A foaming treatment method and system for a hydrogen-based shaft furnace CO2 removal system

Abstract

This invention relates to the field of gas-based vertical shaft furnace smelting technology, and discloses a foaming treatment method and system for a hydrogen-based vertical shaft furnace CO2 removal system, comprising the following steps: monitoring the pressure difference between the absorption tower and / or stripping tower in the CO2 removal system; when the pressure difference reaches or exceeds a preset threshold, determining that foaming has occurred in the CO2 removal system, and initiating the defoamer dosing procedure; mixing the defoamer and dilution water in a preset ratio using a defoamer adding device to prepare a diluted defoamer solution; injecting the diluted defoamer solution into one or more defoamer injection points in the CO2 removal system, wherein the defoamer injection point is selected from at least one of the following locations: the gas phase outlet section of the stripping tower, the lean liquid inlet section of the heat exchanger, and the circulation pipeline from the reboiler to the lower part of the stripping tower. This invention can quickly destroy foam stability, prevent foam accumulation, maintain normal operating conditions in the tower, and ensure the continuity and efficiency of the carbon dioxide removal process.

Description

Technical Field

[0001] This invention relates to the field of gas-based vertical shaft furnace smelting technology, and in particular to a foaming treatment method and system for a hydrogen-based vertical shaft furnace CO2 removal system. Background Technology

[0002] In the direct reduction ironmaking process using a gas-based vertical shaft furnace, a CO2 removal system is typically installed in the reduction loop to enhance the reducing capacity of the circulating gas. Its main purpose is to remove the reduction product CO2 from the furnace top gas, thereby increasing the concentration of reducing gas components in the process gas and improving reduction efficiency. The CO2 removal system usually employs an amine solution (such as MDEA) chemical absorption method. The absorbent liquid absorbs carbon dioxide from the process gas through an absorption tower, and then the dissolved carbon dioxide is released through a stripping tower, achieving the recycling and reuse of the absorbent liquid.

[0003] However, during production, the absorbent can become contaminated due to corrosion of the system towers and impurities introduced by the process gas from the vertical shaft furnace (such as grease, fine suspended solids, residual dust, high hydrocarbons, or degradation products). When the absorbent is severely contaminated, a large number of bubbles will be generated in the solution, especially when the pressure difference in the absorption tower and stripping tower increases and the CO2 content in the process gas is high, the foaming phenomenon will increase significantly. Severe foaming can cause gas-liquid entrainment, liquid retention at the top of the tower, or even unit shutdown, leading to obstruction of gas-liquid flow within the tower, causing problems such as flooding and decreased gas-liquid mass transfer efficiency, seriously affecting the continuity and efficiency of the carbon dioxide removal process.

[0004] In existing technologies, the defoamer injection location for amine decarbonization systems is usually quite limited, generally only in the regeneration tower (stripping tower), making it impossible to specifically target the foaming area for defoaming treatment. Furthermore, current defoamer addition methods are mostly manual or simple direct dosing, making it difficult to achieve precise and automated defoamer dosing control, resulting in poor defoaming effects and inconvenience and cost-effectiveness.

[0005] Therefore, there is an urgent need for a foaming treatment method and system for a hydrogen-based vertical shaft furnace CO2 removal system that can automatically determine the foaming phenomenon based on the pressure difference changes of the absorption tower and / or stripping tower, and accurately add defoamer to different foaming parts. Summary of the Invention

[0006] The purpose of this invention is to provide a foaming treatment method and system for a hydrogen-based vertical shaft furnace CO2 removal system, which aims to solve or improve at least one of the above-mentioned technical problems, and can quickly destroy foam stability, prevent foam accumulation, maintain normal operating conditions in the tower, and ensure the continuity and efficiency of the carbon dioxide removal process.

