System and method for purifying raw reaction product by utilizing purified flue gas of boiler
By replacing nitrogen with boiler clean flue gas to purify heavy liquid and light liquid, the problems of poor economy and complex system in the prior art are solved, and efficient and low-cost purification effect is achieved.
Patent Information
- Application Number
- CN202510566937.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-30
- Publication Date
- 2025-08-01
AI Technical Summary
In the prior art, the purification process of heavy and light liquids requires additional preparation or procurement of nitrogen for heating and purge, resulting in poor economic efficiency. After purge, the nitrogen contains sulfur dioxide and needs further treatment, and the system process is complicated and industrial production cannot be achieved.
The boiler clean flue gas is used instead of nitrogen for purging, and the high-temperature flue gas from the outlet of the boiler induced fan is used to purify the heavy liquid and light liquid, and the reaction between the clean flue gas and the solution is used for separation and purification, simplifying the system process and reducing the need for additional heat sources.
It saves operating costs and investment costs, simplifies system processes, improves purification efficiency, and reduces the processing complexity of sulfur dioxide flue gas.
Smart Images
Figure CN120393887A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical fields of hydrogen production and boiler environmental protection, and particularly relates to a system and method for purifying the products of the Bunsen reaction by using the clean flue gas of a boiler. Background Art
[0002] In the sulfur-iodine cycle for hydrogen production, sulfur dioxide, iodine and water react to produce a sulfuric acid solution and a hydrogen iodide solution, and this reaction is called the Bunsen reaction. After the Bunsen reaction proceeds to a certain extent, the mixed solution of hydrogen iodide and iodine has a relatively large density and is called the heavy liquid, while the sulfuric acid solution has a relatively small density and is called the light liquid. After the heavy liquid and the light liquid stand still, they are stratified, and the heavy liquid and the light liquid can be separated by using the stratification. However, at this time, the heavy liquid still contains a small amount of sulfuric acid, and the sulfuric acid in the heavy liquid needs to be removed by purification. The light liquid still contains a small amount of the mixed solution of hydrogen iodide and iodine, and the small amount of the mixed solution of hydrogen iodide and iodine in the light liquid needs to be removed by purification.
[0003] At present, the purification of the heavy liquid and the light liquid requires heating nitrogen to 100°C to 180°C, using nitrogen purge, and realizing purification through the reverse reaction of the Bunsen reaction. A small amount of sulfuric acid in the heavy liquid undergoes a reverse reaction during the high-temperature nitrogen purge, and sulfuric acid and the hydrogen iodide solution react to produce sulfur dioxide, iodine and water. A small amount of hydrogen iodide in the light liquid undergoes a reverse reaction during the high-temperature nitrogen purge, and hydrogen iodide and the sulfuric acid solution react to produce sulfur dioxide, iodine and water. This method has the following problems, making its economy poor and unable to achieve industrial production.
[0004] (1) Additional preparation or purchase of nitrogen; (2) Additional heating of nitrogen is required; (3) The purged nitrogen contains sulfur dioxide and needs further treatment; (4) The purged nitrogen contains heat and needs further recovery. Summary of the Invention
[0005] In view of the current uneconomical purification of the heavy liquid and the light liquid, the present invention provides a system and method for purifying the products of the Bunsen reaction by using the clean flue gas of a boiler.
[0006] To achieve the above object, the present invention adopts the following technical solutions: A system for purifying the products of the Bunsen reaction by using the clean flue gas of a boiler includes an outlet flue of a boiler induced draft fan, a heat exchanger, a Bunsen reaction module, a clean flue gas fan and a chimney; The outlet of the outlet flue of the boiler induced draft fan is communicated with the flue gas inlet of the heat exchanger, the flue gas outlet of the heat exchanger is communicated with the flue gas inlet of the Bunsen reaction module, the clean flue gas outlet of the Bunsen reaction module is divided into two branches, one branch is communicated with the chimney, and the other branch is communicated with the clean flue gas inlet of the heat exchanger through the clean flue gas fan.
[0007] A further improvement of the present invention is that it further includes a heavy and light liquid separation module, a heavy liquid purification module, and a light liquid purification module; The mixed solution outlet of the Bunsen reaction module is connected to the inlet of the heavy and light liquid separation module, the heavy liquid outlet of the heavy and light liquid separation module is connected to the heavy liquid inlet of the heavy liquid purification module, and the light liquid outlet of the heavy and light liquid separation module is connected to the light liquid inlet of the light liquid purification module.
