A compressed boiler flue gas dewatering drying system and process

Abstract

The present application belongs to the technical field of flue gas drying and purification, and particularly relates to a compressed boiler flue gas dehydration drying system and process. The compressed boiler flue gas dehydration drying system comprises an adsorption tower, a PSA carbon capture device and a buffer tank. The adsorption tower is provided with a compressed boiler flue gas inlet pipeline, a compressed boiler flue gas outlet pipeline, a purge gas inlet pipeline and a purge gas outlet pipeline. The compressed boiler flue gas outlet pipeline is connected with the PSA carbon capture device inlet pipeline. The purge gas inlet pipeline is connected with the PSA carbon capture device overhead vent gas outlet pipeline. The compressed boiler flue gas dehydration drying system can regenerate the drying agent in the adsorption tower without energy consumption.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of flue gas drying and purification, and particularly relates to a compressed flue gas dehydration and drying system and process. BACKGROUND

[0002] Power plants are major carbon emitters in China, and carbon dioxide recovery and utilization from the flue gas of power plant boilers is the trend of carbon peak and carbon neutrality.

[0003] Generally, after the flue gas is compressed, it is introduced into a carbon capture device for carbon dioxide capture. After the gas is compressed, the water content in the flue gas reaches saturation, and the reaction of nitrogen oxides, sulfides, carbon dioxide and water in the flue gas will generate acidic substances, which will corrode the pipelines and equipment. Therefore, it is necessary to dehydrate and dry the acidic flue gas to protect the pipelines and equipment and the carbon dioxide recovery device.

[0004] Chinese patent document CN2021225168098 proposes a device for drying and regenerating adsorbents in an adsorption tower using compressor waste heat. However, using compressor waste heat requires that the outlet temperature of the compressor be high enough to ensure that the outlet temperature can vaporize all the water in the adsorbent. However, in actual operation, the temperature of the flue gas compressor cannot reach the ideal temperature, and the drying agent is not fully regenerated. Although it is zero gas consumption, the flue gas drying effect is not ideal. In field use, ice water cooling or additional heat source must be used to ensure the flue gas drying effect, which increases energy consumption.

[0005] Therefore, it is necessary to provide an improved technical solution to overcome the above-mentioned deficiencies of the prior art. SUMMARY

[0006] The purpose of the present application is to provide a compressed flue gas dehydration and drying system and process to solve the problem of high energy consumption of compressed flue gas drying.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solution: a compressed flue gas dehydration and drying system, comprising an adsorption tower, a PSA carbon capture device and a buffer tank; the adsorption tower is provided with a compressed flue gas inlet pipeline, a compressed flue gas outlet pipeline, a purge gas inlet pipeline and a purge gas outlet pipeline; the compressed flue gas outlet pipeline is connected in communication with the PSA carbon capture device inlet pipeline; the purge gas inlet pipeline is connected in communication with the PSA carbon capture device overhead vent gas outlet pipeline.

[0008] Preferably, the compressed boiler flue gas dehydrating and drying system further comprises a buffer tank, the buffer tank is provided with a buffer tank gas inlet pipeline and a buffer tank gas outlet pipeline, the buffer tank gas inlet pipeline is in communication with the PSA carbon capture device overhead vent gas outlet pipeline, and the buffer tank gas outlet pipeline is in communication with the purge gas inlet pipeline.

[0009] Preferably, the compressed boiler flue gas inlet pipeline and / or the purge gas outlet pipeline are arranged at the bottom of the adsorption tower; the compressed boiler flue gas outlet pipeline and / or the purge gas inlet pipeline are arranged at the top of the adsorption tower; and the adsorption tower comprises a first adsorption tower and a second adsorption tower.

[0010] Preferably, the compressed boiler flue gas inlet pipeline is in communication with the first adsorption tower and the second adsorption tower respectively; the compressed boiler flue gas inlet pipeline is provided with a first valve and a second valve in series; and the compressed boiler flue gas inlet is arranged between the first valve and the second valve.

[0011] Preferably, the purge gas outlet pipeline is in communication with the first adsorption tower and the second adsorption tower respectively; the purge gas outlet pipeline is provided with a third valve and a fourth valve in series; the purge gas outlet is arranged between the third valve and the fourth valve; and the purge gas outlet is further provided with a silencer.

[0012] Preferably, the compressed boiler flue gas outlet pipeline is in communication with the first adsorption tower and the second adsorption tower respectively; the compressed boiler flue gas outlet pipeline is provided with a fifth valve and a sixth valve in series; and the compressed boiler flue gas outlet is arranged between the fifth valve and the sixth valve.

[0013] Preferably, the purge gas inlet pipeline is in communication with the first adsorption tower and the second adsorption tower respectively; the purge gas inlet pipeline is provided with a seventh valve and an eighth valve in series; and the purge gas inlet is arranged between the seventh valve and the eighth valve.

[0014] Preferably, the compressed boiler flue gas inlet pipeline and the purge gas outlet pipeline are arranged at the bottom of the adsorption tower, and the compressed boiler flue gas inlet pipeline and the purge gas outlet pipeline are arranged in parallel; and the compressed boiler flue gas outlet pipeline and the purge gas inlet pipeline are arranged at the top of the adsorption tower, and the compressed boiler flue gas outlet pipeline and the purge gas inlet pipeline are arranged in parallel.

