Absorption tower, system and method for removing carbon dioxide and controlling escape of organic amine by amine method

Abstract

The invention provides an absorption tower, system and method for removing carbon dioxide and controlling escape of organic amine through an amine method. The absorption tower comprises an absorption section, a cooling amine condenser, a washing section and a first multi-layer demister. The system comprises the absorption tower, a regeneration tower, a heat exchanger, a primary condenser, a first gas-liquid separation tank, a secondary condenser and a second gas-liquid separation tank. The method comprises the following steps: enabling flue gas to enter an absorption tower, absorbing CO2 in the flue gas, and washing with water; the rich liquor enters a regeneration tower for regeneration and CO2 release after heat exchange, and the barren liquor enters an absorption tower after heat exchange; and the regenerated gas enters a condenser to be cooled and then is separated by a gas-liquid separation tank to obtain CO2 gas and condensed water, and the condensed water flows back to the regeneration tower. According to the invention, the escape of organic amine in the process of removing CO2 by using an amine method is reduced, the environmental pollution is effectively reduced, and the problem that the system operation cost is increased due to amine loss is reduced.

Description

Technical Field

[0001] The invention relates to an absorption tower, a system and a method for removing carbon dioxide by an amine method and controlling the escape of organic amines, belonging to the technical field of flue gas treatment. Background Art

[0002] CO2 capture, utilization, and storage (CCUS) is considered an essential technology for achieving current emission reduction targets. CO2 capture primarily involves separating high-purity CO2 from flue gases from fossil and biomass fuel combustion in the power and industrial sectors.

[0003] Among the numerous capture methods, the organic amine method for removing CO2 from flue gas has the greatest potential for industrial application. Its principle is to separate CO2 from flue gas through a reversible chemical reaction between CO2 and an organic amine absorbent. The organic amine absorbent reacts with the flue gas in an absorption tower to absorb CO2, and then is sent to a regeneration tower for a high-temperature reverse reaction to release CO2, thereby producing high-purity CO2 gas. However, while capturing CO2 from the flue gas, the organic amine comes into direct contact with the flue gas, and the flue gas carries some of the organic amine into the atmosphere, causing significant solvent loss and secondary environmental pollution. Conventional organic amine-based CO2 removal processes are subject to amine escape. Organic amine escape primarily occurs in the form of gaseous emissions and aerosol emissions.

[0004] The schematic diagram of the structure of the system for removing CO2 by amine method and controlling the escape of organic amines in the prior art is as follows: Figure 2 As shown. Figure 2 As can be seen, existing technology utilizes a water scrubber and wire mesh demister to control the escape of organic amines. After the flue gas enters the absorption section and directly contacts the organic amine absorbent for decarbonization, it is first cooled in the water scrubber to remove some of the gaseous organic amines. It then passes through a wire mesh demister to remove liquid particles and large aerosol droplets entrained in the gas and liquid, before ultimately being discharged into the atmosphere. Furthermore, the regeneration gas condensate from the top of the regeneration tower, due to its high amine concentration, is generally directly returned to the regeneration tower for reflux.

[0005] However, the current amine-based CO2 removal system and method for controlling organic amine escape have at least the following problems:

[0006] 1. The water wash section can only achieve the organic amine separation efficiency of one tray at most. In the water wash section, wash water is repeatedly pumped from the bottom of the tower, cooled, and circulated to the top. Once the system reaches stable operation, the amine concentration of the wash water can be roughly considered the same from top to bottom throughout the entire water wash section. From the perspective of gaseous organic amine separation, no matter how high the water wash section is, only one tray of gas-liquid equilibrium can be achieved.

[0007] 2. High amine concentration in the water wash section. To recover the organic amines in the wash water, it is typically added to the absorbent as makeup water. Therefore, the water scrubber cannot be overfilled with fresh water, as this would leave the excess wash water with nowhere to go and would have to be treated as waste. Furthermore, large amounts of gaseous and aerosolized organic amines in the flue gas, after being removed by the water wash section, accumulate in the wash section, resulting in high amine concentrations in the wash section and poor control effectiveness.

[0008] 3. Conventional wire mesh mist eliminators have poor control effectiveness. Conventional wire mesh mist eliminators can only effectively control particles larger than 2μm, and their control effectiveness for aerosol droplets is poor. Moreover, in actual working conditions, the low operating air velocity of conventional wire mesh mist eliminators makes their control effectiveness even worse.

[0009] 4. The regeneration gas condensate has a high amine concentration and a narrow application range, and is generally not suitable for replenishing the water washing section. Summary of the Invention

[0010] To solve the above technical problems, the present invention aims to provide an absorption tower, system and method for controlling the escape of organic amines in the amine-based CO2 removal process. The present invention can reduce the escape of organic amines in the amine-based CO2 removal process.

[0011] In order to achieve the above-mentioned object, the first aspect of the present invention provides an absorption tower for removing carbon dioxide by an amine method and controlling the escape of organic amines, which comprises, from bottom to top, at least: an absorption section, a cooling condenser, a water washing section, and a first multi-layer demister;

[0012] The absorption tower is provided with a flue gas inlet and a rich liquid outlet below the absorption section, a lean liquid inlet is provided between the absorption section and the cooling condenser, and a flue gas outlet is provided above the first multi-layer demister;

[0013] The cooling condenser includes a heat exchange unit and a gas-liquid mass transfer unit; the gas-liquid mass transfer unit is arranged below the heat exchange unit, or the heat exchange unit is interspersed inside the gas-liquid mass transfer unit.

[0014] The second aspect of the present invention provides a system for removing carbon dioxide by an amine method and controlling the escape of organic amines, comprising: an absorption tower for removing carbon dioxide by an amine method and controlling the escape of organic amines, a regeneration tower, a heat exchanger, a regeneration gas condensation and a gas-liquid separation device;

[0015] The upper portion of the regeneration tower is provided with a rich liquid inlet, a condensed water inlet and a regeneration gas outlet, and the lower portion of the regeneration tower is provided with a lean liquid outlet;

[0016] The rich liquid outlet of the absorption tower is connected to the rich liquid inlet of the regeneration tower through the heat exchanger, and the lean liquid inlet of the absorption tower is connected to the lean liquid outlet of the regeneration tower through the heat exchanger;

[0017] The regenerated gas condensation and gas-liquid separation device comprises at least one condenser and at least one gas-liquid separation tank; the gas-liquid separation tank is provided with an inlet, a gas outlet and a condensed water outlet;

[0018] The regeneration gas outlet of the regeneration tower is connected to the inlet of the gas-liquid separation tank through the condenser, and the condensed water outlet of the gas-liquid separation tank is connected to the condensed water inlet of the regeneration tower.

[0019] A third aspect of the present invention provides a method for controlling the escape of organic amines by removing carbon dioxide using an amine method, which is performed using the above-mentioned system for controlling the escape of organic amines by removing carbon dioxide using an amine method. The method comprises the following steps:

[0020] (1) The flue gas enters the absorption tower, contacts with the organic amine absorbent in the absorption section in countercurrent flow, and absorbs CO2 in the flue gas to obtain a rich liquid. The flue gas is then cooled by a cooling condenser and then enters the water washing section for water washing. After passing through the first multi-layer demister, the treated flue gas is obtained and discharged through the flue gas outlet.

[0021] (2) The rich liquid is heat-exchanged with the lean liquid in a heat exchanger and then enters a regeneration tower for regeneration and releases CO2 to obtain regenerated gas and lean liquid. The lean liquid is heat-exchanged with the rich liquid in a heat exchanger and then enters an absorption tower;

[0022] (3) The regenerated gas enters the condenser for cooling and then is separated in the gas-liquid separation tank to obtain CO2 gas and condensed water, and the condensed water is refluxed to the regeneration tower.

[0023] The technical solution of the present invention has at least the following beneficial effects:

[0024] Under the premise of ensuring system feasibility and reasonable investment cost, the present invention minimizes the escape of organic amines in both gaseous and aerosol forms in the amine-based CO2 removal process, effectively reduces environmental pollution, and alleviates the problem of increased system operating costs caused by amine loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic structural diagram of the absorption tower and system for removing CO2 by the amine method and controlling the escape of organic amines in Example 1 of the present invention.

[0026] Figure 2 This is a schematic diagram of the structure of a system for removing CO2 by the amine method and controlling the escape of organic amines in the prior art.

[0027] Figure 3 This is a schematic structural diagram of the absorption tower and system for removing CO2 by the amine method and controlling the escape of organic amines in Example 2 of the present invention.

[0028] Figure 4This is a schematic diagram of the structure of the absorption tower and system for removing CO2 by the amine method and controlling the escape of organic amines in Examples 3 and 4 of the present invention.

[0029] Figure 5 This is a schematic diagram of the structure of the absorption tower and system for removing CO2 by the amine method and controlling the escape of organic amines in Example 5 of the present invention.

[0030] Figure 6 This is a schematic structural diagram of the absorption tower and system for removing CO2 by the amine method and controlling the escape of organic amines in Example 7 of the present invention.

[0031] Figure 7 This is a schematic structural diagram of the absorption tower and system for removing CO2 by the amine method and controlling the escape of organic amines in Example 8 of the present invention.

[0032] Description of Figure Numbers:

[0033] 1-Absorption tower; 2-Regeneration tower; 3-Heat exchanger; 4-First condenser; 5-First gas-liquid separation tank; 6-Second condenser; 7-Second gas-liquid separation tank; 8-Condenser; 9-Gas-liquid separation tank;

[0034] 101-absorption section; 102-cooling condenser; 103-water washing section; 104-first multi-layer demister; 105-second multi-layer demister; 106-water washing water cooler; 107-lean liquid cooler; 108-water washing return water nozzle; 109-wire mesh demister;

[0035] 121-heat exchange unit; 122-gas-liquid mass transfer unit;

[0036] 131-first-stage water washing section; 132-second-stage water washing section;

[0037] 161-first wash water cooler; 162-second wash water cooler;

[0038] 181-first water washing return water nozzle; 182-second water washing return water nozzle;

[0039] 201-Reboiler. DETAILED DESCRIPTION

[0040] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be understood as limiting the scope of implementation of the present invention.

[0041] According to a specific embodiment of the present invention, Figure 1 and Figures 3 to 7As shown, the first aspect of the present invention provides an absorption tower 1 for removing carbon dioxide by an amine method and controlling the escape of organic amines, which comprises, from bottom to top, at least: an absorption section 101, a cooling condenser 102, a water washing section 103 and a first multi-layer demister 104;

[0042] The absorption tower 1 is provided with a flue gas inlet and a rich liquid outlet below the absorption section 101, a lean liquid inlet between the absorption section 101 and the cooling condenser 102, and a flue gas outlet above the first multi-layer demister 104;

[0043] The cooling condenser 102 includes a heat exchange unit 121 and a gas-liquid mass transfer unit 122 ; the gas-liquid mass transfer unit 122 is provided below the heat exchange unit 121 , or the heat exchange unit 121 is interspersed inside the gas-liquid mass transfer unit 122 .

