Cement kiln flue gas psa carbon capture - fly ash water wash liquid carbon sequestration decarbonization recycling system

Abstract

The present application belongs to the field of carbon capture technology, and particularly relates to a cement kiln flue gas PSA carbon capture-fly ash water washing liquid carbon sequestration and decalcification circulating system, which comprises a fly ash water washing system and a carbon capture system, the fly ash water washing system comprises a carbon dioxide absorption tower, the carbon capture system is used for pressurizing and conveying input cement kiln flue gas through a flue gas pressurizing machine, the gas outlet of the carbon dioxide absorption tower is connected with an overflow gas buffer tank through a pipeline, and the gas outlet pipe of the overflow gas buffer tank is connected with the inlet of the flue gas pressurizing machine through a circulating gas pressurizing machine and a water distribution tank one by one. The present application can treat the carbon dioxide mixed gas after the fly ash water washing reaction, and then re-introduce the carbon dioxide mixed gas into the PSA carbon capture system for recycling, so that the comprehensive energy consumption is greatly reduced.

Description

Technical Field

[0001] This utility model belongs to the field of carbon capture technology, specifically relating to a cement kiln flue gas PSA carbon capture-fly ash washing liquid carbon fixation and decalcification circulation system. Background Technology

[0002] Fly ash washing solution is highly alkaline and rich in calcium. 2+ Cl - Na + K + Features such as... Currently, in the Wuhu fly ash washing project, NaCO3 is mainly used to precipitate Ca... 2+ The subsequent pH adjustment using hydrochloric acid is not only costly but also produces CaCO3 with low economic value. CO2 absorption decalcification technology is feasible for engineering applications and can co-produce high-value nano-calcium carbonate. The carbon dioxide concentration used in fly ash washing is typically around 50%, and after the absorption reaction, the carbon dioxide utilization rate is only about 50%, with the overflowing carbon dioxide gas concentration around 25%. This is usually either directly discharged or recycled. Direct discharge results in waste and high carbon emissions, while recycling, due to the low carbon dioxide concentration, not only leads to a slow reaction but also negatively impacts the production of the target product. Utility Model Content

[0003] The purpose of this invention is to provide a circulating system for PSA carbon capture of cement kiln flue gas and carbon fixation and decalcification of fly ash washing liquid, which overcomes the technical problems of high equipment cost, high temperature and high pressure production environment and various polluting organic solvents in the existing technology, resulting in high energy consumption, high cost and high pollution in the preparation process.

[0004] The aforementioned cement kiln flue gas PSA carbon capture-fly ash washing liquid carbon fixation and decalcification circulation system is characterized by: including a fly ash washing system and a carbon capture system. The fly ash washing system includes a carbon dioxide absorption tower. The carbon capture system pressurizes and transports the input cement kiln flue gas through a flue gas booster. The outlet of the carbon dioxide absorption tower is connected to an overflow gas buffer tank through a pipeline. The outlet pipe of the overflow gas buffer tank is connected to the inlet of the flue gas booster in sequence through a circulating gas booster and a water separator.

[0005] Preferably, the carbon capture system further includes a flue gas pretreatment system, a carbon dioxide pressure swing adsorption system, and a product gas buffer tank. The flue gas booster is connected to the flue gas pretreatment system, the flue gas pretreatment system is connected to the carbon dioxide pressure swing adsorption system, the carbon dioxide pressure swing adsorption system is connected to the product gas buffer tank, and the product gas buffer tank is connected to the carbon dioxide absorption tower.

[0006] Preferably, the carbon capture system includes a flue gas buffer tank connected to the inlet of the flue gas booster, and a water separator is provided between the flue gas pretreatment system and the flue gas booster.

[0007] Preferably, the flue gas pretreatment system is provided with an exhaust port, which is connected in parallel to an exhaust pipe and a residual gas transmission pipe. The exhaust pipe discharges gas to the outside, and the residual gas transmission pipe is connected to the product gas buffer tank.

[0008] Preferably, a vacuum pump is provided between the carbon dioxide pressure swing adsorption system and the product gas buffer tank.

[0009] Preferably, the unadsorbed gas in the carbon dioxide pressure swing adsorption system is transported to the flue gas pretreatment system through a pipeline, and the vent gas from the flue gas pretreatment system enters the product gas buffer tank through the residual gas conveying pipeline.

[0010] Preferably, a flow meter is installed on the pipeline that supplies product gas to the product gas buffer tank; a carbon dioxide concentration detector is installed on the pipeline that supplies product gas to the product gas buffer tank.

