Comprehensive reaction tower based on CO2 capture phase change absorbent

Abstract

The invention provides a comprehensive reaction tower based on a CO2 capture phase change absorbent. The comprehensive reaction tower comprises a washing section, a reaction section, an absorption section and a tail gas washing section which are arranged in sequence, the washing section comprises a washing section reaction tank, a flue gas inlet, a flue gas distributor and a washing section wire mesh demister; the reaction section comprises a self-circulation bubbling reaction tank, a micro-cyclone bubbler arranged in the self-circulation bubbling reaction tank, and a buffer separation cavity arranged below the self-circulation bubbling reaction tank; the absorption section comprises a filler, a barren liquor inlet and a liquid distributor. The comprehensive reaction tower integrates the functions of flue gas deep purification, phase change absorbent self-circulation reaction, tail gas amine escape control and the like, simplifies the technological process and a material flow channel, effectively optimizes the internal structure of the reaction tower, is more uniform in gas-liquid distribution of the system, and is beneficial to improving the reaction efficiency of the system. Meanwhile, the construction land of the trapping system can be greatly reduced, and the equipment investment is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of low-carbon emission reduction and specifically relates to a method based on CO 2 Integrated reaction tower for capturing phase change absorbent. Background Art

[0002] There is a large amount of low-pressure CO in the tail gas emitted by coal-fired power plants, cement kilns, steel mills, refineries and other enterprises. 2 , is the national CO 2 The key areas of emission reduction are CO 2 Considering factors such as capture cost and technology maturity, the current low partial pressure CO 2 The capture system mostly adopts chemical absorption method, using amine absorbent to capture CO in the absorption tower. 2 Previously, the raw gas needed to be washed in a water scrubber to control the temperature and solid particles, SO 2 、NO x At the same time, it is necessary to control the amine escape and water balance of the capture system. The entire absorption reaction system needs to be equipped with flue gas deep purification tower, absorption tower, washing tower and other links. The system process is long, occupies a large area, and has a high cost, which is not conducive to large-scale CO 2 Construction of capture system.

[0003] For large-scale low partial pressure CO 2 The design and manufacture of large reactors such as capture towers, water scrubbers and absorption towers is a difficult and challenging task. 2 In the case of capture engineering application, the reaction towers are designed and built separately, and the system is huge. There is no million-ton low-pressure CO 2 Application cases of capture engineering. Summary of the invention

[0004] In order to solve the above problems in the prior art, the present invention proposes a method based on CO 2 The comprehensive reaction tower for capturing phase-change absorbent integrates functions such as deep flue gas purification, self-circulating reaction of phase-change absorbent, and control of tail gas amine escape. It has built-in micro-cyclone bubblers, gas distributors, liquid distributors, amine escape high-efficiency wire mesh demisters, micro-cyclone separators and other components based on high mass transfer efficiency. Due to high absorption efficiency, small reactor volume, small footprint, low equipment investment, easy operation and maintenance, and significant social and economic benefits, it can greatly simplify the process flow, reduce the footprint, and reduce the project cost by more than 20%.

[0005] The present invention proposes a method based on CO 2 A comprehensive reaction tower for capturing phase-change absorbent, comprising a water washing section, a reaction section, an absorption section and a tail gas washing section arranged in sequence;

[0006] The water washing section includes a water washing section reaction tank, a flue gas inlet, a flue gas distributor, and a water washing section wire mesh demister;

[0007] The end of the smoke inlet is connected to the smoke distributor;

[0008] The water washing section wire mesh demister is arranged above the flue gas inlet;

[0009] The reaction section comprises a self-circulating bubbling reaction pool, a micro-cyclone bubbler arranged in the self-circulating bubbling reaction pool, and a buffer separation chamber arranged below the self-circulating bubbling reaction pool;

[0010] The micro-cyclone bubbler comprises a bubble cap, a bubble cap micro-pore, a disassembly flange, a support baffle, a gas inlet, a cyclone section, a cone section, and a liquid seal column which are arranged in sequence;

[0011] The absorption section includes a filler, a lean liquid inlet and a liquid distributor;

[0012] The lean liquid inlet and the liquid distributor are arranged above the packing;

[0013] The tail gas washing section includes a tail gas washing wire mesh demister, a micro-cyclone separator, and a flue gas outlet;

[0014] The micro-cyclone separator comprises a micro-cyclone separator inlet and a micro-cyclone separator body;

[0015] The micro-cyclone separator is arranged above the tail gas washing wire mesh demister.

