JP2003054928A - Method and apparatus for separating carbon dioxide and system therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate only carbon dioxide efficiently from a gas containing carbon dioxide. SOLUTION: Carbon dioxide is separated from a gas containing carbon dioxide by bringing the gas into contact with an adsorption member 11 at a fixed temperature set by a cooler 14 under a pressurized atmosphere to condense and fix carbon dioxide contained in the gas on the surface of the adsorption member 11. The cooler 14 supplies heat so that the gas temperature becomes equal to or below the sublimation point of carbon dioxide in the adsorption of carbon dioxide and supplies heat so that the gas temperature becomes equal to or above the sublimation temperature of carbon dioxide in the releasing of carbon dioxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adsorbing and releasing only carbon dioxide from a gas containing carbon dioxide, an apparatus and a system therefor, and particularly effective for efficiently releasing carbon dioxide after separating carbon dioxide. The present invention relates to a method of use, an apparatus and a system thereof.

[0002]

2. Description of the Related Art Currently, there is a direction to reduce the emission of greenhouse gases such as carbon dioxide. Regarding carbon dioxide, although accurate grasp is difficult, research and development on carbon dioxide fixation technology are also underway. In addition, technological development for collecting and disassembling what exists in the city is underway. In this way, as a whole of greenhouse gas countermeasures, while advancing gas emission reduction measures, gas absorption / fixation / recovery, such as construction of a system for forest / agricultural land conservation / maintenance and recovery of alternative CFCs, etc. -It is also extremely important to proceed with various measures related to disassembly and the like.

The carbon dioxide emission concentration of exhaust gas is about 10% for diesel engines and about 1 for boilers.
3%, digestion gas from sewage treatment plants and food factories is about 40%. In particular, digestive gas that produces manure and the like has methane as a main component, and its use as fuel for power generation facilities and the like is considered.

However, since the digestive gas contains a large amount of carbon dioxide and the efficiency as a fuel is low as it is, a purification technique for separating and purifying carbon dioxide is strongly desired.

The current carbon dioxide separation technology is as follows:
(1) Absorption method that separates and collects using sodium hydroxide, water, etc., (2) Adsorption method that separates and collects using a solid adsorbent such as zeolite, and (3) using a membrane that passes only carbon dioxide There is a membrane separation method that "sieves" carbon dioxide and other exhaust gas. The features of these methods are briefly described.

In method (1), carbon dioxide is adsorbed on an amine solution and a caustic soda solution. The method has been introduced to power plant exhaust gas treatment and sewage treatment methane purification. The adsorbed solution is heated to separate carbon dioxide and then returned to the amine solution. However, this method is disadvantageous in that waste liquid treatment is required and that it is weak against acid components.

The method (2) separates carbon dioxide by adsorbing carbon dioxide to the zeolite by a pressure swing method using zeolite.
It has been introduced to treat exhaust gas from power plants. Zeolite can adsorb about 0.1 liter of carbon dioxide per gram and has a strong property against acid components.

The method (3) recovers a hydrogen separation membrane such as cellulose acetate or polystyrene. There are also systems that make membrane permeation efficient by adding steam to the feed gas. It has been introduced to remove carbon dioxide from natural gas and landfill gas and fermentation gas.

[0009]

[Problems to be Solved by the Invention] Various gases (natural gas,
As shown in Table 1, methods such as amine method, PSA method, and membrane method are generally used to remove carbon dioxide contained in digestive gas and other process gases). It is applied to the purification of working gas. In particular, the methods listed in this table are established mainly as a method for separating carbon dioxide in methane gas.

[0010]

[Table 1]

However, in these methods, the initial cost and running cost are generally high, and the control tends to be complicated. In addition, the current situation is that it is extremely inconvenient to use, as parts are severely deteriorated, maintenance is complicated, and a large amount of dangerous substances, sodium hydroxide, is required.

There is also a separation method using the adsorption phenomenon using other zeolites. In this method, carbon dioxide (gas) is adsorbed on the surface of the zeolite, the temperature is raised, and the carbon dioxide is collected. However, according to this principle, the water contained in the gas is more likely to be adsorbed first, and it is necessary to provide a large-scale dehydration facility in the preceding stage of the apparatus.

