Carbon dioxide recovery system, vessel, and carbon dioxide recovery method

Abstract

To measure liquefied carbon dioxide discharged from a storage unit with higher precision.SOLUTION: A carbon dioxide recovery system includes: a carbon dioxide recovery unit for recovering gaseous carbon dioxide from carbon dioxide-containing gas; a liquefying unit for liquefying gaseous carbon dioxide recovered by the carbon dioxide recovery unit; a plurality of storage units capable of storing the liquefied carbon dioxide liquefied by the liquefying unit; a switching unit for feeding the liquefied carbon dioxide liquefied by the liquefying unit when some of the plurality of storage units are discharging the liquefied carbon dioxide to other storage units not discharging the liquefied carbon dioxide among the plurality of storage units; and a measuring unit for measuring the liquefied carbon dioxide discharged from the storage units.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a carbon dioxide capture system, a vessel, and a carbon dioxide capture method. [Background technology]

[0002] Patent Document 1 discloses a ship (liquefied carbon dioxide transport ship) equipped with a tank (LCD container) for storing liquefied carbon dioxide (LCD) and a pump (cargo discharge pump, booster pump) for discharging the liquefied carbon dioxide from the container. After arriving at a destination, such a ship unloads the liquefied carbon dioxide by discharging the liquefied carbon dioxide in the tank with the pump. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-266068 A Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, in ships and the like, in order to reduce greenhouse gas emissions, for example, carbon dioxide is sometimes captured from exhaust gas generated when burning fuel. In this way, the gaseous carbon dioxide captured from the exhaust gas may be liquefied and stored in a tank from the viewpoint of storage space. In general, the amount of liquefied gas discharged from a tank is measured using a level gauge that measures the liquid level in the tank. However, in ships and the like as described above, even while the liquefied carbon dioxide in the tank is being discharged, carbon dioxide may be captured from the exhaust gas and liquefied carbon dioxide may flow into the tank. This makes it difficult to measure the amount of liquefied carbon dioxide discharged from the tank with high accuracy.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a carbon dioxide capture system, a ship, and a carbon dioxide capture method that are capable of measuring with greater accuracy the liquefied carbon dioxide dispensed from the storage section. [Means for solving the problem]

[0006] In order to solve the above problems, the carbon dioxide capture system according to the present disclosure includes a carbon dioxide capture unit, a liquefaction unit, a plurality of storage units, a switching unit, and a metering unit. The carbon dioxide capture unit captures gaseous carbon dioxide from a carbon dioxide-containing gas. The liquefaction unit liquefies the gaseous carbon dioxide captured by the carbon dioxide capture unit. The plurality of storage units are capable of storing the liquefied carbon dioxide liquefied by the liquefaction unit. When some of the plurality of storage units are dispensing liquefied carbon dioxide, the switching unit sends the liquefied carbon dioxide liquefied in the liquefaction unit to other of the plurality of storage units that are not dispensing liquefied carbon dioxide. The metering unit measures the liquefied carbon dioxide dispensed from the storage unit.

[0007] A vessel according to the present disclosure includes a hull and a carbon dioxide metering system as described above.

[0008] The carbon dioxide capture method according to the present disclosure includes the steps of: sending liquefied carbon dioxide to other storage sections among a plurality of storage sections capable of storing liquefied carbon dioxide that are not discharging liquefied carbon dioxide when one of the storage sections is discharging liquefied carbon dioxide; sending liquefied carbon dioxide to any one of the plurality of storage sections after stopping the discharging of liquefied carbon dioxide from some of the storage sections; and weighing the liquefied carbon dioxide sent to the other storage sections while liquefied carbon dioxide is being discharged from some of the storage sections after stopping the discharging of liquefied carbon dioxide from some of the storage sections. Effect of the Invention

[0009] According to the carbon dioxide capture system, ship, and carbon dioxide capture method disclosed herein, the liquefied carbon dioxide dispensed from the storage section can be measured with greater accuracy. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a side view of a marine vessel according to a first embodiment of the present disclosure. [Diagram 2] FIG. 1 is a diagram showing a configuration of a carbon dioxide metering system according to a first embodiment of the present disclosure. [Diagram 3] 1 is a diagram showing a state in which the collection tank is dispensing liquefied carbon dioxide in the carbon dioxide metering system according to the first embodiment of the present disclosure. FIG. [Figure 4] FIG. 2 is a diagram illustrating a hardware configuration of a calculation device provided in a marine vessel according to an embodiment of the present disclosure. [Diagram 5] FIG. 2 is a functional block diagram of a calculation device provided in a marine vessel according to an embodiment of the present disclosure. [Figure 6] 1 is a flowchart showing the steps of a carbon dioxide metering method according to a first embodiment of the present disclosure. [Figure 7] FIG. 11 is a side view of a vessel according to a second embodiment of the present disclosure. [Figure 8] FIG. 11 is a diagram showing the configuration of a carbon dioxide metering system according to a second embodiment of the present disclosure. [Figure 9] A figure showing a state in which the first recovery tank is dispensing liquefied carbon dioxide in the carbon dioxide metering system according to the second embodiment of the present disclosure. [Figure 10] A figure showing a state in which the second recovery tank is dispensing liquefied carbon dioxide in the carbon dioxide metering system according to the second embodiment of the present disclosure. [Figure 11] 4 is a flowchart showing the steps of a carbon dioxide capture method according to a second embodiment of the present disclosure. [Figure 12] 4 is a flowchart showing the steps of a carbon dioxide capture method according to a second embodiment of the present disclosure. [Figure 13]FIG. 13 is a diagram showing the configuration of a carbon dioxide metering system according to a modified example of the second embodiment of the present disclosure. [Figure 14] A figure showing a state in which the first storage compartment is dispensing liquefied carbon dioxide in a carbon dioxide metering system related to a modified example of the second embodiment of the present disclosure. [Figure 15] A figure showing a state in which the second storage compartment is dispensing liquefied carbon dioxide in a carbon dioxide metering system related to a modified example of the second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] First Embodiment Hereinafter, a carbon dioxide capture system, a ship, and a carbon dioxide capture method according to an embodiment of the present disclosure will be described with reference to Figs. (Overall configuration of the ship) As shown in FIG. 1, a ship 1A of this embodiment includes at least a hull 2, a combustion device 8, and a carbon dioxide capture system 20A (see FIG. 2).

[0012] (Hull configuration) The hull 2 ​​has a pair of side panels 3A, 3B that form its outer hull, a ship bottom 4, and an upper deck 5. The side panels 3A, 3B are made up of a pair of side panel shells that form the port and starboard sides, respectively. The ship bottom 4 is made up of a ship bottom panel that connects the side panels 3A, 3B. The upper deck 5 is a full-length deck that is exposed to the outside. In the hull 2, for example, a superstructure 6 having accommodation areas is formed on the upper deck 5 on the stern 2b side.

[0013] The hull 2 ​​exemplified in this embodiment has a cargo carrying section (hold) 7 closer to the bow 2a than the superstructure 6. Furthermore, this cargo carrying section 7 is provided with a plurality of cargo tanks 11. Note that, although the above embodiment illustrates a case in which a plurality of cargo tanks 11 is provided in the cargo carrying section 7, the present invention is not limited to this configuration, and for example, various types of cargo, such as containers, may be loaded in the cargo carrying section 7. Furthermore, although the above embodiment illustrates a case in which the hull 2 ​​has a cargo carrying section 7, the present invention is not limited to a hull 2 ​​having a cargo carrying section 7.

[0014] The combustion device 8 is a device that generates thermal energy by burning fuel, and is provided inside the hull 2. Examples of the combustion device 8 include an internal combustion engine used in the main engine for propelling the ship 1A, an internal combustion engine used in a power generation facility that supplies electricity to the ship, and a boiler that generates steam as a working fluid. The combustion device 8 is connected to a fuel tank 9 provided inside the hull 2 ​​via a fuel supply piping system 101. The combustion device 8 combusts fuel supplied from the fuel tank 9 via the fuel supply piping system 101.

[0015] (Configuration of carbon dioxide capture system) FIG. 2 is a diagram showing a configuration of a carbon dioxide capture system according to an embodiment of the present disclosure. As shown in FIG. 2, the carbon dioxide capture system 20A includes a carbon dioxide capture section 23, a liquefaction section 25, a plurality of storage sections 21, a switching section 27, and a measurement section 80.

[0016] (Configuration of carbon dioxide capture unit) The carbon dioxide capture unit 23 is provided in the hull 2, and captures gaseous carbon dioxide from the exhaust gas of the combustion device 8, which is a carbon dioxide-containing gas. In the present embodiment, the carbon dioxide capture unit 23 is provided on the upper deck 5 of the hull 2, but the location of the carbon dioxide capture unit 23 is not limited to on the upper deck 5.

[0017] The carbon dioxide capture unit 23 captures carbon dioxide (gas) contained in the exhaust gas sent from the combustion device 8 (see FIG. 1) through the exhaust gas pipe 102. For example, a method for capturing carbon dioxide may be a chemical absorption method in which carbon dioxide is absorbed in an absorbing liquid. In addition, an example of an absorbing liquid when carbon dioxide is absorbed by a chemical absorption method is MEA (monoethanolamine). The carbon dioxide capture unit 23 separates the carbon dioxide absorbed in the absorbing liquid in a gaseous state from the absorbing liquid by heating the absorbing liquid that has absorbed carbon dioxide. This separated gaseous carbon dioxide is sent to the liquefaction unit 25. Here, the exhaust gas after the carbon dioxide has been absorbed in the absorbing liquid is subjected to, for example, a cleaning process and then released into the atmosphere through an exhaust funnel (not shown) or the like provided on the ship 1A.

[0018] (Configuration of the liquefaction section) The liquefaction unit 25 liquefies the gaseous carbon dioxide captured by the carbon dioxide capture unit 23. In this embodiment, the carbon dioxide capture unit 23 and the liquefaction unit 25 are connected by a discharge piping system 105, and the liquefaction unit 25 liquefies the gaseous carbon dioxide sent from the carbon dioxide capture unit 23 through the discharge piping system 105. More specifically, the liquefaction unit 25 compresses the gaseous carbon dioxide sent through the discharge piping system 105, and liquefies the compressed gaseous carbon dioxide by cooling it.

