Amine composition for carbon dioxide separation

Abstract

To provide a carbon dioxide separation composition having high carbon dioxide desorption performance, and a method for separating carbon dioxide.SOLUTION: A carbon dioxide separation composition comprises: an amine compound (A) represented by general formula (1); an amine compound (B) represented by general formula (2); an amine compound (C) represented by general formula (3); and water; where the weight ratio of the amine compound (A) to the total composition is 25 wt.% or more.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a composition for carbon dioxide separation for separating carbon dioxide from a mixed gas containing carbon dioxide.

Background Art

[0002] In recent years, due to the global warming problem, the separation and recovery of carbon dioxide have attracted attention, and the development of carbon dioxide absorbents has been actively carried out.

[0003] As a carbon dioxide absorbent, an aqueous monoethanolamine solution is the most common. Monoethanolamine is inexpensive and industrially easy to obtain, but it has the property that carbon dioxide absorbed at low temperature does not dissipate unless the temperature is raised to 120°C or higher. And when the carbon dioxide dissipation temperature is set above the boiling point of water, due to the high latent heat and specific heat of water, a large amount of energy is required for the recovery of carbon dioxide.

[0004] Therefore, amines with a lower carbon dioxide dissipation temperature and lower carbon dioxide recovery energy than monoethanolamine have been developed. For example, N,N,N’,N’’,N’’-pentamethyldiethylenetriamine (Patent Document 1) has been proposed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Conventionally known carbon dioxide absorption liquids using aqueous amine solutions have had the problem of low carbon dioxide desorption performance. Regarding the separation and recovery of carbon dioxide, it is carried out by repeating (i) the absorption of carbon dioxide from the mixed gas into the absorbent and (ii) the desorption of the carbon dioxide absorbed in the absorption liquid. However, when the desorption performance of carbon dioxide is low, the energy required for the desorption step in (ii) increases, resulting in the problem of reducing the energy efficiency of the entire carbon dioxide separation and recovery process. The present invention has been made in view of the above problems, and an object thereof is to provide a composition for carbon dioxide separation having high carbon dioxide desorption performance and a method for separating carbon dioxide.

Means for Solving the Problems

[0007] As a result of intensive studies to solve the above problems, the present inventors have found that a composition for carbon dioxide separation containing a specific amine compound and a specific amine compound can solve the above problems, and have completed the present invention.

[0008] That is, the present invention is a composition for carbon dioxide separation as shown below.

[0009] [1] A composition for carbon dioxide separation containing an amine compound (A) represented by the following general formula (1), an amine compound (B) represented by the following general formula (2), an amine compound (C) represented by the following general formula (3), and water, wherein the weight ratio of the amine compound (A) in the whole composition is 25 weight percent or more. A composition for carbon dioxide separation, characterized by the above.

[0010]

Chemical formula

[0011] [In the above general formula (1), R 1 each independently represents an alkyl group having 1 to 3 carbon atoms.]

[0012]

Chemical formula

[0013] In the above general formula (2), R 2 , and R 3 each independently represents an alkylene group having 2 to 3 carbon atoms.]

[0014]

Chemical formula

[0015] In the above general formula (3), R 1 ~R 6 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. a and b each independently represent 0 or 1.] [2] The composition for carbon dioxide separation according to the above [1], wherein the amine compound (A) is 1-(2-dimethylaminoethyl)-4-methylpiperazine.

[0016] [3] The composition for carbon dioxide separation according to the above [1], wherein the amine compound (B) is piperazine.

[0017] [4] The composition for carbon dioxide separation according to the above [1], wherein the amine compound (C) is 1,4-diazabicyclo[2.2.2]octane-2-methanol.

[0018] [5] The composition for carbon dioxide separation according to claim 1, characterized in that the concentration of water is 50 to 60% by mass of the whole composition for carbon dioxide separation.

[0019] [6] A method for separating carbon dioxide, comprising a step of bringing a gas containing carbon dioxide into contact with the composition for carbon dioxide separation according to any one of the above [1] to [5] to absorb carbon dioxide in the mixed gas into the composition for carbon dioxide separation.

[0020] [7] A step of bringing a gas containing carbon dioxide into contact with the composition for carbon dioxide separation according to any one of [1] to [5] above to absorb carbon dioxide in the mixed gas into the composition for carbon dioxide separation, and a step of heating and / or depressurizing the composition for carbon dioxide that has absorbed the carbon dioxide to dissipate carbon dioxide from the composition for carbon dioxide separation. A method for separating carbon dioxide, characterized by including the steps.

