JP7338577B2 - Carbon dioxide recovery device and carbon dioxide recovery method - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a carbon dioxide recovery device and a carbon dioxide recovery method.

The method of recovering carbon dioxide is attracting attention from the viewpoint of reducing carbon dioxide emissions in the global warming problem.

Patent Document 1 discloses a reactor equipped with a carbon dioxide storage reduction type catalyst having carbon dioxide storage capacity and methane production capacity, a reactor equipped with a methanation catalyst, a means for supplying a purge gas, and a means for supplying a reducing gas. means for producing methane from a carbon dioxide-containing gas, wherein reactors comprising two or more carbon dioxide storage-reduction catalysts are arranged in parallel, and at least one purge gas is supplied. means for supplying at least one reducing gas are arranged upstream of the reactor comprising a carbon dioxide storage reduction catalyst in the gas flow path, and the reactor comprising at least one methanation catalyst is and at least one carbon dioxide storage reduction other than the gas outlet of the reactor equipped with the carbon dioxide storage reduction catalyst and the reactor located downstream of the reactor equipped with the carbon dioxide storage reduction catalyst in the gas flow path. A methane production apparatus in which the gas inlet of another reactor equipped with a type catalyst is connected by a purge gas recirculation line for supplying the purge gas discharged from the gas outlet of the reactor from the gas inlet of the other reactor is described.

JP 2019-108290 A

When separating and recovering carbon dioxide from a gas containing carbon dioxide, it is required to reduce energy consumption.

The present invention has been made in view of such circumstances, and the problem to be solved by one embodiment of the present invention is to recover carbon dioxide from a gas containing carbon dioxide and convert it to methane with low energy. It is to provide a carbon dioxide capture device.
Another problem to be solved by another embodiment of the present invention is to provide a carbon dioxide recovery method for recovering carbon dioxide from a gas containing carbon dioxide and converting it into methane with low energy.

The present invention includes the following aspects.
<1> A carbon dioxide recovery reducer accommodating a carbon dioxide storage reduction catalyst containing a metal oxide having carbon dioxide storage performance and a metal having methanation catalyst performance, and an adsorption material having carbon dioxide storage performance. a carbon dioxide storage device, a hydrogen supply source that supplies hydrogen to the carbon dioxide recovery and reduction device, a carbon dioxide-containing gas supply channel that supplies the carbon dioxide-containing gas to the carbon dioxide storage device, and carbon dioxide from the carbon dioxide storage device A first gas supply channel for supplying gas to the carbon dioxide recovery/reduction device, a discharge channel for discharging gas from the carbon dioxide recovery/reduction device to the atmosphere, and a second gas supply channel for supplying gas from the carbon dioxide recovery/reduction device to the carbon dioxide storage device. and a gas supply channel.
<2> The carbon dioxide recovery apparatus according to <1>, further comprising a combustor that generates a carbon dioxide-containing gas, and a methane converter that converts carbon dioxide desorbed from the adsorption material into methane.
<3> The carbon dioxide recovery device according to <1> or <2>, further comprising a pump that reduces the pressure in the carbon dioxide absorber.
<4> The carbon dioxide recovery device according to any one of <1> to <3>, comprising two or more carbon dioxide absorbers and two or more carbon dioxide recovery reducers in parallel.
<5> Equipped with two or more carbon dioxide storage devices and two or more carbon dioxide recovery and reduction devices, at least one carbon dioxide storage device to which a carbon dioxide-containing gas is supplied, and the carbon dioxide recovery and reduction device discharged from the carbon dioxide storage and reduction devices and at least one carbon dioxide storage device to which the gas discharged from the carbon dioxide storage device is supplied. a second exchange part for exchanging the carbon dioxide storage reduction catalyst contained between the primary carbon dioxide recovery reducer and the at least one carbon dioxide recovery reducer to which hydrogen is supplied; , the carbon dioxide recovery device according to any one of <1> to <3>.
<6> The first exchange part moves each adsorption material in each carbon dioxide occluding device in a direction opposite to the gas flow direction, and the second exchange part moves each carbon dioxide recovery reducer in each , the carbon dioxide recovery device according to <5>, wherein each carbon dioxide storage reduction catalyst is moved in a direction opposite to the gas flow direction.
<7> The carbon dioxide recovery device according to any one of <1> to <6>, further comprising a dehumidifier for removing moisture between the carbon dioxide recovery reducer and the carbon dioxide absorber.
<8> The carbon dioxide recovery device according to any one of <1> to <7>, further comprising a heat accumulator that stores exhaust heat generated by the carbon dioxide recovery reducer.
<9> A step of supplying hydrogen to a carbon dioxide recovery reducer containing a carbon dioxide storage reduction catalyst containing a metal oxide having carbon dioxide storage performance and a metal having methanation catalyst performance, and carbon dioxide storage performance a step of supplying a carbon dioxide-containing gas to a carbon dioxide storage device containing an adsorption material having and a step of supplying gas from a carbon dioxide recovery reducer to a carbon dioxide occlusion device.

According to embodiments of the present invention, carbon dioxide can be recovered from a gas containing carbon dioxide and converted to methane with low energy.

FIG. 1 is a schematic diagram showing the carbon dioxide capture device of the first embodiment. FIG. 2 is a flow chart showing a carbon dioxide recovery method using the carbon dioxide recovery device of the first embodiment. FIG. 3 is a schematic diagram showing the carbon dioxide capture device of the second embodiment. FIG. 4 is a schematic diagram showing a carbon dioxide capture device of a third embodiment. FIG. 5 is a flow chart showing a carbon dioxide recovery method using the carbon dioxide recovery device of the third embodiment. FIG. 6 is a schematic diagram showing the carbon dioxide capture device of the fourth embodiment. FIG. 7 is a flow chart showing a carbon dioxide recovery method using the carbon dioxide recovery device of the fourth embodiment. FIG. 8 is a schematic diagram showing the carbon dioxide capture device of the fifth embodiment. 9 is a schematic diagram showing a carbon dioxide recovery device of Comparative Example 1. FIG. FIG. 10 is a schematic diagram showing a carbon dioxide recovery device of Comparative Example 2. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First embodiment]
FIG. 1 is a schematic diagram showing the carbon dioxide capture device of the first embodiment. As shown in FIG. 1, the carbon dioxide recovery device 100 includes a combustor A, a heat utilization device B that is an example of a source gas supply source, a carbon dioxide absorber C, a carbon dioxide recovery reducer D, a methane A converter E and a hydrogen source H are provided.

Combustor A is a device for burning gas. The combustor A is connected to an air supply channel 11 , a combustion gas supply channel 12 and a methane supply channel 19 . Operation of combustor A is controlled by a controller (not shown).

The combustor A burns fuel (specifically, hydrogen, methane, etc.) to generate combustion gas. Although the combustion temperature is not particularly limited, it is, for example, 800°C to 1500°C. Heaters used for combustion include burners, gas turbines, and boilers.

The atmosphere supply channel 11 is a channel for supplying the combustor A with the atmosphere. An atmosphere supply valve V<b>1 is provided on the atmosphere supply channel 11 . The atmosphere is supplied to the combustor A when the atmosphere supply valve V1 is open. On the other hand, when the air supply valve V1 is closed, the supply of air to the combustor A is stopped. Opening and closing of the atmosphere supply valve V1 is controlled by a control unit (not shown). The atmosphere contains oxygen, nitrogen, carbon dioxide, and the like.

