Carbon dioxide adsorbent, module for adsorption, separation and capture of carbon dioxide, and direct air capture method

Abstract

Provided is a carbon dioxide adsorbent which comprises a plurality of fibrous structure sheets and a porous material B forming a porous inorganic support layer among the plurality of fibrous structure sheets, wherein in the porous material B, the holding amount of the porous inorganic support layer is 10 g / m2 to 500 g / m2 inclusive with respect to the plurality of fibrous structure sheets and the air permeation resistance with respect to a thickness direction of the fibrous structure sheets is 0.01-50 kPa·s / m inclusive.

Description

Carbon dioxide adsorbent, carbon dioxide adsorption / separation / capture module, and direct air capture method

[0001] The present invention relates to a carbon dioxide adsorbent, a module for adsorption, separation and capture of carbon dioxide, and a direct air capture method.

[0002] In recent years, abnormal weather events such as heavy rains and droughts, as well as rising sea levels, have occurred, and global average temperatures are rising year by year, making global warming a serious issue. The primary cause of global warming is greenhouse gases, such as carbon dioxide, known as "green house gas." Atmospheric carbon dioxide concentrations are gradually increasing, and there is no doubt that rising carbon dioxide concentrations have a significant impact on global warming. Therefore, reducing atmospheric carbon dioxide is an urgent task in order to prevent global warming. Efforts to reduce carbon dioxide emissions are being undertaken around the world, and in 2015, the Paris Agreement was adopted at the United Nations Framework Convention on Climate Change Conference (COP21) held in Paris. This agreement states that "we will limit the increase in global average temperature to well below 2°C above pre-industrial levels, pursue efforts to limit it to 1.5°C, and significantly reduce the risks and impacts of climate change."

[0003] As a method for reducing the concentration of carbon dioxide in the atmosphere, in addition to the technology of capturing carbon dioxide emitted from factories, "Direct Air Capture (DAC)", a technology that captures carbon dioxide directly from the atmosphere, is attracting attention. A method using liquid amines is widely used as a technology for capturing carbon dioxide from factory exhaust gases. On the other hand, a technology for capturing carbon dioxide at very low concentrations of around 400 ppm is the solid amine method, in which amines are supported on a solid carrier. The solid amine method is being developed worldwide as a technology that can reduce the energy required for the desorption temperature of carbon dioxide.

[0004] As an example of a technique for supporting an amine on a solid support, Patent Document 1 discloses a method for separating carbon dioxide from a gas mixture using surface-modified cellulose nanofibers that are capable of reversible adsorption and desorption of carbon dioxide. Patent Document 1 also discloses a porous adsorptive structure comprising surface-modified cellulose nanofibers. The porous adsorptive structure described in Patent Document 1 includes a support matrix that is a surface-modified cellulose nanofiber coated with a coupling agent containing at least one monoalkyldialkoxy-aminosilane in a covalently bonded state, and the support matrix is ​​a structure that is a woven fabric of nanofibers having a porosity of at least 20%.

[0005] For example, Patent Document 2 discloses a radial flow system that uses porous particles based on nanofibrillated cellulose that are supported with an amine compound as a carbon dioxide absorbent.

[0006] For example, Patent Document 3 discloses a method for applying a coating of an adsorbent, such as a gas such as carbon dioxide, onto a substrate, a carrier, and / or a substrate coated with a carrier. Patent Document 3 also discloses that the sorbent is selected from the group consisting of amines, amides including melamine, amine-containing polymers, and combinations thereof, the substrate is a woven or nonwoven plastic or cellulose fiber, and the carrier is alumina, silica, silica-alumina, titania, zirconia, carbon, zeolite, metal-organic framework (MOF), or a combination thereof.

[0007] Furthermore, Patent Document 3 discloses that a substrate having a monolithic structure of metal or plastic is manufactured by laminating corrugated plastic sheets.

[0008] International Publication No. 2012 / 168346 International Publication No. 2014 / 170184 Special Publication No. 2014-533195

[0009] The problem with DAC is its high energy cost. To reduce the energy cost, it is necessary to reduce the power required to adsorb carbon dioxide onto the adsorbent and to reduce the temperature required to desorb the carbon dioxide adsorbed onto the adsorbent.

[0010] To reduce the power consumption during carbon dioxide adsorption, it is important to adsorb the carbon dioxide-containing gas onto the adsorbent with as little power as possible, i.e., to minimize the pressure loss during adsorption.

[0011] As described above, Patent Documents 1 and 3 disclose the use of a specific nonwoven fabric as a substrate for a carbon dioxide adsorbent, but do not disclose a module for adsorbing, separating, and capturing carbon dioxide that takes pressure loss into consideration, or a nonwoven fabric suitable for such a module.

[0012] Furthermore, in order to reduce the power consumption during carbon dioxide adsorption, it is necessary to support as much carbon dioxide adsorbent as possible on the carrier, that is, to increase the specific surface area of ​​the carrier as much as possible.

[0013] Furthermore, in order to increase the carbon dioxide adsorption efficiency, it is important to maximize the opportunity for the gas to be treated to come into contact with the carbon dioxide adsorbent. For example, this may involve suppressing uneven flow of the gas to be treated within the device and reducing dead space.

[0014] For example, in Patent Document 2, since the carbon dioxide absorbent material is in the form of particles, there is a large pressure loss when air is introduced, and in order to reduce the amount of electricity used, the thickness of the bed of the carbon dioxide adsorption unit and the air volume when air is introduced are limited.

[0015] Furthermore, for example, Patent Document 3 discloses a carbon dioxide adsorbent having a honeycomb structure coated with porous particles carrying an amine compound. By forming the carbon dioxide adsorbent into a honeycomb structure, pressure loss can be reduced even when a large volume of air is introduced. However, there is a problem in that the thickness of the coating porous particle layer is limited in order to diffuse the air introduced into the honeycomb structure, which limits the amount of carbon dioxide adsorbed per cycle.

[0016] An object of the present invention is to provide a carbon dioxide adsorbent that reduces pressure loss during carbon dioxide adsorption and can increase the amount of carbon dioxide adsorbed, as well as an efficient carbon dioxide adsorption, separation, and capture module and direct air capture method.

[0017] The gist of the present invention is as follows: <<Aspect 1>> A porous inorganic carrier layer is formed between a plurality of fiber structures, and a porous material B is formed between the plurality of fiber structures, and the porous material B is formed in such a manner that the amount of the porous inorganic carrier layer supported by the porous material B is 10 g / m with respect to the plurality of fiber structures. ２ More than 500g / m ２ a carbon dioxide adsorbing material having an airflow resistance in the thickness direction of the fiber structure of 0.01 kPa·s / m or more and 50 kPa·s / m or less. <<Aspect 2>> A carbon dioxide adsorbing material comprising a fiber structure and a porous material A supported on a surface or in voids of the fiber structure, wherein 50 volume % or more of the porous material A is supported in the voids of the fiber structure, and the supported amount of the porous material A with respect to the fiber structure is 10 g / m ２ More than 500g / m ２ a carbon dioxide adsorbing material having an airflow resistance in the thickness direction of the fiber structure of 0.01 kPa·s / m or more and 50 kPa·s / m or less. <<Aspect 3>> The carbon dioxide adsorbing material comprises a plurality of fiber structures, and a porous material A supported on a surface or in voids of at least one of the fiber structures, wherein 50 volume % or more of the porous material A is supported in the voids of the fiber structures, and the supported amount of the porous material A with respect to the fiber structures is 10 g / m ２ More than 500g / m ２ The carbon dioxide adsorbing material according to aspect 1 or 2, wherein the fiber structure has an airflow resistance in a thickness direction of 0.01 kPa·s / m or more and 50 kPa·s / m or less. <<Aspect 4>> The total amount of the porous materials A and B supported on the fiber structure is 50 g / m or less. ２The carbon dioxide adsorbent according to any one of Aspects 1 to 3, wherein the carbon dioxide adsorbent has a laminated structure in which at least one layer of the carbon dioxide adsorbent according to any one of Aspects 1 to 4 is laminated. ２ Above, 500g / m ２ The amount of the porous material B supported on the fiber structure is 10 g / m or less. ２ Above, 500g / m ２ The total amount of the porous materials A and B supported on the fiber structure is 50 g / m or less. ２ The carbon dioxide adsorbent according to any one of Aspects 1 to 5, wherein the porous material A comprises: porous inorganic particles having an average particle size of 0.1 μm to 30 μm; and at least one type of porous inorganic particles selected from the group consisting of colloidal silica, colloidal alumina, and precursors of colloidal silica or colloidal alumina, the porous inorganic particles having an average particle size of 1 nm to 400 nm, and the porous inorganic particles having an average particle size of 0.1 μm to 30 μm account for 10 mass % to 99 mass % of 100 mass % of porous material A. <<Aspect 8>> The carbon dioxide adsorbent according to Aspect 7, wherein the porous material A comprises: porous inorganic particles having an average particle size of 0.1 μm to 30 μm; and a polymer emulsion. <<Aspect 9>> The carbon dioxide adsorbing material according to any one of Aspects 1 to 8, wherein the porous inorganic carrier layer is formed from the porous material B, which contains porous inorganic particles having an average particle diameter of 30 μm to 3 mm and a hot-melt material having a melting point of 50°C to 150°C, and the hot-melt material is contained in an amount of 1% by mass to 80% by mass based on the total of the porous inorganic particles and the hot-melt material. <<Aspect 10>> The porous inorganic particles contained in each of the porous materials A and B each have a BET specific surface area of ​​50 m ２ / g or more 3000m ２The carbon dioxide adsorbent according to any one of Aspects 1 to 9, wherein the fiber structure has a pore size of 1 μm or more and an average pore diameter of 1 nm or more and 50 nm or less, and is at least one or more selected from the group consisting of silica, alumina, silica alumina, titania, zirconia, activated carbon, zeolite, alkali metal ferrite, and MOF. <<Aspect 11>> The carbon dioxide adsorbent according to any one of Aspects 1 to 10, wherein the average fiber diameter of the fiber structure is 1 μm or more and 50 μm or less, and the porosity of the fiber structure is 50% or more and 95% or less. <<Aspect 12>> The carbon dioxide adsorbent according to any one of Aspects 1 to 11, wherein a compound having an amino group is supported in an amount of 10% by mass to 300% by mass relative to the porous material A and / or B. <<Aspect 13>> The carbon dioxide adsorbent according to Aspect 12, wherein the compound having an amino group includes at least one or more silicone compounds selected from the group consisting of silicone oil, silsesquioxane, and MQ resin. <<Aspect 14>> The carbon dioxide adsorbent according to Aspect 13, wherein the silicone compound is contained in the compound having an amino group in an amount of 1% by mass or more and 90% by mass or less. <<Aspect 15>> A module for adsorption, separation, and capture of carbon dioxide, having a laminate structure in which at least one layer of the carbon dioxide adsorbent according to any one of Aspects 1 to 14 and at least one layer of a spacer are laminated. <<Aspect 16>> A module for adsorption, separation, and capture of carbon dioxide, having a corrugated structure in which at least one layer of the carbon dioxide adsorbent according to any one of Aspects 1 to 14 is used.<<Aspect 17>> The carbon dioxide adsorption, separation, and capture module according to Aspect 15 or 16, wherein the corrugated structure includes a core portion and a liner portion, and the carbon dioxide adsorbent according to any one of Aspects 1 to 14 is used for each of the core portion and the liner portion. <<Aspect 18>> The carbon dioxide adsorption, separation, and capture module according to Aspect 17, wherein at least one selected from the group consisting of a mesh, a nonwoven fabric, and a porous sheet is used for the liner portion. <<Aspect 19>> A direct air capture (DAC) method for directly capturing carbon dioxide from the atmosphere, comprising the following steps: an adsorption step of adsorbing carbon dioxide onto the carbon dioxide adsorbent in the carbon dioxide adsorption, separation, and capture module according to any one of Aspects 15 to 18; and a desorption step of changing the temperature or pressure to desorb the carbon dioxide.

[0018] According to the present invention, there are provided a carbon dioxide adsorbent that has a small pressure loss during carbon dioxide adsorption and can adsorb a large amount of carbon dioxide, a module for adsorption, separation and capture of carbon dioxide, and a direct air capture method.

[0019] FIG. 1 shows a conceptual diagram of a carbon dioxide adsorbent comprising porous material B of this embodiment. FIG. 2 shows a scanning electron microscope image of a carbon dioxide adsorbent comprising porous material B of this embodiment. FIG. 3 shows a conceptual diagram of a carbon dioxide adsorbent comprising porous material A of this embodiment. FIG. 4 shows a scanning electron microscope image of a carbon dioxide adsorbent comprising porous material A of this embodiment. FIG. 5 shows a schematic diagram of a spiral-wound module of this embodiment. FIG. 6 shows a schematic diagram of a corrugated module of this embodiment. FIG. 7 shows a system diagram of DAC (Direct Air Capture) technology.

[0020] Hereinafter, a mode for carrying out the present invention (hereinafter also referred to as the present embodiment) will be described in detail. Note that the present embodiment is not limited to the embodiment described below, and various modifications can be made within the scope of the embodiment.

[0021] <Carbon dioxide adsorbent> The carbon dioxide adsorbent is a material that adsorbs carbon dioxide (CO ２It is preferable to adsorb carbon dioxide from process gases such as synthetic gas, natural gas, and exhaust gas, or from the atmosphere, or a mixture thereof, and it is particularly preferable to adsorb carbon dioxide from the atmosphere.

[0022] As a technology for capturing carbon dioxide from the atmosphere, there is DAC (Direct Air Capture) technology, which includes a solid adsorption method (Solid DAC) in which the target for adsorbing carbon dioxide is a solid, and a liquid adsorption method (Liquid DAC) in which the target for adsorbing carbon dioxide is a solution. As the carbon dioxide adsorbent of this embodiment, the solid adsorption method (Solid DAC) is preferred.

[0023] In one aspect, the carbon dioxide adsorbent of this embodiment includes a plurality of fibrous structures and a porous material B that forms a porous inorganic carrier layer between the plurality of fibrous structures. In another aspect, the carbon dioxide adsorbent of this embodiment includes a fibrous structure and a porous material A that is supported on the surface of the fibrous structures or in voids of the fibrous structures. In another aspect, the carbon dioxide adsorbent of this embodiment includes a plurality of fibrous structures, a porous material A that is supported on the surface of at least one fibrous structure or in voids of the fibrous structure, and a porous material B that forms a porous inorganic carrier layer between the plurality of fibrous structures.

[0024] As long as the carbon dioxide adsorbent has at least one layer of the carbon dioxide adsorbent of this embodiment (in one aspect, a carbon dioxide adsorbent layer), it can be suitably used for adsorbing carbon dioxide. From the viewpoint of improving the amount of carbon dioxide adsorbed, the carbon dioxide adsorbent of this embodiment preferably has a laminated structure in which carbon dioxide adsorbent layers are laminated.

[0025] The carbon dioxide adsorbent of this embodiment has an airflow resistance in the thickness direction of the fiber structure of 0.01 kPa·s / m or more and 50 kPa·s / m or less. As a result, even if the carbon dioxide adsorbent of this embodiment has a thick structure in which carbon dioxide adsorbent layers are stacked, the pressure loss is small and the diffusibility of carbon dioxide into the carbon dioxide adsorbent layer is high.

[0026] The airflow resistance of a carbon dioxide adsorbent is measured as follows: Using a KES-F8 air permeability tester (manufactured by Kato Tech Co., Ltd.), measurements are taken at 20 locations evenly spaced across the width of the carbon dioxide adsorbent and 10 locations evenly spaced across the length of the adsorbent, for a total of 200 locations, within an area of ​​1 m wide and 50 cm long, and the average value and standard deviation are taken as the airflow resistance and standard deviation of the airflow resistance of the carbon dioxide adsorbent (measurement area 0.2π cm). ２ : diameter 8.9 mm).

[0027] In the present disclosure, the term "supported" refers to a substance being immobilized on a carrier by adhesion, electrostatic adsorption, reaction, or the like.

[0028] In the present disclosure, the term "carrier" refers to a substance that serves as the base for a certain substance, and in the present disclosure refers to a "fibrous structure" or a "porous material" for supporting a compound having an amino group.

[0029] (Fiber structure) Structures from which fibers can be obtained, such as woven fabrics, knitted fabrics, nonwoven fabrics, felts, papermaking, three-dimensional net-like structures, and sheet-like materials, can all be preferably used as the fiber structure according to this embodiment. Among them, at least one fiber structure selected from the group consisting of nonwoven fabrics, papermaking, and sheet-like materials is preferably used as the fiber structure. As the fiber structure, nonwoven fabrics are particularly preferred from the viewpoints of strength, porosity, breathability, and moldability. In one aspect, nonwoven fabrics are made of fibers, and therefore have voids between the fibers. Furthermore, the fiber structure according to this embodiment has a sheet-like shape and a large specific surface area, and therefore has a large portion in contact with air, and CO ２ Furthermore, the fiber structure according to this embodiment can support a porous material A on the surface or in the voids thereof, and can form a porous inorganic carrier layer in which a porous material B is sandwiched between a plurality of fiber structures.

