A CO2 mixed gas separation device

Abstract

The application belongs to the field of gas separation and relates to a CO2 mixed gas separation device, which comprises a hollow fiber membrane contactor, the hollow fiber membrane contactor comprising a contactor shell and a plurality of hollow fiber membranes arranged in the contactor shell, the contactor shell being provided with an absorbent liquid inlet and a rich liquid outlet at two ends respectively, the hollow fiber membranes being provided with a mixed gas inlet and a residual gas outlet at two ends respectively, the mixed gas inlet and the rich liquid outlet being located at a first end of the hollow fiber membrane contactor, and the residual gas outlet and the absorbent liquid inlet being located at a second end of the hollow fiber membrane contactor, and the inner surface of the contactor shell being provided with a corrugated groove structure; a desorption unit for desorbing CO2 from the rich liquid; and a storage unit for storing the desorbed CO2. The CO2 mixed gas separation device provided by the application can separate CO2 mixed gas for a long time without causing membrane blockage.

Description

Technical Field

[0001] This application belongs to the field of gas separation and relates to a CO2 mixed gas separation device. Background Technology

[0002] Against the backdrop of global climate change and energy transition, the reduction and resource utilization of carbon dioxide (CO2) emissions has become one of the core issues in scientific research and technological applications. With the acceleration of industrialization, CO2 emissions from fossil fuel combustion, chemical production, and other processes continue to rise, leading to increased concentrations of greenhouse gases in the atmosphere and causing environmental problems such as global warming and frequent extreme weather events. At the same time, CO2, as an important carbon resource, has broad application potential in chemical synthesis, food processing, biopharmaceuticals, and other fields. Its efficient separation and recovery are of great significance for achieving the goal of "carbon neutrality" and a circular economy.

[0003] Traditional CO2 separation technologies, such as chemical absorption and physical adsorption, are mature but suffer from problems such as high energy consumption, equipment corrosion, and secondary pollution. For example, amine solution absorption faces efficiency bottlenecks due to high energy consumption for absorbent regeneration and loss of volatile amines; physical methods such as pressure swing adsorption (PSA) and cryogenic distillation are more suitable for treating high-concentration CO2, but their cost is too high for separating low-concentration flue gas. Against this backdrop, membrane separation technology has become a research hotspot due to its advantages of simple operation, low energy consumption, and environmental friendliness. Among them, membrane absorption technology combines the dual characteristics of membrane separation and chemical / physical absorption, overcoming the limitations of traditional separation technologies by coupling gas-liquid contact with membrane transfer.

[0004] The core of membrane absorption technology lies in utilizing hollow fiber membranes as the gas-liquid interface to reduce membrane wetting and gas-liquid resistance, extend membrane lifespan, and achieve selective and efficient CO2 absorption. Unlike traditional membrane separation, which relies on gas partial pressure differences, membrane absorption technology uses a concentration gradient formed by a chemical or physical reaction between the absorbent in the membrane shell and CO2, driving CO2 diffusion from the gas phase to the liquid phase. This process not only improves the CO2 capture rate but also allows for recycling through absorbent regeneration, significantly reducing energy consumption. Compared to traditional absorption towers, its core advantages are: independent control of the gas and liquid phases, avoiding flooding and mist entrainment; large contact area and high mass transfer efficiency, enabling efficient CO2 capture with lower energy consumption (capture rate ≥90%, desorbed CO2 purity ≥95%). Furthermore, the hydrophobic design of the membrane material inhibits membrane pore wetting, suppresses membrane fouling, reduces absorbent loss, and improves membrane chemical stability and lifespan, making it particularly suitable for the direct capture of low-concentration CO2 sources in complex conditions such as flue gas from thermal power plants, associated gas from oil fields, and industrial emissions. In the future, this technology is expected to play a key role in carbon capture and storage (CCS) and carbon capture, utilization and storage (CCUS), providing technical support for global emission reduction targets. Existing membrane absorption technologies typically use absorbents such as alkanolamine solutions, alkaline carbonate solutions, ionic liquids, and amino acid salt solutions. These absorbents can cause corrosion and pore blockage of membrane modules during long-term operation, and desorption also requires relatively high temperatures, resulting in high energy consumption and costs. Therefore, developing a membrane absorption technology capable of absorbing and desorbing carbon dioxide at relatively low temperatures and achieving low-pressure storage of high-purity CO2 is of significant importance. Summary of the Invention

[0005] The primary objective of this application is to provide a novel CO2 mixture separation device that can stably separate CO2 mixtures over a long period without causing blockage of the hollow fiber membrane.

[0006] The CO2 mixed gas separation device provided in this application includes:

[0007] A hollow fiber membrane contactor includes a contactor housing and a plurality of hollow fiber membranes disposed within the contactor housing. The contactor housing has an absorbent inlet and a rich liquid outlet at both ends. The hollow fiber membranes have a mixed gas inlet and a residual gas outlet at both ends. The mixed gas inlet and the rich liquid outlet are both located at the first end of the hollow fiber membrane contactor, and the residual gas outlet and the absorbent inlet are both located at the second end of the hollow fiber membrane contactor. The inner surface of the contactor housing has a corrugated groove structure.

[0008] The desorption unit is used to desorb CO2 from the rich liquid;

[0009] Storage unit for storing desorbed CO2.

[0010] The key to the CO2 mixed gas separation device provided by this invention lies in the fact that the mixed gas inlet and the rich liquid outlet are both located at the same end of the hollow fiber membrane contactor, while the residual gas outlet and the absorbent inlet are located at the other end of the hollow fiber membrane contactor. Simultaneously, the inner surface of the hollow fiber membrane contactor shell has a corrugated groove structure. During operation, the CO2 mixed gas is introduced into the hollow fiber membrane from the tube side, while the absorbent is introduced into the membrane contactor from the shell side. The CO2 mixed gas in the tube side and the absorbent in the shell side are transported in opposite directions. CO2 in the mixed gas enters the liquid phase through the pores on the surface of the hollow fiber membrane and is absorbed by the absorbent flowing in the shell side. The residual gas in the mixed gas is discharged from the hollow fiber membrane tube side and serves as the primary product gas. The absorbent (rich liquid) in the hollow fiber membrane shell side enters the desorption device for CO2 desorption. The counter-current transport between the CO2 mixed gas and the absorbent makes it easier for CO2 in the mixed gas to enter the absorbent, while the corrugated groove structure on the inner surface of the membrane contactor shell keeps the absorbent in a turbulent state, thereby ensuring sufficient gas-liquid contact time and preventing the formation of inclusions that clog the pores of the hollow fiber membrane. In other words, the countercurrent transmission between the CO2 mixture and the absorbent liquid, along with the corrugated groove structure on the inner surface of the hollow fiber membrane contactor shell, work together to give this CO2 mixture separation device the advantage of being able to separate CO2 mixtures for a long time without causing membrane blockage.

