Hydroiodic acid preparation device and method

Abstract

The invention relates to a hydroiodic acid preparation device and method, and relates to the technical field of new energy. The hydriodic acid preparation device comprises a first phosphoric acid circulating device, a second phosphoric acid circulating device, a hydriodic acid circulating device, a deiodide ion device and a membrane module, and the membrane module comprises a first phosphoric acid chamber, a second phosphoric acid chamber and a hydriodic acid chamber which are sequentially arranged and are in fluid communication. The second phosphoric acid chamber is communicated with the iodide ion removal device, so that even if a small amount of iodide ions enter the second phosphoric acid chamber, the iodide ions can enter the iodide ion removal device along with the circulation of the liquid to be subjected to deiodination treatment, the liquid subjected to deiodination treatment returns to the membrane module again to be recycled, and at the moment, the iodide ions contained in the circulating liquid do not exceed the standard; the iodide ions in the second phosphoric acid chamber cannot migrate to the first phosphoric acid chamber, so that the anode membrane cannot be damaged due to migration of the iodide ions, the service life of the membrane module can be greatly prolonged, and the production efficiency of the membrane module can be greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy, and particularly to a hydroiodic acid preparation device and method, especially a preparation device and method for raw materials of iodine batteries. Background Art

[0002] Hydroiodic acid is a raw material widely used in industry, especially an important raw material for iodine batteries. In existing devices for producing hydroiodic acid, for example, in a membrane group structure of one membrane and two chambers, the anode chamber and the cathode chamber share a single anode membrane. Hydroiodic acid is obtained by respectively carrying out oxidation and reduction reactions in the anode chamber and the cathode chamber. In actual production, it is found that the service life of the anode membrane far fails to reach its expected life. During the production process, production needs to be interrupted multiple times to replace the anode membrane, resulting in a serious decline in production capacity and high production costs. Summary of the Invention

[0003] The present invention provides a hydroiodic acid preparation device and method for solving at least one of the above technical problems.

[0004] According to a first aspect of the present invention, there is provided a hydroiodic acid preparation device, comprising: a first phosphoric acid circulation device, a second phosphoric acid circulation device, a hydroiodic acid circulation device, a deiodination ion device, and a membrane group. The membrane group includes a first phosphoric acid chamber, a second phosphoric acid chamber, and a hydroiodic acid chamber that are sequentially arranged and fluidly connected;

[0005] Wherein, the first phosphoric acid chamber is connected to the first phosphoric acid circulation device to form a circulation system, so that the liquid circulates between the first phosphoric acid chamber and the first phosphoric acid circulation device;

[0006] The second phosphoric acid chamber is connected to the deiodination ion device, and the liquid in the deiodination ion device flows into the second phosphoric acid circulation device after deiodination;

[0007] The hydroiodic acid chamber is connected to the hydroiodic acid circulation device, so that the liquid circulates between the hydroiodic acid chamber and the hydroiodic acid circulation device.

[0008] In an embodiment, the membrane group includes an anode membrane and a cation membrane. The space between the anode membrane and the cation membrane defines the second phosphoric acid chamber, and the concentration of iodide ions permeating from the hydroiodic acid chamber through the cation membrane into the liquid in the second phosphoric acid chamber is less than 0.05%.

[0009] In one embodiment, a second phosphoric acid chamber partition is provided between the anode membrane and the cationic membrane. A plurality of second phosphoric acid chamber partition channels are provided in the second phosphoric acid chamber partition. The liquid in the second phosphoric acid chamber can flow into the deiodination ion device through the plurality of second phosphoric acid chamber partition channels respectively, and the liquid in the second phosphoric acid circulation device can flow into the second phosphoric acid chamber through the second phosphoric acid chamber partition channels.

[0010] In one embodiment, the membrane assembly further includes an anode end plate having an anode end plate channel, an anode plate, and a positive chamber partition arranged in sequence. The positive chamber partition is located on the side of the anode membrane away from the cationic membrane, the anode end plate is located on the side of the anode plate away from the positive chamber partition, and the space between the anode end plate, the anode plate, the positive chamber partition, and the anode membrane defines the first phosphoric acid chamber. The reaction formula in the first phosphoric acid chamber is: O 2- - 2e = O 2 , 2H 2 O = 2OH - + 2H + = O 2 + 2H + .

[0011] In one embodiment, the membrane assembly further includes a cathode end plate having a cathode end plate channel and a cathode plate. The cathode plate is located on the side of the cationic membrane away from the anode membrane, the cathode end plate is located on the side of the cathode plate away from the cationic membrane, and the space between the cationic membrane, the cathode plate, and the cathode end plate defines the hydroiodic acid chamber. The reaction formula in the hydroiodic acid chamber is: I + e = I - , I - + H + = HI.

[0012] In one embodiment, a negative chamber partition is provided between the cationic membrane and the cathode plate. The membrane assembly further includes gaskets, and the gaskets are respectively located between the anode end plate and the anode plate, between the anode plate and the anode membrane, between the anode membrane and the second phosphoric acid chamber partition, between the second phosphoric acid chamber partition and the cationic membrane, between the cationic membrane and the negative chamber partition, between the negative chamber partition and the cathode plate, and between the cathode plate and the cathode end plate.

