KR20180086566A - Nitrogenous compound emission reduction apparatus and operation method in ship - Google Patents

Abstract

The present invention relates to an exhaust gas harmful substance reduction apparatus in a ship and an exhaust gas harmful substance reduction operation method and, more specifically, relates to an exhaust gas harmful substance reduction apparatus in a ship and an exhaust gas harmful substance reduction operation method. When a ship sails and operates, in accordance with a sailing section of the ship or an operation section of a marine plant, any one of air or oxygen that is an oxidizer of fuel supplied to an engine is selected to be supplied to the engine. As the supplied oxygen is applied with oxygen generated in a ballast water treatment unit or oxygen generated by gasifying liquid oxygen, a conventional engine is used for a ship or a marine plant, and exhaust gas nitrogen oxide emission control Tier 3 of the engine can be satisfied.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for reducing harmful substances in exhaust gas of a ship, and a method for reducing harmful substances in exhaust gas.

The present invention relates to a device for reducing harmful substances in exhaust gas of ships and a method for reducing exhaust gas harmful substances, and more particularly, to a method for reducing harmful substances in exhaust gas, (Oxygen) or oxygen (O ₂ ) which is an oxidant of the fuel to be supplied to the engine, and the supplied oxygen is oxygen generated by the ballast water treatment unit or by applying oxygen generated by vaporizing the liquid oxygen The present invention relates to an exhaust gas harmful material abatement apparatus and a method for reducing exhaust gas harmful substances of a ship that can meet the exhaust gas nitrogen oxide (NOx) emission regulation Tier 3 of the engine while using the existing engine as it is for a ship or an offshore plant.

Natural gas is usually liquefied and transported over a long distance in the form of Liquefied Natural Gas (LNG). Liquefied natural gas is obtained by cooling natural gas at a cryogenic temperature of about -163 ° C at normal atmospheric pressure, and its volume is considerably less than when it is in a gaseous state, making it well suited for long distance transportation through the sea.

There is a limit to completely block the external heat even if the liquefied natural gas storage tank is insulated, and the liquefied natural gas is constantly vaporized in the storage tank by heat transmitted to the liquefied natural gas.

Liquefied natural gas vaporized in the storage tank is called Boil-Off Gas (BOG). When the pressure of the storage tank rises above the set safety pressure due to the generation of evaporative gas, the evaporative gas is discharged to the outside of the storage tank through the safety valve. The evaporated gas discharged to the outside of the storage tank is used as the fuel of the ship or is re-liquefied and returned to the storage tank.

Meanwhile, the International Maritime Organization has established and operates an Emission Control Area (ECA) with the approval of the Canadian and the North Sea / Baltic States. An emission control zone (ECA) is an area that regulates the emission of SOx and NOx of a ship for environmental protection.

With the recent interest in environmental issues due to shipbuilding, it is expected that the emission control zone will expand to Mexico, the Mediterranean Sea, the Malacca Straits and Japan in the future. Therefore, it is very important for ships that are going to pass or pass through the above emission control zone to meet emission control zone emission standards.

Regulations for the emission of nitrogen oxides (NOx) are regulated by the International Maritime Organization (IMO) through the following regulations, and the standards are strengthened as shown in [Table 1].

[Table 1]

Tier regulation means the stage or level of the EPA and CARB air pollution control system. The higher the number, the higher the regulation intensity, The standards for the regulation of nitrogen oxides (NOx) in the standards can be divided into Tier 1, Tier 2, and Tier 3.

Engine manufacturers and shipyards are paying a lot of attention and efforts in order to meet the regulations in [Table 1], and the current Tier 2 regulations can be satisfied by improving engine design.

However, the provisions of Tier 3 for nitrogen oxides abatement are at a level that can not be satisfied by the design optimization of engines for the present ship technology. Although the Tier 3 regulatory area is limited to the Emission Control Area (ECA), the range of emissions control areas is increasing, and even considering the current emission control area, the Tier 3 regulations If not, it is impossible to operate the ship. Therefore, it is inevitable to dispose of waste gas of engine in order to meet Tier 3 regulations for nitrogen oxide reduction.

In case of ECA NOx, it is impossible to operate the vessel in excess of the ECA NOx Tire 3 standard unless additional NOx abatement facilities are installed by using MDO (Marine Diesel Oil) and LNG fuel as marine fuel.

In the ECA zone from 2016, stringent criteria of Tier 3 for nitrogen oxides abatement apply. Tier 3 emission reduction standards for nitrogen oxides should be reduced by an additional 80% over Tier 1.

It is submitted through the Protocol of the Maritime Pollution from Ships (MARPOL) in 1997, and it has been passed into force regulation in May, 2005. In order to meet these regulations, NOx) emissions are being developed.

Among the engines used in ships, natural gas-fueled engines include DFDE (Dual Fuel Diesel Electric) engine, X-DF (Extra Long Stroke Duel Fuel), ME-GI (Main Engine Electronic Control Gas Injection) .

The DFDE engine consists of four strokes and adopts the Otto Cycle, which injects natural gas with a pressure of about 6.5 bar, which is relatively low pressure, into the combustion air inlet and compresses the piston as it rises.

The ME-GI engine consists of two strokes and employs a diesel cycle in which high pressure natural gas near 300 bar is injected directly into the combustion chamber at the top of the piston.

The ME-GI engine can be installed in an LNG carrier that stores LNG (Liquefied Natural Gas) in a cryogenic storage tank and transports it. In this case, natural gas is used as the fuel, and approximately 150 to 250 bara (Absolute pressure) is required. In the case of the ME-GI engine, NOx of about 6 g / kWh in the exhaust gas (waste gas) must be reduced to satisfy the Tier 3 of the ECA NOx reduction standard.

