Flue gas carbon dioxide trapping system

Abstract

The utility model discloses a flue gas carbon dioxide trapping system which comprises a vertically arranged absorption tower, a flue gas inlet pipe arranged on one side of the lower part of the absorption tower, and a flue gas outlet pipe upwards arranged at the upper end of the absorption tower, and is characterized in that an alcohol amine solution return port is also arranged on one side of the upper part of the absorption tower; a downward spray head device is further arranged at the upper end of the inner cavity of the absorption tower, the spray head device is connected with an alcohol amine solution return port, a vertically-through porous filler is arranged between the gas distribution device and the spray head device, and an alcohol amine solution outlet is further formed in the lower end of the absorption tower outwards; and an alcohol amine solution regeneration device is connected between the alcohol amine solution outlet and the alcohol amine solution return port through a liquid pipeline to form a regeneration circulation system. The device can be directly driven by solar energy to realize regeneration and cyclic utilization of an adsorption solvent, and has the advantages of simple structure, convenience in operation, high carbon dioxide removal efficiency, sustainability in carbon dioxide absorption treatment and the like.

Description

Technical Field

[0001] This utility model relates to the field of waste gas harmless treatment technology, specifically to a flue gas carbon dioxide capture system. Background Technology

[0002] Industrial flue gas is a harmful gas produced during modern industrial production (especially power plant generation) and requires harmless treatment before being discharged. Current industrial flue gas harmless treatment is typically achieved in adsorption towers. However, industrial flue gas has a complex composition, so adsorption towers usually have multiple layers of adsorption packing to separately adsorb various harmful components, achieving decarbonization, desulfurization, and denitrification requirements. Because flue gas contains a large amount of carbon dioxide, and the presence of carbon dioxide can significantly impact desulfurization and denitrification processes, some flue gas treatment technologies consider separately implementing carbon dioxide desorption.

[0003] Methods for carbon dioxide capture typically include chemical absorption, pressure swing adsorption (PSA), membrane separation, and cryogenic fractionation, with chemical absorption being the most widely used. Chemical absorption involves contacting the adsorbent material with the flue gas, causing the carbon dioxide to react with the effective components in the material and be absorbed and removed. In practical engineering applications, solid adsorption packing is generally used for carbon dioxide removal via chemical absorption, which facilitates continuous desulfurization and denitrification of the flue gas.

[0004] However, this method of capturing carbon dioxide using solid adsorption packing has drawbacks, such as relatively low carbon dioxide adsorption efficiency, a gradual decrease in adsorption rate as the packing is used, the need to stop production and replace the packing after adsorption is complete, and troublesome regeneration of the packing. Therefore, it is not suitable for the separate desorption treatment of carbon dioxide.

[0005] In the laboratory, adsorbing carbon dioxide using alkanolamine solutions is a common method for removing carbon dioxide. Therefore, the applicant is considering designing a flue gas carbon dioxide capture device based on alkanolamine solutions to achieve carbon dioxide removal, making it suitable for industrial applications, improving carbon dioxide removal efficiency, and further considering the problem of regenerating and reusing the adsorbent. Utility Model Content

[0006] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is: how to provide a flue gas carbon dioxide capture system that is simple in structure, easy to operate, has high carbon dioxide removal efficiency, and good sustainability, and further enable it to use solar energy to directly drive the regeneration and recycling of the adsorption solvent.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A flue gas carbon dioxide capture system includes a vertically arranged absorption tower, a flue gas inlet pipe on one side of the lower part of the absorption tower, the flue gas inlet pipe being connected to a horizontally arranged gas distribution device inside the absorption tower cavity, the gas distribution device having evenly distributed gas outlet holes, and a flue gas outlet pipe being arranged upward at the upper end of the absorption tower. The system is characterized by having an amine solution return port on one side of the upper part of the absorption tower, and a downward-facing nozzle device at the upper end of the absorption tower cavity, connected to the amine solution return port. A vertically penetrating porous packing is arranged between the gas distribution device and the nozzle device. An amine solution outlet is also provided externally at the lower end of the absorption tower. The amine solution outlet and the amine solution return port are connected to an amine solution regeneration device via a liquid pipeline, forming a regeneration circulation system.

