Exhaust gas purification method for vessel

Abstract

To provide an exhaust gas purification apparatus and method for vessel in which a risk for a vessel and crew of being exposed to ammonia gas used to collect carbon dioxide included in exhaust gas emitted from a vessel may be minimized and an ammonia solution may be recycled and reused to collect carbon dioxide.SOLUTION: An exhaust gas purification method for vessel includes: i) the first step in which carbon dioxide and water contained in exhaust gas emitted from a vessel react to generate carbonic acid; ii) the second step in which the carbonic acid generated in the first step reacts with an ammonia solution to generate ammonium bicarbonate; iii) the third step in which the ammonium bicarbonate generated in the second step reacts with the ammonia solution to generate ammonium carbonate; iv) the fourth step in which the ammonium bicarbonate and ammonium carbonate react with a divalent metal oxide or divalent metal hydroxide to generate a carbonate and ammonia solution; and v) the fifth step in which the ammonia solution generated in the fourth step is resupplied to the second step.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an exhaust gas purification method and device for ships and a ship equipped with the same for transferring carbon dioxide contained in exhaust gas discharged from ships to land by absorbing and solidifying the carbon dioxide. More specifically, the present invention relates to an exhaust gas purification method and device for ships and a ship equipped with the same that can eliminate the risk of exposure of ships and crew by regenerating and reusing aqueous ammonia used as a reaction liquid of a wet scrubber, so that a tank for storing ammonia gas is not provided on the ship.

[0002] The present invention also relates to an exhaust gas purification method and device for ships and a ship equipped with the same for absorbing and solidifying carbon dioxide and sulfur dioxide contained in exhaust gas discharged from ships so that the exhaust gas can be easily transferred to land.

Background Art

[0003] Pollutants contained in exhaust gas discharged from ships include SOx, NOx, and CO 2 etc. These pollutants are not only harmful to the human body, but also cause environmental pollution when discharged directly into the atmosphere without filtration treatment.

[0004] Therefore, the United Nations has entrusted the International Maritime Organization (IMO) with the issue of exhaust gas emission regulations for ships navigating all seas around the world. IMO is promoting various exhaust gas reduction plans with the goal of reducing the exhaust gas emissions from ships by 40% compared to 2008 by 2030 and 50% by 2050.

[0005] Therefore, solutions for reducing the emissions of carbon dioxide, a typical greenhouse gas, are being sought in the shipping industry and the shipbuilding industry.

[0006] On the other hand, according to the International Energy Agency (IEA), the world's CO due to fuel combustion in 20162 The emission amount is 32.3 billion tons, and among them, the CO emissions due to the combustion of marine bunker oil are 2 6.8 tons, which is known to be at the level of 2.1% of the total.

[0007] In South Korea, in order to achieve the 2030 greenhouse gas reduction target of 40% proposed by the IMO, a medium- and long-term roadmap has been made and research projects are being carried out, developing and promoting technologies for reducing greenhouse gas emissions from ships.

[0008] In particular, by aiming to reduce carbon dioxide emissions by more than 50% of the 2008 emission amount by 2050, technologies that do not emit CO or recover the emitted CO 2 are attracting attention. 2 Therefore, technologies that collect and store carbon dioxide, a typical pollutant contained in ship exhaust gas, without releasing it into the atmosphere and then reuse it are attracting great attention. Technologies related to this are called carbon dioxide capture and storage technologies (CCS). Typical technologies include wet absorption methods, adsorption methods, and membrane separation methods. Among these, the wet absorption method has a high technical maturity level in onshore plants and is easy to handle large amounts of CO.

[0009] Therefore, it can be said that it is the recovery technology closest to the commercialization of CCS technology. As the reaction liquid for the wet absorption method, amine-based and ammonia gas are mainly used. 2 The ammonia gas is a highly corrosive and toxic gas. Inhaling it may cause severe burns while irritating the nose, throat, airway mucosa, etc., and may induce hemoptysis, vomiting, nosebleeds, etc.

[0010] Therefore, there is an urgent need to develop technologies that eliminate the risk of leakage of the ammonia gas in a closed facility such as a ship, and that absorb the carbon dioxide contained in the exhaust gas discharged from the ship and convert it into a substance that does not affect the environment and then discharge it, or store it and transfer it to land.

[0011] ​

[0012] In addition, the pollutants contained in the exhaust gas discharged from ships include carbon dioxide (hereinafter referred to as CO 2 ), sulfur dioxide (hereinafter referred to as SO 2 ), etc. These pollutants are not only harmful to the human body, but also cause environmental pollution when discharged directly into the atmosphere without filtration treatment.

[0013] Therefore, the United Nations has entrusted the International Maritime Organization (hereinafter referred to as IMO) with the issue of regulating exhaust gas emissions from ships navigating all seas around the world. IMO is promoting various exhaust gas reduction plans with the goal of reducing the emissions of environmental pollutants in exhaust gas from ships by 40% compared to 2008 by 2030 and 50% by 2050.

[0014] In South Korea, a mid- to long-term roadmap has been created and research projects are being carried out to achieve the 2030 greenhouse gas reduction target proposed by IMO. Therefore, it is necessary to proactively enter the environmentally friendly ship market through aggressive technology development for reducing greenhouse gases generated from ships at this time.

[0015]

[0016] ​Second, there is a method of installing and utilizing a device (scrubber) that dissolves pollutants contained in the engine exhaust gas with a large amount of water, converting SOx into low-concentration sulfurous acid or sulfuric acid, and then discharging it into seawater, or converting it into sodium or calcium salts, storing it, and then disposing of it. However, in this method, the demand for special steel of expensive materials increases, and an additional economic burden occurs, such as having to install a scrubber of a very large scale on the ship.

[0017] Therefore, various forms of ship exhaust gas reduction devices have been developed to absorb and process the exhaust gas generated from ships and reduce the pollutants contained in the exhaust gas. However, for 2 CO 2 and SO

Summary of the Invention

Problems to be Solved by the Invention

[0018] The present invention has been made in view of the above circumstances, and its object is to regenerate and reuse aqueous ammonia, which is a reaction liquid used to recover carbon dioxide contained in the exhaust gas generated from ships, so that the exposure of ships and crew to ammonia gas can be minimized. The present invention relates to a ship exhaust gas purification method, a purification device, and a ship equipped with the same.

[0019] Another object of the present invention is to recover CO 2 and SO 2 which are pollutants contained in the exhaust gas generated from ships, using a reaction liquid, convert them into substances that do not affect the environment, store them, and then transfer them to land. The present invention relates to a ship exhaust gas purification method, a purification device, and a ship equipped with the same.

Means for Solving the Problems

[0020] The exhaust gas purification device 100 for ships according to the first embodiment of the present invention for solving the above problems is provided on a ship and can process the exhaust gas generated from an exhaust gas generating device, and reacts the exhaust gas generated from the exhaust gas generating device provided on the ship with a reaction liquid to convert carbon dioxide contained in the exhaust gas into an ammonium salt. A wet scrubber 110, an inlet 115 through which the exhaust gas flows into the wet scrubber 110, and an outlet 112 through which the exhaust gas is discharged to the outside of the wet scrubber 110, and a circulation tank 120 for producing a reaction liquid that reacts with the exhaust gas and supplying this to the wet scrubber 110, a transfer pump 123 for transferring the ammonium salt generated by reacting carbon dioxide contained in the exhaust gas flowing in through the inlet 115 with the reaction liquid, the ammonium salt transferred from the wet scrubber 110, and an impeller 135 provided in a mixing tank 130 for reacting with a divalent metal oxide or a divalent metal hydroxide to generate sludge containing carbonate and aqueous ammonia, a sludge pump 131 for transferring the sludge from the mixing tank 130 to a solid-liquid separation device 150, a solid-liquid separation device 150 for separating precipitates such as carbonate and aqueous ammonia from the sludge transferred from the mixing tank, a first storage tank 151 for storing the aqueous ammonia separated by the solid-liquid separation device 150, a second storage tank 160 for storing precipitates such as carbonate separated by the solid-liquid separation device 150, a third storage tank 140 for supplying a divalent metal oxide or a divalent metal hydroxide, and a transfer pump 152 for transferring the aqueous ammonia stored in the first storage tank 151 to the circulation tank 120 when necessary. The divalent metal oxide is calcium oxide or magnesium oxide, the divalent metal hydroxide is calcium hydroxide or magnesium hydroxide, and the divalent metal oxide or the divalent metal hydroxide is preferably supplied in the form of powder, aqueous solution or sludge.

[0021] Also, the exhaust gas purification method using the exhaust gas purification device 100 for ships according to the first embodiment of the present invention is as follows: i) Carbon dioxide and water contained in the exhaust gas discharged from the ship react to form carbonic acid (H 2 CO 3) to generate the first stage, and ii) the carbonic acid and aqueous ammonia generated in the first stage react to form ammonium bicarbonate (NH 4 HCO 3 ) in the second stage, and iii) ammonium bicarbonate (NH 4 HCO 3 ) generated in the second stage reacts with aqueous ammonia to form ammonium carbonate (NH 4 ) 2 CO 3 ) in the third stage, and iv) ammonium bicarbonate (NH 4 HCO 3 ) and ammonium carbonate (NH 4 ) 2 CO 3 react with a divalent metal oxide or divalent metal hydroxide to form a carbonate and aqueous ammonia in the fourth stage, and v) the aqueous ammonia generated in the fourth stage is re-supplied to the second stage. In the ship exhaust gas purification method, insufficient aqueous ammonia can be generated and supplemented by the reaction of an inorganic compound and calcium hydroxide. The inorganic compound is ammonium bicarbonate (NH 4 HCO 3 ), ammonium carbonate ((NH 4 ) 2 CO 3 ), ammonium bisulfate (NH 4 HSO 4 ), ammonium sulfate ((NH 4 ) 2 SO 4 ), ammonium nitrate (NH 4 NO 3 ), ammonium chloride (NH 4 Cl), ammonium sulfamate (NH 4 SO 3 NH 2 ), and ammonium sulfite ((NH 4 ) 2 SO 3 ), and is one or more selected from the group consisting of. The usage amount of the inorganic compound is preferably input at 1.0 to 2.0 times the molar ratio of the insufficient aqueous ammonia.

[0022] Furthermore, the marine exhaust gas purification device 1000 according to the second embodiment of the present invention is provided on a ship for treating exhaust gas generated from an exhaust gas generating device. It includes a wet scrubber 1100 that reacts the exhaust gas generated from the exhaust gas generating device with water and a reaction liquid to convert carbon dioxide and sulfur dioxide contained in the exhaust gas into inorganic salts; a first tank 1200 that stores the reaction liquid that reacts with the exhaust gas and supplies it to the wet scrubber 1100; a transfer pump 1230 provided at the lower part of the wet scrubber 1100 for transferring the reaction liquid containing the inorganic salts to a second tank 1300; a second tank 1300 that reacts the inorganic salts contained in the reaction liquid containing the inorganic salts generated in the wet scrubber 1100 with a divalent metal oxide or a divalent metal hydroxide to regenerate the reaction liquid, and generates sludge containing carbonates and sulfates at this time; a third tank 1400 that stores the divalent metal oxide or the divalent metal hydroxide and supplies it to the second tank 1300; a solid-liquid separation device 1500 that separates carbonates and sulfates from the sludge transferred from the second tank 1300; a sludge pump 1310 for transferring carbonates and sulfates from the second tank 1300 to the solid-liquid separation device 1500; a fourth tank 1600 that stores the carbonates and sulfates separated by the solid-liquid separation device 1500; and a fifteenth tank 1510 that stores the regenerated reaction liquid separated by the solid-liquid separation device 1500 and supplies it to the first tank 1200. The reaction liquid is an aqueous sodium hydroxide solution, an aqueous ammonia solution, or a mixture thereof. One or more of an aqueous lithium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous calcium hydroxide solution, and an aqueous magnesium hydroxide solution can be added to the reaction liquid as an auxiliary reaction liquid. At this time, the concentrations of the aqueous lithium hydroxide solution and the aqueous potassium hydroxide solution can be contained at 15% by weight or less based on the total amount of the reaction liquid, and the concentrations of the aqueous calcium hydroxide solution and the aqueous magnesium hydroxide solution are preferably contained at 2% by weight or less based on the total amount of the reaction liquid.

