An interface enhanced carbon capture system and method

Abstract

The application discloses an interface reinforced carbon capture system and method, which is used for CO2 absorption and desorption process and at least comprises: an absorption tower which is used for receiving a solution absorption system running from top to bottom and a carbon-containing gas from bottom to top, and performing gas-liquid mass transfer under high pressure conditions, so that CO2 gas is physically adsorbed in the solution absorption system; the solution absorption system contains nanometer-micron particles with functional groups, the nanometer-micron particles adopt a nanometer oxide material as a base, an intermediate modified layer is an ionic liquid film layer, and the outermost side is a surface modified functional group; a desorption tower which receives the solution with adsorbed CO2 from the bottom of the absorption tower, and performs CO2 desorption under vacuum conditions, and the solution absorption system after desorption returns to the absorption tower for recycling. Through the construction of the absorption system with the nanometer-micron scale interface structure (namely the absorption liquid containing the nanometer-micron particles), the gas-liquid mass transfer process can be effectively reinforced, and the CO2 absorption efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of carbon capture technology, and in particular to an interface-enhanced carbon capture system and method based on physical absorption. Background Technology

[0002] With the increasing severity of global climate change, carbon capture, utilization, and storage (CCUS) technology has become one of the key pathways to achieving carbon neutrality. Among numerous carbon capture technologies, absorption has become the mainstream technology for capturing industrial flue gas and high-concentration CO2. Absorption achieves separation of CO2 through the selective absorption of CO2 by chemical or physical solvents, and its core lies in the optimization of absorbent performance and process system.

[0003] Traditional chemical absorption methods, represented by amine solvents, rely on the reversible chemical reaction between amine compounds and CO2 to achieve capture. Amine solvents have the advantages of fast reaction rates and high CO2 loading, but they also suffer from high energy consumption, solvent degradation and corrosion, and increased waste disposal costs due to degradation products. New mixed amine solvents and non-amine solvents (such as amino acid salts and ionic liquids) are gradually being developed. However, while mixed solvents improve stability, they sacrifice reaction kinetics performance, and ionic liquids are limited by high viscosity and synthesis costs, making large-scale application difficult.

[0004] Physical absorption separates CO2 through the physical dissolution of CO2 by a solvent. It offers advantages such as low energy consumption, high solvent stability, and no chemical degradation products, making it particularly suitable for high-pressure, high-concentration CO2 sources (e.g., natural gas processing, ammonia synthesis tail gas). While the energy consumption for solvent regeneration in physical absorption is lower than that in chemical absorption, traditional methods like vacuum flash evaporation or inert gas purging still consume significant amounts of energy, and inert gas purging cannot yield high-purity CO2. Low-temperature methanol washing is a traditional physical absorption carbon capture method. Using methanol as a solvent, CO2 solubility is high at low temperatures. Although desorption energy consumption can be further reduced through process optimization, this method still has a relatively high energy consumption level. Polyol ether physical solvents have high CO2 solubility and do not absorb gases such as H2 and CO, exhibiting high selectivity; however, the operating pressure is high, resulting in significant energy consumption. Ionic liquids can significantly improve CO2 solubility by adjusting the anion and cation structures (e.g., imidazoles, amino functionalization). Ionic liquids have extremely low vapor pressures, reducing solvent loss and environmental pollution, and possess strong resistance to thermal degradation and oxidation, allowing for recycling. However, most ionic liquids have high viscosity and slow CO2 diffusion rate, requiring larger tower volume or longer contact time, which increases equipment investment costs; the raw materials for ionic liquids are expensive, leading to increased raw material costs; and physical absorption ionic liquids rely on ordinary vacuum flash evaporation regeneration, which also consumes a lot of energy.

[0005] For example, Korean Patent KR102634991B1 discloses a carbon dioxide capture system using ionic liquids. This system expands the heat transfer area between the flue gas and the ionic liquid generated in industrial processes, enabling effective temperature control of the ionic liquid with minimal energy consumption. This allows for efficient cooling of the ionic liquid while using a small amount of it, and the storage of carbon dioxide after selectively absorbing carbon dioxide using the waste heat from high-temperature waste gas. This method uses ionic liquids to absorb CO2 via physical absorption. However, this type of physical absorption method suffers from low mass transfer efficiency between CO2 molecules and the liquid, resulting in a slow absorption rate and low carbon capture efficiency. Furthermore, the energy utilization rate during CO2 absorption and desorption is low.

[0006] Therefore, there is an urgent need to develop a carbon capture device and method with high absorption efficiency and high energy utilization rate, which can not only effectively improve the gas-liquid mass transfer efficiency, thereby improving the CO2 absorption efficiency of carbon capture, but also effectively and fully utilize the heat inside the system.

[0007] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0008] The purpose of this invention is to provide an interface-enhanced carbon capture system and method. By constructing an absorption system with a nano- to micro-scale interface structure (i.e., an absorption liquid containing nano- to micro-scale particles), the gas-liquid mass transfer process can be effectively enhanced, thereby improving CO2 absorption efficiency.

