Carbon dioxide adsorbent

Abstract

To provide a composition for a carbon dioxide adsorbent enabling suppression of reduction in carbon dioxide adsorption capacity.SOLUTION: A composition for a carbon dioxide adsorbent includes a compound (A) containing a polyalkyleneimine-based compound, and a compound (B) having at least one amino group and / or imino group, and at least one acidic group (salt) selected from the group consisting of a carboxyl group, a phosphonic acid group, a sulfonic acid group, and neutralized salts thereof.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a composition for a carbon dioxide adsorbent, which comprises a compound (A) containing a polyalkyleneimine-based compound, at least one amino group and / or imino group, and a compound (B) having at least one acidic group (salt) selected from the group consisting of a carboxyl group, a phosphonic acid group, a sulfonic acid group, and their neutralized salts.

Background Art

[0002] Conventionally, as one of the measures against global warming, in order to reduce the emission of carbon dioxide (CO2), which is a greenhouse gas, the development of a CO2 separation and recovery material for separating and recovering CO2 in the gas has been carried out. For example, Japanese Patent Application Laid-Open No. 2012-55886 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2019-507674 (Patent Document 2) describe silica particles treated with an amine as a solid carbon dioxide adsorbent for absorbing carbon dioxide from a mixed gas.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, although the adsorbent treated with an amine has a carbon dioxide adsorption ability, it has been found that there is a problem that the carbon dioxide adsorption ability decreases by repeating the carbon dioxide adsorption step and the desorption step. An object of the present invention is to provide a composition for a carbon dioxide adsorbent capable of suppressing a decrease in carbon dioxide adsorption ability.

Means for Solving the Problems

[0005] The inventors of the present invention have speculated that the decrease in carbon dioxide adsorption capacity is due to the oxidative degradation of amines caused by heating during the desorption process, and that the oxidative degradation of amines is induced by the metal components contained in the adsorbent. After various investigations, by using a composition for a carbon dioxide adsorbent containing a compound (A) containing a polyalkyleneimine-based compound, a compound (B) having at least one amino group and / or imino group, and at least one acidic group (salt) selected from the group consisting of a carboxyl group, a phosphonic acid group, a sulfonic acid group, and their neutralized salts, they have found that a carbon dioxide adsorbent capable of solving the above problems can be provided, and thus completed the present invention.

Advantages of the Invention

[0006] According to the present invention, there are provided a composition for a carbon dioxide adsorbent capable of suppressing a decrease in carbon dioxide adsorption capacity and a utilization technology thereof.

Embodiments for Carrying Out the Invention

[0007] One embodiment of the present invention will be described below, but the present invention is not limited thereto. Unless otherwise specified in this specification, "A to B" representing a numerical range means "A or more and B or less".

[0008] <Compound A> The composition for a carbon dioxide absorbent of the present disclosure contains a compound (A). The compound (A) of the present disclosure is a polyalkyleneimine-based compound. <Polyalkyleneimine> In this specification, the polyalkyleneimine-based compound refers to a compound (polymer) having a structural unit consisting of an alkylene group and an amino group in the main chain, that is, a structural unit represented by the following formula (A-1), (A-2) and / or (A-3).

[0009]

Chemical Formula

[0010] In the above formulas (A-1), (A-2) and (A-3), Q represents an alkylene group. Here, examples of the alkylene group represented by Q include an ethylene group, a propylene group, a butylene group, etc. In the structural units represented by the above formulas (A-1), (A-2) or (A-3) contained in plural in the polyalkyleneimine compound, Q may be the same or different from each other.

[0011] More specifically, examples of the polyalkyleneimine compound of the present disclosure include polyethyleneimine, polypropyleneimine, polybutyleneimine, etc. These polyalkyleneimine compounds may have a linear structure, or may have a branched structure or a cyclic structure. Among them, polyethyleneimine is preferable, and linear, branched, and dendritic polyethyleneimines are more preferable. In addition, in this specification, "branched polyethyleneimine" means that polyethyleneimine has a secondary polymer chain branched from the main chain, and "dendritic polyethyleneimine" means that polyethyleneimine typically has a dense plurality of branched structures composed of a core from which branches extend and a large number of terminal groups.

[0012] When the polyalkyleneimine compound of the present disclosure has a branched structure, the degree of branching of the polyalkyleneimine compound exceeds 0%, preferably 1% or more, more preferably 5% or more, still more preferably 10% or more, and particularly preferably 15% or more. Further, the upper limit of the degree of branching of polyethyleneimine is preferably 50% or less, more preferably 40% or less, and still more preferably 35% or less. The degree of branching of the polyalkyleneimine compound can be calculated from the following formula based on the intensity ratio between the carbon atom bonded to the tertiary amine and the carbon atom bonded to the secondary amine based on the chart obtained by measuring the 13C-NMR of the polyalkyleneimine compound, thereby calculating the number a of tertiary amines and the number b of secondary amines: Degree of branching (%) = [a / (a + b)] × 100. Since linear polyalkyleneimine does not have a tertiary amine, its branching degree is 0%. Also, a polyalkyleneimine in which all nitrogen atoms are tertiary amines, that is, a polyalkyleneimine-based compound with the maximum degree of branching, has a branching degree of 100%.

[0013] As the polyalkyleneimine-based compound of the present disclosure, a homopolymer or copolymer of one or more alkyleneimines having 2 to 6 carbon atoms such as ethyleneimine, propyleneimine, 1,2-butyleneimine, 2,3-butyleneimine, 1,1-dimethylethyleneimine, etc., obtained by polymerizing them by a conventional method, is suitable. These may be used alone or in combination of two or more. More preferably, it is a homopolymer of ethyleneimine (polyethyleneimine; PEI). Also, those obtained by polymerizing ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, etc. may be used.

[0014] Regarding the number average molecular weight (Mn) of the polyalkyleneimine-based compound of the present disclosure, from the viewpoints of efficient loading on the carrier and oxidation stability, 300 or more is preferable, 500 or more is more preferable, and 600 or more is even more preferable. Also, from the viewpoints of efficient loading on the carrier and the diffusion rate of the absorbed carbon dioxide, 100,000 or less is preferable, 70,000 or less is more preferable, 10,000 or less is even more preferable, 5,000 or less is particularly preferable, and 3,000 or less is most preferable. The number average molecular weight of the polyalkyleneimine compound can be measured by the boiling point elevation method using an ebulliometer or the like. In the boiling point elevation method, a certain amount of solvent is taken and its boiling point is measured. Then, a trace amount of solute is dissolved in the solvent, and after measuring the boiling point of the solution, it is calculated using the following formula. Thereby, the molar mass of the solute can be determined, and when the polyalkyleneimine compound is used as the solute, the molar mass can be used as the number average molecular weight. As the solvent, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, etc. can be used. ·Δtb = ΔKb×m (boiling point elevation: Δtb 〔K〕, molar boiling point elevation: ΔKb 〔K〕, molality of solute: m 〔mol / kg〕) ·m = w / M×1000 / W (molality of solute: m [mol / kg], mass of solute: w 〔g〕, molar mass of solute: M 〔g / mol〕, mass of solvent: W 〔g〕)

