Air trapping carbon dioxide adsorption device with adsorption tree structure

Abstract

The utility model discloses an air capture carbon dioxide adsorption device with an adsorption tree structure, the air capture carbon dioxide adsorption device comprises a plurality of adsorption modules which are arranged on a support column at intervals from top to bottom, each adsorption module comprises a fixed steel frame and adsorption fibers which are spread and fixed on the fixed steel frame, and the adsorption modules have a large contact area with air; a spraying unit for spraying liquid to each adsorption module is arranged above each adsorption module, a liquid backflow collecting tank is further arranged on the outer side of the side part of the supporting column, and the liquid backflow collecting tank is arranged below all the adsorption modules and is used for collecting and recycling liquid dripping from the adsorption modules. The adsorption device disclosed by the utility model is small in occupied area, can be flexibly arranged, is not influenced by temperature / humidity / dust in the environment and the like, integrates the adsorption device and the desorption device, not only can realize in-situ regeneration cycle adsorption, but also can realize systematic layout of dispersive trapping-centralized regeneration, and has a wide application prospect.

Description

Technical Field

[0001] This application relates to a gas capture device, belonging to the field of gas adsorption, specifically to an air capture carbon dioxide adsorption device with an adsorption tree structure. Background Technology

[0002] Linhe Climate Technology Co., Ltd. has reported in detail a CO2 direct air capture system (CN221085126U) using a wet-process regenerable adsorption material. The system aims to achieve desorption by increasing humidity through variable-humidity materials, thereby saving energy. However, the material's adsorption / desorption capacity is only 0.2 mol / kg, resulting in relatively low capture efficiency. While liquid-phase absorption is commonly used for capturing high-concentration (10% CO2) flue gas, it is prone to solution loss under high-volume air capture conditions and suffers from slow adsorption rates under low-concentration air conditions. Therefore, most air capture systems use solid materials for trace adsorption, but the desorption / regeneration performance of solid materials is often overlooked.

[0003] Currently, air capture materials mainly employ solid-based materials, such as the amine-functionalized cellulose adsorbent reported by the Swiss Institute for Testing and Materials (CN103702740B), the solid particulate adsorbent reported by Climeworks (CN105163830B), and the quaternary ammonium resin adsorbent from Linhe Enterprises (CN114031701B). Furthermore, Global Thermostat employs a rotating continuous multi-capture system and equipment utilizing solid amine adsorbents to capture carbon dioxide (US12172123B2); Climeworks has also designed box-type, "C"-shaped low-pressure-drop structures within the box, and array-type capture devices based on these materials (CN106488795B, US10427086B2, CN113727773A). However, the desorption process of solid amine materials typically involves vacuum desorption followed by water vapor desorption to obtain high-purity CO2 (US10279306B2, US11420149B2). While steam desorption can effectively improve the purity of the desorbed CO2, the temperature difference between the adsorption environment and the desorption temperature often leads to steam condensation, resulting in significant energy consumption for direct air capture (DAV) technology. To address this issue, Xi'an Jiaotong University has utilized waste heat from steel plants for carbon capture, incorporating the captured CO2 into the steel plant's smelting reaction to save energy (CN114432832B). China National Petroleum Corporation (CNPC) has adopted a method of alternating operation between the first and second adsorption-desorption towers to utilize waste heat (CN118615826A). However, the high energy consumption of these methods is limited by the solid adsorption materials, necessitating new air capture technologies to overcome the limitations of energy consumption in the large-scale expansion of DAV technology.

[0004] Therefore, based on traditional liquid-phase absorption and solid-phase adsorption, our research group has innovatively proposed a solid-liquid film method combining solid and liquid phases (CN117000020A). Through carrier optimization and solvent screening, we have developed a set of technologies related to the capture of low-concentration airborne carbon dioxide, including related patents (CN118179209A and CN118558296A). The solid-liquid film method balances the shortcomings of slow liquid-phase absorption and high energy consumption of solid-phase adsorption and desorption, and combines the high capacity of liquid-phase absorption with the high rate of solid-phase adsorption, thereby achieving rapid adsorption and easy desorption (desorption temperature ≤ 95℃) adsorption effects, while also possessing cycle stability.

