Carbon dioxide storage system

Abstract

Provided is a carbon dioxide storage system using a wind turbine device. 【Solution means】A cylindrical tower, a wind turbine device disposed on the tower, a carbon dioxide separation and recovery device that is driven by the rotational shaft power obtained from the wind turbine device and separates and recovers carbon dioxide from the gas sucked in through the opening provided in the tower, a carbon dioxide gas compressor that is driven by the rotational shaft power obtained from the wind turbine device and compresses the carbon dioxide gas separated and recovered by the carbon dioxide separation and recovery device, an injection pump that is driven by the rotational shaft power obtained from the wind turbine device and pumps the carbon dioxide compressed by the compressor into the underground carbon dioxide storage tank, and an injection well that injects and stores the carbon dioxide separated and recovered from the gas into the underground carbon dioxide storage tank. A carbon dioxide storage system comprising a carbon dioxide separation and recovery device, a carbon dioxide gas compressor, and an injection pump inside the cylinder of the tower.

Description

Technical Field

[0001] The present invention relates to a carbon dioxide storage system.

Background Art

[0002] In Patent Document 1, a wind power generation unit, an air compressor unit, an air expander unit, and an electric generator provided in a wind power generation engine room, and a composite air storage device provided outside the wind power generation engine room are provided. The electric generator includes a first input shaft and a first output shaft. The first input shaft is connected to the wind power generation unit via a first switcher, the first output shaft is connected to the air compressor unit, the composite air storage device includes a first air storage device provided in a tower-shaped cylinder and a second air storage device provided underground, internal cavities of the first air storage device and the second air storage device communicate with each other, an input end of the composite air storage device is connected to the air compressor unit, and an output end of the composite air storage device is connected to the air expander unit. An onshore wind power generation unit with a compressed air storage system is disclosed.

[0003] Further, in Patent Document 2, a wind turbine including at least two separated units assembled to form a nacelle coupled to a wind turbine tower is disclosed. The two separated units include a first unit incorporating a rotor support assembly and a second unit incorporating an electrolytic cell stack powered by a generator.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] After the extraction of oil and natural gas from oil fields and gas fields, voids remain in the underground strata after the extraction of oil and natural gas. Carbon Capture and Storage (CCS) can be carried out by pressurizing and injecting the carbon dioxide gas separated and recovered from power plants into the ground through these voids for storage. Additionally, Enhanced Oil Recovery (EOR) or Enhanced Gas Recovery (EGR) can be performed, where the injection of carbon dioxide pushes out the remaining oil and natural gas in the voids for enhanced recovery. However, when separating and recovering carbon dioxide at the location where it is generated for injection into the ground, in addition to consuming a large amount of electricity and heat, since the oil fields and gas fields for carbon dioxide storage are far away, there are significant cost burdens and energy consumption involved in pumping high-pressure carbon dioxide gas through long-distance pipeline laying, or in the process of pressurizing and liquefying carbon dioxide for transportation to the storage site by vehicles or ships. Moreover, when consuming fossil fuel-derived energy in the process of carbon dioxide separation, recovery, and transportation to the storage site, there is an issue that the reduction effect achieved by storing carbon dioxide in oil fields and gas fields is reduced due to the impact of carbon dioxide emissions during the separation, recovery, and transportation processes.

[0006] Also, by installing wind power generation facilities on land or at sea with good wind conditions, renewable energy electricity without carbon dioxide emissions can be obtained. However, in many cases, the locations for installing power generation facilities on land or at sea are far from the electricity consumption areas. When transmitting the generated electricity to the consumption areas, it is necessary to build long-distance power transmission networks, which require a large amount of cost and time. Additionally, in places where the transmission distance is too long, there is an issue that even if the wind conditions are favorable, wind power generation facilities cannot be installed and utilized for power generation.

[0007] On the one hand, although both the onshore and offshore wind power development suitable areas with good wind conditions and the onshore and submarine depleted oil and gas fields suitable for carbon dioxide storage are far from the power and fuel consumption areas, they are close to each other. Therefore, it is possible to efficiently separate and recover carbon dioxide using unused wind energy and store it in depleted oil and gas fields, but the specific methods and devices have not been disclosed. For example, in the sea areas where undersea oil and natural gas are mined and transported by offshore platforms, the wind conditions are good and it is also a suitable area for wind power generation. However, it is difficult to construct a power transmission network and wind energy is not utilized. In addition, there is a problem that the undersea oil and gas fields after mining have not been effectively utilized as carbon dioxide storage sites. The present invention aims to utilize wind energy without carbon dioxide emissions in a place where a wind energy utilization suitable area with difficult power transmission network construction is close to a carbon dioxide storage suitable area, so as to efficiently separate and recover carbon dioxide and store it underground without constructing a power transmission network and without the need for long-distance transportation of carbon dioxide.

Means for Solving the Problems

[0008] The carbon dioxide storage system to which the present invention is applied includes a cylindrical tower, a wind turbine device disposed in the tower, a carbon dioxide separation and recovery device that separates and recovers carbon dioxide from the gas inhaled through an opening provided in the tower by supplying rotational shaft power obtained from the wind turbine device or electric power generated by a generator connected to the wind turbine device, a carbon dioxide gas compressor that is driven by supplying rotational shaft power obtained from the wind turbine device or electric power generated by a generator connected to the wind turbine device and compresses the carbon dioxide gas separated and recovered by the carbon dioxide separation and recovery device, a press-fitting pump that is driven by supplying rotational shaft power obtained from the wind turbine device or electric power generated by a generator connected to the wind turbine device and press-feeds the carbon dioxide compressed by the compressor into a subsurface carbon dioxide storage tank, and a press-fitting well that press-fits and stores the carbon dioxide separated and recovered from the gas into the subsurface carbon dioxide storage tank, and the carbon dioxide storage system includes the carbon dioxide separation and recovery device, the carbon dioxide gas compressor, and the press-fitting pump inside the cylinder of the tower.