[0009] Another objective of this invention is to provide an interface-enhanced carbon capture system and method, which, by setting heat exchangers at different locations in the system, can recover and utilize the heat and cold energy of different materials within the system, thereby reducing energy consumption and improving the economic efficiency of the process.

[0010] To achieve the above objectives, according to a first aspect of the present invention, an interface-enhanced carbon capture system is provided for CO2 absorption and desorption processes, comprising at least: an absorption tower for receiving a solution absorption system running from top to bottom and carbon-containing gas running from bottom to top, and performing gas-liquid mass transfer under high pressure, so that CO2 gas is physically adsorbed in the solution absorption system; the solution absorption system contains functional group-modified nano-sized particles, which use nano-sized oxide materials as substrates, an ionic liquid film layer in the middle, and surface-modified functional groups on the outermost side; and a desorption tower for receiving the CO2-adsorbed solution from the bottom of the absorption tower and performing CO2 desorption under vacuum conditions, wherein the desorbed solution absorption system is returned to the absorption tower for recycling.

[0011] Furthermore, in the above technical solution, the nanoscale oxide material can be one or more of silicon oxide, titanium oxide, and aluminum oxide.

[0012] Furthermore, in the above technical solution, the ionic liquid can be one or more of 1-aminopropyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium acetate, and 1-hexyl-3-methylimidazolium diimide; the film thickness of the ionic liquid is preferably 1 to 100 nm.

[0013] Furthermore, in the above technical solution, the surface-modified functional group can be one or more of sodium dodecylbenzenesulfonate, sodium tetrapolypropylenebenzenesulfonate, sodium dibutylnaphthalenesulfonate, and sodium dodecyl sulfate; based on the mass of nano-micro particles, the content of the surface-modified functional group on the nano-micro particles can be 0.001 to 0.1%.

[0014] Furthermore, in the above technical solution, the solution absorption system may also include a dispersant, an anti-settling agent, and a solvent; the dispersant may be one or more of Tween-80, F127, and P123; the anti-settling agent may be one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, xanthan gum, and hydrogenated castor oil; and the solvent may be one or more of water and low-carbon alcohols.

[0015] Furthermore, in the above technical solution, the molar ratio of alcohol to water in the solvent can be 0.01 to 0.1; in the solution absorption system, the mass ratio of functional group modified nano-micro particles: dispersant: anti-settling agent: solvent can be (0.1 to 10%): (0.001 to 1%): (0.001 to 1%): 100.

[0016] Furthermore, in the above technical solution, the absorption tower can be a packed tower structure; a liquid distributor is provided at the top for uniformly distributing the solution absorption system downwards; a gas distributor is provided at the bottom for uniformly distributing the carbon-containing gas upwards; and packing is filled in the middle.

[0017] Furthermore, in the above technical solution, the desorption tower can also be a packed tower structure; the upper part is provided with a liquid distributor for uniformly distributing the solution absorption system from the bottom of the absorption tower after CO2 absorption downwards; the middle part is filled with packing material.

[0018] Furthermore, in the above technical solution, the system of the present invention may also include a heat exchange unit for recovering and utilizing the heat and cold energy of different materials in the system. Specifically, the heat exchange unit may include: a first heat exchanger, which is installed at the raw gas inlet of the absorption tower, used to cool the carbon-containing raw gas with low-temperature CO2 gas generated in the system; a second heat exchanger, installed on the gas pipeline after CO2 removal at the top of the absorption tower, used to cool the gas after CO2 removal, so that the water vapor entrained in the gas is cooled into liquid; a third heat exchanger, installed on the solution outlet pipeline at the bottom of the desorption tower, used to cool the solution flowing out from the bottom of the desorption tower with low-temperature CO2 gas; the low-temperature CO2 gas after heat exchange enters the first heat exchanger; and a fourth heat exchanger, installed on the CO2 gas outlet pipeline at the top of the desorption tower, used to cool the CO2 gas, so that the water vapor entrained in the gas is cooled into liquid.

[0019] Furthermore, in the above technical solution, an absorption tower gas-liquid separator can be installed downstream of the second heat exchanger. The separated gas is discharged as purified gas, and the condensed liquid is recovered and used for solution circulation.

[0020] Furthermore, in the above technical solution, a desorption tower gas-liquid separator can be provided downstream of the fourth heat exchanger. This desorption tower gas-liquid separator is preferably configured in two stages. The gas separated in both stages is low-temperature CO2 gas, and the condensed liquid, along with the cooled solution flowing out from the bottom of the desorption tower, flows into a liquid storage tank. The liquid storage tank is used to provide the solution absorption system for the absorption tower, and this liquid storage tank may include a first liquid storage tank and a backup second liquid storage tank.