The first combustion gas supply channel 12 is a channel for supplying the combustion gas generated in the combustor A to the heat utilization equipment B. As shown in FIG. A first combustion gas supply valve V<b>2 is provided on the first combustion gas supply passage 12 . Combustion gas is supplied to the heat utilization equipment B when the first combustion gas supply valve V2 is open. On the other hand, when the first combustion gas supply valve V2 is closed, the supply of the combustion gas to the heat utilization equipment B is stopped. Opening and closing of the first combustion gas supply valve V2 is controlled by the controller.

The methane supply channel 19 is a channel for supplying the product gas generated in the methane converter E to the combustor A. The product gas mainly contains methane. A methane supply valve V<b>9 is provided on the methane supply flow path 19 . The generated gas is supplied to the combustor A when the methane supply valve V9 is open. On the other hand, when the methane supply valve V9 is closed, the supply of the produced gas to the combustor A is stopped. Opening and closing of the methane supply valve V9 is controlled by the controller.

The heat utilization device B is a device that utilizes the thermal energy of the combustion gas generated in the combustor A. After the combustion gas is converted into thermal energy by the heat utilization equipment B and used, the temperature of the combustion gas decreases. The combustion gas contains carbon dioxide, nitrogen, water vapor, and the like. Examples of heat utilization equipment B include water heaters and air conditioners. A first combustion gas supply channel 12 and a second combustion gas supply channel 13 are connected to the heat utilization device B. As shown in FIG.

The second combustion gas supply channel 13 is a channel for supplying the combustion gas discharged from the heat utilization equipment B to the carbon dioxide storage device C. As shown in FIG. A second combustion gas supply valve V3 is provided on the second combustion gas supply passage 13 . Combustion gas is supplied to the carbon dioxide absorber C when the second combustion gas supply valve V3 is open. On the other hand, when the second combustion gas supply valve V3 is closed, the supply of combustion gas to the carbon dioxide absorber C is stopped. Opening and closing of the second combustion gas supply valve V3 is controlled by the controller.

The carbon dioxide absorber C contains zeolite as an adsorption material. A second combustion gas supply channel 13 , a gas supply channel 14 , a gas supply channel 15 , and a generated gas supply channel 18 are connected to the carbon dioxide absorber C.

Adsorbent materials include activated carbon, silica gel, and amine-supported solids, in addition to zeolites.

A carbon dioxide detection sensor (not shown) is attached to the carbon dioxide storage device C as a concentration detection unit. The carbon dioxide detection sensor is a device that detects the concentration of carbon dioxide in the atmosphere of the carbon dioxide absorber C, and is connected to the controller.

The carbon dioxide recovery reducer D absorbs carbon dioxide contained in the residual gas after the carbon dioxide is absorbed by the carbon dioxide absorber C, and reduces the absorbed carbon dioxide with the supplied hydrogen. A device for conversion to methane. The carbon dioxide recovery reducer D accommodates a carbon dioxide storage reduction catalyst. The carbon dioxide storage reduction catalyst contains a metal oxide having carbon dioxide storage performance and a metal having methanation catalyst performance.

The carbon dioxide storage reduction catalyst is preferably a catalyst in which a metal oxide having carbon dioxide storage performance and a metal having methanation catalyst performance are supported on a carrier. The carrier is alumina, the metal oxide having carbon dioxide storage performance is calcium oxide, and the metal having methanation catalyst performance is ruthenium (Ru).

Other than alumina, carriers include, for example, silica, silica-alumina, titania, zirconia, ceria and ceria-zirconia. Examples of metal oxides having carbon dioxide storage capacity include alkali metal oxides and alkaline earth metal oxides, and in addition to calcium oxide, potassium oxide and magnesium oxide are included. Other than ruthenium (Ru), metals having methanation catalytic performance include, for example, nickel (Ni), platinum (Pt), palladium (Pd), rhodium (Rd), cobalt (Co), iron (Fe) and manganese. (Mn). These metals may be used alone or in combination of two or more.

In addition, the carbon dioxide storage reduction catalyst may contain a sintering inhibitor. When the metal oxide having carbon dioxide storage capacity is calcium oxide, the sintering inhibitor can prevent the calcium oxide from sintering. When calcium oxide particles are sintered together, the specific surface area decreases and the interface for reaction becomes smaller. In addition, as the diffusion distance in the solid increases, the reactivity between calcium oxide and carbon dioxide tends to decrease. By preventing the sintering of calcium oxide, the reactivity between calcium oxide and carbon dioxide can be maintained at a high level.

Sintering inhibitors include, for example, magnesia, alumina, calcium aluminate, silica, calcium silicate, titania, calcium titanate, zirconia, calcium zirconate, yttria, and lanthania.

A gas supply channel 14 , a gas supply channel 15 , a gas discharge channel 16 , and a hydrogen supply channel 17 are connected to the carbon dioxide recovery reducer D.

A carbon dioxide detection sensor (not shown) is attached to the carbon dioxide recovery reducer D as a concentration detection unit. The carbon dioxide detection sensor is a device for detecting the concentration of carbon dioxide in the atmosphere of the carbon dioxide recovery reducer D, and is connected to the controller.

The gas supply flow path 14 is a flow path for supplying the residual gas after carbon dioxide has been occluded in the carbon dioxide occluding device C to the carbon dioxide recovering and reducing device D. As shown in FIG. A gas supply valve V<b>4 is provided on the gas supply flow path 14 . Residual gas is supplied to the carbon dioxide recovery reducer D when the gas supply valve V4 is opened. On the other hand, when the gas supply valve V4 is closed, the supply of residual gas to the carbon dioxide recovery reducer D is stopped. Opening and closing of the gas supply valve V4 is controlled by the controller.

The gas supply flow path 15 is a flow path for supplying the generated gas obtained by the methanation reaction of the carbon dioxide occluded in the carbon dioxide recovery reducer D to the carbon dioxide occluder C. A gas supply valve V5 is provided on the gas supply flow path 15 . When the gas supply valve V5 is open, the generated gas is supplied to the carbon dioxide occluding device C. As shown in FIG. On the other hand, when the gas supply valve V5 is closed, the supply of the produced gas to the carbon dioxide absorber C is stopped. Opening and closing of the gas supply valve V5 is controlled by the controller.

The gas discharge channel 16 is a channel for discharging residual gas after carbon dioxide is occluded in the carbon dioxide recovery/reduction device D into the atmosphere. The residual gas is gas other than carbon dioxide that has not been occluded in the carbon dioxide recovery reducer D, and mainly consists of nitrogen and water vapor. A gas discharge valve V<b>6 is provided on the gas discharge flow path 16 . Residual gas is discharged into the atmosphere when the gas discharge valve V6 is opened. On the other hand, when the gas exhaust valve V6 is closed, the discharge of residual gas into the atmosphere is stopped. The opening and closing of the gas exhaust valve V6 is controlled by the controller.