Advantages of the Invention

[0021] The composition for carbon dioxide separation of the present invention has a characteristic that the carbon dioxide dissipation rate per unit mass is faster than that of conventionally known materials and is excellent in carbon dioxide dissipation performance, and has an effect that a large amount of carbon dioxide can be absorbed and separated. Therefore, the present invention is extremely useful industrially in that it can efficiently separate carbon dioxide in exhaust gas discharged in large quantities in large-scale thermal power generation and the like, and can improve the efficiency of the entire carbon dioxide separation and recovery process.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, the present invention will be described in detail.

[0023] First, the composition for carbon dioxide separation of the present invention will be described.

[0024] The composition for carbon dioxide separation of the present invention is a composition for carbon dioxide separation containing an amine compound (A) represented by the above general formula (1), an amine compound (B) represented by the above general formula (2), an amine compound (C) represented by the above general formula (3), and water, and is characterized in that the weight ratio of the amine compound (A) in the whole composition is 25 weight percent or more.

[0025] In the present invention, the amine compound (A) represented by the above general formula (1), the amine compound (B) represented by the above general formula (2), and the amine compound (C) represented by the above general formula (3) all play roles of adsorbing and dissipating carbon dioxide.

[0026] In the above general formula (1), R 1 each independently represents an alkyl group having 1 to 3 carbon atoms.

[0027] In the above general formula (1), R 1 may conform to the above definition and is not particularly limited. For example, each independently, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group can be mentioned. Among these, in terms of excellent carbon dioxide emission efficiency, R 1 is preferably a methyl group.

[0028] Specific examples of the amine compound (A) represented by the above general formula (1) include, for example, 1-(2-dimethylaminoethyl)-4-methylpiperazine.

[0029]

Chemical formula

[0030] In the above general formula (2), R 2 , and R 3 each independently represents an alkylene group having 2 to 3 carbon atoms.

[0031] In the above general formula (2), R 2 , and R 3 may conform to the above definition and is not particularly limited. For example, an ethylene group or a propylene group can be mentioned. For the said R 2 , and R 3 , in terms of excellent carbon dioxide emission efficiency, it is preferably a 1,2-ethylene group, a 1,2-propylene group, or a 1,3-propylene group.

[0032] Specific examples of the amine compound (B) represented by the above general formula (2) include, for example, piperazine or homopiperazine.

[0033]

Chemical formula

[0034] In the above general formula (3), R 1 ~R 6 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0035] In the above general formula (3), R 1 ~R 6 only needs to conform to the above definition and is not particularly limited. Each independently, for example, a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group can be mentioned. In terms of excellent carbon dioxide emission efficiency, it is preferably a hydrogen atom.

[0036] In the above general formula (3), a and b each independently represent 0 or 1. However, at least one of a or b must represent 1.

[0037] When a = 1 and b = 1, the above general formula (3) is represented by the following general formula (3a).

[0038]

Chemical formula

[0039] [In the above general formula (3a), the definition and preferred range of R 1 ~R 6 are the same as the definition and preferred range of R 1 ~R 6 shown in the above general formula (3).] When a = 0 and b = 1, the above general formula (3) is represented by the following general formula (3b).

[0040]

Chemical formula

[0041] [In the above general formula (3b), R 1 ~R 6The definition and preferred range of R shown in the above general formula (3) 1 ~R 6 are synonymous with the definition and preferred range thereof.] Specific examples of the amine compound represented by the above general formula (3) include, for example, the following compounds (Exemplary Compounds 1 to 14), but the present invention is not limited thereto.

[0042] [Chemical formula]

[0043] Regarding the amine compound represented by the above general formula (3), in terms of excellent carbon dioxide emission efficiency, 1,4-diazabicyclo[2.2.2]octane-2-methanol (R 1 =R 2 =R 3 =R 4 =R 5 =R 6 = hydrogen atom, a = 0, b = 1, Exemplary Compound 1) is preferred.

[0044] In the present invention, the amine compounds (A), (B), and (C) may be commercially available ones or those synthesized by known methods, and are not particularly limited. Further, the purity of these amine compounds is not particularly limited, but in each case, it is preferably 95% or more, and particularly preferably 99% or more.

[0045] Regarding the composition for carbon dioxide separation of the present invention, as described above, it is characterized in that the weight ratio of the amine compound (A) in the whole composition is 25 weight percent or more.

[0046] The composition for carbon dioxide separation of the present invention is characterized by containing water in addition to the above-mentioned amine compound. When the composition for carbon dioxide separation of the present invention contains water, the absorbed carbon dioxide is easily ionized into bicarbonate ions, and the amount of carbon dioxide absorbed by the composition for carbon dioxide separation increases.

[0047] Examples of the type of water include tap water, ion-exchanged water, distilled water, etc., and any of these waters can be used without any problem.

[0048] The concentration of water is preferably in the range of 50 to 60% by mass of the entire composition for carbon dioxide separation.

