Ammonia gas treatment device and ammonia gas treatment method

Abstract

The purpose of the present invention is to provide an ammonia gas treatment device and an ammonia gas treatment method using a neutralizing agent that is easier and safer than sulfuric acid and the like. The purpose is achieved by the ammonia gas treatment device. The ammonia gas treatment device is arranged in a ship carrying liquefied ammonia as fuel for cargo or ship power machinery, and is provided with a disinfestation device (6) for accommodating ammonia gas volatilized from the cargo or ammonia gas generated by the gasification of liquefied ammonia gas remaining in a fuel supply line of the power machinery and / or ammonia gas, and in the disinfestation device (6), an ammonia gas treatment device (7) for treating the liquefied ammonia gas and / or the ammonia gas generated by the gasification of the liquefied ammonia gas remaining in the fuel supply line of the power machinery is provided. Ammonia gas and / or ammonia gas generated by gasification of the liquefied ammonia gas are / is absorbed by clear water and neutralized by organic acid, and the neutralized water after neutralization is conveyed to a neutralized water storage tank (15).

Description

TECHNICAL FIELD

[0001] The present application relates to an ammonia gas treatment method in a ship carrying liquefied ammonia as cargo or engine fuel, and more particularly to an ammonia gas treatment device and an ammonia gas treatment method using a neutralizing agent that is easier to handle and safer than sulfuric acid or the like. BACKGROUND

[0002] In recent years, with the problem of global warming, liquefied ammonia is considered to be used as fuel for engines for ship propulsion. In the case of using liquefied ammonia as fuel, in order to purge the residual gas in the fuel piping after combustion is stopped or to control it within the combustion range when an abnormality occurs, it is sometimes necessary to empty the inside of the fuel supply system. In addition, in a tank storing ammonia, ammonia gas called boil-off gas is generated due to natural heat input or the like. If ammonia gas is allowed to generate, the pressure in the tank will rise to above the design pressure, so it is necessary to be treated by being discharged to the atmosphere or the like.

[0003] However, since ammonia gas is flammable and toxic, if ammonia gas is directly discharged to the atmosphere, it will have an impact on the human body. Therefore, it is necessary to remove ammonia gas from exhaust gas to be discharged to the atmosphere by a decontamination device.

[0004] Furthermore, there is also a method of returning ammonia gas to the tank after being re-liquefied. However, since re-liquefaction requires a large amount of electric power, there is a problem from the viewpoint of energy efficiency.

[0005] In Patent Literature 1, as a decontamination device, a method of absorbing ammonia gas with water and recovering it as ammonia water is described. The recovered ammonia water is diluted or neutralized with an acidic neutralizing agent.

[0006] It is known that a strong acid such as sulfuric acid or nitric acid is used as an acidic neutralizing agent for neutralizing ammonia water.

[0007] In addition, even if ammonia water is neutralized, considering the impact on the marine environment, depending on the discharge restrictions of different sea areas, there are cases where it cannot be discharged to the outside of the ship, and in such cases, it is necessary to store or treat the neutralized water in the ship.

[0008] PRIOR ART DOCUMENTS

[0009] PATENT LITERATURE

[0010] Patent Literature 1: Japanese Patent No. 6934555

[0011] However, since the neutralizing agent of a strong acid such as sulfuric acid or nitric acid is a hazardous substance, it needs to be extremely careful in use and storage in the ship. SUMMARY

[0012] Accordingly, an object of the present application is to provide an ammonia treatment device and an ammonia treatment method using a neutralizing agent that is easier and safer to handle than sulfuric acid or the like.

[0013] Further objects of the present application are apparent from the following description.

[0014] The above objects are solved by the following means.

[0015] 1. An ammonia treatment device provided in a ship that carries liquefied ammonia as a cargo or a fuel for a ship power machine, in which

[0016] a decontamination device that houses ammonia gas that has been volatilized from the cargo or liquefied ammonia gas that has been generated by gasification of liquefied ammonia remaining in a fuel supply line of the power machine and / or ammonia gas,

[0017] in the decontamination device, the liquefied ammonia gas that has been generated by gasification and / or the ammonia gas is absorbed with clean water and neutralized with an organic acid, and neutralized water is transported to a neutralized water storage tank.

[0018] 2. In the ammonia treatment device described in 1, a neutralizing liquid manufacturing device that manufactures a neutralizing liquid that is an aqueous organic acid solution based on clean water and an organic acid, and supplies the clean water and the organic acid as components of the neutralizing liquid to the decontamination device.

[0019] 3. In the ammonia treatment device described in 1, a neutralizing liquid tank that stores a neutralizing liquid that is an aqueous organic acid solution including clean water and an organic acid, and supplies the clean water and the organic acid as components of the neutralizing liquid to the decontamination device.

[0020] 4. In the ammonia treatment device described in 1, the decontamination device is supplied with the clean water,

[0021] the ammonia treatment device has a neutralizing agent tank that stores a solid organic acid, and supplies the solid organic acid as the organic acid to the decontamination device.

[0022] 5. An ammonia treatment device provided in a ship that carries liquefied ammonia as a cargo or a fuel for a ship power machine, in which

[0023] a decontamination device that houses ammonia gas that has been volatilized from the cargo or liquefied ammonia gas that has been generated by gasification of liquefied ammonia remaining in a fuel supply line of the power machine and / or ammonia gas, absorbs the ammonia gas with clean water to generate ammonia water, and transports the ammonia water to a neutralization treatment device; and

[0024] a neutralizing agent tank that stores an organic acid, and supplies the organic acid to the neutralization treatment device.

[0025] In the neutralization treatment device, the ammonia water is neutralized by the organic acid, and the neutralized neutralization water is transported to a neutralization water storage tank.

[0026] 6. In the ammonia gas treatment device described in 5, a return pipe is provided, which leads from a downstream of the neutralization treatment device to an upstream of the neutralization treatment device.

[0027] 7. An ammonia gas treatment device provided in a ship that carries liquefied ammonia as a cargo or a fuel of a power machine of the ship, comprising:

[0028] a decontamination device that accommodates ammonia gas that is volatilized from the cargo or is generated by gasification of liquefied ammonia remaining in a fuel supply line of the power machine, and / or ammonia gas, absorbs the ammonia gas with clean water to generate ammonia water, and transports the ammonia water to a neutralization water storage tank; and

[0029] a neutralizer tank that stores an organic acid and supplies the organic acid to the neutralization water storage tank,

[0030] In the neutralization water storage tank, the ammonia water is neutralized by the organic acid.

