Polymeric compound and method for accelerating reaction from carbon dioxide to bicarbonate ion

Abstract

Provided is a polymeric compound which has a constituent unit (a1) represented by general formula (a1) and a constituent unit (a2) represented by general formula (a2). In the formulae, R1 represents a hydrogen atom or a methyl group; R2 represents a hydrogen atom or a methyl group; m represents an integer of 1 or 2; n1 represents an integer of 1 or 2; n2 represents an integer of 1 or 2; n3 represents an integer of 1 or 2; n4 represents an integer of 0, 1, 2 or 3; and n5 represents an integer of 0, 1 or 2. When m is 2, the plurality of n1s may be the same as or different from each other. In the formula, the hydrogen atom in the -CH2- group represented by > may be substituted with an alkyl group.

Description

Polymer compound and method for promoting the reaction from carbon dioxide to bicarbonate ions

[0001] The present invention relates to a polymer compound and a method for promoting the reaction of carbon dioxide to bicarbonate ions. This application claims priority to Japanese Patent Application No. 2024-062955, filed on April 9, 2024, the contents of which are incorporated herein by reference.

[0002] Carbon dioxide fixation technology is a general term for technologies that fix carbon dioxide contained in the atmosphere or exhaust gases. A widely known technology is to capture carbon dioxide in an absorption solution by wet physical absorption and fix it as bicarbonate or carbonate.

[0003] As for existing carbon dioxide fixation technologies, the presence of sulfur oxides inhibits carbon dioxide capture, so a technology that is mainly being considered involves using low-sulfur fuel, sufficiently reducing the concentration of sulfur oxides in exhaust gas, and then capturing and isolating carbon dioxide using a wet scrubber that uses an absorbing liquid such as an alkanolamine, as disclosed in Patent Document 1, for example.

[0004] Special Publication No. 2011-504806 Publication Patent No. 7075152

[0005] Yaqin Fu, et. al. “Ultra-thin enzymatic liquid membrane for CO2 separation and capture” “nature communications” volume 9, Article number: 990, (2018).Marta Diez-Castellnou, et. al. “The Zn(II)-1,4,7-Trimethyl-1,4,7-Triazacyclononane Complex: A Monometallic Catalyst Active in Two Protonation “Frontiers in Chemistry” Volume 7, Article 469, (2019).

[0006] There is a need to reduce carbon dioxide emissions from marine vessels. However, technology to capture and fix carbon dioxide from the exhaust gases of main or auxiliary engines on board ships has not yet been put to practical use due to the enormous cost of installing such technology on ships.

[0007] Patent Document 2 discloses a carbon dioxide fixation device including a capture container that captures carbon dioxide in an absorbing liquid by wet physical absorption and a pressurized container, and a carbon dioxide fixation method using the same.

[0008] As disclosed in Non-Patent Documents 1 and 2, a catalyst having a 1,4,7-triazacyclononane structure is ２ +H ２ O ⇔ H ２ CO ３ ⇔ HCO ３ － +H ＋ However, when 1,4,7-triazacyclononane is used as a catalyst in the wet carbon dioxide fixation devices described in Patent Documents 1 and 2, it precipitates in water, making it difficult to use as a catalyst in wet carbon dioxide fixation devices.

[0009] Therefore, the present invention provides a wet carbon dioxide fixation device that ２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３ － +H ＋ The present invention aims to provide a polymer compound that can be used as a catalyst for the reaction of " and can make carbon dioxide recovery more efficient, and a method for promoting the reaction from carbon dioxide to bicarbonate ions.

[0010] The present invention includes the following aspects: [1] A polymeric compound having a structural unit (a1) represented by the following general formula (a1) and a structural unit (a2) represented by the following general formula (a2):

[0011] [In the formula, R １ is a hydrogen atom or a methyl group; R ２is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; n3 is an integer of 1 or 2; n4 is an integer of 0, 1, 2, or 3; and n5 is an integer of 0, 1, or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0012] [2] A polymeric compound having a structural unit (a0) represented by the following general formula (a0) and a structural unit (a2) represented by the following general formula (a2):

[0013] [In the formula, R １ is a hydrogen atom or a methyl group; R ２ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; n3 is an integer of 1 or 2; n4 is an integer of 0, 1, 2, or 3; and n5 is an integer of 0, 1, or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0014] [3] A method for producing a carbon dioxide absorbent comprising contacting a polymer compound with an absorbing solution in which carbon dioxide has been physically absorbed, wherein the polymer compound is "CO ２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３ － +H ＋ " a polymer compound having a viscosity-average molecular weight of 1,000 or more, and having the property of dissolving in a carbon dioxide saturated aqueous solution at a concentration of 0.01 mg / mL. [4] A method for promoting a reaction from carbon dioxide to bicarbonate ions according to [3], wherein the functional group is a group having a nitrogen-containing ring.

[0015] [5] The method for promoting the reaction of carbon dioxide to bicarbonate ions according to [4], wherein the functional group is a group represented by the following formula (a1-a1):

[0016] [In the formula, m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group. ２＋ may be accompanied by a counter anion.]

[0017] [6] The method for promoting the reaction of converting carbon dioxide to bicarbonate ions according to [3], wherein the polymer compound has a structural unit derived from a (meth)acrylic ester, a structural unit derived from a (meth)acrylamide, a structural unit derived from a vinyl compound, or a structural unit derived from a polysaccharide.

[0018] [7] The method for promoting the reaction of converting carbon dioxide to bicarbonate ions according to [6], wherein the polymer compound has a structural unit (a1-0) represented by the following general formula (a1-0):

[0019] [In the formula, R １ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group. ２＋may be accompanied by a counter anion.] [8] The method for promoting the reaction of converting carbon dioxide to bicarbonate ions according to [3], wherein the polymer compound has a structural unit derived from a (meth)acrylic ester having one or more hydrophilic groups selected from the group consisting of a hydroxy group, an ether group, an amide group, a carboxyl group, and an amino group, a structural unit derived from a (meth)acrylamide having one or more hydrophilic groups selected from the group consisting of a hydroxy group, an ether group, an amide group, a carboxyl group, and an amino group, a structural unit derived from a vinyl compound having one or more hydrophilic groups selected from the group consisting of a hydroxy group, an ether group, an amide group, a carboxyl group, and an amino group, or a structural unit derived from a polysaccharide having one or more hydrophilic groups selected from the group consisting of a hydroxy group, an ether group, an amide group, a carboxyl group, and an amino group.

[0020] [9] The method for promoting the reaction of converting carbon dioxide to bicarbonate ions according to [3], wherein the polymer compound is brought into contact with the absorption liquid as a solution.

[10] The method for promoting the reaction of converting carbon dioxide to bicarbonate ions according to [3], wherein the polymer compound is brought into contact with the absorption liquid as an immobilized catalyst.

[0021]

[11] A polymeric compound having a structural unit (a1) represented by the following general formula (a1) and a structural unit (a3) ​​represented by the following general formula (a3):

[0022] [In the formula, R １ is a hydrogen atom or a methyl group; R ３ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0023]

[12] A polymeric compound having a structural unit (a0) represented by the following general formula (a0): and a structural unit (a3) ​​represented by the following general formula (a3):

[0024] [In the formula, R １ is a hydrogen atom or a methyl group; R ３ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0025] According to the present invention, it is possible to provide a polymer compound that can be used as a catalyst in a wet carbon dioxide fixation device and that can make carbon dioxide recovery more efficient, and a method for promoting the reaction from carbon dioxide to bicarbonate ions.