[0015] From the viewpoint of enhancing the carbon dioxide adsorption ability, the amine value per nonvolatile content of the polyalkyleneimine compound of the present disclosure is preferably 5 or more, more preferably 10 or more, and even more preferably 15 or more. Further, the above amine value is preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less. The nonvolatile content (resin content) of the polyalkyleneimine compound of the present disclosure can be measured by the Karl Fischer method or the drying weight method. Specific measurement methods are described below. ·Karl Fischer method Measuring instrument; Karl Fischer moisture meter Solvent; 20 - 30 ml of methanol Amine neutralizer; 7 ml of acetic acid Calculation formula: Resin content (wt%) = 100 - V×F / S×100 V = KF titration volume (ml) F = Titre of KF (mg / ml) S = Sample collection amount (mg) · Drying weight method: Collect about 1 g of the sample in an aluminum dish, dry it in a hot air circulation dryer at 150 ± 5 °C for 1 hour, and then allow it to cool in a desiccator for 10 minutes. Calculation formula: Resin content (wt%) = W / S × 100 W: Residual mass after drying (g) S: Sample mass before drying (g)

[0016] The amine value per non-volatile content of the above polyalkyleneimine-based compound of the present disclosure is the number of moles (mmol) of amino groups contained in 1 g of the non-volatile content of polyalkyleneimine. The amine value of polyethyleneimine can be calculated by potentiometric titration using a 0.5 mol / L p-toluenesulfonic acid standard solution in a methanol solution.

[0017] The degree of cationization of the polyalkyleneimine-based compound of the present disclosure is preferably 5 meq / g or more, more preferably 10 meq / g or more, and still more preferably 15 meq / g or more. Also, the above degree of cationization is preferably 30 meq / g or less, more preferably 25 meq / g or less, and still more preferably 22 meq / g or less. The degree of cationization of the present disclosure can be measured using a known method. For example, it can be determined based on the following formula from the measured value of the N content measured by the Kjeldahl method, which is the second method of nitrogen determination in the general test method for cosmetic raw materials. The unit of meq / g for the degree of cationization is the number of milliequivalents of cationic groups per 1 g of the polyalkyleneimine-based compound. Degree of cationization (meq / g) = (Number of moles of cationic units in 1 g of polyalkyleneimine) × 1000 Number of moles of cationic units in 1 g of polyalkyleneimine = (Nitrogen content in polyalkyleneimine) / (Atomic weight of N)

[0018] The polyalkyleneimine compound of the present disclosure has at least one of a primary amine, a secondary amine, and a tertiary amine. From the viewpoint of enhancing the carbon dioxide adsorption ability, the molar ratio of the primary amine, secondary amine, and tertiary amine in the polyalkyleneimine is preferably 10 to 50:10 to 60:10 to 50, more preferably 20 to 45:20 to 55:10 to 40, and even more preferably 25 to 40:30 to 50:20 to 35.

[0019] The content ratio of the primary amine in the polyalkyleneimine compound of the present disclosure is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, and particularly preferably 27 mol% or more, based on the total amount (100 mol%) of the alkyleneimine constituting the polyalkyleneimine. Also, the content ratio is preferably 50 mol% or less, more preferably 45 mol% or less, even more preferably 40 mol% or less, and particularly preferably 37 mol% or less.

[0020] The content ratio of the secondary amine in the polyalkyleneimine compound of the present disclosure is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, based on the total amount (100 mol%) of the alkyleneimine constituting the polyalkyleneimine. Also, the content ratio is preferably 60 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less.

[0021] The content ratio of the tertiary amine in the polyalkyleneimine compound of the present disclosure is preferably 10 mol% or more, more preferably 15 mol% or more, and even more preferably 20 mol% or more, based on the total amount (100 mol%) of the alkyleneimine constituting the polyalkyleneimine compound. Also, the content ratio is preferably 50 mol% or less, more preferably 40 mol% or less, and even more preferably 35 mol% or less.

[0022] As the polyalkyleneimine compound of the present disclosure, as long as it is a compound having a structural unit represented by the above formula (A-1), (A-2) and / or (A-3), it may have other structural units. For example, modified polyalkyleneimine (polyalkyleneimine derivative) is also included. As the polyalkyleneimine compound of the present disclosure, a compound in which the content ratio of the structural units represented by the above formula (A-1), (A-2) and (A-3) in 100 parts by mass of the compound (A) is 80 parts by mass or more is preferable, 90 parts by mass or more is more preferable, and 95 parts by mass or more is still more preferable.

[0023] The modified polyalkyleneimine (polyalkyleneimine derivative) of the present disclosure may be a polymer containing a structural unit derived from alkyleneimine (that is, the structural unit represented by the above formula (A-1), (A-2) and / or (A-3)) and a structural unit derived from alkylene oxide.

[0024] The structural unit derived from alkylene oxide contained in the polyalkyleneimine derivative of the present disclosure refers to, for example, the structural unit represented within the parentheses in the following general formula (2). The two asterisks each represent an element or a group that binds to the structural unit derived from alkylene oxide. R2 represents an alkylene group having 2 to 10 carbon atoms which may have a substituent. Examples of the alkylene group include an ethylene group, -CH2CH2-; a propylene group, -CH(-CH3)CH2-, and the like. Examples of the above substituent include an alkoxy group, an acetoxy group, an ester group and the like.

[0025]

Chemical formula

[0026] The structural unit derived from an alkylene oxide contained in the polyalkyleneimine derivative of the present disclosure may be bonded to a hydrogen atom; a bonding group such as an ester group, a thioester group, an amide group, a thioamide group, an acetal group, a hemiacetal group, or a hemiketal group; a structural unit derived from an alkyleneimine, a structural unit derived from an alkylene oxide, a residue of a group capable of reacting with a hydroxyl group, or the like. The polyalkyleneimine derivative of the present disclosure may contain a structural site in which the structural units derived from an alkylene oxide are continuous (hereinafter, also referred to as a structural site derived from a polyalkylene oxide).

[0027] The polyalkyleneimine derivative of the present disclosure or the structural unit derived from an alkylene oxide may have a structure represented by the following general formula (3), for example.

[0028]

Chemical formula

[0029] In the above general formula (3), R2 represents an alkylene group having 2 to 10 carbon atoms which may have a substituent, and n represents the number of repetitions of the structural unit derived from an alkylene oxide, and is preferably, for example, 1 to 9. Among all R2 (alkylene groups contained in the structural unit derived from an alkylene oxide) contained in the polyalkyleneimine derivative of the present disclosure, it is preferable that 50 mol% or more is an ethylene group, —CH2CH2—, more preferably 80 mol% or more is an ethylene group, and still more preferably 90 mol% or more is an ethylene group. The polyalkyleneimine derivative of the present disclosure may have a structural unit other than the structural unit derived from alkyleneimine and the structural unit derived from alkylene oxide (hereinafter, also referred to as other structural units). The other structural units are not particularly limited, but include a hydrogen atom; a residue derived from an initiator such as an amino group although not limited; a bonding group such as an ester group, a thioester group, an amide group, a thioamide group, an acetal group, a hemiacetal group, a hemiketal group; a residue of a compound capable of reacting with a hydroxyl group such as an acid anhydride, an isocyanate, an ester compound although not limited; and the like. The above bonding group may bond a structural part derived from polyalkyleneimine and a structural unit derived from alkylene oxide or a structural part derived from polyalkylene oxide.

