Floating body and method for treating ammonia in the floating body

Abstract

To suppress the increase of a tank installation space, the increase of fuel consumption, and the burden increase of an operator while using ammonia as fuel.SOLUTION: This float comprises: a floating body; a dilution tank that is provided in the floating body and that stores an absorbent capable of absorbing ammonia; an ammonia introduction line through which the ammonia in the floating body can be introduced into the absorbent in the dilution tank; a diluted gas introduction line through which a diluted gas for lowering an ammonia concentration of a gas phase can be introduced into the gas phase in the dilution tank; a derivation line through which a gas in the gas phase in the dilution tank is derived from the dilution tank; an atmosphere releasing part that releases the gas derived from the dilution tank through the derivation line into the atmosphere; and a bypass line through which a fluid bypassing the dilution tank and flowing through the ammonia introduction line is guided to the atmosphere releasing part.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a floating body and a method for treating ammonia in the floating body.

Background Art

[0002] In a floating body such as a ship, when ammonia is used as fuel for a main engine or the like, it is assumed that other fuels such as light oil and ammonia are switched and used. In such a floating body that performs such fuel switching, ammonia remaining in the fuel system piping is purged by an inert gas and discharged from the fuel piping. Since ammonia discharged in this way and ammonia leaked inside the floating body may affect the surrounding environment, it is not preferable to directly release it into the water or the atmosphere around the floating body.

[0003] Patent Document 1 proposes a technique for preventing ammonia leakage to the outside of a compartment by providing a sealed duct communicating with the inside of the compartment, spraying water in this duct, absorbing ammonia in the water in the duct, and making the inside of the compartment negative pressure. In this Patent Document 1, the water that has absorbed ammonia is returned to the water tank and circulated through the sprinkler nozzles again, or discharged to other treatment facilities.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when ammonia is absorbed in water as in Patent Document 1, it is necessary to store the ammonia water that has absorbed ammonia inside the floating body. Therefore, when a large amount of ammonia water is generated, a large tank installation space is required inside the floating body. On the one hand, as a method of rendering ammonia harmless without absorbing it in water, there is a method of burning it in a combustion decontamination device. However, since the combustion decontamination device takes time to start up, in order to cope with ammonia emissions that occur irregularly such as emergency purges and need to be completed in a short time, a pilot flame is required at all times, resulting in increased fuel consumption. Furthermore, as a method of decontaminating ammonia, there is a method of using an acid such as dilute sulfuric acid. However, acids such as dilute sulfuric acid may be difficult to obtain at ports of call or mooring locations, etc., and there is also a problem that the burden on workers increases because they require skill in handling.

[0006] The present disclosure has been made in view of the above circumstances, and when using ammonia as a fuel, it is an object to provide a floating body and a method for treating ammonia of the floating body capable of suppressing an increase in the size of the decontamination device, an increase in the tank installation space, an increase in fuel consumption, and an increase in the burden on workers.

Means for Solving the Problems

[0007] In order to solve the above problems, the following configuration is adopted. According to a first aspect of the present disclosure, a floating body includes a floating body main body, a dilution tank provided in the floating body main body and storing an absorption liquid capable of absorbing ammonia, an ammonia introduction line capable of introducing ammonia in the floating body main body into the absorption liquid of the dilution tank, a dilution gas introduction line capable of introducing a dilution gas for reducing the ammonia concentration in the gas phase of the dilution tank into the gas phase of the dilution tank, a derivation line for deriving the gas in the gas phase of the dilution tank from the dilution tank, an atmosphere release part for discharging the gas derived from the dilution tank through the derivation line to the atmosphere, and a bypass line for bypassing the dilution tank and guiding the ammonia gas in the introduction line to the atmosphere release part.

[0008] According to a second aspect of the present disclosure, a method for treating ammonia of a floating body, when purging ammonia from the system through which the ammonia flows supplies the discharged fluid to a dilution tank and mixes it with the absorption liquid stored in the dilution tank, and a purge step of discharging the gas in the gas phase of the dilution tank to the atmosphere, and the ammonia Emergency purgeincluding an emergency purge process In the emergency purge process, with the gas in the gas phase of the dilution tank not being discharged from the dilution tank, a fluid discharged from the system through which the ammonia flows is supplied to the dilution tank and mixed with the absorption liquid stored in the dilution tank in an absorption step; and after the absorption step, in order to depressurize the system through which the ammonia flows to a predetermined pressure, the dilution tank is bypassed and vented to the atmosphere without supplying the fluid discharged from the system through which the ammonia flows to the dilution tank. The emergency purge process includes an atmospheric discharge step 。

Advantages of the Invention

[0009] According to the floating body and the ammonia treatment method of the floating body, when ammonia is used as fuel, it is possible to suppress the enlargement of the decontamination device, the increase in the tank installation space, the increase in fuel consumption, and the increase in the burden on workers.

Brief Description of the Drawings

[0010]

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[0011] Hereinafter, a floating body and an ammonia treatment method for the floating body according to embodiments of the present disclosure will be described with reference to the drawings. [First Embodiment] (Configuration of the Floating Body) FIG. 1 is a diagram showing a schematic configuration of a floating body in an embodiment of the present disclosure. As shown in FIG. 1, the floating body 1 of this embodiment includes a floating body main body 2, an upper structure 4, a combustion device 8, an ammonia tank 10, a piping system 20, a compartment 30, and an ammonia treatment device 60. Note that the floating body 1 of this embodiment will be described by taking a ship that can navigate by a main engine or the like as an example. The ship type when the floating body 1 is a ship is not limited to a specific ship type. Examples of the ship type include, for example, a liquefied gas carrier, a ferry, a RORO ship, an automobile carrier, a passenger ship, and the like. Further, examples of the floating body 1 that is not a ship include an FSU (Floating Storage Unit) and an FSRU (Floating Storage and Regasification Unit).

[0012] The floating body main body 2 has a pair of side hulls 5A and 5B forming its outer shell and a bottom hull 6. The side hulls 5A and 5B include a pair of side hull outer plates forming the left and right side hulls respectively. The bottom hull 6 includes a bottom hull outer plate connecting these side hulls 5A and 5B. With these pair of side hulls 5A and 5B and the bottom hull 6, the outer shell of the floating body main body 2 forms a U shape in a cross section orthogonal to the bow-stern direction FA.

[0013] The floating body main body 2 further includes a upper deck 7 which is an all-through deck arranged at the uppermost layer. The superstructure 4 is formed on this upper deck 7. Living quarters and the like are provided inside the superstructure 4. In the floating body 1 of the present embodiment, for example, a cargo space (not shown) for loading cargo is provided on the bow 3a side in the fore-and-aft direction FA rather than the superstructure 4.

[0014] The combustion device 8 is a device that generates thermal energy by burning fuel, and is provided inside the floating body main body 2 described above. Examples of the combustion device 8 include an internal combustion engine used as a main engine for propelling the floating body 1, an internal combustion engine used for a power generation facility that supplies electricity to the ship, a boiler that generates steam as a working fluid, and the like. The combustion device 8 used as the main engine in the floating body 1 of the present embodiment can switch between using ammonia as fuel and other fuels such as light oil different from ammonia.

[0015] The ammonia tank 10 is a tank that stores liquid ammonia (hereinafter referred to as liquefied ammonia). In the floating body 1 of this embodiment, the ammonia tank 10 is installed on the upper deck 7 on the stern 3b side rather than the superstructure 4. This arrangement of the ammonia tank 10 is an example and is not limited to the upper deck 7 on the stern 3b side rather than the superstructure 4. The ammonia tank 10 of the present embodiment stores liquefied ammonia as fuel for the combustion device 8.

[0016] The piping system 20 connects the combustion device 8 and the ammonia tank 10, and is configured to be able to supply at least the liquefied ammonia stored in the ammonia tank 10 to the combustion device 8. The piping system 20 includes at least ammonia-related equipment and fuel piping. Here, the ammonia-related equipment means all equipment that handles ammonia, and examples thereof include ammonia fuel equipment that handles ammonia and ammonia cargo equipment that handles ammonia as cargo.

[0017] Compartment 30 houses at least ammonia-related equipment in the piping system 20. That is, the piping system 20 described above connects the combustion device 8 and the ammonia tank 10 via Compartment 30. In this embodiment, among the ammonia fuel equipment and the ammonia cargo equipment, the case where Compartment 30 houses the ammonia fuel equipment will be described as an example, but Compartment 30 may be a compartment that houses the ammonia cargo equipment.

[0018] Examples of Compartment 30 that houses ammonia fuel equipment include an ammonia fuel supply device room, an ammonia fuel pressure regulating valve room, and an ammonia fuel intake room (in other words, a bunker station). Examples of the ammonia fuel equipment housed in the ammonia fuel supply device room include, for example, a pump that pumps ammonia from the ammonia tank 10 to the combustion device 8, a heat exchanger for heating the ammonia sent to the combustion device 8, an electric valve, a mixing tank, a catch tank, an evaporator, etc. Examples of the ammonia fuel equipment housed in the ammonia fuel pressure regulating valve room include, for example, a fuel pressure regulating device that regulates ammonia as fuel. Further, examples of the ammonia fuel equipment housed in the ammonia fuel intake room include, for example, a gas manifold. The Compartment 30 illustrated in this embodiment is not limited to the above ammonia fuel supply device room, ammonia fuel pressure regulating valve room, and ammonia fuel intake room as long as it is a compartment that houses ammonia fuel equipment. In the following description, the case where the floating body 1 has an ammonia fuel supply device room 30A (see FIG. 3) and an ammonia fuel intake room 30B (see FIG. 3) as Compartment 30 will be described as an example.

[0019] FIG. 2 is a diagram showing a schematic configuration of a piping system and an inert gas supply device in the first embodiment of the present disclosure. As shown in FIG. 2, the piping system 20 that connects the combustion device 8 as the main unit and the ammonia tank 10 includes at least a first supply pipe 21A, a mixing tank 40, a second supply pipe 21B, a return pipe 22, on-off valves 23, 24, and a high-pressure pump 25.

[0020] The mixing tank 40 is capable of temporarily storing the liquefied ammonia supplied from the ammonia tank 10 via the first supply pipe 21A. The second supply pipe 21B and the return pipe 22 connect the mixing tank 40 and the combustion device 8 respectively. The second supply pipe 21B supplies the liquefied ammonia in the mixing tank 40 to the combustion device 8. The return pipe 22 returns the surplus ammonia that has not been used as fuel in the combustion device 8 to the mixing tank 40. The high-pressure pump 25 is provided in the second supply pipe 21B to pump the liquefied ammonia toward the combustion device 8. A heat exchanger (not shown) for cooling the ammonia returned to the mixing tank 40 may be provided in the return pipe 22.

[0021] The on-off valve 23 is provided in the second supply pipe 21B. The on-off valve 24 is provided in the return pipe 22. These on-off valves 23, 24 are always in the open state during the operation of the combustion device 8. On the other hand, the on-off valves 23, 24 are in the closed state when the combustion device 8 is stopped or the like. By setting these on-off valves 23, 24 in the closed state, the flow paths formed inside the second supply pipe 21B and the return pipe 22 are blocked. In the present embodiment, an inert gas supply device 50 is connected to the second supply pipe 21B.

[0022] The inert gas supply device 50 performs so-called purging to replace the ammonia remaining in the flow path R through which ammonia flows with an inert gas (purging gas) such as nitrogen when switching the fuel of the combustion device 8 from ammonia to another fuel or performing maintenance. The inert gas supply device 50 includes an inert gas supply section 51, an inert gas supply pipe 52, and an inert gas supply valve 53. Here, as the inert gas, for example, an inert gas generated inside the floating body 2 by an inert gas generator (not shown) or an inert gas previously stored in an inert gas tank (not shown) provided in the floating body 2 can be used. The inert gas only needs to be a gas that does not chemically react when it comes into contact with ammonia. For example, nitrogen can be exemplified.

[0023] The inert gas supply section 51 supplies the inert gas to the inert gas supply pipe 52. The inert gas supply pipe 52 connects the inert gas supply unit 51 and the flow path R through which ammonia flows. More specifically, the inert gas supply pipe 52 connects the inert gas supply unit 51 and the purge target area 20p of the piping system 20. In the present embodiment, a case is exemplified in which the second supply pipe 21B on the combustion device 8 side of the on-off valve 23, the return pipe 22 on the combustion device 8 side of the on-off valve 24, and the flow path R formed in the combustion device 8 are the purge target area 20p.

[0024] The inert gas supply valve 53 is provided in the inert gas supply pipe 52. The inert gas supply valve 53 is normally in a closed state, blocking the supply of inert gas from the inert gas supply unit 51 to the purge target area 20p. Here, the normal time is when the combustion device 8 is operating with ammonia as fuel, etc., when ammonia can be supplied to the combustion device 8. In this normal time, the on-off valves 23 and 24 are in an open state, and ammonia can be supplied from the mixing tank 40 to the combustion device 8 through the second supply pipe 21B. Also, among the ammonia supplied to the combustion device 8, the excess ammonia is returned to the mixing tank 40 through the return pipe 22.

[0025] The inert gas supply valve 53 is changed from a closed state to an open state when the combustion device 8 is in an emergency stop, a long-term stop, maintenance, etc. In other words, the inert gas supply valve 53 is operated from a closed state to an open state when purging the ammonia remaining in the purge target area 20p. At this time, the supply of liquefied ammonia from the mixing tank 40 to the combustion device 8 is stopped. Thereby, inert gas can be supplied from the inert gas supply unit 51 to the purge target area 20p. For example, at the initial stage of purging, the liquefied ammonia remaining in the purge target area 20p may be returned to the mixing tank 40 by a line (not shown) for returning the liquefied ammonia.

[0026] The residual ammonia supply line 26 guides the liquefied ammonia purged by the inert gas supply device 50, the liquefied ammonia purged by the inert gas supply device 50, the mixed fluid of ammonia gas and inert gas to the ammonia treatment device 60. The residual ammonia supply line 26 includes a pipe 27 and an on-off valve 28. The pipe 27 connects the return pipe 22 and the ammonia treatment device 60. The on-off valve 28 is normally in a closed state and is operated from the closed state to the open state when purging is performed by the inert gas supply device 50.

[0027] In the above description, the case where the residual ammonia supply line 26 is branched and connected to the return pipe 22 is exemplified. However, the residual ammonia supply line 26 may be branched and connected to the second supply pipe 21B. Also, a plurality of residual ammonia supply lines 26 may be provided so that these residual ammonia supply lines 26 are branched and connected to both the second supply pipe 21B and the return pipe 22. Further, a plurality of residual ammonia supply lines 26 may be connected to the second supply pipe 21B and the return pipe 22.

[0028] In the description of the purging of residual ammonia by the above-described inert gas supply device 50, the case of purging the purging target region 20p of the piping system 20 between the mixing tank 40 and the main combustion device 8 in the piping system 20 has been described. However, in the floating body main body 2, there may be a case where a plurality of combustion devices 8 such as a generator and a boiler are provided. In such a case, in the floating body main body 2, the ammonia remaining in the piping system 20 between these plurality of combustion devices 8 and the ammonia tank 10 can also be purged by the inert gas supply device 50 in the same manner as above. In such a case, the ammonia purged from the piping system 20 that supplies fuel to the generator, boiler, etc. is also introduced into the ammonia treatment device 60 in the same manner as above. Note that the ammonia purged by the inert gas supply device 50 is not limited to liquefied ammonia and may be ammonia gas.

[0029] In this embodiment, the inert gas supply device 50 is capable of supplying an inert gas into tanks such as the mixing tank 40 that store ammonia. And these tanks are connected to a tank opening line 29 that guides the internal gas to the ammonia treatment device 60. By configuring in this way, when opening the tanks such as the mixing tank 40 for maintenance, the gas containing ammonia gas inside is replaced with an inert gas, and the gas containing ammonia gas inside can be introduced into the ammonia treatment device 60 via the tank opening line 29. The tank opening line 29 has the same configuration as the above-mentioned residual ammonia supply line 26 and includes a pipe 27 and an on-off valve 28.

[0030] In the ammonia fuel supply device chamber 30A, an ammonia fuel device such as a mixing tank 40, a part of the second supply pipe 21, a part of the return pipe 22, a high-pressure pump 25, and on-off valves 23, 24, etc. are accommodated. In the compartment 30, a spraying device 31, a decontamination fan, and a ventilation fan are provided respectively. The spraying device 31 sprays an absorbent liquid capable of absorbing ammonia into the compartment 30.

[0031] The spraying device 31 of this embodiment sprays the absorbent liquid, for example, in a shower shape from the upper part near the ceiling in the internal space of the compartment 30. The sprayed absorbent liquid moves downward from the upper part of the internal space of the compartment 30 by gravity. If ammonia leaks into the internal space of the compartment 30, the absorbent liquid contacts the leaked ammonia and absorbs the ammonia. Then, the absorbent liquid that has absorbed ammonia reaches the floor surface of the compartment 30. Note that the internal space of the compartment 30 means the indoor space where ammonia-related equipment is installed and does not include the inside of the ammonia-related equipment.

[0032] The decontamination fan 32 sends the gas in the internal space of the compartment 30 to the ammonia treatment device 60. The ventilation fan 33 is a fan for ventilating the compartment 30 and discharges the gas in the internal space of the compartment 30 to the outside.

[0033] In the above description, the ammonia fuel supply device chamber 30A is taken as an example of the section 30 in which ammonia leakage may occur, but the section 30 in which ammonia leakage may occur is not limited to the ammonia fuel supply device chamber 30A. For example, sections 30 such as an ammonia fuel pressure regulating valve chamber in which a valve unit of a fuel pipe that supplies ammonia as fuel to the combustion device 8 of the generator is disposed, and an ammonia fuel intake chamber (bunker station) 30B are also provided with a spraying device 31, an abatement fan 32, and a ventilation fan 33, similar to the ammonia fuel supply air chamber.

[0034] In this embodiment, the second supply pipe 21B and the return pipe 22 between the ammonia fuel supplying device chamber 30A and the combustion device 8 as the main unit are double-walled pipes. An air intake duct 34 for ventilation is connected to the space between the outer and inner tubes of the double-walled pipes, and the space between the outer and inner tubes of the double-walled pipes is connected to the inner space of the ammonia fuel supplying device chamber 30A. The position of the air intake duct 34 is not limited to the above position, and for example, ventilation air may be directly introduced into the ammonia fuel supplying device chamber 30A. The space between the outer and inner tubes of the double-walled pipes may be ventilated separately without being connected to the ammonia fuel supplying device chamber 30A.

