Absorption liquid for carbon dioxide, and method for separating and recovering carbon dioxide

Abstract

Provided are: a carbon dioxide absorption / release liquid which has a high carbon dioxide absorption ability, a high carbon dioxide release ability at low temperatures, and little deterioration even if an absorption / release cycle is repeated; a method for separating and recovering carbon dioxide; and a method for producing an amine compound. This absorption liquid is used for separating and recovering carbon dioxide from a gas containing carbon dioxide, and contains an amine compound (A) represented by general formula (1) and a liquid medium (B). # imgabs0 #

Description

Technical Field

[0001] The present disclosure relates to an absorbent for 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 sharp increase in the emissions of greenhouse gases such as carbon dioxide or methane accompanying social activities has been cited as one of the causes of global warming. In particular, carbon dioxide is also the most major among greenhouse gases, and according to the Paris Agreement that came into force in 2016, countermeasures for reducing carbon dioxide emissions are an urgent priority.

[0003] As a measure for reducing carbon dioxide emissions, the separation and recovery of carbon dioxide has attracted much attention, and the development of carbon dioxide absorbents has been actively carried out. Therefore, in recent years, for the gas containing carbon dioxide discharged from power plants or steel mills, the development of carbon dioxide separation and recovery technology based on chemical absorption using an aqueous solution of an amine compound as the main component has been vigorously promoted.

[0004] As the amine compound, the following are known: Monoethanolamine (MEA) as a primary alkanolamine, Diglycolamine (DGA), 2-Amino-2-methyl-1-propanol (AMP); 2-(Methylamino)ethanol (MAE), 2-(Ethylamino)ethanol (EAE), 2-(Isopropylamino)ethanol (IPAE), 3-(Isopropylamino)propanol (IPAP), Diethanolamine (DEA), Diisopropanolamine (DIPA) as secondary alkanolamines; N-Methyldiethanolamine (MDEA), 2-(Dimethylamino)ethanol (DMAE), Triethanolamine (TEA) as tertiary alkanolamines; N,N,N',N'-Tetramethyl-1,6-diaminohexane (TMDAH), N,N,N',N'-Tetramethyl-1,4-diaminobutane (TMDAB), Bis(2-dimethylaminoethyl)ether (BDER) as tertiary alkylamines. In particular, MEA is widely used.

[0005] As an existing technique for separating and recovering carbon dioxide with less energy, for example, Patent Document 1 describes a method for removing carbon dioxide from combustion exhaust gas based on a method of contacting an aqueous solution of a secondary alkanolamine having an alkyl steric hindrance around the amino group with combustion exhaust gas at atmospheric pressure.

[0006] As for 2 hydrogen sulfide (H 2One of the amine compounds contained in a carbon dioxide absorbent in a method for deacidifying a gaseous effluent of at least one acidic compound in a group is related to 4-amino-2,2,6,6-tetramethylpiperidine having a hindered amine skeleton or a specific solvent. In these documents, after absorbing acidic compounds such as carbon dioxide, a phase separation state is formed, but specific examples of 4-amino-2,2,6,6-tetramethylpiperidine or the specific solvent are not shown, and there is no description of the carbon dioxide absorption ability or release efficiency (Patent Document 2 and Patent Document 3).

[0007] In addition, a carbon dioxide absorption liquid containing 4-amino-2,2,6,6-tetramethylpiperidine, water, and sulfolane has been reported. For the carbon dioxide release temperature of the absorption liquid reacting with carbon dioxide, only an example in which the temperature is 120°C is described, and the release efficiency or repeated durability when the carbon dioxide release temperature is reduced to below 100°C is not described (Patent Document 4 and Patent Document 5).

[0008] On the other hand, as a carbon dioxide separation material using a compound having a plurality of amine structures introduced into one molecule, it is reported that a triazine derivative is used, and a compound in which a plurality of amine compounds are chemically bonded to a triazine skeleton and an epoxy compound and introduced therein is used as a gas separation membrane for separating carbon dioxide and other gases (Patent Document 6).

[0009] Prior Art Documents

[0010] Patent Documents

[0011] Patent Document 1: Japanese Patent Laid-Open No. 5-301023

[0012] Patent Document 2: Japanese Patent Application Laid-Open No. 2009-529420

[0013] Patent Document 3: US Patent Application Publication No. 2006 / 104877

[0014] Patent Document 4: Japanese Patent Laid-Open No. 2012-223766

[0015] Patent Document 5: Japanese Patent Laid-Open No. 2012-516761

[0016] Patent Document 6: Japanese Patent Laid-Open No. 2008-247749 Summary of the Invention

[0017] Problems to be Solved by the Invention

[0018] The object of the present disclosure is to provide a carbon dioxide absorption and release liquid and a method for separating and recovering carbon dioxide, which have a high carbon dioxide absorption capacity, a high carbon dioxide release capacity at low temperatures, and little deterioration even when absorption and release cycles are repeated.

[0019] Technical means for solving the problem

[0020] The present disclosure provides the following carbon dioxide absorption liquid and method for separating and recovering carbon dioxide.

[0021] [1] An absorption liquid for separating and recovering carbon dioxide from a gas containing carbon dioxide,

[0022] The absorption liquid contains an amine compound (A) represented by the following general formula (1) and a liquid medium (B).

[0023] [Chemical formula 1]

[0024]

[0025] In the formula,

[0026] R 1 is a hydrogen atom or a hydrocarbon group which may have a substituent and may have a heteroatom in the carbon chain, and the carbon atom adjacent to N is a primary carbon atom or a carbon atom constituting a ring,

[0027] R 2 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms and the carbon atom adjacent to N is a primary carbon atom, or is -CH 2 CH(OH)CH 2 X 2 A 2 ,

[0028] X 1 is a direct bond, -O-, -OC(=O)-, -CO(=O)- or -NA 3 -,

[0029] A 1 is a hydrogen atom or an n-valent organic residue (except when X 1 is a direct bond and A 1 is a hydrogen atom),

[0030] n is an integer from 1 to 6,

[0031] X 2 is a direct bond, -O-, -OC(=O)-, -CO(=O)- or -NA 3 -,

[0032] A 2 is a hydrogen atom or a monovalent organic residue (where X 2 is a direct bond and A2 except for the case of a hydrogen atom)

[0033] A 3 is a hydrogen atom or a monovalent organic residue.

[0034] [2] The absorbent according to [1], wherein the R 1 has a nitrogen atom.

[0035] [3] The absorbent according to [1] or [2], wherein the R 1 is a group represented by the following general formula (2), general formula (3), general formula (4), or general formula (5).

[0036] [Chemical formula 2]

[0037]

[0038] In the formula,

[0039] R 3 , R 4 , R 5 , and R 6 are each independently a hydrogen atom or a methyl group,

[0040] R 7 is a hydrogen atom or a methyl group,

[0041] R 8 is a hydrogen atom or a methyl group,

[0042] p is an integer from 0 to 4,

[0043] R 9 is an alkyl group having 1 to 8 carbon atoms,

[0044] m is an integer from 0 to 4,

[0045] R 10 and R 12 are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a hydroxyalkyl group,

[0046] R 11 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a hydroxyalkyl group, or -(CH 2 ) s -R 13 ,

[0047] R 13 is a hydroxy group or -N(R 14 )R 15 , R 14 and R 15 are each independently a hydrogen atom, a methyl group, or a hydroxyalkyl group,

[0048] q is 2 or 3,

[0049] r is 2 or 3,

[0050] s is 2 or 3.

[0051] [4] The absorbent according to any one of [1] to [3], wherein the A 1 is an n-valent organic residue.

[0052] [5] The absorbent according to any one of [1] to [4], wherein the 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 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 or an aromatic heterocyclic residue which may have a substituent.

[0053] [6] The absorbent according to any one of [1] to [5], wherein the R 2 is a hydrogen atom.

[0054] [7] The absorbent according to any one of [1] to [6] further comprises at least one amine compound (C) selected from the group consisting of amino alcohols, cyclic polyamines and linear polyamines.

[0055] [8] The absorbent according to any one of [1] to [7], wherein the total Hansen solubility parameter (δT) of the liquid medium (B) is 17 MPa 1 / 2 or more.

[0056] [9] The absorbent according to any one of [1] to [8], wherein the proportion of water in the liquid medium (B) is 50% by mass or less.

[0057]

[10] The absorbent according to any one of [1] to [9] contains 5% by mass or more of the amine compound (A) represented by the formula (1).

[0058]

[11] The absorbent according to any one of [1] to

[10] , further, the gas contains hydrogen sulfide, and the absorbent absorbs the hydrogen sulfide.

[0059]

[12] A method comprising the following steps A and B and used for separating and recovering carbon dioxide from a gas containing carbon dioxide, the method is:

[0060] Step A: A step of bringing the absorbent according to any one of [1] to

[11] into contact with a gas containing carbon dioxide to obtain an absorbent that has absorbed carbon dioxide from the gas containing carbon dioxide,

[0061] Process B: A process of heating the carbon dioxide-absorbed absorption liquid obtained in Process A to cause carbon dioxide to separate from the absorption liquid and diffuse, and recovering the diffused carbon dioxide.

[0062]

[13] The method according to

[12] , wherein the heating temperature in the process B is 50°C or higher and 160°C or lower.

[0063] Effects of the Invention

[0064] According to the present disclosure, the absorption liquid has a high carbon dioxide recovery amount and absorption rate, has a carbon dioxide release ability at low energy, and suppresses deterioration of materials caused by repeated recovery and release of carbon dioxide. Thus, carbon dioxide separation and recovery can be performed with low energy as a whole system. Furthermore, by improving the absorption efficiency, a more compact carbon dioxide separation and recovery device can be designed, and the initial cost is reduced. Detailed Description of the Invention

[0065] Hereinafter, the absorption liquid and the method for separating and recovering carbon dioxide will be described.

[0066] In addition, 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.

[0067] 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 may be different substituents within the range of defining the symbols.

[0068] [Absorption Liquid]

[0069] The absorption liquid of the present disclosure is used for separating and recovering carbon dioxide from a gas containing carbon dioxide, and the absorption liquid contains an amine compound (A) represented by the following general formula (1) and a liquid medium (B).

[0070] [Chemical Formula 3]

[0071]

[0072] In the formula,

[0073] R 1 is a hydrogen atom or a hydrocarbon group that may have a substituent and may have a heteroatom in the carbon chain, and the carbon atom adjacent to N is a primary carbon atom or a carbon atom constituting a ring.