[0023] Also, the marine exhaust gas purification method according to the second embodiment of the present invention includes: i) carbon dioxide and water contained in the exhaust gas discharged from the ship react to form carbonic acid (H 2 CO3 ) to generate a first stage (S100), and ii) sulfur dioxide and water contained in the exhaust gas react to form sulfurous acid (H 2 SO 3 ) and sulfuric acid (H 2 SO 4 ) to generate a second stage (S200), and iii) carbonic acid (H 2 CO 3 ) generated in the first stage (S100) and sulfurous acid (H 2 SO 3 ) and sulfuric acid (H 2 SO 4 ) generated in the second stage (S200) react with the reaction solution to generate a reaction solution containing inorganic salts in a third stage (S300), and iv) the reaction solution containing inorganic salts generated in the third stage (S300) reacts with a divalent metal oxide or a divalent metal hydroxide to generate carbonates and sulfates while regenerating the reaction solution in a fourth stage (S500), and v) separating the carbonates and sulfates contained in the reaction solution regenerated through the solid-liquid separation device 1500 in a fifth stage (S600), wherein the reaction solution is an aqueous sodium hydroxide solution, an aqueous ammonia solution, or a mixture thereof, in the aqueous sodium hydroxide solution, the sodium hydroxide is contained at 0.1 to 20% by weight, in the aqueous ammonia solution, the ammonia is contained at 0.1 to 25% by weight, and in the reaction solution, any one or more of an aqueous lithium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous calcium hydroxide solution, and an aqueous magnesium hydroxide solution can be added as an auxiliary reaction solution. At this time, the concentrations of the aqueous lithium hydroxide solution and the aqueous potassium hydroxide solution can be contained at 15% by weight or less with respect to the whole reaction solution, and the concentrations of the aqueous calcium hydroxide solution and the aqueous magnesium hydroxide solution are preferably contained at 2% by weight or less with respect to the whole reaction solution.

[0024] And in the potassium hydroxide aqueous solution, the potassium hydroxide is contained at 20% by weight or less. In the lithium hydroxide aqueous solution, the lithium hydroxide is contained at 15% by weight or less. The reaction solution can be produced using pure water or seawater. The divalent metal oxide is calcium oxide or magnesium oxide. The divalent metal hydroxide is calcium hydroxide or magnesium hydroxide. The divalent metal oxide or divalent metal hydroxide can be supplied in the form of powder, aqueous solution, or sludge. The ship exhaust gas purification method includes, as a step of replenishing the reaction solution, measuring the oxidation-reduction potential (ORP), acidity (pH), or electrical conductivity of the reaction solution and then measuring the concentration of the reaction solution to replenish the reaction solution lost during operation. It is particularly preferable to include the step of replenishing the reaction solution.

Advantages of the Invention

[0025] According to the ship exhaust gas purification device 100 according to the first embodiment of the present invention, carbon dioxide contained in the exhaust gas discharged from the ship is recovered and solidified, which has the effect of facilitating storage and transfer to land. Also, by autonomously regenerating and reusing aqueous ammonia, which is the reaction solution used in the wet scrubber 110 for absorbing the carbon dioxide, there is an effect of fundamentally blocking the risk of the ship and crew being exposed to ammonia gas. As a result, the required amount of ammonia (NH 3 ) can be reduced, so that the purification cost of ship exhaust gas can be significantly reduced. And thereby, by absorbing the carbon dioxide contained in the exhaust gas discharged from the ship, it is possible to meet the exhaust gas emission regulations by the IMO and minimize the outflow of substances that can affect marine pollution.

[0026] Also, according to the ship exhaust gas purification device according to the second embodiment of the present invention, by collecting and solidifying pollutants contained in the exhaust gas discharged from the ship, it has the effect of facilitating storage and transfer to land. Furthermore, by autonomously regenerating and reusing the reaction liquid used in the wet scrubber for absorbing the pollutants on the ship, the purification cost of ship exhaust gas can be significantly reduced.

[0027] And by measuring the redox potential, pH, or electrical conductivity of the reaction liquid, etc., the lost reaction liquid can be replenished, and there is an advantage that a higher exhaust gas absorption efficiency can be obtained. In particular, by absorbing the pollutants contained in the exhaust gas discharged from the ship, it is possible to meet the exhaust gas emission regulations by the IMO and minimize the outflow of substances that can affect marine pollution.

Brief Description of the Drawings

[0028]

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Figure 10

Embodiments for Carrying Out the Invention

[0029] Terms such as "including", "having", or "comprising" in this application are intended to specify the presence of the features, numbers, steps, components, parts, or combinations thereof described in the specification, and do not preclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0030] Also, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries are interpreted to have a meaning consistent with the meaning they have in the context of the related art, and are not interpreted as having an ideal or overly formal meaning unless clearly defined in this application.

[0031] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, for the sake of easy overall understanding, the same reference numerals are assigned to the same components in the drawings, and duplicate descriptions of the same components are omitted.

[0032] Hereinafter, a marine exhaust gas purification device 100 according to a first embodiment of the present invention and a marine exhaust gas purification method using the same will be described in detail with reference to the accompanying drawings. FIG. 1 attached to the present invention is a schematic configuration diagram of the marine exhaust gas purification device 100 according to the first embodiment of the present invention, FIG. 2 is a configuration diagram of a third storage tank 140 for storing and supplying a divalent metal oxide or a divalent metal hydroxide according to the first embodiment of the present invention, FIG. 3 is a configuration diagram of a wet scrubber 110 according to the first embodiment of the present invention, and FIG. 4 is a powder X-ray diffraction (XRD) analysis chart of the solid matter generated by the marine exhaust gas purification device 100 according to the first embodiment of the present invention.

[0033] Referring to FIG. 1, a marine exhaust gas purification device 100 according to a first embodiment of the present invention reacts exhaust gas generated from an exhaust gas generating device provided on a ship with a reaction liquid to convert carbon dioxide contained in the exhaust gas into an ammonium salt. It includes a wet scrubber 110, an inlet 115 through which the exhaust gas flows into the interior of the wet scrubber 110, an outlet 112 through which the exhaust gas is discharged to the exterior of the wet scrubber 110, a circulation tank (Circulation Tank, 120) that produces a reaction liquid that reacts with the exhaust gas and supplies this to the wet scrubber 110, a transfer pump 123 for transferring the ammonium salt generated by reacting carbon dioxide contained in the exhaust gas flowing in through the inlet 115 with the reaction liquid, a mixing tank (Mixing Tank, 130) provided with an impeller that reacts the ammonium salt transferred from the wet scrubber 110 with a divalent metal oxide or a divalent metal hydroxide to generate sludge containing carbonate and aqueous ammonia, a sludge pump 131 for transferring the sludge from the mixing tank 130 to a solid-liquid separation device 150, a solid-liquid separation device 150 that separates precipitates such as carbonate and aqueous ammonia from the sludge transferred from the mixing tank 130, a first storage tank 151 for storing the aqueous ammonia separated by the solid-liquid separation device 150, a second storage tank 160 for storing precipitates such as carbonate separated by the solid-liquid separation device 150, and a transfer pump 152 for transferring the aqueous ammonia stored in the first storage tank 151 to the circulation tank 120 when necessary. It is preferable to include these components.

[0034] The exhaust gas purification device 100 for ships according to the first embodiment of the present invention configured as described above can be provided on a ship. That is, the exhaust gas generating device can be provided on the hull of the ship, and the exhaust gas generating device can be, for example, a main engine, a power generation engine, or a boiler of the ship. However, the exhaust gas generating device is not particularly limited, and any well-known device can be used as long as it is provided on the ship and discharges exhaust gas.

[0035] Looking closely at the exhaust gas purification device 100 for ships according to the first embodiment of the present invention, the inlet 115 is provided on one side of the wet scrubber 110, and exhaust gas generated after fuel combustion in the exhaust gas generating device provided on the ship flows in.

[0036] Also, on one side of the wet scrubber 110, an outlet 112 through which the inlet exhaust gas is discharged to the outside after being treated is provided.

[0037] According to the first embodiment of the present invention, the wet scrubber 110 reacts the exhaust gas flowing in through the inlet 115 with the reaction liquid to generate an ammonium salt. For this purpose, the wet scrubber 110 repeatedly circulates the process of injecting the reaction liquid that absorbs gaseous pollutants and the like contained in the exhaust gas, and pollutants precipitate or deposit in a sludge state at the lower part of the wet scrubber 110. As described above, it is preferable that the wet scrubber 110 is provided with the inlet 115 and the outlet 112 for the inflow and discharge of exhaust gas.

[0038] Looking closely at the wet scrubber 110, as shown in FIG. 3, in the wet scrubber 110, a reaction liquid supply line 117 is provided so that the reaction liquid can be injected downward from the upper end inside, and a large number of injection nozzles (not shown) are provided in the reaction liquid supply line 117 to inject the reaction liquid downward.

[0039] At this time, the exhaust gas moves upward from the lower part in the reverse direction with respect to the reaction liquid jetted downward from the injection nozzle as described above.

[0040] Further, at the lower part of the reaction liquid supply line 117 provided inside the wet scrubber 110, as shown in FIG. 3, a filling member 119 having a high surface area is provided. By passing through the filling member 119, the exhaust gas can increase the contact efficiency with the reaction liquid, and thereby increase the removal efficiency of the pollutants contained in the exhaust gas.

[0041] According to the first embodiment of the present invention, the circulation tank 120 manufactures a reaction liquid that reacts with the carbon dioxide using the regenerated aqueous ammonia stored in the first storage tank 151, and serves to supply the reaction liquid to the wet scrubber 110.

[0042] At this time, in the circulation tank 120, the regenerated aqueous ammonia and the service water are appropriately mixed to manufacture aqueous ammonia which is a reaction liquid for carbon dioxide.

[0043] Further, at the lower part of the wet scrubber 110, a transfer pump 123 for transferring the ammonium salt formed by reacting with the carbon dioxide contained in the exhaust gas to the mixing tank 130 is provided as in the following General Formulas 1 to 4.

[0044] The mixing tank 130 reacts the ammonium salt transferred from the wet scrubber 110 by the transfer pump 123 with a divalent metal oxide or a divalent metal hydroxide to regenerate aqueous ammonia and form sludge containing carbonate.

[0045] According to the first embodiment of the present invention, the divalent metal oxide is calcium oxide (CaO) or magnesium oxide (MgO), and the divalent metal hydroxide is calcium hydroxide (Ca(OH) 2 ) or magnesium hydroxide (Mg(OH) 2 ).

[0046] According to the first embodiment of the present invention, in order to facilitate the mixing of the ammonium salt and the divalent metal oxide or divalent metal hydroxide in the mixing tank 130, as shown in FIG. 2, an impeller 135 driven by a motor is preferably provided.

[0047] Further, according to the first embodiment of the present invention, in the mixing tank 130, the ammonium salt reacts with the divalent metal oxide or divalent metal hydroxide to form sludge containing carbonates and the like and aqueous ammonia as shown in the following general formulas 5 to 6.

[0048] After the reaction is completed as described above, in order to transfer the sludge containing carbonates and the like generated in the mixing tank 130, a sludge pump 131 can be further provided on one side of the mixing tank 130.

[0049] And the exhaust gas purification device 100 for ships according to the present invention preferably includes a solid-liquid separation device 150 in order to separate the sludge containing carbonates and the like and aqueous ammonia generated after the reaction is completed as shown in the general formulas 7 to 12.

