JP7448926B1 - Carbon dioxide adsorption method, carbon dioxide treatment device, and carbon dioxide adsorption system - Google Patents

Abstract

[Problem] To provide a carbon dioxide adsorption method that can reduce carbon dioxide emissions by directly utilizing combustion exhaust gas in the industrial field, particularly during waste treatment. SOLUTION: A first gas containing carbon dioxide is treated with a carbon dioxide adsorption compound that is at least one selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide, or ammonia; A method for adsorbing carbon dioxide, which comprises heating an adsorbent containing an amine compound and a metal member to adsorb the carbon dioxide and precipitate solid matter on the surface of the metal member. [Selection diagram] Figure 1

Description

The present invention relates to a carbon dioxide adsorption method, a carbon dioxide treatment device, and a carbon dioxide adsorption system.

A large amount of carbon dioxide emitted from power generation equipment, incineration equipment, steel manufacturing equipment, etc. is known as a greenhouse gas that causes global warming, and it is desired to reduce it.

As a method for reducing carbon dioxide emissions, a carbon dioxide recovery method is known in which exhaust gas containing carbon dioxide is fed to a carbon dioxide absorption device, and carbon dioxide in the exhaust gas is absorbed, and further separated and recovered. (Patent Document 1)

Japanese Patent Application Publication No. 2005-262051

Technology Development Center, Research Association for Innovative Utilization of Unused Thermal Energy, “Survey Report on Exhaust Heat Status in the Industrial Sector”, March 2019

However, in the above carbon dioxide recovery method, it is necessary to strictly adjust the temperature of the exhaust gas fed to the carbon dioxide absorption device. Specifically, it was necessary to cool it to a predetermined temperature (for example, 90° C. or lower). Regarding the heat value of exhaust gases in the industrial field, the proportion of exhaust gases emitted at temperatures of 99° C. or lower is extremely small at 14% of the total. In the field of cleaning, particularly regarding exhaust gas during waste treatment, it has been reported that 0% of exhaust gas is emitted at temperatures below 99°C. (Non-Patent Document 1) Therefore, there is a problem in that it is practically difficult to feed the exhaust gas discharged during waste treatment to the carbon dioxide absorption device described in Patent Document 1.
Furthermore, the recovery rate of carbon dioxide by the carbon dioxide recovery method described in Patent Document 1 was not sufficient.

Therefore, an object of the present invention is to provide a carbon dioxide adsorption method that can reduce carbon dioxide emissions by directly utilizing combustion exhaust gas in the industrial field, particularly during waste treatment. Another object of the present invention is to provide a carbon dioxide treatment device and a carbon dioxide adsorption system.

As a result of intensive studies to solve the above problems, the present inventor found that the above problems could be solved by the following configuration.

[1] The first gas containing carbon dioxide is mixed with a carbon dioxide adsorption compound that is at least one selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, or ammonia, and an amine. A method for adsorbing carbon dioxide, which comprises bringing an adsorbent containing a compound and a metal member into contact with each other and heating them to adsorb the carbon dioxide and precipitate solid matter on the surface of the metal member.
[2] The carbon dioxide adsorption method according to [1], wherein the metal member is at least one selected from the group consisting of a sphere, a tubular body, a planar body, and a spiral body.
[3] The carbon dioxide adsorption method according to [2], wherein the surface of the metal member is subjected to blasting.
[4] The carbon dioxide adsorption method according to [3], wherein the metal member is made of stainless steel.
[5] The carbon dioxide adsorption method according to [4], wherein the metal member is approximately spherical with a diameter of 1.5 to 2 mm.
[6] The carbon dioxide adsorption method according to [5], wherein the adsorbent further contains a solvent selected from water and anhydrous ethanol.
[7] The carbon dioxide adsorption method according to [6], wherein the carbon dioxide adsorption compound is a saturated solution of the alkali metal hydroxide, and the alkali metal hydroxide is sodium hydroxide.
[8] A carbon dioxide treatment device that introduces a first gas containing carbon dioxide and adsorbs carbon dioxide in the gas,
An adsorbent containing at least one carbon dioxide adsorption compound selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide, or ammonia, an amine compound, and a metal member is made airtight. A carbon dioxide processing apparatus, comprising: a reactor housed in the reactor, and configured to allow the first gas to flow into the reactor from the outside.
[9] A carbon dioxide adsorption system comprising the carbon dioxide treatment device according to [8] and an incinerator that supplies the first gas to the carbon dioxide treatment device.