[0015] Preferably, the compressed boiler flue gas dehydrating and drying system further comprises a PSA nitrogen purification system; the gas inlet of the PSA nitrogen purification system is in communication with the PSA carbon capture device overhead vent gas outlet pipeline; the tower bottom gas outlet pipeline of the PSA nitrogen purification system is in communication with the buffer tank gas inlet pipeline; and the PSA carbon capture device is provided with a plurality of.

[0016] Preferably, a vent valve is further arranged on the buffer tank outlet pipeline.

[0017] Preferably, at least one of the compressed boiler flue gas inlet pipeline, the compressed boiler flue gas outlet pipeline, the purge gas inlet pipeline, the purge gas outlet pipeline, the PSA carbon capture device inlet pipeline, the buffer tank outlet pipeline, the buffer tank inlet pipeline and the PSA carbon capture device overhead vent gas outlet pipeline is provided with a thermometer and / or a pressure gauge; the filler in the adsorption tower is at least one of alumina, zeolite molecular sieve and silica gel.

[0018] Preferably, a gas flow diffusion device is arranged at a position corresponding to the purge gas inlet and / or the purge gas outlet inside the adsorption tower; the gas flow diffusion device comprises a support plate and a sieve pipe; the support plate is convex and faces the inside of the adsorption tower; the sieve pipe is in the shape of a hollow column and comprises a plurality of ribs and fixing ribs; the plurality of ribs are arranged along the circumference of the sieve pipe, and the gaps between adjacent ribs form purge gas channels allowing the purge gas to pass through; the fixing ribs are arranged on the pipe wall of the sieve pipe and are used to connect the plurality of ribs.

[0019] Preferably, the gap between adjacent ribs is smaller than the gap between adjacent fixing ribs.

[0020] Preferably, the sieve pipe is arranged on the convex surface of the support plate; the support plate is provided with a through hole, one end of the sieve pipe is connected to the through hole, and the other end of the sieve pipe is provided with a sealing cover; the support plate is provided with a plurality of sieve pipes; the plurality of sieve pipes are uniformly dispersed on the surface of the support plate.

[0021] The present application also provides a compressed boiler flue gas dehydration drying process, which adopts the following technical scheme: a compressed boiler flue gas dehydration drying process comprises the following steps: the compressed boiler flue gas enters the adsorption tower through the compressed boiler flue gas inlet pipeline; the dried compressed boiler flue gas enters the PSA carbon capture device through the compressed boiler outlet pipeline and the PSA carbon capture device inlet pipeline; the overhead vent gas of the PSA carbon capture device enters the adsorption tower through the PSA carbon capture device overhead vent gas outlet pipeline and the purge gas inlet pipeline; and the desiccant in the adsorption tower is regenerated and discharged through the purge gas outlet pipeline.

[0022] And / or, the compressed boiler flue gas enters the adsorption tower through the compressed boiler flue gas inlet pipeline; the dried compressed boiler flue gas enters the PSA carbon capture device through the compressed boiler outlet pipeline and the PSA carbon capture device inlet pipeline; the overhead vent gas of the PSA carbon capture device enters the PSA nitrogen purification system; the bottom outlet gas of the PSA nitrogen purification system enters the adsorption tower through the purge gas inlet pipeline; and the desiccant in the adsorption tower is regenerated and discharged through the purge gas outlet pipeline.

[0023] Advantages:

[0024] The compressed boiler flue gas dewatering and drying system of the present application utilizes the waste gas vented from the top of the PSA carbon capture device to purge and regenerate the desiccant in the adsorption tower, so that the desiccant desorbs the absorbed water, effectively utilizes the flow of the waste gas, and is a zero-gas-consumption and zero-electricity-consumption device, which has remarkable energy-saving effect and can greatly reduce carbon emission. BRIEF DESCRIPTION OF DRAWINGS

[0025] The drawings accompanying the specification of this application form a part thereof, serve to further provide a further understanding of the application, and together with the description of the exemplary embodiments of the present application, serve to explain the present application, and do not constitute an improper limitation of the present application. Among them:

[0026] Figure 1 Structure schematic view of the compressed boiler flue gas dewatering and drying system of an embodiment of the present application;

[0027] Figure 2 Structure schematic view of the valve state when the first adsorption tower in the compressed boiler flue gas dewatering and drying system of an embodiment of the present application adsorbs the water in the compressed boiler flue gas and the second adsorption tower is regenerated;

[0028] Figure 3 Structure schematic view of the valve state when the first adsorption tower in the compressed boiler flue gas dewatering and drying system of an embodiment of the present application adsorbs the water in the compressed boiler flue gas and the second adsorption tower is standby;

[0029] Figure 4 Structure schematic view of the valve state when the first adsorption tower and the second adsorption tower in the compressed boiler flue gas dewatering and drying system of an embodiment of the present application are switched;

[0030] Figure 5 Structure schematic view of the valve state when the first adsorption tower in the compressed boiler flue gas dewatering and drying system of an embodiment of the present application is regenerated and the second adsorption tower adsorbs the water in the compressed boiler flue gas;

[0031] Figure 6 Structure schematic view of the valve state when the first adsorption tower in the compressed boiler flue gas dewatering and drying system of an embodiment of the present application is standby and the second adsorption tower adsorbs the water in the compressed boiler flue gas;

[0032] Figure 7 Partial sectional view (air flow diffusion device) of the compressed boiler flue gas dewatering and drying system of an embodiment of the present application;

[0033] Figure 8 Top view of the air flow diffusion device of the compressed boiler flue gas dewatering and drying system of an embodiment of the present application;

[0034] Figure 9 A front view of a gas flow diffusion device of a compressed boiler flue gas dehydration drying system according to an embodiment of the present application;

[0035] Figure 10 A front view of another gas flow diffusion device of a compressed boiler flue gas dehydration drying system according to an embodiment of the present application.