[0050] According to the first embodiment of the present invention, since the sludge contains precipitates such as carbonates and the generated aqueous ammonia, if the aqueous ammonia and the sludge are not separated, the aqueous ammonia cannot be reused as a reaction solution later.

[0051] That is, since the sludge contains 20 to 50% by weight of the aqueous ammonia, various techniques or devices for separating the aqueous ammonia from the sludge are presented. Among them, a typical device is the solid-liquid separation device 150.

[0052] Examples of the solid-liquid separator 150 as described above include a filter press type or a belt press type. Such a filter press type or belt press type solid-liquid separator 150 is provided such that a filter cloth belt passes through a number of rollers, and sludge is fed and transferred between the filter cloths and pressurized by the rollers, so that ammonia water is separated from the sludge.

[0053] Further, according to the first embodiment of the present invention, an ammonia water transfer pump 152 for transferring the ammonia water from the first storage tank 151 to the circulation tank 120 can be further provided so that the ammonia water separated by the solid-liquid separator 150 can be reused when recovering carbon dioxide contained in the exhaust gas.

[0054] The exhaust gas purification device 100 for ships according to the first embodiment of the present invention configured as described above can be provided on a ship. That is, an exhaust gas generating device for generating the exhaust gas can be provided on the hull of the ship, and the exhaust gas generating device can be, for example, a main engine, a power generation engine, or a boiler of the ship. However, the exhaust gas generating device is not particularly limited, and any well-known device that discharges exhaust gas is possible.

[0055] In the exhaust gas generating device, bunker C oil can be used as fuel. Bunker C oil, which is a marine fuel, has the advantage of generating a large amount of energy because it has a high calorific value and efficiency during combustion. That is, while the calorific value of coal is 5,000 to 7,000 kcal / kg, the calorific value of bunker C oil is about twice as high at 10,000 to 11,000 kcal / kg.

[0056] In addition, since bunker C oil is cheaper than crude oil, it is widely used in ships, power plants, etc.

[0057] Generally, bunker C oil is composed of hydrocarbon compounds having 13 or more carbon atoms, and is likely to generate pollutants during the combustion process, and contains particularly a large amount of environmental pollutants such as sulfur.

[0058] Referring to FIG. 2, a method for regenerating and reusing aqueous ammonia used as a reaction liquid for recovering carbon dioxide contained in exhaust gas in the exhaust gas purification device 100 for ships according to the first embodiment of the present invention using a divalent metal oxide or a divalent metal hydroxide will be specifically described as follows.

[0059] That is, the reaction of aqueous ammonia, which is a reaction liquid with carbon dioxide, a pollutant contained in the exhaust gas generated from the exhaust gas generating device provided on the ship, is as shown in the following general formulas 1 to 4. Usually, aqueous ammonia is produced by dissolving ammonia gas in water. At this time, the solubility of the ammonia gas in water is about 29 to 30% by weight. Therefore, about 70% by weight of water is present together in the aqueous ammonia.

[0060] Therefore, as in general formula 1, carbon dioxide contained in the exhaust gas reacts with water to form carbonic acid (first stage). At this time, it is preferable to use the water present together in the aqueous ammonia as the water that reacts with the carbon dioxide.

[0061] (Formula 1) CO 2 +H 2 O → H 2 CO 3

[0062] (Formula 2) NH 4 OH + H 2 CO 3 → NH 4 HCO 3 +H 2 O

[0063] (Formula 3) NH 4 OH + NH 4 HCO 3 → (NH 4 ) 2 CO 3 +H 2 O

[0064] (Formula 4) 2NH 4 OH + H 2CO 3 →(NH 4 ) 2 CO 3 +2H 2 O

[0065] As shown in the general formula 2, carbonic acid reacts with aqueous ammonia to form ammonium bicarbonate (NH 4 HCO 3 ) and water (second stage). Further, ammonium bicarbonate (NH 4 HCO 3 ) generated in the general formula 2 reacts with aqueous ammonia to form ammonium carbonate ((NH 4 ) 2 CO 3 ) and water are generated (third stage).

[0066] As described above, if ammonium bicarbonate (NH 4 HCO 3 ) and ammonium carbonate ((NH 4 ) 2 CO 3 ), which are reaction products of carbon dioxide and aqueous ammonia, are removed and aqueous ammonia is continuously supplied to the wet scrubber 110, carbon dioxide, which is a pollutant contained in the exhaust gas generated from the ship, can be continuously removed.

[0067] According to the prior art, in order to continuously supply aqueous ammonia, which is the reaction liquid, to the wet scrubber 110, a large amount of ammonia gas for producing the aqueous ammonia must be stored on the ship. However, when a large amount of ammonia gas is stored and operated on the ship as described above, there is a risk of exposure of the ammonia gas.

[0068] In order to solve such problems, in the first embodiment of the present invention, ammonium bicarbonate (NH 4 HCO 3 ) and ammonium carbonate ((NH 4 ) 2 CO 3) is reacted with a divalent metal oxide or a divalent metal hydroxide to regenerate sludge containing carbonate and aqueous ammonia (the fourth step). Further, by separating the aqueous ammonia and the sludge, the aqueous ammonia can be reused as a reaction solution for recovering carbon dioxide contained in the exhaust gas (the fifth step).

[0069] Further, the sludge containing the carbonate can be easily stored on a ship and can be stored on the ship more safely by solidifying it.

[0070] That is, the method of solidifying the sludge containing the carbonate as described above is a method capable of storing the carbon dioxide most stably, and there is no risk of re-release of the carbon dioxide.

[0071] The reaction for regenerating aqueous ammonia by reacting ammonium bicarbonate and ammonium carbonate, which are products generated after reacting carbon dioxide with aqueous ammonia as a reaction solution as described above, with calcium hydroxide, which is a divalent metal hydroxide, is as shown in the following general formulas 5 to 6.

[0072] (Formula 5) NH 4 HCO 3 + Ca(OH) 2 → NH 4 OH + CaCO 3 + H 2 O

[0073] (Formula 6) (NH 4 ) 2 CO 3 + Ca(OH) 2 → 2NH 4 OH + CaCO 3

[0074] As described above, the results of analyzing the sludge generated by the reaction of aqueous ammonia, which is a reaction solution, with ammonium bicarbonate or ammonium carbonate by XRD (X-ray diffraction) are shown in FIG. 4. When FIG. 4 is closely examined, it can be confirmed that the generated sludge is calcium carbonate.

[0075] According to another embodiment of the first embodiment of the present invention, the general formulas for regenerating aqueous ammonia by reacting ammonium bicarbonate and ammonium carbonate, which are products generated after reacting carbon dioxide with aqueous ammonia as a reaction solution as described above, with calcium oxide, which is a divalent metal oxide, are as shown in the following general formulas 7 and 8.

[0076] (Formula 7) NH 4 HCO 3 + CaO → NH 4 OH + CaCO 3

[0077] (Formula 8) (NH 4 ) 2 CO 3 + CaO + H 2 O → 2NH 4 OH + CaCO 3

[0078] Also, the general formulas for regenerating aqueous ammonia by reacting ammonium bicarbonate and ammonium carbonate, which are products generated after reacting carbon dioxide with aqueous ammonia as a reaction solution as described above, with magnesium oxide, which is a divalent metal oxide, are as shown in the following general formulas 9 and 10.

[0079] (Formula 9) NH 4 HCO 3 + MgO → NH 4 OH + MgCO 3

[0080] (Formula 10) (NH 4 ) 2 CO 3 + MgO → 2NH 4 OH + MgCO 3

[0081] And, the general formulas for regenerating aqueous ammonia by reacting ammonium bicarbonate and ammonium carbonate, which are products generated after reacting carbon dioxide with aqueous ammonia as a reaction solution as described above, with magnesium hydroxide, which is a divalent metal hydroxide, are as shown in the following general formulas 11 and 12.

[0082] (Formula 11) NH 4 HCO 3 + Mg(OH) 2 → NH 4 OH + MgCO 3 + 2H 2 O

[0083] (Formula 12) (NH 4 ) 2 CO 3 + Mg(OH) 2 → 2NH 4 OH + MgCO 3

[0084] The reaction solution that has reacted with the carbon dioxide contained in the exhaust gas in the wet scrubber 110 is transferred to the mixing tank 130 via the transfer pump 123.

[0085] The divalent metal oxide or divalent metal hydroxide is supplied from the third storage tank 140 to the mixing tank 130 filled with the reaction solution that has reacted with the carbon dioxide contained in the exhaust gas transferred as described above. At this time, the divalent metal oxide or divalent metal hydroxide can be supplied in an appropriate form such as powder, aqueous solution, or sludge.

[0086] According to the first embodiment of the present invention, the amount of the divalent metal oxide or divalent metal hydroxide supplied to the mixing tank 130 can be calculated from the general formulas 5 to 12. That is, since the divalent metal oxide or divalent metal hydroxide reacts with ammonium bicarbonate and ammonium carbonate in an equivalent ratio of 1:1, the divalent metal oxide or divalent metal hydroxide is supplied in the same equivalent ratio as the treatment amount of ammonium bicarbonate and ammonium carbonate.

[0087] When the divalent metal oxide or divalent metal hydroxide is supplied to the mixing tank 130 as described above, as in the general formulas 5 to 12, the reaction solution that has reacted with the carbon dioxide contained in the exhaust gas reacts with the divalent metal oxide or divalent metal hydroxide.

[0088] When the reaction liquid that has reacted with the carbon dioxide contained in the exhaust gas reacts with the divalent metal oxide or divalent metal hydroxide, carbonates such as calcium carbonate or magnesium carbonate and aqueous ammonia are formed as represented by General Formulas 5 to 12.

[0089] At this time, the reaction time for the reaction liquid that has reacted with the carbon dioxide and the divalent metal oxide or divalent metal hydroxide is preferably 30 to 120 minutes.

[0090] The carbonate such as calcium carbonate or magnesium carbonate produced by the reaction of the reaction liquid that has reacted with the carbon dioxide contained in the exhaust gas and the divalent metal oxide or divalent metal hydroxide is mixed with aqueous ammonia and precipitated in the lower part of the mixing tank 130 in a sludge state. After the reaction time has elapsed, the sludge is transferred to the solid-liquid separation device 150 using the sludge pump 131 provided at the lower part of the mixing tank 130. The sludge transferred by the sludge pump 131 is separated in the solid-liquid separation device 150 into a carbonate as a solid component and aqueous ammonia as a liquid component.

[0091] The precipitate containing the carbonate separated as described above is transferred to the second storage tank 160, and the separated aqueous ammonia is transferred to the first storage tank 151.

[0092] As described above, the aqueous ammonia stored in the first storage tank 151 is transferred to the circulation tank 120 using the transfer pump 152 when necessary, and then supplied as a reaction liquid to the wet scrubber 110 that treats the exhaust gas and reused as a reaction liquid.

[0093] Also, the precipitate containing the carbonate stored in the second storage tank 160 is preferably solidified and stored through a known method. The precipitate solidified and stored as described above is unloaded and processed when the ship arrives on land.

[0094] At this time, when separating aqueous ammonia and the precipitate with the solid-liquid separator 150, or when discharged together with the exhaust gas from the upper end of the wet scrubber 110, some aqueous ammonia, which is the reaction liquid, may be lost.

[0095] When the aqueous ammonia is lost and insufficient as described above, there is a risk that the operation time of the exhaust gas purification device 100 will become longer, and the absorption efficiency of carbon dioxide contained in the exhaust gas will become lower.

[0096] In the first embodiment of the present invention, in order to solve such a problem, the insufficient aqueous ammonia during operation is replenished by supplying 1.0 to 2.0 times the equivalent ratio of ammonium bicarbonate and ammonium carbonate to be treated. By replenishing the aqueous ammonia as described above, the operation time of the exhaust gas purification device 100 can be shortened, and the absorption efficiency of carbon dioxide can be improved.