[0011] The advantages of this invention are as follows: This invention can purify cement kiln flue gas (CO2 concentration of 18-20%) to approximately 50% CO2 concentration using pressure swing adsorption (PSA) carbon capture. The resulting mixture with approximately 50% CO2 concentration is then applied to the fly ash washing system. The carbon dioxide mixture (CO2 concentration of approximately 25%) after the fly ash washing reaction is reintroduced into the PSA carbon capture system for recycling, significantly reducing overall energy consumption. This invention can control the flow rate of overflow gas via valves to maintain a carbon dioxide concentration of approximately 50% in the gas entering the carbon capture system, thus reducing the overall energy consumption of the entire system by approximately 20%. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the PSA carbon capture-fly ash washing liquid carbon fixation and decalcification circulation system for cement kiln flue gas according to this utility model.

[0013] The labels in the attached diagram include: 1 flue gas buffer tank, 2 flue gas booster, 3 water separator tank II, 4 flue gas pretreatment system, 5 carbon dioxide pressure swing adsorption system, 6 vacuum pump, 7 product gas buffer tank, 8 carbon dioxide absorption tower, 9 overflow gas buffer tank, 10 circulating gas booster, 11 water separator tank I, 12 flow meter I, 13 carbon dioxide concentration detector, 14 flow meter II. Detailed Implementation

[0014] The following detailed description of the embodiments, with reference to the accompanying drawings, will further illustrate the specific implementation of this utility model, in order to help those skilled in the art to have a more complete, accurate, and in-depth understanding of the inventive concept and technical solution of this utility model.

[0015] like Figure 1As shown, this utility model provides a PSA carbon capture-fly ash washing liquid carbon fixation and decalcification circulation system for cement kiln flue gas, including a fly ash washing system and a carbon capture system. The fly ash washing system includes a carbon dioxide absorption tower 8. The carbon capture system pressurizes and transports the input cement kiln flue gas through a flue gas booster 2. The outlet of the carbon dioxide absorption tower 8 is connected to an overflow gas buffer tank 9 through a pipeline. The outlet pipe of the overflow gas buffer tank 9 is connected to the inlet of the flue gas booster 2 via a circulating gas booster 10 and a water separator 11. The carbon dioxide concentration in the flue gas after treatment by the circulating gas booster 10 and the water separator is about 25%, which is higher than the carbon dioxide concentration in cement kiln flue gas (18-20%). The carbon dioxide concentration in the gas produced by the original carbon capture system can reach about 50%. Therefore, by adding overflow gas with a higher carbon dioxide concentration, the CO2 concentration in the product gas of the carbon capture system is higher than 60%. In this scenario, the system can control the flow rate of the valves to distribute the exhaust air from the pretreatment system through the residual gas delivery pipeline, adjusting the carbon dioxide concentration entering the product gas buffer tank 7 to approximately 50%. This reduces the overall energy consumption of the entire system by about 20%.

[0016] The carbon capture system also includes a flue gas pretreatment system 4, a carbon dioxide pressure swing adsorption (PSA) system 5, and a product gas buffer tank 7. A flue gas booster 2 is connected to the flue gas pretreatment system 4, which in turn is connected to the PSA system 5. The PSA system 5 is connected to the product gas buffer tank 7, which is then connected to the carbon dioxide absorption tower 8. After flue gas pretreatment and carbon dioxide adsorption followed by desorption, carbon dioxide is enriched, resulting in a carbon dioxide concentration of approximately 50% in the product gas. This product gas is then fed into the carbon dioxide absorption tower 8 of the fly ash washing system for efficient carbon dioxide absorption.

[0017] A water separator 3 is provided between the flue gas pretreatment system 4 and the flue gas booster 2 to separate moisture from the flue gas.

[0018] The flue gas pretreatment system 4 is equipped with an exhaust port, which is connected in parallel to an exhaust pipe and a residual gas transmission pipe. The exhaust pipe discharges gas to the outside, and the residual gas transmission pipe is connected to the product gas buffer tank 7 to transport the gas output from the exhaust port.

[0019] A vacuum pump 6 is installed between the carbon dioxide pressure swing adsorption system 5 and the product gas buffer tank 7 for carbon dioxide desorption. The desorbed gas then enters the product gas buffer tank 7.

[0020] The unadsorbed gas in the carbon dioxide pressure swing adsorption system 5 is transported to the flue gas pretreatment system 4 through the pipeline, and the vent gas from the flue gas pretreatment system 4 enters the product gas buffer tank 5 through the residual gas conveying pipeline.

