Device for electrolyzing sodium chloride

Abstract

The device comprises an electrolyte diaphragm tube, a positive stirring shaft and a negative shell, the electrolyte diaphragm tube is filled with sodium chloride and sodium tetrachloroaluminate, the positive stirring shaft is located in the electrolyte diaphragm tube and mixes the sodium chloride and the sodium tetrachloroaluminate, the negative shell is arranged outside the electrolyte diaphragm tube in a sleeving mode, and the positive stirring shaft is located in the negative shell and mixes the sodium chloride and the sodium tetrachloroaluminate. And the cathode shell is electrically connected with the electrolyte diaphragm tube through a conductive card. The device is applied to industrial production, sodium chloride powder can be continuously added for production, the sodium chloride powder is in full contact with molten sodium tetrachloroaluminate, the sodium chloride powder floats above the molten sodium tetrachloroaluminate, and the sodium chloride powder is in contact with the sodium tetrachloroaluminate only at an interface. And the problem of solid-solid contact between the electrolyte sodium chloride and the positive electrode material is effectively avoided, so that the electrolytic current efficiency is effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of electrolysis devices, and more specifically, to a device for electrolyzing sodium chloride. Background Art

[0002] The traditional sodium chloride melting electrolysis method is gradually replaced by diaphragm electrolysis, using beta-Al2O3 ceramics as diaphragm materials for electrolysis. However, the defects of this technology are: the cathode is filled with refined sodium as sodium species in advance, but refined sodium is easily oxidized or comes into contact with moisture in the air, which poses a high risk in the production process.

[0003] In view of the above-mentioned defects, the Chinese patent with publication number CN114622248A has been improved, and sodium tetrachloroaluminate and sodium chloride powder are mixed in a fixed ratio, as the raw material for electrolysis in the anode area, and placed in a diaphragm beta-Al2O3 ceramic tube, the anode is inserted into the sodium tetrachloroaluminate and sodium chloride powder, and the cathode and the conductive layer are electrically connected by a conductive connecting sheet to form a cathode area, and the anode area is provided with a chlorine gas collection device, and the cathode area is provided with a sodium discharge port. However, the current efficiency of this device when applied to industrial production is low, and the reasons are as follows: within the given electrolysis temperature range, the sodium tetrachloroaluminate in the anode area is in a molten state, and the sodium chloride powder is still in a solid state. When the sodium chloride powder is continuously supplemented during the electrolysis process, the sodium chloride powder easily floats above the molten sodium tetrachloroaluminate, and the additional sodium chloride powder is only in contact with the molten sodium tetrachloroaluminate at the interface, and the sodium tetrachloroaluminate is difficult to play a good sodium ion conduction effect, which reduces the electrolysis current efficiency. Utility Model Content

[0004] In order to improve the electrolysis current efficiency during the industrial production of electrolytic sodium chloride, the present application provides a device for electrolyzing sodium chloride.

[0005] The present application provides a device for electrolyzing sodium chloride, which adopts the following technical solution:

[0006] A device for electrolyzing sodium chloride, comprising:

[0007] An electrolyte membrane container, wherein the electrolyte membrane container is filled with sodium chloride and sodium tetrachloroaluminate;

[0008] A positive electrode stirring shaft is installed in the electrolyte membrane container and can rotate in the electrolyte membrane container;

[0009] A negative electrode shell is sleeved outside the electrolyte membrane container, and a sodium storage space is reserved between the negative electrode shell and the electrolyte membrane container;

[0010] A conductive card is installed in the sodium storage space, and the conductive card electrically connects the negative electrode shell and the electrolyte membrane container.

[0011] By adopting the above technical solution, the electrolyte diaphragm container can selectively allow sodium ions of sodium chloride to pass through while also being conductive. Sodium ions migrate to the negative electrode under the action of the electric field, and liquid metallic sodium is generated in the sodium storage space. The electrolyte diaphragm container separates the cathode region and the anode region, so that chlorine gas and metallic sodium can be generated separately, which can ensure production safety and omit the purification step to obtain high-purity metallic sodium.