[0009] In this way, the amine solution enters the absorption tower from the return port and is sprayed downwards through the nozzle device. The flue gas to be treated enters the absorption tower from the flue gas inlet pipe and is evenly discharged upwards through the gas distribution device. The flue gas and the amine solution flow countercurrently in the inner cavity of the absorption tower, contacting and reacting, thus absorbing carbon dioxide. The porous packing allows some of the amine solution to adhere to it, slowing down the downward movement of the solution, increasing the contact area and efficiency between the flue gas and the solution, and improving the reaction absorption efficiency. Simultaneously, the solution that has absorbed carbon dioxide flows directly out from the outlet and is regenerated and recycled through a regeneration device, ensuring that the solution sprayed from the nozzles continuously maintains maximum absorption efficiency and does not decrease over time. Therefore, the system features high carbon dioxide removal efficiency and good sustainability.

[0010] Furthermore, the alcoholamine solution is an ethanolamine solution.

[0011] The absorption effect is good when using ethanolamine solution and carbon dioxide reaction, and it is easily decomposed upon heating, making recovery convenient. The chemical reaction formula for the absorption process is: CH2OH.CH2NH2 + CO2 + H2O → CH2OH.CH2NH3 + +HCO3 - .

[0012] Furthermore, the spray head device comprises multiple nozzles evenly arranged on the same horizontal plane. This better ensures the spraying effect.

[0013] Furthermore, the air distribution device includes a plurality of air distribution pipes arranged in a uniform array, and the air outlet is formed on the lower surface of the air distribution pipes.

[0014] This prevents the amine solution from dripping into the vent and avoids clogging the vent.

[0015] Furthermore, the porous packing includes multiple vertical corrugated packing plates arranged in a staggered and overlapping manner.

[0016] This allows for a better increase in the contact area between the solution and the flue gas, preventing it from obstructing the upward movement of the flue gas.

[0017] Furthermore, the amine solution regeneration device includes a regeneration reactor, a gas distribution device, and a trough-type solar collector for reflecting sunlight. The regeneration reactor is cylindrical in shape and located at the reflection center of the trough-type solar collector's reflector. The two ends of the regeneration reactor are fixed to the two ends of the trough-type solar collector's reflector by mounting brackets. The regeneration reactor includes a regeneration tube that is conical in shape. The cross-sectional area of ​​the regeneration tube gradually increases along the direction of solution flow. The regeneration tube is provided with porous heat-conducting skeletons (preferably honeycomb-shaped) along the cross-section at intervals. The outer surface of the regeneration tube is also provided with a layer of heat-absorbing material for absorbing sunlight. The liquid outlet of the regeneration reactor is connected to the gas distribution device.

[0018] In this way, the amine solution enters the regeneration reactor and flows into the regeneration tube from the inlet. The solution is heated by sunlight reflected by the reflective mirrors of the trough-type solar collector, resulting in reduction and decomposition to produce carbon dioxide and hydrogen. The cross-sectional area of ​​the regeneration tube gradually increases in the direction of solution flow to better accommodate the expansion caused by the generated gases and to facilitate gas decomposition. After the decomposition reaction is complete, the solution enters the gas separator from the outlet. The gas separator is used to guide the generated gases away, while the flowing-down solution is recycled. The chemical formula for the decomposition reaction is: CH2OH·CH2NH3. + +HCO3 - →CH2OH.CH2NH2+CO2+H2.

[0019] The aforementioned trough solar collector is a mature existing device. Its structure includes a parabolic reflector with two rotatable support frames on both sides, which are mounted on the reflector via a pivot. Mounting frames are also provided at both ends of the reflector, and the components to be heated are fixed to the reflector's center by the mounting frames. The trough solar collector also includes a tracking control device with two-dimensional tracking function, which can control the reflector to rotate with the sunlight to ensure the adjustment of the light-collecting angle and ensure the heating effect.