[0026] Fig. 1 is a schematic diagram showing a carbon dioxide fixation device 1 of the fifth embodiment. Fig. 2 shows the results of a weak magnetic field gradient strength (w) (5 × 10) for the polymer compound (1) [E401], the polymer compound (2) [E401-N4], and the polymer compound (3) [E401-N4-Zn]. －４ T / cm) and strong magnetic field gradient strength (s) (50 × 10 －４ T / cm), １ 3 is a H-NMR chart of polymer compound (4) [E501], polymer compound (5) [E501-N4], and polymer compound (6) [E501-N4-Zn]. １ 1H-NMR chart.

[0027] Polymer Compound First Embodiment The polymer compound of the first embodiment has a structural unit (a1) represented by the following general formula (a1) and a structural unit (a2) represented by the following general formula (a2):

[0028] [In the formula, R １ is a hydrogen atom or a methyl group; R ２is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; n3 is an integer of 1 or 2; n4 is an integer of 0, 1, 2, or 3; and n5 is an integer of 0, 1, or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0029] The polymer compound of the first embodiment has the structural unit (a1) represented by general formula (a1), and therefore, ２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３ － +H ＋ " and has the structural unit (a2) represented by general formula (a2), which can provide favorable water dispersibility and solubility. Therefore, in the wet fixation of carbon dioxide, the reaction from carbon dioxide to bicarbonate ions can be promoted, resulting in more efficient carbon dioxide recovery.

[0030] The zinc atom Zn in the structural unit (a1) is a monovalent cation (Zn ＋ ) or divalent cations (Zn ２＋ ) and may have the same equivalent anion moiety. Examples of the anion moiety include chloride ion, perchlorate ion, chlorate ion, hypochlorite ion, sulfate ion, and hydrogen sulfate ion.

[0031] The bond between the zinc atom Zn and the nitrogen atom N is a coordinate bond. When the zinc atom Zn forms a complex, tri-, tetra-, penta-, and hexa-coordinate complexes are known. In addition, the zinc atom Zn in the structural unit (a1) can also bond with a water molecule H ２ The polymer compound of the first embodiment may be in a hydrated state by coordinating O. In the structural unit (a1), the number of ions of zinc atom Zn, coordinated water molecules, and anion moieties are omitted.

[0032] The total proportion of the structural unit (a1) and the structural unit (a2) in the polymer compound of the first embodiment, relative to all structural units constituting the polymer compound, is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 99 mol% or more, and may be 100 mol%.

[0033] The proportion of the structural unit (a1) in the polymer compound of the first embodiment is preferably 2.0 mol % or more and 20 mol % or less, more preferably 2.5 mol % or more and 10 mol % or less, even more preferably 3.0 mol % or more and 8.0 mol % or less, and particularly preferably 3.5 mol % or more and 5.0 mol % or less, relative to all structural units constituting the polymer compound. ２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３ － +H ＋ When the content is equal to or less than the upper limit, the water dispersibility and water solubility can be made favorable.

[0034] The proportion of the structural unit (a2) in the polymer compound of the first embodiment is preferably 80 mol% or more and 98 mol% or less, more preferably 90 mol% or more and 97.5 mol% or less, even more preferably 92 mol% or more and 97 mol% or less, and particularly preferably 95 mol% or more and 96.5 mol% or less, relative to all structural units constituting the polymer compound. By being equal to or greater than the lower limit, water dispersibility and water solubility can be made favorable. By being equal to or less than the upper limit, the catalytic effect can be made more excellent.

[0035] The viscosity average molecular weight of the polymer compound of the first embodiment may be 1,000 to 1,000,000, 5,000 to 200,000, or 20,000 to 50,000.

[0036] Specific examples of the polymer compound of the first embodiment include a polymer compound having a structural unit (a1-10) represented by the following formula (a1-10) and a structural unit (a2-0) represented by the following formula (a2-0); a polymer compound having a structural unit (a1-20) represented by the following formula (a1-20) and a structural unit (a2-0) represented by the following formula (a2-0); a polymer compound having a structural unit (a1-1) represented by the following formula (a1-1) and a structural unit (a2-0) represented by the following formula (a2-0); a polymer compound having a structural unit (a1-2) represented by the following formula (a1-2) and a structural unit (a2-0) represented by the following formula (a2-0); a polymer compound having a structural unit (a1-1) represented by the following formula (a1-1) and a structural unit (a2-1) represented by the following formula (a2-1); Examples of the polymer compound include, but are not limited to, a polymer compound having a structural unit (a1-2) represented by the following formula (a1-2) and a structural unit (a2-1) represented by the following formula (a2-1), a polymer compound having a structural unit (a1-2) represented by the following formula (a1-2) and a structural unit (a2-3) represented by the following formula (a2-3), a polymer compound having a structural unit (a1-2) represented by the following formula (a1-2) and a structural unit (a2-4) represented by the following formula (a2-4), a polymer compound having a structural unit (a1-2) represented by the following formula (a1-2) and a structural unit (a2-5) represented by the following formula (a2-5), and a polymer compound having a structural unit (a1-2) represented by the following formula (a1-2) and a structural unit (a2-6) represented by the following formula (a2-6).

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047] The polymer compound of the first embodiment can be synthesized by a known method by coordinating three or four nitrogen atoms N of the structural unit (a0) of the polymer compound of the second embodiment described below to a zinc atom Zn. For example, a polymer compound having a structural unit (a0) represented by the following general formula (a0) of the second embodiment and a structural unit (a2) represented by the following general formula (a2), and Zn(ClO ４ ) ２ and a Zn compound such as the above, according to the following formula:

[0048] [In the formula, R １ is a hydrogen atom or a methyl group; R ２ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; n3 is an integer of 1 or 2; n4 is an integer of 0, 1, 2, or 3; and n5 is an integer of 0, 1, or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0049] The polymer compound of the second embodiment is dispersed and dissolved in a reaction solvent, and Zn(ClO) dissolved in a solvent such as ethanol is added. ４ ) ２ Alternatively, a method of adding a Zn compound such as

[0050] The reaction solvent is a mixture of the raw materials, the polymer compound of the second embodiment and Zn(ClO ４ ) ２ Any solvent capable of dissolving Zn compounds such as Zn(ClO) may be used, and specific examples include dioxane, 1-butanol, dimethylformamide (DMF), dimethylacetamide, dimethylsulfoxide (DMSO), and acetonitrile. ４ ) ２The amount of Zn compound such as the above is preferably about 1 to 100 equivalents, and more preferably 1 to 50 equivalents, relative to the structural unit (a0). The reaction temperature is preferably 20 to 140°C, and more preferably 60 to 120°C. The reaction time is generally preferably 0.5 to 6 hours, and more preferably 1 to 3 hours.

[0051] After the reaction is complete, the reaction mixture may be used in the next step as is, or the polymer compound of the first embodiment in the reaction mixture may be isolated and purified. For isolation and purification, a conventionally known method can be used, and for example, concentration, solvent extraction, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more thereof.

[0052] [Second Embodiment] The polymer compound of the second embodiment is an intermediate compound for synthesizing the polymer compound of the first embodiment. The polymer compound of the second embodiment has a structural unit (a0) represented by the following general formula (a0) and a structural unit (a2) represented by the following general formula (a2).

[0053] [In the formula, R １ is a hydrogen atom or a methyl group; R ２ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; n3 is an integer of 1 or 2; n4 is an integer of 0, 1, 2, or 3; and n5 is an integer of 0, 1, or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0054] In the polymer compound of the second embodiment, the total proportion of the structural unit (a0) and the structural unit (a2) relative to all structural units constituting the polymer compound is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 99 mol% or more, and may be 100 mol%.

[0055] The proportion of the structural unit (a0) in the polymer compound of the second embodiment is preferably 2.0 mol% or more and 20 mol% or less, more preferably 2.5 mol% or more and 10 mol% or less, even more preferably 3.0 mol% or more and 8.0 mol% or less, and particularly preferably 3.5 mol% or more and 5.0 mol% or less, relative to all structural units constituting the polymer compound. By being equal to or greater than the lower limit, when the polymer compound of the first embodiment is synthesized from the polymer compound of the second embodiment, the catalytic effect of the polymer compound of the first embodiment can be made more excellent. By being equal to or less than the upper limit, the water dispersibility and water solubility of the polymer compound of the first embodiment can be made favorable.

