Anti-freezing type ccus system for cold environment

Abstract

The application provides a freezing-proof CCUS system for a cold environment, and relates to the technical field of carbon dioxide capture, utilization and storage. The freezing-proof CCUS system for the cold environment comprises an absorption tower, a regeneration tower and a lean-liquid-rich-liquid heat exchanger; the absorption tower is provided with a smoke inlet channel, a rich-liquid outlet of the absorption tower is connected with the top of the regeneration tower through the lean-liquid-rich-liquid heat exchanger, and a high-temperature lean-liquid outlet of the regeneration tower is connected with a sprayer at the inner top of the absorption tower through the lean-liquid-rich-liquid heat exchanger; the inner wall of the absorption tower is provided with a freezing-proof flow guide, which is communicated with the high-temperature lean-liquid outlet of the regeneration tower and used for receiving the high-temperature lean liquid, heating a low-temperature area in the absorption tower and guiding the condensate in the absorption tower. The technical effect that the overall system is not prone to freezing is achieved.

Description

Technical Field

[0001] This invention relates to the field of carbon dioxide capture, utilization and storage technology, and more specifically, to an antifreeze CCUS system for use in cold environments. Background Technology

[0002] Carbon capture, utilization, and storage (CCUS) refers to the process of separating CO2 from industrial processes, energy use, or the atmosphere and utilizing it directly or injecting it into the ground to achieve permanent CO2 emission reduction. CCUS is one of the key technologies for achieving the "dual carbon" goal (carbon reduction, energy conservation, and environmental protection). In the capture stage, chemical absorption (such as using amine solutions) is currently the most mature and widely used CO2 capture technology in industry. Its core equipment consists of an absorption tower and a regeneration tower, and the process is mainly completed in the absorption tower (low-temperature operation) and the regeneration tower (high-temperature operation).

[0003] In cold regions (such as northern my country, Northern Europe, and Canada), ambient temperatures can drop to -20°C or even lower during autumn and winter. When moisture-rich flue gas enters the absorption tower, its moisture and absorbent vapors (such as MEA aqueous solution) condense and freeze on the low-temperature inner walls, trays, packing, demister, and other components. The accumulation of ice can clog the pores of the packing bed and cover the openings of the trays, leading to a sharp decrease in gas-liquid mass transfer efficiency, reduced effective contact area, lower CO2 absorption rate, narrower flow channels, increased system pressure drop, and increased fan energy consumption. In severe cases, it can cause equipment shutdown, and the expansion of ice can cause physical damage to internal tower components, posing a structural risk to the equipment.

[0004] The rich and lean solution pipelines connecting the absorption tower and regeneration tower, as well as the solvent supply pipelines, are highly susceptible to freezing in low-temperature environments, especially in sections with low flow rates or dead zones. Pipeline freezing can directly lead to system failure and poses a risk of pipeline rupture. Conventional insulation measures have limitations; traditional insulation can only slow down heat absorption and loss but cannot actively replenish heat. In sustained low-temperature environments, the internal temperature of the equipment will eventually drop below freezing. Simply relying on increasing the temperature of the flue gas entering the tower or adding steam tracing would result in enormous energy costs. Summary of the Invention

[0005] The purpose of this invention is to provide an antifreeze CCUS system for cold environments to alleviate the technical problem of easy freezing of absorption towers and their pipelines in the prior art.

[0006] In a first aspect, embodiments of the present invention provide an antifreeze CCUS system for cold environments, comprising an absorption tower, a regeneration tower, and a lean-rich liquid heat exchanger; The absorption tower is provided with a flue gas inlet channel. The rich liquid outlet of the absorption tower is connected to the top of the regeneration tower through the rich-lean liquid heat exchanger. The high-temperature lean liquid outlet of the regeneration tower is connected to the sprayer at the top of the absorption tower through the rich-lean liquid heat exchanger. The inner wall of the absorption tower is provided with an antifreeze guide, which is connected to the high-temperature lean liquid outlet of the regeneration tower. It is used to receive the high-temperature lean liquid, heat the low-temperature area in the absorption tower, and guide the condensate in the absorption tower.

[0007] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein the interior of the absorption tower is divided from top to bottom into a low-temperature flow guiding zone, an antifreeze buffer zone, and a main mass transfer zone; A gas-liquid contact element is provided in the main mass transfer zone, and the sprayer is located in the low-temperature flow guiding zone.

