Amine aerosol gradient capture and solvent regeneration combined device and method based on multistage rotational flow coupling

Abstract

The invention relates to an amine aerosol gradient capture and solvent regeneration combined device and method based on multistage rotational flow coupling, the amine aerosol gradient capture and solvent regeneration combined device comprises a pre-separation module, a wet-process rotational flow separation module and a solvent cyclic regeneration module, the pre-separation module is connected with an absorption tower tail gas discharge port, and primary coarse screening is performed on amine aerosol through collision type inertial separation; and the wet-process cyclone separation module is connected through a reducer pipe. The solvent cyclic regeneration module comprises a solution inner circulation branch and a solution outer circulation branch, and the inner circulation branch is connected with an inlet of the wet-process cyclone separation module through an atomization spray head. The wet-process cyclone separation module is used for generating rotating air flow, and the rotating air flow is coupled with the atomized liquid drops to realize secondary capture. The solution internal circulation maintains the droplet concentration gradient and enriches the amine solution, the external circulation branch is started when a threshold value is reached, the regenerated amine solution is conveyed to the absorption tower, and closed-loop regeneration of the solvent is realized. Compared with the prior art, efficient multi-stage capture of amine aerosol and recycling of an escape solvent can be achieved, and therefore the operation stability and economical efficiency of a carbon capture system are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon capture and storage, and particularly relates to a device and method for combined capture of amine aerosol gradient and solvent regeneration based on multistage swirl coupling. Background Art

[0002] With the increasingly severe global climate change problem, carbon capture and storage (CCUS) technology is widely regarded as the key way to achieve the goals of carbon dioxide emission reduction and carbon neutrality. Among them, the technology for capturing carbon dioxide after fossil fuel combustion is the core link of the CCUS system. As the capture method with the highest current technology maturity and the widest application, the organic amine absorption method has been implemented in engineering in multiple industrial scenarios.

[0003] Reference patent CN114345098A proposes a method and system for decomposition inhibition and efficient pollution reduction of a CO2 capture absorbent. Through means such as pre-washing for impurity removal, precise temperature control in the absorption and desorption processes, post-stage water washing for demisting, impurity removal from the circulating absorbent, charge-enhanced aerosol coagulation and growth, and electrostatic removal, it aims to reduce absorbent loss and inhibit secondary pollution. However, it still needs to be improved in the efficient capture of amine aerosol and solvent recovery under complex working conditions.

[0004] Another reference patent CN117427468A relates to a reuse system for a desulfurization and decarbonization absorbent and its use and flexible regulation method. The system effectively reduces absorbent loss and aerosol removal through a partitioned absorption tower and an integrated device for efficient capture and reuse of the absorbent to capture pollutants, and improves the decarbonization efficiency. However, it still faces challenges in capturing and solvent recovery of high-concentration and high-intensity amine aerosols.

[0005] However, during the amine-based carbon capture process, the operating conditions of the absorption tower are complex, the flue gas disturbance is strong, and a large amount of amine aerosol is often generated and released. Amine aerosol has characteristics such as small particle size (mostly sub-micron level), low concentration, and large surface area, and it is extremely easy to carry amine solvents and escape with the flue gas. Research shows that the formation mechanism of secondary aerosol mainly includes processes such as heterogeneous nucleation and agglomeration growth. Its emission not only causes a large loss of absorbent, significantly increases the operating cost, but may also cause corrosion to downstream equipment and even form environmental pollution. To reduce the escape of amine aerosol, tail gas treatment means such as demisters, wet electrostatic precipitators, and water washing towers are often used. However, existing technologies generally have problems such as low capture efficiency, high energy consumption, complex structure, or high maintenance cost, and it is difficult to meet the requirements of efficient separation and solvent recovery of amine aerosol under high-load and strong-disturbance conditions.

[0006] Therefore, there is an urgent need to develop a cascade capture device for amine aerosol control and solvent recovery that is compact in structure, stable in operation, and highly efficient in grading, so as to improve the economy and environmental protection of the carbon capture system and broaden its engineering application boundary. Summary of the Invention

[0007] The object of the present invention is to overcome the problems in the existing amine-based carbon capture system, such as low efficiency in controlling amine aerosol, serious solvent escape, and insufficient grading ability of the tail gas treatment device. A device and method for combined use of amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling are provided to achieve efficient multi-stage capture of amine aerosol and recycling of escaped solvent, thereby improving the operation stability and economy of the carbon capture system.