[0007] To achieve the above objectives, the present invention provides the following solution: The present invention provides a foaming treatment method for a hydrogen-based vertical shaft furnace CO2 removal system, comprising the following steps: Monitor the pressure difference between the absorption tower and / or stripping tower in the CO2 removal system; When the pressure difference reaches or exceeds a preset threshold, it is determined that the CO2 removal system has foaming, and the defoamer dosing procedure is initiated. The defoamer and dilution water are mixed in a preset ratio using a defoamer addition device to prepare a diluted defoamer solution. The diluted defoamer solution is injected into one or more defoamer injection points of the CO2 removal system, wherein the defoamer injection points are selected from at least one of the following locations: the vapor phase outlet section of the stripper, the lean liquid inlet section of the heat exchanger, and the circulation pipeline from the reboiler to the lower part of the stripper.

[0008] Optionally, the preset threshold is a pressure difference ≥ 4 kPa.

[0009] Optionally, when the pressure difference is the upper pressure difference of the stripping tower, the defoamer solution is injected via the injection point of the gas phase outlet section of the stripping tower; when the pressure difference is the lower pressure difference of the stripping tower, the defoamer solution is injected via the injection point of the reboiler to the lower circulation pipeline of the stripping tower; when the pressure difference is the pressure difference of the absorber tower, the defoamer solution is injected via the injection point of the lean liquid inlet section of the heat exchanger.

[0010] Optionally, the defoamer dosing program is started automatically, triggered by a control signal to simultaneously open the defoamer shut-off valve and the water inlet shut-off valve, injecting the defoamer and dilution water into the dilution tank according to the PLC preset ratio.

[0011] Optionally, the following solution preparation steps may also be included: Once the liquid level in the dilution tank reaches the set value, the defoamer shut-off valve and the water inlet shut-off valve are closed to complete the quantitative liquid preparation. Open the shut-off valve from the dilution tank to the injection tank, allowing the diluted defoamer solution to flow into the injection tank by gravity. Close the shut-off valve from the dilution tank to the injection tank, and introduce nitrogen gas into the injection tank; When the pressure in the injection tank is higher than the pressure in the CO2 removal system, the shut-off valve from the injection tank to the system is opened, allowing the defoamer solution to be injected into the CO2 removal system under the action of pressure difference.

[0012] Optionally, it also includes: before starting the defoamer dosing procedure, by controlling the opening of the solution filtration main valve, sending a portion of the absorbent liquid to the filtration system for filtration; if the pressure difference cannot be adjusted by adjusting the solution filtration main valve and continues to rise to reach the preset threshold, then starting the defoamer dosing procedure.

[0013] Optionally, it also includes a pressure relief step after the defoamer is added: close the nitrogen injection shut-off valve, the pressure-reducing nitrogen injection shut-off valve, and the shut-off valve from the injection tank to the system; open the pressure relief shut-off valve of the injection tank; and close the valve after releasing the remaining pressure in the injection tank to a safe value.

[0014] This invention also provides a foaming treatment system for a hydrogen-based vertical shaft furnace CO2 removal system, comprising: Absorption towers are used to absorb carbon dioxide from process gases; A stripping tower is used to release carbon dioxide dissolved in the absorbent. A differential pressure detection device is installed in the absorption tower and / or the stripping tower to monitor the differential pressure inside the tower; An antifoaming agent adding device is connected to the absorption tower and / or the stripping tower; When the differential pressure detected by the differential pressure detection device reaches or exceeds a preset threshold, the defoamer addition device is automatically activated, and the diluted defoamer solution is injected into the absorption tower and / or the stripping tower in the CO2 removal system under the action of differential pressure.

[0015] Optionally, the defoamer adding device includes a defoamer storage tank, a water tank, a dilution tank, an injection tank, and a nitrogen supply pipeline. The defoamer storage tank is connected to the dilution tank via a defoamer shut-off valve. The water tank is connected to the dilution tank via a water inlet shut-off valve. The dilution tank is connected to the injection tank via a dilution tank to injection tank shut-off valve. The nitrogen supply pipeline is connected to the injection tank via a pressure reducing valve and a nitrogen injection shut-off valve. The injection tank is connected to the defoamer injection point of the CO2 removal system via an injection tank to system shut-off valve.