[0019] (Storage section configuration) In this embodiment, a collection tank 22 and a buffer tank 24 are provided as the multiple storage units 21.

[0020] The recovery tank 22 can store carbon dioxide liquefied in the liquefaction section 25 (hereinafter referred to as liquefied carbon dioxide). The recovery tank 22 is a storage section 21A among the multiple storage sections 21. The recovery tank 22 illustrated in this embodiment is provided on the upper deck 5. The location of the recovery tank 22 is not limited to the upper deck 5, and may be located, for example, below the upper deck 5. Note that, although the embodiment illustrates a case in which one recovery tank 22 is provided, the number of recovery tanks 22 is not limited to one and may be multiple. Furthermore, although the embodiment illustrates a so-called horizontal cylindrical tank as the recovery tank 22, the shape of the recovery tank 22 is not limited in any way and may be, for example, spherical or rectangular.

[0021] The recovery tank 22 is connected to the liquefaction section 25 via a transfer piping system 103. The transfer piping system 103 sends the liquefied carbon dioxide liquefied in the liquefaction section 25 to the recovery tank 22. A pump (not shown) for pressure-feeding the liquefied carbon dioxide to the recovery tank 22 is provided in the middle of the transfer piping system 103. Note that the pump may be omitted if the liquefied carbon dioxide can be transferred from the liquefaction section 25 to the storage section 21 due to the positional relationship and pressure difference between the liquefaction section 25 and the storage section 21. The transfer piping system 103 illustrated in this embodiment penetrates the top of the recovery tank 22 and extends to the lower part of the recovery tank 22 and opens therein, but is not limited to this configuration, and may be configured in any manner as long as it is capable of sending the liquefied carbon dioxide liquefied in the liquefaction section 25 to the recovery tank 22.

[0022] The buffer tank 24 is provided midway through the transfer piping system 103. The buffer tank 24 is capable of temporarily storing the liquefied carbon dioxide liquefied by the liquefaction unit 25. The liquefied carbon dioxide liquefied by the liquefaction unit 25 can be temporarily stored in the buffer tank 24 and then sent to the recovery tank 22. The buffer tank 24 is another storage unit 21B that is different from storage unit 21A (recovery tank 22), which is one of the multiple storage units 21. The buffer tank 24 has a smaller capacity than the recovery tank 22.

[0023] A discharge piping system 104 is connected to the recovery tank 22. The discharge piping system 104 connects the recovery tank 22 to a manifold (not shown) provided in the hull 2. An external piping system (not shown) for sending the liquefied carbon dioxide in the recovery tank 22 outside the ship can be connected to the manifold. The discharge piping system 104 extends upward from the lower part in the recovery tank 22, penetrates the top of the recovery tank 22, and extends toward the manifold provided outside the recovery tank 22. A lifting pump 108 is provided at the tip of the discharge piping system 104 arranged at the lower part in the recovery tank 22. This lifting pump 108 is capable of pumping the liquefied carbon dioxide in the recovery tank 22 outside the recovery tank 22. The discharge piping system 104 pumps the liquefied carbon dioxide pumped by the lifting pump 108 outside the ship via the manifold (not shown).

[0024] (Switching section configuration) The switching unit 27 is provided in the transfer piping system 103, between the buffer tank 24 and the recovery tank 22. The switching unit 27 is capable of interrupting the supply of liquefied carbon dioxide to the recovery tank 22 through the transfer piping system 103. The switching unit 27 illustrated in this embodiment is an on-off valve 27v. The on-off valve 27v opens and closes a flow path in the transfer piping system 103, thereby interrupting the supply of liquefied carbon dioxide to the recovery tank 22 through the transfer piping system 103.

[0025] When the on-off valve 27v is opened, the buffer tank 24 and the recovery tank 22 are connected via the transfer piping system 103, and the liquefied carbon dioxide liquefied in the liquefaction section 25 is sent to the recovery tank 22 via the buffer tank 24.

[0026] FIG. 3 is a diagram showing a state in which the recovery tank is discharging liquefied carbon dioxide. 3, when the on-off valve 27v is closed, communication between the buffer tank 24 and the recovery tank 22 via the transfer piping system 103 is blocked. As a result, after the on-off valve 27v is closed, the liquefied carbon dioxide liquefied in the liquefaction unit 25 is prevented from being sent to the recovery tank 22, and is stored in the buffer tank 24.

[0027] The on-off valve 27v is opened except when the recovery tank 22 is discharging liquefied carbon dioxide. In other words, while the ship 1A is sailing or at anchor, in a state in which the recovery tank 22 is not discharging liquefied carbon dioxide, the liquefied carbon dioxide liquefied by the liquefaction unit 25 is sent to the recovery tank 22 and stored therein. On the other hand, the on-off valve 27v is closed when the recovery tank 22 is dispensing liquefied carbon dioxide. In other words, when the recovery tank 22, which is one of the storage sections 21A among the multiple storage sections 21, is dispensing liquefied carbon dioxide, the liquefied carbon dioxide liquefied by the liquefaction section 25 is stored in the buffer tank 24, which is the other storage section 21B among the multiple storage sections 21 that is not dispensing liquefied carbon dioxide.

[0028] (Measuring section configuration) 2, the metering unit 80 measures the liquefied carbon dioxide dispensed from the storage unit 21. The metering unit 80 of the present embodiment includes a level meter 81, a thermometer 82, a pressure meter 83, a flow meter 92, a purity detector 87, a fuel meter 88, a fuel thermometer 84, and a computing device 50.

[0029] A level gauge 81, a thermometer 82, and a pressure gauge 83 are provided in the recovery tank 22. The level gauge 81 detects the liquid level in the recovery tank 22. The thermometer 82 detects the temperature of the liquefied carbon dioxide in the recovery tank 22. The pressure gauge 83 detects the pressure in the recovery tank 22 (gas phase pressure).

[0030] The flow meter 92 is provided in the discharge piping system 104. The flow meter 92 detects the flow rate of the liquefied carbon dioxide discharged from the recovery tank 22 by the discharge piping system 104. As the flow meter 92, a volumetric flow meter capable of detecting the volumetric flow rate of the liquefied carbon dioxide discharged from the recovery tank 22 by the discharge piping system 104 can be used.

[0031] The purity detector 87 is provided in the discharge piping system 104. The purity detector 87 detects the purity of the liquefied carbon dioxide discharged from the recovery tank 22 via the discharge piping system 104.

[0032] The fuel meter 88 is provided in the fuel supply piping system 101. The fuel meter 88 detects the flow rate of fuel supplied from the fuel tank 9 to the combustion device 8 via the fuel supply piping system 101. The fuel meter 88 can detect the amount of fuel consumed by the combustion device 8. In addition, the fuel thermometer 84 is provided in the fuel supply piping system 101. The fuel thermometer 84 detects the temperature of the fuel supplied from the fuel tank 9 to the combustion device 8 via the fuel supply piping system 101.

[0033] (Hardware configuration diagram) FIG. 4 is a diagram illustrating a hardware configuration of a computing device according to an embodiment of the present disclosure. 4, the arithmetic device 50 is a computer including a CPU 51 (Central Processing Unit), a ROM 52 (Read Only Memory), a RAM 53 (Random Access Memory), a storage 54, and a signal transmission / reception module 55. The signal transmission / reception module 55 receives detection signals from a level gauge 81, a thermometer 82, a pressure gauge 83, a flow meter 92, a purity detector 87, a fuel gauge 88, and a fuel temperature gauge 84.

[0034] (Function block diagram) FIG. 5 is a functional block diagram of a control device according to an embodiment of the present disclosure. As shown in Figure 5, the CPU 51 of the calculation device 50 executes a program pre-stored in a storage device such as a ROM 52 or storage 54, thereby realizing each of the functional configurations of a signal input unit 70, an information acquisition unit 71, a payout amount acquisition unit 72, and an information output unit 73.

[0035] The signal input unit 70 receives detection signals from each of the level gauge 81, temperature gauge 82, pressure gauge 83, flow meter 92, purity detector 87, fuel gauge 88, and fuel temperature gauge 84 via the signal transmitting / receiving module 55.

[0036] Based on the detection signals received by the signal input unit 70, the information acquisition unit 71 acquires the detection values ​​of each parameter detected by each of the level gauge 81, thermometer 82, pressure gauge 83, flow meter 92, purity detector 87, fuel gauge 88, and fuel temperature gauge 84.

[0037] The discharge amount acquisition unit 72 acquires the mass of liquefied carbon dioxide dispensed from the collection tank 22 based on the detection values ​​of each parameter detected by each of the level gauge 81, the thermometer 82, the pressure gauge 83, the flow meter 92, and the purity detector 87, which are acquired by the information acquisition unit 71. Note that while the discharge amount acquisition unit 72 of this embodiment acquires the mass of liquefied carbon dioxide dispensed from the collection tank 22, it may also acquire the volume of the liquefied carbon dioxide dispensed from the collection tank 22.

[0038] The dispensing amount acquisition unit 72 first obtains the mass of liquefied carbon dioxide dispensed from the recovery tank 22 based on the detection results of the level gauge 81, the thermometer 82, the pressure gauge 83, and the purity detector 87. As shown in Fig. 2, the dispensing amount acquisition unit 72 acquires the detection value of the liquid level L1 by the level gauge 81 before dispensing the liquefied carbon dioxide from the recovery tank 22. Also, as shown in Fig. 3, the dispensing amount acquisition unit 72 acquires the detection value of the liquid level L2 by the level gauge 81 while the liquefied carbon dioxide is being dispensed from the recovery tank 22. The dispensing of the liquefied carbon dioxide from the recovery tank 22 continues until the liquid level L2 reaches a predetermined threshold value, and stops (dispensing completed) when the predetermined threshold value is reached.

