Molded body, carbon dioxide collecting molded body including same, carbon dioxide collecting element, carbon dioxide isolation and recovery device, method for manufacturing molded body, method for manufacturing carbon dioxide collecting molded body, and method for manufacturing carbon dioxide collecting element

Abstract

Provided is a molded body of a basic functional group-containing resin, wherein the total basic functional group amount per 1 g of the molded body is 2.5 mmol or more, the neutral salt decomposition capacity per 1 g of the molded body is 0.1 mmol or more, the specific surface area per 1 g of the molded body as measured by mercury intrusion is 10 m2 or more, the pore capacity per 1 g of the molded body as measured by mercury intrusion is 0.5 cm3 or more, and the average pore diameter of the molded body as measured by mercury intrusion is 100 nm to 1000 nm.

Description

Molded body, carbon dioxide sorption molded body including same, carbon dioxide sorption element, carbon dioxide separation and recovery device, method for manufacturing molded body, method for manufacturing carbon dioxide sorption molded body, and method for manufacturing carbon dioxide sorption element

[0001] The present invention relates to a molded article, a carbon dioxide sorption molded article including the molded article, a carbon dioxide sorption element, a carbon dioxide separation and capture device, a method for manufacturing a molded article, a method for manufacturing a carbon dioxide sorption molded article, and a method for manufacturing a carbon dioxide sorption element.

[0002] In recent years, direct air capture (DAC) technology, which directly separates and captures carbon dioxide from the atmosphere, has attracted attention as a negative emission technology. As an example of DAC, a method of adsorbing and separating carbon dioxide using a solid adsorbent (adsorption method) has been developed.

[0003] International Publication No. 2020 / 095934 (Patent Document 1) discloses a solid adsorbent having a specific pore structure in which an amine compound is filled. ２ "Capture from Air using Poly(ethyleneimine)-Loaded Polymer / Silica Fiber Sorbents," ACS Sustainable Chemical & Engineering, 2019, 7, 5264-5273 (Non-Patent Document 1) discloses a solid adsorbent in which polyethyleneimine is supported on a fibrous structure obtained by semi-wet spinning a mixture of cellulose acetate and mesoporous silica. These solid adsorbents are problematic because of concerns about the immobilization of amines, which may result in the release of amines into the environment.

[0004] On the other hand, in order to solve the above problems, the immobilization of amine compounds by chemical bonding to a substrate has been studied. International Publication No. 2010 / 091831 (Patent Document 2) discloses a method in which functional groups are imparted to the fiber surface by air oxidation of carbon fibers, and an amine compound is chemically bonded to the fiber surface via an epoxy resin. International Publication No. 2023 / 065050 (Patent Document 3) discloses a porous sheet containing a polymer in which an amine compound is chemically fixed with epoxy. Japanese Patent No. 7177980 (Patent Document 4) discloses a gas filter for removing acidic gases such as nitrogen oxides and hydrogen chloride, using an amine compound containing a nitrogen-containing six-membered ring.

[0005] International Publication No. 2020 / 095934 International Publication No. 2010 / 091831 International Publication No. 2023 / 065050 Patent No. 7177980

[0006] A. R. Sujan et al. , Direct CO2 Capture From Air using Poly(ethylenemine)-Loaded Polymer / Silica Fiber Sorbents, ACS Sustainable Chemical & Engineering, 2019, 7, 5264-5273

[0007] The fibers obtained by the method of Patent Document 2 and the porous sheet of Patent Document 3 do not have a high efficiency of absorbing carbon dioxide from the atmosphere. This is presumably because the reaction product between epoxy and amine is generally a gel or cured product, which impairs the mobility of molecules in the system and reduces the diffusion coefficient of carbon dioxide. The reaction product in a gel or cured product is difficult to handle and post-process. In addition, the reaction between epoxy and amine is very fast and generates a lot of heat, raising concerns about safe handling.

[0008] In view of the above-mentioned circumstances, an object of the present invention is to provide a molded body that can be handled safely and that can efficiently sorb carbon dioxide directly from the atmosphere, a carbon dioxide sorption molded body containing the same, a carbon dioxide sorption element, a carbon dioxide separation and capture apparatus, a method for manufacturing a molded body, a method for manufacturing a carbon dioxide sorption molded body, and a method for manufacturing a carbon dioxide sorption element.

[0009] The present inventors conducted extensive research to provide a molded article that can solve the above-mentioned problems. The inventors discovered that a porous body formed from a basic functional group-containing resin having a specific pore structure, a predetermined amount or more of total basic functional groups, and a predetermined capacity or more of neutral salt decomposition ability can efficiently sorb carbon dioxide directly from the atmosphere. Furthermore, the inventors discovered that by selecting a resin containing nitrile groups as the raw material resin in the production of the basic functional group-containing resin, it is possible to chemically fix amino groups to the resin in an industrially easy and safe manner. The basic functional group-containing resin was also easy to post-process. Based on the above, the inventors arrived at the present invention.

[0010] The present invention provides the following molded body, a carbon dioxide sorption molded body including the same, a carbon dioxide sorption element, a carbon dioxide separation and capture apparatus, a method for manufacturing a molded body, a method for manufacturing a carbon dioxide sorption molded body, and a method for manufacturing a carbon dioxide sorption element.

[0011] [1] A molded body of a basic functional group-containing resin, wherein the total amount of basic functional groups per 1 g of the molded body is 2.5 mmol or more, the neutral salt decomposition capacity per 1 g of the molded body is 0.1 mmol or more, and the specific surface area per 1 g of the molded body measured by mercury intrusion porosimetry is 10 m ２ The pore volume per 1 g of the molded body measured by the mercury intrusion method is 0.5 cm or more. ３ [1] The average pore diameter of the molded body measured by the mercury intrusion method is 100 nm or more and 1000 nm or less. [2] The specific surface area per 1 g of the molded body measured by the Barrett-Joyner-Halenda method is 0.1 m or more. ２or more, and the pore volume per 1 g of the molded body measured by the Barrett-Joyner-Halenda method is 0.005 cm ３ The molded body according to [1], wherein the average pore diameter of the molded body measured by the Barrett-Joyner-Halenda method is 10 nm or more and 200 nm or less. [3] The molded body according to [1] or [2], wherein the saturated moisture absorption rate at 20°C and a relative humidity of 97% is 20 mass% or more. [4] The molded body according to any one of [1] to [3], wherein the molded body is in the form of particles or fibers. [5] The molded body according to [4], wherein the fibers include a plurality of fibrillated fibers. [6] The molded body according to any one of [1] to [5], wherein the amount of carbon dioxide sorption per 1 g of the molded body measured by contacting the molded body with a mixed gas of carbon dioxide, nitrogen, and water for 12 hours is 1.0 mmol or more, the mixed gas contains 400 ppm by volume of carbon dioxide, the temperature of the mixed gas is 20°C, and the relative humidity of the mixed gas is 97% RH. [7] The molded article according to any one of [1] to [6], which is for direct air capture. [8] A carbon dioxide sorption molded article comprising the molded article according to any one of [1] to [7]. [9] The carbon dioxide sorption molded article according to [8], which has a sheet shape or a monolith shape.

[10] A carbon dioxide sorption element comprising the carbon dioxide sorption molded article according to [8], wherein the carbon dioxide sorption element has a plain wave shape or a corrugated shape.

[11] A carbon dioxide separation and capture device comprising the carbon dioxide sorption element according to

[10] .

[12] A method for producing the molded article according to any one of [1] to [7], comprising the steps of: preparing a raw material resin containing a nitrile group; treating the raw material resin to obtain a molded intermediate; and chemically reacting the intermediate with an amino group-containing organic compound to obtain a molded article of the basic functional group-containing resin.

