Carbon dioxide recovery device and carbon dioxide recovery method

Abstract

The present invention provides a carbon dioxide recovery device and a carbon dioxide recovery method for recovering carbon dioxide in a liquid at a low cost. A carbon dioxide recovery device according to one embodiment of the present invention is characterized by comprising: a storage unit that is constituted of a partition wall separating the atmosphere from an internal space, and that stores a liquid, in which carbon dioxide is dissolved, in the internal space; a vibration transmission unit that transmits, to the liquid stored in the storage unit, vibrations from a vibration source disposed at or in proximity to the storage unit; and an accumulation unit that recovers and accumulates the carbon dioxide discharged from the liquid by the vibrations transmitted via the vibration transmission unit.

Description

Carbon dioxide recovery device and carbon dioxide recovery method

[0001] The present invention relates to a carbon dioxide recovery device and a carbon dioxide recovery method for recovering carbon dioxide from a liquid at low cost.

[0002] As a measure against global warming, there is a worldwide demand to reduce the burden on the global environment by reducing the amount of carbon dioxide in the atmosphere. To achieve this, two things are necessary: ​​reducing carbon dioxide emissions and reducing the carbon dioxide concentration in the atmosphere by capturing carbon dioxide that is already present in the atmosphere. The carbon dioxide concentration in the atmosphere is low, at around 400 ppm, so in order to reduce the carbon dioxide concentration in the atmosphere, a method that minimizes the release of new carbon dioxide as energy for capture is required.

[0003] One method of capturing carbon dioxide without releasing new carbon dioxide is to capture it through seawater or freshwater, which contains dissolved carbon dioxide from the atmosphere, and a known method is to extract carbon dioxide from the aforementioned seawater or freshwater by reducing the pressure.

[0004] Patent Document 1 describes a carbon dioxide removal device for a fish breeding tank that removes carbon dioxide dissolved in seawater in the fish breeding tank by depressurizing the seawater. Specifically, it discloses that in order to remove carbon dioxide from the seawater, carbon dioxide bubbles are released to the outside in a depressurized space, and seawater from which carbon dioxide has been removed is supplied into the tank.

[0005] JP 2003-259759

[0006] However, the device described in Patent Document 1 requires a nozzle and a control unit for maintaining a reduced pressure state inside the tank, resulting in a complex device configuration and high costs.

[0007] An object of the present invention is to provide a carbon dioxide recovery device and a carbon dioxide recovery method that recover carbon dioxide from a liquid at low cost.

[0008] In order to solve the above problems, one aspect of the present invention provides a carbon dioxide recovery device, which is characterized by having: a storage section that is composed of a partition wall that separates the atmosphere from an internal space and that stores a liquid in which carbon dioxide is dissolved in the internal space; a vibration transmission section that transmits vibrations from the storage section or a vibration source that is arranged in the vicinity of the storage section to the liquid stored in the storage section; and a storage section that recovers and stores the carbon dioxide released from the liquid by the vibrations transmitted via the vibration transmission section.

[0009] According to the present invention, carbon dioxide in a liquid can be recovered at low cost.

[0010] 1. A schematic diagram of a carbon dioxide capture device according to a first embodiment of the present invention. 2. A schematic diagram of a carbon dioxide capture device according to a second embodiment of the present invention. 3. A schematic diagram of a carbon dioxide capture device according to a third embodiment of the present invention. 4. A schematic diagram of a carbon dioxide capture device according to a fourth embodiment of the present invention. 5. A schematic diagram of a carbon dioxide capture device according to a fifth embodiment of the present invention. 6. A schematic diagram of a carbon dioxide capture device according to a sixth embodiment of the present invention. 7. A schematic diagram of a carbon dioxide capture device according to an eighth embodiment of the present invention. 9. A schematic diagram of a carbon dioxide capture device according to a ninth embodiment of the present invention.

[0011] A carbon dioxide capture device according to one aspect of the present invention captures carbon dioxide from the atmosphere at low cost by heating or reducing the pressure of a liquid in which carbon dioxide is dissolved. Examples of liquids in which carbon dioxide is dissolved include rainwater, river water, lake water, and seawater. In fresh water such as rainwater and river water, atmospheric carbon dioxide is dissolved at equilibrium pressure. In comparison, seawater has an even higher solubility of carbon dioxide. Furthermore, the solubility of carbon dioxide in water is high at low temperatures and low at high temperatures. Additionally, the higher the atmospheric pressure, the higher the solubility of carbon dioxide, and the lower the atmospheric pressure, the lower the solubility.

[0012] In order to reduce the amount of carbon dioxide in the atmosphere as a measure against global warming, it is necessary to extract carbon dioxide while feeding and discharging large amounts of seawater or freshwater into the device. In order to capture carbon dioxide from seawater or freshwater using low energy, it is desirable to extract carbon dioxide by depressurizing the seawater or freshwater.