[0031] 8. An ammonia gas treatment device provided in a ship that carries liquefied ammonia as a cargo or a fuel of a power machine of the ship, comprising:

[0032] a decontamination device that accommodates ammonia gas that is volatilized from the cargo or is generated by gasification of liquefied ammonia remaining in a fuel supply line of the power machine, and / or ammonia gas, absorbs the ammonia gas with clean water to generate ammonia water, and transports the ammonia water to a neutralization water storage tank; and

[0033] a neutralizer tank that stores an organic acid and supplies the organic acid to a neutralization treatment device,

[0034] the ammonia water circulates between the neutralization treatment device and the neutralization water storage tank, and the circulating ammonia water is neutralized by the organic acid.

[0035] 9. In the ammonia gas treatment device described in 8, the ammonia water supply from the decontamination device toward the neutralization water storage tank is performed via the neutralization treatment device.

[0036] 10. In the ammonia gas treatment device described in any one of 1 to 9, comprising:

[0037] a reducing agent supply device that generates ammonia gas based on neutralization water generated by the neutralization of the ammonia; and

[0038] a delivery section that supplies the ammonia gas generated by the reducing agent supply device to a selective reduction catalyst unit connected to the power machine.

[0039] 11. The ammonia gas treatment device as set forth in 10, wherein a neutralizer residue after the ammonia gas is generated in the reducing agent supply device is stored as a neutralizer to be reused.

[0040] 12. An ammonia gas treatment method for treating ammonia gas in a ship that carries liquefied ammonia as a cargo or a fuel of a power machine of the ship, the ammonia gas treatment method comprising:

[0041] collecting ammonia gas generated by vaporization of the liquefied ammonia from the cargo or remaining in a fuel supply line of the power machine and / or the ammonia gas in a pest control device; and

[0042] absorbing and neutralizing the ammonia gas generated by vaporization of the liquefied ammonia and / or the ammonia gas with water in the pest control device, and delivering neutralized water to a neutralized water storage tank.

[0043] 13. The ammonia gas treatment method as set forth in 12, wherein a neutralizing liquid manufacturing device manufactures a neutralizing liquid as an aqueous organic acid solution based on water and an organic acid, and supplies the water and the organic acid as components of the neutralizing liquid to the pest control device.

[0044] 14. The ammonia gas treatment method as set forth in 12, wherein a neutralizing liquid as an aqueous organic acid solution including water and an organic acid is stored in a neutralizing liquid tank, and the water and the organic acid as components of the neutralizing liquid are supplied to the pest control device.

[0045] 15. The ammonia gas treatment method as set forth in 12, wherein the water is supplied to the pest control device,

[0046] a solid organic acid is stored in a neutralizer tank, and the solid organic acid is supplied as the organic acid to the pest control device.

[0047] 16. An ammonia gas treatment method for treating ammonia gas in a ship that carries liquefied ammonia as a cargo or a fuel of a power machine of the ship, the ammonia gas treatment method comprising:

[0048] collecting ammonia gas generated by vaporization of the liquefied ammonia from the cargo or remaining in a fuel supply line of the power machine and / or the ammonia gas in a pest control device, absorbing the ammonia gas with water to generate ammonia water, and delivering the ammonia water to a neutralizing treatment device;

[0049] storing an organic acid in a neutralizer tank, and supplying the organic acid to the neutralizing treatment device; and

[0050] In the neutralization treatment device, the ammonia gas is neutralized using the organic acid, and the neutralized neutralization water is sent to a neutralization water storage tank.

[0051] 17. The ammonia gas treatment method according to claim 16, wherein a return pipe is provided from a downstream of the neutralization treatment device to an upstream of the neutralization treatment device.

[0052] 18. An ammonia gas treatment method for treating ammonia gas in a ship that carries liquefied ammonia as a cargo or a fuel of a ship power machine, the ammonia gas treatment method comprising:

[0053] collecting ammonia gas that is generated by gasification of ammonia gas that is volatilized from the cargo or liquefied ammonia that remains in a fuel supply line of the power machine and / or ammonia gas in a pest control device, absorbing the ammonia gas with clean water to generate ammonia water, and sending the ammonia water to a neutralization water storage tank;

[0054] storing an organic acid in a neutralizer tank and supplying the organic acid to the neutralization water storage tank; and

[0055] neutralizing the ammonia water using the organic acid in the neutralization water storage tank.

[0056] 19. An ammonia gas treatment method for treating ammonia gas in a ship that carries liquefied ammonia as a cargo or a fuel of a ship power machine, the ammonia gas treatment method comprising:

[0057] collecting ammonia gas that is generated by gasification of ammonia gas that is volatilized from the cargo or liquefied ammonia that remains in a fuel supply line of the power machine and / or ammonia gas in a pest control device, absorbing the ammonia gas with clean water to generate ammonia water, and sending the ammonia water to a neutralization water storage tank;

[0058] storing an organic acid in a neutralizer tank and supplying the organic acid to a neutralization treatment device; and

[0059] circulating the ammonia water between the neutralization treatment device and the neutralization water storage tank, and neutralizing the ammonia water that is circulated using the organic acid.

[0060] 20. The ammonia gas treatment method according to claim 19, wherein the supply of the ammonia water from the pest control device to the neutralization water storage tank is performed via the neutralization treatment device.

[0061] 21. The ammonia gas treatment method according to any one of claims 12 to 20, comprising:

[0062] generating ammonia gas from neutralization water that is generated by neutralization of the ammonia by a reducing agent supply device; and

[0063] supplying the ammonia gas that is generated by the reducing agent supply device to a selective reduction catalyst unit that is connected to the power machine.

[0064] 22. The ammonia treatment method as claimed in claim 21, wherein a neutralizer residue after the ammonia gas is generated in the reducing agent supply device is stored and reused as the neutralizer.

[0065] Effects of the Invention

[0066] According to the present application, it is possible to provide an ammonia treatment device and an ammonia treatment method using a neutralizer which is easier and safer to handle than sulfuric acid or the like. BRIEF DESCRIPTION OF DRAWINGS

[0067] Figure 1 is a block diagram showing the structure of an ammonia treatment device of a first embodiment of the present application.

[0068] Figure 2 is a graph showing the reduction rate of ammonia in the reducing agent supply device.

[0069] Figure 3 is a block diagram showing the structure of an ammonia treatment device of a modified form (1) of the first embodiment of the present application.

[0070] Figure 4 is a block diagram showing the structure of an ammonia treatment device of a modified form (2) of the first embodiment of the present application.

[0071] Figure 5 is a block diagram showing the structure of an ammonia treatment device of a second embodiment of the present application.