[13] The amino group-containing organic compound is NH ２ - (CH ２ ) ３ -NX-(CH ２ )３ -NH ２ wherein X is a compound represented by the formula (I) and X is hydrogen or a methyl group.

[14] The method for producing a molded body according to

[12] or

[13] , wherein the step of obtaining a molded body of the basic functional group-containing resin is a step of immersing the intermediate in a solution containing the amino group-containing organic compound, and the concentration of the amino group-containing organic compound in the solution is 50 mass% or more.

[15] A method for producing a carbon dioxide sorption molded body, comprising a step of preparing a carbon dioxide sorption molded body obtained by the method for producing a molded body according to any one of

[12] to

[14] , as a carbon dioxide sorption molded body.

[16] A method for producing a carbon dioxide sorption element, comprising a step of preparing a carbon dioxide sorption molded body obtained by the method for producing a carbon dioxide sorption molded body according to

[15] , as a carbon dioxide sorption element.

[0012] According to the present invention, there are provided a molded body that can be handled safely and that can efficiently sorb carbon dioxide directly from the atmosphere, a carbon dioxide sorption molded body containing the same, a carbon dioxide sorption element, a carbon dioxide separation and capture device, a method for manufacturing a molded body, a method for manufacturing a carbon dioxide sorption molded body, and a method for manufacturing a carbon dioxide sorption element.

[0013] Fig. 1 is an explanatory diagram illustrating a chemical reaction for obtaining a molded body of a basic functional group-containing resin according to this embodiment. Fig. 2 is a flowchart illustrating an example of a method for producing a carbon dioxide sorption molded body and a carbon dioxide sorption element, including a method for producing a molded body according to this embodiment.

[0014] Hereinafter, a molded article according to an embodiment of the present invention (hereinafter also referred to as "the present embodiment"), a carbon dioxide sorption molded article including the same, a carbon dioxide sorption element, a carbon dioxide separation and capture apparatus, a method for manufacturing a molded article, a method for manufacturing a carbon dioxide sorption molded article, and a method for manufacturing a carbon dioxide sorption element will be described in detail. Herein, in this specification, an expression in the form of "A to B" means the upper and lower limits of a range (i.e., A or more and B or less), and when no unit is specified for A and only a unit is specified for B, the unit of A and the unit of B are the same.

[0015] In this specification, "adsorption" means adsorption, and is the process of adsorbing CO into pores present on the surface of a porous material such as zeolite, which is an adsorbent. ２ The term "adsorption" as used herein refers to the phenomenon in which an absorbent such as CO is absorbed into an absorbent (e.g., an absorbing solution) having an amino group such as an amine. ２ The term "absorption" as used herein refers to the phenomenon in which CO2 and other absorbents are mutually dissolved. The term "absorption" as used herein primarily refers to chemical absorption. The term "sorption" as used herein refers to the absorption of CO2 onto the surface of a solid or the like. ２ The term "sorption" as used herein refers to a phenomenon in which a sorbate such as a sorbent is adsorbed and simultaneously diffuses into and is absorbed within the solid. Alternatively, the term "sorption" as used herein refers to a phenomenon in which the above-mentioned "adsorption" and "absorption" occur together.

[0016] [Molded Product] The molded product according to this embodiment is a molded product of a basic functional group-containing resin. In the molded product, the total amount of basic functional groups per 1 g of the molded product is 2.5 mmol or more, and the neutral salt decomposition capacity per 1 g of the molded product is 0.1 mmol or more. In the molded product, the specific surface area per 1 g of the molded product measured by mercury intrusion porosimetry is 10 m ２ The pore volume per 1 g of the molded body measured by the mercury intrusion method is 0.5 cm ３ The average pore size of the molded body measured by the mercury intrusion method is 100 nm or more and 1000 nm or less. A molded body having such characteristics can directly absorb carbon dioxide (hereinafter, "CO ２ " can be efficiently adsorbed.

[0017] The form of the molded article is not particularly limited. Examples of the form of the molded article include particles as the form when a molded article of a basic functional group-containing resin is obtained by the manufacturing method described below, fibers or nanofibers obtained by spinning a stock solution prepared from the particles, yarns spun from the fibers or nanofibers, tows obtained by bundling the yarns, knitted fabrics or nonwoven fabrics made from the yarns, etc. In particular, the molded article is preferably in the form of particles or fibers.

[0018] The fibers preferably contain a plurality of fibrillated fibers. The fibrillated fibers can be produced by beating or otherwise processing fibers obtained by spinning a stock solution prepared from the particles. In this specification, "fibrillation" means that the approximately circular cross-section of the fibers is destroyed, the fiber diameter becomes broad, and the fibers have a fluffy shape. When the fibers are beated or otherwise processed, the fiber diameter of the fibers contained in the molded body is preferably in a wide range, for example, 0.1 to 100 μm. The fiber diameter is more preferably 10 μm or more and 30 μm or less. The fiber length of the fibers contained in the molded body is not particularly limited, but is preferably 2 mm or more, and more preferably 5 mm or more. Having a fiber length of 2 mm or more improves productivity when forming the molded body into a sheet.

[0019] <Basic Functional Group-Containing Resin> As described above, the molded article is a molded article of a basic functional group-containing resin. ２ It is preferable that the resin contains an amino group (other than a tetrahydropyrimidinyl group) and a tetrahydropyrimidinyl group as basic functional groups that function to sorb . The amino group is preferably a primary amino group. The tetrahydropyrimidinyl group is preferably a 2-tetrahydropyrimidinyl group. In the case of a basic functional group-containing resin in which the basic functional groups are amino groups and tetrahydropyrimidinyl groups, the amount of functional groups corresponding to the total amount of amino groups and tetrahydropyrimidinyl groups is measured by measuring the total amount of basic functional groups per 1 g of a molded product, as described below. Furthermore, in the case of a basic functional group-containing resin in which the basic functional groups are amino groups and tetrahydropyrimidinyl groups, the amount of functional groups corresponding to the amount of tetrahydropyrimidinyl groups is measured by measuring the neutral salt decomposition capacity per 1 g of a molded product, as described below.

[0020] The basic functional group-containing resin may be obtained by chemically reacting a raw material resin containing a nitrile group with an amino group-containing organic compound, as described below. The raw material resin is preferably at least one selected from the group consisting of a cellulose-based resin containing a nitrile group and an acrylic-based resin containing a nitrile group. The raw material resin may be a polyester, polyamide, polyimide, or vinyl-based polymer having a nitrile group, or an acrylonitrile-based polymer.

[0021] The amino group-containing organic compound preferably has a chemical structure in which the total number of amino groups in one molecule is 3 or more, the number of primary amino groups is 2 or more, and adjacent amino groups are bonded by an alkylene group having 3 carbon atoms. For example, a preferred amino group-containing organic compound is ２ - (CH ２ ) ３ -NX-(CH ２ ) ３ -NH ２ In this case, X is hydrogen or a methyl group.

[0022] FIG. 1 is an explanatory diagram illustrating the chemical reaction for obtaining a molded article of the basic functional group-containing resin according to this embodiment. As shown in FIG. 1, the basic functional group-containing resin containing the amino group and the tetrahydropyrimidinyl group can be produced, for example, by the following chemical reaction. First, resin I is obtained by a chemical reaction between the nitrile group of the raw resin and the primary amino group in the amino group-containing organic compound. Further, resin I undergoes intramolecular cyclization accompanied by deamination to obtain basic functional group-containing resin II containing amino groups and tetrahydropyrimidinyl groups. In the presence of water, resin II is considered to be in equilibrium with resin III. Both resin II and resin III are CO ２It has sorption ability. Resin II obtained by the reaction shown in FIG. 1 has 2-tetrahydropyrimidinyl groups. Furthermore, the basic functional group-containing resin may contain a structure in which the main chain of the raw resin is crosslinked at the amino group-containing organic compound moiety (hereinafter also simply referred to as a "crosslinked structure") as a result of the free amino groups in Resins II and III obtained by the reaction shown in FIG. 1 reacting with the nitrile groups of the raw resin. Note that the chemical structure of the raw resin shown in FIG. 1 is one example and is not intended to be limiting. Properties such as the amount of amino groups, specific surface area, and pore volume possessed by the molded article of the basic functional group-containing resin of this embodiment will be described in detail below.