[0009] Here, the gas supplied from an air supply port, which is an opening provided at the upper part of the tower, may be air that can be inhaled from around the tower, biogas obtained from an anaerobic digester installed in the vicinity of the tower, combustion exhaust gas obtained when burning biomethane obtained after separating carbon dioxide from the biogas, or combustion exhaust gas generated when burning fossil fuel.

[0010] In addition, as a method for separating and recovering carbon dioxide from the supply air, a compressor is driven using shaft power or generated power obtained by the rotational driving force of a wind turbine to compress the supply air, and the high-pressure supply gas is supplied to a carbon dioxide separation membrane for separation. Alternatively, on the carbon dioxide gas flow path downstream of the carbon dioxide separation membrane, a suction pump for separating and sucking carbon dioxide gas is provided, and this suction pump is used to separate and suck using shaft power or generated power obtained by the rotational driving force of a wind turbine, that is, by using a separation membrane method for separation and recovery. In addition to this method, a pressure vessel containing a carbon dioxide adsorbent is built into the tower, and after supplying the high-pressure supply gas pressurized via a compressor to the pressure vessel to adsorb carbon dioxide in the supply gas onto the adsorbent, the carbon dioxide may be separated and recovered by an adsorption method in which the pressure vessel is depressurized via a suction pump to desorb the carbon dioxide. In addition, as a method for separating and recovering carbon dioxide from the supply air, a separation and recovery tower using a carbon dioxide absorption liquid is provided in the tower. The gas supplied to the separation and recovery tower is supplied through an air supply port, which is an opening provided at the upper part of the tower, and the air supply and the circulation of the absorption liquid are performed by an air supply blower and a circulation pump of the absorption liquid driven by the rotational shaft power obtained from the wind turbine device or the generated power obtained from a generator connected to the wind turbine device. While this is being done, a method for separating and recovering carbon dioxide from the supply air gas may be applied by circulating and supplying the absorption liquid that has absorbed carbon dioxide while heating and regenerating it using the generated power obtained from a generator connected to the wind turbine device.

[0011] Furthermore, the carbon dioxide gas separated and recovered by the above method is driven by the rotational shaft power obtained from the wind turbine device or the supply of generated electric power obtained by a generator connected to the wind turbine device, and is compressed by a carbon dioxide gas compressor that compresses the carbon dioxide gas separated and recovered by the carbon dioxide separation and recovery device. The carbon dioxide gas compressed by the compressor is pumped into a subsurface carbon dioxide storage tank located directly below or in the vicinity of the tower installation site by an injection pump that pumps the compressed carbon dioxide into the subsurface carbon dioxide storage tank in the ground. Carbon dioxide can be stored underground by injecting it into the ground through an injection well that stores the carbon dioxide separated and recovered from the gas.

[0012] Here, the gas from which carbon dioxide has been separated by the carbon dioxide separation and recovery device and the concentration of carbon dioxide has decreased can be configured to be exhausted from an exhaust port that is an opening of the tower and is located below the position of the air supply port.

Advantages of the Invention

[0013] According to the invention of the present application, in a location where a wind energy utilization site where it is difficult to maintain a power transmission network is close to a carbon dioxide storage site, by utilizing unused wind energy that does not involve carbon dioxide emissions, it is possible to efficiently separate and recover carbon dioxide and store it underground without maintaining a power transmission network and without the need for long-distance transportation of carbon dioxide.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

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Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 〔Overall Configuration of Carbon Dioxide Storage System〕 FIG. 1 is a diagram showing the whole carbon dioxide storage system 1 according to the first embodiment. The carbon dioxide storage system 1 takes in ambient air, separates and recovers carbon dioxide in the atmosphere, and injects and stores the carbon dioxide underground. The carbon dioxide storage system 1 includes an offshore platform 100 installed on the seabed at the mining site of a depleted oil field or gas field on the seabed, a tower 90, a wind power drive unit 10, and a carbon dioxide injection pipe 8. Hereinafter, the direction in which the tower 90 extends may be referred to as the vertical direction, the side where the wind power drive unit 10 is provided may be referred to as the upper side, and the side of the offshore platform 100 may be referred to as the lower side. The offshore platform 100 includes a plurality of legs 110 fixed to the seabed and extending to the sea surface, and a deck 120 fixed to the ends of the plurality of legs 110 on the sea surface. In the present embodiment, the offshore platform 100 uses an offshore platform on a depleted undersea oil field where oil has been depleted and is no longer used in a sea area favored by a wind condition where it is difficult to maintain power transmission lines. The tower 90 is provided on the deck 120 of the offshore platform 100 from which the drilling rig for excavating oil has been removed.

[0016] The carbon dioxide injection pipe 8 can reuse, for example, the pipes for oil extraction provided in oil wells that were used to pump oil. The carbon dioxide injection pipe 8 extends from the injection pump 51 (described later) in the tower 90 to the void layer after oil extraction deeper than the rock formation or stratum that does not allow carbon dioxide to pass through, that is, to the underground injection storage tank for carbon dioxide.

[0017] FIG. 2 is a diagram showing an example of the configuration of the wind power drive unit 10 according to the first embodiment and the inside of the tower 90. The tower 90 includes a gas compression unit 20, a separation unit 30, a liquefaction unit 40, and an injection unit 50. The tower 90 has a cylindrical shape with a hollow interior. The tower 90 includes a cylindrical side surface 91. The side surface 91 is provided with a gas intake port 911 for taking in air in the atmosphere and a gas discharge port 912 for discharging air with a reduced carbon dioxide concentration. The gas intake port 911 is disposed above the gas discharge port 912. The gas intake port 911 is an example of an air supply port. The dimensions of the tower 90 are not particularly limited, but for example, the height in the vertical direction can be exemplified as 100 to 200 m, and the diameter of the cross-section in the direction perpendicular to the vertical direction can be exemplified as 5 to 10 m.

