A two-tower pressure swing adsorption system for flue gas recovery with a CO2 concentration of 40%.

Abstract

This utility model relates to the field of flue gas recovery and treatment technology, specifically disclosing a two-tower pressure swing adsorption (PSA) system for recovering CO2 concentration of 40% from flue gas. The system includes adsorption tower A and adsorption tower B, with their bottom inlets connected in parallel by pipes A and B. Pneumatic butterfly valves are connected in series on pipes A and B, and these valves are connected to a vacuum pump and a blower via pipes. The top outlet of each adsorption tower is connected to a buffer tank via pipe F. This system borrows from the two-tower PSA oxygen production process to efficiently recover carbon dioxide from flue gas. After purification, the carbon dioxide concentration of the product can reach approximately 40%. Its innovative process effectively reduces the number of adsorption towers required, and combined with a low-pressure ratio operation, significantly reduces energy consumption in the carbon dioxide capture process, thereby reducing production costs and improving the overall economic and environmental benefits of the process. It has promising application prospects in the field of flue gas carbon dioxide recovery and utilization.

Description

Technical Field

[0001] This utility model relates to the field of flue gas recovery and treatment technology, specifically to a two-tower pressure swing adsorption system for flue gas recovery products with a CO2 concentration of 40%. Background Technology

[0002] In the field of carbon dioxide capture and recovery technology, numerous patents have proposed various process methods. For example, patent CN-101745288B describes a carbon dioxide capture method using a multi-tower vacuum approach to ultimately obtain carbon dioxide with a concentration of 60-70%. Patent CN11130441782B illustrates a two-stage pressure swing adsorption process for carbon dioxide recovery. Additionally, patent publication CN113041782 introduces a process involving four towers, obtaining carbon dioxide product gas through adsorption, forward release, reverse release, and regeneration steps. However, the processes involved in the aforementioned patents all have certain limitations. They generally employ a large number of adsorption towers to implement carbon dioxide capture and purification, which not only complicates the process route and increases the difficulty of operation and control, but also significantly increases the number of valves required by the system due to the large number of adsorption towers, raising equipment costs and the probability of failure. Furthermore, a larger number of adsorption towers also means a larger adsorbent loading, further increasing investment and operating costs. Therefore, developing a carbon dioxide capture system with fewer adsorption towers and a simpler process route is of significant practical importance. Utility Model Content

[0003] To address the aforementioned technical problems in related technologies, this utility model provides a two-tower pressure swing adsorption system for flue gas recovery products with a CO2 concentration of 40%, which can solve the above problems.

[0004] To achieve the above-mentioned technical objectives, the technical solution of this utility model is implemented as follows: A two-tower pressure swing adsorption (PSA) system for flue gas recovery with a CO2 concentration of 40% includes adsorption tower A and adsorption tower B. The bottom inlets of both adsorption towers A and B are connected to pipes A and B, respectively. Pipes A and B are connected in parallel. Pneumatic butterfly valves A and B are connected in series on pipe A, and pneumatic butterfly valves C and D are connected in series on pipe B. Pipe C connects pneumatic butterfly valves A and B, with one end of pipe C connected to a vacuum pump. Pneumatic butterfly valve C is connected to a pneumatic... Pipeline D is installed between the switch butterfly valves D. One end of pipeline D is connected to a vacuum pump via pneumatic switch butterfly valve E. Pipeline E is installed between pneumatic switch butterfly valve C and pneumatic switch butterfly valve D. A blower is installed via pipeline E. The top outlets of adsorption towers A and B are both connected to pipeline F. Pneumatic switch butterfly valves F and G are connected in series via pipeline F. Pipeline G is installed between pneumatic switch butterfly valves F and G. Pipeline G is connected to the inlet of the buffer tank via a pneumatic regulating butterfly valve.

[0005] Furthermore, needle valve A is installed in the external connection of adsorption tower A, and needle valve B is installed in the external connection of adsorption tower B.

[0006] Furthermore, an exhaust muffler is installed in connection with pipe D.

[0007] Furthermore, an oxygen analyzer is connected to the outlet end of the buffer tank.

[0008] Furthermore, a manual ball valve is installed at the bottom of the buffer tank.

[0009] The beneficial effects of this utility model are as follows: The device of this application adopts the two-tower pressure swing adsorption oxygen production process to achieve efficient recovery of carbon dioxide from flue gas. After purification, the carbon dioxide concentration in the obtained product can reach about 40%. In terms of process design, the innovative process of this invention can effectively reduce the number of adsorption towers used. At the same time, combined with the low pressure ratio operation mode, the energy consumption in the carbon dioxide capture process can be greatly reduced, thereby effectively reducing production costs and improving the overall economic efficiency and environmental friendliness of the process. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] The present invention will now be described in further detail with reference to the accompanying drawings.

[0012] Figure 1This is a schematic diagram of a two-tower pressure swing adsorption system for flue gas recovery products with a CO2 concentration of 40%.

