Seawater electrolysis hydrogen production process and equipment

Abstract

The invention discloses a seawater electrolysis hydrogen production process and equipment, and relates to the field of seawater hydrogen production, the seawater electrolysis hydrogen production equipment comprises an electrolysis mechanism, the front surface of the electrolysis mechanism is provided with a settling tank, the top surface of the settling tank is fixedly communicated with a material passing pipe, the top end of the material passing pipe is fixedly communicated with a hopper, and the outer wall of the upper part of the hopper is fixedly communicated with a feeding pipe; and the two sides of the settling tank are fixedly communicated with liquid pumping pipes. According to the device, seawater is introduced into the settling tank after being pretreated, sodium hydroxide is injected into the hopper through the feeding pipe, the pH value of the seawater in the settling tank is increased, the electrolytic efficiency is improved, the influence of divalent ions in the water is reduced, sodium hydroxide is added by means of the same ion effect, so that the seawater in the settling tank forms sodium chloride salting-out sediment, and the water quality is improved. The device has three functions of hydrogen production, oxygen production and sodium chloride extraction, the chloride ion concentration is reduced, chloride ions are prevented from being oxidized on the anode to form chlorine, the service life of the device is prolonged, and the economic benefit of hydrogen production through seawater electrolysis is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production from seawater, and in particular to a process and equipment for producing hydrogen by electrolysis of seawater. Background Art

[0002] As an ideal secondary energy carrier, hydrogen has a high unit energy density and is an ideal interconnected medium for promoting clean and efficient utilization and supporting the large-scale development of renewable energy. The development of hydrogen energy is an effective way to achieve large-scale deep decarbonization in transportation, industry, construction and other fields. Water electrolysis hydrogen production technology has the advantages of high electrolysis efficiency, high hydrogen purity, and pollution-free reaction. It can be coupled with renewable energy sources such as photovoltaics and wind power. It is recognized as one of the most promising hydrogen production technologies. Seawater contains a high concentration of soluble inorganic salts such as sodium chloride. It is a natural electrolyte with high ionic conductivity. Combining seawater electrolysis hydrogen production technology is an ideal way to achieve a green hydrogen economy.

[0003] At present, in the traditional process of hydrogen production by electrolysis of seawater, due to the high concentration of chloride ions in seawater, the chloride ions will be oxidized at the anode to form chlorine gas during the electrolysis process, which will not only affect the purity of the hydrogen, but may also cause corrosion to the equipment. In addition, seawater contains a variety of impurities, such as magnesium, calcium, sulfate and organic matter, which will affect the efficiency of electrolysis and the life of the equipment. Summary of the invention

[0004] The object of the present invention is to provide a process and equipment for producing hydrogen by electrolysis of seawater, so as to solve the problem raised in the above-mentioned background technology that due to the high concentration of chloride ions in seawater, during the electrolysis process, the chloride ions will be oxidized on the anode to form chlorine gas, which will not only affect the purity of the hydrogen, but also may cause corrosion to the equipment. In addition, seawater contains a variety of impurities, such as magnesium, calcium, sulfate and organic matter, which will affect the efficiency of electrolysis and the life of the equipment.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a seawater electrolysis hydrogen production device, comprising an electrolysis mechanism, a sedimentation box is arranged on the front of the electrolysis mechanism, a feed pipe is fixedly connected to the top surface of the sedimentation box, a hopper is fixedly connected to the top of the feed pipe, a feed pipe is fixedly connected to the upper outer wall of the hopper, a feed pipe is fixedly connected to both sides of the sedimentation box, a liquid extraction pipe is fixedly connected to one end of the liquid extraction pipe, a water pump is fixedly installed on the outer wall of the electrolysis mechanism, a water outlet end of the water pump is fixedly connected to a delivery pipe, the top of the delivery pipe is fixedly connected to the outer wall of the electrolysis mechanism, and the upper outer wall of the sedimentation box is fixedly connected to There is a water inlet pipe, the bottom surface of the water inlet pipe is fixedly connected to a sedimentation pipe, the bottom surface of the sedimentation pipe is fixedly connected to a screw feeder, the outer wall of one end of the sedimentation pipe passes through a transmission shaft that is rotatably connected, a reducer is installed on the lower outer wall of the sedimentation box, the output shaft end of the reducer is fixedly connected to one end of the transmission shaft, a servo motor is installed on the outer wall of the reducer, the output shaft end of the servo motor is fixedly connected to the input shaft end of the reducer, a baffle is arranged inside the sedimentation pipe, the baffle is fixedly connected to the outer wall of the transmission shaft, one end of the baffle is fixedly connected to a sealing strip, and a filter is installed on the inner wall of the sedimentation box.