Several methods have been known for post-treatment of exhaust gas of engines. Among them, the methods that have been proven to be effective so far include a method using Selective Catalytic Reduction (SCR) and a method using EGR Exhausted Gas Re-circulation). The selective catalytic reduction apparatus and the EGR for circulating a part of the exhaust gas are well known in the art, so a detailed description thereof will be omitted.

However, in the conventional method, when the ME-GI engine is applied to a ship, additional NOx emission reduction devices such as EGR (Exhausted Gas Re-circulation) and SCR (Selective Catalytic Reduction) Installation is required. In the case of EGR, the nitrogen oxide (NOx) reduction rate is about 70%, and maximum power production is impossible when EGR is applied. In addition, the operating cost (OPEX) is high and a large urea tank is needed.

In addition, by using the seawater as a heating medium in a high pressure vaporizer of FGSS, the LNG is vaporized to NG, and a cryogenic cooling source (-163 ° C) is thrown into the sea, , There is a problem of polluting the environment.

Korean Patent Publication No. 10-2005-0017291 Domestic Registration No. 10-1157127

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to provide an air-fuel separator for an internal combustion engine, Or oxygen (O ₂ ) and carbon dioxide (CO ₂ ), and supplies the oxygen to the engine. The supplied oxygen applies oxygen generated by vaporizing the oxygen or liquid oxygen generated by the ballast water processing unit, (NOx) emission standard of the engine while using only the oxygen, which is the oxidizing agent of the fuel, in the exhaust gas control zone, while it is used for the ship or the offshore plant, Carbon dioxide is recovered from the exhaust gas, and the carbon dioxide and oxygen are re-supplied to the engine so that the nitrogen oxide emission in the exhaust gas of the engine is zero Is the number of vessels and reduced emissions system of marine plants and hazardous material abatement operational way to provide.

The second object of the present invention is to provide an exhaust gas purification device capable of satisfactorily satisfying exhaust gas regulation against carbon dioxide emission since it can separate carbon dioxide from exhaust gas discharged from an engine as well as to reduce (or reduce) nitrogen oxide emissions. The present invention provides a method for reducing the emission of toxic substances and a method for reducing the emission of toxic substances in ships and offshore plants applicable to ships and applicable to ships.

According to an aspect of the present invention, there is provided an engine including: an engine; A fuel supply line for supplying fuel to the engine; An oxidant supply line for supplying an oxidant to the engine; A first oxidant supply unit connected to the oxidant supply line to supply air as an oxidant of the fuel; And a second oxidant supply unit connected to the oxidant supply line and supplying oxygen and carbon dioxide as oxidizing agents of the fuel, wherein the second oxidant supply unit includes a ballast water treatment unit for supplying oxygen, Wherein either one of the air supply by the first oxidant supply unit and the supply of oxygen and carbon dioxide by the second oxidant supply unit is selectively supplied to the oxidant supply line, An exhaust gas harmful material abatement device is provided.

Wherein the ballast water processing unit comprises: an air compressor for compressing air; An oxygen generator for generating oxygen in the air compressed in the air compressor; And an ozone generator for generating ozone using oxygen generated in the oxygen generator, wherein the ozone generated in the ozone generator is used to sterilize the ballast water, and oxygen generated in the oxygen generator is supplied to the oxidizer supply line .

The engine receives fuel from a gas fuel or a boil-off gas (BOG) of a liquefied gas storage tank through the fuel supply line, and the liquefied gas includes liquefied natural gas (LNG), LEG, LPG, Fuel gas is preferable.

Preferably, the second oxidant supply unit further includes a liquid oxygen processing unit for vaporizing the liquid oxygen to supply oxygen.

The carbon dioxide recovery unit separates carbon dioxide contained in the exhaust gas discharged from the engine and supplies the separated carbon dioxide to the oxidant supply line. The carbon dioxide separated from the carbon dioxide recovery unit is removed from the oxygen generated in the equilibrium water treatment unit, It is preferable that the oxygen generated by vaporization is fed together when supplied to the oxidant supply line.

Preferably, some of the carbon dioxide separated in the carbon dioxide recovery unit is supplied to the oxidant supply line and the rest is stored in the carbon dioxide storage.

The carbon dioxide recovery unit includes a cooler for cooling the exhaust gas discharged from the engine; A gas-liquid separator for separating water and carbon dioxide from the exhaust gas cooled in the cooler; And a first compressor for compressing carbon dioxide separated from the gas-liquid separator to a pressure required by the engine, wherein the carbon dioxide compressed in the first compressor is preferably stored in the carbon dioxide storage or supplied to the oxidant supply line Do.

The engine includes an ME-GI engine, an engine capable of using gas of XDF and DFDE as a fuel, and the vessel is a container ship having a gas carrier of LNGC, LPGC, LEGC, an engine using gas as fuel, , And a general merchant vessel in which an LNG storage tank and a fuel gas supply system (FGSS) are installed and operated.

When the ship is operating in a pollution zone, it is preferable that air discharged from the first oxidizer supply unit is supplied to the oxidizer supply line.

When the ship is operating an emission gas control zone (ECA), it is preferable that oxygen and carbon dioxide discharged from the second oxidant supply unit are supplied to the oxidant supply line.

The fuel supply line includes an evaporation gas supply line for supplying evaporation gas generated in the liquefied gas storage tank to the engine; And a liquefied gas supply line for vaporizing the liquefied gas stored in the liquefied gas storage tank and supplying it to the engine.

