Method for separating / collecting carbon dioxide and method for regenerating carbon dioxide

Abstract

Provided is a method for separating / collecting carbon dioxide in which an amine compound is used to absorb and collect carbon dioxide. The method reduces the energy for regenerating a CO2-absorbing / releasing agent and simplifies processes between an absorption step and a collection step. The method for separating / collecting carbon dioxide comprises: a step (A1) in which an amine-compound polar solution comprising an amine compound and a polar solvent is caused to absorb carbon dioxide and a solid product of reaction between the amine compound and the carbon dioxide is thereby precipitated in the amine-compound polar solution to obtain a polar reaction product which is either a polar suspension or a slurry obtained therefrom; a step (B1) in which the polar reaction product obtained in the step (A1) is treated with a non-polar solvent and the polar solvent is removed, thereby obtaining a non-polar reaction product which is either a non-polar suspension comprising the solid reaction product and the non-polar solvent or a slurry obtained therefrom; a step (C1) in which the non-polar reaction product obtained in the step (B1) is heated at an elevated, ordinary, or reduced pressure to separate and collect the carbon dioxide and regenerate the amine compound from the non-polar reaction product, thereby obtaining an amine-compound non-polar solution; and a step (D1) in which the amine-compound non-polar solution obtained in the step (C1) is treated with a polar solvent to conduct solvent displacement, thereby obtaining an amine-compound polar solution.

Description

Carbon Dioxide Separation and Recovery Method and Carbon Dioxide Regeneration Method

[0001] The present invention relates to a carbon dioxide separation and recovery method and a carbon dioxide regeneration method.

[0002] According to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), in order to limit the increase in the global average temperature caused by anthropogenic greenhouse gas emissions to within 1.5°C compared to before the Industrial Revolution, it is necessary to reduce the global carbon dioxide (CO ２ , ２ ,

[0004] , ) emissions to net zero by 2050. Thus, the development and social implementation of technologies for low-energy-cost CO ２ separation and recovery, transportation, and fixation from emission sources or the atmosphere have become urgent issues. As methods for CO ２ separation and recovery, thermal swing, pressure swing, and more recently, new methods such as electric swing, humidity swing, and pH swing have been proposed. ２ In thermal swing, by using a CO

[0003] absorption and release agent that undergoes a phase change from liquid to solid when absorbing CO ２ , it is known from Patent Document 1 that the energy loss due to the sensible heat and latent heat of vaporization of the solvent when heating the CO ２ absorption and release agent to recover CO ２ can be reduced. As an example where the energy loss due to the sensible heat and latent heat of vaporization of the solvent becomes a problem, in a general amine process used for combustion exhaust gas treatment, in order to mitigate the corrosiveness of the amine, the concentration of the amine needs to be, for example, an aqueous solution of 30 wt% or less, which requires a large amount of energy input for heating the water. Also, when the temperature of the thermal swing is significantly higher than normal temperature, it becomes a factor increasing the input energy. ２ According to Patent Document 1, when a compound represented by the following general formula (1), for example, isophoronediamine (IPDA) which is a liquid at normal temperature and pressure (see the following formula (2)), absorbs CO

[0004] and the precipitated carbamic acid (CA1) (see the following formula (3)) is dried and then heated in a nitrogen gas atmosphere, CO is obtained at a relatively low temperature of about 60°C at atmospheric pressure. ２ and heated in a nitrogen gas atmosphere after drying the precipitated carbamic acid (CA1) (see the following formula (3)) obtained by absorbing CO２ It is believed that it can release [something].

[0005]

[0006]

[0007]

[0008]

[0009] In industrial-scale processes, CA1 is heated in a suspension state mixed with IPDA and a solvent. When water is used as the solvent, CA1 attracts water of hydration and forms CA1·H ２ O (see formula (4) above). CA1·H in IPDA aqueous solution ２ O to CO ２ The pressure and temperature required to extract it are, for example, around 120°C at 20 kPa and around 140°C at atmospheric pressure, and a considerably long regeneration process is necessary.

[0010] By using an organic solvent such as DMSO instead of water as the solvent for the IPDA stock solution, CO ２ The precipitate formed when it absorbs is CA1·H ２ It can be in the state of CA1 instead of O, and CA1·H ２ O is better than CO ２ It may be possible to lower the temperature required for release. However, CO2 can be released from exhaust gases and air. ２ When attempting to absorb it, water contamination is unavoidable.

[0011] Precipitated CA1 or CA1·H ２ Since O is a fine particle, CO ２ After absorption, the polar solvent becomes suspended in these particles. Separating the solvent requires filtration or a solid-liquid separation process such as a filter press, which increases process costs and energy costs. A more manageable state for CO2 absorption is desirable. ２ It is desirable to transfer the absorption-release agent between the absorption and recovery processes.

[0012] Patent No. 7441557

[0013] CO shown in Patent Document 1２ The separation and recovery method is CA1·H ２ When regenerating oxygen in an IPDA solution, low-pressure conditions such as 20 kPa and 120°C, as well as a high-temperature heat source, are required. A challenge is to reduce the amount of power required for depressurization and the energy input for heating by shortening the regeneration time.

[0014] Also, CO ２ CO2 in a suspended state after absorption ２ absorbent and release agent CO ２ The entire process becomes inefficient if a batch process, such as dehydration (solvent removal) using a filter press, is inserted between the recovery and the next stage of processing. Simplifying the process is a challenge.

[0015] The present invention relates to a carbon dioxide separation and recovery method that uses an amine compound to absorb and recover carbon dioxide, ２ The objectives are to reduce the energy required for the regeneration of absorption-release agents and to simplify the process between the absorption and recovery steps.

[0016] To solve the above-mentioned problems, by using solvents with different polarities in the carbon dioxide absorption process and the recovery process, CO ２ We have completed the present invention by discovering that it is possible to reduce the energy required for the regeneration of the absorption-release agent and to simplify the process between the absorption and recovery steps.

[0017] An aspect of the present invention that achieves the above objective is a method for separating and recovering carbon dioxide, comprising the steps of: (A1) absorbing carbon dioxide into an amine compound polar solution containing an amine compound represented by the following formula (1) and a polar solvent to precipitate a solid reaction product of the amine compound and the carbon dioxide in the amine compound polar solution, thereby obtaining a polar reaction product which is a polar suspension or slurry obtained therefrom; (B1) treating the polar reaction product obtained in step (A1) with a nonpolar solvent to remove the polar solvent, thereby obtaining a nonpolar reaction product which is a nonpolar suspension or slurry obtained therefrom containing the solid reaction product and the nonpolar solvent; (C1) heating the nonpolar reaction product obtained in step (B1) under pressure, atmospheric pressure or reduced pressure to separate and recover carbon dioxide and regenerate the amine compound from the nonpolar reaction product, thereby obtaining an amine compound nonpolar solution; and (D1) treating the amine compound nonpolar solution obtained in step (C1) with a polar solvent to replace the solvent and obtain an amine compound polar solution.