[0012] At the same time, the positive electrode stirring shaft continuously stirs and mixes sodium chloride and sodium tetrachloroaluminate during the electrolysis process. Sodium chloride can be continuously added to the electrolyte diaphragm container during the electrolysis process, and it is ensured that the sodium chloride powder is in full contact with the molten sodium tetrachloroaluminate. The molten sodium tetrachloroaluminate has a good sodium ion conductivity, which avoids the problem of sodium chloride powder floating above the molten sodium tetrachloroaluminate and contacting the sodium tetrachloroaluminate only at the interface. It also effectively avoids the problem of solid-solid contact between the electrolyte sodium chloride and the positive electrode material, thereby effectively improving the electrolysis current efficiency.

[0013] Furthermore, at least one set of stirring blades is installed on the positive electrode stirring shaft.

[0014] By adopting the above technical solution, multiple groups of stirring blades can efficiently mix sodium chloride powder and molten sodium tetrachloroaluminate, thereby increasing the input amount of sodium chloride and expanding the production of metallic sodium.

[0015] Furthermore, the electrolyte membrane container includes a β"-Al2O3 membrane tube and a conductive layer, and the conductive layer is located on the outer wall of the β"-Al2O3 membrane tube.

[0016] By adopting the above technical solution, when the electrolyte membrane container is broken, the generated metallic sodium will come into contact with sodium tetrachloroaluminate, and the following reaction will occur: NaAlCl4+3Na→4NaCl+Al, and the metallic sodium will be converted into solid sodium chloride, thus avoiding the violent oxidation reaction of metallic sodium in contact with oxygen, and ensuring the safety of the device during use. At the same time, aluminum is generated in the cracks of the damaged electrolyte membrane container, and the aluminum blocks the cracks, preventing the short-circuit reaction from proceeding further.

[0017] Furthermore, a sealing cover is installed on the electrolyte membrane container, and a chlorine gas discharge port and a feed port are provided on the sealing cover.

[0018] By adopting the above technical solution, the sealing cover and the electrolyte diaphragm container form a sealing structure, the chlorine gas generated in the anode area is discharged from the chlorine gas outlet, and the sodium chloride solid can be continuously added from the feed port, thereby ensuring the safety of continuous production of the device.

[0019] Furthermore, the sealing cover is provided with a stirring shaft installation sealing opening, and the positive electrode stirring shaft extends into the electrolyte membrane container from the stirring shaft installation sealing opening.

[0020] By adopting the above technical solution, a sealing ring is installed at the sealing port, which further reduces the possibility of chlorine gas from the electrolysis device drifting into the air, thereby improving the safety of device production.

[0021] Furthermore, a power part is connected to the power end of the positive electrode stirring shaft.

[0022] By adopting the above technical solution, the power component can be a motor, and the power component is fixed on the sealing cover, so that the rotation speed of the positive electrode stirring shaft can be adjusted as needed.

[0023] Furthermore, a charging port is provided on the top of the negative electrode shell, and the charging port is connected to the sodium storage space.

[0024] By adopting the above technical solution, since the negative electrode shell and the electrolyte diaphragm container are sealed, the metallic sodium can be replaced by introducing nitrogen into the inflation port.

[0025] Furthermore, a high-temperature seal is installed between the conductive card and the electrolyte membrane container, and the high-temperature seal surrounds the outer side of the upper end opening of the electrolyte membrane container.

[0026] By adopting the above technical solution, the high-temperature seal seals the gap between the conductive card and the electrolyte diaphragm container, further reducing the possibility of chlorine gas leaking into the sodium storage space.

[0027] Furthermore, a sodium discharge port is provided at the bottom of the negative electrode shell.

[0028] By adopting the above technical solution, liquid metallic sodium can be fully discharged from the electrolysis device under the action of gravity. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the cross-sectional structure of the device for electrolyzing sodium chloride in Example 1.

[0030] Figure 2 for Figure 1 A magnified view of the structure.

