Method, system and activated carbon concentration device for recovering decarbonized gas after capture

Abstract

The application discloses a kind of recovery method, system and activated carbon concentration device of post-decarbonization gas capture, wherein the device is recycled to the decarbonization gas output by carbon capture absorption tower, and the device includes: at least two cabins, each cabin contains activated carbon, and the flow direction of the decarbonization gas is controlled by the air inlet valve of each cabin;Activated carbon adsorption efficiency determination unit is used to determine the adsorption efficiency of activated carbon in each cabin;Air inlet valve controller is used to control the air inlet valve of the cabin to be closed and the air inlet valve of another cabin to be opened when the adsorption efficiency of activated carbon in the cabin is lower than the predetermined value, so that the activated carbon in the other cabin can adsorb and treat the decarbonization gas. By the application, resource waste can be reduced, and pollution probability can be reduced.

Description

Technical Field

[0001] This invention relates to the field of greenhouse gas emission reduction and resource utilization technology, specifically to a method, system, and activated carbon concentration device for recovering captured and decarbonized gases. Background Technology

[0002] A common capture process involves absorbing carbon dioxide with an organic amine solution that is highly selective for carbon dioxide, followed by heating and regeneration to produce high-purity carbon dioxide for storage. In this process, the flue gas after absorption by the organic solvent is discharged from the top of the absorption tower. The residual gas components discharged mainly include: VOCs (Volatile Organic Compounds), organic amines volatilized from the absorbent, small amounts of uncaptured CO2 gas, and moisture.

[0003] The residual gases emitted contain not only harmful substances, but also reusable organic amines, CO2, and moisture. Directly releasing these residual gases into the atmosphere not only wastes resources but also causes secondary air pollution. Summary of the Invention

[0004] The present invention provides a method, system and activated carbon concentration device for recovering decarbonized gas after capture, in order to solve at least one of the problems mentioned above.

[0005] According to a first aspect of the present invention, an activated carbon concentration apparatus for capturing decarbonized gas is provided. The apparatus recovers decarbonized gas output from a carbon capture and absorption tower. The apparatus includes: at least two compartments, each containing activated carbon, wherein the flow direction of the decarbonized gas is controlled by a respective inlet valve of each compartment; an activated carbon adsorption efficiency determination unit for determining the adsorption efficiency of the activated carbon in each compartment; and an inlet valve controller for controlling the inlet valve of the compartment to close and the inlet valve of the other compartment to open when the adsorption efficiency of the activated carbon in the compartment is lower than a predetermined value, so that the activated carbon in the other compartment can adsorb the decarbonized gas.

[0006] Furthermore, each compartment receives high-temperature steam from the reboiler through its own steam input valve. The device also includes a steam input valve controller, which controls the steam input valve of a compartment to open after the inlet valve of the compartment is closed, so that the high-temperature steam from the reboiler can enter the compartment and desorb the gas adsorbed by the activated carbon in the compartment.

[0007] Furthermore, the device also includes a reflux pipe for returning the desorbed gas to the desorption tower in the form of steam.

[0008] Preferably, the device further includes: an air supply fan, a three-way ventilation valve, and a burner, wherein: after the air inlet valve of the compartment is closed, the remaining gas in the compartment after being adsorbed by activated carbon is input to the burner through the air supply fan and the three-way ventilation valve.

[0009] According to a second aspect of the present invention, a recovery system for captured decarbonized gas is provided, the system comprising: an activated carbon concentration device for captured decarbonized gas, a carbon capture absorption tower, a reboiler, and a desorption tower, wherein the desorption tower desorbs carbon dioxide entering from the carbon capture absorption tower by means of heating treatment in the reboiler.

[0010] Preferably, the desorption tower recovers the desorbed gas that is returned in the form of steam from the activated carbon concentration device, and performs a heating operation based on the heat of the steam.

