A continuous flue gas carbon dioxide capture system based on solid amines

Abstract

This application discloses a continuous flue gas carbon dioxide capture system based on solid amine. The system includes: a flue gas inlet pipe for introducing raw flue gas; an adsorption reactor for adsorbing carbon dioxide from the raw flue gas; a flue gas and adsorbent inlet at the bottom of the adsorption reactor, connected to the flue gas inlet pipe; a dust collector connected to the adsorption reactor for gas-solid separation and discharging the decarbonized flue gas; a buffer chamber connected to the dust collector for buffering the solid amine adsorbent; and a desorption device connected to the buffer chamber for desorbing carbon dioxide from the solid amine adsorbent; the outlet of the desorption device is connected to the flue gas inlet pipe. The solid amine adsorbent achieves a closed-loop, continuous circulation in this system and method, enabling efficient and low-energy capture of carbon dioxide from the flue gas.

Description

Technical Field

[0001] This application belongs to the field of carbon capture technology, specifically relating to a continuous carbon dioxide capture system for flue gas based on solid amines. Background Technology

[0002] Currently, the capture, utilization, and storage of carbon dioxide in flue gas has become a research hotspot. Among the many capture technologies, solid-state amine adsorption shows promising application prospects due to its relatively low energy consumption and lack of equipment corrosion issues.

[0003] Currently, most carbon dioxide capture systems using solid amine adsorbents employ fixed-bed processes. In this process, the adsorption tower and desorption unit are typically two or more independent fixed-bed reactors. The system switches valves to allow the adsorption tower to switch to desorption mode after adsorption saturation, and the regenerated adsorption tower to switch to adsorption mode, thus achieving semi-continuous operation. However, this process is energy-intensive, requiring heating and cooling of the bed during switching, which consumes a significant amount of additional energy. The equipment is also bulky and has high investment costs; continuous operation requires at least two large fixed-bed reactors and a complex valve switching system, resulting in substantial equipment investment and floor space requirements. Furthermore, the mass and heat transfer efficiency is low, the gas-solid contact efficiency within the fixed bed is relatively low, the bed pressure drop is large, and temperature unevenness within the bed is prone to occur, affecting desorption efficiency and adsorbent lifespan.

[0004] Furthermore, current solid amine adsorbent carbon dioxide capture systems cannot meet the requirements of low energy consumption, high energy efficiency, and high adsorption capacity. Solid amine adsorbents cannot achieve sufficient contact with carbon dioxide during fluidization to achieve adsorption, and their desorption efficiency is also unsatisfactory, resulting in high energy consumption. Additionally, the carbon dioxide desorbed by heating is not utilized effectively, leading to energy waste. Moreover, the operation is discontinuous, being intermittent, with process parameters (such as temperature and pressure) fluctuating periodically, which is detrimental to stable system control and integration with upstream and downstream processes. Utility Model Content

[0005] In order to overcome the shortcomings of the prior art, this application provides a continuous flue gas carbon dioxide capture system based on solid amine that can achieve continuous operation, low energy consumption, compact equipment structure and low investment cost. It realizes the continuous circulation of solid amine adsorbent and efficiently and seamlessly connects adsorption, desorption and cooling processes in the equipment, thereby significantly reducing energy consumption and investment costs.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] A continuous flue gas carbon dioxide capture system based on solid amines, comprising:

[0008] The flue gas inlet duct is used to introduce raw flue gas;

[0009] An adsorption reactor is used to adsorb carbon dioxide from raw flue gas; the bottom of the adsorption reactor is provided with a flue gas inlet and an adsorbent inlet, which are connected to the flue gas inlet pipe.

[0010] A dust collector, connected to the adsorption reactor, is used for gas-solid separation and to discharge the decarbonized flue gas;

[0011] A buffer chamber, connected to the dust collector, is used to buffer the solid amine adsorbent; and

[0012] A desorption device, connected to the buffer chamber, is used to desorb carbon dioxide from the solid amine adsorbent; the outlet of the desorption device is connected to the flue gas inlet pipe, and the solid amine adsorbent after desorption of carbon dioxide enters the flue gas inlet pipe from the outlet and is carried by the original flue gas to the adsorption reactor to adsorb carbon dioxide in the original flue gas in the adsorption reactor.

