Treatment device and treatment method for ammonia gas

Abstract

To provide a treatment device and a treatment method for ammonia gas capable of effectively treating ammonia gas vaporized from a cargo or remaining in a fuel supply line of an engine in a vessel without discharging ammonia water dissolved in fresh water to outside of the vessel and of eliminating the necessity of an additional ammonia water supply tank.SOLUTION: Ammonia gas remaining in a fuel supply line of an engine 3 is converted into ammonia water by a detoxification device 6. Exhaust gas of the engine 3, urea water from a urea water tank 8 and the ammonia water generated by the detoxification device 6 are introduced to a selection type reduction catalyst unit 17. Denitration treatment of the exhaust gas is performed, and treatment for making the ammonia water harmless is performed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an ammonia gas treatment device and treatment method for a ship carrying liquefied ammonia as cargo or engine fuel, and more particularly to an ammonia gas treatment device and treatment method capable of effectively treating ammonia gas volatilized from the cargo or remaining in the engine fuel supply line in ammonia water dissolved in fresh water without being discharged outside the ship, and which does not require an additional ammonia water supply tank. [Background technology]

[0002] As described in Patent Document 1, a urea SCR (selective catalytic reduction) system is known as an exhaust gas purification device for purifying NOx (nitrogen oxides) contained in exhaust gas discharged from an engine.

[0003] The urea SCR system uses ammonia gas, which is produced when urea solution is injected into exhaust gas and hydrolyzed by the heat of the exhaust gas, as a reducing agent, and causes a chemical reaction between NOx and the ammonia gas in the presence of an SCR catalyst, reducing it to nitrogen and water.

[0004] Due to the strengthening of regulations on NOx emissions from ships, urea SCR systems are being introduced onto ships.

[0005] Meanwhile, in light of the recent global warming issue, the use of liquefied ammonia as fuel for marine propulsion engines is expected. When liquefied ammonia is used as fuel, it is necessary to empty the fuel supply system in order to purge the fuel supply line and to keep it within the flammable range in the event of an abnormality. In addition, in a tank that stores liquefied ammonia, ammonia gas called boil-off gas is generated due to natural heat input, etc., because liquefied ammonia is volatile. If ammonia gas is allowed to generate, the pressure in the tank will rise and exceed the design pressure.

[0006] Moreover, since ammonia gas is flammable and toxic, storing ammonia gas as is may have an adverse effect on the human body. Therefore, it is necessary to remove the toxicity of ammonia gas using a detoxification device. As a detoxification device, a device that dissolves ammonia gas in clean water to produce ammonia water is used.

[0007] Furthermore, under current environmental regulations, ammonia water cannot be discharged overboard, so any ammonia water recovered on board must be treated on board. Furthermore, since various devices and the like must be installed in a limited space on a ship, a method that can perform treatment in a small space is desirable.

[0008] In Patent Document 2, denitration is carried out by supplying liquefied ammonia, which is a fuel, to a selective catalytic reduction device.

[0009] In Patent Document 3, residual ammonia in a fuel supply system is recovered, and the recovered ammonia water is treated on board by increasing the concentration of the recovered ammonia water to a predetermined high concentration (e.g., several tens of percent) and supplying it to a selective catalytic reduction (SCR). The ammonia component is consumed in the denitrification treatment of engine exhaust gas. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2020-045769 A [Patent Document 2] Special Publication No. 2022-528443 [Patent Document 3] Patent Publication No. 2022-179983 Summary of the Invention [Problem to be solved by the invention]

[0011] Incidentally, in Patent Document 2, the residual ammonia in the fuel supply system is not recovered, and therefore the problem of recovering the residual ammonia is not presented.

[0012] In Patent Document 3, which recovers residual ammonia in a fuel supply system, the recovered ammonia water is used to perform denitration treatment of engine exhaust gas. However, there is a risk that the recovered ammonia water may not have an adequate concentration for denitration treatment, so an additional ammonia water supply tank is provided, which requires additional space.

[0013] An object of the present invention is to provide an ammonia gas treatment device and treatment method which can effectively treat ammonia water obtained by dissolving ammonia gas volatilized from cargo or remaining in an engine fuel supply line in fresh water on board without discharging the ammonia water overboard and which does not require an additional ammonia water supply tank.

[0014] Further objects of the present invention will become apparent from the following description. [Means for solving the problem]

[0015] The above problems are solved by the following inventions. 1. An ammonia gas treatment device for a ship carrying liquefied ammonia as fuel for cargo or ship engines and equipped with a selective catalytic reduction unit, the selective reduction catalyst unit is provided with a selective reduction catalyst into which exhaust gas from an engine of the ship is introduced, a urea solution serving as a reducing agent is supplied, and which performs a denitration treatment of the exhaust gas; A detoxification device is provided for dissolving ammonia gas and / or ammonia gas vaporized from liquefied ammonia remaining in the fuel supply line of the engine of the ship, or ammonia gas vaporized from the cargo, in fresh water to produce ammonia water, The ammonia water generated in the detoxification device is supplied to the selective reduction catalyst unit, and the ammonia water is detoxified. 2. An ammonia gas treatment device comprising: 2. a supply path for the ammonia water to the selective reduction catalyst unit is independent of a supply path for the urea water to the selective reduction catalyst unit, and the supply path for the ammonia water to the selective reduction catalyst unit is independent of a supply path for the urea water to the selective reduction catalyst unit, The urea water and the ammonia water can be simultaneously supplied to the selective reduction catalyst unit through a nozzle, The nozzle is a three-fluid nozzle having a flow path connected to an air supply source and supplying air for diffusing the urea water and / or the ammonia water, a flow path connected to the urea water supply path and spraying the urea water, and a flow path connected to the ammonia water supply path and spraying the ammonia water, and is disposed upstream in the selective reduction catalyst unit. 2. The ammonia gas treatment device according to claim 1, 3. a supply path for the ammonia water to the selective reduction catalyst unit is independent of a supply path for the urea water to the selective reduction catalyst unit, and the supply path for the ammonia water to the selective reduction catalyst unit is independent of a supply path for the urea water to the selective reduction catalyst unit, The urea water and the ammonia water can be simultaneously supplied to the selective reduction catalyst unit through a nozzle, The nozzle includes a first nozzle and a second nozzle, the first nozzle is a two-fluid nozzle having two flow paths, a flow path connected to the air supply source and supplying air, and a flow path connected to the urea water supply path and spraying the urea water, and is disposed upstream within the selective reduction catalyst unit, The second nozzle is a two-fluid nozzle having two flow paths, a flow path connected to the air supply source and for supplying air, and a flow path connected to the ammonia water supply path and for spraying the ammonia water, and is disposed on the upstream side within the selective reduction catalyst unit. 2. The ammonia gas treatment device according to claim 1, 4. a supply path for the ammonia water to the selective reduction catalyst unit is independent of a supply path for the urea water to the selective reduction catalyst unit, and the supply path for the ammonia water to the selective reduction catalyst unit is independent of a supply path for the urea water to the selective reduction catalyst unit, The urea water and the ammonia water can be simultaneously supplied to the selective reduction catalyst unit through a nozzle, The nozzle includes a first nozzle and a second nozzle, the first nozzle is a two-fluid nozzle having two flow paths, a flow path connected to the air supply source and supplying air, and a flow path connected to the urea water supply path and spraying the urea water, and is disposed upstream within the selective reduction catalyst unit, The second nozzle is a two-fluid nozzle having two flow paths, a flow path connected to the air supply source for supplying air and a flow path connected to the ammonia water supply path for spraying the ammonia water, and is disposed in an exhaust receiver through which the exhaust gas passes before the selective reduction catalyst unit, and the air and the ammonia water are supplied into the selective reduction catalyst unit through this exhaust receiver. 2. The ammonia gas treatment device according to claim 1, 5. a supply path of the ammonia water to the selective reduction catalyst unit merges with a supply path of the urea water to the selective reduction catalyst unit before the supply path reaches the selective reduction catalyst unit, Either the urea water or the ammonia water is supplied to the selective reduction catalyst unit through a nozzle, The nozzle is a two-fluid nozzle having two flow paths: a flow path connected to an air supply source for supplying air, and a flow path where the urea water supply path and the ammonia water supply path join and are connected to each other, and where the urea water or the ammonia water is sprayed, and the nozzle is disposed on the upstream side within the selective reduction catalyst unit. 2. The ammonia gas treatment device according to claim 1, 6. A meter for measuring the density of the ammonia water is provided, The urea water and the ammonia water are simultaneously supplied to the selective reduction catalyst unit, The density of the ammonia water measured by an instrument for measuring the density of the ammonia water is converted into a concentration of the ammonia water, and a molar equivalent of the ammonia water to be supplied to the selective reduction catalyst unit is calculated from the concentration; Calculating a molar equivalent of the urea water to be supplied to the selective reduction catalyst unit from the known concentration of the urea water; The molar equivalent of the ammonia water and the molar equivalent of the urea water supplied to the selective reduction catalyst unit are summed up, and the flow rates of the urea water and the ammonia water are adjusted according to the summed molar equivalent, thereby performing a denitrification treatment of the exhaust gas as the detoxification treatment. 5. The ammonia gas treatment device according to any one of 1 to 4 above. 7. A supply path of the ammonia water to the selective catalytic reduction unit is joined with liquefied ammonia supplied from a fuel supply device of the ship, and the ammonia water and the liquefied ammonia are mixed to become ammonia water, which is supplied to the selective catalytic reduction unit; a meter for measuring the density of the ammonia water obtained by mixing the ammonia water and the liquefied ammonia; The molar equivalent of the ammonia water to be supplied to the selective reduction catalyst unit is calculated from the density of the ammonia water measured by an instrument for measuring the density of the ammonia water, and the flow rate of the ammonia water is adjusted according to the calculated molar equivalent, thereby performing a denitrification treatment of the exhaust gas as the detoxification treatment. 6. The ammonia gas treatment device according to any one of 1 to 5 above. 8. A meter for measuring a leak ammonia concentration in the exhaust gas is provided, measuring an exhaust gas flow rate of the engine, and calculating a leak ammonia amount from the measured exhaust gas flow rate and the leak ammonia concentration, or from an exhaust gas flow rate calculated from load information based on an output of the engine and the leak ammonia concentration; The flow rate of the urea water or the ammonia water is adjusted so that the sum of the amount of ammonia supplied into the selective reduction catalyst unit by the urea water and / or the ammonia water and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit, and a denitrification treatment of the exhaust gas is performed as the detoxification treatment. 6. The ammonia gas treatment device according to any one of 1 to 5 above. 9. an ammonia slip catalyst is disposed within the selective reduction catalyst unit; The ammonia slip catalyst detoxifies the ammonia water supplied to the selective reduction catalyst unit. 6. The ammonia gas treatment device according to any one of 1 to 5 above. 10. A method for treating ammonia gas in a ship carrying liquefied ammonia as cargo or ship engine fuel and equipped with a selective catalytic reduction unit, comprising: The selective reduction catalyst unit is provided with a selective reduction catalyst into which exhaust gas from an engine of the ship is introduced, urea water as a reducing agent is supplied, and which performs a denitrification treatment of the exhaust gas; Ammonia gas generated by vaporization of liquefied ammonia remaining in the fuel supply line of the engine of the ship and / or ammonia gas, or ammonia gas volatilized from the cargo is dissolved in fresh water by a decontamination device to produce ammonia water; The ammonia water generated by the detoxification device is supplied to the selective reduction catalyst unit, and the ammonia water is detoxified. 1. A method for treating ammonia gas comprising the steps of: 11. The urea water and the ammonia water are simultaneously supplied to the selective reduction catalyst unit, measuring a density of the ammonia water, converting the measured density of the ammonia water into a concentration of the ammonia water, and calculating a molar equivalent of the ammonia water to be supplied to the selective reduction catalyst unit from the concentration; Calculating a molar equivalent of the urea water to be supplied to the selective reduction catalyst unit from the known concentration of the urea water; The molar equivalent of the ammonia water and the molar equivalent of the urea water to be supplied to the selective reduction catalyst unit are summed up, and the flow rates of the urea water and the ammonia water are adjusted according to the summed molar equivalent, and a denitrification treatment of the exhaust gas is performed as the detoxification treatment. 11. The method for treating ammonia gas according to claim 10, 12. merging liquefied ammonia supplied from a fuel supply device of the ship into a supply path of the ammonia water to the selective catalytic reduction unit, mixing the ammonia water and the liquefied ammonia to obtain ammonia water, and supplying the ammonia water to the selective catalytic reduction unit; measuring a density of the ammonia water obtained by mixing the ammonia water and the liquefied ammonia; The molar equivalent of the ammonia water to be supplied to the selective catalytic reduction unit is calculated from the measured density of the ammonia water, and the flow rate of the ammonia water is adjusted according to the calculated molar equivalent, and a denitrification treatment of the exhaust gas is performed as the detoxification treatment. 11. The method for treating ammonia gas according to claim 10, 13. providing an instrument for measuring a leak ammonia concentration in the exhaust gas; measuring an exhaust gas flow rate of the engine, and calculating a leak ammonia amount from the measured exhaust gas flow rate and the leak ammonia concentration, or from an exhaust gas flow rate calculated from load information based on an output of the engine and the leak ammonia concentration; The flow rate of the urea water or the ammonia water is adjusted so that the sum of the amount of ammonia supplied into the selective reduction catalyst unit by the urea water and / or the ammonia water and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit, and a denitrification treatment of the exhaust gas is performed as the detoxification treatment. 11. The method for treating ammonia gas according to claim 10, 14. an ammonia slip catalyst is provided within the selective reduction catalyst unit; The ammonia slip catalyst detoxifies the ammonia water supplied to the selective reduction catalyst unit. 11. The method for treating ammonia gas according to claim 10, Effect of the Invention