[0036] Figures 2-6 In the figure, the valve includes two forms of solid valve and hollow valve, the hollow valve represents that the valve is in an open state, and the solid valve represents that the valve is in a closed state.

[0037] Reference signs:

[0038] 1-adsorption tower; 2-buffer tank; 3-PSA carbon capture device; 4-PSA nitrogen purification system; 5-electric control box;

[0039] 10-gas flow diffusion device; 101-supporting plate; 102-sieve pipe;

[0040] 102A-rib; 102B-fixing rib; 102C-purge gas passage; 102D-sealing cover;

[0041] 11-first valve; 12-second valve; 13-third valve; 14-fourth valve; 15-fifth valve; 16-sixth valve; 17-seventh valve; 18-eighth valve; 19-silencer;

[0042] 1A-first adsorption tower; 1B-second adsorption tower;

[0043] 21-vent valve;

[0044] I-compressed boiler flue gas inlet pipeline; II-purge gas outlet pipeline; III-compressed boiler flue gas outlet pipeline; IV-purge gas inlet pipeline; V-buffer tank outlet pipeline; VI-buffer tank inlet pipeline; VII-PSA carbon capture device overhead vent gas outlet pipeline; VIII-PSA nitrogen purification system bottom gas outlet pipeline. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the present application belong to the scope of protection of the present application.

[0046] In the description of the present application, the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and are not required to be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. The terms "connected", "connected" used in the present application should be understood broadly, for example, it can be fixed connection, or detachable connection; it can be directly connected, or indirectly connected through intermediate components, and the specific meaning of the above terms can be understood by those skilled in the art according to the specific circumstances.

[0047] In the description of the present application, the meaning of several is one or more, the meaning of multiple is more than two, greater than, less than, more than, etc. are not included in the number, above, below, within, etc. are understood to include the number. If the first, second is described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the sequence of indicated technical features.

[0048] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include one or more features.

[0049] The present application will be described in detail below with reference to the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0050] In view of the problem that the energy consumption of the compressed boiler flue gas drying is large, the present application provides a compressed boiler flue gas dehydration drying system.

[0051] As shown in Figure 1 The compressed boiler flue gas dehydration drying system of the present application comprises: an adsorption tower 1, a PSA carbon capture device 3 and a buffer tank 2; the adsorption tower 1 is provided with a compressed boiler flue gas inlet pipeline I, a compressed boiler flue gas outlet pipeline III, a purge gas inlet pipeline IV and a purge gas outlet pipeline II; the compressed boiler flue gas outlet pipeline III is connected in communication with the PSA carbon capture device inlet pipeline; the purge gas inlet pipeline IV is connected in communication with the buffer tank outlet pipeline V, and the buffer tank inlet pipeline VI is connected in communication with the PSA carbon capture device overhead vent gas outlet pipeline VII.

[0052] The adsorption tower 1 is internally provided with an adsorbent for absorbing moisture in the compressed boiler flue gas (flue gas after desulfurization and denitrification) ; the "purge regeneration" means that the adsorbent after absorbing moisture can be kept dry again by purging, so that the adsorbent can be recycled, the treatment cost is reduced, and the generation of waste residue is reduced; the bottom product of the PSA carbon capture device 3 is carbon dioxide, and the overhead vent gas of the PSA carbon capture device 3 is waste gas containing a small amount of carbon dioxide; after the waste gas passes through the PSA carbon capture device 3, the moisture is further adsorbed, and the dew point of the waste gas is lower than that of the gas in the adsorption tower compressed boiler flue gas outlet pipeline III; and the overhead vent gas of the PSA carbon capture device 3 has a certain pressure, so it can be used to purge and regenerate the drying agent in the adsorption tower; using the overhead vent gas of the PSA carbon capture device 3 to purge the adsorbent in the adsorption tower not only enables the adsorbent to be more fully regenerated, but also saves raw material flue gas, and does not require additional energy consumption, thereby truly achieving the effect of energy saving and consumption reduction.

[0053] The PSA carbon capture device 3 is connected to the buffer tank through the PSA carbon capture device overhead vent gas outlet pipeline VII and the buffer tank gas inlet pipeline VI, and the buffer tank gas outlet pipeline V is connected to the purge gas inlet pipeline IV, so that the overhead vent gas of the PSA carbon capture device 3 is used as purge gas to purge the adsorbent in the adsorption tower, so that the adsorbent after absorbing moisture in the adsorption compressed boiler flue gas is kept dry again, thereby realizing the recycling of the adsorbent in the adsorption tower, reducing the treatment cost, and reducing the generation of waste residue; without consuming additional energy, the dehydration and drying of the compressed boiler flue gas and the drying and regeneration of the adsorbent in the adsorption tower are realized.