[0013] Furthermore, the adsorption reactor is provided with a number of mass transfer enhancement components, which are arranged at an inclined interval and cross each other, and are arranged at an acute angle to the inner wall of the adsorption reactor.

[0014] Furthermore, the acute angle is 40°-60°.

[0015] Furthermore, a heat exchange tube is provided inside the buffer chamber; the heat exchange tube is connected to the desorption device, and the carbon dioxide desorbed by the desorption device is introduced into the heat exchange tube to preheat the solid amine adsorbent inside the buffer chamber.

[0016] Furthermore, the desorption device includes a housing; the interior of the housing includes a feed inlet, an upper heating desorption zone, a lower material cooling zone, and a discharge outlet; the upper heating desorption zone is provided with a plurality of heating plates arranged side by side; the upper heating desorption zone is also provided with a filter screen, and a vacuum chamber is formed between the filter screen and the housing, the vacuum chamber being used to collect the carbon dioxide desorbed from the solid amine adsorbent; the lower material cooling zone is provided with a plurality of cooling plates arranged side by side.

[0017] Furthermore, the heating plate has a folded structure, which includes two or more plates connected by folds, and the angle between two adjacent plates is 170°-175°; the heating plate is provided with a downward-facing exhaust channel at the fold of the folded structure, and the exhaust channel is used to collect the carbon dioxide desorbed by the solid amine adsorbent.

[0018] Furthermore, the heating plate includes a first plate and a second plate, with the lower end of the first plate and the upper end of the second plate connected in a folded manner; the first plate includes a first side plate, which extends downward at the folded corner between the first plate and the second plate and forms the exhaust channel between the side plate and the second plate; the exhaust channel is connected to the filter screen, and carbon dioxide in the exhaust channel enters the vacuum chamber through the filter screen.

[0019] Furthermore, a vibrating discharge device is provided at the lower end of the lower material cooling zone. The vibrating discharge device is used to control the flow rate of the solid amine adsorbent in the upper heating desorption zone and the lower material cooling zone.

[0020] Compared with the prior art, this application has the following advantages:

[0021] This application enables continuous operation with low energy consumption, achieving continuous circulation of the solid amine adsorbent and completely avoiding the huge sensible heat loss caused by the periodic heating and cooling of the reactor in the fixed bed process, thus significantly reducing system energy consumption.

[0022] This application achieves higher adsorption efficiency by fully utilizing the flue gas itself as the power source for pneumatic conveying. In the adsorption reactor, the solid amine adsorbent is fully mixed with the flue gas, resulting in a long contact time and high mass transfer efficiency, thus ensuring a high carbon dioxide adsorption efficiency. The arrangement of the mass transfer enhancement component causes the flow direction of the flue gas and the solid amine adsorbent to bend, resulting in a longer contact time and more thorough contact.

[0023] This application requires less equipment investment and can directly use flue gas as the adsorbent supply source, eliminating the need for an adsorbent delivery system. In addition, after the flue gas comes into contact with the adsorbent, a low-efficiency adsorption reaction begins in the flue gas inlet pipe, which reduces the design of the adsorption reactor. The innovative use of the adsorption reactor, which can be a vertical pipe, eliminates the need for customized large and complex adsorption equipment. The requirements can be met simply by appropriately expanding the diameter of the existing pipe, which greatly saves equipment manufacturing costs and space.

[0024] This application integrates energy utilization and boasts high energy efficiency. Firstly, it recovers waste heat: the high-temperature carbon dioxide gas exiting the desorption unit is introduced into the heat exchange tubes of the buffer chamber to preheat the cold material about to enter the desorption unit; this reduces both the external steam energy consumption required for desorption and the cooling of the carbon dioxide gas. Secondly, it reduces vacuum pump power consumption: the cooled carbon dioxide gas shrinks in volume, reducing the work done by the subsequent vacuum pump to extract a unit mass of gas, further lowering the overall power consumption of the system. Finally, it features a compact structure: the desorption unit uses built-in hollow heating and cooling plates, enabling the sequential completion of the desorption (heating) and cooling processes within the same equipment, resulting in a compact structure and small footprint. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of the application and, together with their description, serve to explain the application, but do not constitute an undue limitation of the application. In the drawings:

[0026] Figure 1 This is a schematic diagram of the flue gas carbon dioxide continuous capture system based on solid amines according to this application;

[0027] Figure 2 This is a schematic diagram of the adsorption reactor of this application;

[0028] Figure 3 This is a schematic diagram of the desorption device of this application;

[0029] Figure 4 For this application Figure 3 AA view;

[0030] Figure 5 For this application Figure 3 Detailed drawing A;

[0031] Figure 6 For this application Figure 3 Detailed drawing B;

[0032] Figure 7 This is a structural diagram of the filter screen of this application;

[0033] Figure 8 For this application Figure 3 CC view;

[0034] Figure 9 This is a flowchart of the method in this application.

[0035] Explanation of reference numerals in the attached figures:

[0036] 111 Adsorption fan, 112 Working vacuum pump, 113 Exhaust vacuum pump, 114 Flue gas inlet duct;

[0037] 12 Adsorption reactor, 121 Flue gas and adsorbent inlet, 122 Flue gas and adsorbent outlet, 123 Mass transfer enhancement component;

[0038] 13. Dust collector;

[0039] 14 Buffer chamber, 141 Buffer chamber feed valve, 142 Buffer chamber discharge valve, 143 Heat exchange tube;

[0040] 16. Flue gas cooler; 17. Filter;

[0041] 11 Desorption device, 151 Desorption device discharge valve;

[0042] 1.1 Outer shell; 1.2 Inlet; 1.3 Outlet;

[0043] 2.1 Heating plate; 2.2 Heat medium inlet branch pipe; 2.3 Heat medium outlet branch pipe; 2.4 Heat medium inlet main pipe; 2.5 Heat medium outlet main pipe;

[0044] 3.1 Cooling plate; 3.2 Refrigerant inlet branch pipe; 3.3 Refrigerant outlet branch pipe; 3.4 Refrigerant inlet main pipe; 3.5 Refrigerant outlet main pipe;

[0045] 4. Solid amine adsorbent;

[0046] 5. Vibrating discharge device;

[0047] 6.1 Air extraction filter assembly, 6.2 Vacuum chamber, 6.3 Air extraction port, 6.4 Air extraction microchannel, 6.5 Heating plate sealing plate, 6.6 Metal filter screen;

[0048] Area A is the feeding area, Area B is the heating and desorption area, Area C is the material cooling area, and Area D is the discharging area. Detailed Implementation

[0049] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0050] In the description of this application, it should be understood that the relationship between the method steps can be sequential or non-sequential, as long as it does not affect the overall technical effect, and therefore should not be construed as a limitation of this application. The following description of this application is merely a description of individual embodiments of the technical solution of this application; other embodiments are not shown in the following description, but this does not mean that this application excludes these other embodiments, nor is the technical solution of this application limited to the specific implementations described below, and the scope of protection of this application is not limited to the specific implementations described below. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0051] It should be noted that if the terms "first," "second," etc., appear in the specification, claims, and accompanying drawings of this application, such descriptions are only used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0052] In some embodiments, such as Figure 1-8 As shown, this application provides a continuous carbon dioxide capture system for flue gas based on solid amine, including: flue gas inlet pipe 114, adsorption reactor 12, dust collector 13, buffer chamber 14 and desorption device 11.

[0053] The flue gas inlet pipe 114 is used to introduce raw flue gas.

[0054] An adsorption reactor 12 is used to adsorb carbon dioxide from the raw flue gas. The bottom of the adsorption reactor 12 is provided with a flue gas and adsorbent inlet 121, which is connected to the flue gas inlet pipe 114. Specifically, the adsorption reactor 12 is internally provided with several mass transfer enhancement components 123. These components are arranged at inclined intervals and cross each other, forming an acute angle with the inner wall of the adsorption reactor 12. The acute angle is preferably 30°-50°. The mass transfer enhancement components 123 are made of 304 stainless steel, ensuring airflow disturbance and increasing resistance. Specifically, the structure can be an internally connected semi-circular disk, which disturbs the airflow, increases the residence contact time between the raw flue gas and the solid amine adsorbent, and improves adsorption efficiency.