[0005] Based on our group's previous research, this patent application aims to innovatively propose an adsorption device for air capture. The adsorption device of this application has a small footprint, can be flexibly arranged, is not affected by environmental temperature / humidity / dust, and integrates adsorption and desorption devices. It can achieve both in-situ regeneration and cyclic adsorption, as well as a systematic layout of decentralized capture and centralized regeneration, and has broad application prospects. Summary of the Invention

[0006] In view of the above-mentioned technical problems existing in the prior art, the purpose of this application is to provide an air capture carbon dioxide adsorption device with an adsorption tree structure, which achieves high adsorption efficiency and low regeneration energy consumption for low concentrations of CO2 in the air, realizes innovation in air capture CO2 adsorption equipment, and provides new ideas for the industrial application of air capture carbon dioxide.

[0007] The technical solution adopted by this invention to solve its technical problem is:

[0008] An air capture carbon dioxide adsorption device with an adsorption tree structure includes an absorbent liquid storage tank, a cleaning liquid storage tank, a liquid transfer pump, a support column, and multiple adsorption modules arranged at intervals from top to bottom on the support column. Each adsorption module includes a fixed steel frame and adsorption fibers laid and fixed on the fixed steel frame. Each adsorption module is provided with a spray unit above it for spraying liquid. The inlet of the liquid transfer pump is divided into two paths, which are respectively connected to the absorbent liquid storage tank and the cleaning liquid storage tank by pipelines. The outlet of the liquid transfer pump is connected to each of the spray units by pipelines.

[0009] A liquid reflux collection tank is also provided on the outer side of the support column. The liquid reflux collection tank is located below all the adsorption modules and is used to collect and recycle the liquid dripping from the adsorption modules. The bottom of the liquid reflux collection tank 4 is provided with a liquid outlet, and then it is connected to the absorption liquid storage tank and the cleaning liquid storage tank through two pipelines respectively.

[0010] Control valves are installed on all the corresponding pipelines.

[0011] Furthermore, the support column gradually tapers from bottom to top to form a tree trunk-like structure, and each of the adsorption modules is fixedly disposed on the outer side of the support column.

[0012] Furthermore, the adsorption module has an overall umbrella-shaped structure. Its fixed steel frame includes multiple inclined steel rods evenly spaced along the circumference on the side of the support column. The upper end of the steel rod is fixedly connected to the support column, and the lower end of the steel rod is suspended in the air. An inwardly curved arc-shaped steel edge is fixedly arranged between the lower ends of two adjacent steel rods to form a steel frame support unit. Each steel frame support unit is fixedly provided with corresponding adsorption fibers.

[0013] Furthermore, the lower end of the steel rod has a curved arc structure tangent to the horizontal plane, which facilitates the slow falling of droplets adsorbed on the fibers.

[0014] Furthermore, along the top-to-bottom direction, the umbrella-shaped diameter of the adsorption module increases sequentially.

[0015] Furthermore, the liquid reflux collection tank has an inverted conical structure with an opening at the top and inclined sidewalls, the angle between the sidewalls and the vertical direction being 75-85°; the diameter of each adsorption module is smaller than the diameter of the opening at the top of the liquid reflux collection tank.

[0016] Furthermore, a conical top plate for rain protection is provided at the top of the support column. The conical top plate is located above all the adsorption modules, and the diameter of the conical top plate is larger than the diameter of each adsorption module and the liquid reflux collection tank.

[0017] Furthermore, the support column has a hollow structure inside, and a liquid infusion pipe is installed inside the support column. The liquid infusion pipe is connected to each spray unit, and the lower inlet of the liquid infusion pipe extends out from the lower side of the support column and is connected to the outlet of the liquid delivery pump by a pipeline.

