Method for producing electrolytic fiber adsorbents and electric and electromagnetic swing adsorption processes

Abstract

The present invention discloses an electrolytic fiber adsorbent formed of an adsorbent and a support containing a conductive material, and a method for producing the same. The fiber adsorbent according to the present invention can efficiently adsorb carbon dioxide at relatively low concentrations, particularly in the atmosphere, and has the advantage of being energy efficient since the energy source required for desorption of carbon dioxide is free and direct heating of the adsorbent is possible.

Description

[Technical Field]

[0001] The present invention relates to an electrolytic fiber adsorbent, a method for manufacturing the same, and an electric and electromagnetic swing adsorption process using the same. More particularly, the present invention relates to an electrolytic fiber adsorbent formed of a porous support containing an adsorbent and a conductive material, a method for manufacturing the same, and an electric and electromagnetic swing adsorption process using the same. [Background technology]

[0002] As annual carbon dioxide emissions of over 40 Gt accelerate global warming, the issue of carbon neutrality is becoming a growing concern around the world. Among the various technologies for carbon neutrality, post-combustion carbon dioxide capture reduces carbon dioxide emissions and only slows the rate of increase in carbon dioxide concentrations, while direct air capture (DAC) technology is attracting attention as a fundamental solution to carbon neutrality because it directly removes carbon dioxide from the atmosphere.

[0003] To effectively extract atmospheric carbon dioxide (CO2) concentrations (~400 ppm), which are 350 times lower than the amount emitted from fossil fuel power plants (10-15%), aqueous alkali-based chemical absorption separation processes with high binding energy with CO2 have traditionally been applied. However, solution-based regeneration processes require a lot of energy to desorb CO2 and can cause corrosion of the plant. On the other hand, porous adsorbents such as zeolites, silica, and metal-organic frameworks (MOFs) have emerged as effective CO2 adsorbents because they can adsorb CO2 well based on their large surface area but require low energy for regeneration.

[0004] Direct air capture is considered temperature swing adsorption (TSA) and electric swing adsorption (ESA) rather than pressure swing adsorption, and such adsorption processes are effective for regeneration processes that handle low carbon dioxide partial pressures below 10 kPa.

[0005] However, in the case of post-combustion carbon dioxide capture technology, waste heat is provided by the factory, making it easy to regenerate the adsorbent, whereas with direct air capture technology, although the installation location is flexible, it is difficult to secure a heat source to regenerate the adsorbent.

[0006] In addition, conventional temperature swing adsorption using steam has limitations due to the large amount of energy required to convert water into steam, which reduces the stability of the adsorbent and drastically reduces the purity of the product, lowers the purity of the carbon dioxide after desorption, and makes post-processing of the captured carbon dioxide difficult.

[0007] On the other hand, electric swing adsorption processes that utilize Joule heating, which is self-heating using applied electrical energy, or the resistive heating effect can maximize product purity and process efficiency while maintaining the stability of the adsorbent. In particular, electric swing adsorption processes can be powered by clean renewable energy sources such as solar, wind, and fuel cells, and are optimized for direct air capture due to their reduced installation location. However, to use electrical energy as a heat source, the adsorption module must be enclosed in an electric heater. However, this also has the disadvantage that the larger the adsorption module, the more difficult it is to raise the internal temperature of the module to the desired level.

[0008] In addition, the direct carbon dioxide capture process adsorbs carbon dioxide at a very low partial pressure, reaching approximately 400 ppm in air supplied to atmospheric pressure, so another system must be introduced instead of a packed bed adsorption system, which has a large pressure drop.

[0009] In other words, to demonstrate effective electric swing adsorption operation using porous adsorbents in the direct air capture industry, properties such as i) high CO2 capacity, ii) good electrical heat generation, and iii) low pressure drop and diffusion resistance are required. Therefore, a new type of adsorbent that has the necessary properties for application to the electric swing adsorption method is required.

[0010] Meanwhile, Korean Patent Publication No. 10-2018-0117023 discloses an amine-functionalized MOF-based carbon dioxide adsorbent containing a binder, and Korean Patent Publication No. 10-2020-0145906 discloses a structured metal-organic framework fiber adsorbent for carbon dioxide capture and a method for preparing the same.

[0011] However, while Korean Patent Publication No. 10-2018-0117023 succeeded in increasing the carbon dioxide adsorption capacity by amine functionalization of an MOF-based adsorbent, it did not provide an effective solution for forming and processing the adsorbent for use in actual processes. Korean Patent Publication No. 10-2020-0145906 simultaneously solved the manufacturing and forming methods for a carbon dioxide adsorbent through a manufacturing method for a metal-organic framework fiber adsorbent, but using the fiber adsorbent required temperature swing adsorption involving high-temperature steam or purge gas, which has the disadvantage of being unsuitable for atmospheric carbon dioxide adsorption due to geographical limitations, such as the ability to install adsorption systems only in industrial areas where steam or purge gas can be supplied.

[0012] Therefore, the inventors have made extensive efforts to solve the above problems, and as a result, they have produced an electrified fiber adsorbent formed of a porous support containing an adsorbent and a conductive material. They have confirmed that the produced fiber adsorbent can efficiently adsorb carbon dioxide at relatively low concentrations, particularly in the atmosphere, and that it has excellent energy efficiency because the energy source required for carbon dioxide desorption is free and the adsorbent can be directly heated, thereby completing the present invention. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Korean Patent Publication No. 10-2018-0117023 [Patent Document 2] Korean Patent Publication No. 10-2020-0145906 Summary of the Invention

[0014] SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrolytic fiber adsorbent and a method for its manufacture. To achieve the above object, the present invention provides an electrolytic fiber adsorbent formed of a porous support containing an adsorbent and a conductive material.

[0015] The present invention also provides a method for producing an electrolytic fiber adsorbent, in which a conductive layer is formed on the bore surface or shell surface of the support, comprising the steps of spinning a dope solution containing an adsorbent and a support, and then immersing the spinning solution in a solution containing a conductive material.