[0018]

[0019] However, in the formula, m is either 0 or 1; R １ and R ２ Each of these is independently an alkyl group, an alkoxy group, a carboxyl group, an alkyloxycarbonyl group, a formyl group, an alkylcarbonyl group, an alkylthio group, a sulfo group, an alkyloxysulfonyl group, a nitro group, a hydroxyl group, a thiol group, a cyano group, or a halogen atom, and the alkyl group may have substituents; p １ and p ２ Each is independently either 1 or 2; if m is 0, q １ is an integer from 0 to 11, where p １ +q １ If q is 12 or less, and m is 1, １ is an integer between 0 and 10, where p １ +q １ q is 11 or less, ２ is an integer between 0 and 10, and q １ If is an integer greater than or equal to 2, then two or more R １ They may be the same or different from each other, q ２If is an integer greater than or equal to 2, then two or more R ２ They may be the same or different from each other, q １ If is an integer greater than or equal to 2, and there are two or more R １ If the alkyl group may have substituents, then the two or more R １ They may be bonded to each other to form a ring, q ２ If is an integer greater than or equal to 2, and there are two or more R ２ If the alkyl group may have substituents, then the two or more R ２ They may be bonded to each other to form a ring. However, m is 0 and p １ Since is 2, p １ Except when the two amino groups with the notation are positioned at the meta position relative to each other.

[0020] A second aspect of the present invention is a method for separating and recovering carbon dioxide as described above, wherein the amine compound polar solution obtained in step (D1) is used as the amine compound polar solution in step (A1), and a step (E1) is performed in which steps (A1) to (D1) are repeated.

[0021] A third aspect of the present invention is a method for separating and recovering carbon dioxide as described above, wherein in step (B1), a suspension or slurry is used as the polar reactant, the nonpolar solvent is mixed thereto, and then the polar solvent is separated and removed to obtain the nonpolar reactant.

[0022] A fourth aspect of the present invention is that in step (C1), the nonpolar reactant is heated to 100 to 150°C under a pressure of atmospheric pressure to 20 kPa to generate CO ２ The method for separating and recovering carbon dioxide according to the above embodiment involves releasing the amine compound to obtain a nonpolar solution of the amine compound.

[0023] A fifth aspect of the present invention is a method for separating and recovering carbon dioxide as described above, wherein in step (D1), a polar solvent is mixed with the nonpolar solution of the amine compound to transfer the amine compound to the polar solvent, and then the nonpolar solvent is separated and recovered to obtain the polar solution of the amine compound.

[0024] A sixth aspect of the present invention is a method for separating and recovering carbon dioxide according to the above aspect, wherein the polar solvent is at least one selected from the group consisting of water, methanol, ethanol, acetone, and dimethyl sulfoxide (DMSO).

[0025] A seventh aspect of the present invention is a method for separating and recovering carbon dioxide according to the above aspect, wherein the nonpolar solvent is at least one selected from the group consisting of hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, diethyl ether, cyclopentane, and cyclohexane.

[0026] An eighth aspect of the present invention is a method for separating and recovering carbon dioxide according to the above aspect, wherein the amine compound comprises at least one selected from monoxylenediamine (MXDA), paraxylenediamine (PXDA), and isophoronediamine (IPDA).

[0027] A ninth aspect of the present invention is a method for separating and recovering carbon dioxide according to the above aspect, wherein the solid reactant includes solid carbamic acid.

[0028] A tenth aspect of the present invention is a method for separating and recovering carbon dioxide according to the above aspect, comprising the step (A1) being carried out at a first location, the step (F1) being transported to a second location where carbon dioxide is regenerated, and the step (C1) being carried out at the second location.

[0029] An eleventh aspect of the present invention is a method for separating and recovering carbon dioxide according to the above aspect, comprising the steps (A1) and (B1) performed at a first location, the step (G1) of transporting the obtained nonpolar reactant to a second location where carbon dioxide is regenerated, and the step (C1) performed at the second location.

[0030] A twelfth aspect of the present invention is a method for separating and recovering carbon dioxide as described above, comprising the step (H1) of transporting the nonpolar solution of the amine compound obtained in step (C1) or the polar solution of the amine compound obtained in step (D1) from the second location to the first location, and repeating steps (A1) to (D1), steps (F1) and (H1).

[0031] A thirteenth aspect of the present invention is a method for separating and recovering carbon dioxide as described above, comprising a step (H1) of transporting the nonpolar solution of the amine compound obtained in step (C1) or the polar solution of the amine compound obtained in step (D1) from the second location to the first location, wherein if the nonpolar solution of the amine compound obtained in step (C1) is transported, after performing step (D1), steps (A1) to (D1), steps (G1) and (H1) are repeated.

[0032] A fourteenth aspect of the present invention is a method for separating and recovering carbon dioxide according to the above aspect, wherein in the step (C1) performed at the second location, renewable energy is used for the heating step.

[0033] A fifteenth aspect of the present invention is a method for separating and recovering carbon dioxide as described above, wherein the amine compound used is an amine compound comprising at least one selected from monoxylenediamine (MXDA), paraxylenediamine (PXDA), and isophoronediamine (IPDA), and the polar solvent used is water.

[0034] A sixteenth aspect of the present invention is a method for separating and recovering carbon dioxide as described above, wherein the nonpolar solvent is at least one selected from the group consisting of hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, diethyl ether, cyclopentane, and cyclohexane.

[0035] A 17th aspect of the present invention is a method for regenerating carbon dioxide, comprising: absorbing carbon dioxide into a polar solution of an amine compound containing at least one selected from monoxylenediamine (MXDA), paraxylenediamine (PXDA), and isophoronediamine (IPDA) and a polar solvent to obtain a polar reaction product which is a polar suspension or slurry containing solid carbamic acid, which is a reaction product of the amine compound and the carbon dioxide; and regenerating carbon dioxide from this polar reaction product, wherein the polar reaction product is treated with a nonpolar solvent to remove the polar solvent to obtain a nonpolar reaction product which is a nonpolar suspension or slurry containing the reaction product and the nonpolar solvent; heating the obtained nonpolar reaction product under normal or reduced pressure to separate and recover carbon dioxide and regenerate the amine compound from the nonpolar reaction product to obtain a nonpolar solution of the amine compound.

[0036] An eighteenth aspect of the present invention is a method for separating and recovering carbon dioxide according to the above aspect, wherein the polar solvent is at least one selected from the group consisting of water, methanol, and ethanol, and the nonpolar solvent is at least one selected from the group consisting of toluene, hexane, heptane, n-octane, nonane, decane, cyclopentane, and cyclohexane.