[0016] Optionally, the defoamer adding device further includes a PLC controller. The PLC controller is signal-connected to the differential pressure detection device and is used to receive differential pressure signals and compare them with a preset threshold. When the differential pressure reaches the threshold, the PLC controller sequentially controls the opening and closing of the defoamer shut-off valve, the water inlet shut-off valve, the dilution tank to injection tank shut-off valve, the nitrogen injection shut-off valve, and the injection tank to system shut-off valve to automatically complete the dilution, delivery, and injection of the defoamer solution.

[0017] The present invention discloses the following technical effects: This invention monitors the pressure difference between the absorption tower and / or stripping tower. When the pressure difference reaches or exceeds a preset threshold, it automatically detects the occurrence of foaming and initiates the defoamer dosing procedure, enabling rapid response to foaming problems. Simultaneously, based on the specific location of the pressure difference—whether it's the upper or lower pressure difference of the stripping tower, or the pressure difference of the absorption tower—the corresponding defoamer injection point is selected: the gas phase outlet section of the stripping tower, the circulation pipeline from the reboiler to the lower part of the stripping tower, or the lean liquid inlet section of the heat exchanger, achieving precise and directional defoaming. The defoamer makes full contact with the foam, rapidly breaking it down and maintaining a stable gas-liquid interface within the tower.

[0018] This invention uses a PLC controller to automatically start the defoamer dosing program. The control signal triggers the defoamer shut-off valve and the water inlet shut-off valve to open synchronously, automatically preparing the defoamer and dilution water into a diluted defoamer solution according to a preset ratio, thus avoiding inaccurate dosing and cost waste caused by manual operation.

[0019] This invention effectively prevents foam from impacting and corroding components such as tower packing and trays, reducing the probability of equipment blockage, wear, or leakage, and extending the service life of core equipment such as absorption towers and stripping towers. Simultaneously, it ensures efficient capture of carbon dioxide by the absorbent, improving decarbonization efficiency.

[0020] This invention addresses different foaming scenarios in absorption towers and stripping towers by allowing for targeted defoaming through the addition of defoamer at different injection points, achieving precise defoaming and reducing interference with other parts of the system. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the CO2 removal system of the present invention; Figure 2 This is a schematic diagram of the defoamer adding device of the present invention.

[0022] In the diagram: 1. Filtration system; 2. Absorbent temperature control system; 3. Absorbent tower; 4. Absorbent cooler; 5. Cooling water filter; 6. Absorbent cooling water system; 7. Filter; 8. Heat exchanger; 9. Stripping tower; 10. Absorbent filter; 11. Solution preparation system; 12. Solution filtration main valve; 13. Absorbent temperature control valve; 14. Absorbent flow control valve; 15. Circulating pump; 16. Reboiler; 17. Defoamer addition device; 18. Stripping tower differential pressure gauge; 19. Reboiler differential pressure gauge; 20. Absorbent tower differential pressure gauge; 21. Defoamer to absorbent tower shut-off valve; 22. Defoamer to... 23. Lower shut-off valve of stripping tower; 24. Upper shut-off valve of defoamer to stripping tower; 25. Defoamer storage tank; 26. Water tank; 27. Defoamer shut-off valve; 28. Inlet shut-off valve; 29. ​​Dilution tank; 30. Shut-off valve from dilution tank to injection tank; 31. Level gauge of dilution tank; 32. Upper shut-off valve of level gauge of injection tank; 33. Lower shut-off valve of level gauge of injection tank; 34. Level gauge of injection tank; 35. Pressure relief shut-off valve of injection tank; 36. Pressure reducing valve; 37. Nitrogen injection shut-off valve; 38. Pressure reducing nitrogen injection shut-off valve; 39. Check valve from injection tank to system; 40. Shut-off valve from injection tank to system. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Reference Figures 1 to 2 This invention provides a foaming treatment method for a hydrogen-based vertical shaft furnace CO2 removal system, comprising the following steps: Monitor the pressure difference between the absorption tower 3 and / or the stripping tower 9 in the CO2 removal system; When the pressure difference reaches or exceeds the preset threshold, it is determined that the CO2 removal system has foaming phenomenon, and the defoamer dosing procedure is started; The defoamer and dilution water are mixed in a preset ratio using the defoamer adding device 17 to prepare a diluted defoamer solution. The diluted defoamer solution is injected into one or more defoamer injection points of the CO2 removal system, wherein the defoamer injection points are selected from at least one of the following locations: the gas phase outlet section of stripper 9, the lean liquid inlet section of heat exchanger 8, and the circulation line from reboiler 16 to the lower part of stripper 9.