[0035] FIG. 3 is a diagram showing a schematic configuration of an ammonia treatment apparatus according to the first embodiment of the present disclosure. The ammonia treatment device 60 treats ammonia purged by the inert gas supply device 50 and ammonia leaked from the section 30. As shown in Fig. 3, the ammonia treatment device 60 includes an ammonia introduction line 61, a knockout drum 62, a mixing section 63, a dilution tank 64, a diluted gas introduction line 65, an outlet line 66, a bypass line 67, a diluted absorption liquid discharge line 68, an ammonia waste liquid tank 69, a combustion abatement device 70, a diluted combustion line 71, a section combustion line 72, a section opening line 73, a section liquid discharge line 74, an ammonia liquid bilge tank 75, and a landing line 76.

[0036] The ammonia introduction line 61 is a line for introducing the ammonia purged by the above-mentioned inert gas supply device 50 into the dilution tank 64. The fluid flowing through this ammonia introduction line 61 changes during the initial, middle, and final stages of purging. For example, liquefied ammonia flows during the initial stage of purging, and a mixed fluid of liquefied ammonia, ammonia gas, and inert gas flows during the intermediate stage of purging. Then, substantially only inert gas flows during the final stage of purging.

[0037] The knock out drum 62 is provided midway through the ammonia introduction line 61. The knock out drum 62 separates the fluid flowing through the ammonia introduction line 61 into gas and liquid, and discharges the gas. In other words, the liquid is removed by the knock out drum 62, and only the gas is introduced into the mixing section 63 via the ammonia introduction line 61. The removed liquid is stored in the knock out drum 62, and is gradually vaporized and discharged from the knock out drum 62.

[0038] The mixing section 63 is provided in the middle of the ammonia introduction line 61. The mixing section 63 mixes the ammonia in the ammonia introduction line 61 with the absorbing liquid capable of absorbing the ammonia stored in the dilution tank 64. The mixing section 63 of this embodiment includes a mixer 77, an absorbing liquid supply line 78, and an absorbing liquid circulation pump 79. The mixer 77 mixes the gas discharged from the knockout drum 62 with the absorbing liquid before being introduced into the dilution tank 64. For example, an ejector or a microreactor can be used as the mixer 77. By mixing in this way by the mixer 77, the ammonia gas contained in the gas discharged from the knockout drum 62 becomes easily absorbed by the absorbing liquid. The absorbing liquid supply line 78 supplies the absorbing liquid in the dilution tank 64 to the mixer 77. The absorbing liquid circulation pump 79 sends the absorbing liquid in the absorbing liquid supply line 78 toward the mixer 77. The mixed fluid mixed by the mixing section 63 is introduced into the dilution tank 64.

[0039] The dilution tank 64 is provided in the floating body main body 2 and stores an absorption liquid capable of absorbing ammonia. Examples of the absorption liquid include the water (seawater and fresh water) around the floating body main body 2 and the fresh water stored in the fresh water tank of the floating body main body 2. In the dilution tank 64, an absorption liquid (liquid phase) and a gas phase exist. The dilution tank 64 of the present embodiment is an atmospheric pressure tank, and the pressure of the gas phase is atmospheric pressure. However, for example, in order to increase the ammonia solubility, the inside of the dilution tank 64 may be set to a pressure higher than the atmospheric pressure.

[0040] At the outlet end of the ammonia introduction line 61 described above, an air diffuser pipe 80 for discharging the gas contained in the mixed fluid as small bubbles is provided. The air diffuser pipe 80 extends along the bottom of the dilution tank 64 in the liquid phase of the dilution tank 64, and the bubbles contained in the mixed fluid discharged from the air diffuser pipe 80 spread throughout the absorption liquid in the dilution tank 64. Thereby, the ammonia gas contained in the mixed fluid comes into contact with the absorption liquid in the dilution tank 64, and the ammonia gas is easily absorbed by the absorption liquid in the dilution tank 64. Note that the dilution tank 64 may use a ballast tank provided in the floating body main body 2, a seawater tank provided separately from the ballast tank, or a fresh water tank.

[0041] The dilution gas introduction line 65 is capable of introducing a dilution gas for reducing the ammonia concentration in the gas phase into the gas phase of the dilution tank 64. In other words, the dilution gas introduction line 65 can adjust the concentration of ammonia gas in the gas phase of the dilution tank 64. Examples of the dilution gas include outside air. The dilution gas introduction line 65 is provided with a dilution fan 81 capable of adjusting the flow rate of the dilution gas sent into the gas phase of the dilution tank 64. In addition, an absorption liquid replenishment line 82 capable of replenishing the absorption liquid into the dilution tank 64 from the outside is connected to the dilution tank 64.

[0042] The gas phase in the dilution tank 64 and the absorption liquid (liquid phase) tend to reach a gas-liquid equilibrium state. That is, as the ammonia solubility in the absorption liquid increases, the ammonia concentration in the gas phase also gradually increases. On the other hand, when the ammonia concentration in the gas phase decreases, ammonia in the liquid phase is diffused by the partial pressure difference and sequentially supplied to the gas phase, so the ammonia solubility in the liquid phase decreases.

[0043] The lead-out line 66 leads out the gas in the gas phase of the dilution tank 64 from the dilution tank 64. The lead-out line 66 of the present embodiment is connected to the atmosphere release part 83. The atmosphere release part 83 releases the gas led out from the dilution tank 64 by the lead-out line 66 to the atmosphere. As the atmosphere release part 83, for example, a vent post provided on the upper deck 7 of the floating body main body 2 or the like can be used.

[0044] The bypass line 67 bypasses the dilution tank 64 and guides the fluid flowing through the ammonia introduction line 61 to the atmosphere release part 83. The bypass line 67 of the present embodiment branches from the ammonia introduction line 61 on the side closer to the residual ammonia supply line 26 than the knock-out drum 62 in the ammonia introduction line 61 and merges into the lead-out line 66. The bypass line 67 only needs to be configured to be able to bypass the dilution tank 64 and guide the fluid to the atmosphere release part 83, and is not limited to the configuration of merging into the lead-out line 66. For example, the bypass line 67 may be directly connected to the atmosphere release part 83.

[0045] The diluted absorption liquid discharge line 68 is capable of discharging the absorption liquid in the dilution tank 64. The diluted absorption liquid discharge line 68 of the present embodiment can allow the absorption liquid in the dilution tank 64 to flow into the ammonia waste liquid tank 69 by using gravity. The discharge of the absorption liquid by the diluted absorption liquid discharge line 68 is not limited to the discharge of the absorption liquid by gravity. For example, a pump may be provided in the diluted absorption discharge line to discharge the absorption liquid in the dilution tank 64.

[0046] The ammonia waste liquid tank 69 stores the absorption liquid discharged from the dilution tank 64. The absorption liquid stored in the ammonia waste liquid tank 69 becomes the absorption liquid that has absorbed ammonia. The ammonia waste liquid tank 69 of the present embodiment is connected to a landing line 76 shared with an ammonia liquid build-up tank 75 described later.

[0047] The combustion decontamination device 70 combusts and decontaminates the gas containing ammonia. The combustion decontamination device 70 decontaminates ammonia by burning it using a fuel such as light oil. The decontaminated gas is discharged into the atmosphere through, for example, a funnel (not shown) provided in the floating body main body 2.

[0048] The dilution combustion line 71 guides the gas in the gas phase of the dilution tank 64 to the combustion decontamination device 70. The dilution combustion line 71 exemplified in the present embodiment is branched and connected to the lead-out line 66, and the lead-out destination of the gas in the gas phase of the dilution tank 64 can be switched between the atmosphere release part 83 and the combustion decontamination device 70 by valves 84 and 85. Note that the dilution combustion line 71 may be directly connected to the dilution tank 64 and the combustion decontamination device 70 without passing through the lead-out line 66.

[0049] The compartment combustion line 72 guides the gas inside the compartment 30 to the combustion decontamination device 70. The compartment combustion line 72 exemplified in the present embodiment is connected in a confluent manner to the dilution combustion line 71. The compartment combustion line 72 is provided with a suction fan 86 for sucking the gas inside the compartment 30 and a check valve 87. The compartment combustion line 72 exemplified in the present embodiment is connected to the ammonia fuel supply device room 30A and the ammonia fuel intake room (bunker station) 30B one by one, and after two compartment combustion lines 72 merge, they are connected to the dilution combustion line 71.

[0050] The compartment opening line 73 guides the gas inside the compartment 30 to the atmosphere opening portion 83. The compartment opening line 73 exemplified in this embodiment is composed of the compartment combustion line 72 and a part of the diluted combustion line 71. Here, a part of the diluted combustion line 71 means a portion of the diluted combustion line 71 on the lead-out line 66 side from the position P1 where the compartment combustion line 72 is joined. That is, the gas inside the compartment 30 can be guided to the atmosphere opening portion 83 via the compartment combustion line 72, a part of the diluted combustion line 71, and the lead-out line 66. And by switching the above-described valves 84, 85 and the valve 88 of the lead-out line 66, the lead-out destination of the gas inside the compartment 30 can be switched between the atmosphere opening portion 83 and the combustion decontamination device 70.

[0051] The compartment liquid discharge line 74 discharges the absorption liquid sprayed into the compartment 30 by the spraying device 31 from the compartment 30. The compartment liquid discharge line 74 exemplified in this embodiment guides the absorption liquid discharged from the ammonia fuel supply device chamber 30A and the ammonia fuel intake chamber (bunker station) 30B to the ammonia liquid build-up tank 75 by gravity. Note that the compartment liquid discharge line 74 is not limited to the case of guiding the absorption liquid downward from the compartment 30 by gravity. For example, a pump (not shown) may be provided to guide the absorption liquid to the ammonia liquid build-up tank 75 located above the compartment 30.

[0052] The ammonia liquid build-up tank 75 stores the absorption liquid discharged by the compartment liquid discharge line 74. The landing line 76 is configured to be able to land the absorption liquid stored in the ammonia liquid building tank 75. As described above, the absorption liquid stored in the ammonia wastewater tank in the present embodiment is also configured to be able to be landed via the ammonia waste liquid line 89 and the landing line 76. Here, since the absorption liquid stored in the ammonia liquid building tank 75 is the absorption liquid sprayed in the compartment 30, for example, it may be contaminated by oil or the like adhering to the ammonia-related equipment in the compartment 30. Therefore, the absorption liquid stored in the ammonia liquid building tank 75 will be landed at a port or the like using the landing line 76 and disposed of at onshore facilities without being regenerated inside the floating body 2.

[0053] In the present embodiment, the landing line 76 is shared by the ammonia liquid building tank 75 and the ammonia waste liquid tank 69, and is provided with an ammonia waste liquid line 89 that communicates the ammonia waste liquid tank 69 and the landing line 76. Landing pumps 90 are provided in the ammonia waste liquid line 89 and the landing line 76, respectively. Further, a check valve 91 is provided in the ammonia waste liquid line 89 to prevent the liquid in the ammonia liquid building tank 75 from flowing back into the ammonia waste liquid tank 69.

[0054] (Ammonia treatment method) Next, the ammonia treatment method of the floating body in the present embodiment will be described with reference to the drawings. In the description of this ammonia treatment method, the crew of the floating body 1 makes judgments and operations.

[0055] FIG. 4 is a flowchart of the ammonia treatment method according to the first embodiment of the present disclosure. FIG. 5 is a flowchart of the purge step of FIG. 4. FIG. 6 is a flowchart of the leak decontamination step of FIG. 4. FIG. 7 is a flowchart of the emergency purge step of FIG. 4. FIG. 8 is a diagram corresponding to FIG. 3 in the case of combustion decontamination in the purge step. FIG. 9 is a diagram corresponding to FIG. 3 in the case of atmospheric discharge in the purge step. FIG. 10 is a diagram corresponding to FIG. 3 in the case of combustion decontamination of the gas in the ammonia fuel intake chamber in the leak decontamination step. FIG. 11 is a diagram corresponding to FIG. 3 in the case of combustion decontamination of the gas in the ammonia fuel supply device chamber in the leak decontamination step. FIG. 12 is a diagram corresponding to FIG. 3 in the case of atmospheric discharge of the gas in the ammonia fuel intake chamber in the leak decontamination step. FIG. 13 is a diagram corresponding to FIG. 3 in the case of atmospheric discharge of the gas in the ammonia fuel supply device chamber in the leak decontamination step. FIG. 14 is a diagram corresponding to FIG. 3 in the absorption step of the emergency purge step. FIG. 15 is a diagram corresponding to FIG. 3 in the atmospheric discharge step of the emergency purge step.

[0056] As shown in FIG. 4, in the ammonia treatment method of the present embodiment, it is determined whether it is a purge of ammonia with an inert gas or an ammonia leak in compartment 30 (step S01). As a result of this determination, if it is determined that there is an ammonia leak in compartment 30 ( "leak" in step S01), the process proceeds to the leak decontamination step (step S20). On the other hand, if it is determined that it is a purge of the piping system 20 ( "purge" in step S01), it is determined whether it is an emergency purge (step S02). As a result of this determination, if it is determined that it is not an emergency purge ( "No" in step S02), the process proceeds to the purge step (step S10). On the other hand, if it is determined that it is an emergency purge ( "Yes" in step S02), the process proceeds to the emergency purge step (step S30). Here, the emergency purge means a case where it is necessary to perform a purge of ammonia when the combustion decontamination device 70 cannot be started due to a power loss or a failure, or a case where the combustion device 8 stops emergency and a purge is required. In addition, in the emergency purge of the present embodiment, it is assumed that the absorption liquid circulation pump 79 and the dilution fan 81 that drive the mixer 77 do not operate due to a power loss, and further, the internal pressure of the knockout drum 62 does not decrease.

[0057] Next, it is determined whether the absorption liquid that has absorbed ammonia generated in the purge process (step S10), the leakage decontamination process (step S20), and the emergency purge process (step S30) can be landed (step S03). That is, it is determined whether the absorption liquid can be transferred from the floating body main body 2 to the onshore facilities. As a result of this determination, if it is determined that the absorption liquid can be landed (''Yes'' in step S03), the process proceeds to the landing process (step S04), and the absorption liquid stored in the ammonia waste liquid tank 69 and the ammonia liquid building tank 75 is landed via the landing line 76. If, as a result of the above determination, it is determined that the absorption liquid cannot be landed (''No'' in step S03), the above-described series of processes are repeated until landing becomes possible (return). Here, the cases where it is determined that landing is possible include, for example, cases where the floating body 1 is ashore or moored in the port and the onshore piping can be connected, or cases where it can be transferred to a ship equipped with a tank capable of recovering the absorption liquid.

[0058] As shown in FIG. 5, in the purge process (step S10), first, an absorption process (step S11) is performed. In this absorption process (step S11), ammonia discharged when purging ammonia is mixed with the absorption liquid stored in the dilution tank 64 to cause the absorption liquid to absorb ammonia. Next, it is determined whether the floating body 1 is within the emission control area (step S12). If it is determined by this determination that the floating body 1 is not within the emission control area (''No'' in step S12), the process proceeds to the non-combustion emission process (step S15). Here, the emission control area is a legally defined regulated area.

[0059] On the other hand, if it is determined that the floating body 1 is within the emission control area (''Yes'' in step S12), it is determined whether the emission control can be complied with only by the absorption process (step S11) (step S13). Here, the emission control is defined as the regulated value of the ammonia concentration released into the atmosphere within a predetermined emission control area (for example, within the port).

[0060] If it is determined that the emission regulations can be complied with based on the determination in step S13 (No in step S13), the process proceeds to the non-combustion emission process (step S15). On the other hand, if it is determined that the emission regulations cannot be complied with only by the absorption process (Yes in step S13), the process proceeds to the combustion emission process (step S14).

[0061] In the combustion emission process (step S14), the gas in the gas phase of the dilution tank 64 is subjected to combustion decontamination by the combustion decontamination device 70 and then released to the atmosphere. Specifically, as shown in FIG. 8, the gas in the gas phase of the dilution tank 64 is sent to the combustion decontamination device 70 through the lead-out line 66 and the dilution combustion line 71 from the dilution tank 64. Thereby, the ammonia contained in the gas in the gas phase of the dilution tank 64 is combusted and decontaminated, and the decontaminated gas is released to the atmosphere.

[0062] In the non-combustion emission process (step S15), the gas in the gas phase of the dilution tank 64 is released to the atmosphere from the atmosphere release section 83. Specifically, as shown in FIG. 9, the gas in the gas phase of the dilution tank 64 is sent to the atmosphere release section 83 through the lead-out line 66 from the dilution tank 64. Thereby, when the floating body 1 is in a place where it is not in the emission control area (for example, on the high seas, etc.) or when the emission regulations can be complied with only by the absorption process, the gas in the gas phase of the dilution tank 64 is released to the atmosphere from the atmosphere release section 83 and diffused. Here, since the ammonia concentration of the gas present in the gas phase of the dilution tank 64 is diluted by the dilution gas introduced from the dilution gas introduction line 65, the ammonia released to the atmosphere from the atmosphere release section 83 is sufficiently lower than the ammonia concentration of the fluid flowing through the ammonia introduction line 61.

[0063] As shown in FIG. 6, in the leakage decontamination process (step S20), first, the spraying process (step S21) is performed. In this spraying process, the absorption liquid is sprayed into the section 30 where the ammonia leakage is detected. The absorption liquid sprayed into the section 30 and absorbing ammonia is stored in the ammonia liquid build-up tank 75.

[0064] Next, it is determined whether the floating body 1 is within the emission control area (step S22). If it is determined by this determination that the floating body 1 is within the emission control area ( "No" in step S22), the process proceeds to the in-compartment gas non-combustion emission process (step S25). On the other hand, if it is determined that the floating body 1 is within the emission control area ( "Yes" in step S22), it is determined whether the emission control can be complied with only by the spraying process (step S23). If it is determined by this determination that the emission control cannot be complied with ( "No" in step S23), the process proceeds to the in-compartment gas non-combustion emission process (step S25). On the other hand, if it is determined by the above determination that the emission control can be complied with ( "Yes" in step S23), the process proceeds to the in-compartment gas combustion emission process (step S24).

