Utilization method and utilization system of carbon dioxide

Abstract

To provide a utilization system and a utilization method of carbon dioxide which can efficiently utilize carbon dioxide collected from sea water.SOLUTION: A utilization method of carbon dioxide according to the present disclosure includes the steps of: collecting carbon dioxide 24 in sea water in a DOC (Direct Ocean Capture) facility; converting the collected carbon dioxide 24 into dry ice 81 on the ocean; and using the dry ice 81 to freeze or store a food in a ship 9 which transports the food.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a method and system for utilizing carbon dioxide. [Background technology]

[0002] Patent Document 1 discloses an electrodialysis system for recovering carbon dioxide (CO2), a greenhouse gas, from ocean water. The electrodialysis system in Patent Document 1 acidifies ocean water to recover the carbon dioxide. A separation membrane separates the carbon dioxide gas from the acidified liquid. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 99174 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a strong demand for the development of more efficient carbon dioxide capture technologies. For example, Direct Ocean Capture (DOC) facilities are installed on the ocean and can capture carbon dioxide from seawater. However, in order to bury the carbon dioxide captured by DOC facilities underground, it must be transported to land far from the coast or to distant ocean areas. This poses a problem: energy is required to transport the carbon dioxide.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a method and system for utilizing carbon dioxide that can efficiently utilize carbon dioxide recovered from seawater. [Means for solving the problem]

[0006] The method of utilizing carbon dioxide according to the present disclosure comprises the steps of capturing carbon dioxide in seawater at a DOC (Direct Ocean Capture) facility, converting the captured carbon dioxide into dry ice at sea, and using the dry ice to freeze or store food on a ship transporting the food.

[0007] The carbon dioxide utilization system according to the present disclosure includes a recovery unit at a DOC facility that recovers carbon dioxide from seawater, a dry ice production unit at sea that converts the recovered carbon dioxide into dry ice, and a storage unit on a ship that transports food that uses the dry ice to freeze or store the food. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a method and system for utilizing carbon dioxide that can efficiently utilize carbon dioxide recovered from seawater. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing the overall configuration of a DOC facility. [Figure 2] 1 is a block diagram showing the overall configuration of a carbon dioxide utilization system according to a first embodiment. [Figure 3] 1 is a flowchart showing a method for utilizing carbon dioxide according to a first embodiment. [Figure 4] FIG. 10 is a block diagram showing the overall configuration of a utilization system according to a second embodiment. [Figure 5] 1 is a flowchart showing a method for utilizing carbon dioxide according to a first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the invention according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential means for solving the problems. For clarity of explanation, the following description and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and duplicate explanations are omitted as necessary.

[0011] Embodiment 1 The system according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing the overall configuration of a system 100 that utilizes carbon dioxide. The system 100 is a system for capturing and utilizing carbon dioxide. The system 100 includes a DOC facility 1 and a ship 9.

[0012] As shown in Figure 1, the DOC facility 1 is a floating facility that floats on the sea. The DOC facility 1 is equipped with a water supply pipe 2, a collection facility 3, and a discharge pipe 4. The ends of the water supply pipe 2 and the discharge pipe 4 are submerged in the sea. The collection facility 3 floats on the sea.

[0013] The water supply pipe 2 sucks in seawater 5 in a shallow area of ​​the ocean and supplies it to the recovery facility 3. The water supply pipe 2 may be provided with a pump or the like for sucking in the seawater 5. The recovery facility 3 recovers carbon dioxide from the seawater.

[0014] The discharge pipe 4 discharges the seawater from which carbon dioxide has been recovered into the sea. The recovery facility 3 extracts carbon dioxide from the seawater 5, thereby reducing the carbon dioxide concentration in the seawater. The seawater with a low carbon dioxide concentration returns to the sea through the discharge pipe 4. The recovery facility 3 is equipped with facilities for utilizing the carbon dioxide extracted from the seawater. For example, the recovery facility 3 is equipped with an extraction unit 30 and a recovery unit 20, which will be described later.

[0015] Fig. 2 is a block diagram showing the configuration of the system 100. As shown in Fig. 2, the DOC facility 1 includes a collection unit 20 and a cooling unit 12. The ship 9 also includes a storage facility for storing food. The DOC facility 1 may further include an extraction unit 30.

[0016] The extraction unit 30 extracts hydrogen chloride 34 (hereinafter also referred to as HCl) from the seawater 5. For example, the extraction unit 30 has an ion exchange membrane 31. Specifically, HCl is extracted from the seawater 5 by electrodialysis using the ion exchange membrane 31. By using the electrodialysis method, HCl is precipitated. The seawater from which HCl has been extracted becomes desalinated seawater 33. The HCl is supplied to the recovery unit 20 to adjust the pH.

[0017] For example, NaOH (sodium hydroxide) and HCl are extracted by bipolar membrane electrodialysis (BMED) using an anion exchange membrane, a cation exchange membrane, and a bipolar membrane.

[0018] 2, HCl for making the pH acidic may be supplied to the recovery unit 20. The extraction unit 30 is not limited to electrodialysis, and may extract NaOH by electrolysis of seawater.