[0021] To achieve the above objectives, according to a first aspect of the present invention, the present invention provides an interface-enhanced carbon capture method, employing the aforementioned system, comprising at least the following steps: A. CO2 absorption process: In an absorption tower, a solution absorption system is in countercurrent contact with carbon-containing gas flowing from bottom to top, performing gas-liquid mass transfer under high pressure; the irregular movement of functionally modified nano-sized particles in the solution absorption system is used to suppress the coalescence of bubbles during the gas-liquid mass transfer process; the ionic liquid film layer in the nano-sized particles serves as the center for CO2 adsorption, adsorbing CO2 from the gas phase, and then passing through the gas-liquid interface to transport CO2 to the liquid phase for absorption; B. CO2 desorption process: The solution absorption system after CO2 absorption enters a desorption tower, where CO2 desorption occurs under vacuum, and the desorbed solution absorption system is recycled; the desorbed CO2 gas, after cooling and two-stage gas-liquid separation, is used for cascade heat exchange with the desorbed solution and the carbon-containing raw material gas.

[0022] Furthermore, in the above technical solution, in step A, the nano-micro particles can form a turbulence enhancement region at the nano-micro interface structure through the combined action of adjacent surface-modified functional groups. The high-speed turbulence of the fluid releases CO2 molecules from the surface of the nano-micro particles, which are then absorbed by the liquid phase.

[0023] Furthermore, in the above technical solution, the operating temperature of the CO2 absorption process can be 5–50℃; the operating pressure can be 0–2 MPa; and the liquid-to-gas volume ratio can be 0.1–2. The CO2 desorption process preferably employs a two-stage desorption method; the operating temperature for both stages can be 5–50℃, and the operating pressure can be -200–0 kPa. The CO2 concentration range of the carbon-containing gas can be 10–90%.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) This invention, based on the physical adsorption mechanism, designs a special absorption solution system containing solid particles (i.e., nano- and micro-sized particles). These nano- and micro-sized particles flow through the liquid film layer at the gas-liquid interface with the bulk liquid phase. Utilizing the selective adsorption of CO2 by the ionic liquid film layer, CO2 molecules are adsorbed onto the nano- and micro-sized particles. Compared to existing technologies where CO2 molecules pass through the liquid film alone, the nano- and micro-sized solid particles can significantly accelerate the mass transfer rate, making it more conducive to the selective adsorption of a large number of CO2 molecules at the gas-liquid interface. The nano- and micro-sized particles carrying CO2 molecules can quickly pass through the liquid film into the bulk liquid phase. In the bulk liquid phase, the microscopic nano- and micro-interface structure of the particles forms a turbulence-enhanced region between adjacent surface-modified functional groups. The high-speed turbulence of the fluid releases CO2 molecules from the solid particles, thereby allowing them to be absorbed by the bulk liquid phase. Therefore, this invention achieves the diffusion and absorption of CO2 from the gas phase to the liquid phase through the cyclical movement of nano- and micro-sized particles in the liquid film and bulk liquid phase at the gas-liquid interface. It can reduce the resistance of CO2 molecules to passing through the liquid film, thereby more effectively enhancing the gas-liquid mass transfer process and improving CO2 absorption efficiency.

[0026] 2) This invention uses four heat exchangers at different locations in the heat exchange unit to recover and utilize the heat and cold of different materials according to the thermodynamic characteristics of the absorption tower and desorption tower materials. That is, by using low-temperature CO2 gas to perform two-stage stepped heat exchange with the solution discharged from the bottom of the desorption tower and the carbon-containing raw material gas of the absorption tower, it can not only improve the CO2 absorption efficiency, but also effectively reduce energy consumption and improve the economic efficiency of the process.

[0027] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, and to make the above and other objects, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with reference to the accompanying drawings. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the connection of the interface-enhanced carbon capture system of the present invention.

[0029] Figure 2 This is a schematic diagram of the microstructure of nano-sized particles in the solution absorption system used in the system of this invention (showing the innermost substrate, the middle ionic liquid film layer, and the outermost surface-modified functional groups).

[0030] Figure 3 yes Figure 2 A schematic diagram illustrating the working principle of nano- and micro-sized particles in a solution absorption system.

[0031] Explanation of key figure labels:

[0032] 1-Absorption tower, 11-Absorption tower liquid distributor, 12-Absorption tower packing, 13-Absorption tower gas distributor, 13-Absorption unit packing, 2-Desorption tower, 21-Desorption tower liquid distributor, 22-Desorption tower packing, 31-First heat exchanger, 32-Second heat exchanger, 321-Absorption tower gas-liquid separator, 33-Third heat exchanger, 34-Fourth heat exchanger, 341-Desorption tower primary gas-liquid separator, 342-Desorption tower secondary gas-liquid separator, 41-First liquid storage tank, 42-Second liquid storage tank;

[0033] 100 - Functional group modified nano-scale particles, 100A - Substrate, 100B - Ionic liquid film, 100C - Surface modified functional groups, 100D - Turbulent region. Detailed Implementation