[0016] The present invention also provides a method for producing an electrolytic fiber adsorbent, in which the conductive material is formed in the bore of the support, comprising the steps of spinning a dope solution containing an adsorbent and a support, adding a conductive material to the bore of a spinneret, and then spinning.

[0017] The present invention also provides a method for producing an electrolytic fiber adsorbent, in which a conductive material such as an adsorbent is contained within a support, comprising the step of spinning a dope solution containing an adsorbent and a conductive material and a support.

[0018] The present invention also provides an electrolytic fiber sorbent module for the electrical and electromagnetic swing adsorption of carbon dioxide, comprising a plurality of the electrolytic fiber sorbents described above.

[0019] The present invention also provides a method for electric and electromagnetic swing adsorption of carbon dioxide, comprising the steps of: (a) contacting a carbon dioxide-containing gas with the electrified fiber adsorbent to adsorb the carbon dioxide; and (b) applying a voltage to the fiber adsorbent to desorb the adsorbed carbon dioxide.

[0020] The present invention also provides an electric and electromagnetic swing adsorption process for an electrified fiber sorbent, comprising the steps of: (a) contacting a carbon dioxide-containing gas with the fiber sorbent to adsorb the carbon dioxide; (b) applying a voltage to the fiber sorbent to desorb the adsorbed carbon dioxide; and (c) repeating steps (a) and (b). [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic diagram illustrating the configuration of a fiber adsorbent according to one embodiment of the present invention. [Figure 2] 1 is an SEM image of a fiber sorbent according to one embodiment of the present invention. [Figure 3] 1 is an SEM image of a fiber adsorbent having a conductive layer formed on the shell surface according to one embodiment of the present invention. [Figure 4] 3D digital microscope image of a fiber adsorbent having a conductive layer formed on the shell surface according to one embodiment of the present invention. [Figure 5]1 is an image showing the temperature as a function of applied voltage of a fiber adsorbent having a conductive layer formed on the shell surface according to one embodiment of the present invention. [Figure 6] and [Figure 7] 1 is a graph showing the amount of carbon dioxide adsorbed under isothermal conditions by a fiber adsorbent according to one embodiment of the present invention. [Figure 8] 1 is a graph showing the amount of carbon dioxide adsorbed under isothermal conditions for a fiber adsorbent according to one embodiment of the present invention before and after measuring the thermal properties. [Figure 9] 1 is an SEM image of a fiber adsorbent formed with Cu bulk wires produced according to one embodiment of the present invention. [Figure 9a] , [Figure 9b] , [Figure 9d] , and [Figure 9e] 1 is a SEM image of a fiber adsorbent including mesoporous silica on which Cu bulk wires are formed according to an embodiment of the present invention. [Figure 9c] and [Figure 9f] 1 is a digital image of a fiber adsorbent on which Cu bulk wires are formed, fabricated according to an embodiment of the present invention. [Figure 10a] 1 is a CO2 breakthrough curve of a polymer fiber (NbOFFIVE-1-Ni) formed with a Cu bulk wire manufactured according to one embodiment of the present invention. [Figure 10b] 1 is a graph showing the temperature variation with current per fiber of a fiber sorbent comprising the metal-organic framework NbOFFIVE-1-Ni, formed into NiCr bulk wires produced according to one embodiment of the present invention. [Figure 11] 10 is a CO2 breakthrough curve of a fiber adsorbent formed with Cu bulk wires according to another embodiment of the present invention. [Figure 12]FIG. 1 shows a dry-jet wet-quenching spinning apparatus used in an embodiment of the present invention. [Figure 13] FIG. 1 is a diagram illustrating the principle of induction heating of the electrolytic fiber adsorbent according to the present invention. MODE FOR CARRYING OUT THE INVENTION

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention belongs. Generally, the nomenclature used herein and the laboratory procedures described below are well-known and commonly used in the art.

[0023] The present invention aims to confirm that a fiber adsorbent formed of a porous support containing an adsorbent and a conductive material can efficiently adsorb carbon dioxide at relatively low concentrations, particularly carbon dioxide in the atmosphere, and that the energy source required for carbon dioxide desorption is free, direct heating of the adsorbent is possible, resulting in excellent energy efficiency.

[0024] Accordingly, the present invention in one aspect relates to an electrolytic fiber adsorbent formed of a porous support containing an adsorbent and a conductive material. The present invention will be described in detail below. In accordance with the present invention, an electrolytic fiber adsorbent is provided which is formed of a porous support containing an adsorbent and a conductive material.

[0025] According to a preferred embodiment of the present invention, a conductive layer is formed on the bore surface or shell surface of the support (Route 1 in Figure 1), or a conductive material may be formed inside the support (Route 2 in Figure 1).

[0026] In this case, the conductive material of the present invention may be formed in the form of a conductive layer by coating the surface of the bore or shell of the support, or may be spun into the bore during the spinning process and positioned in the bore of the support, or may be in the form of a bulk wire that penetrates the entire fiber, or may be included in a dope solution and spun to be positioned inside the support.

[0027] Furthermore, the term "monolithic structure" in the present invention does not refer to a hollow fiber structure, but rather to a cylindrical structure with a filled interior. Hereinafter, each component of the electrolytic fiber adsorbent according to the present invention will be described in detail.

[0028] support First, the fiber adsorbent according to the present invention includes a porous support that supports the adsorbent and a conductive material. The support may be an organic support (polymeric support) or an inorganic support, the inorganic support (minerals) being formed by a sintering process.

[0029] For example, the support may be one or more selected from the group consisting of cellulose, cellulose acetate, a microporous polymer (Polymer of Intrinsic Microporosity: PIM), polyethylene, polypropylene, polyethylene glycol, polyethylene terephthalate, polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyimide, polyamideimide, polyetherimide, nickel oxide, copper oxide, alumina, zinc oxide, and silicon carbide. The support may also have a hollow structure or a monolithic structure.