[0031] Reference numerals:

[0032] 1. Electrolyte diaphragm container; 11. β"-Al2O3 diaphragm tube; 12. Conductive layer; 2. Positive stirring shaft; 21. Stirring blades; 22. Power parts; 3. Negative housing; 31. Sodium discharge port; 32. Inflating port; 4. Sealing cover; 41. Feeding port; 42. Chlorine discharge port; 43. Stirring shaft installation sealing port; 5. Sodium storage space; 6. Conductive card; 7. High-temperature sealing part; 8. Heating device; 81. Heating box; 82. Circulating oil. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the utility model clearer, the device proposed in the utility model is further described in detail below in combination with the accompanying drawings and specific implementation methods. According to the following description, the advantages and features of the utility model will be clearer. It should be noted that the accompanying drawings adopt a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the implementation method of the utility model. In order to make the purpose, features and advantages of the utility model more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structure, proportion, size, etc. illustrated by the accompanying drawings of this specification are only used to match the content disclosed in the specification, so that people familiar with this technology can understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so it has no technical substantive significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effect that the utility model can produce and the purpose that can be achieved, should fall within the scope of the technical content disclosed by the utility model.

[0034] Example

[0035] Example 1

[0036] Figure 1 The schematic diagram of the cross-sectional structure of the device for electrolyzing sodium chloride in Example 1 is shown in FIG. Figure 1 , a device for electrolyzing sodium chloride, comprises an electrolyte membrane container 1, a positive electrode stirring shaft 2 and a negative electrode shell 3. Sodium chloride and sodium tetrachloroaluminate are used as positive electrode materials and filled in the electrolyte membrane container 1. The positive electrode stirring shaft 2 extends into the electrolyte membrane container 1 to mix two positive electrode materials in different phases. The electrolyte membrane container 1 selectively passes sodium ions of the positive electrode material, and the sodium ions migrate to the negative electrode to generate liquid metallic sodium.

[0037] See also Figure 1The electrolyte membrane container 1 includes a β"-Al2O3 membrane tube 11 and a conductive layer 12. The β"-Al2O3 membrane tube 11 separates the anode area and the cathode area, avoiding the generation of chlorine in the anode area and the generation of metallic sodium in the cathode area. The chlorine and metallic sodium do not come into contact, thereby improving the safety of the device. If the electrolyte membrane container 1 ruptures, the generated metallic sodium will come into contact with sodium tetrachloroaluminate, and the following reaction will occur: NaAlCl4+3Na→4NaCl+Al, and the metallic sodium will be converted into solid sodium chloride, thereby avoiding the violent oxidation reaction of metallic sodium in contact with oxygen. At the same time, aluminum is generated in the broken cracks of the electrolyte membrane container 1, and the aluminum blocks the cracks, preventing the short-circuit reaction from proceeding further. The safety of the device production is guaranteed. The conductive layer 12 is attached to the outer wall of the β"-Al2O3 membrane tube 11. The material of the conductive layer 12 can be a conductive carbon layer or a conductive metal layer. The conductive carbon layer is used in this embodiment.

[0038] See also Figure 1 A sealing cover 4 is installed at the open end of the electrolyte membrane container 1, and a feeding port 41, a chlorine gas discharge port 42 and a stirring shaft installation sealing port 43 are provided on the sealing cover 4. The feeding port 41 is used to continuously add sodium chloride powder. In this embodiment, the amount of sodium chloride powder added is controlled to ensure that the sodium chloride powder can be quickly mixed with the liquid sodium tetrachloroaluminate and is not easy to float in the sealing cover 4. Liquid sodium tetrachloroaluminate has good sodium ion conductivity. The sodium chloride powder is fully coated by the liquid sodium tetrachloroaluminate, which avoids the problem that the conduction of sodium ions only occurs at the solid-liquid interface and the solid-solid contact between sodium chloride and the positive electrode material occurs, and the efficient conduction of sodium ions is achieved, thereby improving the electrolytic current efficiency.