[0072] Figure 6 is a block diagram showing the structure of an ammonia treatment device of a modified form of the second embodiment of the present application.

[0073] Figure 7 is a block diagram showing the structure of an ammonia treatment device of a third embodiment of the present application.

[0074] Figure 8 is a block diagram showing the structure of an ammonia treatment device of a fourth embodiment of the present application.

[0075] Figure 9 is a block diagram showing the structure of an ammonia treatment device of a modified form of the fourth embodiment of the present application.

[0076] Explanation of Reference Numerals

[0077] 1 liquefied ammonia tank 2 fuel supply device

[0078] 2a on-off valve 3 engine

[0079] 4 fuel pipe 4a gas-liquid separator

[0080] 5 on-off valve 6 decontamination device

[0081] 9 neutralizing liquid (aqueous citric acid solution) tank 10 on-off valve

[0082] 11 nitrogen gas supply device 12 heavy oil tank

[0083] 13 heavy oil fuel supply device 14 neutralizing liquid (aqueous citric acid solution) manufacturing device

[0084] 15 neutralizing water storage tank 17 selective reduction catalyst (SCR) unit

[0085] 18 delivery section 18a delivery pump

[0086] 19 reductant supply device 20 air exchange fan

[0087] 21 neutralizing agent tank 22 fresh water tank

[0088] 22a water supply pump 23 neutralizing treatment device

[0089] 23a return pipe 23b circulation pump DETAILED DESCRIPTION

[0090] Hereinafter, embodiments of the present application will be described using the drawings. Various features shown in each of the embodiments shown below can be combined with each other.

[0091] The present application is an ammonia gas treatment device in a ship on which liquefied ammonia is loaded as a cargo or a fuel of a ship power machine, and an ammonia gas treatment method executed in the ammonia gas treatment device.

[0092] The present application performs neutralization of ammonia water using a neutralizing agent that is easier to handle and safer than a strong acid such as sulfuric acid. In the present application, as a neutralizing agent that is easier to handle and safer than sulfuric acid or the like, an organic acid such as citric acid (C6H8O7-H2O) can be used.

[0093] In each of the embodiments below, citric acid is used as the organic acid, but is not limited thereto, and as the organic acid, formic acid, acetic acid, malic acid, oxalic acid, lactic acid, succinic acid, tartaric acid, butyric acid, fumaric acid, propionic acid, or the like can be used.

[0094] Hereinafter, embodiments of the present application will be described with reference to the drawings, classified according to the place where neutralization of ammonia water is performed.

[0095] In the first embodiment, as shown in Figure 1 , Figure 3 , Figure 4 neutralization is performed in the decontamination device 6.

[0096] In the second embodiment, as shown in Figure 5 , Figure 6As shown, the neutralization is performed in the neutralization treatment device 23.

[0097] In the third embodiment, as shown in Figure 7 the neutralization is performed in the neutralized water storage tank 15.

[0098] In the fourth embodiment, as shown in Figure 8 , Figure 9 the neutralization is performed in the circulation process between the neutralized water storage tank 15 and the neutralization treatment device 23.

[0099] (First Embodiment)

[0100] Figure 1 is a block diagram showing the structure of an ammonia gas treatment device of the first embodiment of the present application. The ammonia gas treatment method of the first embodiment of the present application is executed by this ammonia gas treatment device. In Figure 1 , the flow path of a liquid is shown by a solid line, and the flow path of a gas is shown by a broken line. The same applies to other drawings described later.

[0101] As shown in Figure 1 , the ammonia gas treatment device of the present embodiment treats ammonia gas generated by gasification of liquefied ammonia gas introduced from a fuel supply line that supplies liquefied ammonia fuel from a liquefied ammonia tank 1 to an engine 3 as a marine power machine, and / or ammonia gas (residual gas), or ammonia gas (evaporated gas) introduced from a cargo ammonia tank not shown.

[0102] The fuel supply line includes a fuel supply device 2 and a fuel pipe 4, and is a path through which liquefied ammonia fuel is supplied to the engine 3 through a compressor or a pump, a heat exchanger, or the like possessed by the fuel supply device 2, via the fuel pipe 4. In addition, the fuel supply device 2 can not be provided if not necessary. In addition, the fuel pipe 4 can include a supply pipe that supplies ammonia gas from the fuel supply device 2 to the engine 3, and a return pipe that returns the remaining ammonia gas from the engine 3 to the fuel supply device 2. Although not shown, a switching valve that can close an interval between the liquefied ammonia tank 1 side of the fuel supply device 2 and the engine 3 side of the fuel pipe 4 can be provided on the liquefied ammonia tank 1 side of the fuel supply device 2 and the engine 3 side of the fuel pipe 4.

[0103] The liquefied ammonia tank 1 stores ammonia as a part of fuel for the engine 3 or the like. The ammonia is stored as liquefied ammonia in the liquefied ammonia tank 1. In order to maintain the liquid state of the liquefied ammonia, the liquefied ammonia tank 1 keeps the inside at high pressure or low temperature. In the case where a large amount of liquefied ammonia is carried in a ship for a long-term voyage or the like, as the liquefied ammonia tank 1, a full refrigeration type (atmospheric pressure type) or a semi-refrigeration type (semi-pressurized type) ammonia tank, which is thin in wall thickness and easy to process, is mainly used. A suction pump is provided in the liquefied ammonia tank 1, and the stored liquefied ammonia is sent out to a pipe leading to the fuel supply device 2 by the suction pump.

[0104] The cargo ammonia tank stores liquefied ammonia as cargo, not as fuel for the engine 3 or the like. As with the liquefied ammonia tank 1, in the cargo ammonia tank, in order to maintain the liquid state of the liquefied ammonia, the cargo ammonia tank keeps the inside at high pressure or low temperature. In the case where a large amount of liquefied ammonia is carried in a ship, as the cargo ammonia tank, a full refrigeration type (atmospheric pressure type) or a semi-refrigeration type (semi-pressurized type) ammonia tank, which is thin in wall thickness and easy to process, is mainly used.

[0105] The liquefied ammonia fuel is supplied from the liquefied ammonia tank 1 to the engine 3 by the fuel supply device 2. In addition, the pilot fuel can be supplied from the heavy oil tank 12 to the engine 3 by the heavy oil fuel supply device 13. A suction pump is provided in the heavy oil tank 12, and the stored pilot fuel is sent out to a pipe leading to the heavy oil fuel supply device 13 by the suction pump.