According to the present invention, it is possible to provide a carbon dioxide adsorption method that can directly utilize combustion exhaust gas in the industrial field, particularly during waste treatment, and reduce carbon dioxide emissions. Further, according to the present invention, a carbon dioxide treatment device and a carbon dioxide adsorption system can also be provided.

FIG. 1 is a flow diagram of an embodiment of the carbon dioxide adsorption method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of an embodiment of a carbon dioxide treatment device of the present invention. FIG. 1 is a block diagram of one embodiment of the carbon dioxide treatment system of the present invention. FIG. 3 is a block diagram of another embodiment of the carbon dioxide treatment system of the present invention. FIG. 2 is an explanatory diagram of a carbon dioxide treatment device used in the experiment. It is a figure showing the result of the component analysis of the exhaust gas from a carbon dioxide treatment device. It is a figure showing the result of the component analysis of the exhaust gas from a carbon dioxide treatment device.

The present invention will be explained in detail below.
Although the description of the constituent elements described below may be made based on typical embodiments of the present invention, the present invention is not limited to such embodiments.
In this specification, a numerical range expressed using "~" means a range that includes the numerical values written before and after "~" as the lower limit and upper limit.
Furthermore, in the following description, parts having the same function and/or structure may be denoted by the same reference numerals, and the description thereof may be omitted.

[Carbon dioxide treatment method]
FIG. 1 is a flow diagram of an embodiment of the carbon dioxide adsorption method of the present invention (hereinafter referred to as "the present method").

In this method, a first gas containing carbon dioxide is mixed with a carbon dioxide adsorption compound that is at least one selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide, and ammonia. This is a method in which an adsorbent containing an amine compound and a metal member is brought into contact with each other and heated to adsorb carbon dioxide and deposit solid matter on the surface of the metal member.

One specific form of this method includes the following steps in this order.
- Step of obtaining the first gas - Step of bringing the first gas into contact with the first solution to prepare a mixed solution (preparation step)
・The process of bringing the mixed solution into contact with a metal member and heating it (as an adsorbent) to absorb carbon dioxide and precipitate solid matter on the surface of the metal member (reaction process)
・Process of recovering the obtained solids (recovery process)

According to this method, the concentration of carbon dioxide contained in the first gas containing carbon dioxide can be easily reduced. Below, each step that may be included in this method will be explained in detail.

- First gas acquisition step First, a first gas is acquired (step S1). The first gas is a gas containing carbon dioxide, and is a gas to be treated in this method. The first gas only needs to contain carbon dioxide, and its content (concentration) is not particularly limited, but is generally preferably 10 to 100 mass% (room temperature, 1 atmosphere). Note that the first gas only needs to contain carbon dioxide, and may contain other components. Other components include nitrogen, oxygen, hydrogen chloride, and volatile organic compounds.

The method for obtaining the first gas is not particularly limited. The gas containing a predetermined amount of carbon dioxide can be, for example, exhaust gas from devices that use fossil fuels (boilers, incinerators, etc.). Hereinafter, in this specification, the exhaust gas from the incinerator may be particularly referred to as "combustion exhaust gas."
In addition, when acquiring the exhaust gas from the above-mentioned apparatus, it may be used as it is, or it may be adjusted and used so as to match the preferable processing conditions (temperature, pressure) in the post-process (step S2).

Generally, the temperature and/or pressure of exhaust gas (combustion exhaust gas) from a large incinerator may be higher than the preferable treatment conditions (reaction conditions) in a subsequent process. In this case, the exhaust gas from the notation device may be cooled and/or depressurized and obtained as the first gas.