The present invention has been made in view of such circumstances, and an object thereof is a carbon dioxide separation method, an apparatus and a system therefor capable of efficiently separating only carbon dioxide from a gas containing carbon dioxide. To provide a new product.

[0014]

In order to solve the above-mentioned problems, the carbon dioxide separation method, its apparatus and system according to the present invention are characterized as follows.

According to the first aspect of the present invention, in a carbon dioxide separation method of contacting a gas containing carbon dioxide with an adsorption member to separate carbon dioxide from the gas, the gas containing carbon dioxide is kept at a constant temperature. And carbon dioxide contained in the gas are condensed and fixed on the surface of the adsorbing member by contacting with the adsorbing member in a pressure atmosphere and separating the carbon dioxide.

According to a second aspect of the present invention, in the carbon dioxide separation method according to the first aspect, when releasing the adsorbed carbon dioxide, the temperature atmosphere is adsorbed by raising the temperature above the sublimation point of carbon dioxide. It is characterized by releasing carbon dioxide out of the system.

The present invention according to claim 3 is a carbon dioxide separator for removing carbon dioxide from a gas containing carbon dioxide by bringing the gas into contact with an adsorbing member. A pipe to which a gas containing the gas is supplied, an adsorption member which is installed in the pipe and is brought into contact with the gas under a constant temperature and pressure atmosphere, and an adsorption member which is installed in the pipe and is provided in the adsorption member from the cooler. And a heat conductor for conducting the supplied heat.

According to a fourth aspect of the present invention, in the carbon dioxide separator according to the third aspect, the cooler supplies heat below the sublimation point of carbon dioxide when adsorbing carbon dioxide, and when releasing the adsorbed carbon dioxide. It is characterized by supplying heat above the sublimation point of carbon dioxide.

According to a fifth aspect of the present invention, a gas tank for temporarily storing a gas containing carbon dioxide and a dioxide for removing the carbon dioxide from the gas by bringing the gas supplied from the gas tank into contact with the adsorption member. A carbon separator, a compressor for adjusting the internal pressure of the carbon dioxide separator,
A carbon dioxide separation system comprising a valve means for supplying the gas supplied from the carbon dioxide separation device to a fuel consumption system or a carbon dioxide consumption system, the carbon dioxide separation device further comprising a cooler. However, a pipe or tank to which a gas containing carbon dioxide is supplied, an adsorbing member installed in this pipe or tank and brought into contact with the gas under a constant temperature and pressure atmosphere, and installed in the same pipe or tank And a heat conductor that conducts the heat supplied from the cooler to the adsorption member, the cooler having a carbon dioxide separation temperature not higher than the sublimation point of carbon dioxide when the device is a carbon dioxide adsorption step. Is supplied, and when the carbon dioxide separation device is in the carbon dioxide releasing step, heat above the sublimation point of carbon dioxide is supplied.

According to a sixth aspect of the present invention, in the carbon dioxide separation system according to the fifth aspect, when the carbon dioxide separation device is a carbon dioxide adsorption step, the valve means has a processing gas supply path as a fuel consumption system. It is characterized in that the processing gas supply path is set to the carbon dioxide consuming system side when the carbon dioxide separation device is in the carbon dioxide releasing step.

In the above invention, the target of the gas containing carbon dioxide is, for example, a digestive gas containing methane produced from garbage, manure or sludge.

As the adsorption member, there is a member to which an adsorbent such as activated carbon, activated alumina, silica gel or zeolite is fixed.

Examples of the activated carbon include crushed coconut shell activated carbon or coal, spherical coal or petroleum, and molded coconut shell activated carbon.