[0011] In a preferred embodiment, the width of the corrugated groove structure on the inner surface of the hollow fiber membrane contactor shell is 1mm-5mm, the depth is 0.5mm-1mm, and the distance between the lowest points of two adjacent corrugated grooves is 0.5mm-1mm. This allows for more perfect interference with the flow state of the absorbent liquid, improving its turbulent dissipation rate, and thus better preventing the formed inclusions from clogging the pores of the hollow fiber membrane.

[0012] In a preferred embodiment, the hollow fiber membrane has a pore size of 0.05μm-10μm and a porosity of 30%-85%, which can significantly reduce gas-liquid mass transfer resistance and enhance the adsorption capacity of liquid relative to gas, thereby improving the separation efficiency of CO2 gas.

[0013] In a preferred embodiment, the hollow fiber membrane filling rate in the hollow fiber membrane contactor is 30%-70%. At this point, the transmission space between the gas and liquid phases can achieve optimal balance and adaptation, which is more conducive to the absorption of CO2 by the absorbent in the tube. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the CO2 mixed gas separation device provided in this application;

[0015] Figure 2 This is a schematic diagram of the hollow fiber membrane contactor provided in this application;

[0016] Figure 3 This is a schematic diagram of a membrane contactor used to separate carbon dioxide mixtures.

[0017] Figure 4 This is a partial schematic diagram of a hollow fiber membrane contactor.

[0018] Explanation of reference numerals in the attached drawings: 100-Hollow fiber membrane contactor; 200-Desorption unit; 300-Heat exchanger; 400-First condenser; 500-Second condenser; 800-Third condenser; 900-Pretreatment unit; 101-Hollow fiber membrane; 102-Mixed gas inlet; 103-Residual gas outlet; 104-Rich liquid outlet; 105-Absorbent inlet. Detailed Implementation

[0019] See Figure 1 and Figure 2 The CO2 mixed gas separation device provided in this application includes a hollow fiber membrane contactor 100 and a desorption unit 200. The hollow fiber membrane contactor 100 includes a contactor housing, and a plurality of hollow fiber membranes 101 (e.g., ...) are disposed within the contactor housing. Figure 4 The contactor housing has an absorbent inlet 105 and a rich liquid outlet 104 at both ends. The hollow fiber membrane has a mixed gas inlet 102 and a residual gas outlet 103 at both ends. The mixed gas inlet and the rich liquid outlet are located at the same end (first end) of the hollow fiber membrane contactor, and the residual gas outlet and the absorbent inlet are located at the same end (second end) of the hollow fiber membrane contactor. The tube side is located inside the hollow fiber membrane filaments, and the shell side is located outside the hollow fiber membrane filaments. The CO2 mixed gas is introduced into the hollow fiber membrane tube side through the mixed gas inlet 102, and the absorbent is introduced into the hollow fiber membrane tube side through the absorbent inlet 104. The two are transported in opposite directions in the hollow fiber membrane. The CO2 in the CO2 mixed gas permeates through the hollow fiber membrane and is absorbed by the absorbent under the action of the absorbent.

[0020] In this application, the inner surface of the contactor housing in the hollow fiber membrane contactor has a corrugated groove structure (e.g., Figure 4This design allows the absorbent to flow in a turbulent state, enhancing gas-liquid mixing and effectively preventing the formation of dynamic framework inclusions that could clog the pipes. This ensures stable separation of the CO2 mixture without membrane pore blockage. The width of the corrugated groove structure in the hollow fiber membrane is preferably 1mm-5mm, such as 1mm, 2mm, 3mm, 4mm, 5mm, or any value between them; the depth is preferably 0.5mm-1mm, such as 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, or any value between them; the distance between the lowest points of two adjacent corrugated grooves is preferably 0.5mm-1mm, such as 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, or any value between them. The hollow fiber membrane preferably has a pore size of 0.05 μm-10 μm, such as 0.05 μm, 0.1 μm, 0.5 μm, 1 μm, 2 μm, 4 μm, 6 μm, 8 μm, 10 μm, or any value between them; the porosity is preferably 30%-85%, such as 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or any value between them. Controlling the pore size and porosity of the hollow fiber membrane within the above-mentioned preferred range can reduce gas-liquid mass transfer resistance and enhance the liquid phase adsorption capacity of the gas. The hollow fiber membrane material can be selected from at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polypropylene (PP), and polyethylene (PE). The outer surface of the hollow fiber membrane is preferably hydrophobically modified. The hydrophobically modified hollow fiber membrane has a larger contact angle with the absorbent, which avoids pore blockage and contamination caused by prolonged wetting of the membrane material, thus reducing gas-liquid mass transfer and extending the service life of the hollow fiber membrane filaments. The hydrophobic modification methods include chemical methods (such as functional group grafting) or physical methods (such as acid-base etching, plasma treatment, ion implantation, surface deposition, etc.). The specific surface area of ​​the hollow fiber membrane is preferably 500-2000 m² / g. 2 / m 3 The specific surface area of ​​traditional chemical absorption packed towers is generally 10-100 m². 2 / m 3 The surface area is tens of times larger, which enhances gas-liquid contact and improves the separation efficiency and selectivity of CO2.

[0021] In this application, the membrane filling rate of the hollow fiber membrane in the hollow fiber membrane contactor is preferably 30%-70%, specifically 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or any value between them. When the membrane filling rate of the hollow fiber membrane in the hollow fiber membrane contactor is controlled at 30%-70%, the transmission space between the gas and liquid phases can achieve optimal balance and adaptation, which is more conducive to the absorption of CO2 by the absorbent in the tube side, and CO2 can be separated from the mixed gas more efficiently.