[0074] R 2 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms and the carbon atom adjacent to N is a primary carbon atom, or is -CH 2 CH(OH)CH2 X 2 A 2 ,

[0075] X 1 is a direct bond, -O-, -OC(=O)-, -CO(=O)- or -NA 3 -,

[0076] 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, excepted),

[0077] n is an integer from 1 to 6,

[0078] X 2 is a direct bond, -O-, -OC(=O)-, -CO(=O)- or -NA 3 -,

[0079] A 2 is a hydrogen atom or a monovalent organic residue (wherein, X 2 is a direct bond and A 2 is a hydrogen atom, excepted),

[0080] A 3 is a hydrogen atom or a monovalent organic residue.

[0081] The inventors have found that by using the specific amine compound (A), the energy consumption required for a high carbon dioxide recovery amount and the carbon dioxide recovery amount can be suppressed to a low level. The absorbent liquid of the present disclosure using the specific amine compound (A) can not only efficiently absorb carbon dioxide, but also release carbon dioxide with low energy and recover high-purity carbon dioxide with high efficiency, and is not easily deteriorated even when absorption and release are repeated.

[0082] <Amine Compound (A)>

[0083] The amine compound (A) is a compound represented by the following general formula (1).

[0084] [Chemical Formula 4]

[0085]

[0086] R 1 is a hydrogen atom, or a hydrocarbon group which may have a substituent and may have a hetero atom in the carbon chain, and the carbon atom adjacent to N is a primary carbon atom or a carbon atom constituting a ring. Herein, N represents N explicitly shown in the formula (1).

[0087] Examples of the hydrocarbon group in which the carbon atom adjacent to N is a primary carbon atom include linear alkyl groups. In addition, examples of the hydrocarbon group in which the carbon atom adjacent to N is a carbon atom constituting a ring include cycloalkyl groups and aryl groups.

[0088] Examples of the heteroatom that may be present in the carbon chain include O, N, S, Si, etc., and O or N is preferred. The carbon chain may have two or more heteroatoms.

[0089] In addition, as for R 1 Examples of the "substituent" that may be present include: halogen atom, linear or branched alkyl group, cycloalkyl group, alkoxy group, cyano group, trifluoromethyl group, nitro group, hydroxy group, carbamoyl group, N-substituted carbamoyl group, sulfamoyl group, N-substituted sulfamoyl group, carboxyl group, sulfo group, amino group, imino group, phenyl group, mercapto group, etc. The substituent may further have a substituent, and examples of the substituent include the above-mentioned substituents.

[0090] Among them, R 1 is preferably a hydrogen atom, an alkyl group that may have a substituent and may have a heteroatom in the carbon chain, a heterocyclic group that may have a substituent, or a cycloalkyl group that may have a substituent.

[0091] R 1The alkyl groups that may have substituents and may have heteroatoms in the carbon chain include, for example: methyl, ethyl, propyl, butyl, isobutyl, neopentyl, n-hexyl, n-octyl, stearyl, 2-ethylhexyl, trichloromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, 2,2-dibromoethyl, 2,2,3,3-tetrafluoropropyl, 2-ethoxyethyl, 2-butoxyethyl, 2-nitropropyl, benzyl, 4-methylbenzyl, 4-tert-butylbenzyl, 4-methoxybenzyl, 4-nitrobenzyl, 2,4-dichlorobenzyl, methylthio, ethylthio, propylthio, butylthio, pentylthio, hexylthio, octylthio, decylthio, dodecylthio, octadecylthio, methoxyethylthio, aminoethylthio, benzylaminoethylthio, methylcarbonylaminoethylthio, phenylcarbonylaminoethylthio, mercaptomethyl, 2-mercaptoethyl, 1-mercaptoethyl, aminomethyl, aminoethyl, N-methylaminoethyl, N-dimethylaminoethyl, N-ethylaminoethyl, N-(aminoethyl)aminoethyl, N-(hydroxyethyl)aminoethyl, N-propylaminoethyl, N-isopropylaminoethyl, N-butylaminoethyl, aminopropyl, N-methylaminopropyl, N-ethylaminopropyl, N-propylaminopropyl, N-(aminopropyl)aminopropyl, N-isopropylaminopropyl, N-butylaminopropyl, dibutylaminopropyl, dimethylaminopropyl, diethylaminopropyl, aminobutyl, aminopentyl, aminohexyl, aminooctyl, aminodecyl, aminododecyl, aminooctadecyl, aminoethoxymethyl, aminoethoxyethyl, aminoethylaminoethyl, aminoethylaminomethylphenyl, aminoethylaminocarbonylmethyl, aminoethylaminocarbonylphenyl, hydroxymethyl, 2-hydroxyethyl, N-(hydroxyethyl)aminoethyl, 2-hydroxypropyl, 3-hydroxypropyl, 4-hydroxybutyl, cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl, cyclopentylethyl, cyclohexylethyl, cyclopentylpropyl, cyclohexylpropyl, 2-(1-piperazinyl)ethyl, etc. As the alkyl groups with substituents, aminoethyl, N-methylaminoethyl, N-ethylaminoethyl, N-(aminoethyl)aminoethyl, N-propylaminoethyl, N-isopropylaminoethyl, N-butylaminoethyl, aminopropyl, N-methylaminopropyl, N-ethylaminopropyl, N-propylaminopropyl, N-(aminopropyl)aminopropyl, N-isopropylaminopropyl, N-butylaminopropyl, aminobutyl, 2-(1-piperazinyl)ethyl are preferred, and aminoethyl, N-methylaminoethyl, N-ethylaminoethyl, N-(aminoethyl)aminoethyl are more preferred.

[0092] Heterocyclic groups that may have substituents include, for example: 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrrolyl, 3-pyrrolyl, 2-furyl, 3-furyl, 2-thienyl, 3-thienyl, 2-imidazolyl, 2-oxazolyl, 2-thiazolyl, piperidinyl, 4-piperidinyl, morpholinyl, 2-morpholinyl, N-indolyl, 2-indolyl, 2-benzofuranyl, 2-benzothienyl, 2-quinolyl, N-carbazolyl, piperidinyl group, etc.

[0093] Cycloalkyl groups that may have substituents include, for example: cyclopropyl, methylcyclopropyl, cyclobutyl, cyclopentyl, methylcyclopentyl, ethylcyclopentyl, cyclohexyl, methylcyclohexyl, ethylcyclohexyl, propylcyclohexyl, 4,4'-methylenebis(cyclohexyl) group, etc.

[0094] In terms of taking into account both the carbon dioxide adsorption property and the carbon dioxide release ability at low temperatures, where R 1 is preferably a group having a nitrogen atom, and more preferably a group represented by the following general formula (2), general formula (3), general formula (4), or general formula (5). In addition, * in the formula represents the bonding bond with N in formula (1).

[0095] [Chemical formula 5]

[0096]

[0097] In formula (2), R 3 , R 4 , R 5 and R 6 are each independently a hydrogen atom or a methyl group, and R 7 is a hydrogen atom or a methyl group. In terms of the carbon dioxide adsorption property and the low-temperature release property, R 3 ~R 6 are preferably methyl groups. In addition, in terms of the carbon dioxide adsorption property and the low-temperature release property, R 7 is preferably a hydrogen atom.

[0098] In formula (3), R 8 is a hydrogen atom or a methyl group, and p is an integer from 0 to 4. In terms of the carbon dioxide adsorption property and the low-temperature release property, R 8 is preferably a hydrogen atom. In addition, in terms of the carbon dioxide adsorption property, the low-temperature release property, and the ease of synthesis, p is preferably from 1 to 4, and more preferably from 2 to 3.

[0099] In formula (4), R 9 is an alkyl group having 1 to 8 carbon atoms, and m is an integer from 0 to 4.

[0100] As R 9Examples of the alkyl group in [compound name] include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, hexyl, octyl, etc. In terms of the carbon dioxide adsorption property and low-temperature release property, R 9 is preferably an alkyl group having 1 to 4 carbon atoms, and among them, methyl is preferred. In addition, m represents the number of substitutions of R 9 . In terms of the carbon dioxide adsorption property and low-temperature release property, it is preferably 0 to 2, and more preferably 0 to 1.

[0101] In formula (5), 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 , R 13 is a hydroxy group, or -N(R 14 )R 15 , 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 2 or 3, s is 2 or 3. In terms of the carbon dioxide adsorption property and low-temperature release property, q is preferably 3 and r is preferably 3.

[0102] Examples of the alkyl group having 1 to 8 carbon atoms in R 10 to R 12 include the same alkyl groups as those of the aforementioned R 9 . In terms of the carbon dioxide adsorption property and low-temperature release property, R 10 to R 12 are preferably alkyl groups having 1 to 4 carbon atoms, and preferably methyl or ethyl.

[0103] In the hydroxyalkyl groups in R 10 to R 12 , R 14 and R 15 , in terms of the carbon dioxide adsorption property and low-temperature release property, the carbon number of the alkyl group is preferably 1 to 8, and preferably 1 to 4. Specific examples of the hydroxyalkyl group include hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, etc.

[0104] In terms of the carbon dioxide adsorption property and low-temperature release property, among these, R 1 is preferably a group represented by general formula (5).

[0105] Specific examples of R 1 are represented by the specific examples of the amine compound (A) described later.

[0106] R 2is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms and the carbon atom adjacent to N is a primary carbon atom, or is -CH 2 CH(OH)CH 2 X 2 A 2 。

[0107] As R 2 the alkyl group having 1 to 8 carbon atoms in, for example, may be mentioned: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, neopentyl, isopentyl, sec-pentyl, 1-hexyl, 2-hexyl, heptyl, methylcyclohexyl, octyl, 2-ethylhexyl and the like.

[0108] In R 2 is -CH 2 CH(OH)CH 2 X 2 A 2 case, n in formula (1) is preferably 1. In this case, formula (1) consists of A 2 X 2 CH 2 CH(OH)CH 2 N(R 1 )CH 2 CH(OH)CH 2 X 1 A 1 : represented by formula (1a). In the case where the amine compound (A) is represented by formula (1a), in terms of carbon dioxide adsorption, low-temperature release property and ease of synthesis, X 1 A 1 and X 2 A 2 are preferably the same substituents.

[0109] In terms of carbon dioxide adsorption, low-temperature release property and ease of synthesis, among these, R 2 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom.

[0110] X 1 and X 2 are each independently a direct bond, -O-, -OC(=O)-, -CO(=O)- or -NA 3 -. In terms of carbon dioxide adsorption, 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-, more preferably -O-.

[0111] In addition, in the case where there are a plurality of X 1 present (that is, when n is 2 or more), there are a plurality of X 1They may be the same or different, but there are multiple Xs in terms of the carbon dioxide adsorption property, low-temperature release property, and ease of synthesis. 1 Preferably, they are the same.

[0112] A 1 is a hydrogen atom or an n-valent organic residue. Among them, when X 1 is a direct bond, A 1 is an n-valent organic residue. In addition, 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 name of a monovalent substituent is used, but A 1 is further a residue obtained by removing any n - 1 hydrogen atoms.

