Interface enhanced carbon capture device and method

Abstract

This invention discloses an interface-enhanced carbon capture device and method. The device is an integrated apparatus for CO2 absorption and desorption processes, comprising at least: an absorption unit for receiving a solution absorption system flowing downwards and carbon-containing gas flowing upwards, and performing gas-liquid mass transfer under high pressure to physically adsorb CO2 gas into the solution absorption system; the solution absorption system contains functionalized nano-sized particles, which use nano-scale oxide materials as a substrate, an ionic liquid film layer in the middle, and surface-modified functional groups on the outermost side; a liquid seal for the CO2-absorbed solution is located at the bottom of the absorption unit; and a desorption unit is located outside the absorption unit and is isolated from and heat-conducted by the unit through a wall; while ensuring the height of the liquid seal, the CO2-absorbed solution is pumped into the desorption unit, and CO2 desorption is performed under vacuum conditions. The desorbed solution absorption system is then recycled after gas-liquid separation.

Description

Technical Field

[0001] This invention relates to the field of carbon capture technology, and in particular to an interface-enhanced carbon capture device 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 system stores carbon dioxide after regenerating the ionic liquid by 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 consequently low carbon capture efficiency. Furthermore, the CO2 absorption and desorption processes are conducted in separate reactors under significantly different operating conditions, leading to substantial equipment investment.

[0006] Therefore, there is an urgent need to develop a carbon capture device and method with high absorption efficiency and low energy consumption. This method can not only effectively improve the gas-liquid mass transfer efficiency, thereby improving the CO2 absorption efficiency of carbon capture, but also couple the absorption and desorption processes into the same device, effectively reducing equipment investment while ensuring the cyclic absorption effect.

[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 device and method. By constructing an absorption system with an interface structure at the nanometer to micrometer scale, 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 device and method, which couples the CO2 absorption and desorption processes within the same device. This not only enables high-pressure absorption and vacuum desorption within the same device, but also optimizes the internal energy utilization of the absorption and desorption units, significantly reducing regeneration energy consumption.

[0010] To achieve the above objectives, according to a first aspect of the present invention, the present invention provides an interface-enhanced carbon capture device, which is an integrated device for CO2 absorption and desorption processes, comprising at least: an absorption unit for receiving a solution absorption system running from top to bottom and a 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; a liquid seal of the CO2-absorbed solution is provided at the bottom of the absorption unit; a desorption unit is disposed outside the absorption unit and is isolated from the absorption unit and conducts heat through the device wall; under the premise of ensuring the height of the liquid seal, the CO2-absorbed solution is pumped to the desorption unit and CO2 is desorbed under vacuum conditions, and the desorbed solution absorption system is recycled after gas-liquid separation.

[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 can be 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 also includes a dispersant, an anti-settling agent, and a solvent; the dispersant can be one or more of Tween-80, F127, and P123; the anti-settling agent can be one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, xanthan gum, and hydrogenated castor oil; and the solvent can 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 unit 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 carbon-containing gas upwards; and packing is filled in the middle.

[0017] Furthermore, in the above technical solution, the liquid seal is located below the gas distributor; a liquid level regulating unit can be provided at the corresponding position of the liquid seal structure to isolate the pressure operating range between the absorption unit and the desorption unit and to control the circulation rate of the solution absorption system.

[0018] Furthermore, in the above technical solution, the liquid level regulating unit may include: a regulating valve, which is located at the bottom of the liquid seal structure; a differential pressure level gauge, which is interlocked with the regulating valve to control the liquid seal height and maintain the required pressure range, and to control the circulation rate of the solution absorption system.

[0019] Furthermore, in the above technical solution, the absorber can be equipped with a CO2 gas pipeline array through the packing. The upper end of the pipeline array converges and connects to the upper space of the desorption unit, and the lower end of the pipeline array converges and connects to the atmosphere through a vacuum pump to discharge the desorbed CO2 gas.