[0013] In one embodiment, a plurality of anode end plate side channels, a plurality of anode end plate upper channels, and a plurality of anode end plate lower channels are respectively provided on the anode end plate. A plurality of anode plate channels are provided on the anode plate, and a plurality of positive chamber partition channels are provided on the positive chamber partition;

[0014] The positive end plate, the anode plate, the anode chamber partition plate, and the second phosphoric acid chamber partition plate are in fluid communication through the flow channels thereon, such that the liquid in the second phosphoric acid chamber can flow into the deiodination ion device through a plurality of anode chamber partition plate flow channels, a plurality of second phosphoric acid chamber partition plate flow channels, a plurality of the anode plate flow channels, and a plurality of positive end plate upper end flow channels respectively, and the liquid after deiodination by the deiodination ion device can flow into the second phosphoric acid chamber through a plurality of positive end plate lower end flow channels, a plurality of the anode plate flow channels, a plurality of anode chamber partition plate flow channels, and a plurality of second phosphoric acid chamber partition plate flow channels.

[0015] In one embodiment, the deiodination ion device includes:

[0016] A deiodination circulation tank, the inlet of which is connected to the second phosphoric acid chamber;

[0017] A ceramic membrane iodine separation device, the inlet of which is connected to the outlet of the deiodination circulation tank, the outlet of which is connected to the inlet of the second phosphoric acid circulation device, and the ceramic membrane iodine separation device is used for separating elemental iodine in the liquid and inputting the liquid after solid-liquid separation into the second phosphoric acid circulation device; and

[0018] A chemical dosing device, which is connected to the pipeline between the inlet of the ceramic membrane iodine separation device and the outlet of the deiodination circulation tank.

[0019] In one embodiment, the chemical dosing device includes a metering tank and a metering pump connected to the metering tank, hydrogen peroxide is contained in the metering tank, and the metering pump can add the hydrogen peroxide in the metering tank to the ceramic membrane iodine separation device.

[0020] The present invention also provides a method for preparing hydroiodic acid, including the following steps:

[0021] A cation exchange membrane is disposed between the anode membrane and the cathode plate of the membrane group;

[0022] The second phosphoric acid chamber defined between the anode membrane and the cation exchange membrane is in communication with the deiodination ion device, such that the liquid in the second phosphoric acid chamber flows into the deiodination ion device;

[0023] The liquid in the deiodination ion device is subjected to solid-liquid separation to remove elemental iodine in the liquid, and the liquid after deiodination flows into the second phosphoric acid circulation device;

[0024] The liquid in the hydroiodic acid chamber of the membrane group circulates between the hydroiodic acid chamber and the hydroiodic acid circulation device.

[0025] Compared with the prior art, the advantages of the present invention are as follows: The second phosphoric acid chamber is connected to the deiodination ion device. In this way, even if a small amount of iodide ions enter the second phosphoric acid chamber, they will enter the deiodination ion device for deiodination treatment along with the liquid circulation. The liquid after deiodination treatment will then return to the membrane group for recycling. At this time, the iodide ions contained in the circulating liquid will not exceed the standard, and it will not cause the iodide ions in the second phosphoric acid chamber to migrate to the first phosphoric acid chamber, thereby ensuring that the anode membrane will not be damaged due to the migration of iodide ions. Therefore, the service life of the membrane group can be greatly improved.

[0026] Furthermore, experiments have proven that when the concentration of iodide ions in the liquid in the second phosphoric acid chamber is less than 0.05%, the transfer of iodide ions in the liquid in the second phosphoric acid chamber to the anode chamber will not occur, thus avoiding the damage of the anode membrane caused by the oxidation of iodide ions near the anode chamber side in the anode membrane during the transfer of iodide ions to the first phosphoric acid chamber (i.e., the anode chamber). BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Hereinafter, the present invention will be described in more detail based on embodiments and with reference to the drawings.

[0028] Figure 1 is a schematic structural diagram of a hydroiodic acid preparation device in an embodiment of the present invention;

[0029] Figure 2 is a schematic structural diagram of a membrane group in an embodiment of the present invention;

[0030] Figure 3 is a schematic structural diagram of the structure of the membrane group in an embodiment of the present invention, in which gaskets, anode chamber partitions, second phosphoric acid chamber partitions, and cathode chamber partitions are not shown;

[0031] Figure 4 、 Figure 5 and Figure 6 are respectively the front view, side view, and top view of the anode end plate in an embodiment of the present invention;

[0032] Figure 7 is a schematic structural diagram of the anode plate in an embodiment of the present invention;

[0033] Figure 8 is a schematic structural diagram of the cathode plate in an embodiment of the present invention;

[0034] Figure 9 is a schematic structural diagram of the second phosphoric acid chamber partition in an embodiment of the present invention;

[0035] Figure 10a is a schematic structural diagram of the anode membrane in an embodiment of the present invention;

[0036] Figure 10b is a schematic structural diagram of the anode chamber partition in an embodiment of the present invention;

[0037] Figure 11 It is a schematic structural diagram of the cathode chamber partition in the embodiment of the present invention;

[0038] Figure 12 and Figure 13 are respectively the front view and side view of the cathode end plate in the embodiment of the present invention.