[0106] The pilot fuel is burned together with the ammonia fuel at the time when the ammonia fuel starts to burn, and the inside of the combustion chamber is warmed up, so that the ammonia fuel is burned well. When the inside of the combustion chamber is warmed up to a state where the ammonia fuel can be burned by itself, the supply of the pilot fuel can be discontinued. In addition, in the case where the engine 3 can be burned by the ammonia fuel by itself from the start, the pilot fuel is not needed.

[0107] Nitrogen gas is supplied from the nitrogen gas supply device 11 to the fuel pipe 4 through the on-off valve 10. The nitrogen gas is also supplied to the fuel supply device 2 through the fuel pipe 4. The nitrogen gas purges the ammonia gas and / or ammonia gas generated by the gasification of the remaining liquefied ammonia inside the fuel pipe 4 and the fuel supply device 2 at the time of start, stop and emergency stop of the engine 3.

[0108] The ammonia gas and / or ammonia gas generated by the gasification of the remaining liquefied ammonia is introduced into the hazard removal device 6 from the fuel pipe 4 through the gas-liquid separator 4a and the on-off valve 5 at the time of start, stop or emergency stop of the engine 3. In addition, the ammonia gas and / or ammonia gas generated by the gasification of the remaining liquefied ammonia is also introduced into the hazard removal device 6 from the fuel supply device 2 through the on-off valve 2a at the time of start, stop or emergency stop of the engine 3, and at the time of maintenance or the like. Furthermore, a pump or the like is provided in the fuel supply device 2, and a gas-liquid separator is provided at the discharge port of the ammonia gas and / or ammonia gas generated by the gasification of the remaining liquefied ammonia.

[0109] Further, the gas introduced into the decontamination device 6 from the fuel pipe 4 and the fuel supply device 2 is a mixed gas of ammonia gas and a purge gas such as nitrogen gas or the like. The treatment in the present embodiment is performed with respect to the ammonia component in the mixed gas.

[0110] When ammonia gas is introduced into the decontamination device 6, the section between the liquefied ammonia tank 1 side of the fuel supply device 2 and the engine 3 side of the fuel pipe 4 is closed by the on-off valve. Also, ammonia gas (vaporized gas) is introduced into the decontamination device 6 from the cargo ammonia tank. Further, the nitrogen gas for purge is discharged to the atmosphere through the decontamination device 6.

[0111] In the decontamination device 6, the ammonia gas is absorbed by the clean water and neutralized by the organic acid. In the present embodiment, a neutralizing liquid (for example, a citric acid aqueous solution) as an organic acid aqueous solution is supplied from a neutralizing liquid manufacturing device 14 to the decontamination device 6 by a pump, and the clean water and the neutralizing agent (organic acid) are supplied as components of the neutralizing liquid.

[0112] In the present embodiment, the neutralizing agent as a component of the neutralizing liquid is citric acid as a solid (powder) organic acid. The solid (powder) citric acid is manufactured on land. Further, the citric acid is a colorless or white solid at ordinary temperature. The neutralizing agent is supplied to the neutralizing liquid manufacturing device 14.

[0113] The clean water as a component of the neutralizing liquid is generated, for example, by a water maker in the ship, and is supplied to the neutralizing liquid manufacturing device 14, but it is also possible to supply the clean water stored in advance to the neutralizing liquid manufacturing device 14.

[0114] The neutralizing liquid manufacturing device 14 is supplied with the clean water and the neutralizing agent (citric acid powder), and manufactures the neutralizing liquid (citric acid aqueous solution) as a liquid, and is delivered to the decontamination device 6 by a pump. In the decontamination device 6, the ammonia gas generated from the remaining liquefied ammonia gas introduced from the supply line and / or the ammonia gas is absorbed and neutralized by the neutralizing liquid delivered from the neutralizing liquid manufacturing device 14.

[0115] In order to use the neutralizing liquid as a liquid in the decontamination device 6, for example, a prescribed amount of the neutralizing liquid is added to a pipe of a stirring tank or a static mixer or the like, and the neutralization is performed while confirming the pH value in the decontamination device 6. The case where the neutralization is performed can be confirmed by a pH meter provided to the decontamination device 6.

[0116] The neutralized water (ammonium citrate solution (HOC(COOH)(CH2COONH4)2)) obtained by absorbing the ammonia gas and performing the neutralization is delivered to a neutralized water storage tank 15 and stored. The liquid delivered from the decontamination device 6 to the neutralized water storage tank 15 can be delivered by overflow, gravity, or a pump can also be used.

[0117] The neutralized water can be discharged to the outside of the ship as long as it is in a sea area where there is no discharge restriction.

[0118] In the ammonia treatment device and ammonia treatment method in the ship according to the present embodiment, since an organic acid such as citric acid is used as the neutralizing agent, the treatment becomes easier and safer compared to the case where sulfuric acid or the like is used.

[0119] The neutralized water stored in the neutralized water storage tank 15 can also be delivered to the reducing agent supply device 19 by the delivery pump 18a, heated to a range of 100°C to 150°C in the reducing agent supply device 19, generate ammonia gas, and used as a reducing agent in the selective reduction catalyst (SCR) unit 17. The heating of the neutralized water can be performed using a heater, or can be performed using the waste heat of the engine 3.

[0120] Figure 2 is a graph that confirms the reduction rate of ammonia in the reducing agent supply device.

[0121] The present inventors heated the neutralized water obtained by absorbing 5% of ammonia in 10% of an aqueous citric acid solution in order to confirm the generation of ammonia gas in the reducing agent supply device 19, and confirmed the reduction rate of the amount of the ammonia aqueous solution as shown in Figure 2 .

[0122] It can be confirmed that the amount of the ammonia aqueous solution gradually decreases with heating, decreases by about 90% at 100°C or higher, and decreases by more than 90% at around 150°C. Thus, it can be confirmed that the reduction rate of the amount of the ammonia aqueous solution changes little at 100°C or higher, particularly at 150°C or higher, and thus citric acid remains.

[0123] Therefore, it can be confirmed that by heating the neutralized liquid to 100°C or higher, particularly to around 150°C or higher, ammonia gas that can be used as a reducing agent can be generated.

[0124] The ammonia gas generated by the reducing agent supply device 19 is supplied to the selective reduction catalyst unit 17 connected to the engine 3 through the delivery portion 18 by the air exchange fan 20. In addition, the air exchange fan 20 can be provided separately. In the selective reduction catalyst unit 17, the ammonia gas reacts with NOx in the exhaust gas of the pilot fuel, and denitration treatment is performed using the selective catalytic reduction method (SCR). The exhaust gas after the denitration treatment is discharged to the atmosphere. The same applies to the other embodiments described later. x

[0125] In this way, ammonia gas is generated from the neutralized water and used in the selective reduction catalyst unit 17, and thus the volume of the neutralized water can be reduced. In addition, neither an operation of unloading the neutralized water to land nor a discharge of the neutralized water to the sea is required. ​

[0126] After the generation of ammonia gas, the neutralizer residue (organic acid component) is discharged from the reducing agent supply device 19. This neutralizer residue can be recovered and stored, and after being dissolved in water, used again as a neutralizer. In addition, the neutralizer residue can be incinerated or discharged into the atmosphere.

