JP2019166514A - Carbon dioxide separation device and carbon dioxide separation method - Google Patents

Abstract

To provide a carbon dioxide separation device that can separate carbon dioxide from a gas mixture containing carbon dioxide in a short time at low cost.SOLUTION: A carbon dioxide separation device includes: a carbon dioxide adsorbent capable of adsorbing and desorbing carbon dioxide with a temperature difference; and an electromagnetic wave irradiation part for irradiating the carbon dioxide adsorbent with an electromagnetic wave and heat it.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a carbon dioxide separator and a carbon dioxide separation method.

  A heat swing type separation method is known in which carbon dioxide in a mixed gas is adsorbed onto an adsorbent such as zeolite, and then the adsorbent is heated to desorb carbon dioxide to separate the carbon dioxide from the mixed gas. Yes. For example, Patent Document 1 discloses a thermal swing type separation method in which an adsorbent is heated by heating using a high-temperature gas or electric resistance heating of a conductive filament to desorb carbon dioxide. However, since the method disclosed in Patent Document 1 requires time for heating the adsorbent, there is a risk that the energy consumption is large and the cost is high.

Japanese Patent No. 5904420

  An object of the present invention is to provide a carbon dioxide separator and a carbon dioxide separation method capable of separating carbon dioxide from a mixed gas containing carbon dioxide in a short time and at low cost.

  A carbon dioxide separator according to one embodiment of the present invention includes a carbon dioxide adsorbent capable of adsorbing and desorbing carbon dioxide according to a temperature difference, and an electromagnetic wave irradiation unit that irradiates and heats the carbon dioxide adsorbent with an electromagnetic wave. This is the gist.

  In the carbon dioxide separation method according to another aspect of the present invention, a carbon dioxide adsorbent capable of adsorbing and desorbing carbon dioxide according to a temperature difference is brought into contact with a mixed gas containing carbon dioxide, and the carbon dioxide adsorbent is subjected to carbon dioxide. The gist is provided with an adsorption process for adsorbing carbon, and a desorption process for irradiating and heating the carbon dioxide adsorbent adsorbing carbon dioxide in the adsorption process to desorb carbon dioxide from the carbon dioxide adsorbent. .

  According to the present invention, carbon dioxide can be separated from a mixed gas containing carbon dioxide in a short time and at low cost.

It is a conceptual diagram which shows typically the structure of one Embodiment of the carbon dioxide separator which concerns on this invention. It is a figure of the zeolite and adsorbent container with which the carbon dioxide separator of FIG. 1 is equipped, (a) is a top view of the adsorbent container which accommodated the zeolite, (b) is the adsorbent container which accommodated the zeolite. It is sectional drawing. It is a figure explaining the adsorption | suction process which makes a zeolite adsorb | suck a carbon dioxide. It is a figure explaining the desorption process of desorbing carbon dioxide from a zeolite. It is a figure explaining the air supply process which sends the concentrated carbon dioxide containing the desorbed carbon dioxide to a concentrated carbon dioxide storage chamber.

  An embodiment of the present invention will be described in detail with reference to the drawings. 1 includes a carbon dioxide adsorbent 1 capable of adsorbing and desorbing carbon dioxide according to a temperature difference, an electromagnetic wave irradiation unit 10 that irradiates and heats the carbon dioxide adsorbent 1 with an electromagnetic wave, and carbon dioxide adsorption. An adsorbent container 20 for storing the agent 1 and an adsorption / desorption chamber 30 in which the adsorbent container 20 is arranged to perform adsorption and desorption of carbon dioxide in the carbon dioxide adsorbent 1 are provided.

The type of carbon dioxide adsorbent 1 is not particularly limited as long as carbon dioxide can be adsorbed and desorbed depending on the temperature difference. For example, zeolite (artificial zeolite, natural zeolite), activated carbon, graphite, carbon fiber, carbon Nanotubes, molecular sieves, metal oxides (eg, alumina, silica) can be mentioned. Among these carbon dioxide adsorbents, zeolite is more preferable. Moreover, these carbon dioxide adsorbents may be used alone or in combination of two or more.
The shape of the carbon dioxide adsorbent 1 is not particularly limited, and examples thereof include powder, granule, lump, fiber, rod, and pellet. Among these shapes, the pellet shape is more preferable.

  The shape of the adsorbent container 20 that accommodates the carbon dioxide adsorbent 1 is not particularly limited as long as the carbon dioxide adsorbent 1 can be accommodated, and examples thereof include a cylindrical shape and a rectangular tube shape. However, it is more preferable that at least a part of the adsorbent container 20 is made of a material having gas permeability. Examples of the material having gas permeability include a porous material and a net-like material.