[0044] In some embodiments, when a gas-liquid mass transfer unit 122 is disposed below the heat exchange unit 121 of the cooling condenser 102, the heat exchange unit 121 comprises a plate heat exchanger and / or a tube-fin heat exchanger, and the gas-liquid mass transfer unit 122 comprises packing and / or trays. In other embodiments, when the heat exchange unit 121 is interspersed within the gas-liquid mass transfer unit 122 of the cooling condenser 102, the cooling condenser 102 is a packed heat exchanger.

[0045] In some embodiments, the plate heat exchanger includes at least a plurality of plates, a flue gas channel and a cooling water channel; one end of the flue gas channel is a flue gas inlet and the other end is a flue gas outlet, one end of the cooling water channel is a cooling water inlet and the other end is a cooling water outlet, the cooling water channel and the flue gas channel are respectively arranged on both sides of the plurality of plates, and the cooling water channel is arranged countercurrently with the flue gas channel from top to bottom.

[0046] In some embodiments, a tube-fin heat exchanger includes at least a cooling water pipeline and a plurality of fins disposed on the outer wall of the cooling water pipeline. One end of the cooling water pipeline serves as a cooling water inlet and the other end serves as a cooling water outlet. The channel between the plurality of fins serves as a flue gas channel, with one end of the flue gas inlet and the other end serving as a flue gas outlet. The cooling water pipeline is arranged countercurrently with the flue gas channel from top to bottom (e.g., in an S-shaped arrangement). The plurality of fins in the same vertical direction are interconnected to form a plurality of vertically distributed falling film plates. The falling film plates provide sufficient countercurrent contact and heat transfer space between the cooling water and the flue gas, and ensure that the flue gas condensate obtained after the flue gas is cooled can flow vertically downward along the falling film plates to the gas-liquid mass transfer unit.

[0047] In some embodiments, when a gas-liquid mass transfer unit 122 is provided below the heat exchange unit 121 of the cooling condenser 102 and the gas-liquid mass transfer unit 122 includes a filler, the specific surface area of ​​the filler is 200 m 2 / m 3The area of ​​the gas-liquid mass transfer unit 122 arranged per unit cross-sectional area of ​​the absorption tower 1 is 300m 2 / m 2 When the cooling condenser 102 is provided with a gas-liquid mass transfer unit 122 below the heat exchange unit 121 and the gas-liquid mass transfer unit 122 includes a tray, the tray includes an overflow tray, the tray leakage is 20mm / h or less (ie 0.02m 3 / (m 2 h) below), the number of plates is 3-9.

[0048] In an embodiment of the present invention, a gas-liquid mass transfer unit 122 is preferably further arranged below the plate heat exchanger and / or the tube-fin heat exchanger. The flue gas condensate generated after the flue gas is cooled by cooling water flows out through the flue gas outlet at the bottom of the plate heat exchanger and / or the tube-fin heat exchanger, and passes through the gas-liquid mass transfer unit 122 from top to bottom. The flue gas after passing through the absorption section 101 in the gas-liquid mass transfer unit 122 is in countercurrent contact with the flue gas condensate from bottom to top, thereby allowing the flue gas condensate to further contact and transfer mass with the flue gas, thereby increasing the gas residence time of the cooling condenser 102 and absorbing the organic amines in the flue gas.

[0049] In some embodiments, when a gas-liquid mass transfer unit 122 is provided below the heat exchange unit 121 of the cooling condenser 102 and the gas-liquid mass transfer unit 122 includes a filler, the plate heat exchanger and / or the tube-fin heat exchanger is provided with a flue gas condensate diversion structure. Preferably, the flue gas condensate diversion structure includes a serrated and / or wavy structure formed by a combination of the lower edges of several plates of the plate heat exchanger and / or a combination of the lower edges of several fins of the tube-fin heat exchanger, or the flue gas condensate diversion structure includes a flue gas condensate diversion plate provided below several plates of the plate heat exchanger and / or below several fins of the tube-fin heat exchanger. More preferably, the spacing between each two adjacent serrated peaks and / or wave peaks in the serrated and / or wavy structure is less than 5 cm. In the embodiment of the present invention, the above-mentioned flue gas condensate diversion structure is preferably provided to prevent uneven distribution of flue gas condensate when entering the filler.

[0050] In other embodiments, when a gas-liquid mass transfer unit 122 is provided below the heat exchange unit 121 of the cooling condenser 102 and the gas-liquid mass transfer unit 122 is a tower plate, the plate heat exchanger and / or tube-fin heat exchanger does not need to be provided with the above-mentioned flue gas condensate diversion structure.

[0051] In some embodiments, a packed heat exchanger includes at least a plurality of packing plates and cooling water pipes interspersed within the plurality of packing plates; one end of the cooling water pipe is a cooling water inlet and the other end is a cooling water outlet. The cooling water pipe is interspersed through the plurality of packing plates and is in direct contact with the plurality of packing plates. The gaps in the plurality of packing plates serve as flue gas passages, and the cooling water pipe is arranged in countercurrent with the flue gas passages from top to bottom (e.g., in an S-shaped arrangement). Preferably, the specific surface area of ​​the plurality of packing plates of the packed heat exchanger is 200 m 2 / m 3 The area of ​​the packing plates arranged per unit cross-sectional area of ​​the absorption tower is 300m 2 / m 2 When the cooling condenser 102 is a packed heat exchanger, the heat exchange unit 121 is a cooling water pipeline, and the gas-liquid mass transfer unit 122 is a plurality of packing plates. It can be understood by those skilled in the art that the packing plates not only play a role in gas-liquid mass transfer, but also play a role in heat transfer.

[0052] The present invention incorporates a cooling condenser 102 between the absorption section 101 and the water washing section 103, providing ample space for gas-liquid heat and mass transfer. This cooling condenser 102 can reduce the flue gas temperature by 2-10°C. The flue gas undergoes countercurrent contact heat transfer with cooling water and countercurrent contact mass transfer with flue gas condensate, achieving gas-liquid equilibrium of organic amines across multiple trays. Furthermore, cooling the flue gas promotes aerosol particle size growth, facilitating subsequent aerosol removal.

[0053] In some embodiments, the first multi-layer demister 104 includes a wire mesh layer, wherein the wire mesh layer includes two layers of wire mesh or three layers of wire mesh; when it includes two layers of wire mesh, the specific surface area of ​​the lower layer of wire mesh is 250-650m 2 / m 3 , the specific surface area of ​​the upper screen is 500m 2 / m 3 When it includes 3 layers of wire mesh, the specific surface area of ​​the lower wire mesh is 250-650m 2 / m 3 , the specific surface area of ​​the middle wire mesh is 500m 2 / m 3 Above, the specific surface area of ​​the upper screen is 800m 2 / m 3Above. Preferably, when the wire mesh layer includes two layers of wire mesh, the lower wire mesh includes a metal wire mesh (the wire diameter is preferably 150μm-400μm), and the upper wire mesh includes a metal wire mesh (the wire diameter is preferably 50μm-200μm) or a co-woven wire mesh of non-metallic wire (the wire diameter is preferably 5μm-50μm) and metal wire (the wire diameter is preferably 50μm-200μm); when the wire mesh layer includes three layers of wire mesh, the lower wire mesh includes a metal wire mesh (the wire diameter is preferably 150μm-400μm), the middle wire mesh includes a metal wire mesh (the wire diameter is preferably 50μm-200μm), and the upper wire mesh includes a co-woven wire mesh of non-metallic wire (the wire diameter is preferably 5μm-50μm) and metal wire (the wire diameter is preferably 50μm-200μm). More preferably, the material of the non-metallic wire includes one or a combination of glass fiber, polypropylene, and polytetrafluoroethylene.

[0054] In some embodiments, the total height of the wire mesh layer of the first multi-layer demister 104 is 150 mm to 300 mm. Preferably, when the wire mesh layer includes two layers of wire mesh, the height ratio of the lower wire mesh to the upper wire mesh is 1:1; when the wire mesh layer includes three layers of wire mesh, the height ratio of the lower wire mesh, the middle wire mesh, and the upper wire mesh is 1:1:1 to 2:1:1.

[0055] In some embodiments, the operating air velocity of the first multi-layer demister 104 is 1-3 m / s, preferably 1-2 m / s.

[0056] In some embodiments, the absorption tower 1 further includes a second multi-layer demister 105 disposed between the cooling condenser 102 and the water washing section 103. In addition to the first multi-layer demister 104 disposed above the water washing section 103, the second multi-layer demister 105 is preferably disposed below the water washing section 103. The second multi-layer demister 105 can reduce the amine concentration in the water washing section 103, reduce the amount of aerosolized organic amines entering the water washing section 103, and slow down the accumulation of amines in the water washing section 103.

[0057] In some embodiments, the second multi-layer demister 105 includes a wire mesh layer, wherein the wire mesh layer includes two layers of wire mesh or three layers of wire mesh; when it includes two layers of wire mesh, the specific surface area of ​​the lower layer of wire mesh is 250-650m 2 / m 3 , the specific surface area of ​​the upper screen is 500m 2 / m 3 When it includes 3 layers of wire mesh, the specific surface area of ​​the lower wire mesh is 250-650m 2 / m 3 , the specific surface area of ​​the middle wire mesh is 500m 2 / m 3 Above, the specific surface area of ​​the upper screen is 800m 2 / m 3Above. Preferably, when the wire mesh layer includes two layers of wire mesh, the lower wire mesh includes a metal wire mesh (the wire diameter is preferably 150μm-400μm), and the upper wire mesh includes a metal wire mesh (the wire diameter is preferably 50μm-200μm) or a co-woven wire mesh of non-metallic wire (the wire diameter is preferably 5μm-50μm) and metal wire (the wire diameter is preferably 50μm-200μm); when the wire mesh layer includes three layers of wire mesh, the lower wire mesh includes a metal wire mesh (the wire diameter is preferably 150μm-400μm), the middle wire mesh includes a metal wire mesh (the wire diameter is preferably 50μm-200μm), and the upper wire mesh includes a co-woven wire mesh of non-metallic wire (the wire diameter is preferably 5μm-50μm) and metal wire (the wire diameter is preferably 50μm-200μm). More preferably, the material of the non-metallic wire includes one or a combination of glass fiber, polypropylene, and polytetrafluoroethylene.

[0058] In some embodiments, the total height of the wire mesh layer of the second multi-layer demister 105 is 150 mm to 300 mm. More preferably, when the wire mesh layer includes two layers of wire mesh, the height ratio of the lower wire mesh to the upper wire mesh is 1:1; when the wire mesh layer includes three layers of wire mesh, the height ratio of the lower wire mesh, the middle wire mesh, and the upper wire mesh is 1:1:1 to 2:1:1.

[0059] In some embodiments, the operating air velocity of the second multi-layer demister 105 is 1-3 m / s, more preferably 1-2 m / s.