[0127] In the present embodiment, since an organic acid is used as the neutralizer, the neutralizer residue discharged from the reducing agent supply device 19 is a carbon component, and no additional treatment equipment or the like is required when recovering the neutralizer residue.

[0128] In the case where sulfuric acid is used as the inorganic acid in the neutralizer, since sulfur is a precipitate, a dust explosion or the like can occur. In addition, ammonium sulfate is produced in the catalyst, and can cause clogging of the pores in the catalyst. In the case where nitric acid is used as the inorganic acid in the neutralizer, since harmful gases such as NO2 are produced after neutralization, additional treatment equipment therefor is required.

[0129] (Modified form (1) of the first embodiment)

[0130] Figure 3 is a block diagram showing the structure of the ammonia gas treatment device of the modified form (1) of the first embodiment of the present application.

[0131] As shown in Figure 3 , the ammonia gas treatment device of the modified form (1) is provided with a neutralizer liquid tank 9 instead of the neutralizer liquid manufacturing device 14 in the first embodiment.

[0132] The neutralizer liquid tank 9 stores neutralizer liquid (aqueous citric acid solution) manufactured on land, and supplies the neutralizer liquid to the decontamination device 6 by a pump. In the decontamination device 6, ammonia gas is absorbed by water supplied from the neutralizer liquid tank 9 as a component of the neutralizer liquid, and neutralized by an organic acid as a component of the neutralizer liquid.

[0133] (Modified form (2) of the first embodiment)

[0134] Figure 4 is a block diagram showing the structure of the ammonia gas treatment device of the modified form (2) of the first embodiment of the present application.

[0135] As shown in Figure 4 , the ammonia gas treatment device of the modified form (2) supplies a neutralizer and water to the decontamination device 6 instead of the neutralizer liquid manufacturing device 14 in the first embodiment. In the modified form (2), the neutralizer is citric acid as a solid (powder) organic acid.

[0136] In the modified aspect (2), the clean water as the neutralizing liquid component can be generated by a water generator in the ship and stored in the clean water tank 22, or the clean water can be stored in the tank in advance. The stored clean water is supplied from the clean water tank 22 to the decontamination device 6 by the water supply pump 22a. In the decontamination device 6, the ammonia gas is absorbed and recovered by the clean water supplied from the clean water tank 22, and the ammonia water is generated. In the decontamination device 6, the pH value of the generated ammonia water can be confirmed by the pH meter.

[0137] After the ammonia water is generated in the decontamination device 6, the neutralizing agent is supplied to the decontamination device 6. In the decontamination device 6, the ammonia water is neutralized by the neutralizing agent. In the case of using the neutralizing agent as a solid, a prescribed amount of the neutralizing agent is added to the stirring tank by the solid supply device, and the neutralization is performed while confirming the pH value in the decontamination device 6. The case where the neutralization is performed (the pH value is 8 or less) can be confirmed by the pH meter provided to the decontamination device 6.

[0138] Further, since the use of the neutralizing agent as a solid more suppresses the amount (volume) of the neutralizing water compared to the case of using the neutralizing liquid as a liquid, the capacity of the neutralizing water storage tank 15 can be reduced. In this case, it is preferable to provide a heat exchanger for suppressing the reaction heat in the decontamination device 6 to reduce the liquid temperature.

[0139] (Second Embodiment)

[0140] Figure 5 is a block diagram showing the structure of the ammonia gas treatment device of the second embodiment of the present application. The ammonia gas treatment method of the second embodiment of the present application is executed by the ammonia gas treatment device. The same reference numerals as Figure 1 , Figure 3 , Figure 4 the same structure as the first embodiment, the description of Figure 1 , Figure 3 , Figure 4 is omitted here.

[0141] As shown in Figure 5 , the ammonia gas treatment device of the present embodiment, like the modified aspect (2) of the first embodiment, supplies the clean water from the clean water tank 22 to the decontamination device 6 by the water supply pump 22a, and differs from the modified aspect (2) of the first embodiment in that the neutralizing agent or the neutralizing liquid is stored in the neutralizing agent tank 21, and the neutralizing agent or the neutralizing liquid from the neutralizing agent tank 21 is supplied to the neutralizing treatment device 23.

[0142] The neutralizing agent tank 21 stores a solid (powder) neutralizing agent (citric acid) manufactured on land or a liquid neutralizing liquid (aqueous citric acid solution) manufactured on land. In the case of storing the solid neutralizing agent, the neutralizing agent is sent out from the neutralizing agent tank 21 by a conveyance device such as a screw conveyor, which is not shown. In addition, in the case of storing the liquid neutralizing liquid, the neutralizing liquid is sent out from the neutralizing agent tank 21 by a pump, which is not shown. The same applies to the neutralizing agent tank 21 in the following embodiments and modified examples.

[0143] In the pest control device 6, ammonia is absorbed and recovered by the clean water supplied from the clean water tank 22, and ammonia water is generated. In the pest control device 6, the pH of the generated ammonia water can be confirmed by a pH meter. The ammonia water is supplied to the neutralization treatment device 23. The liquid transported from the pest control device 6 to the neutralization treatment device 23 can be transported by overflow, gravity, or a pump can be used for the transport.

[0144] In the neutralization treatment device 23, the ammonia water is neutralized by the neutralizing agent or the neutralizing liquid supplied from the neutralizing agent tank 21. The case where neutralization is performed (pH is 8 or less) can be confirmed by a pH meter provided to the neutralization treatment device 23.

[0145] The neutralized water obtained by neutralizing the ammonia water by the neutralizing agent or the neutralizing liquid is temporarily stored in the neutralized water storage tank 15 so that ammonia gas does not volatilize. The neutralized water stored in the neutralized water storage tank 15 can be discharged to the outside of the ship, as in the first embodiment, in a sea area where there is no discharge restriction, or transported to the reducing agent supply device 19 by the transport pump 18a, ammonia gas is generated, and used as a reducing agent in the selective reduction catalyst unit 17, as long as there is no discharge restriction.