[0013] The carbon dioxide capture device according to the present invention can capture carbon dioxide at low cost with a simple device configuration. Specifically, seawater or freshwater is pumped, the carbon dioxide released from the storage unit is captured, and the seawater or freshwater is circulated within the device using the siphon principle. Here, for example, the storage unit is a Torricelli vacuum (a vacuum space created at the top as water is pumped). Torricelli vacuum refers to a vacuum space created above the height limit at which water can be pumped by reducing pressure. It is generally known that a Torricelli vacuum is formed due to the relationship between atmospheric pressure, the specific gravity of the solution, and the vapor pressure of the solution. For water at sea level, a Torricelli vacuum occurs when the depth exceeds approximately 10 meters. However, reducing pressure in the storage unit is not essential; the device may be configured to release carbon dioxide by heating using a heating mechanism.

[0014] In one embodiment of the carbon dioxide capture device of the present invention, carbon dioxide dissolved in seawater or freshwater is released as a gas when a Torricelli vacuum is applied, so that the carbon dioxide can be discharged using a vacuum pump and captured in a capture tank. The carbon dioxide capture device of the present invention also utilizes, for example, the siphon principle to circulate the pumped seawater or freshwater within the device under reduced pressure. The method of circulation within the device is not limited to the siphon principle, and any other known technology may be used as long as it is a mechanism for circulating a liquid.

[0015] In the carbon dioxide recovery device of the present invention, the pressure density due to the weight of the liquid in the water supply channel and the pressure density of the liquid in the drainage channel are the same if the water supply channel and the drainage channel are at the same height. In other words, if the water level of the water supply surface is higher than the water level of the drainage surface, the liquid can be made to flow from the water supply side to the drainage side by potential energy without power assistance such as a water flow pump. Furthermore, even if the water supply surface and the drainage surface are at the same height, the liquid can be circulated within the device by providing slight power assistance with a water flow pump.

[0016] By adopting the above-described configuration and method, the carbon dioxide capture device of the present invention enables carbon dioxide capture with low energy in a carbon dioxide capture device. Furthermore, the present invention further enables carbon dioxide to be captured from a liquid at low cost by transmitting vibrations to the liquid, i.e., by vibrating the liquid, as a means for shortening the reaction time for extracting carbon dioxide dissolved in the liquid as a gas. Furthermore, it is preferable to adopt a method in which the vibrations are generated by a vibration source that is not intended to generate vibrations, and are transmitted to the liquid to vibrate it.

[0017] That is, the carbon dioxide capture device of the present invention is composed of a partition wall that separates the atmosphere from an internal space, and has a storage section that stores a liquid in which carbon dioxide is dissolved in the internal space. The device also has a vibration transmission section that transmits vibrations from a vibration source that is disposed in the storage section or in the vicinity of the storage section to the liquid stored in the storage section. The device is further characterized by having a storage section that recovers and accumulates the carbon dioxide released from the liquid by vibrations transmitted via the vibration transmission section, thereby enabling carbon dioxide to be captured at low cost.

[0018] The present invention will be described in detail below with reference to preferred embodiments. However, the present invention is not limited to the following embodiments, and appropriate modifications and improvements to the following embodiments based on the ordinary knowledge of those skilled in the art are also included within the scope of the present invention, provided that they do not deviate from the spirit of the present invention.

[0019] First Embodiment An example of the functional configuration of a carbon dioxide recovery device of the present invention will be described below with reference to FIG.

[0020] Liquid 100, in which carbon dioxide from the atmosphere has been dissolved, is injected by injection pump 104 through injection valve 105 into CO2 release tank (storage section) 101. Drain valve 107 is closed, and a space 111 is created in liquid 100 inside CO2 release tank (storage section) 101 by adjusting the amount of liquid injected. After injection is complete, injection valve 105 is closed.

[0021] Next, the valve 106 is opened, and the pressure inside the CO2 release tank (storage section) 101 is reduced by the vacuum pump 102. In this embodiment, the degree of vacuum inside the CO2 release tank (storage section) 101 is set to 2 kPa, but a higher pressure may be used as long as it is equal to or lower than atmospheric pressure, and the degree of vacuum is not limited.

[0022] Here, the vacuum pump 102 is physically connected to a CO2 release tank (storage portion) 101 via a vibration transmission unit 103. The vibrations generated by the exhaust operation of the vacuum pump 102, which is a vibration source, are transmitted to the liquid inside the storage portion by the vibration transmission unit 103. Specifically, the vibrations are transmitted to the liquid 100 inside the CO2 release tank (storage portion) 101 via the CO2 release tank (storage portion) 101. In other words, the vibrations of a vibration source disposed close to the storage portion 101 are transmitted to the liquid stored in the storage portion 101 via the vibration transmission unit 103.

[0023] Here, the liquid 100 is in a state where excess carbon dioxide is dissolved therein compared to the pressure equilibrium due to the reduced pressure, and the carbon dioxide is released from the liquid 100 into the storage section 101. Furthermore, due to vibrations generated by the vacuum pump 102, the carbon dioxide is released from the liquid 100 as bubbles 110 into the space 111. The carbon dioxide released into the space 111 is collected from the release tank 101 by the vacuum pump 102 and stored in the CO2 storage section (storage section) 108.