[0039] Reference numerals:

[0040] 1. First phosphoric acid circulation device; 2. Second phosphoric acid circulation device; 3. Hydroiodic acid circulation device; 4. Iodine ion removal device; 5. Membrane group; 6. Power supply;

[0041] 11. First phosphoric acid circulation tank; 12. First phosphoric acid circulation pump;

[0042] 21. Second phosphoric acid circulation tank; 22. Second phosphoric acid circulation pump;

[0043] 31. Hydroiodic acid circulation tank; 32. Hydroiodic acid circulation pump;

[0044] 41. Ceramic membrane iodine separation device; 42. Iodine removal circulation tank; 43. Chemical dosing device; 44. Iodine removal circulation pump;

[0045] 431. Metering tank; 432. Metering pump;

[0046] 501. First phosphoric acid chamber; 502. Second phosphoric acid chamber; 503. Hydroiodic acid chamber;

[0047] 51. Anode end plate; 511. Anode end plate side flow channel; 512. Anode end plate upper flow channel; 513. Anode end plate lower flow channel;

[0048] 52. Anode plate; 521. Anode plate connection ear; 522. Anode plate flow channel;

[0049] 50. Anode chamber partition; 5001. Anode chamber partition flow channel;

[0050] 53. Anode membrane; 531. Anode membrane flow channel;

[0051] 54. Second phosphoric acid chamber partition; 541. Second phosphoric acid chamber partition flow channel;

[0052] 55. Cation exchange membrane; 56. Cathode chamber partition;

[0053] 57. Cathode plate; 571. Cathode plate connection ear;

[0054] 58. Cathode end plate; 581. Cathode end plate flow channel;

[0055] 59. Gasket. Detailed implementation manners

[0056] The present invention will be further described below in conjunction with the accompanying drawings.

[0057] When the existing one-membrane-two-chamber membrane group structure is used to produce hydroiodic acid, an important raw material for iodine batteries, the service life of the cation membrane in the membrane group structure is far from its expected life. The production process needs to be interrupted many times to replace the cation membrane, resulting in a serious decline in production capacity and high production costs.

[0058] In view of this phenomenon, the present invention creatively discovered that the anode chamber and the cathode chamber share a cation membrane. Since the cation membrane has the property of allowing cations to pass through and preventing anions from passing through, theoretically, iodine ions will not migrate from the cathode chamber to the anode chamber through the cation membrane. However, in practice, it is found that when the concentration of iodine ions in the liquid is high, for example, when the concentration of iodine ions in the hydroiodic acid in the membrane group is as high as 10% or more, a small amount of iodine ions (I - ) from the cathode chamber through the cation membrane to the anode chamber (the higher the concentration, the higher the iodine ion migration rate). During the migration process, some iodine ions enter the cation membrane and when they reach the side of the membrane close to the anode chamber, due to the oxidizing property of the area affected by the oxidizing property of the anode chamber, some iodine ions that do not have time to pass through the cation membrane will be oxidized. The oxidized iodine ions form elemental iodine. Since these elemental iodine are solid substances with oxidizing properties, their accumulation inside the cation membrane will cause blistering and bulging of the cation membrane, which will seriously affect the life of the cation membrane. In addition, the iodine ions that pass through the cation membrane and enter the cation chamber are oxidized to form elemental iodine. Most of the iodine element adheres to the surface of the cation membrane, causing the conductivity of the cation membrane to decrease, affecting production efficiency and greatly affecting the life of the cation membrane.

[0059] That is to say, based on the phenomenon that the life of the cation membrane in actual production is far from the expected, the present invention creatively discovered the technical problem that causes this phenomenon, namely, a small amount of anions will enter the interior of the cation membrane and / or penetrate the cation membrane and be oxidized into elemental solids. The accumulation of these elemental solids inside the cation membrane causes blistering and bulging of the cation membrane, thereby reducing the service life of the cation membrane.

[0060] Furthermore, in order to solve the technical problem that the life of the cation membrane is reduced due to the bubbling and bulging of the cation membrane during the above-mentioned raw material production process of iodine batteries, the present invention provides a hydroiodic acid preparation device.

[0061] like Figures 1 - 13 As shown, a hydroiodic acid preparation device of the present invention includes a first phosphoric acid circulation device 1, a second phosphoric acid circulation device 2, a hydroiodic acid circulation device 3, a deiodination ion device 4 and a membrane group 5, and the membrane group 5 includes a first phosphoric acid chamber 501, a second phosphoric acid chamber 502 and a hydroiodic acid chamber 503 which are arranged in sequence and are fluid-connected.

[0062] The electrolyte in the hydroiodic acid preparation device of the present invention is phosphoric acid, that is, the liquid circulating between the first phosphoric acid chamber 501 and the second phosphoric acid chamber 502 is phosphoric acid. The reason for using phosphoric acid as the electrolyte is that when other acids, such as sulfuric acid, are used as the electrolyte, sulfate ions are easily reduced to elemental sulfur after sulfuric acid penetrates through the cation exchange membrane into the cathode chamber. In the subsequent purification and concentration process of hydroiodic acid, if elemental sulfur volatilizes into the system, it will affect the evaporation and concentration and the product purity. Therefore, in the present invention, phosphoric acid is used as the electrolyte. Although phosphoric acid also penetrates through the cation exchange membrane into the cathode chamber and mixes into the hydroiodic acid, phosphate ions are generally not reduced. Therefore, the problem of elemental sulfur mixing into the hydroiodic acid is avoided. Further, even if there may be phosphate ions reduced to phosphorous acid, in the subsequent purification and concentration process of hydroiodic acid, it can be used to prevent the oxidation of hydroiodic acid during the concentration process. Therefore, phosphorous acid will not affect the subsequent purification and concentration of hydroiodic acid.