[0049] Regarding the composition for carbon dioxide separation of the present invention, in addition to the amine compound (A), the amine compound (B), and the amine compound (C), it may further contain at least one amine compound (D) selected from the group consisting of alkanolamines, propylenediamines, piperazines, piperidines, morpholines, pyrrolidines, azepanes, and polyethylene polyamines, which are different from these. By coexisting the amine compound (D), it may be possible to increase the N atom content per unit mass of the composition for carbon dioxide separation, and it may be industrially advantageous in that an increase in the carbon dioxide absorption amount per unit mass of the composition for carbon dioxide separation can be expected.

[0050] In the present invention, specific examples of the alkanolamines include, for example, ethanolamine, N-methylethanolamine, N,N-dimethylethanolamine, diethanolamine, 2-(2-aminoethoxy)ethanol, 2-[2-(dimethylamino)ethoxy]ethanol, 2-[2-(diethylamino)ethoxy]ethanol, N-[2-(2-aminoethoxy)ethyl]ethanolamine, N-[2-{2-(dimethylamino)ethoxy}ethyl]-N-methylethanolamine, or N-[2-{2-(diethylamino)ethoxy}ethyl],N-ethylethanolamine, etc. Among these, in terms of expecting an increase in the carbon dioxide absorption amount per unit mass of the composition for carbon dioxide separation, the alkanolamines are preferably at least one selected from the group consisting of ethanolamine, N-(2-aminoethyl)ethanolamine, and 2-(2-aminoethoxy)ethanol.

[0051] In the present invention, specific examples of the propylenediamines include, for example, etc. Among these, from the viewpoints of availability and production cost, the propylenediamines are preferably 1,3-bis(dimethylamino)propane ethanolamine.

[0052] In the present invention, specific examples of the piperazines include, for example, 1-(2-hydroxyethyl)-4-methylpiperazine, 1-(2,3-dihydroxypropyl)-4-methylpiperazine, 1-(2,3-dihydroxypropyl)-4-ethylpiperazine, 1-(2,3-dihydroxypropyl)-4-propylpiperazine, 1-(2,3-dihydroxypropyl)-4-butylpiperazine, 1-(2-hydroxy-3-methoxypropyl)-4-methylpiperazine, 1-(2-hydroxy-3-methoxypropyl)-4-ethylpiperazine, 1-(2-hydroxy-3-methoxypropyl)-4-propylpiperazine, 1-(2-hydroxy-3-methoxypropyl)-4-butylpiperazine, 1-(2,3-dimethoxypropyl)-4-methylpiperazine, 1-(2,3-dimethoxypropyl)-4-ethylpiperazine, 1-(2,3-dimethoxypropyl)-4-propylpiperazine, 1-(2,3-dimethoxypropyl)-4-butylpiperazine, or 1,4-diazabicyclo[2.2.2]octane, etc.

[0053] In the present invention, specific examples of the piperidines include, for example, piperidine, 2-methylpiperidine, 1-(2,3-dihydroxypropyl)-piperidine, 1-(2,3-dihydroxypropyl)-4-methylpiperidine, 1-(2,3-dihydroxypropyl)-4-ethylpiperidine, 1-(2,3-dihydroxypropyl)-4-propylpiperidine, 1-(2,3-dihydroxypropyl)-4-butylpiperidine, 1-(2-hydroxy-3-methoxypropyl)-piperidine, 1-(2-hydroxy-3-methoxypropyl)-4-methylpiperidine, 1-(2-hydroxy-3-methoxypropyl)-4-ethylpiperidine, 1-(2-hydroxy-3-methoxypropyl)-4-propylpiperidine, 1-(2-hydroxy-3-methoxypropyl)-4-butylpiperidine, 1-(2,3-dimethoxypropyl)-piperidine, 1-(2,3-dimethoxypropyl)-4-methylpiperidine, 1-(2,3-dimethoxypropyl)-4-ethylpiperidine, 1-(2,3-dimethoxypropyl)-4-propylpiperidine, or 1-(2,3-dimethoxypropyl)-4-butylpiperidine, etc.

[0054] In the present invention, specific examples of the morpholines include, for example, morpholine, 2-methylmorpholine, 2,6-dimethylmorpholine, 1-(2,3-dihydroxypropyl)-morpholine, 1-(2-hydroxy-3-methoxypropyl)-morpholine, or 1-(2,3-dimethoxypropyl)-morpholine, etc.

[0055] In the present invention, specific examples of the pyrrolidines include, for example, pyrrolidine, 2-methylpyrrolidine, 2,5-dimethylpyrrolidine, 1-(2,3-dihydroxypropyl)-pyrrolidine, 1-(2-hydroxy-3-methoxypropyl)-pyrrolidine, 1-(2,3-dimethoxypropyl)-pyrrolidine, or 1,5-diazabicyclo[4.3.0]-5-nonene, etc.