[0054] In the preferred embodiment of the present application, the compressed boiler flue gas inlet pipeline I and / or the purge gas outlet pipeline II are arranged at the bottom of the adsorption tower; the compressed boiler flue gas outlet pipeline III and / or the purge gas inlet pipeline IV are arranged at the top of the adsorption tower; and the adsorption tower 1 comprises a first adsorption tower 1A and a second adsorption tower 1B. Arranging the compressed boiler flue gas inlet pipeline I at the bottom of the adsorption tower and the compressed boiler flue gas outlet pipeline III at the top of the adsorption tower helps to ensure that the compressed boiler flue gas is in full contact with the adsorbent in the adsorption tower, thereby ensuring the effect of drying the compressed boiler flue gas by using the adsorption tower; arranging the purge gas inlet pipeline IV at the top of the adsorption tower and the purge gas outlet pipeline II at the bottom of the adsorption tower helps to ensure that the purge gas is in full contact with the adsorbent after absorbing moisture, thereby ensuring the effect of drying the compressed boiler flue gas by using the adsorption tower; and arranging the first adsorption tower 1A and the second adsorption tower 1B helps to ensure that the two adsorption towers are alternately and cyclically used to dry the compressed boiler flue gas and regenerate the adsorbent, thereby ensuring the treatment efficiency of the compressed boiler flue gas dehydration and drying system of the present application.

[0055] In the preferred embodiment of the present application, the compressed boiler flue gas inlet pipeline I is connected to the first adsorption tower 1A and the second adsorption tower 1B respectively; the first valve 11 and the second valve 12 are arranged in series on the compressed boiler flue gas inlet pipeline I; and the compressed boiler flue gas inlet is arranged between the first valve 11 and the second valve 12. The above arrangement helps to supply the compressed boiler flue gas to the first adsorption tower 1A or the second adsorption tower 1B or both of the two adsorption towers as needed.

[0056] In the preferred embodiment of the present application, the purge gas outlet pipeline II is connected to the first adsorption tower 1A and the second adsorption tower 1B respectively; the third valve 13 and the fourth valve 14 are arranged in series on the purge gas outlet pipeline II; the purge gas outlet is arranged between the third valve 13 and the fourth valve 14; and the silencer 19 is further arranged at the purge gas outlet. The above arrangement helps to discharge the purge gas from the first adsorption tower 1A or the second adsorption tower 1B or both of the two adsorption towers as needed, and guarantees the regeneration effect of the purge gas on the adsorbent in the first adsorption tower 1A and / or the second adsorption tower 1B. The arrangement of the silencer 19 helps to reduce the working noise of the compressed boiler flue gas dehydration drying system of the present application.

[0057] In the preferred embodiment of the present application, the compressed boiler flue gas outlet pipeline III is connected to the first adsorption tower 1A and the second adsorption tower 1B respectively; the fifth valve 15 and the sixth valve 16 are arranged on the compressed boiler flue gas outlet pipeline III; and the compressed boiler flue gas outlet is arranged between the fifth valve 15 and the sixth valve 16. The above arrangement helps to guide the compressed boiler flue gas dried by the first adsorption tower 1A or the second adsorption tower 1B or the compressed boiler flue gas dried by both of the two adsorption towers out as needed, and into the subsequent processing procedure (the PSA carbon capture device 3, the PSA nitrogen gas purification system 4, etc.).

[0058] In the preferred embodiment of the present application, the purge gas inlet pipeline IV is connected to the first adsorption tower 1A and the second adsorption tower 1B respectively; the seventh valve 17 and the eighth valve 18 are arranged in series on the purge gas inlet pipeline IV; and the purge gas inlet is arranged between the seventh valve 17 and the eighth valve 18. The above arrangement helps to regenerate the drying agent in the first adsorption tower 1A or the second adsorption tower 1B or both of the first adsorption tower 1A and the second adsorption tower 1B as needed.

[0059] In the preferred embodiment of the present application, the compressed boiler flue gas inlet pipeline I and the purge gas outlet pipeline II are arranged at the bottom of the adsorption tower, and are arranged in parallel; and the compressed boiler flue gas outlet pipeline III and the purge gas inlet pipeline IV are arranged at the top of the adsorption tower, and are arranged in parallel.

[0060] In the preferred embodiment of the present application, the compressed boiler flue gas dewatering and drying system further comprises a PSA nitrogen purification system 4; the gas inlet of the PSA nitrogen purification system 4 is connected to the PSA carbon capture device overhead vent gas outlet pipeline VII; the PSA nitrogen purification system bottom gas outlet pipeline VIII is connected to the buffer tank gas inlet pipeline VI; and the PSA carbon capture device 3 is provided with multiple (two or more). By providing the PSA nitrogen purification system 4, the PSA carbon capture device 3 overhead vent gas can be introduced into the PSA nitrogen purification system 4 to obtain high-purity nitrogen. In addition, the PSA nitrogen purification system 4 bottom gas can also be used for the regeneration of the adsorbent in the adsorption tower. The PSA nitrogen purification system bottom gas outlet pipeline VIII is connected to the buffer tank gas inlet pipeline VI (since the buffer tank gas outlet pipeline V is connected to the purge gas inlet pipeline IV, the PSA nitrogen purification system bottom gas outlet pipeline VIII can be connected to the purge gas inlet pipeline IV, and the PSA nitrogen purification system 4 bottom gas can be used as a purge gas for the adsorbent in the adsorption tower to achieve the regeneration of the adsorbent in the adsorption tower). By providing multiple PSA carbon capture devices 3, the PSA carbon capture device 3 overhead vent gas can be selectively introduced into the PSA nitrogen purification system 4 according to actual needs, and used for making high-purity nitrogen or introduced into the buffer tank 2 for use as a purge gas for the adsorbent (in the case of meeting the needs of the PSA nitrogen purification system 4, the excess PSA carbon capture device 3 overhead vent gas is used as a purge gas).