[0008] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein the main mass transfer zone is provided with an antifreeze guide at the gas-liquid contact member, and the antifreeze guide has multiple guide grooves.

[0009] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein the inner wall of the aforementioned low-temperature flow guiding zone and / or the antifreeze buffer zone is provided with the antifreeze flow guiding element.

[0010] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein the top of the absorption tower is provided with a purified flue gas outlet, and a demister is provided inside the absorption tower at the purified flue gas outlet.

[0011] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein the absorption tower is provided with an antifreeze flow guide hood, which is located below the demister.

[0012] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein the absorption tower is connected to both the regeneration tower and the lean-rich liquid heat exchanger via a rich liquid pipeline; The rich liquid pipeline is equipped with a first jacket, which is connected to the high-temperature lean liquid outlet of the regeneration tower.

[0013] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein the regeneration tower is connected to both the absorption tower and the lean-rich and rich-lean heat exchanger via a lean liquid pipeline; A second jacket is provided on the lean liquid pipeline, and the second jacket is connected to the high-temperature lean liquid outlet of the regeneration tower.

[0014] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein the above-mentioned antifreeze guide is connected to the high-temperature lean liquor outlet of the regeneration tower through an antifreeze pipeline; The antifreeze pipeline is equipped with a third jacket, which is connected to the high-temperature lean liquid outlet of the regeneration tower.

[0015] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein the above-mentioned antifreeze CCUS system for cold environments further includes a temperature sensor; The temperature sensor is installed in the absorption tower, the first jacket, the second jacket, and the third jacket.

[0016] Beneficial effects: This invention provides an antifreeze CCUS system for cold environments, comprising an absorption tower, a regeneration tower, and a lean-rich liquid heat exchanger. The absorption tower has a flue gas inlet channel. The rich liquid outlet of the absorption tower is connected to the top of the regeneration tower via the lean-rich liquid heat exchanger. The lean liquid outlet of the regeneration tower is connected to a sprayer at the top of the absorption tower via the lean-rich liquid heat exchanger. The inner wall of the absorption tower is equipped with an antifreeze flow guide, which communicates with the high-temperature lean liquid outlet of the regeneration tower. This flow guide is used to receive the high-temperature lean liquid, heat the low-temperature region within the absorption tower, and guide the condensate within the absorption tower.

[0017] Specifically, during operation, the high-temperature lean liquid discharged from the high-temperature lean liquid outlet of the regeneration tower is sprayed into the absorption tower through a sprayer at the top of the absorption tower. At the same time, the antifreeze guide can be connected to the high-temperature lean liquid outlet of the regeneration tower to discharge the high-temperature lean liquid into the absorption tower. Through the setting of the antifreeze guide, the condensate at the top of the absorption tower can be guided downward to collect. At the same time, the high-temperature lean liquid of the regeneration tower is used to preheat the inner wall of the absorption tower for active antifreeze. This not only achieves active antifreeze but also reduces energy consumption, saving energy and reducing emissions. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of one embodiment of the antifreeze CCUS system for cold environments provided in this invention.

[0020] icon: 100 - Absorption tower; 101 - Purified flue gas outlet; 102 - Flue gas inlet channel; 110 - Low temperature flow guide zone; 120 - Anti-freeze buffer zone; 130 - Main mass transfer zone; 140 - Gas-liquid contact component; 200 - Regeneration tower; 210 - High-temperature lean liquor outlet; 220 - Product gas outlet; 300-Elastic / Rich Liquid Heat Exchanger; 400 - Antifreeze deflector; 510 - Rich solution pipeline; 520 - Lean solution pipeline; 530 - Antifreeze pipeline. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0026] See Figure 1 As shown, this embodiment provides an antifreeze CCUS system for cold environments, including an absorption tower 100, a regeneration tower 200, and a lean-rich liquid heat exchanger 300. The absorption tower 100 is provided with a flue gas inlet channel 102. The rich liquid outlet of the absorption tower 100 is connected to the top of the regeneration tower 200 via the lean-rich liquid heat exchanger 300. The high-temperature lean liquid outlet 210 of the regeneration tower 200 is connected to a sprayer at the top of the absorption tower 100 via the lean-rich liquid heat exchanger 300. An antifreeze flow guide 400 is provided on the inner wall of the absorption tower 100, which communicates with the high-temperature lean liquid outlet 210 of the regeneration tower 200. This flow guide 400 is used to receive the high-temperature lean liquid, heat the low-temperature area within the absorption tower 100, and guide the condensate within the absorption tower 100.