[0011] According to a third aspect of the present invention, a method for recovering decarbonized gas after capture is provided, the method comprising: setting up at least two compartments, each compartment containing activated carbon, wherein each compartment is connected to a carbon capture and absorption tower, and each compartment controls the flow direction of the decarbonized gas output from the carbon capture and absorption tower through its respective inlet valve; determining the adsorption efficiency of the activated carbon in the compartment in response to the decarbonized gas entering the compartment; and when the adsorption efficiency of the activated carbon in the compartment is lower than a predetermined value, controlling the inlet valve of the compartment to close and the inlet valve of the other compartment to open, so that the activated carbon in the other compartment can adsorb the decarbonized gas.

[0012] Furthermore, the method also includes: each compartment receiving high-temperature steam from the reboiler through its own steam input valve; after the air inlet valve of a compartment is closed, the steam input valve of that compartment is opened to allow the high-temperature steam from the reboiler to enter the compartment and desorb the gas adsorbed by the activated carbon in the compartment.

[0013] Preferably, the method further includes: refluxing the desorbed gas back to the desorption tower in the form of steam.

[0014] Preferably, the method further includes: pre-setting an air supply fan, a three-way ventilation valve, and a burner; after the air inlet valve of the compartment is closed, the remaining gas in the compartment after being adsorbed by activated carbon is input to the burner through the air supply fan and the three-way ventilation valve.

[0015] Meanwhile, the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method.

[0016] In addition, the present invention also provides a computer-readable storage medium storing a computer program for performing the above-described method.

[0017] As can be seen from the above technical solution, by setting up a chamber containing activated carbon, this technical solution can achieve adsorption and desorption treatment of decarbonized gas, thereby realizing the recycling of decarbonized gas, reducing resource waste and lowering the probability of pollution.

[0018] To make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the recovery system for the decarbonized gas after capture, according to an embodiment of the present invention.

[0020] Figure 2 This is a structural block diagram of an activated carbon concentration device for capturing decarbonized gas according to an embodiment of the present invention.

[0021] Figure 3 This is a flowchart of a method for recovering decarbonized gas after capture, according to an embodiment of the present invention.

[0022] Figure label:

[0023] 1. Carbon capture and absorption tower; 2. Rich liquid pump; 3. Lean and rich liquid heat exchanger; 4. Lean liquid pump; 5. Desorption tower; 6. Reboiler; 7. Chamber; 8. Inlet control valve; 9. Steam desorption control valve; 10. Air supply fan; 11. Three-way ventilation valve; 12. Burner; 13. Post-combustion capture device; 14. Activated carbon concentration device; 142. Activated carbon adsorption efficiency determination unit; 143. Inlet valve controller. Detailed Implementation

[0024] 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.

[0025] In related technologies, the residual gas discharged from the absorption tower (also known as decarbonized gas) contains not only harmful substances, but also reusable organic amines, CO2 gas, and moisture. Directly releasing this residual gas into the atmosphere would not only waste resources but also cause secondary air pollution.

[0026] Based on this, embodiments of the present invention provide a recovery scheme for decarbonized gas after capture. This scheme can recover and reuse gas components in the decarbonized gas, reduce resource waste, and lower the probability of pollution. On the other hand, the heat recovered from the desorption steam can be used to raise the temperature of the desorption tower, which can reduce the energy consumption of the reboiler.

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

[0028] Figure 1 This is a schematic diagram of a gas recovery system for decarbonized gas after capture, according to an embodiment of the present invention. Figure 1 As shown, the system includes: a post-combustion collection device 13 and an activated carbon concentration device 14 for collecting the decarbonized gas. The activated carbon concentration device 14 recovers the decarbonized gas collected by the post-combustion collection device 13.

[0029] Figure 2 This is a structural block diagram of the activated carbon concentration device 14, as shown below. Figure 2 As shown, the activated carbon concentration device 14 includes: at least two chambers 141, an activated carbon adsorption efficiency determination unit 142, and an air inlet valve controller 143, wherein: Each compartment contains activated carbon, which can adsorb decarbonized gases. The flow direction of the decarbonized gases is controlled by the respective air inlet valve of each compartment.

[0030] The activated carbon adsorption efficiency determination unit 142 is used to determine the adsorption efficiency of activated carbon in each compartment.