[0021] The carbon capture system includes a flue gas buffer tank 1, which is connected to the inlet of a flue gas booster 2. The cement kiln flue gas first enters the flue gas buffer tank 1, and then is conveyed to the flue gas booster 2 at a certain rate. After being boosted, it is conveyed further.

[0022] Flow meters are installed on the pipelines supplying product gas to the product gas buffer tank 7, including flow meter 12 located on the pipeline connected to the vacuum pump 6 and flow meter 14 located on the residual gas delivery pipeline. A carbon dioxide concentration detector 13 is installed on the pipeline output from the product gas buffer tank 7 to detect the carbon dioxide concentration of the product gas.

[0023] In operation, this invention works as follows: During the carbon dioxide adsorption stage, the flue gas output from the flue gas pretreatment system 4 is adsorbed by the carbon dioxide pressure swing adsorption system 5. The unadsorbed gas enters the flue gas pretreatment system 4 to regenerate the pretreatment system. During the desorption stage, a vacuum pump 6 creates a negative pressure in the carbon dioxide adsorption system 5, causing carbon dioxide desorption and enrichment. The resulting product gas is transported to the product gas buffer tank 7. During the desorption stage, the exhaust air from the flue gas pretreatment system 4 is fed into the product gas buffer tank 7 through a valve and a residual gas pipeline. The product gas in the product gas buffer tank 7 is transported to the fly ash treatment system, where it undergoes efficient carbon absorption in the carbon dioxide absorption tower 8. The overflow gas output from the carbon dioxide absorption tower 8 after the reaction has a high carbon dioxide concentration. It is first fed into the overflow gas buffer tank 9, and then processed by the circulating gas booster 10 and the water separator before being fed into the flue gas booster 2 in the carbon capture system. It is then collected together with the cement kiln flue gas for carbon capture, which not only reduces the emission of untreated overflow gas but also recovers the carbon dioxide, achieving the effect of reducing overall energy consumption.

[0024] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A cement kiln flue gas PSA carbon capture-fly ash washing liquid carbon fixation and decalcification circulation system, characterized in that: It includes a fly ash washing system and a carbon capture system. The fly ash washing system includes a carbon dioxide absorption tower. The carbon capture system pressurizes and transports the incoming cement kiln flue gas through a flue gas booster. The outlet of the carbon dioxide absorption tower is connected to an overflow gas buffer tank through a pipeline. The outlet pipe of the overflow gas buffer tank is connected to the inlet of the flue gas booster through a circulating gas booster and a water distribution tank.

2. The cement kiln flue gas PSA carbon capture-fly ash washing liquid carbon fixation and decalcification circulation system according to claim 1, characterized in that: The carbon capture system also includes a flue gas pretreatment system, a carbon dioxide pressure swing adsorption system, and a product gas buffer tank. The flue gas booster is connected to the flue gas pretreatment system, the flue gas pretreatment system is connected to the carbon dioxide pressure swing adsorption system, the carbon dioxide pressure swing adsorption system is connected to the product gas buffer tank, and the product gas buffer tank is connected to the carbon dioxide absorption tower.

3. The cement kiln flue gas PSA carbon capture-fly ash washing liquid carbon fixation and decalcification circulation system according to claim 2, characterized in that: The carbon capture system includes a flue gas buffer tank, which is connected to the inlet of the flue gas booster. A water distribution tank is provided between the flue gas pretreatment system and the flue gas booster.

4. The cement kiln flue gas PSA carbon capture-fly ash washing liquid carbon fixation and decalcification circulation system according to claim 2, characterized in that: The flue gas pretreatment system is equipped with an exhaust port, which is connected in parallel to an exhaust pipe and a residual gas transmission pipe. The exhaust pipe discharges gas to the outside, and the residual gas transmission pipe is connected to the product gas buffer tank.

5. The cement kiln flue gas PSA carbon capture-fly ash washing liquid carbon fixation and decalcification circulation system according to claim 4, characterized in that: A vacuum pump is installed between the carbon dioxide pressure swing adsorption system and the product gas buffer tank.

6. The cement kiln flue gas PSA carbon capture-fly ash washing liquid carbon fixation and decalcification circulation system according to claim 5, characterized in that: Unadsorbed gas in the carbon dioxide pressure swing adsorption system is transported to the flue gas pretreatment system through pipelines, and the vented air from the flue gas pretreatment system enters the product gas buffer tank through the residual gas conveying pipeline.

7. The cement kiln flue gas PSA carbon capture-fly ash washing liquid carbon fixation and decalcification circulation system according to claim 6, characterized in that: Flow meters are installed on the pipelines supplying product gas to the product gas buffer tank; carbon dioxide concentration detectors are installed on the pipelines output from the product gas buffer tank.

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