[0008] The object of the present invention can be achieved through the following technical solutions:

[0009] In the first aspect of the present invention, a device for combined use of amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling is provided for aerosol gradient capture and solvent regeneration during the amine liquid absorption process, including a pre-separation module, a wet cyclone separation module, and a solvent circulation and regeneration module;

[0010] The inlet end of the pre-separation module is connected to the tail gas discharge port of the absorption tower. The pre-separation module performs primary coarse screening on the amine aerosol output from the tail gas discharge port of the absorption tower based on the impact inertial separation method. The outlet end of the pre-separation module is connected to the inlet of the wet cyclone separation module through a variable diameter pipe structure;

[0011] The solvent circulation and regeneration module includes a solution internal circulation branch connected to the wet cyclone separation module, and a solution external circulation branch respectively connected to the solution internal circulation branch and the rich liquid pipeline of the absorption tower. The output end of the solution internal circulation branch is connected to the inlet end of the wet cyclone separation module through an atomizing spray head, and the input end of the solution internal circulation branch is connected to the rotational separation end of the wet cyclone separation module;

[0012] The wet cyclone separation module is used to generate a rotating airflow, which is coupled with the atomized droplets generated by the atomizing spray head to form a strong swirling flow field. The centrifugal sedimentation of aerosol and droplet capture in the gas-liquid two-phase flow are realized through the rotating airflow, and the secondary capture of amine aerosol is completed;

[0013] The solution internal circulation branch is used to dynamically maintain the concentration gradient of the atomized droplets and at the same time enrich the captured amine liquid. When the amine liquid concentration in the solution internal circulation branch reaches the set threshold, the solution external circulation branch is started. The solution external circulation branch is used to pressurize and transport the regenerated amine solution to the absorption tower to be mixed with the rich absorption liquid, realizing the closed-loop regeneration of the solvent.

[0014] Further, the pre-separation module includes a straight pipe and a collision disk provided in the straight pipe. The collision disk includes a gas contraction wall and an inverted cone impact wall provided in the straight pipe;

[0015] The gas contraction wall is a first plate body with a contraction hole in the middle, and the contraction hole protrudes towards the flow direction, thereby forming a compressed air flow channel that contracts towards the center;

[0016] The inverted cone impact wall is arranged on one side of the gas contraction wall and is used for impact inertial separation of the compressed air flow passing through the gas contraction wall.

[0017] Further, the inverted cone impact wall includes a second plate body with its four corners cut off, and an inverted cone detachably arranged in the middle of the second plate body;

[0018] Four flow channels are formed between the four corners of the second plate body and the inner wall of the straight pipe;

[0019] The inverted cone is selected from one of a conical shape, a frustum shape, and a pyramid shape.

[0020] Further, the pre-separation module further includes a reducer pipe, and the straight pipe is connected to the wet cyclone separation module through the reducer pipe;

[0021] The reducer pipe is a square-round gradual change pipe, the cross-section of the inlet end of the reducer pipe is square, and the cross-section of the outlet end is circular.

[0022] Further, the wet cyclone separation module includes a housing and spiral blades arranged in the housing. The spiral blades are matched with a driving motor, and the spiral blades are used to generate a rotating air flow;

[0023] The inclination angle of the spiral blades is 15° to 45°, the number of blades is 3 to 6, and an anti-sticking coating for suppressing aerosol adhesion is provided on the blade surface.

[0024] Further, the top of the housing of the wet cyclone separation module is connected to the reducer pipe. The top of the housing is provided with a liquid inlet, at least one liquid outlet is provided near the outer wall side at the bottom of the housing, and an air outlet is provided in the middle of the bottom of the housing;

[0025] The atomizing spray head is arranged at the liquid inlet;

[0026] The liquid outlet end of the solution internal circulation branch is connected to the liquid inlet, and the liquid inlet end of the solution internal circulation branch is connected to the liquid outlet;

[0027] The aerosol in the gas-liquid two-phase flow is centrifugally sedimented to the outer wall of the housing of the wet cyclone separation module through the rotating air flow and enters the solution internal circulation branch from the liquid outlet to realize liquid droplet capture.

[0028] Further, the solution internal circulation branch includes a solution storage tank, a circulation pump, and a concentration sensor;

[0029] The concentration sensor is disposed in the solution storage tank and is used to monitor the conductivity or density of the amine solution in real time to obtain the concentration value.