[0022] In this application, the desorption unit 200 is used to desorb CO2 from a rich solution. The desorption unit 200 preferably includes a desorption tower and a stirrer and heating wire disposed within the desorption tower. The rich solution is introduced into the desorption tower, where CO2 gas is desorbed under the stirring of the stirrer and the heating of the heating wire. After desorption in the desorption tower, the resulting CO2 gas is condensed and dehydrated from the top of the desorption tower, yielding high-purity CO2 gas and condensate. The high-purity CO2 gas can be stored in a carbon dioxide storage tank using packing material, and the condensate re-enters the bottom of the desorption tower to ensure that the concentration of the absorbent remains constant. Furthermore, the desorption temperature is preferably 30℃-50℃, such as 30℃, 32℃, 35℃, 38℃, 40℃, 42℃, 45℃, 48℃, 50℃, or any value between them.

[0023] When separating a CO2 mixture using the CO2 mixture separation device provided by this invention, the CO2 mixture and the absorbent are transported countercurrently in the tube side and shell side of the hollow fiber membrane, respectively. CO2 in the CO2 mixture permeates through the hollow fiber membrane under pressure and is absorbed by the absorbent, then desorbed from the resulting CO2-rich solution. In the tube side, CO2 permeates through the pores of the hollow fiber membrane under the action of the absorbent and is absorbed by the absorbent flowing in the shell side. The remaining gas in the components is discharged from the tube side of the hollow fiber membrane as product gas. The absorbent (rich solution) in the shell side of the hollow fiber membrane, after CO2 absorption, is desorbed to obtain CO2.

[0024] In this application, the absorbent can be any existing liquid capable of separating the mixed gas from the mixed gas, preferably containing a water-soluble guanidine salt, a quaternary ammonium salt, and a kinetic aid. The mass ratio of the water-soluble guanidine salt, the quaternary ammonium salt, and the kinetic aid is 100:(12.5-100):(2.5-25). The water-soluble guanidine salt in the absorbent is the main absorbent; a higher concentration is more conducive to CO2 absorption, but a high concentration can also increase gas-liquid mass transfer resistance and cause blockage. Specifically, the mass ratio of the water-soluble guanidine salt to the quaternary ammonium salt can be 100:12.5, 100:15, 100:18, 100:20, 100:25, 100:30, 100:35, 100:40, 100:45, 100:50, 100:55, 100:60, 100:65, 100:70, 100:75, 100:80, 100:85, 100:90, 100:95, 100:100, or any value between them. The mass ratio of the water-soluble guanidine salt to the kinetic agent can be 100:2.5, 100:5, 100:8, 100:10, 100:12.5, 100:15, 100:18, 100:20, 100:22, 100:25 or any value between them.

[0025] In a preferred embodiment, the absorbent contains 20wt%-40wt% of a water-soluble guanidine salt, 5wt%-20wt% of a quaternary ammonium salt, and 1wt%-5wt% of a kinetic aid, with the remainder being water. In this configuration, the components can better exert their synergistic effect, enabling longer-term and more effective separation of CO2 from the CO2 mixture. Specifically, the content of the water-soluble guanidine salt can be 20wt%, 22wt%, 25wt%, 28wt%, 30wt%, 32wt%, 35wt%, 38wt%, 40wt%, or any value between these values. The content of the quaternary ammonium salt can be 5wt%, 8wt%, 10wt%, 12wt%, 15wt%, 18wt%, 20wt%, or any value between these values. The content of the kinetic aid can be 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, or any value between these values.

[0026] In this application, the water-soluble guanidine salt molecule disrupts the formation of hydrogen bonds in water. Its unique bond angles and crystal structure interact with water molecules to form a dynamic hydrogen bond framework structure. The guanidine groups on the surface of this unique dynamic hydrogen bond framework structure have a strong "attraction" to acidic gas molecules. At the same time, the internal space of this dynamic hydrogen bond framework structure is about the size of a CO2 molecule, which can adsorb and "lock" acidic gas molecules of the corresponding size into the dynamic hydrogen bond framework structure. Examples of the water-soluble guanidine salt include, but are not limited to, at least one of guanidine sulfate, guanidine hydrochloride, guanidine carbonate, guanidine phosphate, guanidine nitrate, guanidine bromate, guanidine acetate, guanidine lactate, guanidine methanesulfonate, dimethylguanidine hydrochloride, and aminoguanidine bicarbonate, preferably guanidine sulfate. Furthermore, the dynamic hydrogen bond framework structure formed by the water-soluble guanidine salt with carbon dioxide and water molecules is an exothermic reaction. Therefore, lowering the absorption temperature can promote the adsorption effect. At normal pressure, carbon dioxide gas will be slowly released when the temperature exceeds 30°C. The rate of carbon dioxide release is proportional to the temperature, resulting in lower energy consumption than the desorption temperature of traditional membranes (usually 80-100°C).

[0027] In this application, the quaternary ammonium salt can form a semi-cage hydrogen bond structure with water molecules, which can effectively capture CO2 molecules in water. The quaternary ammonium salt is a type of compound formed by substituting four hydrogen atoms in an ammonium ion with a hydrocarbon group, preferably having the general formula R4NX. The four hydrocarbon groups R can be the same or different, and can be independently C1-C10 alkyl groups, preferably C1-C5 alkyl groups, specifically selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, or neopentyl. X can be a halide ion (such as F). - Cl - ,Br - Or I - ) or anions (such as HSO4) - RCOO - (etc.). From the perspective of the availability of raw materials, the quaternary ammonium salt is preferably at least one selected from tetrabutylammonium bromide, tetrabutylammonium fluoride, tetrabutylammonium chloride, tetrabutylphosphine bromide, tetraisopentylammonium bromide, tetrabutylammonium nitrate, and tetrabutylammonium acetate.

[0028] In this application, the kinetic aid is selected from at least one of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, and cucurbita. The cavity structure formed by these kinetic aid molecules themselves can accelerate and enhance the absorption of CO2 molecules in water, acting as a "surfactant" to synergize with water-soluble guanidine salts and quaternary ammonium salts in the selective adsorption of carbon dioxide. It also significantly reduces the viscosity of water-soluble guanidine salts, lowers the interfacial resistance between the absorbent and the hollow fiber membrane, increases the gas flux through the membrane, and significantly enhances the stability of the membrane fibers.

