System and method for obtaining high-concentration hydrogen iodide solution

Abstract

The invention discloses a system and a method for obtaining a high-concentration hydrogen iodide solution. The system comprises a boiler induced draft fan rear flue, a rectifying tower, a first heat exchanger, a Benzoic reactor and the like, the method comprises the following steps: flue gas containing sulfur dioxide discharged from a boiler induced draft fan enters a first heat exchanger and then exchanges heat with a mixed solution of iodine, hydrogen iodide and water in a rectifying tower; iodine, hydrogen iodide and water in the mixed liquid form steam, the steam penetrates through a filler layer from bottom to top to be in contact with low-temperature vaporific liquid from top to bottom, part of iodine and water vapor are condensed and fall into the lower portion of the rectifying tower, and part of iodine upwards reaches the upper portion of the rectifying tower; steam at the upper part of the rectifying tower enters a second heat exchanger to be continuously cooled, iodine and most of water in the steam are condensed and fall into the lower part of a second iodine-rich solution collecting box, a small amount of water vapor and hydrogen iodide gas enter a third heat exchanger to be cooled, and the water vapor is condensed and enters the hydrogen iodide solution collecting box; hydrogen iodide is dissolved in a solution in the hydrogen iodide solution collecting box to form a hydrogen iodide solution.

Description

Technical Field

[0001] The present invention relates to the technical field of boiler flue gas desulfurization and thermochemical hydrogen production, and specifically relates to a system and method for obtaining a high-concentration hydrogen iodide solution. Background Art

[0002] The catalytic decomposition of a high-concentration hydrogen iodide solution at high temperature is an important step in the sulfur-iodine cycle for hydrogen production. Currently, to obtain a high-concentration hydrogen iodide solution, the following steps need to be completed: (1) Sulfuric acid is catalytically decomposed at a high temperature above 800 °C to obtain sulfur dioxide; (2) Sulfur dioxide, iodine, and water undergo the Bunsen reaction to obtain a sulfuric acid solution and a hydrogen iodide solution; (3) In order to separate the sulfuric acid solution and the hydrogen iodide solution, an excessive amount of iodine needs to be added to the hydrogen iodide solution and the sulfuric acid solution. Since the hydrogen iodide solution has a strong ability to dissolve iodine, in the case of adding an excessive amount of iodine, the solution density of hydrogen iodide and iodine is large, and relatively speaking, the density of the sulfuric acid solution is small. After standing, the hydrogen iodide, iodine solution and the sulfuric acid solution are layered, and the hydrogen iodide, iodine solution and the sulfuric acid solution can be separated by using the density difference to form a mixed solution of hydrogen iodide, iodine and a small amount of sulfuric acid; (4) Using the reverse reaction to remove sulfuric acid from the mixed solution of hydrogen iodide, iodine and a small amount of sulfuric acid; (5) Using electrodialysis to remove part of the water in the hydrogen iodide, iodine solution; (6) Removing iodine and part of the water in the hydrogen iodide, iodine solution through rectification to obtain a high-concentration hydrogen iodide solution.

[0003] From the steps of obtaining a high-concentration hydrogen iodide solution above, it can be seen that the current process has the following problems: (1) The process is complex; (2) The decomposition of sulfuric acid requires a high temperature above 800 °C and a catalyst; (3) Electrodialysis requires power consumption; (4) Rectification requires additional heat consumption. Summary of the Invention

[0004] The purpose of the present invention is to provide a system and method for obtaining a high-concentration hydrogen iodide solution in view of the problems existing in the current obtaining of high-concentration hydrogen iodide.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: A system for obtaining a high-concentration hydrogen iodide solution includes a flue duct behind the boiler induced draft fan, a rectification column, a first heat exchanger, a Bunsen reactor and a flue gas discharge device; the flue gas coming out of the flue duct behind the boiler induced draft fan enters the first heat exchanger placed in the rectification column, the flue gas coming out of the first heat exchanger enters the Bunsen reactor, and the flue gas coming out of the Bunsen reactor enters the flue gas discharge device.

[0006] A further improvement of the present invention is that the rectification column is filled with a mixed liquid of iodine, hydrogen iodide and water.