[0097] Generally, ammonia gas for producing aqueous ammonia, which is a reaction liquid used when reacting with exhaust gas, has a bad smell and toxicity, and there is a risk of exposing crew members when handled on a ship. In particular, ammonia gas for producing a reaction liquid of exhaust gas on a ship is highly toxic, and if it leaks on the ship, the safety of crew members may not be ensured.

[0098] In order to prevent such ammonia gas from exposing crew members, the present invention does not include a tank for storing the ammonia gas on the ship, and regenerates it as aqueous ammonia by reacting the reaction liquid reacted with the exhaust gas with a divalent metal oxide or a divalent metal hydroxide.

[0099] Also, by supplying the regenerated aqueous ammonia as described above to the wet scrubber 110 for reuse, a tank for storing ammonia gas on the ship becomes unnecessary.

[0100] That is, according to the first embodiment of the present invention, by regenerating and reusing the aqueous ammonia that has reacted with the carbon dioxide contained in the exhaust gas, the safety of the ship's crew and the entire ship can be improved.

[0101] In the mixing tank 130, a reaction liquid that has reacted with the carbon dioxide contained in the exhaust gas and a divalent metal oxide or divalent metal hydroxide are supplied from the third storage tank 140 and reacted, whereby a regeneration reaction of aqueous ammonia that can be reused as a reaction liquid is carried out.

[0102] As described above, the supply amount of the divalent metal oxide or divalent metal hydroxide supplied from the third storage tank 140 to the mixing tank 130 can be estimated by analyzing the pH or ORP (Oxidation-reduction potential) of the sludge containing ammonium salts such as ammonium bicarbonate (NH 4 HCO 3 ) and ammonium carbonate ((NH 4 ) 2 CO 3 ).

[0103] That is, by analyzing the pH or ORP (Oxidation-reduction potential) of the sludge containing ammonium salts such as ammonium bicarbonate (NH 4 HCO 3 ) and ammonium carbonate (NH 4 ) 2 CO 3 ), the acidity or oxidation-reduction potential of the sludge is measured, and thereby the supply amount of the divalent metal oxide or divalent metal hydroxide can be estimated.

[0104] That is, according to the present invention, as described above, it is preferable to supply the divalent metal oxide or divalent metal hydroxide in a molar ratio of 1.0 to 2.0 times the estimated value.

[0105] When the supply amount of the divalent metal oxide or divalent metal hydroxide is less than 1.0 times in molar ratio, the regeneration efficiency of the aqueous ammonia becomes poor. Further, when the supply amount of the divalent metal oxide or divalent metal hydroxide exceeds 2.0 times in molar ratio, the excess divalent metal oxide or divalent metal hydroxide is precipitated and discharged, so that no problem occurs in the safety of the ship and the crew during the storage and handling processes.

[0106] In addition, the divalent metal oxide or divalent metal hydroxide supplied in excess can increase the concentration of aqueous ammonia, thereby inducing an increase in the absorption efficiency of carbon dioxide.

[0107] Further, according to the first embodiment of the present invention, since a tank for storing ammonia gas is not installed on the ship, it is also possible to directly produce aqueous ammonia by reacting an inorganic compound with calcium hydroxide instead of dissolving ammonia gas.

[0108] That is, as described above, as the inorganic compound for directly producing aqueous ammonia, ammonium bicarbonate (NH 4 HCO 3 ), ammonium carbonate ((NH 4 ) 2 CO 3 ), ammonium bisulfate (NH 4 HSO 4 ), ammonium sulfate (NH 4 ) 2 SO 4 ), ammonium nitrate (NH 4 NO 3 ), ammonium chloride (NH 4 Cl), ammonium sulfamate (NH 4 SO 3 NH 2 ), ammonium sulfite ((NH 4 ) 2 SO 3 ) etc. can be used.

[0109] The inorganic compound reacts with calcium hydroxide to produce aqueous ammonia. By supplying the aqueous ammonia produced as described above to the wet scrubber 110 via the circulation tank 120, it becomes unnecessary to provide a storage tank for ammonia gas for producing aqueous ammonia, which is a reaction liquid, on the ship.

[0110] According to the present invention, when producing aqueous ammonia using an inorganic compound, it is preferable to introduce 1.0 to 2.0 times the molar ratio of the insufficient aqueous ammonia for the amount of the inorganic compound used.

[0111] Further, according to the first embodiment of the present invention, a ship equipped with the exhaust gas purification device 100 for ships described above can be provided.

[0112] By maintaining a constant concentration of aqueous ammonia, which is a reaction liquid, by the exhaust gas purification device 100 for ships as described above, it is possible to prevent a decrease in the absorption performance of the wet scrubber 110, and also to satisfy the exhaust gas emission regulations by IMO, and to convert the carbon dioxide into a substance that does not affect the environment and separate and discharge or store it.

[0113] And by regenerating and reusing aqueous ammonia, it is possible to significantly reduce the purification cost of ship exhaust gas by minimizing the consumption of relatively expensive ammonia.

[0114] On the other hand, by solidifying carbon dioxide contained in the exhaust gas discharged from the ship and storing it in appropriate reservoirs of the ship, it further has the effect of facilitating the storage, resource utilization, and industrial use of the recovered carbon dioxide.

[0115] As described above, the exhaust gas purification method for ships according to the first embodiment of the present invention includes: i) a first step in which carbon dioxide and water contained in the exhaust gas discharged from the ship react to produce carbonic acid (H 2 CO 3 );

[0116] ii) a second step in which the carbonic acid and aqueous ammonia generated in the first step react to form ammonium bicarbonate (NH 4 HCO 3 ); and

[0117] iii) a third step in which the ammonium bicarbonate (NH 4 HCO 3 ) generated in the second step reacts with aqueous ammonia to form ammonium carbonate ((NH 4 ) 2 CO 3 ); and

[0118] iv) a fourth step in which ammonium bicarbonate (NH 4 HCO 3 ) and ammonium carbonate ((NH 4 ) 2 CO 3 ) react with a divalent metal oxide or a divalent metal hydroxide to form a carbonate and aqueous ammonia; and

[0119] v) preferably, a fifth step of re-supplying the aqueous ammonia generated in the fourth step to the second step.

[0120] Also, the ship exhaust gas purification method, purification device, and ship according to the second embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 5 attached to the present invention is a schematic configuration diagram of a ship exhaust gas purification device 1000 according to the second embodiment of the present invention, FIG. 6 is a configuration diagram of a 13th tank 1400 for storing and supplying a divalent metal oxide or a divalent metal hydroxide according to the second embodiment of the present invention, FIG. 7 is a configuration diagram of a wet scrubber 1100 according to the second embodiment of the present invention, FIG. 8 is a measurement graph of the oxidation-reduction potential according to the concentration of the reaction liquid according to the second embodiment of the present invention, FIG. 9 is a measurement graph of the pH according to the concentration of the reaction liquid according to the second embodiment of the present invention, and FIG. 10 is a measurement graph of the electrical conductivity according to the concentration of the reaction liquid according to the present invention.

[0121] Referring to Fig. 5, the exhaust gas purification device 1000 for ships according to the second embodiment of the present invention reacts the exhaust gas generated from the exhaust gas generating device with water and a reaction liquid to convert carbon dioxide and sulfur dioxide contained in the exhaust gas into inorganic salts. It includes a wet scrubber 1100, a first tank 1200 for storing the reaction liquid that reacts with the exhaust gas and supplying it to the wet scrubber 1100, a transfer pump 1230 provided at the lower part of the wet scrubber 1100 for transferring the reaction liquid containing the inorganic salts to a second tank 1300, a second tank 1300 for reacting the inorganic salts contained in the reaction liquid containing the inorganic salts generated in the wet scrubber 1100 with a divalent metal oxide or a divalent metal hydroxide to regenerate the reaction liquid, and generating sludge containing carbonates and sulfates at this time, a third tank 1400 for storing the divalent metal oxide or the divalent metal hydroxide and supplying it to the second tank 1300, a solid-liquid separation device 1500 for separating carbonates and sulfates from the sludge transferred from the second tank 1300, a sludge pump 1310 for transferring carbonates and sulfates from the second tank 1300 to the solid-liquid separation device 1500, a fourth tank 1600 for storing the carbonates and sulfates separated by the solid-liquid separation device 1500, and a fifteenth tank 1510 for storing the regenerated reaction liquid separated by the solid-liquid separation device 1500 and supplying it to the first tank 1200.

[0122] The exhaust gas purification device 1000 for ships according to the second embodiment of the present invention configured as described above can be provided on a ship. That is, on the hull of the ship, the exhaust gas purification device 1000 for ships can be provided on one side, and the exhaust gas generating device can be, for example, the main engine of the ship, a power generation engine, or a boiler. However, the exhaust gas generating device is not particularly limited, and any well-known device that is provided on a ship and discharges exhaust gas is possible.

[0123] Looking closely at the exhaust gas purification device 1000 for ships according to the second embodiment of the present invention, first, the exhaust gas purification device 1000 for ships reacts the exhaust gas with water and a reaction liquid to convert CO 2 and SO2 It includes a wet scrubber 1100 for converting it into inorganic salts.

[0124] On one side of the wet scrubber 1100, as shown in FIG. 5, there is an inlet 1150 through which exhaust gas generated after fuel combustion in an exhaust gas generating device provided on the ship flows in. Also, on one side of the wet scrubber 1100, there are both outlets 1120 through which the inlet exhaust gas is discharged to the outside after being treated.

[0125] According to the second embodiment of the present invention, the wet scrubber 1100 reacts the exhaust gas flowing in through the inlet 1150 with water and a reaction liquid to generate inorganic salts. For this purpose, while the wet scrubber 1100 repeats the process of injecting a reaction liquid for absorbing gaseous pollutants contained in the exhaust gas, pollutants precipitate or deposit in the form of sludge at the lower part of the wet scrubber 1100.

[0126] Looking closely at the wet scrubber 1100, as shown in FIG. 7, at the upper end inside the wet scrubber 1100, there is a reaction liquid supply line 1170 provided so that the reaction liquid can be injected downward. The reaction liquid supply line 1170 is provided with a number of injection nozzles (not shown) for injecting the reaction liquid downward.

[0127] At this time, the exhaust gas moves from the lower part to the upper part in the opposite direction to the reaction liquid with respect to the reaction liquid injected downward from the injection nozzles as described above.

[0128] Also, below the reaction liquid supply line 1170 provided inside the wet scrubber 1100, as shown in FIG. 7, there is a filling member 1190 having a high surface area. By passing through the filling member 1190, the exhaust gas can increase the contact efficiency with the reaction liquid, thereby increasing the removal efficiency of carbon dioxide and sulfur dioxide, which are pollutants contained in the exhaust gas.

[0129] According to the second embodiment of the present invention, the eleventh tank 1200 stores and supplies the reaction liquid supplied to the wet scrubber 1100.

[0130] According to the second embodiment of the present invention, the reaction liquid is an aqueous ammonia solution or an aqueous sodium hydroxide solution, and these can be used by mixing them. Further, the reaction liquid can further contain an aqueous lithium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous calcium hydroxide solution, or an aqueous magnesium hydroxide solution as an auxiliary reaction liquid in order to improve the recovery efficiency of CO 2 and SO 2 At this time, the concentration of the aqueous lithium hydroxide solution and the aqueous potassium hydroxide solution can be contained at 15% by weight or less based on the total amount of the reaction liquid, and the concentration of the aqueous calcium hydroxide solution and the aqueous magnesium hydroxide solution is preferably contained at 2% by weight or less based on the total amount of the reaction liquid.