[0016] According to the present invention, it is possible to provide an ammonia gas treatment device and treatment method that can effectively treat ammonia water, which is made by dissolving ammonia gas that has evaporated from cargo or remained in an engine fuel supply line in fresh water, on board a ship without discharging it overboard, and that does not require an additional ammonia water supply tank. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a block diagram showing the configuration of a fuel supply system for a ship to which the ammonia gas treatment device of the present invention is applied. [Diagram 2] FIG. 1 is a block diagram showing the configuration of an ammonia gas treatment device according to a first embodiment of the present invention. [Diagram 3] FIG. 2 is a block diagram showing the configuration of an ammonia gas treatment device according to a second embodiment of the present invention. [Figure 4] FIG. 1 is a schematic cross-sectional view showing a first structure of a nozzle and a selective reduction catalyst unit applied to an ammonia gas treatment device of the present invention. [Diagram 5] FIG. 11 is a block diagram showing the configuration of an ammonia gas treatment device according to a third embodiment of the present invention. [Figure 6] FIG. 11 is a block diagram showing the configuration of an ammonia gas treatment device according to a fourth embodiment of the present invention. [Figure 7] FIG. 1 is a schematic cross-sectional view showing a second structure of a nozzle and a selective reduction catalyst unit applied to an ammonia gas treatment device of the present invention. [Figure 8] FIG. 11 is a schematic cross-sectional view showing a third structure of a nozzle and a selective reduction catalyst unit applied to the ammonia gas treatment device of the present invention. [Figure 9] FIG. 11 is a schematic cross-sectional view showing a fourth structure of a nozzle and a selective reduction catalyst unit applied to the ammonia gas treatment device of the present invention. [Figure 10] FIG. 11 is a schematic cross-sectional view showing a fifth structure of a nozzle and a selective reduction catalyst unit applied to the ammonia gas treatment device of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Various features shown in each embodiment can be combined with each other. The present invention relates to an ammonia gas treatment device for a ship carrying liquefied ammonia as cargo or fuel for the ship's engine, and an ammonia gas treatment method carried out in the ammonia gas treatment device.

[0019] [Configuration of ship fuel supply system] Fig. 1 is a block diagram showing the configuration of a fuel supply system for a ship to which an ammonia gas treatment system of the present invention is applied, in which the liquid flow path is indicated by a solid line and the gas flow path is indicated by a dotted line.

[0020] As shown in Fig. 1, the fuel supply system of the ship is equipped with a selective catalytic reduction (SCR) unit 17. A selective catalytic reduction (SCR) is installed in the selective catalytic reduction unit 17, and NO in the engine exhaust gas is reduced by selective catalytic reduction (SCR). X A denitration process is carried out by reacting the nitrate with ammonia gas.

[0021] The selective catalytic reduction unit 17 is connected to an exhaust duct of the engine 3, which is the engine of the ship, and engine exhaust gas is introduced into the selective catalytic reduction unit 17. In addition, the selective catalytic reduction unit 17 is supplied with urea water, which is a reducing agent stored in a urea water tank 8. Although not shown, the exhaust duct of the engine 3 may be provided with an instrument (ammonia gas concentration meter) for measuring the leak ammonia concentration in the engine exhaust gas, and may further be provided with an instrument (gas flow meter) for measuring the gas flow rate of the engine exhaust gas.

[0022] The urea water stored in the urea water tank 8 is supplied to the selective reduction catalyst unit 17 by a urea water pump 15a via a urea water transport pipe 15 which serves as a supply path for the urea water. The urea water is hydrolyzed in the high-temperature selective reduction catalyst unit 17 to generate ammonia gas. This ammonia gas denitrifies the engine exhaust gas. The denitrified exhaust gas is discharged into the atmosphere.

[0023] Meanwhile, in this fuel supply device, liquefied ammonia fuel is supplied from a liquefied ammonia tank 1 through a fuel supply line (a fuel supply device 2 and a fuel pipe 4) to an engine 3. The engine 3 is driven by burning the liquefied ammonia fuel.

[0024] In this fuel supply system, ammonia gas and / or ammonia gas (residual gas) vaporized from liquefied ammonia introduced from the fuel supply line, ammonia gas and / or ammonia gas vaporized from liquefied ammonia remaining in the fuel supply system 2, or ammonia gas (boil-off gas) introduced from a cargo ammonia tank (not shown) are subjected to a detoxification treatment by a detoxification device 6.

[0025] The fuel supply line is composed of a fuel supply device 2 and a fuel pipe 4, and is a path for supplying liquefied ammonia fuel to the engine 3 via the fuel pipe 4 by a compressor, a pump, a heat exchanger, etc., of the fuel supply device 2. Note that the fuel supply device 2 does not have to be provided if it is unnecessary. Furthermore, the fuel pipe 4 may be composed of a supply pipe for supplying ammonia gas from the fuel supply device 2 to the engine 3, and a return pipe for returning excess ammonia gas from the engine 3 to the fuel supply device 2. Although not shown, an opening / closing valve capable of closing a section between the liquefied ammonia tank 1 side of the fuel supply device 2 and the engine 3 side of the fuel pipe 4 may 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.

[0026] Liquefied ammonia tank 1 stores ammonia, which is a fuel used for engine 3 and the like. Ammonia is stored as liquefied ammonia inside liquefied ammonia tank 1. In order to maintain the liquid state of the liquefied ammonia, the inside of liquefied ammonia tank 1 is kept at high pressure or low temperature. When a large amount of liquefied ammonia is loaded onto a ship for a long voyage or the like, a fully refrigerated (atmospheric pressure) or semi-refrigerated (semi-pressurized) tank, which is thin and easy to process, is mainly used as the liquefied ammonia tank 1. Inside liquefied ammonia tank 1, there is a suction pump 1a, which sends the stored liquefied ammonia out to a pipe to fuel supply device 2.

[0027] A cargo ammonia tank (not shown) stores liquefied ammonia as cargo, rather than fuel to be used for engine 3 etc. As with liquefied ammonia tank 1, the interior of the cargo ammonia tank is kept at high pressure or low temperature in order to maintain the liquid state of the liquefied ammonia inside the cargo ammonia tank. When a large amount of liquefied ammonia is loaded onto a ship, a fully refrigerated (atmospheric pressure) or semi-refrigerated (semi-pressurized) cargo ammonia tank is mainly used, which are thin-walled and easy to process.

[0028] Liquefied ammonia fuel is supplied to the engine 3 from a liquefied ammonia tank 1 by a fuel supply device 2. Pilot fuel may also be supplied to the engine 3 from a heavy oil tank (not shown). The pilot fuel is burned together with the ammonia fuel when the ammonia fuel starts to burn, and heats up the inside of the combustion chamber, thereby allowing the ammonia fuel to burn well. When the inside of the combustion chamber is heated to a state where only the ammonia fuel can be burned, the supply of the pilot fuel may be stopped. If the engine 3 is capable of burning only the ammonia fuel from the start, pilot fuel is not necessary. Furthermore, the engine 3 may be a dual-fuel engine using liquefied ammonia fuel and a fossil fuel such as heavy oil. In the dual-fuel engine, it is possible to selectively switch between a mode in which the engine is operated mainly using liquefied ammonia fuel and a fossil fuel such as heavy oil as an ignition source, and a fossil fuel mode in which the engine is operated only using fossil fuel.