[0007] A further improvement of the present invention is that the liquid level of the mixed liquid should at least submerge the first heat exchanger.

[0008] A further improvement of the present invention lies in that the molar ratio of hydrogen iodide to water in the mixed solution of iodine, hydrogen iodide and water is greater than 0.23.

[0009] A further improvement of the present invention lies in that the first heat exchanger is a tubular heat exchanger, with flue gas inside the tubes and the mixed solution of iodine, hydrogen iodide and water outside the tubes.

[0010] A further improvement of the present invention lies in that it further includes a hydrogen iodide mixed solution collection tank, a hydrogen iodide mixed solution pump, a first iodine-rich solution collection box, an iodine-rich solution pump and a packing layer; The iodine-rich solution flowing out of the rectification column converges into the first iodine-rich solution collection box. The solution coming out of the first iodine-rich solution collection box enters the Bunsen reactor through the iodine-rich solution pump. The hydrogen iodide mixed solution coming out of the Bunsen reactor enters the hydrogen iodide mixed solution collection tank. The hydrogen iodide mixed solution coming out of the hydrogen iodide mixed solution collection tank enters the upper part of the rectification column through the hydrogen iodide mixed solution pump via an atomizing nozzle and falls to the lower part of the rectification column through the packing layer.

[0011] A further improvement of the present invention lies in that it further includes a second heat exchanger and a second iodine-rich solution collection box. After the iodine vapor hydrogen iodide flowing out of the rectification column is cooled by the second heat exchanger, iodine condenses and falls into the second iodine-rich solution collection box, and hydrogen iodide accumulates in the upper part of the second iodine-rich solution collection box. When the iodine in the second iodine-rich solution collection box reaches a certain amount, it is discharged into the Bunsen reactor.

[0012] A further improvement of the present invention lies in that it further includes a third heat exchanger and a hydrogen iodide solution collection box. The hydrogen iodide in the upper part of the second iodine-rich solution collection box enters the hydrogen iodide solution collection box after being cooled by the third heat exchanger.

[0013] A method for obtaining a high-concentration hydrogen iodide solution, which is based on the system for obtaining a high-concentration hydrogen iodide solution described above, includes: The flue gas containing sulfur dioxide discharged from the boiler induced draft fan, whose temperature is between 100°C and 120°C, enters the first heat exchanger and exchanges heat with the mixed solution of iodine, hydrogen iodide and water in the rectification column. The temperature of the flue gas drops to 40 to 55°C, and the temperature of the mixed solution of iodine, hydrogen iodide and water rises by 80 to 110°C; After the temperature of the mixed solution of iodine, hydrogen iodide and water rises by 80 to 110°C, iodine, hydrogen iodide and water in the mixed solution form steam. The steam passes through the packing layer from bottom to top and contacts the low-temperature mist-like liquid from top to bottom. Part of the iodine and water vapor condense and fall into the lower part of the rectification column, and part of it reaches the upper part of the rectification column. The temperature of the steam reaching the upper part of the rectification column is between 60°C and 90°C; The steam at the upper part of the rectifying column enters the second heat exchanger for further cooling, and its temperature drops to 30°C to 40°C. The iodine and most of the water in the steam condense and fall to the lower part of the second iodine-rich solution collection tank. A small amount of water vapor and hydrogen iodide gas enter the third heat exchanger for further cooling to below 30°C. The water vapor condenses and enters the hydrogen iodide solution collection tank, and the hydrogen iodide dissolves into the solution in the hydrogen iodide solution collection tank to form a hydrogen iodide solution.

[0014] A further improvement of the present invention lies in that the molar ratio of hydrogen iodide to water in the hydrogen iodide solution is greater than 0.4.