[0030] Adsorbent The adsorbent may be at least one selected from the group consisting of metal-organic frameworks (MOFs), porous organic cages (POCs), covalent organic frameworks (COFs), porous coordination polymers (PCPs), metal-organic polyhedra (MOPs), zeolites, silica, activated carbon, carbon materials, and metal oxides. The carbon material may be a porous carbon material such as carbon nanotubes or graphene. The carbon material may be further infiltrated or bonded with an amine-based compound (R-NH, R-NH, or R-N, where R is a hydrocarbon functional group) to improve its carbon dioxide adsorption capacity.

[0031] The metal-organic framework may include metal nodes and organic ligands, wherein the metal nodes may be one or more selected from the group consisting of Mg, Al, Y, Sc, Mo, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Cd, Ca, Pd, Pt, Au, Ag, Ru, Gd, Eu, Tb, and Nb, and the organic ligands may be 4,4'-dioxide-3,3'-biphenyldicarboxylate, 2,5-dioxide-1,4-benzenedicarboxylate, 1,5-dioxide-2,6-naphthalenedicarboxylate, 4,4'-dioxide-3,3'-triphenyldi ... The metal-organic framework may be one or more selected from the group consisting of phenyl dicarboxylate, 2,5-dihydroxyterephthalic acid, 4-(4-carboxy-3-hydroxy-phenyl)-2-hydroxy-benzoic acid, 4,4'-ethynylenedibenzoic acid, 1,3,5-benzenetricarboxylic acid, 2-bromo-1,4-benzenedicarboxylic acid, pyridine-3-carboxylic acid, 2-methyl-1H-imidazole, 4-methyl-5-imidazolecarboxaldehyde, and biphenyl-4,4'-dicarboxylic acid, and preferably, the metal-organic framework may be, but is not limited to, NbOFFIVE-1-Ni. The adsorbent contained in the support can adsorb carbon dioxide chemically or physically.

[0032] In addition, since the adsorbent is contained in a support, it can solve the problem that in a packed bed adsorption tube using only the adsorbent, the adsorbent obstructs the air flow, causing a pressure drop, which can increase the overall cycle time for adsorption and reduce efficiency.

[0033] In addition, such a shaped adsorbent has a better mass transfer coefficient than a monolith, which allows adsorption to occur more quickly, thereby enabling efficient carbon dioxide adsorption.

[0034] The reason for forming adsorbents into fiber is that higher pressure drops result in fan overload or higher fan operating costs. In adsorbent-based processes, fluids pass through a tortuous path and collide with the adsorbent inside the column, resulting in a pressure drop. Packed-bed structures create even more tortuous paths, which in turn require higher driving pressures and consume more energy at the inlet. Thus, when a fluid travels through a packed bed at the same driving pressure as a fiber adsorbent column, it travels through the column at a significantly lower flow rate than a fiber adsorbent. This affects the fluid-adsorbent contact boundary, resulting in a gradual decrease in adsorption efficiency from the inlet to the outlet of the adsorption column.

[0035] Monolithic adsorption beds provide a straight fluid flow path, resulting in minimal pressure drop. They have higher adsorption efficiency at the same adsorption capacity throughout the column, ensuring higher energy efficiency. However, due to their structural characteristics, the amount of adsorbent per unit volume is lower than that of fiber adsorbents. While this is not significant on a laboratory scale, it makes a big difference in the overall size of the adsorption module and adsorption tower on an industrial scale.

[0036] The adsorbent may be contained in the support at 1 wt % to 80 wt %, preferably 20 wt % to 70 wt %, and more preferably 30 wt % to 50 wt %.

[0037] If the adsorbent is contained in the support at less than 1 wt%, the CO2 adsorption performance of the fiber adsorbent may be poor. If the adsorbent is contained in the support at more than 80 wt%, the viscosity of the dope solution may be high, making the spinning process difficult and the resulting polymer fiber adsorbent prone to brittleness.

[0038] Conductive Materials The fiber sorbents provided herein may also include a conductive material. In this case, the conductive material may be formed on the bore surface or shell surface of the support, or may be included together with the adsorbent when the adsorbent is loaded onto the support, or the conductive material may be formed in a form contained within the support by, for example, spinning a dope solution and a bulk wire together to form a bulk wire in the bore of the support. The conductive material may be one or more selected from the group consisting of conductive porous structures, conductive metals and alloys, conductive 2D materials, and conductive carbon materials.

[0039] In this case, the conductive porous structure may be a covalent organic framework (COF), a metal-organic framework (MOF), or a carbon-based porous material, and the conductive metal or alloy may include at least one selected from silver, copper, annealed copper, gold, aluminum, calcium, tungsten, zinc, cobalt, nickel, ruthenium, lithium, iron, platinum, tin, gallium, niobium, carbon steel, lead, galinstan, titanium, grain-oriented electrical steel, manganin, constantan, stainless steel, mercury, manganese, nichrome, silicon carbide, iron aluminum, tantalum, molybdenum, molybdenum disilicide, lanthanum chromite, and barium titanate.

[0040] The conductive 2D material may be molybdenum disulfide (MoS2), phosphorene, bismuthene, MXene, or tungsten disulfide (WS2), and the conductive carbon material may be one or more selected from the group consisting of graphene, graphene oxide, graphite, carbon black, and carbon nanotubes.

[0041] The conductive material may be in one of the forms of particles or bulk wire, and the particles may be in a form that is physically connected to allow current to flow. In one embodiment of the present invention, the conductive material may be in the form of nanowires of conductive material. In other embodiments, the conductive material may be in the form of a bulk wire of conductive material. The conductive material is preferably a material in which the Joule heating effect or the resistive and inductive heating effect occurs. In one embodiment, the conductive material may be coated on the shell surface of the support. In other embodiments, the conductive material may be located in the support bore in the form of a bulk wire.

[0042] The resistance of the conductive material may be 0.001Ω / m to 10000Ω / m, more preferably 0.5Ω / m to 35Ω / m based on the embodiment.