[0034] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0035] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0036] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “upper,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0037] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0038] like Figure 1 As shown, this invention provides an interface-enhanced carbon capture system for CO2 absorption and desorption processes, comprising at least an absorption tower 1 and a desorption tower 2. The absorption tower 1 receives a solution absorption system flowing downwards and carbon-containing gas flowing upwards, and performs gas-liquid mass transfer under high pressure, allowing CO2 gas to be physically adsorbed in the special solution absorption system of this invention (i.e., the liquid phase of the absorption solution contains nano-sized solid particles). Specifically, the solution absorption system of this invention contains functionalized nano-sized particles 100 (see reference). Figure 2 (The microstructure shown in the diagram) The nano-sized particles 100 use a nano-sized oxide material as a substrate 100A, an ionic liquid film layer 100B as the middle modified layer, and surface-modified functional groups 100C as the outermost layer. In addition to the nano-sized particles 100, the solution absorption system may also contain dispersants, anti-settling agents, and solvents. These substances combine to construct the carbon capture and absorption solution of this invention, which utilizes the principle of physical adsorption to adsorb CO2 from carbon-containing gases. The desorption tower 2 and the absorption tower 1 use relatively independent tower bodies. The desorption tower 2 receives the CO2-adsorbed solution from the bottom of the absorption tower 1 and performs CO2 desorption under vacuum conditions. The desorbed solution absorption system can ultimately be returned to the absorption tower 1 for recycling.

[0039] By employing the above-described technical solution of the present invention, an absorption system with a nanometer to micrometer-scale interface structure (i.e., the solution absorption system of the present invention) is constructed, and the absorption system uses... Figure 2The functional group modified nano-scale particles 100 shown in the microstructure (i.e., the substrate 100A of nano-scale oxide material, the ionic liquid film layer 100B, and the surface modified functional groups 100C from the inside out) can increase the gas-liquid contact area in the carbon capture process through the strengthening effect of the nano-scale particles, effectively enhance the gas-liquid mass transfer process, and improve CO2 absorption efficiency.

[0040] Specifically, preferably but not limitingly, the nanoscale oxide material of the substrate 100A can be one or more of silicon oxide, titanium oxide, and aluminum oxide. The ionic liquid can be one or more of 1-aminopropyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium acetate, and 1-hexyl-3-methylimidazolium diimide; the thickness of the ionic liquid film layer 100B is preferably 1-100 nm. The surface-modified functional group 100C can be one or more of sodium dodecylbenzenesulfonate, sodium tetrapropylenebenzenesulfonate, sodium dibutylnaphthalenesulfonate, and sodium dodecyl sulfate; based on the mass of the nanoscale particles 100 of the present invention, the content of the surface-modified functional group 100C on the nanoscale particles 100 is 0.001-0.1%.

[0041] Furthermore, the solution absorption system of the present invention may also include a dispersant, an anti-settling agent, and a solvent; the dispersant may be one or more of Tween-80, F127, and P123; the anti-settling agent may be one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, xanthan gum, and hydrogenated castor oil; the solvent may be one or more of water and lower alcohols, preferably one or more of water, ethanol, and ethylene glycol, and the molar ratio of alcohol to water in the solvent is preferably 0.01 to 0.1. In the solution absorption system, the mass ratio of functional group modified nano-sized particles: dispersant: anti-settling agent: solvent is preferably (0.1 to 10%): (0.001 to 1%): (0.001 to 1%): 100.

[0042] The solution absorption system with nano-micro interface enhancement function of the present invention is prepared by the following steps: (1) a metal oxide precursor, template agent, low carbon alcohol, saturated hydrocarbon and alkaline solution are mixed under certain conditions and subjected to hydrothermal reaction. After washing, drying and calcining, the product is used to obtain the substrate 100A of the nano-micro particles 100 of the present invention; (2) the nano-micro particles 100 are modified with ionic liquid to prepare an intermediate modified layer of a certain thickness (i.e., to prepare an ionic liquid film layer 100B); then the outer surface functional group is modified (i.e., the surface modified functional group 100C), and finally the present invention is obtained. Figure 2 The functional group modified nano-sized particles 100 shown; (3) The functional group modified nano-sized particles 100, dispersant, anti-settling agent and solvent are mixed under the action of an external field, and the solid particles are reacted with the dispersant and anti-settling agent to obtain the solution absorption system of the present invention with uniform solid-liquid dispersion for CO2 capture.

[0043] The solution absorption system of the present invention, prepared by the above method, utilizes the working principle of the functional group-modified nano-sized particles 100 at the microscopic level, as described above. Figure 3 That is, the nanoscale particles 100 flow through the liquid phase and enter the liquid film layer at the gas-liquid interface. Utilizing the selective adsorption of CO2 by the ionic liquid film layer 100B, CO2 molecules are adsorbed onto the nanoscale particles 100. Compared to the prior art where CO2 molecules pass through the liquid film alone, the nanoscale solid particles can significantly accelerate the mass transfer rate, making it more conducive to the selective adsorption of a large number of CO2 molecules at the gas-liquid interface. The nanoscale particles 100 carrying CO2 molecules rapidly pass through the liquid film and enter the liquid phase. In the liquid phase, the microscopic nano-interface structure of the nanoscale particles 100 forms a turbulence-enhancing region 100D between adjacent surface-modified functional groups 100C. Figure 3 The area within the dashed circle (the region within which fluid turbulence is effectively enhanced) utilizes the high-speed turbulence to release CO2 molecules from solid particles, allowing them to be absorbed by the bulk liquid phase. For example... Figure 3 As shown, the nano-sized particles 100 in the solution absorption system of this invention circulate repeatedly within the liquid film and the bulk liquid phase at the gas-liquid interface, completing the diffusion and absorption of CO2 from the gas phase to the liquid phase. Therefore, the resistance of CO2 molecules crossing the liquid film can be reduced, thereby more effectively enhancing the gas-liquid mass transfer process and improving CO2 absorption efficiency.