[0023] <Total Amount of Basic Functional Groups per 1 g of Molded Product> In the above molded product, the total amount of basic functional groups per 1 g of the molded product is 2.5 mmol or more. The total amount of basic functional groups per 1 g of the molded product is preferably 3.0 mmol or more, more preferably 3.5 mmol or more. When the total amount of basic functional groups per 1 g of the molded product is less than 2.5 mmol, the amount of CO required by this embodiment is insufficient. ２ There is a risk that the sorption ability of CO 2 may not be obtained. The upper limit of the total amount of basic functional groups per 1 g of the molded product is not particularly limited, but can be set to, for example, 12.0 mmol. If the total amount of basic functional groups per 1 g of the molded product exceeds 12.0 mmol, swelling may become severe upon water or moisture absorption, and the dimensional stability of the molded product may become insufficient. If the total amount of basic functional groups per 1 g of the molded product exceeds 12.0 mmol, ２ Although the sorption capacity of the amine-modified cellulose acetate is saturated, the reaction time required for amine modification during production may be prolonged, resulting in a significant decrease in productivity. The total amount of basic functional groups per gram of the molded product is preferably 12.0 mmol or less, more preferably 10.0 mmol or less, and even more preferably 9.0 mmol or less.

[0024] The total amount of basic functional groups in the molded body is measured as follows. First, an aqueous solution is prepared by dissolving 3.0 g of sodium chloride in 50 mL of ion-exchanged water. Meanwhile, the thoroughly dried molded body is finely cut to obtain crushed bodies, and approximately 0.2 g of the crushed bodies is precisely weighed (X [g]) to obtain a measurement sample. Next, the measurement sample is dispersed in the aqueous solution to obtain a dispersion. A 0.1 mol / L standard aqueous solution of hydrochloric acid is added dropwise to this dispersion, and a titration curve is created. Furthermore, the amount of the 0.1 mol / L standard aqueous solution of hydrochloric acid added, determined from the titration curve, is taken as Y [mL], and the factor is f [HCl], and the total amount of basic functional groups is calculated according to the following formula (I): Total amount of basic functional groups [mmol / g] = (0.1 × Y × f [HCl]) / X (I)

[0025] <Neutral salt decomposition capacity per 1 g of molded body> The neutral salt decomposition capacity per 1 g of the molded body is 0.1 mmol or more. The neutral salt decomposition capacity per 1 g of the molded body is preferably 0.5 mmol or more, more preferably 0.6 mmol or more. When the total amount of basic functional groups per 1 g of the molded body is less than 0.1 mmol, the amount of CO required by this embodiment is not sufficient. ２ There is a risk that the sorption capacity of CO 2 may not be obtained. The upper limit of the neutral salt decomposition capacity per 1 g of the molded body is not particularly limited, but may be, for example, 8.0 mmol. If the neutral salt decomposition capacity per 1 g of the molded body exceeds 8.0 mmol, swelling may become severe upon water or moisture absorption, and the dimensional stability of the molded body may become insufficient. If the neutral salt decomposition capacity per 1 g of the molded body exceeds 8.0 mmol, ２ Although the sorption capacity of the amine-modified cellulose acetate is saturated, the reaction time required for amine modification during production may be prolonged, resulting in a significant decrease in productivity. The neutral salt decomposition capacity per gram of the shaped body is preferably 5.0 mmol or less, more preferably 4.0 mmol or less, and even more preferably 3.0 mmol or less.

[0026] The method for measuring the neutral salt decomposition capacity of the molded body is as follows: First, the molded body is thoroughly dried and cut into pieces to obtain crushed pieces, and about 0.2 g of the crushed pieces are precisely weighed (X２ A measurement sample is obtained by dispersing the measurement sample in 50 mL of a 1.0 mol / L aqueous sodium hydroxide solution. The dispersion is then stirred for 30 minutes with a magnetic stirrer (100 rpm). The dispersion is then filtered to obtain a filtrate, which is then repeatedly washed with water until the filtrate becomes neutral (pH = 7 ± 1.0), to prepare a filtered product. A 0.1 mol / L aqueous hydrochloric acid standard solution is added dropwise to the filtered product, and a titration curve is created. The amount of 0.1 mol / L aqueous hydrochloric acid standard solution added determined from the titration curve is then calculated as Y ２ [mL], factor f [HCl], and the neutral salt decomposition capacity is calculated by the following formula (II): Neutral salt decomposition capacity [mmol / g] = (0.1 × Y ２ ×f[HCl]) / X ２ (II)

[0027] <Specific surface area and pore volume per 1 g of molded body measured by mercury intrusion porosimetry, and average pore diameter of molded body measured by mercury intrusion porosimetry> The specific surface area per 1 g of the molded body measured by mercury intrusion porosimetry was 10 m ２ More than 50m ２ In the molded body, the pore volume per 1 g of the molded body measured by the mercury intrusion method is 0.5 cm or less. ３ 5.0cm or more ３ The average pore diameter of the molded body measured by the mercury intrusion method is 100 nm or more and 1000 nm or less. ２ In this specification, the term "mercury intrusion porosimetry" refers to a "method for evaluating the pore size distribution and specific surface area of ​​pores of a solid by mercury porosimetry" defined in ISO 15901-1:2016.

[0028] The specific surface area per gram of the molded body measured by the mercury intrusion method was 13 m ２ It is preferable that the length is 14 m or more. ２ More preferably, it is 25 m or more. ２It is even more preferable that the specific surface area per 1 g of the molded body measured by the mercury intrusion method is 45 m or more. ２ Preferably, it is 40 m or less. ２ More preferably, it is 35 m or less. ２ It is even more preferable that the pore volume per 1 g of the molded body measured by the mercury intrusion method is 0.8 cm or less. ３ It is preferable that the length is 1.5 cm or more. ３ More preferably, it is 1.8 cm or more. ３ It is even more preferable that the pore volume per 1 g of the molded body measured by the mercury intrusion method is 4.0 cm or more. ３ Preferably, it is 3.5 cm or less. ３ More preferably, it is 3.0 cm or less. ３ The average pore diameter of the molded body measured by mercury intrusion porosimetry is preferably 200 nm or more and 500 nm or less, more preferably 225 nm or more and 450 nm or less, and even more preferably 275 nm or more and 350 nm or less.

[0029] The specific surface area, pore volume, and average pore diameter per gram of the molded body measured by mercury intrusion porosimetry are determined as follows: First, the molded body is finely crushed to a size convenient for measurement and heat-treated at 70°C for 1 hour to prepare a measurement sample of about 30 mg. Next, the measurement sample is subjected to a pore distribution measurement using a pore size distribution analyzer (trade name: "MICROMERITICS Auto Pore IV", manufactured by Shimadzu Corporation) to obtain a pore size distribution of 2.96 x 10 －３ ~4.14 x 10 ２ A mercury pressure in the range of MPa is introduced, and the pore distribution of the measurement sample is determined from the pressure at the time of introduction and the amount of intrusion. Then, based on the pore distribution of the measurement sample, the specific surface area and pore volume per 1 g of the molded body measured by the mercury intrusion method, and the average pore diameter of the molded body measured by the mercury intrusion method are determined.