The method for cooling the exhaust gas is not particularly limited, and any known method can be used. For example, the exhaust gas may be cooled using a heat exchanger or the like.

- Preparation step Next, the first gas obtained in the first gas acquisition step is brought into contact with the first solution to prepare a mixed solution (step S2).
The first solution contains at least one carbon dioxide adsorption compound selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, and ammonia, an amine compound, and a solvent. include.

Amine compounds include, but are not particularly limited to, primary amines such as monoethanolamine and 2-amino-2-methyl-1-propanol; secondary amines such as diethanolamine and 2-methylaminoethanol. tertiary amines such as triethanolamine and N-methyldiethanolamine; polyethylene polyamines such as ethylenediamine, triethylenediamine, and diethylenetriamine; cyclic amines such as piperazine, piperidine, and pyrrolidine; Examples include polyamines such as xylylene diamine; amino acids such as methylaminocarbon.

The present inventors speculate that the amine compound, as an adsorption film type water-soluble rust preventive agent, has the effect of preventing corrosion of metal members, which will be described later, and increases reactivity.

The carbon dioxide adsorption compound is at least one selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, and ammonia.
Examples of the alkali metal hydroxide include potassium hydroxide and sodium hydroxide, with sodium hydroxide being preferred.
Examples of alkaline earth metal hydroxides include magnesium hydroxide.
The carbon dioxide adsorption compound preferably contains an alkali metal hydroxide, and more preferably contains sodium hydroxide, from the standpoint of obtaining better effects of the present invention.

The solvent contained in the first solution is not particularly limited, but is preferably water and/or anhydrous ethanol.
The method for preparing the first solution is not particularly limited, and may be prepared by adding an amine compound and a carbon dioxide adsorption compound to a solvent, respectively, or by adding a solution containing an amine compound and a carbon dioxide adsorption compound to a solvent. You may mix it with the solution containing.

The first solution is preferably a saturated solution of alkali metal hydroxide, and more preferably a saturated solution of sodium hydroxide, from the viewpoint of obtaining better effects of the present invention.
In addition, in this specification, a saturated sodium hydroxide solution means a saturated solvent under conditions of 25° C. and 1 atm. The solvent used is not particularly limited, but one preferred form is water (H ₂ O).

Although the method of bringing the first gas into contact with the first solution is not particularly limited, a method of diffusing the first gas into a saturated sodium hydroxide solution is preferred. More specifically, there is a method of bubbling the first gas into a saturated sodium hydroxide solution.

In addition, in the flow of FIG. 1, the mixed solution is prepared by bringing the first gas into contact with the first solution prepared in advance, but in the carbon dioxide adsorption method of the present invention, this step is not required.
When the first gas is brought into direct contact with an adsorbent (which may or may not contain a solvent) containing a carbon dioxide adsorption compound, an amine compound, and a metal member (described later), the preparation of a mixed solution (this step ) is unnecessary.

・Reaction step Next, the mixed solution obtained in the preparation step is brought into contact with the metal member (resulting in the preparation of an adsorbent), heated, and carbon dioxide is absorbed onto the surface of the metal member. A solid substance is precipitated (step S3).

The metal member has a function of catalyzing the carbon dioxide absorption reaction and causing the reaction to proceed efficiently.
The material of the metal member is not particularly limited, but preferred materials include, for example, stainless steel, gold, iridium, rhodium, palladium, nickel, chromium, molybdenum, zirconium, and nickel alloys that do not corrode in basic solutions. . Among these, stainless steel, chromium, nickel, molybdenum, etc. are more preferred.

Examples of the stainless steel include austenitic stainless steel, martensitic stainless steel, and ferritic stainless steel. More specifically, austenitic stainless steels such as SUS303, SUS304, SUS304L, and SUS316 are more preferable.