The evaporation gas supply line is preferably provided with a BOG compressor for compressing the evaporation gas to a supply pressure required by the engine.

The first oxidizer supply unit includes: a second compressor for compressing air; A filter for filtering foreign matter contained in the air; And a cooler for cooling the air compressed by the second compressor.

The liquid oxygen treatment section may include an oxygen storage tank for storing liquid oxygen; A feeding pump for pumping oxygen stored in the oxygen storage tank and supplying the oxygen to the oxidant supply line; And a vaporizer for vaporizing the oxygen supplied by the feeding pump.

According to another aspect of the present invention, at least one of air and oxygen, which are oxidants of fuel, is selected and supplied to the engine in order to drive the engine in accordance with the operating area of the ship. In the pollution zone, In the exhaust gas control zone, carbon dioxide and oxygen are supplied as oxidizing agents of the fuel so as to satisfy the specified Tier 3 for nitrogen oxide reduction in the exhaust gas of the engine, and the carbon dioxide to be supplied to the oxidizing agent is exhaust gas And the oxygen to be supplied to the oxidizing agent is oxygen generated in the equilibrium water treatment section, the method for reducing harmful substances of the exhaust gas of the ship is provided.

When the amount of oxygen generated in the equilibrium water treatment unit is less than the amount to be supplied as the oxidizing agent, it is preferable to vaporize the liquid oxygen to supply oxygen.

As described above, the air or oxygen (O 2) and the carbon dioxide (CO 2), which are the oxidizing agents of the fuel supplied to the engine, depend on the operation area of the ship or the operation area of the offshore plant during operation and operation of the ship and offshore plant, The oxygen supplied to the engine is supplied to the ballast water processing unit and oxygen generated by vaporizing the liquid oxygen is applied to the engine so that the existing engine can be used as it is for a ship or an offshore plant, Gaseous Nitrogen Oxide Emissions Regulations Tier 3 can be met.

In the case where only oxygen, which is an oxidant of the fuel, is supplied from the exhaust gas control zone, carbon dioxide is recovered from the exhaust gas discharged from the engine, and the carbon dioxide and oxygen are supplied to the engine again to remove nitrogen oxides Can be set to 0 (zero), which is very environmentally friendly.

In addition, since it is possible to separate carbon dioxide from exhaust gas discharged from the engine as well as to zero (or reduce) nitrogen oxide emissions, it can satisfy exhaust gas regulations for carbon dioxide emissions. Applicable and applicable.

In addition, it is possible to efficiently burn the fuel while satisfying the exhaust gas nitrogen oxide emission regulation Tier 3 of the engine, and to reduce the operating and operating costs.

In addition, since NOx reduction facilities such as SCR and EGR are unnecessary, it is possible to greatly reduce the cost of operation cost (OPEX) and capital expenditure (CAPEX).

In addition, in the future international maritime organization, when the range of not only nitrogen oxide but also carbon dioxide is enlarged in regulation of exhaust gas of a ship, the present invention has the effect of increasing the competitiveness as a solution for ship environmental problem by storing and storing carbon dioxide.

1 is a view showing an apparatus for reducing the emission of toxic substances in an LNG carrier according to the present invention.
2 is a view showing a second oxidizing agent supply unit of the present invention.
3 is a view showing the first oxidant supply unit of the present invention.
4 is a view showing the carbon dioxide recovery unit of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for reducing exhaust gas toxic substances and a method for reducing exhaust gas toxic substances according to the present invention will be described in detail with reference to the accompanying drawings.

The method for reducing harmful emissions of exhaust gases in ships and offshore plants according to the present invention supplies the oxidizing agent into the engine together with the combustion of the fuel gas during operation and operation of the ship and offshore plant. Air or oxygen is supplied as the fuel oxidizer of the engine according to the zone, and one of air and oxygen is selectively supplied to satisfy the exhaust gas nitrogen oxide emission reduction requirement Tier 3 of the marine engine.

That is, in the pollution zone, only air is used as the oxidizing agent of the fuel supplied to the engine.

On the other hand, in the ECA emission control area, only pure oxygen (99.9% O ₂ ) is supplied as an oxidizing agent of the fuel so as to satisfy the requirement Tier 3 for reducing nitrogen oxides in the exhaust gas of the engine. Here, the supply of oxygen may use oxygen generated from a ballast water treatment unit installed in the existing ballast tank to sterilize the ballast tank of the ship, or may be performed at a terminal, It includes all facilities installed on the land for marine plant mooring and mooring.

In the technology of the present invention, it can be applied to ships as well as offshore plants. Since ships are mainly used for transportation, they are referred to as operating areas, and offshore plants are referred to as operating areas because they are mainly used for production and storage.

The liquefied gas is a liquefied fuel gas including LNG, LEG, LPG, DME and the like. The engine includes an ME-GI engine, an engine capable of using gas of XDF and DFDE, and the like. The technology of the present invention is applied to a ship as well as an offshore plant. The ship includes LNGC, LPGC, LEGC gas carrier, Containership where gas-fueled engines are installed, and general merchant vessels where LNG storage tanks and FGSS (FGSS) are installed and operated.

Hereinafter, a method for reducing the emission of harmful substances in exhaust gas of a ship according to the present invention will be described in more detail.

In this embodiment, the process of supplying the oxidizer (air, oxygen) to the engine, for example, the ME-GI engine will be described as an embodiment.

The present invention relates to a marine and marine plant having a fuel supply line connected to a liquefied gas storage tank for operating and operating an air pollution zone and an emission control area (ECA) and fueling the ME-GI engine As a method for reducing exhaust gas harmful substances, ME-GI engine is supplied with oxidizing agent for fuel to ME-GI engine during operation and operation according to the operation and operation area of a ship and an offshore plant. It is possible to satisfy Tier 3 of the exhaust gas nitrogen oxide (NOx) emission reduction of the marine engine while using the existing engine, for example, the ME-GI engine, as it is for the marine vessel.

That is, when the ship and the offshore plant operate and operate in the polluted area, only the air as the fuel oxidizer is supplied to the ME-GI engine, and the reaction formula is CH ₄ + 2 O ₂ + 8 N ₂ → CO ₂ + 2 H ₂ O + (8-α) N ₂ + 2α NOx emissions from the pollution zone.

On the other hand, when the vessel and the offshore plant operate and operate the emission control zone, only the pure oxygen is supplied to the ME-GI engine as the oxidizing agent of the fuel, thereby significantly reducing the nitrogen oxide in the exhaust gas of the ME-GI engine can do.

At this time, the carbon dioxide is recovered from the exhaust gas discharged from the ME-GI engine, and the carbon dioxide and oxygen are mixed and re-supplied to the ME-GI engine, where the NOx emissions from the exhaust gas of the ME- can do. The reaction equation is CH ₄ + 2 O ₂ + 8 CO ₂ → 9 CO ₂ + 2 H ₂ O.

Thus, if the re-ME-GI injection engine to recover about 89% (70-100%) in the exhaust gas of carbon dioxide and nitrogen in the air supplied to the ME-GI engine by the amount of the re-injection of carbon dioxide (N ₂ ), So that the NOx emission from the exhaust gas of the ME-GI engine can be made zero.

FIG. 2 is a view showing a second oxidizing agent supply unit of the present invention. FIG. 3 is a cross-sectional view of the apparatus of the present invention. FIG. FIG. 4 is a view showing the carbon dioxide recovery unit of the present invention. FIG.

As shown in the above drawings, the vessel and the offshore plant of the present invention are provided with a liquefied gas storage tank 1 that can operate as a fuel for operating and operating a pollution zone and an exhaust gas control zone (ECA). The fuel supply line 120 is connected to the liquefied gas storage tank 1 to supply the fuel of the liquefied gas storage tank 1 to the ME-GI engine 111 and the DFDE engine 112, Includes an evaporation gas supply line 121 for supplying a boil-off gas generated in the liquefied gas storage tank 1 to the ME-GI engine 111 and the DFDE engine 112, And a liquefied gas supply line 122 for vaporizing the liquefied gas stored in the gas-liquid separator 1 and supplying it to the ME-GI engine 111 and the DFDE engine 112. The liquefied gas supply line 122 may be provided with a high-pressure pump 122a and a vaporizer 122b.

The evaporation gas supply line 121 is provided with a BOG compressor for compressing the evaporation gas to the supply pressure required by the ME-GI engine 111 and the DFDE engine 112, for example, first to fifth BOG compressors 11 to 15 Can be installed.

The evaporated gas (BOG) discharged from the liquefied gas storage tank 1 is configured to undergo a plurality of compression processes while passing through the first to fifth BOG compressors 11 to 15. When the evaporation gas is compressed, not only the pressure but also the temperature are increased. Therefore, the heat exchangers 21 to 25 are installed at the downstream ends of the first to fifth BOG compressors 11 to 15 to lower the temperature of the evaporated gas BOG .

When the evaporated gas discharged from the liquefied gas storage tank 1 undergoes a multi-stage compression process, the evaporated gas in the state of approximately 300 bar and 40 ° C becomes partially evaporated in the ME-GI engine 111) (B line), and the rest is sent to the self heat exchanger 20 (C line). The evaporation gas at about 300 bar and 40 캜 is heat exchanged with the evaporation gas at about atmospheric pressure, -160 캜, discharged from the liquefied gas storage tank 1 (D line) in the self heat exchanger 20, 120 < 0 > C. The evaporation gas in the state of approximately 300 bar -120 캜 is expanded by the pressure reducing valve to be partially liquefied, and the evaporation gas liquefied by the gas-liquid separator 50 and the gaseous evaporation gas are separated, Is mixed with the evaporation gas (D line) discharged from the storage tank (1) and sent again to the self heat exchanger (20), and the liquefied evaporated gas is sent back to the liquefied gas storage tank (1).

On the other hand, the evaporation gas at approximately atmospheric pressure and -160 deg. C is heat exchanged in the self-heat exchanger 20 with the evaporation gas of approximately 300 bar and 40 deg. C through five compression processes, State. A part of the evaporation gas in the state of approximately 1.05 bar and -72 DEG C is sent to the DFDE engine 112 (A line) to be used as fuel, and the remaining evaporation gas, which is sent to the DFDE engine 112, Or used as a cooling fluid that can liquefy the vaporized gas in the autothermal exchanger 20. [ A line may be provided with a pressure reducing valve to lower the pressure of the compressed evaporative gas supplied to the DFDE engine 112.

The liquefied gas pumped by the feeding pump P1 of the liquefied gas storage tank 1 is supplied to the liquefied gas supply line 122 and is pressurized by the high pressure pump 122a and then through the vaporizer 122b And is supplied to the ME-GI engine 111 and the DFDE engine 112.

As a redundancy, a separate fuel oil tank 60 may be connected to the DFDE engine 112 or the ME-GI engine 111. A pump (Pump) 70 and a heater (80) The DFDE engine 112 or the ME-GI engine 111 can be supplied with the fuel gas by the DFDE engine 112 or the ME-GI engine 111,

The apparatus for reducing harmful substances in exhaust gas of a ship and an offshore plant according to the present invention includes engines 111 and 112, a fuel supply line 120, an oxidant supply line 130, a first oxidant supply unit 140, Unit 180 and the second oxidant supply unit 180 may include a ballast water treatment unit 170, a carbon dioxide recovery unit 160, and a liquefied oxygen treatment unit 150.

In the embodiment of the present invention, an example will be described in which the engine uses the ME-GI engine 111 for propulsion and the DFDE engine 112 for power generation together. The ME-GI engine 111 and the DFDE engine 112 can use the gaseous fuel and the boil-off gas of the liquefied gas storage tank 1 as fuel.

The oxidant supply line 130 is a line for supplying the oxidizing agent (air, oxygen) to the ME-GI engine 111. An oxidant supply line 130 is connected to the DFDE engine 112 so that oxidant (air, oxygen) can be supplied through the oxidant supply line 130.

The first oxidant supply unit 140 is connected to the oxidant supply line 130 to supply air as an oxidant of fuel to the ME-GI engine 111, 2 compressor 141, a filter 142 for filtering foreign substances contained in the air, and a cooler 143 for cooling the air compressed by the second compressor 141.

The second oxidant supply unit 180 is connected to the oxidant supply line 130 for supplying oxygen as an oxidant of the fuel to the ME-GI engine 111. The oxygen supplied from the second oxidant supply unit 180 is supplied to the ME- The oxygen generated by the water treatment section 170 or the oxygen subjected to vaporization of the liquid oxygen in the liquid oxygen treatment section 150 may be used.

The ballast water treatment unit is a device for protecting the marine ecology by disinfecting the seawater used in the ballast tanks, and installation and operation is obligatory for all ships.

The ballast water treatment unit 170 includes an air compressor 171 for compressing air, an oxygen generator 172 for generating oxygen in the air compressed in the air compressor 171, and oxygen generated in the oxygen generator 172 And an ozone generator 173 for generating ozone. The ozone generated by the ozone generator is used to sterilize the ballast water and store it in the ballast tank 174.

In general, the ballast water treatment unit 170 is used only when the cargo hold of the ship is anchored in a ballast condition, and the time for operating the ballast water treatment unit for ballast water sterilization during the entire operation time of the ship is It will only be used for a very short period of time and will not use the ballast water treatment unit during most of the flight times, such as vessel operation or laden condition.

Accordingly, in the present invention, it is possible to basically produce NOx by separating / producing oxygen from an unused ballast water treatment unit during ship operation and supplying it to the ME-GI engine, and the exhaust gas can be composed of only water and carbon dioxide. In addition, separating / storing carbon dioxide from exhaust gas consisting solely of water and carbon dioxide can reduce ship's carbon dioxide emissions, and the separated carbon dioxide can be sold to chemical companies and gas companies for additional profit.

On the other hand, oxygen supplied to the oxidant supply line may be generated in the liquid oxygen processing unit 150, and the liquid oxygen processing unit 150 may include an oxygen storage tank 151 for storing liquid oxygen, A feeding pump 152 for pumping oxygen to supply the oxidizing agent to the oxidizing agent supply line 130, and a vaporizer 153 for vaporizing the oxygen supplied by the feeding pump 152. The liquid oxygen supplied on the terminal is stored in the oxygen storage tank 151 and the feeding pump 152 pumps the oxygen stored in the oxygen storage tank 151 and supplies it to the oxidant supply line 130. The vaporizer 153 vaporizes the oxygen supplied by the feeding pump 152 and supplies it to the oxidizing agent supply line 130. The oxygen storage tank 151 may not be a pressurized tank but may be made of a pressurized tank.

The carbon dioxide recovery unit 160 separates the exhaust gas discharged from the ME-GI engine 111 into water and carbon dioxide to recover the carbon dioxide and supplies the recovered carbon dioxide to the oxidizing agent supply line 130.

The carbon dioxide recovery unit 160 is connected to the exhaust gas bypass line 161 bypassing the exhaust line L 1 of the ME-GI engine 111 and the cooler (heat exchanger) 162 of the exhaust gas bypass line 161 A gas-liquid separator 163 for separating water and carbon dioxide from the exhaust gas to recover carbon dioxide, and a first compressor 164 for compressing the carbon dioxide recovered by the gas-liquid separator 163 to a pressure required by the engine 111 do. The cooler (heat exchanger) 162 is installed in the exhaust gas bypass line 161 to cool the exhaust gas.

The carbon dioxide recovery unit 160 further includes a carbon dioxide reservoir 165 in which a portion of the carbon dioxide separated from the exhaust gas of the engine 11 is supplied to the oxidizer supply line 130 and the rest is supplied to the carbon dioxide reservoir 165 And stored.

The liquid carbon dioxide stored in the carbon dioxide reservoir 165 may be liquefied by the second cooler 166. In the case of a ship carrying cryogenic liquefied gas, the cryogenic liquefied gas may be a Cooling Source (-163 ° C) , Containership where engines using other gas as fuel are installed, and general merchant ships where LNG storage tank and FGSS (Fuel Gas Supply System) are installed and operated.

In the present invention, not only NOx zero or reduction, but also the separation and storage of carbon dioxide in the exhaust gas of the engine is possible, so that it can be satisfied with the regulation of ship exhaust gas against carbon dioxide emission, so that it can be applied and applied to various ships in the future.

The controller 190 controls the operation of the ME-GI engine 111 according to the operation and operation of the ship and the offshore plant. The first oxidant supply unit 140 supplies air to the ME-GI engine 111 as an oxidant of the fuel, And controls the unit 180.

In the present invention, when the ship and the offshore plant operate and operate in a pollution zone, the control unit 190 controls the first oxidizer supply unit 140 to supply only air as the oxidizer of the fuel to the ME-GI engine 111 do.

On the other hand, when the ship and the offshore plant operate and operate the emission control zone, the control unit 190 controls the second oxidizer supply unit 150 to supply only oxygen as the oxidizing agent of the fuel to the ME-GI engine 111 .

In the case where only the oxygen is supplied as the oxidizer of the fuel to the ME-GI engine 111, the controller 190 recovers the carbon dioxide from the exhaust gas discharged from the ME-GI engine 111, mixes the carbon dioxide and oxygen, And supplies it to the engine 111 again. Here, carbon dioxide can act as N ₂ in the air. In this case, the reaction equation is CH ₄ + 2 O ₂ + 8 CO ₂ → 9 CO ₂ + 2 H ₂ O, and the nitrogen oxide emission in the exhaust gas of the ME-GI engine 111 can be zero.

For example, a case in which a ship moves from Europe to the United States into a ballast condition will be described as an example.

That is, when the ship is moored in the European port, the ballast water treatment unit 170 generates ozone to sterilize the ballast water flowing into the ballast tank 174, and the liquid oxygen is loaded on the ship at the LNG terminal.

Thereafter, when the ship is traveling in the European emission control zone (ECA), the oxygen produced by the ballast water treatment unit 170 or the oxygen produced by vaporizing the liquid oxygen stored in the oxygen storage tank 151, The carbon dioxide contained in the discharged exhaust gas is separated and recovered to be supplied to the oxidizing agent of the engine.

When the ship is to travel to the pollution zone through the European Exhaust Gas Control Area (ECA), the ballast water treatment unit 170 produces oxygen, and the produced oxygen is liquefied by the cooling source of the vaporizer And stored in the oxygen storage tank 151.

Now, when the ship is traveling through the pollution zone and operating the emission control zone (ECA) of the United States, it is included in the oxygen produced in the pollution zone or the oxygen generated in the ballast water treatment section 170 and the exhaust gas discharged from the engine And the stored carbon dioxide can be supplied to the oxidizing agent of the engine.

Finally, when the vessel is stationed in the US port, ballast water is discharged from the ballast tank 174, LNG is loaded into the cargo hold, and liquid oxygen is purchased and stored in the oxygen storage tank 151.

Thus, when a ship is to be operated from Europe to the United States, for example, when operating about 9,000 km from Rotterdam in the US to Houston in the United States, the total amount of oxygen required in the whole area is approximately 306.49 tons, 83.57 tons. In Europe, approximately 223 tons of liquid oxygen is purchased from the LNG terminal, and the cooling medium used in the FGSS high-pressure vaporizer is used to store oxygen (10 bar, 25 ° C) produced by the ballast water treatment unit in liquid oxygen (10 bar, -153 ° C) . Thus, if all of the oxygen produced by the ballast water treatment unit is supplied to the ME-GI engine, it is possible to reduce the required oxygen by 27% in the entire emission control zone (ECA).

On the other hand, when a ship moves from the US to Europe in a laden condition, it is as follows.

That is, when a vessel anchored in a US port operates an exhaust gas control zone (ECA) of the United States after loading LNG in a cargo hold, the oxygen or oxygen stored in the oxygen or oxygen storage tank 151 generated in the ballast water treatment unit 170 The oxygen generated by vaporizing the stored liquid oxygen and the carbon dioxide contained in the exhaust gas discharged from the engine are separated and recovered to be supplied to the oxidizing agent of the engine.

When the ship is traveling to the pollution zone after passing through the exhaust gas control zone (ECA), the ballast water treatment section 170 is not operated due to the absence of the cooling medium to liquefy the produced oxygen.

Now, when the ship travels through the pollution zone and operates the European emission control zone (ECA), the oxygen produced in the ballast water treatment unit 170 and the carbon dioxide contained in the exhaust gas discharged from the engine are separated, Carbon dioxide can be supplied as the oxidizing agent of the engine.

Finally, after the LNG is unloaded when the ship is moored in the European port, the ballast water treatment unit 170 generates ozone to sterilize the ballast water flowing into the ballast tank 174.

Thus, when a ship is operated from the United States to Europe, for example, when traveling from Houston, USA to Rotterdam, Europe, the total amount of oxygen required in the entire area is approximately 306.49 tons, and the amount of oxygen that can be produced from the ballast water treatment unit is total 83.57 tons. However, in the case where LNG is accumulated, there is no cooling medium discarded in the high-pressure vaporizer of the FGSS, so it is difficult to liquefy the oxygen produced in the equilibrium water treatment unit. Thus, if you purchase about 299 tonnes of liquid oxygen from a European LNG terminal, if the oxygen produced by the ballast water treatment unit is supplied to the ME-GI engine only in the ECA section, And 2.5% of the required oxygen in LNG carriers. If the LNG carrier runs round the US and Europe routes, the ballast water treatment unit can save 15% of total liquid oxygen purchase cost.

Hereinafter, a fuel supply process and a nitrogen oxide emission reduction process for a ship and an offshore plant according to the present invention will be described.

In the ship having the liquefied gas storage tank and the offshore plant, the fuel supply process is performed such that the evaporated gas (BOG) discharged from the liquefied gas storage tank 1 passes through the first to fifth BOG compressors 11 to 15, Compression process. When the evaporation gas is compressed, not only the pressure but also the temperature are increased. Therefore, the heat exchangers 21 to 25 are installed at the downstream ends of the first to fifth BOG compressors 11 to 15 to lower the temperature of the evaporated gas.

When the evaporated gas discharged from the liquefied gas storage tank 1 is subjected to five compression processes, it becomes a vapor of approximately 300 bar and 40 ° C. A part of the evaporated gas in this state is sent to the ME-GI engine 111 (B line) and used as fuel, and the rest is sent to the self heat exchanger 20 (C line). The evaporation gas at about 300 bar and 40 캜 is heat exchanged with the evaporation gas at about atmospheric pressure, -160 캜, discharged from the storage tank 1 (D line) in the self heat exchanger 20, State. The evaporation gas in the state of approximately 300 bar -120 deg. C is expanded by the pressure reducing valve to be partially liquefied, and the evaporation gas liquefied by the gas-liquid separator 50 and the gaseous evaporation gas are separated, Is mixed with the evaporation gas (D line) discharged from the evaporator (1) and sent to the autothermal exchanger (20), and the liquefied evaporated gas is sent back to the storage tank (1).

Partial Re-liquefaction System (PRS), which is a method of performing self-heat exchange using a volatile gas as a cooling fluid, is used as a method of performing heat exchange with a cooling fluid for cooling the evaporation gas. The system can effectively reduce the overall natural rate of evacuation (BOR: Boil-off Rate) of the liquefied gas storage tank, since the evaporative gas can be re-liquefied without separately installing a costly relusor.

The evaporation gas at approximately atmospheric pressure and -160 ° C. is subjected to heat exchange in the self-heat exchanger 20 and the evaporation gas at approximately 300 bar and 40 ° C. through the five compression processes, and thereafter, approximately 1.05 bar and -72 ° C. do. Evaporative gas is sent to some DFDE engines 112 (A line) to be used as fuel, and the remaining evaporative gas sent to the DFDE engine 112 is used as fuel for the ME-GI engine 111, 20 as a cooling fluid capable of liquefying the evaporation gas. A line may be provided with a pressure reducing valve (not shown) to lower the pressure of the compressed evaporative gas supplied to the DFDE engine 112.

The fuel oil supply supplied from the fuel oil tank 60 is redundancy and is supplied to the DFDE engine 112 or the ME-GI engine 112 by a plurality of pumps 70 and a heater 80. [ And may be supplied to the DFDE engine 112 or the ME-GI engine 111. In this case,

Meanwhile, the operation of the exhaust gas harmful material abatement device of the ship is as follows.

When the ship and the offshore plant operate and operate in the pollution zone, the control unit 190 controls the first oxidizer supply unit 140 to supply only air as the oxidizing agent of the fuel to the ME-GI engine 111.

The second compressor 141 compresses the air and supplies the compressed air to the oxidant supply line 130. The filter 142 filters the foreign substances contained in the air and the cooler 143 separates the second And the air compressed by the compressor (141) is cooled.

Further, when the ship and the offshore plant operate and operate the exhaust gas control zone, the control unit 190 controls the first oxidizer supply unit 150 to supply only oxygen as the oxidizing agent of the fuel to the ME-GI engine 111 .

That is, there are two methods of supplying oxygen, and there is a method of supplying oxygen generated from an oxygen generator of a ballast water treatment unit and a method of storing oxygen and vaporizing oxygen.

When only the oxygen is supplied to the ME-GI engine 111 as an oxidant of the fuel, the control unit 190 recovers carbon dioxide from the exhaust gas discharged from the ME-GI engine 111, mixes the recovered carbon dioxide and oxygen It can be re-supplied to the ME-GI engine 111.

In the carbon dioxide recovery process, the exhaust gas discharged from the ME-GI engine 111 is bypassed to the exhaust gas bypass line 161, and then the exhaust gas is cooled through the cooler 162. By the cooling of the exhaust gas, the exhaust gas is separated into water and carbon dioxide through the gas-liquid separator 163. The carbon dioxide recovered by the gas-liquid separator 163 is compressed by the first compressor 164 to the pressure required by the ME-GI engine 111, then mixed with oxygen and supplied again to the ME-GI engine 111 . At this time, the reaction formula is CH ₄ + 2 O ₂ + 8 CO ₂ → 9 CO ₂ + 2 H ₂ O, and the nitrogen oxide emission in the exhaust gas of the ME-GI engine 111 can be made zero.

// As described above, the air or oxygen (O2) and the carbon dioxide (O2) which are the oxidizing agents of the fuel supplied to the engine according to the operation area of the ship or the operation area of the offshore plant during operation and operation of the ship and offshore plant CO2), and supplies the oxygen to the engine. The supplied oxygen applies oxygen generated by vaporizing the oxygen or liquid oxygen generated by the ballast water treatment unit, thereby using the existing engine as it is for a ship or an offshore plant, Of the emission of nitrogen oxides (Tier 3).

In the case where only oxygen, which is an oxidant of the fuel, is supplied from the exhaust gas control zone, carbon dioxide is recovered from the exhaust gas discharged from the engine, and the carbon dioxide and oxygen are supplied to the engine again to remove nitrogen oxides Can be set to 0 (zero), which is very environmentally friendly.

In addition, since it is possible to separate carbon dioxide from exhaust gas discharged from the engine as well as to zero (or reduce) nitrogen oxide emissions, it can satisfy exhaust gas regulations for carbon dioxide emissions. Applicable and applicable.

In addition, it is possible to efficiently burn the fuel while satisfying the exhaust gas nitrogen oxide emission regulation Tier 3 of the engine, and to reduce the operating and operating costs.