[0037] According to the present invention, a novel CO ２ A separation and recovery system is provided, ２ CO2 absorbed from the reactants ２ By lowering the regeneration temperature during regeneration, the energy input can be reduced. Furthermore, even if regeneration is performed without separating the reactants, the energy input is sufficiently reduced.

[0038] CA1・H ２ The temperature of the solvent and the CO content in the outlet gas when a decane solvent containing solid O or an aqueous solvent is heated. ２ A graph comparing the concentration over time. CA1·H ２ The temperature of the solvent and the CO content in the outlet gas when a decane solvent containing solid O or an IPDA solvent is heated. ２ A graph comparing the concentration over time.

[0039] The present invention will be described in further detail below. The carbon dioxide separation and recovery method of the present invention comprises the steps of: (A1) absorbing carbon dioxide into a liquid carbon dioxide absorbent containing an amine compound represented by the following formula (1) and a polar solvent, thereby precipitating a reaction product of the amine compound and the carbon dioxide in the carbon dioxide absorbent to obtain a polar suspension; (B1) treating the polar suspension obtained in step (A1) with a nonpolar solvent to remove the polar solvent to obtain a nonpolar suspension containing the reaction product and the nonpolar solvent; and heating the nonpolar suspension obtained in step (B1) under normal or reduced pressure to obtain CO ２ The method comprises the steps of: (C1) releasing the reaction product to regenerate it into the amine compound and obtain a nonpolar solution of the amine compound; and (D1) replacing the nonpolar solvent in the nonpolar solution of the amine compound obtained in step (C1) with the polar solvent to obtain the carbon dioxide absorbent.

[0040] Here, the amine compound of formula (1) below is a known compound that was also disclosed in Japanese Patent Application Publication No. 2024-075122, which was filed earlier by the present applicant, and is disclosed below.

[0041]

[0042] In the formula, m is either 0 or 1; R １ and R ２ Each of these is independently an alkyl group, an alkoxy group, a carboxyl group, an alkyloxycarbonyl group, a formyl group, an alkylcarbonyl group, an alkylthio group, a sulfo group, an alkyloxysulfonyl group, a nitro group, a hydroxyl group, a thiol group, a cyano group, or a halogen atom, and the alkyl group may have substituents; p １ and p ２ Each is independently either 1 or 2; if m is 0, q １ is an integer from 0 to 11, where p １ +q １ If q is 12 or less, and m is 1, １ is an integer between 0 and 10, where p １ +q １ q is 11 or less, ２ is an integer between 0 and 10, and q１ When m is an integer of 2 or more, two or more Rs １ may be the same as or different from each other, and when q ２ is an integer of 2 or more, two or more Rs ２ may be the same as or different from each other, and when q １ is an integer of 2 or more, and when two or more Rs １ are the alkyl groups which may have a substituent, the two or more Rs １ may be bonded to each other to form a ring, and when q ２ is an integer of 2 or more, and when two or more Rs ２ are the alkyl groups which may have a substituent, the two or more Rs ２ may be bonded to each other to form a ring. However, this does not include the case where m is 0, p １ is 2, and the two amino groups to which p １ is attached are arranged in the meta position to each other.

[0043] Here, the amine compound represented by the above formula (1) is preferably a compound (11A), (12A) or (11B) represented by the following formula.

[0044]

[0045] In the formula, R １１ , R １２ , R １３ and R ２１ are each independently an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a carboxy group, an alkyloxycarbonyl group having 2 to 11 carbon atoms, a formyl group, an alkylcarbonyl group having 2 to 11 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, a sulfo group, an alkyloxysulfonyl group having 1 to 10 carbon atoms, a nitro group, a hydroxyl group, a thiol group, a cyano group or a halogen atom, and the alkyl group may have an amino group as the substituent; q １１ and q １２ are each independently an integer of 0 to 6, and when q １１ is an integer of 2 or more, two or more Rs １１ may be the same as or different from each other, and when q １２When it is an integer of 2 or more, two or more Rs １２ may be the same as or different from each other, and q １１ is an integer of 2 or more, and when two or more Rs １１ is the alkyl group which may have an amino group as the substituent, the two or more Rs １１ may be bonded to each other to form a ring, and q １２ is an integer of 2 or more, and when two or more Rs １２ is the alkyl group which may have an amino group as the substituent, the two or more Rs １２ may be bonded to each other to form a ring; q １３ and q ２１ are each independently an integer of 0 to 4, and when q １３ is an integer of 2 or more, two or more Rs １３ may be the same as or different from each other, and when q ２１ is an integer of 2 or more, two or more Rs ２１ may be the same as or different from each other, and when q １３ is an integer of 2 or more, and when two or more Rs １３ is the alkyl group which may have an amino group as the substituent, the two or more Rs １３ may be bonded to each other to form a ring, and q ２１ is an integer of 2 or more, and when two or more Rs ２１ is the alkyl group which may have an amino group as the substituent, the two or more Rs ２１ may be bonded to each other to form a ring. However, in the formula (12A), except when two amino groups directly bonded to the carbon atoms constituting the cyclohexane ring skeleton are arranged in the meta position to each other.

[0046] Further, the compound (11A), compound (12A) or compound (11B) which is an amine compound of the formula (1) is preferably a compound represented by the following formula (111A), (121A), (122A) or (111B).

[0047]

[0048] In the formula, R １１１ , R １２１ , R １２２ , R １３１ and R ２１１ Each of these is independently a C1-C5 alkyl group, a C1-C5 alkoxy group, a C2-C6 alkyloxycarbonyl group, a formyl group, a C2-C6 alkylcarbonyl group, a C1-C5 alkylthio group, a hydroxyl group, a thiol group, a cyano group, or a halogen atom, and the alkyl group may have an amino group as a substituent; q １１１ , q １２１ and q １２２ Each of these is an integer from 0 to 4, and q １１１ If is an integer greater than or equal to 2, then two or more R １１１ They may be the same or different from each other, q １２１ If is an integer greater than or equal to 2, then two or more R １２１ They may be the same or different from each other, q １２２ If is an integer greater than or equal to 2, then two or more R １２２ They may be the same or different from each other, q １１１ If is an integer greater than or equal to 2, and there are two or more R １１１ If the alkyl group may have an amino group as a substituent, then the two or more R １１１ They may be bonded to each other to form a ring, q １２１ If is an integer greater than or equal to 2, and there are two or more R １２１ If the alkyl group may have an amino group as a substituent, then the two or more R １２１ They may be bonded to each other to form a ring, q １２２ If is an integer greater than or equal to 2, and there are two or more R １２２ If the alkyl group may have an amino group as a substituent, then the two or more R １２２ They may be bonded to each other to form a ring; q １３１ and q ２１１ Each of these is an integer between 0 and 2, and q １３１ If it is 2, then two R １３１ They may be the same or different from each other, q ２１１If it is 2, then two R ２１１ They may be the same or different from each other, q １３１ If is 2, and there are 2 R １３１ If the alkyl group may have an amino group as a substituent, then the two R １３１ They may be bonded to each other to form a ring, q ２１１ If is 2, and there are 2 R ２１１ If the alkyl group may have an amino group as a substituent, then the two R ２１１ They may be bonded to each other to form a ring.