The shape of the metal member is not particularly limited, but preferably at least one type selected from the group consisting of a sphere, a tubular body, a flat body, and a spiral body.
One example is a structure in which sirocco fan-like fins are attached to a tubular body. The sirocco fan-shaped fins are arranged so that the rectangular stainless steel plate has a cylindrical shape, and the longitudinal direction thereof is on the inside and outside of the concentric cylinder. Furthermore, when viewed from the short side of the rectangle, the rectangular plates are arranged radially. In addition, the rectangular stainless steel plate has circular holes formed at a plurality of locations in a line along the longitudinal direction.

Further, as another form, it is more preferable that the metal member is approximately spherical with a diameter of 1.5 to 2 mm.
It is preferable that the metal member has a substantially spherical shape, since the handleability is higher and the contact area with the first solution is larger.

Further, it is more preferable that the surface of the metal member is subjected to blasting because the contact area with the first solution becomes larger and the reaction progresses more easily.

The size of the metal member is not particularly limited, and may be adjusted as appropriate depending on the reaction vessel used.

The method of contacting the metal member with the first solution is not particularly limited. The metal member may be immersed in the mixed solution, or the mixed solution may be contained in a metal member configured as a container.

Note that in this step, the metal member is brought into contact with a mixed solution obtained by bringing the first gas into contact with the first solution containing the carbon dioxide adsorption compound and the amine compound. The reaction method in this method is not limited to the above.
As described above, the step may be such that an adsorbent containing a carbon dioxide adsorption compound, an amine compound, and a metal member is prepared in advance, and the first gas is brought into contact with the adsorbent. In this case, the preparation step of step S2 may be omitted.

Carbon dioxide adsorbing compounds and the like contained in the adsorbent may be consumed as the reaction progresses. Further, as the reaction progresses, solid matter (white crystals) is deposited on the surface of the metal member. For this reason, when performing the reaction continuously, it is preferable to replace the adsorbent as appropriate.

There are no particular limitations on how to determine when to replace the gas, but it may be determined based on the decrease in the absorption efficiency of carbon dioxide in the first gas.
For example, the presence or absence of a decrease in carbon dioxide absorption efficiency may be determined by measuring and/or analyzing the components of the exhaust gas (second gas) after the reaction.
Alternatively, the upper limit of the usable time of the adsorbent may be determined, and the adsorbent may be replaced every few hours. In this case, the maximum usable time is preferably within 3 hours.

Preferably, the adsorbent is in the form of a replaceable cassette, since the adsorbent can be replaced more easily.
The adsorbent, which is in the form of an exchangeable cassette, includes a carbon dioxide adsorption compound, an amine compound, and a metal member, which are packaged together. Although the packaging method is not particularly limited, for example, the adsorbent may be housed in a mesh-like container.

The reaction temperature in this step is not particularly limited, but from the viewpoint of allowing the catalytic reaction to proceed more efficiently, it is preferably 180 to 400°C, more preferably 200 to 400°C, and even more preferably 300 to 400°C.
Note that when the first gas is obtained from the exhaust gas of the incinerator, the reaction temperature may be adjusted using the exhaust heat of the incinerator.

- Recovery process Next, the obtained solid matter is recovered (step S4). The solid material mainly consists of sodium carbonate, sodium hydrogen carbonate, and a mixture thereof, and is produced to coat a metal member, so it can be easily recovered.
According to this method, carbon dioxide contained in the first gas can be fixed and recovered by a simple procedure (the concentration of carbon dioxide contained in the first gas can be reduced). ).

Next, a carbon dioxide treatment device that can be used to implement this method will be described. FIG. 2 is a schematic diagram of the carbon dioxide treatment device.

The first carbon dioxide treatment device 13 includes a reactor 43 that is configured to be airtight and an adsorbent 32 housed within the reactor 43 . The adsorbent 32 is in the form of a replaceable cassette and includes a metal member, a carbon dioxide adsorption compound, and an amine compound.
Furthermore, the first carbon dioxide treatment device 13 has an introduction pipe 40 for a first gas (raw material gas) containing carbon dioxide, and an exhaust pipe 42 for a second gas (exhaust gas after reaction), Gas inflow and outflow is controlled by a valve (not shown).