[0055] The dust collector 13 is connected to the adsorption reactor 12 and is used for gas-solid separation and emission of decarbonized flue gas.

[0056] A buffer chamber 14 is connected to the dust collector 13 and is used to buffer the solid amine adsorbent 4. A heat exchange tube 143 is provided inside the buffer chamber 14. The heat exchange tube 143 is connected to the desorption device 11, and the carbon dioxide desorbed by the desorption device 11 is introduced into the heat exchange tube 143 to preheat the solid amine adsorbent in the buffer chamber 14.

[0057] The desorption device 11 is connected to the buffer chamber 14 and is used to desorb carbon dioxide from the solid amine adsorbent 4. The outlet of the desorption device 11 is connected to the flue gas inlet pipe 114. After the solid amine adsorbent 4 is desorbed from carbon dioxide, it enters the flue gas inlet pipe 114 from the outlet and is carried by the original flue gas to the adsorption reactor 12 to adsorb carbon dioxide from the original flue gas in the adsorption reactor 12.

[0058] The adsorption reactor 12 of this application has a flue gas inlet 121 at the bottom and its top outlet connected to a dust collector 13 via a pipe. The top of the dust collector 13 is the purified flue gas outlet, and the bottom is the adsorbent discharge port, which is connected to the top of the buffer chamber 14 via a buffer chamber feed valve 141. The bottom of the buffer chamber 14 has a buffer chamber discharge valve 142, which is connected to the feed port at the top of the desorption device 11 via a discharge pipe. The bottom of the desorption device 11 has a desorption device discharge valve 151, which is connected to the outlet flue gas pipe of the adsorption fan 111. The solid amine adsorbent is sent to the adsorption reactor inlet 121 by the flue gas, forming a solid amine adsorbent circulation loop.

[0059] In some embodiments, such as Figure 3-8 As shown, the desorption device 11 is used to desorb carbon dioxide from the solid amine adsorbent 4. It includes a shell 1.1, inside which there is a feed inlet 1.2, an upper heating desorption zone B, a lower material cooling zone C, and a discharge outlet 1.3. It may also include a feed zone A and a discharge zone D. The upper heating desorption zone B is provided with a plurality of heating plates 2.1 arranged side by side. The upper heating desorption zone B is also provided with a filter screen 6.1, which forms a vacuum chamber 6.2 between the filter screen 6.1 and the shell 1.1. The vacuum chamber 6.2 is used to collect the carbon dioxide desorbed from the solid amine adsorbent 4. The lower material cooling zone C is provided with a plurality of cooling plates 3.1 arranged side by side.

[0060] Solid amine adsorbent 4 enters the feeding zone A through the feed inlet 1.2. Feeding zone A can be equipped with high and low level gauges. Feeding stops when the high level is reached and starts when the low level is reached. The feeding zone maintains a certain stacking height to ensure that the solid amine adsorbent 4 can enter the heating desorption zone B evenly.

[0061] A plurality of heating plates 2.1 are disposed within the upper heating desorption zone B, and the plurality of heating plates 2.1 are arranged side by side within the upper heating desorption zone B. Specifically, as shown... Figure 4-8As shown, the front end of the heating plate 2.1 is welded to the outer shell 1.1, and the rear end is welded to the filter screen 6.1. The left and right ends form flow channels for the solid amine adsorbent 4 between the heating plate 2.1 and the outer shell 1.1. The outer shell 1.1 has several heat medium inlet branches 2.2 and several heat medium outlet branches 2.4. The upper end of a single heating plate 2.1 is connected to the corresponding single heat medium inlet branch 2.2, and the lower end of a single heating plate 2.1 is connected to the corresponding single heat medium outlet branch 2.4.