[0008] A further improvement of the present invention is that it further includes a high-temperature clean flue gas pipeline. The clean flue gas outlet of the heat exchanger is connected to the inlet of the high-temperature clean flue gas pipeline. The outlet of the high-temperature clean flue gas pipeline is divided into two branches. One branch is connected to the clean flue gas inlet of the heavy liquid purification module, and the other branch is connected to the clean flue gas inlet of the light liquid purification module. The clean flue gas outlet of the light liquid purification module is connected to the inlet flue of the induced draft fan.
[0009] A further improvement of the present invention is that it further includes a heavy liquid rectification module and a light liquid concentration module. The mixed solution outlet of the heavy liquid purification module is connected to the heavy liquid rectification module, and the sulfuric acid solution outlet of the light liquid purification module is connected to the light liquid rectification module.
[0010] A method for purifying the Bunsen reaction product by using the boiler clean flue gas, which is based on the system for purifying the Bunsen reaction product by using the boiler clean flue gas, includes: The hot flue gas coming out of the outlet flue of the boiler induced draft fan enters the heat exchanger to be cooled, and then enters the Bunsen reaction module. The Bunsen reaction module is filled with an iodine solution. After the sulfur dioxide in the boiler flue gas is absorbed by the iodine solution, clean flue gas is formed. The main components of the clean flue gas are nitrogen, carbon dioxide, a small amount of carbon monoxide, and oxygen. The clean flue gas is divided into two branches. One branch enters the chimney for emission, and the other branch enters the clean flue gas fan to be boosted in pressure and then enters the heat exchanger to be heated up to form high-temperature clean flue gas; In the Bunsen reaction module, sulfur dioxide in the boiler flue gas undergoes a Bunsen reaction with the iodine solution to generate a hydrogen iodide solution and a sulfuric acid solution. During the progress of the Bunsen reaction, iodine is continuously added. Since the hydrogen iodide solution has a strong ability to dissolve iodine, a mixed solution of hydrogen iodide and iodine is formed. The relative density of the mixed solution is greater than that of the sulfuric acid solution, and stratification occurs. The upper layer is the sulfuric acid solution with a smaller density, and the lower layer is the mixed solution of hydrogen iodide and iodine with a larger density.
[0011] A further improvement of the present invention is that it further includes: the mixed solution of hydrogen iodide and iodine discharged from the heavy liquid purification module enters the heavy liquid rectification module, and the sulfuric acid solution discharged from the light liquid purification module enters the light liquid rectification module.
[0012] A further improvement of the present invention is that it further includes: the clean flue gas enters from the bottom of the heavy liquid purification module, and the heavy liquid enters from the upper part of the clean flue gas in the form of spraying. A packing layer is arranged between the heavy liquid inlet and the clean flue gas inlet to enable the flue gas to fully contact with the heavy liquid. During this process, a small amount of sulfuric acid in the heavy liquid reacts with hydrogen iodide to generate water, iodine, and sulfur dioxide. A small amount of iodine generated is dissolved in hydrogen iodide, and sulfur dioxide is discharged upward from the heavy liquid purification module along with the clean flue gas. A small amount of sulfuric acid in the heavy liquid is removed, thereby completing the purification of the heavy liquid, that is, the mixture of hydrogen iodide and iodine.
[0013] A further improvement of the present invention is that it further includes: the clean flue gas enters from the bottom of the light liquid purification module, and the light liquid enters from the upper part of the clean flue gas in the form of spraying. A packing layer is arranged between the light liquid inlet and the clean flue gas inlet to enable the flue gas to fully contact with the light liquid. During this process, a small amount of hydrogen iodide in the light liquid reacts with the sulfuric acid solution to generate water, iodine, and sulfur dioxide. A small amount of iodine generated and the iodine originally dissolved in hydrogen iodide precipitate in sulfuric acid, and sulfur dioxide is discharged upward from the light liquid purification module along with the clean flue gas. A small amount of hydrogen iodide and iodine in the light liquid are removed, thereby completing the purification of the light liquid, that is, the sulfuric acid solution.
[0014] A further improvement of the present invention is that it further includes: the flue gas containing a small amount of sulfur dioxide discharged from the heavy liquid purification module and the light liquid purification module is merged and then enters the inlet flue of the induced draft fan.