[0020] Furthermore, in the above technical solution, the desorption unit can also be a packed tower structure; the lower part of the desorption unit is provided with a solution outlet after desorption, which can be connected to a circulating pump through a pipeline to pump the desorbed solution absorption system into the liquid distributor of the absorption unit for circulation.

[0021] Furthermore, in the above technical solution, the top of the absorption unit may be equipped with a tower top mixing gas pipeline. After gas-liquid separation, the decarbonized gas enters the pressure energy recovery device, which can recover and convert the pressure energy of the high-pressure gas when it is reduced to low pressure for use as power supply for the vacuum pump of the desorption unit and the circulation pump of the solution.

[0022] To achieve the above objectives, according to a second aspect of the present invention, the present invention provides an interface-enhanced carbon capture method, employing the aforementioned apparatus, comprising at least the following steps: A. CO2 absorption process: In the absorption unit, the solution absorption system is in countercurrent contact with the 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. A portion of the solution absorption system after absorption forms a liquid seal at the bottom of the absorption unit; C. CO2 desorption process: The solution absorption system after CO2 absorption enters the desorption unit, where CO2 is desorbed under vacuum, and the desorbed solution absorption system is recycled; the desorbed CO2 gas is discharged.

[0023] Furthermore, in the above technical solution, in step A, the nano-micro particles 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 bulk.

[0024] Furthermore, in the above technical solution, the heat released during the CO2 absorption process can be exchanged with the heat absorbed during the CO2 desorption process through heat exchange via a partition wall.

[0025] Furthermore, in the above technical solution, by setting the CO2 gas exhaust pipelines into an array and arranging them in the absorption unit, the cooling capacity of the low-temperature CO2 can be fully utilized for heat exchange inside the absorption unit.

[0026] Furthermore, in the above technical solution, the method of the present invention may also include: D. recovering the pressure energy of the high-pressure gas after absorbing CO2, and using the recovered energy for the energy consumption of the vacuum pump of the desorption unit and the solution circulation pump of the desorption unit.

[0027] Furthermore, in the above technical solution, the operating temperature of the CO2 absorption process is 5–50℃; the operating pressure is 0–2 MPa; and the liquid-to-gas volume ratio is 0.1–2. The operating temperature of the CO2 desorption process is 5–50℃, and the operating pressure is -150–0 kPa. The CO2 concentration range of the carbon-containing gas is 10–90%.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1) This invention integrates the absorption and desorption units into a single unit through a coupled design of the inner cylinder absorption unit and the outer cylinder desorption unit, effectively reducing process costs. The "coupled" design also fully utilizes the heat change characteristics of absorption exothermic and desorption endothermic processes. The inner cylinder outer wall structure of the two units allows for timely transfer of the heat released during CO2 absorption to the desorption unit, accelerating CO2 release. Simultaneously, the temperature drop during CO2 desorption provides some cooling for the absorption process, contributing to improved CO2 absorption efficiency in the absorption unit. Therefore, this invention not only achieves high-pressure absorption + vacuum desorption in the same device but also optimizes the internal energy utilization of the absorption and desorption units, significantly reducing regeneration energy consumption.

[0030] 2) Based on the physical adsorption mechanism, this invention 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 with 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.

[0031] 3) This invention incorporates axially distributed CO2 gas pipelines within the absorption unit. The desorbed CO2 travels from top to bottom through these pipelines within the packing material, collects at the bottom, and is discharged from the side. This structural design allows the cooling capacity of the low-temperature CO2 to be fully utilized for heat exchange within the absorption unit, thereby improving absorption efficiency.

[0032] 4) This invention uses a pressure energy recovery device to recover pressure energy from the high-pressure gas at the top of the absorption tower. The energy recovered in this way can not only provide energy for the vacuum pump of the desorption unit, but also supplement some energy for the liquid circulation pump, which can further reduce energy consumption and improve economy.