[0056] The proportion of the structural unit (a2) in the polymer compound of the second embodiment is preferably 80 mol% or more and 98 mol% or less, more preferably 90 mol% or more and 97.5 mol% or less, even more preferably 92 mol% or more and 97 mol% or less, and particularly preferably 95 mol% or more and 96.5 mol% or less, relative to all structural units constituting the polymer compound. By being equal to or greater than the lower limit, when the polymer compound of the first embodiment is synthesized from the polymer compound of the second embodiment, the water dispersibility and water solubility of the polymer compound of the first embodiment can be made favorable. By being equal to or less than the upper limit, the catalytic effect of the polymer compound of the first embodiment can be made even better.

[0057] The viscosity average molecular weight of the polymer compound of the second embodiment may be 1,000 to 1,000,000, 5,000 to 200,000, 10,000 to 500,000, or 20,000 to 50,000.

[0058] Specific examples of the polymer compound of the second embodiment include a polymer compound having a structural unit (a0-10) represented by the following formula (a0-10) and a structural unit (a2-0) represented by the following formula (a2-0); a polymer compound having a structural unit (a0-20) represented by the following formula (a0-20) and a structural unit (a2-0) represented by the following formula (a2-0); and a polymer compound having a structural unit (a0-1) represented by the following formula (a0-1) and a structural unit (a2-0) represented by the following formula (a2-0). Examples of suitable polymer compounds include, but are not limited to, polymer compounds having a structural unit (a0-2) represented by the following formula (a0-2) and a structural unit (a2-0) represented by the following formula (a2-0), polymer compounds having a structural unit (a0-1) represented by the following formula (a0-1) and a structural unit (a2-1) represented by the following formula (a2-1), and polymer compounds having a structural unit (a0-2) represented by the following formula (a0-2) and a structural unit (a2-1) represented by the following formula (a2-1).

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065] The polymer compound of the second embodiment can be synthesized by reacting a polymer compound having a structural unit (a) represented by the following general formula (a) and a structural unit (a2) represented by the following general formula (a2), with a compound (ax) represented by the following general formula (ax) using a known method according to the following formula:

[0066] [In the formula, R １ is a hydrogen atom or a methyl group; R ２is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; n3 is an integer of 1 or 2; n4 is an integer of 0, 1, 2, or 3; and n5 is an integer of 0, 1, or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0067] For example, a method may be employed in which a polymer compound having a structural unit (a) represented by general formula (a) and a structural unit (a2) represented by general formula (a2) is dispersed or dissolved in a reaction solvent, and then a compound (ax) represented by the following general formula (ax) dissolved in a solvent such as ethanol is added.

[0068] [In the formula, m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0069] Examples of the compound (ax) include a compound (ax1) represented by the following formula (ax1) (1,4,7-triazacyclononane, m=1, n1=n2=n3=1), a compound (ax2) represented by the following formula (ax2) (m=1, n1=n2=n3=2), a compound (ax3) represented by the following formula (ax3) (1,4,7,10-tetraazacyclododecane, m=2, n1=n2=n3=2), a compound (ax4) represented by the following formula (ax4) (m=2, n1=n2=1, n3=2), and a compound (ax5) represented by the following formula (ax5) (m=2, n1=1 and 2, n2=1, n3=2).

[0070]

[0071] The reaction solvent may be any solvent capable of dissolving the starting polymer compound having the structural unit (a) and the structural unit (a2) and the compound (ax), and specific examples include dioxane, 1-butanol, dimethylformamide (DMF), dimethylacetamide, dimethyl sulfoxide (DMSO), acetonitrile, etc. The amount of compound (ax) added is preferably approximately 1 to 100 equivalents, and more preferably 1 to 50 equivalents, relative to the amount of the structural unit (a). The reaction temperature is preferably 60 to 140°C, and more preferably 80 to 120°C. The reaction time is generally preferably 0.5 to 6 hours, and more preferably 1 to 3 hours.

[0072] After the reaction is complete, the reaction mixture may be used in the next step as is, or the polymer compound of the second embodiment in the reaction mixture may be isolated and purified. For isolation and purification, a conventionally known method can be used, and for example, concentration, solvent extraction, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more thereof.

[0073] Third Embodiment A polymer compound according to a third embodiment has a structural unit (a1) represented by the following general formula (a1) and a structural unit (a3) ​​represented by the following general formula (a3).

[0074] [In the formula, R １ is a hydrogen atom or a methyl group; R ３ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0075] The polymer compound of the third embodiment has the structural unit (a1) represented by general formula (a1), and therefore, ２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３ － +H ＋" reaction, and since it has the structural unit (a3) ​​represented by general formula (a3), it can have favorable water dispersibility and water solubility. Therefore, in the wet fixation of carbon dioxide, it can promote the reaction from carbon dioxide to bicarbonate ions, and as a result, it can make the recovery of carbon dioxide more efficient.

[0076] The zinc atom Zn in the structural unit (a1) is a monovalent cation (Zn ＋ ) or divalent cations (Zn ２＋ ) and may have the same equivalent anion moiety. Examples of the anion moiety include chloride ion, perchlorate ion, chlorate ion, hypochlorite ion, sulfate ion, and hydrogen sulfate ion.

[0077] The bond between the zinc atom Zn and the nitrogen atom N is a coordinate bond. When the zinc atom Zn forms a complex, tri-, tetra-, penta-, and hexa-coordinate complexes are known. In addition, the zinc atom Zn in the structural unit (a1) can also bond with a water molecule H ２ The polymer compound of the third embodiment may be in a hydrated state by coordinating O. In the structural unit (a1), the number of ions of zinc atom Zn, coordinated water molecules, and anion moieties are omitted.

[0078] The total proportion of the structural unit (a1) and the structural unit (a2) in the polymer compound of the third embodiment, relative to all structural units constituting the polymer compound, is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 99 mol% or more, and may be 100 mol%.

[0079] The proportion of the structural unit (a1) in the polymer compound of the third embodiment is preferably 2.0 mol % or more and 20 mol % or less, more preferably 2.5 mol % or more and 10 mol % or less, even more preferably 3.0 mol % or more and 8.0 mol % or less, and particularly preferably 3.5 mol % or more and 5.0 mol % or less, relative to all structural units constituting the polymer compound. ２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３－ +H ＋ When the content is equal to or less than the upper limit, the water dispersibility and water solubility can be made favorable.

[0080] The proportion of the structural unit (a2) in the polymer compound of the third embodiment is preferably 80 mol% or more and 98 mol% or less, more preferably 90 mol% or more and 97.5 mol% or less, even more preferably 92 mol% or more and 97 mol% or less, and particularly preferably 95 mol% or more and 96.5 mol% or less, relative to all structural units constituting the polymer compound. By being equal to or greater than the lower limit, water dispersibility and water solubility can be made favorable. By being equal to or less than the upper limit, the catalytic effect can be made more excellent.

[0081] The viscosity average molecular weight of the polymer compound of the third embodiment may be 1,000 to 1,000,000, 5,000 to 200,000, or 20,000 to 50,000.

[0082] Specific examples of the polymer compound of the third embodiment include a polymer compound having a structural unit (a1-10) represented by the following formula (a1-10) and a structural unit (a3-0) represented by the following formula (a3-0), a polymer compound having a structural unit (a1-20) represented by the following formula (a1-20) and a structural unit (a3-0) represented by the following formula (a3-0), and a polymer compound having a structural unit (a1-1) represented by the following formula (a1-1) and a structural unit (a3-0) represented by the following formula (a3-0). Examples of suitable polymer compounds include, but are not limited to, polymer compounds having a structural unit (a1-2) represented by the following formula (a1-2) and a structural unit (a3-0) represented by the following formula (a3-0), polymer compounds having a structural unit (a1-1) represented by the following formula (a1-1) and a structural unit (a3-1) represented by the following formula (a3-1), and polymer compounds having a structural unit (a1-2) represented by the following formula (a1-2) and a structural unit (a3-1) represented by the following formula (a3-1).