[0030] Furthermore, if the fiber structure is in the form of a sheet, when it is laminated with a spacer or processed into a corrugated structure, porous materials can be supported on both the front and back sides of the fiber structure to allow efficient contact with carbon dioxide.

[0031] As the fibers of the fiber structure, various hydrophobic thermoplastic resin fibers and various hydrophilic fibers can be used. Examples of hydrophobic synthetic resin fibers include polyethylene, polypropylene, and polyester. Examples of hydrophilic fibers include cellulose-based fibers made of cellulose, cellulose derivatives, and regenerated cellulose, polyvinyl alcohol-based fibers, and polyamide-based fibers, with hydrophilic fibers being preferred. Examples of cellulose include wood pulp, recycled paper pulp, cotton, and hemp. Examples of cellulose derivatives include cellulose acetate and carboxymethyl cellulose. Examples of regenerated cellulose include cupra, rayon, and lyocell. Examples of polyvinyl alcohol-based fibers include polyvinyl alcohol and polyvinyl formal. Examples of polyamide-based fibers include nylon (in one embodiment, 6-nylon and 6,6-nylon).

[0032] Commercially available fiber structures include nonwoven fabrics made of regenerated cellulose long fibers (product name: Bemliese, manufactured by Asahi Kasei Corporation), nonwoven fabrics made of nylon long fibers (product name: Eltas N03050, manufactured by Asahi Kasei Corporation), and nonwoven fabrics made of polyethylene terephthalate (PET) long fibers (product name: Eltas E05040, manufactured by Asahi Kasei Corporation).

[0033] The fiber structure according to this embodiment preferably satisfies the following specific requirements.

[0034] The average fiber diameter of the fiber structure according to this embodiment is preferably 1 μm or more and 50 μm or less.

[0035] The specific surface area of ​​the fiber structure according to this embodiment is 0.01 m ２ / g to 100m ２ / g is preferred, and 0.1m ２ / g to 100m ２ / g is more preferred.

[0036] The thickness of the fiber structure according to this embodiment is preferably 0.05 mm to 5 mm, and more preferably 0.1 mm to 2.0 mm.

[0037] The basis weight of the fiber structure according to this embodiment is 0.1 g / m２ ~1000g / m ２ is preferred, and 10 g / m ２ ~150g / m ２ is more preferred.

[0038] The porosity of the fiber structure according to this embodiment is preferably 50% to 95%, more preferably 70% to 95%.

[0039] The fiber structure according to this embodiment has an average fiber diameter, a porosity, and the like within the above-mentioned specific ranges, and is therefore capable of supporting a large amount of porous material while suppressing pressure loss, making it preferable as a substrate for a carbon dioxide adsorbent.

[0040] Although the specific surface area of ​​the fiber structure can be increased by reducing the fiber diameter of the fiber structure, it is important to optimize it while taking into consideration the mechanical properties of the sheet. In addition, the thickness and basis weight of the fiber structure are important from the viewpoint of ensuring the contact area between the carbon dioxide adsorbent and the gas to be treated when the fiber structure is laminated together with a spacer.

[0041] The average fiber diameter of the fiber structure is measured as follows: The fiber structure is observed at a magnification of 10,000 times using a scanning electron microscope (product name: JSM-6380, manufactured by JEOL Ltd.), and an image of the fibers of the fiber structure is taken. 50 fibers are randomly selected from the taken image, and the average value of the measured values ​​is taken as the average fiber diameter.

[0042] The specific surface area of ​​the fiber structure is measured as follows. The specific surface area of ​​the fiber structure is measured using a specific surface area / pore size distribution measuring device (product name: TriStar II, manufactured by Micromeritics). 1 g of the fiber structure is dried under vacuum at 120°C for 2 hours, and then liquid nitrogen is introduced into the dry fiber structure. The amount of nitrogen gas adsorbed to the nonwoven fabric at the boiling point of liquid nitrogen is measured at 5 points in the range of relative vapor pressure (P / P0) of 0.05 to 0.2, and then the BET specific surface area (m ２ / g) is calculated.

[0043] The thickness of the fiber structure is measured as follows: 1 g of the fiber structure is dried in a vacuum at 120°C for 2 hours, and the dried fiber structure is then measured in a thickness test conforming to JIS-L1096 at a load of 1.96 kPa. The measurement is performed 20 times, and the average value is taken as the thickness (mm) of the fiber structure.

[0044] The basis weight of the fiber structure is measured as follows. After drying at 105°C until a constant mass is reached, the fiber structure is left in a thermostatic chamber at 20°C and 65% RH for 16 hours or more, and the mass is measured. ２ The measurement was carried out five times, and the average value was used as the basis weight (g / m) of the fiber structure. ２ )

[0045] The porosity of the fibrous structure was calculated as follows: After the thickness and basis weight of the fibrous structure were measured as described above, the porosity was calculated from the following formula.

[0046] Porosity (%) = basis weight of fiber structure / (density of fiber structure material × thickness of fiber structure) The density of the fiber structure material is determined by a density gradient tube method using xylene-bromobenzene, in which 100 mg of the fiber structure to be measured is placed in a long, thin glass tube having a height of 650 mm and an inner diameter of 30 mm and marked with a scale at 1 mm intervals.

[0047] (Porous Material) In one aspect, an example of the porous material of this embodiment is porous material A. The porous material A of this embodiment preferably contains at least two types of porous inorganic particles having different particle sizes. The porous material A of this embodiment preferably contains porous inorganic particles having an average particle size of 0.1 μm or more and 30 μm or less (in one aspect, porous inorganic particles 1) and porous inorganic particles having an average particle size of 1 nm or more and 400 nm or less (in one aspect, porous inorganic particles 2). The porous material A of this embodiment preferably contains porous inorganic particles 1, porous inorganic particles 2, and a polymer emulsion. The porous material A of this embodiment more preferably contains porous inorganic particles having an average particle size of 1 μm or more and 15 μm or less, and porous inorganic particles having an average particle size of 3 nm or more and 200 nm or less.

[0048] The porous inorganic particles having an average particle size of 0.1 μm to 30 μm include at least one selected from the group consisting of oxides such as alumina, silica, titania, zirconia, magnesia, and alkali metal ferrite, composite oxides such as calcium silicate and silica-alumina, activated carbon, zeolite, and metal-organic frameworks (MOFs). Among the above porous inorganic particles, alumina, silica, zeolite, activated carbon, alkali metal ferrite, and MOFs are particularly preferred from the viewpoints of the carbon dioxide adsorption capacity of the material itself and the pore size and specific surface area when used as a carrier.

[0049] The porous inorganic particles exemplified above can be produced by a conventionally known production method, or commercially available porous inorganic particles can be used. Alternatively, the porous inorganic particles produced by a conventionally known production method or commercially available porous inorganic particles can be crushed using a crusher equipped with a hammer, a cutter, or the like to adjust the average particle size within a predetermined range.

[0050] For example, when alumina is used as the porous inorganic particles of this embodiment, alumina of any crystalline system, such as α-type, γ-type, θ-type, etc. Commercially available alumina includes powdered activated alumina (KC, KCG, A, AC series) and spherical activated alumina (KHS, KHA, KHO, NKHO, NKHD, KHD, HD, FD series) manufactured by Sumitomo Chemical Co., Ltd., and Neobead manufactured by Mizusawa Industrial Chemicals, Ltd.

[0051] For example, when silica is used as the porous inorganic particles of this embodiment, examples thereof include synthetic silica and mesoporous silica, and synthetic silica can be produced by a wet method or a dry method. Examples of wet methods include a precipitation method or a sol-gel method, and examples of dry methods include a combustion method. Examples of mesoporous silica include MCM-41 and SBA-15. Examples of synthetic silica include Sylysia (Sylysia 370 and Sylysia 250N) manufactured by Fuji Silysia Ltd., Nipsil manufactured by Tosoh Silica Corporation, and Carplex manufactured by EVONIK.

[0052] For example, when titania is used as the porous inorganic particles of this embodiment, examples thereof include anatase, rutile, and brookite types, and the structure is not particularly limited. An example of commercially available anatase titania is TA manufactured by Fuji Titanium Co., Ltd. Examples of commercially available rutile titania include the CR series and R series manufactured by Ishihara Sangyo Kaisha, Ltd. For example, when zirconia is used as the porous inorganic particles of this embodiment, the structure is not limited, and any of monoclinic, tetragonal, and cubic crystals can be used. Examples of commercially available zirconia include the UEP and RC series zirconium oxide manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd. For example, when magnesia is used as the porous inorganic particles of this embodiment, examples include cubic types. Examples of commercially available magnesia include MTK-30 manufactured by Iwatani Corporation.

[0053] For example, when an alkali metal ferrite is used as the porous inorganic particles of this embodiment, sodium ferrite, lithium ferrite, etc., are listed, and the structure thereof is not particularly limited. Examples of the alkali metal ferrite structure include α-sodium ferrite having a trigonal layered rock salt structure and β-sodium ferrite having an orthorhombic structure.

[0054] For example, when calcium silicate is used as the porous inorganic particles of this embodiment, Ca ２ SiO ４ , Ca ３ SiO ５ , Ca ３ Si ２ O ７ , CaSiO ３ , CaOSiO ２ and 3CaO ２ SiO ２ However, the structure is not particularly limited, and a mixture of various structures can also be used. Commercially available calcium silicates include xonotlite and tobermorite manufactured by Nippon Insulation Co., Ltd. For example, when silica alumina is used as the porous inorganic particles of this embodiment, the silica / alumina ratio is not particularly limited. An example of commercially available silica alumina is Neobead SA manufactured by Mizusawa Industrial Chemicals, Ltd.

[0055] For example, when activated carbon is used as the porous inorganic particles of this embodiment, the raw material is not particularly limited. Examples of raw materials for activated carbon include wood, sawdust, coconut shells, pulp waste liquid, cellulose waste, coal, petroleum, and synthetic resins. Activated carbon obtained by carbonizing these raw materials may be used as the porous inorganic particles of this embodiment, or may be activated by gas activation with water vapor, carbon dioxide, or air, or by activation with chemicals such as zinc chloride, phosphoric acid, or alkali. When activated carbon is used as the porous inorganic particles by activation treatment, this is preferable because it increases the specific surface area in addition to enlarging the pore size.

[0056] For example, when zeolite is used as the porous inorganic particles of this embodiment, synthetic zeolite, artificial zeolite, and natural zeolite can be used. The elements contained in the zeolite and the manufacturing method thereof are not particularly limited. For example, zeolite can be manufactured by mixing an aluminum compound, a silicon compound, an alkali metal compound, an organic substance, etc., subjecting the mixture to a hydrothermal reaction, followed by drying and calcination. Commercially available zeolites include Mizuka Sieves manufactured by Mizusawa Industrial Chemicals, Zeostar manufactured by Nippon Chemical Industry Co., Ltd., and Zeolum manufactured by Tosoh Corporation.

[0057] For example, when MOFs are used as the porous inorganic particles of this embodiment, the MOFs that can be used are those in which metal ions such as Al, Cu, Zn, and Fe are complexed with organic ligands such as terephthalic acid, benzenetricarboxylic acid, imidazoles, and piperazine.

[0058] The porous inorganic particles having an average particle size of 0.1 μm or more and 30 μm or less are preferably contained in an amount of 10% by mass or more and 99% by mass or less in 100% by mass of the porous material A.

[0059] The porous inorganic particles having an average particle size of 1 nm or more and 400 nm or less contain at least one selected from the group consisting of colloidal silica, colloidal alumina, and precursors of colloidal silica or colloidal alumina, silica sol, and alumina sol.

[0060] The colloidal silica used as the porous inorganic particles of this embodiment may be either one produced from sodium silicate or one produced from tetraalkoxysilane. Examples of colloidal silica produced from sodium silicate include Snowtex manufactured by Nissan Chemical Co., Ltd. Examples of colloidal silica produced from tetraalkoxysilane include the PL series manufactured by Fuso Chemical Co., Ltd. and IDISIL manufactured by Evonik Corporation. Examples of colloidal alumina used as the porous inorganic particles of this embodiment include alumina sol manufactured by Nissan Chemical Co., Ltd.

[0061] The colloidal silica and colloidal alumina used as the porous inorganic particles of this embodiment may be used in the form of precursors. Precursors of the colloidal silica and colloidal alumina used as the porous inorganic particles of this embodiment may include orthosilicic acid and boehmite, respectively. Orthosilicic acid can be obtained by neutralizing sodium silicate with sulfuric acid or by hydrating tetraalkoxysilane with water. Boehmite can also be obtained by heat-treating aluminum hydroxide in a neutral to weakly basic aqueous solution at 150°C to 300°C.

[0062] The silica sol used in the present embodiment is not particularly limited in terms of raw materials or manufacturing method, but may be, for example, a silica sol manufactured using sodium silicate or an alkoxysilane such as tetramethoxysilane as a raw material, dispersed in water or an organic solvent, and mixed with porous inorganic particles.

[0063] The alumina sol used in this embodiment can be prepared by mixing pseudo-boehmite nanoparticles dispersed in water or an organic solvent with porous inorganic particles, and can bond the porous inorganic particles to each other and to the fibrous structures.

[0064] In one embodiment, the porous material A includes porous inorganic particles having an average particle size of 0.1 μm or more and 30 μm or less, and a polymer emulsion. The polymer emulsion used in this embodiment is preferably one that acts as a binder for the porous inorganic particles, and examples thereof include acrylic emulsions, styrene-acrylic emulsions, vinyl acetate emulsions, ethylene-vinyl acetate copolymer emulsions, polyurethane emulsions, polybutadiene emulsions, styrene-butadiene emulsions, and silicone emulsions. Among these, polyurethane emulsions, ethylene-vinyl acetate copolymer emulsions, and styrene-butadiene emulsions are preferred because, when mixed with the porous inorganic particles to support the porous inorganic particles on a fiber structure, they have a high ability to retain the porous inorganic particles, and the emulsion that acts as a binder is less likely to enter the pores of the porous inorganic particles.

[0065] The production method for these emulsions is not particularly limited, but for example, vinyl acetate emulsions, ethylene-vinyl acetate copolymer emulsions, and styrene-butadiene emulsions can be obtained by adding an emulsifier and a stabilizer to water, followed by emulsion polymerization with the addition of raw material monomers and a polymerization initiator. Polyurethane emulsions can be obtained by adding raw material isocyanate and polyol to water to form a urethane precursor, emulsifying the precursor, which then reacts to form polyurethane, and then adding an emulsion stabilizer.

[0066] Commercially available polyurethane emulsions include, for example, DIC's Hydran™ and BASF's Joncryl series. Commercially available ethylene-vinyl acetate copolymer emulsions include, for example, DOW's PEIMAL™ and Sumitomo Chemical's Sumikaflex series (product name: Sumikaflex S-201HQ, manufactured by Sumitomo Chemiflex Co., Ltd., polymer concentration 56% by mass). Commercially available styrene-butadiene emulsions include BASF's Acronal® series. The method for supporting the porous material A and the polymer emulsion of this embodiment is not particularly limited, but can be obtained, for example, by dispersing water and the porous material A in a mixing tank having a stirrer or a disperser, adding the polymer emulsion to the mixing tank and dispersing it, and then supporting the composite material supporting the fiber structure of this embodiment and the porous material B by various coating methods such as dip coating, gravure coating, and die coating, and drying.

[0067] The amount of the polymer emulsion used in this embodiment added to the porous material A is preferably in the range of 1 to 200 parts by mass based on the solid content mass of the polymer emulsion relative to 100 parts by mass of the porous material A, and is used by adding and mixing. The amount is more preferably in the range of 5 to 100 parts by mass, and even more preferably in the range of 10 to 50 parts by mass. Within the above range, when the porous material A is supported on a fiber structure, the retention of the porous material A and the CO ２ It is preferable because of its good adsorption properties.

[0068] A dispersant for dispersing the porous inorganic particles, and a binder and an organic or inorganic binder for supporting the porous material A on the fiber surface of a fiber structure such as a nonwoven fabric may be added to the porous material A.

[0069] The use of porous material A containing porous inorganic particles having an average particle diameter within the above-mentioned range is preferable because it is possible to support the porous material A on the surfaces of the fibers constituting the fiber structure and efficiently support the porous material A in the voids of the fiber structure while suppressing the airflow resistance.

[0070] In one aspect, a porous material A is supported on the fiber surfaces of a fiber structure composed of fibers or in voids between the fibers of the fiber structure. Furthermore, according to one aspect of the present invention, since the porous material A is supported in the voids of the fiber structure, a high specific surface area per volume can be obtained.

[0071] The porous material A of this embodiment is preferably supported in the voids of the fiber structure at 50% by volume or more per fiber structure. More preferably, the amount of porous material A supported in the voids of the fiber structure is 55% by volume or more per fiber structure, even more preferably, the amount of porous material A supported in the voids of the fiber structure is 60% by volume or more per fiber structure, and particularly preferably, the amount of porous material A supported in the voids of the fiber structure is 80% by volume or more per fiber structure. When the carbon dioxide adsorbing material of this embodiment is modularized, the pressure loss when air is flowed through the module is reduced, which is preferable when the porous material A is supported in the voids of the fiber structure at 50% by volume or more. The proportion of porous material A supported in the voids of the fiber structure can be determined by cutting a cross section of a sample in which porous material A is supported on a fiber structure, taking a cross-sectional SEM image, and determining the thickness of the voids in the fiber structure in which porous material A is supported in the thickness direction of the fiber structure and the thickness of porous material A that protrudes from the fiber structure.