[0033] 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

[0034] Figure 1 This is a schematic diagram of the interface-enhanced carbon capture device of the present invention.

[0035] Figure 2 This is a schematic diagram of the microstructure of the solution absorption system used in the device of the present invention (showing the innermost substrate, the middle ionic liquid film layer, and the outermost surface-modified functional groups).

[0036] Figure 3 yes Figure 2 A schematic diagram illustrating the working principle of nano-micro particles in a solution absorption system.

[0037] Explanation of key figure labels:

[0038] 100-carbon capture device;

[0039] 1-Absorption unit, 11-Liquid distributor, 12-Gas distributor, 13-Absorption unit packing, 14-Liquid seal, 141-Regulating valve, 142-Liquid transfer pump, 15-Top mixed gas pipeline, 151-Pressure energy recovery unit, 2-Desorption unit, 21-Solution absorption system, 210-Functional group modified nano-micro particles, 210A-Substrate, 210B-Ionic liquid film layer, 210C-Surface modified functional groups, 210D-Turbulent region, 211-Circulation pump, 22-CO2 gas pipeline, 221-Vacuum pump. Detailed Implementation

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] like Figure 1As shown, the present invention provides an interface-enhanced carbon capture device 100, which is an integrated device for CO2 absorption and desorption processes (i.e., the absorption and desorption processes are completed in the same device), and includes at least an absorption unit 1 and a desorption unit 2. The absorption unit 1 receives a solution absorption system running from top to bottom and carbon-containing gas running from bottom to top, and performs gas-liquid mass transfer under high pressure, so that CO2 gas is physically adsorbed in the special solution absorption system of the present invention (i.e., solid particles with nanoscale dimensions in the liquid phase). Specifically, the solution absorption system of the present invention contains functional group-modified nanoscale particles 210 (see reference). Figure 2 (Illustrated microstructure) The nano-scale particles 210 use nano-scale oxide materials as the substrate 210A, an ionic liquid film layer 210B as the middle modified layer, and surface-modified functional groups 210C as the outermost layer. In addition to the nano-scale particles 210, 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 uses the principle of physical adsorption to adsorb CO2 from carbon-containing gases. The bottom of the absorption unit 1 is equipped with a liquid seal for the CO2-absorbed solution. The desorption unit 2 is located outside the absorption unit 1 and is isolated from and heat-conducted by the container wall. Under the premise of ensuring the liquid seal 14 has a certain height (i.e., the absorption unit 1 and desorption unit 2 are fully isolated, creating two independent pressure environments), the CO2-absorbed solution is pumped into the desorption unit 2 and CO2 is desorbed under vacuum conditions. The desorbed solution absorption system 21 is then recycled after gas-liquid separation.

[0045] By employing the above-mentioned technical solution of this invention, the absorption and desorption units are integrated into a single unit through the coupled design of the inner cylinder absorption unit and the outer cylinder desorption unit, effectively reducing process costs. The "coupled" design also fully utilizes the heat change characteristics of absorption exothermic and desorption endothermic processes. Utilizing the inner cylinder outer wall structure of the two units, the heat released during CO2 absorption can be promptly transferred to the desorption unit to accelerate CO2 release. Simultaneously, the temperature drop during CO2 desorption provides some cooling for the absorption process, contributing to improved CO2 absorption efficiency in the absorption unit. Therefore, this invention not only achieves high-pressure absorption + vacuum desorption in the same device but also optimizes the internal energy utilization of the absorption and desorption units, significantly reducing regeneration energy consumption.

[0046] 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-sized particles 210 (i.e., the substrate 210A of nano-sized oxide material, the ionic liquid film layer 210B, and the surface-modified functional groups 210C from the inside out) shown in the microstructure can effectively enhance the gas-liquid mass transfer process and improve CO2 absorption efficiency.