[0030] <Saturated Moisture Absorption Rate> The above molded article preferably has a saturated moisture absorption rate of 20% by mass or more at 20°C and a relative humidity of 97% (hereinafter also referred to as "97% RH"). ２ In the above-mentioned molded article, the saturated moisture absorption rate at 20°C and 97% RH is more preferably 23% by mass or more, and even more preferably 25% by mass or more. There is no particular upper limit to the saturated moisture absorption rate at 20°C and 97% RH, but it is preferably, for example, 55% by mass or less, and more preferably 51% by mass or less.

[0031] The saturated moisture absorption rate of the molded body at 20°C and 97% RH is determined by the following method. First, about 0.2 g of a measurement sample is precisely weighed out from the sufficiently dried molded body (W ｄｌ Next, the measurement sample is left to stand for 24 hours in an atmosphere of 20°C and 97% RH. The mass of the measurement sample, which has reached moisture absorption saturation in this way, is measured (W ｗｌ From the above measurement results, the saturated moisture absorption rate of the measurement sample at 20°C and 97% RH is calculated based on the following formula (III): Saturated moisture absorption rate at 20°C and 97% RH [mass %] = (W ｗｌ -W ｄｌ ) / W ｄｌ × 100 (III)

[0032] <Specific surface area and pore volume per 1 g of molded body measured by the Barrett-Joyner-Halenda method, and average pore diameter of molded body measured by the Barrett-Joyner-Halenda method> ２ From the viewpoint of efficiently sorbing, the molded body preferably has the following form: That is, in the molded body, the specific surface area per 1 g of the molded body measured by the Barrett-Joyner-Halenda method (hereinafter also referred to as the "BJH method") is 0.1 m ２ In the molded body, the pore volume per 1 g of the molded body measured by the BJH method is preferably 0.005 cm or more. ３It is preferable that the average pore diameter of the molded body measured by the BJH method is 10 nm or more and 200 nm or less. The BJH method is widely used as a method for analyzing the pore distribution of mesopores (pore diameter 2 to 50 nm) based on the pore classification of the International Union of Pure and Applied Chemistry (hereinafter also referred to as "IUPAC"). Mesopores are formed by the direct absorption of CO ２ This is thought to contribute greatly to the efficient sorption of

[0033] The specific surface area per 1 g of the molded body measured by the BJH method was 0.2 m ２ More preferably, it is 1.0 m or more. ２ It is even more preferable that the pore volume per 1 g of the molded body measured by the BJH method is 0.006 cm or more. ３ More preferably, it is 0.01 cm or more. ３ The average pore diameter of the molded body measured by the BJH method is preferably 30 nm or more and 140 nm or less, more preferably 80 nm or more and 120 nm or less, and even more preferably 84 nm or more and 110 nm or less.

[0034] The specific surface area, pore volume, and average pore diameter per gram of the compact measured by the BJH method are determined as follows. First, the compact is finely cut into pieces, and approximately 0.2 g of crushed pieces are weighed. Next, the crushed pieces are vacuum-dried at 100°C for 3 hours and precisely weighed. Thereafter, the nitrogen gas adsorption amount of the crushed pieces at the boiling point of liquid nitrogen (-195.8°C) is measured using a gas adsorption amount measuring device (trade name: "BELSORP MINIX", manufactured by Microtrac-Bell) at a relative pressure of 2.0 x 10 －４ ~1.0 x 10 －４ Measurements are made at 40 or more points within the range of 1000 to 10000, and an adsorption isotherm is created. Finally, the analysis software (BEL Master 7) attached to the gas adsorption amount measuring device is used. ＴＭ) and pore structure analysis is performed by the BJH method based on the adsorption isotherm. From the above, the specific surface area and pore volume per gram of the molded body measured by the BJH method, and the average pore diameter of the molded body measured by the BJH method are determined.

[0035] <Equilibrium CO ２ Sorption amount > CO directly from the atmosphere ２ From the viewpoint of efficiently sorbing carbon dioxide, the molded body preferably has the following properties: The amount of carbon dioxide sorbed per 1 g of the molded body (hereinafter referred to as "equilibrium CO sorption") determined by contacting the molded body with a mixed gas of carbon dioxide, nitrogen, and water for 12 hours is ２ The amount of CO adsorption is preferably 1.0 mmol or more. ２ The temperature of the mixed gas may be 20° C., and the relative humidity of the mixed gas may be 97% RH. ２ As can be seen from the following measurement method, the sorption amount is the amount of CO that the molded body can directly sorb from the atmosphere. ２ It can be used as a typical indicator of quantity.

[0036] Equilibrium CO per 1 g of the molded body ２ The sorption amount is preferably 1.0 mmol or more, more preferably 1.3 mmol or more, and most preferably 1.5 mmol or more. ２ The upper limit of the sorption amount is not particularly limited, but can be set to, for example, 6.0 mmol. ２ If the sorption amount exceeds 6.0 mmol, swelling will occur significantly upon water or moisture absorption, and the dimensional stability of the molded article may become insufficient.

[0037] Equilibrium CO per 1 g of the molded body ２ The sorption amount is calculated as follows. First, a sealed container with an effective volume V [L] is prepared. The atmosphere in this sealed container is filled with CO ２The concentration is adjusted to 400 [volume ppm], the temperature is adjusted to 20°C, and the humidity is adjusted to 97% RH. Next, about 20 mg of the measurement sample of the molded body that has been thoroughly dried is precisely weighed (W ｄ２ The sample is then left to stand for 16 hours. ２ The amount of CO sorption is saturated. ２ A monitor (manufactured by MonotaRO Co., Ltd. (NDIR sensor type)) was used to measure the CO ２ The CO concentration of the molded body is monitored over time. ２ CO in a sealed container immediately after sorption begins ２ Concentration C ０ [ppm by volume], CO after standing for 16 hours ２ Concentration C １ [volume ppm] and the sorption temperature T [K], the equilibrium CO per 1 g of the molded body is calculated based on the following formula (IV): ２ The sorption amount is calculated. ２ Sorption amount [mmol / g] = (C ０ -C １ ) / 1,000,000 x (V / 22.4) x (T / 273.15) x 1,000 / W ｄ２ (IV)

[0038] <Application Invention> The molded article is preferably for direct air capture. That is, the molded article is formed from a basic functional group-containing resin having a predetermined amount or more of basic functional groups and a predetermined capacity or more of neutral salt decomposition ability, and has a specific pore structure, which is an unknown attribute of the porous body, and is capable of capturing CO directly from the atmosphere. ２ It has the function of direct air capture that can sorb

[0039] [Carbon dioxide sorption molded article] The carbon dioxide sorption molded article according to this embodiment includes the above molded article. ２The carbon dioxide sorption molded body can efficiently sorb and remove carbon dioxide. Examples of the external shape of the carbon dioxide sorption molded body include fine particles, powder, threads, yarns, filaments, woven fabrics, knitted fabrics, nonwoven fabrics, paper, sheets, monoliths, laminates, cotton-like bodies, plain waves, and corrugated shapes. In particular, the carbon dioxide sorption molded body preferably has a sheet shape or a monolith shape. In this specification, the term "monolith shape" refers to a shape like a three-dimensional bulk structure with high porosity, such as a sponge or aerogel.

[0040] [Carbon Dioxide Sorption Element] The carbon dioxide sorption element according to this embodiment includes the carbon dioxide sorption molded article. The carbon dioxide sorption element preferably has a plain wave shape or a corrugated shape. In this specification, the term "plain wave shape" refers to a shape in which a two-dimensional structure such as a sheet is processed into a sinusoidal wave-like corrugated shape. In this specification, the term "corrugated shape" refers to a shape similar to cardboard. The carbon dioxide sorption element may be provided with an outer covering in the above-described shape. The carbon dioxide sorption element may be composed of the molded article alone, or may be composed in combination with other functional resins, activated carbon resins or fibers, general natural fibers, synthetic fibers, etc.