[0146] As described above, in the case of using the neutralizing agent as a solid, a prescribed amount of the neutralizing agent is added to the stirring tank by the solid supply device, and neutralization is performed while confirming the pH in the neutralization treatment device 23. Since the use of the neutralizing agent as a solid can more suppress the amount (volume) of the neutralized water than the case of using the neutralizing liquid as a liquid, the capacity of the neutralized water storage tank 15 can be reduced. In this case, it is preferable to provide a heat exchanger for suppressing reaction heat in the neutralization treatment device 23 to reduce the temperature of the liquid.

[0147] Further, the neutralization water storage tank 15 can also be provided with a return pipe that returns the liquid containing an ammonia component that has been transported to the neutralization water storage tank 15 to the neutralization treatment device 23 when a portion of the liquid stored in the neutralization water storage tank 15 is sent out from the neutralization water storage tank 15 by the circulation pump. With this return pipe, in the case where the liquid containing an ammonia component that has been transported to the neutralization water storage tank 15 due to insufficient neutralization is sent to the neutralization water storage tank 15, the liquid can be returned to the neutralization treatment device 23 to be further neutralized. Further, with the return pipe, in the case where the pH of the liquid transported to the neutralization water storage tank 15 is lower than 7 (acidic), the liquid can be returned to the neutralization treatment device 23 to be neutralized by mixing with the liquid before neutralization that has a higher pH (alkaline).

[0148] In the present embodiment, in the ammonia gas treatment device and ammonia gas treatment method in a ship, since an organic acid such as citric acid is also used as a neutralizing agent, the treatment becomes easier and safer compared to the case where sulfuric acid or the like is used.

[0149] In the present embodiment, since an organic acid is also used in the neutralizing agent, in the case where the reducing agent supply device 19 and the selective reduction catalyst unit 17 are provided, the neutralizing agent residue discharged from the reducing agent supply device 19 is a carbon component, and no additional treatment equipment or the like is required when the neutralizing agent residue is recovered.

[0150] (Modified aspect of the second embodiment)

[0151] Figure 6 is a block diagram showing the structure of the ammonia gas treatment device of the modified aspect of the second embodiment of the present application.

[0152] As shown in Figure 6 , in the second embodiment, the modified aspect is provided with a return pipe 23a that leads from the downstream of the neutralization treatment device 23 to the upstream of the neutralization treatment device 23. The return pipe 23a causes the liquid stored in the neutralization treatment device 23 to flow into the neutralization treatment device 23 again when a portion of the liquid is sent out from the neutralization treatment device 23 by the circulation pump 23b.

[0153] In the modified aspect, in the case where the liquid containing an ammonia component that has been transported to the neutralization water storage tank 15 due to insufficient neutralization remains in the neutralization treatment device 23, the liquid can be caused to flow into the neutralization treatment device 23 again by the return pipe 23a to be further neutralized. Further, in the case where the pH of the liquid transported to the neutralization water storage tank 15 is lower than 7 (acidic), the liquid can be returned to the neutralization treatment device 23 by the return pipe 23a to be neutralized by mixing with the liquid before neutralization that has a higher pH (alkaline).

[0154] (Third embodiment)

[0155] Figure 7is a block diagram showing the structure of an ammonia treatment device of a third embodiment of the present application. An ammonia treatment method of the third embodiment of the present application is executed by this ammonia treatment device. The same reference numerals as those of the second embodiment denote the same structures, and the description of the second embodiment is referred to if not particularly described Figure 1 , Figures 3 to 6 herein. Figure 1 , Figures 3 to 6 herein.

[0156] As shown in Figure 7 , the ammonia treatment device of the present embodiment, like the second embodiment, supplies the clean water from the clean water tank 22 to the decontamination device 6 by the water supply pump 22a, but differs from the first and second embodiments in that the neutralizing agent or neutralizing liquid from the neutralizing agent tank 21 is supplied to the neutralized water storage tank 15.

[0157] In the decontamination device 6, the ammonia gas is absorbed and recovered by the clean water supplied from the clean water tank 22, and the ammonia water is generated. In the decontamination device 6, the pH value of the generated ammonia water can be confirmed by the pH meter. The ammonia water is supplied to the neutralized water storage tank 15 to be stored so that the ammonia gas does not volatilize. The liquid transported from the decontamination device 6 to the neutralized water storage tank 15 can be transported by overflow, gravity, or a pump can be used for the transport.

[0158] In the neutralized water storage tank 15, the ammonia water is neutralized by the neutralizing agent or neutralizing liquid supplied from the neutralizing agent tank 21. The storage in the neutralized water storage tank 15 is performed until the ammonia water component is sufficiently neutralized. The neutralization condition (pH value of 8 or less) can be confirmed by the pH meter provided to the neutralized water storage tank 15.

[0159] The neutralized water stored in the neutralized water storage tank 15, like the first embodiment, can be discharged to the outside of the ship as long as there is no discharge restriction in the sea area, or can be transported to the reducing agent supply device 19 by the transport pump 18a, the ammonia gas is generated, and used as a reducing agent in the selective reduction catalyst unit 17.

[0160] In the present embodiment, the neutralizing agent as a solid is also used, and thus the amount (volume) of the neutralized water can be more suppressed compared to the case where the neutralizing liquid as a liquid is used, and thus the capacity of the neutralized water storage tank 15 can be reduced. In this case, it is preferable to provide a heat exchanger for suppressing reaction heat in the neutralized water storage tank 15 to reduce the liquid temperature.

[0161] In the present embodiment, in the ammonia treatment device and ammonia treatment method in the ship, since the organic acid such as citric acid is also used as the neutralizing agent, the treatment becomes easier and safer compared to the case where sulfuric acid or the like is used.

[0162] In the present embodiment, since the organic acid is also used in the neutralizing agent, in the case where the reducing agent supply device 19 and the selective reduction catalyst unit 17 are provided, the neutralizing agent residue discharged from the reducing agent supply device 19 is a carbon component, and no additional treatment equipment or the like is required at the time of recovering the neutralizing agent residue.

[0163] (Fourth Embodiment)

[0164] Figure 8 is a block diagram showing the structure of the ammonia treatment device of the fourth embodiment of the present application. The ammonia treatment method of the fourth embodiment of the present application is executed by this ammonia treatment device. The same reference numerals as Figure 1 Figures 3 to 7 the same structure, and the description of Figure 1 Figures 3 to 7 is referred to if not particularly described, and the description is omitted here.

[0165] As shown in Figure 8 , in the ammonia treatment device of the present embodiment, the neutralizing water stored in the neutralizing water storage tank 15 is circulated between the neutralizing water storage tank 15 and the neutralizing treatment device 23.