In addition, the material of the adsorbent container 20 is not particularly limited, but it is more preferable that the adsorbent container 20 has resistance to the electromagnetic waves to be irradiated. For example, when the irradiated electromagnetic wave is a microwave, it is more preferable that the material of the adsorbent container 20 is polytetrafluoroethylene (PTFE).
FIG. 2 is a view of an adsorbent container 20 containing pellet-shaped zeolite as the carbon dioxide adsorbent 1. This adsorbent container 20 is a cylindrical container made of PTFE, and its bottom portion 20a is formed in a mesh shape. It is gas permeable.

  The adsorbent container 20 is placed on a turntable 22 installed in the adsorption / desorption chamber 30 via a spacer 24. As shown in FIG. 1, since a space is formed between the upper surface of the turntable 22 and the bottom 20a of the adsorbent container 20 by the spacer 24, the gas permeability of the bottom 20a of the adsorbent container 20 is maintained. The adsorption / desorption chamber 30 is airtight and resistant to electromagnetic waves.

The type of electromagnetic wave is not particularly limited as long as the carbon dioxide adsorbent 1 can be heated by irradiation, and is not limited to gamma rays, X-rays, ultraviolet rays, visible rays, infrared rays, radio waves, microwaves, ultrashort waves, A short wave, a medium wave, and a long wave are mentioned, but among these electromagnetic waves, a microwave is more preferable.
The microwave generally refers to a radio wave having a wavelength of 1 to 100 μm and a frequency of 300 MHz to 3 THz, and this range includes a decimeter wave, a centimeter wave, a millimeter wave, and a submillimeter wave.

An electromagnetic wave irradiation unit 10 is connected to the adsorption / desorption chamber 30, and an electromagnetic wave emitted from the electromagnetic wave irradiation unit 10 can be irradiated to the carbon dioxide adsorbent 1. The carbon dioxide adsorbent 1 is heated by the electromagnetic wave irradiation.
Hereinafter, the electromagnetic wave irradiation unit 10 will be described by taking the case where the electromagnetic wave is a microwave as an example. The electromagnetic wave irradiation unit 10 transmits a microwave, a microwave power source 12 having a magnetron that generates a microwave, an isolator 14 that protects the magnetron, a matching unit 16 that controls directions of incident waves and reflected waves, and a microwave. And a waveguide 18 to be provided.

  As shown in FIG. 1, the microwave power source 12, the isolator 14, the matching unit 16, and the waveguide 18 are arranged in this order, and one end of the waveguide 18 is connected to the adsorption / desorption chamber 30. The microwave generated by the microwave power source 12 enters the adsorption / desorption chamber 30 through the waveguide 18 and is irradiated to the carbon dioxide adsorbent 1 accommodated in the adsorbent container 20 in the adsorption / desorption chamber 30. It is like that.

  When the carbon dioxide adsorbent 1 is irradiated with electromagnetic waves to heat the carbon dioxide adsorbent 1, the turntable 22 may be rotated. By irradiating the electromagnetic wave while rotating the turntable 22 using the motor 26, the carbon dioxide adsorbent 1 can be heated more uniformly.

  The adsorption / desorption chamber 30 includes a stirrer 32 for agitating the gas in the adsorption / desorption chamber 30. A plurality (three in the example of FIG. 1) of pipes 42, 44, 46 are connected to the adsorption / desorption chamber 30, and valves 42a, 44a, 46a, 46b are connected to the pipes 42, 44, 46, respectively. Is provided. Then, by combining the driving of the stirrer 32 using the motor 34 and the opening and closing of the valves 42a, 44a, 46a, 46b, the outside air is introduced into the adsorption / desorption chamber 30 or the gas in the adsorption / desorption chamber 30 is moved outside. It is possible to discharge.

  The concentrated carbon dioxide storage chamber 40 may be provided in the carbon dioxide separator, and one of the plurality of pipes 42, 44, 46 may be connected to the concentrated carbon dioxide storage chamber 40. Although details will be described later, if the concentrated carbon dioxide storage chamber 40 is provided, the concentrated carbon dioxide produced in the adsorption / desorption chamber 30 is supplied to the concentrated carbon dioxide storage chamber 40 via the pipe 46 to store the concentrated carbon dioxide. It can be stored in the chamber 40.

  Next, a method for producing concentrated carbon dioxide by separating carbon dioxide from a mixed gas containing carbon dioxide using the carbon dioxide separator of FIG. 1 will be described. The electromagnetic waves are microwaves, the carbon dioxide adsorbent 1 is zeolite, the mixed gas containing carbon dioxide is air (atmosphere), and the number of pipes connected to the adsorption / desorption chamber 30 is three. The case will be described as an example.