[0062] Heating plate 2.1 has a hollow structure. The heat medium in the heat medium inlet branch pipe 2.2 enters the heating plate 2.1, transfers heat to the solid amine adsorbent 4, and then exits from the heat medium outlet branch pipe 2.3. One heating plate 2.1 corresponds to one heat medium inlet branch pipe 2.2 and one heat medium outlet branch pipe 2.3. A heat medium inlet header pipe 2.4 is provided to distribute the heat medium to each heat medium inlet branch pipe 2.2, and a heat medium outlet header pipe 2.5 is provided to collect the heat medium from each heat medium outlet branch pipe 2.3. The heat medium can be steam, heat transfer oil, etc.

[0063] like Figure 3 , 5 As shown in Figure -7, the heating plate 2.1 has a folded structure, which includes two or more plates connected by folds, and the angle between two adjacent plates is 170°-175°; the heating plate 2.1 has a downward-facing exhaust channel 6.4 at the fold of the folded structure, which is used to collect the carbon dioxide desorbed by the solid amine adsorbent 4. Specifically, as... Figure 6 As shown, the heating plate 2.1 includes a first plate 2.11 and a second plate 2.12. The lower end of the first plate 2.11 is folded to the upper end of the second plate 2.12. The first plate 2.11 includes a first side plate 2.111. The first side plate 2.111 extends downward at the angle between the first plate 2.11 and the second plate 2.12 and forms the air extraction channel 6.4 between it and the second plate 2.12.

[0064] like Figure 3 , 6 As shown in Figure 8, the exhaust channel 6.4 is connected to the filter screen 6.1, and the carbon dioxide in the exhaust channel 6.4 enters the vacuum chamber 6.2 through the filter screen 6.1.

[0065] like Figure 3 , 5 As shown in Figure 7, the heating plate 2.1 includes a first plate 2.11, a second plate 2.12, and a third plate 2.13, which are connected in a folded manner; the cooling plate 3.1 includes a fourth plate 3.11 and a fifth plate 3.12, which are connected in a folded manner.

[0066] The heating plate 2.1 adopts a folded connection, which increases the heat exchange contact area and allows the solid amine adsorbent 4 to change direction during flow, increasing material disturbance, breaking the material thermal boundary layer, and enhancing the heat transfer effect. An exhaust channel 6.4 is set at the fold of the heating plate 2.1. The solid amine adsorbent 4 flows by gravity, and the exhaust channel 6.4 will not be completely filled with material, leaving some space. The filter screen 6.1 and the outer shell 1.1 form a vacuum chamber 6.2, which has an exhaust port 6.3. The carbon dioxide gas generated during desorption enters the vacuum chamber 6.2 through the gaps between the solid amine adsorbent 4 and the exhaust channel 6.4 via the filter screen 6.1, and is then extracted through the exhaust port 6.3. The welded part between the filter screen 6.1 and the heating plate 2.1 is made of impermeable steel plate, while the remaining part uses a mesh to allow gas to pass through while trapping the solid amine adsorbent 4. The exhaust channel 6.4 reduces exhaust resistance, allowing the desorbed gas to be discharged better, avoiding accumulation between particles, and improving desorption efficiency.

[0067] Specifically, such as Figure 6 , 8 As shown, one end of the heating plate 2.1 is sealed by the outer shell 1.1, and the other end is sealed by the heating plate sealing plate 6.5 in the vacuum filter assembly 6.1. The heating plate sealing plate 6.5 is a metal plate, slightly wider than the heating plate 2.1, and its shape is consistent with the fold line of the heating plate. The sealing structure composed of the two walls of the heating plate itself, the outer shell, and the heating plate sealing plate can prevent the heating medium from overflowing. The vacuum filter assembly 6.1 consists of the heating plate sealing plate 6.5 and the metal filter 6.6. The pore size of the metal filter 6.6 is smaller than that of the solid amine adsorbent, which can prevent the solid amine adsorbent from leaking out. The vacuum filter assembly 6.1 and the outer shell form a vacuum chamber. The vacuum pump evacuates this area, and the carbon dioxide generated by desorption is drawn into the vacuum chamber and further extracted by the vacuum pump for use at the downstream end. Due to the obstruction of the metal filter 6.6, only carbon dioxide enters the vacuum chamber, and the solid amine material does not enter.