[0065] In the in-compartment gas combustion emission process (step S24), the gas in the compartment 30 where the absorption liquid has been sprayed by the spraying process (step S21) is subjected to combustion decontamination by the combustion decontamination device 70 and then released into the atmosphere, and the process returns to step S03 of FIG. 4 described above. Specifically, in the in-compartment gas combustion emission process, as shown in FIGS. 10 and 11, the gas in the compartment 30 is sent into the combustion decontamination device 70 from the compartment 30 through the compartment combustion line 72 and the dilution combustion line 71. Thereby, when the emission control cannot be complied with only by the spraying process within the emission control area, the ammonia contained in the gas in the compartment 30 burns and is decontaminated, and the decontaminated gas is released into the atmosphere.

[0066] In the in-compartment gas non-combustion emission process (step S25), the gas in the compartment 30 where the absorption liquid has been sprayed by the spraying process (step S21) is released into the atmosphere from the atmosphere release section 83, and the process returns to step S03 of FIG. 4 described above. Specifically, in the in-compartment gas non-combustion emission process, as shown in FIGS. 12 and 13, the gas in the compartment 30 is sent into the atmosphere release section 83 from the compartment 30 through the compartment combustion line 72, the dilution combustion line 71, and the lead-out line 66. Thereby, when the floating body 1 is in a place outside the emission control area (for example, on the high seas, etc.) or when the emission control can be complied with only by the spraying process, the gas in the compartment 30 is released into the atmosphere from the atmosphere release section 83 and diffused.

[0067] As shown in FIG. 7, in the emergency purge process (step S30), first, an absorption process (step S31) is performed. In this absorption process (step S31), as shown in FIG. 14, the fluid introduced through the ammonia introduction line 61 is mixed with the absorption liquid stored in the dilution tank 64. As a result, the ammonia contained in the fluid introduced through the ammonia introduction line 61 is absorbed by the absorption liquid in the dilution tank 64. Here, the gas in the gas phase of the dilution tank 64 is not discharged from the dilution tank 64. Therefore, the ammonia concentration of the gas in the gas phase gradually increases and becomes saturated. Then, as the pressure in the dilution tank 64 increases and the ammonia solubility of the absorption liquid becomes saturated, no more ammonia can be absorbed into the absorption liquid in the dilution tank 64.

[0068] Next, it is determined whether or not there is an increase in the internal pressure of the dilution tank 64 (step S32). As a result of this determination, if it is determined that there is an increase in the internal pressure of the dilution tank 64 (''No'' in step S32), the process proceeds to the atmosphere release process (step S34). On the other hand, as a result of the above determination, if there is no increase in the internal pressure of the dilution tank 64 (''Yes'' in step S32), it is determined whether or not the pressure in the exclusion target range, which is the purge target area 20p, has been reduced to a predetermined pressure within the limit time (step S33). As a result of this determination, if it is determined that the pressure in the exclusion target range has not been reduced to the predetermined pressure within the limit time (''No'' in step S33), the process proceeds to the atmosphere release process (step S34). On the other hand, as a result of the above determination, if it is determined that the pressure in the exclusion target range has been reduced to the predetermined pressure within the limit time (''Yes'' in step S33), the emergency purge process (step S30) is terminated and the process returns to step S03 described above. Here, the above limit time is a time set in advance according to the specifications of the combustion device 8 and the like, and can be, for example, the time during which the pressure balance that can prevent ammonia from mixing into systems other than ammonia can be maintained inside the combustion device 8.

[0069] In the atmosphere discharge step (step S34), as shown in FIG. 15, the fluid (in other words, the exhaust gas) introduced through the ammonia introduction line 61 is led to the atmosphere discharge section 83 and discharged to the atmosphere without passing through the dilution tank 64, and the process returns to step S03 of FIG. 4 described above. Here, the fluid introduced into the dilution tank 64 in the absorption step (step S31) is the fluid in the initial or middle stage of the purge described above, and the fluid discharged to the atmosphere bypassing the dilution tank 64 in the atmosphere discharge step (step S34) is the fluid in the final stage of the purge. That is, the fluid discharged to the atmosphere in the atmosphere discharge step (step S34) is substantially only inert gas and contains almost no ammonia.

[0070] (Function and effect) According to the first embodiment described above, after the ammonia in the fluid introduced into the dilution tank 64 by the ammonia introduction line 61 is absorbed by the absorption liquid in the dilution tank 64, it can be gradually dissipated into the gas phase of the dilution tank 64 due to the partial pressure difference. Then, a dilution gas can be supplied to the gas phase of the dilution tank 64 through the dilution gas introduction line 65 to dilute the ammonia in the gas phase. Then, the gas diluted by the dilution tank 64 can be led to the atmosphere discharge section 83 through the lead-out line 66 and discharged to the atmosphere. Therefore, a large tank installation space for storing the absorption liquid that has absorbed ammonia is not required.

[0071] Furthermore, since the gas in the gas phase of the dilution tank 64 can be led to the combustion decontamination device 70 through the dilution combustion line 71 and decontaminated by combustion by the combustion decontamination device 70, when performing planned fuel purge in an emission control area such as in a port, the gas in the gas phase of the dilution tank 64 can be burned by the combustion decontamination device 70, and the concentration of ammonia contained in the fluid discharged to the atmosphere can be more reliably reduced.

[0072] In addition, the gas inside the compartment 30 can be guided to the combustion decontamination device 70 by the compartment combustion line 72 and to the atmosphere release section 83 by the compartment opening line 73. Therefore, when ammonia leaks into the compartment 30, combustion decontamination by the combustion decontamination device 70 and atmospheric release by the atmosphere release section 83 can be switched and used.

[0073] Therefore, in an emission control area such as a port where the gas released to the atmosphere may come into contact with the human body, the combustion decontamination device 70 can ensure that the ammonia concentration of the gas released to the atmosphere is sufficiently reduced. On the other hand, on the high seas where the gas released to the atmosphere does not come into contact with the human body, the gas diluted by the dilution tank 64 can be released to the atmosphere and diffused without using the combustion decontamination device 70, so that the fuel consumption can be reduced.

[0074] Furthermore, according to the first embodiment, the bypass line 67 can bypass the dilution tank 64 and guide the fluid flowing through the ammonia introduction line 61 to the atmosphere release section 83. Therefore, after the absorption liquid in the dilution tank 64 has absorbed as much ammonia as possible, the dilution tank 64 can be bypassed and the fluid flowing through the ammonia introduction line 61 can be guided to the atmosphere release section 83. As a result, it is not necessary to keep the combustion decontamination device 70 constantly activated for emergency purging. Also, by bypassing the dilution tank 64 with the bypass line 67, an increase in back pressure to the purge target area 20p due to an increase in the internal pressure inside the dilution tank 64 can be suppressed, and the pressure can be reduced to a predetermined pressure or less. Furthermore, since it is not necessary to bring all the gas discharged by the emergency purge into contact with the absorption liquid, the amount of absorption liquid used can be reduced. Also, acids such as dilute sulfuric acid for decontaminating ammonia are no longer required. Furthermore, during emergency purging, after guiding ammonia to the dilution tank 64, the fluid flowing through the ammonia introduction line 61 can be guided to the atmosphere release section 83 by the bypass line 67, so that the pressure of the inert gas due to purging can be quickly reduced. Therefore, an increase in the tank installation space for storing the absorption liquid, an increase in fuel consumption by the combustion decontamination device 70, and an increase in the burden on the operator due to handling of acids can be suppressed.

[0075] Furthermore, according to the first embodiment, the ammonia in the ammonia introduction line 61 and the absorbing liquid stored in the dilution tank 64 can be mixed by the mixing section 63 provided in the middle of the ammonia introduction line 61, so that the ammonia can be efficiently absorbed into the absorbing liquid stored in the dilution tank 64.

[0076] According to the first embodiment, the heat exchanger 92 is provided at the outlet of the mixer 63, so that it is possible to suppress a temperature rise in the dilution tank 64 caused by the heat of absorption when the absorbing liquid absorbs ammonia. Therefore, it is possible to keep the solubility of ammonia as high as possible.

[0077] Furthermore, according to the first embodiment, the knockout drum 62 provided in the ammonia introduction line 61 can separate the gas-liquid mixed fluid discharged during purging into gas and liquid, and discharge the gas, so that only ammonia gas and inert gas can be introduced into the dilution tank 64. This allows the dilution tank 64 to function more stably.

[0078] Furthermore, according to the first embodiment, the absorbing liquid in the dilution tank 64 can be discharged through the diluted absorbing liquid discharge line 68, and the absorbing liquid discharged from the dilution tank 64 can be stored in the ammonia waste liquid tank 69. This allows the absorbing liquid that has absorbed ammonia to be discharged from the dilution tank 64, making it possible to replenish the dilution tank 64 with absorbing liquid that has not absorbed ammonia. Therefore, the amount of ammonia that can be absorbed by the absorbing liquid can be increased without increasing the size of the dilution tank 64.

[0079] Furthermore, according to the first embodiment, the absorbing liquid stored in the ammonia liquid bilge tank 75 and the ammonia waste liquid tank 69 can be unloaded by the unloading line 76, so that the absorbing liquid that has absorbed ammonia inside the floating body 2 can be treated in a treatment facility on land. Therefore, there is no need to provide equipment for disposing of the absorbing liquid stored in the ammonia liquid bilge tank 75 and the ammonia waste liquid tank 69.

[0080] [Second embodiment] Next, a floating body and an ammonia treatment method for a floating body according to a second embodiment of the present disclosure will be described with reference to the drawings. In this second embodiment, a reactor is added to the floating body 1 of the first embodiment described above. Therefore, FIG. 1 will be used to describe the same parts as those in the first embodiment described above, with the same reference numerals assigned, and duplicated descriptions will be omitted.

[0081] The float 101 in this second embodiment, like the float 1 in the first embodiment described above, is equipped with a float body 2, an upper structure 4, a combustion device 8, an ammonia tank 10, a piping system 20, a compartment 30, and an ammonia treatment device 160.

[0082] FIG. 16 is a diagram showing a schematic configuration of an ammonia treatment apparatus according to the second embodiment of the present disclosure. As shown in FIG. 16, the ammonia treatment device 160 in the second embodiment includes an ammonia introduction line 61, a knockout drum 62, a mixing section 63, a dilution tank 64, a diluted gas introduction line 65, an outlet line 166, a bypass line 67, a diluted absorption liquid discharge line 68, an ammonia waste liquid tank 69, a combustion abatement device 70, a diluted combustion line 171, a compartment combustion line 72, a compartment opening line 73, a compartment liquid discharge line 74, an ammonia liquid bilge tank 75, a landing line 76, a reactor 95, an absorption liquid supply section 96, a reactor absorption liquid discharge line 97, a waste liquid tank introduction line 98, and a compartment reactor introduction line 99.

[0083] The extraction line 166 extracts the gas in the gas phase of the dilution tank 64 from the dilution tank 64. The gas extracted by the extraction line 166 is led to the atmosphere release section 83. The extraction line 166 of the present embodiment includes a first extraction line 166A connected to the dilution tank 64 and a second extraction line 166B connected to the atmosphere release section 83.

[0084] The dilution combustion line 171 guides the gas in the gas phase of the dilution tank 64 to the combustion decontamination device 70. The dilution combustion line 171 is branched and connected to the second extraction line 166B among the extraction lines 166. That is, the dilution combustion line 171 is configured to be able to introduce the gas discharged from the reactor 95 to the second extraction line 166B into the combustion decontamination device 70.

[0085] The reactor 95 is provided in the middle of the extraction line 166 and generates an absorption liquid that has absorbed ammonia by reacting the ammonia gas contained in the gas extracted from the dilution tank 64 with an absorption liquid capable of absorbing the ammonia gas. Examples of the reactor 95 include an absorption tower and a microreactor. The reactor 95 exemplified in the present embodiment is an absorption tower.

[0086] The reactor 95 includes a hollow container extending vertically. The reactor 95 allows the absorption liquid to flow down from the upper part of the internal space of the hollow container, so that the gas introduced from the upper and lower middle parts of the hollow container comes into contact with the absorption liquid, and the ammonia contained in the gas is absorbed by the absorption liquid. The absorption liquid that has absorbed ammonia is discharged from the bottom of the hollow container. Also, the gas from which ammonia has been absorbed is discharged from the upper part of the hollow container. In the present embodiment, the first extraction line 166A is connected to the upper and lower middle part of the reactor 95, and the second extraction line 166B is connected to the upper part of the reactor 95.

[0087] The absorbent supply unit 96 supplies an absorbent capable of absorbing ammonia to the reactor 95. The absorbent supply unit 96 of the present embodiment supplies water as the absorbent to the reactor 95. Here, as the absorbent, seawater or fresh water can be exemplified as in the absorbent in the dilution tank 64. Further, as the seawater, the seawater around the floating body 2 can be exemplified, and as the fresh water, the fresh water stored in a fresh water tank (not shown) of the floating body 2 can be exemplified. The absorbent supply unit 96 of the present embodiment pumps up the water (for example, seawater, fresh water) around the floating body 2 and uses it as the absorbent by a pump (not shown).

[0088] The reactor absorbent discharge line 97 discharges the absorbent reacted with ammonia by the reactor 95. The reactor absorbent discharge line 97 of the present embodiment is connected to the bottom of the reactor 95 and guides the absorbent discharged from the reactor 95 to the ammonia waste liquid tank 69 by gravity. Note that the reactor absorbent discharge line 97 is not limited to guiding the absorbent to the ammonia waste liquid tank 69 by gravity. For example, the absorbent may be guided to the ammonia waste liquid tank 69 by a pump.

[0089] The waste liquid tank introduction line 98 communicates the lead-out line 166 with the gas phase inside the ammonia waste liquid tank 69. More specifically, the waste liquid tank introduction line 98 is configured to be able to communicate the first lead-out line 166A with the gas phase of the ammonia waste liquid tank 69. This waste liquid tank introduction line 98 communicates the first lead-out line 166A with the gas phase of the ammonia waste liquid tank 69 during an emergency purge, and is otherwise blocked by a valve.

[0090] The compartment reactor introduction line 99 guides the gas in the compartment 30 to the reactor 95. The compartment reactor introduction line 99 of the present embodiment is connected to the upper and lower middle part of the reactor 95 and supplies the gas in the compartment 30 to the upper and lower middle part of the reactor 95. Further, the compartment reactor introduction line 99 of the present embodiment branches from the compartment combustion line 72 and is connected to the reactor 95.

[0091] In this second embodiment, since the ammonia concentration of the gas introduced from the compartment 30 into the reactor 95 is high, when ammonia cannot be completely absorbed by the absorption liquid in the reactor 95, the gas discharged from the reactor 95 is led to the combustion decontamination device 70. Note that when it is possible to sufficiently absorb ammonia into the absorption liquid of the reactor 95, the combustion decontamination device 70 and the dilution combustion line 71 may be omitted.

[0092] In this second embodiment, since the ammonia concentration of the gas at the outlet of the reactor 95 is high, when ammonia cannot be completely absorbed by the absorption liquid in the reactor 95, a gas circulation line 93 is provided to lead the gas from the outlet of the reactor 95 back to the inlet of the reactor 95 again. The gas circulation line 93 has a valve 94 in the middle thereof, and the switching of the valve 94 may be automatically switched when ammonia with a concentration equal to or higher than the emission regulation value is detected by an ammonia concentration sensor installed at the atmosphere opening 83 at the outlet of the reactor 95. Note that when it is possible to sufficiently absorb ammonia into the absorption liquid of the reactor 95 by this switching operation, the combustion decontamination device 70 and the dilution combustion line 71 may be omitted.

[0093] (Ammonia treatment method) Next, the ammonia treatment method of the floating body in the second embodiment will be described with reference to the drawings. In the description of the ammonia treatment method of the floating body in the second embodiment, the same reference numerals are given to the same steps as those in the ammonia treatment method of the first embodiment described above for explanation. Also, in the description of the ammonia treatment method in this second embodiment, the case where the crew of the floating body 1 makes judgments and operations will be described as an example.

[0094] FIG. 17 is a flowchart of the ammonia treatment method in the second embodiment of the present disclosure. FIG. 18 is a flowchart of the purge step in FIG. 17. FIG. 19 is a flowchart of the leak decontamination step in FIG. 17. FIG. 20 is a flowchart of the emergency purge step in FIG. 17. Note that the flowchart of the ammonia treatment method shown in FIG. 17 is the same as the flowchart shown in FIG. 4 of the first embodiment described above, and only the reference numerals of the purge step, the leak decontamination step, and the emergency purge step are different.

[0095] As shown in FIG. 17, in the ammonia treatment method of the second embodiment, it is determined whether it is a purge of ammonia with an inert gas or an ammonia leak in compartment 30 (step S01). As a result of this determination, if it is determined that there is an ammonia leak in compartment 30 ( "leak" in step S01), the process proceeds to the leak decontamination step (step S120). On the other hand, if it is determined that it is a purge of the piping system 20 ( "purge" in step S01), it is determined whether it is an emergency purge (step S02). As a result of this determination, if it is determined that it is not an emergency purge ( "No" in step S02), the process proceeds to the purge step (step S110). On the other hand, if it is determined that it is an emergency purge ( "Yes" in step S02), the process proceeds to the emergency purge step (step S130).

[0096] Next, it is determined whether the absorbent liquid that has absorbed the ammonia generated by the purge step (step S110), the leak decontamination step (step S120), and the emergency purge step (step S130) can be landed, in the same manner as in the first embodiment (step S03). If it is determined that the absorbent liquid can be landed ( "Yes" in step S03), the process proceeds to the landing step (step S04). If it is determined that the absorbent liquid cannot be landed ( "No" in step S03), the above-described series of steps are repeated until it becomes possible to land (return).

[0097] As shown in Fig. 18, in the purge process (step S110), first, the absorption process (step S11) is performed. When purging ammonia, the exhaust gas discharged is mixed with the absorption liquid stored in the dilution tank 64 to absorb the ammonia contained in the exhaust gas into the absorption liquid.

[0098] Next, it is determined whether the floating body 1 is within the emission control area (step S12). If it is determined that the floating body 1 is not within the emission control area in this determination (''No'' in step S12), the process proceeds to the atmospheric emission process (step S115). On the other hand, if it is determined that the floating body 1 is within the emission control area (''Yes'' in step S12), it is determined whether the emission control can be complied with only by the absorption process (step S11) (step S13). If it is determined that the emission control can be complied with in this determination (''No'' in step S13), the process proceeds to the atmospheric emission process (step S115). On the other hand, if it is determined that the emission control cannot be complied with only by the absorption process (''Yes'' in step S13), the process proceeds to the first reaction process (step S112).