[0072] The amount of porous material A supported on the fiber structure is 10 g / m ２ More than 500g / m ２ The amount of the porous material A supported on the fiber structure is preferably 20 g / m2 or less relative to the fiber structure nonwoven fabric. ２ More than 300g / m ２ The amount of porous material A supported on the fiber structure is more preferably 10 g / m or less. ２ In the case of 500 g / m or more, the amount of carbon dioxide adsorbed can be increased, which is preferable. ２ The following cases are preferable because they can reduce pressure loss in the carbon dioxide adsorption step.

[0073] In one aspect, an example of the porous material of this embodiment is porous material B. Porous material B according to this embodiment contains at least one type of porous inorganic particles selected from the group consisting of oxides such as alumina, silica, titania, zirconia, magnesia, and alkali metal ferrite, composite oxides such as calcium silicate and silica-alumina, activated carbon, zeolite, and metal-organic frameworks (MOFs). Examples of porous material B include zeolite 13X (product name: Mizuka Sieves) manufactured by Mizusawa Industrial Chemicals, Ltd., crushed B-type silica gel manufactured by Toyoda Kako Co., Ltd., and Cariact Q15 and Cariact G manufactured by Fuji Silysia Chemical Ltd.

[0074] The porous material B of this embodiment forms a porous inorganic carrier between the plurality of fiber structures. The porous material B includes porous inorganic particles and a hot-melt material having a melting point of 50° C. to 150° C. The porous inorganic particles included in the porous material B are preferably at least one type selected from the group consisting of the porous inorganic particles having an average particle diameter of 30 μm to 3 mm.

[0075] Examples of hot melt materials with a melting point of 50°C or higher and 150°C or lower include olefin-based materials such as polyethylene and polypropylene, ethylene-vinyl acetate copolymer-based materials, polyamide-based materials, synthetic rubber-based materials, acrylic-based materials, and polyurethane-based hot melt materials, as well as mixtures of olefin and ethylene-vinyl acetate. The proportion of the hot melt material in this embodiment is preferably 1% by mass or higher and 80% by mass or lower based on the total of the porous inorganic particles and the hot melt material. The proportion of the hot melt material in this embodiment is more preferably 10% by mass or higher and 60% by mass or lower based on the total of the porous inorganic particles and the hot melt material. The proportion of the hot melt material in this embodiment is even more preferably 15% by mass or higher and 50% by mass or lower based on the total of the porous inorganic particles and the hot melt material.

[0076] When the porous inorganic particles contained in the porous material B are within the above-mentioned specific range, the air flow resistance in the thickness direction is reduced, and CO ２ Adsorption and CO ２The amount of porous material B that forms the porous inorganic carrier layer sandwiched between two or more fiber structures (in one embodiment, the amount of the porous inorganic carrier layer supported on the fiber structures) is 10 g / m ２ More than 500g / m ２ More preferably, it is 10 g / m or less. ２ More than 400g / m ２ More preferably, it is 30 g / m or less. ２ More than 300g / m ２ Particularly preferably 50 g / m ２ More than 300g / m ２ The amount of the porous material B sandwiched between two or more fiber structures is 10 g / m or less. ２ As a result, CO ２ The adsorption amount of the porous material B is preferably 500 g / m. ２ or less, the air flow resistance in the thickness direction is small, and CO ２ The total amount of the porous materials A and B supported on the fiber structure is preferably 50 g / m ２ More preferably, 55 g / m ２ More preferably, it is 60 g / m ２ If the total amount of the porous materials A and B supported is within the above range, CO ２ This is preferable because it increases the amount of recovery.

[0077] The total amount of porous materials A and B supported on the fiber structure is measured by the following method. The fiber structure before and after supporting porous materials A and B is cut into 10 cm squares, and the weights of each are measured. The amount of porous materials A and B supported on the fiber structure can be measured by multiplying the weight increase before and after supporting by the concentration of porous inorganic particles in the dispersoid contained in the dispersion containing porous materials A and B.

[0078] The carbon dioxide adsorbent of this embodiment can be used in two ways: by supporting porous material A on the surface or in the gaps of a fiber structure, and by sandwiching porous material B between a plurality of fiber structures. Furthermore, a preferred mode of use of the carbon dioxide adsorbent of this embodiment is by sandwiching porous material B between a plurality of fiber structures, and supporting porous material A on the surface or in the gaps of the fiber structure between which porous material B is sandwiched. By further supporting porous material A on the surface or in the gaps of a fiber structure in which porous material B is sandwiched between a plurality of fiber structures, ２ The amount of adsorption can be increased.

[0079] The airflow resistance in the thickness direction after the porous material A is supported on the surface or in the gaps of the fiber structure is preferably 0.01 kPa·s / m or more and 50 kPa·s / m or less. The airflow resistance in the thickness direction after the porous material A is supported on the surface or in the gaps of the fiber structure is more preferably 0.01 kPa·s / m or more and 30 kPa·s / m or less. Still more preferably 0.01 kPa·s / m or more and 15 kPa·s / m or less.

[0080] Furthermore, the airflow resistance in the thickness direction of the fiber structure after porous material B is supported on a plurality of fiber structures is preferably 0.01 kPa·s / m or more and 50 kPa·s / m or less. More preferably, it is 0.01 kPa·s / m or more and 30 kPa·s / m or less. Even more preferably, it is 0.01 kPa·s / m or more and 15 kPa·s / m or less. When the airflow resistance in the thickness direction of the fiber structure after porous material A is supported on the surface or in the gaps of the fiber structure and / or after porous material B is supported between a plurality of fiber structures is 0.01 kPa·s / m or more and 50 kPa·s / m or less, carbon dioxide is more likely to diffuse into porous materials A and B supported on the nonwoven fabric during carbon dioxide adsorption, which is preferable.

[0081] The airflow resistance in the thickness direction of the fiber structure after supporting porous material A on the surface or in the voids of the fiber structure and / or the fiber structure after supporting porous material B is measured by the following method: Using an air permeability tester KES-F8 (manufactured by Kato Tech Co., Ltd.), measurements are made at 20 locations at equal intervals in the width direction and 10 locations at equal intervals in the length direction of the fiber structure supporting porous material A and / or porous material B in an area of ​​1 m width x 50 cm length, for a total of 200 locations, and the average value and standard deviation are taken as the airflow resistance and standard deviation of the airflow resistance of the fiber structure (measurement area 0.2π cm ２ : diameter 8.9 mm).

[0082] In one aspect, the carbon dioxide adsorbing material of the present embodiment includes a plurality of fibrous structures (e.g., nonwoven fabrics) and a porous material B that forms a porous inorganic carrier layer between the plurality of fibrous structures. In one aspect, the porous material B is such that the amount of the porous inorganic carrier layer supported by the plurality of fibrous structures is 10 g / m. ２ More than 500g / m ２ The air resistance in the thickness direction of the fiber structure is 0.01 kPa·s / m or more and 50 kPa·s / m or less.

[0083] In one aspect, the carbon dioxide adsorbing material of the present embodiment includes a fibrous structure (e.g., a nonwoven fabric) and a porous material A supported on the surface or in the voids of the fibrous structure. In one aspect, 50% by volume or more of the porous material A is supported in the voids of the fibrous structure, and the amount of the porous material A supported on the fibrous structure is 10 g / m. ２ More than 500g / m ２ In one embodiment, 80% by volume or more of the porous material A is supported in the voids of the fiber structure, and the amount of the porous material A supported on the fiber structure is 10 g / m or less. ２ More than 500g / m ２ The air resistance in the thickness direction of the fiber structure is 0.01 kPa·s / m or more and 50 kPa·s / m or less.

[0084] In one aspect, the carbon dioxide adsorbing material of the present embodiment includes a plurality of fibrous structures (e.g., nonwoven fabrics) and a porous material A supported on the surface or in the voids of at least one of the fibrous structures. In one aspect, 50% by volume or more of the porous material A is supported in the voids of the fibrous structures, and the amount of the porous material A supported on the fibrous structures is 10 g / m. ２ More than 500g / m ２ In one embodiment, 80% by volume or more of the porous material A is supported in the voids of the fiber structure, and the amount of the porous material A supported on the fiber structure is 10 g / m or less. ２ More than 500g / m ２ The air resistance in the thickness direction of the fiber structure is 0.01 kPa·s / m or more and 50 kPa·s / m or less.

[0085] The specific surface area of ​​the porous inorganic particles contained in each of the porous materials A and B is 10 m ２ / g or more 4000m ２ The specific surface area of ​​the porous inorganic particles contained in each of the porous materials A and B is more preferably 50 m / g or less. ２ / g or more 3000m ２ The specific surface area of ​​the porous inorganic particles contained in each of the porous materials A and B is more preferably 80 m ２ / g or more 3000m ２ / g or less.

[0086] The specific surface area of ​​the porous inorganic particles contained in each of the porous materials A and B is 10 m ２ When the specific surface area of ​​the porous inorganic particles contained in each of the porous materials A and B is 4000 m / g or more, the porous inorganic particles themselves adsorb carbon dioxide, or when another adsorbent material is further supported on the fiber structure, the amount of carbon dioxide adsorbed can be increased, which is preferable. ２ / g or less is preferable because the diffusibility of carbon dioxide improves when the cycle of carbon dioxide adsorption and desorption is repeated.

[0087] The average pore diameter of the porous inorganic particles contained in each of the porous materials A and B is preferably 0.1 nm or more and 100 nm or less. The average pore diameter of the porous inorganic particles contained in each of the porous materials A and B is more preferably 1 nm or more and 50 nm or less. The average pore diameter of the porous inorganic particles contained in each of the porous materials A and B is even more preferably 10 nm or more and 50 nm or less.

[0088] The porous inorganic particles contained in each of the porous materials A and B preferably have an average pore diameter of 0.1 nm or more, because this accelerates the diffusion of carbon dioxide into the porous inorganic particles during carbon dioxide adsorption and desorption. The porous inorganic particles contained in each of the porous materials A and B preferably have an average pore diameter of 100 nm or less, because this increases the specific surface area of ​​the porous inorganic particles contained in each of the porous materials A and B, allowing the porous inorganic particles themselves to adsorb carbon dioxide, or increasing the amount of carbon dioxide adsorption when the nonwoven fabric supports another adsorbent material.

[0089] The porous inorganic particles contained in each of the porous materials A and B may have pores with an average pore diameter of 0.1 nm to 100 nm, macropores with an average pore diameter of 100 nm to 3 μm, and mesopores with an average pore diameter of 1 nm to 30 nm. The porous inorganic particles contained in each of the porous materials A and B preferably have macropores with an average pore diameter of 100 nm to 3 μm and mesopores with an average pore diameter of 1 nm to 30 nm in addition to pores with an average pore diameter of 0.1 nm to 100 nm, because this accelerates the diffusion of carbon dioxide into the pores of the porous inorganic particles during carbon dioxide adsorption and desorption.

[0090] The pore volume of the porous inorganic particles contained in each of the porous materials A and B is preferably 0.1 ml / g or more and 5 ml / g or less. The pore volume of the porous inorganic particles contained in each of the porous materials A and B is more preferably 0.3 ml / g or more and 3 ml / g or less. The pore volume of the porous inorganic particles contained in each of the porous materials A and B is even more preferably 0.5 ml / g or more and 2 ml / g or less. When the pore volume of the porous inorganic particles contained in each of the porous materials A and B is 0.1 ml / g or more, the porous inorganic particles contained in each of the porous materials A and B themselves adsorb carbon dioxide, or the amount of carbon dioxide adsorption when another adsorbent material is further supported can be increased, which is preferable. When the pore volume of the porous inorganic particles contained in each of the porous materials A and B is 5 ml / g or less, the strength of the porous inorganic particles contained in each of the porous materials A and B is increased, which is preferable, as it improves durability.

[0091] The average pore size, pore volume, and specific surface area of ​​the porous inorganic particles contained in porous materials A and B are measured as follows. The average pore size, pore volume, and specific surface area of ​​the porous inorganic particles contained in porous materials A and B are measured using a specific surface area / pore distribution measuring device (product name: TriStar II, manufactured by Micromeritics). 0.2 g of the porous inorganic particles contained in porous materials A and B are dried under vacuum at 120°C for 2 hours, and then liquid nitrogen is introduced into the dried porous inorganic particles. The amount of nitrogen gas adsorbed to the porous inorganic particles at the boiling point of liquid nitrogen is measured at 23 points using a multipoint method in a relative vapor pressure (P / P0) range of 0.05 to 0.2. Subsequently, the average pore size (nm) and pore volume (ml / g) are calculated using the BJH (Barret-Joyner-Halenda) method using the same device program. In addition, the BET (Brunauer-Emmett-Teller) method was used to calculate the BET specific surface area (m ２ / g) is calculated.

[0092] (Compound having an amino group) The carbon dioxide adsorbent of this embodiment contains a CO ２From the viewpoint of increasing the adsorption amount and fulfilling the role of an inorganic binder, it is preferable that a compound having an amino group is supported on the porous material A and / or B. The compound having an amino group may be any compound that can reversibly desorb carbon dioxide. For example, a compound that can adsorb and desorb carbon dioxide by the amino group contained in the compound having an amino group can be used.

[0093] Examples of the compound having an amino group of this embodiment include N,N'-bis(3-aminopropyl)ethylenediamine, diethylenediamine, diethylenetriamine, tetraethylenepentamine, pentaethylenehexamine, polyethyleneimine (PEI), polypropyleneimine, polyallylamine, monoethanolamine, diethanolamine, triethanolamine, 2-ethylaminoethanol, N-methyldiethanolamine, N-ethyldiethanolamine, N,N-dimethylaminoethanol, N-(β-aminoethyl)ethanolamine, and N-(β-aminoethyl)propanol. Examples of amine compounds include amine, diethylisopropanolamine, tris(2-aminoethyl)amine, isophoronediamine, 1,4-bis(3-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, N,N-bis(3-aminopropyl)-N,N-bis(3-aminopropyl)piperazine, hydroxyethylpiperazine, 2-aminoethylaminopropyldimethoxysilane (AEAPDMS), 2-aminoethylaminopropyltrimethoxysilane, 3-aminopropyldimethoxysilane, 3-aminopropyltrimethoxysilane, lysine, and aziridine.

[0094] The primary amino group may be converted to a secondary amino group and the secondary amino group may be converted to a tertiary amino group by using an epoxy compound, a urethane compound, or the like in the compound having an amino group. By using an epoxy compound, a urethane compound, or the like to convert a primary amino group to a secondary amino group and the secondary amino group to a tertiary amino group, the carbon dioxide desorption property of the present embodiment is improved, and therefore the durability of the amine compound can be improved, which is preferable. Examples of epoxy compounds include ethylene oxide, propylene oxide, 1,2-epoxybutane, 1,2-epoxypentane, 1,2-epoxyhexane, 1,2-epoxyheptane, 1,2-epoxyoctane, ethyl glycidyl ether, propyl glycidyl ether, allyl glycidyl ether, glycidyl butyl ether, glycidyl hexyl ether, glycidyl octyl ether, 2-ethylhexyl glycidyl ether, benzyl glycidyl ether, 1,4-butanediol diglycidyl ether, t-butyl glycidyl ether, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, and 3-glycidyloxypropylmethyldiethoxysilane.

[0095] The reaction amount of the epoxy compound relative to the amine compound is not particularly limited, but may be determined based on the molar equivalents of the primary amino groups and secondary amino groups of the amine compound. Preferably, it is determined based on the molar equivalents of the primary amino groups. When protecting a primary amine, it is preferable to add the epoxy compound in an amount of 0.8 to 1.2 times the molar equivalent of the primary amine. The reaction between the amine compound and the epoxy compound can be carried out, for example, by gradually adding the epoxy compound to an alcohol solution of the amine compound, such as methanol or ethanol, and stirring the mixture to obtain a reaction product of the amine compound and the epoxy compound.

[0096] These compounds having an amino group may be used alone, or two or more compounds having an amino group may be used in combination. Among these, compounds having two or more types of amino groups are preferred from the viewpoint of carbon dioxide adsorption power and ease of desorption, such as polyamines such as tetraethylenepentamine, pentaethylenehexamine, polyethyleneimine (PEI), polypropyleneimine, and polyallylamine, compounds having a piperazine ring such as 1,4-bis(3-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine (BAPPRZ), N,N-bis(3-aminopropyl)-N,N-bis(3-aminopropyl)piperazine, and hydroxyethylpiperazine, and compounds in which the primary amino group of the above amine compounds is protected with various epoxy compounds.

[0097] Examples of compounds having an amino group include polyethyleneimine (PEI) (product name: SP-006, manufactured by Nippon Shokubai Co., Ltd.) and 1,4-bis(3-aminopropyl)piperazine (product name: BAPPRZ, manufactured by Koei Chemical Co., Ltd.).