[0063] As Figure 1 shown, the first phosphoric acid circulation device 1 includes a first phosphoric acid circulation tank 11 and a first phosphoric acid circulation pump 12. The liquid outlet of the first phosphoric acid chamber 501 is connected to the inlet of the first phosphoric acid circulation tank 11, and the outlet of the first phosphoric acid circulation tank 11 is connected to the first phosphoric acid chamber 501 through the first phosphoric acid circulation pump 12, so that the liquid (phosphoric acid) circulates between the first phosphoric acid chamber 501 and the first phosphoric acid circulation device 1.

[0064] In addition, a liquid adding port is provided on the first phosphoric acid circulation tank 11, and phosphoric acid can be added to the first phosphoric acid circulation tank 11 through the liquid adding port.

[0065] The second phosphoric acid chamber 502 is connected to the deiodination ion device 4, so that the liquid in the second phosphoric acid chamber 502 flows into the deiodination ion device 4; the deiodination ion device 4 is connected to the second phosphoric acid circulation device 2, and the liquid in the deiodination ion device 4 flows into the second phosphoric acid circulation device 2 after deiodination.

[0066] The deiodination ion device 4 includes a deiodination circulation tank 42, a ceramic membrane iodine separation device 41 and a dosing device 43. The inlet of the deiodination circulation tank 42 is connected to the second phosphoric acid chamber 502, so that the liquid in the second phosphoric acid chamber 502 flows into the deiodination circulation tank 42.

[0067] The inlet of the ceramic membrane iodine separation device 41 is connected to the outlet of the deiodination circulation tank 42 through a deiodination circulation pump 44, and the outlet of the ceramic membrane iodine separation device 41 is connected to the inlet of the second phosphoric acid circulation device 2. The ceramic membrane iodine separation device 41 is used to separate elemental iodine in the liquid and input the liquid after solid-liquid separation into the second phosphoric acid circulation device 2.

[0068] The second phosphoric acid circulation device 2 includes a second phosphoric acid circulation tank 21 and a second phosphoric acid circulation pump 22. The outlet of the ceramic membrane iodine separation device 41 is connected to the liquid inlet of the second phosphoric acid circulation tank 21. Therefore, the ceramic membrane iodine separation device 41 inputs the liquid after solid-liquid separation into the second phosphoric acid circulation tank 21. The liquid outlet of the second phosphoric acid circulation tank 21 is connected to the second phosphoric acid chamber 502 through the second phosphoric acid circulation pump 22. The liquid in the second phosphoric acid circulation tank 21 that does not contain elemental iodine (solid) can be transported to the second phosphoric acid chamber 502 through the second phosphoric acid circulation pump 22.

[0069] The chemical dosing device 43 is connected to the pipeline between the inlet of the ceramic membrane iodine separation device 41 and the outlet of the deiodination circulation tank 42. The chemical dosing device 43 includes a metering tank 431 and a metering pump 432 connected to the metering tank 431. Hydrogen peroxide is contained in the metering tank 431, and the metering pump 432 can add the hydrogen peroxide in the metering tank 431 to the ceramic membrane iodine separation device 41. Since the liquid in the deiodination circulation tank 42 is the liquid from the second phosphoric acid chamber 502 and contains elemental iodine (solid), adding hydrogen peroxide to the ceramic membrane iodine separation device 41 through the metering tank 431 can oxidize iodide ions into elemental iodine under acidic conditions, thereby achieving solid-liquid separation. The separated liquid is the liquid that does not contain elemental iodine and can be returned to the second phosphoric acid circulation device 2.

[0070] The ceramic membrane can be, for example, an acid-alkali and oxidation-resistant separation membrane.

[0071] The hydroiodic acid chamber 503 is connected in a cycle with the hydroiodic acid circulation device 3, enabling the liquid to circulate between the hydroiodic acid chamber 503 and the hydroiodic acid circulation device 3.

[0072] The membrane group 5 includes an anode membrane 53 and a cation membrane 55. The space between the anode membrane 53 and the cation membrane 55 defines the second phosphoric acid chamber 502. Since the anode membrane 53 is in the first phosphoric acid chamber 501, which is the anodic chamber where the oxidation reaction occurs, the anode membrane 53 is set to have higher oxidation resistance than the cation membrane 55.

[0073] Furthermore, a second phosphoric acid chamber partition 54 with flow channels is arranged between the anode membrane 53 and the cation membrane 55. As Figure 9 shown, a plurality of second phosphoric acid chamber partition flow channels 541 are arranged in the second phosphoric acid chamber partition 54 with flow channels. The liquid in the second phosphoric acid chamber 502 can flow into the deiodination ion device 4 through the plurality of second phosphoric acid chamber partition flow channels 541 respectively, and the liquid in the second phosphoric acid circulation device 2 can flow into the second phosphoric acid chamber 502 through the second phosphoric acid chamber partition flow channels 541.

[0074] As Figure 4 、 Figure 5 and Figure 6As shown, the membrane assembly 5 further includes an anodic end plate 51 with an anodic end plate flow channel, an anode plate 52, and an anodic chamber partition 50 arranged in sequence. The anodic chamber partition 50 is located on the side of the anode membrane 53 away from the cation exchange membrane 55. The anodic end plate 51 is located on the side of the anode plate 52 away from the anodic chamber partition 50. The space between the anodic end plate 51, the anode plate 52, the anodic chamber partition 50, and the anode membrane 53 defines a first phosphoric acid chamber 501. The reaction formula in the first phosphoric acid chamber 501 is: O 2- - 2e = O 2 , 2H 2 O = 2OH - + 2H + = O 2 + 2H + .