[0039] In addition, the dispensing amount acquisition unit 72 calculates the specific gravity of the liquefied carbon dioxide in the storage unit 21 based on the temperature of the liquefied carbon dioxide in the storage unit 21 detected by the thermometer 82 and the pressure in the storage unit 21 detected by the pressure gauge 83, both before the liquefied carbon dioxide is dispensed from the storage unit 21 and after the dispensing of the liquefied carbon dioxide from the storage unit 21 is completed. Further, the dispensing amount acquisition unit 72 calculates the mass of the liquefied carbon dioxide before dispensing the liquefied carbon dioxide from the storage unit 21, based on the liquid level L1 before dispensing the liquefied carbon dioxide from the storage unit 21 and the specific gravity of the liquefied carbon dioxide. The dispensing amount acquisition unit 72 also calculates the mass of the liquefied carbon dioxide after dispensing of the liquefied carbon dioxide from the storage unit 21, based on the liquid level L2 after dispensing of the liquefied carbon dioxide from the storage unit 21 is completed, based on the specific gravity of the liquefied carbon dioxide. Then, the dispensing amount acquisition unit 72 calculates the difference between the mass of the liquefied carbon dioxide before dispensing the liquefied carbon dioxide from the storage unit 21 and the mass of the liquefied carbon dioxide after dispensing of the liquefied carbon dioxide from the storage unit 21 is completed. In this way, the dispensing amount acquisition unit 72 acquires the amount of change in the mass of the liquefied carbon dioxide stored in the storage unit 21 before dispensing the liquefied carbon dioxide from the storage unit 21 and after completion of dispensing. In addition, the dispensing amount acquisition unit 72 may, for example, detect the temperature of the liquefied carbon dioxide in the recovery tank 22 detected by a thermometer 82, the pressure in the recovery tank 22 detected by a pressure gauge 83, and the purity of the liquefied carbon dioxide in the recovery tank 22 detected by a purity detector 87 multiple times while the liquefied carbon dioxide is being dispensed from the recovery tank 22, and use the average value to calculate the specific gravity of the liquefied carbon dioxide in the recovery tank 22.

[0040] Here, the dispensing amount acquisition unit 72 of this embodiment acquires an integrated value of the flow rate of liquefied carbon dioxide dispensed from the recovery tank 22 via the dispensing piping system 104 based on the detection result of the flow meter 92, and acquires the amount of liquefied carbon dioxide dispensed via the dispensing piping system 104. The dispensing amount acquisition unit 72 can also compare the flow rate of liquefied carbon dioxide acquired based on the detection result of the flow meter 92 with the dispensing amount of liquefied carbon dioxide acquired based on the detection results of the level gauge 81, the thermometer 82, and the pressure gauge 83 as described above. Thereby, for example, when an abnormality occurs in at least one of the level gauge 81, the thermometer 82, and the pressure gauge 83, the occurrence of an abnormality can be detected with a simple configuration.

[0041] Further, the payout amount acquisition unit 72 of this embodiment acquires the mass of carbon dioxide in the gas discharged from the combustion device 8 based on the fuel consumption detected by the fuel meter 88. More specifically, the payout amount acquisition unit 72 calculates the weight consumption of fuel based on the fuel consumption detected by the fuel meter 88, the fuel temperature detected by the fuel thermometer 84, and the bunker properties (specific gravity, viscosity, calorific value, etc. of the fuel) of the fuel carried in the fuel tank 9. Note that information on the bunker properties of the fuel carried in the fuel tank 9 is available in advance from the manufacturer, etc.

[0042] The payout amount acquisition unit 72 calculates the amount (mass) of carbon dioxide emitted by burning fuel during navigation from the calculated weight consumption of fuel and the carbon dioxide conversion coefficient defined by IMO (International Maritime Organization).The payout amount acquisition unit 72 of this embodiment then calculates the reduction rate of greenhouse gas (GHG) based on the difference between the mass of carbon dioxide emitted by burning fuel during navigation and the mass of the liquefied carbon dioxide paid out from the recovery tank 22.

[0043] The information output unit 73 outputs to the outside information based on the calculation results acquired by the payout amount acquisition unit 72 as described above. Here, examples of information output to the outside from the information output unit 73 include the mass of liquefied carbon dioxide paid out from the recovery tank 22, the reduction rate of greenhouse gases (GHG), etc. Examples of output by the information output unit 73 include displaying an image on a monitor device, transmitting data to an external computer terminal, printing documents on a printer, etc.

[0044] (Procedure for carbon dioxide capture method) Fig. 6 is a flowchart showing the procedure of the carbon dioxide capture method according to the embodiment of the present disclosure. As shown in Fig. 6, the carbon dioxide capture method S10 according to the embodiment of the present disclosure includes a step S11 of blocking the transfer of liquefied carbon dioxide from the buffer tank 24 to the capture tank 22, a step S12 of discharging the liquefied carbon dioxide, a step S12s of feeding the liquefied carbon dioxide to the buffer tank 24, a step S13 of measuring the dispensed liquefied carbon dioxide, a step S14 of feeding the liquefied carbon dioxide to the capture tank 22 after stopping the discharging of the liquefied carbon dioxide, a step S15 of discharging the liquefied carbon dioxide, a step S15s of feeding the liquefied carbon dioxide to the buffer tank 24, and a step S16 of measuring the dispensed liquefied carbon dioxide.

[0045] Steps S11 to S13 described below are carried out the first time the recovery tank 22 dispenses liquefied carbon dioxide after the start of use of the carbon dioxide recovery system 20A. After starting to use the carbon dioxide capture system 20A, the on-off valve 27v is opened in the switching unit 27, as shown in Fig. 2. Carbon dioxide contained in the exhaust gas from the combustion device 8 is captured in the carbon dioxide capture unit 23, and then liquefied in the liquefaction unit 25. The liquefied carbon dioxide liquefied in the liquefaction unit 25 is sent to the capture tank 22 via the transfer piping system 103 and the buffer tank 24. As a result, the liquefied carbon dioxide liquefied in the liquefaction unit 25 is stored in the capture tank 22.

[0046] When the ship 1A arrives at a port or the like, the recovery tank 22 discharges the liquefied carbon dioxide stored in the recovery tank 22. To this end, first, in step S11 for blocking the transfer of liquefied carbon dioxide from the buffer tank 24 to the recovery tank 22, the on-off valve 27v is closed in the switching unit 27. This blocks the transfer of liquefied carbon dioxide from the buffer tank 24 to the recovery tank 22. Thereafter, the process proceeds to step S12 of dispensing liquefied carbon dioxide, and starts dispensing the liquefied carbon dioxide stored in the recovery tank 22. In this step S12, the on-off valve 27v is closed and the transfer of liquefied carbon dioxide from the buffer tank 24 to the recovery tank 22 is blocked, so that only the liquefied carbon dioxide stored in the recovery tank 22 is dispensed.

[0047] Step S12s of sending liquefied carbon dioxide to the buffer tank 24 is executed while the recovery tank 22 is dispensing liquefied carbon dioxide in the above step S12. Step S12s is actually started at the same time as the on-off valve 27v is closed in the above step S11. In step S12s, after the on-off valve 27v is closed, the liquefied carbon dioxide liquefied in the liquefaction section 25 is stored in the buffer tank 24. In step S12, when the discharge of liquefied carbon dioxide from the recovery tank 22 is completed, the discharge of the liquefied carbon dioxide is stopped.

[0048] In step S13 of measuring the dispensed liquefied carbon dioxide, the liquefied carbon dioxide dispensed by the recovery tank 22 is measured. In step S13, the dispensing amount acquisition unit 72 detects the liquid level L1 in the recovery tank 22 on the level gauge 81 immediately before starting to dispense the liquefied carbon dioxide from the recovery tank 22. Also, as shown in Fig. 3, the dispensing amount acquisition unit 72 detects the liquid level L2 in the recovery tank 22 on the level gauge 81 while the liquefied carbon dioxide is being dispensed from the recovery tank 22.

[0049] Furthermore, in step S13, the dispensing amount acquisition unit 72 acquires the temperature of the liquefied carbon dioxide in the recovery tank 22 detected by the thermometer 82 at each liquid level L1, L2, the pressure in the recovery tank 22 detected by the pressure gauge 83, and the purity of the liquefied carbon dioxide in the recovery tank 22 detected by the purity detector 87. The dispensing amount acquisition unit 72 calculates the specific gravity of the liquefied carbon dioxide at each liquid level L1, L2 in the recovery tank 22 based on the temperature of the liquefied carbon dioxide in the recovery tank 22 detected by the thermometer 82 at each liquid level L1, L2, the pressure in the recovery tank 22 detected by the pressure gauge 83, and the purity of the liquefied carbon dioxide in the recovery tank 22 detected by the purity detector 87. The dispensing amount acquisition unit 72 accumulates the liquid level L1 before dispensing, the liquid level L2 at the completion of dispensing, and the specific gravity of the liquefied carbon dioxide at each liquid level L1, L2 in the recovery tank 22, and calculates the difference, thereby acquiring the change in the mass of the liquefied carbon dioxide in the recovery tank 22.

[0050] Here, in this embodiment, while the liquefied carbon dioxide is being dispensed from the recovery tank 22, the flow meter 92 detects the flow rate of the liquefied carbon dioxide dispensed from the recovery tank 22 via the dispensing piping system 104. The dispensed amount acquisition unit 72 may acquire the amount of liquefied carbon dioxide dispensed via the dispensing piping system 104 based on the detection result of the flow meter 92, and compare the amount of liquefied carbon dioxide acquired based on the detection result of the flow meter 92 with the dispensed amount of liquefied carbon dioxide acquired based on the detection results of the level meter 81, thermometer 82, pressure meter 83, and purity detector 87 described above.

[0051] Furthermore, in step S13, the discharge amount acquisition unit 72 acquires the mass of carbon dioxide in the gas discharged from the combustion device 8 based on the fuel consumption detected by the fuel meter 88. The discharge amount acquisition unit 72 calculates the weight consumption of fuel based on the fuel consumption detected by the fuel meter 88, the fuel temperature detected by the fuel thermometer 84, and the bunker properties of the fuel loaded in the fuel tank 9 (specific gravity, viscosity, calorific value, etc. of the fuel). The discharge amount acquisition unit 72 calculates the amount of carbon dioxide emitted by burning fuel during navigation from the calculated weight consumption of fuel and the carbon dioxide conversion coefficient specified by IMO. The discharge amount acquisition unit 72 calculates the greenhouse gas reduction rate based on the difference between the amount of carbon dioxide emitted by burning fuel during navigation and the mass of the liquefied carbon dioxide discharged from the recovery tank 22. Thereafter, the output unit 75 outputs information based on the calculation result acquired by the payout amount acquisition unit 72 to the outside.