[0131] That is, when the concentration of the aqueous lithium hydroxide solution and the aqueous potassium hydroxide solution exceeds 15% by weight based on the total amount of the reaction liquid, or when the concentration of the aqueous calcium hydroxide solution and the aqueous magnesium hydroxide solution exceeds 2% by weight based on the total amount of the reaction liquid, the effect of preventing side reactions of the reaction liquid is poor, and since the effect of increasing the reaction liquid with respect to the saturation concentration is small, the effect of adding the auxiliary reaction liquid is reduced.

[0132] The eleventh tank 1200 stores the reaction liquid and supplies the reaction liquid to the wet scrubber 1100 when necessary.

[0133] Further, at the lower part of the wet scrubber 1100, there is provided a transfer pump 1230 for transferring the inorganic salts formed by reacting with CO

[0134] contained in the exhaust gas and SO 2 to the twelfth tank 1300. 2

[0135] ​The 12th tank 1300 regenerates the reaction solution by reacting the inorganic salts contained in the reaction solution transferred by the transfer pump 1230 from the wet scrubber 1100 with a divalent metal oxide or a divalent metal hydroxide.

[0136] Further, according to the present invention, as described above, in order to supply a divalent metal oxide or a divalent metal hydroxide to the 12th tank 1300, it is preferable to provide a 13th tank 1400 for storing and supplying the divalent metal oxide or the divalent metal hydroxide.

[0137] As described above, in the 12th tank 1300, sludge containing carbonate and sulfate formed while the reaction solution is regenerated is formed.

[0138] According to the second embodiment of the present invention, the divalent metal oxide that reacts with the inorganic salt to regenerate the reaction solution and forms sludge containing carbonate and sulfate is calcium oxide (CaO) or magnesium oxide (MgO), and the divalent metal hydroxide is calcium hydroxide (Ca(OH) 2 ) or magnesium hydroxide (Mg(OH) 2 ) can be.

[0139] According to the present invention, in order to facilitate the mixing of the inorganic salt and the divalent metal oxide or the divalent metal hydroxide generated as described above in the 12th tank 1300, as shown in FIG. 6, it is preferable to provide an impeller 1350 driven by a motor.

[0140] According to the second embodiment of the present invention, in the 12th tank 1300, the inorganic salt reacts with the divalent metal oxide or the divalent metal hydroxide to generate sludge containing carbonate, sulfate, etc., and the reaction solution is regenerated.

[0141] At this time, the reaction time for the reaction solution reacted with the inorganic salt to react with the divalent metal oxide or the divalent metal hydroxide is preferably 30 to 120 minutes.

[0142] CO, which is a pollutant contained in the exhaust gas 2 and SO2 The reaction solution reacted with [substance] and the carbonates and sulfates produced by the reaction of the divalent metal oxide or divalent metal hydroxide are mixed with the regenerated reaction solution and precipitated in a sludge form at the bottom of the 12th tank 1300. After the reaction time has elapsed, the sludge is transferred to the solid-liquid separation device 1500 using the sludge pump 1310 provided at the bottom of the 12th tank 1300.

[0143] The sludge transferred by the sludge pump 1310 is separated by the solid-liquid separation device 1500 into carbonates and sulfates as solid components and a regenerated reaction solution as a liquid component.

[0144] As described above, the carbonates and sulfates separated by the solid-liquid separation device 1500 are transferred to the 14th tank 1600, and the separated reaction solution is transferred to the 15th tank 1510.

[0145] As described above, the regenerated reaction solution regenerated and stored in the 15th tank 1510 is supplied to the wet scrubber 1100 that treats exhaust gas through the 11th tank 1200 when necessary and reused as a reaction solution.

[0146] Also, the precipitates such as carbonates and sulfates stored in the 14th tank 1600 are preferably solidified and stored through a known method. The precipitates solidified and stored as described above are unloaded and processed when the ship arrives on land.

[0147] At this time, the reaction solution may be somewhat lost when separating the reaction solution from the carbonates and sulfates by the solid-liquid separation device 1500 and contained in the precipitate, or discharged together with the exhaust gas at the upper end of the wet scrubber 1100.

[0148] As described above, when the reaction solution is lost and insufficient, the operation time of the ship exhaust gas purification device 1000 becomes longer, and there is a risk that the absorption efficiency of CO 2 and SO 2 contained in the exhaust gas becomes low.

[0149] In the second embodiment of the present invention, in order to solve such a problem, the reaction solution that is insufficient during operation is supplied in an amount 1.0 to 2.0 times the equivalent ratio of carbonic acid, sulfuric acid, sulfurous acid, etc. that are the treatment targets, thereby replenishing the insufficient reaction solution.

[0150] The aqueous sodium hydroxide solution and the aqueous ammonia solution, which are the reaction solutions according to the second embodiment of the present invention, as shown in FIGS. 8 to 10, show a roughly linear correlation with the concentration of the reaction solution, the oxidation reduction potential (hereinafter referred to as ORP), the pH, and the measured value of the electrical conductivity.

[0151] That is, as shown in FIG. 8, the concentration of the reaction solution shows a linear correlation inversely proportional to the ORP measurement value, and as shown in FIG. 9, the reaction solution and the pH show a linear correlation that is proportional. Also, the reaction solution and the electrical conductivity show a linear correlation that is proportional as shown in FIG. 10.

[0152] Therefore, by measuring any one of the ORP, pH, or electrical conductivity of the reaction solution to measure the concentration of the reaction solution, it becomes possible to calculate the concentration of the insufficient reaction solution. Thereby, the insufficient reaction solution can be replenished by supplying the insufficient reaction solution in an amount 1.0 to 2.0 times the equivalent ratio of carbonic acid, sulfurous acid, and sulfuric acid that are the treatment targets.

[0153] By replenishing the reaction solution as described above, the operation time of the marine exhaust gas purification device 1000 according to the second embodiment of the present invention can be shortened, and the absorption efficiency of the pollutants can also be improved.

[0154] As described above, CO 2 and SO 2 After the reaction between the reaction solution is completed, in order to transfer the sludge containing carbonates and sulfates generated in the 12th tank 1300 to the solid-liquid separation device 1500, a sludge pump 1310 can be provided on one side of the 12th tank 1300.

[0155] According to the second embodiment of the present invention, since precipitates such as carbonates and sulfates and the regenerated reaction solution are mixed in the sludge, if the reaction solution and the sludge are not separated, the reaction solution cannot be reused later.

[0156] That is, since the regenerated reaction solution is contained in the sludge at 20 to 50% by weight, various techniques or apparatuses for separating the regenerated reaction solution from the sludge are presented. Among them, the typical apparatus is the solid-liquid separation apparatus 1500.

[0157] Examples of the solid-liquid separation apparatus 1500 as described above include a filter press type or a belt press type. Such a filter press type or belt press type solid-liquid separation apparatus 1500 is provided such that the filter cloth belt passes through a number of rollers, and while the sludge is fed and transferred between the filter cloths, it is pressurized by the rollers so that the reaction solution is separated from the sludge.

[0158] Further, according to the second embodiment of the present invention, the regenerated reaction solution separated by the solid-liquid separation apparatus 1500 can be reused when adsorbing CO 2 and SO 2 in the exhaust gas, and a reaction solution transfer pump 1520 for transferring the reaction solution from the 15th tank 1510 to the 11th tank 1200 can be further provided.

[0159] Further, the exhaust gas purification apparatus 1000 for ships according to the second embodiment of the present invention is provided with a 13th tank 1400 for supplying a divalent metal oxide or a divalent metal hydroxide to the 12th tank 1300. At this time, the divalent metal oxide or the divalent metal hydroxide can be supplied in an appropriate form such as powder, aqueous solution or sludge form.

[0160] In the exhaust gas purification device 1000 for ships according to the second embodiment of the present invention, a fourteenth tank 1600 for storing carbonates, sulfates, etc. separated by the solid-liquid separation device 1500 as described above is provided, and the separated regeneration reaction liquid is transferred to and stored in a fifteenth tank 1510.

[0161] The exhaust gas purification device 1000 for ships according to the second embodiment of the present invention configured as described above can be provided on a ship. That is, an exhaust gas generation device that generates the exhaust gas is provided on the hull of the ship, and the exhaust gas generation device can be, for example, a main engine, a power generation engine, or a boiler of the ship. However, the exhaust gas generation device is not particularly limited, and any well-known device that discharges exhaust gas is possible.

[0162] In the exhaust gas generation device, bunker C oil can be used as fuel. Bunker C oil, which is a marine fuel, has the advantage of generating a large amount of energy because it has a high calorific value and efficiency during combustion. That is, while the calorific value of coal is 5,000 to 7,000 kcal / kg, the calorific value of bunker C oil is about twice as high at 10,000 to 11,000 kcal / kg.

[0163] In addition, since bunker C oil is cheaper than crude oil, it is widely used in ships, power plants, etc.

[0164] Generally, bunker C oil consists of hydrocarbon compounds having 13 or more carbon atoms, and is likely to generate pollutants during the combustion process, and contains particularly many environmental pollutants such as sulfur.

[0165] According to the second embodiment of the present invention, by reacting with pollutants such as CO 2 and SO 2 contained in the exhaust gas discharged from the ship to generate inorganic salts, an aqueous sodium hydroxide solution or an aqueous ammonia solution can be used as the reaction liquid for recovery. Or, a mixture of these can also be used.

[0166] Also, the reaction solution can be produced using pure water or seawater. That is, sodium hydroxide (NaOH) or ammonia (NH 3 ) is dissolved in pure water or seawater to produce a reaction solution that absorbs CO 2 and SO 2 .

[0167] According to the second embodiment of the present invention, in the aqueous sodium hydroxide solution used as the reaction solution, the sodium hydroxide is preferably contained in an amount of 0.1 to 20% by weight, and in the aqueous ammonia solution, the ammonia is particularly preferably contained in an amount of 0.1 to 25% by weight. That is, an aqueous sodium hydroxide solution having a concentration of less than 0.1% by weight has a very low absorption reaction rate and saturation absorption amount with respect to CO 2 and SO 2 , so the recovery ability of the CO 2 and SO 2 decreases. In addition, an aqueous sodium hydroxide solution having a concentration exceeding 20% by weight can corrode the marine exhaust gas purification device 1000. And an aqueous ammonia solution having a concentration of less than 0.1% by weight has a greatly reduced saturation absorption amount with respect to CO 2 and SO 2 , and an aqueous ammonia solution having a concentration exceeding 25% by weight has a reduced solubility in aqueous ammonia at the operating temperature of the marine exhaust gas purification device 1000, and the dissolved ammonia is converted into a gas and discharged.

[0168] In particular, according to the second embodiment of the present invention, in order to improve the recovery efficiency of CO 2 and SO 2 contained in the exhaust gas discharged from the ship, an auxiliary reaction solution such as an aqueous lithium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous calcium hydroxide solution, or an aqueous magnesium hydroxide solution can be added. That is, the auxiliary reaction solution has a slower absorption reaction rate with respect to CO 2 and SO 2 than the aqueous sodium hydroxide solution or the aqueous ammonia solution that is the reaction solution, so the CO 2 and SO 2By preventing a rapid absorption reaction with respect to [substance], it has the effect of preventing side reactions. Further, even when the absorption reaction with respect to CO 2 and SO 2 ends after the reaction solution reaches the saturation concentration, the auxiliary reaction solution can continuously absorb the CO 2 and SO 2 , thereby having the effect of increasing the saturation concentration with respect to CO 2 and SO 2 as a whole.