[0049] Examples of such amine compounds include monoxylenediamine (MXDA), paraxylenediamine (PXDA), and isophoronediamine (IPDA).

[0050] In step (A1) of the present invention, the amine compound described above is in liquid form. This amine compound is mixed with a polar solvent to create a mixture of the amine compound and the polar solvent, which is used as a carbon dioxide absorbent. Since the polar solvent and the amine compound are miscible, when the two are mixed, they become miscible and form a liquid carbon dioxide absorbent containing both.

[0051] The polar solvent is not limited as long as it is compatible with the amine compound, but at least one selected from, for example, water, methanol, ethanol, acetone, and dimethyl sulfoxide (DMSO) may be used. As water, aqueous solutions of acetic acid, ammonia, and sulfuric acid can also be used. There are no particular restrictions in step (A1), but if the same polar solvent as in step (D1) described later is used, it is preferable to use one that has higher compatibility with the amine compound than the nonpolar solvent described later. Considering cost and other factors, it is preferable to use water.

[0052] Step (A1) utilizes the property of amine compounds to solidify upon reaction with carbon dioxide. Specifically, a liquid carbon dioxide absorbent is brought into contact with air or a gas containing carbon dioxide to absorb the carbon dioxide and generate a reaction product between the amine compound and carbon dioxide. This reaction product becomes solid and precipitates in the carbon dioxide absorbent, yielding a polar suspension in which the solid reaction product is suspended in a polar solvent. The solid reaction product of the amine compound and carbon dioxide is a carbamic acid derivative, and it is preferable to carry out the contact between the carbon dioxide absorbent and carbon dioxide under conditions that facilitate the reaction between the amine compound and carbon dioxide and the precipitation of the solid reaction product.

[0053] It is preferable to maximize the contact area and contact efficiency between the carbon dioxide absorbent and carbon dioxide, and to keep the contact temperature as low as possible. While diamines are preferable as the easily precipitated amine compounds, monoamines can also be used if the concentration of the amine compound is as high as possible and the reaction temperature is kept as low as possible.

[0054] Considering the above points, the temperature of the carbon dioxide absorbent is, for example, 0 to 90°C, preferably 5 to 60°C, and more preferably 5 to 40°C. The concentration of the amine compound in the carbon dioxide absorbent is, for example, 0.05 to 10 M, preferably 0.08 to 3 M, and more preferably 0.1 to 1 M. Note that the concentration unit "M" represents "mol / L".

[0055] As described above, in step (A1), a polar suspension is obtained in which a solid carbamic acid derivative, which is a reaction product of an amine compound and carbon dioxide, is suspended in a polar solvent.

[0056] In the present invention, in step (B1), the polar suspension or slurry obtained by removing a portion of the polar solvent from the polar suspension is treated with a nonpolar solvent. This treatment is, for example, a process in which the polar suspension or slurry and the nonpolar solvent are mixed and stirred to form a mixture, and the polar solvent is removed from this mixture to obtain a nonpolar suspension containing a solid reactant and a nonpolar solvent. To explain this treatment in detail, when a nonpolar solvent is mixed with a polar suspension or slurry in which a solid reactant, a carbamic acid derivative, is suspended in a polar solvent, and the mixture is stirred and allowed to stand, it separates into a polar solvent phase and a nonpolar solvent phase, but the solid carbamic acid derivative migrates to the vicinity of the nonpolar solvent phase. That is, a suspension phase is formed between the polar solvent phase and the nonpolar solvent phase, and a nonpolar suspension is obtained by removing the polar solvent from the polar solvent phase. Thus, step (B1) is carried out based on the above-described knowledge. In other words, one of the effects of the present invention is that, instead of separating the carbamic acid derivative from a polar suspension by filtration or the like and mixing it with a nonpolar solvent to obtain a nonpolar suspension, a nonpolar suspension containing a suspended solid carbamic acid derivative can be obtained by mixing a polar suspension with a nonpolar solvent. Of course, substitution can also be performed by adding a nonpolar solvent to a slurry or cake (both sometimes simply called a slurry) obtained by desolvating a polar suspension containing a carbamic acid derivative with a cyclone, and removing the polar solvent. In any case, this step (B1) is an important point of the present invention. Such solvent substitution is possible when water, methanol, ethanol, or a mixture of several types selected from these are used as the polar solvent, and toluene, hexane, heptane, n-octane, nonane, decane, cyclopentane, and cyclohexane are used as the nonpolar solvent, and this has been confirmed with most of the exemplified nonpolar solvents.

[0057] In the present invention, in step (C1), a nonpolar suspension containing a solid carbamic acid derivative is heated under pressure, at atmospheric pressure or reduced pressure, and CO ２ The carbamic acid derivative is regenerated into an amine compound by releasing the amine, and a nonpolar solution of the amine compound is obtained.

[0058] The second important point of this invention is that the energy input required to regenerate amine compounds by releasing carbon dioxide from a non-polar suspension is significantly less than the energy input required to regenerate amine compounds from a polar suspension. That is, when regenerating amine compounds from a polar suspension such as water, it is known that after the peak of carbon dioxide release has passed, the rate of carbon dioxide release decreases and it takes time for the carbon dioxide content to become almost zero. However, when carbon dioxide is released from a non-polar suspension, the carbon dioxide content becomes almost zero immediately after the peak of release has passed, and as a result, the energy input is greatly reduced.

[0059] The reason why less energy is required to release carbon dioxide from a nonpolar suspension and regenerate amine compounds is partly because nonpolar suspensions have a lower specific heat than polar suspensions. However, experiments have shown that the temperature at which carbon dioxide is released from carbamic acid derivatives is lower in nonpolar solvents than in polar solvents, and this finding has also contributed to the completion of this invention.

[0060] In this step (C1), the nonpolar suspension is heated under pressure, at atmospheric pressure to 20 kPa, at 100 to 150°C, preferably at atmospheric pressure to 90 kPa, at 110 to 130°C, thereby generating CO ２ This releases a substance, allowing us to obtain a nonpolar solution containing an amine compound.

[0061] Furthermore, in the present invention, in step (D1), the nonpolar solvent in the nonpolar solution of the amine compound obtained in step (C1) is replaced with a polar solvent, which is then used as a carbon dioxide absorbent in step (A1), and this can be utilized in the next step (A1).