[0099] In the first reaction process (step S112), the gas in the gas phase of the dilution tank 64 is introduced into the reactor 95, and the ammonia gas contained in the gas is reacted with the absorption liquid. That is, the ammonia gas is absorbed into the absorption liquid in the reactor 95. Then, the first emission process (step S113) is performed, and the gas reacted with the absorption liquid in the first reaction process (step S112) is emitted to the atmosphere from the atmosphere release section 83, and the process returns to step S03 in Fig. 17.

[0100] Specifically, in the purge process (step S110), as shown in FIG. 21, the gas in the gas phase of the dilution tank 64 is sent into the reactor 95 through the first outlet line 166A, and the gas reacted with the absorption liquid by this reactor 95 is guided to the atmosphere release section 83 through the second outlet line 166B and released to the atmosphere. On the other hand, in the atmosphere release process (step S115), the gas in the gas phase of the dilution tank 64 is guided to the atmosphere release section 83 through the reactor 95 in a state where the reactor 95 is not operating and released to the atmosphere. That is, in the atmosphere release process (step S115), the gas in the gas phase of the dilution tank 64 simply passes through the reactor 95 without being excluded by the reactor 95.

[0101] As shown in FIG. 19, in the leakage decontamination process (step S120), first, the spraying process (step S21) is performed. In this spraying process (step S21), the absorption liquid is sprayed into the section 30 where ammonia leakage is detected. The absorption liquid sprayed into the section 30 and absorbing ammonia is stored in the ammonia liquid build-up tank 75.

[0102] Next, it is determined whether the floating body 1 is within the emission control area (step S22). If it is determined that the floating body 1 is not within the emission control area in this determination (''No'' in step S22), the process proceeds to the atmosphere release process (step S125). On the other hand, if it is determined that the floating body 1 is within the emission control area (''Yes'' in step S22), it is determined whether the emission control can be complied with only by the spraying process (step S23). If it is determined that the emission control can be complied with in this determination (''No'' in step S23), the process proceeds to the atmosphere release process (step S125). On the other hand, if it is determined that the emission control cannot be complied with only by the spraying process (''Yes'' in step S23), the process proceeds to the second reaction process (step S122).

[0103] In the second reaction step (step S122), after the absorption liquid is sprayed in the spraying step (step S21), the gas in the compartment 30 is introduced into the reactor 95, and the ammonia gas contained in the gas is reacted with the absorption liquid. Then, the second release step (step S123) is performed, and the gas reacted with the absorption liquid in the second reaction step (step S122) is released to the atmosphere from the atmosphere release section 83 and returns to step S03 in FIG. 17.

[0104] Specifically, in the leakage decontamination step (step S120), as shown in FIGS. 22 and 23, the gas in the compartment 30 is sent into the reactor 95 through the compartment combustion line 72 and the compartment reactor introduction line 99, and the gas reacted with the absorption liquid by this reactor 95 is led to the atmosphere release section 83 through the second lead-out line 166B and released to the atmosphere. On the other hand, in the atmosphere release step (step S125), the gas in the compartment 30 is led to the atmosphere release section 83 through the reactor 95 in a state where the reactor 95 is not operating and released to the atmosphere. That is, in the atmosphere release step (step S125), the gas in the compartment 30 simply passes through the reactor 95 without being excluded by the reactor 95.

[0105] As shown in FIG. 20, in the emergency purge step (step S130), first, the absorption step (step S31) is performed. This absorption step (step S31) is the same as the absorption step (step S31) of the first embodiment. As shown in FIG. 24, the fluid introduced by the ammonia introduction line 61 is mixed with the absorption liquid stored in the dilution tank 64, and the ammonia contained in the fluid introduced by the ammonia introduction line 61 is absorbed by the absorption liquid in the dilution tank 64. Next, it is determined whether or not the pressure inside the dilution tank 64 has risen above a specified pressure (step S32). As a result of this determination, if it is determined that the pressure inside the dilution tank 64 has risen above the specified pressure (''No'' in step S32), the process proceeds to the atmosphere discharge step (step S134). On the other hand, as a result of the above determination, if the pressure inside the dilution tank 64 has not risen above the specified pressure (''Yes'' in step S32), it is determined whether or not the pressure in the exclusion target range, which is the purge target area 20p, has been reduced to a predetermined pressure within the limit time (step S33). As a result of this determination, if it is determined that the pressure in the exclusion target range has not been reduced to the predetermined pressure within the limit time (''No'' in step S33), the process proceeds to the atmosphere discharge step (step S134). On the other hand, as a result of the above determination, if it is determined that the pressure in the exclusion target range has been reduced to the predetermined pressure within the limit time (''Yes'' in step S33), the emergency purge step (step S30) is terminated and the process returns to step S03 described above.

[0106] In the atmosphere discharge step (step S134), without passing through the dilution tank 64, the fluid (exhaust gas) introduced by the ammonia introduction line 61 is led to the atmosphere release section 83 for atmosphere discharge, and the process returns to step S03 of FIG. 17 described above. In the atmosphere discharge step (step S134) of this second embodiment, a configuration is adopted in which it is possible to select whether to discharge the fluid introduced by the ammonia introduction line 61 to the atmosphere through the gas phase of the ammonia waste liquid tank 69 that stores the absorption liquid discharged from the dilution tank 64 and the reactor 95 or to discharge it to the atmosphere only through the reactor 95.

[0107] Specifically, in the air release step (step S134), as shown in FIG. 25, the gas in the gas phase of the dilution tank 64 is guided to the air release section 83 through the first lead-out line 166A, the waste liquid tank introduction line 98, the gas phase of the ammonia waste liquid tank 69, the reactor absorption liquid discharge line 97, the reactor 95, and the second lead-out line 166B, enabling air release. Further, for example, when the floating body 1 is equipped with an uninterruptible power supply device, an emergency power generation facility, etc. and the absorption liquid supply section 96 can be operated, the gas can be directly introduced from the first lead-out line 166A to the reactor 95 (the route shown by the broken line in FIG. 25), and the gas fed into the reactor 95 can be reacted with the absorption liquid and then guided to the air release section 83.

[0108] (Function and effect) According to the above second embodiment, by providing the reactor 95 provided in the middle of the lead-out line 166 and the absorption liquid supply section 96 for supplying the absorption liquid to the reactor 95, the ammonia gas contained in the gas led out from the dilution tank 64 can be reacted with the absorption liquid capable of absorbing the ammonia gas. Therefore, in addition to the function and effect of the first embodiment, the ammonia gas contained in the gas led out from the dilution tank 64 can be reacted with the absorption liquid by the reactor 95 and then released to the atmosphere. Thus, for example, even when the floating body main body 2 is within the emission control area (e.g., in the port), the ammonia concentration of the gas guided from the lead-out line 166 to the air release section 83 can be more reliably reduced.

[0109] (First modification example of the second embodiment) In the second embodiment described above, the case where the absorption liquid supply section 96 is operated by an uninterruptible power supply device or an emergency power generation facility is exemplified. However, for example, as shown in FIG. 26, a gravity tank 105 capable of supplying the absorption liquid by gravity may be provided in the absorption liquid supply section 96, and when performing the emergency purge step (step S130), the absorption liquid previously stored in the gravity tank 105 may be supplied to the reactor 95.

[0110] By configuring in this way, even when there is a power loss, it becomes possible to supply the absorption liquid to the reactor 95 without using power and react ammonia with the absorption liquid. Therefore, even in the case of a power loss or the like, it is possible to suppress the release of a gas with a high ammonia concentration from the atmosphere opening portion 83, and thus the marketability can be improved.

[0111] (Second Modified Example of the Second Embodiment) In the second embodiment, the case where the absorption liquid supply unit 96 supplies seawater or fresh water as the absorption liquid to the reactor 95 was illustrated. However, the absorption liquid supply unit 96 may include, for example, a carbonic acid mixing unit 106 capable of mixing carbon dioxide gas with seawater or fresh water as the absorption liquid, as shown in FIG. 27. For mixing the absorption liquid and carbon dioxide gas (CO2), for example, an ejector can be used. Also, with an ejector that forms fine bubbles, ammonia can be absorbed more efficiently.

[0112] By configuring in this way, carbon dioxide gas dissolves in the absorption liquid, and a part of it dissociates to become H2O + CO2 ⇒ CO3 2- + H + . This H + promotes the dissociation of ammonia. NH3 + H + ⇒ NH4 + The ammonia dissociated into NH4 + in the absorption liquid no longer shows a vapor pressure, so an effect of keeping the ammonia concentration in the gas phase at the outlet of the reactor 95 low can be expected. Therefore, the reaction between the absorption liquid and ammonia in the reactor 95 can be enhanced, and ammonia can be efficiently absorbed by the absorption liquid.

[0113] [Third Embodiment] Next, a floating body and an ammonia treatment method for the floating body according to the third embodiment of the present disclosure will be described with reference to the drawings. This third embodiment is obtained by making the absorption liquid in the dilution tank 64 reusable as a reducing agent for the denitration device with respect to the floating body of the second embodiment described above. Therefore, referring to FIG. 1, the same parts as those in the first and second embodiments described above are denoted by the same reference numerals and described, and redundant descriptions are omitted.

[0114] In this third embodiment, the floating body 201 includes a floating body main body 2, an upper structure 4, a combustion device 8, an ammonia tank 10, a piping system 20, a compartment 30, and an ammonia treatment device 260, similar to the floating bodies 1 and 101 in the above-described first and second embodiments.

[0115] FIG. 28 is a diagram showing a schematic configuration of the ammonia treatment device in the third embodiment of the present disclosure. As shown in FIG. 28, the ammonia treatment device 260 in the third embodiment includes an ammonia introduction line 61, a knock-out drum 62, a mixing section 63, a dilution tank 64, a dilution gas introduction line 65, a derivation line 166, a bypass line 67, a diluted absorbent discharge line 68, an ammonia waste liquid tank 69, a combustion decontamination device 70, a dilution combustion line 171, a compartment combustion line 72, a compartment opening line 73, a compartment liquid discharge line 74, an ammonia liquid bulge tank 75, a landing line 76, a reactor 95, an absorbent supply section 96, a reactor absorbent discharge line 97, a waste liquid tank introduction line 98, a compartment reactor introduction line 99, a denitration ammonia introduction line 107, and a denitration ammonia liquid tank 108.

[0116] The denitration ammonia introduction line 107 introduces the absorbent in the dilution tank 64 that has absorbed ammonia into the denitration ammonia liquid tank 108 that stores the denitration ammonia liquid. That is, the denitration ammonia liquid in this third embodiment is a liquid containing ammonia absorbed by the absorbent.

[0117] The ammonia introduction line 107 for denitration in this third embodiment branches from the dilution absorption liquid discharge line 68 that connects the liquid phase of the dilution tank 64 and the ammonia waste liquid tank 69, and reaches the ammonia liquid tank 108 for denitration that produces the reducing agent for the denitration apparatus. Valves 109 and 110 are respectively provided in the ammonia introduction line 107 for denitration and the dilution absorption liquid discharge line 68. By opening and closing these valves 109 and 110, it is possible to distribute the absorption liquid in the dilution tank 64 to the ammonia waste liquid tank 69 and the ammonia liquid tank 108 for denitration. The ammonia introduction line 107 for denitration in this embodiment guides the absorption liquid in the dilution tank 64 to the ammonia liquid tank 108 for denitration by gravity. Note that a pump for sending the absorption liquid in the dilution tank 64 to the ammonia liquid tank 108 for denitration may be provided in the ammonia introduction line 107 for denitration.

[0118] Figure 29 is a diagram showing the piping system around the ammonia liquid tank for denitration of the denitration apparatus in the third embodiment of the present disclosure. As shown in Figure 29, the floating body 201 in the third embodiment further includes an exhaust pipe 111, a denitration apparatus 112, an ammonia liquid supply line 113 for denitration, and a fuel ammonia supply line 114.

[0119] The exhaust pipe 111 guides the exhaust gas G discharged from the combustion apparatus 8 to the outside of the floating body main body 2. The exhaust gas G immediately after being discharged from the combustion apparatus 8 flowing through this exhaust pipe 111 contains nitrogen oxides.

[0120] The denitration apparatus 112 performs a denitration treatment on the exhaust gas G discharged from the combustion apparatus 8. This denitration apparatus 112 is a selective catalytic reduction denitration apparatus (SCR), and converts nitrogen oxides into nitrogen and water by a catalyst. This denitration apparatus 112 is provided in the middle of the exhaust pipe 111, and brings the exhaust gas G sprayed with the ammonia liquid for denitration into contact with a catalyst (not shown). Note that the exhaust gas G subjected to the denitration treatment is discharged into the atmosphere, for example, through a funnel (not shown) provided in the floating body main body 2.

[0121] The ammonia liquid tank 108 for denitration stores the ammonia liquid for denitration used in the denitration apparatus 112. Here, as the ammonia liquid for denitration, ammonia water adjusted to a predetermined ammonia concentration (for example, about 25%) necessary for use as a reducing agent in the denitration apparatus 112 can be exemplified. The ammonia liquid tank 108 for denitration in the present embodiment includes a circulation pipe 115 for stirring the ammonia liquid for denitration and a stirring pump 116. Further, a densitometer 117 for measuring the ammonia concentration of the ammonia liquid for denitration stored in the ammonia liquid tank 108 for denitration is provided in the circulation pipe 115. The ammonia concentration of the absorption liquid stored in the dilution tank 64 is lower (for example, 10% or less, etc.) than the ammonia concentration of the ammonia liquid for denitration described above.

[0122] For example, a liquid level gauge or the like may be provided in the ammonia liquid tank 108 for denitration so that the storage amount of the ammonia liquid for denitration can be measured. Further, instead of providing the circulation pipe 115 and the stirring pump 116, a stirrer of another method may be provided in the ammonia liquid tank 108 for denitration. Furthermore, the configuration for stirring the ammonia liquid for denitration as described above may be provided as necessary and can also be omitted. When the circulation pipe 115 and the stirring pump 116 are omitted, the densitometer 117 for measuring the ammonia concentration of the ammonia liquid for denitration may be provided in the ammonia liquid tank 108 for denitration.

[0123] The ammonia liquid supply line 113 for denitration forms a flow path for supplying the ammonia liquid for denitration stored in the ammonia liquid tank 108 for denitration to the denitration apparatus 112. An ammonia liquid pump 118 is provided in the ammonia liquid supply line 113 for denitration.

[0124] The fuel ammonia supply line 114 includes a first line 114A that supplies ammonia stored in the ammonia tank 10 to the mixing tank 40, and a second line 114B that supplies ammonia stored in the ammonia tank 10 to the ammonia liquid tank 108 for denitration. As described above, since ammonia is liquefied ammonia, its ammonia concentration is higher than that of the absorption liquid in the dilution tank 64. For example, when the ammonia concentration of the liquid in the ammonia liquid tank 108 for denitration is low, the ammonia concentration of the ammonia liquid for denitration can be increased by supplying ammonia to the ammonia liquid tank 108 for denitration through the second line 114B. Note that although the second line 114B in the third embodiment is illustrated as being branched and connected to the first line 114A, the second line 114B only needs to be able to supply ammonia to the ammonia liquid tank 108 for denitration. For example, the ammonia liquid tank 108 for denitration may be connected to the ammonia tank 10, and liquefied ammonia may be supplied from the ammonia tank 10 to the ammonia liquid tank 108 for denitration. The ammonia supplied to the ammonia liquid tank 108 for denitration from the second line 114B is not limited to liquid. A vaporizer (not shown) may be provided in the middle of the second line 114B to introduce gaseous ammonia, or ammonia in the gas phase portion of the ammonia tank 10 may be introduced.

[0125] The second line 114B is provided with a flow control valve 119 that can adjust the flow rate of ammonia flowing from the first line 114A into the second line 114B. This flow control valve 119 can gradually adjust the valve opening degree from the fully closed state to the fully open state.

[0126] The first line 114A is provided with a feed pump 120 that feeds ammonia toward the combustion device 8 on the side closer to the ammonia tank 10 than the branch point P2 of the second line 114B. In other words, the second line 114B branches from the first line 114A between the feed pump 120 and the mixing tank 40. Note that a pump for feeding ammonia toward the ammonia liquid tank 108 for denitration may be provided in the second line 114B.

[0127] The supply pipe 21 is provided with an ammonia pressurizing pump 121 (not shown in the first embodiment) and an ammonia heat exchanger 122. The ammonia pressurizing pump 121 pressurizes the ammonia supplied from the mixing tank 40 to the combustion device 8. The ammonia heat exchanger 122 adjusts the temperature of the ammonia pressurized by the ammonia pressurizing pump 121.

[0128] The mixing tank 40 and the ammonia treatment device 60 of the present embodiment are connected by a gas discharge pipe 123. The gas discharge pipe 123 is configured to introduce the gas discharged by purging when the mixing tank 40 is opened due to maintenance or the like into the ammonia treatment device 60.

[0129] (Ammonia treatment method) Next, the ammonia treatment method for the floating body in the third embodiment will be described with reference to the drawings. In the ammonia treatment method in the third embodiment, a step of producing a reducing agent and a step of performing denitration treatment using the produced reducing agent are added to the ammonia treatment method in the second embodiment. Therefore, in the description of the ammonia treatment method for the floating body in the third embodiment, the same steps as those in the ammonia treatment methods in the first and second embodiments described above will be denoted by the same reference numerals and described. In the description of the ammonia treatment method in this third embodiment, the case where the crew of the floating body 1 makes a determination and performs an operation will be described as an example.

[0130] FIG. 30 is a flowchart of the ammonia treatment method in the third embodiment of the present disclosure. The flowchart of the ammonia treatment method shown in FIG. 30 corresponds to the flowchart shown in FIG. 17 of the second embodiment described above. As shown in FIG. 30, in the ammonia treatment method of the third embodiment, as in the second embodiment, the determinations in steps S01 and S02 are made, and any one of a purge step (step S110), a leakage decontamination step (step S120), and an emergency purge step (step S130) is performed.