[0052] Moreover, step S14 of sending liquefied carbon dioxide to the recovery tank 22 after the discharge of liquefied carbon dioxide is stopped is carried out in step S12 after the discharge of liquefied carbon dioxide from the recovery tank 22 is stopped. This step S14 is actually carried out in parallel with the above-mentioned step S13. In step S14, as shown in Fig. 2, the on-off valve 27v is opened in the switching unit 27. When the on-off valve 27v is opened, the buffer tank 24 and the recovery tank 22 are communicated, and the transfer of liquefied carbon dioxide from the buffer tank 24 to the recovery tank 22 is resumed. Then, first, while the recovery tank 22 is discharging liquefied carbon dioxide, the liquefied carbon dioxide that has been sent to and stored in the buffer tank 24 is sent to the recovery tank 22 via the transfer piping system 103. After the on-off valve 27v is opened, liquefied carbon dioxide that has been newly liquefied in the liquefaction unit 25 while the ship 1A is at anchor, navigating, etc. is sent to the recovery tank 22 via the transfer piping system 103 and the buffer tank 24.

[0053] The step S15 of discharging liquefied carbon dioxide is carried out when the recovery tank 22 discharges liquefied carbon dioxide for the second or subsequent time after the discharge of liquefied carbon dioxide from the recovery tank 22 in the step S12 is completed. When the ship 1A arrives at a port or the like, the recovery tank 22 discharges the liquefied carbon dioxide stored in the recovery tank 22. At this time, as shown in FIG. 3, the switching unit 27 closes the opening / closing valve 27v. As a result, in the step S15 of discharging liquefied carbon dioxide, only the liquefied carbon dioxide stored in the recovery tank 22 is discharged. In this case, the recovery tank 22 discharges the liquefied carbon dioxide that was sent to the buffer tank 24 and then transferred to the recovery tank 22 when the liquefied carbon dioxide was previously discharged from the recovery tank 22, together with the liquefied carbon dioxide that was newly liquefied in the liquefaction unit 25 and sent to the recovery tank 22 after the discharge of liquefied carbon dioxide from the recovery tank 22 was stopped.

[0054] In step S15 of dispensing liquefied carbon dioxide, when the on-off valve 27v is closed, step S15s is executed to send liquefied carbon dioxide to the buffer tank 24. Step S15s is executed while the recovery tank 22 is dispensing liquefied carbon dioxide in the above step S15. Step S15s is actually started at the same time as the on-off valve 27v is closed in the above step S15. In step S15s, liquefied carbon dioxide is sent to the buffer tank 24, which is the other storage section 21B from which liquefied carbon dioxide has not been dispensed, among the multiple storage sections 21 capable of storing liquefied carbon dioxide. At this time, since communication between the buffer tank 24 and the recovery tank 22 via the transfer piping system 103 is cut off, in step S15s, the on-off valve 27v is closed and thereafter the liquefied carbon dioxide liquefied in the liquefaction section 25 is stored in the buffer tank 24.

[0055] In step S15, when the discharge of the liquefied carbon dioxide from the recovery tank 22 is completed, the discharge of the liquefied carbon dioxide is stopped. In step S16 of weighing the dispensed liquefied carbon dioxide, the liquefied carbon dioxide dispensed by recovery tank 22 in step S15 is weighed. That is, in step S16, the liquefied carbon dioxide that was sent to buffer tank 24 while the liquefied carbon dioxide was being dispensed from recovery tank 22 and then transferred to recovery tank 22, and the liquefied carbon dioxide that was newly liquefied in liquefaction section 25 and sent to recovery tank 22 after the dispense of the liquefied carbon dioxide from recovery tank 22 was stopped, are weighed together. The liquefied carbon dioxide dispensed by recovery tank 22 in step S16 may be weighed in the same manner as in step S13. In this way, in step S16, the liquefied carbon dioxide that was sent to the buffer tank 24 and then transferred to the recovery tank 22 when liquefied carbon dioxide was previously discharged from the recovery tank 22, and the liquefied carbon dioxide that was sent to the recovery tank 22 after the discharge of liquefied carbon dioxide from the recovery tank 22 was stopped, are combined and weighed at the time of the next discharge. Here, the time of the next discharge refers to the time when liquefied carbon dioxide is discharged again from the recovery tank 22 after the discharge of liquefied carbon dioxide from the recovery tank 22 is stopped. Thereafter, steps S14 to S16 are sequentially repeated.

[0056] (Action and effect) In the carbon dioxide capture system 20A of the above embodiment, when the capture tank 22, which is one of the multiple storage units 21, is discharging liquefied carbon dioxide, the liquefied carbon dioxide liquefied in the liquefaction unit 25 is sent to the buffer tank 24, which is one of the multiple storage units 21 and is not discharging liquefied carbon dioxide. As a result, when the capture tank 22 is discharging liquefied carbon dioxide, the liquefied carbon dioxide liquefied in the liquefaction unit 25 is not sent to the capture tank 22 that is discharging liquefied carbon dioxide. Therefore, when the liquefied carbon dioxide is being discharged, the measurement unit 80 can measure only the liquefied carbon dioxide dispensed from the capture tank 22 without being influenced by the liquefied carbon dioxide liquefied in the liquefaction unit 25. As a result, the liquefied carbon dioxide dispensed from the storage unit 21 can be measured with higher accuracy.

[0057] Furthermore, in the above embodiment, at the time of the next dispensing, the liquefied carbon dioxide stored in the buffer tank 24 from which liquefied carbon dioxide is not being dispensed while the recovery tank 22 is dispensing liquefied carbon dioxide and the liquefied carbon dioxide that is liquefied by the liquefaction unit 25 and sent to the recovery tank 22 after the dispensing of liquefied carbon dioxide from the recovery tank 22 is stopped are dispensed. The measuring unit 80 can measure the liquefied carbon dioxide including the liquefied carbon dioxide stored in the buffer tank 24 from which liquefied carbon dioxide is not being dispensed while the recovery tank 22 is dispensing liquefied carbon dioxide.

[0058] Furthermore, in the above embodiment, when the switching unit 27 enables the transfer piping system 103 to send liquefied carbon dioxide to the recovery tank 22, the liquefied carbon dioxide liquefied by the liquefaction unit 25 is sent to the recovery tank 22 via the buffer tank 24. This allows the liquefied carbon dioxide liquefied by the liquefaction unit 25 to be collected in the recovery tank 22 when the liquefied carbon dioxide is not being dispensed. Furthermore, when the switching unit 27 blocks the transfer piping system 103 to the recovery tank 22, the liquefied carbon dioxide liquefied by the liquefaction unit 25 is sent to the buffer tank 24. This allows the liquefied carbon dioxide liquefied by the liquefaction unit 25 to be stored in the buffer tank 24 when the recovery tank 22 is discharging liquefied carbon dioxide.

[0059] In addition, in the above embodiment, the mass of liquefied carbon dioxide dispensed from the recovery tank 22 can be obtained with high accuracy based on the liquid level levels L1, L2 of the liquefied carbon dioxide before and after it is dispensed from the recovery tank 22, and the temperature and pressure at each liquid level L1, L2 in the storage section 21.

[0060] In addition, in the above embodiment, the mass of liquefied carbon dioxide discharged from the recovery tank 22 can be obtained with higher accuracy by correcting the mass of liquefied carbon dioxide discharged from the recovery tank 22 based on the purity of the liquefied carbon dioxide.

[0061] In addition, in the above embodiment, the greenhouse gas reduction rate can be calculated based on the mass of carbon dioxide gas discharged from the combustion device 8, which is obtained based on the fuel consumption detected by the fuel meter 88, and the mass of liquefied carbon dioxide discharged from the recovery tank 22.

[0062] Furthermore, in the ship 1A of the above embodiment, it is possible to provide the ship 1A equipped with the carbon dioxide capture system 20A that can obtain the mass of unloaded liquefied carbon dioxide with higher accuracy.

[0063] In the carbon dioxide recovery method S10 in the above embodiment, when the recovery tank 22 is discharging liquefied carbon dioxide, the liquefied carbon dioxide is sent to the buffer tank 24 from which the liquefied carbon dioxide is not being discharged, so that the liquefied carbon dioxide is not sent to the recovery tank 22 from which the liquefied carbon dioxide is being discharged. Therefore, when the liquefied carbon dioxide is being discharged, only the liquefied carbon dioxide discharged from the recovery tank 22 can be measured without being affected by the liquefied carbon dioxide sent to the buffer tank 24. Also, at the time of the next dispensing, the liquefied carbon dioxide stored in the buffer tank 24 from which liquefied carbon dioxide is not being dispensed while the recovery tank 22 is dispensing liquefied carbon dioxide and the liquefied carbon dioxide sent to the recovery tank 22 after the dispensing of liquefied carbon dioxide from the recovery tank 22 is stopped are weighed together. This makes it possible to weigh the liquefied carbon dioxide including the liquefied carbon dioxide stored in the buffer tank 24 from which liquefied carbon dioxide is not being dispensed while the recovery tank 22 is dispensing liquefied carbon dioxide next time. As a result, the liquefied carbon dioxide dispensed from storage section 21 can be continuously measured with high accuracy. In addition, while the recovery tank 22 is discharging liquefied carbon dioxide, the carbon dioxide liquefied in the liquefaction section 25 can be stored continuously in the buffer tank 24 without affecting the measurement accuracy.

[0064] Second Embodiment Next, a second embodiment of the carbon dioxide capture system, the vessel, and the carbon dioxide capture method according to the present disclosure will be described. In the second embodiment described below, the only difference between the first embodiment and the carbon dioxide capture system is the configuration of the carbon dioxide capture system. Therefore, the same parts as those in the first embodiment are denoted by the same reference numerals and will not be described again. Fig. 7 is a side view of a ship according to a second embodiment of the present disclosure. Fig. 8 is a diagram showing a configuration of a carbon dioxide metering system according to a second embodiment of the present disclosure. Note that in Fig. 8, the illustration of the arithmetic device 50 shown in Fig. 2 of the first embodiment is omitted.

[0065] (Configuration of carbon dioxide capture system) As shown in Figures 7 and 8, the carbon dioxide capture system 20B of the ship 1B illustrated in this embodiment includes a carbon dioxide capture unit 23, a liquefaction unit 25, multiple storage units 21, a switching unit 27, and a metering unit 80.