[0062] This invention is also based on the finding that when a polar solvent is mixed with a nonpolar solution in which an amine compound is dissolved in a nonpolar solvent and allowed to stand, the amine compound migrates from the nonpolar solvent to the polar solvent, resulting in a polar solvent solution. In other words, the third important point of this invention is that by mixing and stirring a polar solvent with a nonpolar solution of an amine compound and allowing it to stand, the amine compound migrates to the polar solvent, becoming a polar solution and allowing the original carbon dioxide absorbent to be regenerated.

[0063] The nonpolar solvent that can be used in the present invention is not particularly limited as long as it can carry out steps (B1), (C1), and (D1) and the energy input in step (C1) is reduced compared to when a polar solvent is used. Preferably, it is at least one selected from the group consisting of hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, diethyl ether, cyclopentane, and cyclohexane, and more preferably, it is selected from hydrocarbons such as hexane, cyclopentane, octane, nonane, and decane.

[0064] The present invention relates to a novel CO2 separation and recovery method that includes the above-described steps (A1) to (D1). ２ This is a separation and recovery system that uses a carbon dioxide absorbent containing an amine compound to absorb CO2. ２ By absorbing CO ２ CO2 is obtained from the solid reactant, a carbamic acid derivative, which reacts with CO2. ２ By lowering the regeneration temperature during regeneration, the energy input can be reduced, and even if the solid reactants are not separated during regeneration, the energy input can be sufficiently reduced. Furthermore, the nonpolar solvent in the nonpolar solution of the amine compound remaining after carbon dioxide regeneration can be easily replaced with a polar solvent, allowing the original carbon dioxide absorbent to be regenerated. This carbon dioxide absorbent can then be used in step (A1) (step (E1)), thereby enabling the process from step (A1) to step (D1) to be repeated.

[0065] Furthermore, the carbon dioxide separation and recovery method of the present invention includes a step (F1) in which step (A1) is carried out at a first location, and the obtained polar reaction product is transported by tanker or truck to a second location where carbon dioxide is regenerated, and step (C1) can be carried out at the second location.

[0066] Furthermore, the process may also include a step (G1) in which steps (A1) and (B1) are carried out at a first location, and the resulting nonpolar reactant is transported by tanker or truck to a second location where carbon dioxide is recycled, and step (C1) is carried out at the second location. Here, the second location is, for example, a place where renewable energy can be used, and by carrying out the process at the second location, overall energy reduction can be achieved.

[0067] Furthermore, the nonpolar amine compound solution obtained in step (C1) carried out at the second location can be transported from the second location to the first location, and steps (A1) to (D1), step (F1) or step (G1), and step (H1) can be repeated.

[0068] Alternatively, steps (C1) and (D1) can be carried out at a second location, the resulting amine compound polar solution can be transported from the second location to the first location, and steps (A1) to (D1), step (F1) or step (G1), and step (H1) can be repeated.

[0069] In any case, the present invention provides a method for separating and recovering carbon dioxide, in which carbon dioxide is absorbed into a polar solution of an amine compound containing an amine compound including isophorone diamine (IPDA) and a polar solvent to obtain a polar reaction product which is a polar suspension containing solid carbamic acid, a reaction product of the amine compound and carbon dioxide, or a slurry obtained therefrom, and carbon dioxide is separated and recovered from this polar reaction product. The key point of this method is that the polar reaction product is treated with a nonpolar solvent to remove the polar solvent, resulting in a nonpolar reaction product which is a nonpolar suspension containing the reaction product and the nonpolar solvent, or a slurry obtained therefrom, and the obtained nonpolar reaction product is heated under pressure, atmospheric pressure or reduced pressure to separate and recover carbon dioxide and regenerate the amine compound from the nonpolar reaction product to obtain a nonpolar solution of the amine compound.

[0070] The present invention will be described in more detail below with reference to specific examples. However, the present invention is not limited in any way to the examples shown below. First, the results of an experiment to confirm the effects of steps (D1) and (B1) of the present invention will be described.

[0071] In the experiments and examples, isophorone diamine (IPDA) was used as the amine compound, and the reaction products with carbon dioxide were carbamic acid (CA1) and its hydrate (CA1·H ２ O) was used. In the example, when isophorone diamine (IPDA) reacted with carbon dioxide, carbamic acid (CA1) and its hydrate (CA1·H) were produced. ２ In addition to O), dicarbamic acid (CA2) and its hydrate may also be produced, but this has not been confirmed. Their chemical formulas are shown below.

[0072]

[0073]

[0074]

[0075]

[0076]

[0077] [Experimental Example] The following experiments were conducted on each step of the carbon dioxide separation and recovery method.

[0078] [Experimental Example A11] (Process (A1)) Process (A1), i.e., CO ２ The absorption process was carried out as follows: 100% CO2 was added to a 20 wt% clear IPDA aqueous solution. ２ When the gas was injected, CA1.H occurred 33 minutes later. ２ O solid precipitation caused turbidity, and after 48 minutes, the entire solution became cloudy and opaque, forming a suspension. Upon standing, CA1·H was found at the bottom of the aqueous solution. ２ O solid precipitated.

[0079] [Experimental Examples B11-B15] (Process (B1)) Process (B1), i.e., CA1·H ２ The following experiment was conducted regarding the step (B1) of replacing the water in a polar suspension containing solid O with decane to obtain a nonpolar suspension.

[0080] [Experimental Example B11] CA1・H ２When 10g of solid O, 100mL of decane, and 100mL of water are placed in a 300mL beaker and stirred with a stirrer for 2-3 minutes, then allowed to stand, CA1·H is produced. ２ The solid O floats at the interface between the decane layer and the aqueous layer, with the decane layer and CA1·H from above. ２ It was found to form a three-layer structure of solid layer, aqueous layer, and O. As shown in [Experimental Example A11], originally CA1·H ２ Since solid O precipitates in water, this unusual phenomenon is thought to be due to the effect of decane. The principle is CA1·H ２ Because the solid O is lipophilic, CA1·H ２ It is thought that the solid O becomes lighter in specific gravity when it is coated with decane, causing it to float on water. Due to this property, CA1·H can be filtered through a mesh like a tea strainer. ２ O means such as scooping up the solid or draining only the water layer from below, CA1・H ２ This makes it easier to replace the solvent in solid O from water to decane.

[0081] [Experimental Example B12] This experiment is for the purpose of using a centrifuge in process (B1). Using a centrifuge is effective in quickly eliminating bubbles generated by excessive stirring during process (B1) and in shortening the time required for separation.

[0082] CA1・H ２ 4 g of solid O, 40 mL of water, and 40 mL of decane were placed in a glass container for a centrifuge, shaken by hand, and then centrifuged at 1000 RPM for 10 minutes. The changes before and after the centrifugation were observed. To improve visibility, the aqueous layer was colored blue with food coloring, and the same procedure was performed and observed again. From the color observation, CA1·H was identified. ２ It was found that the O solid was floating on the surface of the lower water layer rather than sinking into the upper Deccan layer.