In addition, since NOx reduction facilities such as SCR and EGR are unnecessary, it is possible to greatly reduce the cost of operation cost (OPEX) and capital expenditure (CAPEX).

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

1: Liquefied gas storage tank
11 to 15: first to fifth BOG compressors
20: Self heat exchanger
21 to 25: heat exchanger
50: gas-liquid separator
60: Fuel oil tank
111: ME-GI engine
112: DFDE engine
120: fuel supply line
130: oxidant supply line
140: first oxidant supply unit
150: liquid oxygen processor
160: Carbon dioxide recovery unit
170: Ballast water treatment unit
180: Second oxidant supply unit
190:

Claims (16)

engine;
A fuel supply line for supplying fuel to the engine;
An oxidant supply line for supplying an oxidant to the engine;
A first oxidant supply unit connected to the oxidant supply line to supply air as an oxidant of the fuel; And
And a second oxidant supply unit connected to the oxidant supply line to supply oxygen and carbon dioxide as oxidants of the fuel,
Wherein the second oxidant supply unit includes a ballast water treatment unit for supplying oxygen and a carbon dioxide recovery unit for recovering carbon dioxide from the exhaust gas discharged from the engine,
Wherein either one of the air supply by the first oxidizing agent supply unit and the supply of oxygen and carbon dioxide by the second oxidizing agent supply unit is selectively supplied to the oxidizing agent supply line. The method according to claim 1,
The ballast water treatment unit includes:
An air compressor for compressing air;
An oxygen generator for generating oxygen in the air compressed in the air compressor; And
And an ozone generator for generating ozone using oxygen generated in the oxygen generator,
Sterilizing the ballast water using ozone generated in the ozone generator,
And supplies oxygen generated in the oxygen generator to the oxidant supply line.
The method according to claim 1,
The engine includes:
(BOG) of the liquefied gas storage tank through the fuel supply line,
Wherein the liquefied gas is a liquefied fuel gas including LNG, LEG, LPG, and DME. The method according to claim 1,
And the second oxidant supply unit further comprises a liquid oxygen processing unit for vaporizing the liquid oxygen to supply oxygen. The method of claim 4,
The carbon dioxide-
Separates carbon dioxide contained in the exhaust gas discharged from the engine and supplies the separated carbon dioxide to the oxidant supply line,
The carbon dioxide separated by the carbon dioxide recovery unit is supplied to the oxidizing agent supply line together with the oxygen produced by the equilibrium water treatment unit or the oxygen generated by the vaporization of the liquid oxygen treatment unit, Device. The method according to claim 1,
Wherein some of the carbon dioxide separated in the carbon dioxide recovery unit is supplied to the oxidant supply line and the remaining carbon dioxide is stored in the carbon dioxide storage. The method according to claim 1,
The carbon dioxide-
A cooler for cooling the exhaust gas discharged from the engine;
A gas-liquid separator for separating water and carbon dioxide from the exhaust gas cooled in the cooler; And
And a first compressor for compressing the carbon dioxide separated from the gas-liquid separator to a pressure required by the engine,
Wherein the carbon dioxide compressed in the first compressor is stored in the carbon dioxide storage or supplied to the oxidant supply line. The method according to claim 1,
The engine includes an engine capable of using the gas of the ME-GI engine, XDF, DFDE as fuel,
The vessel is equipped with a gas carrier of LNGC, LPGC, LEGC, a container with an engine using gas as fuel, an LNG storage tank and a fuel gas supply system (FGSS) And a general merchant ship which is installed and operated. The method according to claim 1,
Wherein the air discharged from the first oxidant supply unit is supplied to the oxidant supply line when the ship is operating in a pollution zone. The method according to claim 1,
Wherein oxygen and carbon dioxide discharged from the second oxidant supply unit are supplied to the oxidant supply line when the ship is operated in an exhaust gas control zone (ECA). The method according to claim 1,
The fuel supply line
An evaporation gas supply line for supplying evaporation gas generated in the liquefied gas storage tank to the engine; And
And a liquefied gas supply line for vaporizing the liquefied gas stored in the liquefied gas storage tank and supplying the liquefied gas to the engine. The method of claim 11,
Wherein the evaporation gas supply line is provided with a BOG compressor for compressing the evaporation gas to a supply pressure required by the engine. The method according to claim 1,
Wherein the first oxidant supply unit includes:
A second compressor for compressing air;
A filter for filtering foreign matter contained in the air; And
And a cooler for cooling the air compressed by the second compressor. The method of claim 4,
The liquid oxygen processing unit may include:
An oxygen storage tank for storing liquid oxygen;
A feeding pump for pumping oxygen stored in the oxygen storage tank and supplying the oxygen to the oxidant supply line; And
And a vaporizer for vaporizing the oxygen supplied by the feeding pump. Wherein at least one of air and oxygen, which are oxidants of the fuel, is selected and supplied to the engine in order to drive the engine according to the operating area of the ship,
In the pollution zone, air is supplied as an oxidizing agent of fuel,
In the exhaust gas control zone, carbon dioxide and oxygen are supplied as oxidizing agents of the fuel so as to satisfy the specified Tier 3 for nitrogen oxide reduction in the exhaust gas of the engine, and the carbon dioxide to be supplied to the oxidizing agent is separated from the exhaust gas Wherein the oxygen to be supplied to the oxidizing agent is oxygen generated in the equilibrium water treatment section. 16. The method of claim 15,
Wherein when the amount of oxygen generated in the equilibrium water treatment unit is less than an amount to be supplied as an oxidizing agent, the oxygen is vaporized to supply oxygen.

Images