[0066] (Storage section configuration) The multiple storage units 21 exemplified in this embodiment include a first collection tank 22C and a second collection tank 22D. In the second embodiment, the case where two storage units 21, the first collection tank 22C and the second collection tank 22D, are provided is exemplified, but the number of storage units 21 is not limited to two and may be three or more. Each of the first recovery tank 22C and the second recovery tank 22D is capable of storing carbon dioxide liquefied in the liquefaction section 25. The first recovery tank 22C and the second recovery tank 22D may be disposed on the upper deck 5, or may be disposed, for example, below the upper deck 5. In this embodiment, so-called horizontally placed cylindrical tanks are exemplified as the first recovery tank 22C and the second recovery tank 22D, but the shapes of the first recovery tank 22C and the second recovery tank 22D are not limited in any way and may be, for example, spherical or rectangular.

[0067] One end of the transfer piping system 103B is connected to the liquefaction unit 25. The transfer piping system 103B branches into a first branch system 1031 and a second branch system 1032 along the way. The first branch system 1031 is connected to the first recovery tank 22C. The second branch system 1032 is connected to the second recovery tank 22D. The transfer piping system 103B sends the liquefied carbon dioxide liquefied in the liquefaction unit 25 to the first recovery tank 22C and the second recovery tank 22D.

[0068] (Switching section configuration) The switching unit 27 is provided in each of the first branch system 1031 and the second branch system 1032 in the transfer piping system 103B. The switching unit 27 illustrated in this embodiment is an on-off valve 27v. The on-off valve 27v provided in the first branch system 1031 can interrupt the supply of liquefied carbon dioxide to the first recovery tank 22C through the transfer piping system 103B. The on-off valve 27v provided in the second branch system 1032 can interrupt the supply of liquefied carbon dioxide to the second recovery tank 22D through the transfer piping system 103B.

[0069] FIG. 9 is a diagram showing a state in which the first collection tank is dispensing liquefied carbon dioxide in the carbon dioxide metering system according to the second embodiment of the present disclosure. 9, in the carbon dioxide capture system 20B, when the first capture tank 22C is discharging liquefied carbon dioxide, the on-off valve 27v provided in the first branch system 1031 is closed, and the on-off valve 27v provided in the second branch system 1032 is opened. As a result, the liquefied carbon dioxide liquefied in the liquefaction unit 25 while the first capture tank 22C is discharging liquefied carbon dioxide is stored in the second capture tank 22D. In this case, the first collection tank 22C dispenses liquefied carbon dioxide as a storage section 21C among the plurality of storage sections 21. The second collection tank 22D receives the carbon dioxide liquefied in the liquefaction section 25 as another storage section 21D different from the storage sections 21C among the plurality of storage sections 21.

[0070] FIG. 10 is a diagram showing a state in which the second collection tank is dispensing liquefied carbon dioxide in the carbon dioxide metering system according to the second embodiment of the present disclosure. As shown in FIG. 10, in this carbon dioxide capture system 20B, after the first capture tank 22C has completed the discharge of liquefied carbon dioxide, in order to discharge the liquefied carbon dioxide stored in the second capture tank 22D, the on-off valve 27v provided in the first branch system 1031 is opened and the on-off valve 27v provided in the second branch system 1032 is closed. As a result, the liquefied carbon dioxide liquefied in the liquefaction unit 25 while the second capture tank 22D is discharging the liquefied carbon dioxide is stored in the first capture tank 22C. In this case, the second capture tank 22D discharges the liquefied carbon dioxide as a storage unit 21C, which is one of the multiple storage units 21. The carbon dioxide liquefied in the liquefaction unit 25 is sent to the first capture tank 22C as another storage unit 21D different from the storage unit 21C, which is one of the multiple storage units 21.

[0071] After the second recovery tank 22D has completed the discharge of liquefied carbon dioxide, the on-off valve 27v provided in the first branch system 1031 and the on-off valve 27v provided in the second branch system 1032 may both be opened or either one of them may be opened.

[0072] In this way, in carbon dioxide capture system 20B, liquefied carbon dioxide stored in multiple storage sections 21 is dispensed in sequence. Then, while some storage sections 21C are dispensing liquefied carbon dioxide, liquefied carbon dioxide liquefied in liquefaction section 25 is sent to other storage sections 21D that are not dispensing liquefied carbon dioxide. In this way, in calculation device 50 (see FIG. 2) of measurement section 80, while some storage sections 21C are dispensing liquefied carbon dioxide, the liquefied carbon dioxide sent to other storage sections 21D can be measured after stopping the dispensation of liquefied carbon dioxide from some storage sections 21C. In the carbon dioxide capture system 20B illustrated in the above embodiment, when liquefied carbon dioxide is being dispensed from the second capture tank 22D, the liquefied carbon dioxide liquefied in the liquefaction unit 25 is sent to the first capture tank 22C from which dispensing has already been completed. This allows the liquefied carbon dioxide liquefied in the liquefaction unit 25 and sent to the first capture tank 22C to be measured, for example, at the time of the next dispensing, when liquefied carbon dioxide is being dispensed from the storage unit 21D. Here, the time of the next dispensing in the second embodiment can be, for example, when the dispensing of liquefied carbon dioxide stored in the storage unit 21 is completed and dispensing of liquefied carbon dioxide from all the storage units 21 is stopped, and then dispensing of liquefied carbon dioxide stored in the storage unit 21 is performed again.

[0073] (Procedure for carbon dioxide capture method) Fig. 11 is a flowchart showing the procedure of the carbon dioxide capture method according to the second embodiment of the present disclosure. As shown in Fig. 11, the carbon dioxide capture method S20 according to the second embodiment of the present disclosure includes a step S21 of blocking the supply of liquefied carbon dioxide to the first capture tank, a step S22 of discharging liquefied carbon dioxide from the first capture tank, a step S22s of feeding liquefied carbon dioxide to the second capture tank, a step S23 of measuring the dispensed liquefied carbon dioxide, a step S24 of determining the completion of discharging, a step S25 of blocking the supply of liquefied carbon dioxide to the second capture tank, a step S26 of discharging liquefied carbon dioxide from the second capture tank, and a step S27 of measuring the amount of liquefied carbon dioxide dispensed to the first capture tank. The method includes a step S26s of sending carbon dioxide, a step S27 of weighing the dispensed liquefied carbon dioxide, a step S28 of determining completion of dispense, a step S29 of cutting off the supply of liquefied carbon dioxide to the first recovery tank, a step S30 of dispensing liquefied carbon dioxide from the first recovery tank, a step S30s of sending liquefied carbon dioxide to the second recovery tank, a step S31 of weighing the dispensed liquefied carbon dioxide, a step S32 of determining completion of dispense, and a step S33 of sending liquefied carbon dioxide to the recovery tank after stopping the dispense of liquefied carbon dioxide.

[0074] Steps S21 to S28 described below are carried out the first time the recovery tank 22 dispenses liquefied carbon dioxide after the start of use of the carbon dioxide recovery system 20B. After starting to use the carbon dioxide capture system 20B, for example, the multiple on-off valves 27v are each opened as shown in Fig. 8. Carbon dioxide contained in the exhaust gas from the combustion device 8 is captured in the carbon dioxide capture section 23 and then liquefied in the liquefaction section 25. The liquefied carbon dioxide liquefied in the liquefaction section 25 is sent to the first capture tank 22C and the second capture tank 22D via the transfer piping system 103B. As a result, the liquefied carbon dioxide liquefied in the liquefaction section 25 is stored in the first capture tank 22C and the second capture tank 22D.

[0075] When the ship 1B arrives at a port or the like, the liquefied carbon dioxide stored in the first recovery tank 22C and the second recovery tank 22D are discharged in order. In this second embodiment, the case where the liquefied carbon dioxide stored in the first recovery tank 22C is discharged and then the liquefied carbon dioxide stored in the second recovery tank 22D is discharged is taken as an example, but the order of discharging is not limited to this. To this end, first, as shown in FIG. 9, in step S21 for blocking the supply of liquefied carbon dioxide to the first recovery tank, the on-off valve 27v provided in the first branch system 1031 is closed. This blocks the supply of liquefied carbon dioxide from the liquefaction unit 25 to the first recovery tank 22C. Thereafter, the process proceeds to step S22 of discharging the liquefied carbon dioxide from the first recovery tank, and discharging of the liquefied carbon dioxide stored in the first recovery tank 22C begins. In this step S22, the on-off valve 27v provided in the first branch system 1031 is closed, and the supply of liquefied carbon dioxide from the liquefaction unit 25 to the first recovery tank 22C is blocked, so that only the liquefied carbon dioxide already stored in the first recovery tank 22C is discharged.

[0076] Step S22s of sending liquefied carbon dioxide to the second recovery tank is executed while the first recovery tank 22C is dispensing liquefied carbon dioxide in the above step S22. Step S22s is actually started at the same time as the opening / closing valve 27v provided in the first branch system 1031 is closed in the above step S21. In step S22s, after the opening / closing valve 27v provided in the first branch system 1031 is closed, the liquefied carbon dioxide liquefied in the liquefaction unit 25 is stored in the second recovery tank 22D.

[0077] In step S23 of measuring the dispensed liquefied carbon dioxide, the liquefied carbon dioxide dispensed by the first collection tank 22C is measured. Note that the measurement of the liquefied carbon dioxide in step S23 is similar to step S13 in the first embodiment, and therefore a detailed description thereof will be omitted.

[0078] In step S24 for determining completion of dispensing, it is determined whether or not dispensing of liquefied carbon dioxide from the first collection tank 22C is completed. If dispensing of liquefied carbon dioxide is not completed, the above steps S22, S22s, and S23 are repeated. On the other hand, if dispensing of liquefied carbon dioxide from the first collection tank 22C is completed, the process proceeds to step S25.

[0079] In step S25 of cutting off the supply of liquefied carbon dioxide to the second recovery tank, as shown in Fig. 10, the on-off valve 27v provided in the second branch system 1032 is closed, and the on-off valve 27v provided in the first branch system 1031 is opened. Then, the supply of liquefied carbon dioxide from the liquefaction unit 25 to the second recovery tank 22D is cut off.