[0024] In this embodiment, the depressurization time for the liquid 100 is set to 3 minutes, but this is not limited to this, and by lengthening the depressurization time, the recovery rate of carbon dioxide from the liquid 100 by the carbon dioxide recovery device is improved. However, by lengthening the depressurization time, the amount of carbon dioxide remaining in the liquid 100 decreases, and therefore the amount of carbon dioxide that can be recovered per hour decreases.

[0025] In this embodiment, after the liquid 100 has been depressurized for a desired depressurization time, the valve 106 is closed and the vacuum pump 102 is stopped. The atmospheric leak valve 122 is opened to return the space 111 to atmospheric pressure, and the drain valve 107 is opened to drain the liquid 100 from the CO2 release tank (storage section) 101. After the liquid 100 has been drained from the CO2 release tank (storage section) 101, the drain valve 107 is closed, completing a series of carbon dioxide recovery operations. Carbon dioxide from the atmosphere is recovered by repeating the series of operations described above.

[0026] In this embodiment, seawater was used as the liquid 100 in which carbon dioxide was dissolved, but this is not limited to seawater as long as it is a liquid in which carbon dioxide from the atmosphere is dissolved, and rainwater, river water, lake water, or tap water may also be used.

[0027] The liquid 100 may be a basic aqueous solution or a fluorine-based activated liquid, and carbon dioxide in the atmosphere may be recovered by exposing these liquids to the atmosphere. It is also possible to use the recovery device of this embodiment to recover CO2 from the recovered liquid, and then use the liquid 100 after carbon dioxide recovery to recover carbon dioxide from the atmosphere again as a circulating system.

[0028] The liquid 100 may be a basic solution for CO2 capture. Examples of basic substances include sodium hydroxide, ammonia, and amines (primary amines, secondary amines, and tertiary amines), which may be used as is or in solution. A solution of a salt such as sodium bicarbonate, which exhibits basicity when dissolved, may also be used. To suppress sudden changes in pH associated with CO2 capture, borate, phosphate buffer, or Tris may be used as a buffer. Recovery efficiency can be improved by using a fluorine-based active liquid with high CO2 solubility. Furthermore, the fluorine-based active liquid with high CO2 solubility is characterized by being selected from fluorocarbons that may have a substituent and may have a branched and / or cyclic structure in terms of viscosity. Examples of such a liquid include, but are not limited to, perflubron, perfluorodecalin, Fluorinert FC-3283, perfluorobutylperfluorotetrahydrofuran, perfluoro-1-isopropoxyhexane, perfluoro-1,4-diisopropoxybutane, and hydrofluoroethers (Novec 7100 and Novec 7300). It is also useful to mix other liquids with the liquid to adjust its physical properties.

[0029] The vacuum pump 102 used in this embodiment is a vacuum pump driven by an induction motor that operates on a single-phase 100 V, 50 Hz commercial power supply. When the vibration of the vacuum pump, which is the vibration source, was measured, large vibrations were observed at frequencies above several Hz, with peaks of vibration amplitude observed around 25 Hz and 50 Hz.

[0030] It is preferable to use a power-saving brushless motor, with a typical control frequency ranging from a few kHz to 10 kHz. The drive current for a brushless motor is generated by amplifying the digital waveform resulting from the PWM signal generated by the drive frequency using a power transistor or FET, and then converting it into an analog current waveform using a low-pass filter. Depending on the drive circuit configuration, high frequencies that cannot be completely removed by the low-pass filter remain in the drive current waveform, affecting the vibration generated by the motor. For this reason, the pump's vibration frequency range, which takes into account the control frequency in addition to the rotational speed and structure, can produce large vibrations in the range of a few Hz to 10 kHz.

[0031] Typical brushless motors often have a maximum rotation speed of 6000 rpm, and at this rotation speed, the rotational frequency of the motor itself is 100 Hz or less. Vibrations can also be generated by controlling the motor's rotational speed to cause unevenness. For example, the motor drive current can be controlled to increase the vibration caused by cogging in the brushless motor. For example, in the case of a motor driven by three-phase current, cogging vibrations are often generated in products with approximately five sets of three-phase coils, resulting in approximately 15 cogging vibrations per motor rotation. Brushless motors come in a wide variety of configurations, and the coil configuration described above is only one example.

[0032] Furthermore, the vibration frequency generated varies depending on the structure of the gears and screws that make up the pump. For example, a pump may be configured so that part of the pump structure rotates at high speed, generating high-frequency vibrations. It is generally known that vibration energy increases as the frequency increases for the same amplitude, and the vibration frequency is not limited as long as it can promote the generation of bubbles 110 from the liquid 100.