[0026] During system operation, the pressure difference at the top of stripping tower 9 is monitored by pressure difference meter 18, the pressure difference at the bottom of stripping tower 9 is monitored by pressure difference meter 19, and the pressure difference in absorption tower 3 is monitored by pressure difference meter 20. When the pressure difference detected by any pressure difference meter reaches or exceeds a preset threshold, it is determined that foaming has occurred in the CO2 removal system, and the defoamer dosing procedure is initiated.

[0027] The selection of defoamer injection points follows these rules: When the stripper differential pressure gauge 18 alarms (i.e., the upper differential pressure of the stripper is high), the defoamer solution is injected through the gas phase outlet section injection point of stripper 9 (i.e., the defoamer to the upper stripper shut-off valve 23); when the reboiler differential pressure gauge 19 alarms (i.e., the lower differential pressure of the stripper is high), the defoamer solution is injected through the reboiler 16 to the lower circulation pipeline injection point of stripper 9 (i.e., the defoamer to the lower stripper shut-off valve 22); when the absorber differential pressure gauge 20 alarms (i.e., the absorber differential pressure is high), the defoamer solution is injected through the lean liquid inlet section injection point of heat exchanger 8 (i.e., the defoamer to the absorber shut-off valve 21).

[0028] In this embodiment, the preset threshold is a pressure difference ≥ 4 kPa.

[0029] In this embodiment, when the pressure difference is the upper pressure difference of the stripper 9, the defoamer solution is injected through the injection point of the gas phase outlet section of the stripper 9; when the pressure difference is the lower pressure difference of the stripper 9, the defoamer solution is injected through the reboiler 16 to the injection point of the lower circulation pipeline of the stripper 9; when the pressure difference is the pressure difference of the absorber 3, the defoamer solution is injected through the injection point of the lean liquid inlet section of the heat exchanger 8.

[0030] In this embodiment, the defoamer dosing program is started automatically. The defoamer shut-off valve 26 and the water inlet shut-off valve 27 are triggered by a control signal to open synchronously, and the defoamer and dilution water are injected into the dilution tank according to the PLC preset ratio.

[0031] In this embodiment, the following solution preparation step is also included: Once the liquid level in dilution tank 28 reaches the set value, close the defoamer shut-off valve 26 and the water inlet shut-off valve 27 to complete the quantitative liquid preparation. Open the stop valve 29 from the dilution tank to the injection tank, so that the diluted defoamer solution flows into the injection tank by gravity; Close the dilution tank to injection tank shut-off valve 29 and introduce nitrogen into the injection tank; When the pressure in the injection tank is higher than the pressure in the CO2 removal system, the valve 40 from the injection tank to the system is opened, allowing the defoamer solution to be injected into the CO2 removal system under the action of pressure difference.

[0032] In this embodiment, the method further includes: before starting the defoamer dosing procedure, by controlling the opening of the solution filtration main valve 12, sending a portion of the absorbent liquid to the filtration system 1 for filtration; if the pressure difference cannot be adjusted by adjusting the solution filtration main valve 12 and continues to rise to reach a preset threshold, the defoamer dosing procedure is started.

[0033] In this embodiment, a pressure relief step is also included after the defoamer is added: close the nitrogen injection shut-off valve 37, the pressure-reducing nitrogen injection shut-off valve 38 and the injection tank to system shut-off valve 40, open the injection tank pressure relief shut-off valve 34, and close the valve after releasing the remaining pressure in the injection tank to a safe value.