[0041] [Carbon dioxide separation and capture device] The carbon dioxide separation and capture device according to this embodiment includes the carbon dioxide sorption element. ２ The carbon dioxide separation and capture device can efficiently sorb and remove CO by applying the carbon dioxide sorption element to a functional section within the housing. ２ The carbon dioxide separation and capture device includes an inlet for introducing air into the functional part, and a CO ２ is sorbed, ２ Preferably, each functional unit includes an exhaust unit having an exhaust port for exhausting the atmosphere from which CO has been removed to the outside of the housing. ２an inlet for introducing a regeneration gas or steam for regenerating the carbon dioxide sorption element that has sorbed carbon dioxide; ２ is desorbed, and CO ２ The carbon dioxide separation and capture device can be preferably applied as a gas treatment device having the carbon dioxide sorption element, a heat cycle device having the carbon dioxide sorption element as a sorption core, a honeycomb rotor type adsorption device in which the carbon dioxide sorption element is formed into a honeycomb rotor, a cylinder type adsorption device in which the carbon dioxide sorption element is formed into a honeycomb laminate and the honeycomb laminate is arranged in a cylindrical shape and rotated about a cylindrical axis, a batch type adsorption device in which the carbon dioxide sorption element is filled into two or more tanks, etc.

[0042] [Method of manufacturing a molded body] Figure 2 is a flowchart illustrating an example of a method of manufacturing a carbon dioxide sorption molded body and a carbon dioxide sorption element, including a method of manufacturing a molded body according to this embodiment. The molded body can be obtained by any appropriate method, but can be obtained with a good yield by, for example, the method described below and shown in Figure 2. That is, this embodiment is a method of manufacturing a molded body for manufacturing the molded body. The manufacturing method includes the following steps.

[0043] That is, the above-mentioned production method includes a step S10 of preparing a raw resin containing a nitrile group (hereinafter also referred to as "step S10 of preparing a raw resin"), a step S20 of obtaining a molded intermediate by processing the raw resin (hereinafter also referred to as "step S20 of obtaining an intermediate"), and a step S30 of obtaining a molded article of the basic functional group-containing resin by chemically reacting the intermediate with an amino group-containing organic compound (hereinafter also referred to as "step S30 of obtaining a molded article of the basic functional group-containing resin"). By this method of producing a molded article having such characteristics, CO can be directly extracted from the atmosphere. ２ The molded article can be obtained by efficiently sorbing the above-mentioned compound. Each step included in the method for producing the molded article will be described in detail below.

[0044] <Step S10 of Preparing Raw Material Resin> The method for producing the molded body includes step S10 of preparing a raw material resin containing a nitrile group. The purpose of step S10 of preparing the raw material resin is to directly extract CO ２ The raw material resin is not particularly limited as long as it is a resin that can form the above-mentioned molded article. However, the raw material resin is not limited to the resin that can sorb CO directly from the atmosphere. ２ From the viewpoint of efficient sorption of the cellulose-based resin containing a nitrile group, the cellulose-based resin is preferably at least one selected from the group consisting of a cellulose-based resin containing a nitrile group and an acrylic resin containing a nitrile group.

[0045] The raw material resin can be any resin containing a nitrile group, without any particular limitations. Examples include polyesters, polyamides, polyimides, or vinyl polymers containing nitrile groups. It is particularly preferable for the raw material resin to be an acrylonitrile polymer (hereinafter referred to as "AN polymer"), since this allows for efficient incorporation of nitrile groups and facilitates adjustment of the amount of nitrile groups. The AN polymer may be either a homopolymer of acrylonitrile or a copolymer of acrylonitrile and another monomer. When the AN polymer is a copolymer of acrylonitrile and another monomer, the AN copolymerization rate can be set to preferably 50% by mass or more, more preferably 75% by mass or more, and even more preferably 85% by mass or more, in order to increase the amount of amino groups in the resin.

[0046] When the AN polymer is a copolymer of acrylonitrile and another monomer, a vinyl compound is preferably used as a monomer copolymerizable with acrylonitrile. When the AN polymer is a copolymer of acrylonitrile and another monomer, one of the above vinyl compounds may be copolymerized with acrylonitrile, or two or more of the above vinyl compounds may be copolymerized with acrylonitrile. Representative examples of the other monomer include carboxylic acid-containing monomers such as (meth)acrylic acid and itaconic acid, and salts thereof, (meth)acrylic acid esters, (meth)acrylamide, or N-alkyl-substituted monomers thereof, vinyl esters such as vinyl acetate and vinyl propionate, vinyl halides or vinylidenes such as vinyl chloride, vinyl bromide, and vinylidene chloride, unsaturated sulfonic acids such as vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, and p-styrene sulfonic acid, or salts thereof, and aromatic vinyl monomers such as styrene and divinylbenzene.

[0047] When the raw material resin is a cellulose-based resin, nitrile group-containing cellulose, glucosamine, etc. Specific examples of the cellulose-based resin include cellulose derivatives such as cellulose acetate, chitin, and chitosan.

[0048] <Obtaining an Intermediate S20> The method for producing the molded body includes a step S20 of obtaining a molded intermediate by treating the raw material resin. The purpose of the step S20 of obtaining an intermediate is to obtain an intermediate molded from the raw material resin in the form of fibers, particles, or the like, for use in the next step S30 of obtaining a molded body of a basic functional group-containing resin. Specifically, the following operations are carried out in the step S20 of obtaining an intermediate.

[0049] That is, in the step S20 for obtaining an intermediate, for example, when an intermediate formed into a fiber is to be obtained, the intermediate is obtained as a non-dried fiber by wet or dry-wet (hereinafter referred to as air gap) spinning from the spinning dope of the AN polymer. In the step S20 for obtaining an intermediate, for example, when an intermediate formed into a particle shape is to be obtained, the AN polymer dispersion is centrifuged and then dried by heating to obtain a particle-shaped intermediate. The method for mixing the raw material resin with a solvent (water, etc.) to obtain the spinning dope or the dispersion can be a conventionally known method.

[0050] <Step S30 of Obtaining Molded Article of Basic Functional Group-Containing Resin> The method for producing the molded article includes a step S30 of obtaining a molded article of the basic functional group-containing resin by chemically reacting the intermediate with an amino group-containing organic compound. The purpose of the step S30 of obtaining a molded article of the basic functional group-containing resin is to convert CO directly from the atmosphere into CO from the intermediate. ２ The present invention aims to prepare a molded article of a resin containing basic functional groups, which is endowed with the ability to sorb .

[0051] The intermediate obtained in step S20 for obtaining an intermediate may be in the form of fibers or particles. In this step, the intermediate in the form of fibers or particles is subjected to the chemical reaction described above with reference to FIG. 1, for example, to obtain a molded article of a basic functional group-containing resin. Specific aspects of the chemical reaction are as described above, so redundant explanations will not be repeated. In this step, the basic functional group-containing resin may be obtained by simultaneously introducing a crosslinked structure and an amino group. Furthermore, the molded article of the basic functional group-containing resin is provided with porosity defined by the predetermined specific surface area, pore volume, and average pore diameter measured by mercury intrusion porosimetry or the like, as described above, through the above treatment.