[0029] In this application, the temperature of the absorbent is preferably 5℃-20℃, such as 5℃, 8℃, 10℃, 12℃, 15℃, 18℃, 20℃, or any value between them. Generally, the temperature of the absorbent can be adjusted according to the CO2 composition in the gas mixture. If the CO2 content in the remaining gas exceeds the automotive fuel standard GB / T18047-2000, the absorption temperature can be appropriately reduced; conversely, the absorption temperature can be increased. The pressure difference between the CO2 gas mixture and the absorbent is preferably 5kPa-15kPa, such as 5kPa, 8kPa, 10kPa, 12kPa, 15kPa, or any value between them.

[0030] See Figure 1 The CO2 mixed gas separation device may further include a heat exchanger 300 located downstream of the hollow fiber membrane contactor and upstream of the desorption unit, for exchanging heat between the rich liquid from the hollow fiber membrane contactor 100 and the lean liquid from the bottom of the desorption tower 200. The rich liquid after heat exchange is introduced into the desorption tower 200 for CO2 desorption, and the lean liquid after heat exchange is returned to the hollow fiber membrane contactor 100 as an absorbent for recycling. At this time, the lean liquid can be used as a heat source to heat the rich liquid, thereby realizing the effective utilization of energy.

[0031] See Figure 1 The CO2 mixed gas separation device may further include a first condenser 400 and a second condenser 500. The first condenser 400 is used to cool the lean liquid after heat exchange, and the second condenser 500 is used to condense, dry and remove water from the CO2 gas drawn from the top of the desorption tower 200.

[0032] See Figure 1 The CO2 mixed gas separation device also includes a compressor 600 and a carbon dioxide storage tank 700. The compressor 600 is used to compress CO2 gas originating from the top of the desorption tower 200, and the carbon dioxide storage tank 700 is used to store the compressed CO2 gas. The packing material in the carbon dioxide storage tank 700 is typically guanidine sulfate powder. High-purity CO2 gas is pressurized and enters the carbon dioxide storage tank 700 filled with guanidine sulfate powder. Due to the high purity of CO2 and its easy combination with guanidine sulfate molecules, CO2 quickly forms inclusion complexes with guanidine sulfate powder at low pressure and ambient temperature. The amount of CO2 stored depends on the given pressure. The amount of CO2 gas stored in guanidine sulfate is directly proportional to the pressure. At a room temperature of 6 MPa, a maximum of 50 wt% of the weight of guanidine sulfate in CO2 gas can be stored, and the stable stored solid can remain stable for several years at a pressure of 20 kPa and ambient temperature. During subsequent use, it can be heated to 30-50℃ to quickly release CO2 gas, and the solid filler can be recycled for a long time without causing environmental pollution. It has higher safety and lower energy consumption than traditional high-pressure cylinder storage.

[0033] See Figure 1 The CO2 mixture separation device further includes a third condenser 800 and a pretreatment unit 900 located upstream of the hollow fiber membrane contactor 100. The first condenser 800 is used to condense and cool the CO2 mixture, and the pretreatment unit 900 is used to pretreat the condensed mixture to remove water, oil and particulate matter.

[0034] The CO2 mixed gas separation device provided in this application is suitable for separating various existing mixed gases (gases) consisting of CO2 and weakly acidic or non-acidic and non-water-soluble gases. Preferably, the volume percentage of CO2 in the CO2 mixed gas is 15% to 85%, and the volume percentage of the mixed gas is also preferably 15% to 85%. Specifically, the volume percentages of CO2 and the mixed gas can each be independently 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or any value between them. The mixed gas can specifically be at least one of N2, H2, O2, CO, CH4, C2H6, and C3H8.

[0035] The present application will be described in detail below through examples.

[0036] Example 1

[0037] See Figure 1 and Figure 2The CO2 mixed gas separation device used in this embodiment includes a hollow fiber membrane contactor 100, a desorption unit 200, a heat exchanger 300, a first condenser 400, a second condenser 500, a compressor 600, and a carbon dioxide storage tank 700. The hollow fiber membrane contactor 100 includes a contactor housing with a plurality of hollow fiber membranes 101 disposed within it. The contactor housing has an absorbent inlet 105 and a rich liquid outlet 104 at both ends. The hollow fiber membranes have a mixed gas inlet 102 and a residual gas outlet 103 at both ends. The mixed gas inlet 102 and the rich liquid outlet 104 are both located at the same end (first end) of the hollow fiber membrane contactor, and the residual gas outlet 103 and the absorbent inlet 105 are both located at the same end (second end) of the hollow fiber membrane contactor 100. The hollow fiber membrane 101 is a polytetrafluoroethylene membrane with a pore size of 10 μm, a porosity of 30%, and a membrane packing ratio of 30%. The inner surface of the contactor housing has a corrugated groove structure with a width of 1 mm and a depth of 1 mm, and the distance between the lowest points of two adjacent corrugated grooves is 0.5 mm. The desorption unit 200 includes a desorption tower and a stirrer and heating wire disposed within the desorption tower. A heat exchanger 300 is disposed downstream of the hollow fiber membrane contactor 100 and upstream of the desorption unit 200, used to exchange heat between the rich liquid originating from the hollow fiber membrane contactor 100 and the lean liquid originating from the bottom of the desorption tower 200. The rich liquid after heat exchange is introduced into the desorption tower 200 for CO2 desorption, and the lean liquid after heat exchange is returned to the hollow fiber membrane contactor 100 as an absorbent for recycling. A first condenser 400 is used to condense the lean liquid after heat exchange, and a second condenser 500 is used to condense and dry the CO2 gas drawn from the top of the desorption tower 200. Compressor 600 is used to compress CO2 gas originating from the top of desorption tower 200, and carbon dioxide storage tank 700 is used to store the compressed CO2 gas. The packing material in carbon dioxide storage tank 700 is guanidine sulfate powder.

[0038] Guanidine sulfate, tetrabutylammonium bromide, α-cyclodextrin and water were mixed evenly. The amount of guanidine sulfate added was 30 wt%, the amount of tetrabutylammonium bromide added was 10 wt%, the amount of α-cyclodextrin added was 3 wt%, and the remainder was water, to obtain an absorbent solution, denoted as ABS-001.