[0044] Further as Figure 1 As shown, the absorption tower 1 of the present invention is preferably a packed tower structure; the upper part is provided with an absorption tower liquid distributor 11 for uniformly distributing the aforementioned solution absorption system of the present invention downwards; the lower part is provided with an absorption tower gas distributor 13 for uniformly distributing carbon-containing gas upwards; and the middle part is filled with packing material 12, which can be one or more of annular, saddle-shaped, and corrugated shapes.

[0045] Further as Figure 1 As shown, the desorption tower 2 of the present invention can also be a packed tower structure. A desorption tower liquid distributor 21 is provided at the upper part of the tower to uniformly distribute the solution absorption system from the bottom of the absorption tower 1 after CO2 absorption downwards; the middle part is filled with packing material 22. The packing material 22 can also be one or more of annular, saddle-shaped, and corrugated shapes. The lower part of the desorption tower 2 is provided with a desorbed solution outlet. The desorbed solution flowing out of this outlet can provide the solution absorption system of the present invention to the liquid distributor 11 of the absorption tower 1, realizing the recycling of the solution.

[0046] Further as Figure 1As shown, the interface-enhanced carbon capture system of the present invention may further include a heat exchange unit for recovering and utilizing the heat and cold energy of different streams in the system. This heat exchange unit may specifically include a first heat exchanger 31, a second heat exchanger 32, a third heat exchanger 33, and a fourth heat exchanger 34. The first heat exchanger 31 is located at the raw gas inlet of the absorption tower 1 and is used to cool the carbon-containing raw gas with the low-temperature CO2 gas generated in the system. The second heat exchanger 32 is located on the gas pipeline at the top of the absorption tower 1 after CO2 removal and is used to cool the gas after CO2 removal, so that the water vapor entrained in the gas is cooled into liquid. The third heat exchanger 33 is located on the solution outlet pipeline at the bottom of the desorption tower 2 and is used to cool the solution flowing out from the bottom of the desorption tower 2 with the low-temperature CO2 gas generated in the aforementioned system; the low-temperature CO2 gas after heat exchange enters the first heat exchanger 31, i.e. Figure 1 The low-temperature CO2 gas in the absorption tower 2 undergoes a two-stage heat exchange with the solution discharged from the bottom of the desorption tower 2 and the carbon-containing feed gas from the absorption tower 1. A fourth heat exchanger 34 is installed on the CO2 gas outlet pipe at the top of the desorption tower 2 to cool the CO2 gas, condensing the entrained water vapor into liquid. This invention, through four heat exchangers used at different locations within the aforementioned heat exchange unit, can recover and utilize the heat and cold energy of different streams based on their thermodynamic characteristics. Specifically, by using low-temperature CO2 gas for a two-stage heat exchange with the solution discharged from the bottom of the desorption tower and the carbon-containing feed gas from the absorption tower, it not only improves CO2 absorption efficiency but also effectively reduces energy consumption and enhances the economics of the process.

[0047] Further as Figure 1 As shown, a gas-liquid separator 321 is installed downstream of the second heat exchanger 32. The separated gas is discharged as purified gas, and the condensed liquid is recovered and used for solution circulation. Further as... Figure 1 As shown, a desorption tower gas-liquid separator is installed downstream of the fourth heat exchanger 34. This desorption tower gas-liquid separator is a two-stage system, namely a primary gas-liquid separator 341 and a secondary gas-liquid separator 342. The gas separated by the two stages is... Figure 1 The aforementioned low-temperature CO2 gas, after condensation, forms a liquid that flows out from the bottom of the desorption tower 2 and is cooled, which then flows into a storage tank. The storage tank is used to provide the absorption tower 1 with the solution absorption system of the present invention, and the storage tank includes a first storage tank 41 and a spare second storage tank 42.

[0048] refer to Figures 1 to 3 The present invention also provides an interface-enhanced carbon capture method, which employs the aforementioned system and includes at least the following steps:

[0049] Step S101, CO2 absorption process: as follows Figure 1As shown, in absorption tower 1, the solution absorption system comes into countercurrent contact with the carbon-containing gas flowing from bottom to top, performing gas-liquid mass transfer under high pressure; the irregular movement of functional group-modified nano-sized particles 100 in the solution absorption system is used to suppress the coalescence of bubbles during the gas-liquid mass transfer process; as shown... Figure 3 As shown, the nano-scale particles 100 use an ionic liquid film layer 100B as the center for CO2 adsorption, adsorbing CO2 from the gas phase and then transporting it to the liquid phase bulk for absorption through the gas-liquid interface. In this step S101, preferably, but not limitingly, the nano-scale particles 100 can form a turbulence-enhancing region 100D at the nano-micro interface structure through the combined action of adjacent surface-modified functional groups 100C. The high-speed turbulence of the fluid can release CO2 molecules from the surface of the nano-scale particles, which are then absorbed by the liquid phase bulk. In this step, the operating temperature of the CO2 absorption process can be 5–50°C; the operating pressure can be 0–2 MPa; and the liquid-to-gas volume ratio can be 0.1–2. The CO2 concentration range of the carbon-containing gas can be 10–90%.