[0061] In the preferred embodiment of the present application, the buffer tank gas outlet pipeline V is further provided with a vent valve 21. For example, after the adsorbent in the adsorption tower is regenerated by purging, the vent valve 21 can be opened to vent the waste gas.

[0062] In the preferred embodiment of the present application, at least one of the compressed boiler flue gas inlet pipeline I, the compressed boiler flue gas outlet pipeline III, the purge gas inlet pipeline IV, the purge gas outlet pipeline II, the PSA carbon capture device inlet pipeline, the buffer tank gas outlet pipeline V, the buffer tank gas inlet pipeline VI, and the PSA carbon capture device overhead vent gas outlet pipeline VII is provided with a thermometer and / or a pressure gauge; and the filler in the adsorption tower is at least one of alumina, zeolite molecular sieve, and silica gel (for example, the adsorbent can be a mixture of alumina and zeolite molecular sieve, a mixture of alumina and silica gel, a mixture of zeolite molecular sieve and silica gel, or a mixture of alumina, zeolite molecular sieve, and silica gel).

[0063] The temperature meter and the pressure gauge are signal-connected with the controller, and the detected parameters are uploaded to the controller, thereby playing the roles of measurement, adjustment, recording, alarm, storage and the like; the controller is an editable logic controller or a distributed control system. Preferably, the pressure gauge is correspondingly arranged at at least one of the first adsorption tower 1A, the second adsorption tower 1B, the inlet of the compressed boiler flue gas and the outlet of the compressed boiler flue gas; and the temperature meter is correspondingly arranged at at least one of the two ends of the first adsorption tower 1A, the two ends of the second adsorption tower 1B, the inlet of the compressed boiler flue gas and the outlet of the compressed boiler flue gas.

[0064] In the preferred embodiment of the present application, the valve can be a pneumatic valve, and is switched between the open and closed states through the control of a solenoid valve; the plurality of valves are correspondingly connected to the controller. The controller can control each valve, and automatically controls each valve through programming, so that the present application operates according to the above-mentioned working process, and has a high degree of automation and does not need manual intervention. The controller can be arranged in the electric control box 5.

[0065] After the compressed boiler flue gas is treated by the desiccant in the adsorption tower, the desiccant in the adsorption tower needs to be regenerated to continue to play a role in drying the compressed boiler flue gas. The regeneration of the desiccant can be divided into hot regeneration and cold regeneration. The hot regeneration is to heat the regeneration gas and then blow the desiccant, heat and vaporize the water in the micropores of the desiccant, and then blow with normal-temperature regeneration gas, so as to reduce the temperature of the adsorbent bed and put into the next drying process. This regeneration method seems to have high regeneration efficiency, but it still needs to be cooled after hot regeneration, which does not save time, and the energy consumption is high due to heating. The cold regeneration is to directly blow the adsorption desiccant with normal-temperature regeneration gas, and to directly blow out the water in the micropores of the desiccant through the gas flow. Due to the existence of liquid water, the blowing difficulty is large, and the blowing gas amount is more than that of the hot regeneration, generally 10-15% of the raw material gas.

[0066] The present application regenerates the desiccant in the adsorption tower by using the vent gas of the PSA carbon capture equipment or the bottom waste gas of the PSA nitrogen purification system, which takes advantage of the large gas amount. After the compressed boiler flue gas is recovered by the PSA carbon capture equipment and / or the PSA nitrogen purification system, the waste gas amount is about 60-80% of the gas source, which is much higher than 10-15%, and is sufficient for the regeneration of the desiccant. In addition to the gas amount of the blowing gas, the gas flow diffusion effect of the blowing gas in the adsorption tower also has an important influence on the regeneration effect of the blowing gas on the adsorbent. To ensure sufficient blowing of the blowing gas on the desiccant, the blowing gas cannot form a channeling or wall flow in the adsorption tower. The present application sets gas flow diffusion devices 10 at the inlet and outlet of the adsorption tower to ensure the blowing and regeneration effect of the blowing gas on the desiccant.

[0067] In the PSA carbon dioxide capture device and the PSA nitrogen purification system, the process is different, the exhaust emission time is also different, and the drying machine working regeneration time is also different. In the PSA carbon dioxide section, the exhaust is continuously discharged, and the purge time can be 3-10 min in the drying machine operation, which fully ensures the regeneration effect. In the PSA nitrogen purification section, the exhaust is intermittently discharged, and is basically discharged once every 1 min. In order to ensure the drying regeneration effect, the regeneration time is controlled to be 1-3 min.

[0068] As shown in Figures 7-8 In the preferred embodiment of the present application, the gas flow diffusion device 10 is arranged at the position corresponding to the purge gas inlet and / or the purge gas outlet inside the adsorption tower; the gas flow diffusion device 10 comprises a support plate 101 and a screen pipe 102 (the support plate 101 can be connected with the head of the adsorption tower and covers the entire purge gas inlet and / or outlet; the support plate 101 is provided with mounting holes at the positions corresponding to the screen pipe 102, so that the purge gas can only enter the inside of the screen pipe 102 through the mounting holes after passing through the purge gas inlet, and the gas flow diffusion is realized); the support plate 101 is convex and faces the inside of the adsorption tower; the screen pipe 102 is in the shape of a hollow column and comprises a plurality of ribs 102A and fixing ribs 102B; the plurality of ribs 102A are arranged along the circumference of the screen pipe 102, and the gaps between the adjacent ribs 102A form the purge gas channels 102C allowing the purge gas to pass through; and the fixing ribs 102B are arranged on the wall of the screen pipe 102 and are used for connecting the plurality of ribs 102A. The gas flow diffusion device 10 of the present application makes the purge gas quickly diffuse to each gas flow diffusion device 10 after passing through the purge gas inlet, the gas diffuses to the inside of the adsorption tower through the gas flow diffusion device 10, and the desiccant is purged; after the gas flow passes through the gas flow diffusion device 10, the gas flow diffusion area can be increased by more than ten times, the gas flow speed is effectively controlled, and the gas flow speed is controlled to be 0.1-0.5 m / s; when the purge gas is purged, both the purge speed and the strength of the desiccant are considered, the gas flow diffusion device 10 of the present application helps to avoid damaging the desiccant during the purging process, and ensures the use effect of the desiccant after regeneration.