[0060] The present invention has found through research that organic amines emitted in the form of aerosols are more difficult to handle than organic amines emitted in the form of gaseous emissions. Organic amines emitted in the form of aerosols are mainly aerosol droplets with a particle size of 0.6μm-10μm. Conventional wire mesh demisters can usually only effectively control particles larger than 2μm, and have poor control effects on aerosol droplets. Moreover, the optimal operating air velocity of conventional wire mesh demisters is generally 3-4m / s, while the air velocity in actual working conditions is about 1-2m / s, which makes its control effect even worse. The optimal operating air velocity of the first multi-layer demister 104 and the second multi-layer demister 105 of the present invention is 1-2m / s, which meets the requirements of actual working conditions.

[0061] The embodiment of the present invention improves the demister in the existing amine method CO2 absorption tower. Under the premise of keeping the mesh layer height unchanged (150mm-300mm), a layered stacking design is adopted, which can be divided into 2 or 3 layers. The lower layer of the first multi-layer demister 104 and the second multi-layer demister 105 has a large liquid load, and a lower specific surface area (250-650m 2 / m 3) and a metal wire mesh with a larger wire diameter (150 μm-400 μm) to promote the convergence of droplets while preventing liquid flooding and gas entrainment. The upper liquid load of the first multi-layer demister 104 and the second multi-layer demister 105 is small, and the specific surface area is 500m 2 / m 3 As mentioned above, metal mesh with a wire diameter of 50μm-200μm, or a co-woven wire mesh of non-metallic wire with a wire diameter of 5μm-50μm and metal wire with a wire diameter of 50μm-200μm, has an operating air velocity more suitable for absorption tower 1, and the wire mesh with a smaller wire diameter is more effective in controlling aerosols around 1μm. Therefore, the specially designed multi-layer wire mesh demister with a dense upper layer and loose lower layer in the embodiment of the present invention promotes droplet convergence while preventing liquid flooding and gas entrainment, improves the control effect of aerosol droplets, and has a more suitable operating air velocity.

[0062] In some embodiments, the absorption tower 1 is further provided with a wash water outlet below the wash section 103, and a wash circulating water inlet above the wash section 103 (specifically, provided between the wash section 103 and the first multi-layer demister 104), the wash water outlet being connected to the wash circulating water inlet via a wash water circulation pipeline; and the absorption tower 1 is further provided with a wash reflux water nozzle 108 above the cooling condenser 102 (preferably between the second multi-layer demister 105 and the cooling condenser 102), the wash reflux water nozzle 108 being connected to the wash water outlet via a wash reflux pipeline. A wash water cooler 106 may be provided on the wash water circulation pipeline. The wash return water nozzles 108 are used to use excess water from the wash section as supplemental return water for the absorption section 101 and to flush the cooling condenser 102. This excess water from the wash section, along with the flue gas condensate, flows from top to bottom through the gas-liquid mass transfer unit 122, cleaning the cooling condenser 102 while increasing the wetting rate of the gas-liquid mass transfer unit 122, thereby improving the gas-liquid mass transfer efficiency. The number of wash return water nozzles 108 can be adjusted routinely by those skilled in the art. The wash return water nozzles 108 can be configured for continuous or intermittent reflux.

[0063] In some embodiments, the water washing section includes a primary water washing section 131 and a secondary water washing section 132 from bottom to top; the primary water washing section 131 and the secondary water washing section 132 are respectively provided with a water washing water outlet below, a water washing circulating water inlet above, and a water washing water circulation pipeline connecting the water washing water outlet and the water washing circulating water inlet of each section; and the primary water washing section 131 and the secondary water washing section 132 are respectively provided with a water washing return water nozzle 108 below, and a water washing return pipeline connected to the water washing water outlet. Specifically, a first washing water outlet is provided below the primary washing section 131, and a first washing circulating water inlet is provided above the primary washing section 131. The first washing water outlet is connected to the first washing circulating water inlet through a first washing water circulating pipeline, and preferably a first washing water cooler 161 is provided on the first washing water circulating pipeline. A first washing return water nozzle 181 is provided above the cooling condenser 102 (preferably between the second multi-layer demister 105 and the cooling condenser 102). The first washing return water nozzle 181 is connected to the first washing water outlet through a first washing return pipeline, and is used to use the excess water of the primary washing section 131 as supplementary return water for the absorption section 101, and to flush the cooling condenser 102. A condenser 102; a second water washing water outlet is provided below the secondary water washing section 132, and a second water washing circulating water inlet is provided above the secondary water washing section 132 (specifically, it is provided between the secondary water washing section 132 and the first multi-layer demister 104); the second water washing water outlet is connected to the second water washing circulating water inlet through a second water washing water circulation pipeline, and preferably a second water washing water cooler 162 is provided on the second water washing water circulation pipeline, and a second water washing return water nozzle 182 is provided below the second water washing water outlet, and the second water washing return water nozzle 182 is connected to the second water washing water outlet through a second water washing return pipeline, for using the excess water of the secondary water washing section 132 as supplementary return water for the primary water washing section 131.

[0064] Those skilled in the art will appreciate that fillers may be provided in both the absorption section 101 and the water washing section 103 (including the primary water washing section 131 and the secondary water washing section 132 ). The fillers used may be conventional fillers in the art, and the present invention does not impose any special restrictions thereon.

[0065] According to a specific embodiment of the present invention, the second aspect of the present invention also provides a system for removing carbon dioxide by an amine method and controlling the escape of organic amines, such as Figure 1 and Figures 3 to 7 As shown, it comprises: the above-mentioned absorption tower 1 for removing carbon dioxide by the amine method to control the escape of organic amines, a regeneration tower 2, a heat exchanger 3, a regeneration gas condensation and gas-liquid separation device;

[0066] The upper part of the regeneration tower 2 is provided with a rich liquid inlet, a condensed water inlet and a regeneration gas outlet, and the lower part of the regeneration tower 2 is provided with a lean liquid outlet;

[0067] The rich liquid outlet of the absorption tower 1 is connected to the rich liquid inlet of the regeneration tower 2 through the heat exchanger 3, and the lean liquid inlet of the absorption tower 1 is connected to the lean liquid outlet of the regeneration tower 2 through the heat exchanger 3;

[0068] The regeneration gas condensation and gas-liquid separation device includes at least one condenser 8 and at least one gas-liquid separation tank 9; the gas-liquid separation tank 9 is provided with an inlet, a gas outlet and a condensed water outlet;

[0069] The regeneration gas outlet of the regeneration tower 2 is connected to the inlet of the gas-liquid separation tank 9 through the condenser 8 , and the condensed water outlet of the gas-liquid separation tank 9 is connected to the condensed water inlet of the regeneration tower 2 .

[0070] It will be understood by those skilled in the art that the absorption tower 1 is used to allow the organic amine absorbent to contact the flue gas in countercurrent flow and thereby absorb CO2 in the flue gas and wash the flue gas with water to obtain treated flue gas and rich liquid. The regeneration tower 2 is used to regenerate the rich liquid and release CO2 to obtain regenerated gas and lean liquid. The heat exchanger 3 is used to exchange heat between the rich liquid from the absorption tower 1 and the lean liquid from the regeneration tower 2. The rich liquid refers to the solution after the organic amine absorbent in the absorption tower 1 absorbs CO2, and the lean liquid refers to the solution after the rich liquid in the regeneration tower 2 is regenerated and releases CO2. The organic amine absorbent refers to fresh organic amine absorbent or lean liquid. The lower part of the regeneration tower 2 is connected to a reboiler 201. The regeneration of the regeneration tower 2 is to regenerate the rich liquid and release CO2 using the heating medium (such as high-temperature steam) in the reboiler 201 to obtain regenerated gas and lean liquid.

[0071] In some embodiments, the regeneration gas condensation and gas-liquid separation device includes a primary condenser 4, a first gas-liquid separation tank 5, a secondary condenser 6 and a second gas-liquid separation tank 7; the absorption tower 1 is provided with a secondary condensate water inlet between the water washing section 103 and the first multi-layer demister 104; the condensate water inlet of the regeneration tower 2 is a primary condensate water inlet; the first gas-liquid separation tank 5 is provided with an inlet, a gas outlet and a primary condensate water outlet, and the second gas-liquid separation tank 7 is provided with an inlet, a gas outlet and a secondary condensate water outlet; the regeneration gas outlet of the regeneration tower 2 is connected to the inlet of the first gas-liquid separation tank 5 through the primary condenser 4, the gas outlet of the first gas-liquid separation tank 5 is connected to the inlet of the second gas-liquid separation tank 7 through the secondary condenser 6, the primary condensate water outlet of the first gas-liquid separation tank 5 is connected to the primary condensate water inlet of the regeneration tower 2, and the secondary condensate water outlet of the second gas-liquid separation tank 7 is connected to the secondary condensate water inlet of the absorption tower 1.

[0072] In some embodiments, when the water washing section 103 of the absorption tower 1 includes a primary water washing section 131 and a secondary water washing section 132 , the secondary condensed water inlet is arranged between the secondary water washing section 132 and the first multi-layer demister 104 .

[0073] In some embodiments, a lean liquid cooler 107 is further provided on the pipeline connected to the lean liquid inlet of the absorption tower 1 .

[0074] Those skilled in the art will appreciate that the above system may also include necessary conventional devices such as temperature instruments and delivery pumps, and the present invention does not impose any special restrictions thereon, and conventional settings may be made by those skilled in the art.

[0075] According to a specific embodiment of the present invention, a third aspect of the present invention provides a method for removing carbon dioxide by an amine method to control the escape of organic amines, which is carried out using the above-mentioned system for removing carbon dioxide by an amine method to control the escape of organic amines. The method comprises the following steps:

[0076] (1) Flue gas enters the absorption tower 1, and is countercurrently contacted with the organic amine absorbent in the absorption section 101 to absorb CO2 in the flue gas to obtain a rich liquid. The flue gas is then cooled by the cooling condenser 102, and then enters the water washing section 103 for water washing. After that, the flue gas passes through the first multi-layer demister 104 to obtain the treated flue gas and is discharged through the flue gas outlet;

[0077] (2) The rich liquid is heat-exchanged with the lean liquid in the heat exchanger 3 and then enters the regeneration tower 2 for regeneration and releases CO2 to obtain regenerated gas and lean liquid. The lean liquid is heat-exchanged with the rich liquid in the heat exchanger 3 and then enters the absorption tower 1;

[0078] (3) The regenerated gas enters the condenser 8 for cooling and then is separated in the gas-liquid separation tank 9 to obtain CO2 gas and condensed water, and the condensed water is refluxed to the regeneration tower 2.

[0079] In some embodiments, in step (1), the CO2 content in the flue gas is 3-20 vol.%.

[0080] In some embodiments, in step (1), the temperature of the flue gas entering the absorption tower 1 is 35-45°C, the temperature of the organic amine absorbent (including fresh organic amine absorbent or lean liquid) entering the absorption tower 1 is 38-42°C, the temperature of the rich liquid flowing out of the absorption tower 1 is 46-52°C, and the temperature of the treated flue gas flowing out of the absorption tower 1 is 35-45°C.