[0050] Step S102, CO2 desorption process: The CO2 absorption system after CO2 absorption enters the desorption tower 2, where CO2 desorption occurs under vacuum. The desorbed solution absorption system is recycled. The desorbed CO2 gas, after cooling and two-stage gas-liquid separation, is used for cascade heat exchange with the desorbed solution and carbon-containing feed gas. In this step, the CO2 desorption process preferably adopts two-stage desorption. The operating temperature of both stages can be 5–50℃, and the operating pressure can be -200–0 kPa.

[0051] The method of this invention, through the innovative design of a solution absorption system with nano-micro interface enhancement, strengthens the mass transfer process between the gas and liquid interfaces. This is achieved through the cyclical adsorption-transportation-release of CO2 molecules by nano-micro particles, reducing the resistance of CO2 molecules crossing the liquid film and increasing the mass transfer rate of CO2 molecules from the gas phase to the liquid phase. This principle also enhances the desorption process of the solution absorption system, significantly reducing energy consumption and offering substantial advantages.

[0052] The following is for reference. Figure 1 Detailed explanation of the entire process of the carbon capture technology of this invention:

[0053] The carbon-containing raw material gas exchanges heat with the lower-temperature CO2 gas in the first heat exchanger 31 and is cooled down. After cooling, it enters from the bottom of the absorption tower 1 and passes through the gas distributor 13. Then, it comes into countercurrent contact with the absorbent liquid (i.e., the solution absorption system of the present invention) from the liquid distributor 11 at the top of the absorption tower 1 in the packing 12 to absorb CO2. The gas after CO2 removal is cooled in the second heat exchanger 32 to cool the water vapor entrained in the gas into liquid. The gas and liquid are separated in the gas-liquid separator 321 of the absorption tower. The gas is discharged as purified gas, and the condensed liquid is recovered for liquid circulation.

[0054] The saturated absorbent liquid containing CO2 from absorber 1 enters from the top of desorption tower 2. After passing through liquid distributor 21, desorption occurs in desorption tower 2 under certain vacuum conditions. The desorbed CO2 gas enters the fourth heat exchanger 34 to cool the entrained water vapor into liquid. Gas and liquid are then separated in the first-stage gas-liquid separator 341 of the desorption tower. The separated gas phase enters the second-stage gas-liquid separator 342 for further separation of the gas and liquid phases. The separated CO2 gas, with a lower temperature, is returned to the third heat exchanger 33 as a cooling medium to desorb CO2 from absorber 2. The liquid at the bottom of the tower is cooled to lower its temperature and improve its absorption efficiency after entering the absorption tower 1. The CO2, after heat exchange, continues into the first heat exchanger 31 to exchange heat with the carbon-containing feed gas, cooling the gas to improve absorption efficiency. The CO2 exiting the first heat exchanger 31 is discharged from the system as a high-purity gas product. The liquid obtained from the bottom of the gas-liquid separator in the desorption tower, along with the liquid after passing through the third heat exchanger 33, enters the first liquid storage tank 41. A liquid circulation pump circulates the liquid (i.e., the solution absorption system of this invention) back to the absorption tower 1. The second liquid storage tank 42 serves as a backup system, providing temporary liquid storage in case the first liquid storage tank 41 malfunctions or requires maintenance.

[0055] Example 1

[0056] The solution absorption system used in this embodiment has the following composition:

[0057] The mass ratio of Tween-80, xanthan gum, and solvent is 2:0.045:0.082:100.

[0058] The solvent has an ethylene glycol / water molar ratio of 0.04, and the nano-micro particles are supported on a sodium dodecylbenzenesulfonate surface-modified 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt / TiO2 with a nano-micro interface structure. The ionic liquid film thickness is 10-25 nm.

[0059] refer to Figure 1Nitrogen and carbon dioxide from utilities are mixed after their flow rates are measured by a gas mass flow control system. The resulting mixture is formulated as a 40% CO2-concentration feed gas. This feed gas exchanges heat with the cooler CO2 gas stream in the first heat exchanger 31. After cooling, the mixture enters the absorption tower 1 from the bottom, passes through a gas distributor 13, and then encounters the liquid absorbent from the top liquid distributor 11 in the packing 12 at 25°C and 0.6 MPa, where it countercurrently absorbs CO2. The CO2-free gas is then cooled in the second heat exchanger 32 to condense any entrained water vapor. Finally, the gas and liquid are separated in the gas-liquid separator 321 of the absorption tower. The gas is discharged as purified gas, and the condensed liquid is recovered for liquid recycling. The CO2 removal efficiency of the decarbonized gas after passing through the absorption tower 1 is 90.1%, with an energy consumption of 0.93 GJ·ton. -1 CO2.