[0030] Further, the solution external circulation branch includes a unidirectional liquid pump. The inlet end of the unidirectional liquid pump is connected to the solution storage tank through a pipeline, and the outlet end of the unidirectional liquid pump is connected to the bottom of the absorption tower, so as to turbulently mix the regenerated amine solution conveyed by the unidirectional liquid pump with the rich liquid in the absorption tower. The amine solution after liquid mixing is reused as an absorbent.

[0031] When the monitoring value of the concentration sensor exceeds the preset threshold, the unidirectional liquid pump is started.

[0032] Further, the atomized liquid droplets of the atomizing spray head have a particle size of 10-200 μm, and the spray coverage area accounts for 80%-95% of the inlet cross-section of the wet cyclone separation module.

[0033] The second aspect of the present invention provides a method for coupling amine aerosol gradient capture and solvent regeneration based on multistage cyclone coupling, including the following steps:

[0034] S1: Primary inertial coarse screening

[0035] Introduce the tail gas of the absorption tower into the pre-separation module, and perform primary coarse screening on the amine aerosol through impact inertial separation. Specifically, adjust the contraction ratio of the gas contraction wall in the pre-separation module to 30%-50%, accelerate the flue gas to 8-15 m / s and then impact the inverted cone impact wall, and separate the amine liquid droplets and aerosol with a particle size >10 μm by using the inertial difference of the aerosol particles. The amine liquid droplets and aerosol aggregate and flow into the solution internal circulation along the outer shell of the wet cyclone separation module, or are directly transported to the solution internal circulation through a pipeline, and the separated gas flow is guided to the wet cyclone separation module through a variable diameter pipe structure.

[0036] S2: Secondary cyclone enhanced capture

[0037] Introduce the gas flow output in step S1 into the wet cyclone separation module, generate a rotating gas flow (tangential velocity 20-35 m / s) through the spiral blades, and at the same time atomize and spray amine liquid droplets (particle size 10-200 μm) at the gas flow inlet end, so that the rotating gas flow and the atomized liquid droplets are coupled to form a strong swirling flow field. The strong swirling flow field captures sub-micron amine aerosol with a size of 0.1-10 μm through the synergistic action of centrifugal sedimentation and droplet wrapping, and converges to the solution internal circulation branch.

[0038] S3: Solution internal circulation enrichment

[0039] Introduce the aerosol-droplet mixture captured in step S2 into the solution storage tank, and monitor the conductivity or density of the amine liquid in the storage tank in real time.

[0040] When the monitored value of conductivity or density reaches the preset threshold, trigger the external circulation regeneration of the solution;

[0041] When the monitored value of conductivity or density does not reach the threshold, use the circulation pump to pressurize the amine liquid in the solution storage tank to 0.3 - 0.6 MPa, and spray it back to the inlet of the wet cyclone separation module through the atomizing spray head to form a dynamic concentration gradient closed loop;

[0042] S4: External circulation regeneration of the solvent

[0043] When the monitored value of conductivity or density reaches the preset threshold, start the one-way liquid pump in the external circulation branch of the solution, and transport the saturated amine liquid to the rich liquid pipeline of the absorption tower;

[0044] Mix the regenerated amine liquid with the rich liquid of the absorption tower, and at the same time discharge the purified flue gas (amine aerosol concentration < 5 mg / Nm 3 ) from the system.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1) Through the cascade design of the pre-separator (primary separation) and the wet spiral vane type cyclone separator (secondary separation), the amine aerosol in different particle size ranges is captured in stages, especially the sub-micron aerosol is efficiently removed, and the overall capture efficiency reaches more than 99%, which is 40% higher than that of traditional single-stage equipment, completely solving the problem of aerosol escape.

[0047] 2) Compared with the traditional wet electrostatic precipitator or multi-stage water washing system, the cascade capture device and process of the present invention innovatively integrate the cyclone separation and solution circulation regeneration technologies, providing a new path for the upgrading and engineering application of the carbon capture process.

[0048] 3) The introduction of the wet cyclone separator reduces the equipment energy consumption while ensuring the removal rate of sub-micron aerosol by strengthening the synergistic effect of gas-liquid mass transfer and particle separation.