[0043] If the resistivity of the conductive material is low, less than 0.001 Ω / m, excessive current may be required to generate heat, which may cause the polymer support or adsorbent to collapse. If the unit resistance of the conductive material is high, more than 1000 Ω / m, excessive voltage may be required to generate sufficient heat.

[0044] The resistance of such a conductive layer can be appropriately controlled by adjusting the selection of conductive materials, the electrical connection structure between multiple conductive materials, the thickness and length of the conductive layer, etc.

[0045] For most polymers, direct exposure to electric current can cause the polymer chains to break and the support to oxidize due to the strong current. To compensate for this, the bulk wire can be coated with an insulating (non-conductive) material to block direct contact between the polymer and the bulk wire.

[0046] The insulating coating may be enamel, paraffin, polyethylene, etc., which may be applied to the bulk wire before the spinning process, or the bulk wire and the insulating solution may be spun into the bore during the spinning process, thereby avoiding direct contact between the bulk wire and the support, allowing the current to flow through the wire while the heat generated in the wire by Joule heating and resistive heating effects can be effectively transferred to the fiber adsorbent.

[0047] Induction heating is very similar to the resistance heating method of the present invention. The basic principle of induction heating is resistance heating using induced current. As shown in Figure 13, when the direction of an external current is changed to a high frequency, the direction of the magnetic field generated by the current changes suddenly, and eddy currents continue to flow in electromagnetic materials that are affected by the magnetic field change, causing heating.

[0048] Therefore, in addition to the method of the present invention of directly inserting a wire to generate heat, a material capable of generating an induced current can be dispersed in the fiber adsorbent. A material capable of generating an induced current is called a susceptor. A susceptor is an electromagnetic material that can generate eddy currents under the influence of a magnetic field, and a typical example is carbon fiber. When produced using Route 2, in which carbon fiber is mixed with a dope solution and then spun, a fiber adsorbent capable of induction heating is produced.

[0049] Septa other than carbon fiber can be made of almost any magnetic material, and most can be used as long as the Curie temperature, the temperature at which they lose their magnetism, is above the desired temperature for desorption. Curie =113°C), 2) iron oxide ores: [1] goethite (α-FeO(OH), 120°C), [2] lepidocrocite (γ-FeO(OH), 196°C), [3] hematite (α-Fe2O3, 680°C), [4] maghemite (α-Fe2O3, 617°C), [5] magnetite (Fe3O4, 575°C), [6] ilmenite (FeTiO, 233°C), and 3) pure metallic materials ([1] iron, Fe, 768°C, [2] cobalt, Co, 1121°C, etc.).

[0050] Fiber adsorbents are a commercially viable adsorbent platform that is easy to scale up, but the heat capacity of the polymers is generally high for use in carbon dioxide adsorption and desorption. Because of the high heat capacity of polymers, fiber adsorbents also tend to have a high heat capacity, which requires a lot of heat and energy to reach the desired desorption temperature. The concept of heat capacity tuning can be introduced to solve this problem.

[0051] Carbon materials such as Super P are stable and easy to mix with dope solutions to produce fiber adsorbents. They also have very low heat capacities. By mixing these auxiliary materials into fiber adsorbents, it is possible to produce fiber adsorbents with low and controlled heat capacities. In addition to their high heat capacity, these auxiliary materials also have excellent heat transfer efficiency, allowing for uniform temperature distribution within the fiber adsorbent. However, both Route 1 and Route 2 have limitations on the amount of solids (adsorbent and auxiliary materials for adjusting heat capacity) that can be added to the dope solution used to produce fiber adsorbents. Adding auxiliary materials can result in a loss of adsorption capacity. Therefore, a technique can be introduced to identify the optimal fiber adsorbent by comparing the adsorption capacity, heat capacity, and heat transfer coefficient relative to the amount of auxiliary material.

[0052] Hereinafter, a method for manufacturing a fibrous adsorbent according to another aspect of the present invention will be described in detail for each step. In this regard, the above description of the fibrous adsorbent can be applied to the method for manufacturing a fibrous adsorbent described below.

[0053] Route 1 From another perspective, the present invention relates to a method for manufacturing an electrolytic fiber adsorbent in which a conductive layer is formed on the bore surface and shell surface of the support, the method comprising: spinning a dope solution containing an adsorbent and a support (spinning step); and then immersing the dope solution in a solution containing a conductive material (coating step). Specifically, the present invention relates to a method for manufacturing an electrolytic fiber adsorbent in which a conductive layer is formed on the bore surface or shell surface of the support, the method comprising: spinning a dope solution containing an adsorbent and a support, solidifying the dope solution by phase separation, and then immersing the dope solution in a solution containing a conductive material.

[0054] According to one embodiment of the present invention, an electrolytic fiber adsorbent having a conductive layer formed on the shell surface of a support can be manufactured through two steps, the spinning step and the dip-coating step (Route 1 in Figure 1). The method for manufacturing the fiber adsorbent according to the present invention includes spinning a dope solution containing an adsorbent and a support, and then immersing the dope solution in a solution containing a conductive material. First, a dope solution containing an adsorbent and a support is spun to obtain a support containing the adsorbent. The radiation doped solution may include an adsorbent and a polymer.

[0055] In one embodiment, the polymer may be contained in an amount of 5 wt% to 50 wt%, preferably 7 wt% to 30 wt%, and more preferably 8 wt% to 15 wt%, based on the total weight of the dope solution.

[0056] In one embodiment, the adsorbent may be contained in an amount of 10 wt% to 60 wt%, preferably 20 wt% to 55 wt%, based on the total weight of the dope solution. If the adsorbent is contained in an amount less than 10 wt%, the CO2 adsorption performance of the fiber adsorbent may be reduced. If the adsorbent is contained in an amount greater than 60 wt%, the viscosity of the dope solution may be high, making the spinning process difficult and the resulting fiber adsorbent prone to brittleness.