[0069] Preferably, the gap between the adjacent ribs 102A is smaller than the particle size of the desiccant, so as to avoid the desiccant entering the inside of the gas flow diffusion device 10 during the use of the gas flow diffusion device 10, which adversely affects the diffusion effect of the purge gas.

[0070] In the preferred embodiment of the present application, the gap between the adjacent ribs 102A is smaller than the gap between the adjacent fixing ribs 102B. As shown in Figure 9 The fixing rib 102B is axially arranged in multiple pieces, the rib 102A is radially wound outside the fixing rib 102B, and the rib 102A is welded at the contact position with the fixing rib 102B to ensure that the position of the rib 102A does not move. Through the above arrangement, the purging effect of the purge gas on the desiccant is better (relative toFigure 10 The gap between the adjacent ribs 102A cannot be too large or too small, and the gap between the adjacent fixed ribs 102B must be large. If the gap between the fixed ribs 102B is too small, the gap for the gas outlet will be greatly reduced.

[0071] In the preferred embodiment of the present application, the screen pipe 102 is arranged on the convex surface of the support plate 101, the support plate 101 is provided with a through hole, one end of the screen pipe 102 is arranged at the through hole and communicates with the through hole in the axial direction of the screen pipe 102, and the other end of the screen pipe 102 away from the support plate 101 is provided with a sealing cover 102D (the screen pipe 102 has a cavity and is in the shape of a cylinder with both ends open in the axial direction). The support plate 101 is provided with a plurality of screen pipes 102, and the plurality of screen pipes 102 are uniformly dispersed on the surface of the support plate 101. The sealing cover 102D is arranged to make the purge gas flow only pass through the purge gas passage 102C between the adjacent ribs 102A to enter (or flow out of) the gas flow diffusion device 10 (when the purge gas enters the adsorption device), which helps to ensure a large gas flow diffusion area and ensure the effect of drying agent regeneration.

[0072] The present application also provides a compressed boiler flue gas dehydration drying process. The compressed boiler flue gas dehydration drying process includes the following steps: the compressed boiler flue gas enters the adsorption tower through the compressed boiler flue gas inlet pipeline, the dried compressed boiler flue gas enters the PSA carbon capture equipment through the compressed boiler outlet pipeline and the PSA carbon capture equipment inlet pipeline, the tower top vent gas of the PSA carbon capture equipment enters the adsorption tower through the PSA carbon capture equipment tower top vent gas outlet pipeline and the purge gas inlet pipeline ((and can first pass through the buffer tank inlet pipeline and the buffer tank outlet pipeline to enter the following purge gas inlet pipeline)), and the drying agent in the adsorption tower is regenerated and discharged through the purge gas outlet pipeline.

[0073] The compressed boiler flue gas enters the adsorption tower through the compressed boiler flue gas inlet pipeline, the dried compressed boiler flue gas enters the PSA carbon capture equipment through the compressed boiler outlet pipeline and the PSA carbon capture equipment inlet pipeline, and the tower top vent gas of the PSA carbon capture equipment enters the PSA nitrogen purification system. The tower bottom gas of the PSA nitrogen purification system enters the adsorption tower through the purge gas inlet pipeline ((and can first pass through the buffer tank inlet pipeline and the buffer tank outlet pipeline to enter the following purge gas inlet pipeline)), the drying agent in the adsorption tower is regenerated, and the regenerated drying agent is discharged through the purge gas outlet pipeline.

[0074] In a preferred embodiment of the compressed boiler flue gas dehydration and drying process of the present invention, the purge gas enters the adsorption tower through the purge gas inlet and the airflow diffusion device 10 to purge the desiccant that needs to be regenerated inside the adsorption tower. Then, after passing through the airflow diffusion device 10 at the purge gas outlet, it is discharged from the adsorption tower. In the above process, the purge gas can be maintained at a suitable gas flow rate, and the airflow diffusion area is large, avoiding damage to the desiccant.

[0075] In a preferred embodiment of the compressed boiler flue gas dehydration and drying process of the present invention, the adsorption tower includes a first adsorption tower and a second adsorption tower, so as to achieve alternating regeneration and normal operation (drying the compressed boiler flue gas) of the first adsorption tower or the second adsorption tower as needed, while maintaining the normal operation of the adsorption tower, thus avoiding the inability of subsequent processes to proceed normally due to the regeneration of the adsorption tower. In a preferred embodiment of the compressed boiler flue gas dehydration and drying process of the present invention, the compressed boiler flue gas dehydration and drying system of the present invention can operate according to the following workflow:

[0076] Step S1: The first adsorption tower 1A performs adsorption, and the second adsorption tower 1B performs purging and regeneration.