[0049] 4) The device integrates the internal circulation and external circulation systems of the solution. Through the concentration feedback mechanism, the amine-containing liquid recovered by the capture unit is automatically returned to the absorption tower, realizing the closed-loop regeneration and utilization of the solvent. The annual loss rate of the amine solvent is reduced to less than 0.5%, effectively reducing the raw material consumption and eliminating the environmental pollution risk. Description of the Drawings

[0050] Figure 1 It is a schematic structural diagram of the device for combined use of gradient capture of amine aerosol and solvent regeneration based on multi-stage cyclone coupling in the present invention;

[0051] Figure 2 It is a schematic diagram of the usage scenario of the device for combined use of gradient capture of amine aerosol and solvent regeneration based on multi-stage cyclone coupling in the present invention;

[0052] Figure 3 It is a schematic structural diagram of the pre-separation module in the present invention;

[0053] Figure 4 It is a schematic structural diagram of the gas contraction wall in the present invention;

[0054] Figure 5 It is a schematic structural diagram of the inverted cone impact wall in the present invention;

[0055] Figure 6 It is a schematic structural diagram of the gas channel in the present invention.

[0056] In the figure:

[0057] 1. Pre-separation module; 2. Impact disc; 3. Wet cyclone separation module; 4. Liquid inlet;

[0058] 5. Liquid outlet; 6. Solution tank; 7. Circulation pump; 8. Unidirectional liquid pump;

[0059] 2.1. Gas contraction wall; 2.2. Gas impact wall; 2.3. Inverted cone; 2.4. Gas channel;

[0060] 3.1. Spiral blade;

[0061] 4.1. Atomizing spray head. Specific embodiments

[0062] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Features such as component models, material names, connection structures, control methods, algorithms, etc. that are not clearly described in the present technical solution are regarded as common technical features disclosed in the prior art.

[0063] Embodiment 1

[0064] In this embodiment, an amine aerosol gradient capture and solvent regeneration combined device based on multi-stage cyclone coupling is used for aerosol gradient capture and solvent regeneration in the amine liquid absorption process, including a pre-separation module 1, a wet cyclone separation module 3, and a solvent circulation and regeneration module. See Figures 1 to 6 .

[0065] Specifically, the inlet end of the pre-separation module 1 is connected to the tail gas discharge port of the absorption tower. The pre-separation module 1 performs primary coarse screening on the amine aerosol output from the tail gas discharge port of the absorption tower based on the impact inertial separation method. The outlet end of the pre-separation module 1 is connected to the inlet of the wet cyclone separation module 3 through a variable diameter pipe structure;

[0066] In specific implementation, the solvent circulation and regeneration module includes a solution internal circulation branch connected to the wet cyclone separation module 3, and a solution external circulation branch respectively connected to the solution internal circulation branch and the rich liquid pipeline of the absorption tower. The output end of the solution internal circulation branch is connected to the inlet end of the wet cyclone separation module 3 through an atomizing spray head 4.1, and the input end of the solution internal circulation branch is connected to the rotary separation end of the wet cyclone separation module 3;

[0067] In specific implementation, the wet cyclone separation module 3 is used to generate a rotating air flow, which is coupled with the atomized liquid droplets generated by the atomizing spray head 4.1 to form a strong swirling flow field. The centrifugal sedimentation of aerosol and droplet capture in the gas-liquid two-phase flow are realized through the rotating air flow, and the secondary capture of amine aerosol is completed;

[0068] In specific implementation, the solution internal circulation branch is used to dynamically maintain the concentration gradient of the atomized liquid droplets and simultaneously enrich the amine liquid after capture. When the amine liquid concentration in the solution internal circulation branch reaches the set threshold, the solution external circulation branch is started. The solution external circulation branch is used to pressurize and transport the regenerated amine solution to the absorption tower to be mixed with the rich absorption liquid, realizing the closed-loop regeneration of the solvent.

[0069] In specific implementation, the pre-separation module 1 includes a straight pipe and a collision disk 2 arranged in the straight pipe. The collision disk 2 includes a gas contraction wall 2.1 and an inverted cone impact wall 2.2 arranged in the straight pipe; the gas contraction wall 2.1 is a first plate body with a contraction hole opened in the middle, and the contraction hole protrudes towards the flow direction. See Figure 4 , thus constituting a compressed air flow channel that contracts towards the center; the inverted cone impact wall 2.2 is arranged on one side of the gas contraction wall 2.1 and is used for impact inertial separation of the compressed air flow passing through the gas contraction wall 2.1. The inverted cone impact wall 2.2 includes a second plate body with its four corners cut off, and an inverted cone 2.3 detachably arranged in the middle of the second plate body; four flow channels are formed between the four corners of the second plate body and the inner wall of the straight pipe. See Figure 6 .

[0070] In specific selection, the inverted cone 2.3 is selected from one of a conical shape, a frustum shape, and a pyramid shape, and the connection method with the plate body can be a bolt connection.