[0098] In addition, a method for supporting a compound having an amino group on the porous material A and / or B may be carried out by impregnating a fiber structure having the porous material A and / or B with a solution obtained by dissolving a polyamine such as tetraethylenepentamine, pentaethylenehexamine, polyethyleneimine (PEI), polypropyleneimine, polyallylamine, 1,4-bis (3-aminoethyl) piperazine, 1,4-bis (3-aminopropyl) piperazine, N,N-bis (3-aminopropyl) -N,N-bis (3-aminopropyl) piperazine, hydroxyethylpiperazine, or the like, in which a primary amino group is protected using various epoxy compounds in the above amine compounds, and / or an amino alkoxysilane such as 2-aminoethylaminopropyldimethoxysilane, 2-aminoethylaminopropyltrimethoxysilane, 3-aminopropyldimethoxysilane, or 3-aminopropyltrimethoxysilane in a solvent such as ethanol, and drying the solution to support the compound having an amino group on the porous material A and / or B. Furthermore, a compound having an amino group may be supported on the porous material A and / or B by graft polymerizing lysine, aziridine, or the like onto the fiber structure containing the porous material A and / or B.

[0099] The amount of the compound having an amino group supported on the carbon dioxide adsorbent of this embodiment relative to the unit mass of the carbon dioxide adsorbent is preferably 0.01 mmol / g or more and 100 mmol / g or less, more preferably 1 mmol / g or more and 30 mmol / g or less, and particularly preferably 6 mmol / g or more and 30 mmol / g or less. Note that the amount of the compound having an amino group supported on the carbon dioxide adsorbent of this embodiment refers to the amount of amino groups contained in the compound having an amino group supported on the carbon dioxide adsorbent containing porous material A and / or B.

[0100] The amount of amino groups contained in the compound having an amino group supported per unit mass of the carbon dioxide adsorbent containing porous material A and / or B can be measured by a known method.

[0101] For example, when the fiber structure according to this embodiment does not contain nitrogen, the amount of nitrogen in the fiber structure carrying the compound having an amino group is measured by the Kjeldahl method or the combustion method.

[0102] Next, a calibration curve is drawn between the absorbance of the peak assigned to the amino group determined using the infrared spectrometer and the amount of nitrogen contained in the fiber structure containing porous material A and / or B determined by the Kjeldahl method or the combustion method. The amount of amino group supported in the compound having an amino group is determined using the calibration curve and the infrared spectrometer, and divided by the weight of the fiber structure containing the porous material supporting the compound having an amino group, thereby making it possible to determine the amount of amino group supported in the compound having an amino group per unit mass of the carbon dioxide adsorbent.

[0103] For example, when the fiber structure containing the porous material A and / or B according to this embodiment contains nitrogen, the amount of nitrogen is determined by the Kjeldahl method or the combustion method for each of the fiber structures containing the porous material A and / or B carrying a compound having an amino group and the fiber structure containing a porous material not carrying an amino group. Specifically, the amount of nitrogen contained in each of the fiber structures containing the porous material not carrying an amino group and the fiber structure containing the porous material A and / or B carrying a compound having an amino group is determined. The amount of nitrogen contained in the compound having an amino group is determined by subtracting the amount of nitrogen contained in the fiber structure containing the porous material A and / or B from the amount of nitrogen contained in the fiber structure containing the porous material carrying the compound having an amino group.

[0104] Next, in the same manner as in the case where the fiber structure containing porous material A and / or B does not contain nitrogen, a calibration curve is drawn between the absorbance of the peak assigned to the amino group determined using an infrared spectrometer and the amount of nitrogen contained in the fiber structure containing porous material A and / or B supporting the compound having an amino group determined by the Kjeldahl method or the combustion method. The amount of the compound having an amino group supported on the fiber structure is determined using the calibration curve and the infrared spectrometer, and this is divided by the weight of the fiber structure containing the porous material supporting the compound having an amino group, thereby making it possible to determine the amount of amino groups contained in the compound having an amino group supported per unit mass of the carbon dioxide adsorbent.

[0105] In this embodiment, the compound having an amino group is preferably supported in the range of 10% by mass to 300% by mass, and more preferably in the range of 50% by mass to 300% by mass, relative to the porous material A and / or B. Here, the amount of the compound having an amino group supported on the porous material A and / or B in this embodiment refers to the amount of amino groups contained in the compound having an amino group supported on the porous material A and / or B. The amount of amino groups contained in the compound having an amino group per unit mass of the porous material A and / or B can be determined by determining the amount of the compound having an amino group supported on the fiber structure using the method described above and dividing this amount by the weight of the porous material A and / or B supporting the compound having an amino group.

[0106] (Silicone Compound) The carbon dioxide adsorbent of this embodiment contains a silicone compound. ２ From the viewpoint of increasing the adsorption and desorption rates and improving the diffusibility of carbon dioxide into the carbon dioxide adsorbent layer, it is preferable that the compound having an amino group contains at least one silicone compound selected from the group consisting of silicone oil, silsesquioxane, and MQ resin.

[0107] Because compounds having amino groups are water-soluble polymers, they have a high Solubility Parameter (SP) value, which is a parameter indicating the solubility of a substance, and it is presumed that compounds having amino groups tend to have poor gas permeability. On the other hand, because silicone compounds are hydrophobic polymers, they have a low SP value and tend to have good gas permeability. Therefore, the present inventors have discovered that by incorporating at least one silicone compound selected from the group consisting of silicone oil, silsesquioxane, and MQ resin into the carbon dioxide adsorbent of this embodiment, the diffusibility of carbon dioxide into the compound having an amino group can be improved.

[0108] Examples of silicone compounds include silicone oils such as dimethylsiloxane, methylphenylsiloxane, diphenylsiloxane, dimethylsiloxane, methylphenylsiloxane, and phenylsiloxane partially modified with amino groups, epoxy groups, allyl groups, carbinol groups, carboxyl groups, ether groups, araalkyl groups, long-chain alkyl groups, and ester groups, as well as silsesquioxanes and MQ resins having methyl groups, ethyl groups, propyl groups, phenyl groups, amino groups, epoxy groups, allyl groups, carbinol groups, carboxyl groups, ether groups, araalkyl groups, long-chain alkyl groups, and ester groups. Silicone oils, silsesquioxanes, and MQ resins may also contain compounds known as silicone rubbers.

[0109] The content of the silicone compound relative to the compound having an amino group is preferably 1% by mass or more and 90% by mass or less. The content of the silicone compound relative to the compound having an amino group is more preferably 2% by mass or more and 60% by mass or less. The content of the silicone compound relative to the compound having an amino group is even more preferably 5% by mass or more and 50% by mass or less. When the content of the silicone compound relative to the compound having an amino group is 1% by mass or more, CO ２ When the content of the silicone compound relative to the compound having an amino group is 90 mass % or less, the rate of adsorption and desorption of CO can be increased. ２ This is preferable because it can increase the amount of adsorption.

[0110] Any method can be used to incorporate a silicone compound into a compound having an amino group. For example, by mixing a surfactant with the silicone compound and emulsifying the mixture, the hydrophobic silicone compound can be incorporated into the hydrophilic compound having an amino group at any ratio. Commercially available silicone emulsions may be used as the emulsified silicone compound. Commercially available silicone emulsions include dimethyl silicone emulsions and silicone emulsions modified with various functional groups (product name: MF-14ES) manufactured by Shin-Etsu Chemical Co., Ltd., various DOWSIL emulsions manufactured by Toray Dow Co., Ltd., and BELSIL manufactured by Wacker Asahi Kasei Silicones Co., Ltd. Furthermore, to increase the amount of carbon dioxide adsorption, inorganic alkalis such as sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide, potassium carbonate, and potassium bicarbonate, or glycols such as polyethylene glycol and polypropylene glycol may be added to the surfactant.

[0111] In addition, as a method for supporting a compound having an amino group that contains a silicone compound on porous material A and / or B, there is a method in which a fiber structure having porous material A and / or B is impregnated with a solution prepared by mixing a compound having an amino group with a silicone compound and dissolving the mixture in a solvent such as ethanol, and then drying the solution to support the compound having an amino group that contains a silicone compound on porous material A and / or B.

[0112] [Method for manufacturing a carbon dioxide adsorbent] The method for manufacturing a carbon dioxide adsorbent according to this embodiment includes the steps of preparing a fibrous structure and impregnating the fibrous structure with porous material A. In one aspect, the method for manufacturing a carbon dioxide adsorbent according to this embodiment includes the steps of preparing a fibrous structure and forming a porous inorganic carrier layer containing porous material B between the fibrous structures. In one aspect, the method for manufacturing a carbon dioxide adsorbent according to this embodiment includes the steps of preparing a fibrous structure, impregnating the fibrous structure with porous material A, and forming a porous inorganic carrier layer containing porous material B between the fibrous structures. The method for manufacturing a carbon dioxide adsorbent according to this embodiment may also include the step of impregnating a compound having an amino group into porous material A and / or porous material B supported on the fibrous structure. Furthermore, the method for manufacturing a carbon dioxide adsorbent according to this embodiment may also include the step of impregnating a silicone compound into the compound having an amino group contained in porous material A and / or porous material B supported on the fibrous structure. In addition, the method for manufacturing a carbon dioxide adsorbent according to this embodiment may include a step (post-step) performed after manufacturing the fibrous structure.

[0113] - Step of Producing a Fiber Structure The step of producing a fiber structure such as a nonwoven fabric as a substrate can be carried out by a known method using materials such as polypropylene, polyester (e.g., polyethylene terephthalate (PET)), nylon, and cellulose.

[0114] The method for producing these fiber structures can be selected from known methods generally known to those skilled in the art according to the purpose.

[0115] For example, when a nonwoven fabric is produced using fibers such as thermoplastic polypropylene, polyester, and nylon, it can be produced by various known methods such as the spunbond method and the meltblowing method.

[0116] For example, in the spunbond method, raw resin is melted in an extruder and continuously spun, and then the resin is opened and deposited on a net to form a web, which is then bonded onto a sheet to produce a nonwoven fabric.

[0117] For example, in the melt-blowing method, when raw resin is melted in an extruder and continuously spun into fibers, high-temperature air is sprayed from around the spinning nozzle to thin the fibers and accumulate them on a sheet to obtain a nonwoven fabric. Also, in the melt-blowing method, the fiber diameter of the nonwoven fabric can be thinned by stretching the fibers with air.

[0118] Short-fiber nonwoven fabrics and paper can be obtained by dry or wet methods. The dry method is a method for producing short-fiber nonwoven fabrics by arranging short fibers of about 15 mm to 100 mm in a fixed direction or randomly using a machine called a card or an air flow called an air laying. The wet method is a method for producing short-fiber nonwoven fabrics when turning paper or glass into nonwoven fabrics, in which short fibers of about 15 mm to 100 mm are dispersed in water or the like, and the dispersion is then combed onto a mesh net to form a fleece.

[0119] A method for producing a long-fiber nonwoven fabric using cellulose fibers includes, for example, dissolving cellulose in a cuprammonium solution and coagulating it by deammoniating. Examples of spinning methods for producing a long-fiber nonwoven fabric include tension spinning, in which a filamentous material is extruded from a nozzle into warm water in a funnel, air-gap spinning, in which the material is extruded into air, and electrospinning, in which an electric charge is applied to a raw material solution to thin the material.

[0120] In a specific example of flow-down tension spinning, a stock solution prepared by dissolving cotton linters, from which foreign matter has been removed and the degree of polymerization has been adjusted, in a cupric ammonium solution is extruded through a spinneret (spinneret) having small holes (stock solution discharge holes) and dropped into a spinning funnel together with water, where the stock solution is coagulated by deammoniating to obtain fibers. The obtained fibers are stretched and then thrown onto a net to spin a web. During this process, the net is vibrated in a direction perpendicular to the direction of travel while moving forward, so that the fibers thrown onto the net form a Sinusoidal curve. Another web spun under similar conditions is superimposed on the obtained single-layer web, finally obtaining a nonwoven fabric consisting of a multi-layered continuous cellulose filament web.

[0121] The obtained continuous cellulose filament web is regenerated with dilute sulfuric acid, washed with water, and then the obtained regenerated continuous cellulose filament web is placed on a perforated sheet to entangle the fibers using a high-pressure water stream, followed by hot air drying to obtain a nonwoven fabric made of regenerated continuous cellulose filaments.

[0122] The fiber diameter of the fiber structure is adjusted by adjusting the draw ratio during spinning of the fiber structure. For example, the draw ratio can be adjusted as desired by changing the shape of the spinning funnel and the amount of spinning water flowing through it. The basis weight of the fiber structure is adjusted by adjusting the thickness of the fiber structure. The thickness of the fiber structure can be adjusted as desired by changing the traveling speed of the spinning net. Furthermore, by controlling the vibration width of the net, the fiber arrangement direction can be controlled, and the strength, elongation, etc. of the fiber structure can be controlled.

[0123] The porosity of the fiber structure can be adjusted by adjusting the basis weight, thickness, and fiber diameter of the yarns constituting the fibers of the fiber structure. For example, in a post-process after the production of a nonwoven fabric, the thickness can be reduced by compressing the nonwoven fabric with, for example, a compression roll, thereby reducing the thickness and the porosity.

[0124] Step of Including Porous Material A in the Fiber Structure The step of incorporating porous material A in the fiber structure is a step of supporting porous material A on the surface or in voids of the fiber structure.

[0125] The step of supporting porous material A on the surface or in the voids of a fiber structure can be performed using a known method. For example, porous inorganic particles having an average particle size of 0.1 μm to 30 μm are dispersed in water or an organic solvent such as methanol or ethanol by stirring or using a homogenizer to obtain a dispersion. Next, a sol containing porous inorganic particles having an average particle size of 1 nm to 400 nm is added to the dispersion while stirring, and then a dispersant is added, thereby obtaining a stable dispersion containing porous material A. Examples of methods for supporting a dispersion containing porous material A on the surface or in the voids of a fiber structure such as a nonwoven fabric include the following. For example, a method in which a dispersion containing porous material A is applied or sprayed onto a fiber structure and then dried to support porous material A on the surface or in the voids of the fiber structure is available. Another method in which porous material A is supported on the surface or in the voids of a fiber structure is available by impregnating a fiber structure with a dispersion containing porous material A and then drying.

[0126] - Step of forming a porous inorganic carrier layer containing porous material B between fiber structures The step of forming a porous inorganic carrier layer containing porous material B in a fiber structure such as a nonwoven fabric is a step of producing a fiber structure in which porous material B is sandwiched, and known methods can be used. For example, a powder of porous particles having an average particle size of 30 μm to 3 mm and a hot-melt material is mixed to obtain a mixture. During mixing, water may be added in any ratio to prevent static electricity. A fixed amount of the obtained mixture of porous inorganic particles having an average particle size of 30 μm to 3 mm and a hot-melt material is supplied to one sheet of nonwoven fabric, sandwiched between another sheet of nonwoven fabric, and pressed with a heated roll to form a porous inorganic carrier layer containing porous material B between the nonwoven fabrics.

[0127] A fiber structure containing both porous material A and porous material B can be obtained by producing a fiber structure in which a porous inorganic carrier layer containing porous material B is formed between fiber structures using the method described above, and then carrying out a step of incorporating the porous material A described above into the obtained fiber structure.

[0128] a step of incorporating a compound having an amino group into porous material A or porous material B carried on a fiber structure, and a step of incorporating a silicone compound into the compound having an amino group contained in porous material A or porous material B carried on a fiber structure. In this step, a compound having an amino group and / or a silicone compound is carried on a fiber structure containing porous material A by drying the fiber structure carrying porous material A, then impregnating the fiber structure carrying porous material A with a solution or dispersion containing a compound having an amino group and / or a silicone compound, and then drying the impregnated fiber structure. In this step, a method of simultaneously carrying porous material A, a compound having an amino group and / or a silicone compound on a nonwoven fabric by impregnating a fiber structure with a solution or dispersion containing a compound having an amino group and / or a silicone compound, and then drying the impregnated fiber structure. In this process, the method for supporting the compound having an amino group and / or the silicone compound on the fiber structure sandwiching the porous material B is a method in which the fiber structure sandwiching the porous material B is dried, and then the fiber structure sandwiching the porous material B is impregnated with a solution or dispersion containing a compound having an amino group and / or the silicone compound, and then dried.

[0129] When obtaining a carbon dioxide adsorbent containing both porous material A and porous material B, the method for producing a carbon dioxide adsorbent of this embodiment includes the steps of producing a fibrous structure, incorporating porous material A into the fibrous structure, and forming a porous inorganic carrier layer containing porous material B between the fibrous structures.

[0130] A carbon dioxide adsorbent containing both porous material A and porous material B can be obtained by preparing a fiber structure having a porous inorganic carrier layer containing porous material B formed between fiber structures by the method described above, and then carrying out a step of impregnating the prepared fiber structure with the porous material A. A carbon dioxide adsorbent containing both porous material A and porous material B and further supporting a compound having an amino group and / or a silicone compound can be obtained by obtaining a fiber structure containing both porous material A and porous material B, and then carrying out a step of impregnating the compound having an amino group into porous material A or porous material B supported on the fiber structure described above, and a step of impregnating the compound having an amino group contained in porous material A and / or porous material B supported on the fiber structure described above with a silicone compound.