[0131] Next, proceed to the reducing agent production step (step S40). In this reducing agent production step, the absorption liquid that has absorbed ammonia through the purge step (step S110), the leak decontamination step (step S120), and the emergency purge step (step S130) is guided from the dilution tank 64 and the reactor 95 to the ammonia liquid tank 108 for denitration. Then, it is mixed with the liquefied ammonia in the ammonia tank 10 in the ammonia liquid tank 108 for denitration to produce an ammonia liquid for denitration with the ammonia concentration required as a reducing agent, and proceed to the denitration step (step S41). In the denitration step, the exhaust gas G is subjected to denitration treatment. More specifically, the ammonia liquid for denitration in the ammonia liquid tank 108 for denitration is supplied to the denitration device 112, and the ammonia liquid for denitration is sprayed onto the exhaust gas G before it comes into contact with the catalyst.

[0132] Thereafter, in the same manner as in the first embodiment, it is determined whether or not it is possible to land (step S03). If it is determined that the absorption liquid can be landed (Yes in step S03), proceed to the landing step (step S04). If it is determined that the absorption liquid cannot be landed (No in step S03), repeat the above-described series of steps until it becomes possible to land (return). In the landing step (step S04), the absorption liquid stored in the ammonia waste liquid tank 69 and the ammonia liquid building tank 75 is landed.

[0133] (Function and effect) According to the above-described third embodiment, in addition to the functions and effects of the above-described first and second embodiments, the absorption liquid in the dilution tank 64 can be supplied to the ammonia liquid tank 108 for denitration through the ammonia introduction line 107 for denitration. Therefore, it is possible to generate an ammonia liquid for denitration using the absorption liquid in the dilution tank 64 in the ammonia liquid tank 108 for denitration, and use the ammonia liquid for denitration in this ammonia liquid tank 108 for denitration as a reducing agent for the denitration device 112. As a result, the absorption liquid in the dilution tank 64 can be effectively utilized, so that the ammonia waste liquid tank 69 for storing the absorption liquid in the dilution tank 64 can be downsized, and as a result, it is possible to suppress the enlargement of the floating body 1.

[0134] [Fourth Embodiment] Next, a floating body and an ammonia treatment method for the floating body according to the fourth embodiment of the present disclosure will be described with reference to the drawings. This fourth embodiment is obtained by adding an ammonia decomposition device to the floating body 101 of the second embodiment described above. Therefore, referring to FIG. 1, the same parts as those in the first and second embodiments described above are denoted by the same reference numerals and described, and redundant descriptions are omitted.

[0135] The floating body 301 in this fourth embodiment includes a floating body main body 2, an upper structure 4, a combustion device 8, an ammonia tank 10, a piping system 20, a compartment 30, and an ammonia treatment device 360, similar to the floating bodies 1 and 101 of the first and second embodiments described above. The water surrounding the floating body main body 2 of the fourth embodiment is seawater.

[0136] FIG. 31 is a diagram showing a schematic configuration of the ammonia treatment device in the fourth embodiment of the present disclosure. As shown in FIG. 31, the ammonia treatment device 360 in the fourth embodiment includes an ammonia introduction line 61, a knock-out drum 62, a mixing section 63, a dilution tank 64, a dilution gas introduction line 65, a derivation line 166, a bypass line 67, a dilution absorbent discharge line 68, an ammonia waste liquid tank 69, a combustion decontamination device 70, a dilution combustion line 171, a compartment combustion line 72, a compartment opening line 73, a compartment liquid discharge line 74, an ammonia liquid build-up tank 75, a landing line 76, an ammonia waste liquid line 89, a reactor 95, an absorbent supply section 96, a reactor absorbent discharge line 97, a waste liquid tank introduction line 98, a compartment reactor introduction line 99, a waste liquid tank discharge line 125, and an ammonia decomposition device 126.

[0137] The waste liquid tank discharge line 125 discharges the absorbent in the ammonia waste liquid tank 69. The waste liquid tank discharge line 125 of the present embodiment branches from the ammonia waste liquid line 89 and is connected to the ammonia decomposition device 126. By switching the valves 127 and 128, the discharge destination of the absorbent in the ammonia waste liquid tank 69 can be selectively selected from the landing line 76 and the ammonia decomposition device 126.

[0138] FIG. 32 is a diagram showing a schematic configuration of the ammonia decomposition device 126 in the fourth embodiment of the present disclosure. As shown in FIG. 32, the ammonia decomposition device 126 is a device that decomposes ammonia contained in the absorbent stored in the ammonia waste liquid tank 69 into harmless substances and then discharges it into the ocean. The ammonia decomposition device 126 includes a water intake section 130, a seawater introduction line 131, an electrolysis section 132, a denitrification reaction tank 151, and a discharge section 134.

[0139] The water intake section 130 takes in seawater around the floating body main body 2 into the floating body main body 2. The water intake section 130 includes a water intake port 135, a seawater pump 136, and a marine organism adhesion prevention treatment device 137. The water intake port 135 opens below the light load water line (not shown) of the outer plate of the floating body main body 2. That is, the water intake port 135 is always located below the sea surface. The seawater pump 136 sends the seawater at the water intake port 135 into the floating body main body 2. The seawater sent out by the seawater pump 136 is branched into the marine organism adhesion prevention treatment device 137 and the seawater introduction line 131, respectively.

[0140] The marine organism adhesion prevention treatment device 137 performs a treatment for preventing the adhesion of marine organisms to the taken-in seawater. Examples of the treatment for preventing the adhesion of marine organisms include a treatment in which seawater is electrolyzed to generate sodium hypochlorite or copper ions, and the taken-in seawater from the water intake port 135 is made to contain these sodium hypochlorite and copper ions. By the treatment for preventing the adhesion of marine organisms by the marine organism adhesion prevention treatment device 137, it is possible to suppress the adhesion and blockage of marine organisms on the inner surface of the piping through which seawater flows in the floating body main body 2 and the inner surface of the water intake port 135.

[0141] The seawater introduction line 131 introduces the seawater taken in by the water intake section 130 into the floating body main body 2. The seawater introduction line 131 of the present embodiment is a pipe that supplies seawater to at least the electrolysis section 132. Here, the seawater introduction line 131 has a plurality of branch lines 138, and seawater can be supplied to facilities other than the ammonia decomposition device 126 by these branch lines 138. The seawater supplied to facilities other than the ammonia decomposition device 126 via these plurality of branch lines 138 is discharged from the discharge section 134 to the outside of the floating body main body 2 via the confluence line 139 and the dilution line 140 described later after being used as cooling water or the like.

[0142] An exhaust heat recovery section 141 is provided in the middle of the seawater introduction line 131 described above. The exhaust heat recovery section 141 recovers the exhaust heat of the heat generating equipment provided in the floating body main body 2. In the present embodiment, the exhaust heat of the combustion device 8 as the heat generating equipment is recovered to heat the seawater flowing through the seawater introduction line 131. Heat exchange is performed between the cooling water (for example, fresh water) of the combustion device 8 and the seawater flowing through the seawater introduction line 131. As a result, regardless of the seawater temperature in the water intake section 130, the temperature of the seawater flowing through the seawater introduction line 131 does not become 10°C or lower. In the present embodiment, a cooling water pump 143 is provided in the cooling water line 142 through which the cooling water of the combustion device 8 flows, and the cooling water circulates between the exhaust heat recovery section 141 and the combustion device 8. In addition, a cooling water branch line 144 for circulating the cooling water to heat generating equipment other than the combustion device 8 is also connected to the cooling water line 142, and the exhaust heat of other heat generating equipment can also be recovered.

[0143] The electrolysis section 132 generates a seawater electrolytic solution containing sodium hypochlorite by subjecting the seawater introduced into the floating body main body 2 by the seawater introduction line 131 to electrolysis. The electrolysis section 132 of the present embodiment includes an electrolysis device 145, a storage tank 146, a circulation line 147, and a circulation pump 148.

[0144] The electrolysis device 145 electrolyzes seawater to produce a seawater electrolytic solution. Specifically, a positive electrode and a negative electrode (not shown) are disposed in seawater, and a voltage is applied between the positive electrode and the negative electrode to electrolyze the seawater. By this electrolysis, sodium hypochlorite is produced from the seawater. The seawater electrolytic solution electrolyzed by the electrolysis device 145 is introduced into a storage tank 146.

[0145] The storage tank 146 is capable of storing the seawater electrolytic solution produced by the electrolysis device 145. The storage tank 146 of the present embodiment is connected to a seawater introduction line 131, and in addition to the seawater electrolytic solution from the electrolysis device 145, seawater from the seawater introduction line 131 is poured in.

[0146] A circulation line 147 circulates the seawater electrolytic solution between the electrolysis device 145 and the storage tank 146. That is, the circulation line 147 guides the seawater electrolytic solution stored in the storage tank 146 to the electrolysis device 145 and guides the seawater electrolytic solution electrolyzed by the electrolysis device 145 to the storage tank 146. The electrolysis unit 132 of the present embodiment further includes an electrolytic solution line 150 for guiding the seawater electrolytic solution stored in the storage tank 146 to a line mixer 149. This electrolytic solution line 150 is branched and connected to the circulation line 147.

[0147] A circulation pump 148 is provided in the middle of the circulation line 147. The circulation pump 148 sends out the seawater electrolytic solution in the circulation line 147 toward the electrolysis device 145 and the line mixer 149. By driving this circulation pump 148, a part of the seawater electrolytic solution in the circulation line 147 circulates between the electrolysis device 145 and the storage tank 146, and the remaining part of the seawater electrolytic solution in the circulation line 147 is supplied to the line mixer 149 via the electrolytic solution line 150. A valve (not shown) whose opening degree can be adjusted from fully closed to fully open is provided in the middle of the electrolytic solution line 150, and it is possible to adjust the flow rate of the seawater electrolytic solution supplied to the line mixer 149.

[0148] According to the electrolysis unit 132, by circulating the seawater electrolytic solution stored in the storage tank 146, it can be electrolyzed again by the electrolysis device 145. Therefore, it is possible to obtain a seawater electrolytic solution with a higher concentration of sodium hypochlorite than the seawater electrolytic solution electrolyzed only once by the electrolysis device 145. Although the case where the electrolytic solution line 150 is branched and connected to the circulation line 147 has been described, the present invention is not limited to this configuration. For example, it may be connected to the storage tank 146, and the seawater electrolytic solution stored in the storage tank 146 may be guided to the line mixer 149 without passing through the circulation line 147. In this case, another pump for sending the seawater electrolytic solution to the line mixer 149 may be provided in the electrolytic solution line 150.

[0149] The line mixer 149 stirs a mixed solution of the seawater electrolytic solution generated by the electrolysis unit 132 and the absorption liquid of the ammonia waste liquid tank 69 supplied by the waste liquid tank discharge line 125. The mixed solution stirred by this line mixer 149 is introduced into the denitrification reaction tank 151.

[0150] The denitrification reaction tank 151 reacts a mixed solution of the absorption liquid flowing through the waste liquid tank discharge line 125 and the seawater electrolytic solution generated in the electrolysis unit 132. More specifically, as shown in formula (1), the ammonia (2NH3) in the absorption liquid and the sodium hypochlorite (3NaClO) in the seawater electrolytic solution are reacted in an acidic environment to decompose into nitrogen (N2), sodium chloride (3NaCl), and water (3H2O). That is, a denitrification reaction is carried out in the denitrification reaction tank 151. 2NH3 + 3NaClO ⇒ N2 + 3NaCl + 3H2O ··· (1)

[0151] The nitrogen generated by the denitrification reaction in the denitrification reaction tank 151 is discharged into the atmosphere through, for example, a vent post (not shown) extending from the upper deck 7. On the other hand, the sodium chloride and water generated by the denitrification reaction in the denitrification reaction tank 151 are discharged to the discharge section 134 as treated liquid.

[0152] Here, in the denitrification reaction in the denitrification reaction tank 151, in order to lower the pH of the mixed water of the absorbent liquid and the seawater electrolytic solution at the start of the reaction, an oxidizing agent such as sulfuric acid or hydrochloric acid is added to the mixed water. Therefore, a chemical liquid tank 152 (pH adjuster) for adding an oxidizing agent may be connected to the above-described denitrification reaction tank 151. Note that, instead of connecting the chemical liquid tank 152, for example, an operator may add an oxidizing agent to the denitrification reaction tank 151 using a hand-held tank. The pH value of the mixed water in the present embodiment is adjusted to a value below which alkaline earth metals contained in seawater do not precipitate. Here, examples of the alkaline earth metals contained in seawater include calcium (Ca) and magnesium (Mg). In the denitrification reaction in an example of the present embodiment under the above acidic environment, two types of intermediates (chloramines), NH2Cl and NHCl2, are generated in an intermediate process, and by reacting these two intermediates of NH2Cl and NHCl2, nitrogen gas (N2) and hydrochloric acid (3HCl) are obtained. That is, since hydrochloric acid is generated, it becomes possible to continue the denitrification reaction under an acidic environment without additionally adding an oxidizing agent to the mixed water in the denitrification reaction tank 151.

[0153] The dilution line 140 merges a part of the seawater introduced into the floating body main body 2 through the seawater introduction line 131 with the treated liquid discharged from the denitrification reaction tank 151. That is, the treated liquid is diluted by the seawater merged by the dilution line 140. The seawater flowing through the dilution line 140 in the present embodiment is seawater diverted from the above-described seawater introduction line 131 and seawater diverted by the branch line 138 and supplied to other facilities other than the ammonia decomposition device 126 and used for cooling or the like.

[0154] The discharge section 134 discharges the treated liquid after the reaction in the denitrification reaction tank 151 into the seawater around the floating body main body 2. The discharge section 134 of the present embodiment discharges the treated liquid diluted by the seawater flowing through the dilution line 140.

[0155] (Ammonia treatment method) Next, the ammonia treatment method in the fourth embodiment will be described with reference to the drawings. FIG. 33 is a flowchart showing the ammonia treatment method in the fourth embodiment of the present disclosure. FIG. 34 is a flowchart of the discharge step of FIG. 33. As shown in FIG. 33, in the ammonia treatment method of the fourth embodiment, similar to the second embodiment, the determinations in steps S01 and S02 are made, and any one of the purge step (step S110), the leak decontamination step (step S120), and the emergency purge step (step S130) is performed, and the process proceeds to the discharge step (step S50). Further, in the ammonia treatment method of this fourth embodiment, after performing the discharge step (step S50), similar to the first embodiment, it is determined whether or not landing is possible (step S03). When it is determined that the landing of the absorption liquid is possible (''Yes'' in step S03), the process proceeds to the landing step (step S04). When it is determined that the absorption liquid cannot be landed (''No'' in step S03), the above-described series of steps are repeated until landing becomes possible (return). In the landing step (step S04), the absorption liquid stored in the ammonia waste liquid tank 69 and the ammonia liquid build-up tank 75 is landed.

[0156] As shown in FIG. 34, the discharge step of the fourth embodiment includes an exhaust heat recovery step (step S51), a generation step (step S52), and a denitrification reaction step (step S53).

[0157] In the exhaust heat recovery step (step S51), the exhaust heat of the equipment in the floating body main body 2 is recovered using the seawater taken in. That is, the seawater introduced into the floating body main body 2 by the above-described seawater introduction line 131 is heated up by the exhaust heat recovery unit 141. In the generation step (step S52), the seawater heated up in the exhaust heat recovery step (step S51) is electrolyzed to generate a seawater electrolytic solution containing sodium hypochlorite. In this embodiment, the seawater electrolytic solution is generated by the above-described electrolysis unit 132, and the seawater electrolytic solution is circulated between the storage tank 146 and the electrolysis device 145 to increase the concentration of sodium hypochlorite.

[0158] In the denitrification reaction step (step S53), sodium hypochlorite in the seawater electrolytic solution is reacted with ammonia in the absorption liquid. Further, in this denitrification reaction step (step S53), the pH of the mixed liquid of the seawater electrolytic solution and the absorption liquid is lowered to a range where alkaline earth metals contained in the seawater do not precipitate. That is, in the present embodiment, an oxidizing agent is added to the mixed liquid in the above-described denitrification reaction tank 151 to adjust the pH value to a value suitable for the denitrification reaction, and sodium hypochlorite and ammonia are reacted in the denitrification reaction tank 151. Then, in the present embodiment, the treated liquid after the reaction in the denitrification reaction step (step S53) is diluted using the seawater introduced into the floating body main body 2 and discharged into the seawater around the floating body main body 2, and the process returns to step S03 in FIG. 33 (return).

[0159] (Function and effect) According to the above-described fourth embodiment, in addition to the function and effect of the second embodiment, there are the following function and effect. That is, the seawater electrolytic solution generated by electrolyzing seawater contains, in addition to sodium chloride (NaCl) which is a raw material of sodium hypochlorite, transition metal ions which have an effect of increasing the denitrification reaction rate as a promoting oxidation catalyst (Fenton catalyst) such as iron and manganese. Therefore, by decomposing ammonia in the absorption liquid using the seawater electrolytic solution obtained by electrolyzing the taken seawater, ammonia can be decomposed more efficiently than when using sodium hypochlorite alone.

[0160] In addition, compared with the case of mounting a large amount of a strongly acidic chemical for decomposing ammonia inside the floating body main body 2 in order to remove ammonia from the absorption liquid in the dilution tank 64, it is possible to suppress an increase in the size of the part related to the use amount and storage of the chemical in the floating body main body 2, and improve the safety of the operator. Furthermore, since there is no need to obtain sodium hypochlorite as an oxidizing agent at the port of call or mooring location, etc., the burden on the operator can be reduced. Therefore, it is possible to easily remove ammonia while suppressing cost increase.

[0161] In the fourth embodiment, the case where seawater is heated using the waste heat generated in the floating body main body 2 has been described. However, it may be used without heating the seawater. In the fourth embodiment, the case where the marine organism adhesion prevention treatment device 137 is provided has been described. However, the marine organism adhesion prevention treatment device 137 may be provided as necessary. For example, when the maintenance of the attached marine organisms is easy, the marine organism adhesion prevention treatment device 137 may be omitted.

[0162] In the above-described fourth embodiment, the case where the line mixer 149 for stirring the mixed solution of the seawater electrolytic solution and the aqueous ammonia solution is provided has been described. However, the line mixer 149 may be provided as necessary. For example, when there is no need to perform stirring, the line mixer 149 may be omitted.

[0163] Furthermore, in the fourth embodiment, the configuration in which the electrolysis unit 132 circulates the seawater electrolytic solution by the circulation line 147 and the circulation pump 148 and repeatedly performs electrolysis to increase the concentration of sodium hypochlorite has been illustrated. However, the configuration for increasing the concentration of sodium hypochlorite is not limited to the one that repeatedly performs electrolysis. For example, the concentration of sodium hypochlorite may be increased by another configuration different from the configuration that repeatedly performs electrolysis, such as increasing the applied voltage to increase the current (NaClO generation amount).

[0164] Also, in the fourth embodiment, the case where the seawater that has been used in the floating body main body 2 is used to dilute the treated liquid has been described. However, the seawater for diluting the treated liquid is not limited to the seawater that has been used in the floating body main body 2. For example, the seawater taken in from the water intake 135 may be directly merged into the treated liquid.

[0165] (Modification Example of the Fourth Embodiment) FIG. 35 is a diagram corresponding to FIG. 35 in the modification example of the fourth embodiment of the present disclosure. In the above-described fourth embodiment, the case where the absorption liquid in the dilution tank 64 is stored in the ammonia waste liquid tank 69, detoxified by the ammonia decomposition device 126, and then discharged into the ocean was described. However, when the floating body is equipped with the denitration device 112, as in the third embodiment, as shown in FIG. 35, a part of the absorption liquid in the dilution tank 64 may be supplied to the ammonia liquid tank 108 for denitration to produce aqueous ammonia as a reducing agent. By configuring in this way, since the volume flow rate of the absorption liquid led to the ammonia waste liquid tank 69 can be reduced, it is possible to suppress the enlargement of the ammonia waste liquid tank 69 and the ammonia decomposition device 126.

[0166] 〈Other Embodiments〉 As described above in detail with reference to the drawings for the embodiments of the present disclosure, the specific configuration is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present disclosure are also included. For example, in the above embodiment, the case where the floating bodies 1, 101, 201, 301 are ships that can navigate by a main engine or the like was described, but it is not limited to ships as long as they are floating bodies capable of storing ammonia. Examples of the floating body 1 include ships such as liquefied gas carriers, ferries, RORO ships, car carriers, passenger ships, and floating storage units (FSU), floating storage and regasification units (FSRU), etc. Furthermore, the arrangement of the ammonia treatment devices 60, 160, 260, 360 is not limited to the arrangements in the above embodiments and modification examples. For example, it may be arranged below the upper deck 7, or may be divided and arranged both on the upper deck 7 and below the upper deck. Also, in FIG. 2, the case where a plurality of inert gas supply devices 50 are provided was illustrated, but a single inert gas supply device 50 may be configured to be able to purge a plurality of purge target regions.

[0167] Also, in each of the above-described embodiments and modifications, when outside the emission control area or in the case of emergency purge, the second embodiment is better than the first embodiment, the third embodiment is better than the second embodiment, and the fourth embodiment is better than the third embodiment in suppressing the concentration of ammonia released to the outside of the floating body main body 2 (atmospheric emission or ocean emission). Therefore, these first to fourth embodiments may be selected according to the required level of ammonia emission.

[0168] In the first embodiment, the case where the gas in the gas phase of the dilution tank 64 is directly guided to the atmosphere release part 83 via the lead-out line 66 has been described. However, for example, outside air may be allowed to flow into the middle of the lead-out line 66. Further, the case where the dilution gas introduction line 65 is provided as a configuration for adjusting the solubility of ammonia in the absorption liquid stored in the dilution tank 64 has been described. However, the configuration for adjusting the solubility of ammonia in the absorption liquid is not limited to the dilution gas introduction line 65. For example, as a configuration for adjusting the solubility of ammonia in the absorption liquid of the dilution tank 64, a heating part for heating the absorption liquid, a pH adjuster for adjusting the pH of the absorption liquid, and a pressure adjuster for adjusting the pressure in the dilution tank 64 may be provided.

[0169] In the first embodiment, for example, a catch tank may be branched and connected to the return pipe 22 so that the liquid phase of the catch tank can communicate with the fuel pipe connecting the mixing tank 40 and the ammonia tank 10. By doing so, it is possible to prevent the mixing tank 40 from becoming large and to easily adjust the liquid level.

[0170] In the ammonia treatment method of each embodiment, the case where the crew of the floating body 1 makes judgments and operations has been exemplified. However, for example, a sensor, a position detection device such as GNSS (Global Navigation Satellite System), a control valve, and a control device may be used to automatically execute the ammonia treatment method, such as controlling the control valve by the control device based on the detection results of the sensor and the position detection device.

[0171] In each of the embodiments and modifications, the case where the absorption liquid is directly sprayed into the compartment 30 has been described. However, the configuration for absorbing the ammonia leaked into the compartment 30 by the absorption liquid is not limited to the spraying of the absorption liquid into the compartment 30. For example, the gas in the compartment 30 may be circulated using a duct and absorbed by the absorption liquid in the middle of the duct. Further, the ammonia gas leaked into the compartment 30 may be led to the combustion decontamination device 70 for combustion decontamination without being absorbed by the absorption liquid.

[0172] In each of the embodiments and modifications, the case where combustion decontamination is performed by the combustion decontamination device 70 has been described. However, any device capable of decomposing ammonia may be used. For example, a decontamination device such as a catalyst may be used.

[0173] In each of the embodiments and modifications, dilution air such as outside air taken in by a fan (not shown) may be merged into the gas flowing through the lead-out lines 66 and 166 between the dilution tank 64 and the atmosphere opening portion 83 or between the reactor 95 and the atmosphere opening portion 83 to reduce the ammonia concentration.

[0174] In the fourth embodiment, the case where the ammonia decomposition device 126 is added to the configuration of the second embodiment has been illustrated. However, the ammonia decomposition device 126 may be added to the configuration of the first embodiment.

[0175] FIG. 36 is a diagram corresponding to FIG. 3 in the first aspect of another embodiment. In the first to third embodiments and the modification examples, the case where the absorption liquid stored in the ammonia liquid build-up tank 75 and the ammonia waste liquid tank 69 is landed by the landing line 76 has been described. However, the configuration for landing the absorption liquid stored in the ammonia liquid build-up tank 75 and the ammonia waste liquid tank 69 is not limited to landing via the landing line 76. For example, it may be detachably provided on the floating body main body 2 like the ammonia liquid build-up tank 175 shown in FIG. 36. Also, although not shown, similar to the ammonia liquid build-up tank 175, the ammonia waste liquid tank may also be detachably provided on the floating body main body 2. In this case, the ammonia liquid build-up tank 75 and the ammonia waste liquid tank 69 may be provided on the upper deck 7. When the ammonia liquid build-up tank 75 and the ammonia waste liquid tank 69 are provided on the upper deck 7, it becomes possible to easily land using a crane installed on the quay of the port. Also, in this case, the ammonia liquid build-up tank 75 and the ammonia waste liquid tank 69 may use a container tank conforming to ISO (International Organization for Standardization) standards.

[0176] FIG. 37 is a view corresponding to FIG. 2 in the second aspect of another embodiment of the present disclosure. In the first to third embodiments and the modification examples, when maintaining tanks such as the residual ammonia supply line 26 and the mixing tank 40, the liquefied ammonia present inside the apparatus provided on the floating body main body 2 is led to the ammonia treatment apparatuses 60, 160, 260, 360 by the residual ammonia supply line 26. However, as in the second aspect of another embodiment shown in FIG. 37, a recovery tank 250 and a recovery line 251 are provided, and before maintaining tanks such as the residual ammonia supply line 26 and the mixing tank 40, the liquefied ammonia present inside the apparatus is transferred to the recovery tank 250 outside the maintenance target range, and then the remaining liquefied ammonia or the gas containing ammonia gas may be led to the ammonia treatment apparatus 60.

[0177] FIG. 38 is a view corresponding to FIG. 3 in the third aspect of another embodiment of the present disclosure. In the first to third embodiments and modification examples, the case where the discharging pumps 90 are provided in the ammonia waste liquid line 89 and the discharging line 76, respectively, has been illustrated. However, the discharging pump 90 is not limited to the above configuration. For example, as shown in FIG. 37, one discharging pump 190 may be provided on the downstream side of the confluence point of the ammonia waste liquid line 89 and the discharging line 76.

[0178] FIG. 39 is a flowchart of the leakage disaster elimination process in the fourth aspect of another embodiment of the present disclosure. In the second embodiment described above, the case where the leakage disaster elimination process (step S120) includes the spraying process (step S21), the second reaction process (step S122), and the second discharging process (step S123) has been described. However, the leakage disaster elimination process is not limited to that described in the second embodiment, and for example, it can also be like the flowchart of the fourth aspect of another embodiment shown in FIG. 39. In the leakage disaster elimination process (step S220) of this fourth aspect, after performing the third reaction process (step S222) and the third discharging process (step S223), each determination as to whether to perform the spraying process (step S21) is sequentially performed by steps S224, S225, and S226.

[0179] In the third reaction process (step S222), the gas in the compartment 30 is introduced into the reactor 95, and the ammonia gas contained in the gas is reacted with the absorbent liquid. In the third discharging process (step S223), the gas reacted with the absorbent liquid in the third reaction process (step S222) is discharged to the atmosphere from the atmosphere release part 83. Next, it is determined whether the ammonia concentration of the gas discharged in this third discharge step (hereinafter referred to as the discharge concentration) is within the set value (step S224). As a result of this determination, if it is determined that it is not within the set value (\"No\" in step S224), the process proceeds to the spraying step (step S21). On the other hand, as a result of the above determination, if it is determined that it is within the regulated value (\"Yes\" in step S224), it is determined whether the discharge concentration has decreased within the regulated value within a preset fixed period (step S225). As a result of this determination, if it is determined that it has not decreased within the regulated value (\"No\" in step S225), the process proceeds to the spraying step (step S21). On the other hand, as a result of the above determination, if it is determined that it has decreased within the regulated value (\"Yes\" in step S225), it is determined whether the ammonia waste liquid tank 69 has a predetermined margin (storage capacity) (step S226). As a result of this determination, if it is determined that there is a predetermined margin (\"Yes\" in step S226), the process returns to step S03 in FIG. 17 without performing the spraying step. On the other hand, as a result of the above determination, if it is determined that there is no predetermined margin (\"No\" in step S226), the process proceeds to the spraying step (step S21). In the spraying step (step S21), the absorption liquid is sprayed into the compartment 30, and the process returns to step S03 in FIG. 17. By doing so in this fourth aspect, it is possible to minimize the watering in the compartment 30. It becomes possible to lower the ammonia emission concentration while keeping the compartment 30 with many electrical devices in a dry condition as much as possible.

[0180] FIG. 40 is a diagram corresponding to FIG. 29 in the fourth aspect of another embodiment of the present disclosure. In the third embodiment, the case where the ammonia concentration of the ammonia liquid for denitration is measured by the concentration meter 117 has been described. However, the ammonia concentration is not limited to being measured by the concentration meter 117. For example, as shown in FIG. 40, instead of the concentration meter 117, a tank pressure gauge 217 that measures the pressure of the ammonia liquid tank 108 for denitration may be provided. According to such a tank pressure gauge 217, it is possible to measure the saturation pressure corresponding to a predetermined ammonia concentration of the ammonia liquid.

[0181] FIG. 41 corresponds to FIG. 3 in the fifth aspect of another embodiment of the present disclosure. FIG. 42 is a diagram for explaining the liquid level of the dilution tank in the fifth aspect of another embodiment of the present disclosure. In each embodiment and modification, the case where the knockout drum 62 is provided in the middle of the ammonia introduction line 61 has been described as an example. However, the knockout drum 62 may be omitted. In this case, when purging, there is a possibility that oil may be mixed into ammonia as fuel. Therefore, as in the fifth aspect shown in FIG. 41, an oil catch tank 252 may be provided. The oil catch tank 252 in this fifth aspect has a structure for recovering the oil floating on the surface layer of the liquid phase of the dilution tank 64 by skimming. An oil detector (not shown) for detecting oil may be provided in the oil recovery line 253 from the dilution tank 64 to the oil catch tank 252. Further, the gas phase of the oil catch tank 252 and the gas phase of the dilution tank 64 are communicated with each other by a pressure equalizing pipe 254.

[0182] As shown in FIG. 42, in the above fifth aspect, during normal operation, the absorption liquid is stored so that the liquid level in the dilution tank 64 does not exceed "NORMAL". Then, when ammonia is absorbed by the absorption liquid and the liquid level reaches "LEVEL HIGH" and a certain period of time has elapsed, or when the pressure inside the dilution tank 64 reaches a preset pressure, clear water is injected through the clear water system such as the absorption liquid replenishment line 82 until the liquid level becomes "SKIMING". After that, the liquid level is maintained at "SKIMING" for a while. As a result, the oil component is recovered into the oil catch tank 252. If an oil detector is provided in the middle of the oil recovery line 253, when the oil component is no longer detected, the supply of clear water is stopped. On the other hand, if no oil detector is provided, the supply of clear water is stopped when a predetermined time has elapsed. If the liquid stored in the oil catch tank 252 is automatically shifted to another tank (not shown), the liquid may be drained to a preset liquid level "LOW" and then new clear water may be poured into the tank. Here, the recovery status of the oil catch tank 252 can be confirmed by the liquid level, weight, etc. The liquid stored in the oil catch tank 252 may be landed. In this case, for example, only the liquid in the oil catch tank 252 may be landed, or the entire oil catch tank 252 may be landed. Also, when the liquid level of the oil catch tank reaches a predetermined upper limit "HIGH - HIGH", an abnormality alarm may be issued.

[0183] FIG. 43 is a flowchart corresponding to FIG. 30 in the sixth aspect of another embodiment of the present disclosure. For example, in the case of the third embodiment, as in the above-described fifth aspect, when the knockout drum 62 is omitted and the oil catch tank 252 is provided, as shown in FIG. 43, for the third embodiment, an oil removal step (step S61) and a reducing agent production determination (step S62) may be added before the reducing agent production step (step S40). Since there is a possibility that oil contained in the ammonia fuel may be mixed during the purge process (step S110) and the emergency purge process (step S130), in the oil removal process (step S61), the ammonia absorption liquid and the oil are separated by specific gravity to remove the oil in order to produce a reducing agent with high purity. Next, as a result of removing the oil in the oil removal process (step S61), it is determined whether or not the ammonia absorption liquid in the dilution tank 64 is suitable for producing a reducing agent (step S62). If it is determined that the ammonia absorption liquid is suitable for producing a reducing agent as a result of this determination ("Yes" in step S62), the process proceeds to the reducing agent production process (step S40). On the other hand, if it is determined that the ammonia absorption liquid is not suitable for producing a reducing agent as a result of the above determination ("No" in step S62), the process proceeds to step S03 without performing the reducing agent production process and the denitrification process. In the sixth embodiment, if the ammonia absorbing liquid in the dilution tank 64 does not contain oil due to its structure, the oil removing step (step S61) and the reducing agent production determination (step S62) may be skipped.

[0184] Fig. 44 is a view corresponding to Fig. 3 in a seventh aspect of another embodiment of the present disclosure. Fig. 45 is a view corresponding to Fig. 3 in an eighth aspect of another embodiment of the present disclosure. Fig. 46 is a view corresponding to Fig. 16 in a ninth aspect of another embodiment of the present disclosure. In the above-mentioned embodiments and modifications, the dilution tank 64 is pressurized by the dilution fan 81, and the gas in the dilution tank 64 is pushed out. However, the arrangement of the fan for drawing out the gas from the dilution tank 64 is not limited to the above. For example, as in a seventh embodiment shown in FIG. 44, instead of the dilution fan 81, an induced draft fan 181 for sucking out the gas in the dilution tank 64 may be provided in the middle of the outlet line 66. Also, as in an eighth embodiment shown in FIG. 45, a gas seal fan 281 may be provided to supply gas to the outlet line 66 between the dilution tank 64 and the valve 88, thereby minimizing the ammonia drawn out from the dilution tank 64. Also, in the second embodiment, instead of the dilution fan 81, an induced draft fan 381 may be provided in the second outlet line 166B on the outlet side of the reactor 95 to draw in the gas in the dilution tank 64.

[0185] Figure 47 is a flowchart corresponding to FIG. 5 in the tenth aspect of another embodiment of the present disclosure. In the above-described first embodiment, the case where the combustion release step (step S14) is performed when it is determined that the emission regulation cannot be complied with (Yes in step S13) in the purge step (step S10) has been described. However, the present invention is not limited to this configuration.

[0186] For example, it may be as in the tenth aspect of another embodiment shown in FIG. 47. In this tenth aspect, when it is determined that the emission regulation cannot be complied with (Yes in step S13), the gas in the gas phase of the dilution tank 64 is not discharged through the lead-out line 66 (for example, the valve 88 is closed (step S69). Then, it is determined whether the dilution tank 64 can receive the fluid discharged by the purge (step S70). As a result of this determination, when it is determined that the dilution tank 64 can receive the above fluid (Yes in step S70), the process proceeds to the holding step (step S71), and the state where the flow of gas from the gas phase of the dilution tank 64 to the lead-out line 66 is stopped is maintained.

[0187] On the other hand, as a result of the above determination, when it is determined that the dilution tank 64 cannot receive the above fluid (No in step S70), it is determined whether the combustion decontamination device 70 is in operation (step S72). As a result of this determination, when it is determined that the combustion decontamination device 70 is in operation (Yes in step S72), the process proceeds to the combustion release step (step S14), and as in the first embodiment, the gas in the gas phase of the dilution tank 64 is decontaminated by the combustion decontamination device 70 and then released to the atmosphere. Further, when it is determined that the combustion decontamination device 70 is not in operation (No in step S72), the process proceeds to the above holding step (step S71).

[0188] Here, in the determination of whether the dilution tank 64 can receive the fluid discharged by purge (step S70), for example, the determination can be made based on the gas-liquid equilibrium state between the gas phase and the liquid phase in the dilution tank 64. When the gas-liquid equilibrium state cannot be maintained in the dilution tank 64, it will reach a state where the absorption liquid in the dilution tank 64 can no longer absorb ammonia. In addition to the determination based on the gas-liquid equilibrium state, for example, it is also possible to determine whether the dilution tank 64 can receive the fluid based on the pressure in the dilution tank 64. In this case, for example, when the pressure in the dilution tank 64 rises and reaches a predetermined upper limit pressure, it can be determined that it cannot be received. Note that a pressure vessel may be used as the dilution tank 64 in the tenth aspect of other embodiments. According to the tenth aspect of the above-described other embodiments, it is advantageous in that the opportunity to burn and detoxify ammonia can be further reduced.

[0189] FIG. 48 is a flowchart corresponding to FIG. 5 in the eleventh aspect of other embodiments of the present disclosure. In the tenth aspect of the other embodiments described above, the case where the holding step (step S71) is performed with the configuration of the first embodiment without the reactor 95 has been described. However, the holding step is also applicable when the reactor 95 is provided as in the second embodiment. In the eleventh aspect of other embodiments, in the purge step (step S110), steps S11 to S13, step S69, and step S70 are performed in the same manner as in the tenth aspect. Then, in step S70, when it is determined that the dilution tank 64 cannot receive it (''No'' in step S70), it is determined whether the reactor 95 is in an operable state (step S172). As a result of this determination, when it is determined that it is operable (''Yes'' in step S172), the holding step (step S71) is performed in the same manner as in the tenth aspect. On the other hand, when it is determined that the reactor 95 is inoperable (''No'' in step S172), the first reaction step (step S112) and the first discharge step (step S113) are performed. According to the eleventh aspect of the above-described other embodiments, even when the reactor 95 cannot be operated for some reason, ammonia can be retained in the dilution tank 64, so that it is possible to suppress ammonia from being released into the atmosphere without being detoxified.

[0190] In the above description, the case where the emission control area is a legally defined control area has been described as an example. However, the emission control area is not limited to a legally defined control area. The emission control area may be set, for example, by the operator of the floating body 1 or the like independently. In such a case, for example, it is also possible to set the area on the floating body 1 as the control area. Therefore, depending on the operator's setting, it is possible to proceed to the non-combustion emission process (steps S15, S25) or the atmospheric emission process (steps S115, S125) only when exhaust regulations can be complied with.

[0191] <Appendix> The floating body and the ammonia treatment method of the floating body described in the embodiment can be understood, for example, as follows.

[0192] (1) According to the first aspect, the floating body includes a floating body main body, a dilution tank 64 provided in the floating body main body for storing an absorption liquid capable of absorbing ammonia, an ammonia introduction line 61 capable of introducing ammonia in the floating body main body into the absorption liquid of the dilution tank 64, a dilution gas introduction line 65 capable of introducing a dilution gas for reducing the ammonia concentration in the gas phase into the gas phase of the dilution tank 64, a lead-out line 66 for leading out the gas in the gas phase of the dilution tank 64 from the dilution tank 64, an atmospheric release part 83 for releasing the gas led out from the dilution tank 64 by the lead-out line 66 into the atmosphere, and a bypass line 67 for bypassing the dilution tank 64 and guiding the fluid flowing through the ammonia introduction line 61 to the atmospheric release part 83. Examples of the floating body 1 include ships such as liquefied gas carriers, ferries, RORO ships, car carriers, and passenger ships, and floating storage units (FSUs), floating storage and regasification units (FSRUs), etc. As a result, after diluting ammonia with the dilution tank 64, it can be discharged to the atmosphere, eliminating the need for a large tank installation space for storing the absorption liquid that has absorbed ammonia. In addition, after absorbing as much ammonia as possible into the absorption liquid of the dilution tank 64, the dilution tank 64 can be bypassed and the fluid flowing through the ammonia introduction line 61 can be guided to the atmosphere release section 83. Therefore, it is no longer necessary to keep the combustion decontamination device 70 running at all times for emergency purging. Also, acids such as dilute sulfuric acid for decontaminating ammonia are no longer required. Furthermore, during emergency purging, after guiding ammonia to the dilution tank 64, the fluid flowing through the ammonia introduction line 61 can be guided to the atmosphere release section 83 by the bypass line 67, enabling the pressure of the inert gas due to purging to be rapidly reduced.

[0193] (2) According to the second aspect, the floating body is the floating body of (1), and includes a combustion decontamination device 70 capable of combusting and decontaminating the gas containing ammonia, and a dilution combustion line 71 for guiding the gas in the gas phase of the dilution tank 64 to the combustion decontamination device 70. Thereby, when performing planned fuel purging within an emission control area (e.g., within a port), the gas in the gas phase of the dilution tank 64 can be combusted by the combustion decontamination device 70, more reliably reducing the concentration of ammonia contained in the fluid released to the atmosphere.

[0194] (3) According to the third aspect, the floating body is the floating body of (2), and includes a compartment 30 for housing ammonia-related equipment, a compartment combustion line 72 for guiding the gas inside the compartment 30 to the combustion decontamination device 70, and a compartment release line 73 for guiding the gas inside the compartment 30 to the atmosphere release section 83. Examples of ammonia-related equipment include ammonia fuel equipment and ammonia cargo equipment. Examples of ammonia fuel equipment include a pump for pumping ammonia, a heat exchanger for heating the ammonia sent to the combustion device 8, an electric valve, a mixing tank, a catch tank, and an evaporator. Examples of the compartment 30 include an ammonia fuel supply device chamber 30A, an ammonia fuel intake chamber 30B, and the like. Thus, when ammonia leaks into the compartment 30, combustion decontamination by the combustion decontamination device 70 and atmospheric release by the atmosphere release section 83 can be switched and used. Therefore, in an emission control area where the gas released into the atmosphere may come into contact with the human body (e.g., inside a port), the combustion decontamination device 70 can ensure that the ammonia concentration in the gas released into the atmosphere is sufficiently reduced. On the other hand, outside the emission control area where the gas released into the atmosphere does not come into contact with the human body (e.g., on the high seas), it can be diffused into the atmosphere without using the combustion decontamination device 70, so that the fuel consumption can be reduced.

[0195] (4) According to the fourth aspect, the floating body is the floating body of (3), and includes a spraying device 31 that sprays an absorbent liquid capable of absorbing ammonia in the compartment 30 into the compartment 30, a compartment liquid discharge line 74 that discharges the absorbent liquid sprayed into the compartment 30 by the spraying device 31 from the compartment 30, and an ammonia liquid build-up tank 75 that stores the absorbent liquid discharged by the compartment liquid discharge line 74. Thus, the ammonia leaked into the compartment 30 can be absorbed by the absorbent liquid sprayed into the compartment 30 and stored in the ammonia liquid build-up tank 75 via the compartment liquid discharge line 74.

[0196] (5) According to the fifth aspect, the floating body is the floating body of (4), and includes a landing line 76 capable of landing the absorbent liquid stored in the ammonia liquid build-up tank 75. Thus, the absorbent liquid stored in the ammonia liquid build-up tank 75 can be landed and processed at a land-side treatment facility. Therefore, it is not necessary to provide equipment for disposing of the absorbent liquid stored in the ammonia liquid build-up tank 75 inside the floating body main body 2.

[0197] (6) According to the sixth aspect, the floating body is the floating body of (4), and the ammonia liquid build-up tank 75 is detachably provided on the floating body main body 2. As a result, the ammonia liquid bilge tank 75 can be landed together with the stored absorption liquid. Therefore, even when there is no piping for landing the absorption liquid at the port, the ammonia liquid bilge tank 75 can be transported to onshore treatment facilities to dispose of the absorption liquid.

[0198] (7) According to the seventh aspect, the floating body is any one of the floating bodies of (1) to (6), provided in the middle of the ammonia introduction line 61, and includes a mixing section 63 that mixes the ammonia in the ammonia introduction line 61 with the absorption liquid stored in the dilution tank 64. As a result, ammonia can be efficiently absorbed into the absorption liquid stored in the dilution tank 64.

[0199] (8) According to the eighth aspect, the floating body is the floating body of (7), and includes a heat exchanger 92 that cools the fluid mixed in the mixing section 63. As a result, it is possible to suppress the temperature rise due to the heat of absorption when ammonia is absorbed into the absorption liquid, and keep the solubility of ammonia in the absorption liquid as high as possible.

[0200] (9) According to the ninth aspect, the floating body is any one of the floating bodies of (1) to (8), provided in the middle of the ammonia introduction line 61, and includes a knockout drum 62 that separates the gas-liquid mixed fluid into gas and liquid and discharges the gas. As a result, only ammonia gas and inert gas can be introduced into the dilution tank 64.

[0201] (10) According to the tenth aspect, the floating body is any one of the floating bodies of (1) to (9), and includes a diluted absorption liquid discharge line 68 that discharges the absorption liquid in the dilution tank 64, and an ammonia waste liquid tank 69 that stores the absorption liquid discharged from the dilution tank 64. As a result, the absorption liquid stored in the dilution tank 64 that has absorbed ammonia can be discharged from the dilution tank 64 and stored in the ammonia waste liquid tank 69, and the dilution tank 64 can be replenished with the absorption liquid that has not absorbed ammonia. Therefore, without increasing the size of the dilution tank 64, the amount of ammonia that can be absorbed by the absorption liquid can be increased.

[0202] (11) According to the eleventh aspect, the floating body is any one of the floating bodies from (1) to (10), provided in the middle of the lead-out line 66, and reacts the ammonia gas contained in the gas led out from the dilution tank 64 with an absorption liquid capable of absorbing the ammonia gas. It comprises a reactor 95 and an absorption liquid supply section 96 for supplying the absorption liquid to the reactor 95. As a result, it becomes possible to react the ammonia gas contained in the gas led out from the dilution tank 64 with the absorption liquid and then release it to the atmosphere. Therefore, the ammonia concentration of the gas led from the lead-out line 66 to the atmosphere release section 83 can be more reliably reduced.

[0203] (12) According to the twelfth aspect, the floating body is the floating body of (11), and in the lead-out line 166, a gas circulation line 93 for returning the gas from the lead-out line 166B on the outlet side of the reactor 95 to the lead-out line 166A on the inlet side of the reactor 95 is provided. As a result, when the reactor 95 cannot completely absorb ammonia into the absorption liquid, the gas can be led from the outlet of the reactor 95 back to the inlet of the reactor 95 again.

[0204] (13) According to the thirteenth aspect, the floating body is the floating body of (11) or (12), and the absorption liquid supply section 96 includes a gravity tank capable of supplying the absorption liquid to the reactor 95 by gravity. As a result, the absorption liquid can be supplied to the reactor 95 without using a pump or the like. Therefore, even during a power failure or the like, it is possible to suppress the release of gas with a high ammonia concentration from the atmosphere release section 83, and thus the power supply and control from the emergency power supply system can be simplified.

[0205] (14) According to the 14th aspect, the floating body is any one of the floating bodies from (11) to (13), and the absorption liquid supply unit 96 includes a carbon dioxide gas supply unit that supplies carbon dioxide gas into the absorption liquid. Thereby, the absorption liquid can be made acidic. Therefore, the reaction between the absorption liquid and ammonia in the reactor can be enhanced, and ammonia can be efficiently absorbed into the absorption liquid.

[0206] (15) According to the 15th aspect, the floating body is any one of the floating bodies from (11) to (14), and includes a diluted absorption liquid discharge line 68 that discharges the absorption liquid in the dilution tank 64, a reactor absorption liquid discharge line 97 that discharges the absorption liquid reacted with ammonia by the reactor 95, and an ammonia waste liquid tank 69 that stores the absorption liquid discharged from the dilution tank 64 and the absorption liquid discharged from the reactor 95. Thereby, the absorption liquid stored in the dilution tank 64 that has absorbed ammonia can be discharged from the dilution tank 64 and stored in the ammonia waste liquid tank 69, and the absorption liquid that has not absorbed ammonia can be replenished to the dilution tank 64. Therefore, the amount of ammonia that can be absorbed by the absorption liquid can be increased without increasing the size of the dilution tank 64.

[0207] (16) According to the 16th aspect, the floating body is the floating body of (15), and includes a waste liquid tank introduction line 98 that communicates the lead-out line 66 with the gas phase inside the ammonia waste liquid tank 69, and the reactor absorption liquid discharge line 97 communicates with the gas phase inside the ammonia waste liquid tank 69. Thereby, the gas flowing through the lead-out line 66 can be guided to the reactor through the diluted absorption liquid discharge line 68, the gas phase of the ammonia waste liquid tank 69, and the reactor absorption liquid discharge line 97, and discharged to the atmosphere from the atmosphere release portion 83. Therefore, for example, the gas that bypasses the dilution tank 64 through the bypass line 67 can be brought into contact with the absorption liquid in the ammonia waste liquid tank 69 to absorb ammonia and then introduced into the reactor.

[0208] (17) According to the 17th aspect, the floating body is any one of the floating bodies from (11) to (16), and includes a sectional reactor introduction line 99 that guides the gas in the section 30 accommodating the ammonia-related equipment to the reactor 95. Thereby, it becomes possible to react the ammonia gas contained in the gas in the section 30 with the absorption liquid in the reactor 95 and absorb it into the absorption liquid.

[0209] (18) According to the 18th aspect, the floating body is any one of the floating bodies (10), (15), and (16), and includes a landing line 76 capable of landing the absorption liquid stored in the ammonia waste liquid tank 69. Thereby, it becomes possible to land the absorption liquid stored in the ammonia waste liquid tank 69 and perform disposal treatment with onshore treatment facilities or the like.

[0210] (19) According to the 19th aspect, the floating body is any one of the floating bodies (10), (15), and (16), the water around the floating body is seawater, and it includes a waste liquid tank discharge line 125 for discharging the absorption liquid in the ammonia waste liquid tank 69, a water intake section for taking in the seawater into the floating body main body, a seawater introduction line for introducing the seawater taken in from the water intake section into the floating body main body, an electrolysis section for generating a seawater electrolysis liquid containing sodium hypochlorite by electrolyzing the seawater introduced by the seawater introduction line, a denitrification reaction section for reacting a mixed liquid of the absorption liquid discharged by the waste liquid tank discharge line 125 and the seawater electrolysis liquid generated by the electrolysis section, and a discharge section for discharging the treated liquid after reacting in the denitrification reaction section into the seawater around the floating body main body. Thereby, it is not necessary to mount a large amount of strongly acidic chemical solution for decomposing ammonia in the floating body main body 2, so that the enlargement of the floating body main body 2 can be suppressed and the safety of the operator can be improved. Furthermore, since the absorption liquid in the ammonia waste liquid tank 69 can be detoxified and discharged into the seawater, the ammonia waste liquid tank 69 can be, for example, miniaturized or omitted.

[0211] (20) According to the 20th aspect, the floating body is any one of the floating bodies from (1) to (19), and is provided on the floating body main body 2 with an ammonia tank 10 for storing ammonia as fuel, a fuel ammonia supply line 114 connected to the ammonia tank 10, and a combustion device 8 that discharges exhaust gas by burning the ammonia introduced from the ammonia tank 10 via the fuel ammonia supply line 114, a denitration device 112 that performs denitration treatment on the exhaust gas discharged from the combustion device 8, a denitration ammonia liquid tank 108 that stores a denitration ammonia liquid used as a reducing agent for the denitration device 112, and a denitration ammonia introduction line 107 that introduces the absorption liquid in the dilution tank 64 into the denitration ammonia liquid tank 108. Thereby, the ammonia contained in the absorption liquid of the dilution tank 64 can be effectively utilized as ammonia for producing a reducing agent for the denitration device 112 that performs denitration treatment on the exhaust gas of the combustion device 8 without being discarded. Therefore, the amount of ammonia loaded for use as a reducing agent can be reduced, and the ammonia waste liquid tank 69 can be downsized.

[0212] (21) According to the 21st aspect, the floating body is the floating body of (20), and includes a pressure gauge 217 that measures the pressure of the denitration ammonia liquid tank 108. Thereby, the ammonia concentration can be detected without using the concentration meter 117.

[0213] (22) According to the 22nd aspect, the floating body is any one of the floating bodies from (1) to (21), and the lead-out lines 66, 166 include suction fans 181, 381 that attract the gas in the dilution tank 64. Thereby, the gas in the dilution tank 64 can be led out to the lead-out lines 66, 166.

[0214] (23) According to the 23rd aspect, the floating body is any one of the floating bodies from (1) to (22), and includes a gas seal fan 281 that supplies seal gas to the lead-out lines 66, 166. As a result, the ammonia derived from the dilution tank 64 can be minimized.

[0215] (24) According to the 24th aspect, the floating body is any one of the floating bodies from (1) to (23), and includes an oil catch tank 252 for removing the oil content in the liquid phase of the dilution tank 64. As a result, even when the knockout drum 62 is omitted and the oil content is mixed into the liquid phase of the dilution tank 64, it is possible to remove the oil content in the liquid phase in the dilution tank 64.

[0216] (25) According to the 25th aspect, the floating body is any one of the floating bodies from (1) to (24), and is provided on the floating body main body 2 and includes a liquefied ammonia recovery tank 250 for recovering liquefied ammonia from the fluid discharged when ammonia is purged. As a result, liquefied ammonia can be efficiently recovered.

[0217] (26) According to the 26th aspect, the ammonia treatment method of the floating body includes a purge step of supplying the fluid discharged when ammonia is purged to a dilution tank and mixing it with the absorption liquid stored in the dilution tank, and releasing the gas in the gas phase of the dilution tank to the atmosphere, and an emergency purge step of bypassing the dilution tank 64 and releasing the fluid to the atmosphere without supplying the fluid discharged when ammonia is purged to the dilution tank 64 after supplying the fluid discharged when ammonia is purged to the dilution tank 64 and mixing it with the absorption liquid stored in the dilution tank 64. As a result, for example, in the case of planned purging, after diluting ammonia with the dilution tank 64, the fluid discharged during purging can be released to the atmosphere. Further, in the case of unplanned emergency purging, after absorbing as much ammonia as possible into the absorption liquid in the dilution tank 64, the dilution tank 64 can be bypassed and the fluid can be guided to the atmosphere release part 83.

[0218] (27) According to the 27th aspect, the ammonia treatment method for the floating body is the ammonia treatment method for the floating body in (26), wherein in the purge step, when the floating body 1 is located within the emission control area, the gas in the gas phase of the dilution tank 64 is subjected to combustion decontamination by the combustion decontamination device 70 and then released to the atmosphere in a combustion emission step, and when the floating body 1 is not located within the emission control area, the gas in the gas phase of the dilution tank 64 is released to the atmosphere without being subjected to combustion decontamination by the combustion decontamination device 70 in a non-combustion emission step. Thereby, within the emission control area (such as in a port, etc.), the gas in the gas phase of the dilution tank 64 can be subjected to combustion decontamination and then released to the atmosphere. Also, for example, when not located within the emission control area, such as outside the emission control area, the gas in the gas phase of the dilution tank 64 can be released to the atmosphere without being subjected to combustion decontamination.