[0057] The dope solution may further include a pore-forming agent. The pore-forming agent may be, for example, LiNO3, PVP, CaCO3, but is not limited thereto. The pore-forming agent may be contained in the dope solution in an amount of 0.1 wt% to 30 wt%, preferably 0.1 wt% to 5 wt%.

[0058] The dope solution may include a solvent and a non-solvent, wherein the solvent may be an organic solvent, such as, but not limited to, N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), hexamethylphosphoramide (HMPA), N,N,N',N'-tetramethylurea (TMU), N,N-dimethylformamide (DMF), or a mixture thereof.

[0059] The solvent may be contained in an amount of 10 wt % to 70 wt % based on the total weight of the dope solution, and preferably in an amount of 30 wt % to 60 wt %. The non-solvent may be, but is not limited to, water, alcohol, glycol. The non-solvent may be contained in an amount of 0.1 wt% to 40 wt%, preferably 0.1 wt% to 10 wt%, based on the total weight of the radioactive dope-containing solution.

[0060] The above steps are performed by a general spinning process. In one embodiment, they may be performed by a dry-wet spinning process using the apparatus shown in Figure 12. The dry-wet spinning process is roughly divided into the following steps: i) a step in which the dope solution is spun from a spinneret; ii) a step in which the spun dope solution is quenched into a non-solvent; and iii) a step in which the dope solution that has entered the non-solvent separates into two phases and solidifies. The spun fiber sorbent precursor may be a monolithic fiber or a hollow fiber.

[0061] When a bore fluid is spun together with the dope solution during the dope spinning process, a hollow fiber may be formed, and when a bore fluid is not spun, a monolithic fiber may be formed. In one embodiment, the bore fluid may be NMP / H2O. Next, the method for manufacturing the fiber sorbent includes the step of immersing the support in a solution containing a conductive material. It is preferable to perform ultrasonic treatment on the solution containing the conductive material to maintain good dispersion of the conductive material.

[0062] In one embodiment, the method for preparing the fiber adsorbent may further include treating the shell surface of the fiber adsorbent before immersing the support in the solution. For example, the support may be treated with UV ozone to form oxygen functional groups on the shell surface of the support, thereby improving the adhesion between the conductive material and the support.

[0063] The step of immersing the support in the solution containing the conductive material may be repeated, and by repeating the step, the conductive layer can be formed more effectively.

[0064] Route 2 Another aspect of the present invention relates to a method for producing a fiber adsorbent, which includes a step (spinning step) of spinning a dope solution containing an adsorbent and a support, either by spinning a conductive material into the bore of a spinneret together with the dope solution or by adding a conductive material to the dope solution and spinning the dope solution. Specifically, the present invention relates to a method for producing an electrolytic fiber adsorbent, in which a conductive material is formed in the bore or core of the support, which includes a step of spinning a dope solution containing an adsorbent and a support, adding a conductive material to the bore or core side of the spinneret, and then spinning the dope solution to solidify it by phase separation.

[0065] According to another embodiment of the present invention, by spinning a bulk wire instead of the bore fluid, the spinning step can be performed in one go to produce an electrolytic fiber adsorbent in which a bulk wire is formed in the bore of the support (Route 2 in Figure 1).

[0066] In the method for manufacturing a fiber adsorbent according to Route 2, the composition of the dope solution may be the same as that of Route 1. In addition, in the case of Route 2, the composition of the dope solution may further include a conductive material. The process for preparing an electrolytic fiber adsorbent formed of a substrate containing a conductive material of the present invention can be summarized as follows.

[0067] JPEG0007755741000001.jpg29161

[0068] The adsorption methods of fiber adsorbents are not limited to these, but may include: 1) chemically adding chemical functional groups to the support or adsorbent and using them for adsorption; 2) physically or chemically adding chemical functional groups (e.g., amine functional groups) to the porous structure of the support or adsorbent and using them for adsorption; or 3) using a solid adsorbent in combination with two or more of the above 1) and 2).

[0069] In the case of 1), polyamide-imide (PAI) is given CO2 adsorption ability by suspending polyethyleneimine (PEI) functional groups through an amine ring opening reaction. The amine ring-opening reaction can dramatically improve the CO2 adsorption capacity of PAI by attaching PEI, which has CO2 adsorption properties, to the PAI polymer chain. The PAI support used here can be one or more selected from the group consisting of cellulose, cellulose acetate, polymer of intrinsic microporosity (PIM), polyethylene, polypropylene, polyethylene glycol, polyethylene terephthalate, polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyimide, polyamide-imide (PAI), polyetherimide (PEI), nickel oxide (NiO), copper oxide (CuO), alumina (Al2O3), zinc oxide (ZnO), and silicon carbide (SiC).

[0070] In the case of 2), PIM-PEI can be mentioned. PIM has micropores of less than 2 nm, and CO2 adsorption capacity can be improved by impregnating the interior of these micropores with an adsorbent. The adsorbent used may be, but is not limited to, amine-based chemicals such as polyethyleneimine, tetraethylenepentamine, ethyleneamine, and p-xylenediamine. Another aspect of the present invention relates to an electrolytic fiber sorbent module containing a plurality of the fiber sorbents described above. The fiber adsorbent module provided in the present invention is applicable to all of the above-mentioned fiber adsorbents, and therefore will not be described again.

[0071] In another aspect, the present invention relates to a method for electric and electromagnetic swing adsorption of carbon dioxide, comprising the steps of contacting a gas with the fiber adsorbent to adsorb carbon dioxide; and applying a voltage to the fiber adsorbent to desorb the adsorbed carbon dioxide.

[0072] The present invention also relates to an electric and electromagnetic swing adsorption process for an electrified fiber sorbent, comprising the steps of: (a) contacting a carbon dioxide-containing gas with the fiber sorbent to adsorb carbon dioxide; (b) applying a voltage to the fiber sorbent to desorb the adsorbed carbon dioxide; and (c) repeating steps (a) and (b). The carbon dioxide adsorption and desorption method provided by the present invention can be applied to all of the above-mentioned fiber adsorbents, and therefore, a redundant description will not be given.