[0077] like Figure 2 As shown, the first valve 11, the fifth valve 15, the eighth valve 18, and the fourth valve 14 are open (the remaining valves are closed), and the vent valve 21 is closed. The compressed boiler flue gas is introduced into the first adsorption tower 1A through the first valve 11. The moisture in the flue gas is adsorbed by the adsorbent in the first adsorption tower 1A. The dried flue gas is discharged through the fifth valve 15 and enters the downstream PSA carbon capture device 3. The downstream exhaust gas (the vent gas at the top of the PSA carbon capture device 3 and / or the gas at the bottom of the PSA nitrogen purification system 4) enters the second adsorption tower 1B after passing through the buffer tank 2. The adsorbent in the second adsorption tower 1B is purged and regenerated. The purging gas enters the silencer 19 through the fourth valve 14 and is discharged after being treated by the silencer 19.

[0078] Step S2: The first adsorption tower 1A performs adsorption, while the second adsorption tower 1B is in standby mode.

[0079] like Figure 3 As shown, the first valve 11 and the fifth valve 15 are open (the remaining valves are closed); after the second adsorption tower 1B is purged and regenerated, the vent valve 21 is opened to release the waste gas, and the seventh valve 17 and the eighth valve 18 are closed at the same time, and the second adsorption tower 1B is put into standby mode; the compressed boiler flue gas is introduced into the first adsorption tower 1A through the first valve 11, and the moisture in the flue gas is adsorbed by the adsorbent in the first adsorption tower 1A. The dried flue gas is discharged through the fifth valve 15 and enters the downstream PSA carbon capture equipment 3 and the PSA nitrogen purification system 4.

[0080] Step S3: Switching between the first adsorption tower 1A1 and the second adsorption tower 1B:

[0081] like Figure 4 As shown, valves 11, 12, 15, and 16 are open (the remaining valves are closed). After a period of adsorption, the first adsorption tower 1A is about to reach saturation and requires regeneration of the adsorbent. At this time, the second adsorption tower 1B is about to start operating. Air is simultaneously introduced into both the first and second adsorption towers 1A, drying and dehydrating the compressed boiler flue gas. This process lasts approximately 3 minutes for transition. After a period of time, the flue gas flow to the first adsorption tower 1A is stopped (valve 11 is closed), putting the first adsorption tower 1A into standby mode, while the second adsorption tower 1B begins adsorption, thus switching between the first and second adsorption towers 1A.

[0082] Step S4: The second adsorption tower 1B performs adsorption, while the first adsorption tower 1A undergoes purging and regeneration.

[0083] like Figure 5 As shown, when the second valve 12, the third valve 13, the sixth valve 16, and the seventh valve 17 are open, and the first valve 11, the fourth valve 14, the fifth valve 15, and the eighth valve 18 are closed, and the vent valve 21 is closed, the compressed boiler flue gas enters the second adsorption tower 1B, is dried by the adsorbent in the second adsorption tower 1B, and is then discharged into the subsequent PSA carbon capture device 3 and PSA nitrogen purification system 4; the subsequent exhaust gas (the vent gas at the top of the PSA carbon capture device 3 and / or the gas at the bottom of the PSA nitrogen purification system 4) enters the first adsorption tower 1A after passing through the buffer tank 2, where the adsorbent in the first adsorption tower 1A is purged and regenerated, and the purging gas enters the silencer 19 after passing through the third valve 13, and is discharged after being treated by the silencer 19.

[0084] Step S5: The second adsorption tower 1B begins adsorption, while the first adsorption tower 1A remains in standby mode.

[0085] like Figure 6 As shown, the second valve 12 and the sixth valve 16 are open (the remaining valves are closed), and the vent valve 21 is open; the compressed boiler flue gas enters the second adsorption tower 1B through the second valve 12, and the dried flue gas after being treated by the desiccant in the second adsorption tower 1B is discharged through the sixth valve 16 and enters the downstream PSA carbon capture device 3 (after being treated by the PSA carbon capture device 3, the vent air at the top of the PSA carbon capture device 3 can be re-entered into the PSA nitrogen purification system 4).

[0086] Step S6: Switch between the first adsorption tower 1A and the second adsorption tower 1B;

[0087] like Figure 4As shown, the second adsorption tower 1B has been adsorbing for a period of time, i.e. will reach a saturated state, and needs to be regenerated, at which time the first adsorption tower 1A will start to work; the first adsorption tower 1A and the second adsorption tower 1B are simultaneously fed with the compressed boiler flue gas, and the compressed boiler flue gas is simultaneously dried and dehydrated in the first adsorption tower 1A and the second adsorption tower 1B, and this process lasts for about 3 min to make a transition; after a period of time, the compressed boiler flue gas is stopped from being guided to the second adsorption tower 1B (the second valve 12 is closed), so that the second adsorption tower 1B is on standby, and the first adsorption tower 1A performs the adsorption work, and the switching of the first adsorption tower 1A and the second adsorption tower 1B is performed.

[0088] Step S7: the above steps (S1-S6) are cycled to circulate the adsorbent in the first adsorption tower 1A and the second adsorption tower 1B to perform regeneration, so that zero consumption is achieved, and the adsorbent does not need to be replaced.