[0131] <Module> In one aspect, the module according to this embodiment has at least one layer of carbon dioxide adsorbent material. The carbon dioxide adsorbent material according to this embodiment that the module according to this embodiment has is the same as described above.

[0132] In one aspect, the module according to this embodiment has at least one spacer layer.

[0133] In one aspect, the module according to this embodiment has a laminated structure in which at least one layer of carbon dioxide adsorbing material and at least one layer of spacer are laminated.

[0134] (Spacer) The spacer serves as a flow path through which air flows in order to allow the carbon dioxide adsorbent to adsorb carbon dioxide in the air.

[0135] In one embodiment, the spacer is preferably a woven fabric or a molded article. In another embodiment, from the viewpoint of breathability, the spacer is more preferably a woven fabric or a molded article having a difference in height between warp and weft threads of 1 μm or more and 1 mm or less in the thickness direction and an opening ratio of 20% or more and 90% or less.

[0136] In one aspect, the module according to the present embodiment preferably has a spacer that is a woven fabric or molded body having a difference in height between the warp and weft threads of 1 μm or more and 1 mm or less in the thickness direction and an opening rate of 20% or more and 90% or less.

[0137] (Laminated structure) In the first embodiment, the laminated structure refers to a structure in which at least one layer of the carbon dioxide adsorbent according to this embodiment (in one embodiment, a carbon dioxide adsorbent layer) and at least one layer of a spacer (in one embodiment, a spacer layer) are laminated.

[0138] In one aspect, the laminate structure is preferably a structure in which one to five layers of the carbon dioxide adsorbent according to the present embodiment (in one aspect, carbon dioxide adsorbent layers) and at least one spacer layer (in one aspect, spacer layer) are laminated.

[0139] In one embodiment, the laminated structure may include a carbon dioxide adsorbent layer having a surface textured with a height difference of 3 μm or more. A laminated structure having a carbon dioxide adsorbent layer textured may or may not include a spacer layer. Texture processing can be performed by a conventional method such as embossing.

[0140] By having a laminated structure, the module of this embodiment can be suitably used for adsorbing carbon dioxide in the atmosphere.

[0141] In one embodiment, the ratio of the carbon dioxide adsorbent layer to the spacer layer in the thickness direction is preferably 0.1 or more and 20 or less, and more preferably 1 or more and 20 or less. From the viewpoint of carbon dioxide adsorption efficiency, it is preferably 0.1 or more, and from the viewpoint of pressure loss within the module, it is preferably 20 or less.

[0142] In a second embodiment, the laminated structure is wound spirally around a pipe. A module having such a laminated structure is a spiral type in which a laminated structure in which a carbon dioxide adsorbent layer and a spacer layer are stacked is wound around the outer periphery of a hollow gas collection pipe having a plurality of holes formed in the wall surface.

[0143] In a third embodiment, the module according to the present embodiment uses at least one layer of the carbon dioxide adsorbing material according to the present embodiment and has a corrugated structure. In one aspect, the module according to the present embodiment may be a corrugated structure formed by laminating at least one layer of the carbon dioxide adsorbing material according to the present embodiment. In one aspect, the module according to the present embodiment is a corrugated laminate formed by laminating a core portion and a liner portion.

[0144] In one aspect, the corrugated structure includes a core portion and a liner portion. In one aspect, the module of the present embodiment having a corrugated structure uses the carbon dioxide adsorbing material of the present embodiment in both the core portion and the liner portion. In one aspect, the module of the present embodiment has a structure in which at least one layer of the carbon dioxide adsorbing material or fiber structure of the present embodiment that has been woven into a corrugated shape is bonded to the liner portion.

[0145] The carbon dioxide adsorbent material of this embodiment can be used as the core portion. The liner portion may be at least one selected from the group consisting of at least one layer of the carbon dioxide adsorbent material of this embodiment, a spacer, a nonwoven fabric, a mesh, and a porous sheet. In one aspect, the module of this embodiment having a corrugated structure may use at least one selected from the group consisting of a mesh (e.g., a polyethylene terephthalate (PET) mesh), a nonwoven fabric, and a porous sheet as the liner portion.

[0146] The height of the corrugated structure is preferably 0.5 mm or more and 10 mm or less, and more preferably 1 mm or more and 5 mm or less. A height of 0.5 mm or more is preferable because it reduces pressure loss when air is flowed through the module, and a height of 10 mm or less is preferable because it increases the efficiency of capturing carbon dioxide in the air.

[0147] The width of the corrugated structure is preferably 1 mm or more and 20 mm or less, more preferably 1.5 mm or more and 10 mm or less. A width of the corrugated structure of 1 mm or more is preferred because it reduces pressure loss when air is passed through the module, and a width of 20 mm or less is preferred because it increases the efficiency of capturing carbon dioxide in the air. The opening rate of the corrugated structure is preferably 10% or more and 70% or less, more preferably 15% or more and 60% or less, and even more preferably 20% or more and 50% or less. Within the above ranges, it is possible to maintain low pressure loss when air is passed through the module while capturing CO ２ This is preferable because it increases the amount of adsorption.

[0148] The corrugated structure may be a laminate of sheets cut to a predetermined size, or a roll of corrugated structure wound around a cylindrical core.

[0149] [Method for manufacturing a module] A method for manufacturing a module according to this embodiment includes a step of manufacturing the carbon dioxide adsorbent according to this embodiment, and a step of stacking the carbon dioxide adsorbent and / or spacers according to this embodiment. Note that the step of manufacturing the carbon dioxide adsorbent is the same as described above.

[0150] The spacer used in the module of this embodiment can be any of various known woven fabrics or molded articles. Specifically, various woven fabrics or molded articles can be used, which are made by plain weave, twill weave, or satin weave using various fibers such as polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, copolymers such as polyethylene phthalate, polybutylene phthalate, and polyethylene naphthalate, polyphenylene sulfide, polyvinylidene chloride, nylon, fluororesin, stainless steel, and glass. By changing the fiber diameter and weaving method of the various fibers, the thickness, mesh size, height difference between warp and weft threads, and opening ratio of the spacer can be controlled.

[0151] Step of Laminating the Carbon Dioxide Adsorbing Materials and / or Spacers of the Present Embodiment The step of laminating the carbon dioxide adsorbing materials and / or spacers is as follows.

[0152] In a first embodiment, a fiber structure (e.g., a nonwoven fabric) not carrying porous material B or a fiber structure (e.g., a nonwoven fabric) having porous material B sandwiched therein, and a spacer sheet are cut to the size of the desired module. A set is formed by stacking a predetermined number of fiber structures not carrying porous material B or nonwoven fabrics having porous material B sandwiched therein and one or more spacer sheets. Furthermore, a module suitable for this embodiment can be obtained by stacking multiple sets produced in the same manner.

[0153] The resulting laminate can be made to carry the porous material A and the compound having an amino group and / or the silicone compound according to the method described above, thereby obtaining the module of this embodiment.

[0154] In a second embodiment, a spiral laminate module suitable for this embodiment can be obtained by spirally winding a roll of a fiber structure (e.g., a nonwoven fabric) not carrying porous material B, or a fiber structure sandwiching porous material B, and a spacer sheet around a tube made of resin, stainless steel, or the like. A spiral laminate can also be produced by spirally winding a laminate produced using one or more rolls of a fiber structure not carrying porous material B, or a fiber structure sandwiching porous material B, and a spacer sheet. The resulting spiral laminate can also be loaded with porous material A and a compound having an amino group and / or a silicone compound according to the method described above to produce the module of this embodiment. The spiral laminate module can be placed in a container for carbon dioxide adsorption and used.

[0155] In a third embodiment, a module (corrugated structure) having a corrugated structure suitable for this embodiment can be obtained by using a liner made of a nonwoven fabric coated with a spacer or an adhesive such as polyvinyl alcohol (PVA) and not carrying porous material B, or a fiber structure (e.g., a nonwoven fabric) sandwiching porous material B, and corrugating the fiber structure not carrying porous material B or the fiber structure sandwiching porous material B into an uneven roll shape while applying heat from 60°C to 200°C. When the spacer, the fiber structure not carrying porous material B, or the fiber structure sandwiching porous material B is heat-meltable at 60°C to 200°C, it can be used as is without any treatment. In the case of a spacer not heat-meltable at 60°C to 200°C, a fiber structure not carrying porous material B, or a fiber structure sandwiching porous material B, an adhesive such as PVA is applied at 5 g / m. ２ 50g / m or more ２ The adhesive may be applied in the following amounts: The adhesive may be applied by a known method, such as by spraying a solution containing PVA.

[0156] When a laminated corrugated structure is to be obtained, a fiber structure or the like is cut to the size of the module, and an adhesive such as PVA is applied thereto, followed by lamination.

[0157] To obtain a cylindrical corrugated structure, the corrugated structure is cut to a predetermined width, and then a cylindrical core is coated with an adhesive such as PVA on one side, and the resulting corrugated structure is wound around the core and laminated to obtain a module of a predetermined size.

[0158] When a module including laminated carbon dioxide adsorbent materials and spacers, a module that is a spiral laminate, or a module having a laminated corrugated structure is installed in a carbon dioxide adsorption vessel, packing or the like may be used to prevent air from becoming an air flow path only in specific locations. Furthermore, mesh or punched panels may be added to the space from the air intake section in the module to these laminates and / or the space between these laminates and the air outlet to adjust the pressure and make the air uniform throughout the module.

[0159] <<Uses>> The carbon dioxide adsorbent and module of this embodiment can ２ The pressure loss during adsorption is small and the specific surface area of ​​the carrier is large, allowing for efficient CO ２ It can be used for adsorption, separation and recovery, and is particularly suitable for direct recovery of carbon dioxide from the atmosphere.

[0160] <Direct Air Capture (DAC) Method> In one aspect, the direct air capture (DAC) method according to this embodiment includes an adsorption step of adsorbing carbon dioxide onto a carbon dioxide adsorbent material in the module according to this embodiment. In one aspect, the direct air capture (DAC) method according to this embodiment includes a desorption step of desorbing carbon dioxide. In one aspect, the desorption step is a step of changing the temperature or pressure to desorb carbon dioxide. In one aspect, the direct air capture (DAC) method according to this embodiment includes a recovery step of recovering the desorbed carbon dioxide.

[0161] Adsorption Step This step is a step of adsorbing carbon dioxide into the carbon dioxide adsorbent of this embodiment, which selectively adsorbs carbon dioxide. The carbon dioxide adsorbent of this embodiment is the same as described above.

[0162] The adsorption method is preferably a dead-end method, as long as the carbon dioxide contained in the air taken into the module can be brought into contact with the carbon dioxide adsorbent.

[0163] Adsorption can be carried out by introducing air, nitrogen, or the like at a relative humidity of about 80% RH for 1 minute to 10 hours at an atmospheric temperature of about −20 to 40° C. and a relative humidity of 20% to 100% RH at a flow rate of 0.001 m / sec to 5 m / sec.

[0164] The module according to this embodiment can adsorb carbon dioxide from ordinary atmospheric carbon dioxide and atmospheric carbon dioxide containing large amounts of carbon dioxide emitted from combustion exhaust gas. The applicable carbon dioxide concentration range is between 300 ppm and 500 ppm or between 1% and 30% by mass.

[0165] Desorption Step This step is a step in which the carbon dioxide adsorbed by the carbon dioxide adsorbent is desorbed by changing the temperature or pressure.

[0166] Desorption can be carried out by introducing nitrogen or the like at a temperature of 50 to 130°C, a pressure of 1 to 101 kPa, and a relative humidity of about 80% RH at a flow rate of 0.001 to 3 m / sec. Raising the temperature after reducing the pressure is preferred because it allows the purity of the desorbed carbon dioxide to be increased.

[0167] It is preferable to add water vapor simultaneously during desorption. By adding water vapor, the carbon dioxide adsorbent becomes hydrated, and the amount of carbon dioxide desorbed and adsorbed can be increased during desorption and the next adsorption cycle.

[0168] (Recovery Step) This step is a step of recovering the desorbed carbon dioxide.

[0169] <<Applications>> The direct air capture (DAC) method of this embodiment is ２ The pressure loss during adsorption is small and the specific surface area of ​​the carrier is large, allowing for efficient CO ２ The present disclosure also includes the following: [1] A porous inorganic carrier layer is formed between a plurality of nonwoven fabrics, and a porous material B is formed between the plurality of nonwoven fabrics, and the porous material B is formed so that the amount of the porous inorganic carrier layer carried by the porous material B is 10 g / m with respect to the plurality of nonwoven fabrics. ２ More than 500g / m ２ [2] A carbon dioxide adsorbing material comprising: a nonwoven fabric; and a porous material A supported on the surface or in voids of the nonwoven fabric, wherein 80% by volume or more of the porous material A is supported in the voids of the nonwoven fabric, and the amount of the porous material A supported relative to the nonwoven fabric is 10 g / m. ２ More than 500g / m ２[3] A carbon dioxide adsorbing material comprising: a plurality of sheets of the nonwoven fabric; and a porous material A supported on the surface or in voids of at least one of the sheets of the nonwoven fabric, wherein 80% by volume or more of the porous material A is supported in the voids of the nonwoven fabric, and the amount of the porous material A supported relative to the nonwoven fabric is 10 g / m. ２ More than 500g / m ２ [4] A carbon dioxide adsorbent according to [1], wherein the nonwoven fabric has an airflow resistance in the thickness direction of 0.01 kPa·s / m or more and 50 kPa·s / m or less. [4] A carbon dioxide adsorbent having a laminated structure in which at least one layer of the carbon dioxide adsorbent according to any one of [1] to [3] is laminated. [5] The carbon dioxide adsorbent according to any one of [1] to [3], wherein the porous material A comprises porous inorganic particles having an average particle size of 0.1 μm or more and 30 μm or less, and at least one kind of porous inorganic particles selected from the group consisting of colloidal silica, colloidal alumina, and precursors of colloidal silica or colloidal alumina, each having an average particle size of 1 nm or more and 400 nm or less, and wherein the porous inorganic particles having an average particle size of 0.1 μm or more and 30 μm or less account for 10% by mass or more and 99% by mass or less relative to 100% by mass of the porous material A. [6] The carbon dioxide adsorbing material according to any one of [1] to [3], wherein the porous inorganic carrier layer is formed from the porous material B containing porous inorganic particles having an average particle diameter of 30 μm to 3 mm and a hot-melt material having a melting point of 50°C to 150°C, and the hot-melt material is contained in an amount of 1 mass% to 80 mass% based on the total of the porous inorganic particles and the hot-melt material. [7] The porous inorganic particles contained in each of the porous materials A and B have a BET specific surface area of ​​50 m ２ / g or more 3000m ２The carbon dioxide adsorbent according to any one of [1] to [3], wherein the nonwoven fabric has a pore size of 1 to 50 nm and an average pore diameter of 1 to 50 nm, and is at least one type selected from the group consisting of silica, alumina, silica-alumina, titania, zirconia, activated carbon, zeolite, alkali metal ferrite, and MOF. [8] The carbon dioxide adsorbent according to any one of [1] to [3], wherein the nonwoven fabric has an average fiber diameter of 1 μm to 50 μm and a porosity of 50% to 95%. [9] The carbon dioxide adsorbent according to any one of [1] to [3], wherein the compound having an amino group is supported in an amount ranging from 10% to 300% by mass relative to the porous material A and / or B.

[10] The carbon dioxide adsorbent according to [9], wherein the compound having an amino group includes at least one type of silicone compound selected from the group consisting of silicone oil, silsesquioxane, and MQ resin.

[11] The carbon dioxide adsorbent according to

[10] , wherein the compound having an amino group contains the silicone compound in an amount of 1% by mass or more and 90% by mass or less.

[12] A module for adsorption, separation, and capture of carbon dioxide, having a laminated structure in which at least one layer of the carbon dioxide adsorbent according to any one of [1] to [3] and at least one layer of a spacer are laminated.

[13] A module for adsorption, separation, and capture of carbon dioxide, having a corrugated structure in which at least one layer of the carbon dioxide adsorbent according to any one of [1] to [3] is used.

[14] A direct air capture (DAC) method for directly capturing carbon dioxide from the atmosphere, comprising the following steps: an adsorption step of adsorbing carbon dioxide onto the carbon dioxide adsorbent in the carbon dioxide adsorption, separation, and capture module according to

[13] ; and a desorption step of changing the temperature or pressure to desorb the carbon dioxide.

[0170] The present embodiment will be specifically described below with reference to examples, but the present embodiment is not limited to these examples.

[0171] Carbon dioxide adsorbents and modules were prepared by the methods shown in Examples 1 to 17 and Comparative Example 1. To evaluate the performance of the carbon dioxide adsorbents and modules of the Examples and Comparative Examples, the carbon dioxide adsorption step and desorption step were carried out by the following methods, and the adsorption and desorption amounts of carbon dioxide in the carbon dioxide adsorbent and module were determined. In addition, the performance of the carbon dioxide adsorbents and modules of the Examples and Comparative Examples was evaluated by measuring the pressure loss in the adsorption step. The physical properties and performance of the carbon dioxide adsorbents and modules prepared in the Examples and Comparative Examples are shown in Tables 1 and 2.