[0068] The desorbed carbon dioxide faces significant resistance when exiting the vacuum chamber through the gaps in the solid amine adsorbent. To improve the carbon dioxide discharge rate and enhance desorption efficiency, a gas extraction microchannel is installed at the corner of the heating plate. The gas extraction microchannel extends 10mm-20mm from the outer wall of the corner of the heating plate. At the same time, a metal filter screen 6.6 and the outer side of the heated plate after the corner are used to form a gas phase region. Due to the barrier of the filter screen, the solid amine adsorbent will not enter the microchannel, but the carbon dioxide gas generated by desorption can enter.

[0069] The solid amine adsorbent 4, after desorption in the upper heating desorption zone B, is at a high temperature and needs to be cooled before re-adsorption. A lower material cooling zone C is located at the outlet of the upper heating desorption zone B. The lower material cooling zone C contains several cooling plates 3.1, with their upper ends connected to refrigerant inlet branch pipes 3.2 and their lower ends connected to refrigerant outlet branch pipes 3.4. The front and rear ends are welded to the outer shell 1.1, and the left and right ends form flow channels for the solid amine adsorbent 4 between the outer shell 1.1 and the cooling plates 3.1. Plate 3.1 is a hollow structure. The refrigerant in the refrigerant inlet branch pipe 3.2 enters the cooling plate 3.1, carries away the heat of the solid amine adsorbent 4, and is discharged from the refrigerant outlet branch pipe 3.3. One cooling plate 3.1 corresponds to one refrigerant inlet branch pipe 3.2 and one refrigerant outlet branch pipe 3.3. A refrigerant inlet header pipe 3.4 is provided to distribute the refrigerant to each refrigerant inlet branch pipe 3.2. A refrigerant outlet header pipe 3.5 is provided to collect the refrigerant from each refrigerant outlet branch pipe 3.3. Cooling water can be used as the refrigerant.

[0070] The cooled solid amine adsorbent 4 enters the discharge zone D. A vibrating discharge device 5 is provided at the lower end of the lower material cooling zone C. The vibrating discharge device 5 is used to control the flow rate of the solid amine adsorbent 4 in the upper heating desorption zone B and the lower material cooling zone C. The discharge rate can be controlled by frequency conversion, thereby controlling the flow rate of the solid amine adsorbent 4 in the upper heating desorption zone B and the lower material cooling zone C. By matching the material flow rate and the length of the upper heating desorption zone and the lower material cooling zone, the full desorption and cooling of the solid amine adsorbent 4 can be ensured. The bottom of the vibrating discharge device 5 is provided with a conical section and a discharge port 1.3. The discharged material can be sent to the adsorption equipment by pneumatic conveying, conveyor, etc.

[0071] The desorption unit 11 contains multiple sets of parallel hollow heating plates and cooling plates installed vertically inside. These heating and cooling plates divide the internal space of the tower into several narrow channels. High-temperature steam is introduced into the heating plates through a steam main to heat and desorb the solid amine adsorbent falling into this area; cooling water is introduced into the cooling plates through a cooling water main to cool the desorbed high-temperature solid amine adsorbent. The desorbed carbon dioxide gas is discharged from the top of the desorption unit and connected through a pipeline to the heat exchange coil 143 inside the buffer chamber 14 to preheat the adsorbent to be entered into the desorption unit, and then connected to the working vacuum pump 112 to be sent to the carbon dioxide user. The buffer chamber 4 is equipped with an air extraction pipeline connected to the exhaust vacuum pump 113. When feeding, the buffer chamber discharge valve 142 is closed and the buffer chamber feed valve 141 is opened. After the material level reaches the set value, the buffer chamber feed valve 141 is closed and the exhaust vacuum pump 113 is turned on to extract the air in the buffer chamber. Then the exhaust vacuum pump 113 is turned off and the buffer chamber discharge valve 142 is opened, and the solid amine adsorbent enters the desorption device for desorption.

[0072] In some embodiments, a flue gas cooler 16 and a filter 17 are also included, wherein the filter 16 is disposed on the buffer chamber 14 and is capable of filtering out solid amine adsorbent when the exhaust vacuum pump 113 is turned on.