[0030] In the polyalkyleneimine derivative of the present disclosure, the molar ratio of the structural unit derived from alkyleneimine to the structural unit derived from alkylene oxide is preferably 1:0.1 to 1:100, more preferably 1:0.3 to 1:80, and further preferably 1:0.5 to 1:50, 1:0.5 to 1:30, 1:0.5 to 1:10, 1:0.5 to 1:5, 1:0.5 to 1:3 in this order.

[0031] In the polyalkyleneimine derivative of the present disclosure, the total content of the structural unit derived from alkyleneimine and the structural unit derived from alkylene oxide is preferably 200% by mass or less, more preferably 100% by mass or less, and further preferably 50% by mass or less with respect to 100% by mass of the polyalkyleneimine derivative of the present disclosure.

[0032] The polyalkyleneimine derivative of the present disclosure preferably has a weight average molecular weight of 300 or more and 100,000 or less, and more preferably 600 or more and 80,000 or less. The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw / Mn) of the polyalkyleneimine derivative of the present disclosure can usually be measured using gel permeation chromatography (GPC).

[0033] The method for producing the polyalkyleneimine derivative of the present disclosure is not particularly limited. For example, it can be produced by adding an alkylene oxide to an amino group contained in a polymer having a structural unit derived from an alkyleneimine such as polyethyleneimine (i.e., polyalkyleneimine). The polyalkyleneimine derivative according to one embodiment of the present invention can be produced by adding, for example, an average of 0.01 to 10 moles, preferably 0.05 to 5 moles, more preferably 0.1 to 3 moles, and still more preferably 0.2 to 2 moles of an alkylene oxide per mole of active hydrogen (hydrogen group bonded to an amino group) contained in the amino group of the polyalkyleneimine.

[0034] <Compound (B)> The composition for a carbon dioxide absorbent of the present disclosure contains Compound (B). The Compound (B) of the present disclosure is a compound having at least one amino group and / or imino group and at least one acidic group (salt) selected from the group consisting of a carboxyl group, a phosphonic acid group, a sulfonic acid group, and their neutral salts.

[0035] The neutral salts of the Compound (B) of the present disclosure with at least one amino group and / or imino group and a carboxyl group, a phosphonic acid group, and / or a sulfonic acid group are not particularly limited, but neutral salts with at least one base selected from the group consisting of amines, ammonia, alkali metals, and alkaline earth metals are preferred, neutral salts with at least one base selected from the group consisting of ammonia and alkali metals are more preferred, and neutral salts with alkali metals are even more preferred.

[0036] As the Compound (B) of the present disclosure, a compound having an amino group and at least one acidic group (salt) selected from the group consisting of a carboxyl group, a phosphonic acid group, a sulfonic acid group, and their neutral salts is more preferred, a compound having an amino group and a carboxyl group or a neutral salt of a carboxyl group is even more preferred, and a compound having a neutral salt of an amino group and a carboxyl group is particularly preferred.

[0037] Examples of the compound having an amino group of the present disclosure and a carboxyl group or a neutralized salt of a carboxyl group include diethylenetriaminepentaacetic acid, lithium salt of diethylenetriaminepentaacetic acid, potassium salt of diethylenetriaminepentaacetic acid, sodium salt of diethylenetriaminepentaacetic acid, ammonium salt of diethylenetriaminepentaacetic acid, 1,2-diaminopropane-N,N,N',N'-tetraacetic acid, lithium salt of 1,2-diaminopropane-N,N,N',N'-tetraacetic acid, potassium salt of 1,2-diaminopropane-N,N,N',N'-tetraacetic acid, sodium salt of 1,2-diaminopropane-N,N,N',Ammonium salt of N'-tetraacetic acid, ethylenediaminetetraacetic acid, lithium salt of ethylenediaminetetraacetic acid, potassium salt of ethylenediaminetetraacetic acid, sodium salt of ethylenediaminetetraacetic acid, ammonium salt of ethylenediaminetetraacetic acid, triethylenetetraminehexaacetic acid, lithium salt of triethylenetetraminehexaacetic acid, potassium salt of triethylenetetraminehexaacetic acid, sodium salt of triethylenetetraminehexaacetic acid, ammonium salt of triethylenetetraminehexaacetic acid, methylglycine diacetic acid, lithium salt of methylglycine diacetic acid, potassium salt of methylglycine diacetic acid, sodium salt of methylglycine diacetic acid, ammonium salt of methylglycine diacetic acid, glutamic acid diacetic acid, lithium salt of glutamic acid diacetic acid, potassium salt of glutamic acid diacetic acid, sodium salt of glutamic acid diacetic acid, ammonium salt of glutamic acid diacetic acid, iminodiacetic acid, lithium salt of iminodiacetic acid, potassium salt of iminodiacetic acid, sodium salt of iminodiacetic acid, ammonium salt of iminodiacetic acid, hydroxyiminodiacetic acid, lithium salt of hydroxyiminodiacetic acid, potassium salt of hydroxyiminodiacetic acid, sodium salt of hydroxyiminodiacetic acid, ammonium salt of hydroxyiminodiacetic acid, hydroxyethyliminodiacetic acid (HIDA), lithium salt of hydroxyethyliminodiacetic acid, potassium salt of hydroxyethyliminodiacetic acid, sodium salt of hydroxyethyliminodiacetic acid, ammonium salt of hydroxyethyliminodiacetic acid, dihydroxyethylglycine, lithium salt of dihydroxyethylglycine, potassium salt of dihydroxyethylglycine, sodium salt of dihydroxyethylglycine, ammonium salt of dihydroxyethylglycine, N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid, lithium salt of N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid, potassium salt of N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid, sodium salt of N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid, ammonium salt of N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid, 1,3-diamino-2-propanol-N,N,N',N'-tetraacetic acid, 1,Examples include the lithium salt of 3-diamino-2-propanol-N,N,N‘,N’-tetraacetic acid, the potassium salt of 1,3-diamino-2-propanol-N,N,N‘,N’-tetraacetic acid, the sodium salt of 1,3-diamino-2-propanol-N,N,N‘,N’-tetraacetic acid, the ammonium salt of 1,3-diamino-2-propanol-N,N,N‘,N’-tetraacetic acid, and the like.,