The hydrogen supply channel 17 is a channel for supplying hydrogen from the hydrogen supply source H to the carbon dioxide recovery reducer D. As shown in FIG. A hydrogen supply valve V7 is provided on the hydrogen supply channel 17 . Hydrogen is supplied to the carbon dioxide recovery reducer D when the hydrogen supply valve V7 is opened. On the other hand, when the hydrogen supply valve V7 is closed, the supply of hydrogen to the carbon dioxide recovery reducer D is stopped. Opening and closing of the hydrogen supply valve V7 is controlled by the control unit.

The generated gas supply channel 18 is supplied with the generated gas obtained by the methanation reaction of the carbon dioxide stored in the carbon dioxide recovery reducer D and the carbon dioxide desorbed from the zeolite accommodated in the carbon dioxide storage device C. , to the methane converter E. A generated gas supply valve V<b>8 is provided on the generated gas supply passage 18 . The mixed gas is supplied to the methane converter E when the generated gas supply valve V8 is opened. On the other hand, when the product gas supply valve V8 is closed, the supply of the mixed gas to the methane converter E is stopped. Opening and closing of the generated gas supply valve V8 is controlled by the controller.

The methane converter E is a device for producing methane from carbon dioxide and hydrogen contained in the mixed gas supplied from the carbon dioxide absorber C. The methane converter E contains a methanation catalyst. The methane converter E is connected to a product gas supply channel 18 and a methane supply channel 19 . The methanation catalyst is preferably a catalyst in which a metal having methanation catalytic performance is supported on a carrier. The metal having methanation catalytic performance is ruthenium (Ru) and the support is alumina.

Other than ruthenium (Ru), metals having methanation catalytic performance include, for example, nickel (Ni), platinum (Pt), palladium (Pd), rhodium (Rd), cobalt (Co), iron (Fe) and manganese. (Mn). These metals may be used alone or in combination of two or more. Supports other than alumina include, for example, silica, silica-alumina, titania, zirconia, ceria and ceria-zirconia.

The methane supply channel 19 is a channel for supplying the product gas generated by the methane converter E to the combustor A. A methane supply valve V<b>9 is provided on the methane supply flow path 19 . The generated gas is supplied to the combustor A when the methane supply valve V9 is open. On the other hand, when the methane supply valve V9 is closed, the supply of the produced gas to the combustor A is stopped. Opening and closing of the methane supply valve V9 is controlled by the controller.

The hydrogen supply source H is a supply source for supplying hydrogen to the carbon dioxide recovery reducer D. A hydrogen supply channel 17 is connected to the hydrogen supply source H. As shown in FIG. Hydrogen is preferably supplied as hydrogen gas.

Next, a carbon dioxide recovery method using the carbon dioxide recovery device of the first embodiment will be described with reference to FIG. FIG. 2 is a flow chart showing a carbon dioxide recovery method using the carbon dioxide recovery device of the first embodiment.

First, atmosphere supply valve V1, first combustion gas supply valve V2, second combustion gas supply valve V3, gas supply valve V4, gas supply valve V5, gas discharge valve V6, hydrogen supply valve V7, generated gas supply valve V8, It is assumed that the methane supply valve V9 is closed. It is also assumed that methane is stored in the combustor A in advance. Although not shown, each valve is electrically connected to a control unit (for example, a computer) so that it can be opened and closed according to a signal from the control unit.

First, the control unit starts the operation of the combustor A, and opens the atmosphere supply valve V1, the first combustion gas supply valve V2, the second combustion gas supply valve V3, the gas supply valve V4, and the gas discharge valve V6 (step S11).

The air is supplied to the combustor A through the air supply passage 11 by opening the air supply valve V1. The concentration of carbon dioxide in the atmosphere is assumed to be approximately 400 ppm. Methane is combusted in combustor A to generate combustion gas.

By opening the first combustion gas supply valve V2, combustion gas is supplied from the combustor A to the heat utilization device B through the first combustion gas supply flow path 12. As shown in FIG. In the heat utilization equipment B, the thermal energy of the combustion gas is used to lower the temperature of the combustion gas.

By opening the second combustion gas supply valve V3, combustion gas is supplied from the heat utilization device B to the carbon dioxide storage device C through the second combustion gas supply flow path 13. As shown in FIG.

In the carbon dioxide absorber C, carbon dioxide contained in the combustion gas is occluded by zeolite. As a result, compared to the carbon dioxide concentration at the gas supply port of the carbon dioxide absorber C, the carbon dioxide concentration at the gas discharge port decreases.

By opening the gas supply valve V4, the residual gas in the carbon dioxide occluding device C is supplied to the carbon dioxide recovering and reducing device D through the gas supply passage 4. As shown in FIG. The residual gas referred to here is the residual gas after carbon dioxide is absorbed by the adsorption material contained in the carbon dioxide absorber C. Residual gases include nitrogen, water vapor, and carbon dioxide.

In the carbon dioxide recovery reducer D, the carbon dioxide contained in the residual gas supplied from the carbon dioxide absorber C is occluded in the carbon dioxide storage reduction catalyst. Specifically, in the carbon dioxide recovery reducer D, calcium oxide contained in the carbon dioxide storage reduction catalyst reacts with carbon dioxide to form calcium carbonate. As a result, the carbon dioxide concentration at the gas discharge port of the carbon dioxide recovery reducer D is reduced compared to the carbon dioxide concentration at the gas supply port.

By opening the gas discharge valve V6, the residual gas in the carbon dioxide recovery reducer D is discharged to the atmosphere through the gas discharge passage 16. FIG. Residual gases include nitrogen, water vapor, and carbon dioxide. The concentration of carbon dioxide contained in the residual gas discharged into the atmosphere is 10 ppm or less.

Next, the control unit determines whether or not a condition for stopping the supply of combustion gas is satisfied (step S12). The condition for stopping the supply includes, for example, a condition that the concentration of carbon dioxide at the gas outlet of the carbon dioxide recovery reducer D exceeds a preset concentration (for example, 10 ppm).

When the control unit determines that the combustion gas supply stop condition is satisfied (step S12: YES), it stops the operation of the combustor A, and closes the atmosphere supply valve V1, the first combustion gas supply valve V2, and the second combustion gas supply valve. Close V3, gas supply valve V4, and gas exhaust valve V6. (Step S13). The combustion gas is supplied from the heat utilization device B to the carbon dioxide occluding device C, and the gas is supplied from the carbon dioxide occluding device C to the carbon dioxide recovery reducer D until the control unit determines that the condition for stopping the supply of the combustion gas is satisfied. , the residual gas in the carbon dioxide recovery reducer D is discharged into the atmosphere through the gas discharge passage 16 . (Step S12: NO).

Next, the controller opens the gas supply valve V5, hydrogen supply valve V7, generated gas supply valve V8, and methane supply valve V9 (step S14).

Hydrogen is supplied from the hydrogen supply source H to the carbon dioxide recovery reducer D through the hydrogen supply flow path 17 by opening the hydrogen supply valve V7.

In the carbon dioxide recovery reducer D, the carbon dioxide stored in the carbon dioxide storage reduction catalyst is desorbed and reduced by hydrogen. This results in a product gas containing mainly methane and hydrogen.

By opening the gas supply valve V<b>5 , the generated gas is supplied from the carbon dioxide recovery/reduction device D to the carbon dioxide storage device C through the gas supply flow path 15 .