[0015] Compared with the prior art, the present invention has at least the following beneficial technical effects: The system and method for obtaining a high-concentration hydrogen iodide solution provided by the present invention absorb sulfur dioxide in the boiler flue gas through an iodine solution, without obtaining sulfur dioxide by decomposing sulfuric acid at a high temperature above 800°C, greatly reducing energy consumption, and at the same time saving the cost of boiler flue gas desulfurization; the process does not require electrodialysis, saving the electricity cost and equipment cost; utilizes the waste heat of the boiler exhaust gas to complete the rectification and purification of the hydrogen iodide solution without additional heat consumption; after utilizing the waste heat of the boiler exhaust gas, the flue gas temperature drops, which is beneficial to the absorption of sulfur dioxide in the boiler flue gas by iodine, and at the same time can reduce the cost of the absorption tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a structural block diagram of a system for obtaining a high-concentration hydrogen iodide solution according to the present invention.

[0018] Description of the reference numerals: 1. Flue after the boiler induced draft fan, 2. First heat exchanger, 3. Bunsen reactor, 4. Flue gas discharge device, 5. Hydrogen iodide mixture collection tank, 8. Hydrogen iodide mixture pump, 7. First iodine-rich solution collection tank, 6. Iodine-rich solution pump, 9. Packing layer, 10. Rectifying column, 11. Second heat exchanger, 12. Second iodine-rich solution collection tank, 13. Third heat exchanger, 14. Hydrogen iodide solution collection tank. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In the following text, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present invention. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive.

[0020] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention.

[0021] Furthermore, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0022] In the present invention, unless otherwise clearly specified and limited, the terms such as "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the present invention, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0024] It should also be understood that the terms used in the specification of the present invention are merely for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms.

[0025] It should be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0026] Schematic diagrams of various structures according to the disclosed embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures and their relative sizes and positional relationships are merely exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations. And those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0027] Embodiments of the present invention will be described in detail below with reference to the drawings.

[0028] Embodiment 1 As Figure 1 shown, a system for obtaining a high-concentration hydrogen iodide solution provided in this embodiment includes a flue after the boiler induced draft fan 1, a rectification column 10, a first heat exchanger 2, a Bunsen reactor 3, and a flue gas discharge device 4; the flue gas coming out of the flue after the boiler induced draft fan 1 enters the first heat exchanger 2 placed in the rectification column 10, the flue gas coming out of the first heat exchanger 2 enters the Bunsen reactor 3, and the flue gas coming out of the Bunsen reactor 3 enters the flue gas discharge device 4. Among them, after the flue gas passes through the first heat exchanger, it enters the Bunsen reactor for further treatment. The Bunsen reactor can react or transform harmful substances in the flue gas to reduce their emission concentration, thereby reducing environmental pollution. This flue gas treatment method helps to improve the environmental protection benefit and conforms to the trend of increasingly strict environmental protection requirements for industrial production.

[0029] In this embodiment, the rectification column 10 is filled with a mixed solution of iodine, hydrogen iodide, and water, and the liquid level of the mixed solution should at least submerge the first heat exchanger 2. The molar ratio of hydrogen iodide to water in the mixed solution of iodine, hydrogen iodide, and water is greater than 0.23.

[0030] In this embodiment, the first heat exchanger 2 is a tube-type heat exchanger, with flue gas inside the tubes and a mixed solution of iodine, hydrogen iodide, and water outside the tubes.