[0018] In the present embodiment, the wind power drive unit 10 is provided above the tower 90, and then the gas compression unit 20, the separation unit 30, the liquefaction unit 40, and the injection unit 50 are arranged in order from the upper side in the vertical direction. The gas compression unit 20 and the separation unit 30 are connected via a pipe 93, and the separation unit 30 and the liquefaction unit 40 are connected via a pipe 93. Also, the liquefaction unit 40 and the injection pump 51 (described later) of the injection unit 50 are connected via a pipe 93.

[0019] Also, in the present embodiment, the wind power drive unit 10 includes a wind power nacelle unit 12 having a rotation unit 11 that obtains rotational power by wind power and an orthogonal gear transmission 16 that converts the horizontal axis rotational power obtained by the rotation unit 11 into vertical axis rotational power for driving a gas compressor or an injection pump disposed in the tower 90. The rotation unit 11 includes a rotor shaft 13 that serves as a rotation axis, a hub 14 fixed to one end of the rotor shaft 13, and a plurality of blades 15 fixed to the hub 14. The plurality of blades 15 are attached to the hub 14 and rotate about the hub 14 when the blades 15 receive wind. The number of blades 15 is not particularly limited, but in FIG. 1, there are three blades 15.

[0020] In addition, the wind power nacelle unit 12 is provided with a control device 17 for detecting the rotational force of the rotor shaft 13, stopping the compression of gas or the operation of the pump when the wind condition is poor and the rotational force of the rotor shaft 13 is insufficient, closing the carbon dioxide backflow prevention valve provided on the press-fitting pipe, and when the wind condition improves and sufficient rotational force is obtained for the separation and recovery of carbon dioxide and underground press-fitting, restarting the operation of the gas compressor and the press-fitting pump, and controlling the opening degree of the carbon dioxide backflow prevention valve to control the start / stop of the separation and recovery of carbon dioxide and the press-fitting and the press-fitting amount according to the wind condition.

[0021] In the wind power drive unit 10, when the blade 15 receives wind power, the blade 15 rotates about the hub 14. When the hub 14 rotates, the rotor shaft 13 rotates. The orthogonal gear transmission 16 converts the rotational energy of the rotating rotor shaft 13 into a rotational force in the vertical direction into the tower 90. The rotational driving force converted in the vertical direction by the orthogonal gear transmission 16 and whose rotational speed is controlled by the speed governor is supplied with the rotational driving force to the compressor or pump constituting the carbon dioxide storage system 1 via the power transmission shaft 94 extending in the vertical direction.

[0022] Here, the power transmission shaft 94 transmits the rotational power of the rotor shaft 13 to the gas compression section 20, the separation section 30, the carbon dioxide compressor 41, and the press-fitting pump 51. However, when the rotational speed of the power transmission shaft 94 is different from the optimum operating rotational speeds of the respective component devices of the gas compressor, the carbon dioxide compressor, and the press-fitting pump, in order to enable each component device to operate at the optimum rotational speed, a transmission is provided on the rotating shaft of each component device and connected so that the rotational driving force of the power transmission shaft can be shifted to the optimum rotational speed and driven. Or, if there is no need to shift the speed, the power transmission shaft may be directly connected. In this way, the rotational driving force obtained by the wind power driving section 10 is transmitted to the rotational driving forces of the gas compressor in the gas compression section 20, the carbon dioxide compressor 41 in the liquefaction section 40, and the press-fitting pump 51 in the press-fitting section 50, so that the rotational shaft power obtained by the wind power driving section is efficiently utilized directly for gas compression and carbon dioxide press-fitting without passing through a generator.

[0023] Also, the control device 17 is connected to a solar power generation facility (not shown) installed on the top surface of the wind nacelle section 12, and constantly supplies power to the control device 17 while storing the surplus power generated by the solar power generation facility in a storage battery installed in the wind nacelle section 12. By supplying power to the sensors that monitor the states of the devices constituting the carbon dioxide storage system 1, including the state where the wind conditions are poor and carbon dioxide separation, recovery, and press-fitting are not possible, the operation state of the carbon dioxide storage system 1 is monitored and controlled.

[0024] Note that the gas compression section 20 is a compressor that compresses a gas. In the present embodiment, the gas compression section 20 compresses the air in the atmosphere and supplies the compressed air to the separation section 30. In the present embodiment, the gas compression section 20 is driven by the rotational driving force obtained from the wind power driving section 10 via the orthogonal gear transmission 16. The gas compression section 20 only needs to be able to compress a gas, and the means for compression is not particularly limited. Examples of the gas compression section 20 include a turbo-type compressor and a positive displacement type compressor. Examples of the turbo-type compressor include an axial flow compressor and a centrifugal compressor. Examples of the positive displacement type compressor include a reciprocating compressor and a rotary compressor.

[0025] The separation unit 30 is an example of a carbon dioxide separation and recovery device that separates and recovers carbon dioxide contained in the compressed air supplied from the gas compression unit 20 through a carbon dioxide separation membrane. Here, the separation unit 30 will be described with reference to FIG. 3. FIG. 3 is a diagram showing an example of the configuration of the separation unit 30. The separation unit 30 includes one or more separation membrane modules 31 and one or more carbon dioxide gas suction pumps 32. The number of separation membrane modules 31 is not particularly limited. In the illustrated example, the separation unit 30 includes three separation membrane modules 31a, 31b, and 31c. The separation membrane modules 31a to 31c are arranged in series, with the separation membrane module 31a arranged on the most upstream side, the separation membrane module 31c arranged on the most downstream side, and the separation membrane module 31b arranged between the separation membrane module 31a and the separation membrane module 31c. The separation membrane module 31 includes a housing 311, an inlet 312, a separation membrane 313, an upstream outlet 314, and a downstream outlet 315.