[0169] According to the second embodiment of the present invention, a ship exhaust gas purification method for recovering CO 4 and SO 2 contained in the exhaust gas generated from a ship using the reaction solution, which is an aqueous solution of sodium hydroxide (NaOH) or an aqueous ammonia solution (NH 2 OH), includes: i) a first stage (S100) in which carbon dioxide and water contained in the exhaust gas discharged from the ship react to generate carbonic acid (H 2 CO 3 ); ii) a second stage (S200) in which sulfur dioxide and water contained in the exhaust gas react to generate sulfurous acid (H 2 SO 3 ) and sulfuric acid (H 2 SO 4 ); iii) a third stage (S300) in which the carbonic acid (H 2 CO 3 ) generated in the first stage (S100) reacts with the sulfurous acid (H 2 SO 3 ) and sulfuric acid (H 2 SO 4 ) generated in the second stage (S200) to react with the reaction solution to generate a reaction solution containing inorganic salts; iv) a fourth stage (S500) in which the reaction solution containing inorganic salts generated in the third stage (S300) reacts with a divalent metal oxide or a divalent metal hydroxide to generate carbonates and sulfates while regenerating the reaction solution; and v) a fifth stage (S600) of separating the carbonates and sulfates contained in the reaction solution regenerated through the solid-liquid separation device 1500. It is preferable to include these steps.

[0170] When examining this in detail, it is as follows.

[0171] <Step a (S100)>

[0172] CO contained in the exhaust gas discharged from the ship according to the second embodiment of the present invention 2 and SO 2 The a-th step for recovering is a step in which the above CO 2 reacts with water to produce carbonic acid (H 2 CO 3 ).

[0173] The a-th step is such that CO contained in the exhaust gas as shown in the following (General Formula 13) 2 reacts with water to form carbonic acid (H 2 CO 3 ). At this time, it is preferable to use the water contained in the reaction liquid injected into the wet scrubber 1100 as the water that reacts with the above CO 2 .

[0174] (Chemical Formula 13) CO 2 + H 2 O → H 2 CO 3

[0175] <Step b (S200)>

[0176] The b-th step is a step in which SO contained in the exhaust gas of the ship 2 reacts with water to form sulfurous acid (H 2 SO 3 ) or sulfuric acid (H 2 SO 4 ). That is, when there is oxygen when the above SO 2 reacts with water, it reacts as shown in (General Formula 14) to produce sulfuric acid, and when there is no oxygen, it reacts with water to form sulfurous acid as shown in (General Formula 15).

[0177] At this time, it is preferable to use the water contained in the reaction liquid injected into the wet scrubber 1100 as the water that reacts with the above SO 2 , as in the a-th step.

[0178] (Formula 14) 2SO 2 +O 2 +2H 2 O → 2H 2 SO 4

[0179] (Formula 15) SO 2 +H 2 O → H 2 SO 3

[0180] <Step c (S300)>

[0181] Step c indicates the step in which the reaction solution reacts with the carbonic acid (H 2 CO 3 ) generated in Step a (S100), the sulfurous acid (H 2 SO 3 ) and sulfuric acid (H 2 SO 4 ) generated in Step b (S200) in the wet scrubber 1100 to produce inorganic salts.

[0182] First, examining the reaction between the carbonic acid generated in Step a and the reaction solution, which is an aqueous sodium hydroxide solution or an aqueous ammonia solution, is as follows.

[0183] The carbonic acid generated as in the above (General Formula 13) reacts with the aqueous sodium hydroxide solution as in (General Formula 16) and (General Formula 17) later to form sodium bicarbonate (NaHCO 3 ) or sodium carbonate (Na 2 CO 3 ), which are inorganic salts, and water.

[0184] (Formula 16) NaOH + H 2 CO 3 → NaHCO 3 + H 2 O

[0185] (Formula 17) 2NaOH + H 2 CO 3 → Na 2 CO3 +2H 2 O

[0186] Also, the carbonic acid generated as in the above (General Formula 13) reacts with an aqueous ammonia solution (NH 4 OH) as in the following (General Formula 18) to (General Formula 19) to produce ammonium bicarbonate (NH 4 HCO 3 ) or ammonium carbonate ((NH 4 ) 2 CO 3 ) and water.

[0187] (Chemical Formula 18) NH 4 OH + H 2 CO 3 → NH 4 HCO 3 + H 2 O

[0188] (Chemical Formula 19) 2NH 4 OH + H 2 CO 3 → (NH 4 ) 2 CO 3 + 2H 2 O

[0189] Also, the sulfurous acid and sulfuric acid generated as in the above (General Formula 14) and (General Formula 15) are reacted with an aqueous sodium hydroxide (NaOH) solution, which is the reaction solution, as in the following (General Formula 20) to (General Formula 23).

[0190] As described above, the sulfurous acid generated by the reaction of SO 2 and water as in (General Formula 15) reacts with sodium hydroxide as in (General Formula 20) to produce sodium bisulfite (NaHSO 3 ) and water, or reacts with sodium hydroxide as in (General Formula 21) to produce sodium sulfite (Na 2 SO 3 ) and water.

[0191] In addition, the sulfuric acid generated as in (General Formula 14) reacts with sodium hydroxide as in (General Formula 22) to produce sodium bisulfate (NaHSO 4 ) which is an inorganic salt and water, or reacts with sodium hydroxide as in (General Formula 23) to produce sodium sulfate (Na 2 SO 4 ) which is an inorganic salt and water.

[0192] (Chemical Formula 20) NaOH + H 2 SO 3 → NaHSO 3 + H 2 O

[0193] (Chemical Formula 21) 2NaOH + H 2 SO 3 → Na 2 SO 3 + 2H 2 O

[0194] (Chemical Formula 22) NaOH + H 2 SO 4 → NaHSO 4 + H 2 O

[0195] (Chemical Formula 23) 2NaOH + H 2 SO 4 → Na 2 SO 4 + 2H 2 O

[0196] As the c-th stage, the reaction of aqueous ammonia with sulfurous acid and sulfur reacts with aqueous ammonia to produce ammonium bisulfite (NH 4 HSO 3 ), ammonium sulfite ((NH 4 ) 2 SO 3 ), ammonium bisulfate (NH 4 HSO 4 ) or ammonium sulfate (NH 4 ) 2 SO 4 ) and water.

[0197] (Chemical formula 24) NH 4 OH + H 2 SO 3 → NH 4 HSO 3 + H 2 O

[0198] (Chemical formula 25) 2NH 4 OH + H 2 SO 3 → (NH 4 ) 2 SO 3 + 2H 2 O

[0199] (Chemical formula 26) NH 4 OH + H 2 SO 4 → NH 4 HSO 4 + H 2 O

[0200] (Chemical formula 27) 2NH 4 OH + H 2 SO 4 → (NH 4 ) 2 SO 4 + 2H 2 O

[0201] <The d-th step (S400)>

[0202] The d-th step according to the second embodiment of the present invention is a step of reacting a reaction solution containing an inorganic salt generated in the c-th step (S300) with a divalent metal oxide or a divalent metal hydroxide to regenerate the reaction solution while generating sludge containing carbonate and sulfate.

[0203] At this time, according to the second embodiment of the present invention, the divalent metal oxide that reacts with the inorganic salt to regenerate the reaction solution and form sludge is calcium oxide (CaO) or magnesium oxide (MgO), and the divalent metal hydroxide is calcium hydroxide (Ca(OH) 2 ) or magnesium hydroxide (Mg(OH) 2 ) can be.

[0204] The divalent metal oxide or divalent metal hydroxide is supplied in the form of powder, aqueous solution or sludge and can react with inorganic salts and the like.

[0205] According to the second embodiment of the present invention, in order to facilitate the mixing of the inorganic salt and the divalent metal oxide or divalent metal hydroxide generated as described above in the 12th tank 1300, as shown in FIG. 6, it is preferable that an impeller 1350 driven by a motor is provided.

[0206] As described above, in the 12th tank 1300, sludge containing carbonate and sulfate formed while the reaction solution is regenerated is formed.

[0207] Examining in detail the reaction in which sludge containing carbonate and sulfate is formed while the reaction solution performed in the dth stage is regenerated, it is as follows.

[0208] 1. Reaction of CO 2 with the inorganic salt generated by the reaction and calcium oxide which is a divalent metal oxide

[0209] First, the method of regenerating the sodium hydroxide through the reaction of the inorganic salt generated by the reaction of the aqueous sodium hydroxide solution and CO 2 with calcium oxide which is a divalent metal oxide is as shown in the following (General formula 28) to (General formula 29).

[0210] That is, carbonic acid (H 2 CO 2 ) generated by the reaction of CO 3 contained in the exhaust gas and water reacts with the aqueous sodium hydroxide solution to form sodium hydrogen carbonate (NaHCO 3 ) or sodium carbonate (Na 2 CO 3 ), which are inorganic salts, as described in the above (General formula 16) to (General formula 17).

[0211] (Formula 28) NaHCO 3 +CaO→NaOH+CaCO 3

[0212] (Chemical formula 29) Na 2 CO 3 + CaO + H 2 O → 2NaOH + CaCO 3

[0213] At this time, the inorganic salt produced, sodium bicarbonate (NaHCO 3 ), or sodium carbonate (Na 2 CO 3 ), reacts with calcium oxide as in the above (General formula 28) to (General formula 29) to regenerate sodium hydroxide while producing CaCO 3 which is a carbonate.

[0214] Also, the reaction to regenerate the NH 2 OH through the reaction between the inorganic salt produced by the reaction of an aqueous ammonia solution and CO 4 and calcium oxide which is a divalent metal oxide is as follows in the following (General formula 30) to (General formula 31).

[0215] That is, carbonic acid (H 2 CO 2 ) produced by the reaction of CO 3 contained in the exhaust gas and water reacts with the aqueous ammonia solution as in the above (General formula 18) to (General formula 19) to produce the inorganic salts NH 4 HCO 3 and (NH 4 ) 2 CO 3 .

[0216] (Chemical formula 30) NH 4 HCO 3 + CaO → NH 4 OH + CaCO 3

[0217] (Chemical formula 31) (NH 4 ) 2 CO 3 + CaO + H 2 O → 2NH 4 OH + CaCO 3

[0218] NH, the inorganic salt generated at this time 4 HCO 3 and (NH 4 ) 2 CO 3 react with calcium oxide as in the above (General Formula 30) to (General Formula 31) to regenerate an aqueous ammonia solution while generating CaCO 3 which is a carbonate.

[0219] 2.SO 2 The reaction between the inorganic salt generated by the reaction of and calcium oxide which is a divalent metal oxide

[0220] The reaction to regenerate the sodium hydroxide through the reaction between the aqueous sodium hydroxide solution which is the reaction solution and the inorganic salt generated by the reaction of SO 2 and calcium oxide which is a divalent metal oxide is as follows in the following (General Formula 32) to (General Formula 35).

[0221] That is, sulfuric acid and sulfurous acid generated by the reaction of SO 2 contained in the exhaust gas and water react with the aqueous sodium hydroxide solution as detailed in the above (General Formula 20) to (General Formula 23) to form inorganic salts such as NaHSO 3 , Na 2 SO 3 , NaHSO 4 or Na 2 SO 4 .

[0222] NaHSO, the inorganic salt generated as described above 3 , Na 2 SO 3 , NaHSO 4 or Na 2 SO 4 react with calcium oxide as in the following (General Formula 32) to (General Formula 35) to regenerate sodium hydroxide while generating CaSO 3 or CaSO 4 which is a sulfate.

[0223] (Chemical Formula 32) NaHSO 3+CaO → NaOH + CaSO 3

[0224] (Equation 33) Na 2 SO 3 +CaO + H 2 O → 2NaOH + CaSO 3

[0225] (Equation 34) NaHSO 4 +CaO → NaOH + CaSO 4

[0226] (Equation 35) Na 2 SO 4 +CaO + H 2 O → 2NaOH + CaSO 4

[0227] Also, the method for regenerating the aqueous ammonia solution through the reaction between the inorganic salt formed by the reaction of the aqueous ammonia solution, which is the reaction solution, and SO 2 is as follows in the following (General Formula 36) to (General Formula 39).