[0015] A further improvement of the present invention is that it further includes: the mixed solution of hydrogen iodide and iodine discharged from the heavy liquid purification module enters the heavy liquid rectification module, and the sulfuric acid solution discharged from the light liquid purification module enters the light liquid rectification module.
[0016] Compared with the prior art, the present invention has at least the following beneficial technical effects: A system and method for purifying the products of the Bunsen reaction by using the clean flue gas of a boiler provided by the present invention uses the clean flue gas at the outlet of the Bunsen reaction to heat and replace nitrogen to achieve purging in the purification. The clean flue gas can be directly obtained from the outlet of the boiler induced draft fan without additional preparation or purchase, saving the operating cost; the present invention proposes the temperature of the purging flue gas, which is heated by the high-temperature flue gas at the outlet of the boiler induced draft fan without additional heat source, reducing the heat required for purification and further saving the operating cost; the present invention uses the cold flue gas at the outlet of the Bunsen reaction to reduce the temperature of the flue gas entering the Bunsen reaction, which is beneficial to the realization of the Bunsen reaction and improves the efficiency of the iodine solution absorbing sulfur dioxide in the boiler flue gas; in addition, the flue gas containing sulfur dioxide after purging enters the original flue to participate in the Bunsen reaction without additional treatment, simplifying the system process and saving the investment cost. Description of the Drawings
[0017] 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 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, without creative efforts, other drawings can also be obtained based on these drawings.
[0018] Figure 1 It is a structural block diagram of a system for purifying the products of the Bunsen reaction by using the clean flue gas of a boiler according to the present invention.
[0019] Description of the reference numerals: 1. Outlet flue of the boiler induced draft fan, 2. Heat exchanger, 3. Bunsen reaction module, 4. Clean flue gas fan, 5. Heavy and light liquid separation module, 6. Heavy liquid purification module, 7. Light liquid purification module, 8. Heavy liquid rectification module, 9. Light liquid concentration module, 10. High-temperature clean flue gas pipeline, 11. Chimney. Specific embodiments
[0020] 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.
[0021] In the description of the present invention, it should be understood that the orientation or positional relationships 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. are based on the orientation or positional relationships shown in the drawings, and are 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 therefore cannot be construed as a limitation to the present invention.
[0022] In addition, 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" means two or more, unless otherwise specifically defined.
[0023] In the present invention, unless otherwise clearly defined or limited, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or a communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside 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.
[0024] In the present invention, unless otherwise clearly defined or limited, the first feature being "above" or "below" 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 therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above or obliquely above the second feature, or merely means 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 or obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.
[0025] It should be understood that when used in this specification and the appended claims, the terms "comprises" and "comprising" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.
[0026] 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.
[0027] It should be further understood that the term " / and" 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.
[0028] Structural schematic diagrams according to various 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 actually deviate due to manufacturing tolerances or technical limitations. Those skilled in the art can additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.
[0029] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0030] Embodiment 1 As Figure 1 shown, a system for purifying the products of the Bunsen reaction by using the clean flue gas of a boiler provided by the present invention includes an outlet flue 1 of a boiler induced draft fan, a heat exchanger 2, a Bunsen reaction module 3, a clean flue gas fan 4, and a chimney 11; the outlet of the outlet flue 1 of the boiler induced draft fan is connected to the flue gas inlet of the heat exchanger 2, the flue gas outlet of the heat exchanger 2 is connected to the flue gas inlet of the Bunsen reaction module 3, the clean flue gas outlet of the Bunsen reaction module 3 is divided into two branches, one branch is connected to the chimney 11, and the other branch is connected to the clean flue gas inlet of the heat exchanger 2 through the clean flue gas fan 4.
[0031] In this embodiment, it further includes a heavy and light liquid separation module 5, a heavy liquid purification module 6, and a light liquid purification module 7; the mixed solution outlet of the Bunsen reaction module 3 is connected to the inlet of the heavy and light liquid separation module 5, the heavy liquid outlet of the heavy and light liquid separation module 5 is connected to the heavy liquid inlet of the heavy liquid purification module 6, and the light liquid outlet of the heavy and light liquid separation module 5 is connected to the light liquid inlet of the light liquid purification module 7.