[0047] Specifically, preferably but not limitingly, the nanoscale oxide material of the substrate 210A 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 210B is preferably 1-100 nm. The surface-modified functional group 210C can be one or more of sodium dodecylbenzenesulfonate, sodium tetrapropylenebenzenesulfonate, sodium dibutylnaphthalenesulfonate, and sodium dodecyl sulfate; based on the mass of the nanoscale particles 210 of the present invention, the content of the surface-modified functional group 210C on the nanoscale particles 210 is 0.001-0.1%.

[0048] 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.

[0049] 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 210A of the nano-micro particles 210 of the present invention; (2) the nano-micro particles 210 are modified with ionic liquid to prepare an intermediate modified layer of a certain thickness (i.e., to prepare the ionic liquid film layer 210B); then the outer surface functional group is modified (i.e., the surface modified functional group 210C), and finally the present invention is obtained. Figure 2 The functional group modified nano-sized particles 210 shown; (3) the functional group modified nano-sized particles 210, 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.

[0050] 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 210 at the microscopic level, as described above. Figure 3 That is, the nanoscale particles 210 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 210B, CO2 molecules are adsorbed onto the nanoscale particles 210. 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 210 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 210 forms a turbulence-enhancing region 210D between adjacent surface-modified functional groups 210C. 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 210 in the solution absorption system of this invention circulate repeatedly in 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.

[0051] Further as Figure 1 As shown, the absorption unit 1 of the present invention is preferably a packed tower structure; a liquid distributor 11 is provided at the top for uniformly distributing the aforementioned solution absorption system of the present invention downwards; a gas distributor 12 is provided at the bottom for uniformly distributing carbon-containing gas upwards; and the middle part is filled with packing material 13, which can be one or more of annular, saddle-shaped, and corrugated shapes.

[0052] Further as Figure 1 As shown, the liquid seal 14 (i.e., a portion of the solution after CO2 absorption) of the present invention is disposed below the gas distributor 12; a liquid level regulating unit is provided at a corresponding position of the liquid seal structure to isolate the pressure operating range between the absorption unit (i.e., high pressure) and the desorption unit (i.e., vacuum) and to control the circulation rate of the solution absorption system. Preferably, but not limitingly, the liquid level regulating unit may include a regulating valve 141 and a differential pressure level gauge (not shown in the figure). The regulating valve 141 is disposed at the bottom of the liquid seal 14 structure; the differential pressure level gauge is interlocked with the regulating valve 141 to control the liquid seal height and maintain the required pressure range, and to control the circulation rate of the solution absorption system.

[0053] Further as Figure 1As shown, an array of CO2 gas pipes 22 is installed in the absorption unit 1, passing through the packing 13. The upper end of the pipe array converges and connects to the upper space of the desorption unit 2, while the lower end converges and connects to the atmosphere via a vacuum pump 221 to discharge the desorbed CO2 gas. This invention incorporates axially distributed CO2 gas pipelines inside the absorption unit. The desorbed CO2 travels from top to bottom through these axial pipelines within the packing, collects at the bottom of the packing, and is discharged from the side. This structural design allows the cooling capacity of the low-temperature CO2 to be fully utilized for heat exchange within the absorption unit 1, thereby improving absorption efficiency.

[0054] Further as Figure 1 As shown, the desorption unit 2 of the present invention can also be a packed tower structure, and the packing can be one or more of the following: annular, saddle-shaped, and corrugated. The lower part of the desorption unit 2 is provided with a solution outlet after desorption. This solution outlet is connected to a circulation pump 211 through a pipeline, which is used to pump the desorbed solution absorption system 21 into the liquid distributor 11 of the absorption unit 1, so as to realize the recycling of the solution absorption system of the present invention.