[0052] When the intermediate is in the form of a fiber (undried fiber), its moisture content is preferably 50 to 130% by mass, more preferably 60 to 120% by mass. In this process, the intermediate is adjusted to the moisture content and subjected to a wet heat treatment, preferably at 105 to 130°C, more preferably 110 to 125°C. The undried fiber is then dried at a temperature lower than that of the wet heat treatment, thereby imparting the above-mentioned porosity. The porous intermediate is then immersed in an aqueous solution containing an amino group-containing organic compound, and the chemical reaction proceeds (see Figure 1). For example, the intermediate is reacted with the amino group-containing organic compound under conditions of 100 to 150°C, more preferably 110 to 140°C, for 1 to 100 hours, preferably 3 to 50 hours. From the above, a molded product of the amino group-containing resin is obtained. In this case, the tetrahydropyrimidinyl group and the amino group in the molded product of the amino group-containing resin are converted to CO ２ The sorption capacity is expressed.

[0053] The step S30 of obtaining a molded article of the basic functional group-containing resin may be a step of immersing the intermediate in a solution containing the amino group-containing organic compound. In this case, the concentration of the amino group-containing organic compound in the solution is preferably 50% by mass or more. The concentration is more preferably 80% by mass or more. By having the concentration of the amino group-containing organic compound in the solution be 50% by mass or more, molded articles of the basic functional group-containing resin may be obtained in good yield.

[0054] As described above, the amino group-containing organic compound preferably has a chemical structure in which the total number of amino groups in one molecule is 3 or more, the number of primary amino groups is 2 or more, and adjacent amino groups are bonded by an alkylene group having 3 carbon atoms. For example, a preferred amino group-containing organic compound is NH ２ - (CH ２ ) ３ -NX-(CH ２ ) ３ -NH ２ In this case, X is hydrogen or a methyl group.

[0055] Specific examples of the amino group-containing organic compound include, in addition to the above-mentioned 3,3'-iminobis(propylamine) (IBPA), N,N'-bis(3-aminopropyl)ethylenediamine, N,N'-bis(3-aminopropyl)propanediamine, N,N'-bis(3-aminopropyl)-1,3-butylenediamine, N,N'-bis(3-aminopropyl)-1,4-butylenediamine, 1,4-bis(3-aminopropyl)piperazine, methyliminobispropylamine (MIBPA), etc. The amino group-containing organic compound may be used alone or in combination of two or more of the compounds listed above.

[0056] If the total number of amino groups in one molecule of the amino group-containing organic compound is less than 3, it may be difficult to introduce a crosslinked structure. In such a case, it may be difficult to obtain sufficient performance from a molded article of the basic functional group-containing resin. If the amino group-containing organic compound does not have a structure in which adjacent amino groups are bonded by an alkylene group having 3 carbon atoms, the tetrahydropyrimidinyl group may not be formed in the basic functional group-containing resin. In addition, if the amino group-containing organic compound does not have a structure in which adjacent amino groups are bonded by an alkylene group, electron donation to the amino group is low, resulting in insufficient basicity and insufficient anion exchange performance, and insufficient CO ２ Therefore, the sorption capacity of the sample may not be achieved.

[0057] The introduction of a crosslinked structure into the intermediate can also be carried out by methods other than those described above. For example, a post-crosslinking method can be used in which a crosslinked structure is introduced by physical energy after an AN polymer intermediate is obtained. The chemical post-crosslinking method for the intermediate can introduce strong crosslinks by covalent bonds, making the crosslinked structure less susceptible to physical and chemical modifications due to water absorption, moisture absorption, etc., and is therefore preferred.

[0058] As a method of post-crosslinking, for example, a method of reacting the nitrile group in an intermediate having a content of 50% by mass or more of a vinyl monomer having a nitrile group with a hydrazine compound or formaldehyde can be mentioned. In particular, the method of using a hydrazine compound is stable against acids and alkalis, and the crosslinked structure formed is itself hydrophilic, so that it has excellent moisture absorption properties and CO ２ This is preferable because it can contribute to improving various performances such as sorption capacity.

[0059] The post-crosslinking method using a hydrazine compound is not particularly limited as long as the desired crosslinked structure can be obtained, and is appropriately selected depending on various conditions such as the physical properties of the AN polymer, the concentration of the hydrazine compound, the solvent used, the reaction time, and the reaction temperature. The reaction temperature is preferably 50 to 150° C., for example, and more preferably 80 to 120° C. Examples of the hydrazine compound include hydrazine salts such as hydrazine hydrate, hydrazine sulfate, hydrazine hydrochloride, hydrazine nitrate, and hydrazine carbonate, and hydrazine derivatives such as ethylenediamine, guanidine sulfate, guanidine hydrochloride, guanidine nitrate, guanidine phosphate, and melamine.

[0060] The porosity of the molded body of the basic functional group-containing resin can also be imparted by using a plurality of spinning dope obtained from raw resins and conducting conjugate spinning in the form of sheath-core, side-by-side, sandwich, random conjugate, etc. to obtain the above-mentioned never-dried fiber, and then subjecting the never-dried fiber to the above-mentioned wet heat treatment. The porosity of the molded body of the basic functional group-containing resin can also be imparted by using a spinning dope obtained from an acrylic antistatic resin comprising an AN polymer and methoxypolyethylene glycol methacrylate as raw resins and conducting the above-mentioned wet or air-gap spinning to obtain the never-dried fiber, and then subjecting the never-dried fiber to the above-mentioned wet heat treatment.

[0061] The molded article of the basic functional group-containing resin is preferably in the form of fibers, and the fibers are preferably fibrillated. A conventionally known beating method can be used for the fibrillation. Furthermore, when an easily beaten AN polymer is used to produce the basic functional group-containing resin, the molded article of the basic functional group-containing resin is preferably such that the fibers are sufficiently finely divided up to the center of the fibrillated fibers, and the micropores (mesopores) formed between the fine fibers are sufficiently developed.

[0062] 2, the method for producing a carbon dioxide sorption molded body according to this embodiment includes step S40 of preparing a molded body obtained by the above-mentioned molded body production method as a carbon dioxide sorption molded body. As described above, the carbon dioxide sorption molded body can have an external shape such as particulate, powder, thread, yarn, filament, woven fabric, knitted fabric, nonwoven fabric, paper, sheet, monolith, laminate, or cotton-like shape. Therefore, in step S40, a carbon dioxide sorption molded body can be prepared by processing the shape of the molded body obtained by the above-mentioned molded body production method as is or by an appropriate method.

[0063] [Method for manufacturing a carbon dioxide sorption element] As shown in Figure 2, the method for manufacturing a carbon dioxide sorption element according to this embodiment includes a step S50 of preparing the carbon dioxide sorption molded body obtained by the method for manufacturing a carbon dioxide sorption molded body as a carbon dioxide sorption element. The carbon dioxide sorption element preferably has an external shape such as a plain wave shape or a corrugated shape. Therefore, in this step S50, the molded body obtained by the method for manufacturing a carbon dioxide sorption molded body can be processed directly or by an appropriate method to prepare a carbon dioxide sorption element. The carbon dioxide sorption element may be provided with an outer covering. Furthermore, the carbon dioxide sorption element may be constructed alone, or may be constructed in combination with other functional resins, activated carbon resins or fibers, general natural fibers, synthetic fibers, etc. by an appropriate method. By a method for manufacturing a carbon dioxide sorption element having these characteristics, it is possible to directly extract CO from the atmosphere and form a carbon dioxide sorption element. ２Therefore, a carbon dioxide sorption element capable of efficiently sorbing carbon dioxide can be obtained.

[0064] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The terms "parts" and "percentages" used to describe each sample in the examples refer to parts by mass and % by mass, respectively, unless otherwise specified. In the following description, Samples 11 to 16 are examples, and Samples 101 to 106 are comparative examples.