[0026] The housing 311 is a substantially cylindrical container. The inlet 312 is an opening for allowing gas to flow into the housing 311. When there is a gas pressure difference in the region sandwiching the separation membrane 313, the separation membrane 313 selectively permeates carbon dioxide gas from the side with higher pressure to the side with lower pressure. The separation membrane 313 is fixed inside the housing 311 and divides the inside of the housing 311 into two regions. Hereinafter, the region on the side where the inlet 312 is arranged among the two regions separated by the separation membrane 313 may be referred to as the upstream region, and the other side with respect to the upstream region may be referred to as the downstream region. The upstream outlet 314 and the downstream outlet 315 are openings for discharging the gas inside the housing 311 to the outside of the housing 311. The upstream outlet 314 is arranged in the upstream region of the housing 311, and the downstream outlet 315 is arranged in the downstream region of the housing 311. In the illustrated example, it is shown that nitrogen (N2) and oxygen (O2) after carbon dioxide is separated and recovered from the compressed air are discharged from the upstream outlet 314.

[0027] The carbon dioxide gas suction pump 32 sucks in the upstream gas and sends it to the downstream side. In the illustrated example, the separation unit 30 includes two carbon dioxide gas suction pumps 32a and 32b. The carbon dioxide gas suction pump 32a is provided between the separation membrane module 31a and the separation membrane module 31b, depressurizes the downstream region of the separation membrane module 31a, and pressurizes and pumps the upstream region of the separation membrane module 31b. Also, the carbon dioxide gas suction pump 32b is provided between the separation membrane module 31b and the separation membrane module 31c, depressurizes the downstream region of the separation membrane module 31b, and pressurizes and pumps the upstream region of the separation membrane module 31c.

[0028] Here, similar to the gas compression unit 20, the rotational drive shaft of the carbon dioxide gas suction pump 32 has the rotational driving force obtained from the wind power driving unit 10 via the orthogonal gear transmission 16 transmitted to the power transmission shaft 94, so that the rotational driving force of the wind power is directly utilized as the pump driving force. The method of depressurizing and sucking the carbon dioxide gas suction pump 32 is not particularly limited, and a vacuum pump or a vacuum pump is an example. When the gas sucked by the pump is pressurized and pumped, a gas compressor or a blower may be driven.

[0029] As shown in FIG. 2, the liquefaction unit 40 includes a carbon dioxide compressor 41 and a turbo refrigerator 42. The carbon dioxide compressor 41 is supplied with the carbon dioxide gas separated by the separation unit 30 and pressurizes the supplied carbon dioxide gas. The carbon dioxide compressor 41 only needs to be able to compress a gas, and the means for compression is not particularly limited. Similar to the gas compression unit 20, the carbon dioxide compressor 41 can exemplify a turbo compressor or a positive displacement compressor. The turbo refrigerator 42 has a compressor inside, compresses a refrigerant using the compressor, and executes a refrigeration cycle. The carbon dioxide gas cooled by this turbo refrigerator 42 is liquefied to become liquefied carbon dioxide. In this example, the compressors of the carbon dioxide compressor 41 and the turbo refrigerator 42 are both driven by the rotational driving force obtained via the power transmission shaft 94 in the tower, so that the rotational driving force of the wind power is directly used for the compression of the separated and recovered carbon dioxide gas and the driving of the compressor of the turbo refrigerator, and is also used for the liquefaction of carbon dioxide.

[0030] In addition, when injecting carbon dioxide into the ground, it is desirable to change carbon dioxide into a supercritical fluid by applying a pressure so that the carbon dioxide gas reaches 7.38 MPa or more. Here, the supercritical fluid is one of the states of carbon dioxide, in a state where the distinction between gas and liquid disappears, having the characteristics that the volume is small, the viscosity is low, and it is easy to perform injection. Carbon dioxide becomes a supercritical fluid when the pressure is 7.38 MPa or more and the temperature is 31.1 °C or more. The supercritical fluidized carbon dioxide is pressurized by the injection pump 51 of the injection unit 50 driven by the power via the power transmission shaft 94 and is poured into the carbon dioxide injection pipe 8. The carbon dioxide poured into the carbon dioxide injection pipe 8 flows into the carbon dioxide storage layer through the check valve 55.

[0031] Here, the injection part 50 is provided with, in addition to the injection pump 51, a flow rate adjustment valve 52 and pressure measuring instruments 53 and 54. Among these, the injection pump 51 is connected to the carbon dioxide injection pipe 8, adds energy to the carbon dioxide liquefied in the liquefaction part 40, and injects the liquefied carbon dioxide into the formation. The injection pump 51 is also connected to the power transmission shaft 94 in the tower 90 and is driven by the rotational driving force obtained from the wind power driving part 10 via the orthogonal gear transmission 16, so that the rotational driving force of the wind power is directly utilized for injecting the separated and recovered carbon dioxide gas into the ground. Here, as the injection pump 51, for example, a positive displacement pump can be considered, but it may also be a non-positive displacement pump. Examples of non-positive displacement pumps include centrifugal pumps and propeller pumps.

[0032] Also, the flow rate adjustment valve 52 is provided in the middle part of the carbon dioxide injection pipe 8 and adjusts the flow rate of the liquefied carbon dioxide flowing in the carbon dioxide injection pipe 8. The flow rate adjustment valve 52 can be exemplified as an electromagnetic valve. In this case, the flow rate adjustment valve 52 controls the magnitude of the current flowing through the electromagnetic valve to adjust the opening degree of the valve. Note that the flow rate adjustment valve 52 may be a check valve that allows the liquefied carbon dioxide to flow only in one direction to prevent backflow. Also, the pressure measuring instruments 53 and 54 measure the pressure of the liquefied carbon dioxide flowing through the carbon dioxide injection pipe 8. The pressure measuring instrument 53 is provided on the upstream side of the flow rate adjustment valve 52, and the pressure measuring instrument 54 is provided on the downstream side of the flow rate adjustment valve 52.