[0027] Specifically, during use, the high-temperature lean liquid discharged from the high-temperature lean liquid outlet 210 of the regeneration tower 200 is sprayed into the absorption tower 100 through a sprayer at the top of the absorption tower 100. At the same time, the antifreeze guide 400 can be connected to the high-temperature lean liquid outlet 210 of the regeneration tower 200 to discharge the high-temperature lean liquid into the absorption tower 100. Through the setting of the antifreeze guide 400, the condensate at the top of the absorption tower 100 can be guided downward to collect. At the same time, the high-temperature lean liquid of the regeneration tower 200 is used to preheat the inner wall of the absorption tower 100 for active antifreeze. This not only achieves active antifreeze but also reduces energy consumption and saves energy and reduces emissions.

[0028] The absorption tower 100 is divided into a low-temperature flow guiding zone 110, an anti-freezing buffer zone 120 and a main mass transfer zone 130 from top to bottom. A gas-liquid contact element 140 is provided in the main mass transfer zone 130, and a sprayer is located in the low-temperature flow guiding zone 110.

[0029] The gas-liquid contact element 140 can be either packing material or a tray, which can be selected by those skilled in the art according to actual needs.

[0030] It should be noted that a flue gas inlet channel 102 is provided on the absorption tower 100. The flue gas inlet channel 102 can lead to the main mass transfer zone 130 or the antifreeze buffer zone 120. Those skilled in the art can set it according to actual needs.

[0031] The top of the regeneration tower 200 is provided with a product gas outlet 220.

[0032] It should also be noted that the antifreeze CCUS system for cold environments provided in this embodiment can make full use of the waste heat of the regeneration tower 200. Through the synergistic effect of structural design and energy management, it can effectively prevent freezing inside the tower and icing of connecting pipelines, improve system reliability, and facilitate technology promotion.

[0033] See Figure 1 As shown, in the optional scheme of this embodiment, the main mass transfer zone 130 is provided with an antifreeze guide 400 at the gas-liquid contact member 140, and the antifreeze guide 400 has multiple guide grooves.

[0034] Specifically, an antifreeze guide 400 is provided in the main mass transfer zone 130. The antifreeze guide 400 can heat the gas-liquid contact element 140 so that the temperature of the gas-liquid contact element 140 is above the freezing point, thus preventing the liquid from freezing and blocking the gas-liquid contact element 140.

[0035] Additionally, the antifreeze guide 400 used for the gas-liquid contact element 140 can be a guide plate. The guide plate has internal channels for the flow of high-temperature lean liquid, multiple guide grooves, and multiple through holes to ensure the flow of CO2 and its liquid. The antifreeze guide 400 can be directly installed at the bottom of the gas-liquid contact element 140 without affecting the CO2 absorption efficiency.

[0036] See Figure 1 As shown, in an optional embodiment, the inner wall of the low-temperature flow guiding zone 110 and / or the antifreeze buffer zone 120 is provided with an antifreeze flow guiding component 400.

[0037] Specifically, an antifreeze guide component 400 is installed on the inner wall of the low-temperature guide zone 110. The antifreeze guide component 400 is heated by the high-temperature lean liquid in the regeneration tower 200, so that the surface temperature of the antifreeze guide component 400 is above the freezing point, preventing the condensate from freezing on the inner wall of the absorption tower 100, so that the liquid can smoothly collect downwards.

[0038] In addition, an antifreeze guide 400 is provided on the inner wall of the antifreeze buffer zone 120. The antifreeze guide 400 is heated by the high temperature lean liquid of the regeneration tower 200, so that the surface temperature of the antifreeze guide 400 is above the freezing point, preventing the condensate from freezing on the inner wall of the absorption tower 100, so that the liquid can smoothly collect downwards.

[0039] Alternatively, antifreeze guide components 400 are provided on the inner walls of both the low-temperature guide zone 110 and the antifreeze buffer zone 120. The antifreeze guide components 400 are heated by the high-temperature lean liquid in the regeneration tower 200, so that the surface temperature of the antifreeze guide components 400 is above the freezing point, preventing the condensate from freezing on the inner wall of the absorption tower 100, and allowing the liquid to flow smoothly downwards.