[0032] In this embodiment, it further includes a high-temperature clean flue gas pipeline 10, the clean flue gas outlet of the heat exchanger 2 is connected to the inlet of the high-temperature clean flue gas pipeline 10, the outlet of the high-temperature clean flue gas pipeline 10 is divided into two branches, one branch is connected to the clean flue gas inlet of the heavy liquid purification module 6, and the other branch is connected to the clean flue gas inlet of the light liquid purification module 7, and the clean flue gas outlet of the light liquid purification module 7 is connected to the inlet flue of the induced draft fan.
[0033] In this embodiment, it further includes a heavy liquid rectification module 8 and a light liquid concentration module 9, the mixed solution outlet of the heavy liquid purification module 6 is connected to the heavy liquid rectification module 8, and the sulfuric acid solution outlet of the light liquid purification module 7 is connected to the light liquid concentration module 9.
[0034] Embodiment 2 As Figure 1 shown, a method for purifying the products of the Bunsen reaction by using the clean flue gas of a boiler provided by the present invention includes: The hot flue gas coming out from the outlet flue 1 of the boiler induced draft fan enters the heat exchanger 2 for cooling, and then enters the Bunsen reaction module 3. The Bunsen reaction module 3 is filled with iodine solution. After the sulfur dioxide in the boiler flue gas is absorbed by the iodine solution, clean flue gas is formed. The main components of the clean flue gas are nitrogen, carbon dioxide, a small amount of carbon monoxide and oxygen. The clean flue gas is divided into two streams. One stream enters the chimney 11 for emission, and the other stream enters the clean flue gas fan 4 to be boosted in pressure and then enters the heat exchanger 2 to be heated up to form high-temperature clean flue gas; in the Bunsen reaction module 3, the sulfur dioxide in the boiler flue gas undergoes a Bunsen reaction with the iodine solution to generate hydrogen iodide solution and sulfuric acid solution. During the progress of the Bunsen reaction, iodine is continuously added. Since the hydrogen iodide solution has a strong ability to dissolve iodine, a mixed solution of hydrogen iodide and iodine is formed. The relative density of the mixed solution is greater than that of the sulfuric acid solution, and stratification will occur. The upper layer is the sulfuric acid solution with a smaller density, and the lower layer is the mixed solution of hydrogen iodide and iodine with a larger density. The present invention uses the clean flue gas at the outlet of the Bunsen reaction to heat and replace nitrogen to achieve purging in purification. The clean flue gas can be directly obtained from the outlet of the boiler induced draft fan without additional preparation or procurement, saving the operation cost.
[0035] In this embodiment, it further includes: after the high-temperature clean flue gas enters the high-temperature clean flue gas pipeline 10, it is divided into two streams. One stream enters the heavy liquid purification module 6, and the other stream enters the light liquid purification module 7. The present invention proposes that the temperature of the purging flue gas is heated by the high-temperature flue gas at the outlet of the boiler induced draft fan without additional heat source, reducing the heat required for purification and further saving the operation cost.
[0036] In this embodiment, it further includes: the mixed solution of hydrogen iodide and iodine discharged from the heavy liquid purification module 6 enters the heavy liquid rectification module 8, and the sulfuric acid solution discharged from the light liquid purification module 7 enters the light liquid rectification module 9.
[0037] In this embodiment, it further includes: the clean flue gas enters from the bottom of the heavy liquid purification module 6, and the heavy liquid enters from the upper part of the clean flue gas in the heavy liquid purification module 6 in a spray form. A packing layer is arranged between the heavy liquid inlet and the clean flue gas inlet to enable the flue gas to fully contact with the heavy liquid. During this process, a small amount of sulfuric acid in the heavy liquid reacts with hydrogen iodide to generate water, iodine and sulfur dioxide. A small amount of iodine generated is dissolved in hydrogen iodide, and sulfur dioxide is discharged upward from the heavy liquid purification module 6 along with the clean flue gas. In this way, a small amount of sulfuric acid in the heavy liquid is removed, thus completing the purification of the heavy liquid, that is, the mixed liquid of hydrogen iodide and iodine. The flue gas containing sulfur dioxide after purging enters the original flue to participate in the Bunsen reaction without additional treatment, simplifying the system process and saving the investment cost.