[0038] Examples of the compound having an amino group of the present disclosure and a carboxyl group or a neutralized salt of a carboxyl group include, from the viewpoint of suppressing a decrease in carbon dioxide adsorption ability, methylglycine diacetic acid, lithium salt of methylglycine diacetic acid, potassium salt of methylglycine diacetic acid, sodium salt of methylglycine diacetic acid, ammonium salt of methylglycine diacetic acid, glutamic acid diacetic acid, lithium salt of glutamic acid diacetic acid, potassium salt of glutamic acid diacetic acid, sodium salt of glutamic acid diacetic acid, ammonium salt of glutamic acid diacetic acid, iminodisuccinic acid, lithium salt of iminodisuccinic acid, potassium salt of iminodisuccinic acid, sodium salt of iminodisuccinic acid, ammonium salt of iminodisuccinic acid, hydroxyiminodisuccinic acid, lithium salt of hydroxyiminodisuccinic acid, potassium salt of hydroxyiminodisuccinic acid, sodium salt of hydroxyiminodisuccinic acid, ammonium salt of hydroxyiminodisuccinic acid, hydroxyethyliminodiacetic acid, lithium salt of hydroxyethyliminodiacetic acid, potassium salt of hydroxyethyliminodiacetic acid, sodium salt of hydroxyethyliminodiacetic acid, ammonium salt of hydroxyethyliminodiacetic acid. At least one selected from the group consisting of them is more preferable, and at least one selected from the group consisting of methylglycine diacetic acid, sodium salt of methylglycine diacetic acid, ammonium salt of methylglycine diacetic acid, glutamic acid diacetic acid, sodium salt of glutamic acid diacetic acid, ammonium salt of glutamic acid diacetic acid, iminodisuccinic acid, sodium salt of iminodisuccinic acid, ammonium salt of iminodisuccinic acid, hydroxyiminodisuccinic acid, sodium salt of hydroxyiminodisuccinic acid, ammonium salt of hydroxyiminodisuccinic acid, hydroxyethyliminodiacetic acid, sodium salt of hydroxyethyliminodiacetic acid, ammonium salt of hydroxyethyliminodiacetic acid is more preferable, and at least one selected from the group consisting of methylglycine diacetic acid, sodium salt of methylglycine diacetic acid, glutamic acid diacetic acid, sodium salt of glutamic acid diacetic acid, iminodisuccinic acid, sodium salt of iminodisuccinic acid, hydroxyiminodisuccinic acid, sodium salt of hydroxyiminodisuccinic acid, hydroxyethyliminodiacetic acid, sodium salt of hydroxyethyliminodiacetic acid, ammonium salt of hydroxyethyliminodiacetic acid is particularly preferable.

[0039] As the hydroxyiminodiacetic acid of the present disclosure, 3-hydroxy-2,2'-iminodiacetic acid is preferable. Examples of the neutral salt of hydroxyiminodiacetic acid include the lithium salt of 3-hydroxy-2,2'-iminodiacetic acid, the potassium salt of 3-hydroxy-2,2'-iminodiacetic acid, the sodium salt of 3-hydroxy-2,2'-iminodiacetic acid, and the ammonium salt of 3-hydroxy-2,2'-iminodiacetic acid, and the sodium salt of 3-hydroxy-2,2'-iminodiacetic acid is more preferable.

[0040] Examples of the compound having an amino group of the present disclosure and a phosphonic acid group or a neutralized salt of a phosphonic acid group include diethylenetriamine pentakis(methylphosphonic acid), lithium salt of diethylenetriamine pentakis(methylphosphonic acid), potassium salt of diethylenetriamine pentakis(methylphosphonic acid), sodium salt of diethylenetriamine pentakis(methylphosphonic acid), ammonium salt of diethylenetriamine pentakis(methylphosphonic acid), hexamethylenediamine tetra(methylenephosphonic acid), lithium salt of hexamethylenediamine tetra(methylenephosphonic acid), potassium salt of hexamethylenediamine tetra(methylenephosphonic acid), sodium salt of hexamethylenediamine tetra(methylenephosphonic acid), ammonium salt of hexamethylenediamine tetra(methylenephosphonic acid), aminotris(methylenephosphonic acid), lithium salt of aminotris(methylenephosphonic acid), potassium salt of aminotris(methylenephosphonic acid), sodium salt of aminotris(methylenephosphonic acid), ammonium salt of aminotris(methylenephosphonic acid), ethylenediamine tetra(methylenephosphonic acid), lithium salt of ethylenediamine tetra(methylenephosphonic acid), potassium salt of ethylenediamine tetra(methylenephosphonic acid), sodium salt of ethylenediamine tetra(methylenephosphonic acid), ammonium salt of ethylenediamine tetra(methylenephosphonic acid), diethylenetriamine penta(methylenephosphonic acid), lithium salt of diethylenetriamine penta(methylenephosphonic acid), potassium salt of diethylenetriamine penta(methylenephosphonic acid), sodium salt of diethylenetriamine penta(methylenephosphonic acid), ammonium salt of diethylenetriamine penta(methylenephosphonic acid), bis(hexamethylenetriamine penta(methylenephosphonic acid), lithium salt of bis(hexamethylenetriamine penta(methylenephosphonic acid), potassium salt of bis(hexamethylenetriamine penta(methylenephosphonic acid), sodium salt of bis(hexamethylenetriamine penta(methylenephosphonic acid), ammonium salt of bis(hexamethylenetriamine penta(methylenephosphonic acid), 4-amino-1-hydroxybutane-1,1-diphosphonic acid, 4-amino-1-hydroxybutane-1,Examples include lithium salts of 1-diphosphonic acid, potassium salts of 4-amino-1-hydroxybutane-1,1-diphosphonic acid, sodium salts of 4-amino-1-hydroxybutane-1,1-diphosphonic acid, ammonium salts of 4-amino-1-hydroxybutane-1,1-diphosphonic acid, etc.

[0041] Examples of the compound having an amino group of the present disclosure and a sulfonic acid group or a neutralized salt of a sulfonic acid group include amidosulfonic acid, lithium salt of amidosulfonic acid, potassium salt of amidosulfonic acid, sodium salt of amidosulfonic acid, ammonium salt of amidosulfonic acid, 2-aminoethanesulfonic acid, lithium salt of 2-aminoethanesulfonic acid, potassium salt of 2-aminoethanesulfonic acid, sodium salt of 2-aminoethanesulfonic acid, ammonium salt of 2-aminoethanesulfonic acid, 3-aminobenzenesulfonic acid, lithium salt of 3-aminobenzenesulfonic acid, potassium salt of 3-aminobenzenesulfonic acid, sodium salt of 3-aminobenzenesulfonic acid, ammonium salt of 3-aminobenzenesulfonic acid, 4-aminobenzenesulfonic acid, lithium salt of 4-aminobenzenesulfonic acid, potassium salt of 4-aminobenzenesulfonic acid, sodium salt of 4-aminobenzenesulfonic acid, ammonium salt of 4-aminobenzenesulfonic acid, 3-sulfo-L-alanine, lithium salt of 3-sulfo-L-alanine, potassium salt of 3-sulfo-L-alanine, sodium salt of 3-sulfo-L-alanine, ammonium salt of 3-sulfo-L-alanine, etc. The compound (B) of the present disclosure is a compound having at least one amino group and / or imino group and at least one acidic group (salt) selected from the group consisting of a carboxyl group, a phosphonic acid group, a sulfonic acid group, and their neutralized salts. For the neutralized salts in the above-exemplified compounds, they may be partially neutralized or completely neutralized.

