freshwater production support plate, and the coarse glass fiber tube is installed on the freshwater production support plate with its upper opening facing upwards and extending beyond the freshwater production support plate.

[0015] This invention also relates to a method for producing hydrogen and chlor-alkali using a seawater-based hydrogen production and chlor-alkali production apparatus, comprising: Sodium chloride crystals precipitate at the upper end of the fine glass fiber tube; The freshwater production platform uses solar energy to produce freshwater and supplies it to the crystallization support plate to dissolve the sodium chloride crystals precipitated at the upper end of the fine glass fiber tube, forming brine, which is then supplied to the electrolysis device. The electrolysis device electrolyzes brine, producing chlorine gas at the anode plate and hydrogen gas at the cathode plate; The hydrogen storage space collects and stores hydrogen, and the chlorine storage space collects and stores chlorine.

[0016] After adopting the above technical solution, the Peclet number (Pe) of the liquid in the thin glass fiber tube is less than 1, which suppresses non-selective convection. Ion migration is mainly diffusion. The diameter of the thin tube is less than 0.1 μm. NaCl has a larger diffusion rate difference compared with other salts such as KCl. Na⁺ is more easily enriched and preferentially crystallized at the interface, which can form high-purity sodium chloride crystals at the opening of the thin glass fiber tube 12. The freshwater production platform uses solar energy to produce freshwater and dissolves the high-purity sodium chloride crystals to obtain brine. The electrolysis device then electrolyzes the brine under solar power. Due to the barrier effect of the ion membrane on OH⁻, hydrogen and chlorine are generated by electrolysis, and sodium hydroxide is left in the electrolysis tank. In this invention, high-purity sodium chloride is obtained by selectively crystallizing seawater using a microporous membrane. The sodium chloride is then dissolved directly in desalinated water to obtain an electrolyte. Electrolysis is then performed on the sea surface using natural solar energy to obtain completely green hydrogen, chlorine, and caustic soda. The entire process utilizes natural energy sources, consumes no energy, requires no manual operation, and avoids the use of special electrodes, thus greatly reducing manufacturing costs and ensuring stable operation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the apparatus for producing hydrogen and chlor-alkali from seawater according to the present invention. Figure 2 This is a partially enlarged view of the sodium chloride crystallization platform of the present invention; Figure 3 This is a schematic diagram of another freshwater production platform according to the present invention; In the diagram, 1. Sodium chloride crystallization platform; 11. Crystallization support plate; 111. Water flow channel; 12. Fine glass fiber tube; 2. Freshwater production platform; 21. Glass cavity; 22a. Floating block; 22b. Coarse glass fiber tube; 23b. Photothermal catalyst; 24b. Freshwater production support plate; 3. Electrolysis device; 4. Solar power generation platform; 5. Hydrogen storage space; 6. Chlorine storage space; 7. Freshwater hose; 8. Brine hose. Detailed Implementation

[0018] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0019] like Figures 1 to 3 As shown, an apparatus for producing hydrogen and chlor-alkali using seawater includes: Sodium chloride crystallization platform 1 includes a crystallization support plate 11 and a plurality of black fine glass fiber tubes 12. The fine glass fiber tubes 12 are fixed on the crystallization support plate 11, with an inner diameter of less than 0.1 μm, the lower end opening into seawater, and the upper end opening upward beyond the crystallization support plate 11. The freshwater production platform 2 is used to produce freshwater using solar energy and supply freshwater to the crystallization support plate 11 to dissolve the sodium chloride crystals precipitated at the upper end of the fine glass fiber tube 12 to form brine. Electrolysis device 3 is used to receive brine and electrolyze it. An ion membrane is provided between its anode plate and cathode plate to prevent OH⁻ from migrating from the cathode area to the anode area. The solar power generation platform 4 is connected to the electrolysis device 3 to supply power; The gas storage device includes a hydrogen storage space 5 connected to the gas outlet of the cathode plate and a chlorine storage space 6 connected to the gas outlet of the anode plate.

[0020] The inner diameter of the fine glass fiber tube 12 can be 0.08~0.1μm. The electrolysis tank of the electrolysis device 3 is a tank below the water surface, which can be suspended in the water or submerged. The anode plate can be a titanium plate electrode, and the cathode plate can be a stainless steel plate. The hydrogen storage space 5 and the chlorine storage space 6 can be gasbags set on the sea surface, respectively. The crystallization support plate 11 can be made of lightweight materials. The solar power generation platform 4 can include a floating platform, solar panels, and batteries. The floating platform floats on the sea surface, and the solar panels and batteries are placed on the floating platform. The solar panels generate electricity using solar energy, and the batteries store electrical energy. The positive and negative electrodes are connected to the anode plate and the cathode plate.