[0038] In this embodiment, it further includes: The clean flue gas enters from the bottom of the light liquid purification module 7, and the light liquid enters from the upper part of the clean flue gas in the form of spraying. A packing layer is arranged between the light liquid inlet and the clean flue gas inlet to enable the flue gas to fully contact with the light liquid. In this process, a small amount of hydrogen iodide in the light liquid reacts with the sulfuric acid solution to generate water, iodine, and sulfur dioxide. Among them, a small amount of iodine generated and the iodine originally dissolved in hydrogen iodide precipitate in the sulfuric acid, and the sulfur dioxide is discharged upward from the light liquid purification module 7 along with the clean flue gas. In this way, a small amount of hydrogen iodide and iodine in the light liquid are removed, thus completing the purification of the light liquid, that is, the sulfuric acid solution.
[0039] In this embodiment, it further includes: The flue gas containing a small amount of sulfur dioxide discharged from the heavy liquid purification module 6 and the light liquid purification module 7 is merged and then enters the inlet flue of the induced draft fan.
[0040] In this embodiment, it further includes: The mixed solution of hydrogen iodide and iodine discharged from the heavy liquid purification module 6 enters the heavy liquid rectification module 8, and the sulfuric acid solution discharged from the light liquid purification module 7 enters the light liquid rectification module 9.
[0041] Embodiment 3 As Figure 1 shown, the flue gas temperature at the outlet of the boiler induced draft fan is about 120 °C, the sulfur dioxide content in the flue gas is 3000 g / m³. After the flue gas passes through the heat exchanger 2, the temperature drops to about 40 °C and enters the Bunsen reaction module 3. The sulfur dioxide in the flue gas is absorbed. The flue gas temperature at the outlet of the Bunsen reaction module 3 is about 30 °C, and the sulfur dioxide content is less than 2 g / m³. A part of the flue gas at the outlet of the Bunsen reaction module 3 is pressurized by the clean flue gas fan 4 to a pressure of 10 KPa. After passing through the heat exchanger 2, its temperature rises to about 110 °C and enters the heavy liquid purification module 6 and the light liquid purification module 7 respectively. After the heavy liquid and the light liquid are purified, the sulfur dioxide content in the discharged flue gas is about 100 g / m³ and the temperature is about 80 °C. This flue gas returns to the outlet flue 1 of the boiler induced draft fan.
[0042] The foregoing has shown and described 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 can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.
[0043] 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 the protection scope of the present invention cannot be limited thereby. 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 purifying the products of the Bunsen reaction using the clean flue gas of a boiler, characterized in that, It includes the outlet flue of the boiler induced draft fan (1), the heat exchanger (2), the Bunsen reaction module (3), the clean flue gas fan (4) and the chimney (11); The outlet of the outlet flue of the boiler induced draft fan (1) is connected to the flue gas inlet of the heat exchanger (2), the flue gas outlet of the heat exchanger (2) is connected to the flue gas inlet of the Bunsen reaction module (3), and the clean flue gas outlet of the Bunsen reaction module (3) is divided into two branches. One branch is connected to the chimney (11), and the other branch is connected to the clean flue gas inlet of the heat exchanger (2) through the clean flue gas fan (4).
2. The system for purifying the product of the Bunsen reaction by using the clean flue gas of a boiler according to claim 1, wherein It also includes the heavy and light liquid separation module (5), the heavy liquid purification module (6) and the light liquid purification module (7); The mixed solution outlet of the Bunsen reaction module (3) is connected to the inlet of the heavy and light liquid separation module (5), the heavy liquid outlet of the heavy and light liquid separation module (5) is connected to the heavy liquid inlet of the heavy liquid purification module (6), and the light liquid outlet of the heavy and light liquid separation module (5) is connected to the light liquid inlet of the light liquid purification module (7).
3. A system for purifying the products of the Bunsen reaction using the clean flue gas of a boiler according to claim 2, characterized in that, It also includes the high-temperature clean flue gas pipeline (10). The clean flue gas outlet of the heat exchanger (2) is connected to the inlet of the high-temperature clean flue gas pipeline (10). The outlet of the high-temperature clean flue gas pipeline (10) is divided into two branches. One branch is connected to the clean flue gas inlet of the heavy liquid purification module (6), and the other branch is connected to the clean flue gas inlet of the light liquid purification module (7). The clean flue gas outlet of the light liquid purification module (7) is connected to the induced draft fan inlet flue.
4. A system for purifying the product of the Bunsen reaction using the clean flue gas of a boiler according to claim 3, characterized in that, It also includes the heavy liquid rectification module (8) and the light liquid concentration module (9). The mixed solution outlet of the heavy liquid purification module (6) is connected to the heavy liquid rectification module (8), and the sulfuric acid solution outlet of the light liquid purification module (7) is connected to the light liquid concentration module (9).