[0039] When separating CO2 mixtures using the above CO2 mixture separation device, the CO2 mixture (volume ratio of 15% CO2 + 85% N2) enters the hollow fiber membrane from the tube side, flowing counter-currently with the absorbent (ABS-001) introduced from the shell side. The gas phase pressure is controlled at 10 kPa, and the liquid phase pressure is controlled at 5 kPa (gas phase pressure is greater than liquid phase pressure). The membrane absorption temperature is controlled at 5℃. CO2 in the tube side mixture enters the liquid phase through the pores on the surface of the hollow fiber membrane and is absorbed by the absorbent flowing in the shell side. The remaining gas in the mixture is discharged from the tube side of the hollow fiber membrane and serves as the initial product gas. The shell side absorbent (rich liquid) of the hollow fiber membrane is heated by heat exchanger 300 and then enters the desorption tower for CO2 desorption. The desorption temperature is controlled at 40℃. The product gas obtained after desorption is compressed by compressor 600 and then introduced into carbon dioxide storage tank 700 for storage. The pressure absorbed by the guanidine sulfate powder packing is 2 MPa.

[0040] Using the above device and method, the separation of a mixture of 15% CO2 and 85% N2 by volume can be achieved. The purity of the remaining N2 gas is 98%, and the purity of the desorbed CO2 gas is 99%. The hollow fiber membrane contactor has been running continuously for 12 months without any blockage causing a decrease in mass transfer rate.

[0041] Example 2

[0042] See Figure 1 and Figure 2The CO2 mixed gas separation device used in this embodiment includes a hollow fiber membrane contactor 100, a desorption unit 200, a heat exchanger 300, a first condenser 400, a second condenser 500, a compressor 600, and a carbon dioxide storage tank 700. The hollow fiber membrane contactor 100 includes a contactor housing with a plurality of hollow fiber membranes 101 disposed therein. The contactor housing has an absorbent inlet 105 and a rich liquid outlet 104 at both ends. The hollow fiber membranes have a mixed gas inlet 102 and a residual gas outlet 103 at both ends. The mixed gas inlet 102 and the rich liquid outlet 104 are both located at the same end (first end) of the hollow fiber membrane contactor, and the residual gas outlet 103 and the absorbent inlet 105 are both located at the same end (second end) of the hollow fiber membrane contactor 100. The hollow fiber membrane 101 is a polytetrafluoroethylene membrane with a pore size of 1 μm, a porosity of 85%, and a membrane packing ratio of 70%. The inner surface of the contactor housing has a corrugated groove structure with a width of 5 mm and a depth of 0.5 mm, and the distance between the lowest points of two adjacent corrugated grooves is 1 mm. The desorption unit 200 includes a desorption tower and a stirrer and heating wire disposed within the desorption tower. A heat exchanger 300 is disposed downstream of the hollow fiber membrane contactor 100 and upstream of the desorption unit 200, used to exchange heat between the rich liquid originating from the hollow fiber membrane contactor 100 and the lean liquid originating from the bottom of the desorption tower 200. The rich liquid after heat exchange is introduced into the desorption tower 200 for CO2 desorption, and the lean liquid after heat exchange is returned to the hollow fiber membrane contactor 100 as an absorbent for recycling. A first condenser 400 is used to condense the lean liquid after heat exchange, and a second condenser 500 is used to condense the CO2 gas drawn from the top of the desorption tower 200. A compressor 600 is used to compress the CO2 gas originating from the top of the desorption tower 200, and a carbon dioxide storage tank 700 is used to store the compressed CO2 gas. The packing material in the carbon dioxide storage tank 700 is guanidine sulfate powder.

[0043] Guanidine sulfate, tetrabutylammonium fluoride, β-cyclodextrin and water were mixed evenly. The amount of guanidine sulfate added was 30 wt%, the amount of tetrabutylammonium fluoride added was 10 wt%, the amount of β-cyclodextrin added was 3 wt%, and the balance was water, to obtain the absorbent solution, which was denoted as ABS-002.

[0044] When separating CO2 mixtures using the above CO2 mixture separation device, the CO2 mixture (volume ratio of 15% CO2 + 85% H2) enters the hollow fiber membrane from the tube side, flowing counter-currently with the absorbent (ABS-002) introduced from the shell side. The gas phase pressure is controlled at 10 kPa, the liquid phase pressure at 2 kPa, and the membrane absorption temperature at 5°C. CO2 in the tube-side mixture enters the liquid phase through the pores on the surface of the hollow fiber membrane and is absorbed by the absorbent flowing in the shell side. The remaining gas in the mixture is discharged from the tube side of the hollow fiber membrane as the initial product gas. The shell-side absorbent (rich liquid) of the hollow fiber membrane is heated by heat exchanger 300 and then enters the desorption tower for CO2 desorption. The desorption temperature is controlled at 40°C. The product gas obtained after desorption is compressed by compressor 600 and then introduced into carbon dioxide storage tank 700 for storage. The pressure absorbed by the guanidine sulfate powder packing is 2 MPa.

[0045] Using the above device and method, the separation of a mixture of 15% CO2 and 85% H2 by volume can be achieved. The purity of the residual H2 gas is 96%, and the purity of the desorbed CO2 gas is 95%. The hollow fiber membrane contactor has been running continuously for 8 months without reducing the purity of the product gas or causing a decrease in mass transfer rate due to blockage.

[0046] Example 3

[0047] See Figure 1 and Figure 2The CO2 mixed gas separation device used in this embodiment includes a hollow fiber membrane contactor 100, a desorption unit 200, a heat exchanger 300, a first condenser 400, a second condenser 500, a compressor 600, and a carbon dioxide storage tank 700. The hollow fiber membrane contactor 100 includes a contactor housing, and a plurality of hollow fiber membranes 101 are disposed within the contactor housing. The hollow fiber membrane contactor 100 includes a mixed gas inlet 102 and a residual gas outlet 103 disposed at both ends of the tube side of the hollow fiber membrane 101, and an absorbent liquid inlet 105 and a rich liquid outlet 104 disposed at both ends of the shell side of the hollow fiber membrane 101. The mixed gas inlet 102 and the rich liquid outlet 104 are both located at the same end (first end) of the hollow fiber membrane contactor, and the residual gas outlet 103 and the absorbent liquid inlet 105 are both located at the same end (second end) of the hollow fiber membrane contactor 100. The hollow fiber membrane 101 is a polytetrafluoroethylene membrane with a pore size of 5 μm, a porosity of 50%, and a membrane packing ratio of 50%. The inner surface of the contactor shell has a corrugated groove structure with a width of 2 mm and a depth of 0.8 mm, and the distance between the lowest points of two adjacent corrugated grooves is 0.8 mm. The desorption unit 200 includes a desorption tower and a stirrer and heating wire disposed within the desorption tower. The heat exchanger 300 is disposed downstream of the hollow fiber membrane contactor 100 and upstream of the desorption unit 200, and is used to exchange heat between the rich liquid originating from the hollow fiber membrane contactor 100 and the lean liquid originating from the bottom of the desorption tower 200. The rich liquid after heat exchange is introduced into the desorption tower 200 for CO2 desorption, and the lean liquid after heat exchange is returned to the hollow fiber membrane contactor 100 as an absorbent for recycling. The first condenser 400 is used to condense the lean liquid after heat exchange, and the second condenser 500 is used to condense the CO2 gas drawn from the top of the desorption tower 200. Compressor 600 is used to compress CO2 gas originating from the top of desorption tower 200, and carbon dioxide storage tank 700 is used to store the compressed CO2 gas. The packing material in carbon dioxide storage tank 700 is guanidine sulfate powder.