[0042] <Composition for carbon dioxide adsorbent> The composition for a carbon dioxide adsorbent of the present disclosure contains a compound (A) containing a polyalkyleneimine-based compound, at least one amino group and / or imino group, and a compound (B) having at least one acidic group (salt) selected from the group consisting of a carboxyl group, a phosphonic acid group, a sulfonic acid group, and their neutral salts.

[0043] As the composition for a carbon dioxide adsorbent of the present disclosure, the content of the compound (B) with respect to 100 parts by mass of the compound (A) is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, and even more preferably 0.5 part by mass or more from the viewpoint of trapping the metal contained in the carbon dioxide adsorbent composition, and is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and even more preferably 5 parts by mass or less from the viewpoint of suppressing the decrease in carbon dioxide absorption ability.

[0044] The amount of transition metal contained in 100 parts by mass of the composition for a carbon dioxide adsorbent of the present disclosure is preferably 50 ppm or less, more preferably 30 ppm or less, and even more preferably 10 ppm or less from the viewpoint of suppressing the decrease in carbon dioxide adsorption ability. The lower limit of the amount of transition metal contained in 100 parts by mass of the composition for a carbon dioxide adsorbent may be 1 ppm or more, 0.5 ppm or more, and may not be substantially contained.

[0045] The transition metal refers to an element of any of Groups 3 to 12 of the periodic table of elements, and specifically, may be at least one selected from scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, etc., and further may be at least one selected from chromium, manganese, iron, cobalt, nickel, copper, etc.

[0046] The amount of transition metal contained in 100 parts by mass of the composition for a carbon dioxide adsorbent of the present disclosure is the total amount of elements of any of Groups 3 to 12 of the periodic table of elements, and can be measured by the method described in the examples.

[0047] The composition for a carbon dioxide adsorbent of the present disclosure may contain water in addition to the above-described compound (A) and compound (B). The content of water contained in 100 parts by mass of the composition for a carbon dioxide adsorbent may be 0.01 part by weight or more, may be 0.1 part by weight or more, may be 1 part by weight or more, may be 50 parts by weight or less, may be 40 parts by weight or less, and may be 30 parts by weight or less.

[0048] The composition for a carbon dioxide adsorbent of the present disclosure may contain other components such as a surfactant, an antioxidant, and a crystallization inhibitor in addition to the above-described compound (A) and compound (B). As the surfactant of the present disclosure, a nonionic surfactant, an anionic surfactant, a cationic surfactant, or an amphoteric surfactant can be used. For the HLB (hydrophilic-lipophilic balance) of the surfactant, those having 10 or more can be used, preferably those having 12 or more, and more preferably those having 15 or more can be used.

[0049] As the antioxidant of the present disclosure, a radical scavenger and a peroxide decomposer can be used. As the radical scavenger, a phenolic antioxidant and an amine antioxidant can be used, and preferably an amine antioxidant. The peroxide decomposer is not particularly limited as long as it can effectively decompose peroxides, but a sulfur-based antioxidant, a phosphorus-based antioxidant, a phenolic antioxidant, and a hindered amine antioxidant can be used. Examples of the sulfur-based antioxidant include 2-hydroxyethyl disulfide, 1,2-bis[(2-hydroxyethyl)thio]ethane, thiodipropionic acid, dilauryl thiodipropionate, distearyl thiodipropionate, lauryl stearyl thiodipropionate, dimyristyl thiodipropionate, distearyl-β,β'-thiodibutyrate, thiobis(β-naphthol), thiobis(N-phenyl-β-naphthylamine, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, dodecyl mercaptan, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel diptyl dithiocarbamate, nickel isopropyl xanthate, dodecanethiol, etc., and 2-hydroxyethyl disulfide and 1,2-bis[(2-hydroxyethyl)thio]ethane are more preferable.Examples of phosphorus-based antioxidants include phosphites (phosphite-based antioxidants) such as triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris(nonylphenyl) phosphite, diisodecyl pentaerythritol phosphite, tris(2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetrayl bis(octadecyl) phosphite, cyclic neopentanetetrayl bis(2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetrayl bis(2,4-di-t-butyl-4-methylphenyl) phosphite, bis[2-t-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl] hydrogen phosphite, etc.; and oxaphosphaphenanthrene oxides such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, etc.Examples of phenolic antioxidants include monophenols such as 4-methoxyphenol, hydroquinone, 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-p-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl) propionate; bisphenols such as 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 3,9-bis[1,1-dimethyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl] 2,4,8,10-tetraoxaspiro[5.5]undecane; polymeric phenols such as 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-t-butylphenyl)butyric acid] glycol ester, 1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, and tocopherol. Examples of hindered amine antioxidants include bis(1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butyl malonate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, methyl-1,2,2,6,6-pentamethyl-4-piperidyl sebacate, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-hydroxy-2,2,6,6-tetramethylpiperidine, etc. Examples of the crystallization inhibitor include water-soluble polymers such as polyvinylpyrrolidone, polyvinyl alcohol, and hydroxyethyl cellulose. By using a water-soluble polymer as the crystallization inhibitor, it is possible to suppress the secondary interaction between the carbamic acid generated by the reaction of the oligoamine compound and carbon dioxide and the oligoamine compound, thereby preventing the formation of an insoluble salt.

[0050] Other components of the present disclosure may be included as long as they do not impair the performance of the composition for a carbon dioxide adsorbent. For example, it is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, further preferably 0.5 part by mass or more, preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and further preferably 10 parts by mass or less with respect to 100 parts by mass of the composition for a carbon dioxide adsorbent.

[0051] <Carbon dioxide adsorbent> The composition for a carbon dioxide adsorbent of the present disclosure is not particularly limited, but it may be supported on a carrier and used as a carbon dioxide adsorbent. That is, the carbon dioxide adsorbent of the present disclosure may contain any components other than the composition for a carbon dioxide adsorbent of the present disclosure, but it preferably further contains a carrier.

[0052] From the viewpoint of enhancing the carbon dioxide adsorption ability, the carrier of the present disclosure is preferably porous carrier particles.

[0053] The carrier of the present disclosure preferably contains one or more of bentonite, attapulgite, kaolinite, montmorillonite, ball clay, fuller's earth, hectorite, palygorskite, saponite, sepiolite, halloysite, silica, calcium sulfate, zeolite, alumina, fumed silica, activated carbon, or a metal organic framework, more preferably silica and alumina, and further preferably silica. As the carrier of the present disclosure, a polymer material may be used. Examples of the polymer material include ether sulfone (PES), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), cellulose mixed ester or nitrocellulose (NC), polyolefin, polyethylene, polypropylene, polymethylpentene, polyketone, polyimide, polystyrene, polymethyl methacrylate, polydimethylsiloxane, polyester, nylon, polycaprolactone, polylactic acid, polyvinyl alcohol, and polyglycolic acid.

[0054] Regarding the amount of transition metal contained in 100 parts by mass of the carrier of the present disclosure, from the viewpoint of suppressing the decrease in carbon dioxide adsorption ability, it is preferably 10,000 ppm or less, more preferably 5,000 ppm or less, still more preferably 3,000 ppm or less. As the lower limit value, from the viewpoint of industrial applicability (productivity), it may be 50 ppm or more, 30 ppm or more, or 10 ppm or more.