[0083] [Experimental Example B13] Based on [Experimental Example A11] and [Experimental Example B11], CA1・H ２ Since it was found that solid O preferentially coats with decane rather than water, a mixture of water and decane was used to form CA1·H ２ Simply washing the solid O easily produces CA1·H ２It is thought that the solvent in solid O can be replaced from water to decane.

[0084] Using a tea strainer with a mesh size of about 1 mm, mix 100 mL of decane, 100 mL of water, and CA1·H. ２ When the mixture of 10g of solid O was filtered 3 or 4 times, CA1·H ２ It was found that most of the solid O was captured by the tea strainer, allowing only the liquid to be separated. When the mixed solution of water and decane that passed through the tea strainer was separated using a separatory funnel and weighed, it was found that there was 79.4 g of water (81.2% of the total water volume) and 35.3 g of decane (49.4% of the total decane volume). From these measurement results, it was also found that CA1·H ２ The solid O tends to surround itself with decane more than water, and the combination of water and decane creates CA1·H ２ Simply by mixing in solid O, CA1·H ２ It was found that the substitution of water with decane was completed to some extent in the O solid.

[0085] [Experimental Example B14] 100 mL of water, 100 mL of decane, CA1·H ２ A mixture of 10g of solid O was filtered by suction, and both water and decane were separated into CA1·H. ２ O was removed from the solid. At this time, 95.0 g of water (95.7% of the total amount of water) and 67.3 g of decane (93.5% of the total amount of decane) were added to CA1·H ２ It was possible to remove O from the solid. Since both water and decane were removed to roughly the same extent, it was found that simple suction filtration preferentially removes only water, making it difficult to replace water with decane.

[0086] [Experimental Example B15] To solve the problems of [Experimental Example B14], a chromatographic tube was used and a plug flow was performed using 100 mL of decane, 100 mL of water, and CA1·H. ２ Only the aqueous layer was pushed out from a mixture containing 10g of solid O. After standing for one hour, 88.5g of water (83.2% of the total water volume) was discharged by gravity alone, and not a single drop of decane was discharged. From this, it was found that the plug flow method is a promising means of replacing water with decane.

[0087] [Experimental Example C11] (Process (C1)) Process (C1), i.e., CO ２The following experimental examples were conducted regarding the release of [the substance].

[0088] In this experiment, under atmospheric pressure, CA1·H ２ By heating a decane solvent, aqueous solvent, or IPDA solvent containing a solid O, CO ２ It releases CA1-H ２ The experiment involves regenerating IPDA from solid O. The experimental procedure is as follows: 1. CA1·H ２ Add a suspension containing 10 g of solid O and 100 mL of decane solvent, aqueous solvent, or IPDA solvent to a three-necked flask. Record the temperature inside the flask with a data logger. Stir the contents of the three-necked flask. 2. Set the oil bath temperature to 150°C. 3. Sweep gas N ２ Blow in 450 mL / min, and the CO2 is the outlet gas from the three-necked flask. ２ The concentration is measured using Vaisala CARBOCAP (registered trademark) GMP251 CO ２ Monitor with a probe. 4. Confirm that the oil bath temperature has reached 150°C, and immerse the three-necked flask up to its neck. 5. CO ２ From the probe's real-time measurement data, CO ２ The experiment will be concluded once the release has subsided.

[0089] The solvent temperature inside the three-necked flask and the CO2 in the outlet gas obtained from the experiment ２ Time-series data of concentration are shown in Figures 1 and 2. Figure 1 compares the experimental results for the decane solvent case and the aqueous solvent case, and Figure 2 compares the experimental results for the decane solvent case and the IPDA solvent case. IPDA was used as the solvent in the experiment because, with aqueous solvent, the boiling point of water is 100°C, so the temperature rise stagnation could not be observed. Therefore, the same experiment was conducted with IPDA as the solvent to observe this.

[0090] When using the decane solvent, a temperature rise plateau associated with the phase transition was observed at approximately 120°C when heated to 150°C (Figures 1 and 2). On the other hand, no temperature rise plateau associated with the phase transition was observed when using the IPDA solvent (Figure 2). Therefore, CA1·H ２The temperature at which IPDA is regenerated from solid O is thought to be lower in the decane solvent compared to the IPDA solvent. In the case of the aqueous solvent, the temperature rise stops at 100°C, which is the boiling point of water, so CO ２ The release rate of CO decreased compared to when using decane solvent (Figure 1). However, in aqueous solvent, ２ After the peak of CO emissions, ２ The rate of decrease in CO concentration slows down, ２ It was found that it takes a considerable amount of time for the concentration to become zero. CO in the case of decane solvent ２ The release rate is CO2 in the case of IPDA solvent. ２ Faster than the emission rate of CO ２ Immediately after the peak of CO emissions, ２ The concentration of the substance became almost zero, demonstrating that nonpolar solvents are superior to polar solvents in regeneration (Figure 2).

[0091] When IPDA is used as a solvent, CO2 is regenerated by heating. ２ The volatile IPDA recombined and adhered to the top of the three-necked flask as a white deposit or transparent crystals. On the other hand, when decane was used as the solvent, no such white deposit due to recombination was observed on the top of the three-necked flask. This is because nonpolar solvents, compared to polar solvents, ２ This is thought to be because it inhibits absorption, i.e., recombination. Thus, from the perspective of practical processes, decane solvents were found to be superior to IPDA solvents.

[0092] [Experimental Example] (Process (D1)) The following experiment was conducted regarding process (D1), that is, the replacement of the solvent from decane to water in a decane solution containing IPDA.

[0093] [Experimental Example D11] When 100 mL of water was added to a completely mixed solution of 100 mL of IPDA and 100 mL of decane, it was observed that the solution separated into two layers: an upper decane layer and a lower aqueous layer. It is thought that the IPDA was distributed and dissolved in each layer. When only the aqueous layer was separated using a separatory funnel and its weight was measured, it was 186.4 g. Therefore, it was found that 98.0% by weight of the IPDA that was completely mixed with decane moved to the aqueous layer. From this, it can be concluded that IPDA is soluble in both polar and nonpolar solvents, but has a higher affinity for polar solvents. Due to this characteristic, it is possible to easily replace decane containing IPDA with water.

[0094] [Experimental Example D12] We investigated whether nonpolar solvents other than decane containing IPDA, as well as the polar solvent acetone, could be easily replaced with water by adding water, using the following procedure.

[0095] • Experimental Procedure 1. Add 2 ml each of the nonpolar solvents toluene, cyclopentane, hexane, heptane, n-octane, and decane to 2 ml of IPDA. Mix all thoroughly. 2. Add 2 ml of water to the sample and check if it separates. 3. Further CO ２ Blow in the mixture and check if a solid is formed.