[0073] In some embodiments, such as Figure 9 As shown, this application provides a method for continuous capture of carbon dioxide from flue gas based on solid amines, used in the continuous capture system for carbon dioxide from flue gas based on solid amines as described above, comprising:

[0074] S1: Raw flue gas is introduced into the flue gas inlet pipe, carrying the desorbed solid amine adsorbent discharged from the bottom of the desorption device into the bottom of the adsorption reactor; in the adsorption reactor, the solid amine adsorbent is carried upward by the raw flue gas and is in a fluidized state, and the carbon dioxide in the raw flue gas is adsorbed by the solid amine adsorbent.

[0075] Specifically, the pretreated flue gas (approximately 40°C, moisture content <7%) is pressurized by the adsorption fan 111 and flows at a velocity of 2-3 m / s, carrying the desorbed adsorbent discharged from the bottom of the desorption device 11 into the bottom of the adsorption reactor 12. In the vertical pipe of the adsorption reactor 12, the adsorbent is carried upwards by the flue gas, flowing in a fluidized state at a velocity of 0.5-1 m / s, and its residence time in the adsorption reactor 12 is 10-20 s, resulting in efficient adsorption of carbon dioxide from the flue gas. To ensure thorough mixing, several mass transfer enhancement components are installed inside the adsorption reactor 12 to enhance mass transfer.

[0076] S2: The gas-solid mixture after adsorption enters the dust collector from the adsorption reactor for gas-solid separation. The decarbonized flue gas is discharged from the dust collector, and the solid amine adsorbent that has adsorbed carbon dioxide enters the buffer chamber for buffering.

[0077] After adsorption, the gas-solid mixture enters the dust collector 3 (such as a cyclone dust collector or a bag filter) from the top of the adsorption reactor 12. The clean flue gas after carbon dioxide removal is discharged from the top of the dust collector 3. The adsorbent saturated with adsorption falls into the buffer chamber 14 at the bottom under the action of gravity.

[0078] After the buffer chamber 14 reaches the predetermined material level, the inlet and outlet valves of the buffer chamber 14 are closed, and the buffer chamber 14 is evacuated to ensure that the material falling into the desorption equipment does not carry air and affect the purity of the desorption gas.

[0079] S3: The solid amine adsorbent that has adsorbed carbon dioxide is discharged from the buffer chamber and enters the desorption device, where it is first heated to desorb carbon dioxide and then cooled.

[0080] Specifically, the saturated solid amine adsorbent is discharged from the bottom of the buffer chamber 14 and enters the top of the desorption device 11. Under the influence of gravity, the solid amine adsorbent moves downward between the channels formed by multiple hollow heat exchange plates. In the upper high-temperature steam heating zone (approximately 100-120°C), the solid amine adsorbent is heated, carbon dioxide is desorbed, and after being cooled by the heat exchange coil 143 in the buffer chamber 14, it is sent to the carbon dioxide user. The solid amine adsorbent continues to fall into the lower cooling water coil zone, where it is cooled to near the adsorption temperature (e.g., 40-60°C), completing regeneration.

[0081] S4: The cooled solid amine adsorbent is discharged from the desorption device and enters the flue gas inlet pipe to start the next adsorption and desorption cycle.

[0082] Specifically, the regenerated solid amine adsorbent is discharged from the bottom of the desorption unit 11 and is pneumatically transported back to the bottom of the adsorption reactor 12 by the flue gas to start the next adsorption cycle.

[0083] Through the above process, the solid amine adsorbent achieves a closed and continuous circulation in the system, completing the efficient and low-energy capture of carbon dioxide in flue gas. In terms of equipment layout, the dust collector 3, buffer chamber 14, and desorption device 11 are connected sequentially from top to bottom. The inlet of the adsorption reactor 12 is connected to the outlet of the desorption device 11, and the outlet is connected to the inlet of the dust collector 3, which reduces the size of the adsorption reactor 12 and makes the layout compact.

[0084] In some embodiments, the carbon dioxide desorbed from the solid amine adsorbent by the desorption device is introduced into the buffer chamber to preheat the solid amine adsorbent in the buffer chamber.