[0113] As the n-valent organic residue in A 1 , for example, there may be mentioned: 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. As the heteroatom, there may be mentioned O, N, S, Si, etc. As the heteroatom in the aliphatic hydrocarbon residue, O or N is preferred, and O is more preferred. In addition, as the heteroatom in the alicyclic hydrocarbon residue, O or N is preferred, and N is more preferred. The organic residue may have two or more heteroatoms. As the linear or branched aliphatic hydrocarbon residue having a heteroatom, there may be mentioned a linear or branched polyoxyalkyl residue, etc.

[0114] In addition, n represents an integer of 1 to 6, preferably 1 to 4, and more preferably 1 to 2.

[0115] As the aliphatic hydrocarbon residue which may have an n-valent substituent, there may be mentioned: an alkyl group, an alkenyl group, an alkynyl group.

[0116] As specific alkyl groups, there may be mentioned: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, tetradecyl, pentadecyl, octadecyl, etc., alkyl groups having 1 to 18 carbon atoms.

[0117] In addition, as alkenyl groups, there may be mentioned: vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-octenyl, 1-decenyl, 1-octadecenyl, etc., alkenyl groups having 2 to 18 carbon atoms.

[0118] In addition, as alkynyl groups, there may be mentioned: ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-octynyl, 1-decynyl, 1-octadecynyl, etc., alkynyl groups having 2 to 18 carbon atoms.

[0119] Examples of the substituent in the linear or branched hydrocarbon residue which may have an n-valent substituent include: linear or branched alkyl group, alkoxy group, polyoxyalkylene group, phenyl group, 4-nitrophenyl group, 2-methoxyphenyl group, hydroxyl group, halogen atom, epoxy group, etc. The substituent may further have a substituent, and examples of the substituent include the above-mentioned substituents.

[0120] The specific alkyl group as the substituent has the same meaning as the alkyl group in the linear or branched hydrocarbon residue which may have an n-valent substituent.

[0121] Examples of the specific alkoxy group as the substituent include methoxy group, ethoxy group, etc.

[0122] Examples of the specific polyoxyalkylene group as the substituent include oxyethylene groups with a repetition number of 4 to 16, linear or branched oxypropylene groups with a repetition number of 4 to 16.

[0123] Examples of the specific halogen atom as the substituent include: chlorine atom, bromine atom, iodine atom.

[0124] Examples of the linear or branched polyoxyalkylene group which may have an n-valent substituent include oxyethylene groups with a repetition number of 4 to 16, linear or branched oxypropylene groups with a repetition 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, and is preferably an alkyl group, phenyl group, hydroxyl group, etc.

[0125] Regarding the (meth)acryloyl residue which may have an n-valent substituent, examples of the (meth)acryloyl include methacryloyl group and 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.

[0126] Examples of the alicyclic hydrocarbon group of the alicyclic hydrocarbon residue which may have an n-valent substituent include cycloalkyl groups. Specifically, examples include cycloalkyl groups having 3 to 18 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclooctadecyl group, 2-indanyl group, etc. In addition, as the alicyclic hydrocarbon group, a group in which a plurality of cycloalkyl groups are linked by an alkylene group or the like is also included. 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, and is preferably a branched alkylene group, and particularly preferably a tert-butylene group.

[0127] Examples of the aromatic hydrocarbon of the aromatic hydrocarbon residue which may have an n-valent substituent include aromatic hydrocarbons having a condensation number of 1 to 4. Specifically, examples include benzene, biphenyl, naphthalene, anthracene, phenanthrene, tetracene, pyrene, 9,9-diphenylfluorene, bis(3-methylphenyl)fluorene, binaphthyl group, etc.

[0128] Regarding the substituents in the aromatic hydrocarbon residue that may have an n-valent substituent, they are the same as the substituents in the linear or branched hydrocarbon residue that may have an n-valent substituent, preferably an alkyl group, an alkylene group, a halogen atom, and particularly preferably, examples include: a methyl group, a methylene group, a tert-butylidene group, a bromine atom.

[0129] The aromatic heterocycle as the aromatic heterocyclic residue that may have an n-valent substituent is an aromatic heterocycle with a condensation number of 1 to 4. For example, examples include: pyrrole, imidazole, pyridine, triazine, indole, quinoline, carbazole, phthalimide, etc. Regarding the substituents, they are the same as the substituents in the linear or branched hydrocarbon residue that may have an n-valent substituent.

[0130] As A 1 (X 1 ) n The structure of, for example, can also be understood as: a linear or branched alkoxy residue that may have an n-valent substituent, an alkyl ester residue that may have an n-valent substituent, an aromatic ester residue that may have an n-valent substituent, an amino residue that may have an n-valent substituent.

[0131] As the alkoxy of the linear or branched alkoxy residue that may have an n-valent substituent, examples include methoxy, ethoxy, etc. Regarding the substituents, they are the same as the substituents in the linear or branched hydrocarbon residue that may have an n-valent substituent.

[0132] As the alkyl ester group of the alkyl ester residue that may have an n-valent substituent, examples include: methyl ester group, ethyl ester group, propyl ester group, butyl ester group, pentyl ester group, heptyl ester group, hexyl ester group, octyl ester group, cetyl ester group, cyclohexyl ester group, 1,2-cyclohexanedicarboxylate group, 1,2-cyclohexenedicarboxylate group, etc. Regarding the substituents, they are the same as the substituents in the linear or branched hydrocarbon residue that may have an n-valent substituent.

[0133] As the aromatic ester group of the aromatic ester residue that may have an n-valent substituent, examples include phenyl ester group, 4-tert-butylphenyl ester group, etc. Regarding the substituents, they are the same as the substituents in the linear or branched hydrocarbon residue that may have an n-valent substituent.

[0134] As the amino of the amino residue that may have an n-valent substituent, aniline group can be cited. In addition, regarding the substituents, they are the same as the substituents in the linear or branched hydrocarbon residue that may have an n-valent substituent, preferably an alkyl group, and more preferably, examples include a methyl group.

[0135] A 1 Preferably, it is a linear or branched hydrocarbon residue that may have an n-valent substituent, or an aromatic hydrocarbon residue that may have an n-valent substituent, and further preferably, it is a linear or branched hydrocarbon residue that may have an n-valent substituent, and particularly preferably, it is an n-valent linear hydrocarbon residue.

[0136] A 1The carbon number is preferably from 1 to 15, more preferably from 1 to 10, still more preferably from 2 to 8.

[0137] A 2 and A 3 are each independently a hydrogen atom or a monovalent organic residue. Among them, when X 2 is a direct bond, A 2 is a monovalent organic residue.

[0138] A 2 and A 3 The monovalent organic residue in is the same as the organic residue obtained by replacing n in the n-valent organic residue of the said A 1 with 1.

[0139] Hereinafter, Compounds (A1) to (A128) as representative examples of the amine compound (A) are shown in Tables 1-1 to 1-8, but the present embodiment is not limited to the said representative examples.

[0140] [Table 1-1]

[0141] Table 1-1

[0142]

[0143] [Table 1-2]

[0144] Table 1-2

[0145]

[0146] [Table 1-3]

[0147] Table 1-3

[0148]

[0149] [Table 1-4]

[0150] Table 1-4

[0151]

[0152] [Table 1-5]

[0153] Table 1-5

[0154]

[0155] [Table 1-6]

[0156] Table 1-6

[0157]

[0158] [Table 1-7]

[0159] Table 1-7

[0160]

[0161] [Table 1-8]

[0162] Table 1-8

[0163]

[0164] (Method for producing amine compound (A))

[0165] For the method for producing amine compound (A), an example will be described, but the method for producing amine compound (A) is not limited to the following method. In addition, when there are commercially available products, the commercially available products can also be used.

[0166] 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.

[0167] Examples of the solvent include: alkanols (such as methanol, ethanol, propanol, butanol, etc.), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), etc. In addition, in terms of obtaining the amine compound (A) represented by formula (1) as the target product, the reaction is preferably carried out under anhydrous conditions.

[0168] For example, when producing an amine compound (A) in which R 1 is a group represented by the general formula (2), 4-amino-2,2,6,6-tetramethylpiperidine, etc. can be used as the compound (1b).

[0169] In addition, examples of the compound (1b) include compounds (b1) to (b26) in Table 2 below.

[0170] [Table 2]

[0171] Table 2

[0172]

[0173] The mixing amount of the compound (1b) and the epoxy compound (1c) is preferably in the range of 0.95 equivalent to 1.1 equivalent in terms of the primary amino equivalent ratio of the compound (1b) relative to the epoxy equivalent of the epoxy compound (1c).

[0174] In the epoxide (1c), a monofunctional epoxide refers to a compound having one epoxy group in one molecule, and a polyfunctional epoxide is a compound having two or more epoxy groups in one molecule.

[0175] Examples of the monofunctional epoxide include monofunctional aliphatic epoxides and monofunctional aromatic epoxides.

[0176] Examples of the monofunctional aliphatic epoxide include glycidyl ethers of aliphatic alcohols, glycidyl esters of alkyl carboxylic acids, etc. Specific examples thereof include allyl glycidyl ether, butyl glycidyl ether, sec-butylphenyl glycidyl ether, 2-ethylhexyl glycidyl ether, alkyl glycidyl ether composed of a mixture of C12 and C13, glycidyl ether of alcohol, monoglycidyl ether of higher aliphatic alcohol, glycidyl ester of higher fatty acid, etc.

[0177] As the monofunctional aliphatic epoxide, a synthesized compound or a commercially available product can be used. In the case of a commercially available product, for example, Denacol EX-121, Denacol EX-171, Denacol EX-192 (manufactured by Nagase ChemteX Corporation);

[0178] Epolight M-1230 (manufactured by Kyoeisha Chemical Co., Ltd.), Adeka Glycilol ED-502, Adeka Glycilol ED-502S, Adeka Glycilol ED-509E, Adeka Glycilol ED-509S, Adeka Glycilol ED-529 (manufactured by ADEKA Corporation), etc.

[0179] Examples of the monofunctional aromatic epoxide include monoglycidyl ethers of phenol compounds such as phenol, cresol, butylphenol, or their alkylene oxide adducts;

[0180] Monoglycidyl etherified products of aromatic compounds having two or more phenolic hydroxyl groups such as resorcinol, hydroquinone, catechol, etc.;

[0181] Monoglycidyl etherified products of aromatic compounds having two or more alcoholic hydroxyl groups such as phenyl dimethanol, phenyl diethanol, phenyl dibutanol, etc.;

[0182] Monoglycidyl esters of polybasic acid aromatic compounds having two or more carboxylic acids such as phthalic acid, terephthalic acid, trimellitic acid, etc.;

[0183] Glycidyl benzoate, styrene oxide, or monocyclic oxides such as divinylbenzene monoxide, etc.