[0055] Further as Figure 1 As shown, the top of the absorption unit 1 is equipped with a tower top mixing gas pipeline 15. After gas-liquid separation, the decarbonized gas enters the pressure energy recovery device 151, which can fully utilize the energy converted from the pressure energy of the high-pressure gas when it is reduced to low pressure. This energy is used to power the vacuum pump 221 of the desorption unit 2 and the solution circulation pump 211. This invention uses a pressure energy recovery device (i.e., turbine expansion) to recover the pressure energy of the high-pressure gas at the top of the absorption tower. The energy recovered in this way can not only be used to power the vacuum pump of the desorption unit, but also supplement the liquid circulation pump with some energy, which can further reduce energy consumption and improve economy.

[0056] refer to Figures 1 to 3 The present invention also provides an interface-enhanced carbon capture method, employing the aforementioned apparatus, comprising the following steps:

[0057] Step S101, CO2 absorption process: as follows Figure 1 As shown, in absorption unit 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 motion of functional group-modified nano-sized particles 210 in the solution absorption system is used to suppress the coalescence of bubbles during the gas-liquid mass transfer process; as shown... Figure 3As shown, the nano-scale particles 210 use an ionic liquid film layer 210B 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 step S101, preferably, but not limitingly, the nano-scale particles 210 can form a turbulence-enhancing region 210D at the nano-micro interface structure through the combined action of adjacent surface-modified functional groups 210C. 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%.

[0058] In step S102, a liquid seal 14 is formed at the bottom of the absorption unit 1 after absorption of a portion of the solution absorption system. The liquid seal 14 can be interlocked to control the required pressure and solution circulation rate in the absorption unit 1 and the desorption unit 2.

[0059] Step S103, CO2 desorption process: The CO2 absorption system enters the desorption unit 2 after absorbing CO2, where CO2 desorption occurs under vacuum. The desorbed solution absorption system is recycled; the desorbed CO2 gas is discharged. In this step, the operating temperature of the CO2 desorption process can be 5–50℃, and the operating pressure can be -150–0 kPa.

[0060] Step S104 is a preferred step, which is to recover the pressure energy of the high-pressure gas after absorbing CO2. The recovered energy is used for the energy consumption of the vacuum pump 221 of the desorption unit 2 and the solution circulation pump 211 of the desorption unit 2.

[0061] Furthermore, in the absorption and desorption processes of this invention, the heat released during CO2 absorption can be exchanged with the heat absorbed during CO2 desorption through heat exchange via the partition walls. Additionally, by arranging the CO2 gas exhaust pipelines 22 in an array within the absorption unit 1, this invention allows for the full utilization of the cooling energy of the low-temperature CO2 for heat exchange within the absorption unit. Therefore, the thermal energy utilization of this invention is more efficient.

[0062] 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.

[0063] Example 1

[0064] The solution absorption system used in this embodiment has the following composition:

[0065] The mass ratio of Tween-80, carboxymethyl cellulose, and solvent is 4:0.015:0.03:100.

[0066] The solvent has a water / ethylene glycol molar ratio of 20 to 30, and the nano-micro particles are supported on sodium dodecylbenzenesulfonate with a nano-micro interface structure. The ionic liquid film thickness is 30 to 40 nm.

[0067] refer to Figure 1 Nitrogen and carbon dioxide from the utility are measured and their flow rates are controlled by the gas mass flow control. The two gases are mixed to prepare a raw material gas with a CO2 concentration of 30%. The gas enters the gas distributor 12 of the absorption unit from the bottom of the self-packed absorption unit 1. After being evenly distributed, the gas passes through the packing layer 13 from bottom to top.

[0068] The solution from desorption unit 2, after being fed by liquid circulation pump 211 and metered by a flow meter and control valve, is sprayed into the liquid distributor 11 at the top of the packing layer at a liquid-to-gas ratio of 0.3, where it is absorbed by countercurrent contact with the raw gas below at 25°C and 0.8 MPa. The gas from which CO2 has been absorbed enters the pressure energy recovery unit 151 from the top pipeline 15 of absorption unit 1, where energy is recovered through pressure changes and used to power the vacuum pump 221 and the liquid circulation pump 211. The CO2 removal efficiency in the decarbonized gas after absorption unit 1 is 92.2%, with an energy consumption of 1.36 GJ·ton. -1 CO2.