[0085] Specifically, the buffer chamber 14's feed valve 141 and discharge valve 142 serve as airlocks and material buffers. When the material level in the chamber reaches a certain point, the feed valve 141 is closed, and the exhaust vacuum pump 113 is activated to evacuate the chamber, preventing air from entering the desorption unit and oxidizing the high-temperature adsorbent material, while also reducing the operating load of the subsequent desorption unit 11. High-temperature carbon dioxide gas from the desorption unit 11 flows through the heat exchange tubes 143 in the buffer chamber 14 to preheat the cold material inside, achieving energy recovery.

[0086] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims. The selected and described embodiments are intended to best elucidate the principles of this application and its practical application, thereby enabling other those skilled in the art to best utilize this application with various modifications suitable for the contemplated specific purpose, as well as the various described embodiments.

Claims

1. A continuous flue gas carbon dioxide capture system based on solid amines, characterized in that, include: The flue gas inlet duct is used to introduce raw flue gas; An adsorption reactor is used to adsorb carbon dioxide from raw flue gas; the bottom of the adsorption reactor is provided with a flue gas inlet and an adsorbent inlet, which are connected to the flue gas inlet pipe. A dust collector, connected to the adsorption reactor, is used for gas-solid separation and to discharge the decarbonized flue gas; A buffer chamber, connected to the dust collector, is used to buffer the solid amine adsorbent; A desorption device, connected to the buffer chamber, is used to desorb carbon dioxide from the solid amine adsorbent; the outlet of the desorption device is connected to the flue gas inlet pipe, and the solid amine adsorbent after desorption of carbon dioxide enters the flue gas inlet pipe from the outlet and is carried by the original flue gas to the adsorption reactor to adsorb carbon dioxide in the original flue gas in the adsorption reactor.

2. The continuous carbon dioxide capture system for flue gas based on solid amine according to claim 1, characterized in that: The adsorption reactor is equipped with several mass transfer enhancement components, which are arranged at an inclined interval and cross each other, and are at an acute angle to the inner wall of the adsorption reactor.

3. The continuous carbon dioxide capture system for flue gas based on solid amines according to claim 2, characterized in that: The acute angle is 30°-50°.

4. The continuous carbon dioxide capture system for flue gas based on solid amine according to claim 1, characterized in that: The buffer chamber is equipped with a heat exchange tube; the heat exchange tube is connected to the desorption device, and the carbon dioxide desorbed by the desorption device is passed into the heat exchange tube to preheat the solid amine adsorbent in the buffer chamber.

5. The continuous carbon dioxide capture system for flue gas based on solid amine according to claim 1, characterized in that: The desorption device includes a housing; the interior of the housing includes a feed inlet, an upper heating desorption zone, a lower material cooling zone, and a discharge outlet; the upper heating desorption zone is provided with a plurality of heating plates arranged side by side; the upper heating desorption zone is also provided with a filter screen, and a vacuum chamber is formed between the filter screen and the housing, the vacuum chamber being used to collect carbon dioxide desorbed from the solid amine adsorbent; the lower material cooling zone is provided with a plurality of cooling plates arranged side by side.

6. The continuous carbon dioxide capture system for flue gas based on solid amines according to claim 5, characterized in that: The heating plate has a folded structure, which includes two or more plates connected by folds, and the angle between two adjacent plates is 170°-175°; the heating plate is provided with a downward-facing exhaust channel at the fold of the folded structure, and the exhaust channel is used to collect the carbon dioxide desorbed by the solid amine adsorbent.

7. The continuous flue gas carbon dioxide capture system based on solid amine according to claim 6, characterized in that: The heating plate includes a first plate and a second plate, with the lower end of the first plate and the upper end of the second plate connected in a folded manner; the first plate includes a first side plate, which extends downward at the folded corner between the first plate and the second plate and forms the exhaust channel between the side plate and the second plate; the exhaust channel is connected to the filter screen, and carbon dioxide in the exhaust channel enters the vacuum chamber through the filter screen.

8. The continuous carbon dioxide capture system for flue gas based on solid amine according to claim 5, characterized in that: A vibrating discharge device is provided at the lower end of the lower material cooling zone. The vibrating discharge device is used to control the flow rate of the solid amine adsorbent in the upper heating desorption zone and the lower material cooling zone.

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