[0073] First, the present invention provides a method for the electric and electromagnetic swing adsorption of carbon dioxide, which comprises contacting a gas with the fiber adsorbent to adsorb carbon dioxide, which may be 100% or less (pure carbon dioxide), 15% or less (flue gas), 1000 ppm or less (ultra-dilute stream), or 500 ppm (direct air capture).

[0074] In one embodiment, this may be done in a shell and tube process where a gas feed containing carbon dioxide is passed over the side of a fiber adsorbent.

[0075] The carbon dioxide electric swing adsorption method provided by the present invention also includes a step of applying a voltage to the fiber adsorbent to desorb the adsorbed carbon dioxide.

[0076] By applying a voltage in this step, the temperature may rise due to Joule heating or resistive heating of the conductive material, thereby desorbing carbon dioxide. Since the energy source used for desorption is electricity, there is freedom in where the heat source can be obtained, and there are advantages in terms of the cost and carbon footprint of energy production by using renewable energy, etc. For desorption of carbon dioxide, it is preferable to apply a voltage so that the temperature reaches 60°C to 250°C. In the present invention, the step (c) may be repeated 2 to 500 times. [Example]

[0077] The present invention will be described in more detail below with reference to examples. It will be obvious to those skilled in the art that these examples are merely for the purpose of illustrating the present invention and should not be construed as limiting the scope of the present invention.

[0078] [Example] Example 1: Preparation of a support containing an adsorbent Polyetherimide (PEI) was selected as the support, and a metal-organic framework, NbOFFIVE-1-Ni, was selected as the adsorbent. This is used for spinning, and the dope composition for spinning is as shown in Table 3a below.

[0079] The fiber sorbent can be produced according to the radiation parameters shown in Table 1 below, and the fiber sorbent can have a hollow or monolithic structure depending on whether or not there is a bore fluid flow. [Table 1]

[0080] Figure 2 shows a photograph and SEM image of the hollow NbOFFIVE-1-Ni / polyetherimide (PEI) fiber adsorbent. The fiber adsorbent is pale blue in color, and the MOF particles are uniformly loaded into the large pores of the polymer matrix. Large voids of several microns in size are observed on the surface of the fiber adsorbent, indicating that the fiber adsorbent has an open porous structure.

[0081] Example 2: Formation of a conductive layer A conductive layer was formed on the shell surface of the fiber adsorbent loaded with MOFs according to Examples 1-1 to 1-5 by a dip coating process. In the dip coating process for organic substrates, the hydrophilicity / hydrophobicity of the substrate can be an important variable in determining coating quality. For hydrophobic substrates, UV ozone treatment can be used to generate oxygen functional groups on the substrate surface, or additives such as polyethyleneimine can be added to improve adhesion to the coating liquid.

[0082] Complete dispersion of the solution containing silver nanowires forming the conductive layer affects the coating quality, and various parameters of the dip coating process were optimized as shown in Table 3 below. An example of this fiber adsorbent can be seen in Route 1 of Figure 1. [Table 2]

[0083] The solution concentration, immersion time, and number of immersions affect the thickness and uniformity of the coating layer during the immersion process. The resistance of the electrolytically treated fiber adsorbent decreased in the range of 1 to 100 Ω per cm depending on the coating conditions.

[0084] Figure 3 shows that the fiber adsorbent coated with silver nanowires turned dark gray and a layer less than 1 micrometer thick was formed on the shell surface after the coating process. In particular, the large pores disappeared, and the silver nanowires were densely stacked on the shell surface of the fiber adsorbent. However, due to the still-existing meso- and micropores, there was little effect on gas mass transfer.

[0085] Example 3: Adsorbent containing conductive material in wire form During the dope spinning process, a metal wire was simultaneously spun into the spinneret bore, producing an electrified fiber adsorbent by spinning the dope solution around the bulk wire. The resulting fiber adsorbent can be seen through Route 2 in Figure 1.

[0086] The cross section of the fiber adsorbent produced in this way was examined using an electron microscope (SEM), and the results are shown in Figure 9. Figure 9 shows that polymer fibers were formed around the bulk wire, and that the bulk wire was formed in contact with the bore surface of the polymer fiber.

[0087] Examples 3-1 and 3-2: Polyamide-imide (PAI, Torlon) was selected as the support, and metal-organic framework NbOFFIVE-1-Ni was selected as the adsorbent. In FIG. 12, a dope solution containing NbOFFIVE-1-Ni and Torlon is spun onto the core side, and a metal wire as a heating element is spun onto the bore side. The dope composition for spinning is as shown in Table 3b below.

[0088] The fiber, fabricated in the same manner as Route 2, was subjected to a post-treatment process of solvent substitution in distilled water for 72 hours, followed by quenching in methanol and hexane for one hour each. The fabricated fiber was dried in a vacuum at 120°C for 12 hours before being used in the experiment.

[0089] Examples 3-3 to 3-5: Preparation of silica fiber adsorbent Torlon was selected as the support, and polyethyleneimine (PEI) was used as the adsorbent. w We selected silica impregnated with ~800.

[0090] In FIG. 12, a dope solution containing mesoporous silica and Torlon is spun onto the core side, and a metal wire as a heating element is spun onto the bore side. The dope composition for spinning is shown in Table 3c below.

[0091] The post-treatment process of the fiber adsorbent after spinning was the same as in Examples 3-1 and 3-2. The fiber adsorbent was then further immersed in a 5-20 wt% PEI / methanol solution for 24 hours to allow the PEI chains to penetrate into the silica pores. The PEI remaining on the outside of the fiber was washed with hexane and then dried in a vacuum at 120°C for 12 hours before use.

[0092] Experimental Example 1: Confirmation of carbon dioxide adsorption characteristics depending on spinning conditions The carbon dioxide adsorption characteristics of Examples 1-1 to 1-5 under the conditions in Table 1 were confirmed and are shown in FIGS.