[0018] Furthermore, the spray unit has a hub-type structure, including multiple diversion pipes and an annular cavity. The multiple diversion pipes are evenly spaced along the circumference on the side of the infusion pipe. One end of the diversion pipe passes through the support column and is connected to the infusion pipe, while the other end is located outside the support column and is connected to the annular cavity. A drip hole is provided at the bottom of the part of the diversion pipe outside the support column.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] (1) High adsorption rate: Compared with the traditional solution adsorption method, the liquid film adsorption method is loaded on a carrier with a high specific surface area. Combined with the enrichment effect of the carrier itself and the strong adsorption force of the adsorbent liquid on CO2, it enhances the mass transfer effect between the gas and liquid phases and has a stronger adsorption rate than single solution adsorption. In addition, the adsorption rate can be enhanced by natural wind purging.

[0021] (2) Simple adsorption conditions and convenient regeneration: The adsorption device of this application can be placed in any location and has a rainproof component. It can achieve both adsorption and desorption integration and dispersed collection and centralized regeneration. Attached Figure Description

[0022] Figure 1 This is a schematic cross-sectional view of an air capture carbon dioxide adsorption device with an adsorption tree structure.

[0023] Figure 2 This is a schematic diagram of the structure of the device in this application;

[0024] Figure 3 This is a top view of the adsorption module of this application.

[0025] Figure 4 This is a schematic diagram of the connection between the spray unit and the infusion pipe in this application;

[0026] Figure 5 This is an adsorption rate graph of Example 1 under windless and natural wind conditions;

[0027] In the diagram: 1. Conical top plate, 2. Adsorption module, 21. Steel rod, 22. Arc-shaped steel edge, 3. Spray unit, 31. Diversion pipe, 32. Annular cavity, 4. Liquid return collection tank, 5. Support column, 51. Infusion pipe, 6. Absorbent liquid storage tank, 7. Cleaning liquid storage tank. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto. Detailed Implementation

[0030] As attached Figure 1-2 As shown, this patent application provides an air capture carbon dioxide adsorption device with an adsorption tree structure, which can spontaneously capture CO2 in the environment. The adsorption modules are independent of each other, and the adsorbent can be reused after simple low-temperature regeneration, which improves adsorption efficiency and greatly reduces energy consumption.

[0031] The adsorption device of this application includes an absorption liquid storage tank 6, a cleaning liquid storage tank 7, a liquid transfer pump, a support column 5, and a plurality of adsorption modules 2 arranged at intervals from top to bottom on the support column 5. The adsorption module 2 includes a fixed steel frame and adsorption fibers laid and fixed on the fixed steel frame. The adsorption fibers are made of materials such as activated carbon fibers, and CO2 absorption solution is loaded on the adsorption fibers.

[0032] Each adsorption module 2 is equipped with a spray unit 3 above it for spraying liquid. The inlet of the liquid transfer pump is divided into two paths, which are respectively connected to the absorption liquid storage tank 6 and the cleaning liquid storage tank 7 by pipelines. The outlet of the liquid transfer pump is connected to each of the spray units 3 by pipelines.

[0033] A liquid reflux collection tank 4 is also provided on the outer side of the support column 5. The liquid reflux collection tank 4 is located below all the adsorption modules 2 and is used to collect and recover the liquid dripping from the adsorption modules 2. The liquid reflux collection tank 4 is located directly below the lowest adsorption module 2 and is used to collect the solution dripping from each of the adsorption modules 2. The bottom of the liquid reflux collection tank 4 is provided with a liquid outlet, which is divided into two paths and connected to the absorption liquid storage tank 6 and the cleaning liquid storage tank 12 respectively by pipelines. Control valves are provided on the corresponding pipelines.

[0034] Comparison Figure 1 The support column 5 gradually tapers from bottom to top, giving it a tree trunk-like structure, and each of the adsorption modules 2 is fixedly installed on the outer side of the support column 5.

[0035] The adsorption module 2 has an umbrella-shaped structure. Its fixing steel frame includes multiple inclined steel rods 21 evenly spaced along the circumference on the side of the support column 5. The upper ends of the steel rods 21 are fixedly connected to the support column 5, and the lower ends of the steel rods 21 are suspended in the air. An inwardly curved arc-shaped steel edge 22 is fixedly installed between the lower ends of two adjacent steel rods 21 to form a steel frame support unit. Each steel frame support unit has corresponding adsorption fibers fixedly installed on it. The lower ends of the steel rods 21 have a gently curved structure with the concave side facing upwards, i.e., a curved arc structure tangent to the horizontal plane. Figures 1-2 In this way, it is easy to absorb the droplets on the fiber and allow them to fall slowly.