[0228] That is, sulfuric acid and sulfurous acid formed by the reaction of SO 2 contained in the exhaust gas and water react with the aqueous ammonia solution to form inorganic salts NH 4 HSO 3 , (NH 4 ) 2 SO 3 , NH 4 HSO 4 or (NH 4 ) 2 SO 4 as follows.

[0229] (Equation 36) NH 4 HSO 3 +CaO → NH 4 OH + CaSO 3

[0230] (Equation 37) (NH 4 ) 2 SO3 +CaO + H 2 O → 2NH 4 OH + CaSO 3

[0231] (Formula 38) NH 4 HSO 4 +CaO → NH 4 OH + CaSO 4

[0232] (Formula 39) (NH 4 ) 2 SO 4 +CaO + H 2 O → 2NH 4 OH + CaSO 4

[0233] At this time, the inorganic salts NH4HSO3, (NH4)2SO3, NH4HSO4, or (NH4)2SO4 generated react with calcium oxide to generate CaSO3 or CaSO4, which is a sulfate, while regenerating an aqueous ammonia solution.

[0234] 3. CO 2 Reaction of the inorganic salt generated by the reaction with magnesium oxide, which is a divalent metal oxide

[0235] According to the second embodiment of the present invention, the reaction for regenerating sodium hydroxide through the reaction of the inorganic salt generated by the reaction of the sodium hydroxide aqueous solution, which is the reaction solution, with CO 2 and magnesium oxide, which is a divalent metal oxide, is as shown in the following (General Formula 40) to (General Formula 41).

[0236] That is, carbonic acid (H 2 ) generated by the reaction of CO 2 contained in the exhaust gas with water reacts with the sodium hydroxide aqueous solution to generate sodium bicarbonate (NaHCO 3 ), which is an inorganic salt, and sodium carbonate (Na 3 ) as shown in the above (General Formula 16) to (General Formula 17). 2 CO 3 )

[0237] (Formula 40) NaHCO 3 + MgO → NaOH + MgCO 3

[0238] (Formula 41) Na 2 CO 3 + MgO + H 2 O → 2NaOH + MgCO 3

[0239] Sodium bicarbonate (NaHCO 3 ), which is the inorganic salt produced as described above, and sodium carbonate (Na 2 CO 3 ), react with magnesium oxide as in the above (General Formula 40) to (General Formula 41) to regenerate sodium hydroxide while producing MgCO 3 , which is a carbonate. At this time, water may be required as in (General Formula 41).

[0240] And the reaction to regenerate the aqueous ammonia solution through the reaction between the inorganic salt produced by the reaction of the aqueous ammonia solution, which is the reaction solution, and CO 2 and magnesium oxide, which is a divalent metal oxide, is as shown in the following (General Formula 42) to (General Formula 43).

[0241] That is, carbonic acid (H 2 CO 2 ), which is produced by the reaction of CO 3 contained in the exhaust gas and water, reacts with the aqueous ammonia solution as in the above (General Formula 18) to (General Formula 19) to produce the inorganic salts NH 4 HCO 3 and (NH 4 ) 2 CO 3 .

[0242] (Formula 42) NH 4 HCO 3 + MgO → NH 4 OH + MgCO 3

[0243] (Formula 43) (NH4 ) 2 CO 3 +MgO+H 2 O→2NH 4 OH+MgCO 3

[0244] The inorganic salts NH 4 HCO 3 and (NH 4 ) 2 CO 3 react with magnesium oxide as in the above (General Formula 42) to (General Formula 43) to regenerate an aqueous ammonia solution while producing MgCO 3 which is a carbonate. At this time, water may be required as in (General Formula 43).

[0245] 4. Reaction of the inorganic salts produced by the reaction of SO2 with magnesium oxide which is a divalent metal oxide

[0246] The method of regenerating the NaOH through the reaction of an aqueous sodium hydroxide solution which is a reaction solution with SO 2 and the inorganic salts produced by the reaction and magnesium oxide which is a divalent metal oxide is as follows in the following (General Formula 44) to (General Formula 47).

[0247] That is, sulfuric acid and sulfurous acid produced by the reaction of SO 2 contained in the exhaust gas with water react with the aqueous sodium hydroxide solution to produce inorganic salts NaHSO 3 , Na 2 SO 3 , NaHSO 4 and Na 2 SO 4 as detailed in the above (General Formula 20) to (General Formula 23).

[0248] (Chemical Formula 44) NaHSO 3 +MgO→NaOH+MgSO 3

[0249] (Chemical Formula 45) Na 2 SO 3 +MgO+H 2 O→2NaOH+MgSO3

[0250] (Chemical formula 46) NaHSO 4 + MgO → NaOH + MgSO 4

[0251] (Chemical formula 47) Na 2 SO 4 + MgO + H 2 O → 2NaOH + MgSO 4

[0252] At this time, the inorganic salts NaHSO 3 , Na 2 SO 3 , NaHSO 4 and Na 2 SO 4 react with magnesium oxide to regenerate sodium hydroxide while producing magnesium sulfate as a sulfate, MgSO 3 or MgSO 4 .

[0253] Also, the method for regenerating the aqueous ammonia solution through the reaction between the inorganic salts formed by the reaction of the aqueous ammonia solution with SO 2 and magnesium oxide, which is a divalent metal oxide, is as follows in the following (General formula 48) to (General formula 51).

[0254] That is, sulfuric acid and sulfurous acid formed by the reaction of SO 2 contained in the exhaust gas with water react with the aqueous ammonia solution to form inorganic salts NH 4 HSO 3 , (NH 4 ) 2 SO 3 , NH 4 HSO 4 or (NH 4 ) 2 SO 4 .

[0255] (Chemical formula 48) NH 4 HSO 3+MgO → NH 4 OH + MgSO 3

[0256] (Chemical formula 49) (NH 4 ) 2 SO 3 + MgO + H 2 O → 2NH 4 OH + MgSO 3

[0257] (Chemical formula 50) NH 4 HSO 4 + MgO → NH 4 OH + MgSO 4

[0258] (Chemical formula 51) (NH 4 ) 2 SO 4 + MgO + H 2 O → 2NH 4 OH + MgSO 4

[0259] At this time, the inorganic salts generated, NH 4 HSO 3 , (NH 4 ) 2 SO 3 , NH 4 HSO 4 or (NH 4 ) 2 SO 4 react with magnesium oxide to regenerate an aqueous ammonia solution while generating magnesium sulfate (MgSO 3 or MgSO 4 . At this time, water may be required as in (Chemical formula 49) and (Chemical formula 51).

[0260] 5. Reaction of the inorganic salt formed by the reaction of SO 2 with calcium hydroxide, a divalent metal hydroxide

[0261] The reaction solution, an aqueous sodium hydroxide solution, and SO 2The reaction for regenerating the sodium hydroxide through the reaction between the inorganic salt generated by the reaction and calcium hydroxide which is a divalent metal hydroxide is as shown in the following (General Formula 52) to (General Formula 55).

[0262] That is, sulfuric acid and sulfurous acid generated by the reaction of SO 2 contained in the exhaust gas and water react with the aqueous sodium hydroxide solution to form inorganic salts such as NaHSO 3 , Na 2 SO 3 , Na 2 SO 4 or Na 2 SO 4 are produced.

[0263] (Chemical Formula 52) NaHSO 3 + Ca(OH) 2 → NaOH + CaSO 3 + H 2 O

[0264] (Chemical Formula 53) Na 2 SO 3 + Ca(OH) 2 → 2NaOH + CaSO 3

[0265] (Chemical Formula 54) NaHSO 4 + Ca(OH) 2 → NaOH + CaSO 4 + H 2 O

[0266] (Chemical Formula 55) Na 2 SO 4 + Ca(OH) 2 → 2NaOH + CaSO 4

[0267] At this time, the inorganic salts generated, such as NaHSO 3 , Na 2 SO 3 , NaHSO 4 or Na 2 SO 4reacts with calcium hydroxide to regenerate sodium hydroxide while producing CaSO, which is a sulfate 3 or CaSO 4 and water.

[0268] In addition, the method for regenerating the NH 2 OH through the reaction between the inorganic salt produced by the reaction of an aqueous ammonia solution with SO 4 and calcium hydroxide, which is a divalent metal hydroxide, is as follows in the following (General Formulas 56) to (General Formulas 59).

[0269] That is, sulfuric acid and sulfurous acid produced by the reaction of SO 2 contained in the exhaust gas with water react with an aqueous ammonia solution to form inorganic salts such as NH 4 HSO 3 , (NH 4 ) 2 SO 3 , (NH 4 ) 2 SO 4 or NH 4 HSO 4 .

[0270] (Formula 56) NH 4 HSO 3 + Ca(OH) 2 → NH 4 OH + CaSO 3 + H 2 O

[0271] (Formula 57) (NH 4 ) 2 SO 3 + Ca(OH) 2 → 2NH 4 OH + CaSO 3

[0272] (Formula 58) NH 4 HSO 4 + Ca(OH) 2 → NH 4 OH + CaSO 4 + H 2 O

[0273] (Formula 59) (NH 4 ) 2 SO 4 + Ca(OH) 2 → 2NH 4 OH + CaSO 4

[0274] At this time, the inorganic salts NH 4 HSO 3 , (NH 4 ) 2 SO 3 , (NH 4 ) 2 SO 4 or NH 4 HSO 4 react with calcium hydroxide as in the above (General Formula 56) to (General Formula 59) to regenerate an aqueous ammonia solution while producing calcium sulfate CaSO 3 or CaSO 4 and water.

[0275] 6. Reaction of calcium hydroxide, a divalent metal hydroxide, with the inorganic salts produced by the reaction of CO 2 The reaction to regenerate sodium hydroxide through the reaction between an aqueous sodium hydroxide solution, which is the reaction solution, and the inorganic salts produced by the reaction of CO

[0276] is as follows in the following (General Formula 60) to (General Formula 61). 2 That is, carbonic acid (H

[0277] produced by the reaction of CO 2 contained in the exhaust gas with water reacts with an aqueous sodium hydroxide solution as in the above (General Formula 16) to (General Formula 17) to produce sodium bicarbonate (NaHCO 2 CO 3 ) or sodium carbonate (Na 3 ) as inorganic salts. 2 CO 3 )

[0278] (Formula 60) NaHCO3 +Ca(OH) 2 →NaOH + CaCO 3 +H 2 O

[0279] (Chemical formula 61) Na 2 CO 3 +Ca(OH) 2 → 2NaOH + CaCO 3

[0280] At this time, the inorganic salts produced, sodium bicarbonate (NaHCO 3 ) or sodium carbonate (Na 2 CO 3 ) reacts with calcium hydroxide as in the above (General formula 60) to (General formula 61), regenerating sodium hydroxide while producing calcium carbonate (CaCO 3 and water are produced.

[0281] Also, the method of regenerating the aqueous ammonia solution through the reaction between the inorganic salts produced by the reaction of the aqueous ammonia solution as the reaction liquid with CO 2 and calcium hydroxide as the divalent metal hydroxide is as follows in the following (General formula 62) to (General formula 63).

[0282] That is, carbonic acid (H 2 CO 2 ) produced by the reaction of CO 3 contained in the exhaust gas with water reacts with the aqueous ammonia solution as in the above (General formula 18) to (General formula 19) to produce an inorganic salt, NH 4 HCO 3 or (NH 4 ) 2 CO 3 is produced.

[0283] (Chemical formula 62) NH 4 HCO 3 +Ca(OH) 2 →NH 4 OH + CaCO 3 +H 2 O

[0284] (Chemical formula 63) (NH4 ) 2 CO 3 +Ca(OH) 2 →2NH 4 OH+CaCO 3

[0285] At this time, NH 4 HCO 3 or (NH 4 ) 2 CO 3 which is an inorganic salt generated at this time, reacts with calcium hydroxide to regenerate an aqueous ammonia solution while producing CaCO 3 which is a carbonate and water.