[0080] In step S26 of discharging liquefied carbon dioxide from the second recovery tank, discharging of the liquefied carbon dioxide stored in the second recovery tank 22D is started. In this step S26, the on-off valve 27v provided in the second branch system 1032 is closed and the supply of liquefied carbon dioxide from the liquefaction section 25 to the second recovery tank 22D is blocked, so that only the liquefied carbon dioxide stored in the second recovery tank 22D is discharged. Here, the liquefied carbon dioxide stored in the second recovery tank 22D includes liquefied carbon dioxide that has been recovered during navigation or the like and stored in the second recovery tank 22D, and liquefied carbon dioxide that has been sent to the second recovery tank 22D while the above steps S22 to S23 are being performed.

[0081] Step S26s of sending liquefied carbon dioxide to the first collection tank is executed when the second collection tank 22D is dispensing liquefied carbon dioxide in the above step S26. Step S26s is actually started at the same time as closing the on-off valve 27v provided in the second branch system 1032 in the above step S25. In step S26s, after closing the on-off valve 27v provided in the second branch system 1032, the liquefied carbon dioxide liquefied in the liquefaction unit 25 is stored in the first collection tank 22C. Note that steps S22s and S26s correspond to steps of sending liquefied carbon dioxide to other storage units that are not dispensing liquefied carbon dioxide among a plurality of storage units capable of storing liquefied carbon dioxide when some storage units among a plurality of storage units capable of storing liquefied carbon dioxide are dispensing liquefied carbon dioxide in the present disclosure.

[0082] In step S27 of measuring the dispensed liquefied carbon dioxide, the liquefied carbon dioxide dispensed by the second collection tank 22D is measured. That is, in step S22, after the dispense of liquefied carbon dioxide from the first collection tank 22C is stopped, the liquefied carbon dioxide dispensed by the second collection tank 22D is measured. The liquefied carbon dioxide measured in this step S27 includes the liquefied carbon dioxide sent to the second collection tank 22D while performing the above steps S22 to S23. Note that the measurement of liquefied carbon dioxide in this step S27 is similar to step S13 of the first embodiment and the above-mentioned step S23, and therefore a detailed description will be omitted.

[0083] In step S28 for determining completion of dispensing, it is determined whether or not dispensing of liquefied carbon dioxide from the second collection tank 22D is completed. If dispensing of liquefied carbon dioxide is not completed, the above steps S26, S26s, and S27 are repeated. On the other hand, if dispensing of liquefied carbon dioxide from the second collection tank 22D is completed, the process proceeds to step S29.

[0084] In step S29 of cutting off the supply of liquefied carbon dioxide to the first recovery tank, the on-off valve 27v provided in the first branch system 1031 is closed. This cuts off the supply of liquefied carbon dioxide from the liquefaction unit 25 to the first recovery tank 22C.

[0085] In step S30 of discharging liquefied carbon dioxide from the first recovery tank, discharging of the liquefied carbon dioxide stored in the first recovery tank 22C is started. In this step S30, the on-off valve 27v provided in the first branch system 1031 is closed and the supply of liquefied carbon dioxide from the liquefaction section 25 to the first recovery tank 22C is blocked, so that only the liquefied carbon dioxide already stored in the first recovery tank 22C is discharged. In this step S30, the liquefied carbon dioxide already stored in the first recovery tank 22C is essentially the liquefied carbon dioxide recovered in the first recovery tank 22C when the liquefied carbon dioxide was being discharged from the second recovery tank 22D.

[0086] Step S30s of sending liquefied carbon dioxide to the second recovery tank is executed when the first recovery tank 22C is dispensing liquefied carbon dioxide in the above step 30. Step S30s is actually started at the same time as closing the on-off valve 27v provided in the first branch system 1031 in the above step S29. In step S30s, after closing the on-off valve 27v provided in the first branch system 1031, the liquefied carbon dioxide liquefied in the liquefaction unit 25 is stored in the second recovery tank 22D. When this step S30s is performed, the dispensing of the second recovery tank 22D has already been completed in step 26, so the liquefied carbon dioxide stored in the second recovery tank 22D is substantially the liquefied carbon dioxide recovered when the liquefied carbon dioxide is being dispensed from the first recovery tank 22C.

[0087] In step S31 of measuring the dispensed liquefied carbon dioxide, the liquefied carbon dioxide dispensed from the first collection tank 22C in step S30 is measured. In step S32 for determining completion of dispensing, it is determined whether or not dispensing of liquefied carbon dioxide from the first collection tank 22C is completed. If dispensing of liquefied carbon dioxide is not completed, the above steps S30, S30s, and S31 are repeated. On the other hand, if dispensing of liquefied carbon dioxide from the first collection tank 22C is completed, the process proceeds to step S33.

[0088] In step S33 of sending liquefied carbon dioxide to the collection tank after the discharge of liquefied carbon dioxide is stopped, after the discharge of liquefied carbon dioxide from the first collection tank 22C and the second collection tank 22D, i.e., all storage units 21, is stopped, the liquefied carbon dioxide liquefied by the liquefaction unit 25 is sent to the first collection tank 22C and the second collection tank 22D, for example, during navigation, and at the time of the next discharge, the process returns to step S21, and the above-mentioned series of steps are repeated. Here, the above-mentioned steps S27 and S31 each correspond to the steps of this disclosure of measuring the liquefied carbon dioxide stored in some of the storage units after the discharge of liquefied carbon dioxide from the other storage units is stopped. In the above second embodiment, a case has been described where the liquefied carbon dioxide recovered in the first recovery tank 22C by steps S29 to 32 is metered. However, this is not limited to the configuration, and for example, steps S29 to 32 may be omitted, and the liquefied carbon dioxide sent to the first recovery tank 22C in step S26s may be metered together with the liquefied carbon dioxide recovered during the voyage at the time of the next dispensing.

[0089] (Action and effect) In the carbon dioxide capture system 20B of the above embodiment, when some of the storage sections 21C among the multiple storage sections 21 are dispensing liquefied carbon dioxide, the liquefied carbon dioxide liquefied in the liquefaction section 25 is sent to other storage sections 21D among the multiple storage sections 21 that are not dispensing liquefied carbon dioxide. This prevents the liquefied carbon dioxide liquefied in the liquefaction section 25 from being sent to some of the storage sections 21C that are dispensing liquefied carbon dioxide. Therefore, when dispensing liquefied carbon dioxide, the measurement section 80 can measure only the liquefied carbon dioxide dispensed from some of the storage sections 21C without being affected by the liquefied carbon dioxide liquefied in the liquefaction section 25. As a result, as in the first embodiment, the liquefied carbon dioxide dispensed from the storage section 21 can be measured with higher accuracy.

[0090] (Modification of the second embodiment) In the second embodiment, the first collection tank 22C and the second collection tank 22D are provided as the multiple storage sections 21, but the present invention is not limited to this. Fig. 13 is a diagram showing the configuration of a carbon dioxide metering system according to a modified example of the second embodiment of the present disclosure, in which the metering unit 80 is omitted. As shown in FIG. 13, in a carbon dioxide capture system 20C of this modified example, a plurality of storage sections 21 are formed by dividing the inside of one tank 28 into a plurality of sections.

[0091] Tank 28 is capable of storing carbon dioxide liquefied in liquefaction section 25. Tank 28 may be disposed on upper deck 5, or may be disposed, for example, below upper deck 5. In this embodiment, a so-called horizontal cylindrical tank is exemplified as tank 28, but the shape of tank 28 is not limited in any way and may be, for example, spherical or rectangular.

[0092] The tank 28 includes a partition 28k that divides the inside of the tank 28 into a plurality of compartments (for example, two). By dividing the inside of the tank 28 into a plurality of compartments by the partition 28k, a first storage compartment 26E and a second storage compartment 26F are formed in the tank 28. In the tank 28 exemplified in this embodiment, the first storage compartment 26E and the second storage compartment 26F are formed, but the number of storage compartments formed in the tank 28 is not limited to two, and may be three or more. Each of the first storage compartment 26E and the second storage compartment 26F is capable of storing the carbon dioxide liquefied in the liquefaction section 25.

[0093] One end of the transfer piping system 103C is connected to the liquefaction unit 25. The transfer piping system 103C branches into a first branch system 1033 and a second branch system 1034 along the way. The first branch system 1033 is connected to the first storage compartment 26E. The second branch system 1034 is connected to the second storage compartment 26F. The transfer piping system 103C sends the liquefied carbon dioxide liquefied in the liquefaction unit 25 to the first storage compartment 26E and the second storage compartment 26F.

[0094] (Switching section configuration) The switching unit 27 is provided in each of the first branch system 1033 and the second branch system 1034 in the transfer piping system 103C. The switching unit 27 illustrated in this embodiment is an on-off valve 27v. The on-off valve 27v provided in the first branch system 1033 can interrupt the feeding of liquefied carbon dioxide to the first storage compartment 26E via the transfer piping system 103C. The on-off valve 27v provided in the second branch system 1034 can interrupt the feeding of liquefied carbon dioxide to the second storage compartment 26F via the transfer piping system 103C.

[0095] FIG. 14 is a diagram showing a state in which the first storage compartment is dispensing liquefied carbon dioxide in the carbon dioxide metering system according to a modified example of the second embodiment of the present disclosure. 14, when the first storage compartment 26E is dispensing liquefied carbon dioxide, the switching unit 27 closes the on-off valve 27v provided in the first branch system 1033 and opens the on-off valve 27v provided in the second branch system 1034. As a result, the liquefied carbon dioxide liquefied in the liquefaction unit 25 while the first storage compartment 26E is dispensing liquefied carbon dioxide is stored in the second storage compartment 26F. In this case, the first storage section 26E dispenses liquefied carbon dioxide as storage section 21C, one of the multiple storage sections 21. The second storage section 26F receives liquefied carbon dioxide liquefied in liquefaction section 25, as storage section 21D, one of the multiple storage sections 21.

[0096] FIG. 15 is a diagram showing a state in which the second storage compartment is dispensing liquefied carbon dioxide in the carbon dioxide metering system according to the modified example of the second embodiment of the present disclosure. As shown in FIG. 15, when the second storage section 26F is dispensing liquefied carbon dioxide, the switching section 27 closes the on-off valve 27v provided in the second branch system 1034 and opens the on-off valve 27v provided in the first branch system 1033. As a result, when the second storage section 26F is dispensing liquefied carbon dioxide, the liquefied carbon dioxide liquefied in the liquefaction section 25 is stored in the first storage section 26E. In this case, the second storage section 26F dispenses liquefied carbon dioxide as the storage section 21C, which is one of the multiple storage sections 21. The liquefied carbon dioxide liquefied in the liquefaction section 25 is sent to the first storage section 26E as the other storage section 21D, which is one of the multiple storage sections 21.