[0006] Preferably, a driving motor is installed at one end of the screw conveyor, and the other end of the screw conveyor is fixedly connected to a discharge pipe.

[0007] Preferably, a feeding screw is rotatably connected to the inner wall of the screw feeder, and one end of the feeding screw is fixedly connected to the output shaft end of the driving motor.

[0008] Preferably, the top surface of the electrolysis mechanism is fixedly connected to a top cover, the top surface of the top cover is fixedly connected to an exhaust pipe, and the lower outer wall of the electrolysis mechanism is fixedly connected to a waste liquid discharge pipe.

[0009] Preferably, the electrolysis mechanism comprises an electrolytic cell, an outer wall of the electrolytic cell is mounted with an electric controller, a top surface of the electric controller is fixedly connected with an energized wire, and a liquid storage chamber is provided inside the electrolytic cell.

[0010] Preferably, a diaphragm is fixedly connected to the inner wall of the liquid storage cavity, a cathode plate is fixedly installed on one side of the diaphragm, an anode plate is fixedly installed on the other side of the diaphragm, and the top end of the current-carrying wire is electrically connected to the cathode plate and the anode plate respectively.

[0011] Preferably, side heating plates are provided on both sides of the liquid storage chamber, the side heating plates are fixedly connected to the inner wall of the electrolytic cell, a bottom heating plate is fixedly connected to the bottom of the electrolytic cell, and the bottom heating plate and the side heating plates are electrically connected to the electric controller.

[0012] A process for producing hydrogen by electrolysis of seawater comprises the following steps:

[0013] S1. Introducing seawater from the ocean through a pumping device, pre-treating the seawater and separating the divalent ions in the seawater using a nanofiltration process;

[0014] S2, injecting sodium hydroxide into the hopper through the feed pipe, and transporting the seawater after nanofiltration to the sedimentation tank through the water inlet pipe by a high-pressure pump, and using sodium hydroxide to increase the pH value of the seawater in the sedimentation tank and form sodium chloride salting precipitation;

[0015] S3, the treated seawater is pumped from the sedimentation tank into the electrolysis mechanism through a pumping pipe and a delivery pipe, and the water molecules of the seawater in the electrolysis mechanism undergo oxidation and reduction reactions at the anode and cathode respectively;

[0016] Anode reaction: water decomposes to produce oxygen and hydrogen ions;

[0017] Cathode reaction: hydrogen ions gain electrons to form hydrogen;

[0018] S4. Oxygen and hydrogen generated by seawater electrolysis are discharged from two exhaust pipes and collected for treatment;

[0019] S5. Purify the collected hydrogen to remove residual impurities and moisture.

[0020] Preferably, in step S1, the pre-treating of seawater and separation of divalent ions in seawater by nanofiltration process comprises the following steps:

[0021] S11, preliminarily filtering the seawater to remove large particles and removing dissolved gases in the seawater by degassing;

[0022] S12, using a high-pressure pump to deliver seawater into the nanofiltration device and provide pressure to push the seawater through the nanofiltration membrane, the nanofiltration membrane is a polyamide membrane or a cellulose membrane;

[0023] S13. Under a certain pressure, sodium ions and water molecules in seawater can pass through the membrane, while divalent ions are retained on one side of the membrane.