[0013] In the picture: 1. Vacuum pump; 2. Exhaust silencer; 3. Pneumatic butterfly valve E; 4. Blower; 5. Pneumatic butterfly valve C; 6. Pneumatic butterfly valve D; 7. Pneumatic butterfly valve A; 8. Pneumatic butterfly valve B; 9. Adsorption tower A; 10. Adsorption tower B; 11. Needle valve A; 12. Needle valve B; 13. Pneumatic butterfly valve F; 14. Pneumatic butterfly valve G; 15. Pneumatic regulating butterfly valve; 16. Buffer tank. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model are within the protection scope of the present utility model.

[0015] Example 1: As Figure 1 As shown, this utility model discloses a two-tower pressure swing adsorption system for recovering CO2 concentration of 40% from flue gas. The system includes adsorption tower A9 and adsorption tower B10, both of which can adopt axial or radial tower structures. The adsorbent packed in the adsorption towers includes one or more of molecular sieves such as silica gel, carbon molecular sieve, alumina, 5A, and 13X. The blower 4 in the system can be one or more of the form of a Roots blower, centrifugal blower, etc., to provide the power for gas flow; the vacuum pump 1 can be one or more of the form of a Roots vacuum pump, screw vacuum pump, etc., to realize the vacuum operation of the adsorption towers.

[0016] The bottom inlets of adsorption towers A9 and B10 are connected to pipes A and B, respectively. Pipes A and B are connected in parallel. Pipe A is connected in series with pneumatic butterfly valves A7 and B8, and pipe B is connected in series with pneumatic butterfly valves C5 and D6. Pipe C is installed between pneumatic butterfly valves A7 and B8, with one end of pipe C connected to vacuum pump 1. Pipe D is installed between pneumatic butterfly valves C5 and D6, with one end of pipe D connected to vacuum pump 1 via pneumatic butterfly valve E3. Pipe D is also connected to a drain valve. A silencer 2 is installed. A pipe E connects pneumatic butterfly valves C5 and D6, and a blower 4 is installed via pipe E. The top outlets of adsorption towers A9 and B10 are connected to pipe F. Pipe F is connected in series with pneumatic butterfly valves F13 and G14. Pipe G connects pneumatic butterfly valves F13 and G14, and is connected to the inlet of buffer tank 16 via pneumatic regulating butterfly valve 15. A needle valve A11 and a needle valve B12 are installed externally on adsorption tower A9 and B10, respectively. An oxygen analyzer 17 is installed at the outlet of buffer tank 16, and a manual ball valve is installed at the bottom.

[0017] II. Specific operating procedures (taking adsorption tower A as an example) Step 1: Equalizing pressure increase During system operation, when pressure boosting of adsorption tower A9 is required, pneumatic switch butterfly valves G14 and F13 are opened. At this time, a connecting channel is formed between adsorption tower A and adsorption tower B, and the gas in the two towers flows to each other, so that the pressure of adsorption tower A and adsorption tower B gradually tends to be balanced, realizing the pressure equalization and boosting process. This step helps to rationally distribute the gas pressure and prepare for subsequent adsorption operations.

[0018] Step 2: Adsorption After pressure equalization is completed, adsorption operation is performed. Pneumatic butterfly valves E3, C5, and F13 are opened. The raw material gas is transported to adsorption tower A under the pressure boosting effect of the blower. Under fixed adsorption pressure conditions, the adsorbent in adsorption tower A selectively adsorbs carbon dioxide in the raw material gas. As the adsorption process proceeds, the carbon dioxide concentration in the adsorption tail gas will gradually change. The carbon dioxide concentration in the adsorption tail gas is detected in real time by oxygen analyzer 17. When the concentration reaches a certain preset value (the preset value is a specific value between 36% and 38%, such as 37%), it indicates that the adsorbent is close to adsorption saturation, and the adsorption operation is stopped at this time.

[0019] Step 3: Equalizing pressure drop After the adsorption operation stops, the pressure equalization step begins. Pneumatic butterfly valves G14 and F13 are reopened to reconnect adsorption tower A and adsorption tower B. Due to the pressure difference between the two towers, gas will flow from the tower with higher pressure to the tower with lower pressure until the pressures of the two towers reach equilibrium, completing the pressure equalization process.

[0020] Step 4: Vacuuming After the pressure drop is equalized, a vacuum operation is performed on adsorption tower A to regenerate the adsorbent. The pneumatic switch butterfly valve A7 is opened, and the vacuum pump 1 is started. Under the action of the vacuum pump, the pressure inside adsorption tower A gradually decreases. The adsorbed carbon dioxide is desorbed from the adsorbent under negative pressure and is extracted through the pipeline. The gas generated during the vacuum process can be further processed through relevant pipelines, while the adsorbent in adsorption tower A9 is restored to its initial state, preparing for the next adsorption operation.