[0048] Guanidine sulfate, tetrabutylammonium chloride, γ-cyclodextrin and water were mixed evenly. The amount of guanidine sulfate added was 30 wt%, the amount of tetrabutylammonium chloride added was 10 wt%, the amount of γ-cyclodextrin added was 3 wt%, and the remainder was water, to obtain an absorbent solution, denoted as ABS-003.

[0049] When separating CO2 mixtures using the above CO2 mixture separation device, the CO2 mixture (volume ratio of 15% CO2 + 85% O2) enters the hollow fiber membrane from the tube side, flowing counter-currently with the absorbent (ABS-003) introduced from the shell side. The gas phase pressure is controlled at 15 kPa, the liquid phase pressure at 2 kPa, and the membrane absorption temperature at 20°C. CO2 in the tube-side mixture enters the liquid phase through the pores on the surface of the hollow fiber membrane and is absorbed by the absorbent flowing in the shell side. The remaining gas in the mixture is discharged from the tube side of the hollow fiber membrane as the initial product gas. The shell-side absorbent (rich liquid) of the hollow fiber membrane is heated by heat exchanger 300 and then enters the desorption tower for CO2 desorption. The desorption temperature is controlled at 40°C. The resulting product gas after desorption is compressed by compressor 600 and then stored in carbon dioxide storage tank 700. The pressure absorbed by the guanidine sulfate powder packing is 2 MPa.

[0050] Using the above device and method, the separation of a mixture of 15% CO2 and 85% O2 by volume can be achieved. The purity of the remaining O2 is 93%, and the purity of the desorbed CO2 is 89%. The hollow fiber membrane contactor has been running continuously for 5 months without reducing the purity of the product gas or causing a decrease in mass transfer rate due to blockage.

[0051] Example 4

[0052] See Figure 1 and Figure 2The CO2 mixed gas separation device used in this embodiment includes a hollow fiber membrane contactor 100, a desorption unit 200, a heat exchanger 300, a first condenser 400, a second condenser 500, a compressor 600, and a carbon dioxide storage tank 700. The hollow fiber membrane contactor 100 includes a contactor housing with a plurality of hollow fiber membranes 101 disposed within it. The contactor housing has an absorbent inlet 105 and a rich liquid outlet 104 at both ends. The hollow fiber membranes have a mixed gas inlet 102 and a residual gas outlet 103 at both ends. The mixed gas inlet 102 and the rich liquid outlet 104 are located at the same end (first end) of the hollow fiber membrane contactor, and the residual gas outlet 103 and the absorbent inlet 105 are located at the same end (second end) of the hollow fiber membrane contactor 100. The hollow fiber membrane 101 is a polytetrafluoroethylene membrane with a pore size of 8 μm, a porosity of 45%, and a membrane packing ratio of 45%. The inner surface of the contactor housing has a corrugated groove structure with a width of 3 mm and a depth of 1 mm, and the distance between the lowest points of two adjacent corrugated grooves is 0.8 mm. The desorption unit 200 includes a desorption tower and a stirrer and heating wire disposed within the desorption tower. A heat exchanger 300 is disposed downstream of the hollow fiber membrane contactor 100 and upstream of the desorption unit 200, used to exchange heat between the rich liquid originating from the hollow fiber membrane contactor 100 and the lean liquid originating from the bottom of the desorption tower 200. The rich liquid after heat exchange is introduced into the desorption tower 200 for CO2 desorption, and the lean liquid after heat exchange is returned to the hollow fiber membrane contactor 100 as an absorbent for recycling. A first condenser 400 is used to condense the lean liquid after heat exchange, and a second condenser 500 is used to condense the CO2 gas drawn from the top of the desorption tower 200. A compressor 600 is used to compress the CO2 gas originating from the top of the desorption tower 200, and a carbon dioxide storage tank 700 is used to store the compressed CO2 gas. The packing material in the carbon dioxide storage tank 700 is guanidine sulfate powder.

[0053] Guanidine sulfate, tetrabutylammonium acetate, cucurbitacin and water were mixed evenly. The amount of guanidine sulfate added was 30 wt%, the amount of tetrabutylammonium acetate added was 10 wt%, the amount of cucurbitacin added was 3 wt%, and the remainder was water, to obtain the absorbent solution, which was denoted as ABS-004.

[0054] When separating CO2 mixtures using the above CO2 mixture separation device, the CO2 mixture (volume ratio of 15% CO2 + 85% CH4) enters the hollow fiber membrane from the tube side, flowing counter-currently with the absorbent (ABS-004) introduced from the shell side. The gas phase pressure is controlled at 10 kPa, the liquid phase pressure at 5 kPa, and the membrane absorption temperature at 10°C. CO2 in the tube-side mixture enters the liquid phase through the pores on the surface of the hollow fiber membrane and is absorbed by the absorbent flowing in the shell side. The remaining gas in the mixture is discharged from the tube side of the hollow fiber membrane as the initial product gas. The shell-side absorbent (rich liquid) of the hollow fiber membrane is heated by heat exchanger 300 and then enters the desorption tower for CO2 desorption. The desorption temperature is controlled at 40°C. The resulting product gas after desorption is compressed by compressor 600 and then stored in carbon dioxide storage tank 700. The pressure absorbed by the guanidine sulfate powder packing is 2 MPa.

[0055] Using the above device and method, the separation of a mixture of 15% CO2 and 85% CH4 by volume can be achieved. The purity of the remaining CH4 gas is 90%, and the purity of the desorbed CO2 gas is 87%. The hollow fiber membrane contactor has been running continuously for 2 months without reducing the purity of the product gas or causing a decrease in mass transfer rate due to blockage.