[0024] Preferably, in step S2, the step of using sodium hydroxide to increase the pH value of seawater in the precipitation tank and forming sodium chloride salting-out precipitation comprises the following steps:

[0025] S21, controlling the sodium hydroxide in the hopper to be fed into the sedimentation tank through the feed pipe to mix with the treated seawater, so as to increase the pH value of the seawater to alkaline;

[0026] S22. When the concentration of sodium chloride in the seawater is relatively high in the sedimentation tank, sodium hydroxide is added to cause the sodium chloride to salt out and precipitate by means of the common ion effect;

[0027] S23, the precipitated sodium chloride settles into the precipitation pipe by gravity, and the servo motor is started regularly to drive the transmission shaft to turn the baffle in the precipitation pipe to discharge the precipitated sodium chloride into the screw feeder for cleaning and discharge;

[0028] S24. Collect the discharged sodium chloride.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. In the present invention, seawater is introduced into the sedimentation tank after pretreatment, and sodium hydroxide is injected into the hopper through the feed pipe to increase the pH value of the seawater in the sedimentation tank, which helps to improve the electrolysis efficiency and reduce the influence of divalent ions in the water. Sodium hydroxide is added by means of the common ion effect to form sodium chloride salting out precipitation in the seawater in the sedimentation tank, so that the present invention has the three functions of hydrogen production, oxygen production and sodium chloride extraction at the same time, and reduces the concentration of chloride ions to prevent chloride ions from being oxidized on the anode to form chlorine gas, thereby improving the service life of the equipment and the economic benefits of electrolyzing seawater to produce hydrogen.

[0031] 2. In the present invention, the sodium chloride precipitated in the sedimentation box is settled into the sedimentation pipe by gravity through the setting of the screw feeder. The servo motor is started regularly to drive the transmission shaft to turn the baffle in the sedimentation pipe to discharge the precipitated sodium chloride into the screw feeder for cleaning and discharge, so that the user can recover the sodium chloride conveniently.

[0032] 3. In the present invention, large particles are removed from seawater by pretreatment to protect subsequent processing equipment, dissolved gases in seawater are removed by degassing to prevent the subsequent electrolysis process or nanofiltration membrane from being affected, and divalent ions in seawater are separated by nanofiltration technology to reduce side reactions caused by divalent ions in seawater electrolysis, increase the yield and purity of hydrogen, and improve the overall electrolysis efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the three-dimensional structure of a seawater electrolysis hydrogen production device according to the present invention;

[0034] Figure 2 The present invention is a seawater electrolysis hydrogen production equipment Figure 1 A magnified view of the structure at center;

[0035] Figure 3 This is a rear structural schematic diagram of a seawater electrolysis hydrogen production device according to the present invention;

[0036] Figure 4 This is a schematic diagram of the internal structure of a seawater electrolysis hydrogen production device according to the present invention;

[0037] Figure 5 This is a schematic diagram of the internal structure of a sedimentation tank of a seawater electrolysis hydrogen production device according to the present invention;

[0038] Figure 6 This is a flow chart of a process for producing hydrogen by electrolysis of seawater according to the present invention;

[0039] Figure 7 The present invention is a sodium chloride salting-out precipitation flow chart of a seawater electrolysis hydrogen production process.

[0040] In the figure: 1. electrolysis mechanism; 11. electrolytic cell; 12. electric controller; 13. power-carrying wire; 14. liquid storage chamber; 15. cathode plate; 16. anode plate; 17. diaphragm; 18. bottom heating plate; 19. side heating plate; 2. water pump; 21. delivery pipe; 22. suction pipe; 3. top cover; 31. exhaust pipe; 4. sedimentation box; 41. water inlet pipe; 42. sedimentation pipe; 43. reducer; 44. servo motor; 45. transmission shaft; 46. baffle; 47. sealing strip; 48. filter; 5. hopper; 51. feed pipe; 52. feed pipe; 6. screw feeder; 61. discharge pipe; 62. drive motor; 63. feed screw; 7. waste liquid discharge pipe. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the implementation regulations described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] Example 1: Reference Figure 1 - Figure 5As shown: a seawater electrolysis hydrogen production equipment, including an electrolysis mechanism 1, a sedimentation tank 4 is arranged on the front of the electrolysis mechanism 1, the top surface of the sedimentation tank 4 is fixedly connected with a feed pipe 52, the top of the feed pipe 52 is fixedly connected with a hopper 5, the upper outer wall of the hopper 5 is fixedly connected with a feed pipe 51, both sides of the sedimentation tank 4 are fixedly connected with a liquid extraction pipe 22, one end of the liquid extraction pipe 22 is fixedly connected with a water pump 2, the water pump 2 is fixedly installed on the outer wall of the electrolysis mechanism 1, the water outlet end of the water pump 2 is fixedly connected with a delivery pipe 21, the top of the delivery pipe 21 is fixedly connected with the outer wall of the electrolysis mechanism 1, the upper outer wall of the sedimentation tank 4 is fixedly connected with a water inlet pipe 41, and the bottom of the water inlet pipe 41 A sedimentation pipe 42 is fixedly connected, and a screw feeder 6 is fixedly connected to the bottom surface of the sedimentation pipe 42. A transmission shaft 45 is rotatably connected to the outer wall of one end of the sedimentation pipe 42. A reducer 43 is installed on the lower outer wall of the sedimentation box 4. The output shaft end of the reducer 43 is fixedly connected to one end of the transmission shaft 45. A servo motor 44 is installed on the outer wall of the reducer 43. The output shaft end of the servo motor 44 is fixedly connected to the input shaft end of the reducer 43. A baffle 46 is arranged inside the sedimentation pipe 42. The baffle 46 is fixedly connected to the outer wall of the transmission shaft 45. A sealing strip 47 is fixedly connected to one end of the baffle 46. A filter screen 48 is installed on the inner wall of the sedimentation box 4.

[0043] In this embodiment, seawater is introduced from the ocean by a pumping device, and is pre-treated before being introduced into the sedimentation tank 4. Sodium hydroxide is injected into the hopper 5 through the feed pipe 51. Increasing the pH value of the seawater in the sedimentation tank 4 helps to improve the electrolysis efficiency and reduce the influence of divalent ions in the water. Sodium hydroxide is added by means of the common ion effect to form sodium chloride salting out precipitation in the seawater in the sedimentation tank 4. Then, the precipitated seawater in the sedimentation tank 4 is pumped into the liquid storage chamber 14 by the water pump 2 and electrolyzed to generate hydrogen and oxygen. Therefore, the present invention has the three functions of hydrogen production, oxygen production and sodium chloride extraction at the same time, and avoids the oxidation of chloride ions on the anode to form chlorine, thereby improving the economic benefit of hydrogen production by electrolyzing seawater.

[0044] Embodiment 2: Figure 1 - Figure 5As shown, a driving motor 62 is installed at one end of the screw feeder 6, and a discharge pipe 61 is fixedly connected to the other end of the screw feeder 6. A feeding screw 63 is rotatably connected to the inner wall of the screw feeder 6, and one end of the feeding screw 63 is fixedly connected to the output shaft end of the driving motor 62. The top surface of the electrolysis mechanism 1 is fixedly connected to the top cover 3, and the top surface of the top cover 3 is fixedly connected to the exhaust pipe 31. The lower outer wall of the electrolysis mechanism 1 is fixedly connected to the waste liquid discharge pipe 7. The electrolysis mechanism 1 includes an electrolytic cell 11, and an electric controller 12 is installed on the outer wall of the electrolytic cell 11. The top surface of the electric controller 12 is fixedly connected to a conductive conductive rod. Line 13, a liquid storage chamber 14 is arranged inside the electrolytic cell 11, a diaphragm 17 is fixedly connected to the inner wall of the liquid storage chamber 14, a cathode plate 15 is fixedly installed on one side of the diaphragm 17, an anode plate 16 is fixedly installed on the other side of the diaphragm 17, the top of the current-carrying wire 13 is electrically connected to the cathode plate 15 and the anode plate 16 respectively, side heating plates 19 are arranged on both sides of the liquid storage chamber 14, the side heating plates 19 are fixedly connected to the inner wall of the electrolytic cell 11, a bottom heating plate 18 is fixedly connected to the bottom of the electrolytic cell 11, and the bottom heating plate 18 and the side heating plates 19 are both electrically connected to the electric controller 12.