[0184] As the monofunctional aromatic epoxide, commercially available products or compounds that can be commercially available 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 cited.

[0185] The polyfunctional epoxide can generally be used in the epoxy resin composition. As long as it has two or more epoxy groups in one molecule, its type is not particularly limited.

[0186] The polyfunctional epoxide can include polyfunctional aliphatic epoxides and polyfunctional aromatic epoxides.

[0187] As the polyfunctional aliphatic epoxide, synthesized compounds or commercially available products can be used.

[0188] As the polyfunctional aliphatic epoxide, bifunctional aliphatic epoxides having two epoxy groups in the molecule such as alkylene glycol diglycidyl ethers and alkenylene glycol diglycidyl ethers can be cited;

[0189] Polyfunctional aliphatic epoxides having three or more epoxy groups in the molecule such as polyglycidyl ethers of trifunctional or higher alcohols such as trimethylolpropane, pentaerythritol, and dipentaerythritol [trimethylolpropane triglycidyl ether, pentaerythritol triglycidyl ether or pentaerythritol tetraglycidyl ether, dipentaerythritol triglycidyl ether, dipentaerythritol tetraglycidyl ether, dipentaerythritol pentaglycidyl ether, or dipentaerythritol hexaglycidyl 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 (for example, 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.

[0190] The polyfunctional aliphatic epoxy compounds can be commercially available products. For example, "EP-4088S" (manufactured by ADEKA Corporation), "EHPE3150" (manufactured by Daicel Corporation), "EX-211L", "EX-212L" (both manufactured by Nagase ChemteX Corporation), etc. can be cited.

[0191] As the polyfunctional aromatic epoxy compounds, polyglycidyl ether compounds of polyphenols having at least one aromatic ring such as bisphenol A and bisphenol F, or their alkylene oxide adducts can be cited;

[0192] Epoxy novolac resins;

[0193] Polyglycidyl ether compounds of aromatic compounds having two or more phenolic hydroxyl groups such as resorcinol, hydroquinone, and catechol;

[0194] Polyglycidyl ether compounds of aromatic compounds having two or more alcoholic hydroxyl groups such as phenyl dimethanol, phenyl diethanol, and phenyl dibutanol;

[0195] Polyglycidyl esters of polybasic acid aromatic compounds having two or more carboxylic acids such as phthalic acid, terephthalic acid, and trimellitic acid;

[0196] Dicycloxides of divinylbenzene, etc.

[0197] As the polyfunctional aromatic epoxy compounds, synthetic compounds can be used, or commercially available products can also be used.

[0198] Commercially available products can be used as the polyfunctional aromatic epoxy compounds. For example, "Denacol EX-201", "Denacol EX-711", and "Denacol EX-721" (all manufactured by Nagase ChemteX Corporation) can be cited;

[0199] "OGSOL EG-280" and "OGSOL CG-400" (both manufactured by Osaka Gas Chemical Co., Ltd.);

[0200] "EXA-80CRP" and "HP4032D" (both manufactured by DIC Corporation);

[0201] "jER828" and "jER828EL" (both manufactured by Mitsubishi Chemical Corporation);

[0202] "ADEKA RESIN EP-4100", "ADEKA RESIN EP-4100G", "ADEKA RESIN EP-4100E", "Gland Resin EP-4100L", "ADEKA RESIN EP-4100TX", "ADEKA RESIN EP-4000", "ADEKA RESIN EP-4005", "ADEKA RESIN EP-4901", "ADEKA RESIN EP-4901E" (all of the above are manufactured by ADEKA CORPORATION), etc.

[0203] The monofunctional epoxy compound and polyfunctional epoxy compound for obtaining the amine compound represented by formula (3) in the present embodiment may be used alone or in combination of different types.

[0204] The structures of the specific monofunctional epoxy compounds or polyfunctional epoxy compounds (c1) to monofunctional epoxy compounds or polyfunctional epoxy compounds (c75) are shown in Tables 3-1 to 3-5.

[0205] [Table 3-1]

[0206] Table 3-1

[0207]

[0208] [Table 3-2]

[0209] Table 3-2

[0210]

[0211] [Table 3-3]

[0212] Table 3-3

[0213]

[0214] [Table 3-4]

[0215] Table 3-4

[0216]

[0217] [Table 3-5]

[0218] Table 3-5

[0219]

[0220] <Liquid medium (B)>

[0221] The liquid medium (B) is not particularly limited as long as it can be mixed with the amine compound (A). The amine compound (A) can absorb carbon dioxide and release carbon dioxide by heating, but the separation of carbon dioxide requires high energy. By using the liquid medium, the separation efficiency of the amine compound (A) from carbon dioxide is improved, the release temperature of carbon dioxide can be reduced, and the release efficiency of carbon dioxide becomes higher.

[0222] As specific examples of the liquid medium (B), water, organic solvents, ionic liquids, or a mixed solvent thereof can be mentioned. As shown in the formula (1), the amine compound (A) has a hydroxyl group, an alkyl group, and an organic residue, and thus can be dissolved not only in water but also appropriately in organic solvents.

[0223] As the ionic liquid, salts containing cations and anions and being liquid at 100 °C and atmospheric pressure can be mentioned. The ionic liquid is particularly preferably liquid at room temperature (25 °C). That is, the melting point of the ionic liquid is not particularly limited as long as it is 100 °C or lower, preferably less than 50 °C, more preferably less than 25 °C, and particularly preferably less than 10 °C. In addition, the lower limit of the melting point of the ionic liquid is not particularly limited. Furthermore, regarding the ionic liquid, even below the melting point, it is often supercooled and in a liquid state, and if this liquid state can be maintained, it can be preferably used when the melting point is high. In addition, the melting point of the ionic liquid sometimes decreases due to the mixing of amines, and such ionic liquids can also be used as carbon dioxide absorbents.

[0224] Examples of the anion constituting this ionic liquid include anions of phosphoric acid, phosphonic acid, phosphate esters, or phosphonate esters.

[0225] In the ionic liquid, the cation is not particularly limited, and imidazolium salts, ammonium salts, or phosphonium salts are preferred.

[0226] Specific examples of water and organic solvents that can be used as the liquid medium (B) are listed in Tables 4-1 and 4-2 together with the total Hansen solubility parameter (δT).

[0227] (Total Hansen solubility parameter (δT))

[0228] Regarding the Hansen solubility parameter, the total Hildebrand value is divided into three parts: the dispersion force (δD), the polar component (δP), and the hydrogen bond (δH) component. The Hildebrand value is calculated using the relationship between vaporization, van der Waals forces, and solubility. The total Hansen solubility parameter (δT) is decomposed into the dispersion (δD) force, the polar (δP), and the hydrogen bond (δH) force, and is calculated using Equation (1).

[0229] δT 2 =δD 2 +δP 2 +δH2 (1)

[0230] In the formula,

[0231] · δD is the dispersion component,

[0232] · δP is the polar component,

[0233] · δH is the hydrogen bond component.

[0234] In addition, in this specification, the calculation of the "Hansen solubility parameter" refers to the value calculated using the computer software "Hansen Solubility Parameters in Practice (HSPiP)". In addition, the version of "HSPiP" used in the calculation is "5.4.02".

[0235] In addition, in the case of using a mixed solvent, first calculate the total Hansen solubility parameter of each solvent separately, find the weighted average with the mass fraction of each solvent as the weight, and use it as the total Hansen solubility parameter (δT) of the liquid medium (B).

[0236] Table 4-1 and Table 4-2 show the calculation results of the dispersion component, polar component, and hydrogen bond component of different solvents and the total Hansen solubility parameter (δT) for different solvents.

[0237] [Table 4-1] Table 4-1

[0238] Solvent type <![CDATA[d D > <![CDATA[d P > <![CDATA[d H > <![CDATA[d T > Hexane 14.9 0 0 14.90 Heptane 15.3 0 0 15.30 Methylcyclohexane 16 0 1 16.03 Dimethylcyclohexane 16.1 0 0.5 16.11 Isobutyl isobutyrate 15.1 2.8 5.8 16.42 tert-Butyl acetate 15 3.7 6 16.57 Cyclohexane 16.8 0 0.2 16.80 Diisobutyl ketone 16 3.7 4.1 16.93 Methyl isobutyl ketone 15.3 6.1 4.1 16.97 Diethylene glycol dibutyl ether 15.9 4.0 4.7 17.00 Isoamyl acetate 15.3 3.1 7 17.11 Triethylene glycol dibutyl ether 15.9 4.2 5.1 17.20 sec-Butyl acetate 15 3.7 7.6 17.22 Methyl oleate 16.2 3.8 4.5 17.24 Amyl acetate 15.8 3.3 6.1 17.26 Butyl acetate 15.8 3.7 6.3 17.41 Propyl propionate 15.5 5.6 5.7 17.44 Methyl isoamyl ketone 16 5.7 4.1 17.47 Isopropyl acetate 14.9 4.5 8.2 17.59 n-Propyl acetate 15.3 4.3 7.6 17.62 n-Butyl propionate 15.7 5.5 5.9 17.65 Cumene 17.4 2.3 2.4 17.71 Cyclopentyl methyl ether 16.7 4.3 4.3 17.77 Tetraethylene glycol dibutyl ether 15.8 5.4 6.1 17.80 d-Limonene 17.2 1.8 4.3 17.82 Ethyl benzoate 17.8 0.6 1.4 17.87 Xylene 17.6 1 3.1 17.90 Tributylphosphine 16.3 6.3 4.3 18.00 Ethyl acetate 15.8 5.3 7.2 18.15 Toluene 18 1.4 2 18.16 2-Pentanone 16 7.6 4.7 18.33 Butyl cellosolve acetate 15.3 7.5 6.8 18.35 Propylene glycol monobutyl ether 15.3 4.5 9.2 18.41 2-(2-Butoxyethoxy)ethyl acetate 16 4.1 8.2 18.44 Propylene glycol monoethyl ether acetate 15.6 6.3 7.7 18.50 2-Ethoxyethyl acetate 16.1 5.9 7.3 18.60 Methyl acetate 15.5 7.2 7.6 18.70 Dodecyl alcohol ester (texanol) 15.1 6.1 9.8 19.01 Methyl ethyl ketone 16 9 5.1 19.05 Propylene glycol monomethyl ether acetate 15.6 5.6 9.8 19.26 Dibasic ester 16.2 6.5 8.4 19.37 Glycerol triacetate 16.5 4.5 9.1 19.37 Isophorone 17 8 5 19.44 Tetrahydrofuran 16.8 5.7 8 19.46 Anisole 17.8 4.4 6.9 19.59 Dipropylene glycol mono-n-butyl ether 15.7 6.5 10 19.72 Butyl benzoate 18.3 5.6 5.5 19.91 Acetone 15.5 10.4 7 19.94 Dipropylene glycol methyl ether 15.5 5.7 11.2 19.95 Methyl isobutyl carbitol 15.4 3.3 12.3 19.98 1,4-Dioxane 17.1 6.8 7.8 19.99

[0239] [Table 4-2]

[0240] Table 4-2

[0241]

[0242]

[0243] As the liquid medium (B), an organic solvent or ionic liquid with a total Hansen solubility parameter (δT) of 17 MPa 1 / 2 to 35 MPa 1 / 2 is preferred, and an organic solvent or ionic liquid with a total Hansen solubility parameter (δT) of 20 MPa 1 / 2 to 35 MPa 1 / 2 is more preferred, and an organic solvent or ionic liquid with a total Hansen solubility parameter (δT) of 23 MPa 1 / 2 to 35 MPa 1 / 2 is further preferred.