[0021] In this embodiment, the liquid Peclet number (Pe) inside the thin glass fiber tube 12 is less than 1, which suppresses non-selective convection. Ion migration is mainly diffusion. The diameter of the thin tube is less than 0.1 μm. NaCl has a larger diffusion rate difference compared to other salts such as KCl. Na⁺ is more easily enriched at the interface and preferentially crystallizes, which can form high-purity sodium chloride crystals at the opening of the thin glass fiber tube 12.

[0022] The freshwater production platform 2 uses solar energy to produce freshwater. Freshwater is supplied to the crystallization support plate 11 through the freshwater hose 7, which dissolves the sodium chloride crystals precipitated at the upper end of the fine glass fiber tube 12 to form brine, which flows naturally into the electrolysis tank from the brine hose 8.

[0023] The ion-exchange membrane inside the electrolysis tank prevents OH⁻ from reaching the anode plate, thus avoiding the generation of oxygen and ensuring that chlorine is the main product. Hydrogen is generated at the cathode plate and connected to the hydrogen storage space 5, while chlorine is generated at the anode and connected to the chlorine storage space 6. As electrolysis continues, sodium hydroxide remains in the electrolysis tank. After a certain concentration is reached over a period of time, a portion of it can be extracted.

[0024] This embodiment utilizes a microporous membrane for selective crystallization of seawater to obtain high-purity sodium chloride. The sodium chloride is then dissolved directly in desalinated water to obtain an electrolyte. Electrolysis is performed on the sea surface using natural solar energy to produce completely green hydrogen, chlorine, and caustic soda. The entire device operates entirely on natural energy sources, requiring no energy consumption, no manual operation, and avoiding the use of special electrodes, thus significantly reducing manufacturing costs and ensuring stable operation.

[0025] In this embodiment, preferably, as follows: Figure 2 As shown, the crystallization support plate 11 is provided with a water flow channel 111; wherein, The inlet of the water flow channel 111 is connected to the freshwater outlet of the freshwater production platform 2, and the outlet is connected to the liquid inlet of the electrolysis device 3. The upper end of each fine glass fiber tube 12 is located in the flow area of ​​the water flow channel 111.

[0026] This allows for better dissolution of the sodium chloride formed during crystallization.

[0027] In this embodiment, more preferably, as Figure 2 As shown, the water flow channel 111 includes grooves formed between any two rows of adjacent fine glass fiber tubes 12. The depth of the grooves can be 0.6~1cm.

[0028] In this embodiment, preferably, as follows: Figure 2 As shown, the freshwater production platform 2 includes a glass cavity 21 with an inclined top. There is a gap between the inner surface of the top of the glass cavity 21 and the seawater plane below, which is used for the condensation of evaporated water vapor and its flow along the inclined top. A freshwater outlet for supplying freshwater to the crystallization support plate 11 is provided at the lower part of the inclined top.

[0029] Specifically, under the sun's rays, water evaporates to the top of the glass cavity 21 and condenses, flowing along the inclined top and eventually into the sodium chloride crystallization platform 1 from the fresh water hose 7 at the inclined bottom.

[0030] In this embodiment, more preferably, as Figure 3 As shown, the freshwater production platform 2 also includes a floating block 22a, which is made of hydrophilic material and is set on the sea level inside the glass cavity 21.

[0031] Specifically, the floating block 22a is hydrophilic, allowing water to permeate from bottom to top. Alternatively, multiple black coarse fiberglass tubes 22b can replace the floating block 22a; these tubes are located within the glass cavity 21, have an inner diameter of 2.5-3 mm, with their lower openings inserted into seawater and their upper openings extending beyond the seawater level, leaving a gap between them and the top inner surface of the glass cavity 21. A photothermal catalyst 23b can also be provided on the outer side wall of the coarse fiberglass tube 22b near its upper opening. The freshwater production platform 2 can also include a freshwater production support plate 24b, on which the coarse fiberglass tubes 22b are mounted, with their upper openings extending upwards beyond the support plate 24b.

[0032] Due to sunlight, seawater evaporates inside the coarse glass fiber tube 22b. Because the tube diameter is relatively large, the seawater inside the tube can undergo capillary evaporation. Furthermore, the increased density after evaporation, combined with the larger tube diameter, causes a density difference that leads to sedimentation, thus preventing crystallization at the opening of the coarse glass fiber tube 22b and extending its service life.