[0065] [Preparation of Samples] <Sample 11> First, a spinning solution (I) was prepared from an acrylonitrile copolymer containing acrylonitrile, methyl acrylate, and sodium methallylsulfonate, with an acrylonitrile content of 90% by mass. Furthermore, a dispersion was prepared by dispersing an acrylic hydrophilic resin containing acrylonitrile and methoxypolyethylene glycol (30 mol) methacrylate with an acrylonitrile content of 30% by mass in water. The dispersion and the spinning solution (I) were mixed using a high-shear mixer to prepare a spinning solution (II), which was then wet-spun. The content of the acrylic hydrophilic resin in the spinning solution (II) was adjusted to 2 parts per 98 parts of the acrylonitrile copolymer in the spinning solution (I). A 12% by mass aqueous sodium rhodanate solution at 5°C was used as the coagulation liquid. Subsequently, the fibrous material obtained by the above wet spinning was washed with water, subjected to hot drawing, and then, without drying, subjected to steam treatment at 115°C in a relaxed state, and then dried at 110°C for 10 minutes, thereby obtaining porous acrylic fibers.

[0066] Next, the porous acrylic fibers were cut to a fixed length of 20 mm and prepared into a 3% by mass aqueous slurry. The slurry was beaten by passing it through the functional section of a KRK high-concentration disc refiner (manufactured by Kumagaya Riki Kogyo Co., Ltd.) once (1 pass) using a D-shaped blade with a gap of 0.3 mm and four times (4 passes) using a D-shaped blade with a gap of 0.1 mm. This resulted in fibrillation of the porous acrylic fibers, yielding fibrillated porous acrylic fibers A. The fiber diameter of the porous acrylic fibers was 17 μm, and the fiber diameter of the fibrillated porous acrylic fibers A was in the range of 0.2 to 60 μm.

[0067] 200 parts of the fibrillated porous acrylic fiber A was placed in an autoclave together with a solution consisting of 1600 parts of iminobispropylamine (IBPA) and 400 parts of water, and the mixture was reacted at 130°C for 6 hours. The mixture was then suction filtered, washed with water, and dried to obtain a molded article of a basic functional group-containing resin (Sample 11). The molded article was in the form of fibrillated fibers. The fiber diameter of the molded article was in the range of 0.05 to 50 μm. Furthermore, a molded article for carbon dioxide sorption (Sample 11) was prepared from the molded article.

[0068] <Sample 12> A monomer mixture consisting of 40 parts acrylonitrile and 10 parts divinylbenzene, and an oxidizing agent solution consisting of 50 parts cyclohexane and 4 parts ammonium persulfate dissolved in 330 parts water were added to a polymerization vessel. The temperature was raised to 65°C and precipitation polymerization was carried out for 4 hours to obtain a polymer dispersion. The polymer dispersion was centrifuged and dried by heating to obtain porous acrylonitrile-based polymer particles. The average particle diameter of the polymer particles was 32 μm. Next, 200 parts of the polymer particles were charged into an autoclave along with a solution consisting of 1800 parts iminobispropylamine (IBPA) and 200 parts water, and the reaction was carried out at 140°C for 48 hours. The reaction mixture was then subjected to suction filtration, water washing, and drying to obtain a molded product of a basic functional group-containing resin (Sample 12). The molded product was in the form of particles (fine particles) and had an average particle diameter of 36 μm. Furthermore, a molded product for carbon dioxide sorption (Sample 12) was prepared from the molded product.

[0069] <Sample 13> The porous acrylic fiber obtained in the process for producing a molded article of the basic functional group-containing resin of Sample 11 was cut to a fixed length of 50 mm and prepared into a 3% by mass aqueous slurry. The slurry was then beaten by passing it through the functional section of a KRK high-concentration disc refiner (manufactured by Kumagai Riki Kogyo Co., Ltd.) three times (three passes) using an H-shaped blade and a 0.1 mm gap. This resulted in fibrillation of the porous acrylic fiber, yielding fibrillated porous acrylic fiber B. The fiber diameter of the porous acrylic fiber was 17 μm, and the fiber diameter of the fibrillated porous acrylic fiber B was in the range of 0.2 to 60 μm.

[0070] 200 parts of the fibrillated porous acrylic fiber B was placed in an autoclave together with a solution consisting of 1,000 parts of iminobispropylamine (IBPA) and 1,000 parts of water, and the mixture was reacted at 130°C for 6 hours. The mixture was then suction filtered, washed with water, and dried to obtain a molded article of a basic functional group-containing resin (Sample 13). The molded article was in the form of fibrillated fiber. The fiber diameter of the molded article was in the range of 0.05 to 50 μm. Furthermore, a molded article for carbon dioxide sorption (Sample 13) was prepared from the molded article.

[0071] <Sample 14> 200 parts of the porous acrylonitrile polymer particles obtained in the process for producing a molded body of basic functional group-containing resin of Sample 12 were charged into an autoclave together with a solution consisting of 1,600 parts of iminobispropylamine (IBPA) and 400 parts of water, and the mixture was reacted at 130°C for 6 hours. The mixture was then suction filtered, washed with water, and dried to obtain a molded body of basic functional group-containing resin of Sample 14. The molded body was in the form of particles (fine particles), and the average particle diameter of the molded body was 36 μm. Furthermore, a molded body for carbon dioxide sorption of Sample 14 was prepared from the above molded body.

[0072] <Sample 15> 200 parts of the porous acrylonitrile polymer particles obtained in the process for producing a molded body of basic functional group-containing resin of Sample 12 were charged into an autoclave together with a solution consisting of 1,800 parts of iminobispropylamine (IBPA) and 200 parts of water, and the mixture was reacted at 140°C for 3 hours. The mixture was then suction filtered, washed with water, and dried to obtain a molded body of basic functional group-containing resin of Sample 15. The molded body was in the form of particles (fine particles), and the average particle diameter of the molded body was 36 μm. Furthermore, a molded body for carbon dioxide sorption of Sample 15 was prepared from the above molded body.

[0073] <Sample 16> 200 parts of the fibrillated porous acrylic fiber A obtained in the process for producing a molded article of basic functional group-containing resin of Sample 11 were placed in an autoclave together with a solution consisting of 1,600 parts of methyliminobispropylamine (MIBPA) and 400 parts of water, and the mixture was reacted at 140°C for 6 hours. The mixture was then suction filtered, washed with water, and dried to obtain a molded article of basic functional group-containing resin of Sample 16. The fiber diameter of the molded article was in the range of 0.05 to 50 μm. Furthermore, a molded article for carbon dioxide sorption of Sample 16 was prepared from the above molded article.

[0074] <Sample 101> 200 parts of the fibrillated porous acrylic fiber A obtained in the process for producing a molded body of the basic functional group-containing resin of Sample 11 were placed in an autoclave together with a solution consisting of 1,200 parts of diethylenetriamine (DETA) and 800 parts of water, and the mixture was reacted at 130°C for 6 hours. The mixture was then suction filtered, washed with water, and dried to obtain a molded body of Sample 101. The molded body was in the form of fibrillated fibers. The fiber diameter of the molded body was in the range of 0.05 to 50 μm. Furthermore, a molded body for carbon dioxide sorption of Sample 101 was prepared from the above molded body.

[0075] <Sample 102> 200 parts of the porous acrylonitrile polymer particles obtained in the process for producing a molded body of the basic functional group-containing resin of Sample 12 were charged into an autoclave together with a solution consisting of 1,200 parts of diethylenetriamine (DETA) and 800 parts of water, and the mixture was reacted at 130°C for 16 hours. The mixture was then suction filtered, washed with water, and dried to obtain a molded body of Sample 102. The molded body was in the form of particles (fine particles), and the average particle diameter of the molded body was 36 μm. Furthermore, a molded body for carbon dioxide sorption of Sample 102 was prepared from the above molded body.