[0036] Comparison Figure 3 In the middle, one adsorption module 2 includes 6 steel frame support units, and the included angle between the two steel rods 21 of each steel frame support unit is 120°.

[0037] Along the top-to-bottom direction, the umbrella-shaped diameter of the adsorption module 2 increases sequentially.

[0038] The liquid reflux collection tank 4 has an inverted conical structure with an opening at the top and inclined side walls. The angle between the side walls and the vertical direction is 75-85°. The diameter of each of the adsorption modules 2 is smaller than the diameter of the opening at the top of the liquid reflux collection tank 4.

[0039] The top of the support column 5 is also provided with a conical top plate 1 for rain protection. The conical top plate 1 is located above all the adsorption modules 2, and the diameter of the conical top plate 1 is larger than the diameter of each of the adsorption modules 2 and the liquid reflux collection tank 4.

[0040] The support column 5 has a hollow structure inside, and a liquid infusion pipe 51 is installed inside the support column. The liquid infusion pipe 51 is connected to each spray unit 3. The lower inlet of the liquid infusion pipe 51 extends out from the lower side of the support column and is connected to the outlet of the liquid transfer pump by a pipeline.

[0041] The spray unit 3 has a hub-type structure, including multiple diversion pipes 31 and an annular cavity 32. The multiple diversion pipes 31 are evenly spaced along the circumference on the side of the infusion pipe 51. One end of the diversion pipe 31 passes through the support column 5 and is connected to the infusion pipe 51, while the other end is located outside the support column 5 and is connected to the annular cavity 32. A drip hole is provided at the bottom of the part of the diversion pipe 31 outside the support column 5.

[0042] The required CO2 absorption solution or cleaning solution can be transported upwards by a liquid transfer pump. The solution dripping from the adsorption module 2 can be transported downwards through the inverted cone-shaped liquid return collection tank 4, and then flows to the absorption liquid storage tank 6 or the cleaning liquid storage tank 7. During the spraying process, when the CO2 absorption solution or cleaning solution flows above the adsorption module 2, the spraying unit 3 will spray the liquid evenly onto the top of the umbrella-shaped adsorption module 2, and then slowly and evenly flow down.

[0043] The umbrella-shaped adsorption module 2, which spreads activated carbon fibers, is loaded with a solution for adsorbing CO2. In addition, the collection efficiency is positively correlated with the wind speed to a certain extent. The adsorption effect can be enhanced by natural wind or by adding a fan. It also integrates adsorption and desorption. It can also perform decentralized collection and centralized regeneration.

[0044] When the device of this application is in operation: during the impregnation and loading stage of the CO2 absorption solution in the adsorption module 2, the CO2 absorption solution is stored in the absorption liquid storage tank 6. The CO2 absorption solution is transported to the top of the adsorption module 2 by the liquid transfer pump and discharged through the drip hole at the bottom of the spray unit 3 to drip and form a film on the adsorption fiber of the adsorption module 2. The CO2 absorption solution that does not form a film is collected through the liquid return collection tank 4 below and then returned to the absorption liquid storage tank 6 to form a cycle until the CO2 absorption solution forms a film on the adsorption fiber.

[0045] When the adsorption fibers loaded with CO2 absorption solution complete their first CO2 capture, clean water is first added to the cleaning solution storage tank 7. Then, a liquid transfer pump transports the cleaning solution from the storage tank 7 to the top of the adsorption module 2, where it drips and washes the adsorption fibers. The dripping CO2-rich solution is collected through the liquid return collection tank 4 below and then returned to the cleaning solution storage tank 7 to form a cycle until the CO2 absorption solution film is eluted from the adsorption fibers. In subsequent washing and collection stages, the CO2-rich solution from the storage tank 7 is used for circulating washing until the CO2 adsorption concentration in the CO2-rich solution reaches the concentration required for regeneration. This solution is then transported out for regeneration and desorption, yielding high-purity carbon dioxide. Regeneration can be performed at relatively low temperatures, with high desorption efficiency, and the solution can be recycled multiple times.