[0031] In actual operation, the activated carbon adsorption efficiency determination unit 142 can be two gas analyzers installed at the inlet and outlet of the chamber to measure the concentration of gases (e.g., CO and CO2) and determine the adsorption efficiency of activated carbon in the chamber based on the concentration difference between the inlet and outlet gases.

[0032] The air intake valve controller 143 is used to control the air intake valve of the chamber to close and the air intake valve of another chamber to open when the adsorption efficiency of the activated carbon in the chamber is lower than a predetermined value (the predetermined value can be determined according to the actual situation, and the present invention does not limit it), so that the activated carbon in the other chamber can adsorb the decarbonized gas.

[0033] Furthermore, each compartment can also receive high-temperature steam from the reboiler through its own steam input valve. Accordingly, the activated carbon concentration device 14 also includes a steam input valve controller, used to control the opening of the steam input valve of a compartment after the air inlet valve of the compartment is closed, so that the high-temperature steam from the reboiler can enter the compartment to desorb the gas adsorbed by the activated carbon in the compartment.

[0034] In actual operation, the activated carbon concentration unit 14 also includes a reflux pipe for returning the desorbed gas to the desorption tower in the form of steam. The desorbed gas mainly includes reusable organic amines, CO2 gas, etc. The desorption tower can then recover and process these gases.

[0035] In one embodiment, the activated carbon concentration device 14 further includes an air supply fan, a three-way ventilation valve, and a burner, wherein: after the air inlet valve of the chamber is closed, the remaining gas in the chamber after activated carbon adsorption is introduced into the burner through the air supply fan and the three-way ventilation valve. This remaining gas is clean air and can be introduced into the burner for continued use.

[0036] To better understand this invention, the following is combined with... Figure 1 To describe in detail the working principle of the recycling system.

[0037] Continue to refer to Figure 1 The post-combustion capture device 13 includes: a carbon capture absorption tower 1, a rich liquid pump 2, a lean and rich liquid heat exchanger 3, a lean liquid pump 4, a desorption tower 5, and a reboiler 6; the activated carbon concentration device 14 includes: a chamber 7, an air inlet control valve 8, a steam desorption control valve 9, an air supply fan 10, a three-way ventilation valve 11, and a burner 12.

[0038] During operation of the recovery system, the desorption tower 5 desorbs the carbon dioxide entering from the carbon capture and absorption tower 1 through heating treatment in the reboiler 6. The decarbonized gas in the carbon capture and absorption tower 1 enters the activated carbon concentration unit 14 for adsorption and desorption treatment. Subsequently, the desorption tower 5 recovers the desorbed gas that is returned in the form of steam from the chamber 7 of the activated carbon concentration unit 14, and heats it based on the heat of the steam.

[0039] By using activated carbon concentration device 14 to adsorb and desorb the decarbonized gas, and desorption tower 5 to recover the desorbed gas, the gas components in the decarbonized gas can be recovered and reused, reducing resource waste and lowering the probability of pollution. At the same time, desorption tower 5 operates by heating with steam heat, which can reduce the energy consumption of the reboiler.

[0040] In actual operation, after the flue gas from the power plant is discharged from the combustion furnace, it undergoes desulfurization, denitrification, and dust removal pretreatment before entering the carbon capture absorption tower 1. From bottom to top, it fully contacts the lean solution used for carbon capture. Carbon dioxide in the flue gas is absorbed by the lean solution (generated by the lean solution pump 4) and falls to the bottom of the tower under gravity. Powered by the rich solution pump 2, it enters the lean-rich solution heat exchanger 3 for sufficient heat exchange and preheating with the hot lean solution. The solution then enters the carbon dioxide desorption tower 5, where it is heated by the reboiler 6, desorbing carbon dioxide and some water vapor. The desorbed gas is discharged from the top of the desorption tower 5 and enters the condenser for further processing. The decarbonized gas generated in the absorption tower 1 enters the activated carbon concentration chamber 7 from the top of the absorption tower 1 through the inlet control valve 8 (which has the function of the aforementioned inlet valve controller). The porous structure and excellent adsorption properties of the activated carbon in the chamber absorb any incompletely absorbed carbon dioxide, carbon monoxide, and other components in the decarbonized gas. Afterwards, the adsorbed clean air is controlled by the air supply fan 10 and the three ventilation valves 11, with part of it being supplied to the boiler burner 12 and part being discharged normally.