[0033] In this embodiment, the injection pump 51, the flow rate adjustment valve 52, and the pressure measuring instruments 53 and 54 are connected to a solar power generation facility (not shown) installed on the top surface of the wind power nacelle part 12 and are supplied with power from a storage battery installed in the wind power nacelle part 12. Note that the pressure measuring instruments 53 and 54 may be supplied with power from a storage battery installed in the wind power nacelle part 12, which is connected to a small wind turbine installed on the top surface of the wind power nacelle part 12, a solar power generation panel installed on the tower surface or in the vicinity, for example.

[0034] 〔Operation of Separating and Recovering Carbon Dioxide〕 First, the air in the atmosphere is supplied from the gas intake port 911 of the tower 90 to the gas compression unit 20. The gas compression unit 20 compresses the air in the atmosphere and supplies the compressed air to the separation unit 30. In the separation unit 30, first, air flows into the upstream region of the separation membrane module 31a from the inlet 312 of the separation membrane module 31a. Since the air in the upstream region of the separation membrane module 31a is compressed, the pressure is high, and carbon dioxide selectively passes through the separation membrane 313 and flows into the downstream region of the separation membrane module 31a. The gas remaining in the upstream region of the separation membrane module 31a is discharged from the upstream discharge port 314 to the outside of the housing 311 and then discharged from the gas discharge port 912 to the outside of the tower 90.

[0035] The gas that has flowed into the downstream region of the separation membrane module 31a has an increasing carbon dioxide concentration. The gas in the downstream region of the separation membrane module 31a has a higher carbon dioxide concentration than the gas in the upstream region. The gas in the downstream region of the separation membrane module 31a is supplied to the separation membrane module 31b by the carbon dioxide gas suction pump 32. A part of the gas in the upstream region of the separation membrane module 31b passes through the separation membrane 313 and flows into the downstream region of the separation membrane module 31b. The gas remaining in the upstream region of the separation membrane module 31b is discharged from the upstream discharge port 314 to the outside of the housing 311 and then discharged from the gas discharge port 912 to the outside of the tower 90.

[0036] Similarly, the gas that has flowed into the downstream region of the separation membrane module 31b has a higher carbon dioxide concentration in the downstream region of the separation membrane module 31b than in the upstream region. The gas in the downstream region of the separation membrane module 31b is supplied to the separation membrane module 31c by the carbon dioxide gas suction pump 32. A part of the gas in the upstream region of the separation membrane module 31c passes through the separation membrane 313 and is separated and recovered as high-concentration carbon dioxide gas and flows into the downstream region of the separation membrane module 31c. The gas remaining in the upstream region of the separation membrane module 31c is discharged from the upstream discharge port 314 to the outside of the housing 311 and then discharged from the gas discharge port 912 to the outside of the tower 90.

[0037] The high-concentration carbon dioxide gas that has flowed into the downstream region of the separation membrane module 31c is supplied from the separation unit 30 to the liquefaction unit 40. The high-concentration carbon dioxide gas supplied to the liquefaction unit 40 is pressurized by the carbon dioxide compressor 41 and liquefied by being cooled by the turbo refrigerator 42. The liquefied carbon dioxide is pressurized by the injection pump 51 of the injection unit 50 and poured into the carbon dioxide injection pipe 8. The flow rate of the liquefied carbon dioxide is adjusted by the flow rate adjustment valve 52 and conveyed to the seabed formation. The flow rate adjustment valve 52 adjusts the flow rate according to the measurement results of the pressure measuring instruments 53 and 54. For example, when the pressure on the upstream side of the flow rate adjustment valve 52 is lower than the pressure on the downstream side, the valve is closed to prevent the liquefied carbon dioxide from flowing backward. Also, for example, when the pressure on the upstream side is higher than the pressure on the downstream side, the opening degree may be changed according to the value of the difference between the pressure on the upstream side and the pressure on the downstream side.

[0038] In the present embodiment, since the carbon dioxide storage system 1 is installed using the offshore platform 100 for drilling oil and gas, it is possible to reduce or omit the transport pipe for the separated and recovered carbon dioxide and recover and immobilize the carbon dioxide at the storage site. Also, it is possible to significantly reduce the construction period and the equipment and construction costs for constructing the offshore platform 100. Further, by effectively utilizing existing depleted oil fields and gas fields for the storage and immobilization of carbon dioxide, it is possible to omit the exploration and excavation development of the carbon dioxide storage tank and significantly reduce the construction period and costs for the exploration and development of the storage tank.

[0039] Furthermore, in the present embodiment, on the ocean with good wind conditions away from power consumption areas where it is difficult to lay transmission lines, the rotational drive shaft power using wind energy without carbon dioxide emissions is directly used in the processes from the separation and recovery of carbon dioxide to the compression, liquefaction of the recovered carbon dioxide, and injection and storage of the liquefied carbon dioxide into the ground without going through power generation respectively. Therefore, it is possible to efficiently realize the separation, recovery, and immobilization of carbon dioxide by using renewable energy.

[0040] In this embodiment, the gas intake port 911 is disposed at the upper part of the tower 90 to take in air from above, thereby suppressing intake of air containing salt near the sea surface.

[0041] [Modification Example 1] FIG. 4 is a schematic diagram showing an example of the configuration of the wind power drive unit 10 and the inside of the tower 90 according to Modification Example 1 of the first embodiment. The carbon dioxide storage system 2 according to Modification Example 1 of the first embodiment includes a wind turbine 18, a gas compression unit 20, a separation unit 130, a liquefaction unit 40, an injection unit 50, and a tower 90. The wind turbine 18, the gas compression unit 20, the separation unit 130, the liquefaction unit 40, and the injection unit 50 are housed in the tower 90. In this embodiment, the wind turbine 18 is provided above the tower 90, and then the gas compression unit 20, the separation unit 130, the liquefaction unit 40, and the injection unit 50 are arranged in order from above in the vertical direction.