Further, a temperature regulator 33 is arranged so as to surround the outer periphery of the reactor 43, and is configured to be able to adjust the temperature within the reactor 43 (particularly of the solvent 46). As the temperature controller 33, an industrial heater such as a planar heater, a mantle heater, and/or an industrial heater can be used.

A solvent 46 is accommodated inside the reactor 43 . The contained solvent may be a solvent that can be contained in the first solution described above. The reactor 43 may not contain the solvent 46, in which case the first gas will directly contact the adsorbent 32.

One end of the introduction pipe 40 is inserted into the solvent 46, and the first gas flowing into the first carbon dioxide treatment device 13 through this comes into contact with the adsorbent 32 in the solvent 46. .
On the other hand, one end of the discharge pipe 42 for discharging the gas (second gas) after the reaction to the outside of the first carbon dioxide treatment device 13 is provided in the gas phase portion of the reactor 43. By appropriately operating a valve (not shown), the second gas after the reaction (with a reduced concentration of carbon dioxide) is discharged to the outside of the reactor 43.
Note that the second gas may contain hydrogen, which may be collected and used for secondary use as a fuel in an incinerator or the like.

Next, a carbon dioxide adsorption system including a carbon dioxide treatment device will be explained. FIG. 3 is a block diagram of a first embodiment of a carbon dioxide treatment system incorporating a first carbon dioxide treatment device 13. As shown in FIG.

The carbon dioxide treatment system 100 includes an incinerator 12, a decompression/cooling device 37, a first solution preparation tank 19, a first gas collection tank 21, a first carbon dioxide treatment device 13, a crystallization tank 23, and a solid-liquid separation unit. It includes a device 24, a solids recovery tank 25, a waste liquid storage tank 26, a neutralization tank 27, a second carbon dioxide treatment device 22, a second gas collection tank, a residue dissolution tank 29, and a residue neutralization tank 30.

The incinerator 12 is a device into which, for example, waste and organic matter such as biomass are input and incinerated. Examples of the incinerator 12 include a stoker type incinerator, a rotary kiln type incinerator, and an incinerator using a combination of these.
The type of incineration material and the method of incineration thereof are not particularly limited, and any known method may be used. The incineration temperature and incineration time can be adjusted as appropriate depending on the type and amount of waste to be incinerated.
The materials to be incinerated are supplied to the incinerator 12 by a conveyor, a crane, etc., and are incinerated.
The combustion exhaust gas discharged from the incinerator 12 contains carbon dioxide, which can be used as (a raw material for) the first gas.

Combustion exhaust gas usually contains components other than carbon dioxide, and these components may be analyzed. Further, instead of directly analyzing the combustion exhaust gas, the components of the incinerated material may be analyzed to make a prediction. These analysis results can be used for determining the operating method of the carbon dioxide treatment system 100, etc.

The combustion exhaust gas generated in the incinerator 12 is sent to the decompression/cooling device 37. The pressure reduction/cooling device 37 is a device installed to collect the combustion exhaust gas generated in the incinerator 12, cool it, and reduce the pressure to prepare a first gas. Typically, a waste heat boiler or the like can be used. Furthermore, a power saving device such as an economizer or an air preheater may be provided.
The first gas prepared by being depressurized in the decompression/cooling device 37 is sent to the first gas collection tank 21 that is airtightly connected to the decompression/cooling device 37 .

The first gas collection tank 21 collects and stores the first gas adjusted by the decompression/cooling device 37. Specifically, it's a gas tank.
The first gas collection tank 21 is airtightly connected to the first carbon dioxide treatment device 13 via a pump.
Further, the first solution preparation tank 19 is a reaction tank for producing the first solution. The components of the first solution are as described above.
The first gas collection tank 21 and the first solution preparation tank 19 are airtightly connected to the first carbon dioxide treatment device 13, and respectively supply the first gas and the first solution to the first gas collection tank 21 and the first solution preparation tank 19. The carbon dioxide is introduced into the carbon dioxide treatment device 13.