[0021] Detailed operating steps (taking adsorption tower B as an example) Step 1: Equalizing pressure drop After the adsorption operation stops, the pressure equalization step begins. Pneumatic butterfly valves G14 and F13 are opened to connect adsorption tower A and adsorption tower B. Due to the pressure difference between the two towers, gas will flow from the tower with higher pressure to the tower with lower pressure until the pressures of the two towers reach equilibrium, completing the pressure equalization process.

[0022] Step 2: Vacuuming After the pressure drop equalization is completed, a vacuum operation is performed on adsorption tower B to regenerate the adsorbent. The pneumatic switch butterfly valve B8 is opened, and vacuum pump 1 is started. Under the action of the vacuum pump, the pressure inside adsorption tower B10 gradually decreases. The adsorbed carbon dioxide is desorbed from the adsorbent under negative pressure and extracted through the pipeline. The gas generated during the vacuum process can be further processed through relevant pipelines, while the adsorbent inside adsorption tower B10 returns to its initial state, preparing for the next adsorption operation. Step 3: Equalizing pressure increase During system operation, when pressure boosting of adsorption tower B10 is required, pneumatic switch butterfly valves G14 and F13 are opened. At this time, a connecting channel is formed between adsorption tower A and adsorption tower B, and the gas in the two towers flows to each other, so that the pressure of adsorption tower A and adsorption tower B gradually tends to be balanced, realizing the pressure equalization and boosting process. This step helps to rationally distribute the gas pressure and prepare for subsequent adsorption operations.

[0023] Step 4: Adsorption After pressure equalization is completed, adsorption operation is performed. Pneumatic butterfly valves E3, D6, and G14 are opened. The raw material gas is transported to adsorption tower B under the pressure boosting effect of the blower. Under fixed adsorption pressure conditions, the adsorbent in adsorption tower B selectively adsorbs carbon dioxide from the raw material gas. As the adsorption process proceeds, the carbon dioxide concentration in the adsorption tail gas will gradually change. The carbon dioxide concentration in the adsorption tail gas is monitored in real time by oxygen analyzer 17. When the concentration reaches a certain preset value (the preset value is a specific value between 36% and 38%, such as 37%), it indicates that the adsorbent is close to adsorption saturation, and the adsorption operation is stopped at this time.

[0024] Two Towers Time Sequence Through the cyclical operation of the above steps, adsorption tower A and adsorption tower B alternately carry out the adsorption and regeneration process, realizing the continuous recovery of carbon dioxide products with a concentration of about 40% (fluctuating by ±5%) from the flue gas. The product is then transported to a buffer tank through pipelines and further processed by oxygen analyzer and other methods before it can be used in sugar mills, sodium carbonate production plants, and other related industries.

[0025] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A two-tower pressure swing adsorption system for flue gas recovery products with a CO2 concentration of 40%, characterized in that, The system includes adsorption tower A (9) and adsorption tower B (10). The bottom inlet of both adsorption tower A (9) and adsorption tower B (10) is connected to pipe A and pipe B, respectively. Pipe A and pipe B are connected in parallel. Pipe A is connected in series with pneumatic switch butterfly valve A (7) and pneumatic switch butterfly valve B (8). Pipe B is connected in series with pneumatic switch butterfly valve C (5) and pneumatic switch butterfly valve D (6). Pipe C is installed between pneumatic switch butterfly valve A (7) and pneumatic switch butterfly valve B (8). One end of pipe C is connected to vacuum pump (1). Pipe D is installed between pneumatic switch butterfly valve C (5) and pneumatic switch butterfly valve D (6). One end of the pipeline D is connected to the vacuum pump (1) through the pneumatic switch butterfly valve E (3). The pneumatic switch butterfly valve C (5) and the pneumatic switch butterfly valve D (6) are connected by a pipeline E. The pipeline E is connected to a blower (4). The top outlets of the adsorption tower A (9) and the adsorption tower B (10) are both connected to the pipeline F. The pipeline F is connected in series with the pneumatic switch butterfly valve F (13) and the pneumatic switch butterfly valve G (14). The pneumatic switch butterfly valve F (13) and the pneumatic switch butterfly valve G (14) are connected by a pipeline G. The pipeline G is connected to the inlet of the buffer tank (16) through the pneumatic regulating butterfly valve (15).

2. The two-tower pressure swing adsorption system for flue gas recovery product with a CO2 concentration of 40% as described in claim 1, characterized in that, The adsorption tower A (9) is externally connected to a needle valve A (11), and the adsorption tower B (10) is externally connected to a needle valve B (12).

3. The two-tower pressure swing adsorption system for flue gas recovery product CO2 concentration of 40% according to claim 1, characterized in that, The pipe D is connected to an exhaust muffler (2).

4. The two-tower pressure swing adsorption system for flue gas recovery product CO2 concentration of 40% according to claim 1, characterized in that, An oxygen analyzer (17) is connected to the outlet end of the buffer tank (16).

5. The two-tower pressure swing adsorption system for flue gas recovery product with a CO2 concentration of 40% according to claim 1, characterized in that, A manual ball valve is connected to the bottom of the buffer tank (16).

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