[0055] Regarding the carbon dioxide adsorbent of the present disclosure, the content of the compound (A) with respect to 100 parts by mass of the carrier is preferably 5 parts by mass or more, more preferably 7 parts by mass or more, still more preferably 10 parts by mass or more from the viewpoint of carbon dioxide adsorption ability. From the viewpoint of carbon dioxide adsorption ability, it is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, still more preferably 100 parts by mass or less.

[0056] Regarding the amount of transition metal contained in 100 parts by mass of the carbon dioxide adsorbent of the present disclosure, from the viewpoint of suppressing the decrease in carbon dioxide adsorption ability, it is preferably 10,000 ppm or less, more preferably 3,000 ppm or less, still more preferably 2,000 ppm or less. As the lower limit value, from the viewpoint of industrial applicability (productivity), it may be 50 ppm or more, 30 ppm or more, or 10 ppm or more.

[0057] As the carbon dioxide adsorbent of the present disclosure, the content of the compound (B) with respect to 100 parts by mass of the metal contained in the carbon dioxide adsorbent is preferably 100 parts by mass or more, more preferably 300 parts by mass or more, still more preferably 500 parts by mass or more, from the viewpoint of suppressing the decrease in carbon dioxide adsorption ability, and preferably 5000 parts by mass or less, more preferably 3000 parts by mass or less, still more preferably 2000 parts by mass or less, from the viewpoint of suppressing the decrease in carbon dioxide absorption ability.

[0058] As the specific surface area of the carbon dioxide adsorbent of the present disclosure, from the viewpoint of carbon dioxide adsorption ability, it is preferably 70 m 2 / g or more, more preferably 80 m 2 / g or more, still more preferably 100 m 2 / g or more, and may be 800 m 2 / g or less, may be 650 m 2 / g or less, and may be 500 m 2 / g or less.

[0059] The carbon dioxide adsorbent of the present disclosure can adsorb (separate) not only high-concentration gas with a high carbon dioxide content concentration but also carbon dioxide in air-conditioning air and the atmosphere. In addition, by going through the process of desorbing the adsorbed carbon dioxide, it becomes possible to adsorb carbon dioxide again, and even when the adsorption and desorption of carbon dioxide are repeated, it is possible to suppress the decrease in carbon dioxide adsorption ability by using the carbon dioxide adsorbent of the present disclosure.

[0060] <Method for producing carbon dioxide adsorbent> As the method for producing the carbon dioxide adsorbent of the present disclosure, it includes a step of supporting a composition for a carbon dioxide adsorbent containing a compound (A) containing a polyalkyleneimine-based compound, at least one amino group and / or imino group, and a compound (B) having at least one acidic group (salt) selected from the group consisting of a carboxyl group, a phosphonic acid group, a sulfonic acid group, and their neutral salts on a carrier.

[0061] The composition for a carbon dioxide adsorbent of the present disclosure may be in a solid form, but is preferably liquid from the viewpoint of efficiency when supporting on a carrier. When the composition for a carbon dioxide adsorbent of the present disclosure is in a liquid form, the method for producing a carbon dioxide adsorbent may include a step of immersing a carrier in the composition for a carbon dioxide adsorbent of the present disclosure, a step of separating excess liquid from the impregnated carrier, and a drying step. As the step of immersing the carrier in the composition for a carbon dioxide adsorbent of the present disclosure, the composition for a carbon dioxide adsorbent may be added dropwise to the carrier or the like, or after filling the carrier into a container such as a column, the composition for a carbon dioxide adsorbent may be passed therethrough to effect impregnation. However, from the viewpoint of simplicity of operation and equipment, it is preferable to adopt the immersion method.

[0062] The pressure during treatment can be arbitrarily selected from normal pressure and reduced pressure. In order to remove bubbles in the pores of the carrier and efficiently support it on the carrier, it is preferable to carry out the treatment under reduced pressure. The specific pressure during treatment is preferably -0.08 MPaG to -0.004 MPaG, more preferably -0.07 MPaG to -0.01 MPaG, and still more preferably -0.06 MPaG to -0.02 MPaG. When impregnating the carrier with the composition for a carbon dioxide adsorbent of the present disclosure, the temperature is preferably in the range of 20°C to 90°C. This treatment temperature is more preferably 30°C to 80°C, and still more preferably 40°C to 70°C.

[0063] As the step of separating the excess liquid from the impregnated carrier of the present disclosure, for the separation, any solid-liquid separation method such as filtration, decantation, centrifugation, etc. can be adopted. From the viewpoint of simplicity of procedure, etc., separation by filtration is preferable. The drying temperature in the drying step of the present disclosure is preferably 30°C to 100°C, more preferably 40°C to 98°C, still more preferably 50°C to 95°C, and most preferably 50°C to 90°C. The treatment time in the drying step of the present disclosure is preferably 0.1 hour to 48 hours, more preferably 0.2 hour to 24 hours, and still more preferably 0.5 hour to 12 hours. During the drying process of the present disclosure, the pressure can be arbitrarily selected from normal pressure and reduced pressure. In order to gently dry while maintaining the state in which the carrier and the composition for the carbon dioxide adsorbent are held in the pores, it is preferably carried out at normal pressure.

[0064] <Method of using carbon dioxide adsorbent> The carbon dioxide adsorbent of the present disclosure is intended to be used in an apparatus for separating and recovering carbon dioxide from a gas to be treated containing carbon dioxide. The gas to be treated is a carbon dioxide-containing gas containing carbon dioxide, but also contains gases other than carbon dioxide. The gas to be treated is air or a high-concentration gas having a higher carbon dioxide content concentration than air. The high-concentration gas is, for example, discharged from an internal combustion engine or a factory. The carbon dioxide adsorbent of the present disclosure is installed and used in a carbon dioxide recovery apparatus. As a method of using the carbon dioxide adsorbent of the present disclosure, it includes a step of contacting a gas containing carbon dioxide (step (1)) and a step of desorbing carbon dioxide from the carbon dioxide adsorbent on which carbon dioxide has been adsorbed (step (2)).

[0065] When contacting a gas containing carbon dioxide as step (1) of the present disclosure, it may be under atmospheric pressure conditions in the range of 0.8 atm or more and 1.1 atm or less, and may be contacted under temperature conditions of -40°C or more and 60°C or less. When desorbing carbon dioxide from the carbon dioxide adsorbent as step (2) of the present disclosure, it may be desorbed under reduced pressure, may be 0.02 atm or more and 0.5 atm or less, and may be 0.1 atm or more and 0.3 atm or less. When desorbing carbon dioxide from the carbon dioxide adsorbent as step (2) of the present disclosure, it may be desorbed under heating. The temperature at the time of desorption may be 60°C or more and 130°C or less.

Examples

[0066] Examples are given below to explain the present invention in more detail, but the present invention is not limited only to these examples. Unless otherwise specified, "part" means "part by mass" and "%" means "mass%".