[0034] In this embodiment, the specific steps of the defoamer addition procedure are as follows: Step 1: Differential Pressure Monitoring and Judgment During normal operation of the CO2 removal system, the differential pressure of the absorption tower 3 and / or stripping tower 9 is continuously monitored using the differential pressure gauges 18 (stripping tower), 19 (reboiler), and 20 (absorption tower). Before initiating the defoamer dosing procedure, a portion of the absorbent is first sent to the filtration system 1 for filtration by controlling the opening of the solution filtration valve 12. If the differential pressure cannot be adjusted by regulating the solution filtration valve 12 and continues to rise to a preset threshold (≥4 kPa), the defoamer dosing procedure is initiated.

[0035] Step 2: Preparation of defoamer solution When the pressure difference reaches or exceeds the preset threshold, the control signal triggers the defoamer shut-off valve 26 and the inlet water shut-off valve 27 to open simultaneously, injecting the defoamer and dilution water into the dilution tank 28 for mixing according to the PLC preset ratio. The defoamer can be polydimethylsiloxane (organosilicon), polyethers, or polyether-polysiloxane copolymers modified from both, or other defoamer active ingredients known in the art. The dilution water can be demineralized water or process water. The mixing ratio of the defoamer and dilution water can be preset by the PLC according to the actual foaming degree and the type of defoamer; typically, the amount of defoamer added is 0.2%-1% of the total foaming system.

[0036] When the level gauge 30 of the dilution tank detects that the level of the dilution tank 28 has reached the set value, the PLC controller sequentially closes the defoamer shut-off valve 26 and the water inlet shut-off valve 27 to complete the quantitative liquid preparation process.

[0037] Step 3: Delivery of the defoamer solution After the quantitative solution preparation is completed, the dilution tank to injection tank shut-off valve 29 is opened, and the diluted defoamer solution flows into the injection tank from the dilution tank 28 by gravity. When the injection tank level gauge 33 detects that the injection tank level has reached the set value, the dilution tank to injection tank shut-off valve 29 is closed. Subsequently, the nitrogen injection shut-off valve 37 and the pressure-reducing nitrogen injection shut-off valve 38 are opened to introduce nitrogen gas (reduced from 16MPa to 5MPa through the pressure-reducing valve 36) into the injection tank.

[0038] Step 4: Injection of defoamer solution When the pressure in the injection tank is higher than the pressure in the CO2 removal system, the injection tank to system shut-off valve 40 is opened, and the diluted defoamer solution is injected into the CO2 removal system under the action of pressure differential. The corresponding injection point is selected according to the specific location of the pressure differential alarm: if the stripper pressure differential detector 18 alarms (high pressure differential at the top of stripper 9), the defoamer to stripper upper shut-off valve 23 is opened; if the reboiler pressure differential detector 19 alarms (high pressure differential at the bottom of stripper 9), the defoamer to stripper lower shut-off valve 22 is opened; if the absorber pressure differential detector 20 alarms (high pressure differential at absorber 3), the defoamer to absorber shut-off valve 21 is opened. The injection tank to system check valve 39 prevents the system solution from flowing back into the injection tank.

[0039] Step 5: Depressurization and Reset After the defoamer solution is injected, the nitrogen injection shut-off valve 37, the pressure-reducing nitrogen injection shut-off valve 38, and the injection tank to system shut-off valve 40 are closed sequentially to cut off the nitrogen supply. Finally, the injection tank pressure relief shut-off valve 34 is opened to release the remaining pressure in the injection tank to a safe value before closing, completing the entire defoamer addition cycle. The defoamer addition device 17 then enters standby mode, waiting for the next differential pressure trigger signal.

[0040] This invention also provides a foaming treatment system for a hydrogen-based vertical shaft furnace CO2 removal system, comprising: Absorption tower 3 is used to absorb carbon dioxide from process gas; Stripping tower 9 is used to release carbon dioxide dissolved in the absorbent; A differential pressure detection device is installed in the absorption tower 3 and / or the stripping tower 9 to monitor the differential pressure inside the tower; Defoamer adding device 17 is connected to absorption tower 3 and / or stripping tower 9; When the differential pressure detected by the differential pressure detection device reaches or exceeds the preset threshold, the defoamer addition device 17 is automatically started, and the diluted defoamer solution is injected into the absorption tower 3 and / or stripping tower 9 in the CO2 removal system under the action of differential pressure.

[0041] In this embodiment, the CO2 removal system mainly includes: a filtration system 1, an absorbent temperature control system 2, an absorption tower 3, an absorbent cooler 4, a cooling water filter 5, an absorbent cooling water system 6, a filter 7, a stripping tower 9, an absorbent filter 10, a solution preparation system 11, a solution filtration main valve 12, an absorbent temperature control valve 13, an absorbent flow control valve 14, a circulating pump 15, a reboiler 16, an antifoaming agent addition device 17, a stripping tower differential pressure gauge 18, a reboiler differential pressure gauge 19, an absorbent tower differential pressure gauge 20, an antifoaming agent to absorbent tower shut-off valve 21, an antifoaming agent to lower stripping tower shut-off valve 22, and an antifoaming agent to upper stripping tower shut-off valve 23.

[0042] The prepared absorbent is transported to the circulation system via the solution preparation system 11, and circulated by the circulation pump 15. The stripping tower 9 maintains a high-temperature, low-pressure environment, which is conducive to the release of dissolved carbon dioxide from the absorbent. The absorbent discharged from the stripping tower 9 is first filtered by the absorbent filter 10, then preliminarily cooled by the heat exchanger 8, and then further cooled in the absorbent cooler 4. The cooled absorbent enters the absorption tower 3 to absorb carbon dioxide from the process gas. The absorbent, after absorbing carbon dioxide in the absorption tower 3, has a low temperature; after passing through the filter 7, it enters the heat exchanger 8 to cool the absorbent discharged from the stripping tower 9. Cooling water is provided by the absorbent cooling water system 6, and is filtered by the cooling water filter 5 before cooling to prevent clogging of the absorbent cooler 4.

[0043] In this embodiment, the defoamer adding device 17 includes a defoamer storage tank 24, a water tank 25, a dilution tank 28, an injection tank, and a nitrogen supply pipeline. The defoamer storage tank 24 is connected to the dilution tank 28 through a defoamer shut-off valve 26, and the water tank 25 is connected to the dilution tank 28 through a water inlet shut-off valve 27.

[0044] In this embodiment, the defoamer adding device 17 also includes a dilution tank level gauge 30, an upper shut-off valve 31 for the injection tank level gauge, a lower shut-off valve 32 for the injection tank level gauge, an injection tank level gauge 33, a pressure reducing valve venting shut-off valve 35, and a check valve 39 from the injection tank to the system.

[0045] The defoamer storage tank 24 is connected to the dilution tank 28 via the defoamer shut-off valve 26, and the water tank 25 is connected to the dilution tank 28 via the inlet shut-off valve 27, for supplying defoamer and dilution water to the dilution tank 28. The dilution tank 28 is connected to the injection tank via the dilution tank to injection tank shut-off valve 29, for conveying the diluted defoamer solution to the injection tank. The nitrogen supply pipeline is connected to the injection tank via the pressure reducing valve 36 (reducing nitrogen pressure from 16MPa to 5MPa) and the nitrogen injection shut-off valve 37, for introducing nitrogen into the injection tank to establish pressure. The injection tank is connected to the defoamer injection points of the CO2 removal system (including the defoamer to absorber shut-off valve 21, the defoamer to lower stripper shut-off valve 22, and the defoamer to upper stripper shut-off valve 23) via the injection tank to system shut-off valve 40 and the injection tank to system check valve 39, for injecting the diluted defoamer solution into the CO2 removal system under pressure differential.

[0046] In this embodiment, the defoamer adding device 17 also includes a PLC controller. The PLC controller is connected to the differential pressure detection devices (stripper differential pressure detector 18, reboiler differential pressure detector 19, and absorber differential pressure detector 20) to receive differential pressure signals and compare them with a preset threshold. When the differential pressure reaches the threshold, the PLC controller sequentially controls the opening and closing of the defoamer shut-off valve 26, the water inlet shut-off valve 27, the dilution tank to injection tank shut-off valve 29, the nitrogen injection shut-off valve 37, and the injection tank to system shut-off valve 40 to automatically complete the dilution, delivery, and injection of the defoamer solution. At the same time, the PLC controller automatically selects the corresponding defoamer injection point (defoamer to stripper upper shut-off valve 23, defoamer to stripper lower shut-off valve 22, or defoamer to absorber shut-off valve 21) according to the differential pressure alarm source (upper differential pressure of stripper 9, lower differential pressure of stripper 9, or absorber 3 differential pressure) to achieve fully automatic and precise defoaming.

[0047] In this embodiment, the defoamer shut-off valve 26, the water inlet shut-off valve 27, the dilution tank to injection tank shut-off valve 29, the nitrogen injection shut-off valve 37, the pressure-reducing nitrogen injection shut-off valve 38, the injection tank to system shut-off valve 40, the injection tank pressure venting shut-off valve 34, the defoamer to absorption tower shut-off valve 21, the defoamer to the lower part of the stripping tower shut-off valve 22, and the defoamer to the upper part of the stripping tower shut-off valve 23 can all be pneumatic valves or electric valves, and are uniformly controlled by a PLC controller.

[0048] In this embodiment, a level sensor can be installed inside the defoamer storage tank 24 to monitor the remaining amount of defoamer in the tank. When the remaining amount of defoamer is lower than a set value, an alarm signal is issued to remind the operator to replenish the defoamer in time. Similarly, a level sensor can also be installed inside the water tank 25 to monitor the remaining amount of dilution water.

[0049] In this embodiment, a stirring device can be installed in the dilution tank 28. After the defoamer and dilution water are injected into the dilution tank 28, the stirring device is started to stir, so that the defoamer and dilution water are fully mixed evenly, thereby improving the defoaming effect.

[0050] In this embodiment, the preset threshold can be adjusted according to the actual operating conditions, and is not limited to 4 kPa. For example, it can be set in the range of 3 kPa to 6 kPa according to factors such as the type of absorbent, the composition of the process gas, and the system operating load.

[0051] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0052] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A foaming treatment method for a hydrogen-based vertical shaft furnace CO2 removal system, characterized in that, Includes the following steps: Monitor the pressure difference between the absorber (3) and / or stripper (9) in the CO2 removal system; When the pressure difference reaches or exceeds a preset threshold, it is determined that the CO2 removal system has foaming, and the defoamer dosing procedure is initiated. The defoamer and dilution water are mixed in a preset ratio using the defoamer adding device (17) to prepare a diluted defoamer solution; The diluted defoamer solution is injected into one or more defoamer injection points of the CO2 removal system, wherein the defoamer injection points are selected from at least one of the following locations: the gas phase outlet section of the stripper (9), the lean liquid inlet section of the heat exchanger (8), the reboiler (16) to the lower circulation line of the stripper (9).

2. The foaming treatment method for a hydrogen-based vertical shaft furnace CO2 removal system according to claim 1, characterized in that, The preset threshold is a pressure difference ≥ 4 kPa.

3. The foaming treatment method for a hydrogen-based vertical shaft furnace CO2 removal system according to claim 1, characterized in that, When the pressure difference is the upper pressure difference of the stripper (9), the defoamer solution is injected through the gas phase outlet section injection point of the stripper (9); when the pressure difference is the lower pressure difference of the stripper (9), the defoamer solution is injected through the reboiler (16) to the lower circulation pipeline injection point of the stripper (9); when the pressure difference is the pressure difference of the absorber (3), the defoamer solution is injected through the lean liquid inlet section injection point of the heat exchanger (8).

4. The foaming treatment method for a hydrogen-based vertical shaft furnace CO2 removal system according to claim 1, characterized in that, The defoamer dosing program is started automatically. The defoamer shut-off valve (26) and the water inlet shut-off valve (27) are triggered by the control signal to open synchronously, and the defoamer and dilution water are injected into the dilution tank according to the PLC preset ratio.