[0069] The solution at the bottom of absorption unit 1, after its level is controlled by the interlock between the absorption unit liquid regulating valve 141 and the absorption unit differential pressure level gauge, enters desorption unit 2 via liquid transfer pump 142. In the solution absorption system 21 (which is also a liquid-sealed area), it flows downwards through the packing layer and undergoes desorption under a vacuum of 25°C and -60 kPa. The desorbed CO2 enters the axially distributed CO2 gas pipeline 22 from the upper part of desorption unit 2, passing through the packing from top to bottom and collecting at the bottom of the packing before being discharged from the side.

[0070] The desorbed solution is then fed into the absorption unit 1 via the liquid circulation pump 211 after the liquid level is controlled by the liquid regulating valve and differential pressure level gauge of the desorption unit, thus completing the recycling of the solution.

[0071] Example 2

[0072] Unlike Example 1, the solution absorption system has the following composition:

[0073] The mass ratio of nano-sized particles: F127: hydroxypropyl methylcellulose: solvent is 0.5, 0.008: 0.01: 100.

[0074] The solvent has a water / ethanol molar ratio of 5 to 10, and the nano-micro particles are supported on a tetrapoly(propylene benzenesulfonate) surface modified with a nano-micro interface structure, consisting of 1-aminopropyl-3-methylimidazolium bromide / SiO2, with an ionic liquid film thickness of 10 to 20 nm.

[0075] The absorption and desorption operating conditions are as follows: CO2 concentration in carbon-containing gas is 50%, liquid-to-gas ratio is 0.4; absorption temperature is 28℃, absorption pressure is 0.6MPa; and desorption vacuum is -65kPa.

[0076] The CO2 removal efficiency in the decarbonized gas was 91.4%, and the energy consumption was 0.95 GJ·ton. -1 CO2.

[0077] Example 3

[0078] Unlike Example 1, the solution absorption system has the following composition:

[0079] Nanoscale particles: P123: sodium dibutylnaphthalenesulfonate: solvent mass ratio is 8, 0.45: 0.58: 100.

[0080] The solvent has a water / ethylene glycol molar ratio of 8 to 15, and the nano-micro particles have a nano-micro interface structure. The surface-modified supported 1-butyl-3-methylimidazolium acetate / Al2O3 is 15 to 30 nm thick.

[0081] The absorption and desorption operating conditions are as follows: CO2 concentration in carbon-containing gas is 70%, liquid-to-gas ratio is 0.4; absorption temperature is 30℃, absorption pressure is 0.6MPa; and desorption vacuum degree is -70kPa.

[0082] The CO2 removal efficiency is 95.1%, and the energy consumption is 0.83 GJ·ton. -1 CO2.

[0083] Example 4

[0084] Unlike Example 1, the solution absorption system has the following composition:

[0085] Nanoscale particles: Tween-80: hydrogenated castor oil: solvent mass ratio is 6, 0.25: 0.16: 100.

[0086] The solvent has a water / ethanol molar ratio of 15–20, and the nano-micro particles are supported on a sodium dodecyl sulfate surface modified with a nano-micro interface structure, consisting of 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt / TiO2, with an ionic liquid film thickness of 10–20 nm.

[0087] The absorption and desorption operating conditions are as follows: CO2 concentration in carbon-containing gas is 90%, liquid-to-gas ratio is 0.4; absorption temperature is 32℃, absorption pressure is 0.8MPa; and desorption vacuum degree is -80kPa.

[0088] The CO2 removal efficiency is 97.5%, and the energy consumption is 0.68 GJ·ton. -1 CO2.