[0042] Compared with the first embodiment, in this system, the component devices such as compressors and pumps that are driven in the compression of gas using wind power, the compression, liquefaction of carbon dioxide, and the underground injection of liquefied carbon dioxide are performed by the power generated by the wind turbine 18 provided inside the wind nacelle unit 12, and the configuration of the separation unit 130 for separating carbon dioxide is different. That is, the devices constituting the gas compression unit 20, the separation unit 30, and the liquefaction unit 40 are composed of an in-tower consumption type motor group that is connected by a power supply wiring (not shown) in the tower by the power generated by the wind turbine 18 and is driven by the supply of the generated power. In the first embodiment, carbon dioxide was separated using the separation membrane module 31. In the separation unit 130 of Modification Example 1 of the first embodiment, carbon dioxide is separated by a physical adsorption type separation method using a plurality of pressure vessels filled with a carbon dioxide adsorbent. Examples of the carbon dioxide adsorbent include zeolite and activated carbon. Note that the same reference numerals are used for the same functions as those in the first embodiment, and the description thereof is omitted here.

[0043] FIG. 5 is a diagram showing an example of the separation unit 130. The separation unit 130 includes an adsorption tank 131, a heater 132, and a vacuum pump 133. The adsorption tank 131 is a pressure vessel and stores an adsorbent for adsorbing carbon dioxide inside. The adsorption tank 131 also has an openable and closable discharge port 131a. The discharge port 131a is used to replace the gas inside the adsorption tank 131. The heater 132 heats the inside of the adsorption tank 131. An electric heater is an example of the heater 132. The vacuum pump 133 reduces the pressure inside the adsorption tank 131. The vacuum pump 133 is driven by electricity. 〔Operation of Separating and Recovering Carbon Dioxide〕 In the physical adsorption method, as shown in FIG. 5, carbon dioxide is separated from other gases by utilizing a pressure difference or a temperature difference. Specifically, first, the discharge port 131a of the adsorption tank 131 is closed, and the gas compression unit 20 is driven. The air compressed by the gas compression unit 20 is supplied to the adsorption tank 131, thereby increasing the pressure inside the adsorption tank 131. When the pressure inside the adsorption tank 131 increases, the adsorbent adsorbs carbon dioxide. Next, the discharge port 131a is opened to discharge the gas with a lower carbon dioxide concentration. Then, after closing the discharge port, the vacuum pump 133 is driven to reduce the pressure inside the adsorption tank 131. When the pressure inside the adsorption tank 131 decreases, carbon dioxide is desorbed from the adsorbent, and the desorbed carbon dioxide can be recovered.

[0044] 〔Modification 2〕 FIG. 6 is a diagram showing an example of the configuration of the separation unit 230 using a carbon dioxide absorption liquid. In Modification 2 of the first embodiment, the separation unit 130 is different from that in Modification 1 of the first embodiment in that the separation unit 130 is replaced with a separation unit 230 using a carbon dioxide absorption liquid. The separation unit 230 includes an absorption tower 231, a fine bubble supply pipe 232, a regeneration tower 233, a heating unit 234, and absorption liquid pipes 235 and 236. The absorption tower 231 stores an absorption liquid for absorbing carbon dioxide, and a fine bubble supply pipe 232 for injecting the air compressed by the gas compression unit 20 is inserted therein. The absorption liquid is, for example, an aqueous amine solution. The fine bubble supply pipe 232 ejects fine bubbles into the absorption liquid. Here, the fine bubbles are those in which the gas is made into fine bubbles so that carbon dioxide is easily absorbed by the absorption liquid. For example, they are nanobubbles with a bubble size of less than 0.001 mm, microbubbles with a size of 0.001 mm or more and less than 0.1 mm, and the like.

[0045] The regeneration tower 233 desorbs carbon dioxide from the absorption liquid that has absorbed carbon dioxide and recovers the carbon dioxide. The heating unit 234 heats the absorption liquid in the regeneration tower 233. The absorption liquid pipe 235 connects the absorption tower 231 and the regeneration tower 233. The absorption liquid pipe 235 is provided with a liquid feed pump 235a that feeds the absorption liquid from the absorption tower 231 to the regeneration tower 233. The absorption liquid pipe 236 connects the absorption tower 231 and the regeneration tower 233. The absorption liquid pipe 236 is provided with a liquid feed pump 236a that feeds the absorption liquid from the regeneration tower 233 to the absorption tower 231. Here, an electric heater that heats the carbon dioxide absorption liquid and a liquid feed pump that feeds the absorption liquid are supplied by the generated electric power obtained from the wind power generator 18.

[0046] 〔Operation of Separating and Recovering Carbon Dioxide〕 First, the air in the atmosphere is supplied from the gas intake port 911 of the tower 90 to the gas compression unit 20. The gas compression unit 20 compresses the air in the atmosphere and supplies the compressed air to the separation unit 230. In the separation unit 230, the supplied air is supplied into the absorption tower 231 through the fine bubble supply pipe 232. A part of the carbon dioxide in the air supplied into the absorption tower 231 is absorbed by the absorption liquid. Hereinafter, the absorption liquid that has absorbed carbon dioxide may be referred to as rich absorption liquid. The absorption tower 231 discharges the air in which carbon dioxide has been absorbed and the carbon dioxide concentration has decreased into the atmosphere through the gas discharge port 912.