[0045] In this embodiment, the sodium chloride precipitated in the sedimentation box 4 is settled into the sedimentation pipe 42 by gravity through the setting of the screw feeder 6. The servo motor 44 is started regularly to drive the transmission shaft 45 to turn the baffle 46 in the sedimentation pipe 42 to discharge the precipitated sodium chloride into the screw feeder 6 for cleaning and discharge, so that the user can recover the sodium chloride conveniently. The cathode plate 15 and the anode plate 16 are energized by the electric controller 12 to electrolyze the seawater in the liquid storage chamber 14. The anode reaction at the anode plate 16 decomposes the water to generate oxygen and hydrogen ions, and the cathode reaction at the cathode plate 15 causes the hydrogen ions to obtain electrons to form hydrogen. The bottom heating plate 18 and the side heating plate 19 are used in combination to fully heat the interior of the liquid storage chamber 14 to achieve stable temperature control of hydrogen production by electrolyzing seawater. The oxygen and hydrogen generated by the electrolysis of seawater are discharged outward from the two exhaust pipes 31 respectively and collected for treatment.

[0046] Embodiment 3: According to Figure 6 and Figure 7 As shown, a process for producing hydrogen by electrolysis of seawater comprises the following steps:

[0047] Step 1: Introduce seawater from the ocean through a pumping device, pre-treat the seawater and use a nanofiltration process to separate divalent ions in the seawater, thereby reducing side reactions caused by divalent ions in seawater electrolysis, increasing the yield and purity of hydrogen, and improving the overall electrolysis efficiency;

[0048] The process of pre-treating seawater and separating divalent ions from seawater by nanofiltration includes the following steps:

[0049] 11) Preliminary filtration of seawater to remove large particles to protect subsequent processing equipment, and remove dissolved gases in seawater through degassing to prevent the impact on subsequent electrolysis processes or nanofiltration membranes;

[0050] 12) Use a high-pressure pump to send seawater into the nanofiltration device and provide pressure to push the seawater through the nanofiltration membrane. The nanofiltration membrane is made of polyamide membrane or cellulose membrane;

[0051] 13) Under a certain pressure, sodium ions and water molecules in seawater can pass through the membrane, while divalent ions are retained on one side of the membrane;

[0052] Step 2: Sodium hydroxide is injected into the hopper 5 through the feed pipe 51. The seawater after nanofiltration is transported to the sedimentation tank 4 through the water inlet pipe 41 by a high-pressure pump. Sodium hydroxide is used to increase the pH value of the seawater in the sedimentation tank 4 and form sodium chloride salting precipitation, thereby achieving the three functions of hydrogen production, oxygen production and sodium chloride extraction, and reducing the concentration of chloride ions to prevent chloride ions from being oxidized on the anode to form chlorine gas, thereby improving the economic benefits of hydrogen production by electrolysis of seawater;

[0053] The process of using sodium hydroxide to increase the pH value of seawater in the precipitation tank 4 and forming sodium chloride salting-out precipitation comprises the following steps:

[0054] 21) Controlling the sodium hydroxide in the hopper 5 to be fed into the sedimentation tank 4 through the feed pipe 52 to mix with the treated seawater to increase the pH value of the seawater to alkaline;

[0055] 22) In the sedimentation tank 4, when the concentration of sodium chloride in the seawater is relatively high, sodium hydroxide is added to cause the sodium chloride to salt out and precipitate by means of the common ion effect;