[0016] According to one embodiment of the present application, the shell type of the comprehensive reaction tower is a round tower.

[0017] According to one embodiment of the present application, the water washing sections are arranged in multiple groups;

[0018] The water washing section also includes a water washing reaction tank overflow plate and a water washing reaction tank overflow port arranged at the upper part of the water washing reaction tank.

[0019] According to one embodiment of the present application, in the water washing section, a water washing reaction tank level gauge is provided on the inner wall of the water washing reaction tank.

[0020] According to an embodiment of the present application, in the water washing section, a water washing heat exchange coil is provided in the water washing reaction tank; a cooling water inlet and a cooling water outlet are provided at both ends of the water washing heat exchange coil.

[0021] According to one embodiment of the present application, in the water washing section, a water washing water inlet and a water washing water outlet are provided on the side wall of the water washing reaction tank.

[0022] According to one embodiment of the present application, in the water washing reaction tank, the flue gas is fully contacted with the water washing water through the flue gas distributor to remove solid particles, SO 2 、NO x At the same time, the water-washing heat exchange coils installed in the water-washing reaction tank can effectively control the flue gas temperature, which is conducive to controlling the subsequent absorption reaction temperature field. The flue gas after water washing passes upward through the water-washing section wire mesh demister to further control the free water carried in the flue gas. The overflow port of the water-washing reaction tank set at the top of the water-washing reaction tank is used to control the liquid level of the water-washing reaction tank. Too high a liquid level will affect the gas-liquid mass transfer efficiency.

[0023] According to one embodiment of the present application, in the reaction section, a bubbling reaction tank overflow trough and a bubbling reaction tank overflow plate are provided on the upper portion of the self-circulating bubbling reaction tank.

[0024] According to one embodiment of the present application, in the reaction section, the self-circulating bubbling reaction tank is provided with a buffer separation chamber built-in liquid level gauge.

[0025] According to one embodiment of the present application, in the reaction section, a rich liquid outlet is provided at the lower end of the buffer separation chamber.

[0026] According to one embodiment of the present application, the flue gas passes through a water washing reaction tank to remove solid particles, SO 2 、NO x After the harmful components, they enter the micro-cyclone bubbler set in the self-circulating bubbling reaction pool. After gas-liquid separation, most of the washing water carried is separated out. The flue gas reacts with the absorption liquid in the self-circulating bubbling reaction pool in the form of bubbles from the top of the micro-cyclone bubbler, which increases the gas-liquid contact area and greatly improves the gas-liquid reaction rate and absorption efficiency of the system. The overflow tank of the bubbling reaction pool set on the top of the self-circulating bubbling reaction pool is used to control the liquid level of the self-circulating bubbling reaction pool. Too high a liquid level will affect the gas-liquid mass transfer efficiency.

[0027] According to one embodiment of the present application, in the lower buffer separation chamber of the self-circulating bubbling reaction tank, the phase change absorbent and CO 2 The products generated by the reaction will be enriched to form a rich phase, which will settle to the bottom of the buffer separation chamber because of its higher density than the lean liquid. The unreacted or incompletely reacted phase change absorbent lean liquid will continuously flow from the bottom of the buffer separation chamber into the self-circulating bubbling reaction tank because of its lower density than the rich phase, thus achieving the phase change absorbent and CO 2 Compared with the traditional phase change absorption process, it can realize the self-circulation reaction of phase change absorbent and CO 2 Automatic enrichment of the rich phase reduces the number of decantation units used to separate the rich and lean liquids, requiring little modification of the device and reducing equipment investment.