[0029] Nitrogen gas is supplied to the fuel pipe 4 from a nitrogen gas supply device 51 via a purge gas supply valve 50. This nitrogen gas is also supplied to the fuel supply device 2 via the fuel pipe 4. This nitrogen gas is an inert gas that purges ammonia gas and / or ammonia gas vaporized from liquefied ammonia remaining in the fuel pipe 4 and the fuel supply device 2 when the engine 3 is started, stopped, or stopped in an emergency.

[0030] At the start, stop or emergency stop of the engine 3, ammonia gas and / or ammonia gas vaporized from the remaining liquefied ammonia is introduced from the fuel pipe 4 through the gas-liquid separator 4a and the purge gas exhaust valve 5 into the detoxification device 6. At the start, stop or emergency stop of the engine 3 and during maintenance, ammonia gas and / or ammonia gas vaporized from the remaining liquefied ammonia is also introduced from the fuel supply device 2 through the on-off valve 2a into the detoxification device 6. In addition, in the fuel supply device 2, a gas-liquid separator is provided at an outlet for the ammonia gas and / or ammonia gas vaporized from the remaining liquefied ammonia, together with a pump, etc. The gas introduced from the fuel pipe 4 and the fuel supply device 2 to the detoxification device 6 is a mixture of ammonia gas and a purge gas such as nitrogen. The treatment in this embodiment is performed on the ammonia component in the mixed gas. When ammonia gas is introduced into the abatement 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 an on-off valve. Ammonia gas (boil-off gas) is also introduced into the abatement device 6 from the cargo ammonia tank. Nitrogen gas for purging is released into the atmosphere via the abatement device 6.

[0031] Fresh water, for example, generated by an onboard water maker and stored in a fresh water tank 22, is introduced into the decontamination device 6 by a water supply pump 22a. Here, the fresh water is water that contains as few impurities and additives as possible, such as distilled water, ion-exchanged water, filtered water, etc.

[0032] The detoxification device 6 is configured to include a water tank and a scrubber tank. The mixed gas of ammonia gas and nitrogen introduced into the detoxification device 6 is introduced into the water tank and the scrubber tank.

[0033] In the water tank or scrubber tank, the mixture of ammonia gas and nitrogen is passed through fresh water or fresh water is sprayed from above to dissolve the ammonia component in the fresh water, producing ammonia water. The nitrogen gas used for purging is released into the atmosphere from the abatement device 6.

[0034] As the detoxification device 6, it is preferable to use a water-sealed tank or a scrubber tank.

[0035] When a water seal tank is used, ammonia gas is introduced from the bottom of the water seal tank and absorbed into the fresh water stored in the water seal tank, becoming ammonia water. Furthermore, when a scrubber tank is used, ammonia gas is introduced from the bottom of the scrubber tank and comes into contact with fresh water sprayed from the top of the scrubber tank, whereby the ammonia gas is absorbed into the fresh water and becomes ammonia water.

[0036] More preferably, a water seal tank and a scrubber tank are provided in parallel, and ammonia gas re-volatilized from the ammonia water produced in the water seal tank and ammonia gas that has not been completely absorbed in the water seal tank are introduced into the lower part of the scrubber tank. In the scrubber tank, it is preferable to spray the ammonia water stored in the scrubber tank again from the upper part of the scrubber tank and circulate the ammonia gas, thereby further absorbing the ammonia gas re-volatilized from the ammonia water in the scrubber tank and the ammonia gas that has not been completely absorbed. By providing the water seal tank and the scrubber tank in parallel, ammonia gas can be reliably absorbed and discharge of ammonia gas overboard can be reliably prevented.

[0037] Even when only a water tank is used as the abatement device 6, a circulation mechanism can be provided to reintroduce the ammonia gas that has evaporated from the ammonia water and the ammonia gas that has not been absorbed by the fresh water back into the lower part of the water tank, thereby ensuring that the ammonia gas is absorbed and preventing it from being discharged overboard. Furthermore, even when only a scrubber tank is used as the abatement device 6, by providing a circulation mechanism that sprays the ammonia water accumulated in the scrubber tank again from the top of the scrubber tank in order to further absorb the ammonia gas that has evaporated from the ammonia water and the ammonia gas that the fresh water has not been able to completely absorb, it is possible to reliably absorb the ammonia gas and reliably prevent the ammonia gas from being discharged overboard.

[0038] The wastewater (ammonia water) from the detoxification device 6 is sent by gravity to the ammonia water tank 7, where it is temporarily stored. The ammonia water tank 7 is preferably a sealed pressurized tank so that ammonia gas does not volatilize from the stored ammonia water. When the ammonia water tank 7 is not a sealed pressurized tank, the ammonia gas volatilized from the stored ammonia water is preferably returned to the detoxification device 6 (water seal tank and / or scrubber tank).

[0039] The ammonia water temporarily stored in the ammonia water tank 7 is denitrified by a selective reduction catalyst unit 17. The ammonia water stored in the ammonia water tank 7 is supplied to the selective reduction catalyst unit 17 by an ammonia water pump 18a via an ammonia water transport pipe 18, which serves as an ammonia water supply path. The ammonia water generates ammonia gas in the high-temperature selective reduction catalyst unit 17, and this ammonia gas converts the NOx in the engine exhaust gas into ammonia gas. XAlternatively, the ammonia gas generated in the selective catalytic reduction unit 17 is rendered harmless by an ammonia slip catalyst (ASC) installed in the selective catalytic reduction unit 17. The denitration process in the selective reduction catalyst unit 17 is carried out in both an operation mode mainly using liquefied ammonia fuel and a fossil fuel mode.

[0040] The supply path of the ammonia water from the ammonia water tank 7 to the selective reduction catalyst unit 17 and the supply path of the urea water from the urea water tank 8 to the selective reduction catalyst unit 17 will be described in each embodiment described later. The structure of the selective reduction catalyst unit 17 and the structure of the nozzles that supply urea water and ammonia water to the selective reduction catalyst unit 17 will also be described later.

[0041] [First embodiment] 2 is a block diagram showing the configuration of an ammonia gas treatment apparatus according to the first embodiment of the present invention, in which the ammonia gas treatment method according to the first embodiment of the present invention is carried out.

[0042] In the ammonia gas treatment device of this embodiment, the liquid level of the urea water stored in the urea water tank 8 is measured by an LIT 8a (hereinafter referred to as "liquid level gauge 8a"), and the urea water is pumped from the urea water tank 8 to a urea water transport pipe 15 by a urea water pump 15a.

[0043] The urea water discharged from the urea water tank 8 passes through a first opening / closing valve 16, a urea water flow rate control valve 19, and an FT 20 (hereinafter referred to as a "urea water flow meter 20") provided in a urea water transport pipe 15, and is supplied to a selective reduction catalyst unit 17. The urea water flow rate control valve 19 is operated in response to the measurement result of the urea water flow meter 20.

[0044] The urea water transport pipe 15 branches between the urea water pump 15a and the urea water flow rate regulating valve 19, and the branch pipe returns to the urea water tank 8 via a urea water circulation valve 21. The urea water circulation valve 21 is a back pressure valve (regulator). The urea water circulation valve 21 opens when the pressure in the urea water transport pipe 15 exceeds a predetermined pressure, and limits the pressure in the urea water transport pipe 15 to equal to or lower than the predetermined pressure. The urea water circulation valve 21 may be a pressure reducing valve.

[0045] The urea water transport pipe 15 is joined with an ammonia water transport pipe 18, which serves as a supply path for ammonia water, before reaching the selective reduction catalyst unit 17. The piping after the urea water transport pipe 15 and the ammonia water transport pipe 18 are joined becomes a urea water or ammonia water transport pipe 28.

[0046] The liquid level of the ammonia water stored in the ammonia water tank 7 is measured by an LIT 7a (hereinafter referred to as a "liquid level gauge 7a"), and the ammonia water is sent from the ammonia water tank 7 to an ammonia water transport pipe 18 by an ammonia water pump 18a.

[0047] The ammonia water delivered from the ammonia water tank 7 passes through a second on-off valve 9 provided in an ammonia water transport pipe 18, an FD10 (hereinafter referred to as a "flow / density meter 10") which is an instrument for measuring the density of the ammonia water, an FT11 (hereinafter referred to as an "ammonia water flow meter 11") and a third on-off valve 12, and is supplied to a selective reduction catalyst unit 17. The flow / density meter 10 is a Coriolis type flow meter and can measure the flow rate and density of the ammonia water.

[0048] The ammonia water transport pipe 18 branches between the flow rate / density meter 10 and the ammonia water flow meter 11, and the branch pipe returns to the ammonia water tank 7 via an ammonia water circulation valve 14. The ammonia water circulation valve 14 is a back pressure valve (regulator). The ammonia water circulation valve 14 opens when the pressure in the ammonia water transport pipe 18 exceeds a predetermined pressure, and limits the pressure in the ammonia water transport pipe 18 to below the predetermined pressure. The ammonia water circulation valve 14 may be a pressure reducing valve.

[0049] The ammonia water transport pipe 18 is joined to the urea water transport pipe 15 before reaching the selective reduction catalyst unit 17. The piping after the urea water transport pipe 15 and the ammonia water transport pipe 18 are joined becomes a urea water or ammonia water transport pipe 28.

[0050] Air is supplied from an air supply source 25 to the urea water or ammonia water transport pipe 28, which is supplied into the selective reduction catalyst unit 17 together with the urea water or ammonia water. The pressure inside the urea water or ammonia water transport pipe 28 is measured by a PT 24 (hereinafter referred to as a "pressure gauge 24"). The temperature inside the selective reduction catalyst unit 17 is measured by a TT 26 (hereinafter referred to as a "thermometer 26"). The ammonia water circulation valve 14 and the urea water circulation valve 21 may be flow rate adjustment valves that are operated in response to the measurement results of the pressure gauge 24. The flow rates of the urea water and the ammonia water may be adjusted by adjusting the rotation speed of the pump using an inverter in response to the load of the engine 3.

[0051] Air and urea water, or air and ammonia water, are supplied into the selective reduction catalyst unit 17 through a nozzle 13. The structure of the selective reduction catalyst unit 17 and the shape of the nozzle 13 will be described later.

[0052] The abatement device 6, the ammonia water tank 7, and the urea water tank 8 are installed outside the engine room of the ship, and the selective reduction catalyst unit 17 is installed inside the engine room of the ship.

[0053] In this embodiment, in water areas subject to Tier 3 regulations on exhaust gas from marine diesel engines, urea water is supplied to the selective catalytic reduction unit 17 to perform denitration treatment, and in water areas subject to Tier 2 regulations, ammonia water is supplied to the selective catalytic reduction unit 17 to perform denitration treatment of the ammonia water. In the denitration treatment of the ammonia water, it is not necessary to denitrify the entire amount of nitrogen oxides (NOx) in the engine exhaust gas.

[0054] When supplying ammonia water to the selective reduction catalyst unit 17, the concentration of the ammonia water is calculated from the density of the ammonia water measured by the flow / density meter 10, and the output of the ammonia water pump 18a is adjusted according to this concentration, thereby making it possible to control the concentration of the ammonia water supplied to the selective reduction catalyst unit 17, and it is possible to make the entire amount of the ammonia water supplied in the selective reduction catalyst unit 17 be detoxified.

[0055] In this ammonia gas treatment device, the urea water and / or the ammonia water is supplied, for example, as follows.

[0056] (1) Supply in Tier 3 regulated waters In the ammonia gas treatment device of this embodiment, in a sea area subject to Tier 3 regulations, if the engine 3 is running and the temperature inside the selective reduction catalyst unit 17 measured by the thermometer 26 is sufficiently high, a reducing agent is supplied to the selective reduction catalyst unit 17 to perform denitration treatment. As the reducing agent, if ammonia water generated by the detoxification device 6 is stored, this ammonia water is preferably supplied, and if this ammonia water is insufficient, urea water is preferably supplied. By prioritizing the treatment of ammonia water, the amount of urea water consumed can be reduced. In addition, the capacity of the urea water tank can be reduced.

[0057] The supply amount of ammonia water is adjusted by measuring the density of the ammonia water in the ammonia water transport pipe 18 with a flow / density meter 10 and converting it into an ammonia water concentration, and by operating the third on-off valve 12 in accordance with this ammonia water concentration. The relationship between the concentration and flow rate of the supplied ammonia water and the amount of nitrogen oxides (NOx) in the engine exhaust gas to be treated is known in advance.

[0058] When the water level of the ammonia water in the ammonia water tank 7 reaches or exceeds the low level (L), the ammonia water pump 18a is started, and the second and third on-off valves 9 and 12 are opened to supply the ammonia water.

[0059] The flow rate of ammonia water is adjusted so that the amount of ammonia water supplied to the selective reduction catalyst unit 17 is a necessary and sufficient supply amount for the denitrification treatment in the selective reduction catalyst unit 17, calculated from the molar equivalent of ammonia water. In addition, in an operation mode in which liquefied ammonia fuel is mainly used, leak ammonia in the engine exhaust gas enters the selective reduction catalyst unit 17, so the amount of ammonia water supplied is set to an amount obtained by subtracting the amount of leak ammonia. In this case, it is preferable to provide an instrument (ammonia gas concentration meter) that measures the leak ammonia concentration in the engine exhaust gas. That is, the amount of leak ammonia is calculated from the exhaust gas flow rate calculated from the load information from the output of engine 3 and the leak ammonia concentration measured by the device. The load information is the relationship between the output of engine 3 and the exhaust gas flow rate, and is obtained in advance. The exhaust gas flow rate is calculated from the output of engine 3 based on this load information. Note that the load information varies depending on whether the operating mode is a liquefied ammonia fuel-based operating mode or a fossil fuel mode, and whether the navigation area is Tier 3 regulation (Tier 3) or Tier 2 regulation (Tier 2), so it is obtained for each case. Alternatively, a meter (gas flow meter) for measuring the flow rate of exhaust gas from the engine 3 may be further provided, and the amount of leaked ammonia may be calculated from the exhaust gas flow rate measured by the device and the leaked ammonia concentration. When urea water and ammonia water are supplied simultaneously, the amount of leaked ammonia is subtracted from the amount of ammonia supplied by ammonia water into the selective reduction catalyst unit 17 when there is no leaked ammonia, and the flow rate of ammonia water is adjusted so that this amount of ammonia is supplied by ammonia water. Then, the shortage of the amount of ammonia necessary and sufficient for the denitrification treatment of exhaust gas in the selective reduction catalyst unit 17 is made up by the ammonia supplied by the urea water. Note that the supply of ammonia by the urea water refers to the hydrolysis of the urea water by the heat of the exhaust gas in the selective reduction catalyst unit 17 to generate ammonia. That is, when urea water and ammonia water are supplied simultaneously, the flow rate of ammonia water is adjusted so that the sum of the amount of ammonia supplied into the selective reduction catalyst unit 17 by the urea water and ammonia water and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit 17, and denitrification treatment of the exhaust gas is performed as a detoxification treatment. When only urea water is supplied, the amount of leaked ammonia is subtracted from the amount of ammonia supplied by urea water into the selective reduction catalyst unit 17 when there is no leaked ammonia, and the flow rate of urea water is adjusted so that this amount of ammonia is supplied by urea water. By adjusting the flow rate in this way, the amount of ammonia supplied into the selective reduction catalyst unit 17 is adjusted to an amount necessary and sufficient for the denitrification treatment of exhaust gas. That is, when only urea water is supplied, the flow rate of the urea water is adjusted so that the sum of the amount of ammonia supplied into the selective reduction catalyst unit 17 by the urea water and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit 17, thereby performing denitrification treatment of the exhaust gas. The amount of nitrogen oxides (NOx) in the engine exhaust gas may be measured, and the flow rate of the ammonia water may be adjusted according to the measurement result.

[0060] When the water level of the ammonia water in the ammonia water tank 7 falls below the minimum level (LL), the ammonia water pump 18a is stopped to stop the supply of ammonia water.

[0061] In this embodiment, when urea water is supplied, the ammonia water pump 18a is stopped, the urea water pump 15a is started, the first opening / closing valve 16 is opened, and the supply of urea water is started. The flow rate of the urea water is adjusted so that the amount of urea water supplied is a necessary and sufficient supply amount for the denitrification treatment in the selective reduction catalyst unit 17, calculated from the molar equivalent of the urea water.

[0062] Since the concentration of the urea water is known, the molar equivalent of the urea water to be supplied can be calculated from this concentration. That is, the amount of urea water to be supplied can be adjusted by adjusting the urea water flow rate control valve 19 while measuring the flow rate of the urea water in the urea water transport pipe 15 with the urea water flow meter 20 according to the molar equivalent of the urea water in the urea water transport pipe 15. The amount of nitrogen oxides (NOx) in the engine exhaust gas may be measured, and the urea water flow rate control valve 19 may be adjusted in accordance with the measurement result.

[0063] (2) Supply in Tier 2 regulated waters In the sea area subject to the Tier 2 regulation, only ammonia water is supplied to perform detoxification or denitrification treatment. That is, in the sea area subject to the Tier 2 regulation, the urea water pump 15a is stopped and the supply of urea water is stopped.

[0064] When the water level of the ammonia water in the ammonia water tank 7 reaches or exceeds the low level (L), the ammonia water pump 18a is started, and the second and third on-off valves 9 and 12 are opened to supply the ammonia water.

[0065] The flow rate of ammonia water is adjusted so that the amount of ammonia water supplied to the selective reduction catalyst unit 17 is equal to or less than the amount required for denitrification treatment in the selective reduction catalyst unit 17, calculated from the molar equivalent of ammonia water. In addition, in an operation mode in which liquefied ammonia fuel is mainly used, leak ammonia in the engine exhaust gas enters the selective reduction catalyst unit 17, so the amount of ammonia water supplied is set to an amount obtained by subtracting the amount of leak ammonia. In this case, it is preferable to provide a meter (ammonia gas concentration meter) that measures the leak ammonia concentration in the engine exhaust gas. That is, the amount of leak ammonia is calculated from the exhaust gas flow rate calculated from the load information from the output of the engine 3 and the leak ammonia concentration measured by the device. Alternatively, a meter (gas flow meter) that measures the exhaust gas flow rate of the engine 3 may be further provided, and the amount of leak ammonia may be calculated from the exhaust gas flow rate measured by the device and the leak ammonia concentration. In Tier 2 regulated sea areas, only ammonia water is supplied, so the amount of leaked ammonia is subtracted from the amount of ammonia supplied to the selective reduction catalyst unit 17 by ammonia water when there is no leaked ammonia, and the flow rate of ammonia water is adjusted so that this amount of ammonia is supplied by ammonia water. By adjusting the flow rate, the amount of ammonia supplied to the selective reduction catalyst unit 17 is set to an ammonia amount within the denitrification processing capacity of the selective reduction catalyst unit 17. That is, the flow rate of ammonia water is adjusted so that the sum of the amount of ammonia supplied into the selective reduction catalyst unit 17 by the ammonia water and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit 17, and denitrification treatment of the exhaust gas is performed as a detoxification treatment.

[0066] In addition, when an ammonia slip catalyst (ASC) 17c described later is used in combination, the flow rate of the ammonia water is adjusted so that the amount of ammonia water supplied to the selective reduction catalyst unit 17 is equal to or less than the processing capacity of the ammonia slip catalyst (ASC) 17c, calculated from the molar equivalent of ammonia water.

[0067] As described above, the supply amount of ammonia water is adjusted by converting the density of the ammonia water in the ammonia water transport pipe 18 measured by the flow / density meter 10 into an ammonia water concentration, and operating the third on-off valve 12 in accordance with the ammonia water concentration while measuring the flow rate of the ammonia water flowing in the ammonia water transport pipe 18 by the flow / density meter 10. Note that the relationship between the concentration and flow rate of the ammonia water to be supplied and the amount of nitrogen oxides (NOx) in the engine exhaust gas to be treated is previously understood.

[0068] When the water level of the ammonia water in the ammonia water tank 7 falls below the minimum level (LL), the ammonia water pump 18a is stopped to stop the supply of ammonia water.

[0069] Second Embodiment 3 is a block diagram showing the configuration of an ammonia gas treatment apparatus according to a second embodiment of the present invention, in which an ammonia gas treatment method according to the second embodiment of the present invention is carried out.

[0070] As shown in Fig. 3, this embodiment is the first embodiment (Fig. 2) provided with a mixer 29 for mixing additional liquefied ammonia with the ammonia water sent from the abatement device 6, and an FD10b (hereinafter referred to as "second flow rate / density meter 10b") which is an instrument for measuring the density of the ammonia water. The second flow rate / density meter 10b is a Coriolis type flow meter and can measure the flow rate and density of the ammonia water after the additional liquefied ammonia has been mixed.

[0071] In this ammonia gas treatment device, liquefied ammonia supplied from the fuel supply device 2 joins with ammonia water at a position downstream of the third on-off valve 12 of the ammonia water transport pipe 18. The liquefied ammonia is supplied from the fuel supply device 2 to the ammonia water transport pipe 18 via a liquefied ammonia back pressure valve (regulator) 31 and a liquefied ammonia flow meter 32.

[0072] The mixer 29 is supplied with ammonia water mixed with liquefied ammonia, and mixes the liquefied ammonia and ammonia water to produce ammonia water. Cooling water is supplied to the mixer 29 from the outside to cool the ammonia water transport pipe 18, and the cooling ensures good mixing. The ammonia water transport pipe 18, to which the ammonia water that has passed through the mixer 29 is sent, passes through a second flow rate / density meter 10b and a check valve 30 and merges with the urea water transport pipe 15. The piping after the urea water transport pipe 15 and the ammonia water transport pipe 18 merge becomes the urea water or ammonia water transport pipe 28.

[0073] A check valve 33 is provided downstream of the urea water flow meter 20 provided in the urea water transport pipe 15.

[0074] In this improved embodiment, in water areas subject to Tier 3 regulations on exhaust gas from marine diesel engines, urea water or ammonia water is supplied to the selective catalytic reduction unit 17 to perform denitration treatment, and in water areas subject to Tier 2 regulations, ammonia water is supplied to the selective catalytic reduction unit 17 to perform denitration treatment of the ammonia water. In the denitration treatment of the ammonia water, it is not necessary to denitrify the entire amount of nitrogen oxides (NOx) in the engine exhaust gas.

[0075] In the denitration process, when the concentration and / or flow rate of the ammonia water is insufficient, the liquefied ammonia delivery pressure from the fuel supply device 2 is increased, and the liquefied ammonia is merged with the ammonia water via the liquefied ammonia back pressure valve 31 and the liquefied ammonia flow meter 32. The supply amount of liquefied ammonia is adjusted by adjusting the liquefied ammonia delivery pressure from the fuel supply device 2 and adjusting the flow rate through the liquefied ammonia back pressure valve 31 while measuring the flow rate of the liquefied ammonia with the liquefied ammonia flow meter 32 and measuring the flow rate and density of the ammonia water upstream and downstream of the mixer 29 with the flow rate / density meter 10 and the second flow rate / density meter 10b. By mixing the liquefied ammonia, the ammonia water supplied to the selective reduction catalyst unit 17 has a concentration sufficient for performing the denitration process. In this case, the amount of urea water consumed can be reduced.

[0076] In this ammonia gas treatment device, the urea water and / or the ammonia water is supplied, for example, as follows.

[0077] (1) Supply in Tier 3 regulated waters In the ammonia gas treatment device of this embodiment, the supply of the reducing agent in a sea area subject to Tier 3 regulations is similar to that of the first embodiment (FIG. 2). However, in this embodiment, when the concentration of the ammonia water generated by the detoxification device 6 is insufficient, the mixer 29 mixes additional liquefied ammonia. In this embodiment, if ammonia water generated by the detoxification device 6 is stored as the reducing agent, this ammonia water is supplied, and if this ammonia water is insufficient, it is preferable to add liquefied ammonia or supply urea water. By prioritizing the treatment of ammonia water, the consumption of urea water can be reduced. Also, it becomes possible to reduce the capacity of the urea water tank.

[0078] The density of the ammonia water mixed with the additional liquefied ammonia is measured by the second flow / density meter 10b. That is, the supply amount of ammonia water is adjusted by calculating the amount of liquefied ammonia to be added from the density of the ammonia water in the ammonia water transport pipe 18 measured by the flow-density meter 10, measuring the density of the ammonia water in the ammonia water transport pipe 18 after the addition by the second flow-density meter 10b and converting it into an ammonia water concentration, and operating the third opening / closing valve 12 according to this ammonia water concentration.

[0079] In this embodiment, when urea water is supplied in a sea area subject to Tier 3 regulations, the supply amount of urea water is adjusted in the same manner as in the first embodiment (FIG. 2).

[0080] (2) Supply in Tier 2 regulated waters In this embodiment, in sea areas subject to Tier 2 regulations, only ammonia water is supplied, and the amount of ammonia water supplied is adjusted in the same manner as in the first embodiment (FIG. 2). In this case, since liquefied ammonia is not added, the amount of ammonia water supplied to the selective reduction catalyst unit 17 can be adjusted by calculating the concentration of ammonia water from the density of the ammonia water measured by the flow / density meter 10 and adjusting the output of the ammonia water pump 18a in accordance with this concentration, as in the first embodiment (FIG. 2).

[0081] [Nozzle and selective catalytic reduction unit structure (1)] FIG. 4 is a schematic cross-sectional view showing a first structure of the nozzle and selective reduction catalyst unit applied to the ammonia gas treatment apparatus of the first embodiment (FIG. 2) and the second embodiment (FIG. 3).

[0082] As shown in FIG. 4, exhaust gas from the engine 3 is introduced into the selective reduction catalyst unit 17 from the combustion chamber 3a of the engine 3 through the exhaust receiver 27. The exhaust gas that has passed through the exhaust receiver 27 rotates the turbine of the turbocharger 52 and is exhausted into the atmosphere. Intake air compressed by the turbine of the turbocharger 52 is supplied to the combustion chamber 3a. In the selective reduction catalyst unit 17, two-stage selective reduction catalysts (SCR) 17a, 17b are arranged on the upstream side (introduction side) and downstream side (exhaust side). By providing multiple stages of selective reduction catalysts, it becomes easy to divide the roles of each catalyst, and a sufficient reaction area can be secured without increasing the size of the selective reduction catalyst unit 17. The selective reduction catalyst does not have to be provided in multiple stages.

[0083] The nozzle 13 that supplies urea water or ammonia water together with air into the selective reduction catalyst unit 17 is a two-fluid nozzle having two flow paths: a flow path connected to the air supply source 25 for supplying air, and a flow path connected to the urea water or ammonia water transport pipe 28 for spraying urea water or ammonia water.

[0084] This nozzle 13 supplies air from upstream of the upstream selective reduction catalyst 17a via a flow path for supplying air, and also sprays urea water or ammonia water from upstream of the upstream selective reduction catalyst 17a via a flow path for spraying urea water or ammonia water.

[0085] In this nozzle 13, both ammonia water and urea water can be sprayed from the central axis of the selective reduction catalyst unit 17, so that they can be diffused uniformly. In addition, this nozzle 13 has a simple structure because only one nozzle (one port) is required to be disposed in the selective reduction catalyst unit 17.

[0086] Third embodiment 5 is a block diagram showing the configuration of an ammonia gas treatment apparatus according to a third embodiment of the present invention, in which an ammonia gas treatment method according to the third embodiment of the present invention is carried out.

[0087] As shown in FIG. 5, in this embodiment, the urea water transport pipe 15 and the ammonia water transport pipe 18 in the first embodiment (FIG. 2) are not joined together, but are each independently connected to the nozzle 13.

[0088] In this ammonia gas treatment device, the urea water flow rate control valve 19 is operated according to the measurement results of the urea water flow meter 20 and the flow / density meter 10. This is to make the sum of the molar equivalent of the urea water and the molar equivalent of the ammonia water supplied equal to the molar equivalent when only urea water is supplied. The molar equivalent when only urea water is supplied is a molar equivalent necessary and sufficient for the denitrification treatment in the selective reduction catalyst unit 17.

[0089] In this embodiment, the pressure gauge 24 measures the pressure inside the urea water transport pipe 15. The pressure inside the ammonia water transport pipe 18 is measured by a PT 23 (hereinafter referred to as an "ammonia water pressure gauge 23").

[0090] The air supply source 25 supplies air to be supplied into the selective reduction catalyst unit 17 together with the urea water to the urea water transport pipe 15, and supplies air to be supplied into the selective reduction catalyst unit 17 together with the ammonia water to the ammonia water transport pipe . The air supply source 25 may supply air directly to the nozzle 13 through one pipe, instead of through the urea water transport pipe 15 and the ammonia water transport pipe 18. The same applies to a fourth embodiment (FIG. 6) described later.

[0091] In this improved embodiment, it is possible to simultaneously supply and spray urea water and ammonia water. In this embodiment, in water areas subject to Tier 3 regulations on exhaust gas from marine diesel engines, urea water and / or ammonia water is supplied to the selective catalytic reduction unit 17 to perform denitration treatment, and in water areas subject to Tier 2 regulations, ammonia water is supplied to the selective catalytic reduction unit 17 to perform denitration treatment of the ammonia water. In the denitration treatment of the ammonia water, it is not necessary to denitrify the entire amount of nitrogen oxides (NOx) in the engine exhaust gas.

[0092] When supplying ammonia water to the selective reduction catalyst unit 17, the concentration of the ammonia water is calculated from the density of the ammonia water measured by the flow / density meter 10, and the output of the ammonia water pump 18a is adjusted according to this concentration, thereby making it possible to control the concentration of the ammonia water supplied to the selective reduction catalyst unit 17, and it is possible to make the entire amount of the ammonia water supplied in the selective reduction catalyst unit 17 be detoxified.

[0093] In this ammonia gas treatment device, the urea water and / or the ammonia water is supplied, for example, as follows.

[0094] (1) Supply in Tier 3 regulated waters In the ammonia gas treatment device of this embodiment, urea water and ammonia water can be simultaneously supplied to perform denitrification treatment in Tier 3 regulation sea areas. In this embodiment, if ammonia water generated by the detoxification device 6 is stored as the reducing agent, this ammonia water is preferably supplied, and if the ammonia water is insufficient, urea water is preferably supplied at the same time. By prioritizing the treatment of ammonia water, the consumption of urea water can be reduced. In addition, the capacity of the urea water tank can be reduced.

[0095] In this embodiment, the urea water pump 15a and the ammonia water pump 18a are started to simultaneously supply urea water and ammonia water. The flow rates of the urea water and ammonia water are adjusted so that the total supply amount of the urea water and ammonia water supplied to the selective reduction catalyst unit 17 is a necessary and sufficient supply amount for the denitrification treatment in the selective reduction catalyst unit 17, calculated from the total molar equivalent of the urea water and ammonia water. The total molar equivalent of urea water and ammonia water necessary and sufficient for the denitrification treatment in the selective reduction catalyst unit 17 is equal to the molar equivalent of urea water to be supplied when only urea water is supplied to the selective reduction catalyst unit 17.

[0096] In addition, regarding the total supply amount of the urea water and the ammonia water, the supply amount of either the urea water or the ammonia water may be 0 (not supplied). When the urea water and the ammonia water are not sprayed simultaneously, the supply amount of either the urea water or the ammonia water is set to 0 (not supplied).

[0097] When the supply amount of ammonia water is set to 0 (no supply), the ammonia water pump 18a is stopped and only the urea water is supplied. In this case, the adjustment of the supply amount of the urea water is similar to that in the first embodiment (FIG. 2). When the supply amount of urea water is set to 0 (no supply), the urea water pump 15a is stopped and only ammonia water is supplied. In this case, the adjustment of the supply amount of ammonia water is similar to that in the first embodiment (FIG. 2).

[0098] (2) Supply in Tier 2 regulated waters In this embodiment, in sea areas subject to Tier 2 regulations, only ammonia water is supplied, and the amount of ammonia water supplied is adjusted in the same manner as in the first embodiment (FIG. 2).

[0099] [Fourth embodiment] 6 is a block diagram showing the configuration of an ammonia gas treatment apparatus according to a fourth embodiment of the present invention, in which an ammonia gas treatment method according to the fourth embodiment of the present invention is carried out.

[0100] As shown in Fig. 6, this embodiment is the third embodiment (Fig. 5) provided with a mixer 29 for mixing additional liquefied ammonia with the ammonia water sent from the abatement device 6, and a second flow / density meter 10b, as in the second embodiment (Fig. 3). The second flow / density meter 10b is a Coriolis flowmeter, and can measure the flow rate and density of the ammonia water after the additional liquefied ammonia has been mixed.

[0101] In this ammonia gas treatment device, liquefied ammonia is supplied from the fuel supply device 2 to a downstream position of the third on-off valve 12 of the ammonia water transport pipe 18 and merges with the ammonia water. The liquefied ammonia is supplied from the fuel supply device 2 to the ammonia water transport pipe 18 via a liquefied ammonia back pressure valve (regulator) 31 and a liquefied ammonia flow meter 32.

[0102] The ammonia water mixed with the liquefied ammonia is sent to the mixer 29, and the liquefied ammonia and the ammonia water are mixed to produce ammonia water. Cooling water for cooling the ammonia water transport pipe 18 from the outside is supplied to the mixer 29. The ammonia water that has passed through the mixer 29 is sent to the nozzle 13 via a check valve 30. A check valve 33 is provided downstream of the urea water flow meter 20 provided in the urea water transport pipe 15.

[0103] In this improved embodiment, it is possible to simultaneously spray urea water and ammonia water. In this improved embodiment, in water areas subject to Tier 3 regulations on exhaust gas from marine diesel engines, urea water and / or ammonia water is supplied to the selective reduction catalyst unit 17 to perform denitration treatment, and in water areas subject to Tier 2 regulations, ammonia water is supplied to the selective reduction catalyst unit 17 to perform denitration or non-toxic treatment of the ammonia water.

[0104] In the denitration process, when the concentration and / or flow rate of ammonia water is insufficient, the liquefied ammonia delivery pressure from the fuel supply device 2 is increased, and the liquefied ammonia is merged with the ammonia water via the liquefied ammonia back pressure valve 31 and the liquefied ammonia flow meter 32. The supply amount of liquefied ammonia is adjusted by adjusting the liquefied ammonia delivery pressure from the fuel supply device 2 and adjusting the flow rate through the liquefied ammonia back pressure valve 31 while measuring the flow rate of liquefied ammonia with the liquefied ammonia flow meter 32 and measuring the flow rate and density of the ammonia water with the flow / density meter 10. By mixing the liquefied ammonia, the ammonia water supplied to the selective reduction catalyst unit 17 has a concentration sufficient for performing the denitration process. In this case, the amount of urea water consumed can be reduced.

[0105] In this ammonia gas treatment device, the urea water and / or the ammonia water is supplied, for example, as follows.

[0106] (1) Supply in Tier 3 regulated waters In this embodiment, when urea water and ammonia water are simultaneously supplied in a sea area subject to Tier 3 regulations, the supply amounts of urea water and ammonia water are adjusted in the same manner as in the third embodiment (FIG. 5). However, the amount of ammonia water supplied to the selective reduction catalyst unit 17 is adjusted by calculating the concentration of ammonia water from the density of the ammonia water measured by a second flow-density meter 10b, not by the flow-density meter 10, and adjusting the output of the ammonia water pump 18a according to this concentration. This is because liquefied ammonia may be added.

[0107] In this embodiment, if ammonia water generated by the detoxification device 6 is stored as the reducing agent, this ammonia water is preferably supplied, and if this ammonia water is insufficient, liquefied ammonia is added and / or urea water is simultaneously supplied. By prioritizing the treatment of ammonia water, the consumption of urea water can be reduced. Also, the capacity of the urea water tank can be reduced.

[0108] In this embodiment, when only urea water is supplied in a sea area subject to Tier 3 regulations, the supply amount of urea water is adjusted in the same manner as in the first embodiment (FIG. 2). In this embodiment, when only ammonia water is supplied in a sea area subject to Tier 3 regulations, the supply amount of ammonia water is adjusted in the same manner as in the second embodiment (FIG. 3), because liquefied ammonia may be added.

[0109] (2) Supply in Tier 2 regulated waters In this embodiment, in sea areas subject to Tier 2 regulations, only ammonia water is supplied, and the amount of ammonia water supplied is adjusted in the same manner as in the second embodiment (FIG. 3). In this case, since liquefied ammonia is not added, the amount of ammonia water supplied to the selective reduction catalyst unit 17 can be adjusted by calculating the concentration of ammonia water from the density of the ammonia water measured by the flow / density meter 10 and adjusting the output of the ammonia water pump 18a in accordance with this concentration, as in the first embodiment (FIG. 2).

[0110] [Nozzle and selective catalytic reduction unit structure (2)] FIG. 7 is a schematic cross-sectional view showing a second structure of the nozzle and selective reduction catalyst unit applied to the ammonia gas treatment apparatus of the third embodiment (FIG. 5) and the fourth embodiment (FIG. 6).

[0111] 7, the nozzle 13 can be a three-fluid nozzle having three flow paths: a flow path connected to an air supply source 25 for supplying air, a flow path connected to an ammonia water transport pipe 18 for supplying ammonia water, and a flow path connected to a urea water transport pipe 15 for supplying urea water. In this structural example, the flow path for supplying air is used in common for diffusing ammonia water and urea water.

[0112] This nozzle 13 supplies air for diffusion from upstream of the upstream selective reduction catalyst 17a via a flow path for air, sprays ammonia water from upstream of the upstream selective reduction catalyst 17a via a flow path for ammonia water, and sprays urea water from upstream of the upstream selective reduction catalyst 17a via a flow path for urea water.

[0113] In this nozzle 13, both ammonia water and urea water can be sprayed from the central axis of the selective reduction catalyst unit 17, so that they can be diffused uniformly. In addition, this nozzle 13 has a simple structure because only one nozzle (one port) is required to be disposed in the selective reduction catalyst unit 17.

[0114] In this nozzle 13, the urea water and the ammonia water are sprayed through dedicated flow paths, so that it is possible to accommodate a large difference between the amount of ammonia water to be sprayed and the amount of urea water to be sprayed.

[0115] In the selective reduction catalyst unit 17 using this nozzle 13, urea water and / or ammonia water is sprayed in water areas subject to Tier 3 regulations of exhaust gas regulations for marine diesel engines, and ammonia water is sprayed in water areas subject to Tier 2 regulations. When spraying ammonia water in Tier 3 regulated sea areas, the concentration of the ammonia water must be controlled to ensure that there is a sufficient amount of ammonia for denitrification treatment.

[0116] In this nozzle 13, the flow path for the urea water can be a high flow path, and the flow path for the ammonia water can be a low flow path. The flow rate of air is adjusted by a control valve with a flow meter according to a signal indicating whether the mode is for spraying urea water or ammonia water. By using this nozzle 13, it is possible to execute a small flow rate mode for only treating ammonia water in sea areas subject to Tier 2 regulations. In this case, urea water and ammonia water are not sprayed simultaneously.

[0117] In the structural example of the nozzle 13 described above, a flow path for supplying air is shared between the diffusion of ammonia water and the diffusion of urea water, but this is not limited to this, and a flow path for supplying air for diffusing ammonia water and a flow path for supplying air for diffusing urea water may be provided separately.

[0118] That is, the nozzle 13 may be a three-fluid nozzle having four flow paths: a flow path connected to the urea water transport pipe 15 for spraying urea water, a flow path connected to the ammonia water transport pipe 18 for spraying ammonia water, a flow path connected to the air supply source 25 having an opening for supplying air for diffusing the urea water, and a flow path connected to the air supply source 25 having an opening for supplying air for diffusing the ammonia water.

[0119] This nozzle 13 supplies air for diffusing ammonia water and ammonia water from upstream of the upstream selective reduction catalyst 17a via a flow path for air for diffusing ammonia water and a flow path for ammonia water, and sprays air for diffusing urea water and urea water from upstream of the upstream selective reduction catalyst 17a via a flow path for air for diffusing urea water and a flow path for urea water.

[0120] By using this nozzle 13, the supply amounts of air for diffusing ammonia water and ammonia water, and the supply amounts of air for diffusing urea water and urea water can be changed according to the load of the engine 3.

[0121] [Nozzle and selective catalytic reduction unit structure (3)] FIG. 8 is a schematic cross-sectional view showing a third structure of the nozzle and selective reduction catalyst unit applied to the ammonia gas treatment apparatus of the third embodiment (FIG. 5) and the fourth embodiment (FIG. 6).

[0122] As shown in FIG. 8, the nozzle may be composed of a first nozzle 13a and a second nozzle 13b. The first nozzle 13a is a two-fluid nozzle having two flow paths: a flow path connected to the air supply source 25 for supplying air, and a flow path connected to the urea water transport pipe 15 for spraying urea water. The second nozzle 13b is a two-fluid nozzle having two flow paths: a flow path connected to the air supply source 25 for supplying air, and a flow path connected to the ammonia water transport pipe 18 for spraying ammonia water.

[0123] The first nozzle 13a supplies air via an air flow path from upstream of the upstream selective reduction catalyst 17a, and sprays urea water via a urea water flow path from upstream of the upstream selective reduction catalyst 17a. The second nozzle 13b supplies air via an air flow path from upstream of the upstream selective reduction catalyst 17a, and sprays ammonia water via an ammonia water flow path from upstream of the upstream selective reduction catalyst 17a.

[0124] The first nozzle 13a and the second nozzle 13b are both arranged near the central axis of the selective reduction catalyst unit 17, but the central axis may be the Z-axis, and the X-axis and Z-axis directions may be the same and only the Y-axis direction may be different, or the Y-axis and Z-axis directions may be the same and only the X-axis direction may be different.

[0125] When the first nozzle 13a and the second nozzle 13b are used, the urea water and the ammonia water are sprayed from the dedicated first nozzle 13a and the second nozzle 13b, respectively, so that the urea water and the ammonia water can be sprayed simultaneously, and it is possible to deal with even a large difference between the amount of ammonia water to be sprayed and the amount of urea water to be sprayed. The amount of urea water and the amount of ammonia water sprayed can be adjusted according to the operating state of the engine 3.

[0126] In the selective reduction catalyst unit 17 using this nozzle 13, urea water and / or ammonia water is sprayed in water areas subject to Tier 3 regulations of exhaust gas regulations for marine diesel engines, and ammonia water is sprayed in water areas subject to Tier 2 regulations. When spraying ammonia water in Tier 3 regulated sea areas, the concentration of the ammonia water must be controlled to ensure that there is a sufficient amount of ammonia for denitrification treatment.

[0127] [Nozzle and selective catalytic reduction unit structure (4)] FIG. 9 is a schematic cross-sectional view showing a fourth structure of the nozzle and selective reduction catalyst unit applied to the ammonia gas treatment apparatus of the third embodiment (FIG. 5) and the fourth embodiment (FIG. 6).

[0128] As shown in FIG. 9, the nozzle may be composed of a first nozzle 13a and a second nozzle 13b, and the second nozzle 13b may be disposed within the exhaust receiver 27.

[0129] The first nozzle 13a is a two-fluid nozzle having two flow paths: a flow path connected to the air supply source 25 for supplying air, and a flow path connected to the urea water transport pipe 15 for spraying urea water. The second nozzle 13b is a two-fluid nozzle having two flow paths: a flow path connected to the air supply source 25 for supplying air, and a flow path connected to the ammonia water transport pipe 18 for spraying ammonia water.

[0130] The first nozzle 13a supplies air via an air flow path from upstream of the upstream selective reduction catalyst 17a, and sprays urea water via a urea water flow path from upstream of the upstream selective reduction catalyst 17a in the selective reduction catalyst unit 17. The second nozzle 13b supplies air from upstream of the upstream selective reduction catalyst 17a via an air flow path, and sprays ammonia water into the exhaust receiver 27 via an ammonia water flow path.

[0131] In the first nozzle 13a and the second nozzle 13b, both the ammonia water and the urea water can be sprayed from the central axis of the selective reduction catalyst unit 17, and therefore can be diffused uniformly.

[0132] When the first nozzle 13a and the second nozzle 13b are used, the urea water and the ammonia water are sprayed from the dedicated first nozzle 13a and the second nozzle 13b, respectively, so that the urea water and the ammonia water can be sprayed simultaneously, and it is possible to deal with even a large difference between the amount of urea water to be sprayed and the amount of ammonia water to be sprayed. The amount of urea water and the amount of ammonia water sprayed can be adjusted according to the operating state of the engine 3.

[0133] When the first nozzle 13a and the second nozzle 13b are used, the outlet temperature of the exhaust receiver 27 is higher than the inlet temperature of the selective reduction catalyst unit 17. Therefore, even if the concentration of ammonia water is low and the amount of spray is large, a decrease in the temperature of the exhaust gas can be suppressed. These first nozzle 13a and second nozzle 13b are suitable for the case where the amount of ammonia water sprayed is about 1 / 10 or less of the amount of urea water sprayed.

[0134] In the selective reduction catalyst unit 17 using this nozzle 13, urea water and / or ammonia water is sprayed in water areas subject to Tier 3 regulations of exhaust gas regulations for marine diesel engines, and ammonia water is sprayed in water areas subject to Tier 2 regulations. When spraying ammonia water in Tier 3 regulated sea areas, the concentration of the ammonia water must be controlled to ensure that there is a sufficient amount of ammonia for denitrification treatment.

[0135] The first nozzle 13a that sprays the urea water may also be disposed in the exhaust receiver 27, similar to the second nozzle 13b.

[0136] [Nozzle and selective catalytic reduction unit structure (5)] FIG. 10 is a schematic cross-sectional view showing a fifth structure of the nozzle and selective reduction catalyst unit applied to the ammonia gas treatment apparatus of the third embodiment (FIG. 5) and the fourth embodiment (FIG. 6).

[0137] As shown in FIG. 10, the nozzle may be composed of a first nozzle 13a and a second nozzle 13b, and the second nozzle 13b may be disposed upstream of an ammonia slip catalyst (ASC) 17c installed in place of the downstream selective reduction catalyst 17b.

[0138] The first nozzle 13a is a two-fluid nozzle having two flow paths: a flow path connected to the air supply source 25 for supplying air, and a flow path connected to the urea water transport pipe 15 for spraying urea water. The second nozzle 13b is a two-fluid nozzle having two flow paths: a flow path connected to the air supply source 25 for supplying air, and a flow path connected to the ammonia water transport pipe 18 for spraying ammonia water.

[0139] The first nozzle 13a supplies air via an air flow path from upstream of the upstream selective reduction catalyst 17a, and sprays urea water via a urea water flow path from upstream of the upstream selective reduction catalyst 17a in the selective reduction catalyst unit 17. The second nozzle 13b supplies air via an air flow path from upstream of the upstream selective reduction catalyst 17a, and sprays ammonia water via an ammonia water flow path from downstream of the upstream selective reduction catalyst 17a, inside the selective reduction catalyst unit 17, and upstream of an ammonia slip catalyst (ASC) 17c installed in place of the downstream selective reduction catalyst 17b.

[0140] In the first nozzle 13a and the second nozzle 13b, both the ammonia water and the urea water can be sprayed from the central axis of the selective reduction catalyst unit 17, and therefore can be diffused uniformly.

[0141] When the first nozzle 13a and the second nozzle 13b are used, the urea water and the ammonia water are sprayed from the dedicated first nozzle 13a and the second nozzle 13b, respectively, so that the urea water and the ammonia water can be sprayed simultaneously, and it is possible to deal with even a large difference between the amount of ammonia water to be sprayed and the amount of urea water to be sprayed. The amount of urea water and the amount of ammonia water sprayed can be adjusted according to the operating state of the engine 3.

[0142] When the first nozzle 13a and the second nozzle 13b are used, the nitrogen oxide reduction treatment is completed only by the upstream selective reduction catalyst 17a, and the downstream ammonia slip catalyst is specialized for the treatment of ammonia water. These first nozzle 13a and second nozzle 13b are suitable for the case where the amount of ammonia water sprayed is about 1 / 10 or less of the amount of urea water sprayed.

[0143] In this nozzle, the second nozzle 13b may also be configured to spray ammonia water from the upstream of the upstream selective reduction catalyst 17a in the selective reduction catalyst unit 17. In this case, if there is excess ammonia gas in the denitrification process by the selective reduction catalyst 17a, this ammonia gas is rendered harmless by the downstream ammonia slip catalyst.

[0144] In the selective reduction catalyst unit 17 using this nozzle 13, urea water and ammonia water are sprayed in water areas subject to Tier 3 regulations on exhaust gas from marine diesel engines, and ammonia water is sprayed in water areas subject to Tier 2 regulations. In the selective reduction catalyst unit 17 using this nozzle 13, since the ammonia water is not involved in the denitrification treatment, there is no need to perform concentration management. However, concentration management may be performed to confirm that the amount of the ammonia component is equal to or less than the treatment capacity of the ammonia slip catalyst (ASC) 17c.

[0145] As described above, in the ammonia gas treatment device and treatment method, in water areas subject to Tier 3 regulations on exhaust gas from marine diesel engines, the selective catalytic reduction unit 17 reliably performs denitration treatment using urea water, making it possible to satisfy the regulations and to treat ammonia gas generated on board the ship. Since the ammonia water is consumed in the detoxification process and an additional ammonia water supply tank is not required, the capacity of the ammonia water tank can be reduced. In addition, in a mode in which the ammonia water produced by the denitrification device is used for denitrification treatment, by performing denitrification treatment using ammonia water in sea areas subject to Tier 2 regulations where denitrification treatment is not necessarily required, it is possible to provide a clean ship that produces clean exhaust gas with reduced nitrogen oxides in all sea areas. [Explanation of symbols]

[0146] 1. Liquefied ammonia tank 1a Suction pump 2 Fuel supply device 2a Ammonia discharge valve 3 Engine 3a Combustion chamber 4 Fuel piping 4a Gas-liquid separator 5 Purge gas exhaust valve 6 Abatement equipment 7. Ammonia water tank 7a Level gauge 8. Urea tank 9 Second opening and closing valve 10 Flow rate / density meter (Coriolis flow meter) 10b Second flow / density meter (Coriolis flow meter) 11 Ammonia water flow meter 12 Third opening and closing valve 13 Nozzle 13a No. 1 nozzle 13b No. 2 nozzle 14 Ammonia water circulation valve (back pressure valve) 15 Urea water transport pipe 15a Urea water pump 16 First opening and closing valve 17 Selective catalytic reduction unit 17a Selective catalytic reduction (SCR) 17b Selective catalytic reduction (SCR) 17c Ammonia Slip Catalyst (ASC) 18 Ammonia water transport pipe 18a Ammonia water pump 19. Urea water flow control valve 20 Urea water flow meter 21 Urea water circulation valve (back pressure valve) 22 Fresh Water Tank 22a Water pump 23 Ammonia water pressure gauge 24 Pressure gauge 25 Air supply source 26 Thermometer 27 Exhaust receiver 28 Urea solution or ammonia solution transport pipe 29 Mixer 30 Check valve 31 Liquefied ammonia back pressure valve 32 Liquid ammonia flow meter 33 Check valve 50 Purge gas supply valve 51 Nitrogen gas supply device 52 Turbocharger

Claims

1. An ammonia gas treatment device for a ship carrying liquefied ammonia as fuel for cargo or ship engines and equipped with a selective catalytic reduction unit, the selective reduction catalyst unit is provided with a selective reduction catalyst into which exhaust gas from an engine of the ship is introduced, a urea solution serving as a reducing agent is supplied, and which performs a denitration treatment of the exhaust gas; A detoxification device is provided for dissolving ammonia gas and / or ammonia gas vaporized from liquefied ammonia remaining in the fuel supply line of the engine of the ship, or ammonia gas vaporized from the cargo, in fresh water to produce ammonia water, The ammonia water generated in the detoxification device is supplied to the selective reduction catalyst unit, and the ammonia water is detoxified.