[0031] In this embodiment, it further includes a hydrogen iodide mixed solution collection tank 5, a hydrogen iodide mixed solution pump 8, a first iodine-rich solution collection tank 7, an iodine-rich solution pump 6, and a packing layer 9; the iodine-rich solution flowing out of the distillation column 10 converges into the first iodine-rich solution collection tank 7, and the solution coming out of the first iodine-rich solution collection tank 7 enters the Bunsen reactor 3 through the iodine-rich solution pump 6. The hydrogen iodide mixed solution coming out of the Bunsen reactor 3 enters the hydrogen iodide mixed solution collection tank 5, and the hydrogen iodide mixed solution coming out of the hydrogen iodide mixed solution collection tank 5 enters the upper part of the distillation column 10 through the hydrogen iodide mixed solution pump 8 via an atomizing nozzle, and then falls to the lower part of the distillation column 10 through the packing layer 9. The present invention designs a recycling system for the iodine-rich solution, converges the iodine-rich solution flowing out of the distillation column 10 into the first iodine-rich solution collection tank 7, and then sends it into the Bunsen reactor 3 through the iodine-rich solution pump 6 for reaction. The hydrogen iodide mixed solution after the reaction returns to the hydrogen iodide mixed solution collection tank 5 and finally re-enters the distillation column 10 through the hydrogen iodide mixed solution pump 8 and the atomizing nozzle for further treatment. This recycling design not only improves the utilization efficiency of resources but also reduces the waste of raw materials. The hydrogen iodide mixed solution enters the upper part of the distillation column 10 through the atomizing nozzle and falls to the lower part of the distillation column 10 through the packing layer 9. This atomizing injection method increases the contact area between the mixed solution and the packing layer, improves the mass transfer and heat transfer efficiency, thereby strengthening the distillation process and contributing to better separation and purification of hydrogen iodide. The present invention designs a perfect solution collection and transportation system to ensure the stable flow and controllable transmission of the iodine-rich solution and the hydrogen iodide mixed solution in each link. This helps to maintain the stable operation of the entire system and improve the controllability and reliability of the production process. Through the cyclic treatment of the distillation column and the reaction of the Bunsen reactor, the present invention can effectively improve the yield and purity of hydrogen iodide. The packing layer and atomizing nozzle design in the distillation column contribute to better separation of hydrogen iodide and other impurities, thereby obtaining a higher purity hydrogen iodide product. The recycling system and efficient distillation process design of the present invention help to reduce production costs. By reducing the waste of raw materials and improving the utilization efficiency of resources, and by strengthening the distillation process to improve the yield and purity of hydrogen iodide, the cost expenditure in the production process can be reduced.

[0032] In this embodiment, it further includes a second heat exchanger 11 and a second iodine-rich solution collection tank 12. After the iodine vapor hydrogen iodide flowing out of the distillation column 10 is cooled by the second heat exchanger 11, iodine condenses and falls into the second iodine-rich solution collection tank 12, and hydrogen iodide accumulates in the upper part of the second iodine-rich solution collection tank 12. When the iodine collected in the second iodine-rich solution collection tank 12 reaches a certain amount, it is discharged into the Bunsen reactor 3.

[0033] In this embodiment, it further includes a third heat exchanger 13 and a hydrogen iodide solution collection tank 14. The hydrogen iodide in the upper part of the second iodine-rich solution collection tank 12 enters the hydrogen iodide solution collection tank 14 after being cooled by the third heat exchanger 13.

[0034] Example 2 As Figure 1 shown, a method for obtaining a high-concentration hydrogen iodide solution provided in this embodiment includes: The flue gas containing sulfur dioxide discharged from the boiler induced draft fan, whose temperature is between 100°C and 120°C, enters the first heat exchanger 2 and exchanges heat with the mixture of iodine, hydrogen iodide and water in the rectification column 10. The temperature of the flue gas drops to 40 to 55°C, and the temperature of the mixture of iodine, hydrogen iodide and water rises by 80 to 110°C; After the temperature of the mixture of iodine, hydrogen iodide and water rises by 80 to 110°C, iodine, hydrogen iodide and water in the mixture form steam. The steam passes through the packing layer 9 from bottom to top and contacts the low-temperature fog-like liquid from top to bottom. Part of the iodine and water vapor condense and fall into the lower part of the rectification column 10, and part of it reaches the upper part of the rectification column 10. The temperature of the steam reaching the upper part of the rectification column 10 is between 60°C and 90°C; The steam in the upper part of the rectification column 10 enters the second heat exchanger 11 to continue cooling, and the temperature drops to 30°C to 40°C. The iodine and most of the water in the steam condense and fall into the lower part of the second iodine-rich solution collection tank 12. A small amount of water vapor and hydrogen iodide gas enter the third heat exchanger 13 to be further cooled to below 30°C. The water vapor condenses and enters the hydrogen iodide solution collection tank 14, and hydrogen iodide dissolves into the solution in the hydrogen iodide solution collection tank 14 to form a hydrogen iodide solution. The molar ratio of hydrogen iodide to water in the hydrogen iodide solution is greater than 0.4.