As the zeolite, for example, A type (Me
_{12 / n}((AlO₂)₁₂・ (SiO₂) ₁₂) ・ 27H₂O,
Me = Na, K, Ca) and X type (Me_{86 / n}((Al
O₂)₈₆・ (SiO₂)₁₀₆) ・ 276H₂O, Me = N
a, K, Ca). Furthermore, for A type
Are, for example, 3A type, 4A type, and 5A type. Also, X
There is a 13X type, for example. 3A type has an average pore size of 3
× 10^-TenIt has become m. Here, type 4A is the average
Pore size is 4 × 10^-Tenm and 5A type have an average pore size of 5 ×
10^-Tenm and 13X type have an average pore size of 10 × 10.^-Ten
It has become m.

In order to selectively separate carbon dioxide, adsorption is carried out by a molecular sieving action, especially in the initial stage of the separation process. For example, when only carbon dioxide is adsorbed and separated from a gas containing methane and carbon dioxide, the average pore diameter is 3
A material of ^x10-10 to 4x10-10m is most ^suitable . This is because the molecular diameter of carbon dioxide is approximately 2.8 × 10 ^-10 m and the molecular diameter of methane is approximately 4.0 × 10 ^-10 m, and the adsorbed carbon dioxide molecules prevent the adsorption of methane molecules. This is because Therefore, in the adsorbent, 3A type and 4A type
Type of zeolite is most suitable.

However, at the initial stage of the carbon dioxide adsorption step performed below the sublimation point of carbon dioxide, after the methane molecules and the carbon dioxide molecules are adsorbed and solidified on the surface of the adsorbing member, only the carbon dioxide molecules are solidified. Therefore, in such a state, carbon dioxide can be separated regardless of the pore diameter of the adsorbent. Therefore, in this case, the adsorbent is 3A type or 4A type.
Not only the type zeolite but also the above-mentioned activated carbon, activated alumina, silica gel, and zeolites other than 3A type and 4A type are applicable.

The member for fixing the adsorbent may have any shape, but is formed so that the contact area with the gas to be treated is as large as possible. Desirably, the adsorbent may be formed so that the load of the gas to be treated on the adsorbent can be arbitrarily adjusted. Therefore, for example, a plate-shaped member, a cylindrical member, a cylindrical member, a polygonal pillar member, a polygonal cylindrical member, a corrugated plate member, a substantially blade-shaped member, or a honeycomb-shaped member is separably formed. At this time, the adsorbent is molded in consideration of the pressure loss of the pipe in which it is installed. Further, as the material of the member, one having a high thermal conductivity, for example, one based on aluminum or copper is used. Desirably, the same kind as the heat conductor is adopted.

As the heat conductor, one having good heat conductivity at -161 ° C. to room temperature is used. Specifically, silver (heat conductivity (W / mK): 419 (room temperature), about 500 (-170)
° C.), the coefficient of thermal expansion ^{(× 10 -6 / ℃):} 15~19, hardness: 26Hv), aluminum (thermal conductivity (W / m ·
K): 238 (room temperature), about 300 (-170 ° C), thermal expansion coefficient (x10 ^-6 / ° C): 12 to 23, hardness: 18H
v), made of copper (thermal conductivity (W / mK): 394 (room temperature), about 500 (-170 ° C), coefficient of thermal expansion (× 10 ^-6)
/ ° C): 10 to 16, hardness: 96 Hv), made of gold (thermal conductivity (W / mK): 293 (room temperature), coefficient of thermal expansion (x)
Examples thereof include those of 10 ⁻⁶ / ° C.): 15 to 16 and hardness: 20 Hv). The material made of copper is the best in consideration of the hardness and cost of the material, but the material made of silver and gold may be used as the coating material for the copper base material, for example.

The temperature and pressure atmosphere for adsorbing and removing carbon dioxide is below the sublimation point of carbon dioxide, that is, according to the state diagram of carbon dioxide, for example, 1 atm (0.10 MPa).
Under a), the temperature atmosphere is kept below -79 ° C. At this time, in the initial stage of the reaction, the carbon dioxide (gas) captured on the surface of the adsorption member is adsorbed on the surface but immediately condensed to become a solid. Further, the carbon dioxide (gas) colliding with the condensed carbon dioxide (solid) is condensed and solidified, so that the condensation occurs in a chain regardless of the surface area of the adsorption member. Further, even when water is present in the gas, it becomes ice after adsorption, and this becomes the nucleus for capturing carbon dioxide.