[0097] In this way, in the carbon dioxide capture system 20C, the liquefied carbon dioxide stored in the multiple storage sections 21 is dispensed in sequence, as in the second embodiment described above. Then, when some of the storage sections 21C are dispensing liquefied carbon dioxide, the liquefied carbon dioxide liquefied in the liquefaction section 25 is sent to other storage sections 21D that are not dispensing liquefied carbon dioxide. In other words, the liquefied carbon dioxide is not sent to some of the storage sections 21C that are dispensing liquefied carbon dioxide. Therefore, when some of the storage sections 21C are dispensing liquefied carbon dioxide, the liquefied carbon dioxide liquefied in the liquefaction section 25 can be measured with high accuracy. Furthermore, in carbon dioxide capture system 20C, when liquefied carbon dioxide is being dispensed from second storage compartment 26F, liquefied carbon dioxide liquefied in liquefaction section 25 is sent to first storage compartment 26E from which dispensing has already been completed. This allows the liquefied carbon dioxide that is liquefied in liquefaction section 25 and sent to first storage compartment 26E when liquefied carbon dioxide is being dispensed from second storage compartment 26F to be weighed, for example, at the time of the next dispensing.

[0098] In this modified carbon dioxide capture system 20C, multiple storage sections 21 formed in tank 28 are used, and while one of the multiple storage sections 21, storage section 21C, is dispensing liquefied carbon dioxide, liquefied carbon dioxide liquefied in liquefaction section 25 can be sent to another storage section 21D. Moreover, in the above modification, like the above second embodiment, the liquefied carbon dioxide dispensed from the storage section 21 can be measured with higher accuracy.

[0099] (Other embodiments) Although the embodiments of the present disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not depart from the gist of the present disclosure are also included. For example, in the above embodiment, the flow meter 92 detects the flow rate of liquefied carbon dioxide dispensed by the dispensing piping system 104, but it may also detect the pressure and temperature of the liquefied carbon dioxide flowing through the dispensing piping system 104. In this way, based on the volumetric flow rate of liquefied carbon dioxide detected by the flow meter 92 and the pressure and temperature of the liquefied carbon dioxide flowing through the dispensing piping system 104, the mass flow rate of liquefied carbon dioxide dispensed by the dispensing piping system 104 can be obtained.

[0100] In addition, while using a flowmeter 92 that detects the volumetric flow rate of liquefied carbon dioxide, the mass flow rate of liquefied carbon dioxide flowing through the discharge piping system 104 may be obtained based on the pressure of the liquefied carbon dioxide detected by the pressure gauge 83 and the temperature of the liquefied carbon dioxide detected by the thermometer 82.

[0101] Furthermore, the flowmeter 92 may be configured to detect the mass flow rate of the liquefied carbon dioxide flowing through the discharge piping system 104. This allows for more accurate abnormality detection by comparing the detection result of the flowmeter 92 with the mass of the liquefied carbon dioxide discharged from the storage section 21.

[0102] In the above embodiment, the purity of the liquefied carbon dioxide is detected by the purity detector 87, but the detection position of the purity of the liquefied carbon dioxide may be, for example, inside the storage portion 21 or the like. In addition, in the above embodiment, the mass of liquefied carbon dioxide dispensed from the recovery tank 22 is corrected based on the purity of the liquefied carbon dioxide detected by the purity detector 87, but the correction based on the purity of the liquefied carbon dioxide may be omitted depending on the purpose of use of the liquefied carbon dioxide, etc.

[0103] <Additional Notes> The carbon dioxide capture systems 20A, 20B, and 20C, ships 1A and 1B, and carbon dioxide capture methods S10 and S20 described in the respective embodiments can be understood, for example, as follows.

[0104] (1) The carbon dioxide capture systems 20A, 20B, and 20C of the first embodiment include a carbon dioxide capture unit 23 that captures gaseous carbon dioxide from a carbon dioxide-containing gas, a liquefaction unit 25 that liquefies the gaseous carbon dioxide captured by the carbon dioxide capture unit 23, a plurality of storage units 21 capable of storing the liquefied carbon dioxide liquefied by the liquefaction unit 25, a switching unit 27 that sends the liquefied carbon dioxide liquefied in the liquefaction unit 25 to the other storage units 21B, 21D of the plurality of storage units 21 that are not dispensing liquefied carbon dioxide while some of the storage units 21A, 21C of the plurality of storage units 21 are dispensing liquefied carbon dioxide, and a measuring unit 80 that measures the liquefied carbon dioxide dispensed from the storage unit 21.

[0105] This prevents the liquefied carbon dioxide liquefied in liquefaction unit 25 from being sent to some of the storage units 21A, 21C that are dispensing the liquefied carbon dioxide. Therefore, when dispensing the liquefied carbon dioxide, measuring unit 80 can measure only the liquefied carbon dioxide dispensed from some of the storage units 21A, 21C without being affected by the liquefied carbon dioxide liquefied in liquefaction unit 25. As a result, the liquefied carbon dioxide dispensed from storage unit 21 is measured with higher accuracy. Furthermore, while some of the storage sections 21A, 21C are dispensing liquefied carbon dioxide, carbon dioxide liquefied in liquefaction section 25 can be continuously stored in the other storage sections 21B, 21D without affecting the measurement accuracy.

[0106] (2) The carbon dioxide capture systems 20A, 20B, and 20C of the second aspect are the carbon dioxide capture systems 20A, 20B, and 20C of (1), in which, while some of the storage sections 21C are dispensing liquefied carbon dioxide, the liquefied carbon dioxide stored in other storage sections 21D that are not dispensing liquefied carbon dioxide is weighed after the dispensing of liquefied carbon dioxide from some of the storage sections 21C is stopped.

[0107] This makes it possible to measure the amount of liquefied carbon dioxide, including liquefied carbon dioxide sent to the other storage sections 21B, 21D that are not dispensing liquefied carbon dioxide, while some storage sections 21A, 21C are dispensing liquefied carbon dioxide. Furthermore, when some of the storage sections 21B, 21C are dispensing liquefied carbon dioxide, the carbon dioxide liquefied in the liquefaction section 25 can be stored continuously without affecting the measurement accuracy.

[0108] (3) The carbon dioxide capture systems 20A, 20B, and 20C of the third aspect are the carbon dioxide capture systems 20A, 20B, and 20C of (1) or (2), and the measuring unit 80 measures the liquefied carbon dioxide stored in the other storage units 21B, 21D that are not dispensing liquefied carbon dioxide while some of the storage units 21A, 21C are dispensing liquefied carbon dioxide, and the liquefied carbon dioxide that has been liquefied by the liquefaction unit 25 and sent to any of the plurality of storage units 21 after the dispensing of liquefied carbon dioxide from some of the storage units 21A, 21C has been stopped, at the time of the next dispensing.

[0109] This makes it possible to measure liquefied carbon dioxide including liquefied carbon dioxide stored in the other storage section 21B from which liquefied carbon dioxide is not being dispensed, while some storage sections 21A, 21C are dispensing liquefied carbon dioxide. Furthermore, when some of the storage sections 21A, 21C are dispensing liquefied carbon dioxide, the carbon dioxide liquefied in the liquefaction section 25 can be stored continuously without affecting the measurement accuracy.

[0110] (4) The carbon dioxide capture system 20A, 20B, 20C relating to the fourth aspect is any one of the carbon dioxide capture systems 20A, 20B, 20C of (1) to (3), wherein the other storage section 21B is a buffer tank 24, and some of the storage sections 21A, 21C are recovery tanks 22 to which liquefied carbon dioxide liquefied by the liquefaction section 25 is sent when liquefied carbon dioxide is not being discharged, the buffer tank 24 is provided midway through a transfer piping system 103 that sends liquefied carbon dioxide from the liquefaction section 25 to the recovery tank 22, and the switching section 27 is capable of interrupting the sending of liquefied carbon dioxide to the recovery tank 22 via the transfer piping system 103.

[0111] As a result, the liquefied carbon dioxide liquefied by the liquefaction unit 25 when the liquefied carbon dioxide is not being discharged can be recovered in the recovery tank 22. In addition, when the recovery tank 22 is discharging the liquefied carbon dioxide, the liquefied carbon dioxide liquefied by the liquefaction unit 25 can be sent to the buffer tank 24.

[0112] (5) A carbon dioxide capture system 20C according to a fifth aspect is any one of the carbon dioxide capture systems 20C of (1) to (3), in which the multiple storage sections 21 are formed by dividing a hollow tank 28 into multiple sections.

[0113] This allows multiple storage sections 21 formed within tank 28 to be used, and while one of the multiple storage sections 21, storage section 21C, is dispensing liquefied carbon dioxide, liquefied carbon dioxide liquefied in liquefaction section 25 can be sent to another storage section 21D.

[0114] (6) The carbon dioxide capture system 20A, 20B, 20C relating to the sixth aspect is any one of the carbon dioxide capture systems 20A, 20B, 20C of (1) to (5), wherein the measuring unit 80 includes a level gauge 81 for detecting the liquid level in the storage unit 21, a thermometer 82 for detecting the temperature in the storage unit 21, and a pressure gauge 83 for detecting the pressure in the storage unit 21, and the measuring unit 80 obtains the mass of liquefied carbon dioxide stored in the storage unit 21 based on the detection results of the level gauge 81, the thermometer 82, and the pressure gauge 83.

[0115] This makes it possible to obtain the mass of liquefied carbon dioxide dispensed from storage section 21 with high accuracy based on the volume of liquefied carbon dioxide dispensed from storage section 21 and the temperature and pressure within storage section 21.

[0116] (7) The carbon dioxide capture systems 20A, 20B, and 20C relating to the seventh aspect are the carbon dioxide capture systems 20A, 20B, and 20C of (6), further comprising a purity detector 87 for detecting the purity of the liquefied carbon dioxide dispensed from the storage section 21, and the measuring section 80 corrects the mass of the liquefied carbon dioxide dispensed from the storage section 21 based on the purity of the liquefied carbon dioxide detected by the purity detector 87.

[0117] This makes it possible to obtain the mass of liquefied carbon dioxide dispensed from storage section 21 with higher accuracy by correcting the mass of liquefied carbon dioxide dispensed from storage section 21 based on the purity of the liquefied carbon dioxide.