[0035] The present invention uses the flue gas containing sulfur dioxide discharged from the boiler induced draft fan as a heat source and exchanges heat with the mixture of iodine, hydrogen iodide and water in the rectification column through the first heat exchanger. This design not only effectively utilizes the waste heat of the flue gas, but also avoids the energy waste caused by direct flue gas emission, improving the energy utilization efficiency. The present invention precisely controls the heat exchange process between the flue gas and the mixture, enabling the temperature of the mixture to rise by 80 to 110°C, promoting the effective separation of iodine, hydrogen iodide and water. The steam passes through the packing layer from bottom to top in the rectification column and contacts the low-temperature fog-like liquid, realizing an efficient mass transfer and heat transfer process and improving the rectification efficiency. After being processed by the rectification column and subsequent heat exchangers, a high-concentration hydrogen iodide solution with a molar ratio of hydrogen iodide to water greater than 0.4 is finally obtained. This high-concentration solution has wide application value in the fields of chemical industry, medicine, etc., and can meet the requirements of specific processes for the concentration of hydrogen iodide. The present invention effectively utilizes the waste heat of the flue gas, reduces the dependence on traditional energy sources, and reduces carbon emissions. At the same time, the steam and condensed water generated during the rectification process are fully utilized, reducing wastewater discharge and having significant environmental benefits. By optimizing the rectification process and increasing the concentration of the hydrogen iodide solution, the present invention reduces the production cost and increases the added value of the product. In addition, due to the utilization of the waste heat of the flue gas, the energy consumption is also reduced, further reducing the production cost and improving the economic benefits of the enterprise.

[0036] Example 3 In a certain power plant, the flue gas at 110 °C is extracted from behind the boiler induced draft fan and enters the surface heat exchanger in the rectification column, heating the superazeotropic solution formed by hydrogen iodide and iodine in the rectification column to 95 °C. Since the sublimation temperature of iodine is 44 °C, when the solution is heated to 95 °C, most of the iodine in the solution turns into iodine vapor. Since the boiling point of hydrogen iodide is -35 °C, a large amount of hydrogen iodide also volatilizes from the solution. Part of the water also evaporates to form water vapor. The iodine vapor, hydrogen iodide gas, and water vapor form a mixed gas. When the mixed gas ascends, it encounters the cooler fog-like droplets sprayed from the upper part, and the mixed gas cools down. Part of the iodine in the mixed gas sublimes and the water condenses and falls. Since the boiling point of hydrogen iodide is the lowest, less hydrogen iodide condenses, and the content of hydrogen iodide in the remaining mixed gas is relatively high. After the mixed gas is further cooled to 40 °C by the second heat exchanger 11, all the iodine in the mixed gas sublimes, and the remaining gas is water vapor and hydrogen iodide gas. The remaining gas is further cooled to below 30 °C by the third heat exchanger 13, and the water vapor condenses and enters the hydrogen iodide solution collection tank 14, and the hydrogen iodide dissolves into the solution in the hydrogen iodide solution collection tank 14, and the molar ratio of hydrogen iodide to water in the formed hydrogen iodide solution is greater than 0.4.

[0037] The foregoing shows and describes the basic principles, main features, and advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic features of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0038] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A system for obtaining a high concentration hydrogen iodide solution, characterized in that: It comprises a flue after a boiler induced draft fan (1), a distillation tower (10), a first heat exchanger (2), a Bunsen reactor (3) and a flue gas discharge device (4); The flue gas coming out of the flue duct (1) after the boiler induced draft fan enters the first heat exchanger (2) placed in the distillation tower (10), the flue gas coming out of the first heat exchanger (2) enters the Bunsen reactor (3), and the flue gas coming out of the Bunsen reactor (3) enters the flue gas discharge device (4).

2. A system for obtaining a high concentration hydrogen iodide solution according to claim 1, characterized in that: The distillation tower (10) contains a mixed liquid of iodine, hydrogen iodide and water.

3. A system for obtaining a high concentration hydrogen iodide solution according to claim 2, characterized in that: The liquid level of the mixed liquid must at least submerge the first heat exchanger (2).

4. A system for obtaining a high concentration hydrogen iodide solution according to claim 2, characterized in that: The molar ratio of hydrogen iodide to water in the mixed solution of iodine, hydrogen iodide and water is greater than 0.