[0056] In the present invention, specific examples of the azepanes include, for example, azepane, 2-methylazepane, 2,7-dimethylazepane, or 1,8-diazabicyclo[5.4.0]-7-undecene, etc.

[0057] In the present invention, specific examples of the polyethylene polyamines include, for example, diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), hexaethyleneheptamine (HEHA), or polyethylene polyamines having 8 or more amino groups, etc.

[0058] Here, the above-mentioned "TETA" refers to a compound in which four amino groups are connected linearly or branched via an ethylene chain. In the present invention, those having four amino groups and a piperazine ring structure are also included. Specific compound names of TETA include, for example, 1,4,7,10-tetraazadecane, N,N-bis(2-aminoethyl)-1,2-ethanediamine, 1-[2-[(2-aminoethyl)amino]ethyl]-piperazine, or 1,4-bis(2-aminoethyl)-piperazine, etc.

[0059] Also, the above-mentioned "TEPA" refers to a compound in which five amino groups are connected linearly or branched via an ethylene chain. In the present invention, those having five amino groups and a piperazine ring structure are also included. Specific compound names of TEPA include, for example, 1,4,7,10,13-pentaazatridecane, N,N,N'-tris(2-aminoethyl)-1,2-ethanediamine, 1-[2-[2-[2-[(2-aminoethyl)amino]ethyl]amino]ethyl]-piperazine, 1-[2-[bis(2-aminoethyl)amino]ethyl]-piperazine, or bis[2-(1-piperazinyl)ethyl]amine, etc.

[0060] In addition, the above-mentioned "PEHA" refers to a compound in which six amino groups are linearly or branchedly connected via an ethylene chain. In the present invention, those having six amino groups and a piperazine ring structure are also included. Specific compound names of PEHA include, for example, 1,4,7,10,13,16-hexaazadecane, N,N,N',N'-tetrakis(2-aminoethyl)-1,2-ethanediamine, N,N-bis(2-aminoethyl)-N'-[2-[(2-aminoethyl)amino]ethyl]-1,2-ethanediamine, 1-[2-[2-[2-[2-[2-[(2-aminoethyl)amino]ethyl]amino]ethyl]amino]ethyl]-piperazine, 1-[2-[2-[2-[bis(2-aminoethyl)amino]ethyl]amino]ethyl]-piperazine, or N,N'-bis[2-(1-piperazinyl)ethyl]-1,2-ethanediamine, etc.

[0061] In addition, the above-mentioned "HEHA" refers to a compound in which seven amino groups are linearly or branchedly connected via an ethylene chain. In the present invention, those having seven amino groups and a piperazine ring structure are also included. Specific compound names of HEHA include, for example, 1,4,7,10,13,16,19-heptaazanonadecane, N-[2-[(2-aminoethyl)amino]ethyl]-N,N',N'-tris(2-aminoethyl)-1,2-ethanediamine, 1-[2-[2-[2-[2-[2-[2-[(2-aminoethyl)amino]ethyl]amino]ethyl]amino]ethyl]amino]ethyl]-piperazine, or N-(2-aminoethyl)-N,N'-bis[2-(1-piperazinyl)ethyl]-1,2-ethanediamine, etc.

[0062] In addition, the "polyethylene polyamine having 8 or more amino groups" refers to a compound in which 8 or more amino groups are linearly or branchedly connected via an ethylene chain. In the present invention, those having 8 or more amino groups and having a piperazine ring structure are also included. Specific examples of the polyethylene polyamine having 8 or more amino groups include, for example, the product name "Poly8" (manufactured by Tosoh Corporation), polyethyleneimine, and the like.