[0081] In some embodiments, in step (1), the residence time of the flue gas in the cooling condenser 102 is more than 1.5 seconds, preferably 1.5 seconds to 3 seconds.

[0082] In some embodiments, in step (1), the temperature of the cooling water used in the cooling condenser 102 (i.e., the temperature at the cooling water inlet) is 25-35°C, and the temperature of the flue gas after passing through the cooling condenser 102 is 44-50°C.

[0083] In some embodiments, step (1) further comprises: cooling a portion of the washing water after washing in the washing section 103 and recirculating it as washing circulating water to the washing section 103, and returning another portion of the washing water after washing in the washing section 103 as washing return water to the absorption section 101 and flushing the cooling condenser 102; wherein the temperature of the washing circulating water is 36-46°C. Preferably, the flow ratio of the washing circulating water to the washing return water is 50:1-1000:1.

[0084] In some embodiments, in step (1), the process of washing in the washing section 103 specifically includes: when the primary washing section 131 and the secondary washing section 132 are used for washing, a portion of the washing water after washing in the primary washing section 131 is cooled and then re-entered into the primary washing section 131 as the first washing circulating water for circulation, and another portion of the washing water after washing in the primary washing section 131 is refluxed to the absorption section 101 as the first washing reflux water and flushed the cooling condenser 102; a portion of the washing water after washing in the secondary washing section 132 is cooled and then re-entered into the secondary washing section 132 for circulation as the second washing circulating water, and another portion of the washing water after washing in the secondary washing section 132 is refluxed to the primary washing section 131 as the second washing reflux water; wherein, the temperature of the first washing circulating water is 43-49°C, and the temperature of the second washing circulating water is 36-46°C. Preferably, the flow ratio of the first washing circulating water to the first washing return water in the primary washing section is 50:1-1000:1; the flow ratio of the second washing circulating water to the second washing return water in the secondary washing section is 100:1-2000:1.

[0085] In some embodiments, in step (1), the liquid-gas mass ratio of the absorption section 101 under stable operating conditions is 1-5.

[0086] In some embodiments, in step (1), the liquid-to-gas mass ratio of the water washing section 103 under stable operating conditions is 2-6.

[0087] In some embodiments, in step (2), the temperature of the rich liquid entering the regeneration tower 2 is 92-110°C, the temperature of the lean liquid flowing out of the regeneration tower 2 is 100-120°C, and the temperature of the regenerated gas flowing out of the regeneration tower 2 is 90-106°C.

[0088] In some embodiments, in step (3), the condenser 8 cools the regeneration gas to 35-45°C.

[0089] In some embodiments, step (3) specifically includes: the regenerated gas enters the primary condenser 4 for cooling and then passes through the first gas-liquid separator 5 for separation to obtain gas components and primary condensed water; the primary condensed water is refluxed to the regeneration tower 2, the gas components enter the secondary condenser 6 for cooling and then pass through the second gas-liquid separator 7 for separation to obtain CO2 gas and secondary condensed water; the secondary condensed water is refluxed to the water washing section 103 of the absorption tower 1. When the absorption tower 1 adopts the primary water washing section 131 and the secondary water washing section 132, the secondary condensed water is refluxed to the secondary water washing section 132 of the absorption tower 1.

[0090] In some embodiments, in step (3), the primary condenser 4 cools the regeneration gas to 70-85°C.

[0091] In some embodiments, in step (3), the organic amine concentration of the primary condensed water is 0.2-10 wt.%.

[0092] In some embodiments, in step (3), the secondary condenser 6 cools the gas components to 35-45°C.

[0093] In some embodiments, in step (3), the organic amine concentration of the secondary condensed water is 0.001-0.8 wt.%.

[0094] In some embodiments, in step (3), the flow ratio of the primary condensed water to the secondary condensed water is 3:7-7:3.

[0095] In some embodiments, the concentration of organic amines in the treated flue gas discharged through the flue gas outlet is 0.1-8 mg / Nm 3 , more preferably 0.1-3.5 mg / Nm 3 .

[0096] It will be understood by those skilled in the art that in the above method, when the system of the present invention is used for the first time, fresh organic amine absorbent can enter the absorption section 101 of the absorption tower 1 through the lean liquid inlet. When the system of the present invention is used for the first time, fresh wash water can enter the wash section 103 of the absorption tower 1 through the secondary condensate inlet and / or through the wash circulating water inlet.

[0097] The present invention improves the condensation of regenerated gas by employing a two-stage condensation process. After cooling to 70-85°C and undergoing gas-liquid separation in a primary condenser 4, the gas components are then cooled to 35-45°C and separated in a secondary condenser 6, resulting in primary and secondary condensate. The primary condensate is high-amine condensate and can be directly refluxed to the regeneration tower 2; the secondary condensate is low-amine condensate and is directly fed to the water wash section 103 (preferably the secondary water wash section 132), significantly reducing amine emissions from the flue gas outlet of the absorption tower 1. This improved process requires minimal modification, is easy to implement, and significantly controls amine slip.

[0098] The technical solutions of the present invention are specifically described below through examples and comparative examples, but the present invention is not limited to these examples and can of course be implemented with various modifications within the scope of the gist of the present invention.

[0099] Example 1

[0100] This embodiment provides an absorption tower and system for removing carbon dioxide using an amine method and controlling the escape of organic amines.

[0101] like Figure 1 As shown, the absorption tower 1 includes at least: an absorption section 101, a cooling condenser 102, a water washing section 103 and a first multi-layer demister 104 from bottom to top; the absorption tower 1 is provided with a flue gas inlet and a rich liquid outlet below the absorption section 101, a lean liquid inlet is provided between the absorption section 101 and the cooling condenser 102, and a flue gas outlet is provided above the first multi-layer demister 104, and the flue gas outlet discharges the treated flue gas.

[0102] Among them, the cooling condenser 102 adopts a packed heat exchanger, which includes 350Y structured packing plates and cooling water pipes inserted inside the 350Y structured packing plates. The height of the packed heat exchanger is 3m. Specifically, one end of the cooling water pipe of the packed heat exchanger is a cooling water inlet and the other end is a cooling water outlet. The cooling water inlet is arranged above the cooling water outlet. The cooling water pipe is inserted through the 350Y structured packing plates and is in direct contact with the packing plates. The gaps in the packing plates serve as flue gas channels. The cooling water pipe is arranged countercurrently with the flue gas channel from top to bottom (in an S-shaped arrangement). The area of ​​the 350Y structured packing plates arranged per unit cross-sectional area of ​​the absorption tower 1 is 1050m 2 / m 2 .

[0103] The first multi-layer demister 104 includes a wire mesh layer, which includes two layers of wire mesh; the lower wire mesh is a 304 stainless steel wire mesh with a wire diameter of 190 μm and a specific surface area of ​​600 m 2 / m 3, porosity of 0.98, height of 75mm; the upper wire mesh is a co-woven wire mesh of glass fiber with an average wire diameter of 10μm and 304 stainless steel wire with a wire diameter of 190μm, and its specific surface area is 1100m 2 / m 3 The porosity is 0.985, the height is 75 mm, and the upper and lower layers are stacked in contact. The working air velocity of the first multi-layer demister 104 is 1.6 m / s.

[0104] The absorption tower 1 further includes a second multi-layer demister 105, which is disposed between the cooling condenser 102 and the water washing section 103. The second multi-layer demister 105 has the same structure and material as the first multi-layer demister 104. The operating air velocity of the second multi-layer demister 105 is 1.7 m / s.

[0105] Both the absorption section 101 and the water washing section 103 are provided with 250Y stainless steel structured packing. The packing height of the absorption section 101 is 12m, and the packing height of the water washing section 103 is 3m.

[0106] The absorption tower 1 is further provided with a wash water outlet below the wash section 103, and a wash circulating water inlet above the wash section 103 (specifically, between the wash section 103 and the first multi-layer demister 104). The wash water outlet is connected to the wash circulating water inlet via a wash water circulation pipeline, and a wash water cooler 106 is provided on the wash water circulation pipeline. In addition, the absorption tower 1 is further provided with a wash reflux water nozzle 108 above the cooling condenser 102 (specifically, between the second multi-layer demister 105 and the cooling condenser 102). The wash reflux water nozzle 108 is connected to the wash water outlet via a wash reflux pipeline. The wash reflux water nozzle 108 is used to use excess water from the wash section 103 as supplementary reflux water for the absorption section 101 and to flush the cooling condenser 102. The specific number of the wash reflux water nozzles 108 can be routinely adjusted by those skilled in the art. The water washing return water nozzle 108 is set to intermittent return.

[0107] like Figure 1 As shown, the system includes an absorption tower 1, a regeneration tower 2, a heat exchanger 3, a primary condenser 4, a first gas-liquid separation tank 5, a secondary condenser 6 and a second gas-liquid separation tank 7;

[0108] The absorption tower 1 is used to allow the organic amine absorbent to contact the flue gas in countercurrent flow, thereby absorbing CO2 in the flue gas and washing the flue gas with water to obtain treated flue gas and rich liquid; the absorption tower 1 is provided with a secondary condensate inlet between the water washing section 103 and the first multi-layer demister 104;

[0109] The regeneration tower 2 is used to regenerate the rich liquid and release CO2 to obtain regenerated gas and lean liquid. The upper part of the regeneration tower 2 is provided with a rich liquid inlet, a first-stage condensed water inlet and a regenerated gas outlet, and the lower part of the regeneration tower is provided with a lean liquid outlet. The lower part of the regeneration tower is connected to a reboiler 201.

[0110] The heat exchanger 3 is used to exchange heat between the rich liquid from the absorption tower 1 and the lean liquid from the regeneration tower 2. The rich liquid outlet of the absorption tower 1 is connected to the rich liquid inlet of the regeneration tower 2 through the heat exchanger 3. The lean liquid inlet of the absorption tower 1 is connected to the lean liquid outlet of the regeneration tower 2 through the heat exchanger 3. A lean liquid cooler 107 is provided on the pipeline connected to the lean liquid inlet of the absorption tower 1.

[0111] The first gas-liquid separation tank 5 is provided with an inlet, a gas outlet and a primary condensed water outlet, and the second gas-liquid separation tank 7 is provided with an inlet, a gas outlet and a secondary condensed water outlet;

[0112] The regeneration gas outlet of the regeneration tower 2 is connected to the inlet of the first gas-liquid separation tank 5 through the first condenser 4, the gas outlet of the first gas-liquid separation tank 5 is connected to the inlet of the second gas-liquid separation tank 7 through the second condenser 6, the first condensed water outlet of the first gas-liquid separation tank 5 is connected to the first condensed water inlet of the regeneration tower 2, the second condensed water outlet of the second gas-liquid separation tank 7 is connected to the second condensed water inlet of the absorption tower 1, and the gas outlet of the second gas-liquid separation tank 7 is a CO2 gas outlet.

[0113] This embodiment also provides a method for removing carbon dioxide by amine method to control the escape of organic amines, which is carried out using the above-mentioned system for removing carbon dioxide by amine method to control the escape of organic amines. The flue gas to be treated is coal-fired flue gas, and the condensation nucleus content in the flue gas is measured to be greater than 10 6 cm -3 , CO2 content is 12vol.%. The fresh organic amine absorbent used is 30wt.% MEA (ethanolamine) aqueous solution.

[0114] The method comprises the following steps:

[0115] (1) Flue gas at a temperature of 40°C enters the absorption tower 1, and is countercurrently contacted with an organic amine absorbent at a temperature of 40°C in the absorption section 101 to absorb CO2 in the flue gas. Under stable working conditions, the liquid-gas mass ratio of the absorption section 101 is 3-4, and a rich liquid is obtained; then the flue gas is cooled to 47°C by the cooling condenser 102, the temperature of the cooling water used in the cooling condenser 102 is 28°C, and the residence time of the flue gas in the cooling condenser 102 is 2.5-3.0s; then, after passing through the second multi-layer demister 105, it enters the water washing section 103 for water washing, and the liquid-gas mass ratio of the water washing section 103 is 4-5, so that the water washing section 103 is water washed. A portion of the washing water after washing is cooled to 41°C and then re-enters the washing section 103 as washing circulating water for circulation, and another portion of the washing water after washing in the washing section 103 is refluxed to the absorption section 101 as washing reflux water to flush the cooling condenser 102. The flow ratio of the washing circulating water to the washing reflux water is 80:1, and the washing section 103 does not need to be supplemented with additional fresh water; after passing through the first multi-layer demister 104, the treated flue gas is obtained and discharged through the flue gas outlet; the temperature of the rich liquid flowing out of the absorption tower 1 is 48°C, and the temperature of the treated flue gas flowing out of the absorption tower 1 is 40-41°C;

[0116] (2) The rich liquid is heat exchanged with the lean liquid in heat exchanger 3 and then enters regeneration tower 2 for regeneration and releases CO2, obtaining regenerated gas and lean liquid. The lean liquid is heat exchanged with the rich liquid in heat exchanger 3 and then enters absorption tower 1. The temperature of the rich liquid entering regeneration tower 2 is 97°C, the temperature of the lean liquid flowing out of regeneration tower 2 is 103°C, and the temperature of the regenerated gas flowing out of regeneration tower 2 is 98°C.

[0117] (3) The regenerated gas enters the primary condenser 4 and is cooled to 78°C and then separated by the first gas-liquid separation tank 5 to obtain gas components and primary condensed water; the primary condensed water is refluxed to the regeneration tower 2, and the gas components enter the secondary condenser 6 and are cooled to 40°C and then separated by the second gas-liquid separation tank 7 to obtain CO2 gas and secondary condensed water; the secondary condensed water is refluxed to the water washing section 103 of the absorption tower 1; the flow ratio of the primary condensed water and the secondary condensed water is 1:1.

[0118] When the system is used for the first time, fresh organic amine absorbent can enter the absorption section 101 of the absorption tower 1 through the lean liquid inlet, and fresh washing water can enter the washing section 103 of the absorption tower 1 through the washing circulating water inlet or the secondary condensed water inlet.

[0119] After the above system and method were used to operate continuously for 24 hours, the CO2 capture rate was tested to be 90%, and the MEA emission in the treated flue gas discharged through the flue gas outlet was tested to be 0.4-3.1 mg / Nm 3 , average emission 1.1mg / Nm 3The MEA concentration in the washing circulating water of the washing section 103 was tested to be 0.08 wt.%, the MEA concentration in the first-level condensed water was tested to be 0.98 wt.%, and the MEA concentration in the second-level condensed water was tested to be 0.06 wt.%.

[0120] Comparative Example 1

[0121] This comparative example provides a system for removing CO2 by amine method in the prior art to control the escape of organic amines, and its structure is as follows: Figure 2 As shown, the system includes: an absorption tower 1, a regeneration tower 2, a heat exchanger 3, a condenser 8 and a gas-liquid separation tank 9;

[0122] The absorption tower 1 comprises, from bottom to top, an absorption section 101, a water washing section 103, and a wire mesh demister 109. The absorption tower 1 is provided with a flue gas inlet and a rich liquid outlet below the absorption section 101; a lean liquid inlet is provided between the absorption section 101 and the water washing section 103; a wash water outlet is provided below the water washing section 103, and a wash circulating water inlet is provided above the water washing section 103. The wash water outlet is connected to the wash circulating water inlet via a wash water circulation pipeline, and a wash water cooler 106 is provided on the wash water circulation pipeline; a flue gas outlet is provided above the wire mesh demister 109, and the treated flue gas is discharged from the flue gas outlet.

[0123] The upper portion of the regeneration tower 2 is provided with a rich liquid inlet, a condensed water inlet and a regeneration gas outlet, the lower portion of the regeneration tower 2 is provided with a lean liquid outlet, and the lower portion of the regeneration tower 2 is connected to a reboiler 201;

[0124] The rich liquid outlet of the absorption tower 1 is connected to the rich liquid inlet of the regeneration tower 2 through the heat exchanger 3, and the lean liquid inlet of the absorption tower 1 is connected to the lean liquid outlet of the regeneration tower 2 through the heat exchanger 3. A lean liquid cooler 107 is provided on the pipeline connected to the lean liquid inlet of the absorption tower 1;

[0125] The gas-liquid separation tank 9 is provided with an inlet, a gas outlet and a condensed water outlet;

[0126] The regeneration gas outlet of the regeneration tower 2 is connected to the inlet of the gas-liquid separation tank 9 through the condenser 8, the condensed water outlet of the gas-liquid separation tank 9 is connected to the condensed water inlet of the regeneration tower 2, and the gas outlet of the gas-liquid separation tank 9 is a CO2 gas outlet.

[0127] The absorption section 101 and the water washing section 103 are both provided with 250Y stainless steel structured packing. The packing height of the absorption section 101 is 12m, and the packing height of the water washing section 103 is 3m.

[0128] Metal mesh mist eliminator 109 uses DP high-efficiency 304 stainless steel wire mesh mist eliminator, which includes 1 layer of stainless steel wire mesh with a wire diameter of 190μm and a specific surface area of ​​600m 2 / m 3The porosity is 0.98, and the total height of the wire mesh layer is 150 mm. The working air velocity of the wire mesh demister 109 is 1.7 m / s.

[0129] This comparative example also provides a method for removing carbon dioxide by amine method to control the escape of organic amines, which is carried out using the above-mentioned system for removing carbon dioxide by amine method to control the escape of organic amines. The flue gas to be treated is coal-fired flue gas, and the condensation nucleus content in the flue gas is measured to be >10 6 cm -3 , CO2 content is 12 vol.%. The fresh organic amine absorbent used is 30 wt.% MEA aqueous solution.

[0130] The method comprises the following steps:

[0131] (1) Flue gas at a temperature of 40°C is allowed to enter the absorption tower 1, and is countercurrently contacted with an organic amine absorbent at a temperature of 40°C in the absorption section 101 to absorb CO2 in the flue gas. Under stable working conditions, the liquid-gas mass ratio of the absorption section 101 is 3-4, and a rich liquid is obtained; then the flue gas enters the water washing section 103 for water washing, and the liquid-gas mass ratio of the water washing section 103 is 4-5. The washing water after the water washing section 103 is cooled to 41°C and then enters the water washing section 103 again as washing circulating water for circulation, and the water washing section 103 does not need to be supplemented with fresh water; then, the flue gas is obtained after passing through the wire mesh demister 109 and discharged through the flue gas outlet; the temperature of the rich liquid flowing out of the absorption tower 1 is 48°C, and the temperature of the treated flue gas flowing out of the absorption tower 1 is 40-41°C;

[0132] (2) The rich liquid is heat exchanged with the lean liquid in heat exchanger 3 and then enters regeneration tower 2 for regeneration and releases CO2, obtaining regenerated gas and lean liquid. The lean liquid is heat exchanged with the rich liquid in heat exchanger 3 and then enters absorption tower 1. The temperature of the rich liquid entering regeneration tower 2 is 97°C, the temperature of the lean liquid flowing out of regeneration tower 2 is 103°C, and the temperature of the regenerated gas flowing out of regeneration tower 2 is 98°C.

[0133] (3) The regenerated gas enters the condenser 8 and is cooled to 40°C. It is then separated in the gas-liquid separation tank 9 to obtain CO2 gas and condensed water. The condensed water is refluxed to the regeneration tower 2.

[0134] When the system is used for the first time, fresh organic amine absorbent can enter the absorption section 101 of the absorption tower 1 through the lean liquid inlet, and fresh washing water can enter the washing section 103 of the absorption tower 1 through the washing circulating water inlet.

[0135] After the above system and method were used for continuous operation for 24 hours, the CO2 capture rate was tested to be 90%, and the MEA emission in the treated flue gas discharged through the flue gas outlet was tested to be 23-43 mg / Nm 3 , average emission 29mg / Nm3 The MEA concentration in the washing circulating water of the washing section 103 was tested to be 1.21 wt.%, and the MEA concentration in the regenerated gas condensate was tested to be 0.51 wt.%.

[0136] Comparative Example 2

[0137] This comparative example provides a system for removing carbon dioxide by an amine method and controlling the escape of organic amines. The structure of the system is basically the same as that of Example 1, except that the cooling condenser 102 is not provided.

[0138] This comparative example also provides a method for removing carbon dioxide by amine method to control the escape of organic amines, which is carried out using the above-mentioned system for removing carbon dioxide by amine method to control the escape of organic amines. The flue gas to be treated is coal-fired flue gas, and the condensation nucleus content in the flue gas is measured to be >10 6 cm -3 , CO2 content is 12 vol.%. The fresh organic amine absorbent used is 30 wt.% MEA aqueous solution.

[0139] The specific steps of this method are basically the same as those of Example 1, except that: in step (1), the flue gas is countercurrently contacted with the organic amine absorbent in the absorption section 101 to absorb CO2 in the flue gas, then passes through the second multi-layer demister 105 and then enters the water washing section 103 for water washing.

[0140] After the above system and method were used for continuous operation for 24 hours, the CO2 capture rate was tested to be 90%, and the MEA emission in the treated flue gas discharged through the flue gas outlet was tested to be 6.7-9.6 mg / Nm 3 , average emission 7.8mg / Nm 3 The MEA concentration in the washing circulating water of the washing section 103 was tested to be 0.26 wt.%, the MEA concentration in the first-level condensed water was tested to be 1.01 wt.%, and the MEA concentration in the second-level condensed water was tested to be 0.06 wt.%.

[0141] Example 2

[0142] This embodiment provides an absorption tower and system for removing carbon dioxide by an amine method and controlling the escape of organic amines, such as Figure 3 As shown, its structure is basically the same as that of Example 1, except that:

[0143] The water washing section 103 includes a primary water washing section 131 and a secondary water washing section 132 from bottom to top; a first water washing water outlet is provided at the bottom of the primary water washing section 131, and a first water washing circulating water inlet is provided at the top. The first water washing water outlet is connected to the first water washing circulating water inlet through a first water washing water circulating pipeline, and a first water washing water cooler 161 is provided on the first water washing water circulating pipeline. A first water washing reflux water nozzle 181 is provided above the cooling condenser 102 (specifically between the second multi-layer demister 105 and the cooling condenser 102). The first water washing reflux water nozzle 181 is connected to the first water washing water outlet through the first water washing reflux pipeline, and is used to use the excess water of the primary water washing section as the absorption section 101. The secondary water washing section 132 is provided with a second water washing water outlet below and a second water washing circulating water inlet above (specifically, between the secondary water washing section 132 and the first multi-layer demister 104). The second water washing water outlet is connected to the second water washing circulating water inlet via a second water washing water circulation pipeline, and a second water washing water cooler 162 is provided on the second water washing water circulation pipeline. A second water washing return water nozzle 182 is provided below the second water washing water outlet. The second water washing return water nozzle 182 is connected to the second water washing water outlet via a second water washing return pipeline, and is used to use the excess water in the secondary water washing section 132 as supplementary return water for the primary water washing section 131. In addition, the secondary condensate water inlet is provided between the secondary water washing section 132 and the first multi-layer demister 104. The packing height of the primary water washing section 131 and the secondary water washing section 132 is 2m respectively, and the packing is 250Y stainless steel structured packing.

[0144] This embodiment also provides a method for removing carbon dioxide by amine method to control the escape of organic amines, which is carried out using the above-mentioned system for removing carbon dioxide by amine method to control the escape of organic amines. The flue gas to be treated is coal-fired flue gas, and the condensation nucleus content in the flue gas is measured to be greater than 10 6 cm -3 , CO2 content is 12 vol.%. The fresh organic amine absorbent used is 30 wt.% MEA aqueous solution.

[0145] The method comprises the following steps:

[0146] (1) Flue gas at a temperature of 40°C is allowed to enter the absorption tower 1, and is countercurrently contacted with an organic amine absorbent at a temperature of 40°C in the absorption section 101 to absorb CO2 in the flue gas. Under stable working conditions, the liquid-gas mass ratio of the absorption section 101 is 3-4, and a rich liquid is obtained; then the flue gas is cooled to 47°C by the cooling condenser 102, the temperature of the cooling water used in the cooling condenser 102 is 28°C, and the residence time of the flue gas in the cooling condenser 102 is 2.5-3.0s; then, after passing through the second multi-layer demister 105, it enters the water washing section 103 for water washing, and the liquid-gas mass ratio of the water washing section 103 is 4-5. A part of the water washed in the first water washing section 131 is cooled to 46°C and then enters the first water washing section 131 again as the first water washing circulating water for circulation, and another part of the water washed in the first water washing section 131 is used as the first water washing reflux water Reflux to the absorption section 101 and flush the cooling condenser 102; a portion of the washing water after washing in the secondary washing section 132 is cooled to 41°C and then re-enters the secondary washing section 132 as the second washing circulating water for circulation, and another portion of the washing water after washing in the secondary washing section 132 is refluxed to the primary washing section 131 as the second washing reflux water; the flow ratio of the first washing circulating water to the first washing reflux water in the primary washing section 131 is 80:1, and the flow ratio of the second washing circulating water to the second washing reflux water in the secondary washing section 132 is 120:1; no additional fresh water is required to be added to the washing section 103; thereafter, the treated flue gas is obtained after passing through the first multi-layer demister 104 and discharged through the flue gas outlet; the temperature of the rich liquid flowing out of the absorption tower 1 is 48°C, and the temperature of the treated flue gas flowing out of the absorption tower 1 is 40-41°C;

[0147] (2) The rich liquid is heat exchanged with the lean liquid in heat exchanger 3 and then enters regeneration tower 2 for regeneration and releases CO2, obtaining regenerated gas and lean liquid. The lean liquid is heat exchanged with the rich liquid in heat exchanger 3 and then enters absorption tower 1. The temperature of the rich liquid entering regeneration tower 2 is 97°C, the temperature of the lean liquid flowing out of regeneration tower 2 is 103°C, and the temperature of the regenerated gas flowing out of regeneration tower 2 is 98°C.

[0148] (3) The regenerated gas enters the primary condenser 4 and is cooled to 78°C and then separated by the first gas-liquid separation tank 5 to obtain gas components and primary condensed water; the primary condensed water is refluxed to the regeneration tower 2, and the gas components enter the secondary condenser 6 and are cooled to 40°C and then separated by the second gas-liquid separation tank 7 to obtain CO2 gas and secondary condensed water; the secondary condensed water is refluxed to the secondary water washing section 132 of the absorption tower 1; the flow ratio of the primary condensed water and the secondary condensed water is 1:1.

[0149] After the above system and method were operated continuously for 24 hours, the CO2 capture rate was 90% and the MEA emission in the treated flue gas discharged through the flue gas outlet was 0.3-2.2 mg / Nm3 , average emission 0.7mg / Nm 3 The MEA concentration in the second water washing circulating water of the secondary water washing section 132 was tested to be 0.07wt.%, the MEA concentration in the first condensed water was tested to be 0.98wt.%, and the MEA concentration in the second condensed water was tested to be 0.06wt.%.

[0150] Example 3

[0151] This embodiment provides an absorption tower and system for removing carbon dioxide by an amine method and controlling the escape of organic amines. The structure is basically the same as that of Example 1, except that: Figure 4 As shown, the cooling condenser 102 includes a heat exchange unit 121 and a gas-liquid mass transfer unit 122 arranged below the heat exchange unit 121. The heat exchange unit 121 is a tube-and-fin heat exchanger. The tube-and-fin heat exchanger includes a cooling water pipeline and a plurality of fins arranged on the outer wall of the cooling water pipeline. Specifically, one end of the cooling water pipeline of the tube-and-fin heat exchanger is a cooling water inlet and the other end is a cooling water outlet. The cooling water inlet is arranged above the cooling water outlet. The channel between the plurality of fins serves as a flue gas channel. One end of the flue gas channel is a flue gas inlet and the other end is a flue gas outlet. The cooling water pipeline is arranged in countercurrent with the flue gas channel from top to bottom (in an S-shaped arrangement). The plurality of fins in the same vertical direction are interconnected to form a plurality of vertically distributed falling film plates. The gas-liquid mass transfer unit 122 is a 350Y structured packing with a height of 2m. The area of ​​the 350Y structured packing arranged per unit cross-sectional area of ​​the absorption tower 1 is 700m 2 / m 2 The heat transfer area of ​​the tube-fin heat exchanger is 160m 2 / m 2 The tube-fin heat exchanger is provided with a flue gas condensate water diversion structure, which includes a zigzag structure formed by the lower edges of several fins of the tube-fin heat exchanger ( Figure 4 It is only a schematic diagram and the sawtooth structure is not shown). The distance between every two adjacent sawtooth peaks in the sawtooth structure is less than 5 cm.

[0152] This embodiment also provides a method for removing carbon dioxide by amine method to control the escape of organic amines, which is carried out using the above-mentioned system for removing carbon dioxide by amine method to control the escape of organic amines. The flue gas to be treated is coal-fired flue gas, and the condensation nucleus content in the flue gas is measured to be greater than 10 6 cm -3 , CO2 content is 12 vol.%. The fresh organic amine absorbent used is 30 wt.% MEA aqueous solution.

[0153] The specific steps of the method are the same as those of Example 1. The residence time of the flue gas in the cooling condenser 102 is 2.0-2.5 seconds.

[0154] After the above system and method were operated continuously for 24 hours, the CO2 capture rate was tested to be 90%, and the MEA emission in the treated flue gas discharged through the flue gas outlet was tested to be 0.5-3.3 mg / Nm 3 , average emission 1.6mg / Nm 3 The MEA concentration in the washing circulating water of the washing section 103 was tested to be 0.10 wt.%, the MEA concentration in the first-level condensed water was tested to be 1.01 wt.%, and the MEA concentration in the second-level condensed water was tested to be 0.06 wt.%.

[0155] Example 4

[0156] This embodiment provides an absorption tower and system for removing carbon dioxide by an amine method and controlling the escape of organic amines. The structure is basically the same as that of Example 1, except that: Figure 4 As shown, the cooling condenser 102 includes a heat exchange unit 121 and a gas-liquid mass transfer unit 122 arranged below the heat exchange unit 121. The heat exchange unit 121 is a plate heat exchanger with a height of 0.5m. The plate heat exchanger includes a plurality of plates, a flue gas channel and a cooling water channel; one end of the flue gas channel is a flue gas inlet and the other end is a flue gas outlet, one end of the cooling water channel is a cooling water inlet and the other end is a cooling water outlet, the cooling water inlet is arranged above the cooling water outlet, the cooling water channel and the flue gas channel are respectively arranged on both sides of a plurality of plates, and the cooling water channel is arranged in countercurrent with the flue gas channel from top to bottom. The gas-liquid mass transfer unit 122 is a 350Y structured packing with a height of 2m. The area of ​​the 350Y structured packing arranged per unit cross-sectional area of ​​the absorption tower 1 is 700m 2 / m 2 The heat exchange area of ​​the plate heat exchanger is 200m 2 / m 2 The plate heat exchanger is provided with a flue gas condensate water diversion structure, which includes a wave-shaped structure formed by the lower edges of several plates of the plate heat exchanger ( Figure 4 It is only a schematic diagram and the wavy structure is not shown). The distance between every two adjacent wave peaks in the wavy structure is less than 5 cm.

[0157] This embodiment also provides a method for removing carbon dioxide by amine method to control the escape of organic amines, which is carried out using the above-mentioned system for removing carbon dioxide by amine method to control the escape of organic amines. The flue gas to be treated is coal-fired flue gas, and the condensation nucleus content in the flue gas is measured to be greater than 10 6 cm -3 , CO2 content is 12 vol.%. The fresh organic amine absorbent used is 30 wt.% MEA aqueous solution.

[0158] The specific steps of the method are the same as those of Example 1. The residence time of the flue gas in the cooling condenser 102 is 2.0-2.5 seconds.

[0159] After the above system and method were used to operate continuously for 24 hours, the CO2 capture rate was tested to be 90%, and the MEA emission in the treated flue gas discharged through the flue gas outlet was tested to be 0.5-2.2 mg / Nm 3 , average emission 1.0mg / Nm 3 The MEA concentration in the washing circulating water of the washing section 103 was tested to be 0.09 wt.%, the MEA concentration in the first-level condensed water was tested to be 0.99 wt.%, and the MEA concentration in the second-level condensed water was tested to be 0.06 wt.%.

[0160] Example 5

[0161] This embodiment provides an absorption tower and system for removing carbon dioxide by an amine method and controlling the escape of organic amines. The structure is basically the same as that of Example 4, except that: Figure 5 As shown, the second multi-layer demister 105 is not provided, and the gas-liquid mass transfer unit 122 is an S-shaped bubble cap tray. The liquid leakage rate of the S-shaped bubble cap tray is less than 20 mm / h, and the number of S-shaped bubble cap trays is four. In addition, the plate heat exchanger does not have the flue gas condensate diversion structure of Example 4.

[0162] This embodiment also provides a method for removing carbon dioxide by amine method to control the escape of organic amines, which is carried out using the above-mentioned system for removing carbon dioxide by amine method to control the escape of organic amines. The flue gas to be treated is coal-fired flue gas, and the condensation nucleus content in the flue gas is measured to be greater than 10 6 cm -3 , CO2 content is 12 vol.%. The fresh organic amine absorbent used is 30 wt.% MEA aqueous solution.

[0163] The specific steps of this method are the same as those of Example 4. The residence time of the flue gas in the cooling condenser 102 is 2.0-2.5 seconds.

[0164] After the above system and method were used to operate continuously for 24 hours, the CO2 capture rate was tested to be 90%, and the MEA emission in the treated flue gas discharged through the flue gas outlet was tested to be 1.2-3.5 mg / Nm 3 , average emission 2.2mg / Nm 3 The MEA concentration in the washing circulating water of the washing section 103 was tested to be 0.10 wt.%, the MEA concentration in the first-level condensed water was tested to be 0.97 wt.%, and the MEA concentration in the second-level condensed water was tested to be 0.07 wt.%.

[0165] Example 6

[0166] This embodiment provides an absorption tower and system for removing carbon dioxide by amine method and controlling the escape of organic amines. Its structure is basically the same as that of Example 2, except that: the first multi-layer demister 104 includes a wire mesh layer, and the wire mesh layer includes three layers of wire mesh; the lower wire mesh is a 304 stainless steel wire mesh with a wire diameter of 240 μm and a specific surface area of ​​400 m 2 / m 3 , porosity of 0.97, height of 100mm; the middle wire mesh is 304 stainless steel wire mesh with a wire diameter of 190μm, and its specific surface area is 600m 2 / m 3 , porosity of 0.98, height of 50mm; the upper wire mesh is a co-woven wire mesh of glass fiber with an average wire diameter of 10μm and 304 stainless steel wire with a wire diameter of 190μm, and its specific surface area is 1100m 2 / m 3 The first multi-layer demister 104 has a working air velocity of 1.6 m / s. The second multi-layer demister 105 has the same structure and material as the first multi-layer demister 104. The working air velocity of the second multi-layer demister 105 is 1.7 m / s.

[0167] This embodiment also provides a method for removing carbon dioxide by amine method to control the escape of organic amines, which is carried out using the above-mentioned system for removing carbon dioxide by amine method to control the escape of organic amines. The flue gas to be treated is coal-fired flue gas, and the condensation nucleus content in the flue gas is measured to be greater than 10 6 cm -3 , CO2 content is 12 vol.%. The fresh organic amine absorbent used is 30 wt.% MEA aqueous solution.

[0168] The specific steps of this method are the same as those in Example 2.

[0169] After the above system and method were used to operate continuously for 24 hours, the CO2 capture rate was tested to be 90%, and the MEA emission in the treated flue gas discharged through the flue gas outlet was tested to be 0.2-0.9 mg / Nm 3 , average emission 0.4mg / Nm 3 The MEA concentration in the washing circulating water of the washing section 103 was tested to be 0.07 wt.%, the MEA concentration in the first-level condensed water was tested to be 1.01 wt.%, and the MEA concentration in the second-level condensed water was tested to be 0.06 wt.%.

[0170] Example 7

[0171] This embodiment provides an absorption tower and system for removing carbon dioxide by an amine method and controlling the escape of organic amines. The structure is basically the same as that of Example 5, except that: Figure 6As shown, the primary condenser 4, the first gas-liquid separator 5, the secondary condenser 6 and the second gas-liquid separator 7 are not provided. Instead, the condenser 8 and the gas-liquid separator 9 identical to those in Comparative Example 1 are provided, and the absorption tower 1 is not provided with a secondary condensed water inlet. The gas-liquid separator 9 is provided with an inlet, a gas outlet and a condensed water outlet; the regeneration gas outlet of the regeneration tower 2 is connected to the inlet of the gas-liquid separator 9 through the condenser 8, the condensed water outlet of the gas-liquid separator 9 is connected to the condensed water inlet of the regeneration tower 2, and the gas outlet of the gas-liquid separator 9 is a CO2 gas outlet.

[0172] This embodiment also provides a method for removing carbon dioxide by amine method to control the escape of organic amines, which is carried out using the above-mentioned system for removing carbon dioxide by amine method to control the escape of organic amines. The flue gas to be treated is coal-fired flue gas, and the condensation nucleus content in the flue gas is measured to be greater than 10 6 cm -3 , CO2 content is 12 vol.%. The fresh organic amine absorbent used is 30 wt.% MEA aqueous solution.

[0173] The specific steps of this method are basically the same as those of Example 5, except that: in step (3), the regenerated gas enters the condenser 8, is cooled to 40°C, and then is separated in the gas-liquid separation tank 9 to obtain CO2 gas and condensed water, and the condensed water is refluxed to the regeneration tower 2.

[0174] After the above system and method were used to operate continuously for 24 hours, the CO2 capture rate was tested to be 90%, and the MEA emission in the treated flue gas discharged through the flue gas outlet was tested to be 4.0-7.8 mg / Nm 3 , with an average emission of 6.3 mg / Nm 3 The MEA concentration in the washing circulating water of the washing section 103 was tested to be 0.31 wt.%, and the MEA concentration in the regeneration gas condensate was tested to be 0.46 wt.%. The amine content of the regeneration gas condensate was high and was not suitable for replenishing the washing section 103.

[0175] Example 8

[0176] This embodiment provides an absorption tower and system for removing carbon dioxide by an amine method and controlling the escape of organic amines. The structure is basically the same as that of Example 4, except that: Figure 7 As shown, the primary condenser 4, the first gas-liquid separator 5, the secondary condenser 6 and the second gas-liquid separator 7 are not provided. Instead, the condenser 8 and the gas-liquid separator 9 identical to those in Comparative Example 1 are provided, and the absorption tower 1 is not provided with a secondary condensed water inlet. The gas-liquid separator 9 is provided with an inlet, a gas outlet and a condensed water outlet; the regeneration gas outlet of the regeneration tower 2 is connected to the inlet of the gas-liquid separator 9 through the condenser 8, the condensed water outlet of the gas-liquid separator 9 is connected to the condensed water inlet of the regeneration tower 2, and the gas outlet of the gas-liquid separator 9 is a CO2 gas outlet.

[0177] This embodiment also provides a method for removing carbon dioxide by amine method to control the escape of organic amines, which is carried out using the above-mentioned system for removing carbon dioxide by amine method to control the escape of organic amines. The flue gas to be treated is coal-fired flue gas, and the condensation nucleus content in the flue gas is measured to be greater than 10 6 cm -3 , CO2 content is 12 vol.%. The fresh organic amine absorbent used is 30 wt.% MEA aqueous solution.

[0178] The specific steps of this method are basically the same as those of Example 4, except that: in step (3), the regenerated gas enters the condenser 8, is cooled to 40°C, and then is separated in the gas-liquid separation tank 9 to obtain CO2 gas and condensed water, and the condensed water is refluxed to the regeneration tower 2.

[0179] After the above system and method were used to operate continuously for 24 hours, the CO2 capture rate was tested to be 90%, and the MEA emission in the treated flue gas discharged through the flue gas outlet was tested to be 3.6-6.1 mg / Nm 3 , average emission 5.0mg / Nm 3 The MEA concentration in the washing circulating water of the washing section 103 was tested to be 0.28 wt.%, and the MEA concentration in the regeneration gas condensate was tested to be 0.49 wt.%. The amine content of the regeneration gas condensate was high and was not suitable for replenishing the washing section 103.

Claims

1. An absorption tower for removing carbon dioxide by an amine process and controlling the escape of organic amines, comprising, from bottom to top, at least: Absorption section, cooling condenser, water washing section and first multi-layer demister; The absorption tower is provided with a flue gas inlet and a rich liquid outlet below the absorption section, a lean liquid inlet is provided between the absorption section and the cooling condenser, and a flue gas outlet is provided above the first multi-layer demister; The cooling condenser includes a heat exchange unit and a gas-liquid mass transfer unit; the gas-liquid mass transfer unit is arranged below the heat exchange unit, or the heat exchange unit is interspersed inside the gas-liquid mass transfer unit.

2. The absorption tower for removing carbon dioxide by amine method and controlling the escape of organic amine according to claim 1, wherein: When the gas-liquid mass transfer unit is provided below the heat exchange unit of the cooling condenser, the heat exchange unit comprises a plate heat exchanger and / or a tube-fin heat exchanger, and the gas-liquid mass transfer unit comprises a packing and / or a tower plate; When the heat exchange unit is interspersed inside the gas-liquid mass transfer unit of the cooling condenser, the cooling condenser is a packed heat exchanger.

3. The absorption tower for removing carbon dioxide by amine method and controlling the escape of organic amine according to claim 2, wherein: The plate heat exchanger comprises at least a plurality of plates, a flue gas channel and a cooling water channel; one end of the flue gas channel is a flue gas inlet and the other end is a flue gas outlet; one end of the cooling water channel is a cooling water inlet and the other end is a cooling water outlet; the cooling water channel and the flue gas channel are respectively arranged on both sides of the plurality of plates, and the cooling water channel is arranged in countercurrent with the flue gas channel from top to bottom; Preferably, the tube-fin heat exchanger includes at least a cooling water pipeline and a plurality of fins arranged on the outer wall of the cooling water pipeline; one end of the cooling water pipeline is a cooling water inlet and the other end is a cooling water outlet, the channel between the plurality of fins serves as a flue gas channel, one end of the flue gas channel is a flue gas inlet and the other end is a flue gas outlet, the cooling water pipeline is arranged countercurrently with the flue gas channel from top to bottom, and the plurality of fins in the same vertical direction are interconnected to form a plurality of vertically distributed falling film plates.

4. The absorption tower for removing carbon dioxide by amine method and controlling the escape of organic amine according to claim 2, wherein: When the gas-liquid mass transfer unit is provided below the heat exchange unit of the cooling condenser and the gas-liquid mass transfer unit includes a filler, the specific surface area of ​​the filler is 200m 2 / m 3 The area of ​​the gas-liquid mass transfer unit arranged per unit cross-sectional area of ​​the absorption tower is 300m 2 / m 2 above; When the gas-liquid mass transfer unit is provided below the heat exchange unit of the cooling condenser and the gas-liquid mass transfer unit includes a tower plate, the tower plate includes an overflow tower plate, the leakage rate of the tower plate is less than 20 mm / h, and the number of the tower plates is 3-9.

5. The absorption tower for removing carbon dioxide by amine method and controlling the escape of organic amine according to claim 3, wherein: When the gas-liquid mass transfer unit is provided below the heat exchange unit of the cooling condenser and the gas-liquid mass transfer unit includes filler, the plate heat exchanger and / or the tube-fin heat exchanger is provided with a flue gas condensate water diversion structure; Preferably, the flue gas condensate water diversion structure includes a serrated and / or wavy structure formed by a combination of the lower edges of several plates of the plate heat exchanger and / or a combination of the lower edges of several fins of the tube-fin heat exchanger, or the flue gas condensate water diversion structure includes a flue gas condensate water diversion plate arranged under several plates of the plate heat exchanger and / or under several fins of the tube-fin heat exchanger.

6. The absorption tower for removing carbon dioxide by amine method and controlling the escape of organic amine according to claim 2, wherein: The packed heat exchanger comprises at least a plurality of packing plates and a cooling water pipe inserted and arranged inside the packing plates; one end of the cooling water pipe is a cooling water inlet and the other end is a cooling water outlet. The cooling water pipe is inserted through the packing plates and is in direct contact with the packing plates. The gaps between the packing plates serve as flue gas passages, and the cooling water pipe is arranged in countercurrent with the flue gas passage from top to bottom. Preferably, the specific surface area of ​​the several filler plates of the packed heat exchanger is 200m 2 / m 3 The area of ​​the several filler plates arranged per unit cross-sectional area of ​​the absorption tower is 300m 2 / m 2 above.

7. The absorption tower for removing carbon dioxide by amine method and controlling organic amine escape according to claim 1, wherein: The first multi-layer demister includes a wire mesh layer, and the wire mesh layer includes two layers of wire mesh or three layers of wire mesh; when it includes two layers of wire mesh, the specific surface area of ​​the lower layer of wire mesh is 250-650m 2 / m 3 , the specific surface area of ​​the upper screen is 500m 2 / m 3 When it includes 3 layers of wire mesh, the specific surface area of ​​the lower wire mesh is 250-650m 2 / m 3 , the specific surface area of ​​the middle wire mesh is 500m 2 / m 3 Above, the specific surface area of ​​the upper screen is 800m 2 / m 3 above; Preferably, the operating air velocity of the first multi-layer demister is 1-3 m / s.

8. The absorption tower for removing carbon dioxide by amine method and controlling organic amine escape according to claim 1, wherein: The absorption tower further comprises: a second multi-layer demister, which is arranged between the cooling condenser and the water washing section; Preferably, the second multi-layer demister includes a wire mesh layer, and the wire mesh layer includes two layers of wire mesh or three layers of wire mesh; when it includes two layers of wire mesh, the specific surface area of ​​the lower layer of wire mesh is 250-650m 2 / m 3 , the specific surface area of ​​the upper screen is 500m 2 / m 3 When it includes 3 layers of wire mesh, the specific surface area of ​​the lower wire mesh is 250-650m 2 / m 3 , the specific surface area of ​​the middle wire mesh is 500m 2 / m 3 Above, the specific surface area of ​​the upper screen is 800m 2 / m 3 above; Preferably, the operating air velocity of the second multi-layer demister is 1-3 m / s.

9. The absorption tower for removing carbon dioxide by amine method and controlling organic amine escape according to claim 1, wherein: The absorption tower is further provided with a washing water outlet below the washing section, and is further provided with a washing circulating water inlet above the washing section, and the washing water outlet is connected to the washing circulating water inlet through a washing water circulation pipeline; and the absorption tower is further provided with a washing reflux water nozzle above the cooling condenser, and the washing reflux water nozzle is connected to the washing water outlet through a washing reflux pipeline.

10. The absorption tower for removing carbon dioxide by amine method and controlling the escape of organic amines according to claim 9, wherein: The water washing section includes a primary water washing section and a secondary water washing section from bottom to top; the primary water washing section and the secondary water washing section are respectively provided with a water washing water outlet below, a water washing circulating water inlet above, and a water washing water circulation pipeline connecting the water washing water outlet and the water washing circulating water inlet of each section; and the primary water washing section and the secondary water washing section are respectively provided with a water washing return water nozzle below, and a water washing return pipeline connected to the water washing water outlet.

11. A system for removing carbon dioxide by an amine process and controlling the escape of organic amines, comprising: The absorption tower, regeneration tower, heat exchanger, regeneration gas condensation and gas-liquid separation device for removing carbon dioxide by the amine method and controlling the escape of organic amines according to any one of claims 1 to 10; The upper portion of the regeneration tower is provided with a rich liquid inlet, a condensed water inlet and a regeneration gas outlet, and the lower portion of the regeneration tower is provided with a lean liquid outlet; The rich liquid outlet of the absorption tower is connected to the rich liquid inlet of the regeneration tower through the heat exchanger, and the lean liquid inlet of the absorption tower is connected to the lean liquid outlet of the regeneration tower through the heat exchanger; The regenerated gas condensation and gas-liquid separation device comprises at least one condenser and at least one gas-liquid separation tank; the gas-liquid separation tank is provided with an inlet, a gas outlet and a condensed water outlet; The regeneration gas outlet of the regeneration tower is connected to the inlet of the gas-liquid separation tank through the condenser, and the condensed water outlet of the gas-liquid separation tank is connected to the condensed water inlet of the regeneration tower.

12. The system for removing carbon dioxide by amine method and controlling organic amine escape according to claim 11, wherein: The regenerated gas condensation and gas-liquid separation device includes a primary condenser, a first gas-liquid separation tank, a secondary condenser and a second gas-liquid separation tank; The absorption tower is provided with a secondary condensed water inlet between the water washing section and the first multi-layer demister; The condensed water inlet of the regeneration tower is a first-level condensed water inlet; The first gas-liquid separation tank is provided with an inlet, a gas outlet and a first-level condensed water outlet, and the second gas-liquid separation tank is provided with an inlet, a gas outlet and a second-level condensed water outlet; The regeneration gas outlet of the regeneration tower is connected to the inlet of the first gas-liquid separation tank through the first condenser, the gas outlet of the first gas-liquid separation tank is connected to the inlet of the second gas-liquid separation tank through the second condenser, the first condensed water outlet of the first gas-liquid separation tank is connected to the first condensed water inlet of the regeneration tower, and the second condensed water outlet of the second gas-liquid separation tank is connected to the second condensed water inlet of the absorption tower.

13. A method for removing carbon dioxide by an amine process and controlling the escape of an organic amine, the method being carried out using the system for removing carbon dioxide by an amine process and controlling the escape of an organic amine according to claim 11 or 12, the method comprising the following steps: (1) The flue gas enters the absorption tower, contacts with the organic amine absorbent in the absorption section in countercurrent flow, and absorbs CO2 in the flue gas to obtain a rich liquid. The flue gas is then cooled by a cooling condenser and then enters the water washing section for water washing. After passing through the first multi-layer demister, the treated flue gas is obtained and discharged through the flue gas outlet. (2) The rich liquid is heat-exchanged with the lean liquid in a heat exchanger and then enters a regeneration tower for regeneration and releases CO2 to obtain regenerated gas and lean liquid. The lean liquid is heat-exchanged with the rich liquid in a heat exchanger and then enters an absorption tower; (3) The regenerated gas enters the condenser for cooling and then is separated in the gas-liquid separation tank to obtain CO2 gas and condensed water, and the condensed water is refluxed to the regeneration tower.

14. The method for removing carbon dioxide by amine method and controlling the escape of organic amines according to claim 13, wherein: In step (1), the CO2 content in the flue gas is 3-20 vol.%; Preferably, in step (1), the temperature of the flue gas entering the absorption tower is 35-45°C, the temperature of the organic amine absorbent entering the absorption tower is 38-42°C, the temperature of the rich liquid flowing out of the absorption tower is 46-52°C, and the temperature of the treated flue gas flowing out of the absorption tower is 35-45°C; Preferably, in step (1), the residence time of the flue gas in the cooling condenser is more than 1.5 seconds; Preferably, in step (1), the temperature of the cooling water used in the cooling condenser is 25-35°C, and the temperature of the flue gas after passing through the cooling condenser is 44-50°C; Preferably, step (1) further comprises: cooling a portion of the washing water after washing in the washing section and re-entering the washing section as washing circulating water for circulation, and returning another portion of the washing water after washing in the washing section as washing reflux water to the absorption section and flushing the cooling condenser; wherein the temperature of the washing circulating water is 36-46°C; more preferably, the flow ratio of the washing circulating water to the washing reflux water is 50:1-1000:1; Preferably, in step (1), the process of washing in the washing section specifically includes: cooling a portion of the washing water after washing in the primary washing section and then re-entering the primary washing section as first washing circulating water for circulation, and allowing another portion of the washing water after washing in the primary washing section to flow back to the absorption section as first washing reflux water and flush the cooling condenser; cooling a portion of the washing water after washing in the secondary washing section and then re-entering the secondary washing section as second washing circulating water for circulation, and allowing another portion of the washing water after washing in the secondary washing section to flow back to the primary washing section as second washing reflux water; wherein the temperature of the first washing circulating water is 43-49°C, and the temperature of the second washing circulating water is 36-46°C; More preferably, the flow ratio of the first water washing circulating water to the first water washing return water in the primary water washing section is 50:1-1000:1; the flow ratio of the second water washing circulating water to the second water washing return water in the secondary water washing section is 100:1-2000:1; Preferably, in step (1), the liquid-gas mass ratio of the absorption section under stable operating conditions is 1-5; Preferably, in step (1), the liquid-to-gas mass ratio of the water washing section under stable operating conditions is 2-6.

15. The method for removing carbon dioxide by amine method and controlling the escape of organic amines according to claim 13, wherein: In step (2), the temperature of the rich liquid entering the regeneration tower is 92-110°C, the temperature of the lean liquid flowing out of the regeneration tower is 100-120°C, and the temperature of the regeneration gas flowing out of the regeneration tower is 90-106°C.

16. The method for removing carbon dioxide by amine method and controlling the escape of organic amines according to claim 13, wherein: Step (3) specifically includes: the regenerated gas enters the primary condenser for cooling and then passes through the first gas-liquid separation tank for separation to obtain gas components and primary condensed water; the primary condensed water is refluxed to the regeneration tower, the gas components enter the secondary condenser for cooling and then pass through the second gas-liquid separation tank for separation to obtain CO2 gas and secondary condensed water; the secondary condensed water is refluxed to the water washing section of the absorption tower.

17. The method for removing carbon dioxide by amine method and controlling the escape of organic amines according to claim 16, wherein: In step (3), the primary condenser cools the regenerated gas to 70-85°C; Preferably, in step (3), the organic amine concentration of the primary condensed water is 0.2-10 wt.%; Preferably, in step (3), the secondary condenser cools the gas component to 35-45°C; Preferably, in step (3), the organic amine concentration of the secondary condensed water is 0.001-0.8 wt.%; Preferably, in step (3), the flow ratio of the primary condensed water to the secondary condensed water is 3:7-7:

3.

18. The method for removing carbon dioxide by amine method and controlling the escape of organic amines according to claim 13, wherein: The concentration of organic amines in the treated flue gas discharged through the flue gas outlet is 0.1-8 mg / Nm 3 .

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