[0020] Furthermore, the regeneration reactor also includes a cylindrical outer shell coaxially sleeved outside the regeneration tube, the outer shell being made of transparent material and a vacuum jacket being provided between the outer shell and the regeneration tube.

[0021] In this way, the outer shell can heat the regeneration tube through sunlight, while the vacuum jacket can isolate the regeneration tube from the outside heat transfer, preventing heat from being carried away by the outside airflow.

[0022] Furthermore, the inlet and outlet ends of the regeneration reactor are each connected to a flexible hose or rotary joint.

[0023] This ensures that the regeneration reactor will not affect other components when it rotates with the reflector of the trough collector.

[0024] Furthermore, a flow control valve is installed on the liquid pipeline at the inlet end of the regeneration reactor, and a light intensity sensor is installed on the reflective lens. The light intensity sensor is connected to the controller, and the controller is connected to the flow control valve.

[0025] In this way, the light intensity of the reflecting mirror can be detected, and the flow rate of the solution entering the regeneration reactor can be adjusted to match it, ensuring the regeneration effect.

[0026] Furthermore, an inlet storage tank and a solution pump are installed on the liquid pipeline before it enters the amine solution regeneration device.

[0027] In this way, the solution pump can better provide sufficient fluid pressure to the regeneration circulation system. At the same time, the inlet storage tank can realize the storage and transfer of the solution, facilitating the flow control of the solution entering the regeneration reactor.

[0028] Furthermore, an electrothermal film is also installed on the regeneration tube of the regeneration reactor.

[0029] In this way, when the light intensity is insufficient at night or on cloudy days, the regeneration reaction can be maintained by heating with an electric heating film, ensuring the sustainability of industrial production.

[0030] Furthermore, the amine solution regeneration device also includes a bypass pipe, which is installed in parallel at both ends of the regeneration reactor via a three-way valve.

[0031] In this way, when maintenance is required, the solution input to the regeneration device can be switched off by switching the three-way valve, and the continuous operation of the circulation system can be ensured by switching the bypass pipe, thus realizing online maintenance.

[0032] Furthermore, the gas separation device includes a gas separation and liquid storage tank. An inlet is provided in the middle of one side of the gas separation and liquid storage tank and is connected to the liquid outlet of the regeneration reactor through a liquid pipeline. An exhaust pipe is provided at the upper end of the gas separation and liquid storage tank and is connected to the gas storage container. An outlet is provided at the lower end of the gas separation and liquid storage tank and is connected to the amine solution return port of the absorption tower through a liquid pipeline.

[0033] In this way, the solution and gas after the reaction in the regeneration reactor enter the gas-liquid separator in a mixed state. The increased volume of the gas-liquid separator allows sufficient space for the gas to overflow upwards and be extracted through the extraction pipe to a storage container for storage and reuse. The regenerated solution flows out through the outlet and returns to the amine solution return port of the absorption tower for recycling. This gas-liquid separator better assists in gas separation and also has a storage and regulation function for the separated solution, ensuring a continuous supply of regenerated solution to the absorption tower for a certain period during regeneration reactor maintenance. In practice, a return pump can be installed on the liquid pipeline between the lower outlet of the gas-liquid separator and the amine solution return port of the absorption tower to ensure sufficient return pressure to supply the spray pressure of the nozzle device.

[0034] In summary, this invention can utilize solar energy to directly regenerate and recycle the adsorbent solvent, and also has the advantages of simple structure, convenient operation, high carbon dioxide removal efficiency, and sustainable carbon dioxide absorption and treatment. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the flue gas carbon dioxide capture system during implementation.

[0036] Figure 2 for Figure 1 A schematic diagram of the three-dimensional structure.

[0037] Figure 3 for Figure 1 A magnified schematic diagram of the structure of a single absorption tower.

[0038] Figure 4 for Figure 1 A schematic diagram of the enlarged structure of the individual regeneration reactor. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to specific embodiments.