[0244] In addition, regarding the absorbent of the present disclosure, even when the proportion of water is small, it has high carbon dioxide absorption ability and release ability. Specifically, the proportion of water in the liquid medium (B) may be 50% by mass or less, preferably 20% by mass or less, more preferably 10% by mass or less. In addition, when using the absorbent, sometimes the proportion of water in the liquid medium (B) may change according to the gas composition, but the proportion of water here is the initial value (at the start of use), and it does not prevent the proportion of water in the liquid medium (B) from exceeding 50% by mass due to the change.

[0245] In the absorbent of the present disclosure, the mass ratio of the amine compound (A) to the liquid medium (B) in the absorbent is preferably in the range of 5:95 to 95:5, more preferably in the range of 5:95 to 50:50, and particularly preferably in the range of 10:90 to 25:75. The content rate of the amine compound (A) in the absorbent is preferably 5% by mass or more, more preferably 10% by weight or more, particularly preferably 25% by mass or more, and preferably 75% by mass or less from the viewpoint of the absorption efficiency of the absorbent.

[0246] The liquid medium (B) used in the absorbent may be a medium that dissolves the reaction product of the amine compound (A) and carbon dioxide, or may be a medium that does not dissolve it.

[0247] <Optional Components>

[0248] Within the range where the absorbent of the present disclosure exhibits the effects of the present invention, it may also contain other components. As other components, at least one amine compound (C) selected from the group consisting of amino alcohols, cyclic polyamines, and linear polyamines can be cited; stabilizers (side reaction inhibitors such as antioxidants) for ensuring the chemical stability or physical stability of the absorbent; inhibitors (corrosion inhibitors, etc.) for preventing the deterioration of the materials of the devices or equipment using the absorbent, etc. The total content of these other components in the absorbent is preferably 5% by mass or less. In addition, a compound that can conform to both the amine compound (A) and the amine compound (C) is regarded as conforming to the amine compound (A). That is, the amino alcohols in the amine compound (C) do not conform to the amino alcohols of the general formula (1).

[0249] (Amine Compound (C))

[0250] By using the amine compound (C), improvements or enhancements in, for example, the absorption amount, release amount, absorption rate, and release rate of the absorbent can be achieved.

[0251] As preferred amino alcohols, for example, the following can be cited: 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, etc. One of these compounds can be used alone, or two or more thereof can be used in combination.

[0252] Among these, as amino alcohols, from the viewpoint of further improving the reaction ability or release ability 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 preferred.

[0253] As preferred cyclic polyamines, compounds in which two or more nitrogen atoms are substituted in a cycloalkyl group are exemplified. Specifically, the following can be cited: piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, 2,6-dimethylpiperazine, N-(2-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, 1-hydroxyethylpiperazine, diazabicycloundecene, and diazabicyclononene. One of these compounds can be used alone, or two or more thereof can be used in combination.

[0254] Among these, as cyclic polyamines, from the viewpoint of further improving the reaction ability or release ability 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 preferred.

[0255] As preferred chain polyamines, specifically, compounds having two or more nitrogen atoms substituted thereon and having a straight-chain or branched alkyl group with 2 to 6 carbon atoms therebetween include: ethylenediamine, N-isopropylethylenediamine, N-methylethylenediamine, N-ethylethylenediamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, diethylenetriamine, 2,2-diamino-N-methyldiethylamine, 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-methyldipropylamine, 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 may be used alone, or two or more thereof may be used in combination.

[0256] Among these, as chain polyamines, from the viewpoint of further improving the reaction ability or release ability 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-methyldipropylamine, N,N'-bis(3-aminopropyl)ethylenediamine, and N,N-dibutyl-1,3-propanediamine is preferred.

[0257] (Antioxidant)

[0258] Examples of the antioxidant include: dibutylhydroxytoluene, butylhydroxyanisole, sodium erythorbate, sodium sulfite, sulfur dioxide, and the like.

[0259] (Corrosion inhibitor)

[0260] 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 (for example, copolymers of maleic acid and amylene, or terpolymers of maleic acid, acrylic acid, and styrene), and the like.

[0261] (Defoamer)

[0262] As the defoamer, for example, silicone-based, polyether-based, acetylene glycol-based, metal soap-based, phosphate ester-based, fatty acid ester-based, etc. can be cited.

[0263] (pH adjuster)

[0264] As the pH adjuster, for example, inorganic acids (hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, etc.), organic acids (citric acid, formic acid, acetic acid, oxalic acid, p-toluenesulfonic acid, etc.), inorganic bases (sodium bicarbonate, sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, ammonia, etc.), organic bases (methylamine, dimethylamine, trimethylamine, diazabicycloundecene, piperazine, ethanolamine, triethanolamine, etc.) can be cited.

[0265] (Viscosity adjuster)

[0266] As the viscosity adjuster, for example, polyimine, polyvinyl alcohol, polyethylene oxide, etc. can be cited.

[0267] <Gas containing carbon dioxide>

[0268] As the gas containing carbon dioxide, for example, exhaust gas from thermal power stations, boilers in manufacturing plants, kilns in cement factories, blast furnaces for ironmaking using coke to reduce iron oxide, converters for steelmaking by burning carbon in pig iron, integrated gasification combined cycle power generation equipment, etc. using coal, heavy oil, natural gas, etc. as fuels, natural gas during mining, reformed gas, etc. can be cited. The carbon dioxide concentration in the gas is usually about 5% to 50% by volume concentration, especially about 10% to 40% is sufficient. Within the range of the carbon dioxide concentration, the effect of the present absorbent can be preferably exerted. In addition, in the gas containing carbon dioxide, in addition to carbon dioxide, gases such as nitrogen, water vapor, carbon monoxide, hydrogen sulfide, carbonyl sulfide, sulfur dioxide, nitrogen dioxide, methane, hydrogen, etc. can also be contained.

[0269] The absorbent of the present disclosure is excellent in absorbing hydrogen sulfide in addition to carbon dioxide.

[0270] [Method for separating and recovering carbon dioxide using an absorbent]

[0271] The method for separating and recovering carbon dioxide of the present disclosure is a method for separating and recovering carbon dioxide in a gas containing carbon dioxide, and the method includes the following steps: Step A of bringing the absorbent of the present disclosure into contact with the gas containing carbon dioxide to obtain an absorbent that has absorbed carbon dioxide from the gas containing carbon dioxide, and heating the absorbent that has absorbed carbon dioxide obtained in Step A to cause carbon dioxide to be released and diffused from the absorbent, and recovering the diffused carbon dioxide.

[0272] (Step A)

[0273] In step A, by bringing the absorbent into contact with the gas containing carbon dioxide, the absorbent absorbs the carbon dioxide in the gas containing carbon dioxide and separates it.

[0274] In step A, the method of bringing the absorbent into contact with the gas containing carbon dioxide is not particularly limited. For example, there may be mentioned: a method of bubbling the gas containing carbon dioxide in the absorbent, a method of spraying the absorbent in a mist onto the gas containing carbon dioxide (spraying or jetting method), a method of countercurrently contacting the high-pressure gas containing carbon dioxide with the absorbent in an absorption tower filled with a packing material made of porcelain or wire mesh, etc.

[0275] The temperature in process A can be set to 25°C to 40°C. If within the said range, the carbon dioxide recovery amount and carbon dioxide absorption rate of the absorbent are excellent. The temperature in process A is preferably 25°C to 35°C.

[0276] The pressure in process A can generally be set to 1.0 bar or more, preferably set to 1.0 bar to 3.5 bar. In addition, by carrying out at a higher pressure, higher carbon dioxide absorption performance can be obtained.

[0277] (Process B)

[0278] In process B, the absorbent that has absorbed carbon dioxide obtained in process A is heated to cause the carbon dioxide to dissociate from the absorbent and diffuse, and the diffused carbon dioxide is recovered.

[0279] The temperature in the process of causing the carbon dioxide in process B to dissociate and diffuse can be set to 50°C to 160°C. If within the said range, the diffusion rate of carbon dioxide in the absorbent is excellent. The heating temperature in process B is preferably 50°C to 80°C, more preferably 50°C to 60°C.

[0280] The pressure in the process of causing the carbon dioxide in process B to dissociate and diffuse can generally be set to 3.5 bar or less, preferably set to 1.0 bar to 3.5 bar. In addition, by carrying out at a lower pressure, higher carbon dioxide release performance can be obtained.

[0281] The method of heating the absorbent that has absorbed carbon dioxide to cause the carbon dioxide to dissociate and diffuse for recovery is not particularly limited. For example, there may be mentioned: a method of heating the absorbent to cause it to foam and dissociate in the kettle in the same way as distillation, a method of expanding the liquid interface and heating in a multi-layer distillation tower, a spray tower, a diffusion tower filled with a packing material made of porcelain, wire mesh, etc. By these methods, pure or very high-concentration carbon dioxide can be recovered.

[0282] In Process B, the absorbent after carbon dioxide diffusion can be returned to Process A again and recycled. During the recycling process, the heat applied in Process B is used to heat the absorbent through heat exchange with the absorbent that has absorbed carbon dioxide. Through the heat exchange, the overall energy of the carbon dioxide separation and recovery process can be reduced.

[0283] The carbon dioxide separated and recovered by the carbon dioxide separation and recovery method using the absorbent of the present disclosure generally has a volume concentration of 95% to 100%, and can be pure or at a very high concentration. The separated and recovered carbon dioxide can be used for underground or undersea isolation storage (Carbon Capture and Storage, CCS) or Enhanced Oil Recovery (EOR) being developed by the current technology. In addition, the utilization uses of the separated and recovered carbon dioxide are not particularly limited. For example, synthetic raw materials such as chemicals, or refrigerants for food refrigeration, etc. can be cited.

[0284] [Examples]

[0285] Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples, etc. In addition, the molecular weight is measured by a time-of-flight mass spectrometer (TOF-MS).