[0067] [Example 1] 0.25 part of polyethyleneimine (SP-012; manufactured by Nippon Shokubai Co., Ltd., number average molecular weight 1200 (catalog value, boiling point elevation method)), 0.015 part of a 50% aqueous solution of 3-hydroxy-2,2'-iminodisuccinic acid tetrasodium (HIDS; manufactured by Nippon Shokubai Co., Ltd.), and 2.5 parts of water were mixed to form a uniform solution. Subsequently, 0.50 part of MCM-41 (manufactured by ACS MATERIAL) was added and impregnated while stirring for 30 minutes. Subsequently, after treatment at 60°C and 20 Pa under reduced pressure, it was heated and dried in an oven at 80°C for 2 hours to obtain a solid absorbent for carbon dioxide separation (X-1) supporting the above carbon dioxide separation composition on a porous material.

[0068] [Method of oxidative degradation] 0.03 g of the prepared solid absorbent for carbon dioxide separation was weighed into a 10 mL vial. The upper part of the vial was protected with filter paper having a plurality of holes to prevent foreign matter from entering while allowing air to pass through. This was left standing in an oven at 100°C for 24 hours and then cooled to obtain a solid absorbent for carbon dioxide separation (Y-1) subjected to an oxidative degradation treatment.

[0069] [Comparative Example 1] 0.25 part of polyethyleneimine (SP-012; manufactured by Nippon Shokubai Co., Ltd., number average molecular weight 1200 (catalog value, boiling point elevation method)) and 2.5 parts of water were mixed to form a uniform solution. Subsequently, 0.50 part of MCM-41 (manufactured by ACS MATERIAL) was added and impregnated while stirring for 30 minutes. Subsequently, after treatment at 60°C and 20 Pa under reduced pressure, it was heated and dried in an oven at 80°C for 2 hours to obtain a solid absorbent for carbon dioxide separation (X-2) supporting the above carbon dioxide separation composition on a porous material. Using X-2, a solid absorbent for carbon dioxide separation (Y-2) subjected to an oxidative degradation treatment was obtained in the same manner as Y-1.

[0070] Using the obtained solid absorbent for carbon dioxide separation, a carbon dioxide adsorption / desorption test was carried out. The experimental results are shown in Table 1. [Method for evaluating heat resistance of solid absorbent for carbon dioxide separation] The retention rate is calculated as (CO₂ absorption amount after heating) ÷ (CO₂ absorption amount before heating) × 100. Evaluation criterion 〇: Retention rate of 60% or more ×: Retention rate less than 60%

[0071]

Table 1

[0072] As shown in Comparative Example 1, although the retention rate after heating was low for polyethyleneimine alone, the composition for a carbon dioxide adsorbent shown in Example 1 was a CO₂ absorbent with high heat resistance.

[0073] [Carbon dioxide adsorption and desorption test using carbon dioxide-containing gas simulating dry air] To measure the absorption amount and desorption amount of carbon dioxide, TG-DTA (TG-DTA8120 and 8122 manufactured by Rigaku Corporation) is used to measure the weight mass at the absorption temperature (40 °C) and desorption temperature (110 °C). Using a mass flow controller, a carbon dioxide-containing gas with adjusted flow rates of nitrogen and carbon dioxide is supplied into the TG-DTA oven at 200 ml / min. The carbon dioxide concentration of the simulated gas is about 400 ppm, and the humidity of the supplied gas is kept constant at an absolute humidity of 2 g / kg. From the TG-DTA measurement, the mass of the solid absorbent material during carbon dioxide absorption at each temperature and the mass of the solid absorbent material during carbon dioxide desorption by heating are measured, and the carbon dioxide adsorption and desorption amount is determined from the following formula. Carbon dioxide adsorption and desorption amount (mmol / g) = (mass of solid absorbent material (g) after carbon dioxide absorption - mass of solid absorbent material (g) after carbon dioxide desorption) ÷ molecular weight of carbon dioxide (g / mmol) ÷ mass of solid absorbent material (g)

[0074] <Amount of metal in the carrier> Regarding the amount of metal in the carrier, it was measured by X-ray fluorescence (XRF) analysis and taken as the total amount of components containing Cr, Mn, Fe, Co, Ni, and Cu. The amount of metal in MCM-41 was as shown in Table 2.

[0075]

Table 2

[0076] [Example 2] 0.25 part of polyethyleneimine (SP-012; manufactured by Nippon Shokubai Co., Ltd., number average molecular weight 1200 (catalog value, boiling point elevation method)), 0.0075 part of 4-amino-1-hydroxybutane-1,1-diphosphonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 2.5 parts of water were mixed to form a uniform solution. Subsequently, 0.50 part of MCM-41 (manufactured by ACS MATERIAL) was added and impregnated while stirring for 30 minutes. Subsequently, after treatment at 60°C and 20 Pa under reduced pressure, it was heated and dried in an oven at 80°C for 2 hours to obtain a solid absorbent for carbon dioxide separation (X-3) carrying the above composition for carbon dioxide separation on a porous material. Using X-3, a solid absorbent for carbon dioxide separation (Y-3) subjected to an oxidation degradation treatment in the same manner as Y-1 was obtained. When carbon dioxide adsorption / desorption tests were carried out on X-3 and Y-3 respectively, the CO2 absorption amount of X-3 was 0.78 mmol / g, the CO2 absorption amount of Y-3 was 0.67 mmol / g, the retention rate was 86%, and the heat resistance evaluation was ○.

[0077] [Example 3] 0.25 part of polyethyleneimine (SP-012; manufactured by Nippon Shokubai Co., Ltd., number average molecular weight 1200 (catalog value, boiling point elevation method)), 0.005 part of 4-amino-1-hydroxybutane-1,1-diphosphonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 2.5 parts of water were mixed to form a uniform solution. Subsequently, 0.50 part of MCM-41 (manufactured by ACS MATERIAL) was added and impregnated while stirring for 30 minutes. Subsequently, after treatment at 60°C and 20 Pa under reduced pressure, it was heated and dried in an oven at 80°C for 2 hours to obtain a solid absorbent for carbon dioxide separation (X-4) carrying the above composition for carbon dioxide separation on a porous material. Using X-4, a solid absorbent for carbon dioxide separation (Y-4) subjected to an oxidation degradation treatment in the same manner as Y-1 was obtained. When carbon dioxide adsorption / desorption tests were carried out on X-4 and Y-4 respectively, the CO2 absorption amount of X-4 was 0.92 mmol / g, the CO2 absorption amount of Y-4 was 0.70 mmol / g, the retention rate was 76%, and the heat resistance evaluation was ○.

[0078] [Example 4] 0.25 part of polyethyleneimine (SP-012; manufactured by Nippon Shokubai Co., Ltd., number average molecular weight 1200 (catalog value, boiling point elevation method)), 0.005 part of hydroxyethyliminodiacetic acid (Chirex EA; manufactured by Chirex Co., Ltd.), and 2.5 parts of water were mixed to form a uniform solution. Subsequently, 0.50 part of MCM-41 (manufactured by ACS MATERIAL) was added and impregnated while stirring for 30 minutes. Subsequently, after treatment at 60 °C and 20 Pa under reduced pressure, it was heated and dried in an oven at 80 °C for 2 hours to obtain a solid absorbent for carbon dioxide separation (X-5) carrying the above composition for carbon dioxide separation on a porous material. Using X-5, a solid absorbent for carbon dioxide separation (Y-5) subjected to an oxidation degradation treatment in the same manner as Y-1 was obtained. When carbon dioxide adsorption / desorption tests were performed on X-5 and Y-5 respectively, the CO2 absorption amount of X-5 was 0.79 mmol / g, the CO2 absorption amount of Y-5 was 0.74 mmol / g, the retention rate was 94%, and the heat resistance evaluation was ○.