[0041] The aforementioned chamber 7 has a two- or multi-chamber structure. When the inlet valve of one chamber is open, that chamber performs flue gas adsorption. Subsequently, based on the gas analysis data from the chamber's inlet and outlet, the concentrations of carbon monoxide (CO) and carbon dioxide (CO2) are tested to determine the activated carbon adsorption efficiency. Specifically, two gas analyzers can be installed at the inlet and outlet of chamber 7 to measure CO and CO2 concentrations, and the adsorption efficiency of the activated carbon within the chamber is determined based on the gas concentration difference between the inlet and outlet.

[0042] When the adsorption efficiency drops to 50%~60% after a period of adsorption, the inlet valve of this chamber is closed, while the inlet valve of the other chamber is opened to continue gas adsorption. Simultaneously, the remaining steam from reboiler 6 is introduced into this chamber through an insulated pipeline and steam desorption control valve 9. High-temperature steam is used to desorb and regenerate the gas components in the activated carbon channels. The steam carrying carbon dioxide after stripping, along with the water that falls back to the bottom of the chamber, enters the desorption tower 5 through a pipeline (i.e., the aforementioned reflux pipeline). Once the activated carbon desorption in the chamber is complete and the activated carbon adsorption efficiency in the other chamber approaches 50%~60%, the inlet valve of the other chamber is closed, and the inlet valve of this chamber is opened, repeating the cycle to maintain synchronous adsorption and desorption across multiple chambers. This improves the efficiency of decarbonized gas recovery and treatment.

[0043] In practice, the intake valve and steam desorption control valve can be electric, and the valve opening and closing can be manually controlled by an electric valve PLC (Programmable Logic Controller).

[0044] In actual operation, the activated carbon concentration device 14 can be set with 2 to N compartments depending on the actual scenario. The gas flow direction between multiple compartments is controlled by valves. The multiple compartments work synchronously by using a partitioned adsorption and partitioned desorption method, without the risk of stopping the equipment to perform desorption, thus ensuring work efficiency.

[0045] This invention employs activated carbon adsorption and concentration to replace the traditional water scrubbing tower process for treating decarbonized tail gas (i.e., decarbonized gas). This method efficiently recovers and separates incompletely absorbed carbon dioxide, escaped organic amine absorbent, and moisture from the decarbonized tail gas, reducing the waste of effective resources and the water and electricity consumption in the water scrubbing process. Simultaneously, by utilizing the highly efficient capture performance of activated carbon for organic matter, it absorbs other gaseous components in the tail gas, preventing secondary air pollution caused by direct discharge.

[0046] In addition, the embodiments of the present invention make full use of the residual steam heat after carbon dioxide capture and steam regeneration to heat and steam desorb and regenerate the gas molecules adsorbed in the pores of activated carbon, thereby restoring the adsorption performance of activated carbon. At the same time, high-temperature steam is used to recover the CO2, organic amines and other components adsorbed in the pores in the form of steam and return them to the desorption tower. This will not generate excess waste liquid and reduce the cost of secondary treatment of wastewater and waste.

[0047] In other words, in this embodiment of the invention, the desorption liquid from the activated carbon concentration device is refluxed. On the one hand, the effective components of the organic amines volatilized in the decarbonized gas can be recovered and reused. The carbon dioxide in the steam enters the next condensation section for storage as the desorption tower is heated. On the other hand, the heat of the recovered desorption steam can be used to heat the desorption tower and reduce the energy consumption of the reboiler. At the same time, the refluxed water and steam can provide water replenishment to the recovery system to maintain the high efficiency of carbon capture solution.