The first carbon dioxide treatment device 13 is a device similar to that described in Example 1, and includes a reactor 43 and an adsorbent 32 housed in the reactor 43. Note that in Example 1, a solvent was contained in the reactor 43, but in this example, a first solution is contained in place of this solvent. The adsorbent 32 is immersed in the first solution in the reactor 43 .

In the first carbon dioxide treatment device 13, the first gas sent from the first gas collection tank 21, the first solution, and the adsorbent immersed therein react, and carbon dioxide is adsorbed. .
Note that in the first carbon dioxide treatment device 13, a first solution containing a solvent (and the adsorbent 32 that comes into contact with the solution) is housed in the reactor 43. Therefore, components other than carbon dioxide (especially toxic gas, etc.) contained in the first gas are removed by this solvent. That is, the carbon dioxide treatment device containing the first solution (or mixed solution) has the functions of a so-called detoxification device, a scrubber, and the like.

The components removed in the first carbon dioxide treatment device 13 are not particularly limited, but include, for example, hydrogen chloride (HCl), nitrogen oxides (NOx), sulfur oxides (SOx), and dioxins. Can be mentioned.
In addition to the above, the first carbon dioxide treatment device 13 further includes a filtration type dust collector, a dry method scrubber, a wet method scrubber, a NOx removal device, and the like for removing toxic substances from exhaust gas. A dioxin removal device or the like may be provided downstream.

The solution (waste liquid) after the reaction in the first carbon dioxide treatment device 13 is sent to the crystallization tank 23. In the crystallization tank 23, the waste liquid is allowed to stand at room temperature for a predetermined period of time, and is separated into a supernatant layer and a solid substance (which may be in the form of a slurry). The separated solids are stored in a solids collection tank 25.
The supernatant layer is further sent to a solid-liquid separator 24 (centrifuge, filter press, etc.) via a pump. The liquid separated by the solid-liquid separator 24 is collected into a waste liquid storage tank 26, and the solids are collected into a solid recovery tank 25.

The solids collected in the solids recovery tank 25 contain sodium carbonate hydrate, sodium hydrogen carbonate, and a mixture thereof as components.

The waste liquid storage tank 26 stores the liquid sent from the solid-liquid separator 24 via a pump. The liquid is sent from the waste liquid storage tank 26 to the neutralization tank 27.

The neutralization tank 27 is a tank in which a liquid substance and hydrogen chloride are reacted. The inventors believe that the reaction of _Na2CO3 + _2HCl →2NaCl+ _CO2 + _H2O is promoted in the neutralization tank 27, and the exhaust gas (including carbon dioxide) generated in the neutralization tank 27 is sent to the second carbon dioxide treatment device 22. The waste liquid generated by the reaction in the neutralization tank 27 is sent to the solid-liquid separator 24, the solids are separated into the solids recovery tank 25, and the liquids (not shown) are drained.

The second carbon dioxide treatment device 22 is similar to the first carbon dioxide treatment device 13 described above, except that it does not contain a solvent.
The exhaust gas (containing carbon dioxide) from the neutralization tank 27 and the exhaust gas (containing carbon dioxide) from the residue neutralization tank 30 (described later) are introduced into the second carbon dioxide treatment device 22 as first gases. be done.
In the second carbon dioxide treatment device 22, the content of carbon dioxide in the first gas is reduced, and the second gas is discharged.

The second gas generated within the second carbon dioxide treatment device 22 is sent to the second gas collection tank 20 . At this time, the second gas may be compressed using a compressor or the like.

In the residue dissolving tank 29, the adsorbent 32 that has adsorbed the amount of carbon dioxide that can be adsorbed in the exchange cassette is washed and separated into residue and waste liquid. Since the main components of the residue are metal parts, they can be reused. Further, the waste liquid is sent to the residual neutralization tank 30.

In the residue neutralization tank 30, the waste liquid generated in the residue dissolution tank 29 is reacted with hydrogen chloride. It is assumed that the reaction of Na ₂ CO ₃ + 2HCl → 2NaCl + CO ₂ + H ₂ O is promoted in the residue neutralization tank 30, and the exhaust gas (including carbon dioxide) generated in the residue neutralization tank 30 is converted into the second dioxide. The gas is sent to the carbon processing device 22 and made into a first gas.