[0047] The rich absorption liquid in the absorption tower 231 is supplied to the regeneration tower 233 through the absorption liquid pipe 235 by the liquid delivery pump 235a. In the regeneration tower 233, the heating unit 234 generates heat to heat the rich absorption liquid. The heated rich absorption liquid is separated into the absorption liquid and carbon dioxide. Here, the separated carbon dioxide is supplied to the liquefaction unit 40. Further, the regenerated absorption liquid is supplied again to the absorption tower 231 through the absorption liquid pipe 236 by the liquid delivery pump 236a and circulates. The separation unit 230 is an example of a carbon dioxide separation device. Note that even if the absorption liquid has been heated and regenerated, if the temperature of the absorption liquid is high, the absorption performance when absorbing carbon dioxide again will deteriorate. Therefore, a cooler for cooling the regenerated absorption liquid may be provided in the absorption liquid pipe 236, and the cooling heat supplied to the cooler may also be obtained from a refrigerator operated by the electric power generated by the wind power generator 18. In addition, in the separation and recovery of carbon dioxide using a chemical absorption liquid, in addition to the method of atomizing the compressed air and discharging it into the absorption liquid container, an open-type absorption tower in which the air flowing down in the wind tower comes into contact with the absorption liquid is installed. After absorbing carbon dioxide into the absorption liquid in the wind tower, the carbon dioxide absorption liquid accumulated at the lower part of the recovery unit is heated and regenerated to separate and recover carbon dioxide gas, and then the regenerated absorption liquid may be pumped up to the upper part of the tower.

[0048] The carbon dioxide separated in this way is liquefied in the liquefaction unit 40 by being pressurized by the carbon dioxide compressor 41 and cooled by the turbo refrigerator 42, in the same manner as in the first embodiment. The liquefied carbon dioxide is pressurized by the injection pump 51 in the injection unit 50 and flows into the carbon dioxide injection pipe 8. Here, regarding the operation of the carbon dioxide compressor 41, the turbo refrigerator 42, and the injection pump 51, the electric power obtained from the wind power generator 18 may be supplied by wiring connection in the tower for operation. When the operation state of the system fluctuates due to the fluctuation of wind power generation and has an adverse effect on the stable injection of carbon dioxide or the component devices of the system, a large-capacity battery facility may be installed in the wind tower and connected to the wind power generator. For the purpose of alleviating fluctuations during operation and achieving long-term stable operation, the system may be operated by stably supplying power from the large-capacity battery facility.

[0049] [Second Embodiment] FIG. 7 is a diagram showing the overall configuration of the carbon dioxide storage system 3 according to the second embodiment. The carbon dioxide storage system 3 according to the second embodiment is different from the first embodiment in that an onshore wind power utilization facility is installed on the above-ground part of the carbon dioxide storage tank existing on land, and a biogas fermentation tank 210, a purification filter 211, and a methane gas tank 220 are further provided in the vicinity of the onshore wind power utilization facility. Note that the same reference numerals are used for the same functions as those in the first embodiment, and the description thereof is omitted here. The biogas fermentation tank 210 generates biogas mainly composed of methane and carbon dioxide from the biomass resource 101 for methane fermentation such as food residues, inedible parts of agriculture, or livestock excrement by anaerobic methane fermenting bacteria. The purification filter 211 removes hydrogen sulfide and excessive moisture contained in the biogas generated from the biogas fermentation tank 210. The methane gas tank 220 is a tank for storing methane gas separated from biogas. The methane gas stored in the methane gas tank 220 may be filled into a gas cylinder or the like for use, for example. Further, the methane gas may be used as fuel for driving any device of the carbon dioxide storage system 4, for example.

[0050] FIG. 8 is a schematic diagram showing an example of the configuration of the wind power driving unit 10 and the inside of the tower 90 according to the second embodiment. The carbon dioxide storage system 3 according to the second embodiment includes a wind power driving unit 10, a gas compression unit 20, a separation unit 30, a liquefaction unit 40, and an injection unit 50. The wind power driving unit 10, the gas compression unit 20, the separation unit 30, the liquefaction unit 40, and the injection unit 50 are housed in the tower 90. The wind power driving unit 10 is provided above the tower 90, and then the gas compression unit 20, the separation unit 30, the liquefaction unit 40, and the injection unit 50 are arranged side by side in the vertical direction from above.

[0051] [Operation of Separating and Recovering Carbon Dioxide] The biogas generated from the biogas fermentation tank 210 is purified by the purification filter 211 to remove impurities and excessive moisture. The biogas that has passed through the purification filter 211 contains carbon dioxide gas and methane gas, and is supplied from the gas intake port 911 of the tower 90 to the gas compression unit 20. The gas compression unit 20 compresses the biogas and supplies the compressed biogas to the separation unit 30. In the separation unit 30, the biogas is separated into carbon dioxide gas and methane gas. The separated methane gas is transported from the gas discharge port 912 to the methane gas tank 220 and stored.

[0052] The carbon dioxide gas separated in the separation unit 30 is supplied to the liquefaction unit 40. In the liquefaction unit 40, the carbon dioxide gas is pressurized by the carbon dioxide compressor 41 and liquefied by being cooled by the turbo refrigerator 42. The liquefied carbon dioxide is pressurized by the injection pump 51 of the injection unit 50 and poured into the carbon dioxide injection pipe 8. Also, the separated methane gas can also be cooled and liquefied by the turbo refrigerator 42 to make it liquefied methane that is easy to store and transport. Also, in the second embodiment, carbon dioxide was separated and recovered from biogas. However, the gas from which carbon dioxide is separated and recovered is not limited to biogas, and for example, carbon dioxide may be separated and recovered from exhaust gas generated when fossil fuel or biogas is burned. In the second embodiment, the separation unit 30 is used to separate carbon dioxide, but the separation unit 130 or the separation unit 230 may be used to separate carbon dioxide.

[0053] 〔Others〕 In the illustrated example, the rotor shaft 13 extends in a substantially horizontal direction. However, the direction of the rotor shaft 13 is not particularly limited and may extend in a substantially vertical direction. That is, the rotating unit 11 may be a so-called vertical-axis windmill. Examples of the vertical-axis windmill include a Darrieus windmill and a Savonius windmill. For example, in the third embodiment, when a vertical-axis windmill is used, the rotor shaft 13 will be arranged along the vertical direction, and the rotor shaft 13 can be used as a power transmission shaft 94 to drive the carbon dioxide gas suction pump 32 and the like.