[0040] For specific implementation: see: Figures 1-4A flue gas carbon dioxide capture system includes a vertically arranged absorption tower 1, a flue gas inlet pipe 2 on one side of the lower part of the absorption tower 1, the flue gas inlet pipe 2 being connected to a horizontally arranged gas distribution device 3 inside the absorption tower cavity, the gas distribution device 3 having evenly distributed gas outlet holes, a flue gas outlet pipe 4 being arranged upward at the upper end of the absorption tower 1, wherein an alkanolamine solution return port 5 is also provided on one side of the upper part of the absorption tower 1, and a downward-facing nozzle device 6 is also provided at the upper end of the absorption tower cavity, the nozzle device 6 being connected to the alkanolamine solution return port 5, a vertically penetrating porous packing 7 being provided between the gas distribution device and the nozzle device, and an alkanolamine solution outlet 8 being provided externally at the lower end of the absorption tower 1, the alkanolamine solution outlet and the alkanolamine solution return port being connected to an alkanolamine solution regeneration device through a liquid pipeline to form a regeneration circulation system.

[0041] In this way, the amine solution enters the absorption tower from the return port and is sprayed downwards through the nozzle device. The flue gas to be treated enters the absorption tower from the flue gas inlet pipe and is evenly discharged upwards through the gas distribution device. The flue gas and the amine solution flow countercurrently in the inner cavity of the absorption tower, contacting and reacting, thus absorbing carbon dioxide. The porous packing allows some of the amine solution to adhere to it, slowing down the downward movement of the solution, increasing the contact area and efficiency between the flue gas and the solution, and improving the reaction absorption efficiency. Simultaneously, the solution that has absorbed carbon dioxide flows directly out from the outlet and is regenerated and recycled through a regeneration device, ensuring that the solution sprayed from the nozzles continuously maintains maximum absorption efficiency and does not decrease over time. Therefore, the system features high carbon dioxide removal efficiency and good sustainability.

[0042] The alcoholamine solution is an ethanolamine solution.

[0043] The absorption effect is good when using ethanolamine solution and carbon dioxide reaction, and it is easily decomposed upon heating, making recovery convenient. The chemical reaction formula for the absorption process is: CH2OH.CH2NH2 + CO2 + H2O → CH2OH.CH2NH3 + +HCO3 - .

[0044] The spray head device 6 comprises multiple nozzles evenly arranged on the same horizontal plane. This ensures a better spraying effect.

[0045] The air distribution device 3 includes a plurality of air distribution pipes arranged in a uniform array, and the air outlet is formed on the lower surface of the air distribution pipes.

[0046] This prevents the amine solution from dripping into the vent and avoids clogging the vent.

[0047] The porous packing 7 includes multiple vertical corrugated packing plates arranged in a staggered and overlapping manner.

[0048] This allows for a better increase in the contact area between the solution and the flue gas, preventing it from obstructing the upward movement of the flue gas.

[0049] The amine solution regeneration device includes a regeneration reactor, a gas distribution device, and a trough-type solar collector for reflecting sunlight. The regeneration reactor is cylindrical and located at the reflection center of the reflector 10 of the trough-type solar collector. The two ends of the regeneration reactor are fixed to the two ends of the reflector 10 of the trough-type solar collector by mounting brackets 11. The regeneration reactor includes a regeneration tube 12 that is conical in shape. The cross-sectional area of ​​the regeneration tube 12 gradually increases along the direction of solution flow. The regeneration tube is provided with porous heat-conducting skeletons 13 at intervals along the cross-section. In practice, the heat-conducting skeletons are honeycomb-shaped to better conduct heat and ensure sufficient fluid flow efficiency. A heat-absorbing material layer 14 for absorbing sunlight is also provided on the outer surface of the regeneration tube 12. The liquid outlet of the regeneration reactor is connected to the gas distribution device.