[0046] The device has no restrictions on the temperature, humidity, and water content of the carbon dioxide in the air it captures, and the adsorption device has no pressure drop and low regeneration energy consumption, making it economical and environmentally friendly.

[0047] <Example 1>

[0048] The structure of an air capture carbon dioxide adsorption device with an adsorption tree structure is as follows: Figure 1-4 As shown.

[0049] In this embodiment, the adsorbent used includes an adsorption carrier and an adsorption liquid loaded on the adsorption carrier for air capture. The adsorption fiber of the high specific surface area carrier is activated carbon fiber. The CO2 absorption solution is stored in the absorption liquid storage tank 6 and transported by a liquid transfer pump to leach the CO2 absorption solution onto the activated carbon fiber carrier. After the leaching and loading are completed, it has the ability to adsorb CO2 and can be used for air capture.

[0050] In this embodiment, the prepared CO2 absorption solution is rinsed and loaded onto the adsorption module. (Comparison) Figure 1 and Figure 2 The adsorption module 2 of this application has an umbrella-shaped structure. Excess CO2 absorption solution gathers at the lowest point at the bottom of the adsorption module 2 and drips down. Thus, excess unloaded CO2 absorption solution drips down in stages and is finally recovered through the inverted cone-shaped liquid reflux collection tank 4 for recycling.

[0051] In this embodiment, the adsorbent used will not affect SO2 or NO. x The device reacts with other substances and selectively adsorbs CO2 with high efficiency. Generally, the CO2 concentration in the air is around 430 ppm. Furthermore, the device has no limitations regarding air temperature or moisture content (humidity), making it widely applicable.

[0052] In this embodiment, for air capture and absorption testing, two scenarios are employed: static placement and natural wind capture. The adsorbent loading is at a specific surface area of ​​2000 cm². 3 / g of activated carbon fiber, this example uses a total of 15m 2 The adsorption area was determined using an adsorption solution containing 5 wt% polyethylene glycol (PEG) and 20 wt% tetraethylenepentamine-imidazolium ([TEPA][IM]2), with a tetraethylenepentamine to imidazolium molar ratio of 1:2. The adsorption solution was then rinsed onto activated carbon fibers, and after standing for a period of time to allow excess solution to drip off, the loaded solid-liquid membrane adsorbent was obtained. The loading amount was 7-8 times the weight of the activated carbon fibers.

[0053] In this embodiment, after the activated carbon fibers were impregnated with the absorbent, adsorption was performed at 293K under different wind speeds. The wind speed was controlled by a fan to blow air onto the adsorption module, with controlled wind speeds of 0 m / s and 2-3 m / s. After sufficient adsorption, the absorbent on the activated carbon fibers was washed off with water to obtain a CO2-rich solution. The CO2 content of the eluted CO2-rich solution was detected using a strong acid-weak acid titration method. Carbonic acid was displaced from the saturated absorption solution as CO2 gas by sulfuric acid titration. The adsorption capacity was calculated by measuring the volume of gas expansion during the process. The CO2 adsorption capacity of the activated carbon fibers loaded with the adsorption solution film at different wind speeds according to the above experimental method is shown in Table 1.

[0054] Table 1

[0055] In addition, the adsorption capacity of activated carbon fiber loaded with adsorption solution liquid film was tested at different wind velocities and different adsorption times. (See attached image.) Figure 5 As shown.

[0056] From Table 1 and Figure 5 It can be seen that wind speed only affects the adsorption rate at 15m. 2 On the fiber with a total adsorption area, adsorption saturation occurs in about 6 hours under natural wind and about 10 hours without wind. Wind enhances the adsorption rate by about 30%. Therefore, even a slight breeze can greatly enhance the adsorption effect.

[0057] In summary, this patent provides a method for efficiently capturing CO2 from the air by using an air-capturing carbon dioxide adsorption device with an adsorption tree structure, which has promising prospects for industrial application.

[0058] The contents described in this specification are merely an enumeration of the implementation forms of the inventive concept, and the scope of protection of this invention should not be regarded as limited to the specific forms described in the embodiments.