[0166] In the present embodiment, the clean water stored in the clean water tank 22 is also supplied to the decontamination device 6 by the clean water pump 22a. In the decontamination device 6, the ammonia gas is absorbed and recovered by the clean water delivered from the clean water tank 22, and the ammonia water is generated. In the decontamination device 6, the pH value of the generated ammonia water can be confirmed by the pH meter. The ammonia water is supplied to the neutralizing water storage tank 15, and a part thereof is supplied to the neutralizing treatment device 23 from the neutralizing water storage tank 15 by the circulation pump 23b. The liquid delivered from the decontamination device 6 to the neutralizing water storage tank 15 can be delivered by overflow, gravity, or can also be delivered using a pump.

[0167] The neutralizing agent or the neutralizing liquid stored in the neutralizing agent tank 21 is supplied to the neutralizing treatment device 23. In the neutralizing treatment device 23, the ammonia water is neutralized by the neutralizing agent or the neutralizing liquid supplied from the neutralizing agent tank 21. The case where the neutralization is performed (pH value is 8 or less) can be confirmed by the pH meter provided to the neutralizing treatment device 23. The neutralizing water obtained by neutralizing the ammonia water by the neutralizing agent or the neutralizing liquid is returned to the neutralizing water storage tank 15 to be stored so that the ammonia gas does not volatilize. That is, the ammonia water and the neutralizing water are circulated between the neutralizing water storage tank 15 and the neutralizing treatment device 23.

[0168] ​​The circulation of the ammonia water and the neutralized water between the neutralized water storage tank 15 and the neutralization treatment device 23 is performed until the ammonia water component is sufficiently neutralized. The neutralized water stored in the neutralized water storage tank 15, as in the first embodiment, can be discharged to the outside of the ship, as long as the sea area is not subject to discharge restrictions, or can also be delivered to the reducing agent supply device 19 by the delivery pump 18a, generate ammonia gas, and be used as a reducing agent in the selective reduction catalyst unit 17.

[0169] In the present embodiment, since a part of the ammonia water is extracted from the neutralized water storage tank 15 and supplied to the neutralization treatment device 23, compared to the second embodiment in which the entire ammonia water from the pest control device 6 is subjected to the neutralization treatment, there is an advantage that the capacity of the neutralization treatment device 23 can be reduced.

[0170] In the present embodiment, the neutralizing agent is also used as a solid, and thus compared to the case where a neutralizing liquid is used as a liquid, the amount (volume) of the neutralized water can be more suppressed, and the capacity of the neutralized water storage tank 15 can be reduced. In this case, it is preferable to provide a heat exchanger for suppressing reaction heat within the neutralization treatment device 23 to reduce the liquid temperature.

[0171] In the present embodiment, in the ammonia gas treatment device and the ammonia gas treatment method in the ship, since an organic acid such as citric acid is also used as a neutralizing agent, compared to the case where sulfuric acid or the like is used, the treatment becomes easier and safer.

[0172] In the present embodiment, the neutralizing agent is also used as an organic acid, and thus in the case where the reducing agent supply device 19 and the selective reduction catalyst unit 17 are provided, the neutralizing agent residue discharged from the reducing agent supply device 19 is a carbon component, and no additional treatment equipment or the like is required when the neutralizing agent residue is recovered.

[0173] (Modified aspect of the fourth embodiment)

[0174] Figure 9 is a block diagram showing the structure of the ammonia gas treatment device of the modified aspect of the fourth embodiment of the present application.

[0175] As shown in Figure 9 , the ammonia gas treatment device of the present modified aspect is one in which the ammonia water is supplied from the pest control device 6 to the neutralized water storage tank 15 via the neutralization treatment device 23 in the fourth embodiment ( Figure 8 ). The other structures are the same as in the fourth embodiment ( Figure 8 ).

[0176] In the present embodiment, the neutralizing agent or neutralizing liquid from the neutralizing agent tank 21 is supplied to the ammonia water supplied from the pest control device 6 to start neutralization in the neutralization processing device 23, and the ammonia water and the neutralizing water are supplied to the neutralizing water storage tank 15. The liquid transported from the neutralization processing device 23 to the neutralizing water storage tank 15 can be transported by overflow, gravity, or a pump can be used for the transport.

[0177] In the present embodiment, neutralization starts earlier than in the fourth embodiment, and thus the volatilization of ammonia gas from the ammonia water can be further suppressed.

[0178] As in the fourth embodiment, a portion of the liquid collected in the neutralizing water storage tank 15 is supplied again from the neutralizing water storage tank 15 to the neutralization processing device 23 by the circulation pump 23b. That is, the ammonia water and the neutralizing water are circulated between the neutralizing water storage tank 15 and the neutralization processing device 23. The circulation of the ammonia water and the neutralizing water between the neutralizing water storage tank 15 and the neutralization processing device 23 is performed until the ammonia water component is sufficiently neutralized.

Claims

1. An ammonia treatment device, wherein the ammonia treatment device is installed in a ship carrying liquefied ammonia as fuel for cargo or marine propulsion machinery, characterized in that: Includes a purging device that contains ammonia gas volatilized from the cargo or ammonia gas and / or ammonia gas generated from the vaporization of liquefied ammonia gas remaining in the fuel supply line of the power machinery. In the pest control device, the ammonia gas generated by the vaporization of liquefied ammonia and / or the ammonia gas is absorbed by clean water and neutralized by organic acid. The neutralized water is then transported to a neutralized water storage tank.

2. The ammonia treatment device according to claim 1, characterized in that: The ammonia treatment device includes a neutralization liquid manufacturing device, which manufactures a neutralization liquid as an aqueous solution of organic acid based on water and organic acid, and supplies the water and organic acid, which are components of the neutralization liquid, to the pest control device.

3. The ammonia treatment device according to claim 1, characterized in that: The ammonia treatment device has a neutralization tank that stores a neutralization liquid comprising water and organic acid as an aqueous solution of the organic acid, and supplies the water and the organic acid, which are components of the neutralization liquid, to the pest control device.

4. The ammonia treatment device according to claim 1, characterized in that: The pest control device is supplied with the clean water. The ammonia treatment device has a neutralizing agent tank that stores solid organic acid and supplies the solid organic acid to the pest control device.