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089] The polymer compound of the third embodiment can be synthesized by a known method by coordinating three or four nitrogen atoms N of the structural unit (a0) of the polymer compound of the fourth embodiment described below to a zinc atom Zn. For example, a polymer compound having the structural unit (a0) of the fourth embodiment represented by the following general formula (a0) and the structural unit (a3) ​​represented by the following general formula (a3), and Zn(ClO ４ ) ２ and a Zn compound such as the above, according to the following formula:

[0090] [In the formula, R １ is a hydrogen atom or a methyl group; R ３ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0091] The polymer compound of the fourth embodiment is dispersed and dissolved in a reaction solvent, and Zn(ClO) dissolved in a solvent such as ethanol is added. ４ ) ２ Alternatively, a method of adding a Zn compound such as

[0092] The reaction solvent is a solvent containing the raw materials, the polymer compound of the fourth embodiment and Zn(ClO ４ ) ２ Any solvent capable of dissolving Zn compounds such as Zn(ClO) may be used, and specific examples include dioxane, 1-butanol, dimethylformamide (DMF), dimethylacetamide, dimethylsulfoxide (DMSO), and acetonitrile. ４ ) ２The amount of Zn compound such as the above is preferably about 1 to 100 equivalents, and more preferably 1 to 50 equivalents, relative to the structural unit (a0). The reaction temperature is preferably 20 to 140°C, and more preferably 60 to 120°C. The reaction time is generally preferably 0.5 to 6 hours, and more preferably 1 to 3 hours.

[0093] After the reaction is complete, the reaction mixture may be used in the next step as is, or the polymer compound of the third embodiment in the reaction mixture may be isolated and purified. For isolation and purification, a conventionally known method can be used, and for example, concentration, solvent extraction, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more thereof.

[0094] [Fourth Embodiment] The polymer compound of the fourth embodiment is an intermediate compound for synthesizing the polymer compound of the third embodiment. The polymer compound of the fourth embodiment has a structural unit (a0) represented by the following general formula (a0) and a structural unit (a3) ​​represented by the following general formula (a3).

[0095] [In the formula, R １ is a hydrogen atom or a methyl group; R ３ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0096] In the polymer compound of the fourth embodiment, the total proportion of the structural unit (a0) and the structural unit (a3) ​​relative to all structural units constituting the polymer compound is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 99 mol% or more, and may be 100 mol%.

[0097] The proportion of the structural unit (a0) in the polymer compound of the fourth embodiment is preferably 2.0 mol% or more and 20 mol% or less, more preferably 2.5 mol% or more and 10 mol% or less, even more preferably 3.0 mol% or more and 8.0 mol% or less, and particularly preferably 3.5 mol% or more and 5.0 mol% or less, relative to all structural units constituting the polymer compound. By being equal to or greater than the lower limit, when the polymer compound of the third embodiment is synthesized from the polymer compound of the fourth embodiment, the catalytic effect of the polymer compound of the third embodiment can be made more excellent. By being equal to or less than the upper limit, the water dispersibility and water solubility of the polymer compound of the third embodiment can be made favorable.

[0098] The proportion of the structural unit (a3) ​​in the polymer compound of the fourth embodiment is preferably 80 mol% or more and 98 mol% or less, more preferably 90 mol% or more and 97.5 mol% or less, even more preferably 92 mol% or more and 97 mol% or less, and particularly preferably 95 mol% or more and 96.5 mol% or less, relative to all structural units constituting the polymer compound. By being equal to or greater than the lower limit, when the polymer compound of the third embodiment is synthesized from the polymer compound of the fourth embodiment, the water dispersibility and water solubility of the polymer compound of the third embodiment can be made favorable. By being equal to or less than the upper limit, the catalytic effect of the polymer compound of the third embodiment can be made even better.

[0099] The viscosity average molecular weight of the polymer compound of the fourth embodiment may be 1,000 to 1,000,000, 5,000 to 200,000, 10,000 to 500,000, or 20,000 to 50,000.

[0100] Specific examples of the polymer compound of the fourth embodiment include a polymer compound having a structural unit (a0-10) represented by the following formula (a0-10) and a structural unit (a3-0) represented by the following formula (a3-0), a polymer compound having a structural unit (a0-20) represented by the following formula (a0-20) and a structural unit (a3-0) represented by the following formula (a3-0), and a polymer compound having a structural unit (a0-1) represented by the following formula (a0-1) and a structural unit (a3-0) represented by the following formula (a3-0). Examples of suitable polymer compounds include, but are not limited to, polymer compounds having a structural unit (a0-2) represented by the following formula (a0-2) and a structural unit (a3-0) represented by the following formula (a3-0), polymer compounds having a structural unit (a0-1) represented by the following formula (a0-1) and a structural unit (a3-1) represented by the following formula (a3-1), and polymer compounds having a structural unit (a0-2) represented by the following formula (a0-2) and a structural unit (a3-1) represented by the following formula (a3-1).

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107] The polymer compound of the fourth embodiment can be synthesized by reacting a polymer compound having a structural unit (a) represented by the following general formula (a) and a structural unit (a2) represented by the following general formula (a2), with a compound (ax) represented by the following general formula (ax) using a known method according to the following formula:

[0108] [In the formula, R １ is a hydrogen atom or a methyl group; R ２is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; n3 is an integer of 1 or 2; n4 is an integer of 0, 1, 2, or 3; and n5 is an integer of 0, 1, or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0109] For example, a method may be employed in which a polymer compound having a structural unit (a) represented by general formula (a) and a structural unit (a3) ​​represented by general formula (a3) ​​is dispersed or dissolved in a reaction solvent, and then the compound (ax) represented by general formula (ax) dissolved in a solvent such as ethanol is added. Conversely, a method may be employed in which a dropwise solution prepared by dissolving a polymer compound having a structural unit (a) represented by general formula (a) and a structural unit (a3) ​​represented by general formula (a3) ​​in a solvent such as 1-butanol or ethanol is added to the compound (ax) represented by general formula (ax) dissolved in a solvent such as ethanol.

[0110] The reaction solvent may be any solvent capable of dissolving the starting polymer compound having the structural units (a) and (a3) ​​and the compound (ax), and specific examples include dioxane, ethanol, 1-butanol, dimethylformamide (DMF), dimethylacetamide, dimethyl sulfoxide (DMSO), acetonitrile, etc. The amount of compound (ax) added is preferably approximately 1 to 100 equivalents, and more preferably 1 to 50 equivalents, relative to the amount of the structural unit (a). The reaction temperature is preferably 60 to 140°C, and more preferably 80 to 120°C. The reaction time is generally preferably 0.5 to 6 hours, and more preferably 1 to 3 hours.

[0111] After the reaction is complete, the reaction mixture may be used in the next step as is, or the polymer compound of the fourth embodiment in the reaction mixture may be isolated and purified. For isolation and purification, a conventionally known method can be used, and for example, concentration, solvent extraction, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more thereof.

[0112] <<Carbon dioxide fixation device and carbon dioxide fixation method>> Below, a carbon dioxide fixation device and a carbon dioxide fixation method using the same, which are embodiments of the present invention, will be described in detail. Note that the drawings used in the following description may conveniently show characteristic parts in an enlarged manner to make the features easier to understand, and the dimensional proportions of the components may not necessarily be the same as those in reality. The present invention is not limited to the embodiments described below.

[0113] Fifth Embodiment A carbon dioxide fixation device according to a fifth embodiment includes: a capture container that captures carbon dioxide in an absorption solution by wet physical absorption; a first pressure container that intermittently pressurizes the absorption solution in which carbon dioxide has been captured; a first injection pump that injects alkali into the absorption solution; a second injection pump that injects calcium chloride into the absorption solution; a third injection pump that injects the polymer compound described in [1] or [2] into the absorption solution; a circulation path that discharges the absorption solution from an outlet of the capture container and returns the absorption solution to an inlet of the capture container; a detour path that bypasses part of the circulation path and passes through the first pressure container; and a centrifuge that centrifugally separates and recovers calcium carbonate from the waste absorption solution removed from the first pressure container.

[0114] A fifth embodiment provides a method for fixation of carbon dioxide, the method comprising: using a carbon dioxide fixation device comprising: a capture container that captures carbon dioxide in an absorbing solution by wet physical absorption; a first pressure container that intermittently pressurizes the absorbing solution in which carbon dioxide has been captured; a first injection pump that injects alkali into the absorbing solution; a second injection pump that injects calcium chloride into the absorbing solution; a third injection pump that injects the polymer compound described in [1] or [2] into the absorbing solution; a circulation path that discharges the absorbing solution from an outlet of the capture container and returns the absorbing solution to an inlet of the capture container; and a detour path that bypasses part of the circulation path and passes through the first pressure container;

[0115] 1 is a schematic diagram illustrating a carbon dioxide fixation device 1 according to a fifth embodiment. The carbon dioxide fixation device 1 according to the fifth embodiment includes a capture container 10 that captures carbon dioxide in an absorbing solution S by wet physical absorption, a first pressure container 11 that intermittently pressurizes the absorbing solution S with the captured carbon dioxide, a first injection pump 13 that injects alkali into the absorbing solution S, a second injection pump 14 that injects calcium chloride into the absorbing solution S, a third injection pump 15 that injects the polymer compound described in the first embodiment into the absorbing solution S, circulation paths 151 to 154 that discharge the absorbing solution S from the outlet of the capture container 10 and return the absorbing solution S to the inlet of the capture container 10, detour paths 161 to 162 that bypass part of the circulation paths 151 to 154 and pass through the first pressure container 11, and a centrifuge 17 that centrifuges and recovers calcium carbonate from the waste absorbing solution S removed from the first pressure container 11.

[0116] In the carbon dioxide fixation device 1 of the fifth embodiment, a treatment gas introduction pipe 20 and a circulation pump 21 are provided in a circulation path 154 immediately before the capture container 10. The treatment gas is introduced into the capture container 10 from the treatment gas introduction pipe 20. A first injection pump 13 and a third injection pump 15 are provided in a circulation path 151 immediately after the capture container 10. The first injection pump 13 injects an alkali into the absorption solution S. The third injection pump 15 injects the polymer compound into the absorption solution S. The polymer compound can be injected as, for example, an aqueous solution or an ethanol solution.

[0117] The installation positions of the process gas introduction pipe 20 and the circulation pump 21 are not limited to the above, and they may be installed anywhere in the circulation paths 151 to 154. The installation positions of the first injection pump 13 and the third injection pump 15 are not limited to the above, and they may be installed anywhere in the circulation paths 151 to 154, and may be installed in the capture container 10 or the first pressurized container 11. The process gas introduced from the process gas introduction pipe 20 is not limited as long as it is a gas intended for absorbing and treating carbon dioxide.

[0118] In this specification, alkali refers to a chemical containing sodium, and examples thereof include an aqueous sodium hydroxide solution and an aqueous sodium carbonate solution. The treatment gas introduced from the treatment gas introduction pipe 20 may be exhaust gas from the main engine or auxiliary engine of the ship, or may be exhaust gas after desulfurization. By injecting an alkali into the absorption solution S, the carbon dioxide absorption efficiency per unit volume of the absorption solution S is increased. By injecting the polymer compound into the absorption solution S, the carbon dioxide absorption efficiency is further increased.

[0119] First, the valves 41 and 42 provided before and after the first pressurized vessel 11 are closed. The absorbing solution S circulates through the thick-lined route from the capture vessel 10 through circulation paths 151-152-153-154 to the capture vessel 10. The treatment gas is bubbled through the absorbing solution S in the capture vessel 10 into which alkali has been injected, and carbon dioxide in the treatment gas is captured by wet physical absorption into the absorbing solution S.

[0120] Next, the valves 41 and 42 provided before and after the first pressurized container 11 are opened. The absorbing solution S in which the carbon dioxide has been captured circulates through the capture container 10 and circulation paths 151 to 154, and also circulates via the capture container 10, circulation path 151, bypass path 161, first pressurized container 11, bypass path 162, and circulation path 154 in this order. The first pressurized container 11 is filled with the absorbing solution S in which the carbon dioxide has been captured.

[0121] Valves 41 and 42 are closed. A second injection pump 14 is provided to the first pressurized vessel 11 via a valve 45. A valve 47 is provided between the first pressurized vessel 11 and the pressurized pump 26, and a valve 50 is provided between the pressurized pump 26 and the circulation path 152. The valve 45 is opened, and calcium chloride is injected into the absorbing solution S by the second injection pump 14. The valves 47 and 50 are opened, and the absorbing solution S on the circulation path 152 side is sent to the first pressurized vessel 11 side, and the absorbing solution S in which carbon dioxide has been captured in the first pressurized vessel 11 is pressurized. By pressurizing the absorbing solution S, the partial pressure of carbon dioxide in the absorbing solution S is increased, and a reaction in which the dissolved gas of carbon dioxide captured in the absorbing solution S is converted into carbonate ions is promoted.

[0122] The carbon dioxide captured in the absorbing solution S precipitates as calcium carbonate. The first pressure vessel 11 is provided with a centrifuge 17 via a valve 46, a valve 53, and a liquid feed pump 27. A part of the absorbing solution S is taken out from the first pressure vessel 11 as waste liquid, and calcium carbonate is recovered by centrifugation using the centrifuge 17. At the same time as the calcium carbonate is recovered by centrifugation, the absorbing solution is recovered and recycled. Using a separation membrane or the like, unnecessary salts can be discharged from the recovered absorbing solution while retaining the polymer compound within the system.

[0123] Sodium carbonate may be further added to the remaining liquid in the first pressure vessel 11, and the pressure may be reduced to remove dissolved gases. By using the pressure pump 26 used to pressurize the first pressure vessel 11 in the reverse direction, the internal pressure of the first pressure vessel 11 can be reduced to about 200 hPa.

[0124] While the valves 41 and 42 are closed and the absorbing solution S with captured carbon dioxide is being pressurized and / or depressurized in the sealed first pressurized container 11, the absorbing solution S circulates through the capture container 10 and the thick-lined circulation paths 151-154. Because the reaction of converting the dissolved carbon dioxide gas captured in the absorbing solution S into carbonate ions takes at least several minutes, it is preferable to continue pressurizing and forcing the absorbing solution S for 10 minutes or more. By injecting the polymer compound into the absorbing solution S, the reaction of converting the dissolved carbon dioxide gas into carbonate ions can be expedited. During this time, the treatment gas is bubbled through the absorbing solution S in the capture container 10, and the carbon dioxide in the treatment gas is captured by the absorbing solution S through wet physical absorption, as described above.

[0125] The carbon dioxide fixation method using the fixation device 1 of the fifth embodiment can efficiently simultaneously perform the following operations: capturing carbon dioxide in the treated gas into the absorbent S by wet physical absorption while circulating the absorbent S through the capture container 10 and the circulation paths 151 to 154 by repeating the above operations; and pressurizing the absorbent S with the captured carbon dioxide to precipitate it as calcium carbonate, and recovering the calcium carbonate by centrifugation. That is, the carbon dioxide fixation method using the fixation device 1 of the fifth embodiment can efficiently fix carbon dioxide. Since the absorbent S with the captured carbon dioxide is intermittently pressurized in the first pressurized container 11, the fixation device 1 can be made smaller.

[0126] By adding the operation of depressurizing the first pressurized container 11, the method for fixation of carbon dioxide using the fixation device 1 of the fifth embodiment can fix carbon dioxide more efficiently.

[0127] The first pressurized container 11 of the fixing device 1 of the fifth embodiment is provided with a first degassing line 24 via a valve 52, and the first pressurized container 11 can be degassed as needed to reduce the pressure in the first pressurized container 11.

[0128] The first pressurized vessel 11 of the fixing device 1 of the fifth embodiment is further provided with a centrifuge 22 and a sludge container 23 via a valve 51 and a liquid feed pump 28, and as necessary, sludge such as oil and solid matter in the treated gas can be removed from the absorption liquid S and collected in the sludge container 23.

[0129] <<Method for Promoting the Reaction of Carbon Dioxide to Bicarbonate Ions>> [Sixth Embodiment] The method for promoting the reaction of carbon dioxide to bicarbonate ions, which is an embodiment to which the present invention is applied, is not limited to the method for promoting the reaction of carbon dioxide to bicarbonate ions using the fixation device 1 of the fifth embodiment described above. The method for promoting the reaction of carbon dioxide to bicarbonate ions of the sixth embodiment includes contacting a polymer compound with an absorption solution in which carbon dioxide has been physically absorbed, and the polymer compound is capable of converting carbon dioxide into bicarbonate ions. ２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３ －+H ＋ ", the polymer compound has a functional group having catalytic ability to promote the reaction of ", the viscosity average molecular weight of the polymer compound is 1,000 or more, and the polymer compound has the property of being soluble in a carbon dioxide saturated aqueous solution at a concentration of 0.01 mg / mL.

[0130] The method for promoting the reaction of carbon dioxide to bicarbonate ions according to the sixth embodiment can be used in various ways because the use of the polymer compound increases the recovery rate and recovery efficiency. For example, by supporting the polymer compound on a packing material in a flue gas recovery scrubber, the dissolution of carbon dioxide into water or seawater can be promoted, resulting in more carbon dioxide being absorbed from flue gas into water or seawater. Furthermore, the polymer compound can be gelled and suspended in the absorption solution, allowing bicarbonate ions to be efficiently generated in the absorption solution. The resulting bicarbonate ions can be removed from the system through a separation membrane, such as a filter or reverse osmosis membrane, and then subjected to processes such as neutralization with an alkali, precipitation separation, or re-recovery as carbon dioxide. Even when using the polymer compound itself, efficient carbon dioxide recovery can be achieved by contacting and recovering carbon dioxide with an absorption solution containing the polymer compound, separating the resulting bicarbonate ions from the polymer compound through a separation membrane, extracting the bicarbonate ions, and recycling the polymer compound.

[0131] The polymer compound is "CO ２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３ － +H ＋ Since the polymer compound has a catalytic functional group that promotes the reaction of "carbon dioxide absorption," bicarbonate ions can be enriched by contacting the polymer compound with an absorption solution in which carbon dioxide has been physically absorbed, and further, carbonate ions, bicarbonate salts, or carbonate salts can be obtained by contacting a cation source. Bicarbonate ions, carbonate ions, bicarbonate salts, and carbonate salts can be recovered by conventionally known methods such as ion exchange and centrifugation.

[0132] The polymer compound has a viscosity average molecular weight of 1,000 or more, and has the property of dissolving in a carbon dioxide saturated aqueous solution at a concentration of 0.01 mg / mL. This prevents precipitation in water and promotes the reaction of carbon dioxide to bicarbonate ions in a wet process, thereby enabling more efficient fixation and recovery of carbon dioxide in a wet process.

[0133] The absorbing solution in which carbon dioxide is physically absorbed can be prepared by a conventionally known method. The absorbing solution in which carbon dioxide is physically absorbed may be prepared by physically absorbing carbon dioxide into an aqueous medium, and may be prepared by dissolving carbon dioxide in the aqueous medium, water, bicarbonate ions (HCO ３ － ), carbonate ions (CO ３ ２－ ), proton (H ＋ ), and carbonic acid (H ２ CO ３ ) may be included.

[0134] The functional group of the polymer compound is "CO ２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３ － +H ＋ The functional group may be a group having a nitrogen-containing ring, and an example of the group having a nitrogen-containing ring is a group represented by the following formula (a1-a1):

[0135] [In the formula, m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group. ２＋ may be accompanied by a counter anion.]

[0136] The polymer compound may have a structural unit derived from a (meth)acrylic ester, a structural unit derived from a (meth)acrylamide, a structural unit derived from a vinyl compound, or a structural unit derived from a polysaccharide. The polymer compound may have a structural unit derived from a (meth)acrylic ester having the functional group, a structural unit derived from a (meth)acrylamide having the functional group, a structural unit derived from a vinyl compound having the functional group, or a structural unit derived from a polysaccharide having the functional group.

[0137] Examples of the structural unit derived from a (meth)acrylic ester having the above functional group include the structural unit (a1-0) represented by the following general formula (a1-0).

[0138] [In the formula, R １ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group. ２＋ may be accompanied by a counter anion.]

[0139] The polymer compound may have a structural unit derived from a (meth)acrylic ester having one or more hydrophilic groups selected from the group consisting of a hydroxy group, an ether group, an amide group, a carboxyl group, and an amino group; a structural unit derived from a (meth)acrylamide having one or more hydrophilic groups selected from the group consisting of a hydroxy group, an ether group, an amide group, a carboxyl group, and an amino group; a structural unit derived from a vinyl compound having one or more hydrophilic groups selected from the group consisting of a hydroxy group, an ether group, an amide group, a carboxyl group, and an amino group; or a structural unit derived from a polysaccharide having one or more hydrophilic groups selected from the group consisting of a hydroxy group, an ether group, an amide group, a carboxyl group, and an amino group.

[0140] The polymer compound may have a structural unit (a1) represented by the following general formula (a1) and a structural unit (a2) represented by the following general formula (a2).

[0141] [In the formula, R １ is a hydrogen atom or a methyl group; R ２ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; n3 is an integer of 1 or 2; n4 is an integer of 0, 1, 2, or 3; and n5 is an integer of 0, 1, or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0142] The polymer compound may have a structural unit (a1) represented by the following general formula (a1) and a structural unit (a3) ​​represented by the following general formula (a3).

[0143] [In the formula, R １ is a hydrogen atom or a methyl group; R ３ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

[0144] In the method for promoting the reaction of converting carbon dioxide to bicarbonate ions according to this embodiment, the polymer compound can be injected as a solution into the absorption liquid and brought into contact with it.

[0145] In the method for promoting the reaction of converting carbon dioxide to bicarbonate ions of this embodiment, the polymer compound can be brought into contact with the absorbing solution as an immobilized catalyst.