[0060] The saturated absorbent liquid that has absorbed CO2 from absorbent tower 1 enters from the top of desorption tower 2, passes through liquid distributor 21, and is desorbed in packing 22 under vacuum of 30°C and -60 kPa. The desorbed CO2 gas enters the fourth heat exchanger 34 to cool the entrained water vapor into liquid. In the first-stage gas-liquid separator 341 of the desorption tower, gas and liquid are separated. The separated gas phase enters the second-stage gas-liquid separator 342 for further separation of the gas and liquid phases. The separated CO2 gas has a lower temperature and is returned to the third heat exchanger 33 as a cooling medium to cool the liquid at the bottom of the desorption tower 2, reducing the liquid temperature and improving the absorption efficiency in the absorption tower 1. The CO2 after heat exchange continues to enter the first heat exchanger 31 to exchange heat with the carbon-containing feed gas, cooling the feed gas to improve absorption efficiency. The CO2 at the outlet of the first heat exchanger 31 is discharged from the system as a high-purity gas product. The liquid obtained at the bottom of the gas-liquid separator of the desorption tower and the liquid after passing through the third heat exchanger 33 enter the first liquid storage tank 41. The liquid (i.e., the solution absorption system of this invention) is circulated to the absorption tower 1 by a liquid circulation pump.

[0061] Example 2

[0062] Unlike Example 1, the solution absorption system has the following composition:

[0063] Nanoscale particles: P123: hydrogenated castor oil: solvent mass ratio is 3.5, 0.25: 0.18: 100.

[0064] The solvent has an ethanol / water molar ratio of 0.09, and the nano-micro particles are supported on a sodium dodecyl sulfate surface modified with a nano-micro interface structure. The ionic liquid film thickness is 15–30 nm.

[0065] The absorption and desorption operating conditions are as follows: CO2 concentration in carbon-containing gas is 60%, liquid-to-gas ratio is 0.3; absorption temperature is 22℃, absorption pressure is 0.8MPa; and desorption vacuum degree is -72kPa.

[0066] The CO2 removal efficiency in the decarbonized gas was 94.6%, and the energy consumption was 0.79 GJ·ton. -1 CO2.

[0067] Example 3

[0068] Unlike Example 1, the solution absorption system has the following composition:

[0069] Nanoscale particles: P123: sodium dibutylnaphthalenesulfonate: solvent mass ratio is 0.8, 0.55: 0.02: 100.

[0070] The solvent has an ethylene glycol / water molar ratio of 0.05, and the nano-micro particles are supported on the surface of sodium dibutylnaphthalene sulfonate with a nano-micro interface structure, which is modified with 1-aminopropyl-3-methylimidazolium bromide / Al2O3. The ionic liquid film thickness is 20-30 nm.

[0071] The absorption and desorption operating conditions are as follows: CO2 concentration in carbon-containing gas is 80%, liquid-to-gas ratio is 0.3; absorption temperature is 20℃, absorption pressure is 0.7MPa; and desorption vacuum is -80kPa.

[0072] The CO2 removal efficiency is 96.5%, and the energy consumption is 0.72 GJ·ton. -1 CO2.

[0073] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. Any simple modifications, equivalent changes, and alterations made to the foregoing exemplary embodiments should fall within the scope of protection of the present invention.

Claims

1. An interface-enhanced carbon capture system, characterized in that, Used in CO2 absorption and desorption processes, including: An absorption tower is used to receive a solution absorption system running from top to bottom and carbon-containing gas running from bottom to top, and to carry out gas-liquid mass transfer under high pressure, so that CO2 gas is physically adsorbed in the solution absorption system; the solution absorption system contains functional group modified nano-micro particles, which use nano-scale oxide materials as substrates, an ionic liquid film layer in the middle, and surface modified functional groups on the outermost side. The desorption tower receives the CO2-adsorbed solution from the bottom of the absorption tower and desorbs the CO2 under vacuum conditions. The desorbed solution absorption system is then returned to the absorption tower for recycling.

2. The interface-enhanced carbon capture system according to claim 1, characterized in that, The nanoscale oxide material is one or more of silicon oxide, titanium oxide, and aluminum oxide.

3. The interface-enhanced carbon capture system according to claim 2, characterized in that, The ionic liquid is one or more of 1-aminopropyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium acetate, and 1-hexyl-3-methylimidazolium diimide; the film thickness of the ionic liquid is 1–100 nm.

4. The interface-enhanced carbon capture system according to claim 3, characterized in that, The surface-modifying functional group is one or more of sodium dodecylbenzenesulfonate, sodium tetrapolypropylenebenzenesulfonate, sodium dibutylnaphthalenesulfonate, and sodium dodecyl sulfate; based on the mass of the nano-micro particles, the content of the surface-modifying functional group on the nano-micro particles is 0.001 to 0.1%.