[0063] Among these, in terms of the expected increase in the carbon dioxide absorption amount per unit mass of the carbon dioxide separation composition, as polyethylene polyamines, diethylenetriamine (DETA), 1,4,7,10-tetraazadecane, N,N-bis(2-aminoethyl)-1,2-ethanediamine, 1-[2-[(2-aminoethyl)amino]ethyl]-piperazine, and triethylenetetramine (TETA) composed of a mixture of 1,4-bis(2-aminoethyl)-piperazine, 1,4,7,10,13-pentaazatridecane, N,N,N’-tris(2-aminoethyl)-1,2-ethanediamine, 1-[2-[2-[2-[(2-aminoethyl)amino]ethyl]amino]ethyl]-piperazine, 1-[2-[bis(2-aminoethyl)amino]ethyl]-piperazine, and tetraethylenepentamine (TEPA) composed of a mixture of bis[2-(1-piperazinyl)ethyl]amine, 1,4,7,10,13,16-hexaazapentadecane, N,N,N’,N’-tetrakis(2-aminoethyl)-1,2-ethanediamine, N,N-bis(2-aminoethyl)-N’-[2-[(2-aminoethyl)amino]ethyl]-1,2-ethanediamine, 1-[2-[2-[2-[2-[2-[(2-aminoethyl)amino]ethyl]amino]ethyl]amino]ethyl]-piperazine, 1-[2-[2-[2-[bis(2-aminoethyl)amino]ethyl]amino]ethyl]-piperazine, and pentaethylenehexamine (PEHA) composed of a mixture of N,N’-bis[2-(1-piperazinyl)ethyl]-1,2-ethanediamine, 1,4,7,10,13,16,19-heptaazanonadecane, N-[2-[(2-aminoethyl)amino]ethyl]-N,N’,N’-tris(2-aminoethyl)-1,2-ethanediamine, 1-[2-[2-[2-[2-[2-[2-[(2-aminoethyl)amino]ethyl]amino]ethyl]amino]ethyl]amino]ethyl]-piperazine, and hexaethyleneheptamine (HEHA) composed of a mixture of N-(2-aminoethyl)-N,N’-bis[2-(1-piperazinyl)ethyl]-1,2-ethanediamine, and at least one selected from the group consisting of the product named "Poly8" (manufactured by Tosoh Corporation), which is a polyethylene polyamine having 8 or more amino groups, is preferred.

[0064] In the present invention, the amine compound (D) may be a commercially available product or a product synthesized by a known method, and is not particularly limited. Also, the purity of the amine compound (D) is not particularly limited, but is preferably 95% or more, and particularly preferably 99% or more. If the purity is less than 95%, the amount of carbon dioxide absorbed may decrease.

[0065] In the present invention, when the composition for carbon dioxide separation contains the amine compound (D), the mass of the amine compound (D) in the total mass of the amine compounds (A), (B), (C), and (D) is not particularly limited, but is preferably 1 to 50% by mass, more preferably 1 to 30% by mass, and even more preferably 1 to 20% by mass in terms of excellent carbon dioxide dissipation efficiency.

[0066] Next, a method for separating carbon dioxide using the above composition for carbon dioxide separation will be described.

[0067] The method for separating carbon dioxide of the present invention is characterized by having a step of bringing the above composition for carbon dioxide separation into contact with a gas containing carbon dioxide and selectively absorbing the carbon dioxide into the composition for carbon dioxide separation. Further, the method for separating carbon dioxide of the present invention may include a step of dissipating the carbon dioxide absorbed in the composition for carbon dioxide separation by heating and / or depressurizing the composition for carbon dioxide separation after the above step.

[0068] In the method for separating carbon dioxide of the present invention, the method of bringing a gas containing carbon dioxide into contact with the composition for carbon dioxide separation of the present invention is not particularly limited, and a known method can be used. Examples of known methods include a bubbling method and a countercurrent contact method using a packed tower or a tray tower.

[0069] In the method for separating carbon dioxide of the present invention, the temperature at which the gas containing carbon dioxide is absorbed by the composition for separating carbon dioxide of the present invention is not particularly limited, but usually the range of 0°C to 50°C can be mentioned.

[0070] In the method for separating carbon dioxide of the present invention, the temperature at which carbon dioxide is released from the composition for separating carbon dioxide of the present invention is not particularly limited, but usually the range of 60 to 150°C can be mentioned. However, from the viewpoint of energy reduction, it is preferably 100°C or lower.

[0071] Further, with respect to the composition for separating carbon dioxide of the present invention, it can be used in the chemical absorption method of carbon dioxide as a carbon dioxide absorption and desorption agent obtained by supporting or adhering it to an arbitrary carrier.

[0072] The chemical absorption method refers to a method in which the above-mentioned composition for separating carbon dioxide is brought into contact with a gas containing carbon dioxide, carbon dioxide is absorbed, and then the absorbed carbon dioxide is desorbed by heating and / or reducing the pressure. In this chemical absorption method, generally the temperature for desorbing carbon dioxide is 100°C or higher, but when using the composition for separating carbon dioxide of the present invention, there are no particular restrictions on the temperature, and a temperature lower than 100°C may also be used.

[0073] The carrier is not particularly limited, and for example, silica, alumina, magnesia, porous glass, activated carbon, polymethyl methacrylate-based porous resin, or fiber can be used.

[0074] The silica has crystalline and non-crystalline (amorphous) forms, and various types such as zeolite-like silica and mesoporous silica having pores are known. In the carbon dioxide absorption and desorption agent of the present invention, there are no particular restrictions on the silica that can be used, and industrially available ones can be used, but silica having a large surface area is preferred.