[0096] Observing these results, it was found that in the case of acetone, a polar solvent, no two phases were formed when water was added. In the case of nonpolar solvents, water always settled at the bottom, forming two phases. The larger volume was the lower water tank, indicating that in both cases, IPDA was largely distributed in the nonpolar solvent. From this, it was confirmed that hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, cyclopentane, and cyclohexane can be used similarly as nonpolar solvents.

[0097] Note that each sample except for acetone is CO ２ The turbidity was confirmed by blowing the solution into the solution. This blowing test confirmed that the IPDA had not been deactivated.

[0098] [Example] (1) Step (A1), i.e., CO ２Absorption step: IPDA is used as the amine compound and water as the polar solvent. 600 g of an aqueous solution of IPDA containing 10 wt% IPDA is prepared and then converted to CO2. ２ Use as an absorbent. Compress air (CO2) ２ CO2 is released at a concentration of 0.04 vol% at room temperature and pressure at a rate of 500 mL / min. ２ It absorbs the fumes. CA1·H occurs approximately 102 hours after ventilation begins. ２ O solid precipitation begins, causing the IPDA aqueous solution to become cloudy and precipitate. CO in the supplied air continues for at least 212 hours from the start of aeration. ２ The entire amount has been absorbed, CO ２ This was confirmed by measuring the total organic carbon (TOC) of the absorbent. CO2 after 212 hours ２ CO absorbed by the absorbent ２ The total amount is CO2 per 1 mol of IPDA. ２ Since it is known to absorb 1 mol, the measurement was found to be about 1 / 3 of the maximum absorption amount. Therefore, the CO2 absorption period was about three times the 212 hours, i.e., about 650 hours. ２ This is an estimate of the ventilation time required for absorption saturation.

[0099] (2) Step (B1), i.e., the substitution step from polar solvent to nonpolar solvent: Add 500 mL of decane, a nonpolar solvent, to the polar suspension containing the carbamic acid derivative precipitated in the polar solvent in step (A1) and stir with a stirrer at 200 RPM for about 1 minute. Upon standing, the decane layer, which is the nonpolar solvent, separates to the upper layer and the aqueous layer, which is the polar solvent, separates to the lower layer, and CA1·H is found at the interface between them. ２ The solid O floats. This decane-CA1·H ２ The solid-water mixture is placed in a chromatography tube, and only the water at the bottom is drained. This single operation removes approximately 83 wt% of the total water volume without losing almost any decane. After this, the mixture is stirred again, and the operation of draining the water in a plug-flow manner in the chromatography tube after the decane-water phase separation is repeated twice. Calculations show that more than 99 wt% of the water can be removed, completing the solvent replacement from water to decane.

[0100] For comparison, CO2 in aqueous solvent ２Compared to the case of regenerating CO ２ To play it, use CA1-H ２ While it is desirable to remove water from the solid, this process, such as dewatering with a filter press, is complicated and energy-intensive. An example of a commercially available filter press catalog value is approximately 56 L of cake capacity and 4.8 m² of dewatering area. ２ The required power is 2.3 kW in total, consisting of a 1.5 kW dewatering pump, a 0.4 kW hydraulic pump, and a 0.4 kW plate-opening motor. When using decane solvent for regeneration, this input energy can be almost eliminated by using the aforementioned water-to-decane substitution method.

[0101] (3) Process (C1), i.e., CO ２ Regeneration process: CA1·H obtained by replacing water with decane in process (B1). ２ The decane containing solid O is heated to 120°C under atmospheric pressure while being stirred with a stirrer, and CA1·H ２ O solids IPDA and CO ２ It regenerates. When the temperature of the decane reaches 84.9°C, CO ２ Bubbles are generated, and the bubbles become more intense at 116°C, so 120°C is CO ２ This temperature is considered suitable for regeneration.

[0102] Decane 100 mL, CA1·H ２ When 10 g of solid CO2 is heated in an oil bath at 150°C under normal pressure, 0.93 g of CO2 is produced in 25 minutes. ２ The regeneration process was completed, during which the temperature was raised from 25°C to 145°C. The specific gravity of decane was 0.73 g / cc, the molecular weight of decane was 142.29, and the specific heat of decane was 315.46 JK-1 mol. -１ Therefore, the energy invested for regeneration can be estimated to be 1.9 kJ.

[0103] For comparison, let's consider the case of water, under the same pressure, heating conditions, and the same CA1·H. ２ The weight of the solid and the volume of the solvent are the same, and 0.93 mol of CO2 is present. ２The regeneration process took more than 80 minutes. Therefore, by approximation, multiplying 1.94 kJ by the value 80 / 25, the energy input for regeneration was 6.1 kJ, which is more energy required than in the case of decane.

[0104] CO2 in the same 25-minute period ２ Comparing the release amounts, the decane solvent releases 0.93 mol, while the aqueous solvent releases 0.46 mol, meaning the decane solvent releases approximately twice as much CO2 in the same amount of time. ２ It was discovered that it could be reproduced.

[0105] (4) Step (D1), i.e., the substitution step from a nonpolar solvent to a polar solvent: Water is added to the decane solution of IPDA produced in step (C1) to move the IPDA from the decane phase to the aqueous phase and separate the decane phase. Specifically, an amount of water equivalent to that used in the first step (A1), i.e., 540 g, is added to the decane containing IPDA. Before adding water, the IPDA and decane are completely mixed, but after adding water and stirring for about 1 minute, stirring is stopped and it is allowed to stand for 1 minute to separate into an upper decane layer and a lower aqueous layer. Since IPDA is hydrophilic, 98.0 wt% of the IPDA is immediately distributed to the aqueous layer by this operation, and the remaining 2.0 wt% is distributed to the decane layer. Only the lower IPDA aqueous solution could be extracted using a chromatography tube.

[0106] (5) Step (E1): The aqueous solution of IPDA obtained in step (D1) was returned to step (A1), and the decane, a nonpolar solvent, was returned to step (B1), and steps (A1) to (D1) were repeated multiple times.

[0107] This invention is CO ２ Fixation, CO ２ CO2 recovery ２ It can be used in all areas of transportation.

Claims

1. A process (A1) of obtaining a polar reactant, which is a polar suspension or a slurry obtained therefrom, by absorbing carbon dioxide in an amine compound polar solution containing an amine compound represented by the following formula (1) to precipitate a solid reactant of the amine compound and the carbon dioxide in the amine compound polar solution; a process (B1) of treating the polar reactant obtained in the process (A1) with a nonpolar solvent to remove the polar solvent to obtain a nonpolar reactant, which is a nonpolar suspension or a slurry obtained therefrom, containing the solid reactant and the nonpolar solvent; a process (C1) of heating the nonpolar reactant obtained in the process (B1) under pressure, normal pressure or reduced pressure to separate and recover carbon dioxide and regenerate the amine compound from the nonpolar reactant to obtain an amine compound nonpolar solution; and a process (D1) of treating the amine compound nonpolar solution obtained in the process (C1) with a polar solvent to replace the solvent to obtain an amine compound polar solution. A method for separating and recovering carbon dioxide. However, in the formula, m is 0 or 1; R １ and R ２ are each independently an alkyl group, an alkoxy group, a carboxy group, an alkyloxycarbonyl group, a formyl group, an alkylcarbonyl group, an alkylthio group, a sulfo group, an alkyloxysulfonyl group, a nitro group, a hydroxyl group, a thiol group, a cyano group or a halogen atom, and the alkyl group may have a substituent; p １ and p ２ are each independently 1 or 2; when m is 0, q １ is an integer from 0 to 11, provided that p １ + q １ is 12 or less; when m is 1, q １ is an integer from 0 to 10, provided that p １ + q １ is 11 or less; q ２ is an integer from 0 to 10; when q １ is an integer of 2 or more, two or more R １ may be the same as or different from each other; when q ２ is an integer of 2 or more, two or more R ２ may be the same as or different from each other; q １ If is an integer greater than or equal to 2, and there are two or more R １ If the alkyl group may have substituents, then the two or more R １ They may be bonded to each other to form a ring, q ２ If is an integer greater than or equal to 2, and there are two or more R ２ If the alkyl group may have substituents, then the two or more R ２ They may be bonded to each other to form a ring. However, m is 0 and p １ Since is 2, p １ Except when the two amino groups with the notation are positioned at the meta position relative to each other.

2. The method for separating and recovering carbon dioxide according to claim 1, wherein the amine compound polar solution obtained in step (D1) is used as the amine compound polar solution in step (A1), and step (E1) is repeated from step (A1) to step (D1).

3. The method for separating and recovering carbon dioxide according to claim 1 or 2, wherein in step (B1), a suspension or slurry is used as the polar reactant, the nonpolar solvent is mixed thereto, and then the polar solvent is separated and removed to obtain the nonpolar reactant.

4. In step (C1), the nonpolar reactant is heated to 100-150°C under a pressure of atmospheric pressure to 20 kPa to produce CO2 ２ A method for separating and recovering carbon dioxide according to any one of claims 1 to 3, comprising releasing and obtaining a nonpolar solution of the amine compound.

5. The method for separating and recovering carbon dioxide according to any one of claims 1 to 4, wherein in step (D1), a polar solvent is mixed with the nonpolar solution of the amine compound to transfer the amine compound to the polar solvent, and then the nonpolar solvent is separated and recovered to obtain the polar solution of the amine compound.

6. The method for separating and recovering carbon dioxide according to any one of claims 1 to 5, wherein the polar solvent is at least one selected from the group consisting of water, methanol, ethanol, acetone, and dimethyl sulfoxide (DMSO).

7. The method for separating and recovering carbon dioxide according to any one of claims 1 to 6, wherein the nonpolar solvent is at least one selected from the group consisting of hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, diethyl ether, cyclopentane, and cyclohexane.

8. The method for separating and recovering carbon dioxide according to any one of claims 1 to 7, wherein the amine compound comprises at least one selected from monoxylenediamine (MXDA), paraxylenediamine (PXDA), and isophoronediamine (IPDA).

9. The method for separating and recovering carbon dioxide according to claim 8, wherein the solid reactant includes solid carbamic acid.

10. A method for separating and recovering carbon dioxide according to any one of claims 1 to 9, comprising the step (A1) being carried out at a first location, the step (F1) being transported to a second location where carbon dioxide is regenerated, and the step (C1) being carried out at the second location.

11. A method for separating and recovering carbon dioxide according to any one of claims 1 to 10, comprising the steps (A1) and (B1) above to be performed at a first location, the step (G1) of transporting the obtained nonpolar reactant to a second location where carbon dioxide is regenerated, and the step (C1) above to be performed at the second location.

12. A method for separating and recovering carbon dioxide according to claim 10, comprising the step (H1) of transporting the nonpolar solution of the amine compound obtained in step (C1) or the polar solution of the amine compound obtained in step (D1) from the second location to the first location, and repeating steps (A1) to (D1), steps (F1) and (H1).

13. A method for separating and recovering carbon dioxide according to claim 11, comprising step (H1) of transporting the nonpolar solution of the amine compound obtained in step (C1) or the polar solution of the amine compound obtained in step (D1) from the second location to the first location, wherein if the nonpolar solution of the amine compound obtained in step (C1) is transported, after performing step (D1), steps (A1) to (D1), steps (G1) and (H1) are repeated.

14. The method for separating and recovering carbon dioxide according to any one of claims 10 to 13, wherein in the step (C1) performed at the second location, renewable energy is used for the heating step.

15. The method for separating and recovering carbon dioxide according to any one of claims 10 to 13, wherein the amine compound used is an amine compound comprising at least one selected from monoxylenediamine (MXDA), paraxylenediamine (PXDA), and isophoronediamine (IPDA), and the polar solvent used is water.

16. The method for separating and recovering carbon dioxide according to any one of claims 10 to 13, wherein at least one selected from the group consisting of hexane, heptane, octane, nonane, decane, benzene, toluene, xylene, diethyl ether, cyclopentane, and cyclohexane is used as the nonpolar solvent.

17. A method for regenerating carbon dioxide, comprising: absorbing carbon dioxide into a polar solution of an amine compound containing at least one selected from monoxylenediamine (MXDA), paraxylenediamine (PXDA), and isophoronediamine (IPDA) and a polar solvent to obtain a polar reaction product which is a polar suspension or slurry containing solid carbamic acid, which is a reaction product of the amine compound and the carbon dioxide; and regenerating carbon dioxide from this polar reaction product, wherein the polar reaction product is treated with a nonpolar solvent, the polar solvent is removed to obtain a nonpolar reaction product which is a nonpolar suspension or slurry containing the reaction product and the nonpolar solvent; the polar reaction product is treated with a nonpolar solvent, the polar solvent is removed to obtain a nonpolar reaction product which is a nonpolar suspension or slurry containing the reaction product and the nonpolar solvent; and heating the obtained nonpolar reaction product under pressure, atmospheric pressure or reduced pressure to separate and recover carbon dioxide and regenerate the amine compound from the nonpolar reaction product to obtain a nonpolar solution of the amine compound.

18. The method for regenerating carbon dioxide according to claim 17, wherein the polar solvent is at least one selected from the group consisting of water, methanol, and ethanol, and the nonpolar solvent is at least one selected from the group consisting of toluene, hexane, heptane, n-octane, nonane, decane, cyclopentane, and cyclohexane.

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