[0033] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A device for producing hydrogen and chlor-alkali from seawater, characterized in that, include: Sodium chloride crystallization platform (1) includes a crystallization support plate (11) and a plurality of black fine glass fiber tubes (12). The fine glass fiber tubes (12) are fixed on the crystallization support plate (11), with an inner diameter of less than 0.1 μm, and the lower end opening extends into seawater, while the upper end opening extends upward beyond the crystallization support plate (11). The freshwater production platform (2) is used to produce freshwater using solar energy and supply freshwater to the crystallization support plate (11) to dissolve the sodium chloride crystals precipitated at the upper end of the fine glass fiber tube (12) to form brine. Electrolysis device (3) is used to receive the brine and electrolyze it, and an ion membrane is provided between its anode plate and cathode plate to prevent OH⁻ from migrating from the cathode region to the anode region; A solar power generation platform (4) is connected to the electrolysis device (3) to supply power; The gas storage device includes a hydrogen storage space (5) connected to the gas outlet of the cathode plate and a chlorine storage space (6) connected to the gas outlet of the anode plate.

2. The apparatus for producing hydrogen and chlor-alkali from seawater according to claim 1, characterized in that, The crystallization support plate (11) is provided with a water flow channel (111); wherein, The inlet of the water flow channel (111) is connected to the fresh water outlet of the fresh water production platform (2), and the outlet is connected to the liquid inlet of the electrolysis device (3). The upper end of each fine glass fiber tube (12) is located in the flow area of ​​the water flow channel (111).

3. The apparatus for producing hydrogen and chlor-alkali from seawater according to claim 2, characterized in that, The water flow channel (111) includes a groove formed between any two adjacent rows of fine glass fiber tubes (12).

4. The apparatus for producing hydrogen and chlor-alkali from seawater according to claim 1, characterized in that, The inner diameter of the fine glass fiber tube (12) is 0.08~0.1μm.

5. The apparatus for producing hydrogen and chlor-alkali from seawater according to claim 1, characterized in that, The freshwater production platform (2) includes a glass cavity (21) with an inclined top. There is a gap between the inner surface of the top of the glass cavity (21) and the seawater plane below, which is used for the condensation of evaporated water vapor and its flow along the inclined top. A freshwater outlet for supplying freshwater to the crystallization support plate (11) is provided at the lower part of the inclined top.

6. The apparatus for producing hydrogen and chlor-alkali from seawater according to claim 5, characterized in that, The freshwater production platform (2) also includes a floating block (22a), which is made of hydrophilic material and is set on the sea level inside the glass cavity (21).

7. The apparatus for producing hydrogen and chlor-alkali from seawater according to claim 5, characterized in that, The freshwater production platform (2) also includes multiple black coarse glass fiber tubes (22b); wherein, The coarse glass fiber tube (22b) is located inside the glass cavity (21), with an inner diameter of 2.5~3mm. The lower end of the tube is inserted into the seawater, and the upper end of the tube extends beyond the seawater level. There is a gap between the tube and the top inner surface of the glass cavity (21).

8. The apparatus for producing hydrogen and chlor-alkali from seawater according to claim 7, characterized in that, The coarse glass fiber tube (22b) has a photothermal catalyst (23b) on its outer side wall near the upper opening.

9. The apparatus for producing hydrogen and chlor-alkali from seawater according to claim 7, characterized in that, The freshwater production platform (2) also includes a freshwater production support plate (24b), and the coarse glass fiber tube (22b) is installed on the freshwater production support plate (24b), with its upper opening facing upward and extending beyond the freshwater production support plate (24b).

10. A method for producing hydrogen and chlor-alkali based on the seawater hydrogen production and chlor-alkali production apparatus according to any one of claims 1-9. Its features are, include: Sodium chloride crystals precipitate at the upper end of the fine glass fiber tube (12); The freshwater production platform (2) uses solar energy to produce freshwater and supplies freshwater to the crystallization support plate (11) to dissolve the sodium chloride crystals precipitated at the upper end of the fine glass fiber tube (12) to form brine, which is then supplied to the electrolysis device (3). Electrolysis device (3) electrolyzes brine, producing chlorine gas at the anode plate and hydrogen gas at the cathode plate; Hydrogen storage space (5) collects and stores hydrogen, and chlorine storage space (6) collects and stores chlorine.

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