2. An ammonia gas treatment device comprising:

2. a supply path for the ammonia water to the selective reduction catalyst unit is independent of a supply path for the urea water to the selective reduction catalyst unit, and the supply path for the ammonia water to the selective reduction catalyst unit is independent of a supply path for the urea water to the selective reduction catalyst unit, The urea water and the ammonia water can be simultaneously supplied to the selective reduction catalyst unit through a nozzle, The nozzle is a three-fluid nozzle having a flow path connected to an air supply source and supplying air for diffusing the urea water and / or the ammonia water, a flow path connected to the urea water supply path and spraying the urea water, and a flow path connected to the ammonia water supply path and spraying the ammonia water, and is disposed upstream in the selective reduction catalyst unit.

2. The apparatus for treating ammonia gas according to claim 1 .

3. a supply path for the ammonia water to the selective reduction catalyst unit is independent of a supply path for the urea water to the selective reduction catalyst unit, and the supply path for the ammonia water to the selective reduction catalyst unit is independent of a supply path for the urea water to the selective reduction catalyst unit, The urea water and the ammonia water can be simultaneously supplied to the selective reduction catalyst unit through a nozzle, The nozzle includes a first nozzle and a second nozzle, the first nozzle is a two-fluid nozzle having two flow paths, a flow path connected to the air supply source and for supplying air, and a flow path connected to the urea water supply path and for spraying the urea water, and is disposed upstream within the selective reduction catalyst unit, The second nozzle is a two-fluid nozzle having two flow paths, a flow path connected to the air supply source and for supplying air, and a flow path connected to the ammonia water supply path and for spraying the ammonia water, and is disposed on the upstream side within the selective reduction catalyst unit.

2. The apparatus for treating ammonia gas according to claim 1 .

4. a supply path for the ammonia water to the selective reduction catalyst unit is independent of a supply path for the urea water to the selective reduction catalyst unit, and the supply path for the ammonia water to the selective reduction catalyst unit is independent of a supply path for the urea water to the selective reduction catalyst unit, The urea water and the ammonia water can be simultaneously supplied to the selective reduction catalyst unit through a nozzle, The nozzle includes a first nozzle and a second nozzle, the first nozzle is a two-fluid nozzle having two flow paths, a flow path connected to the air supply source and for supplying air, and a flow path connected to the urea water supply path and for spraying the urea water, and is disposed upstream within the selective reduction catalyst unit, The second nozzle is a two-fluid nozzle having two flow paths, a flow path connected to the air supply source for supplying air and a flow path connected to the ammonia water supply path for spraying the ammonia water, and is disposed in an exhaust receiver through which the exhaust gas passes before the selective reduction catalyst unit, and the air and the ammonia water are supplied into the selective reduction catalyst unit through the exhaust receiver.

2. The apparatus for treating ammonia gas according to claim 1 .

5. a supply path of the ammonia water to the selective reduction catalyst unit merges with a supply path of the urea water to the selective reduction catalyst unit before the supply path reaches the selective reduction catalyst unit, Either the urea water or the ammonia water is supplied to the selective reduction catalyst unit through a nozzle, The nozzle is a two-fluid nozzle having two flow paths: a flow path connected to an air supply source for supplying air, and a flow path where the urea water supply path and the ammonia water supply path join and are connected to each other, and where the urea water or the ammonia water is sprayed, and the nozzle is disposed on the upstream side within the selective reduction catalyst unit.

2. The apparatus for treating ammonia gas according to claim 1 .

6. A meter for measuring the density of the ammonia water is provided, The urea water and the ammonia water are simultaneously supplied to the selective reduction catalyst unit, The density of the ammonia water measured by an instrument for measuring the density of the ammonia water is converted into a concentration of the ammonia water, and a molar equivalent of the ammonia water to be supplied to the selective reduction catalyst unit is calculated from the concentration; Calculating a molar equivalent of the urea water to be supplied to the selective reduction catalyst unit from the known concentration of the urea water; The molar equivalent of the ammonia water and the molar equivalent of the urea water supplied to the selective reduction catalyst unit are summed up, and the flow rates of the urea water and the ammonia water are adjusted according to the summed molar equivalent, thereby performing a denitrification treatment of the exhaust gas as the detoxification treatment.

5. The ammonia gas treatment device according to claim 1,

7. A supply path of the ammonia water to the selective catalytic reduction unit is joined with liquefied ammonia supplied from a fuel supply device of the ship, and the ammonia water and the liquefied ammonia are mixed to become ammonia water, which is supplied to the selective catalytic reduction unit; a meter for measuring the density of ammonia water obtained by mixing the ammonia water and the liquefied ammonia; The molar equivalent of the ammonia water to be supplied to the selective reduction catalyst unit is calculated from the density of the ammonia water measured by an instrument for measuring the density of the ammonia water, and the flow rate of the ammonia water is adjusted according to the calculated molar equivalent, thereby performing a denitrification treatment of the exhaust gas as the detoxification treatment.

6. The ammonia gas treatment device according to claim 1,

8. A meter for measuring a leak ammonia concentration in the exhaust gas is provided, measuring an exhaust gas flow rate of the engine, and calculating a leak ammonia amount from the measured exhaust gas flow rate and the leak ammonia concentration, or from an exhaust gas flow rate calculated based on load information from an output of the engine and the leak ammonia concentration; The flow rate of the urea water or the ammonia water is adjusted so that the sum of the amount of ammonia supplied into the selective reduction catalyst unit by the urea water and / or the ammonia water and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit, and a denitrification treatment of the exhaust gas is performed as the detoxification treatment.

6. The ammonia gas treatment device according to claim 1,

9. an ammonia slip catalyst is disposed within the selective reduction catalyst unit; The ammonia slip catalyst detoxifies the ammonia water supplied to the selective reduction catalyst unit.

6. The ammonia gas treatment device according to claim 1,

10. A method for treating ammonia gas in a ship carrying liquefied ammonia as cargo or ship engine fuel and equipped with a selective catalytic reduction unit, comprising: The selective reduction catalyst unit is provided with a selective reduction catalyst that introduces exhaust gas from an engine of the ship, supplies urea water as a reducing agent, and performs a denitrification treatment of the exhaust gas; Ammonia gas generated by vaporization of liquefied ammonia remaining in the fuel supply line of the engine of the ship and / or ammonia gas, or ammonia gas volatilized from the cargo is dissolved in fresh water by a decontamination device to produce ammonia water; The ammonia water generated by the detoxification device is supplied to the selective reduction catalyst unit, and the ammonia water is detoxified.

1. A method for treating ammonia gas comprising the steps of:

11. The urea water and the ammonia water are simultaneously supplied to the selective reduction catalyst unit, measuring a density of the ammonia water, converting the measured density of the ammonia water into a concentration of the ammonia water, and calculating a molar equivalent of the ammonia water to be supplied to the selective reduction catalyst unit from the concentration; Calculating a molar equivalent of the urea water to be supplied to the selective reduction catalyst unit from the known concentration of the urea water; The molar equivalent of the ammonia water and the molar equivalent of the urea water to be supplied to the selective reduction catalyst unit are summed up, and the flow rates of the urea water and the ammonia water are adjusted according to the summed molar equivalent, and a denitrification treatment of the exhaust gas is performed as the detoxification treatment. The method for treating ammonia gas according to claim 10 .

12. merging liquefied ammonia supplied from a fuel supply device of the ship into a supply path of the ammonia water to the selective catalytic reduction unit, mixing the ammonia water and the liquefied ammonia to obtain ammonia water, and supplying the ammonia water to the selective catalytic reduction unit; measuring a density of the ammonia water obtained by mixing the ammonia water and the liquefied ammonia; The molar equivalent of the ammonia water to be supplied to the selective catalytic reduction unit is calculated from the measured density of the ammonia water, and the flow rate of the ammonia water is adjusted according to the calculated molar equivalent, and a denitrification treatment of the exhaust gas is performed as the detoxification treatment. The method for treating ammonia gas according to claim 10 .

13. providing an instrument for measuring a leak ammonia concentration in the exhaust gas; measuring an exhaust gas flow rate of the engine, and calculating a leak ammonia amount from the measured exhaust gas flow rate and the leak ammonia concentration, or from an exhaust gas flow rate calculated based on load information from an output of the engine and the leak ammonia concentration; The flow rate of the urea water or the ammonia water is adjusted so that the sum of the amount of ammonia supplied into the selective reduction catalyst unit by the urea water and / or the ammonia water and the amount of leaked ammonia becomes the amount of ammonia treated in the selective reduction catalyst unit, and a denitrification treatment of the exhaust gas is performed as the detoxification treatment. The method for treating ammonia gas according to claim 10 .

14. an ammonia slip catalyst is provided within the selective reduction catalyst unit; The ammonia slip catalyst detoxifies the ammonia water supplied to the selective reduction catalyst unit. The method for treating ammonia gas according to claim 10 .

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