5. An ammonia treatment device, wherein the ammonia treatment device is installed in a ship carrying liquefied ammonia as fuel for cargo or marine propulsion machinery, characterized in that, include: A pest control device that contains ammonia gas volatilized from the cargo or ammonia gas generated from the vaporization of liquefied ammonia gas remaining in the fuel supply line of the power machinery, absorbs the ammonia gas with clean water to generate ammonia water, and conveys the ammonia water to a neutralization treatment device; and A neutralizing agent tank, which stores organic acids and supplies them to the neutralization treatment device. Inside the neutralization treatment device, the ammonia water is neutralized by the organic acid, and the neutralized water is then transported to a neutralized water storage tank.

6. The ammonia treatment device according to claim 5, characterized in that: The ammonia treatment unit has a return piping that runs from downstream of the neutralization treatment unit to upstream of the neutralization treatment unit.

7. An ammonia treatment device, wherein the ammonia treatment device is installed in a ship carrying liquefied ammonia as fuel for cargo or marine propulsion machinery, characterized in that, include: A pest control device that contains ammonia gas volatilized from the cargo or ammonia gas generated from the vaporization of liquefied ammonia gas remaining in the fuel supply line of the power machinery, absorbs the ammonia gas with clean water to generate ammonia water, and transports the ammonia water to a neutralization water storage tank; and The neutralizing agent tank stores organic acids and supplies these organic acids to the neutralizing water storage tank. Inside the neutralized water storage tank, the ammonia water is neutralized by the organic acid.

8. An ammonia treatment device, wherein the ammonia treatment device is installed in a ship carrying liquefied ammonia as fuel for cargo or ship propulsion machinery, characterized in that, include: A pest control device that contains ammonia gas volatilized from the cargo or ammonia gas generated from the vaporization of liquefied ammonia gas remaining in the fuel supply line of the power machinery, absorbs the ammonia gas with clean water to generate ammonia water, and transports the ammonia water to a neutralization water storage tank; and A neutralizing agent tank stores organic acids and supplies them to the neutralization treatment unit. The ammonia water circulates between the neutralization treatment device and the neutralized water storage tank, and the circulating ammonia water is neutralized by the organic acid.

9. The ammonia treatment device according to claim 8, characterized in that: The ammonia water is supplied from the pest control device toward the neutralized water storage tank via the neutralization treatment device.

10. The ammonia treatment apparatus according to any one of claims 1 to 9, characterized in that, include: A reducing agent supply device that generates ammonia gas based on the neutralized water produced by the neutralization of the ammonia; as well as The conveying unit supplies ammonia generated by the reducing agent supply device to the selective reduction catalyst unit connected to the power machinery.

11. The ammonia treatment device according to claim 10, characterized in that: The neutralizing agent residue after ammonia is generated in the reducing agent supply device is stored as a neutralizing agent to be reused.

12. A method for treating ammonia gas, the method being used to treat ammonia gas in a ship carrying liquefied ammonia as cargo or fuel for marine propulsion machinery, characterized in that, include: The ammonia gas generated from the vaporization of ammonia gas volatilized from the cargo or from the vaporization of liquefied ammonia gas remaining in the fuel supply line of the power machinery is contained in a hazard removal device. as well as Inside the pest control device, clean water is used to absorb and organic acid is used to neutralize the ammonia gas generated by the vaporization of liquefied ammonia, and the neutralized water is then transported to a neutralized water storage tank.

13. The ammonia treatment method according to claim 12, characterized in that: A neutralizing solution, which is an aqueous solution of organic acid, is produced by a neutralizing solution manufacturing device based on water and organic acid, and the water and organic acid, which are components of the neutralizing solution, are supplied to the pest control device.

14. The ammonia treatment method according to claim 12, characterized in that: A neutralization solution, comprising water and organic acid as an aqueous solution of organic acid, is stored in a neutralization solution tank, and the water and organic acid, which are components of the neutralization solution, are supplied to the pest control device.

15. The ammonia treatment method according to claim 12, characterized in that: The clean water is supplied to the pest control device. Solid organic acid is stored in a neutralizing agent tank and supplied to the pest control device as said organic acid.

16. A method for treating ammonia gas, the method being used to treat ammonia gas in a ship carrying liquefied ammonia as cargo or fuel for marine propulsion machinery, characterized in that, include: The ammonia gas generated by vaporizing the ammonia gas volatilized from the cargo or the liquefied ammonia gas remaining in the fuel supply line of the power machinery is contained in a pest control device, the ammonia gas is absorbed with clean water to generate ammonia water, and the ammonia water is transported to a neutralization treatment device. The organic acid is stored in a neutralizing agent tank and supplied to the neutralization treatment device; and In the neutralization treatment device, the organic acid is used to neutralize the ammonia water, and the neutralized water is then transported to the neutralized water storage tank.

17. The ammonia treatment method according to claim 16, characterized in that: A return piping is provided from downstream of the neutralization treatment device to upstream of the neutralization treatment device.

18. A method for treating ammonia gas, the method being used to treat ammonia gas in a ship carrying liquefied ammonia as cargo or fuel for ship propulsion machinery, characterized in that, include: The ammonia gas generated by vaporizing the ammonia gas volatilized from the cargo or the liquefied ammonia gas remaining in the fuel supply line of the power machinery is contained in a pest control device, the ammonia gas is absorbed with clean water to generate ammonia water, and the ammonia water is transported to a neutral water storage tank. The organic acid is stored in a neutralizing agent tank, and the organic acid is supplied to the neutralized water storage tank; and The organic acid is used to neutralize the ammonia in the neutralized water storage tank.

19. An ammonia treatment method, said ammonia treatment method being used to treat ammonia in a ship carrying liquefied ammonia as cargo or fuel for ship propulsion machinery, characterized in that, include: The ammonia gas generated by vaporizing the ammonia gas volatilized from the cargo or the liquefied ammonia gas remaining in the fuel supply line of the power machinery is contained in a pest control device, the ammonia gas is absorbed with clean water to generate ammonia water, and the ammonia water is transported to a neutral water storage tank. The organic acid is stored in a neutralizing agent tank and then supplied to a neutralization treatment unit; and The ammonia water is circulated between the neutralization treatment device and the neutralized water storage tank, and the circulated ammonia water is neutralized using the organic acid.

20. The ammonia treatment method according to claim 19, characterized in that: The ammonia water is supplied from the pest control device toward the neutralized water storage tank via the neutralization treatment device.

21. The ammonia treatment method according to any one of claims 12 to 20, characterized in that: Ammonia gas is generated from the neutralized water produced by the neutralization of the ammonia via a reducing agent supply device; and The ammonia gas generated by the reducing agent supply device is supplied to the selective reduction catalyst unit connected to the power machinery.

22. The ammonia treatment method according to claim 21, characterized in that: The neutralizing agent residue after ammonia is generated in the reducing agent supply device is stored and reused as a neutralizing agent.

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