[0075] As Figure 12 and Figure 13 shown, the membrane assembly 5 further includes a cathodic end plate 58 with a cathodic end plate flow channel 581 and a cathode plate 57. The cathode plate 57 is located on the side of the cation exchange membrane 55 away from the anode membrane 53. The cathodic end plate 58 is located on the side of the cathode plate 57 away from the cation exchange membrane 55. A cathodic chamber partition 56 is arranged between the cation exchange membrane 55 and the cathode plate 57; the space between the cation exchange membrane 55, the cathodic chamber partition 56, the cathode plate 57, and the cathodic end plate 58 defines a hydroiodic acid chamber 503. The reaction formula in the hydroiodic acid chamber 503 is: I + e = I - , I - + H + = HI.

[0076] Preferably, the cathode plate 57 is made of the same material as the anode plate 52. For example, both of them are made of noble metals such as ruthenium-iridium coated titanium. The cathode plate 57 designed in this way can play a role in suppressing the generation of hydrogen, thereby ensuring that iodine is first reduced to iodide ions and avoiding the generation of hydrogen.

[0077] A cathodic chamber partition 56 is arranged between the cation exchange membrane 55 and the cathode plate 57. The membrane assembly 5 further includes gaskets 59, which are respectively located between the anodic end plate 51 and the anode plate 52, between the anode plate 52 and the anode membrane 53, between the anode membrane 53 and the second phosphoric acid chamber partition 54, between the second phosphoric acid chamber partition 54 and the cation exchange membrane 55, between the cation exchange membrane 55 and the cathodic chamber partition 56, between the cathodic chamber partition 56 and the cathode plate 57, and between the cathode plate 57 and the cathodic end plate 58.

[0078] As Figure 2 and Figure 3As shown in the figure, generally speaking, the membrane assembly 5 includes a positive electrode end plate 51, a positive electrode plate 52, a positive chamber partition plate 50, a positive electrode membrane 53, a second phosphoric acid chamber partition plate 54, a cation exchange membrane 55, a negative chamber partition plate 56, a negative electrode plate 57, and a negative electrode end plate 58 arranged in sequence. Among them, gaskets 59 are provided between every two adjacent structures; for example, gaskets 59 are provided between the positive electrode end plate 51 and the positive electrode plate 52, between the positive electrode plate 52 and the positive chamber partition plate 50, between the positive chamber partition plate 50 and the positive electrode membrane 53, between the positive electrode membrane 53 and the second phosphoric acid chamber partition plate 54, between the second phosphoric acid chamber partition plate 54 and the cation exchange membrane 55, between the cation exchange membrane 55 and the negative chamber partition plate 56, between the negative chamber partition plate 56 and the negative electrode plate 57, and between the negative electrode plate 57 and the negative electrode end plate 58. In addition, holes (through holes penetrating in the thickness direction) are provided at corresponding positions on these gaskets 59, that is, the gaskets 59 are constructed in the form of perforated gaskets, and the holes on them can be used to form fluid communication channels with the adjacent structures on their left and right sides.

[0079] The space between the positive electrode end plate 51, the positive electrode plate 52, and the positive electrode membrane 53 defines the first phosphoric acid chamber 501, and the first phosphoric acid chamber 501 is a positive chamber, and the reaction therein is an oxidation reaction. The first phosphoric acid chamber 501 plays a role in generating hydrogen ions during the electrochemical reaction process in the membrane assembly 5.

[0080] The space between the positive electrode membrane 53 and the cation exchange membrane 55 defines the second phosphoric acid chamber 502, and the second phosphoric acid chamber 502 is a proton chamber, and the liquid therein does not participate in the reaction but only transfers hydrogen ions (protons). The space between the cation exchange membrane 55, the negative electrode plate 57, and the negative electrode end plate 58 defines the hydroiodic acid chamber 503, and the hydroiodic acid chamber 503 is a negative chamber, and the reaction therein is a reduction reaction.

[0081] Since the second phosphoric acid chamber 502 that does not participate in the reaction is defined in the present invention, the concentration of iodide ions permeating through the cation exchange membrane 55 from the hydroiodic acid chamber 503 in the liquid in the second phosphoric acid chamber 502 should be ensured to be less than 0.05% (the iodide ion concentration in the liquid in the second phosphoric acid chamber 502 can be ensured to be less than 0.05% through the deiodination ion device). Under this concentration condition, it will not cause the migration of iodide ions in the second phosphoric acid chamber 502 to the first phosphoric acid chamber 501, thereby ensuring that the positive electrode membrane 53 will not be damaged due to the migration of iodide ions.

[0082] As described above, a small amount of iodide ions may penetrate through the cation exchange membrane 55 and enter the second phosphoric acid chamber 502. The second phosphoric acid chamber 502 is connected to the deiodination ion device 4, so that the liquid in the second phosphoric acid chamber 502 flows into the deiodination ion device 4 for deiodination treatment, thereby removing the iodide ions in the original liquid, and the liquid after removing the iodide ions returns to the second phosphoric acid chamber 502 for continuous circulation.

[0083] Therefore, in the present invention, by adding the second phosphoric acid chamber 502 (proton chamber) between the anode membrane 53 and the cation membrane 55 and the deiodination ion device 4, even if iodide ions can permeate through the cation membrane 55 into the second phosphoric acid chamber 502, the iodide ion concentration in the second phosphoric acid chamber 502 is made lower than 0.05% through the deiodination ion process. Under this concentration condition, no iodide ions will permeate through the anode membrane 53 into the first phosphoric acid chamber 501 (anode chamber), thereby improving the service life of the cation membrane 55 and ensuring the production efficiency of the membrane module.