[0019] The capture unit 20 captures carbon dioxide 24 (hereinafter also referred to as CO2) from the seawater 5. The capture unit 20 includes an ion exchange membrane 21 for capturing CO2. For example, the capture unit 20 captures CO2 by electrodialysis using the ion exchange membrane 21. Bipolar membrane electrodialysis (BMED) using an anion exchange membrane, a cation exchange membrane, and a bipolar membrane can be used. Specifically, CO2 is captured using the technology described in Patent Document 1.

[0020] Furthermore, the recovery unit 20 can recover carbon dioxide 24 as CO2 gas by lowering the pH of the seawater. For example, the recovery unit 20 supplies HCl to the seawater 5 to make the seawater 5 acidic. Alternatively, the recovery unit 20 increases the pH of the seawater to convert carbon dioxide into carbonate ions. In other words, the seawater 5 becomes alkaline by supplying sodium hydroxide to the seawater. In this case, carbonate ions are generated.

[0021] The recovery unit 20 supplies the recovered carbon dioxide 24 to the dry ice production unit 80. Here, the carbon dioxide 24 gas (carbon dioxide gas) is supplied to the dry ice production unit 80. The dry ice production unit 80 is located within the DOC facility 1. The dry ice production unit 80 turns the carbon dioxide 24 into dry ice 81 at sea.

[0022] Specifically, the dry ice production unit 80 removes impurities from carbon dioxide 24 gas (carbon dioxide gas) in a purification process to produce highly pure carbon dioxide gas. The dry ice production unit 80 removes moisture from the carbon dioxide gas using a dryer, dehumidifier, etc. The dry ice production unit 80 liquefies the highly pure carbon dioxide gas by cooling it in a compressed state. This produces liquefied carbon dioxide gas.

[0023] The dry ice production unit 80 adiabatically expands liquefied carbon dioxide gas under atmospheric pressure. The heat of vaporization is removed, and the liquid carbon dioxide 24 solidifies. This produces powdered dry ice 81. The dry ice production unit 80 may also form the powdered dry ice 81 into a desired shape by pressing it using a molding machine or the like. The dry ice production unit 80 produces dry ice at sea. Dryers, dehumidifiers, liquefiers, containers, and the like for producing dry ice are installed in the DOC facility 1. Alternatively, some of the equipment for producing dry ice may be installed on the ship 9.

[0024] Dry ice production unit 80 supplies dry ice 81 to ship 9. Ship 9 is a transport vessel for transporting food products, and has storage unit 91 for storing food products. Storage unit 91 is equipped with a storehouse, container, etc. for storing frozen food products. Storage unit 91 may also be equipped with a freezer, etc. Ship 9 transports the food products that are frozen and stored in storage unit 91.

[0025] The dry ice 81 transported onto the ship 9 is used to freeze or store food in the storage section 91. For example, the dry ice 81 is used to freeze food in the storage room. Alternatively, the dry ice 81 is used to maintain frozen food at a low temperature. In this way, the storage section 91 uses the dry ice to freeze or store food.

[0026] The system 100 can utilize the carbon dioxide 24 captured at the DOC facility 1 at sea. Therefore, carbon dioxide can be utilized without transporting it far away. In this way, it is possible to reduce the cost of transporting carbon dioxide and also to reduce the amount of carbon dioxide generated by transportation. Furthermore, since carbon dioxide can be captured from seawater 5, ocean acidification can be mitigated.

[0027] A method for utilizing carbon dioxide will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the method for utilizing carbon dioxide. First, the capture unit 20 captures carbon dioxide 24 from seawater 5 (S11). It is preferable that the capture unit 20 captures carbon dioxide as a gas.

[0028] Next, the dry ice production unit 80 produces dry ice 81 from carbon dioxide (S12). For example, the dry ice production unit 80 liquefies carbon dioxide gas to produce liquefied carbon dioxide gas. Then, the dry ice production unit 80 adiabatically expands the liquefied carbon dioxide gas in the atmosphere, causing the carbon dioxide to solidify. In this way, dry ice 81 is produced.

[0029] The dry ice 81 is used to freeze or store food (S13). That is, the dry ice 81 is transported to the ship 9. The dry ice 81 is then used to freeze or store food in the storage section 91 of the ship 9. For example, the dry ice 81 is supplied to food before freezing, thereby freezing the food. Alternatively, the dry ice 81 can be supplied to a storage facility where frozen food is kept, thereby maintaining the food at a low temperature.

[0030] In this way, the carbon dioxide captured at the DOC facility 1 can be effectively utilized. Furthermore, the carbon dioxide can be utilized without transporting it to land far from the coast or to distant ocean areas. This reduces transportation costs. Furthermore, the amount of carbon dioxide generated by transportation can be reduced.

[0031] Embodiment 2 The utilization system and utilization method according to the second embodiment will be described with reference to FIG. 4. FIG. 4 is a block diagram showing the overall configuration of the immobilization system. In the second embodiment, the configuration for utilizing carbon dioxide differs from that of the first embodiment. The basic configuration of the system 100 is the same as that of the first embodiment, and therefore a description thereof will be omitted where appropriate. For example, the recovery section 20 is the same as that of the first embodiment, and therefore a description thereof will be omitted.