23.

5. A system for obtaining a high concentration hydrogen iodide solution according to claim 2, characterized in that: The first heat exchanger (2) is a tubular heat exchanger, wherein the inside of the tube is flue gas and the outside of the tube is a mixed liquid of iodine, hydrogen iodide and water.

6. A system for obtaining a high concentration hydrogen iodide solution according to claim 2, characterized in that: It also includes a hydrogen iodide mixed liquid collection tank (5), a hydrogen iodide mixed liquid pump (8), a first iodine-rich solution collection box (7), an iodine-rich solution pump (6) and a packing layer (9); The iodine-rich solution flowing out of the distillation tower (10) is collected in the first iodine-rich solution collecting box (7), the solution flowing out of the first iodine-rich solution collecting box (7) enters the Bunsen reactor (3) through the iodine-rich solution pump (6), the hydrogen iodide mixed liquid flowing out of the Bunsen reactor (3) enters the hydrogen iodide mixed liquid collecting tank (5), the hydrogen iodide mixed liquid flowing out of the hydrogen iodide mixed liquid collecting tank (5) enters the upper part of the distillation tower (10) through the hydrogen iodide mixed liquid pump (8) and the atomizing nozzle, and falls to the lower part of the distillation tower (10) through the packing layer (9).

7. A system for obtaining a high concentration hydrogen iodide solution according to claim 6, characterized in that: The invention also comprises a second heat exchanger (11) and a second iodine-rich solution collecting box (12). After the iodine vapor hydrogen iodide flowing out of the distillation tower (10) is cooled by the second heat exchanger (11), the iodine condenses and falls into the second iodine-rich solution collecting box (12). The hydrogen iodide accumulates at the upper part of the second iodine-rich solution collecting box (12). After a certain amount of iodine is collected in the second iodine-rich solution collecting box (12), it is discharged into the Bunsen reactor (3).

8. A system for obtaining a high concentration hydrogen iodide solution according to claim 7, characterized in that: It also includes a third heat exchanger (13) and a hydrogen iodide solution collection box (14). The hydrogen iodide in the upper part of the second iodine-rich solution collection box (12) is cooled by the third heat exchanger (13) and then enters the hydrogen iodide solution collection box (14).

9. A method for obtaining a high concentration hydrogen iodide solution, characterized in that: The method is based on a system for obtaining a high-concentration hydrogen iodide solution according to claim 8, comprising: The flue gas containing sulfur dioxide discharged from the boiler induced draft fan has a temperature between 100°C and 120°C. After entering the first heat exchanger (2), the flue gas exchanges heat with the mixed liquid of iodine, hydrogen iodide and water in the distillation tower (10). The flue gas temperature drops to 40 to 55°C, while the temperature of the mixed liquid of iodine, hydrogen iodide and water rises to 80 to 110°C. After the temperature of the mixed liquid of iodine, hydrogen iodide and water rises to 80 to 110° C., the iodine, hydrogen iodide and water in the mixed liquid form steam, which passes through the packing layer (9) from bottom to top and contacts the low-temperature mist liquid from top to bottom. Part of the iodine and water vapor condenses and falls into the lower part of the distillation tower (10), and part of it goes up to the upper part of the distillation tower (10). The temperature of the steam reaching the upper part of the distillation tower (10) is between 60 and 90° C.; The steam from the upper part of the distillation tower (10) enters the second heat exchanger (11) and continues to cool. The temperature drops to 30°C to 40°C. The iodine and most of the water in the steam condense and fall into the lower part of the second iodine-rich solution collection tank (12). A small amount of water vapor and hydrogen iodide gas enter the third heat exchanger (13) and are further cooled to below 30°C. The water vapor condenses and enters the hydrogen iodide solution collection tank (14). The hydrogen iodide dissolves in the solution in the hydrogen iodide solution collection tank (14) to form a hydrogen iodide solution.

10. A method for obtaining a high concentration hydrogen iodide solution according to claim 9, characterized in that: The molar ratio of hydrogen iodide to water in the hydrogen iodide solution is greater than 0.4.

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