[0040] Among them, the antifreeze guide component 400 can be a guide ring plate, with a flow channel for high-temperature lean liquid to flow inside the guide ring plate, and a guide groove for condensate to flow on the side wall of the guide ring plate.

[0041] It should be noted that the location of the antifreeze guide 400 can be arranged by those skilled in the art based on the actual location of the cold zone of the absorption tower 100.

[0042] See Figure 1 As shown, in an optional embodiment, the top of the absorption tower 100 is provided with a purified flue gas outlet 101, and a demister is provided inside the absorption tower 100 at the purified flue gas outlet 101.

[0043] The absorption tower 100 is equipped with an antifreeze flow guide shroud, which is located below the demister.

[0044] Specifically, an antifreeze guide hood is installed inside the absorption tower 100. The antifreeze guide hood is located below the demister. The antifreeze guide hood is used to guide the condensate to flow back down quickly and prevent the liquid from accumulating and freezing on the surface of the demister. At the same time, it blocks the low-temperature flue gas from directly impacting the top components of the tower, thus achieving antifreeze protection for the demister and the top area of ​​the tower.

[0045] See Figure 1 As shown, in the optional scheme of this embodiment, the absorption tower 100 is connected to both the regeneration tower 200 and the lean and rich liquid heat exchanger 300 through the rich liquid pipeline 510; the rich liquid pipeline 510 is provided with a first jacket, which is connected to the high temperature lean liquid outlet 210 of the regeneration tower 200.

[0046] Specifically, a first jacket is installed on the rich liquid pipeline 510, and the first jacket is connected to the high-temperature lean liquid outlet 210 of the regeneration tower 200. With this setting, the rich liquid pipeline 510 can be heated to prevent the inside of the rich liquid pipeline 510 from freezing.

[0047] See Figure 1 As shown, in the optional scheme of this embodiment, the regeneration tower 200 is connected to both the absorption tower 100 and the lean and rich liquid heat exchanger 300 through the lean liquid pipeline 520; a second jacket is provided on the lean liquid pipeline 520, and the second jacket is connected to the high temperature lean liquid outlet 210 of the regeneration tower 200.

[0048] Specifically, a second jacket is installed on the lean liquid pipeline 520, and the second jacket is connected to the high-temperature lean liquid outlet 210 of the regeneration tower 200. With this setting, the lean liquid pipeline 520 can be heated to prevent the inside of the lean liquid pipeline 520 from freezing.

[0049] See Figure 1 As shown, in the optional scheme of this embodiment, the antifreeze guide 400 is connected to the high-temperature lean liquid outlet 210 of the regeneration tower 200 through the antifreeze pipeline 530; a third jacket is provided on the antifreeze pipeline 530, and the third jacket is connected to the high-temperature lean liquid outlet 210 of the regeneration tower 200.

[0050] Specifically, a third jacket is installed on the antifreeze pipeline 530, which is connected to the high-temperature lean liquid outlet 210 of the regeneration tower 200. This design allows the antifreeze pipeline 530 to be heated, preventing the inside of the antifreeze pipeline 530 from freezing.

[0051] It should be noted that a diversion structure is set at the high-temperature lean liquid outlet 210 of the regeneration tower 200. The diversion structure allows a portion of the high-temperature lean liquid to enter the lean-rich liquid heat exchanger 300 for heat exchange and circulation, a portion to be supplied to the antifreeze guide 400 for heat preservation and heating of the absorption tower 100 and the regeneration tower 200, and a portion to be supplied to each pipeline jacket for heat preservation of each flow channel pipeline to prevent the flow channel pipeline from freezing.

[0052] See Figure 1 As shown, in the optional scheme of this embodiment, the antifreeze CCUS system for cold environments also includes a temperature sensor; temperature sensors are installed in the absorption tower 100, the first jacket, the second jacket and the third jacket.

[0053] Specifically, the temperature sensor can perform real-time temperature detection on key cold spots of the absorption tower 100, real-time temperature detection on the upstream and downstream of the gas-liquid contact component 140, and real-time temperature detection on the mechanical properties of the lean liquid pipeline 520, the rich liquid pipeline 510, and the antifreeze pipeline 530. When the monitored temperature approaches the set freezing threshold, the control system automatically heats the lean liquid in the regeneration tower 200 to prevent freezing. When the temperature is detected to be at a suitable temperature for non-freezing, the control system can automatically adjust the flow rate of the hot fluid to achieve precise heat replenishment and avoid overheating of the entire system.