[0033] In this embodiment, the vibration transmission unit 103 uses a metal member made of iron. The vacuum pump 102, which is the vibration source, and the CO2 release tank (storage unit) 101 are fixed together using the metal member described above. The vibration transmission unit 103 is not limited to the metal member made of iron described above as long as it can transmit the vibration of the vacuum pump 102, which is the vibration source, to the liquid 100. For example, the vibration transmission unit 103 may be made of stainless steel, an alloy of aluminum or copper, or a resin material. The vibration transmission unit 103 may also be an exhaust pipe for reducing the pressure inside the CO2 release tank (storage unit) 101, or the vacuum pump 102 may be installed on an apparatus stand 124, which may then serve as the vibration transmission unit 103.

[0034] The CO2 release tank (storage unit) 101 is supported on a mounting unit such as an apparatus stand 124 via an elastic unit 123, making the CO2 release tank (storage unit) 101 prone to vibration. In this embodiment, a rubber member is used for the elastic unit 123, but it may also be a springy metal, resin, or wood structure, or a damper structure. The mounting unit is not limited to the stand, and may be the ground, etc.

[0035] Furthermore, in the carbon dioxide recovery device, the liquid 100 in the storage unit 101 may be heated by a heating unit 109 comprising a heating mechanism. The heating unit 109 is preferably a heat source that does not release new carbon dioxide into the atmosphere for heating, and is preferably one that uses, for example, factory waste heat, solar-based energy, geothermal energy, or green electricity. The solution 100 in which carbon dioxide is in atmospheric pressure equilibrium will release carbon dioxide not only by reducing the pressure but also by increasing the solution temperature, so it is desirable to heat the solution as well as reducing the pressure.

[0036] Second Embodiment An example of the functional configuration of a carbon dioxide recovery device of the present invention will be described below with reference to FIG.

[0037] The following mainly describes the differences from the first embodiment. In this embodiment, the liquid 100 having dissolved carbon dioxide is seawater, and the CO2 release tank (storage unit) 101 is installed so that the pumping height H2 of the liquid 100 inside the CO2 release tank (storage unit) 101 is approximately 10 m above the seawater level H2. The liquid 100 is pumped by a pumping pump 104 through a water supply pipe 113 into the CO2 release tank (storage unit) 101 in the direction shown by the arrow.

[0038] At the same time, the pressure inside the CO2 release tank (storage portion) 101 is reduced by a vacuum pump 102. The liquid 100 pumped from the water supply port is stored inside the CO2 release tank (storage portion) 101 in an amount based on the shape of the CO2 release tank (storage portion) 101 and the pumping height H2.

[0039] In the carbon dioxide capture device of this embodiment, the pumped liquid 100 is drained from the drain port 118 by the drain pipe 114 and the drain pump 106 as a flow shown by the arrow. In this embodiment, the pressure in the space 111 is reduced to 2 kPa. The height relationship between the water supply pipe 113 and the drain pipe 114 inside the CO2 release tank (storage section) 101 is preferably a height relationship that allows drainage from the liquid 100 with a reduced concentration of residual carbon dioxide, and this height relationship differs depending on the liquid 100 that is the solvent, so there are no limitations on this.

[0040] In this embodiment, the liquid 100 is drained using the drain pump 106. The upper limit of the pumping height H2 is determined by a principle known as the "Torricelli vacuum height." When pumping seawater at sea level, the pumping height H2 is approximately 10 m. The Torricelli vacuum height is determined by the relationship between the vapor pressure of the liquid 100, the weight density of the liquid 100, and the atmospheric pressure at sea level H1. In other words, the carbon dioxide capture device in this embodiment includes a water supply pipe 113, which is a structure for suppressing the flow rate of the water supply channel that supplies the liquid to the storage unit 101, and a drain pipe 114, which is a drainage mechanism that drains the liquid from the storage unit. Furthermore, the liquid level inside the storage unit 101 is characterized by being lower than the Torricelli vacuum height in the storage unit. Note that the liquid level of the liquid 100 described above varies depending on the atmospheric pressure, the temperature of the liquid 100, the degree of vacuum inside the CO2 release tank (storage unit) 101, and the constituent elements of the liquid 100.

[0041] Furthermore, if the pumping height H2 is the Torricelli vacuum height, the liquid 100 will be drained by its own weight even without the drain pump 106, so the configuration may not require the drain pump 106. Furthermore, if both the pumping pump 104 and the drain pump 106 are used to supply and drain the liquid 100, the pumping height H2 can be set to any height equal to or lower than the Torricelli vacuum height. Alternatively, the pumping height H2 may be adjusted by reducing the supply flow rate of the liquid 100 using a flow rate suppression mechanism and draining the liquid 100 using the drain pump 106.

[0042] The flow rate control mechanism described above may be any mechanism capable of increasing the flow resistance of the water being supplied, and may be, for example, a structure in which a flow rate adjustment valve is provided in the water supply pipe 113 or a structure in which the diameter of the water supply pipe 113 is reduced.

[0043] When the pumping height H2 is set to the Torricelli vacuum height, the liquid 100 can be drained using the drain pump 106. Specifically, even if the configuration does not include the pumping pump 104, the liquid 100 is pumped due to the relationship between the pressure inside the CO2 release tank (storage section) 101 and the atmospheric pressure that the liquid 100 receives. Therefore, from the perspective of power saving, it is desirable to use either the pumping pump 104 or the drain pump 106.