In the carbon dioxide occluding device C, the carbon dioxide occluded in the zeolite is desorbed by applying heat.

By opening the produced gas supply valve V8, the produced gas obtained in the carbon dioxide recovery reducer D is desorbed from the zeolite from the carbon dioxide storage device C to the methane converter E through the produced gas supply passage 18. and a mixed gas is supplied. The mixed gas contains methane, carbon dioxide and hydrogen.

In the methane converter E, carbon dioxide contained in the mixed gas is converted into methane by a methanation catalyst and hydrogen. This yields hydrogen and a high concentration of methane.

By opening the methane supply valve V 9 , hydrogen produced in the methane converter E and high-concentration methane are supplied from the methane converter E to the combustor A through the methane supply flow path 19 .

Next, the control unit determines whether or not the hydrogen supply stop condition is satisfied (step S15). As a hydrogen supply stop condition, for example, the ratio of the cumulative amount of hydrogen (hydrogen/carbon dioxide) to the cumulative amount of carbon dioxide discharged from the gas outlet of the carbon dioxide absorber C to the methanation reactor exceeds 4. conditions. Further, as a hydrogen supply stop condition, for example, there is a condition that the methane concentration at the gas outlet of the methane converter E is below a preset concentration (for example, 99% by volume).

When the control unit determines that the hydrogen supply stop condition is satisfied (step S15: YES), it closes the gas supply valve V5, the hydrogen supply valve V7, the generated gas supply valve V8, and the methane supply valve V9 (step S16). Hydrogen is supplied to the carbon dioxide recovery reducer D until the control unit determines that the hydrogen supply stop condition is satisfied (step S15: NO).

The control unit determines whether or not there is a request for heat from the heat-utilizing device B (step S17).

When the control unit determines that there is a heat request from the heat-utilizing device B (step S17: YES), the control unit returns to step S11 and repeats the processes after step S11. When the control unit determines that there is no heat request from the heat-utilizing device B (step S17: NO), the processing ends.

By using the carbon dioxide capture device 100 of the first embodiment, carbon dioxide can be separated and recovered from the taken air. The carbon dioxide absorber C contains an adsorption material, and by causing the adsorption material to absorb carbon dioxide, the concentration of carbon dioxide in the atmosphere can be reduced to about 3000 ppm. The carbon dioxide storage reduction catalyst housed in the carbon dioxide recovery reducer D contains calcium oxide, and by converting carbon dioxide into calcium carbonate, the concentration of carbon dioxide in the atmosphere can be reduced to about 10 ppm. . Further, the carbon dioxide storage reduction catalyst housed in the carbon dioxide recovery reducer D contains ruthenium, and by supplying hydrogen to the carbon dioxide recovery reducer D, calcium carbonate can be converted into methane.

When hydrogen is circulated through a carbon dioxide storage reduction catalyst that has stored carbon dioxide to generate methane, if the concentration of methane, which is a reaction product, increases, the reaction that generates methane from calcium carbonate and hydrogen becomes difficult to proceed. For example, when hydrogen is introduced into a carbon dioxide absorber, a mixed gas of hydrogen and carbon dioxide is discharged. When this mixed gas is supplied to the carbon dioxide recovery and reduction vessel, carbon dioxide in the gas is converted to methane with priority over calcium carbonate, so the methane concentration rises, and a reaction that produces methane from calcium carbonate and hydrogen. becomes difficult to progress. On the other hand, in the carbon dioxide recovery device 100 of the first embodiment, the gas supplied from the carbon dioxide absorber C to the carbon dioxide recovery reducer D does not contain carbon dioxide, so the methanation reaction of calcium carbonate proceeds. It's easy to do.

In the carbon dioxide recovery device 100 of the first embodiment, a mixed gas containing methane and hydrogen is supplied from the carbon dioxide recovery reducer D to the carbon dioxide storage device C. As shown in FIG. The mixed gas supplied to the carbon dioxide absorber C does not contain carbon dioxide. Therefore, in the carbon dioxide absorber C, the desorption of carbon dioxide from the adsorption material proceeds without being hindered by carbon dioxide.

Usually, it is necessary to heat up to about 1000° C. in order to desorb carbon dioxide from calcium carbonate. In contrast, the reaction that converts calcium carbonate to methane proceeds at about 300°C. In the carbon dioxide recovery apparatus 100 of the first embodiment, the carbon dioxide storage amount per 1 g of calcium oxide is 18 mmol, the specific heat of calcium oxide is 47 J/mol·K, the molecular weight of calcium oxide is 56 g/mol, and the Assuming that the temperature range is 300° C., the sensible heat of calcium oxide is 14 kJ per 1 mol of carbon dioxide, and the desorption heat of carbon dioxide from calcium carbonate is 175 kJ per 1 mol of carbon dioxide. That is, the energy consumption is 189 kJ per mole of carbon dioxide.

[Second embodiment]
FIG. 3 is a schematic diagram showing the carbon dioxide capture device of the second embodiment. Regarding the carbon dioxide recovery device of the second embodiment, the same reference numerals are used for the same configurations and effects as those of the carbon dioxide recovery device of the first embodiment, and the description thereof is omitted.

A configuration of the carbon dioxide recovery device 200 of the second embodiment that is different from the carbon dioxide recovery device 100 of the first embodiment will be described.

The carbon dioxide recovery device 200 of the second embodiment includes a pump P1 between the carbon dioxide absorber C and the methane converter E that reduces the pressure inside the carbon dioxide absorber C. As shown in FIG. The operation of the pump P1 is controlled by the controller. The pressure inside the carbon dioxide absorber is preferably adjusted to 10-200,000Pa.

Next, a carbon dioxide recovery method using the carbon dioxide recovery device 200 of the second embodiment will be described.

In the second embodiment, in step S14 of the first embodiment, the control unit opens the gas supply valve V5, the hydrogen supply valve V7, the generated gas supply valve V8, and the methane supply valve V9, and starts the operation of the pump P1. It differs from the first embodiment in that the Further, in the second embodiment, in step S16 of the first embodiment, the control unit closes the gas supply valve V5, the hydrogen supply valve V7, the generated gas supply valve V8, and the methane supply valve V9, and operates the pump P1. is stopped, which is different from the first embodiment.

In the carbon dioxide recovery device 200 of the second embodiment, when the carbon dioxide is desorbed from the adsorption material in which carbon dioxide is occluded, the pressure in the carbon dioxide occluder C is lowered to desorb the carbon dioxide. can promote Compared to the case where the pump P1 is not provided, more carbon dioxide can be desorbed from the adsorbent material, increasing the occlusion capacity of the adsorbent material. Therefore, when carbon dioxide is absorbed in the next cycle, the amount of carbon dioxide absorbed increases, and the amount of carbon dioxide recovered and the amount of methane produced per cycle are improved.

The timing for starting the operation of the pump P1 is not limited to simultaneous with the gas supply valve V5, the hydrogen supply valve V7, the generated gas supply valve V8, and the methane supply valve V9. may be the timing of The earlier the timing of starting the operation of the pump P1, the greater the capacity of the adsorption material that can be absorbed. The timing for starting the operation of the pump P1 may be appropriately adjusted in consideration of the balance with the energy consumption for operating the pump P1.