[0039] See also Figure 1 The chlorine gas outlet 42 is directly connected to a chlorine gas collecting device (not shown) for chlorine gas purification. The agitator shaft installation sealing port 43 is used to insert the positive agitator shaft 2, and the positive agitator shaft 2 is sealed by a sealing ring to prevent chlorine gas from leaking from the gap between the positive agitator shaft 2 and the sealing cover 4, further ensuring the safety of production.

[0040] See also Figure 1 The power end of the positive stirring shaft 2 is connected to a power member 22, which is fixed on the sealing cover 4, and the power member 22 drives the positive stirring shaft 2 to rotate. At least one set of stirring blades 21 is installed on the positive stirring shaft 2, and the stirring blades 21 are located at one end of the positive stirring shaft 2 away from the power member 22. The material of the stirring blades 21 and the positive stirring shaft 2 can be selected from any one of nickel, graphite, ruthenium titanium, platinum and gold. In this embodiment, the material of the positive stirring shaft 2 is nickel.

[0041] See also Figure 1The negative electrode housing 3 is sleeved outside the electrolyte diaphragm container 1, and the top of the negative electrode housing 3 forms a sealing structure with the electrolyte diaphragm container 1 to prevent oxygen in the air from oxidizing the metallic sodium and ensure the quality of the metallic sodium. There is a sodium storage space 5 between the negative electrode housing 3 and the β"-Al2O3 diaphragm tube 11, and the sodium storage space 5 is used to collect the liquid metallic sodium generated by the negative electrode. The material of the negative electrode housing 3 can be selected from any one of carbon steel, tungsten steel, stainless steel, nickel, aluminum and graphite. In this embodiment, the material of the negative electrode housing 3 is nickel. A sodium discharge port 31 is arranged at the bottom of the negative electrode housing 3, and the sodium discharge port 31 is connected to the sodium storage space 5, and the generated liquid metallic sodium is fully discharged under the action of gravity.

[0042] See also Figure 1 A charging port 32 is provided on the top of the negative electrode shell 3, and the charging port 32 is connected to the sodium storage space 5. Nitrogen is introduced into the charging port 32, and the metallic sodium is fully discharged by air pressure. The operator can adjust the flow rate of the nitrogen so that the liquid level of the metallic sodium is consistent with the liquid level of the liquid sodium tetrachloroaluminate. At this time, the liquid metallic sodium is used as the negative electrode material to increase the contact surface between the negative electrode and the β"-Al2O3 ceramic tube, thereby improving the electrolysis efficiency.

[0043] See also Figure 1 A conductive card 6 is installed in the sodium storage space 5, and the conductive card 6 is electrically connected to the negative electrode housing 3 and the electrolyte membrane container 1. The conductive card 6 does not affect the production of liquid metal sodium. In this embodiment, the electrolysis voltage is controlled to be 2.72-3V. When the electrolysis voltage exceeds this electrolysis voltage or is lower than this electrolysis voltage range, sodium tetrachloroaluminate will also be electrolyzed, and the sodium ion conduction effect on sodium chloride is weakened, which reduces the electrolysis current efficiency.

[0044] Figure 2 for Figure 1 A magnified view of the structure at A. Figure 1 and Figure 2 A high-temperature seal 7 is installed between the conductive card 6 and the electrolyte membrane container 1. The high-temperature seal 7 surrounds the outer side of the upper end opening of the electrolyte membrane container 1. The high-temperature seal 7 seals the gap between the conductive card 6 and the electrolyte membrane container 1, further reducing the possibility of chlorine leakage into the sodium storage space 5.

[0045] See also Figure 1 A heating device 8 is provided outside the negative electrode shell 3, and the heating device 8 includes a heating box 81 and a circulating oil 82. The circulating oil 82 is stored in the heating box 81 and heated by the heating box 81. The negative electrode shell 3 is immersed in the circulating oil 82, and the oil bath is heated to the electrolysis reaction temperature of 270-320°C to achieve precise temperature control.