[0054] It should be noted that the internal heating auxiliary in the regeneration tower 200 reduces the risk of freezing from the source. Moreover, by using the high-temperature lean liquid of the regeneration tower 200 as a heat source, there is no need to rely on high-energy-consuming external heating, thus realizing energy cascade utilization, reducing operating costs, and reducing energy consumption.

[0055] The high-temperature lean liquid inside the jacket can flow into the absorption tower 100 or the regeneration tower 200, which can be set by those skilled in the art according to actual needs.

[0056] In addition, inclined or rounded transition designs are adopted for structures such as the regeneration tower 200 and other delivery pipelines that are prone to dead angles, to reduce liquid stagnation.

[0057] It should be noted that the antifreeze CCUS system for cold environments provided in this embodiment is suitable for the continuous operation of CCUS devices in cold and extremely cold regions, significantly improving system reliability and having good engineering feasibility and industrial promotion value.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A freeze-resistant CCUS system for cold environments, characterized in that, include: Absorption tower (100), regeneration tower (200) and lean and rich liquid heat exchanger (300); The absorption tower (100) is provided with a flue gas inlet channel (102). The rich liquid outlet of the absorption tower (100) is connected to the top of the regeneration tower (200) through the lean-rich liquid heat exchanger (300). The high-temperature lean liquid outlet (210) of the regeneration tower (200) is connected to the sprayer at the top of the absorption tower (100) through the lean-rich liquid heat exchanger (300). The inner wall of the absorption tower (100) is provided with an antifreeze guide (400), which is connected to the high temperature lean liquid outlet (210) of the regeneration tower (200) for receiving high temperature lean liquid and heating the low temperature area in the absorption tower (100) and guiding the condensate in the absorption tower (100).

2. The antifreeze CCUS system for cold environments according to claim 1, characterized in that, The interior of the absorption tower (100) is divided into a low-temperature flow guiding zone (110), an anti-freezing buffer zone (120), and a main mass transfer zone (130) from top to bottom. A gas-liquid contact element (140) is provided in the main mass transfer zone (130), and the sprayer is located in the low-temperature flow guiding zone (110).

3. The antifreeze CCUS system for cold environments according to claim 2, characterized in that, The main mass transfer zone (130) is provided with an antifreeze guide (400) at the gas-liquid contact member (140), and the antifreeze guide (400) has multiple guide grooves.

4. The antifreeze CCUS system for cold environments according to claim 3, characterized in that, The inner walls of the low-temperature flow guiding zone (110) and / or the antifreeze buffer zone (120) are provided with the antifreeze flow guiding element (400).

5. The antifreeze CCUS system for cold environments according to claim 1, characterized in that, The top of the absorption tower (100) is provided with a purified flue gas outlet (101), and a demister is provided inside the absorption tower (100) at the purified flue gas outlet (101).

6. The antifreeze CCUS system for cold environments according to claim 5, characterized in that, The absorption tower (100) is equipped with an antifreeze flow guide hood inside, which is located below the demister.

7. The antifreeze CCUS system for cold environments according to claim 1, characterized in that, The absorption tower (100) is connected to both the regeneration tower (200) and the lean and rich liquid heat exchanger (300) via a rich liquid pipeline (510); The rich liquid pipeline (510) is provided with a first jacket, which is connected to the high temperature lean liquid outlet (210) of the regeneration tower (200).

8. The antifreeze CCUS system for cold environments according to claim 7, characterized in that, The regeneration tower (200) is connected to both the absorption tower (100) and the lean and rich liquid heat exchanger (300) via a lean liquid pipeline (520); A second jacket is provided on the lean liquid pipeline (520), and the second jacket is connected to the high-temperature lean liquid outlet (210) of the regeneration tower (200).

9. The antifreeze CCUS system for cold environments according to claim 8, characterized in that, The antifreeze guide (400) is connected to the high-temperature lean liquid outlet (210) of the regeneration tower (200) via an antifreeze pipeline (530); The antifreeze pipeline (530) is provided with a third jacket, which is connected to the high-temperature lean liquid outlet (210) of the regeneration tower (200).

10. The antifreeze CCUS system for cold environments according to claim 9, characterized in that, It also includes a temperature sensor; The temperature sensor is installed in the absorption tower (100), the first jacket, the second jacket and the third jacket.

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