[0044] In this embodiment, the liquid 100 is circulated within the device by the siphon principle. Therefore, when the liquid 100 is circulated by the pumping pump 104, for example, only a small amount of pumping is required, and therefore the liquid can be circulated with little pump driving power.

[0045] The carbon dioxide released into the depressurized space 111 is recovered by the vacuum pump 102 through a water vapor filter 115, temporarily stored in a carbon dioxide buffer tank 116, and then stored in a CO2 storage unit (accumulator) 108 by a pressure pump 117. In this embodiment, the recovered carbon dioxide is stored in the CO2 storage unit (accumulator) 108 at a pressure equal to or higher than atmospheric pressure.

[0046] In this embodiment, the water supply pipe 113 serves as a vibration transmission part that transmits the vibrations of the water pumping pump 104, which is a vibration source, to the liquid 100 inside the CO2 release tank (storage part) 101. Additionally, the drain pipe 114 serves as a vibration transmission part that transmits the vibrations of the drainage pump 106. Although stainless steel pipes are used for the water supply pipe 113 and the drainage pipe 114, the material is not limited thereto. With this configuration, the vibrations of the water pumping pump 104 are transmitted to the water supply pipe 113, which serves as a vibration transmission part, causing the water supply pipe to vibrate. The vibrations of the water supply pipe 113 are then transmitted to the storage part 111, thereby releasing carbon dioxide from the liquid in the storage part 101. Furthermore, the vibrations of the drainage pump 106 are transmitted to the storage part 111 by vibrating the drainage pipe 114, which serves as a vibration transmission part, causing further carbon dioxide to be released from the liquid in the storage part 101. As in the first embodiment, the vibration of the vacuum pump may be transmitted via a vibration transmitting section, or may be appropriately combined with any of the vibration transmitting sections described above.

[0047] The vibration frequency of a water pump or a drainage pump varies depending on the structure, such as the rotation speed of the motor and the number of blades that generate the water flow. It is generally known that the vibration energy increases as the frequency increases for the same amplitude, and there are no restrictions on the vibration frequency as long as it can promote the generation of bubbles 110 from the liquid 100.

[0048] In this embodiment, the liquid 100 is seawater, but any liquid containing dissolved carbon dioxide may be used, such as rainwater, river water, lake water, tap water, a basic aqueous solution, or a fluorine-based active liquid, and is not limited to seawater. Furthermore, the liquid 100 may be combined with the configuration described in the first embodiment, in which carbon dioxide is recovered from the atmosphere by exposing the liquid 100 to the atmosphere, to form a circulatory carbon dioxide recovery device.

[0049] [Third Embodiment] An example of the functional configuration of a carbon dioxide recovery device of the present invention will be described below with reference to FIG.

[0050] In particular, differences from the above-described embodiment will be described. In this embodiment, the liquid 300 containing dissolved carbon dioxide is river water, and the height of the drain outlet 118, which is the drain surface, is lower than the height of the surface of the liquid 300, which is the water supply surface where the water supply inlet is located. The water supply inlet is also located vertically above the drain outlet. In this embodiment, the carbon dioxide capture device is configured in this manner, so that the supplied liquid 300 can be circulated and drained inside the carbon dioxide capture device using the siphon principle without requiring a power source to move the liquid. In this embodiment, the drain outlet 118 and the drained liquid 301 are configured not to come into contact with each other, but contact is not an issue as long as the configuration allows drainage using the siphon principle.

[0051] A hydraulic generator 302 is attached to the flow path of the drain pipe 114, and hydroelectric power is generated based on the potential energy generated by the drainage of the liquid 300. The power generated by the generator 302 is used as power source for the vacuum pump 102, the pressure pump 117, and the device control system. The vibrations generated by the generator 302 are transmitted to the liquid 300 in the storage section 101 via the drain pipe 114, which serves as a vibration transmission section. The vibration frequency caused by the power generation operation of the generator 302 varies depending on the number of blades that convert the water flow into rotational motion and the rotation speed of the generator, but the vibration amplitude and vibration frequency are not limited as long as they promote the generation of bubbles 110 from the carbon dioxide dissolved in the liquid 300. While the drain pipe 114 is made of stainless steel, it may also be made of polyvinyl chloride or iron, and the material is not limited.

[0052] The height of the liquid surface of the liquid 300 varies depending on the atmospheric pressure, the temperature of the liquid 300, the degree of vacuum inside the CO2 release tank (storage section) 101, and the constituent elements of the liquid 300. In this embodiment, the degree of vacuum inside the CO2 release tank (storage section) 101 was set to about 2 kPa, and the height from the air-contact surface of the liquid 300 to the liquid surface of the liquid 300 inside the CO2 release tank (storage section) 101 was set to about 10 m. The length of the drain pipe 114 was set to 10 m or more, so that the generator 302 could obtain sufficient potential energy of the liquid 300 to generate electricity.