[0286] TOF-MS device name: AutoFlexII manufactured by Bruker Daltonics

[0287] 1. Example Group 1

[0288] [Synthesis Example 1]

[0289] Synthesis method of compound (A1)

[0290] [Chemical Formula 6]

[0291]

[0292] Under a nitrogen atmosphere, 20.0 g (128.0 mmol) of 4-amino-2,2,6,6-tetramethylpiperidine mixed with 50 ml of methanol and 11.15 g (64.0 mmol) of ethylene glycol diglycidyl ether (c1) were added and stirred. After the addition, stirring was carried out at room temperature for 24 hours. (c1) as a reaction substance was not detected by TOF-MS, thereby confirming the progress of the reaction. Methanol as a solvent was removed by reduced pressure at 40°C or lower to obtain the target compound (A1).

[0293] <TOF-MS measurement results of compound (A1)>

[0294] Calculated molecular weight: C26H54N4O4, Mol.Wt. 486.7;

[0295] Observed molecular weight: m / z 486.9

[0296] [Synthesis Examples 2 to 74]

[0297] In the same manner as in Synthesis Example 1, 4-amino-2,2,6,6-tetramethylpiperidine and monofunctional or polyfunctional epoxy compounds ((c2) to (c74)) described in Tables 3-1 to 3-5 were used to synthesize compounds (A2) to (A74). The obtained compounds were identified by TOF-MS in the same manner as in Synthesis Example 1. The mass spectrometry results of the synthesized compounds are shown in Table 5. In addition, the compound numbers are the same as those described in Tables 1-1 to 1-5 of this specification.

[0298] [Synthesis Example 75]

[0299] Synthesis method of compound (A75)

[0300] [Chemical Formula 7]

[0301]

[0302] Under a nitrogen atmosphere, 5.0 g (49.9 mmol) of 4-amino-2,2,6,6-tetramethylpiperidine mixed with 50 ml of methanol and 8.69 g (49.9 mmol) of 2,2-bis(4-glycidyloxyphenyl)methane (c70) were added and stirred. After the addition, the mixture was stirred at room temperature for 24 hours. (c70) as a reaction substance was not detected by TOF-MS, confirming the progress of the reaction. Methanol as a solvent was removed by reduced pressure at 40 °C or lower to obtain the target compound (A75).

[0303] [Synthesis Example 76]

[0304] Synthesis method of compound (A76)

[0305] [Chemical Formula 8]

[0306]

[0307] Under a nitrogen atmosphere, 5.0 g (49.9 mmol) of 4-amino-piperidine and 4.34 g (25.0 mmol) of ethylene glycol diglycidyl ether (c1) mixed with 50 ml of methanol were added and stirred. After the addition, the mixture was stirred at room temperature for 24 hours. (c1) as a reaction substance was not detected by TOF-MS, thereby confirming the progress of the reaction. Methanol as a solvent was removed by reduced pressure at 40 °C or lower, thereby obtaining the target compound (A76).

[0308] [Synthesis Example 77]

[0309] Synthesis method of compound (A77)

[0310] [Chemical Formula 9]

[0311]

[0312] Under a nitrogen atmosphere, 20 g of 4-amino-2,2,6,6-tetramethylpiperidine in Synthesis Example 1 was changed to 10 g (64 mmol), and the synthesis reaction was carried out in the same manner. After the addition, the mixture was stirred at room temperature for 24 hours. 4-amino-2,2,6,6-tetramethylpiperidine as a reaction substance was not detected by TOF-MS, thereby confirming the progress of the reaction. Methanol as a solvent was removed by reduced pressure at 40 °C or lower, thereby obtaining the target compound (A77).

[0313] [Synthesis Example 78]

[0314] Synthesis method of compound (A78)

[0315] [Chemical Formula 10]

[0316]

[0317] Under a nitrogen atmosphere, 20.0 g of 4-amino-2,2,6,6-tetramethylpiperidine in Synthesis Example 7 was changed to 10.5 g (64.0 mmol), and the synthesis reaction was carried out in the same manner. After the addition, the mixture was stirred at room temperature for 24 hours. 4-amino-2,2,6,6-tetramethylpiperidine as a reaction substance was not detected by TOF-MS, thereby confirming the progress of the reaction. Methanol as a solvent was removed by reduced pressure at 40 °C or lower, thereby obtaining the target compound (A78).

[0318] [Table 5]

[0319] Table 5

[0320] [Method for measuring the release efficiency of carbon dioxide gas]

[0321] 100 g of the carbon dioxide absorbent prepared in the following examples (in a state of being filled in a gas absorption bottle with a capacity of 200 ml) was adjusted to 25°C in a water bath. While bubbling a mixed gas of 100 ml / min of carbon dioxide gas and 400 ml / min of nitrogen gas (500 ml / min), it was blown into the carbon dioxide absorbent for 1 hour. The absorption amount of carbon dioxide gas at this time (carbon dioxide absorption amount per hour (L)) was measured using a gas flow meter and a carbon dioxide concentration meter. Using the carbon dioxide absorption amount per hour (L), the carbon dioxide absorption amount per 1 kg of the carbon dioxide absorbent (L) was calculated.

[0322] Next, the carbon dioxide absorbent was adjusted to 60°C in a water bath. While bubbling 500 ml / min of nitrogen gas, it was blown into the carbon dioxide absorbent for 2 hours. The release amount of carbon dioxide gas at this time (carbon dioxide release amount per 2 hours (L)) was measured using a gas flow meter and a carbon dioxide concentration meter. Using the carbon dioxide release amount per 2 hours (L), the carbon dioxide release amount per 1 kg of the carbon dioxide absorbent (L) was calculated. Based on the carbon dioxide release amount per 2 hours (L) and the carbon dioxide absorption amount per 1 hour (L), the carbon dioxide gas release efficiency (=carbon dioxide release amount per 2 hours (L)÷carbon dioxide absorption amount per 1 hour (L)) was calculated.

[0323] Based on the measurement of the calculated carbon dioxide gas release efficiency, the following criteria were set and evaluated, and S, A, and B were regarded as regions where it could be actually used. The evaluation results are shown in Tables 7-1 to 7-8.

[0324] S: The release efficiency is 0.8 or more

[0325] A: The release efficiency is 0.7 or more and less than 0.8

[0326] B: The release efficiency is 0.6 or more and less than 0.7

[0327] C: The release efficiency is less than 0.6

[0328] [Materials for evaluation, and types of gases]

[0329] In order to simplify the description, the following abbreviated symbols were used.

[0330] ATMP: 4-Amino-2,2,6,6-tetramethylpiperidine

[0331] MDEA: N-Methyldiethanolamine

[0332] MBZA: Methylbenzylamine

[0333] MEA: Monoethanolamine

[0334] AB: 2-Aminobutanol

[0335] DMAPA: Dimethylaminopropylamine

[0336] The types of gases used for evaluation are as described in Table 6.

[0337] [Table 6]

[0338]

[0339] [Example 1]

[0340] To 30 g of the compound (A1) obtained in Synthesis Example 1, 70 g of dimethyl sulfoxide was added and mixed and stirred to prepare a carbon dioxide absorption liquid (100 g), which was placed in a 200 ml gas absorption bottle to measure the release efficiency of carbon dioxide gas.

[0341] The amount of carbon dioxide absorbed in 1 hour (L), converted to standard conditions, was 2.12 L. That is, the amount of carbon dioxide absorbed per 1 kg of the carbon dioxide absorption liquid in 1 hour (L) was 21.2 L under standard conditions. (The amount of carbon dioxide absorbed per 1 kg of the carbon dioxide absorption liquid per 1 hour (ml / min) was 353 ml / min (= 21.2 [L / hour] × 1000 [ml / L] ÷ 60 [min / hour]).

[0342] The amount of carbon dioxide released in 2 hours (L), converted to standard conditions, was 1.83 L.

[0343] That is, the amount of carbon dioxide released per 1 kg of the carbon dioxide absorption liquid in 2 hours (L), converted to standard conditions, was 18.3 L.

[0344] (The amount of carbon dioxide released per 1 kg of the carbon dioxide absorption liquid in 2 hours (mL / min) was 152 ml / min (= 18.3 [L / 2 hours] × 1000 [ml / L] ÷ 120 [min / hour]).

[0345] Thus, the release efficiency of carbon dioxide gas was 0.85. The above results are shown in Table 7-1.

[0346] [Example 2 (Absorption Liquid 2)]

[0347] The 30 g of the compound (A1) was changed to 15 g, and the dimethyl sulfoxide was changed from 70 g to 85 g. Similarly, a carbon dioxide absorption liquid (100 g) was prepared, which was placed in a 200 ml gas absorption bottle to measure the release efficiency of carbon dioxide gas. The evaluation results are shown in Table 7-1.

[0348] [Examples 3 to 116, Examples E1 to E20, Examples G1 to G99 (Absorbent Liquids 3 to 116, E1 to E20, G1 to G99)]

[0349] The compounds and liquid media described in Example 1 were changed to the compounds and liquid media described in Tables 7-1 to 7-8 respectively, and the same experiments were conducted. The evaluation results are shown in Tables 7-1 to 7-8.

[0350]

[0351]

[0352]

[0353]

[0354]

[0355]

[0356]

[0357]

[0358] [Example 117 (Absorbent Liquid 117)]

[0359] 70 g of dimethyl sulfoxide was added to 25 g of compound (A1) and 5 g of MDEA, and the mixture was stirred to prepare a carbon dioxide absorbent liquid (100 g). It was placed in a 200 ml gas absorption bottle, and the same experiment was conducted. The evaluation results are shown in Table 8-1.

[0360] [Example 118 (Absorbent Liquid 118)]

[0361] 60 g of sulfolane and 10 g of water were added to 25 g of compound (A7) and 5 g of MBZA, and the mixture was stirred to prepare a carbon dioxide absorbent liquid (100 g). It was placed in a 200 ml gas absorption bottle, and the same experiment was conducted. The evaluation results are shown in Table 8-1.

[0362] [Example 119 (Absorbent Liquid 119)]

[0363] 60 g of dimethyl sulfoxide and 10 g of water were added to 25 g of compound (A30) and 5 g of MBZA, and the mixture was stirred to prepare a carbon dioxide absorbent liquid (100 g). It was placed in a 200 ml gas absorption bottle, and the same experiment was conducted. The evaluation results are shown in Table 8-1.

[0364] [Example 120 (Absorbent Liquid 120)]

[0365] Add 70 g of dimethyl sulfoxide to 25 g of compound (A1) and 5 g of compound (A77), and mix and stir to prepare a carbon dioxide absorption solution (100 g). Place it in a 200-ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 8-1.

[0366] [Example 121 (Absorbent 121)]

[0367] Add 70 g of dimethyl sulfoxide to 25 g of compound (A7) and 5 g of compound (A78), and mix and stir to prepare a carbon dioxide absorption solution (100 g). Place it in a 200-ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 8-1.