The carbon dioxide adsorption system of this example includes two carbon dioxide adsorption devices, and since the first stage is used in a form that uses the first solution (also serves as a gas cleaning device), carbon dioxide adsorption is possible. This can be carried out in conjunction with the removal of toxic gases, etc. Furthermore, since metal parts and the like can be recycled and used within the system, running costs are also low.

FIG. 4 is a block diagram of another embodiment of a carbon dioxide treatment system including the carbon dioxide treatment device of the present invention. The carbon dioxide treatment system 200 is characterized in that it uses exhaust heat from the incinerator when heating the carbon dioxide treatment device.

The carbon dioxide treatment system 200 includes an incinerator 12 , a boiler 16 , a mixed liquid tank 17 , a binary power generator 18 , a first solution preparation tank 19 , and a second gas collection tank 20 .

In the carbon dioxide treatment system 200, the third carbon dioxide treatment device 56 is installed integrally with the incinerator 52.
The combustion exhaust gas released from the incinerator 52 is first sent to the boiler 16. The combustion exhaust gas is then depressurized in the boiler 16 and collected as a first gas. The collected first gas is sent to the mixed liquid tank 17. A binary power generator 18 is attached to the boiler 16, and the energy generated when reducing the pressure of the first gas is also utilized.

The first solution produced in the first solution preparation tank 19 is sent to the mixed liquid tank 17, and the heat of fusion generated during the preparation of the first solution is sent to the binary power generator 18.
The binary power generation device 18 is a device that converts energy generated in the boiler 16 and/or the first solution preparation tank 19 into electric power. The power output by the binary power generator 18 can supplement the power required for preparing the first solution in the first solution preparation tank 19 and for operating the carbon dioxide treatment system. .

In the mixed liquid tank 17, the first gas discharged from the boiler 16 and the first solution prepared in the first solution preparation tank 19 are brought into contact to prepare a mixed solution.
The prepared mixed solution is sent to the third carbon dioxide treatment device 56, contacts the adsorbent housed inside, and carbon dioxide is adsorbed.
The third carbon dioxide treatment device 56 is similar to the carbon dioxide treatment device described above, except that it is configured to utilize the heat of the combustion chamber of the incinerator and is not equipped with a temperature controller. .

The second gas, which is the exhaust gas generated in the third carbon dioxide treatment device 56, is collected in the second gas collection tank 20 and used as auxiliary combustion gas for the incinerator 52. Since the carbon dioxide processing system 200 is configured to utilize the exhaust heat of the incinerator 52, it is superior in energy efficiency.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited thereto.

(Example 1)
Sodium hydroxide (NaOH) granular reagent (FUJIFILM Wako Pure Chemical Corporation, Osaka, Japan) 500 g, Sodium hydroxide reagent (FUJIFILM _Wako Pure Chemical Corporation, Osaka, Japan) Japan) 500g, absolute ethanol ( _C2H5OH ) 500mL, 500 mL of purified water and an amine compound were mixed to create a saturated sodium hydroxide solution.

The saturated sodium hydroxide solution was diluted with purified water to obtain a 14% by mass saturated sodium hydroxide solution.
The prepared 14% by mass sodium hydroxide saturated solution was placed in a reactor of a carbon dioxide treatment device.

FIG. 5 is an explanatory diagram of the carbon dioxide treatment device used in the experiment. The carbon dioxide treatment device includes a reactor 102 and a temperature controller 109 arranged to surround the reactor 102. A CO ₂ gas cylinder 103 and a N ₂ gas cylinder 107 are connected to the reaction furnace 102 and are configured so that CO ₂ and N ₂ can be introduced into the reaction furnace 102 independently.
Furthermore, the exhaust gas from the reactor was configured to be subjected to component analysis using a combustion exhaust gas analyzer 111 (manufactured by Hodaka Co., Ltd., HT-1300Z).
Further, the temperature of the reactor 102 was monitored by a temperature sensor 112.
In FIG. 5, the reference numeral 101 represents a 14% by mass saturated sodium hydroxide solution. Further, the reference numeral 106 represents a bead-shaped metal (diameter 1.7 mm) containing austenitic stainless steel.