[0089] The above only describes the preferred embodiments of the present application and is not used to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A compressed boiler flue gas dewatering drying system characterized by, The adsorption tower, the PSA carbon capture device and the buffer tank are included. The adsorption tower is provided with a compressed boiler flue gas inlet pipeline, a compressed boiler flue gas outlet pipeline, a purge gas inlet pipeline and a purge gas outlet pipeline. The compressed boiler flue gas outlet pipeline is in communication with the PSA carbon capture device inlet pipeline. The purge gas inlet pipeline is in communication with the PSA carbon capture device overhead vent gas outlet pipeline. The buffer tank is provided with a buffer tank inlet pipeline and a buffer tank outlet pipeline, the buffer tank inlet pipeline is in communication with the PSA carbon capture device overhead vent gas outlet pipeline, and the buffer tank outlet pipeline is in communication with the purge gas inlet pipeline. The compressed boiler flue gas inlet pipeline and / or the purge gas outlet pipeline are arranged at the bottom of the adsorption tower, and the compressed boiler flue gas outlet pipeline and / or the purge gas inlet pipeline are arranged at the top of the adsorption tower. The adsorption tower is provided with a gas flow diffusion device at the position corresponding to the purge gas inlet and the purge gas outlet inside the adsorption tower.

2. The compressed boiler flue gas dewatering drying system of claim 1, wherein, The gas flow diffusion device includes a support plate and a screen pipe.

3. The compressed boiler flue gas dewatering drying system of claim 2, wherein, The support plate is convex to the inside of the adsorption tower. The screen pipe is in the shape of a hollow column and includes a plurality of ribs and fixing ribs.

4. The compressed boiler flue gas dewatering drying system of claim 2, wherein, The ribs are arranged along the circumference of the screen pipe. The gaps between adjacent ribs form purge gas channels. The gaps between adjacent ribs are smaller than the gaps between adjacent fixing ribs.

5. The compressed boiler flue gas dewatering drying system of claim 2, wherein, The fixing ribs are arranged on the pipe wall of the screen pipe and are used to connect the ribs. The screen pipe is arranged on the convex surface of the support plate. The support plate is provided with a through hole. One end of the screen pipe is in communication with the through hole. The other end of the screen pipe is provided with a sealing cover. The support plate is provided with a plurality of screen pipes. The screen pipes are uniformly dispersed on the surface of the support plate. The adsorption tower includes a first adsorption tower and a second adsorption tower. The compressed boiler flue gas inlet pipeline is in communication with the first adsorption tower and the second adsorption tower. The compressed boiler flue gas inlet pipeline is provided with a first valve and a second valve in series. The compressed boiler flue gas inlet is arranged between the first valve and the second valve. The compressed boiler flue gas outlet pipeline is in communication with the first adsorption tower and the second adsorption tower. The compressed boiler flue gas outlet pipeline is provided with a fifth valve and a sixth valve in series. The compressed boiler flue gas outlet is arranged between the fifth valve and the sixth valve. The purge gas inlet pipeline is in communication with the first adsorption tower and the second adsorption tower. The purge gas inlet pipeline is provided with a seventh valve and an eighth valve in series. The purge gas inlet is arranged between the seventh valve and the eighth valve. The purge gas outlet pipeline is in communication with the first adsorption tower and the second adsorption tower. The purge gas outlet pipeline is provided with a third valve and a fourth valve in series. The purge gas outlet is arranged between the third valve and the fourth valve. The purge gas outlet is further provided with a silencer. The compressed boiler flue gas inlet pipeline and the purge gas outlet pipeline are arranged at the bottom of the adsorption tower. The compressed boiler flue gas inlet pipeline and the purge gas outlet pipeline are arranged in parallel. The compressed boiler flue gas outlet pipeline and the purge gas inlet pipeline are arranged at the top of the adsorption tower, and the compressed boiler flue gas outlet pipeline and the purge gas inlet pipeline are arranged in parallel.

6. The compressed boiler flue gas dewatering drying system of claim 2, wherein, The compressed boiler flue gas dewatering and drying system further comprises a PSA nitrogen purification system. The gas inlet of the PSA nitrogen purification system is connected with the tower top vent gas outlet pipeline of the PSA carbon capture device. The tower bottom gas outlet pipeline of the PSA nitrogen purification system is connected with the buffer tank gas inlet pipeline. The PSA carbon capture device is provided with a plurality of. The buffer tank gas outlet pipeline is further provided with a vent valve.

7. A compressed boiler flue gas de-watering drying process of the compressed boiler flue gas de-watering drying system as claimed in claim 6, wherein, The method comprises the following steps: compressed boiler flue gas enters the adsorption tower through the compressed boiler flue gas inlet pipeline, the dried compressed boiler flue gas enters the PSA carbon capture device through the compressed boiler outlet pipeline and the PSA carbon capture device gas inlet pipeline, the tower top vent gas of the PSA carbon capture device enters the adsorption tower through the PSA carbon capture device tower top vent gas outlet pipeline and the purge gas inlet pipeline, and the desiccant in the adsorption tower is regenerated and discharged through the purge gas outlet pipeline; And / or, the compressed boiler flue gas enters the adsorption tower through the compressed boiler flue gas inlet pipeline, the dried compressed boiler flue gas enters the PSA carbon capture device through the compressed boiler outlet pipeline and the PSA carbon capture device gas inlet pipeline, the tower top vent gas of the PSA carbon capture device enters the PSA nitrogen purification system, the tower bottom gas of the PSA nitrogen purification system enters the adsorption tower through the purge gas inlet pipeline, and the desiccant in the adsorption tower is regenerated and discharged through the purge gas outlet pipeline.

Images