[0172] Adsorption step: The carbon dioxide adsorbents (hereinafter referred to as samples) obtained in Examples 1 to 14 were placed in a carbon dioxide adsorption vessel, and nitrogen at a temperature of 60°C and a relative humidity of 80% RH was introduced at a flow rate of 0.05 m / s to measure the CO adsorbed on the samples during sample preparation. ２ was released.

[0173] Next, the temperature was lowered to 30°C, and air with a carbon dioxide concentration of 400 ppm and a relative humidity of 80% RH was flowed into the adsorption vessel at a flow rate of 0.05 m / sec to perform the carbon dioxide adsorption process on the sample. Specifically, the carbon dioxide concentration of the air discharged from the adsorption vessel was measured in real time using an infrared spectrometer (product name: FT / IR6800, manufactured by JASCO) to measure the peak of the discharged air. －１ The amount of carbon dioxide discharged was measured using the peak of the adsorption vessel, and the sample was allowed to adsorb carbon dioxide until the carbon dioxide concentration in the discharged air reached 400 ppm. The amount of carbon dioxide adsorbed in the sample was calculated by subtracting the amount of carbon dioxide in the air discharged from the adsorption vessel after 2 hours from the carbon dioxide concentration of 400 ppm in the air discharged from the adsorption vessel, and this amount was applied to a known equation and integrated to determine the amount of carbon dioxide adsorbed in the sample.

[0174] The amount of carbon dioxide adsorbed by the sample was 0.2 CO per g of porous material. ２ mmol / g~6CO ２ If the carbon dioxide adsorbing capacity is 0.05 mmol / g, the nonwoven fabric (fibrous structure) containing the porous material can be suitably used as the carbon dioxide adsorbing material of this embodiment.

[0175] The amount of carbon dioxide adsorbed by the sample was measured using the carbon dioxide adsorbent sheet (m ３ ) to 10CO ２ kg / m ３ ~50CO ２ kg / m ３ If so, it can be suitably used as the module of this embodiment.

[0176] Desorption step: The samples obtained in the examples and comparative examples were placed in a carbon dioxide adsorption vessel, and nitrogen at a temperature of 60°C and a relative humidity of 80% RH was introduced into the adsorption vessel by mass flow at a flow rate of 3 m / sec. The desorption step of carbon dioxide adsorbed on the sample was carried out while measuring the amount of carbon dioxide desorbed from the sample. Specifically, the desorption step was carried out until the amount of carbon dioxide discharged from the adsorption vessel became almost zero in the nitrogen. The amount of carbon dioxide desorbed from the sample was determined by the following method. The peak of nitrogen discharged from the adsorption vessel was measured using an infrared spectrometer (product name: FT / IR6800, manufactured by JASCO). －１ The amount of carbon dioxide desorbed was measured using the peak, and the amount of carbon dioxide in the nitrogen discharged from the adsorption vessel was calculated by applying a known formula to the amount of carbon dioxide desorbed and integrating it.

[0177] Differential Pressure (Pressure Loss) Measurement Differential pressure gauges (product name: GC30, manufactured by Nagano Keiki Co., Ltd.) were provided on the air intake side and outlet side of the adsorption vessel, and the pressure loss was measured when air was allowed to flow at a wind speed of 0.3 m / s in the adsorption step using the modules of Examples 15 to 17 and the module of Comparative Example 1. If the pressure loss was 1 kPa or less, it was evaluated as ◯ (passable), and if the pressure loss was more than 1 kPa, it was evaluated as × (unacceptable).

[0178] The ventilation resistance of the carbon dioxide adsorbents prepared in the examples was measured according to the method described above.

[0179] The physical properties such as fiber diameter of the carbon dioxide adsorbing materials produced in the examples were measured according to the methods described above.

[0180] The amount of amino groups in the compound having amino groups supported on the carbon dioxide adsorbents or the porous materials contained in the carbon dioxide adsorbents prepared in the Examples and the like was measured according to the method described above.

[0181] The physical properties of the porous inorganic particles, such as the average particle size, were measured according to the methods described above.

[0182] (Example 1) Particle diameter 1 mm, pore diameter 1 nm, pore volume 1 ml / g, and BET specific surface area 700 m ２ 100 g of zeolite 13X (product name: Mizuka Sieves, manufactured by Mizusawa Industrial Chemicals Co., Ltd.) having a particle size of 1 / g was crushed using a hammer mill manufactured by LabNect Co., Ltd. to an average particle size of 10 μm. The crushed zeolite 13X was gradually added to 1,300 g of water with stirring to disperse it in water. 200 g of a 20% by mass aqueous solution of colloidal silica (product name: Snowtex UP, manufactured by Nissan Chemical Industries, Ltd.) having a particle size of 40 to 100 nm was added to the resulting dispersion, followed by the addition of 0.7 g of a dispersant (product name: SD-10, manufactured by Toa Gosei Co., Ltd.) to obtain a dispersion of porous material A. The particle size values ​​of zeolite 13X in Example 1 listed in Table 1 are the particle size values ​​of zeolite 13X after crushing.

[0183] Fiber diameter 12 μm, basis weight 100 g / m ２ , porosity 88%, specific surface area 0.2m ２ A nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers having a density of 80 g / m and a thickness of 0.6 mm was impregnated with a dispersion of the porous material A, and then dried at 150°C for 2 hours. ２ A cellulose nonwoven fabric carrying the carbon dioxide adsorbent (hereinafter referred to as the carbon dioxide adsorbent material of Example 1 or Sample 1) was obtained.

[0184] 95% by volume of the porous material A was supported in the pores of the carbon dioxide adsorbent in Example 1. The airflow resistance of the carbon dioxide adsorbent in Example 1 was 0.56 kPa·s / m.

[0185] The amount of carbon dioxide adsorbed by Sample 1 and the amount of carbon dioxide desorbed from Sample 1 were 0.4 CO per mass (g) of the cellulose nonwoven fabric supporting porous material A. ２ The concentration was mmol / g.

[0186] Example 2: Average particle size 1 mm, pore size 1 nm, pore volume 1 ml / g, and BET specific surface area 700 m ２500 g of zeolite 13X (product name: Mizuka Sieves, manufactured by Mizusawa Industrial Chemicals Co., Ltd.) having a melting point of 110°C or higher was mixed with 400 g of a polyethylene (PE)-based hot melt material (manufactured by Asahi Kasei Corporation) in a mass ratio of 5:4 to prepare a powder of porous material B. The content of the hot melt material in porous material B was 45 mass%. The particle size values ​​of zeolite 13X in Example 2 listed in Table 1 are the particle size values ​​of zeolite 13X after mixing with the hot melt material.

[0187] Fiber diameter 6 μm, basis weight 50 g / m ２ , porosity 89%, specific surface area 0.6m ２ The powder of porous material B was fed to a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers with a fiber diameter of 12 μm and a basis weight of 38 g / m2. ２ , porosity 92%, specific surface area 0.2m ２ The porous material B was sandwiched between a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers with a mass of 270 g / m² and a thickness of 0.3 mm, and the resulting mixture was hot-rolled at 120°C until the amount of porous material B carried was 270 g / m². ２ A cellulose nonwoven fabric having the above formula (hereinafter referred to as the carbon dioxide adsorbent of Example 2 or Sample 2) was obtained. The carbon dioxide adsorbent of Example 2 had an airflow resistance of 6.3 kPa·s / m.

[0188] The amount of carbon dioxide adsorbed by Sample 2 and the amount of carbon dioxide desorbed from Sample 2 were each 0.4 CO per mass (g) of the cellulose nonwoven fabric carrying porous material B (Sample 2). ２ The concentration was mmol / g.

[0189] (Example 3) Average particle size 6.4 μm, pore size 21 nm, pore volume 1.6 ml / g, and BET specific surface area 300 m ２100 g of silica (product name: Sylysia 370, manufactured by Fuji Silysia Chemical Ltd.) was gradually added to 1,300 g of water with stirring to form a dispersion. 200 g of an aqueous solution of colloidal silica (product name: Snowtex, manufactured by Nissan Chemical Industries, Ltd.) with a concentration of 20% by mass and having a particle size of 40 to 100 nm was added to the resulting dispersion, followed by the addition of 0.7 g of a dispersant (product name: SD-10, manufactured by Toa Gosei Co., Ltd.), to obtain a dispersion containing porous material A.

[0190] Fiber diameter 12 μm, basis weight 100 g / m ２ , porosity 88%, specific surface area 0.2m ２ A nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers having a density of 60 g / m and a thickness of 0.6 mm was impregnated with a dispersion of the porous material A, and then dried at 150°C for 2 hours. ２ A cellulose nonwoven fabric carrying the above-mentioned compound (hereinafter referred to as Sample 3) was obtained.

[0191] Polyethyleneimine (PEI) (product name: SP-006, manufactured by Nippon Shokubai Co., Ltd.) having a number average molecular weight Mn of 600 was dissolved in ethanol to prepare an ethanol solution with a polyethyleneimine concentration of 25% by mass.

[0192] Subsequently, Sample 3 was impregnated in the ethanol solution and then vacuum dried at 80° C. for 4 hours to obtain Sample 3 carrying polyethyleneimine (hereinafter, referred to as the carbon dioxide adsorbent of Example 3).

[0193] The amount of polyethyleneimine supported on the carbon dioxide adsorbent of Example 3 was found to be 8 mmol / g by measuring the weight of the sample before and after supporting polyethyleneimine. The amount of the compound having an amino group supported on the porous material A contained in the carbon dioxide adsorbent of Example 3 was 92 mass%.

[0194] 95% by volume of the porous material A was supported in the pores of the carbon dioxide adsorbent of Example 3. The airflow resistance of the carbon dioxide adsorbent of Example 3 was 0.54 kPa·s / m.

[0195] The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Example 3 and the amount of carbon dioxide desorbed from the carbon dioxide adsorbent of Example 3 were 2.0 CO with respect to the mass (g) of polyethyleneimine, respectively. ２ The concentration was mmol / g.

[0196] (Example 4) Average particle size 100 μm, pore size 6 nm, pore volume 0.8 ml / g, and BET specific surface area 450 m ２ 500 g of crushed B-type silica gel (manufactured by Toyoda Kako Co., Ltd.) with a melting point of 110°C or higher and 400 g of a polyethylene (PE)-based hot melt material (manufactured by Asahi Kasei Corporation) were mixed in a mass ratio of 5:4 to prepare a powder of porous material B. The content of the hot melt material in porous material B was 45 mass%.

[0197] Fiber diameter 6 μm, basis weight 50 g / m ２ , porosity 89%, specific surface area 0.6m ２ The powder was fed to a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers with a fiber diameter of 12 μm and a basis weight of 38 g / m2 so that the silica content in the porous material B was 150 g. ２ , porosity 92%, specific surface area 0.2m ２ The porous material B was sandwiched between a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers with a mass of 270 g / m² and a thickness of 0.3 mm, and the resulting mixture was hot-rolled at 120°C until the amount of porous material B carried was 270 g / m². ２ A cellulose nonwoven fabric (hereinafter referred to as Sample 4) was obtained.

[0198] Next, Sample 4 was impregnated with the ethanol solution of PEI prepared in Example 3, and then vacuum dried at 80°C for 4 hours to obtain Sample 4 carrying polyethyleneimine (hereinafter referred to as the carbon dioxide adsorbent of Example 4).

[0199] The amount of polyethyleneimine supported on the carbon dioxide adsorbent of Example 4 was found to be 7 mmol / g by measuring the weight of a sample before and after the support of polyethyleneimine. The amount of the compound having an amino group supported on the porous material B contained in the carbon dioxide adsorbent of Example 4 was 72 mass%. The airflow resistance of the carbon dioxide adsorbent of Example 4 was 9.6 kPa s / m.

[0200] The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Example 4 and the amount of carbon dioxide desorbed from the carbon dioxide adsorbent of Example 4 were 1.7 CO per mass (g) of polyethyleneimine, respectively. ２ The concentration was mmol / g.

[0201] (Example 5) Sample 4 produced in Example 4 was impregnated with the dispersion containing porous material A prepared in Example 3 and dried at 150°C for 4 hours to obtain a cellulose nonwoven fabric containing porous materials A and B (hereinafter, Sample 5). The amounts of porous material A and porous material B supported in Sample 5 were each 60 g / m ２ and 270 g / m ２ It was.

[0202] Next, Sample 5 was impregnated with the ethanol solution of PEI prepared in Example 3, and then vacuum dried at 80°C for 4 hours to obtain Sample 5 carrying polyethyleneimine (hereinafter referred to as the carbon dioxide adsorbent of Example 5).

[0203] The amount of polyethyleneimine supported on the carbon dioxide adsorbent of Example 5 was found to be 7 mmol / g by measuring the weight of the sample before and after supporting polyethyleneimine. The amount of the compound having an amino group supported on the porous materials A and B contained in the carbon dioxide adsorbent of Example 5 was 60 mass%.

[0204] 98% by volume of the porous material A was supported in the pores of the carbon dioxide adsorbent of Example 5. The airflow resistance of the carbon dioxide adsorbent of Example 5 was 11.2 kPa·s / m.

[0205] The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Example 5 and the amount of carbon dioxide desorbed from the carbon dioxide adsorbent of Example 5 were 1.6 CO per mass (g) of polyethyleneimine, respectively. ２ The concentration was mmol / g.

[0206] Example 6: Average particle size 100 μm, pore size 15 nm, pore volume 1.2 ml / g, and BET specific surface area 300 m ２ 1200 g of spherical porous silica (product name: CARIACT Q15, manufactured by Fuji Silysia Chemical Ltd.) having a molecular weight of 1 / g and 960 g of a polyethylene (PE)-based hot melt material (manufactured by Asahi Kasei Corporation) having a melting point of 110°C or higher were mixed in a mass ratio of 5:4 to prepare a powder of porous material B. The content of the hot melt material in porous material B was 45 mass%.

[0207] Fiber diameter 6 μm, basis weight 50 g / m ２ , porosity 89%, specific surface area 0.6m ２ A powder of porous material B was fed to a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers having a fiber diameter of 12 μm and a basis weight of 38 g / m2, so that the silica content in porous material B was 120 g. ２ , porosity 92%, specific surface area 0.2m ２ The porous material B was sandwiched between a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers with a weight of 216 g / m² and a thickness of 0.3 mm, and the resulting mixture was hot-rolled at 120°C until the amount of porous material B carried was 216 g / m². ２ A cellulose nonwoven fabric having the following properties was obtained.

[0208] A cellulose nonwoven fabric sandwiching porous material B was impregnated with the dispersion containing porous material A prepared in Example 3, and dried at 150°C for 4 hours to obtain a cellulose nonwoven fabric containing porous materials A and B (hereinafter referred to as Sample 6). The amounts of porous material A and porous material B supported in Sample 6 were 60 g / m ２ and 216 g / m ２ It was.

[0209] Next, Sample 6 was impregnated with the ethanol solution of PEI prepared in Example 3, and then vacuum dried at 80°C for 4 hours to obtain Sample 6 carrying polyethyleneimine (hereinafter referred to as the carbon dioxide adsorbent of Example 6).

[0210] The amount of polyethyleneimine supported on the carbon dioxide adsorbent of Example 6 was found to be 8 mmol / g by measuring the weight of the sample before and after supporting polyethyleneimine. The amount of the compound having an amino group supported on the porous materials A and B contained in the carbon dioxide adsorbent of Example 6 was 70 mass%.

[0211] 96% by volume of the porous material A was supported in the pores of the carbon dioxide adsorbent of Example 6. The airflow resistance of the carbon dioxide adsorbent of Example 6 was 2.6 kPa·s / m.

[0212] The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Example 6 and the amount of carbon dioxide desorbed from the carbon dioxide adsorbent of Example 6 were 2.5 CO with respect to the mass (g) of polyethyleneimine, respectively. ２ The concentration was mmol / g.

[0213] (Example 7) Two sheets of nonwoven fabric sandwiching porous material B were fabricated with a fiber diameter of 15 μm and a basis weight of 50 g / m ２ , porosity 81%, specific surface area 0.18m ２ A nylon nonwoven fabric containing porous materials A and B (hereinafter referred to as Sample 7) was obtained in the same manner as in Example 6, except that the porous material A was replaced with a nonwoven fabric made of nylon long fibers (product name: Eltas N03050, manufactured by Asahi Kasei Corporation) having a molecular weight of 60 g / m and a thickness of 0.25 mm. The amounts of porous materials A and B supported in Sample 7 were 60 g / m. ２ and 216 g / m ２ It was.

[0214] Furthermore, Sample 7 was impregnated in the ethanol solution of PEI prepared in Example 3, and then vacuum dried at 80°C for 4 hours to obtain a nylon nonwoven fabric carrying polyethyleneimine (hereinafter referred to as the carbon dioxide adsorbent of Example 7).