[Third embodiment]
FIG. 4 is a schematic diagram showing a carbon dioxide capture device of a third embodiment. Regarding the carbon dioxide recovery device of the third embodiment, the same reference numerals are used for the same configurations and effects as those of the carbon dioxide recovery device 100 of the first embodiment, and the description thereof is omitted.

A configuration of the carbon dioxide recovery device 300 of the third embodiment, which is different from that of the carbon dioxide recovery device 100 of the first embodiment, will be described.

The carbon dioxide recovery device 300 of the third embodiment includes two carbon dioxide occlusion devices C1 and C2, two carbon dioxide recovery reducers D1 and D2, and a carbon dioxide occlusion device C1 and a carbon dioxide occlusion device C2. A first exchange unit 51 exchanges an adsorption material between them, and a second exchange unit 52 exchanges a carbon dioxide storage reduction catalyst between the carbon dioxide recovery reducer D1 and the carbon dioxide recovery reducer D2.

A second combustion gas supply channel 13 and a gas supply channel 14 are connected to the carbon dioxide absorber C1.

A gas supply channel 14 and a gas discharge channel 16 are connected to the carbon dioxide recovery reducer D1.

A gas supply channel 15 and a generated gas supply channel 18 are connected to the carbon dioxide absorber C2.

A gas supply channel 15 and a hydrogen supply channel 17 are connected to the carbon dioxide recovery reducer D2.

The first exchange part 51 is a means for exchanging the adsorbent materials contained between the carbon dioxide occluding device C1 and the carbon dioxide occluding device C2.

It is preferable that the first exchange part 51 moves the adsorption material in the direction opposite to the gas flow direction within the carbon dioxide storage device C1. The direction opposite to the gas flow direction is the direction from the gas outlet connected to the gas supply channel 14 toward the gas supply port connected to the first combustion gas supply channel 13 . Similarly, the first exchange part 51 preferably moves the adsorbent material in the direction opposite to the gas flow direction within the carbon dioxide storage device C2. The direction opposite to the gas flow direction is the direction from the gas outlet connected to the generated gas supply channel 18 toward the gas supply port connected to the gas supply channel 15 .

A material supply port for the adsorbent material is provided, for example, in the upper portion of the carbon dioxide absorber C1, and a material discharge port for the adsorbent material is provided in the lower portion of the carbon dioxide absorber C1. As a result, gravity can be used to move the adsorption material from the top to the bottom of the carbon dioxide storage device C1. On the other hand, the gas supply port for the combustion gas is provided, for example, in the lower portion of the carbon dioxide occlusion device C1, and the gas discharge port for the combustion gas is provided in the upper portion of the carbon dioxide occlusion device C1. The pressure difference can be used to move the combustion gas from the bottom to the top of the carbon dioxide absorber C1.

Note that the moving direction of the adsorbent material and the gas may be the horizontal direction instead of the vertical direction. In order to move the adsorbing material, a conveying device such as a belt conveyor or a screw conveyor may be provided inside the carbon dioxide absorber C1.

The second exchange unit 52 is a means for exchanging the carbon dioxide storage reduction catalyst accommodated between the carbon dioxide recovery reducer D1 and the carbon dioxide recovery reducer D2.

It is preferable that the second exchange unit moves the carbon dioxide storage reduction catalyst in the direction opposite to the gas flow direction within the carbon dioxide recovery reducer D1. The gas flow direction is the direction from the gas discharge port to the outside toward the gas supply port connected to the gas supply channel 14 . Similarly, the second exchange section preferably moves the carbon dioxide storage reduction catalyst in the direction opposite to the gas flow direction within the carbon dioxide recovery reducer D2. The direction opposite to the gas flow direction is the direction from the gas outlet connected to the gas supply channel 15 toward the gas supply port connected to the hydrogen supply channel 17 .

A material supply port for the carbon dioxide storage reduction catalyst is provided, for example, in the upper portion of the carbon dioxide recovery reducer D1, and a material discharge port for the carbon dioxide storage reduction catalyst is provided in the lower portion of the carbon dioxide recovery reduction device D1. As a result, gravity can be used to move the carbon dioxide storage reduction catalyst from the upper portion of the carbon dioxide recovery reducer D1 toward the lower portion. On the other hand, the gas supply port for the gas supplied from the carbon dioxide occlusion device C1 is provided, for example, in the lower portion of the carbon dioxide recovery and reduction device D1, and the gas discharge port for the gas supplied from the carbon dioxide occlusion device C1 is the carbon dioxide It is provided above the recovery reducer D1. Using the pressure difference, the gas supplied from the carbon dioxide occluding device C1 can be moved from the bottom to the top of the carbon dioxide recovery and reducing device D1.

The moving direction of the carbon dioxide storage reduction catalyst and the gas may be the horizontal direction instead of the vertical direction. In order to move the carbon dioxide storage reduction catalyst, a conveying device such as a belt conveyor or a screw conveyor may be provided inside the carbon dioxide recovery and reduction device D1.

Next, a carbon dioxide recovery method using the carbon dioxide recovery device 300 of the third embodiment will be described with reference to FIG. FIG. 5 is a flow chart showing a carbon dioxide recovery method using the carbon dioxide recovery device of the third embodiment.

First, atmosphere supply valve V1, first combustion gas supply valve V2, second combustion gas supply valve V3, gas supply valve V4, gas supply valve V5, gas discharge valve V6, hydrogen supply valve V7, generated gas supply valve V8, and methane supply valve V9 are assumed to be closed.

First, the operation of the combustor A is started, and all valves, that is, the atmosphere supply valve V1, the first combustion gas supply valve V2, the second combustion gas supply valve V3, the gas supply valve V4, the gas supply valve V5, and the gas exhaust Open valve V6, hydrogen supply valve V7, product gas supply valve V8, and methane supply valve V9.

The flow of gas due to the opening of the atmosphere supply valve V1 and the first combustion gas supply valve V2 is the same as in the first embodiment.

By opening the second combustion gas supply valve V3, combustion gas is supplied from the heat utilization device B to the carbon dioxide occluding device C1 through the second combustion gas supply flow path 13. As shown in FIG. At this time, within the carbon dioxide occluding device C1, the adsorbing material accommodated in the carbon dioxide occluding device C1 is moved in a direction opposite to the flow direction of the combustion gas.

By opening the gas supply valve V4, the residual gas in the carbon dioxide occluding device C1 is supplied to the carbon dioxide recovering and reducing device D1 through the gas supply passage 14. As shown in FIG. Residual gases include nitrogen, water vapor, and carbon dioxide. At this time, in the carbon dioxide recovery reducer D1, the carbon dioxide storage reduction catalyst accommodated in the carbon dioxide recovery reducer D1 is moved in a direction opposite to the flow direction of the residual gas.

By opening the gas discharge valve V6, the residual gas in the carbon dioxide recovery and reduction device D1 is discharged to the atmosphere through the gas discharge passage 16. FIG. Residual gases include nitrogen, water vapor, and carbon dioxide. The concentration of carbon dioxide contained in the residual gas discharged into the atmosphere is 10 ppm or less.