[0056] Example 5

[0057] See Figure 1 and Figure 2The CO2 mixed gas separation device used in this embodiment includes a hollow fiber membrane contactor 100, a desorption unit 200, a heat exchanger 300, a first condenser 400, a second condenser 500, a compressor 600, and a carbon dioxide storage tank 700. The hollow fiber membrane contactor 100 includes a contactor housing with a plurality of hollow fiber membranes 101 disposed within it. The contactor housing has an absorbent inlet 105 and a rich liquid outlet 104 at both ends. The hollow fiber membranes have a mixed gas inlet 102 and a residual gas outlet 103 at both ends. The mixed gas inlet 102 and the rich liquid outlet 104 are located at the same end (first end) of the hollow fiber membrane contactor, and the residual gas outlet 103 and the absorbent inlet 105 are located at the same end (second end) of the hollow fiber membrane contactor 100. The hollow fiber membrane 101 is a polytetrafluoroethylene membrane with a pore size of 6 μm, a porosity of 55%, and a membrane packing ratio of 38%. The inner surface of the contactor housing has a corrugated groove structure with a width of 4 mm and a depth of 0.9 mm, and the distance between the lowest points of two adjacent corrugated grooves is 0.8 mm. The desorption unit 200 includes a desorption tower and a stirrer and heating wire disposed within the desorption tower. A heat exchanger 300 is disposed downstream of the hollow fiber membrane contactor 100 and upstream of the desorption unit 200, used to exchange heat between the rich liquid originating from the hollow fiber membrane contactor 100 and the lean liquid originating from the bottom of the desorption tower 200. The rich liquid after heat exchange is introduced into the desorption tower 200 for CO2 desorption, and the lean liquid after heat exchange is returned to the hollow fiber membrane contactor 100 as an absorbent for recycling. A first condenser 400 is used to condense the lean liquid after heat exchange, and a second condenser 500 is used to condense the CO2 gas drawn from the top of the desorption tower 200. Compressor 600 is used to compress CO2 gas originating from the top of desorption tower 200, and carbon dioxide storage tank 700 is used to store the compressed CO2 gas. The packing material in carbon dioxide storage tank 700 is guanidine sulfate powder.

[0058] Guanidine sulfate, tetrabutylammonium nitrate, α-cyclodextrin and water were mixed evenly. The amount of guanidine sulfate added was 30 wt%, the amount of tetrabutylammonium nitrate added was 10 wt%, the amount of α-cyclodextrin added was 3 wt%, and the remainder was water, to obtain an absorbent solution, denoted as ABS-005.

[0059] When separating CO2 mixtures using the above CO2 mixture separation device, the CO2 mixture (volume ratio of 15% CO2 + 85% C2H6) enters the hollow fiber membrane from the tube side, flowing counter-currently with the absorbent (ABS-005) introduced from the shell side. The gas phase pressure is controlled at 10 kPa, the liquid phase pressure at 5 kPa, and the membrane absorption temperature at 10°C. CO2 in the tube-side mixture enters the liquid phase through the pores on the surface of the hollow fiber membrane and is absorbed by the absorbent flowing in the shell side. The remaining gas in the mixture is discharged from the tube side of the hollow fiber membrane and serves as the initial product gas. The shell-side absorbent (rich liquid) of the hollow fiber membrane is heated by heat exchanger 300 and then enters the desorption tower for CO2 desorption. The desorption temperature is controlled at 40°C. The resulting product gas after desorption is compressed by compressor 600 and then stored in carbon dioxide storage tank 700. The pressure absorbed by the guanidine sulfate powder packing is 2 MPa.

[0060] Using the above device and method, the separation of a mixture of 15% CO2 and 85% C2H6 by volume can be achieved. The purity of the residual gas C2H6 is 92%, and the purity of the desorbed gas CO2 is 83%. The hollow fiber membrane contactor has been running continuously for 8 months without reducing the purity of the product gas or causing a decrease in mass transfer rate due to blockage.

[0061] Example 6

[0062] See Figure 1 and Figure 2The CO2 mixed gas separation device used in this embodiment includes a hollow fiber membrane contactor 100, a desorption unit 200, a heat exchanger 300, a first condenser 400, a second condenser 500, a compressor 600, and a carbon dioxide storage tank 700. The hollow fiber membrane contactor 100 includes a contactor housing with a plurality of hollow fiber membranes 101 disposed within it. The contactor housing has an absorbent inlet 105 and a rich liquid outlet 104 at both ends. The hollow fiber membranes have a mixed gas inlet 102 and a residual gas outlet 103 at both ends. The mixed gas inlet 102 and the rich liquid outlet 104 are both located at the same end (first end) of the hollow fiber membrane contactor, and the residual gas outlet 103 and the absorbent inlet 105 are both located at the same end (second end) of the hollow fiber membrane contactor 100. The hollow fiber membrane 101 is a polytetrafluoroethylene membrane with a pore size of 8 μm, a porosity of 55%, and a membrane packing ratio of 60%. The inner surface of the contactor housing has a corrugated groove structure with a width of 3 mm and a depth of 0.7 mm, and the distance between the lowest points of two adjacent corrugated grooves is 0.6 mm. The desorption unit 200 includes a desorption tower and a stirrer and heating wire disposed within the desorption tower. A heat exchanger 300 is disposed downstream of the hollow fiber membrane contactor 100 and upstream of the desorption unit 200, used to exchange heat between the rich liquid originating from the hollow fiber membrane contactor 100 and the lean liquid originating from the bottom of the desorption tower 200. The rich liquid after heat exchange is introduced into the desorption tower 200 for CO2 desorption, and the lean liquid after heat exchange is returned to the hollow fiber membrane contactor 100 as an absorbent for recycling. A first condenser 400 is used to condense the lean liquid after heat exchange, and a second condenser 500 is used to condense the CO2 gas drawn from the top of the desorption tower 200. Compressor 600 is used to compress CO2 gas originating from the top of desorption tower 200, and carbon dioxide storage tank 700 is used to store the compressed CO2 gas. The packing material in carbon dioxide storage tank 700 is guanidine sulfate powder.