[0053] [Fourth embodiment] An example of the functional configuration of a carbon dioxide recovery device of the present invention will be described below with reference to FIG.

[0054] This embodiment is configured by adding a mechanism for floating on the water surface to the carbon dioxide device configuration of the second embodiment. The liquid 400 in which carbon dioxide is dissolved is seawater, but it may also be freshwater such as river water or lake water. The floating body 401 is, for example, the hull of a ship, and has an engine 402, which is an internal combustion engine for the purpose of sailing the ship. That is, the vibration source in this embodiment is, for example, the ship's propulsion engine. Note that the engine 402 may also be an engine for generating electricity, and the purpose of the engine is not limited; for example, the vibration source may be a power generation engine. Furthermore, in this embodiment, the floating body 401 is a ship, but it may be any structure that floats on the water surface, such as a wind turbine generator floating on the ocean.

[0055] The vibration frequency generated by the engine 402 changes depending on the rotation speed of the internal combustion engine. The vibration generated by the engine 402 is transmitted to the water supply pipe 113 and the drain pipe 114 via the floating body 401, and then to the liquid 400 inside the CO2 release tank (storage section) 101. In other words, the vibration generated by the engine 402 promotes the release of carbon dioxide from the liquid 400 inside the CO2 release tank (storage section) 101. In this embodiment, the water supply pipe 113 and the drain pipe 114 are used as vibration transmission sections, but a separate structure may be provided as the vibration transmission section.

[0056] Furthermore, since the liquid 400 is seawater and the floating body 401 floats on the seawater, it sways due to wave forces caused by weather. The swaying of the floating body 401 causes the liquid 400 inside the CO2 release tank (storage section) 101 to sway. The vibration frequency of the hull due to the influence of wave forces varies depending on the size and structure of the hull, but is approximately 0.1 Hz to 1 Hz. Because the CO2 release tank (storage section) 101 is installed at a height of approximately 10 m above sea level, the vibration amplitude due to the influence of wave forces is large, which promotes the release of carbon dioxide from the liquid 400 inside the CO2 release tank (storage section) 101. The height of the liquid surface of the liquid 400 described above varies depending on the atmospheric pressure, the temperature of the liquid 400, the degree of vacuum inside the CO2 release tank (storage section) 101, and the constituent elements of the liquid 400.

[0057] The buffer tank 404 is intended to prevent the vacuum pump 102 from sucking in the liquid 400 inside the CO2 release tank (storage section) 101 when the floating body 401 is rocked significantly by the influence of waves, and prevents a small amount of liquid 400 from flowing into the vacuum pump 102. In this embodiment, the CO2 release tank (storage section) 101 and the buffer tank 404 are configured as separate tanks, but a partition plate may be attached inside the CO2 release tank (storage section) 101 to form separate rooms.

[0058] If the floating body 401 tilts significantly due to the influence of wave force, the valve 403 is closed to prevent the liquid 400 from flowing into the vacuum pump 102. In this embodiment, a sensor is provided to detect the tilt of the hull, and the valve 403 is automatically closed when the tilt exceeds a certain level.

[0059] In this embodiment, the heat generated by the engine 402 is transferred to the liquid 400 via the water supply pipe 113, but a separate heat transfer mechanism may be provided to transfer the heat generated by the engine 402 to the liquid 400. Heating the liquid 400 promotes the release of carbon dioxide from the liquid 400.

[0060] Fifth Embodiment An example of the functional configuration of a carbon dioxide recovery device of the present invention will be described below with reference to FIG.

[0061] This embodiment is configured by adding a mechanism for generating electricity using wind power to the configuration of the second embodiment. It includes a windmill 501, a generator 502 that generates electricity when the windmill rotates, and a vibration transmission unit 503 that transmits vibrations from the generator to the liquid 400 inside the CO2 release tank (storage unit) 101. In this embodiment, the vibration transmission unit 503 is made of an iron member, but the material is not limited to this.

[0062] The vibration frequency of the generator 502 varies depending on the structure of the wind turbine, such as the rotation speed and number of blades. Wind power generators often generate vibrations in the low-frequency range of several tens of hertz or less. It is generally known that vibration energy increases as the frequency increases for the same amplitude, and a larger amplitude promotes the release of carbon dioxide from the liquid 100. There are no restrictions on the vibration frequency as long as it promotes the generation of bubbles 110 from the liquid 100.

[0063] A wind power generator requires a certain height as a structure to prevent the wind turbine 501 from coming into contact with the ground. For this reason, in this embodiment, the height of the liquid surface of the liquid 100 inside the CO2 release tank (storage portion) 101 is set to about 10 m from the height of the water intake surface. The height of the liquid surface of the liquid 100 described above varies depending on the atmospheric pressure, the temperature of the liquid 100, the degree of vacuum inside the CO2 release tank (storage portion) 101, and the constituent elements of the liquid 100.