[0056] 23) The precipitated sodium chloride settles into the precipitation pipe 42 by gravity, and the servo motor 44 is started regularly to drive the transmission shaft 45 to turn the baffle 46 in the precipitation pipe 42 to discharge the precipitated sodium chloride into the screw feeder 6 for cleaning and discharge;

[0057] 24) collecting the discharged sodium chloride;

[0058] Step 3: The treated seawater is pumped from the sedimentation tank 4 into the electrolysis mechanism 1 through the pump 2 through the liquid extraction pipe 22 and the delivery pipe 21. The water molecules of the seawater in the electrolysis mechanism 1 undergo oxidation and reduction reactions at the anode and cathode, respectively.

[0059] Anode reaction: water decomposes to produce oxygen and hydrogen ions;

[0060] Cathode reaction: hydrogen ions gain electrons to form hydrogen;

[0061] Step 4: The oxygen and hydrogen generated by seawater electrolysis are discharged from two exhaust pipes 31 and collected for treatment;

[0062] Step 5: Purify the collected hydrogen to remove residual impurities and moisture.

[0063] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. 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 seawater electrolysis hydrogen production device, comprising an electrolysis mechanism (1), characterized in that: The front of the electrolysis mechanism (1) is provided with a sedimentation box (4), the top surface of the sedimentation box (4) is fixedly connected to a feed pipe (52), the top end of the feed pipe (52) is fixedly connected to a hopper (5), the upper outer wall of the hopper (5) is fixedly connected to a feed pipe (51), both sides of the sedimentation box (4) are fixedly connected to liquid extraction pipes (22), one end of the liquid extraction pipe (22) is fixedly connected to a water pump (2), the water pump (2) is fixedly mounted on the outer wall of the electrolysis mechanism (1), the water outlet end of the water pump (2) is fixedly connected to a delivery pipe (21), the top end of the delivery pipe (21) is fixedly connected to the outer wall of the electrolysis mechanism (1), the upper outer wall of the sedimentation box (4) is fixedly connected to a water inlet pipe (41), the bottom surface of the water inlet pipe (41) is fixedly connected to a sedimentation through pipe ( 42), the bottom surface of the sedimentation tube (42) is fixedly connected to a screw feeder (6), one end of the outer wall of the sedimentation tube (42) is penetrated by a transmission shaft (45) for rotation connection, a reducer (43) is installed on the lower outer wall of the sedimentation box (4), the output shaft end of the reducer (43) is fixedly connected to one end of the transmission shaft (45), a servo motor (44) is installed on the outer wall of the reducer (43), the output shaft end of the servo motor (44) is fixedly connected to the input shaft end of the reducer (43), a baffle (46) is arranged inside the sedimentation tube (42), the baffle (46) is fixedly connected to the outer wall of the transmission shaft (45), one end of the baffle (46) is fixedly connected to a sealing strip (47), and a filter screen (48) is installed on the inner wall of the sedimentation box (4).

2. The seawater electrolysis hydrogen production equipment according to claim 1, characterized in that: A driving motor (62) is installed at one end of the screw conveyor (6), and a discharge pipe (61) is fixedly connected to the other end of the screw conveyor (6).

3. A seawater electrolysis hydrogen production device according to claim 2, characterized in that: The inner wall of the screw feeder (6) is rotatably connected to a feed screw rod (63), and one end of the feed screw rod (63) is fixedly connected to the output shaft end of the driving motor (62).

4. The seawater electrolysis hydrogen production equipment according to claim 2, characterized in that: The top surface of the electrolysis mechanism (1) is fixedly connected to a top cover (3), the top surface of the top cover (3) is fixedly connected to an exhaust pipe (31), and the lower outer wall of the electrolysis mechanism (1) is fixedly connected to a waste liquid discharge pipe (7).