[0075] In the carbon dioxide absorption and desorption agent using the carrier of the present invention, the loading amount of the composition for carbon dioxide separation is preferably 5 to 70% by mass, more preferably 10 to 60% by mass, based on the total mass of the carrier in the state where the composition for carbon dioxide separation is loaded, in terms of excellent carbon dioxide absorption amount and loading operation of the composition for carbon dioxide separation.

[0076] The carbon dioxide absorption and desorption agent using the carrier of the present invention can be applied to a carbon dioxide separation method widely known as a solid absorption method. The solid absorption method represents a method in which a carbon dioxide separation agent is brought into contact with a gas containing carbon dioxide, the carbon dioxide is absorbed, and then the absorbed carbon dioxide is desorbed by heating or reducing the pressure. In the solid absorption method, generally, the temperature for desorbing carbon dioxide is 100°C or higher. However, when using the carbon dioxide separation composition of the present invention, there are no particular restrictions on the temperature, and it may be less than 100°C.

[0077] Regarding the gas containing carbon dioxide described above, it may be pure carbon dioxide gas or a mixed gas containing carbon dioxide and other gases. The other gases are not particularly limited, and examples include air, nitrogen, oxygen, hydrogen, argon, neon, helium, carbon monoxide, water vapor, methane, or nitrogen oxides.

[0078] Regarding the mixed gas applicable to the carbon dioxide separation method of the present invention, there is no particular limitation as long as it is a mixed gas containing carbon dioxide. However, in order to improve the separation performance between carbon dioxide and other gases, the carbon dioxide concentration is preferably 5 to 50% by volume, more preferably 10 to 30% by volume.

[0079] In the carbon dioxide separation method of the present invention, additional steps other than the above steps (absorption step, desorption step) can be carried out without any problem. For example, a cooling step, a heating step, a washing step, an extraction step, an ultrasonic treatment step, a distillation step, a filtration step, or a step of treating with other chemical solutions can be appropriately carried out.

[0080] The method for separating carbon dioxide of the present invention is not particularly limited. For example, it can be applied to the separation of carbon dioxide (CO 2 ) from combustion exhaust gas generated in thermal power plants, steel plants, cement factories, etc., and the separation of carbon dioxide (CO 2 ) from steam reforming gas obtained in a steam reforming process. [Examples]

[0081] The present invention will be described below using examples, but the present invention should not be construed as being limited thereto.

[0082] When measuring the carbon dioxide emission rate and the amount of carbon dioxide emission of the composition for carbon dioxide separation, a mixed gas of 140 mL / min of carbon dioxide gas and 560 mL / min of nitrogen gas (hereinafter referred to as "this mixed gas") was used. The carbon dioxide emission rate and the amount of carbon dioxide emission of the composition for carbon dioxide separation were calculated using a gas flow meter and a carbon dioxide concentration meter (RSIR-2000 manufactured by J Science Lab Co., Ltd.).

[0083] [Example 1] 27 g of 1-(2-dimethylaminoethyl)-4-methylpiperazine (manufactured by Tokyo Chemical Industry), 15 g of piperazine (manufactured by Tokyo Chemical Industry Co., Ltd.), 5 g of 1,4-diazabicyclo[2,2,2]octane-2-methanol (manufactured by Tosoh Corporation) and 53 g of pure water were mixed and stirred to obtain a composition for carbon dioxide separation (100 g). The entire amount of the composition for carbon dioxide separation was placed in a 200 mL gas absorption bottle and the temperature was adjusted to 40 °C in a water bath. When this mixed gas was blown into the composition for carbon dioxide separation and the absorption amount of carbon dioxide gas was measured using a gas flow meter and a carbon dioxide concentration meter, the carbon dioxide gas absorption rate per unit time for 30 minutes immediately after the start of blowing of this mixed gas stream was 171 mL / min per liter of the composition for carbon dioxide separation. Next, the gas absorption bottle was placed in an oil bath at 100°C to dissipate the carbon dioxide gas absorbed by the carbon dioxide separation composition. When the dissipation amount of the carbon dioxide gas was measured using a gas flow meter and a carbon dioxide concentration meter, the carbon dioxide gas dissipation rate per unit time for 30 minutes immediately after the start of blowing the mixed air stream was 140 mL / min per liter of the carbon dioxide separation composition.