[0215] The amount of polyethyleneimine supported on the carbon dioxide adsorbent of Example 7 was found to be 8 mmol / g by measuring the weight of the sample before and after supporting polyethyleneimine. The amount of the compound having an amino group supported on the porous materials A and B contained in the carbon dioxide adsorbent of Example 7 was 72 mass%.

[0216] 98% by volume of the porous material A was supported in the pores of the carbon dioxide adsorbent of Example 7. The airflow resistance of the carbon dioxide adsorbent of Example 7 was 2.8 kPa·s / m.

[0217] The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Example 7 and the amount of carbon dioxide desorbed by the carbon dioxide adsorbent of Example 7 were 2.1 CO per mass (g) of polyethyleneimine, respectively. ２ The concentration was mmol / g.

[0218] Example 8 Polyethyleneimine (PEI) having a number average molecular weight Mn of 600 (product name: SP-006, manufactured by Nippon Shokubai Co., Ltd.) and a 30% by mass aqueous solution of amino-modified silicone emulsion (product name: MF-14ES, manufactured by Shin-Etsu Chemical Co., Ltd.) were dissolved in ethanol to prepare a mixed solution of ethanol and water with a silicone concentration of 25% by mass, in which the polyethyleneimine and silicone were mixed at a ratio of 8:2.

[0219] Sample 6 prepared in Example 6 was impregnated with the prepared mixed solution of ethanol and water with a silicone concentration of 25% by mass, and vacuum dried at 80°C for 4 hours to obtain a regenerated cellulose nonwoven fabric carrying polyethyleneimine (hereinafter referred to as the carbon dioxide adsorbent of Example 8 or Sample 8). The content ratio of the silicone compound in the polyethyleneimine carried by the carbon dioxide adsorbent of Example 8 was 20% by mass. The amount of polyethyleneimine carried by the carbon dioxide adsorbent of Example 8 was found to be 6 mmol / g by measuring the weight of the sample before and after carrying polyethyleneimine. The amount of the compound having an amino group carried by the porous materials A and B contained in the carbon dioxide adsorbent of Example 8 was 54% by mass.

[0220] 97% by volume of the porous material A was supported in the pores of the carbon dioxide adsorbent of Example 8. The airflow resistance of the carbon dioxide adsorbent of Example 8 was 2.9 kPa·s / m.

[0221] The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Example 8 and the amount of carbon dioxide desorbed by the carbon dioxide adsorbent of Example 8 were 2.3 CO per mass (g) of polyethyleneimine, respectively. ２ The concentration was mmol / g.

[0222] Example 9: Average particle size 100 μm, pore size 27 nm, pore volume 1.8 ml / g, and BET specific surface area 280 m ２ 1200 g of spherical porous silica (product name: Cariact G, manufactured by Fuji Silysia Chemical Ltd.) with a fiber diameter of 6 μm and a basis weight of 50 g / m2 was mixed with 960 g of a polyethylene (PE)-based hot melt material (manufactured by Asahi Kasei Corporation) with a melting point of 110°C or higher in a mass ratio of 5:4 to prepare a powder of porous material B. The content of the hot melt material in porous material B was 45 mass%. ２ , porosity 89%, specific surface area 0.6m ２ A powder of porous material B was fed to a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers having a fiber diameter of 12 μm and a basis weight of 38 g / m2, so that the silica content in porous material B was 80 g. ２ , porosity 92%, specific surface area 0.2m ２ The porous material B was sandwiched between a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers with a weight of 144 g / m² and a thickness of 0.3 mm, and the resulting mixture was hot-rolled at 120°C until the amount of porous material B carried was 144 g / m². ２ A cellulose nonwoven fabric having the following properties was obtained.

[0223] Average particle size: 5 μm, pore size: 26 nm, pore volume: 1.8 ml / g, and BET specific surface area: 280 m ２100 g of silica (product name: Sylysia 250N, manufactured by Fuji Silysia Chemical Ltd.) was gradually added to 2600 g of water with stirring to form a dispersion. 30 g of an aqueous solution of colloidal silica (product name: Sumikaflex S-201HQ, manufactured by Sumitomo Chemiflex Co., Ltd.) containing a 56 mass% concentration of ethylene-vinyl acetate copolymer polymer emulsion was added as a binder to obtain a dispersion of porous material A containing a 17 mass% concentration of polymer emulsion. A cellulose nonwoven fabric sandwiching porous material B was impregnated with the dispersion and dried at 150°C for 4 hours to obtain a cellulose nonwoven fabric containing porous materials A and B (hereinafter referred to as Sample 9). The loading amounts of porous material A and porous material B in Sample 9 were 67 g / m. ２ and 144 g / m ２ It was.

[0224] Next, Sample 9 was impregnated with the ethanol solution of PEI prepared in Example 3, and then vacuum dried at 80°C for 4 hours to obtain Sample 9 carrying polyethyleneimine (hereinafter referred to as the carbon dioxide adsorbent of Example 9).

[0225] The amount of polyethyleneimine supported on the carbon dioxide adsorbent of Example 9 was found to be 9 mmol / g by measuring the weight of the sample before and after supporting polyethyleneimine. The amount of the compound having an amino group supported on the porous materials A and B contained in the carbon dioxide adsorbent of Example 9 was 133 mass%.

[0226] For the carbon dioxide adsorbent of Example 9, 91% by volume of the porous material A was supported in the pores of the carbon dioxide adsorbent. The carbon dioxide adsorbent of Example 9 had an airflow resistance of 3.6 kPa·s / m.

[0227] The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Example 9 and the amount of carbon dioxide desorbed from the carbon dioxide adsorbent of Example 9 were 5.9 CO with respect to the mass (g) of polyethyleneimine, respectively. ２ The concentration was mmol / g.

[0228] (Example 10) Average particle size 100 μm, pore size 27 nm, pore volume 1.8 ml / g, and BET specific surface area 280 m ２1200 g of spherical porous silica (product name: Cariact G, manufactured by Fuji Silysia Chemical Ltd.) with a fiber diameter of 15 μm and a basis weight of 40 g / m were mixed with 1920 g of a polyethylene (PE)-based hot melt material (manufactured by Asahi Kasei Corporation) with a melting point of 110°C or higher in a mass ratio of 5:8 to prepare a powder of porous material B. The content of the hot melt material in porous material B was 62 mass%. ２ , porosity 78%, specific surface area 0.19m ２ A powder of porous material B was fed into a nonwoven fabric (product name: Eltas E05040, manufactured by Asahi Kasei Corporation) made of polyethylene terephthalate (PET) long fibers having a fiber diameter of 15 μm and a basis weight of 40 g / m2, so that the silica content in porous material B was 80 g. ２ , porosity 78%, specific surface area 0.19m ２ The porous material B was sandwiched between a nonwoven fabric (product name: Eltas E05040, manufactured by Asahi Kasei Corporation) made of PET long fibers with a density of 188 g / m² and a thickness of 0.14 mm, and the resulting mixture was hot-rolled at 120°C until the amount of porous material B carried was 188 g / m². ２ A cellulose nonwoven fabric having the following properties was obtained.

[0229] Average particle size: 5 μm, pore size: 26 nm, pore volume: 1.8 ml / g, and BET specific surface area: 280 m ２ 100 g of silica (product name: Sylysia 250N, manufactured by Fuji Silysia Chemical Ltd.) was gradually added to 2600 g of water with stirring to form a dispersion. 30 g of an aqueous solution of colloidal silica (product name: Sumikaflex S-201HQ, manufactured by Sumitomo Chemiflex Co., Ltd.) containing a 56 mass% concentration of ethylene-vinyl acetate copolymer polymer emulsion was added as a binder to obtain a dispersion of porous material A containing a 17 mass% concentration of polymer emulsion. A cellulose nonwoven fabric sandwiching porous material B was impregnated with the dispersion and dried at 150°C for 4 hours to obtain a cellulose nonwoven fabric containing porous materials A and B (hereinafter, Sample 10). The loading amounts of porous material A and porous material B in Sample 10 were 35 g / m. ２ and 188 g / m ２ It was.

[0230] Next, Sample 10 was impregnated with the ethanol solution of PEI prepared in Example 3, and then vacuum dried at 80°C for 4 hours to obtain Sample 10 carrying polyethyleneimine (hereinafter referred to as the carbon dioxide adsorbent of Example 10).

[0231] The amount of polyethyleneimine supported on the carbon dioxide adsorbent of Example 10 was found to be 6 mmol / g by measuring the weight of the sample before and after supporting polyethyleneimine. The amount of the compound having an amino group supported on the porous materials A and B contained in the carbon dioxide adsorbent of Example 10 was 129 mass%.

[0232] 67% by volume of the porous material A was supported in the pores of the carbon dioxide adsorbent of Example 10. The airflow resistance of the carbon dioxide adsorbent of Example 10 was 5.4 kPa·s / m.

[0233] The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Example 10 and the amount of carbon dioxide desorbed from the carbon dioxide adsorbent of Example 10 were 5.7 CO per mass (g) of polyethyleneimine, respectively. ２ The concentration was mmol / g.

[0234] Example 11: Average particle size 100 μm, pore size 27 nm, pore volume 1.8 ml / g, and BET specific surface area 280 m ２ 1200 g of spherical porous silica (product name: Cariact G, manufactured by Fuji Silysia Chemical Ltd.) with a fiber diameter of 6 μm and a basis weight of 50 g / m2 was mixed with 960 g of a polyethylene (PE)-based hot melt material (manufactured by Asahi Kasei Corporation) with a melting point of 110°C or higher in a mass ratio of 5:4 to prepare a powder of porous material B. The content of the hot melt material in porous material B was 45 mass%. ２ , porosity 89%, specific surface area 0.6m ２ A powder of porous material B was fed to a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers having a fiber diameter of 12 μm and a basis weight of 38 g / m2, so that the silica content in porous material B was 80 g. ２ , porosity 92%, specific surface area 0.2m ２The porous material B was sandwiched between a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers with a weight of 144 g / m² and a thickness of 0.3 mm, and the resulting mixture was hot-rolled at 120°C until the amount of porous material B carried was 144 g / m². ２ Thus, a cellulosic nonwoven fabric sample 11 was obtained.

[0235] Next, Sample 11 was impregnated with the ethanol solution of PEI prepared in Example 3, and then vacuum dried at 80°C for 4 hours to obtain Sample 11 carrying PEI (hereinafter referred to as the carbon dioxide adsorbent of Example 11).

[0236] The amount of PEI supported on the carbon dioxide adsorbent of Example 11 was found to be 11 mmol / g by measuring the weight of the sample before and after PEI support. The amount of the compound having an amino group supported on the porous material B contained in the carbon dioxide adsorbent of Example 11 was 215 mass%.

[0237] The airflow resistance of the carbon dioxide adsorbent of Example 11 was 0.59 kPa·s / m.

[0238] The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Example 11 and the amount of carbon dioxide desorbed from the carbon dioxide adsorbent of Example 11 were 3.0 CO with respect to the mass (g) of polyethyleneimine, respectively. ２ The concentration was mmol / g.

[0239] Example 12 1,4-bis(3-aminopropyl)piperazine (product name: BAPPRZ, manufactured by Koei Chemical Co., Ltd.) was dissolved in ethanol to prepare an ethanol solution containing BAPPRZ at a concentration of 30% by mass. Subsequently, the porous material B prepared in Example 11 was added to the ethanol solution of BAPPRZ in an amount of 144 g / m. ２ After impregnating the cellulose nonwoven fabric sample 11 with the BAPPRZ, the cellulose nonwoven fabric was vacuum dried at 80° C. for 4 hours to obtain sample 12 carrying BAPPRZ (hereinafter referred to as the carbon dioxide adsorbent of Example 12).

[0240] The amount of BAPPRZ supported on the carbon dioxide adsorbent of Example 12 was found to be 9 mmol / g by measuring the weight of the sample before and after supporting BAPPRZ. The amount of the compound having an amino group supported on the porous material B contained in the carbon dioxide adsorbent of Example 12 was 213 mass%.

[0241] The airflow resistance of the carbon dioxide adsorbent of Example 12 was 0.54 kPa·s / m. The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Example 12 and the amount of carbon dioxide desorbed from the carbon dioxide adsorbent of Example 12 were 3.5 CO ２ The concentration was mmol / g.

[0242] Example 13 PEI was dissolved in ethanol to prepare an ethanol solution with a PEI concentration of 15% by mass. Subsequently, 1,4-epoxyhexane in an amount equal to the amount of PEI was added dropwise while stirring, and the mixture was then stirred for 24 hours to obtain a terminally epoxidized PEI (PEI-EH). The porous material B prepared in Example 11 was added to the ethanol solution containing PEI-EH in an amount of 144 g / m. ２ After impregnating the cellulose nonwoven fabric sample 11 with PEI-EH, the cellulose nonwoven fabric was vacuum dried at 80° C. for 4 hours to obtain sample 13 carrying PEI-EH (hereinafter referred to as the carbon dioxide adsorbent of Example 13).

[0243] The amount of PEI-EH supported on the carbon dioxide adsorbent of Example 13 was found to be 8 mmol / g by measuring the weight of the sample before and after supporting PEI-EH. The amount of the compound having an amino group supported on the porous material B contained in the carbon dioxide adsorbent of Example 13 was 214 mass%.

[0244] The carbon dioxide adsorbent of Example 13 had an airflow resistance of 0.57 kPa·s / m.

[0245] The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Example 13 and the amount of carbon dioxide desorbed from the carbon dioxide adsorbent of Example 13 were 2.4 CO per mass (g) of PEI-EH, respectively. ２ The concentration was mmol / g.

[0246] Example 14 BAPPRZ was dissolved in ethanol to prepare an ethanol solution with a BAPPRZ concentration of 15% by mass. Subsequently, 1,4-epoxyhexane in an amount equal to the amount of BAPPRZ was added dropwise with stirring, and the mixture was then stirred for 24 hours to obtain a terminal epoxidized product of BAPPRZ (BAPRZ-EH). A support amount of the porous material B prepared in Example 11 of 144 g / m was added to the ethanol solution in which BAPPRZ-EH was dissolved in ethanol. ２ After impregnating the cellulose nonwoven fabric sample 11 with the above-mentioned cellulose nonwoven fabric, the cellulose nonwoven fabric was vacuum dried at 80° C. for 4 hours to obtain sample 14 carrying BAPPRZ-EH (hereinafter referred to as the carbon dioxide adsorbent of Example 14).

[0247] The amount of BAPPRZ-EH supported on the carbon dioxide adsorbent of Example 14 was found to be 5 mmol / g by measuring the weight of the sample before and after supporting BAPPRZ-EH. The amount of the compound having an amino group supported on the porous material B contained in the carbon dioxide adsorbent of Example 14 was 214 mass%.

[0248] The airflow resistance of the carbon dioxide adsorbent of Example 14 was 0.64 kPa·s / m.

[0249] The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Example 14 and the amount of carbon dioxide desorbed from the carbon dioxide adsorbent of Example 14 were 3.0 CO per mass (g) of BAPPRZ-EH, respectively. ２ The concentration was mmol / g.

[0250] Example 15 A spiral module was produced using the carbon dioxide adsorbent produced in Example 6. The average particle size was 100 μm, the pore size was 15 nm, the pore volume was 1.2 ml / g, and the BET specific surface area was 300 m ２ 12 kg of spherical porous silica (product name: CARIACT Q15, manufactured by Fuji Silysia Chemical Ltd.) having a melting point of 110°C or higher (product name: CARIACT Q15, manufactured by Fuji Silysia Chemical Ltd.) was mixed in a mass ratio of 5:4 to prepare a powder of porous material B.

[0251] Fiber diameter 6 μm, basis weight 50 g / m ２ , porosity 89%, specific surface area 0.6m ２A powder of porous material B was fed into a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers having a fiber diameter of 12 μm and a basis weight of 38 g / m2, so that the silica content in porous material B was 120 g. ２ , porosity 92%, specific surface area 0.2m ２ Porous material B was sandwiched between a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers having a molecular weight of 1 / g and a thickness of 0.3 mm, and the resulting mixture was hot rolled at 120°C to obtain a roll of cellulose nonwoven fabric sandwiching porous material B.

[0252] A 30 cm wide spacer roll (product name: PROPYLTEX, manufactured by SEFER) of polypropylene mesh, plain woven with 300 μm fiber diameter polypropylene (PP) fibers and having a thickness of 600 μm and an opening ratio of 41% in the thickness direction, was used to spirally wrap one layer of nonwoven fabric (carbon dioxide adsorbent) and one layer of spacer around a 20 mm diameter tube, with the spacer layer being in contact with the tube, to produce a structure in which the carbon dioxide adsorbent and spacer were laminated.