[0079] [Example 5] 0.25 part of polyethyleneimine (SP-012; manufactured by Nippon Shokubai Co., Ltd., number average molecular weight 1200 (catalog value, boiling point elevation method)), 0.0025 part of hydroxyethyliminodiacetic acid (Chirex EA; manufactured by Chirex Co., Ltd.), and 2.5 parts of water were mixed to form a uniform solution. Subsequently, 0.50 part of MCM-41 (manufactured by ACS MATERIAL) was added and impregnated while stirring for 30 minutes. Subsequently, after treatment at 60 °C and 20 Pa under reduced pressure, it was heated and dried in an oven at 80 °C for 2 hours to obtain a solid absorbent for carbon dioxide separation (X-6) carrying the above composition for carbon dioxide separation on a porous material. Using X-6, a solid absorbent for carbon dioxide separation (Y-6) subjected to an oxidation degradation treatment in the same manner as Y-1 was obtained. When carbon dioxide adsorption / desorption tests were performed on X-6 and Y-6 respectively, the CO2 absorption amount of X-6 was 0.76 mmol / g, the CO2 absorption amount of Y-6 was 0.65 mmol / g, the retention rate was 86%, and the heat resistance evaluation was ○.

[0080] [Example 6] 0.25 part of polyethyleneimine (SP-012; manufactured by Nippon Shokubai Co., Ltd., number average molecular weight 1200 (catalog value, boiling point elevation method)), 0.005 part of N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (Chiresto HC; manufactured by Chiresto Co., Ltd.), and 2.5 parts of water were mixed to form a homogeneous solution. Subsequently, 0.50 part of MCM-41 (manufactured by ACS MATERIAL) was added and impregnated while stirring for 30 minutes. Subsequently, after treatment at 60 °C and 20 Pa under reduced pressure, it was heated and dried in an oven at 80 °C for 2 hours to obtain a solid absorbent for carbon dioxide separation (X-7) carrying the above composition for carbon dioxide separation on a porous material. Using X-7, a solid absorbent for carbon dioxide separation (Y-7) subjected to an oxidation degradation treatment in the same manner as Y-1 was obtained. When carbon dioxide adsorption / desorption tests were carried out on X-7 and Y-7 respectively, the CO2 absorption amount of X-7 was 0.84 mmol / g, the CO2 absorption amount of Y-7 was 0.56 mmol / g, the retention rate was 67%, and the heat resistance evaluation was ○.

[0081] [Example 7] 0.25 part of polyethyleneimine (SP-012; manufactured by Nippon Shokubai Co., Ltd., number average molecular weight 1200 (catalog value, boiling point elevation method)), 0.005 part of 1,3-diamino-2-propanol-N,N,N',N'-tetraacetic acid (Chiresto RA; manufactured by Chiresto Co., Ltd.), and 2.5 parts of water were mixed to form a homogeneous solution. Subsequently, 0.50 part of MCM-41 (manufactured by ACS MATERIAL) was added and impregnated while stirring for 30 minutes. Subsequently, after treatment at 60 °C and 20 Pa under reduced pressure, it was heated and dried in an oven at 80 °C for 2 hours to obtain a solid absorbent for carbon dioxide separation (X-8) carrying the above composition for carbon dioxide separation on a porous material. Using X-8, a solid absorbent for carbon dioxide separation (Y-8) subjected to an oxidation degradation treatment in the same manner as Y-1 was obtained. When carbon dioxide adsorption / desorption tests were carried out on X-8 and Y-8 respectively, the CO2 absorption amount of X-8 was 0.89 mmol / g, the CO2 absorption amount of Y-8 was 0.62 mmol / g, the retention rate was 70%, and the heat resistance evaluation was ○.

Claims

1. A composition for a carbon dioxide adsorbent, comprising a compound (A) containing a polyalkyleneimine compound, at least one amino group and / or imino group, and a compound (B) having at least one acidic group (salt) selected from the group consisting of a carboxyl group, a phosphonic acid group, a sulfonic acid group, and their neutralized salts.

2. The composition for a carbon dioxide adsorbent according to Claim 1, wherein the polyalkyleneimine compound is polyethyleneimine.

3. The composition for a carbon dioxide adsorbent according to Claim 1, wherein the molar ratio of primary amine, secondary amine, and tertiary amine in the compound (A) is 10 to 50:10 to 60:10 to 50.

4. The composition for a carbon dioxide adsorbent according to Claim 1, wherein the number average molecular weight of the compound (A) is 300 or more and 100,000 or less.

5. The composition for a carbon dioxide adsorbent according to Claim 1, wherein the compound (B) is at least one selected from methylglycine diacetic acid, glutamic acid diacetic acid, iminodisuccinic acid, hydroxyiminodisuccinic acid, hydroxyethyliminodiacetic acid, and their neutralized salts.

6. The composition for a carbon dioxide adsorbent according to Claim 1, wherein the content of the compound (B) with respect to 100 parts by mass of the compound (A) is 0.1 part by mass or more and 10 parts by mass or less.

7. A carbon dioxide adsorbent comprising the composition for a carbon dioxide adsorbent according to any one of Claims 1 to 6 and a carrier.

8. The carbon dioxide adsorbent according to Claim 7, wherein the carrier is porous carrier particles.

9. The carbon dioxide adsorbent according to Claim 7, wherein the carrier contains one or more of bentonite, attapulgite, kaolinite, montmorillonite, ball clay, fuller's earth, hectorite, palygorskite, saponite, sepiolite, halloysite, silica, calcium sulfate, zeolite, alumina, fumed silica, activated carbon, or metal organic frameworks.

10. The carbon dioxide adsorbent according to Claim 7, wherein the content of the compound (A) with respect to 100 parts by mass of the carrier is 5 parts by mass or more and 200 parts by mass or less.

11. The carbon dioxide adsorbent according to Claim 7, wherein the amount of transition metal contained in 100 parts by mass of the carbon dioxide adsorbent is 5 ppm or more and 10,000 ppm or less.

12. The carbon dioxide adsorbent according to claim 7, wherein the content of the compound (B) is 50 parts by mass or more and 5000 parts by mass or less with respect to 100 parts by mass of the metal contained in the carbon dioxide adsorbent.

13. The specific surface area is 70 m ２ / g or more and 800 m ２ / g or less, the carbon dioxide adsorbent according to claim 7.

14. A method for using the carbon dioxide adsorbent according to any one of claims 7 to 13, comprising the following steps. Step (1): A step of bringing a gas containing carbon dioxide into contact Step (2): A step of desorbing carbon dioxide from the carbon dioxide adsorbent on which carbon dioxide has been adsorbed

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