[0063] Guanidine sulfate, tetraisopentylammonium bromide, γ-cyclodextrin and water were mixed evenly. The amount of guanidine sulfate added was 50 wt%, the amount of tetraisopentylammonium bromide added was 5 wt%, the amount of γ-cyclodextrin added was 5 wt%, and the remainder was water, to obtain the absorbent solution, which was denoted as ABS-006.

[0064] When separating CO2 mixtures using the above CO2 mixture separation device, the CO2 mixture (volume ratio of 15% CO2 + 85% C3H8) enters the hollow fiber membrane from the tube side, flowing counter-currently with the absorbent (ABS-006) introduced from the shell side. The gas phase pressure is controlled at 10 kPa, the liquid phase pressure at 5 kPa, and the membrane absorption temperature at 10°C. CO2 in the tube-side mixture enters the liquid phase through the pores on the surface of the hollow fiber membrane and is absorbed by the absorbent flowing in the shell side. The remaining gas in the mixture is discharged from the tube side of the hollow fiber membrane and serves as the initial product gas. The shell-side absorbent (rich liquid) of the hollow fiber membrane is heated by heat exchanger 300 and then enters the desorption tower for CO2 desorption. The desorption temperature is controlled at 40°C. The resulting product gas after desorption is compressed by compressor 600 and then stored in carbon dioxide storage tank 700. The pressure absorbed by the guanidine sulfate powder packing is 2 MPa.

[0065] Using the above device and method, the separation of a mixture of 15% CO2 and 85% C3H8 by volume can be achieved. The purity of the remaining C3H8 gas is 90%, and the purity of the desorbed CO2 gas is 84%. The hollow fiber membrane contactor has not reduced the purity of the product gas for two consecutive months and has not caused any blockage that would reduce the mass transfer rate.

[0066] Example 7

[0067] The CO2 mixture was separated according to the method of Example 1. The difference was that in this example, the width of the corrugated groove structure of the hollow fiber membrane was 10 mm, the depth was 2 mm, and the distance between the lowest points of two adjacent corrugated grooves was 2 mm. All other conditions were the same as in Example 1. Using this device and method, a mixture of 15% CO2 and 85% N2 by volume could be separated. The purity of the remaining N2 gas was 95%, and the purity of the desorbed CO2 gas was 91%. The hollow fiber membrane contactor operated continuously for 10 months without reducing the purity of the product gas or causing a decrease in mass transfer rate due to blockage.

[0068] Example 8

[0069] The CO2 mixture was separated according to the method of Example 1, except that the hollow fiber membrane filling rate in the CO2 mixture separation device used in this example was 75%, while the other conditions were the same as in Example 1. Using this device and method, a mixture of 15% CO2 and 85% N2 by volume can be separated, with the purity of the residual N2 gas being 94% and the purity of the desorbed CO2 gas being 87%. The hollow fiber membrane contactor operated continuously for 6 months without reducing the purity of the product gas or causing a decrease in mass transfer rate due to blockage.

[0070] Comparative Example 1

[0071] The CO2 mixture was separated according to the method of Example 1. The difference is that the inner surface of the contactor shell in the CO2 mixture separation device used in this example is flat and does not have a corrugated groove structure. The other conditions are the same as in Example 1. Using this device and method, a mixture of 15% CO2 and 85% C3H8 by volume can be separated. The purity of the residual C3H8 gas is 87%, and the purity of the desorbed CO2 gas is 70%. The hollow fiber membrane contactor operated continuously for 2 months without reducing the purity of the product gas or causing a decrease in mass transfer rate due to blockage.

[0072] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application without departing from the principles and spirit of this application.

Claims

1. A CO2 mixed gas separation device, characterized in that, include: A hollow fiber membrane contactor includes a contactor housing and a plurality of hollow fiber membranes disposed within the contactor housing. The contactor housing has an absorbent inlet and a rich liquid outlet at both ends. The hollow fiber membranes have a mixed gas inlet and a residual gas outlet at both ends. The mixed gas inlet and the rich liquid outlet are both located at the first end of the hollow fiber membrane contactor, and the residual gas outlet and the absorbent inlet are both located at the second end of the hollow fiber membrane contactor. The inner surface of the contactor housing has a corrugated groove structure; The desorption unit is used to desorb CO2 from the rich liquid; Storage unit for storing desorbed CO2.

2. The CO2 mixed gas separation device according to claim 1, characterized in that, The width of the corrugated groove structure on the inner surface of the contactor housing is 1mm-5mm, the depth is 0.5mm-1mm, and the distance between the lowest points of two adjacent corrugated grooves is 0.5mm-1mm.

3. The CO2 mixed gas separation device according to claim 1, characterized in that, The hollow fiber membrane has a pore size of 0.05μm-10μm and a porosity of 30%-85%.

4. The CO2 mixed gas separation device according to claim 1, characterized in that, The hollow fiber membrane filling rate in the hollow fiber membrane contactor is 30%-70%.

5. The CO2 mixed gas separation device according to any one of claims 1-4, characterized in that, The desorption unit includes a desorption tower and a stirrer and heating wire disposed within the desorption tower.

6. The CO2 mixed gas separation device according to claim 5, characterized in that, The CO2 mixed gas separation device also includes a heat exchanger located downstream of the hollow fiber membrane contactor and upstream of the desorption unit, used to exchange heat between the rich liquid from the hollow fiber membrane contactor and the lean liquid from the bottom of the desorption tower. The rich liquid after heat exchange is introduced into the desorption tower for CO2 desorption, and the lean liquid after heat exchange is returned to the hollow fiber membrane contactor as an absorbent for recycling.

7. The CO2 mixed gas separation device according to claim 5, characterized in that, The CO2 mixed gas separation device further includes a first condenser and a second condenser. The first condenser is used to condense the lean liquid after heat exchange, and the second condenser is used to condense the CO2 gas drawn from the top of the desorption tower.

8. The CO2 mixed gas separation device according to claim 6 or 7, characterized in that, The CO2 mixed gas separation device also includes a compressor and a carbon dioxide storage tank. The compressor is used to compress the CO2 gas originating from the top of the desorption tower, and the carbon dioxide storage tank is used to store the compressed CO2 gas.

9. The CO2 mixed gas separation device according to claim 1, characterized in that, The CO2 mixture separation device also includes a third condenser and a pretreatment unit located upstream of the hollow fiber membrane contactor. The third condenser is used to cool the CO2 mixture, and the pretreatment unit is used to pretreat the condensed mixture to remove water, oil and particulate matter.

Images