On the other hand, the atmosphere for releasing the adsorbed carbon dioxide is first maintained between the sublimation point and room temperature. At this time, all but carbon dioxide and water adsorbed on the surface of the adsorbing member are released by sublimation and evaporation. When it is desired to completely release the molecules adsorbed on the surface, the temperature atmosphere is raised to 100 ° C. or higher. Further, other releasing methods include a desorbing method by reducing pressure.

According to the state diagram of carbon dioxide, the pressure atmosphere of carbon dioxide is 5.11 atm (0.52 MP).
a) or higher and the temperature atmosphere is −56.6 ° C. or higher,
Some are in liquid form. Therefore, for example, after pressurizing the gas containing carbon dioxide to 5.11 atm or more,
When cooled to a temperature atmosphere of −56.6 ° C. or higher, for example, −50 to 0 ° C., only the carbon dioxide component can be liquefied and separated, and further reduced pressure can be vaporized and separated.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the embodiment of the present invention is not limited to the form disclosed in the drawings described later within the scope of the gist of the invention. (Embodiment 1) FIG. 1 is a schematic view showing an embodiment of the carbon dioxide separation method according to the present invention.

The carbon dioxide separator according to this embodiment is
A plurality of adsorbing members 11 to which adsorbents are fixed are provided in a pipe 10 through which a gas containing carbon dioxide flows. The individual adsorption members 11 are fixedly supported in the pipe 10 by the heat conductors 12 and 13. The heat conductors 12 and 13 transfer the cooling heat introduced from the outside to the adsorption member 11. Here, a cooler 14 is attached to the pipe 10 to maintain the atmosphere inside the pipe and the adsorption member 11 at a predetermined temperature.

The adsorbing member 11 is formed by fixing an adsorbing material to a metal fixing member with a binder. The fixing member is formed in such a shape that the contact surface area with the gas is as large as possible. For example, plate-like, almost blade-like, columnar,
It is molded into a cylindrical shape, a polygonal column shape, a polygonal tube shape, a corrugated plate shape, or a honeycomb shape. The filling amount of the adsorption member 11 into the pipe 10 is determined by the gas load amount. Therefore, the suction member 11 is detachably and separably formed.

As the adsorbent, activated carbon, activated alumina,
There are silica gel, zeolite, etc., and the average particle size of the adsorbent used depends on the type of gas to be treated.

For example, when only carbon dioxide is separated from a gas containing methane and carbon dioxide, the boiling point of methane is -161.5 ° C. and the sublimation point of carbon dioxide or less, and the molecular diameter of methane is smaller than that of carbon dioxide. Is large, the average pore diameter is 3.8 to 4.0 Å (3.8 × 10 ^{-10 to} 4.0 × 10 ^-10
Carbon dioxide can be selectively separated by adopting m) (Table 2).

[0037]

[Table 2]

Considering the heat transfer efficiency, the heat conductors 12 and 13 are made of the same material as that of the fixing member.
For example, if the material of the fixing member is made of copper,
The same kind of heat conductor is adopted.

In the cooler 14, the temperature atmosphere in the pipe 10 is set to the sublimation point range of carbon dioxide (0.10 to 0.52 MPa,
The temperature can be adjusted to -79.0 to -56.6 ° C (Fig. 5). Liquid nitrogen, for example, is used as the refrigerant.

FIG. 2 shows the principle of adsorption / desorption in the carbon dioxide separator. (A) shows the principle of adsorption / desorption of carbon dioxide in the prior art, and (b) shows the principle of adsorption / desorption of carbon dioxide in the present invention.

The prior art is based on the principle that carbon dioxide is captured as a gas on the surface of the adsorbing member 21 and is sufficiently adsorbed, and then the adsorbed carbon dioxide is released by raising the temperature. As mentioned above, in this method, the water coexisting with carbon dioxide is easily captured, and when carbon dioxide or water is captured on the entire surface of the adsorption member 21, the adsorption of carbon dioxide is stopped. The amount depends largely on the surface area of the porous material.