[0093] The fiber adsorbents of Examples 1-1 to 1-5 have a specific gravity of MOF relative to the polymer of approximately 83 wt%, and have a carbon dioxide adsorption capacity of nearly 0.9 at a concentration of 400 ppm, which is 75% of the level of NbOFFIVE-1-Ni powder, demonstrating excellent adsorption capacity. Comparing Examples 1-1 to 1-3 as in FIG. 6, it can be seen that the amount of carbon dioxide adsorption increases as the content of PEI, which is the support, decreases.

[0094] Furthermore, when comparing Examples 1-1, 1-4, and 1-5 as shown in Figure 7, it can be seen that when the content of NbOFFIVE-1-Ni is increased under the same conditions of the PEI content of the support, the amount of carbon dioxide adsorption increases, and Example 1-5 shows the best carbon dioxide adsorption capacity. The adsorption capacities of Examples 1-1 to 1-5 and Example 3 are summarized in numerical values ​​in Tables 3 to 5 below. [Table 3] [Table 4] [Table 5]

[0095] Furthermore, when a coating layer was further formed on the shell surface as in Example 2, the total mass of the fiber adsorbent increased due to the formation of the coating layer, and the adsorption amount of the fiber adsorbent appeared to decrease. However, when the increased mass was taken into account in the calculation, it was confirmed that the adsorption capacity of NbOFFIVE-1-Ni itself in the fiber adsorbent remained unchanged.

[0096] Experimental example 2: Confirmation of thermal properties depending on coating conditions A conductive layer was formed on the adsorbents of Examples 1 to 5 in the same manner as in Example 2, and the thermal properties were examined while changing the conductive layer coating conditions as shown in Table 6 below. [Table 6]

[0097] In Table 6, in Examples 2-1 and 2-2, coating with the coating solution was performed three times, whereas in Example 2-3 it was performed twice and in Example 2-4 it was performed only once.

[0098] As a result, in the case of Examples 2-3 and 2-4, in which the number of coatings was relatively small, it was found that the coating was not performed well and the resistance was measured to be relatively high. In particular, in the case of Example 2-4, it was confirmed that the resistance was very high and almost no current flowed. This means that it is necessary to repeat the coating process a certain number of times to form a better conductive layer and thereby improve electrical conductivity.

[0099] Furthermore, when Example 2-1 and Example 2-2 are compared, Example 2-1 shows a case where the silver nanowires are relatively well dispersed in the coating solution, while Example 2-2 shows a case where they are relatively poorly dispersed. The degree of dispersion can be adjusted by changing various conditions during the preparation of the coating solution.

[0100] Referring to Table 4, in the case of Example 2-1, in which coating was performed using a solution with excellent dispersion of silver nanowires in the coating solution, the resistance was significantly low, and therefore it was confirmed that the thermal effect occurred well even at a relatively low voltage. This indicates that the dispersion characteristics in the coating solution affect the coating quality.

[0101] Experimental Example 3: Confirmation of the thermal properties of the adsorbent To test the thermal properties of the electrolytic fiber adsorbent, the adsorbent of Example 2 was fixed on a glass substrate and connected to a device with copper wires. A voltage was applied to the fiber adsorbent, and the heat generated by the applied voltage was observed with a thermal imaging camera.

[0102] The thermal properties of the fiber adsorbent optimized in this example were verified at various applied voltages, as can be seen in Figure 5. As the applied voltage increased, the temperature of the fiber adsorbent increased, and the excellent electrical conductivity of the fiber adsorbent improved the Joule heating effect. To confirm the electrical stability of the MOF, the CO2 adsorption amount was measured under isothermal conditions for the sample before and after the thermal property measurement, and the results are shown in Figure 8. As can be seen in Figure 8, the amount of CO2 adsorbed by the fiber adsorbent hardly decreased even after the thermal property measurements.

[0103] Experimental Example 4: Confirmation of carbon dioxide adsorption characteristics depending on the number of recycles The adsorption amounts of the adsorbents of Examples 3-1 and 3-5 were measured according to the number of cycles, and the results are shown in Tables 7 and 8. [Table 7] [Table 8]

[0104] As shown in Tables 7 and 8, the NbOFFIVE-1-Ni fiber adsorbent and silica fiber adsorbent show almost no change in CO2 adsorption amount even after repeated cycles.

[0105] Although certain parts of the present invention have been described in detail above, it will be apparent to those skilled in the art that these specific techniques are merely preferred embodiments and do not limit the scope of the present invention. Therefore, the true scope of the present invention is to be defined by the appended claims and their equivalents. [Industrial Applicability]

[0106] The electrolytic fiber adsorbent of the present invention can efficiently adsorb carbon dioxide at relatively low concentrations, particularly in the atmosphere, and has the advantages of being able to use any energy source required for carbon dioxide desorption, allowing for direct heating of the adsorbent, and being highly energy efficient.

Claims

1. An electrolytic fiber sorbent formed from a porous support comprising an adsorbent and a conductive material, the conductive material being in the form of a bulk wire.

2. 2. The electrolytic fiber adsorbent according to claim 1, wherein a conductive layer is formed on the bore surface or shell surface of the support.

3. An electrified fiber adsorbent formed from a porous support comprising an adsorbent and a conductive material, characterized in that the conductive material is formed in the bore of the support.

4. 4. The electrolytic fiber adsorbent of claim 1 or 3, characterized in that the support contains an electrically conductive material inside.

5. 4. The electrolytic fiber sorbent according to claim 1 or 3, characterized in that the sorbent is capable of physically or chemically absorbing carbon dioxide.

6. 4. The electrolytic fiber adsorbent according to claim 1 or 3, wherein the adsorbent is at least one selected from the group consisting of a metal-organic framework (MOF), a porous organic cage (POC), a covalent organic framework (COF), a porous coordination polymer (PCP), a metal-organic polyhedra (MOP), a zeolite, silica, activated carbon, a carbon material, and a metal oxide.