[0084] As Figure 4 shown, the anode end plate 51 is provided with anode end plate flow channels, and the anode end plate flow channels include a plurality of anode end plate side flow channels 511, a plurality of anode end plate upper flow channels 512, and a plurality of anode end plate lower flow channels 513. Each of the above flow channels is independent of each other. As Figure 4 and Figure 6 shown, a plurality of anode end plate upper flow channels 512 are arranged side by side, and their extending directions are all perpendicular to the extending direction of the anode end plate side flow channels 511.

[0085] As Figure 5 shown, the anode end plate side flow channels 511 can be, for example, holes opened on the left and right two sides of the anode end plate 51. The anode end plate upper flow channels 512 and the anode end plate lower flow channels 513 can be holes respectively opened on the upper surface of the anode end plate 51 near its upper end and near its lower end, and the anode end plate upper flow channels 512 and the anode end plate lower flow channels 513 are symmetrically arranged with respect to the anode end plate 51.

[0086] A plurality of anode end plate side flow channels 511 can be respectively communicated with the first phosphoric acid circulation tank 11, so that the liquid can circulate between the first phosphoric acid circulation tank 11 and the first phosphoric acid chamber 501; a plurality of anode end plate upper flow channels 512 can be respectively connected to the second phosphoric acid circulation tank 21 and the deiodination circulation tank 42, and a plurality of anode end plate lower flow channels 513 can be respectively connected to the second phosphoric acid circulation tank 21 and the deiodination circulation tank 42, so that the liquid can circulate between the second phosphoric acid circulation tank 21 and the deiodination circulation tank 42.

[0087] As Figure 7 shown, a plurality of anode plate flow channels 522 are provided on the anode plate 52. The anode plate flow channels 522 are configured as holes penetrating the thickness direction of the anode plate 52 (for example, 6 holes are provided, or more holes can be provided), and the holes on the anode plate 52 for forming the anode plate flow channels 522 correspond one by one to the holes on the anode end plate 51 for forming the anode end plate upper flow channels 512 and the anode end plate lower flow channels 513 respectively. Therefore, after the anode plate 52 and the anode end plate 51 are pressed against each other, the holes on the two are aligned with each other, so that a flow channel for liquid circulation can be formed.

[0088] As Figure 9As shown in the figure, a plurality of second phosphoric acid chamber partition channels 541 are provided on the second phosphoric acid chamber partition 54. The structure of the second phosphoric acid chamber partition channels 541 is holes penetrating the thickness direction of the second phosphoric acid chamber partition (for example, 6 holes are provided, or more holes can be provided) and grooves communicating with the corresponding holes. Moreover, the holes on the second phosphoric acid chamber partition 54 for forming the second phosphoric acid chamber partition channels 541, the holes on the anode plate 52 for forming the anode plate channels 522, and the holes on the positive end plate 51 for forming the upper positive end plate channel 512 and the lower positive end plate channel 513 correspond one by one. Therefore, after the second phosphoric acid chamber partition 54, the anode plate 52, and the positive end plate 51 are pressed together, the holes thereon are aligned with each other, so that channels for liquid to flow through can be formed.

[0089] As Figure 10b shown in the figure, a plurality of positive chamber partition channels 5001 are provided on the positive chamber partition 50. The positive chamber partition channels 5001 are structured as holes penetrating the thickness direction of the positive chamber partition 50 (for example, 6 holes are provided, or more holes can be provided). Moreover, the holes on the second phosphoric acid chamber partition 54 for forming the second phosphoric acid chamber partition channels 541, the holes on the anode plate 52 for forming the anode plate channels 522, and the holes on the positive end plate 51 for forming the upper positive end plate channel 512 and the lower positive end plate channel 513 correspond one by one. Therefore, after the second phosphoric acid chamber partition 54, the positive chamber partition 50, the anode plate 52, and the positive end plate 51 are pressed together, the holes thereon are aligned with each other, so that channels for liquid to flow through can be formed.

[0090] Similarly, as Figure 10a shown in the figure, a plurality of anode membrane channels 531 are provided on the anode membrane 53. The anode membrane channels 531 are structured as holes penetrating the thickness direction of the anode membrane 53 (for example, 6 holes are provided, or more holes can be provided). Moreover, the holes on the anode membrane 53 for forming the anode membrane channels 531, the holes on the positive chamber partition 50 for forming the positive chamber partition channels 5001, the holes on the second phosphoric acid chamber partition 54 for forming the second phosphoric acid chamber partition channels 541, the holes on the anode plate 52 for forming the anode plate channels 522, and the holes on the positive end plate 51 for forming the upper positive end plate channel 512 and the lower positive end plate channel 513 correspond one by one. Therefore, after the positive chamber partition 50, the anode membrane 53, the second phosphoric acid chamber partition 54, the anode plate 52, and the positive end plate 51 are pressed together, the holes thereon are aligned with each other, so that channels for liquid to flow through can be formed.

[0091] As Figure 12 shown in the figure, a cathode end plate channel 581 is provided on the cathode end plate 58. It can have one type of channel, and the number thereof can be multiple, which is used to communicate with the hydroiodic acid circulation device 3, so that the liquid can circulate between the hydroiodic acid chamber 503 and the hydroiodic acid circulation device 3. The cathode end plate channel 581 can be a hole opened on the side surface of the cathode end plate 58.