5. A method for purifying the product of the Bunsen reaction by using the clean flue gas of a boiler, characterized in that, This method is based on a system for purifying Bunsen reaction products using boiler clean flue gas as described in claim 4, including: The hot flue gas coming out of the outlet flue of the boiler induced draft fan (1) enters the heat exchanger (2) to be cooled and then enters the Bunsen reaction module (3). The Bunsen reaction module (3) is filled with iodine solution. After the sulfur dioxide in the boiler flue gas is absorbed by the iodine solution, clean flue gas is formed. The main components of the clean flue gas are nitrogen, carbon dioxide, a small amount of carbon monoxide and oxygen. The clean flue gas is divided into two branches. One branch enters the chimney (11) for emission, and the other branch enters the clean flue gas fan (4) to be pressurized and then enters the heat exchanger (2) to be heated to form high-temperature clean flue gas; In the Bunsen reaction module (3), sulfur dioxide in the boiler flue gas undergoes a Bunsen reaction with the iodine solution to generate hydrogen iodide solution and sulfuric acid solution. During the progress of the Bunsen reaction, iodine is continuously added. Since the hydrogen iodide solution has a strong ability to dissolve iodine, a mixed solution of hydrogen iodide and iodine is formed. The relative density of the mixed solution is greater than that of the sulfuric acid solution, and stratification occurs. The upper layer is the sulfuric acid solution with a smaller density, and the lower layer is the mixed solution of hydrogen iodide and iodine with a larger density.
6. A method for purifying the product of the Bunsen reaction by using the clean flue gas of a boiler according to claim 5, characterized in that, It also includes: The mixed solution of hydrogen iodide and iodine discharged from the heavy liquid purification module (6) enters the heavy liquid rectification module (8), and the sulfuric acid solution discharged from the light liquid purification module (7) enters the light liquid concentration module (9).
7. A method for purifying the product of the Bunsen reaction using the clean flue gas of a boiler, as claimed in claim 5, wherein It also includes: The clean flue gas enters from the bottom of the heavy liquid purification module (6), and the heavy liquid enters from the upper part of the heavy liquid purification module (6) in the form of spraying. A packing layer is arranged between the heavy liquid inlet and the clean flue gas inlet to enable the flue gas to fully contact with the heavy liquid. During this process, a small amount of sulfuric acid in the heavy liquid reacts with hydrogen iodide to generate water, iodine, and sulfur dioxide. A small amount of iodine generated is dissolved in hydrogen iodide, and sulfur dioxide is discharged upward from the heavy liquid purification module (6) along with the clean flue gas. A small amount of sulfuric acid in the heavy liquid is removed, thereby completing the purification of the heavy liquid, i.e., the mixed solution of hydrogen iodide and iodine.
8. A method for purifying the product of the Bunsen reaction by using the clean flue gas of a boiler according to claim 6, characterized in that, It further includes: The clean flue gas enters from the bottom of the light liquid purification module (7), and the light liquid enters from the upper part of the light liquid purification module (7) in the form of spraying. A packing layer is arranged between the light liquid inlet and the clean flue gas inlet to enable the flue gas to fully contact with the light liquid. During this process, a small amount of hydrogen iodide in the light liquid reacts with the sulfuric acid solution to generate water, iodine, and sulfur dioxide. A small amount of iodine generated and the iodine originally dissolved in hydrogen iodide precipitate in sulfuric acid, and sulfur dioxide is discharged upward from the light liquid purification module (7) along with the clean flue gas. A small amount of hydrogen iodide and iodine in the light liquid are removed, thereby completing the purification of the light liquid, i.e., the sulfuric acid solution.
9. A method for purifying the products of the Bunsen reaction by using the clean flue gas of a boiler according to claim 8, characterized in that, It further includes: The flue gas containing a small amount of sulfur dioxide discharged from the heavy liquid purification module (6) and the light liquid purification module (7) is merged and then enters the inlet flue of the induced draft fan.
10. A method for purifying the product of the Bunsen reaction by using the clean flue gas of a boiler according to claim 9, characterized in that, It further includes: The mixed solution of hydrogen iodide and iodine discharged from the heavy liquid purification module (6) enters the heavy liquid rectification module (8), and the sulfuric acid solution discharged from the light liquid purification module (7) enters the light liquid rectification module (9).