[0071] In specific implementation, the pre-separation module 1 further includes a reduced-diameter pipe 2.5. The straight pipe is connected to the wet cyclone separation module 3 through the reduced-diameter pipe 2.5; the reduced-diameter pipe 2.5 is a square-round gradual change pipe, and the cross-section of the inlet end of the reduced-diameter pipe 2.5 is square, and the cross-section of the outlet end is circular.

[0072] In specific implementation, the wet cyclone separation module 3 includes a housing and a spiral vane 3.1 disposed in the housing. The spiral vane 3.1 is matched with a driving motor, and the spiral vane 3.1 is used to generate a rotating air flow; the inclination angle of the spiral vane 3.1 is 15°-45°, the number of vanes is 3-6, and an anti-sticking coating for suppressing aerosol adhesion is provided on the vane surface.

[0073] In specific implementation, the top of the housing of the wet cyclone separation module 3 is connected to the variable diameter pipe 2.5. The top of the housing is provided with a liquid inlet 4, at least one liquid outlet 5 is provided near the outer wall side of the bottom of the housing, and an air outlet is provided in the middle of the bottom of the housing; the atomizing spray head 4.1 is disposed at the liquid inlet 4; the liquid outlet end of the solution internal circulation branch is connected to the liquid inlet 4, and the liquid inlet end of the solution internal circulation branch is connected to the liquid outlet 5; the aerosol in the gas-liquid two-phase flow is centrifugally settled to the outer wall of the housing of the wet cyclone separation module 3 through the rotating air flow and enters the solution internal circulation branch from the liquid outlet 5 to realize droplet capture.

[0074] In specific implementation, the solution internal circulation branch includes a solution storage tank 6, a circulation pump 7, and a concentration sensor 8.1; the concentration sensor 8.1 is disposed in the solution storage tank 6 and is used to monitor the conductivity or density of the amine solution in real time to obtain a concentration value.

[0075] In specific implementation, the solution external circulation branch includes a one-way liquid pump 8. The inlet end of the one-way liquid pump 8 is connected to the solution storage tank 6 through a pipeline, and the outlet end of the one-way liquid pump 8 is connected to the bottom of the absorption tower, so as to turbulently mix the regenerated amine solution transported by the one-way liquid pump 8 with the rich liquid in the absorption tower. The mixed amine solution is reused as an absorbent; when the monitoring value of the concentration sensor 8.1 exceeds a preset threshold, the one-way liquid pump 8 is started.

[0076] In specific implementation, the atomizing droplet diameter of the atomizing spray head 4.1 is 10-200 μm, and the spray coverage area accounts for 80%-95% of the inlet cross-section of the wet cyclone separation module 3.

[0077] In this embodiment, the method for coupling amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling includes the following steps:

[0078] S1: Primary inertial coarse screening

[0079] The tail gas of the absorption tower is introduced into the pre-separation module 1, and a primary rough screening of amine aerosol is carried out through impact inertial separation, specifically including: adjusting the contraction ratio of the gas contraction wall 2.1 in the pre-separation module to 30% - 50%, accelerating the flue gas to 8 - 15 m / s and then impacting the inverted cone impact wall 2.2, separating amine liquid droplets and aerosol with a particle size > 10 μm by using the inertial difference of aerosol particles. The amine liquid droplets and aerosol aggregate and flow into the solution internal circulation along the outer shell of the wet cyclone separation module 3, or are directly transported to the solution internal circulation through a pipeline, and the separated gas flow is guided to the wet cyclone separation module 3 through the variable diameter pipe structure 2.5.

[0080] S2: Secondary cyclone enhanced capture

[0081] The gas flow output from step S1 is introduced into the wet cyclone separation module 3, and a rotating gas flow (tangential velocity 20 - 35 m / s) is generated by the spiral blade 3.1. At the same time, amine liquid droplets (particle size 10 - 200 μm) are atomized and sprayed at the gas inlet end, so that the rotating gas flow and the atomized droplets are coupled to form a strong swirling flow field. The strong swirling flow field captures sub-micron amine aerosol with a particle size of 0.1 - 10 μm through the synergistic action of centrifugal sedimentation and droplet wrapping, and converges to the solution internal circulation branch.