5. The seawater electrolysis hydrogen production equipment according to claim 4, characterized in that: The electrolysis mechanism (1) comprises an electrolytic cell (11), an electric controller (12) is installed on the outer wall of the electrolytic cell (11), a power conducting wire (13) is fixedly connected to the top surface of the electric controller (12), and a liquid storage chamber (14) is arranged inside the electrolytic cell (11).

6. A seawater electrolysis hydrogen production device according to claim 5, characterized in that: A diaphragm (17) is fixedly connected to the inner wall of the liquid storage chamber (14), a cathode plate (15) is fixedly installed on one side of the diaphragm (17), and an anode plate (16) is fixedly installed on the other side of the diaphragm (17), and the top end of the current-carrying wire (13) is electrically connected to the cathode plate (15) and the anode plate (16) respectively.

7. The seawater electrolysis hydrogen production equipment according to claim 6, characterized in that: Side heating plates (19) are provided on both sides of the liquid storage chamber (14), and the side heating plates (19) are fixedly connected to the inner wall of the electrolytic cell (11). A bottom heating plate (18) is fixedly connected to the bottom of the electrolytic cell (11), and the bottom heating plate (18) and the side heating plates (19) are both electrically connected to the electric controller (12).

8. A process for producing hydrogen by electrolysis of seawater, characterized in that: The seawater electrolysis hydrogen production device according to any one of claims 1 to 7 comprises the following steps: S1. Introducing seawater from the ocean through a pumping device, pre-treating the seawater and separating the divalent ions in the seawater using a nanofiltration process; S2, injecting sodium hydroxide into the hopper (5) through the feed pipe (51), and transporting the seawater after nanofiltration to the sedimentation tank (4) through the water inlet pipe (41) by a high-pressure pump, and using sodium hydroxide to increase the pH value of the seawater in the sedimentation tank (4) and form sodium chloride salting precipitation; S3, the treated seawater is pumped from the sedimentation tank (4) into the electrolysis mechanism (1) through the liquid extraction pipe (22) and the delivery pipe (21) by a water pump (2), and the water molecules of the seawater in the electrolysis mechanism (1) undergo oxidation and reduction reactions at the anode and cathode, respectively; Anode reaction: water decomposes to produce oxygen and hydrogen ions; Cathode reaction: hydrogen ions gain electrons to form hydrogen; S4, oxygen and hydrogen generated by seawater electrolysis are discharged from two exhaust pipes (31) respectively and collected for treatment; S5. Purify the collected hydrogen to remove residual impurities and moisture.

9. A process for producing hydrogen by electrolysis of seawater according to claim 8, characterized in that: In step S1, the pretreatment of seawater and separation of divalent ions in seawater by nanofiltration process includes the following steps: S11, preliminarily filtering the seawater to remove large particles and removing dissolved gases in the seawater by degassing; S12, using a high-pressure pump to deliver seawater into the nanofiltration device and provide pressure to push the seawater through the nanofiltration membrane, the nanofiltration membrane is a polyamide membrane or a cellulose membrane; S13. Under a certain pressure, sodium ions and water molecules in seawater can pass through the membrane, while divalent ions are retained on one side of the membrane.

10. A process for producing hydrogen by electrolysis of seawater according to claim 8, characterized in that: In step S2, the step of using sodium hydroxide to increase the pH value of seawater in the precipitation tank (4) and forming sodium chloride salting-out precipitation comprises the following steps: S21, controlling the sodium hydroxide in the hopper (5) to be fed into the sedimentation tank (4) through the feed pipe (52) to mix with the treated seawater, so as to increase the pH value of the seawater to alkaline; S22, in the sedimentation tank (4), when the concentration of sodium chloride in the seawater is relatively high, sodium hydroxide is added to cause salting out and precipitation of sodium chloride by means of the common ion effect; S23, the precipitated sodium chloride settles into the precipitation pipe (42) by gravity, and the servo motor (44) is started regularly to drive the transmission shaft (45) to turn the baffle (46) in the precipitation pipe (42) to discharge the precipitated sodium chloride into the screw feeder (6) for cleaning and discharge; S24. Collect the discharged sodium chloride.

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