Absorption liquid of carbon dioxide, and separation and recovery method of carbon dioxide

Abstract

To provide an absorption / emission liquid of carbon dioxide which has high absorption capability of carbon dioxide and high emission capability of carbon dioxide at low temperature, and is scarcely degraded even when absorption and emission cycles are repeated, and a separation and recovery method of carbon dioxide.SOLUTION: An absorption liquid, which is an absorption liquid for separating and recovering carbon dioxide from gas containing carbon dioxide, contains an amine compound (A) represented by the following general formula (1), and water. In the formula (1), R1 is a group represented by general formula (2).SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to an absorbent for highly efficiently separating and recovering carbon dioxide from a gas containing carbon dioxide, and a method for separating and recovering carbon dioxide using the absorbent.

Background Art

[0002] In recent years, the rapid increase in the emissions of greenhouse gases such as carbon dioxide and methane associated with social activities has been cited as one of the causes of global warming. In particular, carbon dioxide is the most major greenhouse gas, and in accordance with the Paris Agreement that came into force in 2016, measures to reduce carbon dioxide emissions are urgently needed.

[0003] As a measure to reduce carbon dioxide emissions, the separation and recovery of carbon dioxide has attracted attention, and the development of carbon dioxide absorbents has been actively carried out. Therefore, in recent years, for carbon dioxide-containing gases discharged from power plants and steel mills, the development of carbon dioxide separation and recovery technologies by chemical absorption methods mainly using aqueous solutions of amine compounds has been vigorously promoted.

[0004] Examples of the amine compound include primary alkanolamines such as monoethanolamine (MEA), diglycolamine (DGA), 2-amino-2-methyl-1-propanol (AMP); secondary alkanolamines such as 2-(methylamino)ethanol (MAE), 2-(ethylamino)ethanol (EAE), 2-(isopropylamino)ethanol (IPAE), 3-(isopropylamino)propanol (IPAP), diethanolamine (DEA), diisopropanolamine (DIPA); tertiary alkanolamines such as N-methyldiethanolamine (MDEA), 2-(dimethylamino)ethanol (DMAE), triethanolamine (TEA); tertiary alkylamines such as N,N,N',N'-tetramethyl-1,6-diaminohexane (TMDAH), N,N,N',N'-tetramethyl-1,4-diaminobutane (TMDAB), bis(2-dimethylaminoethyl)ether (BDER), etc. Among them, MEA is particularly widely used.

[0005] As a prior art for separating and recovering carbon dioxide with less energy, for example, Patent Document 1 describes a method for removing carbon dioxide in combustion exhaust gas by contacting an aqueous solution of a secondary alkanolamine having a steric hindrance such as an alkyl group around an amino group with combustion exhaust gas under atmospheric pressure to absorb carbon dioxide.

[0006] For example, Patent Document 2 reports an absorbent liquid composed of a secondary alkanolamine compound substituted with a tertiary butyl group as a steric hindrance substituent and water.

[0007] Also, Patent Document 3 describes an absorbent liquid and a method for absorbing carbon dioxide that can exhibit maximum performance by mixing multiple types of alkanolamines while taking advantage of the characteristics of individual amines.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

[0009] The present disclosure aims to provide a carbon dioxide absorption / release liquid and a method for separating and recovering carbon dioxide, which exhibits high carbon dioxide absorption capacity and high carbon dioxide release capacity at low temperatures and is less susceptible to deterioration even when absorption and release cycles are repeated. [Means for solving the problem]

[0010] The present disclosure provides the following carbon dioxide absorption liquid and carbon dioxide separation and recovery method. [1] An absorption liquid for separating and recovering carbon dioxide from a gas containing carbon dioxide, The absorbing liquid contains an amine compound (A) represented by formula (1) and water. Formula (1) [ka] During the ceremony, R 1 is a group represented by general formula (2), R 2 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms in which the carbon atom adjacent to N is a primary carbon atom, or -CH2CH(OH)CH2X 2 A 2 and X 1 is a direct bond, -O-, -OC(=O)-, -CO(=O)-, or -NA 3 - and A 1 is a hydrogen atom or an n-valent organic residue (wherein X 1 is a direct bond, and A 1 is a hydrogen atom), n is an integer from 1 to 6, X 2 is a direct bond, -O-, -OC(=O)-, -CO(=O)-, or -NA 3 -. A 2 is a hydrogen atom or a monovalent organic residue (however, when X 2 is a direct bond and A 2 is a hydrogen atom, this case is excluded), A 3 is a hydrogen atom or a monovalent organic residue. Formula (2)

Chemical formula

[0011] According to the present disclosure, since the absorbent has a high carbon dioxide recovery amount and absorption rate, has the ability to release carbon dioxide with low energy, and the deterioration of the material due to the repetition of carbon dioxide recovery and release is suppressed, carbon dioxide separation and recovery with low energy can be achieved for the entire system. Furthermore, by improving the absorption efficiency, it becomes possible to design a more compact carbon dioxide separation and recovery facility, and the initial cost is reduced.

Mode for Carrying Out the Invention

[0012] Hereinafter, the absorbent and the method for separating and recovering carbon dioxide will be described. In the present disclosure, "~" indicating a numerical range includes the numerical values described before and after it as the lower limit value and the upper limit value, unless otherwise specified. In addition, when there are a plurality of the same symbols in a chemical formula, the same symbols are not limited to representing the same substituents unless otherwise specified, and they may be different substituents from each other within the range defined by the symbols.

[0013] [Absorbent] The absorbent of the present disclosure is an absorbent for separating and recovering carbon dioxide from a gas containing carbon dioxide, and includes an amine compound (A) represented by the following general formula (1) and water. [Chemical formula] In the formula, R 1 is a group represented by the general formula (2), R 2 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, where the carbon atom adjacent to N is a primary carbon atom, or -CH2CH(OH)CH2X 2 A 2 and X 1 is a direct bond, -O-, -OC(=O)-, -CO(=O)-, or -NA 3 -, A 1 is a hydrogen atom, or an n-valent organic residue (provided that X 1 is a direct bond and A1 excluding the case where it is a hydrogen atom), n is an integer from 1 to 6, X 2 is a direct bond, -O-, -OC(=O)-, -CO(=O)-, or -NA 3 -. A 2 is a hydrogen atom or a monovalent organic residue (however, when X 2 is a direct bond and A 2 is a hydrogen atom, this case is excluded), A 3 is a hydrogen atom or a monovalent organic residue.

[0014] The inventors have found that by using the above-specified amine compound (A), a high carbon dioxide recovery amount and a low energy consumption required for the carbon dioxide recovery amount can be achieved. The absorbent of the present disclosure using the above-specified amine compound (A) can efficiently absorb carbon dioxide, release it with low energy, recover high-purity carbon dioxide with high efficiency, and is also less likely to deteriorate even when absorption and release are repeated. Further, the absorbent of the present disclosure has low volatility as an absorbent and exhibits high corrosion resistance to steel materials, and thus is excellent as an absorbent.

[0015] <Amine compound (A)> The amine compound (A) is a compound represented by the following general formula (1). [Chemical formula]

[0016] R 1 is a group represented by the general formula (2). In the formula, * represents a bond with N in the formula (1). [Chemical formula]

[0017] In the formula (2), R 10 and R 12is, independently of one another, a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a hydroxyalkyl group, and R 11 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a hydroxyalkyl group, or -(CH2) s -R 13 wherein R 13 is a hydroxy group or -N(R 14 )R 15 wherein R 14 and R 15 are, independently of one another, a hydrogen atom, a methyl group, or a hydroxyalkyl group, q is 2 or 3, r is 3, s is 2 or 3, and from the viewpoints of carbon dioxide adsorbability and low-temperature release property, q is preferably 3. Examples of the alkyl group having 1 to 8 carbon atoms in R 10 to R 12 are the same as those of the above R 9 . From the viewpoints of carbon dioxide adsorbability and low-temperature release property, R 10 to R 12 are preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group. In the hydroxyalkyl groups of R 10 to R 12 , R 14 and R 15 , the number of carbon atoms of the alkyl group is preferably 1 to 8, more preferably 1 to 4, from the viewpoints of carbon dioxide adsorbability and low-temperature release property. Specific examples of the hydroxyalkyl group include a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, and the like.

[0018] Specific examples of R 1 are shown by the specific examples of the amine compound (A) described later.

[0019] R 2 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms in which the carbon atom adjacent to N is a primary carbon atom, or -CH2CH(OH)CH2X 2 A 2 .

[0020] R 2In the formula, examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a secondary butyl group, an isobutyl group, a neopentyl group, an isopentyl group, a secondary pentyl group, a 1-hexyl group, a 2-hexyl group, a heptyl group, a methylcyclohexyl group, an octyl group, a 2-ethylhexyl group, and the like.

[0021] R 2 is -CH2CH(OH)CH2X 2 A 2 In the case of, n in the formula (1) is preferably 1. In this case, the formula (1) is A 2 X 2 CH2CH(OH)CH2N(R 1 )CH2CH(OH)CH2X 1 A 1 : represented by the formula (1a). When the amine compound (A) is represented by the formula (1a), from the viewpoints of carbon dioxide adsorption property, low-temperature release property, and ease of synthesis, X 1 A 1 and X 2 A 2 are preferably the same substituent.

[0022] From the viewpoints of carbon dioxide adsorption property, low-temperature release property, and ease of synthesis, R 2 among these, a hydrogen atom or an alkyl group having 1 to 4 carbon atoms is preferable, and a hydrogen atom is more preferable.

[0023] X 1 and X 2 are each independently a direct bond, -O-, -OC(=O)-, -CO(=O)-, or -NA 3 -. From the viewpoints of carbon dioxide adsorption property, low-temperature release property, and suppression of deterioration of the absorbent during repeated use, X 1 and X 2 are each independently preferably a direct bond or -O-, and more preferably -O-. Also, when there are a plurality of X 1 (that is, when n is 2 or more), the plurality of X 1may be the same or different, but from the viewpoints of carbon dioxide adsorption, low-temperature release, and ease of synthesis, there are a plurality of Xs 1 are preferably the same.

[0024] A 1 is a hydrogen atom or an n-valent organic residue. However, when X 1 is a direct bond, A 1 is an n-valent organic residue. The n-valent organic residue represents a residue obtained by removing n hydrogen atoms from an organic group. In the specific examples described later, the names of monovalent substituents are used, but A 1 is further a residue obtained by removing any n - 1 hydrogen atoms. A 1 Examples of the n-valent organic residue in A include a linear or branched aliphatic hydrocarbon residue which may have a substituent and may have a heteroatom in the carbon chain; a (meth)acryloyl residue which may have a substituent; an alicyclic hydrocarbon residue which may have a substituent and may have a heteroatom in the carbon chain; an aromatic hydrocarbon residue which may have a substituent; an aromatic heterocyclic residue which may have a substituent, etc. Examples of the heteroatom include O, N, S, Si, etc. As the heteroatom in the aliphatic hydrocarbon residue, O or N is preferable, and O is more preferable. Also, as the heteroatom in the alicyclic hydrocarbon residue, O or N is preferable, and N is more preferable. The organic residue may have two or more heteroatoms. Examples of the linear or branched aliphatic hydrocarbon residue having a heteroatom include a linear or branched polyoxyalkyl residue, etc. Also, n represents an integer from 1 to 6, preferably from 1 to 4, and more preferably from 1 to 2.

[0025] Examples of the aliphatic hydrocarbon residue which may have an n-valent substituent include an alkyl group, an alkenyl group, and an alkynyl group.

[0026] Specific alkyl groups include alkyl groups having 1 to 18 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, dodecyl group, tetradecyl group, pentadecyl group, octadecyl group, etc.

[0027] In addition, examples of alkenyl groups include alkenyl groups having 2 to 18 carbon atoms such as vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-octenyl group, 1-decenyl group, 1-octadecenyl group, etc.

[0028] In addition, examples of alkynyl groups include alkynyl groups having 2 to 18 carbon atoms such as ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-octynyl group, 1-decynyl group, 1-octadecynyl group, etc.

[0029] Examples of substituents in a linear or branched hydrocarbon residue that may have an n-valent substituent include linear or branched alkyl groups, alkoxy groups, polyoxyalkyl groups, phenyl groups, 4-nitrophenyl groups, 2-methoxyphenyl groups, hydroxyl groups, halogen atoms, epoxy groups, etc. The above substituents may further have substituents, and examples of the substituents include the above substituents.

[0030] The specific alkyl group as a substituent has the same meaning as the alkyl group of the linear or branched hydrocarbon residue that may have an n-valent substituent described above.

[0031] Specific alkoxy groups as substituents include methoxy group, ethoxy group, etc.

[0032] Specific polyoxyalkyl groups as substituents include ethylene oxide groups having a repeating number of 4 to 16, and linear or branched propylene oxide groups having a repeating number of 4 to 16.

[0033] Specific halogen atoms as substituents include a chlorine atom, a bromine atom, and an iodine atom.

[0034] Examples of the linear or branched polyoxyalkyl group which may have an n-valent substituent include an ethylene oxide group having a repeating number of 4 to 16, a linear or branched propylene oxide group having a repeating number of 4 to 16. Regarding the substituent, it is the same as the substituent in the linear or branched hydrocarbon residue which may have an n-valent substituent described above, and an alkyl group, a phenyl group, a hydroxyl group, etc. are preferable.

[0035] Examples of the (meth)acryloyl residue which may have an n-valent substituent include (meth)acryloyl groups such as a methacryl group and an acryloyl group. Regarding the substituent, it is the same as the substituent in the linear or branched hydrocarbon residue which may have an n-valent substituent described above.

[0036] Examples of the alicyclic hydrocarbon group of the alicyclic hydrocarbon residue which may have an n-valent substituent include cycloalkyl groups, specifically, cycloalkyl groups having 3 to 18 carbon atoms such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclooctadecyl group, and a 2-indeno group. Further, the alicyclic hydrocarbon group includes a group in which a plurality of cycloalkyl groups are linked by an alkylene group or the like. Regarding the substituent in the alicyclic hydrocarbon residue which may have an n-valent substituent, it is the same as the substituent in the linear or branched hydrocarbon residue which may have an n-valent substituent described above, preferably a branched alkylene group, and particularly preferably a tert-butylene group.

[0037] Examples of the aromatic hydrocarbon of the aromatic hydrocarbon residue which may have an n-valent substituent include aromatic hydrocarbons having 1 to 4 condensed rings, specifically, benzene, biphenyl, naphthalene, anthracene, phenanthrene, tetracene, pyrene, 9,9-diphenylfluorene, bis(3-methylphenyl)fluorene, binaphthyl, etc.

[0038] In the aromatic hydrocarbon residue which may have an n-valent substituent, the substituent is the same as the substituent in the linear or branched hydrocarbon residue which may have an n-valent substituent described above. Preferably, it is an alkyl group, an alkylene group, or a halogen atom. Particularly preferably, a methyl group, a methylene group, a tert-butylene group, and a bromine atom are mentioned.

[0039] The aromatic heterocyclic ring of the aromatic heterocyclic residue which may have an n-valent substituent is an aromatic heterocyclic ring having 1 to 4 condensed rings. For example, pyrrole, imidazole, pyridine, triazine, indole, quinoline, carbazole, phthalimide, etc. are mentioned. The substituent is the same as the substituent in the linear or branched hydrocarbon residue which may have an n-valent substituent described above.

[0040] A 1 (X 1 ) n As the structure of, for example, a linear or branched alkoxy residue which may have an n-valent substituent, an alkyl ester residue which may have an n-valent substituent, an aromatic ester residue which may have an n-valent substituent, or an amino residue which may have an n-valent substituent can also be regarded.

[0041] Examples of the alkoxy group of the linear or branched alkoxy residue which may have an n-valent substituent include a methoxy group and an ethoxy group. The substituent is the same as the substituent in the linear or branched hydrocarbon residue which may have an n-valent substituent described above.

[0042] Examples of the alkyl ester group of the alkyl ester residue which may have an n-valent substituent include a methyl ester group, an ethyl ester group, a propyl ester group, a butyl ester group, a pentyl ester group, a heptyl ester group, a hexyl ester group, an octyl ester group, a hexadecyl ester group, a cyclohexyl ester group, a 1,2-cyclohexane diester group, a 1,2-cyclohexene diester group, etc. The substituents are the same as those in the linear or branched hydrocarbon residue which may have an n-valent substituent described above.

[0043] Examples of the aromatic ester group of the aromatic ester residue which may have an n-valent substituent include a phenyl ester group, a 4-tert-butylphenyl ester group, etc. The substituents are the same as those in the linear or branched hydrocarbon residue which may have an n-valent substituent described above.

[0044] Examples of the amino group of the amino residue which may have an n-valent substituent include an aniline group. The substituents are the same as those in the linear or branched hydrocarbon residue which may have an n-valent substituent described above, preferably an alkyl group, more preferably a methyl group.

[0045] A 1 is preferably a linear or branched hydrocarbon residue which may have an n-valent substituent, or an aromatic hydrocarbon residue which may have an n-valent substituent, more preferably a linear or branched hydrocarbon residue which may have an n-valent substituent, and particularly preferably an n-valent linear hydrocarbon residue. A 1 preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 2 to 8 carbon atoms.

[0046] A 2 and A 3 are each independently a hydrogen atom or a monovalent organic residue. However, when X 2 is a direct bond, A 2 is a monovalent organic residue. A 2 and A3 The monovalent organic residue in the above A 1 is the same as that obtained by reading n of the n-valent organic residue in the above A as 1.

[0047] Hereinafter, compounds (A1) to (A32) which are representative examples of the amine compound (A) are shown in Tables 1-1 to 1-2, but the present embodiment is not limited to this representative example.

[0048] [Table 1-1]

[0049] [Table 1-2]

[0050] (Production method of amine compound (A)) An example of the production method of the amine compound (A) will be described, but the production method of the amine compound (A) is not limited to the following method. When there is a commercially available product, the commercially available product may be used.

[0051] The amine compound (A) can be obtained, for example, by reacting a compound (1b) represented by HNR 1 (R 2 ) with a monofunctional or polyfunctional epoxy compound (1c) in a solvent. Examples of the solvent include alkanols (such as methanol, ethanol, propanol, butanol, etc.), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), etc. The reaction is preferably carried out under anhydrous conditions in order to obtain the amine compound (A) represented by the target formula (1).

[0052] Examples of the compound (1b) include compounds (b1) to (b6) in Table 2 below.

[0053] [Table 2]

[0054] The mixing amount of compound (1b) and epoxy compound (1c) is preferably in the range of 0.95 to 1.1 equivalents in terms of the primary amino group equivalent ratio of compound (1b) to the epoxy equivalent of epoxy compound (1c), for example.

[0055] In the epoxy compound (1c), the monofunctional epoxy compound refers to a compound having one epoxy group in one molecule, and the polyfunctional epoxy compound is a compound having two or more epoxy groups in one molecule.

[0056] Examples of the monofunctional epoxy compound include monofunctional aliphatic epoxy compounds and monofunctional aromatic epoxy compounds.

[0057] Examples of the monofunctional aliphatic epoxy compound include glycidyl ethers of aliphatic alcohols, glycidyl esters of alkyl carboxylic acids, etc. Specific examples thereof include allyl glycidyl ether, butyl glycidyl ether, sec-butyl phenyl glycidyl ether, 2-ethylhexyl glycidyl ether, alkyl glycidyl ether in which carbons 12 and 13 are mixed, glycidyl ether of alcohol, monoglycidyl ether of higher aliphatic alcohol, glycidyl ester of higher fatty acid, etc.

[0058] As the above monofunctional aliphatic epoxy compound, synthesized ones may be used, or commercially available products may also be used. In the case of commercially available products, for example, Denacol EX-121, Denacol EX-171, Denacol EX-192 (manufactured by Nagase ChemteX Corporation); Epolite M-1230 (manufactured by Kyoeisha Chemical Co., Ltd.), Adeka Glycerol ED-502, Adeka Glycerol ED-502S, Adeka Glycerol ED-509E, Adeka Glycerol ED-509S, Adeka Glycerol ED-529 (manufactured by ADEKA Corporation), etc.

[0059] As the monofunctional aromatic epoxy compound, there are monoglycidyl ethers of phenol compounds such as phenol, cresol, butylphenol, or their alkylene oxide adducts; Monoglycidyl etherified products of aromatic compounds having two or more phenolic hydroxyl groups such as resorcinol, hydroquinone, and catechol; Monoglycidyl etherified products of aromatic compounds having two or more alcoholic hydroxyl groups such as phenyldimethanol, phenyldiethanol, and phenyldibutanol; Monoglycidyl esters of polybasic acid aromatic compounds having two or more carboxylic acids such as phthalic acid, terephthalic acid, and trimellitic acid; Examples include glycidyl esters of benzoic acid, styrene oxide, or monoepoxidized products of divinylbenzene.

[0060] As the monofunctional aromatic epoxy compound, commercially available products may be used, and commercially available products can be used. In the case of commercially available products, for example, Denacol EX-141, Denacol EX-146, Denacol EX-147 (manufactured by Nagase ChemteX Corporation), etc. can be mentioned.

[0061] The polyfunctional epoxy compound may be one generally used in the epoxy resin composition, and the type is not particularly limited as long as it has two or more epoxy groups in one molecule.

[0062] The polyfunctional epoxy compound includes polyfunctional aliphatic epoxy compounds and polyfunctional aromatic epoxy compounds.

[0063] As the polyfunctional aliphatic epoxy compound, synthesized ones may be used, or commercially available products may be used.

[0064] As the polyfunctional aliphatic epoxy compound, difunctional aliphatic epoxy compounds having two epoxy groups in the molecule such as alkylene glycol diglycidyl ether and alkenylene glycol diglycidyl ether; Polyfunctional aliphatic epoxy compounds having three or more epoxy groups in the molecule, such as polyglycidyl ethers of trifunctional or higher alcohols like trimethylolpropane, pentaerythritol, dipentaerythritol (e.g., trimethylolpropane triglycidyl ether, pentaerythritol (tri- or tetra-) glycidyl ether, dipentaerythritol (tri-, tetra-, penta-, or hexa-) glycidyl ether, etc.); ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, butanediol diglycidyl ether, hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane diglycidyl ether, trimethylolpropane triglycidyl ether, or a mixture of trimethylolpropane diglycidyl ether and trimethylolpropane triglycidyl ether (e.g., Denacol EX-321L: manufactured by Nagase ChemteX Corporation), such as trimethylolpropane polyglycidyl ether, pentaerythritol triglycidyl ether, pentaerythritol tetraglycidyl ether, sorbitol heptaglycidyl ether, sorbitol hexaglycidyl ether, resorcinol diglycidyl ether, etc. can be mentioned.

[0065] Commercially available products can be used as the polyfunctional aliphatic epoxy compound, for example, "EP-4088S" (manufactured by ADEKA Corporation), "EHPE3150" (manufactured by Daicel Corporation), "EX-211L", "EX-212L" (both manufactured by Nagase ChemteX Corporation), etc.

[0066] Examples of polyfunctional aromatic epoxy compounds include polyglycidyl etherified products of polyhydric phenols having at least one aromatic ring such as bisphenol A and bisphenol F, or their alkylene oxide adducts; Epoxy novolac resins; Polyglycidyl ether compounds of aromatic compounds having two or more phenolic hydroxyl groups such as resorcinol, hydroquinone, and catechol; Polyglycidyl ether compounds of aromatic compounds having two or more alcoholic hydroxyl groups such as phenyldimethanol, phenyldiethanol, and phenyldibutanol; Polyglycidyl esters of polybasic acid aromatic compounds having two or more carboxylic acids such as phthalic acid, terephthalic acid, and trimellitic acid; Examples include diepoxidized divinylbenzene.

[0067] As the polyfunctional aromatic epoxy compound, a synthesized one may be used, or a commercially available product may be used.

[0068] Commercially available polyfunctional aromatic epoxy compounds can be used. For example, "Denacol EX-201", "Denacol EX-711", and "Denacol EX-721" (all manufactured by Nagase ChemteX Corporation); "Ogsool EG-280" and "Ogsool CG-400" (both manufactured by Osaka Gas Chemical Co., Ltd.); "EXA-80CRP" and "HP4032D" (both manufactured by DIC Corporation); "jER828" and "jER828EL" (both manufactured by Mitsubishi Chemical Corporation); "Adeka Resin EP-4100", "Adeka Resin EP-4100G", "Adeka Resin EP-4100E", "Adeka Resin EP-4100L", "Adeka Resin EP-4100TX", "Adeka Resin EP-4000", "Adeka Resin EP-4005", "Adeka Resin EP-4901", "Adeka Resin EP-4901E" (all manufactured by ADEKA Corporation), etc.

[0069] The monofunctional epoxy compound and the polyfunctional epoxy compound used for obtaining the amine compound represented by the formula (3) in this embodiment may be used alone or in combination of a plurality of different types.

[0070] The structures of specific monofunctional or polyfunctional epoxy compounds (c1) to (c75) are shown in Tables 3-1 to 3-5.

[0071]

Table 3-1

[0072]

Table 3-2

[0073]

Table 3-3

[0074]

Table 3-4

[0075]

Table 3-5

[0076] <Amine compound (C)> By using the amine compound (C) in combination, it is possible to improve or enhance, for example, the carbon dioxide absorption amount, carbon dioxide release amount, carbon dioxide absorption rate, and carbon dioxide release rate of the absorption liquid. Compounds that can correspond to both the amine compound (A) and the amine compound (C) are treated as those corresponding to the amine compound (A). That is, the amino alcohols in the amine compound (C) represent amino alcohols that do not correspond to the general formula (1).

[0077] The amine compound (C) used to obtain the absorption liquid in this embodiment may be used alone or in combination of a plurality of different types.

[0078] Suitable amino alcohols include, for example, monoethanolamine, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-dipropanol, 2-aminobutanol, 4-aminobutanol, diethanolamine, bis(2-hydroxy-1-methylethyl)amine, methyldiethanolamine, dimethylethanolamine, diethylethanolamine, triethanolamine, dimethylamino-1-methylethanol, 2-methylaminoethanol, 2-ethylaminoethanol, 2-propylaminoethanol, n-butylaminoethanol, 2-(isopropylamino)ethanol, 3-ethylaminopropanol, triethanolamine, diethanolamine and the like. One of these compounds can be used alone, or two or more of them can be used in combination.

[0079] Among these, as amino alcohols, from the viewpoint of further improving the reactivity or releasability of the amine compound (A) with carbon dioxide, at least one selected from the group consisting of 2-(isopropylamino)ethanol, 2-aminobutanol, and 2-amino-2-methyl-1-propanol is preferable.

[0080] Suitable cyclic polyamines are compounds in which two or more nitrogen atoms are substituted in the cycloalkyl group. Specifically, piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, 2,6-dimethylpiperazine, N-(2-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, and 1-hydroxyethylpiperazine, diazabicycloundecene, and diazabicyclononene can be mentioned. One of these compounds can be used alone, or two or more of them can be used in combination.

[0081] Among these, as cyclic polyamines, from the viewpoint of further improving the reactivity or releasability of the amine compound (A) with carbon dioxide, at least one selected from the group consisting of piperazine, N-(2-aminoethyl)piperazine, and diazabicycloundecene is preferable.

[0082] Suitable chain polyamines specifically include compounds in which two or more nitrogen atoms are substituted and have a linear or branched alkyl group with 2 to 6 carbon atoms in between, such as ethylenediamine, N-isopropylethylenediamine, N-methylethylenediamine, N-ethylethylenediamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, diethylenetriamine, 2,2-diamino-N-methyl diethylamine, N,N'-diisopropylethylenediamine, N,N'-di-tert-butylethylenediamine, N,N',N''-trimethylethylenediamine, triethylenetetramine, triethylenepentamine, N,N,N',N'-tetramethylethylenediamine, N,N-diethyl-N',N'-dimethylethylenediamine, N,N-diethyl-N',N'-dimethylethylenediamine, N,N,N',N'-tetraethylethylenediamine, tetraethylenepentamine, 1,3-diaminopropane, 3-(methylamino)propylamine, N-methyl-1,3-propanediaminopropane, N,N-dimethyl-1,3-propanediamine, N,N-diethyl-1,3-propanediamine, N,N-dibutyl-1,3-propanediamine, 3,3-diaminodipropylamine, tris(3-aminopropyl)amine, 3,3-diamino-N-methyl dipropylamine, N,N'-bis(3-aminopropyl)ethylenediamine, N,N,N',N'-tetramethyl-1,3-propanediamine, N,N,N',N'-tetraethyl-1,3-propanediamine, 1,4-diaminobutane, aminoethylaminoethanol, and guanidine derivatives. One of these compounds can be used alone, or two or more of them can be used in combination.

[0083] Among these, as the chain polyamines, from the viewpoint of further improving the reactivity or releasability of the amine compound (A) with carbon dioxide, at least one selected from the group consisting of 1,4-diaminobutane, 1,3-diaminopropane, 3,3-diaminodipropylamine, 3,3-diamino-N-methyl dipropylamine, N,N'-bis(3-aminopropyl)ethylenediamine, and N,N-dibutyl-1,3-propanediamine is preferable.

[0084] An explanation will be given about water used in the absorbent of this embodiment.

[0085] <Water> In this embodiment, water is used as the liquid medium. The amine compound (A) and the amine compound (C) are not particularly limited as long as they can be miscible with water. The amine compound (A) and the amine compound (C) can absorb carbon dioxide and release carbon dioxide by heating, but high energy is required for the separation of carbon dioxide. Therefore, in order to improve the separation efficiency of the amine compound (A) and the amine compound (C) from carbon dioxide, it has been found that by using water, the release temperature of carbon dioxide can be lowered and the release efficiency of carbon dioxide can be increased.

[0086] Since the amine compound (C) according to this embodiment has both a hydroxyl group and an alkyl group, it can be suitably dissolved in water.

[0087] In the absorbent of this embodiment, the mass ratio of the sum of the amine compound (A) and the amine compound (C) to water is preferably in the range of 5:95 to 95:5, more preferably in the range of 15:85 to 85:15, and particularly preferably in the range of 30:70 to 80:20. The content of the sum of the amine compound (A) and the amine compound (C) in the absorbent is preferably 25% by mass or more, more preferably 30% by weight or more, and particularly preferably 75% by mass or less from the viewpoint of the absorption efficiency of the absorbent.

[0088] In the absorbent of the present embodiment, the mass ratio of the amine compound (A) and the amine compound (C) in the absorbent is preferably (A):(C) = 80:20 to 20:80, more preferably 70:30 to 30:70, and particularly preferably in the range of 60:40 to 40:60. By being in this ratio, the viscosity of the absorbent is low and the volatility of the absorbent is suppressed, making it possible to realize an efficient carbon dioxide absorption and release ability.

[0089] Furthermore, for the purpose of improving the absorption and desorption rate of carbon dioxide, a liquid medium other than water may be used in the absorbent. Specific liquid media other than water are organic solvents and / or ionic liquids.

[0090] Also, the liquid medium may or may not dissolve the reaction product of the amine compound (A) and the amine compound (C) with carbon dioxide.

[0091] The ratio of water to the liquid medium other than water in the liquid medium is not particularly limited, but it is preferably contained mainly with water. Here, the main component means that the content of water is higher than that of the liquid medium other than water in the liquid medium. Specifically, the mass% ratio of water to the liquid medium other than water is preferably 80:20, more preferably 90:10, and may even be 100 mass%. The liquid medium can contain a small amount of organic solvent and / or ionic liquid as required.

[0092] Preferred types of organic solvents include glycol ether-based, sulfoxide-based, and alcohol-based. Specifically, glycol ether-based solvents include diethylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol monopropyl ether, diethylene glycol monoethyl ether, etc. Sulfoxide-based ones include dimethyl sulfoxide, sulfolane, etc. Alcohol-based ones include 1-propanol, 2-propanol, 1-butanol, etc.

[0093] Examples of the anion constituting the ionic liquid include anions of phosphoric acid, phosphonic acid, phosphate ester, or phosphonate ester. Examples of the cation constituting the ionic liquid include imidazoliums, ammoniums, or phosphoniums.

[0094] <Optional component> The absorbent of the present disclosure may further contain other components within the scope where the effects of the present invention are achieved. Examples of other components include stabilizers (side reaction inhibitors such as antioxidants) for ensuring the chemical or physical stability of the absorbent; inhibitors (such as corrosion inhibitors) for preventing deterioration of the materials of the devices and equipment using the absorbent. The total content of these other components in the absorbent is preferably 5% by mass or less.

[0095] (Antioxidant) Examples of the antioxidant include dibutylhydroxytoluene, butylhydroxyanisole, sodium erythorbate, sodium sulfite, sulfur dioxide, and the like.

[0096] (Corrosion inhibitor) Examples of the corrosion inhibitor include 1-hydroxyethane-1,1-diphosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-phosphonopropane-2-dicarboxylic acid, phosphonosuccinic acid, 2-hydroxyphosphonoacetic acid, maleic acid-based polymers (such as copolymers of maleic acid and amylene, or terpolymers of maleic acid, acrylic acid, and styrene), and the like.

[0097] (Defoaming agent) Examples of the defoaming agent include silicone-based, polyether-based, acetylenediol-based, metal soap-based, phosphate ester-based, fatty acid ester-based, and the like.

[0098] (pH adjuster) Examples of the pH adjuster include inorganic acids (such as hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, etc.), organic acids (such as citric acid, formic acid, acetic acid, oxalic acid, p-toluenesulfonic acid, etc.), inorganic bases (such as sodium hydrogen carbonate, sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, ammonia, etc.), organic bases (such as methylamine, dimethylamine, trimethylamine, diazabicycloundecene, piperazine, ethanolamine, triethanolamine, etc.).

[0099] (Viscosity modifier) Examples of the viscosity modifier include polyimine, polyvinyl alcohol, polyethylene oxide, etc.

[0100] <Gas containing carbon dioxide> Examples of the gas containing carbon dioxide include exhaust gases from thermal power plants using coal, heavy oil, natural gas, etc. as fuels, boilers in manufacturing plants, kilns in cement factories, blast furnaces for reducing iron oxide with coke, converters for steelmaking by burning carbon in pig iron, integrated gasification combined cycle power plants, etc., natural gas during mining, reformed gas, etc. The carbon dioxide concentration in the gas is usually about 5 to 50% by volume concentration, particularly about 10 to 40% by volume concentration. In such a carbon dioxide concentration range, the action effect of the present absorbent is preferably exerted. In addition, the gas containing carbon dioxide may contain gases such as nitrogen, water vapor, carbon monoxide, hydrogen sulfide, carbonyl sulfide, sulfur dioxide, nitrogen dioxide, methane, hydrogen, etc. in addition to carbon dioxide.

[0101] The absorbent of the present disclosure is excellent in absorbing hydrogen sulfide in addition to carbon dioxide.

[0102] [Method for separating and recovering carbon dioxide by absorbent] The carbon dioxide separation and recovery method of the present disclosure is a method for separating and recovering carbon dioxide in a gas containing carbon dioxide. In this method, an absorbent of the present disclosure is brought into contact with a gas containing carbon dioxide to obtain an absorbent that has absorbed carbon dioxide from the gas containing carbon dioxide (step A), and the absorbent that has absorbed carbon dioxide obtained in step A is heated to desorb and dissipate carbon dioxide from the absorbent, and the dissipated carbon dioxide is recovered (step B).

[0103] (Step A) In step A, the absorbent is brought into contact with the gas containing carbon dioxide, so that carbon dioxide in the gas containing carbon dioxide is absorbed by the absorbent and separated.

[0104] In step A, the method of bringing the absorbent into contact with the gas containing carbon dioxide is not particularly limited. For example, there are a method of bubbling the gas containing carbon dioxide into the absorbent, a method of spraying the absorbent in a mist form into the gas containing carbon dioxide (spraying or spraying method), and a method of countercurrently contacting the gas containing high-pressure carbon dioxide with the absorbent in an absorption tower filled with a filler made of magnetic material or metal mesh, etc.

[0105] The temperature in step A can be 25 to 40 °C. Within this range, the absorbent is excellent in the amount of carbon dioxide recovered and the carbon dioxide absorption rate. The temperature in step A is preferably 25 to 35 °C.

[0106] The pressure in step A can usually be 1.0 bar or more, preferably 1.0 to 3.5 bar. Also, higher carbon dioxide absorption performance can be obtained by performing at a higher pressure.

[0107] (Step B) In step B, the absorbent that has absorbed carbon dioxide obtained in step A is heated to desorb and dissipate carbon dioxide from the absorbent, and the dissipated carbon dioxide is recovered.

[0108] In the step of desorbing and releasing carbon dioxide in Process B, the temperature can be set to 50 to 160 °C. Within this range, the absorbent has excellent carbon dioxide release rate. The heating temperature in Process B is preferably 50 to 80 °C, and more preferably 50 to 60 °C.

[0109] In the step of desorbing and releasing carbon dioxide in Process B, the pressure can usually be 3.5 bar or less, preferably 1.0 to 3.5 bar. Also, by performing at a lower pressure, higher carbon dioxide release performance can be obtained.

[0110] The method of heating the absorbent that has absorbed carbon dioxide to desorb and release carbon dioxide and then recovering it is not particularly limited. For example, similar to distillation, methods such as heating the absorbent and bubbling it in a kettle for desorption, or heating while expanding the liquid interface in a stripping tower filled with packing materials such as tray towers, spray towers, magnetic or wire mesh can be mentioned. By these methods, pure or very high-concentration carbon dioxide can be recovered.

[0111] After carbon dioxide is released in Process B, the absorbent can be returned to Process A and recycled. In this circulation process, the heat added in Process B is utilized for raising the temperature of the absorbent through heat exchange with the absorbent that has absorbed carbon dioxide. Through this heat exchange, the energy reduction of the entire carbon dioxide separation and recovery process is planned.

[0112] The carbon dioxide separated and recovered by the method for separating and recovering carbon dioxide using the absorbent of the present disclosure usually has a volume concentration of 95 to 100%, and can be pure or very high-concentration. The separated and recovered carbon dioxide can be used for geological or submarine isolation storage (CCS) and enhanced oil recovery (EOR) where the technology is currently being developed. In addition, the utilization applications of the separated and recovered carbon dioxide are not particularly limited. For example, synthetic raw materials such as chemical products, or refrigerants for food refrigeration can be mentioned.

Examples

[0113] Hereinafter, the absorbent for separating and recovering carbon dioxide according to the embodiment will be described in more detail with reference to examples. However, the present disclosure is not limited to these examples. The mass spectra in the examples were measured by TOF-MS for molecular weight measurement. Apparatus name: AutoFlexII (manufactured by Bruker Daltonics)

[0114] [Synthesis Example 1] Synthesis method of compound (A1) [Chemical formula]

[0115] Under a nitrogen atmosphere, 5.0 g (38.1 mmol) of 3,3'-diaminodipropylamine (b1) mixed with 50 ml of methanol and 7.10 g (38.1 mmol) of 2-ethylhexyl glycidyl ether (c13) were added and stirred. After the addition, stirring was carried out at room temperature for 24 hours, and the progress of the reaction was confirmed by the fact that (c13), the reactant, was not detected by TOF-MS. The solvent methanol was removed by decompression at 40 °C or lower to obtain the target compound (A1).

[0116] [TOF-MS measurement results of compound (A1)] Calculated value of molecular weight: C17H39N3O2, Mol.Wt. 317.51; Observed molecular weight: m / z 317.6

[0117] [Synthesis Examples 2 to 8] In the same manner as in Synthesis Example 1, the amine compounds in Table 2 and the epoxy compounds in Tables 3-1 to 3-5 in the previous period were combined to synthesize compounds (A4), (A5), (A6), (A9), (A12), (A15), and (A22), and the molecular weight was measured by TOF-MS. The obtained compounds were identified by TOF-MS in the same manner as in Synthesis Example 1. The yields and mass spectrum results of the synthesized compounds are shown in Table 4. The compound numbers are the same as those described in Tables 1-1 to 1-2 of this specification.

[0118]

Table 4

[0119] (Method for Measuring Carbon Dioxide Gas Emission Efficiency) 100 g of the carbon dioxide absorbent adjusted in the following-described example (in a state of being placed in a gas absorption bottle with a volume of 200 ml) was adjusted to 25°C in a water bath. A mixed gas of carbon dioxide gas at 100 ml / min and nitrogen gas at 400 ml / min (500 ml / min) was blown into this carbon dioxide absorbent while bubbling for 1 hour. The absorption amount of carbon dioxide gas at this time (the carbon dioxide absorption amount (L) for 1 hour) was measured using a gas flow meter and a carbon dioxide concentration meter. Using this carbon dioxide absorption amount (L) for 1 hour, the carbon dioxide absorption amount (L) per 1 kg of the carbon dioxide absorbent was calculated.

[0120] Next, this carbon dioxide absorbent was adjusted to 60°C in a water bath. Nitrogen gas at 500 ml / min was blown into this carbon dioxide absorbent while bubbling for 2 hours. The emission amount of carbon dioxide gas at this time (the carbon dioxide emission amount (L) for 2 hours) was measured using a gas flow meter and a carbon dioxide concentration meter. Using the carbon dioxide emission amount (L) for 2 hours, the carbon dioxide emission amount (L) per 1 kg of the carbon dioxide absorbent was calculated. From the above-described carbon dioxide emission amount (L) for 2 hours and the carbon dioxide absorption amount (L) for 1 hour, the carbon dioxide gas emission efficiency (= carbon dioxide emission amount (L) for 2 hours ÷ carbon dioxide absorption amount (L) for 1 hour) was calculated.

[0121] From the measurement of the calculated carbon dioxide gas emission efficiency, criteria were set and evaluated as follows, and SS, S, A, and B were set as the actually usable regions. The evaluation results are shown in Table 6. SS: Emission efficiency is 0.9 or more S: Emission efficiency is 0.8 or more and less than 0.9 A: Emission efficiency is 0.7 or more and less than 0.8 B: Emission efficiency is 0.6 or more and less than 0.7 C: Emission efficiency is less than 0.6

[0122] [Materials and Gas Types Used for Evaluation] For the sake of brevity in notation, the following abbreviations were used. AMP: 2 - Amino - 2 - methyl - propanol IPAE: 2 - (Isopropylamino)ethanol AEAE: 2 - (2 - Aminoethylamino)ethanol AB: 2 - Aminobutanol DPTA: Dipropylene triamine MDEA: N - Methyldiethanolamine Pz: Piperazine MEA: Monoethanolamine

[0123] The gas species used for evaluation are as shown in Table 5.

Table 5

[0124] [Example 1 (Absorbent A1)] To 30 g of the compound (A1) obtained in Synthesis Example 1, 70 g of water was added and mixed with stirring to prepare a carbon dioxide absorbent (100 g). This was placed in a 200 - ml gas absorption bottle, and the measurement of the carbon dioxide gas release efficiency was carried out.

[0125] The amount of carbon dioxide absorbed in 1 hour (L) was 2.32 L in terms of standard state conversion. That is, the amount of carbon dioxide absorbed in 1 hour per 1 kg of the carbon dioxide absorbent (L) was 23.2 L in the standard state. (The amount of carbon dioxide absorbed per minute per 1 kg of the carbon dioxide absorbent (ml / min) was 386 ml / min (= 23.2 [L / hour] × 1000 [ml / L] ÷ 60 [min / hour]). The amount of carbon dioxide released in 2 hours (L) was 1.62 L in terms of standard state conversion. That is, the amount of carbon dioxide released in 2 hours per 1 kg of the carbon dioxide absorbent (L) was 16.2 L in terms of standard state conversion. (The amount of carbon dioxide released per minute per 1 kg of the carbon dioxide absorbent (mL / min) was 135 ml / min (= 16.2 [L / 2 hours] × 1000 [ml / L] ÷ 120 [min / hour]).

[0126] From these, the emission efficiency of carbon dioxide gas was 0.70. The above results are shown in Table 6.

[0127] [Example 2 (Absorbent 2)] 30 g of compound (A1) was changed to compound (A4), and a carbon dioxide absorbent (100 g) was prepared in the same manner. This was placed in a 200 ml gas absorption bottle, and the emission efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0128] [Example 3 (Absorbent 3)] 30 g of compound (A1) in Example 1 was changed to compound (A5), and a carbon dioxide absorbent (100 g) was prepared in the same manner. This was placed in a 200 ml gas absorption bottle, and the emission efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0129] [Example 4 (Absorbent 4)] 30 g of compound (A1) in Example 1 was changed to compound (A9), and a carbon dioxide absorbent (100 g) was prepared in the same manner. This was placed in a 200 ml gas absorption bottle, and the emission efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0130] [Example 5 (Absorbent 5)] 30 g of compound (A1) in Example 1 was changed to compound (A12), and a carbon dioxide absorbent (100 g) was prepared in the same manner. This was placed in a 200 ml gas absorption bottle, and the emission efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0131] [Example 6 (Absorbent 6)] 30 g of compound (A1) in Example 1 was changed to compound (A15), and a carbon dioxide absorbent (100 g) was prepared in the same manner. This was placed in a 200 ml gas absorption bottle, and the emission efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0132] [Example 7 (Absorbent 7)] Thirty grams of the compound (A1) in Example 1 was changed to the compound (A22), and similarly, a carbon dioxide absorption solution (100 g) was prepared. This was placed in a 200 ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0133] [Example 8 (Absorbent 8)] Thirty grams of the compound (A1) in Example 1 was changed to 20 g of the compound (A1) and 10 g of AMP respectively. Similarly, a carbon dioxide absorption solution (100 g) was prepared. This was placed in a 200 ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0134] [Example 9 (Absorbent 9)] Twenty grams of the compound (A1) and 10 g of AMP in Example 8 were changed to 20 g of the compound (A4) and 10 g of AEAE respectively. Similarly, a carbon dioxide absorption solution (100 g) was prepared. This was placed in a 200 ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0135] [Example 10 (Absorbent 10)] Twenty grams of the compound (A1) and 10 g of AMP in Example 8 were changed to 20 g of the compound (A5) and 10 g of AB respectively. Similarly, a carbon dioxide absorption solution (100 g) was prepared. This was placed in a 200 ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0136] [Example 11 (Absorbent 11)] Twenty grams of the compound (A1) and 10 g of AMP in Example 8 were changed to 20 g of the compound (A6) and 10 g of DPTA respectively. Similarly, a carbon dioxide absorption solution (100 g) was prepared. This was placed in a 200 ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0137] [Example 12 (Absorbent 12)] 20 g of the compound (A1) of Example 8 and 10 g of AMP were respectively changed to 20 g of the compound (A12) and 10 g of IPAE, and a carbon dioxide absorption solution (100 g) was prepared in the same manner. This was placed in a 200 ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0138] [Example 13 (Absorbent 13)] 20 g of the compound (A1) of Example 8 and 10 g of AMP were respectively changed to 20 g of the compound (A15) and 10 g of MDEA, and a carbon dioxide absorption solution (100 g) was prepared in the same manner. This was placed in a 200 ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0139] [Example 14 (Absorbent 14)] 20 g of the compound (A1) of Example 8 and 10 g of AMP were respectively changed to 20 g of the compound (A22) and 10 g of Pz, and a carbon dioxide absorption solution (100 g) was prepared in the same manner. This was placed in a 200 ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0140] [Example 15 (Absorbent 15)] 20 g of the compound (A6) of Example 11 and 10 g of DPTA were respectively changed to 25 g of the compound (A6) and 15 g of DPTA, and a carbon dioxide absorption solution (100 g) was prepared in the same manner. This was placed in a 200 ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0141] [Example 16 (Absorbent 16)] 20 g of the compound (A6) of Example 11 and 10 g of DPTA were respectively changed to 30 g of the compound (A6) and 20 g of DPTA, and a carbon dioxide absorption solution (100 g) was prepared in the same manner. This was placed in a 200 ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0142] [Example 17 (Absorbent 17)] 20 g of the compound (A6) of Example 11 and 10 g of DPTA were changed to 35 g of the compound (A6) and 25 g of DPTA, respectively, and a carbon dioxide absorption solution (100 g) was similarly prepared. This was placed in a 200-ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0143] [Example 18 (Absorbent 18)] 20 g of the compound (A6) of Example 11 and 10 g of DPTA were changed to 15 g of the compound (A6) and 15 g of DPTA, respectively, and a carbon dioxide absorption solution (100 g) was similarly prepared. This was placed in a 200-ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0144] [Example 19 (Absorbent 19)] 20 g of the compound (A6) of Example 11 and 10 g of DPTA were changed to 10 g of the compound (A6) and 20 g of DPTA, respectively, and a carbon dioxide absorption solution (100 g) was similarly prepared. This was placed in a 200-ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0145] [Example 20 (Absorbent 20)] 20 g of the compound (A6) of Example 11 and 10 g of DPTA were changed to 8 g of the compound (A6) and 22 g of DPTA, respectively, and a carbon dioxide absorption solution (100 g) was similarly prepared. This was placed in a 200-ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6. [Example 21 (Absorbent 21)] The DPTA of Example 11 was changed to AEAE, and a carbon dioxide absorption solution (100 g) was similarly prepared. This was placed in a 200-ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0146] [Comparative Example 1] 20 g of the compound (7) of Example 1 and 10 g of AMP were changed to 30 g of MEA, and a carbon dioxide absorption solution (100 g) was similarly prepared. This was placed in a 200-ml gas absorption bottle, and the release efficiency of carbon dioxide gas was measured. The evaluation results are shown in Table 6.

[0147]

Table 6

[0148] [Examples 22 to 42, Comparative Example 2] (Degree of change in absorption amount after repeated evaluation of carbon dioxide gas absorption / emission) Using the absorption liquids 1 to 21 prepared in Table 6, the above-described measurement of carbon dioxide gas absorption / emission was repeated 10 times. Thereafter, in the same manner as in the first test, the absorption amount at the 11th time was calculated, and the degree of decrease with respect to the absorption amount at the first time was evaluated. The evaluation criteria were as follows, and S, A, and B were defined as the actually usable regions. The evaluation results are shown in Table 7. S: The absorption amount at the 11th time is 99.5% or more with respect to the absorption amount at the first time A: The absorption amount at the 11th time is more than 99% and less than 99.5% with respect to the absorption amount at the first time B: The absorption amount at the 11th time is more than 98% and less than 99% with respect to the absorption amount at the first time C: The absorption amount at the 11th time is less than 98% with respect to the absorption amount at the first time

[0149]

Table 7

[0150] [Examples 43 to 63, Comparative Example 3] (Absorption rate of carbon dioxide gas) The absorption rate was evaluated using the absorption liquids 1 to 21 prepared in Table 6. 100 g of the prepared carbon dioxide absorption liquid (in a state of being placed in a gas absorption bottle with a volume of 200 ml) was adjusted to 25°C in a water bath. A mixed gas (500 ml / min) of 100 ml / min of carbon dioxide gas and 400 ml / min of nitrogen gas was blown into this carbon dioxide absorption liquid while bubbling. The absorption amount of carbon dioxide gas at this time (the carbon dioxide absorption amount (L) for 10 minutes) was measured using a gas flow meter and a carbon dioxide concentration meter. The value obtained by dividing the absorption amount by 10 was defined as the absorption rate (L / min).

[0151] The evaluation criteria are as follows, with S, A, and B being the actually usable ranges. The evaluation results are shown in Table 8. For comparison, the results of Comparative Example 3 using the absorbent 22 described in <Example 1> are also shown. S: Absorption rate is 1.00 L / min or more A: Absorption rate is 0.75 L / min or more and less than 1.00 L / min B: Absorption rate is 0.50 L / min or more and less than 0.75 L / min C: Absorption rate is less than 0.50 L / min

[0152]

Table 8

[0153] As described in the above examples, the carbon dioxide absorbent of the present invention has an effect of being superior to conventionally known carbon dioxide absorbents in terms of the carbon dioxide release rate and release efficiency (release amount / absorption amount). Also, it has been found that the absorbent of the present disclosure can efficiently release carbon dioxide at a release temperature of 60°C under the experimental conditions of this time, as opposed to the release temperature of 120°C of the generally known MEA aqueous solution.

Claims

1. An absorbent for separating and recovering carbon dioxide from a gas containing carbon dioxide, wherein the absorbent is an absorbent containing an amine compound (A) represented by formula (1) and water. Formula (1) 【Chemical 1】 In the formula, R １ is a group represented by the general formula (2), R ２ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms in which the carbon atom adjacent to N is a primary carbon atom, or -CH ２ CH(OH)CH ２ X ２ A ２ and X １ is a direct bond, -O-, -OC(=O)-, -CO(=O)-, or -NA ３ -. A １ is a hydrogen atom or an n-valent organic residue (however, when １ is a direct bond and １ is a hydrogen atom, it is excluded). n is an integer from 1 to 6, X ２ is a direct bond, -O-, -OC(=O)-, -CO(=O)-, or -NA ３ -, and A ２ is a hydrogen atom or a monovalent organic residue (however, when ２ X is directly bonded and A ２ is a hydrogen atom, this case is excluded). A ３ is a hydrogen atom or a monovalent organic residue. Formula (2) [Chemical Formula 2] R １０ and R １２ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a hydroxyalkyl group, R １１ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a hydroxyalkyl group, or - (CH ２ ). ｓ -R １３ wherein R １３ is a hydroxy group or -N(R １４ )R １５ wherein R １４ and R １５ are each independently a hydrogen atom, a methyl group, or a hydroxyalkyl group, q is 2 or 3, r is 3, s is 2 or 3.

2. Said A １ The absorbent liquid according to claim 1, wherein A is an n-valent organic residue.

3. Said A １ , A ２ and A ３ are each independently a linear or branched aliphatic hydrocarbon residue which may have a substituent and may have a hetero atom in the carbon chain; a (meth)acryloyl residue which may have a substituent; an alicyclic hydrocarbon residue which may have a substituent and may have a hetero atom in the carbon chain; an aromatic hydrocarbon residue which may have a substituent, or an aromatic heterocyclic residue which may have a substituent. The absorbent according to claim 1.

4. The aforementioned R ２ is a hydrogen atom, and the absorbent according to claim 1.

5. Furthermore, the absorbent according to claim 1, further comprising at least one amine compound (C) selected from the group consisting of amino alcohols, cyclic polyamines, and chain polyamines.

6. The absorbent according to claim 1, wherein the amine compound (A) represented by the formula (1) is contained in an amount of 5% by mass or more.

7. Furthermore, the absorbent according to claim 1, wherein the gas contains hydrogen sulfide and the absorbent absorbs the hydrogen sulfide.

8. A method for separating and recovering carbon dioxide from a gas containing carbon dioxide, comprising the following steps A and B: Step A: A step of bringing the absorbent according to any one of claims 1 to 7 into contact with a gas containing carbon dioxide to obtain an absorbent that has absorbed carbon dioxide from the gas containing carbon dioxide; Step B: A step of heating the absorbent that has absorbed carbon dioxide obtained in Step A to desorb and dissipate carbon dioxide from the absorbent, and recovering the dissipated carbon dioxide.

9. The method according to claim 8, wherein the heating temperature in the step B is 50°C or higher and 160°C or lower.

Images