[0064] In this embodiment, the CO2 release tank (storage unit) 101 is installed at a predetermined height using a structure (not shown) erected on the ground. The CO2 release tank (storage unit) 101 is configured to sway left and right and front and back due to the elasticity of the structure caused by wind force. The swaying of the CO2 release tank (storage unit) 101 vibrates the liquid 100 inside the CO2 release tank (storage unit) 101, promoting the release of carbon dioxide from the liquid 100. The windmill 501 and the generator 502 are installed near the CO2 release tank (storage unit) 101, but it is sufficient that the vibrations can be transmitted to the CO2 release tank (storage unit) 101 via the vibration transmission unit 503. For example, the windmill 501 and the generator 502 may be installed at a height of approximately 40 m, and their relative positions are not limited. While the structure described above is made of iron, the material is not limited and may be metals and alloys such as stainless steel and aluminum, concrete, or wood.

[0065] Although the liquid 100 is seawater, it may be freshwater. The configuration in this embodiment may be combined with the floating body 401 described in embodiment 4. In this embodiment, the configuration is provided with two pumps, the lifting pump 104 and the drainage pump 106, but the liquid 100 can be circulated as long as either one of the pumps is provided, and the pump configuration is not limited thereto.

[0066] Sixth Embodiment An example of the functional configuration of a carbon dioxide recovery device of the present invention will be described below with reference to FIGS. 6A and 6B.

[0067] In this example, in contrast to the configuration of the first embodiment, a CO2 release tank (storage unit) 101 and a vacuum pump 102 are installed on a vibration transmission unit 103. The vacuum pump 102 is a DA-20D model manufactured by ULVAC, and when the vibration frequency was measured, the main vibration frequency peak was 50 Hz. The vibration transmission unit 103 was the top plate of a stainless steel rack for general laboratory equipment, and the elastic unit 123 was a resin caster for the rack.

[0068] The piping connecting the vacuum pump 102 and the water vapor filter 115 and the piping connecting the vacuum pump 102 and the carbon dioxide buffer tank 116 are made of flexible resin piping, so that the installation position of the vacuum pump 102 can be easily changed.

[0069] 6B shows the results of measuring the change in CO2 capture amount over time when the vacuum pump 102 was installed on the vibration transmission unit 103 and when it was installed on the device stand 124. In this example, the liquid 100 was seawater, and the injection valve 105 and the drain valve 107 were closed, and measurements were taken with the liquid 100 not circulating. When the vacuum pump 102 was installed on the vibration transmission unit 103, more CO2 was captured in a shorter time than when it was installed on the device stand 124.

[0070] Furthermore, in measurements where the vacuum pump 102 was installed on the device stand 124, the installation location of the vacuum pump 102 was changed to above the vibration transmission part 103 during the measurement, and the CO2 recovery rate was found to be faster.

[0071] This measurement was performed in a state where the liquid 100 was not circulating, but this was for measurement purposes, and carbon dioxide may be continuously collected by opening the injection valve 105 and the drain valve 107 and circulating the liquid with the drain pump 601. The model number of the vacuum pump 102 was used for measurement experiments, and does not limit the model number or type of the vacuum pump.

[0072] The method of circulating the liquid 100 may be a method of draining the liquid 100 from the CO2 release tank (storage section) 101 and then pouring new water in. Alternatively, when draining the liquid, a method of returning the internal pressure of the CO2 release tank (storage section) 101 to atmospheric pressure may be used, and the method of circulating the liquid is not limited thereto.

[0073] Seventh Embodiment An example of the functional configuration of a carbon dioxide recovery device of the present invention will be described below with reference to FIG.

[0074] This example differs from the configuration of the third embodiment in that a structure is provided inside the water supply pipe 113 that narrows the width of the flow path, and a vibration generating unit 701 is provided that generates vibrations due to changes in the water flow. The vibration generating unit 701 causes local changes in water pressure in the liquid 100, resulting in cavitation or the water hammer phenomenon, which causes vibrations. In other words, the vibration generating unit 701 is characterized by transmitting vibrations generated by at least one of cavitation and the water hammer phenomenon, which are caused by local changes in water pressure inside the liquid due to the flow of the liquid.

[0075] The vibrations generated by the vibration generating unit 701 are transmitted to the liquid 100 inside the CO2 release tank (storage unit) 101 via the water supply pipe 113, which is a vibration transmitting unit. The vibration generating unit 701 may be configured to generate vibrations by changing the water flow, and may be configured, for example, as a screw, a floating structure of metal spheres, stone particles, or pieces of wood, a marine organism such as a crustacean or shellfish, or a marine plant such as seaweed.

[0076] In this embodiment, the vibration generating unit 701 is made of stainless steel, but the material is not limited to this. In this embodiment, the liquid 100 is river water, and the liquid level of the liquid 100 is described as being in a positional relationship in which the water supply side liquid level 300 is higher than the water discharge side liquid level 301, and the liquid 100 circulates according to the siphon principle. However, it may also be configured such that seawater, in which the water supply side liquid level 300 and the water discharge side liquid level 301 are at the same level, is circulated by a circulation pump.