In the present invention, the temperature of the atmosphere and the temperature of the adsorption member 21 are set below the sublimation point of carbon dioxide by the heat conductor 22 (for example, under 1 atm (0.10 MPa)).
The temperature is maintained below 79 ° C). At this time, in the initial stage of the reaction, carbon dioxide (gas) that has come into contact with the surface of the adsorbing member 21 is adsorbed on the surface as in the conventional case, but immediately condenses into a solid. Further, since the carbon dioxide (gas) that collides with the condensed carbon dioxide (solid) is condensed and solidified, the condensation occurs in a chain not depending on the surface area of the adsorption member 21, so that the carbon dioxide (gas) for a long time Carbon separation is possible. Furthermore, even if there is water in the gas,
Since the temperature atmosphere is below the sublimation point of water, water can become ice after adsorption and can become nuclei for capturing carbon dioxide.
There is no effect due to water contamination. For this reason, the dehydration equipment at the front stage of the apparatus becomes unnecessary.

Further, in the release process after the adsorption of carbon dioxide, the temperature atmosphere is set in the region from the sublimation point of carbon dioxide to room temperature. At this time, all but carbon dioxide and water adsorbed on the surface of the adsorbing member 21 are released by sublimation and evaporation. Then, only when it is desired to completely release the molecule adsorbed on the surface, the temperature is increased and released in the same manner as in the conventional method. Incidentally, as another discharging method, there is a desorbing method by reducing pressure. (Embodiment 2) FIG. 3 schematically shows a carbon dioxide separation system which is an embodiment of the carbon dioxide separation method according to the present invention.

Generally, as shown in Table 3, digestive gas produced from garbage, manure and the like has a composition ratio of methane of about 60% and carbon dioxide of about 40%. The melting point of methane is -18
Since it is about 3 ° C., which is sufficiently lower than the sublimation point of carbon dioxide, it is possible to completely separate methane and carbon dioxide. In addition, since adsorption is performed in a low temperature region much lower than the ignition point of methane, it can be handled very safely.

[0045]

[Table 3]

As disclosed in FIG. 3, the carbon dioxide separation system in this embodiment includes a digestion gas tank 31,
Compressor 32, carbon dioxide separator 34, valve means 36, fuel consumption system 37, carbon dioxide consumption system 3
8 and.

The digestion gas tank 31 stores gas produced from raw garbage and manure. In addition, in the tank 31,
A return path 39 for introducing the gas from which carbon dioxide has been separated by the carbon dioxide separator 34 is installed.

The compressor 32 is a digestion gas tank 31.
The gas inside is supplied to the carbon dioxide separator 34. Also,
The compressor 32 arbitrarily adjusts and maintains the pressure atmosphere in the device 34. Therefore, a device 34 is provided in the path connecting the compressor 32 and the carbon dioxide separator 34.
A pressure gauge 33 for monitoring the pressure atmosphere inside is installed.

The carbon dioxide separator 34 separates carbon dioxide from the introduced gas under a predetermined temperature and pressure atmosphere, and has the same structure as the carbon dioxide separator according to the first embodiment. A pressure adjusting valve with a variable pressure set value for controlling the internal pressure to be constant may be installed on the outlet side of the device 34.

The valve means 36 is a three-way valve and switches the gas supply line in the carbon dioxide separator 34 to either the fuel consumption system 37 or the carbon dioxide consumption system 38.

The fuel consumption system 37 is supplied with methane gas from which carbon dioxide has been removed. Examples of the consumption system include a generator facility and a burner facility.

The carbon dioxide consuming system 38 is supplied with the carbon dioxide concentrated by the carbon dioxide separator 34. Examples of the consumption system include a photosynthetic organism culture facility for plants and algae.

An operation example of the carbon dioxide separation system according to this embodiment will be described.