  Of the three pipes 42, 44, 46 connected to the adsorption / desorption chamber 30, one pipe 46 is connected to the concentrated carbon dioxide storage chamber 40, and the concentrated carbon dioxide produced in the adsorption / desorption chamber 30 is used. This is a pipe 46 for supplying air to the concentrated carbon dioxide storage chamber 40 and for taking out the concentrated carbon dioxide from the concentrated carbon dioxide storage chamber 40 to the outside. The remaining two pipes 42 and 44 are connected to the outside air, and a pipe 42 for introducing air from the outside to the adsorption / desorption chamber 30 and a pipe 44 for discharging the gas in the adsorption / desorption chamber 30 to the outside. It is.

  First, the valve 46a (the valve 46a disposed between the adsorption / desorption chamber 30 and the concentrated carbon dioxide storage chamber 40) of the pipe 46 for supplying the concentrated carbon dioxide to the concentrated carbon dioxide storage chamber 40 is closed. Then, the valve 42a of the pipe 42 for introducing air into the adsorption / desorption chamber 30 from the outside and the valve 44a of the pipe 44 for discharging the gas in the adsorption / desorption chamber 30 to the outside are opened. Further, the open / close shutter 36 provided at one end of the waveguide 18 connected to the adsorption / desorption chamber 30 (a connection portion between the adsorption / desorption chamber 30 and the waveguide 18) is closed.

  The agitator 32 is driven by the motor 34 to generate an air flow in the adsorption / desorption chamber 30. Thereby, outdoor air flows into the adsorption / desorption chamber 30 through the pipe 42, and the air contacts the carbon dioxide adsorbent 1 as shown in FIG. 3. At this time, part or all of carbon dioxide in the air is adsorbed to the carbon dioxide adsorbent 1 (adsorption step). That is, carbon dioxide is separated from the air. The air after coming into contact with the carbon dioxide adsorbent 1 and separating the carbon dioxide is discharged out of the adsorption / desorption chamber 30 through the pipe 44. In FIG. 3, arrows indicate the air flow.

  Next, the rotation of the agitator 32 is stopped, and the valve 42a of the pipe 42 and the valve 44a of the pipe 44 are closed. Further, the open / close shutter 36 is opened. And the microwave power supply 12 of the electromagnetic wave irradiation part 10 is started, and a microwave is generated. The operating conditions of the microwave power source 12 are a frequency of 2450 MHz and an output of 500 to 1000 W. As shown in FIG. 4, the generated microwave 50 enters the adsorption / desorption chamber 30 through the isolator 14, the matching unit 16, and the waveguide 18, and is irradiated onto the carbon dioxide adsorbent 1.

  If the microwave 50 is irradiated while rotating the stirrer 32, the microwave 50 can be diffused more uniformly in the adsorption / desorption chamber 30. If the microwave 50 is irradiated while rotating the turntable 22 simultaneously with the rotation of the stirrer 32, the carbon dioxide adsorbent 1 can be irradiated with the microwave 50 more uniformly.

  The carbon dioxide adsorbent 1 irradiated with the microwave 50 rises in temperature because the water contained in the carbon dioxide adsorbent 1 itself and the carbon dioxide adsorbent 1 are vibrated by the microwave 50. The heating temperature varies depending on the type of the carbon dioxide adsorbent 1 and the like. For example, in the case of zeolite, it is more preferable to heat the carbon dioxide adsorbent 1 so that the temperature is 60 ° C. or higher and 180 ° C. or lower.

  After the temperature is raised to a predetermined temperature, the carbon dioxide adsorbed on the carbon dioxide adsorbent 1 is desorbed and released into the adsorption / desorption chamber 30 by holding the temperature for 1 minute to 5 minutes, for example. (Desorption process). As a result, concentrated carbon dioxide that is air having a higher carbon dioxide concentration than the atmosphere is produced in the adsorption / desorption chamber 30.

  When the irradiation of the microwave 50 is completed, the microwave 50 is blocked by closing the open / close shutter 36. Then, the valve 46a disposed between the adsorption / desorption chamber 30 and the concentrated carbon dioxide storage chamber 40 is opened, and the stirrer 32 is rotated. Then, as shown in FIG. 5, the concentrated carbon dioxide in the adsorption / desorption chamber 30 is sent to the concentrated carbon dioxide storage chamber 40 via the pipe 46 and stored in the concentrated carbon dioxide storage chamber 40 (air supply process). . When the supply of the concentrated carbon dioxide to the concentrated carbon dioxide storage chamber 40 is completed, the valve 46a is closed.

  At this time, since the carbon dioxide adsorbent 1 in the adsorption / desorption chamber 30 is in a heated state, the heated carbon dioxide adsorbent 1 is cooled so that carbon dioxide can be adsorbed again. The cooling method is not particularly limited, and may be naturally cooled or may be cooled by a cooling device. That is, the carbon dioxide separator of this embodiment may include a cooling device that cools the carbon dioxide adsorbent 1 in the adsorption / desorption chamber 30.