[0077] Eighth Embodiment An example of the functional configuration of a carbon dioxide recovery device of the present invention will be described below with reference to FIG.

[0078] In this embodiment, compared to the configuration of the seventh embodiment, the liquid level of the liquid 100 is higher on the water supply side liquid level 300 than on the drain side liquid level 301, and the liquid 100 flows due to the difference between atmospheric pressure and the pressure inside the CO2 release tank (storage section) 101.

[0079] The flow rate at which the liquid 100 is injected into the CO2 release tank (storage portion) 101 is adjusted by the injection valve 105. Vibrations caused by the liquid 100 passing through the injection valve 105 are transmitted to the liquid 100 inside the CO2 release tank (storage portion) 101 by the water supply pipe 113, which is a vibration transmission portion.

[0080] The liquid 100 inside the CO2 release tank (storage section) 101 is configured to be drained from the drain outlet 118 by its own weight, but it may also be drained by providing a separate auxiliary circulation pump for the purpose of drainage.

[0081] Ninth Embodiment An example of the functional configuration of a carbon dioxide recovery device of the present invention will be described below with reference to FIG.

[0082] The present example differs from the configuration of the eighth embodiment in that the liquid 100 poured into the CO2 release tank (storage section) 101 is caused to collide with a vibration transmission section 901 to generate vibrations, and the vibrations are transmitted to the liquid 100. The vibrations generated by the collision are transmitted to the entire liquid 100 in the CO2 release tank (storage section) 101 by the liquid 100 inside the CO2 release tank.

[0083] In this embodiment, the injected liquid 100 is configured to collide with the vibration transmission unit 901 to generate vibrations. However, it may also be configured to collide with the liquid 100 inside the CO2 release tank (storage unit) 101, and transmit the generated collision energy to the vibration transmission unit 901 via the liquid 100. In other words, the vibration transmission unit 901 may transmit vibrations generated by the injected liquid colliding with the liquid stored in the storage unit.

[0084] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are appended to apprise the public of the scope of the present invention.

[0085] This application claims priority from Japanese Patent Application No. 2023-094138 filed on June 7, 2023 and Japanese Patent Application No. 2024-075197 filed on May 7, 2024, the contents of which are incorporated herein by reference.

Claims

1. A carbon dioxide recovery device comprising: a storage section which is composed of a partition which separates the atmosphere from an internal space and which stores a liquid in which carbon dioxide is dissolved in the internal space; a vibration transmission section which transmits vibrations from the storage section or a vibration source which is arranged in the vicinity of the storage section to the liquid stored in the storage section; and a storage section which recovers and accumulates the carbon dioxide released from the liquid by the vibrations transmitted via the vibration transmission section.

2. The carbon dioxide recovery device according to claim 1, characterized in that the vibration source is a vacuum pump, a water lifting pump, a drainage pump, a hydroelectric generator, a wind power generator, a ship's propulsion engine, a power generating engine, wave power, or wind power.

3. The carbon dioxide recovery device according to claim 1, wherein the storage section is supported on the mounting section via an elastic section.

4. The carbon dioxide recovery device according to claim 1, wherein the internal space of said storage section is reduced in pressure relative to atmospheric pressure.

5. The carbon dioxide recovery device according to claim 1, further comprising a heating mechanism for heating the liquid stored in the storage section.

6. The carbon dioxide recovery device according to claim 1, characterized in that the liquid stored in the storage section is drained by the liquid's own weight.

7. A carbon dioxide recovery device as described in claim 1, characterized in that the storage section has a water supply port and a drain port, and the water supply port is provided vertically above the drain port with respect to the liquid level.

8. The carbon dioxide recovery device according to claim 7, characterized in that the liquid in which the carbon dioxide is dissolved circulates according to the siphon principle.

9. The carbon dioxide recovery device according to claim 1, characterized in that the storage section has a Torricelli vacuum space formed in the internal space.

10. A carbon dioxide recovery device as described in claim 1, characterized in that it is provided with a structure for suppressing the flow rate of a water supply passage that supplies liquid to the storage section, a drainage mechanism for draining liquid from the storage section, and the liquid level height of the liquid inside the storage section is lower than the Torricelli vacuum height in the storage section.

11. The carbon dioxide recovery device according to claim 1, wherein the vibration transmission part is a metal member.

12. A carbon dioxide recovery device as described in claim 1, characterized in that the vibration is caused by at least one of cavitation and water hammer phenomena, which are caused by changes in local water pressure inside the liquid due to the flow of the liquid.

13. The carbon dioxide capture device as described in claim 1, characterized in that the vibration is generated by the injected liquid colliding with the liquid stored in the storage section.

14. A method for recovering carbon dioxide, comprising: a vibration transmission step of transmitting vibrations from a vibration source arranged in or adjacent to a storage section, to a liquid stored in the storage section, the liquid being composed of a partition wall separating the atmosphere from an internal space, the liquid having carbon dioxide dissolved therein; and a storage step of recovering and storing the carbon dioxide released from the liquid by the transmitted vibrations.

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