[0046] The implementation process of this embodiment is as follows: in the initial state where the negative electrode does not produce metallic sodium, first fill the electrolyte membrane container 1 with sodium tetrachloroaluminate powder; open the heat transfer oil heating box 81, heat the heat transfer oil circulating oil 82 to 270-320°C, and melt the sodium tetrachloroaluminate; open the feed port 41 and the positive electrode stirring shaft 2, and adjust the flow rate of the sodium chloride powder continuously added into the electrolyte membrane container 1, so that the sodium chloride powder is fully mixed with the liquid sodium tetrachloroaluminate molten salt. The liquid sodium tetrachloroaluminate molten salt plays an excellent sodium ion conduction role, greatly reducing the possibility of solid-solid contact between sodium chloride and the positive electrode stirring shaft 2, and also avoiding the situation that sodium chloride can only contact at the interface of liquid sodium tetrachloroaluminate, and the efficient transfer of ions in the solid electrolyte is guaranteed by the effective sodium ion medium conduction. Sodium ions migrate to the negative electrode to generate liquid metallic sodium.

[0047] As the electrolysis time increases, metallic sodium gradually fills up the sodium storage space 5, and the metallic sodium serves as the negative electrode material; the sodium discharge port 31 and the air filling port 32 are opened, and nitrogen enters the sodium storage space 5 as a replacement gas to push the static metallic sodium out of the electrolysis device.

[0048] Based on the production of 1kg of metallic sodium, the device consumes 3163.98kWh of electricity to produce one ton of metallic sodium, and the mass of chlorine produced is 3.08 tons.

[0049] 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.

[0050] Moreover, the above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A device for electrolyzing sodium chloride, characterized in that: include: An electrolyte membrane container (1), wherein the electrolyte membrane container (1) is filled with sodium chloride and sodium tetrachloroaluminate; A positive electrode stirring shaft (2) is installed in the electrolyte membrane container (1) and can rotate in the electrolyte membrane container (1); A negative electrode housing (3) is sleeved outside the electrolyte membrane container (1), and a sodium storage space (5) is reserved between the negative electrode housing (3) and the electrolyte membrane container (1); A conductive card (6) is installed in the sodium storage space (5), and the conductive card (6) electrically connects the negative electrode housing (3) and the electrolyte membrane container (1).

2. A device for electrolyzing sodium chloride as claimed in claim 1, characterized in that: At least one set of stirring blades (21) is installed on the positive electrode stirring shaft (2).

3. A device for electrolyzing sodium chloride as claimed in claim 1, characterized in that: The electrolyte membrane container (1) comprises a β"-Al2O3 membrane tube (11) and a conductive layer (12), wherein the conductive layer (12) is located on the outer wall of the β"-Al2O3 membrane tube (11).

4. A device for electrolyzing sodium chloride as claimed in claim 1, characterized in that: The electrolyte membrane container (1) is provided with a sealing cover (4), and the sealing cover (4) is provided with a chlorine gas discharge port (42) and a feed port (41).

5. A device for electrolyzing sodium chloride as claimed in claim 4, characterized in that: The sealing cover (4) is also provided with a stirring shaft installation sealing opening (43), and the positive electrode stirring shaft (2) extends into the electrolyte membrane container (1) through the stirring shaft installation sealing opening (43).

6. A device for electrolyzing sodium chloride as claimed in claim 1, characterized in that: The power end of the positive electrode stirring shaft (2) is connected to a power piece (22).

7. A device for electrolyzing sodium chloride as claimed in claim 1, characterized in that: The top of the negative electrode housing (3) is provided with an air filling port (32), and the air filling port (32) is in communication with the sodium storage space (5).

8. A device for electrolyzing sodium chloride as claimed in claim 1, characterized in that: A high-temperature seal (7) is installed between the conductive card (6) and the electrolyte membrane container (1), and the high-temperature seal (7) surrounds the outer side of the upper end opening of the electrolyte membrane container (1).

9. A device for electrolyzing sodium chloride as claimed in claim 1, characterized in that: The bottom of the negative electrode housing (3) is provided with a sodium discharge port (31).

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