[0146] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0147] The full names of the monomers and polymerization initiators abbreviated in the examples are shown below: GMA: glycidyl methacrylate HEA: 2-hydroxyethyl acrylate DMAA: N,N-dimethylacrylamide AIBN: azobisisobutyronitrile N4: compound (ax3) represented by formula (ax3) (1,4,7,10-tetraazacyclododecane)

[0148] <Synthesis Example of Polymer Compound> (Synthesis of Polymer Compound (1)) A dropping solution was prepared by dissolving GMA (2 g, 14 mmol), HEA (38 g, 327 mmol), and AIBN (0.2 g) in 1-butanol (10 g). 1-Butanol (40 g) was placed in a three-neck flask equipped with a thermometer, a reflux condenser, and a nitrogen inlet tube. The flask was heated to 95°C under a nitrogen atmosphere, and the dropping solution was added dropwise over 1 hour, followed by the addition of 1 g of 1-butanol. After the dropwise addition was completed, the reaction solution was stirred at 95-97°C for 1.5 hours. The reaction solution was then cooled to 0°C in an ice bath. After a white solid precipitate was precipitated, the supernatant solvent was removed, and 30 mL of 1-butanol was added, dissolved by heating, cooled, and the supernatant was removed for purification, yielding a purified white solid precipitate (12.5 g, solid content 10 g) of 80% by mass of polymer compound (1). The intrinsic viscosity obtained by capillary viscosity measurement in methanol solutions with concentrations of 4%, 2%, and 1% was 0.108 mL / g. Based on this, the viscosity-average molecular weight of polymer compound (1) was calculated based on the reference paper "J. Fort TM Poylzoidis, "Intrinsic viscosity-molecular weight relationships for poly(2-hydroxyethyl methacrylate)," "European Polymer Journal," volume 12, pp. 685-689, (1976)," and was found to be 34,000.

[0149]

[0150] FIG. 2 [E401] shows the results of the weak magnetic field gradient strength (w) (5×10 －４ T / cm) and strong magnetic field gradient strength (s) (50 × 10 －４ T / cm),１ The purified solid precipitate was ２ 0 (containing DSS (0.03%) as a reference material), and analyzed by bipolar pulsed magnetic field gradient spin echo spectroscopy using an NMR device (Bruker, AVANCE III HD 600 MHz). １ H-NMR measurements were performed with a magnetic field gradient duration of 0.5 ms, a diffusion time of 0.1 s, and a weak magnetic field gradient strength (w) of 5 × 10 －４ T / cm, and 50 × 10 for measurements at strong magnetic field gradient strength (s). －４ At a weak magnetic field gradient strength (w), low molecular weight components are included in the measurement, but at a strong magnetic field gradient strength (s), low molecular weight components are not detected and only high molecular weight components are detected. １ H-NMR measurement confirmed that the residual monomers of GMA and HEA in the purified white solid precipitate were 1% or less.

[0151] (Synthesis of Polymer Compound (2)) 1-butanol (17.5 g) was added to a white purified solid precipitate (12.5 g, solids content 10 g) of 80% by mass of polymer compound (1) and dissolved at 90°C. 33.7 mg of N4 dissolved in 1-butanol (6 g) was added dropwise thereto, followed by heating and stirring at 88-95°C for 4 hours. The reaction solution was then cooled to 0°C in an ice bath. After a white solid precipitate precipitated, the supernatant solvent was removed. Further, 1-butanol (38 g) was added, and the mixture was dissolved by heating and cooled to allow precipitation, yielding a white solid precipitate containing 60% polymer compound (2). The viscosity-average molecular weight of polymer compound (2) was 34,000, approximately the same as that of polymer compound (1).

[0152]

[0153] FIG. 2 [E401-N4] shows the relationship between the polymer compound (2) and the polymer compound (1). １ Similar to the H-NMR measurement, a weak magnetic field gradient strength (w) (5 × 10 －４ T / cm) and strong magnetic field gradient strength (s) (50 × 10 －４ T / cm), １1H-NMR chart. At a weak magnetic field gradient strength (w), low molecular weight components such as free N4 are included in the measurement, but at a strong magnetic field gradient strength (s), only high molecular weight components are detected, with no low molecular weight components detected. １ H-NMR measurement revealed that approximately 79% of N4 had reacted with polymer compound (1), and approximately 21% of N4 remained unreacted and was present as a contaminant.

[0154] (Synthesis of Polymer Compound (3)) Ethanol (approximately 6 g) was added to the obtained white solid precipitate (10 g, solid content 6 g) and dispersed at 75°C, and a solution of zinc perchlorate hexahydrate (0.94 g) dissolved in ethanol (4.2 g) was added, followed by heating and stirring at 60 to 74°C for 3 hours. After cooling, a solution containing Polymer Compound (3) was obtained. The viscosity average molecular weight of Polymer Compound (3) was 34,000, which was approximately the same as that of Polymer Compound (1).

[0155]

[0156] FIG. 2 [E401-N4-Zn] shows the relationship between polymer compound (3) and polymer compound (1). １ Similar to the H-NMR measurement, a weak magnetic field gradient strength (w) (5 × 10 －４ T / cm) and strong magnetic field gradient strength (s) (50 × 10 －４ T / cm), １ 1H-NMR chart. At a weak magnetic field gradient strength (w), low molecular weight components are included in the measurement, but at a strong magnetic field gradient strength (s), low molecular weight components are not detected and only high molecular weight components are detected. １ H-NMR confirmed that the polymer compound (3) component accounted for approximately 73% and the component obtained by the reaction of the remaining unreacted free N4 with Zn accounted for approximately 27%, indicating that almost all of the N4 had reacted.

[0157] (Evaluation of Catalytic Activity) The catalytic activity of the synthesized polymer compound (3) was evaluated by a simple stopped-flow method as follows. (1) Bromothymol blue colorimetric indicator was added to 20 mL of a carbon dioxide saturated aqueous solution. The carbon dioxide saturated aqueous solution was yellow. (2) 6 mL of a 0.02 mol / L Tris-HCl buffer solution adjusted to pH 8.0 was prepared. The buffer solution (pH 8.0) was pink. (3) The buffer solution (pH 8.0) was added to the carbon dioxide saturated aqueous solution. The solution was blue immediately after the addition of the buffer solution (pH 8.0). (4) The time required for the reaction to complete and the color to change from blue to green was measured, which was 180 s. (5) The same procedures as in (1) to (4) were repeated, except that the polymer compound (3) was added to 20 mL of a carbon dioxide saturated aqueous solution so that the concentration was 0.01 mg / mL. The time required for the reaction to complete and the color to change from blue to green was measured, which was 19 s.

[0158] (Experiment to confirm the carbon dioxide absorption effect) (1) Put 500 mL of distilled water and 34 g of Na in a gas washing bottle. ２ CO ３ (2) 100 vol% carbon dioxide CO ２ The gas was aerated at a flow rate of 500 mL / min, and the time it took for the coloring due to phenolphthalein to disappear was measured, which was 160 seconds. (3) 500 mL of distilled water and 34 g of Na ２ CO ３ (4) 100 vol% carbon dioxide CO ２ The gas was aerated at a flow rate of 500 mL / min, and the time until the coloring due to phenolphthale disappeared was measured, which was 100 seconds. ２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３ － +H ＋It was confirmed that this catalyst effectively promotes and catalyzes the reaction from carbon dioxide to bicarbonate ions.

[0159] (Synthesis of Polymer Compound (4)) A dropping solution was prepared by dissolving GMA (0.4 g, 2.8 mmol), DMAA (3.6 g, 36.3 mmol), and AIBN (0.069 g) in 1-butanol (3.9 g). 1-Butanol (8 g) was placed in a three-neck flask equipped with a thermometer, a reflux condenser, and a nitrogen inlet tube, and the flask was heated to 86-88°C under a nitrogen atmosphere. The dropping solution was added dropwise over 1 hour, and then 1 g of 1-butanol was added dropwise. After the dropwise addition was completed, the reaction solution was stirred at 86-87°C for an additional 30 minutes, yielding a solution of polymer compound (4) (solid content 25%).

[0160]

[0161] FIG. 3 [E501] shows the structure of polymer compound (4). １ 1 is a H-NMR chart. The residual monomer was below the measurement limit. The viscosity average molecular weight of polymer compound (4) was approximately 36,000.