[0084] [Example 2] 27 g of 1-(2-dimethylaminoethyl)-4-methylpiperazine (manufactured by Tokyo Chemical Industry), 20 g of piperazine (manufactured by Tokyo Chemical Industry Co., Ltd.), 3 g of 1,4-diazabicyclo[2,2,2]octane-2-methanol (manufactured by Tosoh Corporation), and 50 g of pure water were mixed and stirred to obtain a carbon dioxide separation composition (100 g). The same operation as in Example 1 was performed to measure the carbon dioxide gas absorption rate and the carbon dioxide gas dissipation rate of the carbon dioxide separation composition. The carbon dioxide gas absorption rate per unit time for 30 minutes immediately after the start of blowing the mixed air stream was 199 mL / min per liter of the carbon dioxide separation composition. The carbon dioxide gas dissipation rate per unit time for 30 minutes immediately after the start of blowing the mixed air stream was 145 mL / min per liter of the carbon dioxide separation composition.

[0085] [Example 3] 27 g of 1-(2-dimethylaminoethyl)-4-methylpiperazine (manufactured by Tokyo Chemical Industry), 17 g of piperazine (manufactured by Tokyo Chemical Industry Co., Ltd.), 5 g of 1,4-diazabicyclo[2,2,2]octane-2-methanol (manufactured by Tosoh Corporation), and 51 g of pure water were mixed and stirred to obtain a carbon dioxide separation composition (100 g). The same operation as in Example 1 was performed to measure the carbon dioxide gas absorption rate and the carbon dioxide gas dissipation rate of the carbon dioxide separation composition. The carbon dioxide gas absorption rate per unit time for 30 minutes immediately after the start of blowing the mixed air stream was 181 mL / min per liter of the carbon dioxide separation composition. The carbon dioxide gas dissipation rate per unit time for 30 minutes immediately after the start of blowing the mixed air stream was 141 mL / min per liter of the carbon dioxide separation composition.

[0086] [Example 4] 25 g of 1-(2-dimethylaminoethyl)-4-methylpiperazine (manufactured by Tokyo Chemical Industry), 20 g of piperazine (manufactured by Tokyo Chemical Industry Co., Ltd.), 5 g of 1,4-diazabicyclo[2,2,2]octane-2-methanol (manufactured by Tosoh Corporation), and 50 g of pure water were mixed and stirred to obtain a composition for carbon dioxide separation (100 g). The same operations as in Example 1 were carried out to measure the carbon dioxide gas absorption rate and the carbon dioxide gas desorption rate of the composition for carbon dioxide separation. The carbon dioxide gas absorption rate per unit time for 30 minutes immediately after the start of blowing the mixed air stream was 192 mL / min per liter of the composition for carbon dioxide separation. The carbon dioxide gas desorption rate per unit time for 30 minutes immediately after the start of blowing the mixed air stream was 142 mL / min per liter of the composition for carbon dioxide separation.

[0087] [Example 5] 25 g of 1-(2-dimethylaminoethyl)-4-methylpiperazine (manufactured by Tokyo Chemical Industry), 17 g of piperazine (manufactured by Tokyo Chemical Industry Co., Ltd.), 5 g of 1,4-diazabicyclo[2,2,2]octane-2-methanol (manufactured by Tosoh Corporation), and 53 g of pure water were mixed and stirred to obtain a composition for carbon dioxide separation (100 g). The same operations as in Example 1 were carried out to measure the carbon dioxide gas absorption rate and the carbon dioxide gas desorption rate of the composition for carbon dioxide separation. The carbon dioxide gas absorption rate per unit time for 30 minutes immediately after the start of blowing the mixed air stream was 180 mL / min per liter of the composition for carbon dioxide separation. The carbon dioxide gas desorption rate per unit time for 30 minutes immediately after the start of blowing the mixed air stream was 136 mL / min per liter of the composition for carbon dioxide separation.

[0088] [Example 6] 27 g of 1-(2-dimethylaminoethyl)-4-methylpiperazine (manufactured by Tokyo Chemical Industry), 10 g of piperazine (manufactured by Tokyo Chemical Industry Co., Ltd.), 5 g of 1,4-diazabicyclo[2,2,2]octane-2-methanol (manufactured by Tosoh Corporation), and 58 g of pure water were mixed and stirred to obtain a composition for carbon dioxide separation (100 g). The same operations as in Example 1 were carried out to measure the carbon dioxide gas absorption rate and the carbon dioxide gas desorption rate of the composition for carbon dioxide separation. The carbon dioxide gas absorption rate per unit time in the 30 minutes immediately after the start of blowing the mixed air stream was 152 mL / min per liter of the composition for carbon dioxide separation. The carbon dioxide gas desorption rate per unit time in the 30 minutes immediately after the start of blowing the mixed air stream was 139 mL / min per liter of the composition for carbon dioxide separation.