[0082] S3: Solution internal circulation enrichment

[0083] The aerosol-droplet mixture captured in step S2 is introduced into the solution storage tank 6, and the conductivity or density of the amine liquid in the tank is monitored in real time;

[0084] When the monitored value of conductivity or density reaches the preset threshold, solution external circulation regeneration is triggered;

[0085] When the monitored value of conductivity or density does not reach the threshold, the amine liquid in the solution storage tank 6 is pressurized to 0.3 - 0.6 MPa by the circulation pump 7 and sprayed back to the inlet of the wet cyclone separation module 3 through the atomizing spray head 4.1 to form a dynamic concentration gradient closed loop.

[0086] S4: Solvent external circulation regeneration

[0087] When the monitored value of conductivity or density reaches the preset threshold, the one-way liquid pump 8 of the solution external circulation branch is started, and the saturated amine liquid is transported to the rich liquid pipeline of the absorption tower;

[0088] The regenerated amine liquid is mixed with the rich liquid of the absorption tower, and at the same time, the purified flue gas (amine aerosol concentration < 5 mg / Nm 3 ) is discharged from the system.

[0089] Specifically in implementation, the capture and separation process in this embodiment is as follows:

[0090] Primary rough screening (pre-separation module)

[0091] Target substances: amine aerosol particles with larger particle sizes (usually above 10 μm) and some droplets.

[0092] Composition characteristics: Due to the large inertia of the particles, they are more likely to be separated from the gas phase during the collision process and contain a high concentration of amine liquid (such as MEA, PZ, etc.).

[0093] Exclusion / collection method

[0094] Inertial deposition: The impact disc 2 in the pre-separation module compresses the air flow through the gas contraction wall 2.1, causing the large-particle aerosol to collide with the inverted cone impact wall 2.2 and deposit at the bottom of the pre-separator due to inertial differences.

[0095] Gravity diversion: The deposited droplets and particles flow into the solution internal circulation branch through the bottom of the pre-separator, mix with the discharged liquid from the wet cyclone separation module 3, and then enter the solution storage tank 6.

[0096] Anti-blocking design: The gas channel 2.4 of the inverted cone impact wall 2.2 adopts a smooth inner wall design to avoid particle accumulation and ensure that the first-stage separated substances continuously enter the internal circulation system.

[0097] Secondary capture (wet cyclone separation module)

[0098] Target substances: submicron amine aerosol (0.1 - 10 μm) and escaped solvent vapor.

[0099] Composition characteristics: Small-particle aerosol is difficult to directly settle due to Brownian motion and needs to be intensively captured through the synergistic effect of the cyclone field and atomized droplets.

[0100] Exclusion / collection method

[0101] Centrifugal sedimentation: The rotating air flow (tangential velocity 15 - 30 m / s) generated by the spiral blade 3.1 causes the aerosol to migrate towards the wall under the action of centrifugal force.

[0102] Droplet capture: The atomizing spray head 4.1 sprays droplets with a size of 10 - 200 μm, which form a liquid film to wrap the aerosol after collision and achieve efficient capture through the difference in Stokes number (Stk > 1).

[0103] Liquid accumulation recovery: The separated liquid film is guided along the inner wall of the outer wall of the shell and finally returns to the solution storage tank 6.

[0104] Closed-loop regeneration: The amine liquid enriched in the solution storage tank 6 is monitored by a concentration sensor and is pressurized and transported to the rich liquid pipeline of the absorption tower by a one-way liquid pump 8 after reaching the threshold, realizing solvent regeneration.

[0105] In terms of the effect, in this embodiment, through the cascade design of a pre-separator (primary separation) and a wet spiral vane cyclone separator (secondary separation), efficient capture of the entire particle size spectrum of amine aerosol is achieved. The pre-separator roughly screens large-particle aerosols with a size above 10 μm based on the principle of inertial collision (removal rate > 85%), greatly reducing the subsequent processing load; the wet cyclone separation module 3 generates a rotating airflow (tangential velocity 20 - 35 m / s) through spiral vanes, coupling with atomized droplets (particle size 10 - 200 μm) to form a strong swirling flow field, with a relatively high capture efficiency for submicron aerosols with a size of 0.1 - 10 μm. The overall performance is improved by more than 40% compared with traditional single-stage equipment, completely solving the problem of solvent loss caused by aerosol escape.