By opening the hydrogen supply valve V7, hydrogen is supplied from the hydrogen supply source H to the carbon dioxide recovery reducer D2 through the hydrogen supply flow path 17. As shown in FIG.

In the carbon dioxide recovery reducer D2, the carbon dioxide stored in the carbon dioxide storage reduction catalyst is desorbed and reduced by hydrogen. This results in a product gas containing mainly methane and hydrogen.

By opening the gas supply valve V5, the generated gas is supplied from the carbon dioxide recovery/reduction device D2 to the carbon dioxide storage device C2 through the gas supply passage 15. FIG.

By opening the produced gas supply valve V8, the produced gas obtained in the carbon dioxide recovery reducer D1 and the produced gas desorbed from the zeolite are transferred from the carbon dioxide storage device C2 to the methane converter E through the produced gas supply passage 18. and a mixed gas is supplied. The mixed gas contains methane, carbon dioxide and hydrogen.

By opening the methane supply valve V9, the hydrogen produced in the methane converter E and high-concentration methane are supplied from the methane converter E to the combustor A through the methane supply flow path 19. FIG.

The first exchange unit 51 exchanges the adsorbent materials contained in the carbon dioxide occluding device C1 and the carbon dioxide occluding device C2 at an arbitrary timing. In addition, the second exchange unit 52 exchanges the carbon dioxide storage reduction catalyst accommodated in each of the carbon dioxide recovery reducer D1 and the carbon dioxide recovery reducer D2 at an arbitrary timing.

Next, the control unit determines whether or not there is a request for heat from the heat-utilizing device B (step S22).

When the control unit determines that there is a heat request from the heat-utilizing device B (step S22: YES), the control unit returns to step S21 and repeats the processing from step S21 onward. When the control unit determines that there is no heat request from the heat utilization device B (step S22: NO), it stops the operation of the combustor A, closes all the valves (step S23), and ends this process.

The carbon dioxide recovery device 300 of the third embodiment includes at least one carbon dioxide absorber to which a carbon dioxide-containing gas is supplied, and at least one carbon dioxide to which a gas discharged from the carbon dioxide recovery reducer is supplied. a first exchange unit that exchanges the adsorbent material contained with the occlusion device; at least one carbon dioxide recovery and reduction device that is supplied with gas discharged from the carbon dioxide occlusion device; and hydrogen is supplied. and a second exchange part for exchanging the carbon dioxide storage reduction catalyst contained between the at least one carbon dioxide recovery reducer and the carbon dioxide storage reduction device, so that carbon dioxide is continuously recovered and methane is obtained. be able to.

In addition, in the carbon dioxide capture device 300 of the third embodiment, the first exchange section moves the adsorbent material in the direction facing the gas flow direction, and the second exchange section moves the adsorbent material in the direction facing the gas flow direction. Since the carbon dioxide storage-reduction catalyst is moved in the direction of movement, the amount of carbon dioxide stored in the adsorption material and the carbon dioxide storage-reduction catalyst can be increased. When the adsorbent material is fixed to the carbon dioxide storage device, the adsorbent material fixed at a position where the carbon dioxide concentration is low has a small amount of carbon dioxide absorbed. Similarly, when the carbon dioxide storage reduction catalyst is fixed to the carbon dioxide recovery reducer, the carbon dioxide storage reduction catalyst fixed at a position where the carbon dioxide concentration is low has a small amount of carbon dioxide stored. By increasing the amount of carbon dioxide stored, the amount of carbon dioxide recovered can be increased, resulting in excellent energy efficiency.

[Fourth embodiment]
FIG. 6 is a schematic diagram showing the carbon dioxide capture device of the fourth embodiment. Regarding the carbon dioxide recovery apparatus of the fourth embodiment, the same reference numerals are used for the same configurations and effects as those of the carbon dioxide recovery apparatus 100 of the first embodiment, and the description thereof is omitted.

A configuration of the carbon dioxide recovery device 400 of the fourth embodiment, which is different from that of the carbon dioxide recovery device 100 of the first embodiment, will be described.

The carbon dioxide recovery device 400 of the fourth embodiment includes two carbon dioxide absorbers C3 and C4 and two carbon dioxide recovery reducers D3 and D4 in parallel. Incidentally, the number of the carbon dioxide occluding device and the carbon dioxide recovery reducing device may be three or more.

The carbon dioxide absorbers C3 and C4 are provided with second combustion gas supply passages 13a and 13b, gas supply passages 14a and 14b, gas supply passages 15a and 15b, and generated gas supply passages 18a and 18b, respectively. , are connected.

Gas supply channels 14a and 14b, gas supply channels 15a and 15b, and hydrogen supply channels 17a and 17b are connected to the carbon dioxide recovery reducers D3 and D4, respectively.

second combustion gas supply passages 13a, 13b, gas supply passages 14a, 14b, gas supply passages 15a, 15b, gas discharge passages 16a, 16b, hydrogen supply passages 17a, 17b, and generated gas supply passages 18a, 18b are respectively second combustion gas supply valves V3a and V3b, gas supply valves V4a and V4b, gas supply valves V5a and V5b, gas exhaust valves V6a and V6b, hydrogen supply valves V7a and V7b, and generated gas supply valves V8a and V8b. is provided. Opening and closing of each valve is controlled by the controller.

Next, a carbon dioxide recovery method using the carbon dioxide recovery device 400 of the fourth embodiment will be described with reference to FIG. FIG. 7 is a flow chart showing a carbon dioxide recovery method using the carbon dioxide recovery device of the fourth embodiment.

First, the atmosphere supply valve V1, the first combustion gas supply valve V2, the second combustion gas supply valves V3a and V3b, the gas supply valves V4a and V4b, the gas supply valves V5a and V5b, the gas discharge valves V6a and V6b, and the hydrogen supply valve. It is assumed that V7a, V7b, generated gas supply valves V8a, V8b, and methane supply valve V9 are closed.

First, as shown in FIG. 7, the control unit starts the operation of the combustor A, the atmosphere supply valve V1, the first combustion gas supply valve V2, the second combustion gas supply valve V3a, the gas supply valve V4a, and the gas supply valve V4a. The discharge valve V6a is opened (step S31).

Next, the control unit determines whether or not a condition for stopping the supply of combustion gas is satisfied (step S32). An example of the supply stop condition is a condition that the concentration of carbon dioxide at the gas outlet of the carbon dioxide recovery reducer D3 exceeds a preset concentration (for example, 10 ppm).

When the controller determines that the combustion gas supply stop condition is satisfied (step S32: YES), it closes the second combustion gas supply valve V3a, the gas supply valve V4a, and the gas discharge valve V6a (step S33). The combustion gas is supplied from the heat utilization device B to the carbon dioxide occluding device C, and the gas is supplied from the carbon dioxide occluding device C3 to the carbon dioxide recovery reducer D3 until the control unit determines that the condition for stopping the supply of the combustion gas is satisfied. , the residual gas in the carbon dioxide recovery reducer D3 is discharged into the atmosphere through the gas discharge passage 16a. (Step S32: NO).

Next, the controller opens the gas supply valve V5a, hydrogen supply valve V7a, generated gas supply valve V8a, and methane supply valve V9 (step S34).