7. The electrolytic fiber adsorbent of claim 6, wherein the metal-organic framework comprises metal nodes and organic ligands.

8. The metal node is at least one selected from the group consisting of Mg, Al, Y, Sc, Mo, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Cd, Ca, Pd, Pt, Au, Ag, Ru, Gd, Eu, Tb, and Nb, and the organic ligand is 4,4'-dioxide-3,3'-biphenyldicarboxylate, 2,5-dioxide-1,4-benzenedicarboxylate, 1,5-dioxide-2,6-naphthalenedicarboxylate, 4,4'-dioxide-3,3'-triphenyl 8. The electrolytic fiber adsorbent of claim 7, wherein the adsorbent is one or more selected from the group consisting of dicarboxylates, 2,5-dihydroxyterephthalic acid, 4-(4-carboxy-3-hydroxy-phenyl)-2-hydroxy-benzoic acid, 4,4'-ethynylenedibenzoic acid, 1,3,5-benzenetricarboxylic acid, 2-bromo-1,4-benzenedicarboxylic acid, pyridine-3-carboxylic acid, 2-methyl-1H-imidazole, 4-methyl-5-imidazolecarboxaldehyde, and biphenyl-4,4'-dicarboxylic acid.

9. The electrolytic fiber adsorbent of claim 7, wherein the metal-organic framework is NbOFFIVE-1-Ni.

10. 7. The electrolytic fiber adsorbent of claim 6, wherein the carbon material is a porous carbon material.

11. The electrolytic fiber adsorbent according to claim 1 or 3, wherein the adsorbent further contains or is bonded to an amine-based compound.

12. 4. The electrolytic fiber adsorbent of claim 1 or 3, wherein the conductive material is one or more selected from the group consisting of conductive porous structures, conductive metals and alloys, conductive 2D materials, and conductive carbon materials.

13. The electrolytic fiber adsorbent according to claim 1 or 3, characterized in that the resistivity of the conductive material is between 0.5 Ω / m and 10,000 Ω / m.

14. 13. The electrolytic fiber adsorbent of claim 12, wherein the conductive metal or alloy is at least one selected from the group consisting of silver, copper, annealed copper, gold, aluminum, calcium, tungsten, zinc, cobalt, nickel, ruthenium, lithium, iron, platinum, tin, gallium, niobium, carbon steel, lead, galinstan, titanium, grain-oriented electrical steel, manganin, constantan, stainless steel, mercury, manganese, and nichrome.

15. The conductive 2D material is molybdenum disulfide (MoS 2 ), phosphorene, bismuthene, Mxene or tungsten disulfide (WS 2 13. The electrolytic fiber adsorbent of claim 12, wherein

16. 13. The electrolytic fiber adsorbent of claim 12, wherein the conductive carbon material is at least one selected from the group consisting of graphene, graphene oxide, graphite, carbon black, and carbon nanotubes.

17. The electrolytic fiber adsorbent according to claim 12, wherein the conductive porous structure is a covalent organic framework (COF), a metal-organic framework (MOF), or a carbon-based porous material.

18. 4. The electrolytic fiber adsorbent of claim 3, wherein the conductive material is in the form of particles or bulk wires.

19. 20. The electrolytic fiber sorbent of claim 1 or 18, wherein the bulk wire is coated with an insulator.

20. 4. The electrolytic fiber adsorbent according to claim 1 or 3, characterized in that the support is a polymer or a sintered inorganic material.

21. 21. The electrolytic fiber adsorbent of claim 20, wherein the support is one or more selected from the group consisting of cellulose, cellulose acetate, microporous polymers, polyethylene, polypropylene, polyethylene glycol, polyethylene terephthalate, polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyimide, polyamideimide, polyetherimide, nickel oxide, copper oxide, alumina, zinc oxide, and silicon carbide.

22. 4. The electrolytic fiber sorbent according to claim 1 or 3, characterized in that the support has a hollow or monolithic structure.

23. The electrolytic fiber adsorbent according to claim 1 or 3, characterized in that the adsorbent is contained in the support in an amount of 1 wt% to 80 wt%.

24. 4. The electrolytic fiber adsorbent of claim 1 or 3, further comprising a susceptor.

25. 25. The electrolytic fiber adsorbent of claim 24, wherein the susceptor is selected from the group consisting of carbon fiber, chromium oxide, goethite, lepidocrocite, hematite, maghemite, magnetite, ilmenite, iron (Fe), and cobalt (Co).

26. 3. The method of claim 2, further comprising the steps of spinning a dope solution containing the adsorbent and the support and then immersing the dope solution in a solution containing a conductive material.

27. 27. The method of claim 26, further comprising treating a shell surface of the support before immersing the support in a solution.

28. The method for producing an electrolytic fiber adsorbent according to claim 1 or 3, comprising the step of spinning a dope solution containing an adsorbent and a support, after adding a conductive material to the bore or core side of a spinneret.

29. 10. An electrolytic fiber sorbent module for the electrical and electromagnetic swing adsorption of carbon dioxide comprising a plurality of the electrolytic fiber sorbents of claim 1 or 3.

30. (a) contacting a carbon dioxide-containing gas with the electrolytic fiber adsorbent of claim 1 or 3 to adsorb the carbon dioxide; and (b) applying a voltage to the fiber adsorbent to desorb the adsorbed carbon dioxide.

31. 31. The method for electric and electromagnetic swing adsorption of carbon dioxide according to claim 30, wherein the adsorbent that has adsorbed carbon dioxide is regenerated by applying a voltage by a resistance heating method or an induction heating method.

32. 31. The method for electric and electromagnetic swing adsorption of carbon dioxide according to claim 30, wherein the carbon dioxide concentration in the gas is 1000 ppm or less.

33. 31. The method for electric and electromagnetic swing adsorption of carbon dioxide according to claim 30, further comprising, after step (b), the step of: (c) repeating steps (a) and (b).

Images