[0050] In this way, the amine solution enters the regeneration reactor and flows into the regeneration tube from the inlet. The solution is heated by sunlight reflected by the reflective mirrors of the trough-type solar collector, resulting in reduction and decomposition to produce carbon dioxide and hydrogen. The cross-sectional area of ​​the regeneration tube gradually increases in the direction of solution flow to better accommodate the expansion caused by the generated gases and to facilitate gas decomposition. After the decomposition reaction is complete, the solution enters the gas separator from the outlet. The gas separator is used to guide the generated gases away, while the flowing-down solution is recycled. The chemical formula for the decomposition reaction is: CH2OH·CH2NH3. + +HCO3 - →CH2OH.CH2NH2+CO2+H2. The trough-type solar collector is a mature existing device. Its structure includes a parabolic reflector. The reflector is rotatably mounted on support frames on both sides by a pivot. Mounting frames are also provided at both ends of the reflector, and the components to be heated are fixed to the reflection center of the reflector by the mounting frames. The trough-type solar collector also includes a tracking control device with two-dimensional tracking function, which can control the reflector to rotate with the sunlight to ensure the adjustment of the light collection angle and ensure the heating effect.

[0051] The regeneration reactor also includes a cylindrical outer shell 16 coaxially sleeved outside the regeneration tube. The outer shell 16 is made of transparent material and a vacuum jacket is provided between the outer shell and the regeneration tube 12.

[0052] In this way, the outer shell can heat the regeneration tube through sunlight, while the vacuum jacket can isolate the regeneration tube from the outside heat transfer, preventing heat from being carried away by the outside airflow.

[0053] The inlet and outlet of the regeneration reactor are each connected to a flexible hose 17 or a rotary joint.

[0054] This ensures that the regeneration reactor will not affect other components when it rotates with the reflector of the trough collector.

[0055] The regeneration reactor is equipped with a flow control valve 18 on the liquid pipe at the inlet end, and a light intensity sensor (not shown in the figure) is also installed on the reflective lens. The light intensity sensor is connected to the controller, and the controller is connected to the flow control valve 18.

[0056] In this way, the light intensity of the reflecting mirror can be detected, and the flow rate of the solution entering the regeneration reactor can be adjusted to match it, ensuring the regeneration effect.

[0057] The liquid pipeline before entering the amine solution regeneration device is also equipped with a liquid inlet storage tank 19 and a solution pump 20.

[0058] In this way, the solution pump can better provide sufficient fluid pressure to the regeneration circulation system. At the same time, the inlet storage tank can realize the storage and transfer of the solution, facilitating the flow control of the solution entering the regeneration reactor.

[0059] Among them, an electrothermal film 21 is also provided on the regeneration tube 12 of the regeneration reactor.

[0060] In this way, when the light intensity is insufficient at night or on cloudy days, the regeneration reaction can be maintained by heating with an electric heating film, ensuring the sustainability of industrial production.

[0061] The amine solution regeneration device also includes a bypass pipe 22, which is installed in parallel at both ends of the regeneration reactor via a three-way valve 23.

[0062] In this way, when maintenance is required, the solution input to the regeneration device can be switched off by switching the three-way valve, and the continuous operation of the circulation system can be ensured by switching the bypass pipe, thus realizing online maintenance.

[0063] The gas separation device includes a gas separation and liquid storage tank 24. The gas separation and liquid storage tank 24 has an inlet in the middle of one side and is connected to the outlet of the regeneration reactor through a liquid pipe. The upper end of the gas separation and liquid storage tank 24 is provided with an upward-facing exhaust pipe 25 and connected to a gas storage container. The lower end of the gas separation and liquid storage tank is provided with an outlet and is connected to the return port of the amine solution of the absorption tower through a liquid pipe.

[0064] In this way, the solution and gas after the reaction in the regeneration reactor enter the gas-liquid separator in a mixed state. The increased volume of the gas-liquid separator allows sufficient space for the gas to overflow upwards and be extracted through the extraction pipe to a storage container for storage and reuse. The regenerated solution flows out through the outlet and returns to the amine solution return port of the absorption tower for recycling. This gas-liquid separator better assists in gas separation and also has a storage and regulation function for the separated solution, ensuring a continuous supply of regenerated solution to the absorption tower for a certain period during regeneration reactor maintenance. In practice, a return pump 26 can be installed on the liquid pipeline between the lower outlet of the gas-liquid separator and the amine solution return port of the absorption tower to ensure sufficient return pressure to supply the spray pressure of the nozzle device.