The operation of the carbon dioxide separation system is controlled by a control means (not shown). That is, the methane-carbon dioxide mixed gas is supplied to the carbon dioxide separator 34 by the compressor 32. At this time, the gas supply line of the valve means 36 is set to the fuel consumption system 37 side. Here, in the carbon dioxide separation device 34, the atmosphere inside the device 34 is maintained at a constant pressure by the compressor 32 under the supervision of the pressure gauge 33, and is also maintained at a constant temperature by the attached cooler. (Eg 1
Under atmospheric pressure (0.10 MPa), the temperature atmosphere is -79.
Set to 0 ° C). At this time, in the apparatus 34, carbon dioxide molecules in the gas phase are adsorbed on the surface of the adsorbing member and further condensed, and carbon dioxide is separated from the mixed gas. Then, after the completion of adsorption is detected after a lapse of a certain period of time or due to an increase in the pressure gauge, a change in the flow meter, etc., the gas supply line of the valve means 36 is set to the carbon dioxide consumption system 38 side. At this time, the temperature atmosphere in the carbon dioxide separation device 34 is set to be equal to or higher than the sublimation point of carbon dioxide, and the carbon dioxide fixed on the surface of the adsorbent in the device 34 is released to the carbon dioxide consuming facility 38. When it is not necessary to directly supply the load (here, the fuel consumption system 37), the tank 31 is returned to the digestion gas tank 31 via the return path 39.
The carbon dioxide concentration inside is lowered. (Embodiment 3) FIG. 4 schematically shows a carbon dioxide separation system which is an embodiment of the carbon dioxide separation method according to the present invention. Further, FIG. 5 is a state diagram of carbon dioxide.

The phase equilibrium state of the pure substance is unique, and as is clear from FIG. 5, carbon dioxide has a pressure atmosphere of 5.11 atm (0.52 MPa) or more and a temperature atmosphere of −56.6 ° C. When it is above, it exists in a liquid state. Therefore, in the present embodiment, the carbon dioxide-containing gas is brought into contact with the adsorbent in consideration of the phase equilibrium state of carbon dioxide to improve the efficiency of selective separation of carbon dioxide.

The carbon dioxide separation system according to this embodiment comprises a compressor 41 and a carbon dioxide separation device 43.
And valve means V1 and V2, and operation is controlled by control means (not shown).

The compressor 41 arbitrarily adjusts and maintains the pressure atmosphere in the carbon dioxide separator 43. Therefore, a pressure gauge for monitoring the pressure atmosphere in the device 43 is installed in the path connecting the compressor 41 and the carbon dioxide separator 43. Further, as shown in the figure, a gas precooler 42 may be installed in the path in order to reduce energy loss that occurs during the cooling process in the carbon dioxide separator 43.

The carbon dioxide separator 43 is a gas containing carbon dioxide (for example, a mixed gas of methane and carbon dioxide).
A plurality of adsorption members 431 are provided in the tank 430 to which is supplied. Each of the adsorbing members 431 is a heat conductor 43.
2,433 fixedly supported in the tank 430.
The heat conductors 432 and 433 transfer the cooling heat introduced from the outside to the adsorption member 431. Here, a cooler 434 is attached to the tank 430 to maintain the atmosphere in the tank and the adsorption member 431 at a predetermined temperature.

As the adsorbing member 431, there is a member made of metal having good thermal conductivity such as aluminum or copper. Adsorption member 43
1 is formed in, for example, a substantially blade shape, and a plurality of thermal conductors 432 and 433 are attached to the thermal conductors 432 and 433 as shown in FIG. The number of incidents depends on the gas load. Therefore, the adsorbing member 431 is detachably installed on the heat conductors 432 and 433.

When the adsorbing member 431 is obtained by fixing the adsorbing material to the metal fixing member with the binder as in the first embodiment, the reaction of introducing the gas to be treated into the tank 430 is performed. Since carbon dioxide molecules can be captured in the initial stage, carbon dioxide can be efficiently adsorbed and separated.

The carbon dioxide separator 43 in this embodiment can also be used as a carbon dioxide separator in the carbon dioxide fixing system according to the second embodiment.