Next, the control unit determines whether or not the hydrogen supply stop condition is satisfied (step S35). As a hydrogen supply stop condition, for example, the ratio of the cumulative amount of hydrogen (hydrogen/carbon dioxide) to the cumulative amount of carbon dioxide discharged from the gas outlet of the carbon dioxide absorber C3 to the methanation reactor exceeds 4. conditions. Further, as a hydrogen supply stop condition, for example, there is a condition that the methane concentration at the gas outlet of the methane converter E is below a preset concentration (for example, 99% by volume).

When the control unit determines that the hydrogen supply stop condition is satisfied (step S35: YES), it closes the gas supply valve V5a, the hydrogen supply valve V7a, and the generated gas supply valve V8a (step S36). Hydrogen is supplied to the carbon dioxide recovery reducer D3 until the control unit determines that the hydrogen supply stop condition is satisfied (step S35: NO).

The control unit determines whether or not there is a request for heat from the heat-utilizing device B (step S37).

When the control unit determines that there is a request for heat from the heat-utilizing device B (step S37: YES), the process proceeds to step S38. In step S38, the control unit determines whether or not the gas supply valve V3b is closed, and if it is determined that it is closed (step S38: YES), returns to step S31, and repeats the processes after step S31. In the second and subsequent cycles, in step S31, the controller opens the second combustion gas supply valve V3a, the gas supply valve V4a, and the gas exhaust valve V6a. In step S38, the control unit repeats the process of step S38 until it determines that the gas supply valve V3b is closed (step S38: NO).

When the control unit determines that there is no heat request from the heat-utilizing device B (step S37: NO), the processing ends.

On the other hand, after step S33, in step S39, the controller opens the second combustion gas supply valve V3b, the gas supply valve V4b, and the gas exhaust valve V6b.

The processing of steps S40 to S44 is the same as the processing of steps S32 to S36.

The control unit determines whether or not there is a request for heat from the heat-utilizing device B (step S45).

When the control unit determines that there is a request for heat from the heat-utilizing device B (step S45: YES), the process proceeds to step S46. In step S46, the control unit determines whether or not the gas supply valve V3a is closed, and if it is determined that it is closed (step S46: YES), returns to step S39 and repeats the processes after step S39. In step S46, the control unit repeats the process of step S46 until it determines that the gas supply valve V3a is closed (step S46: NO).

When the control unit determines that there is no heat request from the heat-utilizing device B (step S45: NO), the processing ends.

Since the carbon dioxide capture device 400 of the fourth embodiment includes two carbon dioxide absorbers and two carbon dioxide recovery reducers in parallel, carbon dioxide can be recovered continuously. This is absorbed by the carbon dioxide absorber C4 and the carbon dioxide recovery reducer D4 while the carbon dioxide is being absorbed by the carbon dioxide absorber C3 and the carbon dioxide recovery reducer D3. This is because a process for converting carbon dioxide into methane can be performed.

[Fifth embodiment]
FIG. 8 is a schematic diagram showing the carbon dioxide capture device of the fifth embodiment. Regarding the carbon dioxide recovery device of the fifth embodiment, the same reference numerals are used for the same configurations and effects as those of the carbon dioxide recovery device 100 of the first embodiment, and the description thereof is omitted.

A configuration of the carbon dioxide recovery device 500 of the fifth embodiment, which is different from that of the carbon dioxide recovery device 100 of the first embodiment, will be described.

The carbon dioxide recovery device 500 of the fifth embodiment further includes a dehumidifier K between the carbon dioxide absorber C and the carbon dioxide recovery reducer D for removing moisture.

The dehumidifier K is not particularly limited as long as it has a function of removing moisture from the gas supplied to the carbon dioxide absorber C from the carbon dioxide recovery reducer. The dehumidifier K may contain a moisture absorbent such as silica gel. Also, the dehumidifier K may have the function of reducing the temperature of the gas to condense the water.

Since the carbon dioxide recovery device 500 of the fifth embodiment includes the dehumidifier K, the gas obtained by removing water vapor from the gas produced by the methanation reaction in the carbon dioxide recovery reducer D is supplied to the carbon dioxide storage device C. be. Therefore, in the carbon dioxide storage device C, the desorption of carbon dioxide is efficiently performed without being hindered by water vapor.

[Modification 1]
The carbon dioxide recovery apparatuses of the first to fifth embodiments may include a methane storage device for storing the mixed gas produced by the methane converter downstream of the methane converter. The mixed gas mainly contains methane. With the methane storage device, methane can be stored until the demand for heat generated by the combustor increases, thereby reducing unnecessary energy consumption.

[Modification 2]
The carbon dioxide recovery apparatuses of the first to fifth embodiments are provided with a combustor A that burns carbon dioxide in the atmosphere as a supply source of a raw material gas containing carbon dioxide, and use the heat generated by the combustor A. Although the heat utilization equipment B is provided, the combustor A and the heat utilization equipment B may not be provided. The carbon dioxide capture device may comprise a supply source that supplies gas containing carbon dioxide directly to the carbon dioxide absorbers C (C1, C2, C3, C4).

[Modification 3]
The carbon dioxide recovery apparatuses of the first to fifth embodiments may further include an exhaust heat supply channel for supplying the exhaust heat generated in the carbon dioxide recovery reducer D to the carbon dioxide absorber C. In the carbon dioxide recovery reducer D, heat of 175 kJ per 1 mol of carbon dioxide is generated when calcium oxide absorbs carbon dioxide to produce calcium carbonate. By supplying the exhaust heat generated in the carbon dioxide recovery reducer D to the carbon dioxide occlusion device C, the energy to be added in the carbon dioxide occlusion device C to desorb carbon dioxide can be suppressed.

[Modification 4]
In the carbon dioxide recovery devices of the first to fifth embodiments, the , the gas supply channel 4 (4a, 4b) and the gas supply channel 5 (5a, 5b) are connected. The number of gas supply channels may be one. A simplification of the configuration of the carbon dioxide capture device is realized.

[Modification 5]
The carbon dioxide recovery apparatuses of the first to fifth embodiments may further include a heat accumulator that stores exhaust heat generated by the carbon dioxide recovery reducer. The heat storage method may be any of sensible heat storage, latent heat storage, and chemical heat storage. Energy consumption can be suppressed by using the exhaust heat stored in the heat accumulator to desorb carbon dioxide in the carbon dioxide absorber.

[Modification 6]
The carbon dioxide recovery device of the third embodiment may include a storage container for storing the adsorbent material between the carbon dioxide occluding device C1 and the carbon dioxide occluding device C2. Further, the carbon dioxide recovery apparatus of the third embodiment may include a storage container for storing the carbon dioxide storage reduction catalyst between the carbon dioxide recovery reducer D1 and the carbon dioxide recovery reducer D2. With these storage containers, the recovered carbon dioxide can be stored.

[Modification 7]
Further, the carbon dioxide recovery apparatus of the third embodiment may include a heat transfer channel for transporting the exhaust heat generated in the carbon dioxide recovery reducer D1 (or D2) to the carbon dioxide absorber C2 (or C1). good. By utilizing exhaust heat, energy consumption can be suppressed.