[0253] In the same manner as in Example 3, an average particle diameter of 6.4 μm, a pore diameter of 21 nm, a pore volume of 1.6 ml / g, and a BET specific surface area of ​​300 m ２ 100 g of silica (product name: Sylysia 370, manufactured by Fuji Silysia Chemical Ltd.) was gradually added to 1,300 g of water with stirring to form a dispersion. 200 g of a 20% by mass aqueous solution of colloidal silica (product name: Snowtex, manufactured by Nissan Chemical Co., Ltd.) having a particle size of 40 to 100 nm was added to the resulting dispersion, followed by the addition of 0.7 g of a dispersant (product name: SD-10, manufactured by Toa Gosei Co., Ltd.) to prepare a dispersion containing porous material A. A structure in which a carbon dioxide adsorbent and a spacer were spirally laminated was impregnated with the dispersion containing porous material A and dried at 150°C for 4 hours to obtain a spiral roll (hereinafter, Sample 15) carrying porous materials A and B. The amounts of porous materials A and B carried in Sample 15 were each 60 g / m ２ and 216 g / m ２ It was.

[0254] Sample 15 was impregnated with the ethanol solution of polyethyleneimine prepared in Example 3, and then vacuum dried at 80°C for 4 hours to obtain a module carrying polyethyleneimine (hereinafter referred to as the module of Example 15).

[0255] The amount of polyethyleneimine supported on the module of Example 15 was 8 mmol / g, as determined by measuring the weight of a sample before and after polyethyleneimine support. The configuration and physical properties of the carbon dioxide adsorbent included in the module produced in Example 15 were the same as those in Example 6.

[0256] The module of Example 15 prepared above was cut to a width of 200 mm and a length of 1050 mm, and wrapped around a vinyl chloride rod with a diameter of 20 mm to prepare a module sample with a diameter of 55 mm (hereinafter referred to as the module sample of Example 15).

[0257] The module sample of Example 15 was fitted with packing on both ends and placed in a carbon dioxide adsorption vessel (height: 400 mm), and subjected to the carbon dioxide adsorption and desorption process. ２ The desorption process was carried out by blowing air with a concentration of 400 ppm at a wind speed of 0.3 m / s. ２ The test was carried out by blowing air at 0.06 m / sec.

[0258] The amount of carbon dioxide adsorbed by the module sample of Example 15 and the amount of carbon dioxide desorbed by the module sample of Example 15 were 12 kg / m ３ The pressure loss during adsorption was 300 Pa.

[0259] (Example 16) Average particle size 100 μm, pore size 15 nm, pore volume 1.2 ml / g, and BET specific surface area 300 m ２ 12 kg of spherical porous silica (product name: Cariact Q15, manufactured by Fuji Silysia Chemical Ltd.) with a fiber diameter of 6 μm and a basis weight of 50 g / m were mixed with 9.6 kg of a polyethylene (PE)-based hot melt material (manufactured by Asahi Kasei Corporation) with a melting point of 110°C or higher in a mass ratio of 5:4 to prepare a powder of porous material B. ２ , porosity 89%, specific surface area 0.6m ２A powder of porous material B was fed to a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers having a fiber diameter of 12 μm and a basis weight of 38 g / m2, so that the silica content in porous material B was 120 g. ２ , porosity 92%, specific surface area 0.2m ２ Porous material B was sandwiched between a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers having a molecular weight of 1 / g and a thickness of 0.3 mm, and the resulting mixture was hot rolled at 120°C to obtain a roll of cellulose nonwoven fabric sandwiching porous material B.

[0260] The adhesive polyvinyl alcohol (PVA) loading is 10 g / m ２ A PVA aqueous solution was spray-coated onto a roll of cellulose nonwoven fabric sandwiching the porous material B so that the porous material B was sandwiched between the rolls. First, the PVA-coated cellulose nonwoven fabric roll sandwiching the porous material B was cut out to form a liner portion. The cut-out cellulose nonwoven fabric roll was then processed into a corrugated shape to form a core portion. An adhesive (PVA) was applied to the core portion, and then the core portion was overlapped with the liner portion to form a laminate. Next, the cellulose nonwoven fabric roll sandwiching the porous material B was heated at 120°C to adhere to the liner portion of the laminate, and processed into a corrugated shape with a peak height of 2 mm and a width of 3 mm to obtain a corrugated roll.

[0261] Average particle size 6.4 μm, pore diameter 21 nm, pore volume 1.6 ml / g, and BET specific surface area 300 m ２200 g of silica (product name: Sylysia 370, manufactured by Fuji Silysia Chemical Ltd.) with a concentration of 1 / g was gradually added to 2600 g of water while stirring to form a dispersion. 400 g of an aqueous solution of 20% by mass colloidal silica (product name: Snowtex, manufactured by Nissan Chemical Co., Ltd.) with a particle size of 40 to 100 nm was added to the resulting dispersion, followed by the addition of 1.4 g of a dispersant (product name: SD-10, manufactured by Toa Gosei Co., Ltd.) to prepare a dispersion containing porous material A. The corrugated roll prepared above was impregnated with the dispersion containing porous material A and dried at 150°C for 4 hours to obtain a corrugated structure (hereinafter, Sample 16) carrying porous materials A and B. The amounts of porous materials A and B carried in Sample 16 were each 60 g / m. ２ and 216 g / m ２ It was.

[0262] Sample 16 was impregnated with the ethanol solution of polyethyleneimine prepared in Example 3, and then vacuum dried at 80°C for 4 hours to obtain a module carrying polyethyleneimine (hereinafter referred to as the module of Example 16).

[0263] The amount of polyethyleneimine supported on the module of Example 16 was found to be 8 mmol / g by measuring the weight of the sample before and after polyethyleneimine support. The configuration and physical properties of the carbon dioxide adsorbent included in the module produced in Example 16 were the same as those in Example 6.

[0264] The module of Example 16 prepared above was cut to a width of 200 mm and a length of 960 mm, and wrapped around a vinyl chloride rod with a diameter of 20 mm to prepare a module sample with a diameter of 55 mm (hereinafter, the module sample of Example 16). Packing was provided on both ends of the module sample of Example 16, and the sample was placed in a carbon dioxide adsorption container (height 400 mm) to carry out the carbon dioxide adsorption and desorption process. The adsorption process was carried out at a temperature of 25°C and a humidity of 50 RH%. ２ The desorption process was carried out by blowing air with a concentration of 400 ppm at a wind speed of 0.3 m / s. ２ The test was carried out by blowing air at 0.06 m / sec.

[0265] The amount of carbon dioxide adsorbed by the module sample of Example 16 and the amount of carbon dioxide desorbed by the module sample of Example 16 were 16 kg / m ３ The pressure loss was 180 Pa.

[0266] (Example 17) Average particle size 100 μm, pore size 27 nm, pore volume 1.8 ml / g, and BET specific surface area 280 m ２ A powder of porous material B was prepared by mixing 12 kg of spherical porous silica (product name: Cariact G, manufactured by Fuji Silysia Chemical Ltd.) having a fiber diameter of 6 μm and a basis weight of 50 g / m with 9.6 kg of a polyethylene (PE)-based hot melt material (manufactured by Asahi Kasei Corporation) having a melting point of 110°C or higher in a mass ratio of 5:4. ２ , porosity 89%, specific surface area 0.6m ２ A powder of porous material B was fed to a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers having a fiber diameter of 12 μm and a basis weight of 38 g / m2, so that the silica content in porous material B was 120 g. ２ , porosity 92%, specific surface area 0.2m ２ Porous material B was sandwiched between a nonwoven fabric (product name: Bemliese, manufactured by Asahi Kasei Corporation) made of regenerated cellulose long fibers having a molecular weight of 1 / g and a thickness of 0.3 mm, and the resulting mixture was hot rolled at 120°C to obtain a roll of cellulose nonwoven fabric sandwiching porous material B.

[0267] The roll of cellulose nonwoven fabric sandwiching the porous material B was heated at 120°C and bonded to a liner (a low-melting PET mesh) to obtain a corrugated roll with a peak height of 2 mm and a width of 3 mm. The corrugated roll was then wrapped around a rod with a diameter of 20 mm to obtain a module with a corrugated structure.

[0268] In the same manner as in Example 9, an average particle diameter of 5 μm, a pore diameter of 26 nm, a pore volume of 1.8 ml / g, and a BET specific surface area of ​​280 m ２100 g of silica (product name: Sylysia 250N, manufactured by Fuji Silysia Chemical Ltd.) with a concentration of 1 / g was gradually added to 2600 g of water while stirring to form a dispersion. 30 g of an aqueous solution of colloidal silica (product name: Sumikaflex S-201HQ, manufactured by Sumitomo Chemiflex Co., Ltd.) with a concentration of 56 mass% ethylene-vinyl acetate copolymer polymer emulsion was added as a binder to obtain a dispersion of porous material A with an emulsion concentration of 17 mass%. The corrugated module prepared above was impregnated with the dispersion containing porous material A and dried at 150°C for 4 hours to obtain a corrugated structure (hereinafter, Sample 17) carrying porous materials A and B. The amounts of porous materials A and B carried in Sample 17 were 67 g / m. ２ and 144 g / m ２ It was.

[0269] Sample 17 was impregnated with the ethanol solution of polyethyleneimine prepared in Example 3, and then vacuum dried at 80°C for 4 hours to obtain a module carrying polyethyleneimine (hereinafter referred to as the module of Example 17).

[0270] The amount of polyethyleneimine supported on the module of Example 17 was found to be 9 mmol / g by measuring the weight of the sample before and after polyethyleneimine support. The configuration and physical properties of the carbon dioxide adsorbent included in the module produced in Example 17 were the same as those in Example 9.

[0271] The module of Example 17 prepared above was cut to a width of 200 mm and a length of 960 mm, and wrapped around a vinyl chloride rod with a diameter of 20 mm to prepare a module sample with a diameter of 55 mm (hereinafter, the module sample of Example 17). Packing was provided on both ends of the module sample of Example 17, and the sample was placed in a carbon dioxide adsorption container (height 400 mm) to carry out the carbon dioxide adsorption and desorption process. The adsorption process was carried out at a temperature of 25°C and a humidity of 50 RH%. ２ The desorption process was carried out by blowing air with a concentration of 400 ppm at a wind speed of 0.3 m / s. ２ The test was carried out by blowing air at 0.06 m / sec.

[0272] The amount of carbon dioxide adsorbed by the module sample of Example 17 and the amount of carbon dioxide desorbed by the module sample of Example 17 were 35 kg / m ３ The pressure loss was 80 Pa.

[0273] Comparative Example 1 2-aminoethylaminopropyldimethoxysilane (AEAPDMS: manufactured by Wacker) was added to a dispersion containing cellulose nanofibers (CNF) having a fiber diameter of 10 nm to 100 nm, and the mixture was stirred to prepare a dispersion containing CNF and AEAPDMS.

[0274] The dispersion containing CNF and AEAPDMS was freeze-dried to obtain CNF particles carrying AEAPDMS (hereinafter referred to as the carbon dioxide adsorbent of Comparative Example 1). The amount of aminoethylaminopropyl groups carried by the CNF was 5 mmol / g.

[0275] The carbon dioxide adsorbent of Comparative Example 1 was filled up to a height of 400 mm in a carbon dioxide adsorption vessel (height 400 mm), and carbon dioxide adsorption and desorption were carried out.

[0276] The amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Comparative Example 1 and the desorbed amount of carbon dioxide adsorbed by the carbon dioxide adsorbent of Comparative Example 1 were each 4 kg / m ３ and the pressure loss was greater than 1 kPa.

[0277]

[0278]

[0279]

[0280]

[0281] REFERENCE SIGNS LIST 1 Carbon dioxide adsorbent 2 Fiber structure 3 Porous material A or porous material B 3a Porous inorganic particles 3b Porous inorganic particles 4 Hot melt material 5 Porous inorganic carrier layer 6 Voids in fiber structure 7 Module 8 Carbon dioxide adsorption vessel 9 Tube 10 Spacer

[0282] The present invention relates to a method for producing carbon dioxide (CO ２) processing (DAC, etc.) enables its use in a wide range of industrial fields.

Claims

1. A method for producing a porous inorganic carrier layer comprising: a plurality of fiber structures; and a porous material B forming a porous inorganic carrier layer between the plurality of fiber structures, the porous material B being such that the amount of the porous inorganic carrier layer supported by the plurality of fiber structures is 10 g / m. ２ More than 500g / m ２ or less, and the air flow resistance in the thickness direction of the fiber structure is 0.01 kPa·s / m or more and 50 kPa·s / m or less.

2. A fiber structure; and a porous material A supported on the surface or in voids of the fiber structure, wherein 50% by volume or more of the porous material A is supported in the voids of the fiber structure, and the amount of the porous material A supported on the fiber structure is 10 g / m ２ More than 500g / m ２ or less, and the air flow resistance in the thickness direction of the fiber structure is 0.01 kPa·s / m or more and 50 kPa·s / m or less.

3. A method for producing a fiber structure comprising: a plurality of fiber structures; and a porous material A supported on the surface or in voids of at least one of the fiber structures, wherein 50% by volume or more of the porous material A is supported in the voids of the fiber structures, and the amount of the porous material A supported on the fiber structures is 10 g / m. ２ More than 500g / m ２ 2. The carbon dioxide adsorbing material according to claim 1, wherein the fiber structure has an airflow resistance in a thickness direction of 0.01 kPa·s / m or more and 50 kPa·s / m or less.

4. The total amount of the porous materials A and B supported on the fiber structure is 50 g / m ２ The carbon dioxide adsorbent according to any one of claims 1 to 3.

5. A carbon dioxide adsorbing material having a laminated structure in which at least one layer of the carbon dioxide adsorbing material according to any one of claims 1 to 3 is laminated.

6. The amount of the porous material A supported on the fiber structure is 10 g / m ２ Above, 500g / m ２ The amount of the porous material B supported on the fiber structure is 10 g / m or less. ２ Above, 500g / m ２ The total amount of the porous materials A and B supported on the fiber structure is 50 g / m or less. ２ The carbon dioxide adsorbent according to any one of claims 1 to 3.

7. The carbon dioxide adsorbent according to claim 2, wherein the porous material A comprises porous inorganic particles having an average particle diameter of 0.1 μm or more and 30 μm or less, and at least one type of porous inorganic particles selected from the group consisting of colloidal silica, colloidal alumina, and precursors of colloidal silica and colloidal alumina having an average particle diameter of 1 nm or more and 400 nm or less, and the porous inorganic particles having an average particle diameter of 0.1 μm or more and 30 μm or less are contained in an amount of 10 mass% or more and 99 mass% or less in 100 mass% of the porous material A.

8. The carbon dioxide adsorbent according to claim 7, wherein the porous material A comprises porous inorganic particles having an average particle size of 0.1 μm or more and 30 μm or less, and a polymer emulsion.

9. The carbon dioxide adsorbent material described in claim 1, wherein the porous inorganic carrier layer is formed from the porous material B containing porous inorganic particles having an average particle diameter of 30 μm or more and 3 mm or less and a hot melt material having a melting point of 50°C or more and 150°C or less, and the hot melt material is contained in an amount of 1 mass% or more and 80 mass% or less with respect to the total of the porous inorganic particles and the hot melt material.

10. The porous inorganic particles contained in each of the porous materials A and B have a BET specific surface area of ​​50 m ２ / g or more 3000m ２ The carbon dioxide adsorbent according to claim 7 or 9, wherein the carbon dioxide adsorbent has a molecular weight of 1000 to 15000 sq. m / g or less and an average pore diameter of 1 nm or more and 50 nm or less, and is at least one type selected from the group consisting of silica, alumina, silica alumina, titania, zirconia, activated carbon, zeolite, alkali metal ferrite, and MOF.

11. A carbon dioxide adsorbent material described in any one of claims 1 to 3, wherein the average fiber diameter of the fiber structure is 1 μm or more and 50 μm or less, and the porosity of the fiber structure is 50% or more and 95% or less.

12. A carbon dioxide adsorbent material described in any one of claims 1 to 3, in which a compound having an amino group is supported in the range of 10% by mass to 300% by mass on the porous material A and / or B.

13. The carbon dioxide adsorbing material according to claim 12, wherein the compound having an amino group includes at least one silicone compound selected from the group consisting of silicone oil, silsesquioxane and MQ resin.

14. The carbon dioxide adsorbent according to claim 13, wherein the compound having an amino group contains the silicone compound in an amount of 1% by mass or more and 90% by mass or less.

15. A module for adsorbing, separating and capturing carbon dioxide, having a laminated structure in which at least one layer of the carbon dioxide adsorbent material according to any one of claims 1 to 3 and at least one layer of a spacer are laminated.

16. A module for adsorbing, separating and capturing carbon dioxide, having a corrugated structure in which at least one layer of the carbon dioxide adsorbent material according to any one of claims 1 to 3 is used.

17. A module for adsorbing, separating and capturing carbon dioxide, wherein the corrugated structure includes a core portion and a liner portion, and the core portion and the liner portion each use a carbon dioxide adsorbent material described in any one of claims 1 to 3.

18. The carbon dioxide adsorption, separation and capture module according to claim 17, wherein the liner portion uses at least one selected from the group consisting of a mesh, a nonwoven fabric and a perforated sheet.

19. A direct air capture (DAC) method for directly capturing carbon dioxide from the atmosphere, comprising the following steps: an adsorption step of adsorbing carbon dioxide onto a carbon dioxide adsorbent in a carbon dioxide adsorption, separation and capture module as described in claim 15; and a desorption step of changing the temperature or pressure to desorb the carbon dioxide.