Claims

1. A flue gas carbon dioxide capture system, comprising a vertically arranged absorption tower, a flue gas inlet pipe disposed on one side of the lower part of the absorption tower, the flue gas inlet pipe being connected to a horizontally arranged gas distribution device inside the absorption tower, the gas distribution device having evenly distributed gas outlet holes, and a flue gas outlet pipe disposed upward at the upper end of the absorption tower, characterized in that, An alkanolamine solution return port is also provided on one side of the upper part of the absorption tower. A downward-facing nozzle device is also provided at the upper end of the inner cavity of the absorption tower. The nozzle device is connected to the alkanolamine solution return port. A vertically penetrating porous packing is provided between the gas distribution device and the nozzle device. An alkanolamine solution outlet is also provided at the lower end of the absorption tower. An alkanolamine solution regeneration device is connected between the alkanolamine solution outlet and the alkanolamine solution return port through a liquid pipeline, forming a regeneration circulation system. The amine solution regeneration device includes a regeneration reactor, a gas distribution device, and a trough-type solar collector for reflecting sunlight. The regeneration reactor is cylindrical in shape and located at the reflection center of the reflector of the trough-type solar collector. The two ends of the regeneration reactor are fixed to the two ends of the reflector of the trough-type solar collector by mounting brackets. The regeneration reactor includes a regeneration tube that is conical in shape. The cross-sectional area of ​​the regeneration tube gradually increases along the direction of solution flow. The regeneration tube is provided with a porous heat-conducting skeleton at intervals along the cross-section. The outer surface of the regeneration tube is also provided with a layer of heat-absorbing material for absorbing sunlight. The liquid outlet of the regeneration reactor is connected to the gas distribution device.

2. The flue gas carbon dioxide capture system as described in claim 1, characterized in that, The alcoholamine solution is an ethanolamine solution.

3. The flue gas carbon dioxide capture system as described in claim 1, characterized in that, The nozzle assembly comprises multiple nozzles evenly arranged on the same horizontal plane.

4. The flue gas carbon dioxide capture system as described in claim 1, characterized in that, The air distribution device includes multiple air distribution pipes arranged in a uniform array, and the air outlet is formed on the lower surface of the air distribution pipes.

5. The flue gas carbon dioxide capture system as described in claim 1, characterized in that, The porous packing includes multiple vertical corrugated packing plates arranged in a staggered and overlapping manner.

6. The flue gas carbon dioxide capture system as described in claim 1, characterized in that, The regeneration reactor also includes a cylindrical outer shell coaxially fitted outside the regeneration tube. The outer shell is made of transparent material and a vacuum jacket is provided between the outer shell and the regeneration tube.

7. The flue gas carbon dioxide capture system as described in claim 1, characterized in that, The inlet and outlet of the regeneration reactor are each connected to a hose or rotary joint.

8. The flue gas carbon dioxide capture system as described in claim 1, characterized in that, A flow control valve is also installed on the liquid pipeline at the inlet end of the regeneration reactor, and a light intensity sensor is also installed on the reflector. The light intensity sensor is connected to the controller, and the controller is connected to the flow control valve.

9. The flue gas carbon dioxide capture system as described in claim 1, characterized in that, A liquid inlet storage tank and a solution pump are also installed on the liquid pipeline before it enters the amine solution regeneration unit. An electrothermal film is also installed on the regeneration tube of the regeneration reactor; The amine solution regeneration device also includes a bypass pipe, which is installed in parallel at both ends of the regeneration reactor by means of a three-way valve; The gas separation device includes a gas separation and liquid storage tank. An inlet is provided in the middle of one side of the gas separation and liquid storage tank and is connected to the outlet of the regeneration reactor through a liquid pipeline. An exhaust pipe is provided at the upper end of the gas separation and liquid storage tank and is connected to the gas storage container. An outlet is provided at the lower end of the gas separation and liquid storage tank and is connected to the return port of the amine solution of the absorption tower through a liquid pipeline.

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