[0089] 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-strengthened carbon capture device, characterized by, An integrated device for CO2 absorption and desorption processes, comprising: An absorption unit is used to receive a solution absorption system running from top to bottom and carbon-containing gas running from bottom to top, and to perform 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; the bottom of the absorption unit is equipped with a liquid seal for the CO2 absorbed solution. The desorption unit is located outside the absorption unit and is isolated from the absorption unit and conducts heat through the container wall. Under the premise of ensuring the liquid seal height, the CO2 absorbed solution is pumped to the desorption unit and CO2 is desorbed under vacuum conditions. The desorbed solution absorption system is recycled after gas-liquid separation.

2. The interface-strengthened carbon capture device of claim 1, wherein, The nanoscale oxide material is one or more of silicon oxide, titanium oxide, and aluminum oxide.

3. The interface-strengthened carbon capture device of claim 2, wherein, 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 device 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 device 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 device 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 device according to claim 1, characterized in that, The absorption unit 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 filled in the middle.

8. The interface-enhanced carbon capture device according to claim 7, characterized in that, The liquid seal is located below the gas distributor; a liquid level regulating unit is provided at the corresponding position of the liquid seal structure to isolate the pressure operating range between the absorption unit and the desorption unit and to control the circulation rate of the solution absorption system.

9. The interface-enhanced carbon capture device according to claim 8, characterized in that, The liquid level regulating unit includes: A regulating valve is located at the bottom of the liquid seal structure; The differential pressure level gauge is interlocked with the regulating valve to control the liquid seal height and maintain the required pressure range, as well as to control the circulation rate of the solution absorption system.

10. The interface-enhanced carbon capture device according to claim 7, characterized in that, The absorption unit is equipped with a CO2 gas pipeline array through the packing material. The upper end of the pipeline array converges and connects to the upper space of the desorption unit. The lower end of the pipeline array converges and connects to the atmosphere through a vacuum pump to discharge the desorbed CO2 gas.

11. The interface-enhanced carbon capture device according to claim 7, characterized in that, The desorption unit is a packed tower structure; the lower part of the desorption unit is provided with a solution outlet after desorption, which is connected to a circulation pump through a pipeline to pump the desorbed solution absorption system into the liquid distributor of the absorption unit for circulation.

12. The interface-enhanced carbon capture device according to claim 7, characterized in that, The absorption unit is equipped with a tower top mixing gas pipeline. After gas-liquid separation, the decarbonized gas enters the pressure energy recovery unit, which recovers and converts the pressure energy of the high-pressure gas when it is reduced to low pressure. This energy is used to power the vacuum pump of the desorption unit and the circulation pump of the solution.

13. A method for interface-enhanced carbon capture, characterized in that, The apparatus described in any one of claims 1 to 12 comprises the following steps: A. CO2 Absorption Process: In the absorption unit, the solution absorption system comes into countercurrent contact with the carbon-containing gas 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. A liquid seal is formed at the bottom of the absorption unit after the absorption of a portion of the solution system. C. CO2 desorption process: After absorbing CO2, the solution absorption system enters the desorption unit, where CO2 is desorbed under vacuum. The desorbed solution absorption system is recycled; the desorbed CO2 gas is discharged.

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 heat released during the CO2 absorption process is exchanged with the heat absorbed during the CO2 desorption process through a heat exchanger.

16. The interface-enhanced carbon capture method according to claim 13, characterized in that, By arranging the CO2 gas exhaust pipelines in an array within the absorption unit, the cooling capacity of the low-temperature CO2 is fully utilized for heat exchange within the absorption unit.

17. The interface-enhanced carbon capture method according to claim 13, characterized in that, The method further includes: D. The high-pressure gas after absorbing CO2 is subjected to pressure energy recovery, and the recovered energy is used for the energy consumption of the vacuum pump of the desorption unit and the solution circulation pump of the desorption unit.

18. 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.

19. The interface-enhanced carbon capture method according to claim 13, characterized in that, The operating temperature of the CO2 desorption process is 5–50°C, and the operating pressure is -150–0 kPa.

20. 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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