Claims

1. An air capture carbon dioxide adsorption device with an adsorption tree structure, characterized in that... It includes an absorbent liquid storage tank (6), a cleaning liquid storage tank (7), a liquid transfer pump, a support column (5), and multiple adsorption modules (2) arranged at intervals from top to bottom on the support column (5). The adsorption module (2) includes a fixed steel frame and adsorption fibers laid and fixed on the fixed steel frame. Each adsorption module (2) is provided with a spray unit (3) for spraying liquid on it. The inlet of the liquid transfer pump is divided into two paths, which are respectively connected to the absorbent liquid storage tank (6) and the cleaning liquid storage tank (7) by pipelines. The outlet of the liquid transfer pump is connected to each of the spray units (3) through pipelines. A liquid return collection tank (4) is also provided on the outer side of the support column (5). The liquid return collection tank (4) is located below all the adsorption modules (2) and is used to collect and recycle the liquid dripping from the adsorption module (2). The liquid return collection tank (4) has an outlet at the bottom and is connected to the absorption liquid storage tank (6) and the cleaning liquid storage tank (7) through two pipelines respectively. Control valves are installed on all the corresponding pipelines.

2. The air capture carbon dioxide adsorption device with an adsorption tree structure as described in claim 1, characterized in that... The support column (5) gradually tapers from bottom to top, giving it a tree trunk-like structure. Each of the adsorption modules (2) is fixedly installed on the outer side of the support column (5).

3. The air capture carbon dioxide adsorption device with an adsorption tree structure as described in claim 1, characterized in that... The adsorption module (2) has an umbrella-shaped structure. Its fixed steel frame includes multiple inclined steel rods (21) evenly spaced along the circumference on the side of the support column (5). The upper end of the steel rod (21) is fixedly connected to the support column (5), and the lower end of the steel rod (21) is suspended. An inwardly curved arc steel edge (22) is fixedly set between the lower ends of two adjacent steel rods (21) to form a steel frame support unit. Each steel frame support unit is fixedly equipped with corresponding adsorption fibers.

4. The air capture carbon dioxide adsorption device with an adsorption tree structure as described in claim 3, characterized in that... The lower end of the steel rod (21) is a curved arc structure tangent to the horizontal plane, which facilitates the slow falling of the droplets adsorbed on the fiber.

5. The air capture carbon dioxide adsorption device with an adsorption tree structure as described in claim 3, characterized in that... Along the top-to-bottom direction, the umbrella-shaped diameter of the adsorption module (2) increases sequentially.

6. The air capture carbon dioxide adsorption device with an adsorption tree structure as described in claim 1, characterized in that... The liquid reflux collection tank (4) has an inverted conical structure with an opening at the top and inclined side walls. The angle between the side walls and the vertical direction is 75-85°. The diameter of each adsorption module (2) is smaller than the diameter of the opening at the top of the liquid reflux collection tank (4).

7. The air capture carbon dioxide adsorption device with an adsorption tree structure as described in claim 1, characterized in that... The top of the support column (5) is also provided with a conical top plate (1) for rain protection. The conical top plate (1) is located above all the adsorption modules (2), and the diameter of the conical top plate (1) is larger than the diameter of each of the adsorption modules (2) and the liquid reflux collection tank (4).

8. The air capture carbon dioxide adsorption device with an adsorption tree structure as described in claim 1, characterized in that... The support column (5) has a hollow structure inside, and a liquid infusion pipe (51) is installed inside the support column. The liquid infusion pipe (51) is connected to each spray unit (3). The lower end inlet of the liquid infusion pipe (51) passes through the lower side of the support column and is connected to the outlet of the liquid delivery pump by a pipeline.

9. The air capture carbon dioxide adsorption device with an adsorption tree structure as described in claim 8, characterized in that... The spray unit (3) is a hub-type structure, including multiple diversion pipes (31) and an annular cavity (32). The multiple diversion pipes (31) are evenly spaced along the circumference on the side of the infusion pipe (51). One end of the diversion pipe (31) passes through the support column (5) and is connected to the infusion pipe (51), while the other end is located outside the support column (5) and is connected to the annular cavity (32). The bottom of the part of the diversion pipe (31) outside the support column (5) is provided with a drip hole.

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