[0076] <Sample 103> 200 parts of the fibrillated porous acrylic fiber B obtained in the process for producing a molded article of the basic functional group-containing resin of Sample 13 were placed in an autoclave together with a solution consisting of 500 parts of iminobispropylamine (IBPA) and 1,500 parts of water, and the mixture was reacted at 130°C for 6 hours. The mixture was then subjected to suction filtration, water washing, and drying to obtain a molded article of Sample 103. The molded article was in the form of fibrillated fibers. The fiber diameter of the molded article was in the range of 0.05 to 50 μm. Furthermore, a molded article for carbon dioxide sorption of Sample 103 was prepared from the above molded article.

[0077] <Sample 104> A molded article of Sample 104 was obtained from amino group-containing fibers obtained by the method described in Japanese Patent No. 7177980. The molded article had a fibrous form. The fiber diameter of the molded article was 22 μm. Furthermore, a molded article for carbon dioxide sorption of Sample 104 was prepared from the above molded article.

[0078] <Sample 105> Potassium hydroxide (KOH, manufactured by Nacalai Tesque, Inc.) was procured and ground in a mortar to prepare a carbon dioxide sorption molded body of Sample 105.

[0079] <Sample 106> Potassium carbonate (K ２ CO ３ A carbon dioxide sorption molded body of Sample 106 was prepared by grinding the obtained powder using a mortar and pestle.

[0080] [Characteristic Evaluation of Each Sample] Using the measurement methods described above, the total amount of basic functional groups per gram of molded body, the neutral salt decomposition capacity per gram of molded body, the saturated moisture absorption rate at 20°C and 97% RH, the specific surface area per gram of molded body measured by mercury intrusion porosimetry, the pore volume, and the average pore diameter of the molded body measured by the BJH method were determined for each sample. Note that the above-mentioned various characteristic evaluations were not performed on Samples 105 and 106. The results are shown in Tables 1 and 2.

[0081] Using the measurement method described above, the equilibrium CO ２ The sorption amount was also determined, and the results are shown in Tables 1 and 2.

[0082] <Alkaline efficiency> The amount of basic functional groups Q1 [mmol / g] per 1 g of each sample compact (carbon dioxide sorption compact) and the above equilibrium CO ２ The alkaline efficiency was calculated from the sorption amount q1 [mmol / g] based on the following formula (VI). It is estimated that the higher the alkaline efficiency, the higher the performance of the carbon dioxide sorption molded article. The results are shown in Tables 1 and 2. Alkaline efficiency [%] = q １ / Q １ ...(VI)

[0083] <t １／２ > For each sample molded body (molded body for carbon dioxide sorption), ２ When measuring the sorption amount, the equilibrium CO ２ The time it takes for half the amount of adsorption to be sorbed is called t １／２ This was defined and calculated. １／２ The smaller the value of , the higher the performance of the carbon dioxide sorption molded article is. The results are shown in Tables 1 and 2.

[0084]

[0085]

[0086] <Discussion> Samples 11 to 16 have a total amount of basic functional groups of 2.5 mmol or more per 1 g of the molded body, and a neutral salt decomposition capacity of 0.1 mmol or more per 1 g of the molded body. Furthermore, Samples 11 to 16 have a specific surface area of ​​10 m per 1 g of the molded body measured by mercury intrusion porosimetry. ２ or more, and the pore volume per 1 g of the molded body measured by mercury intrusion porosimetry is 0.5 cm ３ The average pore diameter of the molded body measured by mercury intrusion porosimetry is 100 nm or more and 1000 nm or less. In this case, according to Tables 1 and 2, Samples 11 to 16 have a higher CO ２ Performance showing sorption capacity (equilibrium CO ２ Sorption, alkaline efficiency, and t １／２ ) are all at a high level, and it can be seen that the overall performance is excellent.

[0087] Although the embodiments and examples of the present invention have been described above, it is also intended from the beginning that the configurations of the above-described embodiments and examples may be appropriately combined.

[0088] The embodiments and examples disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0089] I, II, III: Resin; S10: Step of preparing raw resin; S20: Step of obtaining intermediate; S30: Step of obtaining molded body of basic functional group-containing resin; S40: Step of preparing as carbon dioxide sorption molded body; S50: Step of preparing as carbon dioxide sorption element.

Claims

1. A molded body of a basic functional group-containing resin, wherein the total amount of basic functional groups per 1 g of the molded body is 2.5 mmol or more, the neutral salt decomposition capacity per 1 g of the molded body is 0.1 mmol or more, and the specific surface area per 1 g of the molded body measured by mercury intrusion porosimetry is 10 m ２ The pore volume per 1 g of the molded body measured by the mercury intrusion method is 0.5 cm or more. ３ The molded body has an average pore diameter of 100 nm or more and 1000 nm or less as measured by mercury intrusion porosimetry.

2. The specific surface area per 1 g of the molded body measured by the Barrett-Joyner-Halenda method is 0.1 m ２ or more, and the pore volume per 1 g of the molded body measured by the Barrett-Joyner-Halenda method is 0.005 cm ３ 2. The molded body according to claim 1, wherein the average pore diameter of the molded body measured by the Barrett-Joyner-Halenda method is 10 nm or more and 200 nm or less.

3. A molded body according to claim 1 or claim 2, having a saturated moisture absorption rate of 20% by mass or more at 20°C and a relative humidity of 97%.

4. The molded body according to any one of claims 1 to 3, wherein the molded body is a particle or a fiber.

5. The molded article of claim 4, wherein the fibers comprise a plurality of fibrillated fibers.

6. A molded body according to any one of claims 1 to 5, wherein the amount of carbon dioxide sorption per 1 g of the molded body determined by contacting the molded body with a mixed gas consisting of carbon dioxide, nitrogen, and water for 12 hours is 1.0 mmol or more, the mixed gas contains 400 ppm by volume of carbon dioxide, the temperature of the mixed gas is 20°C, and the relative humidity of the mixed gas is 97% RH.

7. A molded article according to any one of claims 1 to 6, which is for direct air capture.

8. A molded article for carbon dioxide sorption, comprising the molded article according to any one of claims 1 to 7.

9. The carbon dioxide sorption molded article according to claim 8, which has a sheet shape or a monolith shape.

10. A carbon dioxide sorption element comprising the carbon dioxide sorption molded article according to claim 8, wherein the carbon dioxide sorption element has a plain wave shape or a corrugated shape.

11. A carbon dioxide separation and recovery device comprising the carbon dioxide sorption element according to claim 10.

12. A method for producing a molded body according to any one of claims 1 to 7, comprising the steps of: preparing a raw resin containing a nitrile group; treating the raw resin to obtain a molded intermediate; and chemically reacting the intermediate with an amino group-containing organic compound to obtain a molded body of the basic functional group-containing resin.

13. The amino group-containing organic compound is NH ２ - (CH ２ ) ３ -NX-(CH ２ ) ３ -NH ２ The method for producing a molded article according to claim 12, wherein the compound is a compound represented by the formula: wherein X is hydrogen or a methyl group.

14. A method for producing a molded body according to claim 12 or claim 13, wherein the step of obtaining a molded body of the basic functional group-containing resin is a step of immersing the intermediate in a solution containing the amino group-containing organic compound, and the concentration of the amino group-containing organic compound in the solution is 50 mass% or more.

15. A method for producing a molded body for carbon dioxide sorption, comprising a step of preparing the molded body obtained by the method for producing a molded body described in any one of claims 12 to 14 as a molded body for carbon dioxide sorption.

16. A method for producing a carbon dioxide sorption element, comprising the step of preparing the carbon dioxide sorption molded body obtained by the method for producing a carbon dioxide sorption molded body described in claim 15 as a carbon dioxide sorption element.

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