[0054] Also, in this embodiment, liquefied carbon dioxide is stored in the underground storage tank using the injection pump 51, but liquefied carbon dioxide may be used as a raw material gas for commercial and industrial use. In this case, the injection pump 51 may be used to fill a carbon dioxide cylinder with high-pressure carbon dioxide gas, or to fill a tank truck or the like with liquefied carbon dioxide. Further, the recovered carbon dioxide may be solidified and used as dry ice.

Explanation of Reference Numerals

[0055] 1, 2, 3... carbon dioxide storage system, 8... carbon dioxide injection pipe, 10... wind power drive unit, 11... rotating unit, 12... wind nacelle unit, 13... rotor shaft, 14... hub, 15... blade, 16... orthogonal gear transmission, 17... control device, 18... wind turbine generator, 20... gas compression unit, 30, 130, 230... separation unit, 31... separation membrane module, 32... pump, 40... liquefaction unit, 41... carbon dioxide compressor, 42... turbo refrigerator, 50... injection unit, 51... injection pump, 53, 54... pressure gauges, 55... check valve, 60... biogas fermentation tank, 90... tower, 91... side surface, 911... gas intake port, 912... gas discharge port, 94... power transmission shaft, 100... offshore platform, 311... housing, 312... inlet, 313... separation membrane, 314... upstream discharge port, 315... downstream discharge port, 911... gas intake port, 912... gas discharge port

Claims

1. A cylindrical tower, a wind turbine device disposed on the tower; a carbon dioxide separation and capture device that is driven by a rotary shaft power obtained from the wind turbine device and separates and captures carbon dioxide from a gas taken in through an opening provided in the tower; a carbon dioxide gas compressor driven by a rotary shaft power obtained from the wind turbine device and compressing the carbon dioxide gas separated and captured by the carbon dioxide capture device; an injection pump that is driven by a rotary shaft power obtained from the wind turbine device and that pumps the carbon dioxide compressed by the carbon dioxide gas compressor into an underground carbon dioxide storage tank; An injection well that injects and stores the carbon dioxide separated and recovered from the gas into an underground carbon dioxide storage tank, A carbon dioxide storage system comprising the carbon dioxide separation and capture device, the carbon dioxide gas compressor, and the injection pump within the tower.

2. A cylindrical tower, a wind turbine device disposed on the tower; a carbon dioxide separation and capture device that is driven by a rotary shaft power obtained from the wind turbine device and separates and captures carbon dioxide from a gas taken in through an opening provided in the tower; a carbon dioxide gas liquefaction device that is driven by a rotary shaft power obtained from the wind turbine device and liquefies the carbon dioxide gas separated and captured by the carbon dioxide capture device; an injection pump that is driven by a rotary shaft power obtained from the wind turbine device and that pumps the carbon dioxide liquefied by the carbon dioxide gas liquefaction device into an underground carbon dioxide storage tank; An injection well that injects and stores the carbon dioxide separated and recovered from the gas into an underground carbon dioxide storage tank, A carbon dioxide storage system comprising the carbon dioxide separation and capture device, the carbon dioxide gas liquefaction device, and the injection pump within the tower.

3. The carbon dioxide storage system described in claim 1, characterized in that one or more of the carbon dioxide separation and capture device, the carbon dioxide gas compressor, and the injection pump are driven by electricity generated by rotary shaft power obtained from the wind turbine device.

4. The carbon dioxide storage system described in claim 2, characterized in that one or more of the carbon dioxide separation and capture device, the carbon dioxide gas liquefaction device, and the injection pump are driven by electricity generated by rotary shaft power obtained from the wind turbine device.

5. The carbon dioxide separation and capture device includes a carbon dioxide separation membrane, The gas to be supplied to the separation membrane is supplied from an air intake port, which is an opening provided at the top of the tower, and the gas pressurized by a gas compressor driven by the rotating shaft power obtained from the wind turbine device or the generated power obtained from a generator connected to the wind turbine device is supplied to the separation membrane, or the carbon dioxide gas is separated and recovered from the supply gas by being sucked and separated by a carbon dioxide gas suction pump provided on the carbon dioxide gas suction flow path of the separation membrane and driven by the rotating shaft power obtained from the wind turbine device or the generated power obtained from a generator connected to the wind turbine device.

6. The carbon dioxide separation and capture device includes a pressure vessel containing a carbon dioxide adsorbent, The gas supplied to the pressure vessel is supplied from an air intake port, which is an opening provided at the top of the tower, and carbon dioxide is separated and recovered from the supply gas by supplying high-pressure gas to the pressure vessel by a gas compressor driven by the rotating shaft power obtained from the wind turbine device or the generated power obtained from a generator connected to the wind turbine device, and by reducing pressure and suctioning from the pressure vessel using a suction pump driven by the rotating shaft power obtained from the wind turbine device or the generated power obtained from a generator connected to the wind turbine device.This is the carbon dioxide storage system described in claim 1 or 2, characterized in that:

7. The carbon dioxide separation and capture device includes a separation and capture tower that uses a carbon dioxide absorption liquid, The gas supplied to the separation and capture tower is supplied from an air inlet, which is an opening provided at the top of the tower, and the air supply and absorption liquid are circulated by an air supply blower and an absorption liquid circulation pump driven by either the rotating shaft power obtained from the wind turbine device or the generated power obtained from a generator connected to the wind turbine device, while the absorption liquid that has absorbed carbon dioxide is heated and regenerated using the generated power obtained from the generator connected to the wind turbine device, thereby separating and capturing carbon dioxide from the supply gas.

8. A carbon dioxide storage system, comprising: a carbon dioxide separation and capture apparatus as described in claim 1 or claim 2, wherein the gas in which the carbon dioxide has been separated and has a low carbon dioxide concentration is exhausted from an exhaust port provided in the tower.

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