[0092] Understandably, the holes on the gasket 59 respectively correspond one-to-one to the holes on the positive end plate 51, the anode plate 52, the anode chamber partition 50, the anode membrane 53 and the second phosphoric acid chamber partition 54 for forming flow channels (that is, the number of holes and the spacing between adjacent holes are the same). After pressing it between the positive end plate 51 and the anode plate 52, and between the anode membrane 53 and the second phosphoric acid chamber partition 54, flow channels for liquid to flow through can be formed.

[0093] Similarly, the negative end plate 58, the cathode plate 57, the cathode chamber partition 56 and the gasket therebetween are in fluid communication through the flow channels configured as holes thereon, so that the liquid can enter the hydroiodic acid circulation device 3 from the hydroiodic acid chamber 503 via these flow channels configured as holes, and enter the hydroiodic acid chamber 503 from the hydroiodic acid circulation device 3 via these flow channels configured as holes.

[0094] As Figure 7 and Figure 8 shown, a plurality of anode plate connection lugs 521 are further provided on the anode plate 52, and a plurality of cathode plate connection lugs 571 are further provided on the cathode plate 57. As Figure 1 shown, the membrane assembly 5 is connected to the power supply 6. The power supply 6 is a DC power supply, its positive pole is electrically connected to the anode plate connection lug 521, and its negative pole is electrically connected to the cathode plate connection lug 571, so as to supply power to the membrane assembly 5.

[0095] The raw material for preparing hydroiodic acid is elemental iodine. Elemental iodine is dissolved in hydroiodic acid (for example, with a concentration of 20%) to prepare hydrogen triiodide, and hydrogen triiodide is stored in a hydrogen triiodide storage tank. A metering feed pump is connected to the hydrogen triiodide storage tank. The metering feed pump is connected to the outlet of the hydroiodic acid circulation pump. Hydrogen triiodide is metered by the metering pump and added to the inlet of the hydroiodic acid chamber 503, and enters the membrane assembly 5 to undergo a reduction reaction. Hydrogen triiodide is reduced to form hydroiodic acid. A finished product output port is provided at the outlet of the hydroiodic acid chamber 503 of the membrane assembly 5, which is controlled by two or more regulating valves respectively, and the output amount is adjusted to be equal to the addition amount of the metering pump, so that the finished hydroiodic acid product output enters the hydroiodic acid storage tank. The finished hydroiodic acid product can be further purified into a qualified hydroiodic acid product with a concentration of 57% through an evaporation and concentration system.

[0096] In addition, the present invention also provides a method for preparing hydroiodic acid, including the following steps:

[0097] In the first step, a cation exchange membrane 55 is arranged between the anode membrane 53 and the cathode plate 57 of the membrane assembly 5. Different from the existing membrane assembly structure of one membrane and two chambers, the present invention can improve the service life of the membrane and ensure the production efficiency of the membrane assembly by arranging two cation exchange membranes, namely the anode membrane 53 and the cation exchange membrane 55.

[0098] Second, the space between the anode membrane 53 and the cation membrane 55 defines the second phosphoric acid chamber 502 of the membrane assembly 5. The second phosphoric acid chamber 502 communicates with the deiodination ion device 4, so that the liquid in the second phosphoric acid chamber 502 flows into the deiodination ion device 4.

[0099] Third, the liquid in the deiodination ion device 4 undergoes solid-liquid separation to remove elemental iodine from the liquid, and the deiodinated liquid flows into the second phosphoric acid circulation device 2.

[0100] Fourth, an oxidation reaction occurs in the first phosphoric acid chamber 501.

[0101] Fifth, the liquid in the hydroiodic acid chamber 503 of the membrane assembly 5 circulates between the hydroiodic acid chamber 503 and the hydroiodic acid circulation device 3, and a reduction reaction occurs in the hydroiodic acid chamber 503 to reduce hydrogen triiodide to hydroiodic acid.

[0102] Therefore, it can be known that in the process of obtaining hydroiodic acid in the above cycle, by deiodinating the liquid in the second phosphoric acid chamber 502, even if a small amount of iodide ions can penetrate the cation membrane 55 and enter the second phosphoric acid chamber 502, they will enter the deiodination ion device 4 for deiodination treatment along with the circulation of the liquid. The deiodinated liquid then returns to the second phosphoric acid chamber 502 in the membrane assembly 5 for recycling. At this time, the circulating liquid is the liquid from which iodide ions have been removed, thus avoiding the accumulation of iodide ions in the second phosphoric acid chamber 502 on the anode membrane 53 and the oxidation to elemental iodine, which may cause damage to the anode membrane 53, and greatly improving the service life of the anode membrane 53 and the production efficiency of the membrane assembly.

[0103] Although the present invention has been described with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A hydroiodic acid preparation device, characterized in that, include: A first phosphoric acid circulation device, a second phosphoric acid circulation device, a hydroiodic acid circulation device, a deiodination device and a membrane group, wherein the membrane group comprises a first phosphoric acid chamber, a second phosphoric acid chamber and a hydroiodic acid chamber which are sequentially arranged and connected to each other by fluid; wherein the first phosphoric acid chamber is connected to the first phosphoric acid circulation device to form a circulation system, so that liquid circulates between the first phosphoric acid chamber and the first phosphoric acid circulation device; The second phosphoric acid chamber is connected to the deiodination device, and the liquid in the deiodination device flows into the second phosphoric acid circulation device after deiodination; The hydroiodic acid chamber is connected to the hydroiodic acid circulation device, so that liquid circulates between the hydroiodic acid chamber and the hydroiodic acid circulation device.