The valve means V1 (hereinafter referred to as V1) is a pressure adjusting valve whose pressure setting value is variable, and is installed in a pipe connected to the upper part of the tank 430, and adjusts the pressure in the tank 430 to a constant value. That is, when the carbon dioxide mixed gas is introduced into the tank 430 and the pressure in the tank reaches a certain value or higher (for example, the internal pressure reaches 10 atm (1.01 MPa) in a temperature atmosphere of −50 ° C.), V1 Is set to open, and the gas from which carbon dioxide has been removed is discharged out of the system.
Then, when the pressure inside the tank 430 drops to a predetermined value (for example, 8 atm (0.81 MPa)), V1 is set to be closed.

The valve means V2 (hereinafter referred to as V2) is installed in a pipe connected to the bottom of the tank 430 and transfers gaseous and liquid carbon dioxide to the outside of the system.

An operation example of the carbon dioxide separation system according to this embodiment will be described.

The operation of the carbon dioxide separation system is controlled by a control means (not shown). That is, the carbon dioxide mixed gas is introduced into the tank 430 after being pressurized to a constant pressure (5.11 atm (0.52 MPa) or more) by the compressor 41. In the carbon dioxide separation device 43, V2 is set to be closed, and the device 43
The atmosphere inside the compressor 41 under the supervision of the pressure gauge.
Is maintained at a constant pressure by the cooler 434 (for example, the pressure atmosphere is 5.11 atm (0.52 MPa) or more, the temperature atmosphere is −).
56.6 ° C or higher). At this time, the tank 43
While the atmosphere inside 0 reaches the predetermined pressure and temperature, carbon dioxide in the gas phase is adsorbed on the surface of the adsorption member 431. Further, when the atmosphere in the tank 430 reaches a predetermined pressure and temperature, the carbon dioxide component in the vapor phase and the carbon dioxide component adsorbed on the surface of the adsorbent are liquefied, and the inner wall of the tank 430 and the heat conductors 432, 433 are liquefied. As it is transmitted, it accumulates at the bottom of the tank 430. During this period, the gas from which carbon dioxide has been removed is discharged via V1. Then, when the liquefied carbon dioxide is accumulated in the tank 430 by a certain amount or more, the supply of the gas to be processed is stopped and V2 is set to open. At this time, the liquefied carbon dioxide is transferred to the outside of the system via V2. Further, a part of the liquefied carbon dioxide can be taken out as vaporized carbon dioxide due to the decrease in the internal pressure of the tank 430 accompanying the opening of V2.

As described above, in this embodiment, since the temperature atmosphere is cooled while the carbon dioxide mixed gas is brought into contact with the adsorbent, in addition to the effects of the first and second embodiments, only carbon dioxide is liquefied. You can take it out.
In particular, in this embodiment, when the separated carbon dioxide is released, it can be easily taken out as liquefied carbon dioxide and vaporized carbon dioxide by the internal pressure of the separation device only by operating the valve. Further, when mixing of the mixed gas into the line for discharging the liquefied carbon dioxide out of the system does not pose a problem, the liquefied carbon dioxide can be taken out by the valve means (V2 in FIG. 4) while separating the carbon dioxide, It is possible to continuously supply the gas to be treated, that is, to continuously remove carbon dioxide.

[0067]

As is apparent from the above description, according to the carbon dioxide separation method, the apparatus and the system thereof according to the present invention, it is possible to efficiently separate only carbon dioxide from a gas containing carbon dioxide. Becomes In particular, in the present invention, since the carbon dioxide captured on the surface of the porous material is solidified in a chain by cooling the temperature of the carbon dioxide mixed gas, the adsorption amount of carbon dioxide is increased. Even if the gas to be treated contains water, the carbon dioxide molecules are condensed and fixed, so that the adsorption efficiency of carbon dioxide does not decrease. Furthermore, the separation from the gas whose melting point is lower than the sublimation point of carbon dioxide can be performed very easily. Further, since no chemical change is involved, it is not necessary to treat by-products and the like, and the carbon dioxide separation performance can be maintained for a long time. Further, even when the gas to be treated contains combustible gas such as methane, it can be controlled in a low temperature region sufficiently lower than the ignition point and the flash point, so that there is no danger of explosion.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a carbon dioxide separation method according to the present invention.