[0118] (8) The carbon dioxide capture system 20A, 20B, 20C according to the eighth aspect is any one of the carbon dioxide capture systems 20A, 20B, 20C according to (1) to (7), and further includes a combustion device 8 that burns fuel and a fuel meter 88 capable of detecting the amount of fuel consumed by the combustion device 8, and the metering unit 80 acquires the amount of carbon dioxide emitted from the combustion device 8 based on the amount of fuel consumed detected by the fuel meter 88, and calculates the greenhouse gas reduction rate based on the acquisition result of the amount of carbon dioxide emitted from the combustion device 8 and the metering result of the liquefied carbon dioxide dispensed from the storage unit 21.

[0119] This makes it possible to calculate the greenhouse gas reduction rate based on the mass of carbon dioxide gas discharged from the combustion device 8, which is obtained based on the fuel consumption detected by the fuel meter 88, and the amount of liquefied carbon dioxide dispensed from the storage section 21.

[0120] (9) Ships 1A, 1B according to a ninth aspect include a hull 2 ​​and any one of carbon dioxide capture systems 20A, 20B, 20C according to (1) to (8).

[0121] This makes it possible to provide ships 1A, 1B equipped with carbon dioxide capture systems 20A, 20B, 20C that can measure the liquefied carbon dioxide discharged from storage section 21 with higher accuracy.

[0122] (10) The carbon dioxide capture method of the tenth aspect includes steps S12s, S15s, S22s, S26s, and 30s of sending liquefied carbon dioxide to other storage sections 21B, 21D of a plurality of storage sections 21 capable of storing liquefied carbon dioxide when a portion of the storage sections 21A, 21C of the plurality of storage sections 21 capable of storing liquefied carbon dioxide is discharging liquefied carbon dioxide, and steps S16, S27, and S31 of weighing the liquefied carbon dioxide sent to the other storage sections 21B, 21D when liquefied carbon dioxide is being discharged from some of the storage sections 21A, 21C after stopping the discharge of liquefied carbon dioxide from some of the storage sections 21A, 21C. This allows only the liquefied carbon dioxide dispensed from some of the storage sections 21A, 21C to be measured without being affected by the liquefied carbon dioxide sent to the other storage sections 21B, 21D when some of the storage sections 21A, 21C are dispensing liquefied carbon dioxide. In addition, the liquefied carbon dioxide stored in the other storage sections 21B, 21D when liquefied carbon dioxide is being dispensed from some of the storage sections 21A, 21C can also be measured individually after the dispensing of the liquefied carbon dioxide from some of the storage sections 21A, 21C is stopped. As a result, the liquefied carbon dioxide dispensed from some of the storage sections 21A, 21C and the liquefied carbon dioxide stored in the other storage sections 21B, 21D can be measured with higher accuracy.

[0123] (11) The carbon dioxide recovery method of the eleventh aspect is the carbon dioxide recovery method of (10), wherein in step S16 of weighing the liquefied carbon dioxide that was sent to the other storage sections 21B while liquefied carbon dioxide was being discharged from some of the storage sections 21A after the discharge of liquefied carbon dioxide from some of the storage sections 21A is stopped, the liquefied carbon dioxide that was sent to the other storage sections 21B while liquefied carbon dioxide was being discharged from some of the storage sections 21A and the liquefied carbon dioxide that was sent to any of the multiple storage sections 21 after the discharge of liquefied carbon dioxide from some of the storage sections 21A is stopped are combined and weighed at the time of the next discharge.

[0124] As a result, when liquefied carbon dioxide is being dispensed, only the liquefied carbon dioxide dispensed from some of the storage portions 21A can be measured without being affected by the liquefied carbon dioxide sent to other storage portions 21B. In addition, at the time of the next dispensing, the liquefied carbon dioxide stored in other storage sections 21B that are not dispensing liquefied carbon dioxide while some storage sections 21A are dispensing liquefied carbon dioxide, and the liquefied carbon dioxide sent to any of the multiple storage sections 21 after the dispensing of liquefied carbon dioxide from some storage sections 21A has been stopped, can be weighed together. As a result, the liquefied carbon dioxide dispensed from storage section 21 can be measured with higher accuracy. Furthermore, when some of the storage sections 21A are dispensing liquefied carbon dioxide, the carbon dioxide liquefied in the liquefaction section 25 can be stored continuously without affecting the measurement accuracy. [Explanation of symbols]

[0125] 1A, 1B... Ship 2... Hull 2a... Bow 2b... Stern 3A, 3B... Ship side 4... Ship bottom 5... Upper deck 6... Superstructure 7... Cargo loading section 8... Combustion device 9... Fuel tank 11... Cargo tank 20A-20C... Carbon dioxide capture system 21, 21A-21D... Storage section 22... Capture tank 22C... First capture tank 22D... Second capture tank 23... Carbon dioxide capture section 24... Buffer tank 25... Liquefaction section 26E... First storage section 26F... Second storage section 27... Switching section 27v... Opening / closing valve 28... Tank 28k... Partition 50... Computing device 51... CPU 52... ROM 53... RAM 54... Storage 55... Signal transmission / reception module 70... Signal input section 71... Information acquisition section 72... Discharge amount acquisition section 73...Information output section 75...Output section 80...Measuring section 81...Level gauge 82...Thermometer 83...Pressure gauge 84...Fuel temperature gauge 87...Purity detector 88...Fuel gauge 92...Flow meter 101...Fuel supply piping system 102...Exhaust gas pipe 103, 103B, 103C...Transport piping system 104...Exhaust piping system 105...Discharge piping system 108...Lifting pump 1031, 1033...First branch system 1032, 1034...Second branch system L1, L2...Liquid level

Claims

1. A carbon dioxide recovery unit that recovers gaseous carbon dioxide from the carbon dioxide-containing gas; a liquefaction unit that liquefies the gaseous carbon dioxide recovered by the carbon dioxide recovery unit; A plurality of storage units capable of storing liquefied carbon dioxide liquefied by the liquefaction unit; A switching unit that sends the liquefied carbon dioxide liquefied in the liquefaction unit to another storage unit among the plurality of storage units that is not discharging the liquefied carbon dioxide when some of the storage units among the plurality of storage units are discharging the liquefied carbon dioxide; A measuring unit that measures the liquefied carbon dioxide dispensed from the storage unit; A carbon dioxide capture system comprising:

2. When some of the storage sections are dispensing liquefied carbon dioxide, the liquefied carbon dioxide stored in the other storage sections from which liquefied carbon dioxide is not being dispensed is measured after the dispensing of the liquefied carbon dioxide from the some of the storage sections is stopped.

2. The carbon dioxide capture system of claim 1.

3. The measuring unit includes: Liquefied carbon dioxide stored in the other storage sections that are not discharging liquefied carbon dioxide while some of the storage sections are discharging liquefied carbon dioxide; After stopping the dispensing of the liquefied carbon dioxide from some of the storage parts, the liquefied carbon dioxide that has been liquefied by the liquefaction part and sent to any one of the plurality of storage parts is added and weighed at the time of the next dispensing.

3. A carbon dioxide capture system according to claim 1 or 2.

4. The other storage unit is a buffer tank, Some of the storage units are recovery tanks to which liquefied carbon dioxide liquefied by the liquefaction unit is sent when the liquefied carbon dioxide is not being discharged, The buffer tank is provided in a transfer piping system that sends liquefied carbon dioxide from the liquefaction unit to the recovery tank, The switching unit is capable of interrupting the transfer of liquefied carbon dioxide to the recovery tank through the transfer piping system.

3. A carbon dioxide capture system according to claim 1 or 2.

5. The plurality of storage sections are formed by dividing the inside of a hollow tank into a plurality of sections.

3. A carbon dioxide capture system according to claim 1 or 2.

6. The measuring unit includes: a level meter for detecting a liquid level in the reservoir; A thermometer for detecting a temperature in the storage portion; A pressure gauge for detecting a pressure in the storage portion, The measuring unit includes: The mass of the liquefied carbon dioxide stored in the storage portion is obtained based on the detection results of the level gauge, the thermometer, and the pressure gauge.

3. A carbon dioxide capture system according to claim 1 or 2.

7. Further comprising a purity detector for detecting the purity of the liquefied carbon dioxide dispensed from the storage unit, The measuring unit corrects the mass of the liquefied carbon dioxide dispensed from the storage unit based on the purity of the liquefied carbon dioxide detected by the purity detector.

7. The carbon dioxide capture system of claim 6.

8. A combustion device that burns fuel; A fuel meter capable of detecting the amount of fuel consumed by the combustion device, The measuring unit includes: obtaining an amount of carbon dioxide emitted from the combustion device based on the amount of fuel consumed detected by the fuel gauge; A greenhouse gas reduction rate is calculated based on the amount of carbon dioxide discharged from the combustion device and the amount of liquefied carbon dioxide discharged from the storage unit.

3. A carbon dioxide capture system according to claim 1 or 2.

9. The hull and The carbon dioxide capture system according to claim 1 or 2, ship.

10. A step of feeding liquefied carbon dioxide to other storage sections among the plurality of storage sections capable of storing liquefied carbon dioxide that are not discharging liquefied carbon dioxide when some of the storage sections among the plurality of storage sections capable of storing liquefied carbon dioxide are discharging liquefied carbon dioxide; A step of sending liquefied carbon dioxide to any one of the plurality of storage sections after stopping the discharge of liquefied carbon dioxide from a part of the storage sections; and a step of measuring the liquefied carbon dioxide sent to the other storage sections while the liquefied carbon dioxide is being discharged from a portion of the storage sections after stopping the discharge of the liquefied carbon dioxide from the portion of the storage sections. Carbon dioxide capture methods.

11. In the step of measuring the liquefied carbon dioxide sent to the other storage sections while discharging the liquefied carbon dioxide from a portion of the storage sections, after stopping the discharging of the liquefied carbon dioxide from the portion of the storage sections, The liquefied carbon dioxide sent to some of the storage sections while the liquefied carbon dioxide is being discharged from the other storage sections and the liquefied carbon dioxide sent to any of the plurality of storage sections after the discharge of the liquefied carbon dioxide from some of the storage sections is stopped are combined and weighed at the time of the next discharge. The carbon dioxide recovery method according to claim 10.

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