[0089] [Comparative Example 1] 22 g of 1-(2-dimethylaminoethyl)-4-methylpiperazine (manufactured by Tokyo Chemical Industry), 10 g of piperazine (manufactured by Tokyo Chemical Industry Co., Ltd.), 5 g of 1,4-diazabicyclo[2,2,2]octane-2-methanol (manufactured by Tosoh Corporation), and 63 g of pure water were mixed and stirred to obtain a composition for carbon dioxide separation (100 g). The same operations as in Example 1 were carried out to measure the carbon dioxide gas absorption rate and the carbon dioxide gas desorption rate of the composition for carbon dioxide separation. The carbon dioxide gas absorption rate per unit time in the 30 minutes immediately after the start of blowing the mixed air stream was 174 mL / min per liter of the composition for carbon dioxide separation. The carbon dioxide gas desorption rate per unit time in the 30 minutes immediately after the start of blowing the mixed air stream was 114 mL / min per liter of the composition for carbon dioxide separation.

[0090] [Comparative Example 2] 22 g of 1-(2-dimethylaminoethyl)-4-methylpiperazine (manufactured by Tokyo Chemical Industry), 15 g of piperazine (manufactured by Tokyo Chemical Industry Co., Ltd.), 5 g of 1,4-diazabicyclo[2,2,2]octane-2-methanol (manufactured by Tosoh Corporation), and 58 g of pure water were mixed and stirred to obtain a composition for carbon dioxide separation (100 g). The same operations as in Example 1 were carried out to measure the carbon dioxide gas absorption rate and the carbon dioxide gas desorption rate of the composition for carbon dioxide separation. The carbon dioxide gas absorption rate per unit time in the 30 minutes immediately after the start of blowing the mixed air stream was 177 mL / min per liter of the composition for carbon dioxide separation. The carbon dioxide gas desorption rate per unit time in the 30 minutes immediately after the start of blowing the mixed air stream was 118 mL / min per liter of the composition for carbon dioxide separation.

[0091]

Table 1

[0092]

Table 2

[0093] As is clear from the comparison between the above-mentioned examples and comparative examples shown in Table 1 and Table 2, the composition for carbon dioxide separation of the present invention has a higher CO2 emission rate and is excellent in CO2 emission performance compared to the conventional compositions for carbon dioxide separation.

[0094] Further, the composition for carbon dioxide separation of the present invention has a synergistically higher CO2 emission rate compared to the composition for carbon dioxide separation shown in the comparative example, and a remarkable effect that could not be expected was obtained.

[0095] That is, the composition for carbon dioxide separation of the present invention was excellent in CO2 emission performance because the content of the amine compound (A) was above a specific concentration with respect to the total amount of the composition for carbon dioxide separation.

Industrial Applicability

[0096] The composition for carbon dioxide separation of the present invention can efficiently separate carbon dioxide in exhaust gas discharged in large quantities, for example, in large-scale thermal power generation.

Claims

1. A carbon dioxide separation composition containing an amine compound (A) represented by the following general formula (1), an amine compound (B) represented by the following general formula (2), an amine compound (C) represented by the following general formula (3), and water, wherein the weight ratio of the amine compound (A) in the whole composition is 25 weight percent or more. A carbon dioxide separation composition characterized by the above. 【Chemical 1】 In the general formula (1) above, R １ each independently represents an alkyl group having 1 to 3 carbon atoms.] 【Chemical Formula 2】 [In the general formula (2) above, R ２ , and R ３ each independently represents an alkylene group having 2 to 3 carbon atoms.] [Chemical Formula 3] [In the general formula (3) above, R １ to R ６ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. a and b each independently represent 0 or 1.]

2. The carbon dioxide separation composition according to Claim 1, wherein the amine compound (A) is 1-(2-dimethylaminoethyl)-4-methylpiperazine.

3. The carbon dioxide separation composition according to Claim 1, wherein the amine compound (B) is piperazine.

4. The carbon dioxide separation composition according to Claim 1, wherein the amine compound (C) is 1,4-diazabicyclo[2.2.2]octane-2-methanol.

5. The carbon dioxide separation composition according to Claim 1, wherein the concentration of water is 50 to 60% by mass of the whole carbon dioxide separation composition.

6. A carbon dioxide separation method, comprising the step of bringing a gas containing carbon dioxide into contact with the carbon dioxide separation composition according to any one of Claims 1 to 5, and absorbing carbon dioxide in the mixed gas into the carbon dioxide separation composition.

7. A carbon dioxide separation method, comprising the step of bringing a gas containing carbon dioxide into contact with the carbon dioxide separation composition according to any one of Claims 1 to 5, and absorbing carbon dioxide in the mixed gas into the carbon dioxide separation composition, and heating and / or depressurizing the carbon dioxide separation composition that has absorbed the carbon dioxide to release carbon dioxide from the carbon dioxide separation composition.

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