2. The hydroiodic acid preparation device according to claim 1, characterized in that: The membrane group includes an anode membrane and a cationic membrane, the space between the anode membrane and the cationic membrane defines the second phosphoric acid chamber, and the concentration of iodine ions in the liquid in the second phosphoric acid chamber that permeates the cationic membrane from the hydroiodic acid chamber is less than 0.05%.

3. The hydroiodic acid preparation device according to claim 2, characterized in that: A second phosphoric acid chamber partition is arranged between the anode membrane and the cationic membrane, and a plurality of second phosphoric acid chamber partition flow channels are arranged in the second phosphoric acid chamber partition. The liquid in the second phosphoric acid chamber can flow into the deiodination device respectively through the plurality of second phosphoric acid chamber partition flow channels, and the liquid in the second phosphoric acid circulation device can flow into the second phosphoric acid chamber through the second phosphoric acid chamber partition flow channels.

4. The hydroiodic acid preparation device according to claim 3, characterized in that: The membrane group also includes an anode end plate, an anode plate and a cation chamber partition which are sequentially arranged and have an anode end plate flow channel. The cation chamber partition is located on the side of the anode membrane away from the cation membrane. The anode end plate is located on the side of the anode plate away from the cation chamber partition. The space between the anode end plate, the anode plate, the cation chamber partition and the anode membrane defines the first phosphoric acid chamber. The reaction formula in the first phosphoric acid chamber is: 2- -2e=O2,2H2O=2OH - +2H + =O2+2H + .

5. The hydroiodic acid preparation device according to claim 4, characterized in that: The membrane group also includes a cathode end plate and a cathode plate having a cathode end plate flow channel, wherein the cathode plate is located on a side of the cationic membrane away from the anode membrane, and the cathode end plate is located on a side of the cathode plate away from the cationic membrane. The space between the cationic membrane, the cathode plate and the cathode end plate defines the hydroiodic acid chamber, and the reaction formula in the hydroiodic acid chamber is: I+e=I - , I - +H + =HI.

6. The hydroiodic acid preparation device according to claim 5, characterized in that: A cathode chamber partition is arranged between the cationic membrane and the cathode plate, and the membrane group also includes a gasket, which is respectively located between the anode end plate and the anode plate, between the anode plate and the anode membrane, between the anode membrane and the second phosphoric acid chamber partition, between the second phosphoric acid chamber partition and the cationic membrane, between the cationic membrane and the cathode chamber partition, between the cathode chamber partition and the cathode plate, and between the cathode plate and the cathode end plate.

7. The hydroiodic acid preparation device according to claim 6, characterized in that: The anode end plates are respectively provided with a plurality of anode end plate side flow channels, a plurality of anode end plate upper end flow channels and a plurality of anode end plate lower end flow channels, the anode plate is provided with a plurality of anode plate flow channels, and the anode chamber partition is provided with a plurality of anode chamber partition flow channels; The anode end plate, the anode plate, the cation chamber partition and the second phosphoric acid chamber partition are connected through the flow channel fluid thereon, so that the liquid in the second phosphoric acid chamber can flow into the deiodination device through multiple cation chamber partition flow channels, multiple second phosphoric acid chamber partition flow channels, multiple anode plate flow channels and multiple anode end plate upper flow channels respectively, and the liquid after deiodination by the deiodination device can flow into the second phosphoric acid chamber through multiple anode end plate lower end flow channels, multiple anode plate flow channels, multiple cation chamber partition flow channels and multiple second phosphoric acid chamber partition flow channels.

8. The hydroiodic acid preparation device according to claim 1 or 2, characterized in that: The deiodination ion device comprises: a deiodine circulation tank, the inlet of which is connected to the second phosphoric acid chamber; a ceramic membrane iodine separation device, wherein the inlet of the ceramic membrane iodine separation device is connected to the outlet of the deiodine circulation tank, the outlet of the ceramic membrane iodine separation device is connected to the inlet of the second phosphoric acid circulation device, the ceramic membrane iodine separation device is used to separate the elemental iodine in the liquid, and input the liquid after solid-liquid separation into the second phosphoric acid circulation device; and A dosing device is connected to a pipeline between the inlet of the ceramic membrane iodine separation device and the outlet of the deiodine circulation tank.

9. The hydroiodic acid preparation device according to claim 8, characterized in that: The dosing device comprises a metering box and a metering pump connected to the metering box. The metering box contains hydrogen peroxide. The metering pump can add the hydrogen peroxide in the metering box to the ceramic membrane iodine separation device.

10. A method for preparing hydroiodic acid, characterized in that: The following steps are involved: A cationic membrane is arranged between the anode membrane and the cathode plate of the membrane group; The second phosphoric acid chamber defined between the anode membrane and the cationic membrane is connected to the deiodination device, so that the liquid in the second phosphoric acid chamber flows into the deiodination device; The liquid in the deiodination device is subjected to solid-liquid separation to remove the elemental iodine in the liquid, and the deiodinated liquid flows into the second phosphoric acid circulation device. The liquid in the hydroiodic acid chamber of the membrane group circulates between the hydroiodic acid chamber and the hydroiodic acid circulation device.

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