[0048] Based on a similar inventive concept, embodiments of the present invention also provide a method for recovering decarbonized gas after capture, which is preferably applicable to the above-mentioned recovery system.

[0049] Figure 3 This is a flowchart of the method for recovering decarbonized gas after capture, such as... Figure 3 As shown, the method includes: Step 301: Set up at least two compartments, each containing activated carbon, wherein each compartment is connected to a carbon capture and absorption tower, and each compartment controls the flow direction of the decarbonized gas output from the carbon capture and absorption tower through its own air inlet valve; Step 302: In response to the decarbonization gas entering the chamber, determine the adsorption efficiency of the activated carbon in the chamber; Step 303: When the adsorption efficiency of activated carbon in the chamber is lower than a predetermined value, the air inlet valve of the chamber is closed and the air inlet valve of another chamber is opened so that the activated carbon in the other chamber can adsorb the decarbonized gas.

[0050] Furthermore, the above method also includes: each compartment receiving high-temperature steam from the reboiler through its own steam input valve; after the air inlet valve of a compartment is closed, the steam input valve of that compartment is opened to allow the high-temperature steam from the reboiler to enter the compartment and desorb the gas adsorbed by the activated carbon in the compartment.

[0051] By setting up a chamber containing activated carbon, adsorption and desorption treatment of decarbonized gases can be achieved, enabling the recycling and reuse of decarbonized gases, reducing resource waste, and lowering the probability of pollution.

[0052] In one embodiment, the method further includes: refluxing the desorbed gas back to the desorption tower in the form of steam.

[0053] The heat recovered from the desorbed steam via the desorption tower can be used to raise its temperature, which can reduce the energy consumption of the reboiler.

[0054] In one embodiment, the method further includes: pre-setting an air supply fan, a three-way ventilation valve, and a burner; after the air inlet valve of the compartment is closed, the remaining gas in the compartment after activated carbon adsorption is input to the burner through the air supply fan and the three-way ventilation valve. The remaining gas here is clean air, which can be input to the burner for continued use, further improving resource utilization.

[0055] The specific execution process of each of the above steps can be found in the description of the above system embodiments, and will not be repeated here.

[0056] Before implementing the embodiments of the present invention, after the high-temperature flue gas is discharged from the burner, it undergoes desulfurization, denitrification, and dust removal pretreatment before entering the carbon dioxide absorption tower. There, it is captured by a carbon capture solvent containing organic amines through counter-current contact. Due to incomplete pretreatment and decarbonization reaction, the decarbonized gas contains a large amount of gaseous components such as VOCs, organic amines volatilized from the absorbent, a small amount of uncaptured CO2 gas, and moisture. This results in resource waste and secondary air pollution. To reduce resource waste in the absorption tower, lower the probability of pollution, and fully consider resource reuse in subsequent processes, the embodiments of the present invention use activated carbon adsorption concentration to concentrate the decarbonized gas discharged from the absorption tower, replacing the traditional water washing process and overcoming the problems of water and electricity consumption in the water washing process. Meanwhile, in this embodiment of the invention, the residual steam heat from the reboiler of the desorption tower is used to alternately regenerate the activated carbon in the multi-compartment activated carbon adsorption and concentration device through steam desorption. The desorbed carbon-containing, organic amine-containing, and heated steam, along with the condensate solution, is returned to the desorption tower. This process recovers and reuses gaseous components from the decarbonized gas and recovers the heat from the desorption steam for heating the desorption tower, reducing reboiler energy consumption. Simultaneously, the returned water and steam can replenish the entire recovery system, maintaining the high efficiency of the carbon capture solution.

[0057] This embodiment also provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The electronic device may be a desktop computer, a tablet computer, or a mobile terminal, etc., and this embodiment is not limited thereto. In this embodiment, the electronic device can be implemented with reference to the above-described method embodiments and the above-described device / system embodiments, the contents of which are incorporated herein by reference, and repeated details will not be described again.

[0058] This invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described recycling method.