5. The interface-enhanced carbon capture system according to claim 1, characterized in that, The solution absorption system also includes a dispersant, an anti-settling agent, and a solvent; the dispersant is one or more of Tween-80, F127, and P123; the anti-settling agent is one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, xanthan gum, and hydrogenated castor oil; and the solvent is one or more of water and low-carbon alcohols.

6. The interface-enhanced carbon capture system according to claim 5, characterized in that, The alcohol / water molar ratio of the solvent is 0.01 to 0.1; in the solution absorption system, the mass ratio of functional group modified nano-micro particles: dispersant: anti-settling agent: solvent is (0.1 to 10%): (0.001 to 1%): (0.001 to 1%):

100.

7. The interface-enhanced carbon capture system according to claim 1, characterized in that, The absorption tower is a packed tower structure; a liquid distributor is provided at the top for uniformly distributing the solution absorption system downwards; a gas distributor is provided at the bottom for uniformly distributing the carbon-containing gas upwards; and packing is provided in the middle.

8. The interface-enhanced carbon capture system according to claim 7, characterized in that, The desorption tower is a packed tower structure; the upper part is equipped with a liquid distributor for uniformly distributing the solution absorption system from the bottom of the absorption tower after CO2 absorption downwards; the middle part is filled with packing material.

9. The interface-enhanced carbon capture system according to claim 8, characterized in that, The system also includes a heat exchange unit for recovering and utilizing the heat and cold energy of different materials in the system. This heat exchange unit includes: The first heat exchanger is located at the raw gas inlet of the absorption tower and is used to cool the carbon-containing raw gas with the low-temperature CO2 gas generated in the system. The second heat exchanger is installed on the gas pipeline after CO2 removal at the top of the absorption tower. It is used to cool the gas after CO2 removal, so that the water vapor entrained in the gas is cooled into liquid. The third heat exchanger is installed on the solution outlet pipe at the bottom of the desorption tower and is used to cool the solution flowing out from the bottom of the desorption tower with the low-temperature CO2 gas; the low-temperature CO2 gas after heat exchange enters the first heat exchanger. The fourth heat exchanger is located on the CO2 gas outlet pipeline at the top of the desorption tower. It is used to cool the CO2 gas, thereby cooling the water vapor entrained in the gas into liquid.

10. The interface-enhanced carbon capture system according to claim 9, characterized in that, The second heat exchanger is equipped with an absorption tower gas-liquid separator downstream. The separated gas is discharged as purified gas, and the condensed liquid is recovered and used for solution circulation.

11. The interface-enhanced carbon capture system according to claim 9, characterized in that, Downstream of the fourth heat exchanger is a desorption tower gas-liquid separator, which is a two-stage desorption tower gas-liquid separator. The gas separated by the two stages is the low-temperature CO2 gas, and the condensed liquid and the solution flowing out of the bottom of the desorption tower and cooled together flow into the liquid storage tank.

12. The interface-enhanced carbon capture system according to claim 11, characterized in that, The liquid storage tank is used to provide the solution absorption system to the absorption tower, and the liquid storage tank includes a first liquid storage tank and a backup second liquid storage tank.

13. A method for interface-enhanced carbon capture, characterized in that, The system described in any one of claims 1 to 12 includes the following steps: A. CO2 Absorption Process: In the absorption tower, the solution absorption system comes into countercurrent contact with the carbon-containing gas flowing from bottom to top, performing gas-liquid mass transfer under high pressure. The irregular movement of functional group-modified nano-sized particles in the solution absorption system is used to suppress the coalescence of bubbles during the gas-liquid mass transfer process. Among the nano-sized particles, the ionic liquid film layer serves as the center for CO2 adsorption, adsorbing CO2 from the gas phase and then passing through the gas-liquid interface to transport CO2 to the liquid phase for absorption. B. CO2 desorption process: The solution absorption system after absorbing CO2 enters the desorption tower, where CO2 is desorbed under vacuum. The desorbed solution absorption system is recycled. The desorbed CO2 gas is cooled and separated into two stages of gas and liquid, and then used for cascade heat exchange with the desorbed solution and carbon-containing raw material gas.

14. The interface-enhanced carbon capture method according to claim 13, characterized in that, In step A, the nano-scale particles form a turbulence-enhanced region at the nano-micro interface structure through the combined action of adjacent surface-modified functional groups. The high-speed turbulence of the fluid releases CO2 molecules from the surface of the nano-scale particles, which are then absorbed by the liquid phase.

15. The interface-enhanced carbon capture method according to claim 13, characterized in that, The operating temperature of the CO2 absorption process is 5–50°C; the operating pressure is 0–2 MPa; and the liquid-to-gas volume ratio is 0.1–2.

16. The interface-enhanced carbon capture method according to claim 13, characterized in that, The CO2 desorption process employs a two-stage desorption process; the operating temperature for both stages is 5–50℃, and the operating pressure is -200–0 kPa.

17. The interface-enhanced carbon capture method according to claim 13, characterized in that, The CO2 concentration of the carbon-containing gas ranges from 10% to 90%.

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