[0028] According to one embodiment of the present application, a micro-cyclone separator is arranged on the upper part of the absorption section to facilitate the control of the free amine liquid carried in the raw gas, thereby effectively avoiding the problem of liquid carried by the raw gas and reducing the cost of the absorption liquid.

[0029] The above raw materials in the present invention can be prepared in-house or commercially available, and the present invention is not particularly limited thereto.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The present invention is based on CO 2 The comprehensive reaction tower for capturing phase change absorbent integrates the functions of deep flue gas purification, self-circulating reaction of phase change absorbent, and control of tail gas amine escape, simplifies the process flow and logistics channels, effectively optimizes the internal structure of the reaction tower, and makes the gas-liquid distribution of the system more uniform, which is conducive to improving the reaction efficiency of the system.

[0032] 2. The present invention is based on CO 2 The comprehensive reaction tower for capturing phase change absorbent can significantly reduce the construction land of the capture system and reduce equipment investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural diagram of the comprehensive reaction tower disclosed in this application;

[0034] Figure 2a This is a structural diagram of the micro-cyclone bubbler disclosed in this application;

[0035] Figure 2b It is a cross-sectional view of the micro-cyclone bubbler disclosed in this application.

[0036] Among them, 1. Flue gas inlet; 2. Flue gas distributor; 3. Water washing section wire mesh demister; 4. Gas inlet; 5. Micro-cyclone bubbler; 6. Filler; 7. Lean liquid inlet; 8. Liquid distributor; 9. Tail gas washing wire mesh demister; 10. Micro-cyclone separator inlet; 11. Micro-cyclone separator body; 12. Flue gas outlet; 13. Cooling water inlet; 14. Cooling water outlet; 15. Bubble reaction tank overflow tank; 16. Rich liquid outlet; 17. Water washing reaction tank level gauge; 18. Built-in level gauge for buffer separation chamber; 19. Water washing heat exchange coil; 20. Water washing water inlet; 21. Water washing water outlet; 22. Bubble reaction tank overflow plate; 23. Water washing reaction tank overflow plate; 24. Water washing reaction tank overflow port; 25-gas inlet, 26-support baffle, 27-disassembly flange, 28-bubble cap micropore, 29-bubble cap, 30-swirl section, 31-vertebral section, 32-liquid seal section. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with specific embodiments, but they do not constitute any limitation to the present invention.

[0038] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by terms such as “front”, “up”, “down”, “left”, “right”, “vertical” and “horizontal” are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Example 1

[0041] This embodiment provides a comprehensive reaction tower, such as Figure 1 As shown, the specific structure is as follows:

[0042] From the lower end to the top of the tower body, it is divided into a water washing section, a reaction section, an absorption section and a tail gas washing section in sequence; the water washing section is provided with multiple groups and can be symmetrically arranged.

[0043] The water washing section includes a water washing section reaction tank, a flue gas inlet 1, a flue gas distributor 2, a water washing section wire mesh demister 3, a cooling water inlet 13, and a cooling water outlet 14; the end of the flue gas inlet 1 is connected to the flue gas distributor 2; the water washing section wire mesh demister 3 is arranged above the flue gas inlet 1; a water washing heat exchange coil 19 is arranged in the water washing section reaction tank; cooling water inlet 13 and cooling water outlet 14 are respectively arranged at both ends of the water washing heat exchange coil 19; a water washing reaction tank overflow plate 23 and a water washing reaction tank overflow port 24 are arranged at the upper end of the water washing section reaction tank; a water washing reaction tank liquid level gauge 17 is arranged on the inner wall of the water washing reaction tank; a water washing heat exchange coil 19 is arranged in the water washing reaction tank; a water washing water inlet 20 and a water washing water outlet 21 are arranged on the side wall of the water washing reaction tank.

[0044] The reaction section includes a self-circulating bubbling reaction pool, a micro-cyclone bubbler 5 arranged in the self-circulating bubbling reaction pool, and a buffer separation chamber arranged below the self-circulating bubbling reaction pool; the micro-cyclone bubbler 5 includes a bubble cap, bubble cap micro-pores, a disassembly flange, a support baffle, a gas inlet 4, a cyclone section, a cone section, and a liquid seal column arranged in sequence; the micro-cyclone bubbler 5 is fixed by a support baffle so that the upper part with the bubble cap and the bubble cap micro-pores is in the self-circulating bubbling reaction pool, and the lower part with the gas inlet, the cyclone section, the cone section and the liquid seal column is in the water washing section reaction pool; a bubbling reaction pool overflow groove 15 and a bubbling reaction pool overflow plate 22 are provided on the upper part of the self-circulating bubbling reaction pool; the self-circulating bubbling reaction pool is provided with a buffer separation chamber built-in liquid level gauge 18; and a rich liquid outlet 16 is provided at the lower end of the buffer separation chamber.

[0045] The absorption section includes a filler 6 , a lean liquid inlet 7 and a liquid distributor 8 ; the lean liquid inlet 7 and the liquid distributor 8 are arranged above the filler 7 .

[0046] The tail gas washing section includes a tail gas washing wire mesh demister 9, a micro-cyclone separator, and a flue gas outlet 12; the micro-cyclone separator includes a micro-cyclone separator inlet 10 and a micro-cyclone separator body 11; the micro-cyclone separator is arranged above the tail gas washing wire mesh demister 9.

[0047] Example 2

[0048] This embodiment provides a micro-cyclone bubbler in the comprehensive reaction tower of embodiment 1, combined with Figure 2a-2b , the details are as follows:

[0049] In the water washing reaction tank, the flue gas is fully contacted with the washing water through the flue gas distributor to remove solid particles, SO 2 、NO x And other harmful components, and a water washing heat exchange coil is set in the water washing reaction tank.

[0050] The raw gas from the water washing section enters the cyclone section 30 from the gas inlet 25 of the micro-cyclone bubbler, and the free washing water carried in the raw gas is removed by the micro-cyclone. Then the raw gas enters the bubble cap 29, and reacts with the absorption liquid by bubbling through the micropores 28 on the bubble cap, thereby increasing the gas-liquid contact area and improving the mass transfer rate. The separated free washing water enters the liquid seal column through the cone section 31 to form a liquid seal section 32 to prevent the raw gas from overflowing from the bottom of the micro-cyclone bubbler.

[0051] The cyclone section and the microbubble section in the microcyclone bubbler are connected via a disassembly flange 27, and a support baffle 26 is provided with the wall of the integrated reaction tower for support and isolation.

[0052] The raw gas coming out of the reaction section passes through the packing and the tail gas washing wire mesh demister in turn, and enters the micro-cyclone separator body from the micro-cyclone separator inlet to control the free amine liquid carried in the raw gas. Finally, the separated flue gas is discharged through the flue gas outlet.

[0053] Example 3

[0054] The comprehensive reaction tower provided in Implementation 1 is applied to a certain enterprise. The specific details are as follows:

[0055] The flue gas from the chimney of a power plant enters the tower from the flue gas inlet 1 in the middle of the water washing reaction tank of the comprehensive reaction tower, and reacts with the water washing liquid through the flue gas distributor 2 immersed in the water washing liquid to remove SO in the flue gas. 2 and some NO x At the same time, the temperature drops to 45°C, and then enters the micro-cyclone bubbler 5 through the water washing section wire mesh demister 3. After gas-liquid separation, the separated water washing liquid flows back to the water washing reaction tank. The flue gas passes through the top of the micro-cyclone bubbler in the form of bubbling and reacts with the absorption liquid in the self-circulating bubbling reaction tank to remove CO from the flue gas. 2 After that, the flue gas passes through the absorption section filler 6 and the lean liquid sprayed from the lean liquid inlet 7 and the absorption section liquid distributor 8 for mass and heat transfer, further removing CO from the flue gas. 2 Then, the tail gas passes through the tail gas washing wire mesh demister 9 and enters the micro-cyclone separator body 11 for gas-liquid separation, further removing the amine liquid carried in the flue gas. The separated tail gas returns to the chimney of the power plant through the flue gas outlet 12.

[0056] The washing water of the washing section is cooled to below 40°C and enters the washing reaction tank of the comprehensive reaction tower for circulation operation. In order to ensure the desulfurization effect, the washing water of the comprehensive reaction tower is alkaline, and a small amount of sodium hydroxide is added to the washing water pipeline.

[0057] After passing through the lean liquid inlet 7 and the liquid distributor 8, the lean liquid enters from the upper part of the absorption section of the comprehensive reaction tower to absorb the CO in the flue gas. 2 , the solution changes from lean solution to rich solution and enters the subsequent process through the rich solution outlet 16.

[0058] A water washing reaction tank overflow port 24 and a bubbling reaction tank overflow trough 15 are provided on the upper part of the water washing reaction tank and the self-circulating bubbling reaction tank to control the liquid level of the water washing reaction tank and the self-circulating bubbling reaction tank. Too high a liquid level will affect the gas-liquid mass transfer efficiency.

[0059] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A CO-based 2 A comprehensive reaction tower for capturing phase change absorbents, It is characterized in that It includes a water washing section, a reaction section, an absorption section and a tail gas washing section which are arranged in sequence; The water washing section includes a water washing section reaction tank, a flue gas inlet, a flue gas distributor, and a water washing section wire mesh demister; The end of the smoke inlet is connected to the smoke distributor; The water washing section wire mesh demister is arranged above the flue gas inlet; The reaction section comprises a self-circulating bubbling reaction pool, a micro-cyclone bubbler arranged in the self-circulating bubbling reaction pool, and a buffer separation chamber arranged below the self-circulating bubbling reaction pool; The micro-cyclone bubbler comprises a bubble cap, a bubble cap micro-pore, a disassembly flange, a support baffle, a gas inlet, a cyclone section, a cone section, and a liquid seal column which are arranged in sequence; The absorption section includes a filler, a lean liquid inlet and a liquid distributor; The lean liquid inlet and the liquid distributor are arranged above the packing; The tail gas washing section includes a tail gas washing wire mesh demister, a micro-cyclone separator, and a flue gas outlet; The micro-cyclone separator comprises a micro-cyclone separator inlet and a micro-cyclone separator body; The micro-cyclone separator is arranged above the tail gas washing wire mesh demister.

2. The comprehensive reaction tower according to claim 1, It is characterized in that The shell type of the comprehensive reaction tower is a round tower.

3. The comprehensive reaction tower according to claim 1, It is characterized in that The water washing sections are arranged in multiple groups; The water washing section also includes a water washing reaction tank overflow plate and a water washing reaction tank overflow port arranged at the upper part of the water washing reaction tank.

4. The comprehensive reaction tower according to claim 1, It is characterized in that In the water washing section, a water washing reaction tank level gauge is provided on the inner wall of the water washing reaction tank.

5. The comprehensive reaction tower according to claim 1, It is characterized in that In the water washing section, a water washing heat exchange coil is provided in the water washing reaction tank; The two ends of the water-wash heat exchange coil are respectively provided with a cooling water inlet and a cooling water outlet.

6. The comprehensive reaction tower according to claim 1, It is characterized in that In the water washing section, a water washing water inlet and a water washing water outlet are provided on the side wall of the water washing reaction tank.

7. The comprehensive reaction tower according to claim 1, It is characterized in that In the reaction section, a bubbling reaction pool overflow trough and a bubbling reaction pool overflow plate are provided on the upper part of the self-circulating bubbling reaction pool.

8. The comprehensive reaction tower according to claim 1, It is characterized in that In the reaction section, the self-circulating bubbling reaction tank is provided with a buffer separation chamber built-in liquid level gauge.

9. The comprehensive reaction tower according to claim 1, It is characterized in that In the reaction section, a rich liquid outlet is provided at the lower end of the buffer separation chamber.

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