  The carbon dioxide concentration of the concentrated carbon dioxide in the concentrated carbon dioxide storage chamber 40 is measured using a carbon dioxide concentration meter or the like, and the above adsorption process, desorption process, and air supply process are performed until the desired carbon dioxide concentration is reached. Repeatedly, carbon dioxide is concentrated. The carbon dioxide concentration in the atmosphere is about 400 ppm, but the above-described adsorption process, desorption process, and air supply process are repeated until the carbon dioxide concentration of the concentrated carbon dioxide in the concentrated carbon dioxide storage chamber 40 reaches, for example, 1000 to 2000 ppm. carry out.

  When the carbon dioxide concentration of the concentrated carbon dioxide in the concentrated carbon dioxide storage chamber 40 reaches a desired concentration, the valve 46b installed in the downstream portion of the piping 46 from the concentrated carbon dioxide storage chamber 40 is opened, The concentrated carbon dioxide in the concentrated carbon dioxide storage room 40 is taken out of the room. Extraction of the concentrated carbon dioxide is performed until the carbon dioxide concentration in the concentrated carbon dioxide storage chamber 40 becomes approximately the same as the carbon dioxide concentration in the atmosphere, for example. The take-out time is about several minutes.

  Thus, if the carbon dioxide separator of this embodiment is used, the carbon dioxide adsorbent 1 in the adsorption / desorption chamber 30 can be heated in a short time, so that the amount of energy consumption is small. Therefore, it is possible to produce concentrated carbon dioxide by separating carbon dioxide from a mixed gas containing carbon dioxide in a short time and at low cost by the heat swing method.

  Although the use of the manufactured concentrated carbon dioxide is not specifically limited, For example, it can be used for the cultivation use of agricultural products. That is, the yield and quality of crops can be improved by supplying concentrated carbon dioxide into an agricultural house such as a vinyl house and using it for plant photosynthesis. Alternatively, the produced concentrated carbon dioxide can be used as a raw material for dry ice, for example.

  Furthermore, the use of the carbon dioxide separator of the present embodiment is not limited to the use for producing concentrated carbon dioxide, and may be used for other uses. For example, it can also be used as an exhaust gas treatment device that removes carbon dioxide from various exhaust gases discharged from automobiles, factories, incinerators, and the like. Moreover, it can also be used as an air purification device that removes carbon dioxide from indoor air of buildings (housing, buildings, etc.), automobiles, trains, ships, aircrafts, and the like.

DESCRIPTION OF SYMBOLS 1 Carbon dioxide adsorbent 10 Electromagnetic wave irradiation part 20 Adsorbent container 20a Bottom part 30 Adsorption / desorption room 40 Concentrated carbon dioxide storage room 50 Microwave

Claims (9)

  A carbon dioxide separator comprising: a carbon dioxide adsorbent capable of adsorbing and desorbing carbon dioxide according to a temperature difference; and an electromagnetic wave irradiation unit that irradiates and heats the carbon dioxide adsorbent with electromagnetic waves.   The carbon dioxide separator according to claim 1, wherein the carbon dioxide adsorbent is zeolite.   The carbon dioxide separator according to claim 1 or 2, wherein the electromagnetic wave is a microwave.   The carbon dioxide separator according to any one of claims 1 to 3, wherein the carbon dioxide adsorbent has a pellet shape.   An adsorbent container for containing the carbon dioxide adsorbent; and an adsorption / desorption chamber in which the adsorbent container is disposed to perform adsorption and desorption of carbon dioxide in the carbon dioxide adsorbent. The carbon dioxide separator according to any one of claims 1 to 4, wherein the unit is connected to the adsorption / desorption chamber so that the carbon dioxide adsorbent can be irradiated with electromagnetic waves.   The carbon dioxide separator according to claim 5, wherein at least a part of the adsorbent container is made of a material having gas permeability. An adsorption step in which a mixed gas containing carbon dioxide is brought into contact with a carbon dioxide adsorbent capable of adsorbing and desorbing carbon dioxide according to a temperature difference, and the carbon dioxide adsorbent adsorbs the carbon dioxide;
Desorption step of irradiating and heating the carbon dioxide adsorbent adsorbing carbon dioxide in the adsorption step to desorb carbon dioxide from the carbon dioxide adsorbent;
A carbon dioxide separation method comprising:   The carbon dioxide separation method according to claim 7, wherein the carbon dioxide adsorbent is zeolite.   The carbon dioxide separation method according to claim 7 or 8, wherein the electromagnetic wave is a microwave.

Images