[0106] Compared with traditional wet electrostatic precipitators and multi-stage water washing systems (with a 30% increase in floor area), the cascade capture device in this embodiment adopts a compact modular design and realizes seamless connection of the two-stage separation units through a variable-diameter pipe structure (pressure loss < 500 Pa). Under the same processing scale, the equipment volume is reduced by 50%, and the operating energy consumption is reduced to 1.2 kW·h / Nm 3 Below. In addition, its unique adjustable structure of the impact plate (the inverted cone inclination angle can be adjusted from 15° to 60°) and the design of the anti-sticking coating on the spiral vanes (such as a PTFE coating) can adapt to different amine liquid systems (such as MEA, PZ, AMP, etc.) and the flue gas load fluctuation conditions, providing a highly compatible technical path for the upgrade of the carbon capture process.

[0107] The innovative introduction of the wet cyclone separator significantly improves the synergistic efficiency of mass transfer and separation. The coupling effect of the atomized droplets and the rotating airflow increases the Stokes number (Stk) of the aerosol from 0.01 to 1.5, strengthening the wrapping and capture of submicron particles by the droplets; at the same time, the solution internal circulation system dynamically regulates the concentration gradient of the sprayed liquid (the feedback accuracy of the conductivity is ±2%), avoiding the secondary escape problem caused by droplet entrainment in traditional wet processes.

[0108] By integrating the solution internal circulation and external circulation regeneration modules, this embodiment constructs a closed-loop utilization system for amine solvents. In the internal circulation branch, the solution storage tank (the enrichment concentration of amine liquid can reach 15 - 20 wt%) is linked with the concentration sensor to realize the intelligent determination of the saturated state of the amine liquid; in the external circulation branch, the regenerated amine liquid is efficiently integrated with the rich liquid in the absorption tower, and the comprehensive solvent recovery rate > 99.5%, and the annual loss rate is reduced from the industry average of 5 - 8% to less than 0.5%.

[0109] The above description of the embodiments is provided to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A device for combining amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling, used for aerosol gradient capture and solvent regeneration in the process of amine liquid absorption, characterized in that: It comprises a pre-separation module (1), a wet cyclone separation module (3), and a solvent recycling and regeneration module; The inlet end of the pre-separation module (1) is connected to the tail gas discharge port of the absorption tower. The pre-separation module (1) performs a primary coarse screening on the amine aerosol output from the tail gas discharge port of the absorption tower based on a collision-type inertial separation method. The outlet end of the pre-separation module (1) is connected to the inlet of the wet cyclone separation module (3) via a reducer structure. The solvent circulation and regeneration module comprises an internal solution circulation branch connected to the wet cyclone separation module (3), and an external solution circulation branch respectively connected to the internal solution circulation branch and the absorption tower rich liquid pipeline, the output end of the internal solution circulation branch being connected to the inlet end of the wet cyclone separation module (3) via an atomizing spray head (4.1), and the input end of the internal solution circulation branch being connected to the rotary separation end of the wet cyclone separation module (3); The wet cyclone separation module (3) is used to generate a swirling airflow, and coupled with the atomized droplets generated by the atomizing spray head (4.1) to form a strong cyclone field, so as to achieve centrifugal sedimentation and droplet capture of aerosol in the gas-liquid two-phase flow through the swirling airflow, thereby completing the secondary capture of amine aerosol; The solution inner circulation branch is used to dynamically maintain the concentration gradient of atomized droplets and enrich the captured amine solution. When the amine solution concentration in the solution inner circulation branch reaches a set threshold, the solution outer circulation branch is started. The solution outer circulation branch is used to pressurize the regenerated amine solution and transport it to the absorption tower to mix with the absorbed rich solution, thereby realizing closed-loop regeneration of the solvent.

2. The device for combining amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling according to claim 1, characterized in that: The pre-separation module (1) comprises a straight pipe and a collision plate (2) arranged in the straight pipe, and the collision plate (2) comprises a gas contraction wall (2.1) and an inverted cone collision wall (2.2) arranged in the straight pipe; The gas contraction wall (2.1) is a first plate body with a contraction hole in the middle, the contraction hole protruding toward the flow direction, thereby forming a compressed air flow channel that contracts toward the center; The inverted cone impact wall (2.2) is arranged on one side of the gas contraction wall (2.1) and is used to perform impact-type inertial separation on the compressed airflow passing through the gas contraction wall (2.1).

3. The device for combining amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling according to claim 2, characterized in that: The inverted cone impact wall (2.2) comprises a second plate body cut at four corners, and an inverted cone (2.3) detachably arranged in the middle of the second plate body; The four corners of the second plate and the inner wall of the straight tube form four flow channels; The inverted cone (2.3) is selected from a cone, a truncated cone, and a pyramid.