[0368] [Example 122 (Absorbent 122)]

[0369] Add 60 g of dimethyl sulfoxide and 10 g of N-methyl-2-pyrrolidone to 25 g of compound (A7) and 2 g of ATMP, and mix and stir to prepare a carbon dioxide absorption solution (100 g). Place it in a 200-ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 8-1.

[0370] [Example 123 (Absorbent 123)]

[0371] Add 60 g of dimethyl sulfoxide and 10 g of N-methyl-2-pyrrolidone to 30 g of compound (A1), and mix and stir to prepare a carbon dioxide absorption solution (100 g). Place it in a 200-ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 8-1.

[0372] [Comparative Example 1 (Absorbent 124)]

[0373] Completely change 30 g of the compound (A1) in Example 1 to MEA, add 70 g of water, mix and stir to prepare a carbon dioxide absorption solution (100 g). Place it in a 200-ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 8-1.

[0374] [Comparative Example 2 (Absorbent 125)]

[0375] Completely change 30 g of the compound (A1) in Example 1 to MEA, prepare a carbon dioxide absorption solution (100 g). Place it in a 200-ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 8-1.

[0376] [Reference Example 1 (Absorbent 126)]

[0377] All 30 g of the compound (A1) in Example 1 was changed to ATMP to prepare a carbon dioxide absorption liquid (100 g), which was placed in a 200 ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 8-1.

[0378] [Examples A1 to A83 (Absorption Liquids A1 to A83)]

[0379] The compound and the liquid medium were changed to the compounds and liquid media described in Tables 8-2 to 8-4 respectively. By the method described in the [Method for Measuring the Release Efficiency of Carbon Dioxide Gas], the absorption amount of carbon dioxide gas was measured, and the carbon dioxide absorption amount (L) per 1 kg of the carbon dioxide absorption liquid and the carbon dioxide gas release efficiency were calculated. In addition, the types of gases used for evaluation are as described in Table 6.

[0380] Based on the measurement of the calculated release efficiency of carbon dioxide gas, the following criteria were set for evaluation, and S, A, and B were regarded as the regions that can be actually used. The evaluation results are shown in Tables 8-1 to 8-4.

[0381] S: The release efficiency is 0.8 or more

[0382] A: The release efficiency is 0.7 or more and less than 0.8

[0383] B: The release efficiency is 0.6 or more and less than 0.7

[0384] C: The release efficiency is less than 0.6

[0385]

[0386]

[0387]

[0388]

[0389] [Examples 124 to 246, Comparative Examples 3 to 4, Reference Example 2]

[0390] (Degree of change in absorption amount after repeated evaluation of carbon dioxide gas absorption / release)

[0391] Using the absorption liquids described in Tables 7-1 to 7-5 and Tables 8-1 to 8-4, the absorption / release measurement of the carbon dioxide gas was repeated 10 times. Thereafter, in the same manner as the first test, the absorption amount of the eleventh time was calculated, and the degree of reduction with respect to the absorption amount of the first time was evaluated. The evaluation criteria are as follows, and S, A, and B are regarded as the regions that can be actually used. The evaluation results are shown in Tables 9-1 to 9-2.

[0392] S: The absorption amount at the 11th time is 99.5% or more relative to the absorption amount at the first time.

[0393] A: The absorption amount at the 11th time is 99% or more and less than 99.5% relative to the absorption amount at the first time.

[0394] B: The absorption amount at the 11th time is 98% or more and less than 99% relative to the absorption amount at the first time.

[0395] C: The absorption amount at the 11th time is less than 98% relative to the absorption amount at the first time.

[0396] [Table 9-1]

[0397] Table 9-1

[0398]

[0399] [Table 9-2]

[0400] Table 9-2

[0401]

[0402] [Examples M1 to M78, Comparative Example 5, Reference Example 3]

[0403] (Absorption rate of carbon dioxide gas)

[0404] The absorption rate was evaluated using the absorption liquids 1, 12, 22, 32, 43 to 116, 125, and 126 described in Tables 7-1 to 7-5 and Table 8-1. 100 g of the prepared carbon dioxide absorption liquid (in the state of being filled in a gas absorption bottle with a capacity of 200 ml) was adjusted to 25°C in a water bath. While bubbling a mixed gas of 100 ml / min of carbon dioxide gas and 400 ml / min of nitrogen gas (500 ml / min), it was blown into the carbon dioxide absorption liquid. The absorption amount of the carbon dioxide gas at this time (the carbon dioxide absorption amount (L) in 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 used as the absorption rate (L / min).

[0405] The evaluation criteria are as described below, and S, A, and B are regarded as the regions that can be actually used. The evaluation results are shown in Table 10.

[0406] S: The absorption rate is 1.00 L / min or more

[0407] A: The absorption rate is 0.75 L / min or more and less than 1.00 L / min

[0408] B: The absorption rate is 0.50 L / min or more and less than 0.75 L / min

[0409] C: Absorption rate is less than 0.50 L / min

[0410] [Table 10]

[0411] Table 10

[0412]

[0413] As described in the embodiments, compared with the conventionally known carbon dioxide absorption liquid, the carbon dioxide absorption liquid of the present disclosure has excellent effects on the release rate and release efficiency (release amount / absorption amount) of carbon dioxide. In addition, it can be found that, compared with the release temperature of 120°C of the generally known MEA aqueous solution, the absorption liquid of the present disclosure can efficiently release carbon dioxide at a release temperature of 60°C under the experimental conditions of this time.

[0414] 2. Example Group 2

[0415] [Synthesis Example 79]

[0416] Synthesis method of compound (A79)

[0417] [Chemical Formula 11]

[0418]

[0419] Under a nitrogen atmosphere, 30.0 g (665.5 mmol) of ethylamine (b1) mixed with 300 ml of methanol and 72.0 g (332.7 mmol) of neopentyl glycol diglycidyl ether (c7) were added and stirred. After the addition, the mixture was stirred at room temperature for 24 hours. (b1) as the reaction substance was not detected by TOF-MS, thereby confirming the progress of the reaction. Methanol as the solvent was removed by reduced pressure at 40°C or lower, thereby obtaining the target compound (A79).

[0420] (TOF-MS measurement result)

[0421] Calculated value of molecular weight: C15H34N2O4, Mol.Wt. 306.4;

[0422] Observed molecular weight: m / z 306.5

[0423] [Synthesis Examples 80 to 122]

[0424] In the same manner as in Synthesis Example 79, the amine compounds in Table 2 were appropriately combined with the epoxy compounds in Tables 3-1 to 3-5 to synthesize Compounds (A80) to (A128). The obtained compounds were identified by TOF-MS in the same manner as in Synthesis Example 79. The yields of the synthesized compounds and the mass spectrometry results are shown in Table 11. In addition, the compound numbers are the same as those described in Tables 1-6 to 1-8 of this specification.

[0425] [Table 11]

[0426] Table 11

[0427]

[0428] (Method for measuring the release efficiency of carbon dioxide gas)

[0429] 100 g of the carbon dioxide absorbent adjusted in the following examples (in a state of being filled in a gas absorption bottle with a capacity of 200 ml) was adjusted to 25°C in a water bath. While bubbling a mixed gas of 100 ml / min of carbon dioxide gas and 400 ml / min of nitrogen gas (500 ml / min), it was blown into the carbon dioxide absorbent 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 the carbon dioxide absorption amount (L) for 1 hour, the carbon dioxide absorption amount (L) per 1 kg of the carbon dioxide absorbent was calculated.

[0430] Next, the carbon dioxide absorbent was adjusted to 60°C in a water bath. While bubbling 500 ml / min of nitrogen gas, it was blown into the carbon dioxide absorbent for 2 hours. The release amount of carbon dioxide gas at this time (the carbon dioxide release amount (L) for 2 hours) was measured using a gas flow meter and a carbon dioxide concentration meter. Using the carbon dioxide release amount (L) for 2 hours, the carbon dioxide release amount (L) per 1 kg of the carbon dioxide absorbent was calculated.

[0431] Based on the carbon dioxide release amount (L) for 2 hours and the carbon dioxide absorption amount (L) for 1 hour, the carbon dioxide gas release efficiency (= carbon dioxide release amount (L) for 2 hours ÷ carbon dioxide absorption amount (L) for 1 hour) was calculated.

[0432] Based on the measurement of the calculated carbon dioxide gas release efficiency, the following criteria were set and evaluated, and S, A, and B were used as the regions that can be actually used. The evaluation results are shown in Tables 12-1 to 12-7.

[0433] S: The release efficiency is 0.8 or more

[0434] A: The release efficiency is 0.7 or more and less than 0.8

[0435] B: The release efficiency is 0.6 or more and less than 0.7

[0436] C: The release efficiency is less than 0.6

[0437] [Materials and gas types for evaluation]

[0438] For the sake of concise expression, the following abbreviated symbols are used.

[0439] ATMP: 4-Amino-2,2,6,6-tetramethylpiperidine

[0440] MDEA: N-Methyldiethanolamine

[0441] MBZA: Methylbenzylamine

[0442] MEA: Monoethanolamine

[0443] AB: 2-Aminobutanol

[0444] DMAPA: Dimethylaminopropylamine

[0445] The gas types for evaluation are the same as those in Table 6.

[0446] [Example B1 (absorbent B1)]

[0447] To 30 g of the compound (A79) obtained in Synthesis Example 79, 70 g of dimethyl sulfoxide was added and mixed and stirred to prepare a carbon dioxide absorbent (100 g), which was placed in a 200 ml gas absorption bottle to measure the release efficiency of carbon dioxide gas.

[0448] The carbon dioxide absorption amount (L) in 1 hour was 2.18 L in terms of standard state conversion. That is, the carbon dioxide absorption amount (L) per 1 kg of the carbon dioxide absorbent in 1 hour was 21.8 L under standard state. (The carbon dioxide absorption amount (ml / minute) per 1 kg of the carbon dioxide absorbent per 1 minute was 363 ml / minute (= 21.8 [L / hour] × 1000 [ml / L] ÷ 60 [minutes / hour]).

[0449] The carbon dioxide release amount (L) in 2 hours was 1.80 L in terms of standard state conversion.

[0450] That is, the carbon dioxide release amount (L) per 1 kg of the carbon dioxide absorbent in 2 hours was 18.0 L in terms of standard state conversion.

[0451] (The carbon dioxide release amount (mL / minute) per 1 kg of the carbon dioxide absorbent per 1 minute was 150 ml / minute (= 18.0 [L / 2 hours] × 1000 [ml / L] ÷ 120 [minutes / hour]).

[0452] Thus, the release efficiency of carbon dioxide gas is 0.83. The above results are shown in Table 12-1.

[0453] [Example B2 (Absorbent B2)]

[0454] Change 30 g of the compound (1) to 15 g and change dimethyl sulfoxide from 70 g to 85 g. Similarly, prepare a carbon dioxide absorbent (100 g), put it into a 200-ml gas absorption bottle, and measure the release efficiency of carbon dioxide gas. The evaluation results are shown in Table 12-1.