[Comparative Example 1]
FIG. 9 is a schematic diagram showing a carbon dioxide recovery device 600 of Comparative Example 1. As shown in FIG. Unlike the carbon dioxide recovery device 100 of the first embodiment, the carbon dioxide recovery device 600 does not include the carbon dioxide recovery reducer D. As shown in FIG. A hydrogen supply channel 17c for supplying hydrogen from the hydrogen supply source H to the carbon dioxide absorber C, and a gas discharge channel 16c for discharging residual gas not absorbed by the carbon dioxide absorber C into the atmosphere. and are connected. A hydrogen supply valve V7c is provided on the hydrogen supply channel 17c, and a gas discharge valve V6c is provided on the gas discharge channel 16c.

Since the adsorption material contained in the carbon dioxide absorber C has a small amount of carbon dioxide absorbed, the carbon dioxide recovery efficiency is low. Further, in the carbon dioxide recovery device 600 of Comparative Example 1, if the amount of carbon dioxide absorbed per 1 g of zeolite is 1 mmol, the specific heat of zeolite is 1 J/g·K, and the temperature rise width is 300° C., The sensible heat of zeolite is 300 kJ per 1 mol of carbon dioxide, and the heat of desorption of carbon dioxide from zeolite is 40 kJ per 1 mol of carbon dioxide. That is, the energy consumption is 340 kJ per mole of carbon dioxide.

On the other hand, in the carbon dioxide recovery apparatus of the present embodiment, as described above, the energy consumption is 189 kJ per 1 mol of carbon dioxide, and carbon dioxide can be recovered with less energy than in Comparative Example 1.

[Comparative Example 2]
FIG. 10 is a schematic diagram showing a carbon dioxide recovery device 700 of Comparative Example 2. As shown in FIG. Unlike the carbon dioxide recovery device 100 of the first embodiment, the carbon dioxide recovery device 600 does not include the carbon dioxide storage device C. As shown in FIG. The carbon dioxide recovery reducer D is connected to a produced gas supply passage 18c for supplying the mixed gas produced in the carbon dioxide recovery reducer D to the methane converter E. As shown in FIG. A generated gas supply valve V8c is provided on the generated gas supply passage 18c.

In the carbon dioxide recovery device 700 of Comparative Example 2, the methane concentration of the generated gas discharged from the carbon dioxide recovery reducer D is kept low from the viewpoint of gas equilibrium. Specifically, in the reaction between calcium carbonate and hydrogen, at 300° C. where the conversion rate to methane is maximum, the concentration of hydrogen contained in the produced gas is 78%, the concentration of methane is 7%, and the concentration of water is 15%. is.

On the other hand, in the carbon dioxide recovery apparatus of the present embodiment, carbon dioxide desorbed from the carbon dioxide absorber C is added to the generated gas (mixed gas containing hydrogen and methane) discharged from the carbon dioxide recovery reducer D. Additionally, it can be converted to methane in a methane converter. Thereby, high-concentration methane can be generated.

11 atmosphere supply passage 12 combustion gas supply passages 13, 13a, 13b first combustion gas supply passages 14, 14a, 14b gas supply passages 15, 15a, 15b gas supply passages 16, 16a, 16b, 16c gas discharge Channels 17, 17a, 17b, 17c Hydrogen supply channels 18, 18a, 18b Generated gas supply channel 19 Methane supply channel 51 First exchange part 52 Second exchange part 100, 200, 300, 400, 500, 600 Dioxide Carbon recovery device A Combustor B Heat utilization equipment C Carbon dioxide absorber D Carbon dioxide recovery reducer E Methane converter H Hydrogen supply source K Dehumidifier V1 Air supply valve V2 First combustion gas supply valve V3, V3a, V3b Second Combustion gas supply valves V4, V4a, V4b Gas supply valves V5, V5a, V5b Gas supply valves V6, V6a, V6b, V6c Gas discharge valves V7, V7a, V7b, V7c Hydrogen supply valves V8, V8a, V8b Generated gas supply valve V9 Methane supply valve P1 Pump

Claims (9)

a carbon dioxide recovery reducer containing a carbon dioxide storage reduction catalyst containing a metal oxide having carbon dioxide storage performance and a metal having methanation catalyst performance;
a carbon dioxide storage device containing an adsorption material having carbon dioxide storage performance;
a hydrogen supply source that supplies hydrogen to the carbon dioxide recovery reducer;
a carbon dioxide-containing gas supply channel for supplying the carbon dioxide-containing gas to the carbon dioxide storage device;
a first gas supply passage for supplying gas from the carbon dioxide occlusion device to the carbon dioxide recovery and reduction device;
a discharge channel for discharging gas from the carbon dioxide recovery reducer to the atmosphere;
a second gas supply passage for supplying gas from the carbon dioxide recovery-reduction device to the carbon dioxide storage device;
A carbon dioxide capture device comprising: a combustor that produces the carbon dioxide-containing gas;
a methane converter for converting carbon dioxide desorbed from the adsorbent material into methane;
2. The carbon dioxide capture device of claim 1, further comprising: 3. The carbon dioxide capture device according to claim 1, further comprising a pump that reduces pressure within the carbon dioxide absorber. 4. The carbon dioxide capture device according to any one of claims 1 to 3, comprising two or more carbon dioxide absorbers and two or more carbon dioxide recovery reducers arranged in parallel. Equipped with two or more carbon dioxide absorbers and two or more carbon dioxide recovery reducers,
stored between at least one carbon dioxide absorber to which the carbon dioxide-containing gas is supplied and at least one carbon dioxide absorber to which the gas discharged from the carbon dioxide recovery reducer is supplied; a first exchange part that exchanges the adsorbent materials with each other;
Dioxide stored between at least one carbon dioxide recovery reducer to which the gas discharged from the carbon dioxide absorber is supplied and at least one carbon dioxide recovery reducer to which the hydrogen is supplied 4. The carbon dioxide recovery device according to any one of claims 1 to 3, further comprising a second exchange part that exchanges the carbon storage reduction catalysts with each other. The first exchange unit moves each adsorption material in each carbon dioxide storage device in a direction opposite to the gas flow direction,
6. The carbon dioxide recovery device according to claim 5, wherein said second exchange unit moves each carbon dioxide storage reduction catalyst in each carbon dioxide recovery reducer in a direction opposite to the gas flow direction. The carbon dioxide recovery device according to any one of claims 1 to 6, further comprising a dehumidifier for removing moisture between the carbon dioxide recovery reducer and the carbon dioxide absorber. The carbon dioxide recovery apparatus according to any one of claims 1 to 7, further comprising a heat accumulator that stores exhaust heat generated by the carbon dioxide recovery reducer. a step of supplying hydrogen to a carbon dioxide recovery reducer containing a carbon dioxide storage reduction catalyst containing a metal oxide having carbon dioxide storage performance and a metal having methanation catalyst performance;
a step of supplying a carbon dioxide-containing gas to a carbon dioxide storage device containing an adsorption material having carbon dioxide storage performance;
a step of supplying gas from the carbon dioxide absorber to the carbon dioxide recovery reducer;
a step of discharging gas from the carbon dioxide capture and reducer into the atmosphere;
a step of supplying gas from the carbon dioxide recovery-reduction device to the carbon dioxide storage device;
A carbon dioxide capture method comprising: