JP2015077561A - Carbon dioxide absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carbon dioxide absorber capable of desorbing absorbed carbon dioxide without being heat-treated and capable of being used repeatedly.SOLUTION: There is provided the carbon dioxide absorber containing as a principal component a polymer represented by the general formula [Formula 1], where X represents a hydrocarbon atom selected from among -CH-, -CH=CH-CH- and -C(CH)=CHCH-, Y represents a hydrocarbon atom selected from among -CH-, -CH(CH)-, -CH(CH)-, -CH=CH-CH- and -C(CH)=CHCH- and Y may be same and p and q represent average numbers of repeat and a ratio of p and q, p:q=20:1 to 1:1. The carbon dioxide absorber has a plurality of vacancies.

Description

The present invention relates to a carbon dioxide absorber capable of absorbing carbon dioxide (CO ₂ ) contained in a gas and desorbing the carbon dioxide.

  In recent years, the occurrence of climate change and disasters caused by global warming has become one of the serious environmental problems. This global warming is considered to be the release of so-called greenhouse gases into the atmosphere. Carbon dioxide is the most important greenhouse gas. Sources of carbon dioxide include thermal power plants, steelworks blast furnaces, cement plant kiln furnaces, and transportation equipment such as automobiles and aircraft. A method for separating and recovering carbon dioxide contained in these exhaust gases and appropriately processing the carbon dioxide is desired.

On the other hand, carbon dioxide is being considered for industrially effective use in agriculture and biotechnology. For example, attempts have been made to increase the yield by actively applying carbon dioxide in farms and plant factories using the assimilation of plants. More recently, there has been an example in which carbon dioxide is actively applied to an aqueous solution for culturing specific algae for the purpose of producing health supplements and bioethanol.

  Several methods have been known for materials for separating and recovering carbon dioxide in gas, and various materials have been studied today.

  Patent Document 1 discloses a carbon dioxide absorbent and a carbon dioxide removal method capable of removing carbon dioxide in exhaust gas by using a mixed aqueous solution of secondary amine and tertiary amine at a predetermined concentration or higher, contacting exhaust gas with the mixed aqueous solution. Is described.

  Patent Document 2 is composed of a porous body carrying an amine or amine / polyol in an embodiment thereof, contacting carbon dioxide-containing gas to absorb carbon dioxide, and subsequently heating to 120 ° C. It describes a solid absorbent that can separate and recover carbon dioxide periodically by desorbing carbon dioxide.

  Patent Document 3 discloses a porous body composed of a lithium composite oxide and an alkali metal carbonate, which is brought into contact with a gas at 550 ° C. containing carbon dioxide, captures carbon dioxide, and further heats to remove carbon dioxide. It describes a carbon dioxide absorbent that can be separated, separated and recovered.

If these absorbents are used to absorb carbon dioxide from exhaust gas, and the absorbent can be used as it is as a carbon dioxide supply source for the growth of photosynthetic organisms in the field of agriculture and biotechnology, it is highly significant in reducing carbon dioxide in the atmosphere. it is conceivable that. For this purpose, a carbon dioxide absorbent that can absorb and release carbon dioxide at normal temperature and pressure and can be used repeatedly is desirable.

However, both of the absorbents of Patent Documents 1 and 2 use amine compounds as the main components that absorb carbon dioxide, and these amines chemically adsorb carbon dioxide, so that the absorbed carbon dioxide is removed. Heat treatment was required to release and regenerate the absorbent material. In addition, these absorbent materials have a low carbon dioxide desorption rate, and a part of amine is volatilized or deteriorated by heat regeneration treatment. In addition, amine is eluted in a high humidity environment or in water, so the balance between absorption and desorption. However, there was a problem that the performance deteriorated with repeated use.

Since the carbon dioxide absorbent using ceramics as in Patent Document 3 undergoes a reaction of absorption and desorption of carbon dioxide at several hundred degrees, it has been necessary to heat-treat to that temperature range. Moreover, when it reacts with carbon dioxide, a film of a product is formed on the surface, the reaction efficiency gradually decreases, and there is a problem that the performance deteriorates in repeated use.

Japanese Patent No. 3197183 Special table 2010-500168 JP 2008-221165 A

An object of this invention is to provide the carbon dioxide absorber which can desorb | suck the absorbed carbon dioxide and can be used repeatedly, without performing heat processing.

（式中、Ｘは−ＣＨ_２−、−ＣＨ＝ＣＨ−ＣＨ_２−、−Ｃ（ＣＨ_３）＝ＣＨＣＨ_２−から選ばれる炭化水素基を表し、Ｙは−ＣＨ_２−、−ＣＨ（ＣＨ_３）−、−ＣＨ（Ｃ_６Ｈ_５）−、−ＣＨ＝ＣＨ−ＣＨ_２−、−Ｃ（ＣＨ_３）＝ＣＨＣＨ_２−から選ばれる炭化水素基を表し、XとYは同一であっても良く、ｐおよびｑは繰り返しの平均数を表し、ｐとｑの比ｐ：ｑ＝２０：１〜１：１である。） As a result of intensive research, the present inventors have conducted heat treatment if a carbon dioxide absorber comprising a polymer having a specific structure as a main component and having a plurality of pores is used. It was found that the absorbed carbon dioxide can be desorbed and can be used repeatedly. That is, the carbon dioxide absorber of the present invention is mainly characterized by having a polymer represented by the general formula [Chemical Formula 1] as a main component and having a plurality of pores. Here, the main component refers to what is contained most in the polymer in the composition.

(Wherein X represents a hydrocarbon group selected from —CH ₂ —, —CH═CH—CH ₂ —, —C (CH ₃ ) ═CHCH ₂ —, and Y represents —CH ₂ —, —CH (CH ₃ ) — represents a hydrocarbon group selected from —CH (C ₆ H ₅ ) —, —CH═CH—CH ₂ —, —C (CH ₃ ) ═CHCH ₂ —, and X and Y are the same. P and q represent the average number of repetitions, and the ratio of p to q is p: q = 20: 1 to 1: 1.)

Furthermore, in the carbon dioxide absorber of the present invention, the polymer is at least one of natural rubber, isoprene rubber, butadiene rubber, ethylene-propylene rubber, styrene-butadiene rubber, and polyethylene.

When the volume of the polymer is A and the volume of the pores is B, B / A is 3 to 13.

Furthermore, in the carbon dioxide absorber of the present invention, the polymer contains at least one kind of porous particles selected from zeolite and charcoal.

  The carbon dioxide absorber of the present invention can desorb absorbed carbon dioxide without using a process such as heating, and can be used repeatedly.

FIG. 1 is an enlarged cross-sectional view of a carbon dioxide absorber according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of still another configuration example of the carbon dioxide absorber.

  Hereinafter, although the carbon dioxide absorber which concerns on embodiment of this invention is demonstrated with reference to drawings, this invention is not limited to the following embodiment.

（式中、Ｘは−ＣＨ_２−、−ＣＨ＝ＣＨ−ＣＨ_２−、−Ｃ（ＣＨ_３）＝ＣＨＣＨ_２−から選ばれる炭化水素基を表し、Ｙは−ＣＨ_２−、−ＣＨ（ＣＨ_３）−、−ＣＨ（Ｃ_６Ｈ_５）−、−ＣＨ＝ＣＨ−ＣＨ_２−、−Ｃ（ＣＨ_３）＝ＣＨＣＨ_２−から選ばれる炭化水素基を表し、XとYは同一であっても良く、ｐおよびｑは繰り返しの平均数を表し、ｐとｑの比ｐ：ｑ＝２０：１〜１：１である。） As shown in FIG. 1, the carbon dioxide absorber 1 of the present embodiment has a polymer 2 represented by the general formula [Chemical Formula 1] as a main component and a plurality of holes 3.

(Wherein X represents a hydrocarbon group selected from —CH ₂ —, —CH═CH—CH ₂ —, —C (CH ₃ ) ═CHCH ₂ —, and Y represents —CH ₂ —, —CH (CH ₃ ) — represents a hydrocarbon group selected from —CH (C ₆ H ₅ ) —, —CH═CH—CH ₂ —, —C (CH ₃ ) ═CHCH ₂ —, and X and Y are the same. P and q represent the average number of repetitions, and the ratio of p to q is p: q = 20: 1 to 1: 1.)

When such a carbon dioxide absorber 1 is brought into contact with an atmosphere having a higher carbon dioxide concentration than in the holes 3, the carbon dioxide in the atmosphere can be absorbed into the holes 3. Subsequently, carbon dioxide can be desorbed even at room temperature without being heated by contacting with an atmosphere having a low carbon dioxide concentration such as air.

The above behavior is that polymer 2 has a chemical structure mainly composed of hydrocarbons, is a low-polarity polymer with a small charge bias, has a particularly high affinity with carbon dioxide, and has elasticity. It is thought to originate from.

That is, when the carbon dioxide absorber 1 comes into contact with the internal pores 3 and the atmosphere having different carbon dioxide concentrations, the osmotic pressure generated from the difference in carbon dioxide concentration in the pores 3 is used as a driving force to make the contacted atmosphere and pores. The movement of carbon dioxide occurs between the three. Accordingly, it is considered that the holes 3 expand and contract, and as a result, the ability to absorb and desorb carbon dioxide is developed.

Since the polymer 2 is not irritating to the human body and animals and plants, the carbon dioxide absorber 1 has low toxicity.

Further, since the polymer 2 is insoluble in water, the carbon dioxide absorber 1 can be used by being submerged in water.

The carbon dioxide absorber 1 can be used repeatedly because it does not cause irreversible reaction or deterioration in the application of absorbing and desorbing carbon dioxide.

Thus, the carbon dioxide absorber 1 of the present embodiment has an advantage that the absorbed carbon dioxide can be desorbed and used repeatedly without using a process such as heating. . In addition, since it is low in toxicity and insoluble in water, there is no danger of contaminating the growth environment of photosynthetic organisms, and carbon dioxide absorbed from exhaust gas can be desorbed into water. doing.

Since the carbon dioxide absorber 1 is accompanied by expansion / contraction of the pores 3 in the absorption / desorption of carbon dioxide, the polymer 2 is preferably a polymer having high stretchability.

Specific examples of the polymer represented by the general formula [Chemical Formula 1] include natural rubber, isoprene rubber, butadiene rubber, ethylene-propylene rubber, styrene-butadiene rubber, polyethylene and the like.

Among these, natural rubber has the most stretchability, and the carbon dioxide absorber 1 having this as the main component is excellent in the expansibility and contractibility of the pores 3. Furthermore, natural rubber is a material obtained from the sap of rubber trees, and uses carbon dioxide in the atmosphere as a carbon source. Therefore, the more it is used in industrial applications, the more fixed the carbon dioxide. That is, from the viewpoint of effective use of carbon dioxide and contribution to the environment, it has industrial use value not found in other polymers.

Natural rubber is the most preferred material because it is biodegradable, has extremely low toxicity to living organisms, and even if it is discarded and burned does not directly cause an increase in carbon dioxide.

Specific examples other than natural rubber are all synthetic polymers, and differ in that hydrocarbons obtained from petroleum resources are used as raw materials. However, since physical properties such as stretchability and affinity with carbon dioxide are similar to natural rubber, the same carbon dioxide absorbent 1 can be obtained when used as the polymer 2.

The polymer 2 is given elasticity by being partially crosslinked by vulcanization. Vulcanization is performed by mixing a rubber with a vulcanizing agent such as sulfur or peroxide and heating. Moreover, a vulcanization accelerator etc. may be mix | blended as needed.

In addition, a small amount of a softening agent, a processing aid, an antiaging agent, a filler and the like may be blended with the polymer 2 as necessary as long as the physical properties are not impaired.

The chemical structure of polymer 2 can be identified by analysis of functional group peaks by infrared absorption spectrum or qualitative analysis of decomposition products by pyrolysis gas chromatography. Also, a combination of nuclear magnetic resonance ^{(1 H-NMR, 13 C} -NMR) in the case of a detailed linkage structure analysis can be analyzed.

The pores 3 are formed by a method in which a polymer solution before vulcanization is stirred with a mixer or the like, a method in which a gas such as air is fed into the polymer solution, or a gas generating substance is added to the polymer solution and thermally decomposed. A method of forming the holes 3 and other known methods can be used. Moreover, the volume of the void | hole 3 part can be further increased by apply | coating a latex liquid thinly and covering the hole of the surface thinly on the carbon dioxide absorber 1 whole surface formed.

Most of the holes 3 are completely covered with the polymer and are spatially closed. Thereby, a partial pressure difference of carbon dioxide is generated between the atmosphere to be brought into contact with the inside of the hole 3, and this can be used as a driving force to absorb and desorb carbon dioxide. Although there are no holes in the pores 3 that allow carbon dioxide to freely pass back and forth, the inside of the pores 3 can be diffused by spreading a small gap created by the thermal motion of the polymer polymer chain. It is thought that it can move outside.

The shape of the hole 3 is represented by a sphere in FIG. 1, but may not be a sphere. In the carbon dioxide absorber 1, the volume ratio of the polymer 2 portion and the pore 3 portion can be adjusted by, for example, the magnification when foaming. When the volume of the polymer part is A, the volume of the hole 3 part is B, and the volume ratio of the hole 3 is represented by B / A, the volume ratio of the hole 3 is preferably about 3 to 13. If the volume ratio is less than 3, carbon dioxide cannot be taken in sufficiently. On the other hand, if the volume ratio is greater than 13, it is difficult to foam, and it is difficult to produce the carbon dioxide absorber 1.

The volume ratio between the polymer 2 portion and the pore 3 portion can be calculated from the polymer density and the volume of the carbon dioxide absorber 1. The volume of the carbon dioxide absorber 1 can be obtained as an increase in volume of the liquid when the carbon dioxide absorber 1 is submerged in a liquid such as water.

FIG. 2 shows still another configuration example of the carbon dioxide absorber 1. The carbon dioxide absorber 1 in FIG. 2 has a polymer 2 represented by the general formula [Chemical Formula 1] as a main component, has a plurality of pores 3, and further includes porous particles 4.

By adding the porous particles 4 to the polymer 2, the carbon dioxide absorption / desorption amount of the carbon dioxide absorber 1 can be increased.

This is thought to be due to the following phenomenon. That is, in an atmosphere with a high carbon dioxide concentration such as exhaust gas, carbon dioxide is absorbed into the holes 3 as described above. At this time, the porous particles 4 desorb and absorb carbon dioxide from the neighboring holes 3. Since the carbon dioxide concentration in the holes 3 is lowered by the amount of adsorption, carbon dioxide is further absorbed into the holes 3 from the outside atmosphere. Since this phenomenon occurs continuously until the carbon dioxide adsorption amount of the porous body 4 reaches equilibrium, the carbon dioxide absorption amount of the carbon dioxide absorber 1 can be increased.

Thereafter, when the atmosphere is moved to a low carbon dioxide concentration, carbon dioxide is desorbed from the holes 3 to the external atmosphere as described above. Since the carbon dioxide concentration in the pores 3 is reduced by the amount of desorption, carbon dioxide is supplied from the neighboring porous particles 4 to the pores 3. Since this phenomenon occurs continuously until equilibrium is reached, the amount of carbon dioxide desorbed also increases.

The material of the porous particles 4 can be confirmed by creating a cross section of a part of the carbon dioxide absorber 1 using a cross section sampler such as a cross section polisher and observing it with an electron microscope with an elemental analysis function. .

Examples of the material of the porous particles 4 include zeolite and charcoal. Zeolite includes molecular sieves and the like, and those that are commercially available in pellet form can be made into particles by pulverization and used. Charcoal includes charcoal such as Bincho charcoal, in addition to activated carbon, and charcoal that can be used by pulverization.

About the particle size of the porous particle 4 obtained by the grinding | pulverization process, the thing of arbitrary ranges can be obtained using a mesh from which a sieve and the number of eyes differ. Further, the particle size distribution can be known by performing observation with a particle size distribution meter or an optical microscope.

Although these porous particles 4 are used alone as an adsorbent, they have poor selectivity for adsorbed molecules. For example, if they are used as they are in exhaust gas, moisture, ammonia, nitrogen oxides, sulfur oxides, etc., other than carbon dioxide Even gas and particles will be adsorbed. In order to desorb the adsorbed molecules, the porous particles 4 need to be heated or decompressed.

However, in this embodiment, since the porous particles 4 are included in the carbon dioxide absorber 1 and the exhaust gas and the porous particles 4 are not in direct contact with each other, carbon dioxide is prioritized using the properties of the polymer. Can be adsorbed on the porous particles 4. Furthermore, the amount of carbon dioxide absorbed and desorbed increases without operations such as heating and decompression.

The blending amount of the porous particles 4 is preferably 8 to 33% by mass with respect to the polymer 2. If the amount is less than 8% by mass, the effect of improving the adsorption / desorption performance of carbon dioxide cannot be sufficiently obtained. If the amount is more than 33% by mass, the viscosity increases in the production process, and the volume ratio of the pores 3 is set to a desired value. It becomes difficult.

Regarding the amount of carbon dioxide absorption and desorption, the amount of carbon dioxide absorption and desorption can be measured by monitoring the concentration change of the atmosphere in contact with a carbon dioxide concentration meter. In addition, by simply measuring the change in mass of carbon dioxide, the amount of carbon dioxide absorbed and desorbed can be roughly confirmed.

The amount of carbon dioxide desorbed in water can be measured by increasing the amount of carbonate ion or bicarbonate ion by immersing the carbon dioxide absorber 1 in water, collecting water after a certain period of time, and performing ion chromatography. it can. It can also be measured by neutralization titration using an indicator.

Next, although this invention is demonstrated using an Example, this invention is not limited to these Examples.

(Production of carbon dioxide absorber)
[Example 1]
In a general formula [Chemical Formula 1], 10 g of a natural rubber latex liquid (manufactured by Hyratech, solid content concentration 60%) mainly composed of a polymer having X and Y of —C (CH ₃ ) ═CHCH ₂ — is made of plastic. The mixture was stirred and foamed. When foaming was performed until the volume ratio of the pores reached 5, 0.4 g of a crosslinking agent (Hiratec B solution) and 0.4 g of a gelling agent (Hiratec C solution) were added, and the mixture was stirred. Before gelation started, it was poured into a glass petri dish having a diameter of 8 cm. The mixture was allowed to stand at room temperature for 15 minutes to gel, and then heated and solidified in an oven at 100 ° C. for 60 minutes to obtain a pancake-like carbon dioxide absorber.

[Example 2]
In general formula [Chemical Formula 1], X is —CH ₂ —, Y is —CH (CH ₃ ) — 1000 g of polymer (ethylene-propylene rubber), 10 g of crosslinking agent (DCP manufactured by Mitsui Chemicals), foaming agent (manufactured by Eiwa Kasei) A composition obtained by kneading 70 g of vinylol) was subjected to pressure foam molding with a foam molding machine heated to 110 ° C. so that the volume ratio of pores was 10, to obtain a block-shaped carbon dioxide absorber.

[Comparative Example 1]
10 g of polyethyleneimine (molecular weight Mw 600) was dissolved in 80 mL of methanol and stirred for 30 minutes. Next, while stirring this solution, 40 g of silica gel (manufactured by Kanto Chemical Co., Ltd., specific surface area 500 m ² / g) was slowly added and suspended, and stirring was continued for 1 hour. Thereafter, this suspension was filtered with a 5C filter paper, and the residue was dried in a drying oven at 60 ° C. for 12 hours to obtain a particulate carbon dioxide absorber.

(Evaluation of carbon dioxide desorption performance into the air)
Hereinafter, in the procedures shown in (1) and (2), the carbon dioxide absorbers of Examples and Comparative Examples were measured for carbon dioxide absorption and desorption performance into the air.

(1) Filled gas mixture with high carbon dioxide concentration (90% by volume of carbon dioxide, 10% by volume of air) in a sealed cubic plastic box with a side of 20cm, mixed with 5g of carbon dioxide absorber. And allowed to stand for 6 hours to absorb carbon dioxide.

(2) Next, fill the same type of plastic box separately prepared with the atmosphere (carbon dioxide concentration of about 450 ppm), put the carbon dioxide absorber taken out from the mixed gas in (1), cover it, and cover for 30 minutes. The amount of carbon dioxide desorbed into the air was confirmed by measuring the concentration of carbon dioxide in the later plastic box. The carbon dioxide concentration was measured using a carbon dioxide concentration meter (MB-525 manufactured by Hario Science, or ZG-1163 manufactured by FUSO).

By the operations of (1) and (2), the amount of carbon dioxide desorbed into the air per unit weight of the carbon dioxide absorber was evaluated. Table 1 shows the results of conducting this evaluation five times in succession.

As shown in Table 1, in Examples 1 and 2, a carbon dioxide desorption amount of 6.7 to 7.7 mg-CO2 / g was confirmed. Since the concentration change of the mixed gas cannot be measured with a densitometer, the weight was measured after the operation of (1). As a result, in Examples 1 and 2, the weight increase was about 7.5 mg / g and about 8.0 mg / g, respectively. confirmed. Therefore, it is suggested that carbon dioxide was absorbed from the mixed gas and desorbed into the air without heating the carbon dioxide. Moreover, since the numerical value of the desorption amount is stable in the evaluation of 5 consecutive times, it is suggested that the carbon dioxide absorber can be used repeatedly.

On the other hand, Comparative Example 1 had an extremely low carbon dioxide desorption amount of about 1.0 mg-CO2 / g. Since there is a weight increase of about 20 mg / g in the weight measurement after the operation of (1), Comparative Example 1 absorbs carbon dioxide, but it can hardly desorb carbon dioxide in the situation where it is not heated. Is suggested.

Subsequently, the carbon dioxide desorption performance into water was evaluated.

(Evaluation of carbon dioxide desorption performance in water)
Hereinafter, in the procedures shown in (3) and (4), the carbon dioxide absorbers of Examples and Comparative Examples were measured and evaluated for the carbon dioxide desorption performance of the absorbed carbon dioxide into water.

(3) A sealed cubic plastic box with a side of 20 cm was filled with normal temperature mixed gas (carbon dioxide 90% by volume, air 10% by volume) assumed to be exhaust gas, and produced in Example and Comparative Example 1 therein. 5 g of carbon dioxide absorbent material was added and allowed to stand for 6 hours to absorb carbon dioxide.

(4) Next, 100 mL of room temperature water obtained from the pure water production apparatus was put in a container, and the carbon dioxide absorber taken out from the mixed gas of (3) was immersed in this water and left for 30 minutes. . After 30 minutes, the carbon dioxide absorber was taken out of the container, and water in the container was used as a measurement sample by using an ion chromatograph (manufactured by Thermo Scientific, trade name: DX-500, column: IonPac AS20), and the amount of carbon dioxide was reduced from the amount of carbon dioxide. The carbon concentration was calculated. Separately, water that does not immerse the carbon dioxide absorber was measured as a blank, and the value was subtracted to obtain the carbon dioxide desorption amount.

The carbon dioxide desorption amount per unit weight of the carbon dioxide absorber was evaluated by the operations of (3) and (4). Table 2 shows the results of this evaluation carried out five times in succession.

  As shown in Table 2, the carbon dioxide absorbers of Examples 1 and 2 were confirmed to have a desorption amount of about 5.5 mg-CO2 / g in the evaluation of carbon dioxide desorption performance. From this result, it was confirmed that carbon dioxide derived from the mixed gas can be supplied into water. The value of the desorption amount is slightly smaller than that in the air, which is presumed to be because a part of carbon dioxide in the water was released into the air during the operation of (4). However, the numerical value of the desorption amount is stable in five consecutive evaluations, suggesting that carbon dioxide absorption and desorption into water are reversible.

On the other hand, in Comparative Example 1, in the second and subsequent evaluations, the amount of carbon dioxide desorbed rapidly decreased. For investigation of the cause, the water after the first evaluation was collected and concentrated to find a residue. This residue was qualified as polyethyleneimine by FT-IR. That is, polyethyleneimine, which is the main component of the carbon dioxide absorber of Comparative Example 1, was eluted into water, and the second and subsequent evaluations seemed to have reduced carbon dioxide absorption, suggesting that it cannot withstand repeated use. Is done.

  As is clear from the above results, it was shown that the carbon dioxide absorber of the present invention can desorb absorbed carbon dioxide and can be used repeatedly without using a process such as heating. . It was also shown that carbon dioxide absorbed from exhaust gas can be desorbed not only in air but also in water.

Next, an example in which the relationship between the volume ratio of vacancies and carbon dioxide absorption / desorption is tested is shown. The evaluation was performed according to an evaluation procedure for carbon dioxide desorption performance into water.

[Examples 3-5, Comparative Examples 2-3]
In Example 1, the volume ratio of the void | hole part with respect to a polymer part was changed as shown in Table 3, and the carbon dioxide absorber was produced.

Table 3 shows the results of evaluating the carbon dioxide desorption performance in water for the carbon dioxide absorbers of Examples 1 and 3-5 and Comparative Examples 2-3. When the volume ratio of pores is 3 to 13, the carbon dioxide desorption amount is improved, and the effect is recognized.

Next, the Example about the carbon dioxide absorber which contains a porous particle in a polymer is shown.

[Example 6]
A molecular sieve (4A, manufactured by Kanto Chemical Co., 4A, pellets) 10 g, which is a kind of zeolite, was pulverized for 5 seconds with a freeze pulverizer (manufactured by Nippon Analytical Industries). After pulverization, the mixture was classified with a sieve (60 mesh) to obtain a pulverized molecular sieve having a particle size of 5 to 250 μm, which was used as porous particles. 10 g of a natural rubber latex liquid (REGITEX manufactured by Hiratec) and 1 g of pulverized molecular sieve (17% by mass with respect to the solid content of the polymer) were placed in a plastic container and stirred. Thereafter, a carbon dioxide absorber was obtained in the same manner as in Example 1.

[Example 7]
The molecular sieve of Example 6 was produced in the same manner as in Example 6 except that Bincho charcoal, a kind of charcoal, was used.

In addition, the particle size distribution of the porous particles obtained by the above pulverization treatment was examined by observation using a digital microscope (manufactured by Keyence, VHX-500X).

[Examples 8 to 10]
It was produced in the same manner as in Example 7 except that the blending amount of the pulverized Bincho charcoal of Example 7 was changed as shown in Table 4.

Table 4 shows the results of evaluating the carbon dioxide desorption performance in water for Examples 6 to 10. As shown in Table 4, when the porous particles were added to the polymer, the carbon dioxide desorption amount was 1.35 times or more. When the blending amount of the porous particles was increased, the carbon dioxide absorption / desorption amount tended to increase. When the amount of the porous particles with respect to the polymer solid content is more than 33% by mass, the viscosity is increased, and foaming cannot be performed so as to obtain a desired volume ratio. That is, when the amount of the porous particles is 8 to 33% by mass with respect to the polymer, the amount of carbon dioxide absorbed / desorbed can be effectively increased, which is preferable.

The carbon dioxide absorber of the present invention can separate and recover carbon dioxide from exhaust gas having a high carbon dioxide concentration. The carbon dioxide absorber of the present invention can be used as a carbon dioxide carrier that allows carbon dioxide absorbed from exhaust gas to be desorbed at a plant factory, algae culture facility, etc., and can be used to fix carbon dioxide and promote the growth of photosynthetic organisms. Can be expected. Thus, the present invention has high industrial applicability.

DESCRIPTION OF SYMBOLS 1 Carbon dioxide absorber 2 Polymer represented by general formula (I) 3 Pore 4 Porous particle

Claims (4)

General formula [Chemical formula 1]

(Wherein X represents a hydrocarbon group selected from —CH ₂ —, —CH═CH—CH ₂ —, —C (CH ₃ ) ═CHCH ₂ —, and Y represents —CH ₂ —, —CH (CH ₃ ) — represents a hydrocarbon group selected from —CH (C ₆ H ₅ ) —, —CH═CH—CH ₂ —, —C (CH ₃ ) ═CHCH ₂ —, and X and Y are the same. P and q represent the average number of repetitions, and the ratio of p to q is p: q = 20: 1 to 1: 1.)
The carbon dioxide absorber characterized by having the polymer represented by these as a main component, and having a some void | hole. 2. The carbon dioxide absorber according to claim 1, wherein the polymer is at least one of natural rubber, isoprene rubber, butadiene rubber, ethylene-propylene rubber, styrene-butadiene rubber, and polyethylene. The carbon dioxide absorber according to claim 2, wherein B / A is 3 to 13, where A is the volume of the polymer and B is the volume of the pores. The carbon dioxide absorber according to claim 3, wherein the polymer contains at least one kind of porous particles selected from zeolite and charcoal.

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