5. The foaming treatment method for a hydrogen-based vertical shaft furnace CO2 removal system according to claim 4, characterized in that, It also includes the following solution preparation steps: When the liquid level in the dilution tank (28) reaches the set value, the defoamer shut-off valve (26) and the water inlet shut-off valve (27) are closed to complete the quantitative liquid preparation; Open the stop valve (29) from the dilution tank to the injection tank, so that the diluted defoamer solution flows into the injection tank by gravity; Close the shut-off valve (29) from the dilution tank to the injection tank, and introduce nitrogen into the injection tank; When the pressure in the injection tank is higher than the pressure in the CO2 removal system, the valve (40) from the injection tank to the system is opened, so that the defoamer solution is injected into the CO2 removal system under the action of pressure difference.

6. The foaming treatment method for a hydrogen-based vertical shaft furnace CO2 removal system according to claim 1, characterized in that, Also includes: Before starting the defoamer dosing procedure, a portion of the absorbent liquid is sent to the filtration system (1) for filtration by controlling the opening of the solution filtration main valve (12). If the pressure difference cannot be adjusted by adjusting the solution filtration main valve (12) and continues to rise to the preset threshold, the defoamer dosing procedure is started.

7. The foaming treatment method for a hydrogen-based vertical shaft furnace CO2 removal system according to claim 5, characterized in that, It also includes a pressure relief step after the defoamer is added: close the nitrogen injection shut-off valve (37), the pressure-reducing nitrogen injection shut-off valve (38) and the shut-off valve from the injection tank to the system (40), open the pressure relief shut-off valve (34) of the injection tank, and close it after releasing the remaining pressure in the injection tank to a safe value.

8. A foaming treatment system for a hydrogen-based vertical shaft furnace CO2 removal system, used to perform the foaming treatment method for a hydrogen-based vertical shaft furnace CO2 removal system as described in claims 1-7, characterized in that, include: Absorption tower (3) is used to absorb carbon dioxide in process gas; Stripping tower (9) is used to release carbon dioxide dissolved in the absorbent; A differential pressure detection device is installed in the absorption tower (3) and / or the stripping tower (9) to monitor the differential pressure inside the tower; An antifoaming agent adding device (17) is connected to the absorption tower (3) and / or the stripping tower (9); When the differential pressure detected by the differential pressure detection device reaches or exceeds the preset threshold, the defoamer adding device (17) is automatically started, and the diluted defoamer solution is injected into the absorption tower (3) and / or the stripping tower (9) in the CO2 removal system under the action of differential pressure.

9. The foaming treatment system for a hydrogen-based vertical shaft furnace CO2 removal system according to claim 8, characterized in that, The defoamer adding device (17) includes a defoamer storage tank (24), a water tank (25), a dilution tank (28), an injection tank, and a nitrogen supply pipeline. The defoamer storage tank (24) is connected to the dilution tank (28) through a defoamer shut-off valve (26). The water tank (25) is connected to the dilution tank (28) through a water inlet shut-off valve (27). The dilution tank (28) is connected to the injection tank through a dilution tank to injection tank shut-off valve (29). The nitrogen supply pipeline is connected to the injection tank through a pressure reducing valve (36) and a nitrogen injection shut-off valve (37). The injection tank is connected to the defoamer injection point of the CO2 removal system through an injection tank to system shut-off valve (40).

10. The foaming treatment system for a hydrogen-based vertical shaft furnace CO2 removal system according to claim 9, characterized in that, The defoamer adding device (17) also includes a PLC controller. The PLC controller is connected to the differential pressure detection device and is used to receive the differential pressure signal and compare it with a preset threshold. When the differential pressure reaches the threshold, the PLC controller sequentially controls the opening and closing of the defoamer shut-off valve (26), the water inlet shut-off valve (27), the dilution tank to injection tank shut-off valve (29), the nitrogen injection shut-off valve (37), and the injection tank to system shut-off valve (40) to automatically complete the dilution, delivery, and injection of the defoamer solution.

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