[0219] (28) According to the 28th aspect, the ammonia treatment method for the floating body is the ammonia treatment method for the floating body in (26) or (27), wherein in the purge step, when the floating body is located within the emission control area, the purge step includes a holding step of retaining the gas in the gas phase of the dilution tank 64 within the dilution tank 64. Thereby, when the floating body 1 is located within the emission control area, the opportunity for subjecting ammonia to combustion decontamination can be further reduced.

[0220] (29) According to the 29th aspect, the ammonia treatment method for the floating body is the ammonia treatment method for the floating body according to any one of (26) to (28), wherein when ammonia leakage occurs in the compartment 30 of the floating body 1, a spraying step of spraying an absorbent liquid capable of absorbing ammonia into the compartment 30, when the floating body 1 is located within the emission control area, a compartment internal gas combustion emission step of subjecting the gas in the compartment 30 after spraying the absorbent liquid by the spraying step to combustion decontamination by the combustion decontamination device 70 and then releasing it to the atmosphere, and when the floating body 1 is not located within the emission control area, a compartment internal gas non-combustion emission step of releasing the gas in the compartment 1 after spraying the absorbent liquid by the spraying step to the atmosphere without subjecting it to combustion decontamination by the combustion decontamination device 70. Thus, when ammonia leaks into Compartment 30, the gas in Compartment 30 can be combusted and detoxified and then released into the atmosphere within the emission control area (e.g., within a port, etc.). Also, when not located within the emission control area (e.g., on the high seas), etc., the gas in Compartment 30 can be released into the atmosphere without being combusted and detoxified.

[0221] (30) According to the 30th aspect, the ammonia treatment method for a floating body is the ammonia treatment method for a floating body in (26), and includes a first reaction step of reacting the gas in the gas phase of the dilution tank 64 with an absorbent liquid capable of absorbing ammonia gas contained in the gas, and a first release step of releasing the gas reacted with the absorbent liquid in the first reaction step into the atmosphere. Thereby, ammonia contained in the gas in the gas phase of the dilution tank 64 can be further reduced before being released into the atmosphere.

[0222] (31) According to the 31st aspect, the ammonia treatment method for a floating body is the ammonia treatment method for a floating body in (26) or (30), and includes a spraying step of spraying an absorbent liquid capable of absorbing ammonia in Compartment 30 when ammonia leakage occurs in Compartment 30 of the floating body 1, a second reaction step of reacting the gas in Compartment 30 after spraying the absorbent liquid in the spraying step with an absorbent liquid capable of absorbing ammonia gas contained in the gas, and a second release step of releasing the gas reacted with the absorbent liquid in the second reaction step into the atmosphere. Thereby, ammonia contained in the gas in Compartment 30 can be further reduced before being released into the atmosphere.

[0223] (32) According to the 32nd aspect, the ammonia treatment method for a floating body is the ammonia treatment method for a floating body in (30) or (31), and in the emergency purge step, the fluid discharged during purging is released into the atmosphere through the gas phase of the ammonia waste liquid tank 69 that stores the absorbent liquid discharged from the dilution tank 64. Thereby, in the case of an emergency purge, ammonia contained in the fluid bypassing the dilution tank 64 can be brought into contact with the absorbent liquid in the ammonia waste liquid tank 69 to absorb the ammonia.

[0224] (33) According to the 33rd aspect, the ammonia treatment method for the floating body is any one of the ammonia treatment methods for the floating body from (26) to (32), and includes a landing step of landing the absorption liquid stored in the dilution tank 64. Thereby, the absorption liquid stored in the dilution tank 64 can be landed and treated in a land-side treatment facility. Therefore, it is possible to suppress the enlargement of the dilution tank 64.

[0225] (34) According to the 34th aspect, the ammonia treatment method for the floating body is any one of the ammonia treatment methods for the floating body from (26) to (33), and includes a discharging step of reacting the absorption liquid stored in the dilution tank 64 with a seawater electrolysis solution obtained by electrolyzing seawater and then discharging it into the ocean. Thereby, it is not necessary to mount a large amount of a strongly acidic chemical solution for decomposing ammonia in the floating body 1. Furthermore, since the absorption liquid can be detoxified and discharged into seawater, the tank for storing the absorption liquid that has absorbed ammonia can be downsized or omitted.

[0226] (35) According to the 35th aspect, the ammonia treatment method for the floating body is any one of the ammonia treatment methods for the floating body from (26) to (34), and the absorption liquid stored in the dilution tank 64 is used as a reducing agent for the denitration device 112 provided in the floating body 1. Thereby, the absorption liquid stored in the dilution tank 64 can be effectively used as ammonia for producing a reducing agent for the denitration device 112 without being discarded. Therefore, the amount of ammonia loaded for use as a reducing agent for the denitration device 112 can be reduced.

[0227] (36) According to the 36th aspect, the ammonia treatment method for the floating body is the ammonia treatment method for the floating body of (35), and includes an oil removal step of removing oil contained in the absorption liquid used as a reducing agent for the denitration device 112. Thereby, it becomes possible to produce a reducing agent with high purity.

Explanation of symbols

[0228] 1,101,201,301…Floating body 2…Floating body main body 3a…Bow 3b…Stern 4…Superstructure 5A, 5B…Side 6…Bottom 7…Upper deck 8…Combustion device 10…Ammonia tank 20…Piping system 20p…Purge target area 21…Supply pipe 21A…First supply pipe 21B…Second supply pipe 22…Return pipe 23, 24…On-off valve 25…High-pressure pump 26…Residual ammonia supply line 27…Pipe 28…On-off valve 29…Tank opening line 30…Compartment 30A…Ammonia fuel supply device room 30B…Ammonia fuel intake room (bunker station) 31…Spraying device 32…Decontamination fan 33…Ventilation fan 34…Air supply duct 40…Mixing tank 50…Inert gas supply device 51…Inert gas supply section 52…Inert gas supply pipe 53…Inert gas supply valve 60, 160, 260, 360…Ammonia treatment device 61…Ammonia introduction line 62…Knockout drum 63…Mixing section 64…Dilution tank 65…Dilution gas introduction line 66, 166…Derivation line 67…Bypass line 68…Dilution absorption liquid discharge line 69…Ammonia waste liquid tank 70…Combustion decontamination device 71, 171…Dilution combustion line 72…Compartment combustion line 73…Compartment opening line 74…Compartment liquid discharge line 75, 175…Ammonia liquid bilge tank 76…Landing line 77…Mixer 78…Absorption liquid supply line 79…Absorption liquid circulation pump 80…Diffuser pipe 81…Dilution fan 82…Absorption liquid replenishment line 83…Atmospheric opening section 84, 85…Valve 86…Suction fan 87…Check valve 88…Valve 89…Ammonia waste liquid line 90, 190…Landing pump 91…Check valve 92…Heat exchanger 93…Gas circulation line 94…Valve 95…Reactor 96…Absorption liquid supply section 97…Reactor absorption liquid discharge line 98…Waste liquid tank introduction line 99…Compartment reactor introduction line 105…Gravity tank 106…Carbonic acid mixing section 107…Ammonia introduction line for denitration 108…Ammonia liquid tank for denitration 109,110... valve 111... exhaust pipe 112... denitrification device 113... denitrification ammonia liquid supply line 114... fuel ammonia supply line 114A... first line 114B... second line 115... circulation piping 116... mixing pump 117... concentration meter 118... denitrification ammonia liquid pump 119... flow rate control valve 120... feed pump 121... ammonia pressure pump 122... ammonia heat exchanger 123... gas exhaust pipe 125... waste liquid tank discharge line 126... ammonia decomposition device 127, 128... valve 130... water intake section 131... seawater introduction line 132... electrolysis section 134... discharge section 135... water intake 136... seawater pump 137... marine growth adhesion prevention treatment device 138... branch line 139... merging line 140... dilution line 141... Waste heat recovery section 142... Cooling water line 143... Cooling water pump 144... Cooling water branch line 145... Electrolysis device 146... Storage tank 147... Circulation line 148... Circulation pump 149... Line mixer 150... Electrolyte line 151... Denitrification reaction tank 152... Chemical tank 166A... First outlet line 166B... Second outlet line 181,381... Induction fan 217... Tank pressure gauge 250... Recovery tank 251... Recovery line 252... Oil catch tank 253... Oil recovery line 254... Pressure equalizing pipe 281... Gas seal fan G... Exhaust gas R... Distribution path,

Claims

1. A floating body main body, a dilution tank provided in the floating body main body and storing an absorbent liquid capable of absorbing ammonia, an ammonia introduction line capable of introducing ammonia in the floating body main body into the absorbent liquid in the dilution tank, a dilution gas introduction line capable of introducing a dilution gas for reducing the ammonia concentration in the gas phase into the gas phase in the dilution tank, a lead-out line for leading out the gas in the gas phase in the dilution tank from the dilution tank, an atmosphere release section for releasing the gas led out from the dilution tank to the atmosphere through the lead-out line, a bypass line for bypassing the dilution tank and guiding the fluid flowing through the ammonia introduction line to the atmosphere release section, A floating body comprising.

2. A combustion decontamination device capable of combusting and decontaminating the gas containing ammonia, a dilution combustion line for guiding the gas in the gas phase in the dilution tank to the combustion decontamination device, Comprising The floating body according to claim 1.

3. A compartment for accommodating ammonia-related equipment, a compartment combustion line for guiding the gas inside the compartment to the combustion decontamination device, a compartment release line for guiding the gas inside the compartment to the atmosphere release section, Comprising The floating body according to claim 2.

4. A spraying device for spraying an absorbent liquid capable of absorbing ammonia in the compartment into the compartment, a compartment liquid discharge line for discharging the absorbent liquid sprayed into the compartment by the spraying device from the compartment, an ammonia liquid bilge tank for storing the absorbent liquid discharged by the compartment liquid discharge line, Comprising The floating body according to claim 3.

5. Comprising a landing line capable of landing the absorbent liquid stored in the ammonia liquid bilge tank The floating body according to claim 4.

6. The ammonia liquid bilge tank is detachably provided on the floating body main body The floating body according to claim 4.

7. Provided in the middle of the ammonia introduction line, comprising a mixing section for mixing the ammonia in the ammonia introduction line and the absorbent liquid stored in the dilution tank The floating body according to any one of claims 1 to 6.

8. Comprising a heat exchanger for cooling the fluid mixed in the mixing section The floating body according to claim 7.

9. Provided in the middle of the ammonia introduction line, comprising a knock-out drum for separating the gas-liquid mixed fluid into gas and leading out the gas The floating body according to any one of claims 1 to 8.

10. A dilution absorbent liquid discharge line for discharging the absorbent liquid in the dilution tank, An ammonia waste liquid tank for storing the absorption liquid discharged from the dilution tank, comprising The floating body according to any one of claims 1 to 9.

11. A reactor provided in the middle of the lead-out line, for reacting ammonia gas contained in the gas led out from the dilution tank with an absorption liquid capable of absorbing the ammonia gas; An absorption liquid supply section for supplying the absorption liquid to the reactor; comprising The floating body according to any one of claims 1 to 10.

12. Among the lead-out lines, a gas circulation line is provided for returning gas from the lead-out line on the outlet side of the reactor to the lead-out line on the inlet side of the reactor. The floating body according to claim 11.

13. The absorption liquid supply section includes a gravity tank capable of supplying the absorption liquid to the reactor by gravity. The floating body according to claim 11 or 12.

14. The absorption liquid supply section includes a carbon dioxide gas supply section for supplying carbon dioxide gas into the absorption liquid. The floating body according to any one of claims 11 to 13.

15. A dilution absorption liquid discharge line for discharging the absorption liquid of the dilution tank; A reactor absorption liquid discharge line for discharging the absorption liquid reacted with ammonia by the reactor; An ammonia waste liquid tank for storing the absorption liquid discharged from the dilution tank and the absorption liquid discharged from the reactor; comprising The floating body according to any one of claims 11 to 14.

16. A waste liquid tank introduction line is provided for communicating the lead-out line with the gas phase inside the ammonia waste liquid tank. The reactor absorption liquid discharge line communicates with the gas phase inside the ammonia waste liquid tank. The floating body according to claim 15.

17. A compartment reactor introduction line for guiding the gas in the compartment accommodating the ammonia-related equipment to the reactor. The floating body according to any one of claims 11 to 16.

18. A landing line capable of landing the absorption liquid stored in the ammonia waste liquid tank. The floating body according to any one of claims 10, 15, and 16.

19. The water around the floating body floats is seawater, and A waste liquid tank discharge line for discharging the absorption liquid of the ammonia waste liquid tank; A water intake section for taking in the seawater into the floating body; A seawater introduction line for introducing the seawater taken in from the water intake section into the floating body main body, and an electrolysis section for electrolyzing the seawater introduced by the seawater introduction line to generate a seawater electrolysis solution containing sodium hypochlorite. A denitrification reaction section for reacting the mixed solution of the absorption liquid discharged by the waste liquid tank discharge line and the seawater electrolysis solution generated by the electrolysis section. A discharge section for discharging the treated liquid after the reaction in the denitrification reaction section into the seawater around the floating body main body. Comprising The floating body according to any one of claims 10, 15, and 16.

20. An ammonia tank provided in the floating body main body for storing ammonia as fuel, and a fuel ammonia supply line connected to the ammonia tank. A combustion device for discharging exhaust gas by burning the ammonia introduced from the ammonia tank through the fuel ammonia supply line. A denitration device for performing denitration treatment on the exhaust gas discharged from the combustion device. A denitration ammonia liquid tank for storing a denitration ammonia liquid used as a reducing agent for the denitration device. A denitration ammonia introduction line for introducing the absorption liquid in the dilution tank into the denitration ammonia liquid tank. The floating body according to any one of claims 1 to 19.

21. Equipped with a pressure gauge for measuring the pressure of the denitration ammonia liquid tank. The floating body according to claim 20.

22. The lead-out line is equipped with an induction fan for inducing the gas in the dilution tank. The floating body according to any one of claims 1 to 21.

23. The lead-out line is equipped with a gas seal fan for supplying seal gas. The floating body according to any one of claims 1 to 22.

24. Equipped with an oil catch tank for removing the oil content in the liquid phase of the dilution tank. The floating body according to any one of claims 1 to 23.

25. Provided in the floating body main body, comprising a liquefied ammonia recovery tank for recovering liquefied ammonia from the fluid discharged when purging ammonia. The floating body according to any one of claims 1 to 24.

26. A purge process of supplying the fluid discharged from the system through which ammonia flows when purging ammonia to the dilution tank and mixing it with the absorption liquid stored in the dilution tank, and discharging the gas in the gas phase of the dilution tank to the atmosphere. An emergency purge process for purging the ammonia urgently, including The emergency purge process is An absorption step of supplying a fluid discharged from a system through which ammonia flows to a dilution tank and mixing it with an absorption liquid stored in the dilution tank in a state where the gas in the gas phase of the dilution tank is not discharged from the dilution tank; An atmospheric release step of bypassing the dilution tank and releasing it to the atmosphere without supplying the fluid discharged from the system through which ammonia flows to the dilution tank in order to depressurize the system through which ammonia flows to a predetermined pressure after performing the absorption step; A method for treating ammonia in a floating body.

27. The purge step is When the floating body is located within an emission control area, a combustion emission step of combusting and detoxifying the gas in the gas phase of the dilution tank with a combustion detoxification device and then releasing it to the atmosphere; When the floating body is not located within the emission control area, a non-combustion emission step of releasing the gas in the gas phase of the dilution tank to the atmosphere without combusting and detoxifying it with the combustion detoxification device; further comprising The method for treating ammonia in a floating body according to claim 26.

28. The purge step is When the floating body is located within an emission control area, it includes a holding step of retaining the gas in the gas phase of the dilution tank within the dilution tank. The method for treating ammonia in a floating body according to claim 26 or 27.

29. A spraying step of spraying an absorption liquid capable of absorbing ammonia into the section when ammonia leakage occurs in the section of the floating body; When the floating body is located within an emission control area, a combustion emission step of detoxifying the gas in the section after spraying the absorption liquid by the spraying step with a combustion detoxification device and then releasing it to the atmosphere; When the floating body is not located within the emission control area, a non-combustion emission step of releasing the gas in the section after spraying the absorption liquid by the spraying step to the atmosphere without combusting and detoxifying it with the combustion detoxification device; including The method for treating ammonia in a floating body according to any one of claims 26 to 28.

30. A first reaction step of reacting the gas in the gas phase of the dilution tank with an absorption liquid capable of absorbing ammonia gas contained in the gas; A first release step of releasing the gas reacted with the absorption liquid in the first reaction step to the atmosphere; including The method for treating ammonia in a floating body according to claim 26.

31. A spraying step of spraying an absorption liquid capable of absorbing ammonia into the section when ammonia leakage occurs in the section of the floating body; A second reaction step of reacting the gas in the section after spraying the absorption liquid by the spraying step with an absorption liquid capable of absorbing ammonia gas contained in the gas; A second discharging step of discharging to the atmosphere the gas reacted with the absorption liquid in the second reaction step; comprising The method for treating ammonia of a floating body according to claim 26 or 30.

32. In the emergency purge step, the fluid discharged during purging is discharged to the atmosphere through the gas phase of an ammonia waste liquid tank that stores the absorption liquid discharged from the dilution tank. The method for treating ammonia of a floating body according to claim 30 or 31.

33. including a landing step of landing the absorption liquid stored in the dilution tank The method for treating ammonia of a floating body according to any one of claims 26 to 32.

34. including a discharging step of discharging to the ocean after reacting the absorption liquid stored in the dilution tank with a seawater electrolysis solution obtained by electrolyzing seawater The method for treating ammonia of a floating body according to any one of claims 26 to 33.

35. using the absorption liquid stored in the dilution tank as a reducing agent for a denitration device provided in the floating body The method for treating ammonia of a floating body according to any one of claims 26 to 34.

36. including an oil removal step of removing oil contained in the absorption liquid used as a reducing agent for the denitration device The method for treating ammonia of a floating body according to claim 35.

Images