2A and 2B are explanatory views showing the principle of adsorption / desorption of carbon dioxide, wherein FIG. 2A shows the principle of adsorption / desorption of carbon dioxide in the prior art, and FIG. 2B shows the principle of adsorption / desorption of carbon dioxide in the present invention. .

FIG. 3 is a schematic view showing an embodiment of a carbon dioxide separation method according to the present invention.

FIG. 4 is a schematic view showing an embodiment of a carbon dioxide separation method according to the present invention.

FIG. 5 is a state diagram of carbon dioxide.

[Explanation of symbols]

34, 43 ... Carbon dioxide separators 11, 21, 431 ... Adsorption members 12, 13, 22, 432, 433 ... Heat conductors 14, 434 ... Cooler 36 ... Valve means 37 ... Fuel consumption system (for example, load (power generation Machine, burner, etc.) or fuel tank) 38 ... Carbon dioxide consuming system (for example, photosynthetic organism culture system for plants and algae)

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4D012 CA03 CB11 CD05 CG01 CH02                       CH06                 4D047 AA07 BA02 BA03 BA08 BA10                       BB04 DA10 DA14                 4G046 JB08 JB11 JB17 JB18 JC06

Claims (6)

[Claims] 1. A method for separating carbon dioxide, which comprises contacting a gas containing carbon dioxide with an adsorbing member to separate the carbon dioxide from the gas, wherein the gas containing carbon dioxide is adsorbed at a constant temperature and pressure atmosphere. And a carbon dioxide contained in the gas are condensed and fixed on the surface of the adsorption member to separate the carbon dioxide, thereby separating the carbon dioxide. 2. The method for separating carbon dioxide according to claim 1, wherein when releasing the adsorbed carbon dioxide, the adsorbed carbon dioxide is released outside the system by raising the temperature atmosphere above the sublimation point of carbon dioxide. A method for separating carbon dioxide, which comprises: 3. A carbon dioxide separator for contacting a gas containing carbon dioxide with an adsorbing member to remove carbon dioxide from the gas, which is provided with a cooler and is supplied with the gas containing carbon dioxide. A pipe, an adsorption member that is installed in the pipe and is brought into contact with the gas under a constant temperature and pressure atmosphere, and a pipe that is installed in the pipe and conducts heat supplied from the cooler to the adsorption member. A carbon dioxide separator comprising a heat conductor. 4. The carbon dioxide separation device according to claim 3, wherein the cooler supplies heat below the sublimation point of carbon dioxide when adsorbing carbon dioxide, and above the sublimation point of carbon dioxide when releasing the adsorbed carbon dioxide. A carbon dioxide separator characterized by supplying heat. 5. A gas tank for temporarily storing a gas containing carbon dioxide, a carbon dioxide separation device for contacting the gas supplied from the gas tank with an adsorption member to remove carbon dioxide from the gas, and the carbon dioxide separation device. A carbon dioxide separation system comprising a compressor for adjusting the internal pressure of the carbon separation device, and a valve means for supplying the gas supplied from the carbon dioxide separation device to a fuel consumption system or a carbon dioxide consumption system, The carbon dioxide separator is provided with a cooler, and a pipe or a tank to which a gas containing carbon dioxide is supplied, and a pipe or tank installed in the pipe or tank are brought into contact with the gas under a constant temperature and pressure atmosphere. An adsorption member, and a heat conductor installed in the same pipe or tank to conduct the heat supplied from the cooler to the adsorption member. , The cooler supplies heat below the sublimation point of carbon dioxide when the carbon dioxide separator is in the carbon dioxide adsorption step, and when the carbon dioxide separator is in the carbon dioxide releasing step, A carbon dioxide separation system characterized by supplying heat above the sublimation point. 6. The carbon dioxide separation system according to claim 5, wherein the valve means sets the processing gas supply passage to the fuel consumption system side when the carbon dioxide separation device is in the carbon dioxide adsorption step, A carbon dioxide separation system characterized in that when the carbon separator is a carbon dioxide releasing step, the supply path of the processing gas is set on the side of the carbon dioxide consuming system.