[0455] [Examples B3 to B54, Examples E21 to E40, Examples J1 to J165 (Absorbents B3 to B54, E21 to E40, J1 to J165)]

[0456] Change the compounds and liquid media described in Example B1 to the compounds and liquid media described in Tables 12-1 to 12-7, and conduct the same experiment. The evaluation results are shown in Tables 12-1 to 12-7.

[0457]

[0458]

[0459]

[0460]

[0461]

[0462]

[0463]

[0464] [Example D1 (Absorbent B55)]

[0465] Add 70 g of dimethyl sulfoxide to 25 g of the compound (A84) and 5 g of MDEA, mix and stir to prepare a carbon dioxide absorbent (100 g), put it into a 200-ml gas absorption bottle, and conduct the same experiment. The evaluation results are shown in Table 13-1.

[0466] [Example D2 (Absorbent B56)]

[0467] Add 60 g of sulfolane and 10 g of water to 25 g of compound (A85) and 5 g of MBZA, and mix and stir to prepare a carbon dioxide absorption liquid (100 g). Place it in a 200 ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 13-1.

[0468] [Example D3 (Absorbent B57)]

[0469] Add 60 g of dimethyl sulfoxide and 10 g of water to 25 g of compound (A89) and 5 g of MBZA, and mix and stir to prepare a carbon dioxide absorption liquid (100 g). Place it in a 200 ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 13-1.

[0470] [Example D4 (Absorbent B58)]

[0471] Add 70 g of dimethyl sulfoxide to 25 g of compound (A84) and 5 g of compound (A93), and mix and stir to prepare a carbon dioxide absorption liquid (100 g). Place it in a 200 ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 13-1.

[0472] [Example D5 (Absorbent B59)]

[0473] Add 70 g of dimethyl sulfoxide to 25 g of compound (A85) and 5 g of compound (A94), and mix and stir to prepare a carbon dioxide absorption liquid (100 g). Place it in a 200 ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 13-1.

[0474] [Example D6 (Absorbent B60)]

[0475] Add 60 g of dimethyl sulfoxide and 10 g of N-methyl-2-pyrrolidone to 25 g of compound (A85) and 2 g of ATMP, and mix and stir to prepare a carbon dioxide absorption liquid (100 g). Place it in a 200 ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 13-1.

[0476] [Example A124 (Absorbent A124)]

[0477] Add 70 g of dimethyl sulfoxide and 5 g of 2-aminobutanol to 25 g of compound (A127), and mix and stir to prepare a carbon dioxide absorption liquid (100 g). Place it in a 200 ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 13-1.

[0478] [Example A125 (Absorbent A125)]

[0479] Add 70 g of dimethyl sulfoxide and 5 g of dimethylaminopropylamine to 25 g of the compound (A128), mix and stir to prepare a carbon dioxide absorption liquid (100 g), and put it into a 200 ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 13-1.

[0480] [Example D7 (Absorbent B61)]

[0481] Add 60 g of dimethyl sulfoxide and 10 g of N-methyl-2-pyrrolidone to 30 g of the compound (A84), mix and stir to prepare a carbon dioxide absorption liquid (100 g), and put it into a 200 ml gas absorption bottle to conduct the same experiment. The evaluation results are shown in Table 13-1.

[0482] [Examples C1 - C83, Examples K1 - K128 (Absorbents C1 - C83, K1 - K128)]

[0483] Respectively change the compounds and liquid media described in Example D1 to the compounds and liquid media described in Tables 13-1 to 13-7. Measure the absorption amount of carbon dioxide gas by the method described in the [Method for Measuring the Release Efficiency of Carbon Dioxide Gas], and calculate the carbon dioxide absorption amount (L) per 1 kg of carbon dioxide absorption liquid and the carbon dioxide gas release efficiency. In addition, the types of gases used for evaluation are as described in Table 6.

[0484] Based on the measurement of the calculated carbon dioxide gas release efficiency, set the following criteria for evaluation, and regard S, A, and B as the regions that can be actually used. The evaluation results are shown in Tables 13-1 to 13-7.

[0485] S: The release efficiency is 0.8 or more

[0486] A: The release efficiency is 0.7 or more and less than 0.8

[0487] B: The release efficiency is 0.6 or more and less than 0.7

[0488] C: The release efficiency is less than 0.6

[0489]

[0490]

[0491]

[0492]

[0493]

[0494]

[0495]

[0496] [Examples G1 - G61, Examples H1 - H202, Examples L1 - L128]

[0497] (Degree of change in absorption amount after repeated evaluation of carbon dioxide gas absorption / release)

[0498] Using the absorbents B1 - B61, C1 - C83, E21 - E35, K1 - K128, G1 - G99 described in Tables 12 - 1 to 12 - 7, the absorption / release measurement of the carbon dioxide gas was repeatedly performed 10 times. Thereafter, in the same manner as in the first test, the absorption amount of the eleventh time was calculated, and the degree of reduction with respect to the absorption amount of the first time was evaluated. The evaluation criteria are as described below, and S, A, and B are regarded as the regions where it can be actually used. The evaluation results are shown in Tables 14 - 1 to 14 - 4.

[0499] S: The absorption amount of the eleventh time is 99.5% or more with respect to the absorption amount of the first time

[0500] A: The absorption amount of the eleventh time is more than 99% and less than 99.5% with respect to the absorption amount of the first time

[0501] B: The absorption amount of the eleventh time is more than 98% and less than 99% with respect to the absorption amount of the first time

[0502] C: The absorption amount of the eleventh time is less than 98% with respect to the absorption amount of the first time [Table 14 - 1]

[0503] Table 14 - 1

[0504]

[0505] [Table 14 - 2]

[0506] Table 14 - 2

[0507]

[0508] [Table 14 - 3]

[0509] Table 14 - 3

[0510]

[0511] [Table 14 - 4]

[0512] Table 14 - 4

[0513]

[0514] [Examples M79 - M122]

[0515] (Absorption rate of carbon dioxide gas)

[0516] The absorption rates were evaluated using the absorbents B1, B12, B22, B32, B43 - B54, J1, J110, J125, J141 - J144, J17, J32, J47, J63 - J79, J95 described in Tables 12 - 1 to 12 - 7. 100 g of the prepared carbon dioxide absorbent (in a state of being filled in a gas absorption bottle with a capacity of 200 ml) was adjusted to 25°C in a water bath. While bubbling a mixed gas of 100 ml / min of carbon dioxide gas and 400 ml / min of nitrogen gas (500 ml / min), it was blown into the carbon dioxide absorbent. The absorption amount of carbon dioxide gas at this time (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 taken as the absorption rate (L / min).

[0517] The evaluation criteria are as described below, and S, A, and B are regarded as the regions where it can be actually used. The evaluation results are shown in Table 15. In addition, for comparison, the results of Comparative Example 5 and Reference Example 3 using the absorbents 125 - 126 described in the above-mentioned Example Group 1 are also shown simultaneously.

[0518] S: The absorption rate is 1.00 L / min or more

[0519] A: The absorption rate is 0.75 L / min or more and less than 1.00 L / min

[0520] B: The absorption rate is 0.50 L / min or more and less than 0.75 L / min

[0521] C: The absorption rate is less than 0.50 L / min

[0522] [Table 15]

[0523] Table 15

[0524]

[0525] As described in the above-mentioned examples, compared with the conventionally known carbon dioxide absorbents, the carbon dioxide absorbent of the present invention of the application has excellent effects on the release rate and release efficiency (release amount / absorption amount) of carbon dioxide. In addition, it was found that compared with the release temperature of 120°C of the usually known MEA aqueous solution, 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.

[0526] This application claims priority based on Japanese Patent Application No. 2022-175922 filed on November 2, 2022, Japanese Patent Application No. 2023-393 filed on January 5, 2023, and Japanese Patent Application No. 2023-91519 filed on June 2, 2023, and incorporates the entire contents disclosed therein into this application.

Claims

1. An absorbent for separating and recovering carbon dioxide from a gas containing carbon dioxide, the absorbent comprising an amine compound (A) represented by the following general formula (1) and a liquid medium (B); [Chemical formula 1] In the formula, R 1 is a hydrogen atom or a hydrocarbon group which may have substituents and may have heteroatoms in the carbon chain, and the carbon atom adjacent to N is a primary carbon atom or a carbon atom forming a ring, R 2 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms and the carbon atom adjacent to N is a primary carbon atom, or is -CH 2 CH(OH)CH 2 X 2 A 2 , 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 ( wherein, X 1 is a direct bond and A 1 except when 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 (wherein, X 2 is a direct bond and A 2 is a hydrogen atom, excepted). A 3 is a hydrogen atom or a monovalent organic residue.

2. The absorbent according to claim 1, wherein, The said R 1 has a nitrogen atom.

3. The absorbent according to claim 1, wherein, The R 1 is a group represented by the following general formula (2), general formula (3), general formula (4) or general formula (5); [Chemical formula 2] In the formula, R 3 、R 4 、R 5 、and R 6 are each independently a hydrogen atom or a methyl group, R 7 is a hydrogen atom or a methyl group, R 8 is a hydrogen atom or a methyl group, p is an integer from 0 to 4, R 9 is an alkyl group having 1 to 8 carbon atoms, m is an integer from 0 to 4, R 10 and R 12 each independently represents 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 , R 13 is hydroxy or -N(R 14 )R 15 , 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 2 or 3, s is 2 or 3.

4. The absorbent according to claim 1, wherein, The said A 1 is an n-valent organic residue.

5. The absorbent according to claim 1, wherein, Said A 1 , A 2 and A 3 are each independently an 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 or an aromatic heterocyclic residue which may have a substituent.

6. The absorbent according to claim 1, wherein, The said R 2 is a hydrogen atom.

7. 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 linear polyamines.

8. The absorbent according to claim 1, wherein, The total Hansen solubility parameter (δT) of the liquid medium (B) is 17 MPa 1 / 2 or more.

9. The absorbent according to claim 1, wherein, the proportion of water in the liquid medium (B) is 50% by mass or less.

10. The absorbent according to claim 1, containing 5% by mass or more of the amine compound (A) represented by the formula (1).

11. The absorbent according to claim 1, further, the gas contains hydrogen sulfide, and the absorbent absorbs the hydrogen sulfide.

12. A method comprising the following steps A and B and being a method for separating and recovering carbon dioxide from a gas containing carbon dioxide, the method being: Step A: A step of bringing the absorbent according to any one of claims 1 to 11 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 cause carbon dioxide to be released and diffused from the absorbent and recovering the diffused carbon dioxide.

13. The method according to claim 12, wherein, the heating temperature in Step B is 50°C or higher and 160°C or lower.

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