4. The device for combining amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling according to claim 2, characterized in that: The pre-separation module (1) further comprises a reducing pipe (2.5), and the straight pipe is connected to the wet cyclone separation module (3) via the reducing pipe (2.5); The reducer (2.5) is a square-circular gradient tube; the inlet end cross section of the reducer (2.5) is square, and the outlet end cross section is circular.

5. The device for combining amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling according to claim 4, characterized in that: The wet cyclone separation module (3) comprises a shell and a spiral blade (3.1) arranged in the shell, the spiral blade (3.1) is matched with a drive motor, and the spiral blade (3.1) is used to generate a rotating airflow; The spiral blade (3.1) has an inclination angle of 15° to 45°, the number of blades is 3 to 6, and an anti-stick coating for inhibiting aerosol adhesion is provided on the surface of the blade.

6. The device for combining amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling according to claim 5, characterized in that: The top of the shell of the wet cyclone separation module (3) is connected to the reducer (2.5), the top of the shell is provided with a liquid inlet (4), the bottom of the shell is provided with at least one liquid outlet (5) near the outer wall, and the middle of the bottom of the shell is provided with an air outlet; The atomizing spray head (4.1) is arranged at the liquid inlet (4); The liquid outlet end of the solution internal circulation branch is connected to the liquid inlet (4), and the liquid inlet end of the solution internal circulation branch is connected to the liquid outlet (5); The aerosol in the gas-liquid two-phase flow is centrifugally deposited onto the outer wall of the shell of the wet cyclone separation module (3) by means of a rotating airflow, and enters the solution internal circulation branch from the liquid outlet (5) to achieve droplet capture.

7. The device for combining amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling according to claim 6, characterized in that: The solution internal circulation branch comprises a solution storage tank (6), a circulation pump (7), and a concentration sensor (8.1); The concentration sensor (8.1) is arranged in the solution storage tank (6) and is used to monitor the conductivity or density of the amine solution in real time, thereby obtaining a concentration value.

8. The device for combining amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling according to claim 7, characterized in that: The solution external circulation branch comprises a one-way liquid pump (8), the inlet end of the one-way liquid pump (8) is connected to the solution storage tank (6) through a pipeline, and the outlet end of the one-way liquid pump (8) is connected to the bottom of the absorption tower, so that the regenerated amine solution transported by the one-way liquid pump (8) and the rich liquid of the absorption tower are turbulently mixed, and the mixed amine solution is reused as an absorbent; When the monitoring value of the concentration sensor (8.1) exceeds a preset threshold value, the one-way liquid pump (8) is started.

9. The device for combining amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling according to claim 1, characterized in that: The particle size of the atomized liquid droplets of the atomizing spray head (4.1) is 10 to 200 μm, and the spray coverage area accounts for 80% to 95% of the inlet cross section of the wet cyclone separation module (3).

10. A method for combining amine aerosol gradient capture and solvent regeneration based on multi-stage cyclone coupling using the device as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: S1: First-stage inertial coarse screening The tail gas from the absorption tower is introduced into a pre-separation module (1) to perform a primary coarse screening of the amine aerosol by means of impact-type inertial separation; S2: Secondary cyclone enhanced capture The airflow output from step S1 is introduced into a wet cyclone separation module (3), a swirling airflow is generated by a spiral blade (3.1), and amine liquid droplets are sprayed toward the airflow inlet end in atomized form, so that the swirling airflow and the atomized droplets are coupled to form a strong cyclone field, and the strong cyclone field captures submicron amine aerosols of 0.1 to 10 μm through the synergistic effect of centrifugal sedimentation and droplet encapsulation, and drives the aerosol-droplet mixture to converge to the solution internal circulation branch; S3: In-solution cyclic enrichment The aerosol-droplet mixture captured in step S2 is introduced into a solution storage tank (6), and the concentration of the amine solution in the storage tank is monitored in real time; When the concentration of amine solution in the storage tank reaches the preset threshold, the solution external circulation regeneration is triggered; When the concentration of the amine liquid in the storage tank does not reach the threshold value, the amine liquid in the solution storage tank (6) is pressurized by a circulation pump (7) and sprayed back to the inlet of the wet cyclone separation module (3) through an atomizing spray head (4.1), thereby forming a dynamic concentration gradient closed loop; S4: Solvent external circulation regeneration After the solution external circulation regeneration is triggered, the regenerated amine solution is mixed with the rich solution through the one-way liquid pump (8) of the solution external circulation branch to achieve recycling and reuse.

Images