[0032] In this embodiment, the boat 9 is a fish transport boat. Alternatively, the boat 9 may be a fishing boat. The boat 9 is equipped with a concentration adjusting unit 94 and a water tank 93. The water tank 93 stores seawater. Furthermore, the water tank 93 contains fish to be transported.

[0033] The recovery unit 20 supplies the recovered carbon dioxide 24 to the concentration adjustment unit 94. The concentration adjustment unit 94 increases the carbon dioxide concentration in the seawater in the aquarium 93 by supplying the gaseous carbon dioxide 24 to the aquarium 93. The concentration adjustment unit 94 adjusts the carbon dioxide concentration in the seawater to a desired concentration by supplying carbon dioxide to the seawater in the aquarium 93. This anesthetizes the fish in the aquarium 93.

[0034] For example, the concentration adjusting unit 94 adjusts the carbon dioxide concentration of the seawater in the aquarium to 40 ppm or more. The concentration adjusting unit 94 may also adjust the oxygen concentration in the aquarium 93 by supplying oxygen to the aquarium 93. The method described in International Publication No. 2018 / 229940 can be used as a method for anesthetizing the fish in the aquarium.

[0035] The ship 9 transports the anesthetized fish. In this way, carbon dioxide can be used efficiently. At sea, the recovery unit 20 recovers carbon dioxide. Furthermore, at sea, the concentration adjustment unit 94 supplies carbon dioxide to the water tank 93, thereby adjusting the carbon dioxide concentration of the seawater in the water tank 93. This allows carbon dioxide to be used efficiently.

[0036] For example, carbon dioxide 24 can be used without having to be transported far away. Therefore, the cost of transporting carbon dioxide 24 can be reduced. Furthermore, the amount of carbon dioxide generated by transporting fish can be reduced. Furthermore, since carbon dioxide can be collected from seawater 5, ocean acidification can be mitigated. Furthermore, since the ship 9 can transport fish in an anesthetized state, fish can be transported efficiently.

[0037] In summary, the carbon dioxide utilization system of this embodiment comprises a recovery section at a DOC facility that recovers carbon dioxide from seawater, a concentration adjustment section that uses carbon dioxide to increase the carbon dioxide concentration in seawater in a tank on a transport ship, and a transport ship that transports fish that have been anesthetized in the tank.

[0038] Fig. 5 is a flowchart showing a utilization method according to this embodiment. The utilization method of carbon dioxide will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the utilization method of carbon dioxide. First, the recovery unit 20 recovers carbon dioxide 24 from seawater 5 (S21). It is preferable that the recovery unit 20 recovers carbon dioxide as a gas.

[0039] Next, the concentration adjusting unit 94 increases the carbon dioxide concentration of the seawater in the aquarium 93 (S22). Here, the concentration adjusting unit 94 adjusts the carbon dioxide concentration of the seawater in the aquarium 93 by supplying carbon dioxide to the aquarium 93. As a result, the carbon dioxide concentration in the seawater increases, causing the fish in the aquarium 93 to become anesthetized.

[0040] The anesthetized fish are transported by ship 9 (S23). Because the fish are anesthetized, a large number of fish can be transported relative to their size into tank 93. This allows the fish to be transported efficiently.

[0041] In this way, the carbon dioxide captured at the DOC facility 1 can be effectively utilized. Furthermore, the carbon dioxide can be utilized without transporting it to land far from the coast or to distant ocean areas. This reduces transportation costs. Furthermore, the amount of carbon dioxide generated by transportation can be reduced.

[0042] In summary, the carbon dioxide utilization system of this embodiment comprises the steps of recovering carbon dioxide from seawater at a DOC facility, using carbon dioxide to increase the carbon dioxide concentration in seawater in a tank on a transport ship, and transporting the anesthetized fish in the tank on the transport ship.

[0043] The present disclosure is not limited to the above-described embodiments and can be modified as appropriate without departing from the spirit of the present disclosure. The present disclosure also contributes to carbon neutrality, decarbonization, and the Sustainable Development Goals (SDGs). [Explanation of symbols]

[0044] 100 systems 1 DOC facility 2 Water supply pipe 3. Collection facilities 4 Drain pipe 5 Seawater 9 ships 20 Collection Department 21 Ion exchange membrane 23 Decarbonated seawater 24 Carbon dioxide 30 Extraction part 31 Ion exchange membrane 80 Dry Ice Manufacturing Department 91 Storage Department 93 Aquarium 94 Density adjustment section

Claims

1. Recovering carbon dioxide from seawater at a Direct Ocean Capture (DOC) facility; converting the recovered carbon dioxide into dry ice at sea; and using the dry ice to freeze or store the food on a ship transporting the food.

2. At the DOC facility, a capture unit that captures carbon dioxide from seawater; a dry ice production unit at sea that converts the collected carbon dioxide into dry ice; A carbon dioxide utilization system comprising: a storage section on a ship transporting food, in which the dry ice is used to freeze or store the food.

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