[0162] (Synthesis of Polymer Compound (5)) Ethanol was added to a 1-butanol solution of polymer compound (4) (4 g, solid content 1 g (25% by mass)) to dissolve the polymer compound (4) and prepare a dropwise solution. 8 g of ethanol and 0.3 g of N4 were placed in a three-neck flask equipped with a thermometer, a reflux condenser, and a nitrogen inlet tube. The mixture was heated and stirred at 60°C under a nitrogen atmosphere, and the dropwise solution was added dropwise over 30 minutes. After the dropwise addition was completed, the mixture was heated and stirred at 60-61°C for an additional 30 minutes. The reaction solution was then cooled and precipitated into an oily substance with 100 mL of petroleum ether. The supernatant was removed, yielding 1.7 g of an oily substance containing 50% polymer compound (5). The viscosity-average molecular weight of polymer compound (5) was approximately 36,000.

[0163]

[0164] FIG. 3 [E501-N4] shows the structure of polymer compound (5). １ This is a H-NMR chart. The N4 peak and the DMAA peak overlap, making quantitative determination difficult.

[0165] (Synthesis of Polymer Compound (6)) Ethanol (10 g) was added to the obtained oily product of polymer compound (5) (1.7 g, solid content 0.85 g), and while heating and stirring at 63°C, a solution of zinc perchlorate hexahydrate (0.32 g) dissolved in ethanol (4 g) was added, and the mixture was heated and stirred at 62 to 64°C for 30 minutes. After cooling, an oily precipitate was obtained. The supernatant was removed to obtain an oily product of polymer compound (6) (0.4 g). The viscosity-average molecular weight of polymer compound (6) was approximately 36,000.

[0166]

[0167] FIG. 3 [E501-N4-Zn] shows the structure of polymer compound (6). １ 1H-NMR chart, in which N4-Zn adducts were clearly observed.

[0168] (Evaluation of Catalytic Activity) The catalytic activity of the synthesized polymer compound (6) was evaluated by a simple stopped-flow method as follows. (1) Bromothymol blue colorimetric indicator was added to 20 mL of a carbon dioxide saturated aqueous solution. The carbon dioxide saturated aqueous solution was yellow. (2) 12 mL of 0.02 mol / L Tris-HCl buffer solution adjusted to pH 8.0 was prepared. (3) The buffer solution (pH 8.0) was added to the carbon dioxide saturated aqueous solution. Immediately after adding the buffer solution (pH 8.0), the solution was blue. (4) The time required for the reaction to complete and the color to change from blue to green was measured, which was 16.0 s. (5) The same procedures as in (1) to (4) were performed except that the polymer compound (6) was added to 12 mL of Tris-HCl buffer solution so that the concentration was 8 mg / mL. The time required for the reaction to complete and the color to change from blue to green was measured, which was 3.8 s. From the above experimental results, it was confirmed that the polymer compound (6) is a "CO ２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３ － +H ＋ It was confirmed that this catalyst effectively promotes and catalyzes the reaction from carbon dioxide to bicarbonate ions.

[0169] According to the present invention, in the wet carbon dioxide fixation device,２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３ － +H ＋ " reaction, and can make carbon dioxide capture more efficient, and a method for promoting the reaction from carbon dioxide to bicarbonate ions can be provided. Therefore, this carbon dioxide fixation device can be installed on ships and used as a device to fix and capture carbon dioxide from ships. If a carbon dioxide fixation device can be installed on ships, it can contribute to reducing carbon dioxide emissions from ships.

[0170] REFERENCE SIGNS LIST 1... Fixing device 10... Capture container 11... First pressure container 13... First injection pump 14... Second injection pump 15... Third injection pump 151 to 154... Circulation path 161 to 162... Bypass path 17... Centrifuge 20... Treated gas introduction pipe 21... Circulation pump 22... Centrifuge 23... Sludge container 24... First degassing line 26... Pressure pump 27... Liquid feed pump 28... Liquid feed pump 41 to 53... Valves S... Absorbent

Claims

1. A polymeric compound having a structural unit (a1) represented by the following general formula (a1) and a structural unit (a2) represented by the following general formula (a2): [In the formula, R １ is a hydrogen atom or a methyl group; R ２ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; n3 is an integer of 1 or 2; n4 is an integer of 0, 1, 2, or 3; and n5 is an integer of 0, 1, or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

2. A polymeric compound having a structural unit (a0) represented by the following general formula (a0) and a structural unit (a2) represented by the following general formula (a2): [In the formula, R １ is a hydrogen atom or a methyl group; R ２ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; n3 is an integer of 1 or 2; n4 is an integer of 0, 1, 2, or 3; and n5 is an integer of 0, 1, or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

3. A method for producing a carbon dioxide absorbent, comprising contacting a polymer compound with an absorbing solution in which carbon dioxide has been physically absorbed, wherein the polymer compound is "CO ２ +H ２ O ⇒ H ２ CO ３ ⇒ HCO ３ － +H ＋ " a polymer compound having a functional group having catalytic ability to promote the reaction of ", wherein the polymer compound has a viscosity average molecular weight of 1,000 or more, and the polymer compound has the property of dissolving in a carbon dioxide saturated aqueous solution at a concentration of 0.01 mg / mL.

4. A method for promoting the reaction of carbon dioxide to bicarbonate ions according to claim 3, wherein the functional group is a group having a nitrogen-containing ring.

5. A method for promoting the reaction of carbon dioxide to bicarbonate ions according to claim 4, wherein the functional group is a group represented by the following formula (a1-a1): [In the formula, m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group. ２＋ may be accompanied by a counter anion.] 6. A method for promoting the reaction of carbon dioxide to bicarbonate ions as described in claim 3, wherein the polymer compound has a structural unit derived from a (meth)acrylic ester, a structural unit derived from a (meth)acrylamide, a structural unit derived from a vinyl compound, or a structural unit derived from a polysaccharide.

7. The method for promoting the reaction of converting carbon dioxide to bicarbonate ions according to claim 6, wherein the polymer compound has a structural unit (a1-0) represented by the following general formula (a1-0): [In the formula, R １ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group. ２＋ may be accompanied by a counter anion.] 8. The method for promoting the reaction of carbon dioxide to bicarbonate ions according to claim 3, wherein the polymer compound has a structural unit derived from a (meth)acrylic ester having one or more hydrophilic groups selected from the group consisting of a hydroxy group, an ether group, an amide group, a carboxyl group, and an amino group, a structural unit derived from a (meth)acrylamide having one or more hydrophilic groups selected from the group consisting of a hydroxy group, an ether group, an amide group, a carboxyl group, and an amino group, a structural unit derived from a vinyl compound having one or more hydrophilic groups selected from the group consisting of a hydroxy group, an ether group, an amide group, a carboxyl group, and an amino group, or a structural unit derived from a polysaccharide having one or more hydrophilic groups selected from the group consisting of a hydroxy group, an ether group, an amide group, a carboxyl group, and an amino group.

9. A method for promoting the reaction of carbon dioxide to bicarbonate ions according to claim 3, wherein the polymer compound is injected as a solution into the absorption liquid and brought into contact with the absorption liquid.

10. A method for promoting the reaction of carbon dioxide to bicarbonate ions as described in claim 3, wherein the polymer compound is brought into contact with the absorption liquid as an immobilized catalyst.

11. A polymeric compound having a structural unit (a1) represented by the following general formula (a1) and a structural unit (a3) ​​represented by the following general formula (a3): [In the formula, R １ is a hydrogen atom or a methyl group; R ３ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

12. A polymeric compound having a structural unit (a0) represented by the following general formula (a0) and a structural unit (a3) ​​represented by the following general formula (a3): [In the formula, R １ is a hydrogen atom or a methyl group; R ３ is a hydrogen atom or a methyl group; m is an integer of 1 or 2; n1 is an integer of 1 or 2; n2 is an integer of 1 or 2; and n3 is an integer of 1 or 2. However, when m is 2, multiple n1s may be the same or different. In the formula, -CH represented by > ２ The hydrogen atom in the - group may be substituted with an alkyl group.

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