[0059] In summary, this invention proposes a scheme for the concentration and recovery of decarbonized gas after capture and the reuse of residual steam from the reboiler. This scheme utilizes the residual steam from the reboiler as a desorption heat source to efficiently recover incompletely absorbed carbon dioxide, volatile organic amine absorbent, and moisture from the decarbonized gas, reducing the waste of effective resources and overcoming the problems of water and electricity consumption in the water washing process of related technologies. It also reduces the secondary pollution problem caused by direct discharge of decarbonized gas. Simultaneously, the desorption liquid from the adsorption concentration unit is refluxed. On the one hand, the effective components such as volatile organic amines in the decarbonized gas are recovered and reused; the carbon dioxide in the steam enters the next condensation section for storage as the desorption tower heats up; on the other hand, the heat from the desorption steam is recovered for heating the desorption tower, which can reduce the energy consumption of the reboiler. At the same time, the refluxed water and steam can provide water replenishment for the entire system to maintain the high capture efficiency of the carbon capture solution.

[0060] Specific embodiments have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A system for recovering decarbonized gas after capture, characterized in that, The device includes an activated carbon concentration unit for capturing and decarbonizing gas, a carbon capture and absorption tower, a reboiler, and a desorption tower. The desorption tower desorbs carbon dioxide entering from the carbon capture and absorption tower through the heating treatment of the reboiler. The activated carbon concentration device recovers the decarbonized gas output from the carbon capture and absorption tower. The device includes: The chamber has at least two compartments, each containing activated carbon. Each compartment controls the flow direction of the decarbonized gas through its own inlet valve, and each compartment receives high-temperature steam from the reboiler through its own steam inlet valve. The activated carbon adsorption efficiency determination unit is used to determine the adsorption efficiency of activated carbon in each compartment. An air intake valve controller is used to close the air intake valve of a chamber and open the air intake valve of another chamber when the adsorption efficiency of activated carbon in the chamber is lower than a predetermined value, so that the activated carbon in the other chamber can adsorb the decarbonized gas. A steam input valve controller is used to control the steam input valve of the compartment to open after the air inlet valve of the compartment is closed, so that the high-temperature steam of the reboiler can enter the compartment to desorb the gas adsorbed by the activated carbon in the compartment. A reflux pipeline is used to return the desorbed gas to the desorption tower in the form of steam; The desorption tower recovers the desorbed gas that is returned in the form of steam from the activated carbon concentration device, and heats it based on the heat of the steam.

2. The system for recovering decarbonized gas after capture according to claim 1, characterized in that, It also includes an air supply fan, three ventilation valves, and a burner, among which: After the air intake valve of the compartment is closed, the remaining gas in the compartment after being adsorbed by activated carbon is fed into the burner through the air supply fan and the three ventilation valves.

3. A method for recovering decarbonized gas after capture, implemented using the gas recovery system for decarbonized gas after capture as described in any one of claims 1-2, characterized in that, include: The system is equipped with at least two compartments, each containing activated carbon. Each compartment is connected to a carbon capture and absorption tower, and the flow direction of the decarbonized gas output from the carbon capture and absorption tower is controlled by the respective air inlet valve of each compartment. In response to the decarbonization gas entering the chamber, the adsorption efficiency of the activated carbon in the chamber is determined; When the adsorption efficiency of activated carbon in the chamber is lower than a predetermined value, the air inlet valve of the chamber is closed and the air inlet valve of another chamber is opened so that the activated carbon in the other chamber can adsorb the decarbonized gas. Each compartment receives high-temperature steam from the reboiler through its own steam input valve; After the air inlet valve of the chamber is closed, the steam input valve of the chamber is opened to allow the high-temperature steam from the reboiler to enter the chamber and desorb the gas adsorbed by the activated carbon in the chamber. The desorbed gas is returned to the desorption tower as steam.

4. The method for recovering decarbonized gas after capture according to claim 3, characterized in that, Also includes: Pre-install air supply fan, three ventilation valves and burner; After the air intake valve of the compartment is closed, the remaining gas in the compartment after being adsorbed by activated carbon is fed into the burner through the air supply fan and the three ventilation valves.

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