Thereafter, the valve of the piping connected to the CO ₂ gas cylinder 103 was opened, and the 14% by mass sodium hydroxide saturated solution 101 in the reactor 102 was bubbled (mixed solution).
Furthermore, the valve of the pipe connected to the N ₂ gas cylinder 107 was opened to allow nitrogen gas to flow into the reactor 102 . Thereafter, the inside of the reactor 102 was heated by the temperature controller 109, and when the temperature inside the reactor 102 detected by the sensor reached 380° C., this state was maintained for 30 minutes.

Thereafter, the gas in the reactor 102 was discharged, and component analysis was performed using a gas chromatograph/mass spectrometer (GC/MS). FIG. 6(A) is a table showing the measurement results (m/z is expressed as "mass"), FIG. 6(B) is a mass spectrum, and FIG. 6(C) is a mass chromatogram. represents. From this result, it was found that almost no CO ₂ was contained in the exhaust gas.

(Example 2)
Except that CO ₂ was injected into a saturated sodium hydroxide solution to create a mixed solution, and bead-shaped metal spheres containing sodium hydroxide, an amine compound, and austenitic stainless steel were added to the mixed solution. Carbon dioxide was adsorbed in the same manner as in Example 1.
The reaction continued for 3 hours (a constant amount of CO ₂ continued to flow), and the composition of the exhaust gas (corresponding to the second gas) was measured using a gas chromatograph mass spectrometer. FIG. 7(A) is a table showing the measurement results (m/z is expressed as "mass"), FIG. 7(B) is a mass spectrum, and FIG. 7(C) is a mass chromatogram. represents.
From FIG. 7, even if the reaction was continued for 3 hours, CO ₂ was below the detection limit. The results in FIG. 7 also showed that hydrogen (m/z=2) was also detected at a high rate of 98.73%.

12 Incinerator 13 First carbon dioxide treatment device 16 Boiler 17 Mixed liquid tank 18 Binary power generation device 19 First solution preparation tank 20 Second gas collection tank 21 First gas collection tank 22 Second carbon dioxide treatment device 23 Crystallization tank 24 Solid-liquid separator 25 Solid recovery tank 26 Waste liquid storage tank 27 Neutralization tank 29 Residue dissolution tank 30 Residue neutralization tank 32 Adsorbent 33 Temperature controller 37 Pressure reduction/cooling device 40 Inlet piping 42 Discharge piping 43 Reactor 52 Incinerator 56 Third carbon dioxide treatment device 100, 200 Carbon dioxide treatment system

Claims (3)

A first gas containing carbon dioxide in a mixed solvent of water and absolute ethanol,
An adsorbent containing sodium hydroxide , an amine compound, and a metal member made of stainless steel that is approximately spherical and has a blasted surface and has a diameter of 1.5 to 2 mm is brought into contact with the adsorbent and heated. A method for adsorbing carbon dioxide, which adsorbs carbon and precipitates a solid consisting of sodium hydrogen carbonate as a main component on the surface of the metal member. A carbon dioxide treatment device that introduces a first gas containing carbon dioxide and adsorbs carbon dioxide in the gas,
An adsorbent containing sodium hydroxide , an amine compound, and a nearly spherical metal member made of stainless steel with a diameter of 1.5 to 2 mm and whose surface has been blasted is airtightly housed, and from the outside. The first gas is caused to flow in, and the first gas and the adsorbent are brought into contact with each other in a mixed solvent of water and anhydrous ethanol to form carbon as a main component on the surface of the metal member. and a reactor configured to precipitate a solid consisting of sodium oxyhydrogen. A carbon dioxide adsorption system comprising the carbon dioxide treatment device according to claim 2 and an incinerator that supplies the first gas to the carbon dioxide treatment device.

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