[0286] 7. Reaction of magnesium hydroxide, which is a divalent metal hydroxide, with the inorganic salt formed by the reaction of SO 2 The reaction for regenerating the sodium hydroxide through the reaction of magnesium hydroxide, which is a divalent metal hydroxide, with the inorganic salt formed by the reaction of the sodium hydroxide aqueous solution, which is the reaction solution, with sulfuric acid and sulfurous acid is as follows in the following (General Formula 64) to (General Formula 67).

[0287] That is, sulfuric acid and sulfurous acid formed by the reaction of SO

[0288] contained in the exhaust gas with water react with the sodium hydroxide aqueous solution to form inorganic salts such as NaHSO 2 , Na 3 , Na 2 SO 3 , NaHSO 4 or Na 2 SO 4 as described in detail in the above (General Formula 20) to (General Formula 23).

[0289] (Chemical Formula 64) NaHSO 3 +Mg(OH) 2 →NaOH+MgSO 3 +H 2 O

[0290] (Chemical Formula 65) Na 2 SO 3+Mg(OH) 2 → 2NaOH+MgSO 3

[0291] (Chemical formula 66) NaHSO 4 +Mg(OH) 2 → NaOH+MgSO 4 +H 2 O

[0292] (Chemical formula 67) Na 2 SO 4 +Mg(OH) 2 → 2NaOH+MgSO 4

[0293] At this time, the inorganic salts NaHSO 3 , Na 2 SO 3 , NaHSO 4 or Na 2 SO 4 react with magnesium hydroxide as in the above (General formula 64) to (General formula 67) to regenerate sodium hydroxide while producing MgSO 3 or MgSO 4 and water.

[0294] Also, the method of regenerating the NH 2 OH through the reaction between the inorganic salts produced by the reaction of the ammonia aqueous solution as the reaction solution and SO 4 and calcium hydroxide as the divalent metal hydroxide is as follows in the following (General formula 68) to (General formula 71).

[0295] That is, sulfuric acid and sulfurous acid produced by the reaction of SO 2 contained in the exhaust gas and water react with the ammonia aqueous solution to form inorganic salts NH 4 HSO 3 , (NH 4 ) 2 SO 3 , (NH 4 ) 2 SO 4 or NH 4 HSO 4is generated.

[0296] (Formula 68) NH 4 HSO 3 + Mg(OH) 2 → NH 4 OH + MgSO 3 + H 2 O

[0297] (Formula 69) (NH 4 ) 2 SO 3 + Mg(OH) 2 → 2NH 4 OH + MgSO 3

[0298] (Formula 70) NH 4 HSO 4 + Mg(OH) 2 → 2NH 4 OH + MgSO 4 + H 2 O

[0299] (Formula 71) (NH 4 ) 2 SO 4 + Mg(OH) 2 → 2NH 4 OH + MgSO 4

[0300] At this time, the inorganic salts NH 4 HSO 3 , (NH 4 ) 2 SO 3 , NH 4 HSO 4 or (NH 4 ) 2 SO 4 react with magnesium hydroxide to regenerate an aqueous ammonia solution and produce magnesium sulfate MgSO 3 or MgSO 4 and water as shown in the above (General Formula 68) to (General Formula 71).

[0301] 8. Reaction between the inorganic salts generated by the reaction of CO2 and magnesium hydroxide which is a divalent metal hydroxide

[0302] According to the second embodiment of the present invention, the reaction for regenerating NaOH through the reaction between an aqueous sodium hydroxide solution, which is the reaction solution, and CO 2 and the reaction between an inorganic salt produced by the reaction and magnesium hydroxide, which is a divalent metal hydroxide, is as shown in the following (General Formula 72) to (General Formula 73).

[0303] That is, carbonic acid (H 2 CO 2 ) generated by the reaction between CO 3 contained in the exhaust gas and water reacts with the aqueous sodium hydroxide solution as shown in the above (General Formula 16) to (General Formula 17) to produce sodium bicarbonate (NaHCO 3 ) or sodium carbonate (Na 2 CO 3 ), which is an inorganic salt.

[0304] (Chemical Formula 72) NaHCO 3 + Mg(OH) 2 → NaOH + MgCO 3 + H 2 O

[0305] (Chemical Formula 73) Na 2 CO 3 + Mg(OH) 2 → 2NaOH + MgCO 3

[0306] At this time, the inorganic salt NaHCO 3 or Na 2 CO 3 produced reacts with magnesium hydroxide as shown in the above (General Formula 72) to (General Formula 73) to regenerate sodium hydroxide while producing magnesium carbonate (MgCO 3 ) and water.

[0307] In addition, the reaction for regenerating the aqueous ammonia solution through the reaction between an inorganic salt produced by the reaction between an aqueous ammonia solution, which is the reaction solution, and CO 2 and magnesium hydroxide, which is a divalent metal hydroxide, is as shown in the following (General Formula 74) to (General Formula 75).

[0308] That is, CO contained in the exhaust gas 2 reacts with water to produce carbonic acid (H 2 CO 3 ) reacts with the aqueous ammonia solution as in the above (General Formula 18) and (General Formula 19) to form NH which is an inorganic salt 4 HCO 3 or (NH 4 ) 2 CO 3 .

[0309] (Chemical Formula 74) NH 4 HCO 3 + Mg(OH) 2 → NH 4 OH + MgCO 3 + H 2 O

[0310] (Chemical Formula 75) (NH 4 ) 2 CO 3 + Mg(OH) 2 → 2NH 4 OH + MgCO 3

[0311] NH 4 HCO 3 or (NH 4 ) 2 CO 3 , which is the inorganic salt produced as described above, reacts with magnesium hydroxide to produce magnesium carbonate which is a carbonate and water while regenerating the aqueous ammonia solution as in the above (Chemical Formula 74) to (Chemical Formula 75). 3 .

[0312] As described above, the aqueous sodium hydroxide solution or the aqueous ammonia solution, which is the reaction solution, can be regenerated while producing carbonates and sulfates using the divalent metal oxide or the divalent metal hydroxide.

[0313] <Step e (S500)>

[0314] As described above, the carbonates and sulfates generated through the d-th step are mixed with the regenerated reaction solution and exist in a sludge state. In order to reuse the regenerated reaction solution in which the carbonates and sulfates are mixed as described above, the carbonates and sulfates are separated through the e-th step. At this time, it is preferable to separate the carbonates and sulfates through the solid-liquid separation device 1500.

[0315] The carbonates present in the regenerated reaction solution as described above are, as described above, CaCO 3 、CaCO 4 、MgCO 3 and MgCO 4 etc., and the sulfates are CaSO 3 、CaSO 4 、MgSO 3 and MgSO 4 etc.

[0316] The carbonates and sulfates as described above are easily crystallized in an aqueous sodium hydroxide solution or an aqueous ammonia solution which is a reaction solution. Thereby, the carbonates and sulfates crystallized in a solid state can be easily separated through the solid-liquid separation device 1500.

[0317] As described above, inorganic salts generated by the reaction of CO 2 and SO 2 with the reaction solution react with the inorganic salts and divalent metal oxides or divalent metal hydroxides to regenerate the reaction solution while generating carbonates and sulfates. The carbonates, sulfates, etc. as described above can be easily processed after being solidified and stored on a ship as harmless substances and then arriving on land.

[0318] According to the exhaust gas purification device 1000 for ships according to the second embodiment of the present invention, by collecting and solidifying the pollutants contained in the exhaust gas discharged from the ship, storage and transfer to land become convenient, and the reaction liquid used in the wet scrubber 1100 for absorbing the pollutants is autonomously regenerated and reused on the ship, so that the required amount of the reaction liquid can be reduced, and thus the purification cost of ship exhaust gas can be significantly reduced. Thereby, by absorbing the pollutants contained in the exhaust gas discharged from the ship, the exhaust gas emission regulations by the IMO can be satisfied, and the outflow of substances that can affect marine pollution can be minimized.

[0319] The present invention has been described with reference to the experimental examples shown in the drawings, but these are merely exemplary, and those with ordinary knowledge in the relevant technical field can make various modifications and equivalent other experimental examples from now on. Also, those with ordinary knowledge in the technical field to which the present invention pertains can easily change to other specific forms without changing the technical idea and essential features of the present invention. Therefore, the embodiments described above are exemplary in all aspects and not restrictive, and the true technical protection scope of the present invention is defined by the technical idea of the appended claims.

Claims

1. i) Carbon dioxide contained in the exhaust gas discharged from ships reacts with water to form carbon dioxide (H ２ CO ３ ) and ii) The carbonic acid produced in the first step reacts with aqueous ammonia to produce ammonium bicarbonate (NH ４ HCO ３ ) and iii) Ammonium bicarbonate (NH) produced in the second step ４ HCO ３ ) reacts with aqueous ammonia to produce ammonium carbonate (NH ４ ) ２ CO ３ ) and iv) Ammonium bicarbonate (NH ４ HCO ３ ) and ammonium carbonate (NH ４ ) ２ CO ３ and a fourth step in which the divalent metal oxide or the divalent metal hydroxide reacts with the ammonium hydroxide to produce carbonate and aqueous ammonia. v) a fifth stage of resupplying the ammonia water produced in the fourth stage to the second stage; Includes 1. A method for purifying exhaust gas from a ship.

2. In the method for purifying exhaust gas from a ship, the shortage of ammonia water is replenished by generating it through a reaction between an inorganic compound and calcium hydroxide. The method for purifying marine exhaust gas according to claim 1.

3. The inorganic compound is ammonium bicarbonate (NH ４ HCO ３ ), ammonium carbonate ((NH ４ ) ２ CO ３ ), ammonium hydrogen sulfate (NH ４ HSO ４ ), ammonium sulfate ((NH ４ ) ２ SO ４ ), Ammonium nitrate (NH ４ NO ３ ), ammonium chloride (NH ４ Cl), ammonium sulfamate (NH ４ SO ３ N.H. ２ ), and ammonium sulfite ((NH ４ ) ２ SO ３ ) is one or more selected from the group consisting of The method for purifying marine exhaust gas according to claim 2.

4. The amount of the inorganic compound used is 1.0 to 2.0 times the molar ratio of the ammonia water that is insufficient. The method for purifying marine exhaust gas according to claim 2.

5. i) Carbon dioxide contained in the exhaust gas discharged from ships reacts with water to form carbon dioxide (H ２ CO ３ (S100) ii) The sulfur dioxide contained in the exhaust gas reacts with water to produce sulfurous acid (H ２ SO ３ ) and sulfuric acid (H ２ SO ４ (S200) iii) Carbonic acid (H ２ CO ３ ) and sulfurous acid (H ２ SO ３ ) and sulfuric acid (H ２ SO ４ Step c (S300) of reacting the reaction solution with the inorganic salt to produce a reaction solution containing the inorganic salt; iv) Step d (S500) of reacting the reaction solution containing the inorganic salt generated in step c (S300) with a divalent metal oxide or a divalent metal hydroxide to generate carbonates and sulfates while simultaneously regenerating the reaction solution; v) Step e (S600) of separating carbonates and sulfates contained in the regenerated reaction liquid through a solid-liquid separator 1500; Includes 1. A method for purifying exhaust gas from a ship.

6. The reaction liquid is an aqueous solution of sodium hydroxide, an aqueous solution of ammonia, or a mixture thereof. The method for purifying marine exhaust gas according to claim 5.

7. The reaction solution is supplemented with at least one of an aqueous lithium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous calcium hydroxide solution, and an aqueous magnesium hydroxide solution as an auxiliary reaction solution. The method for purifying marine exhaust gas according to claim 5.

8. The concentration of the lithium hydroxide aqueous solution and the potassium hydroxide aqueous solution is 15% by weight or less based on the total reaction solution. The method for purifying marine exhaust gas according to claim 7.

9. The concentration of the calcium hydroxide aqueous solution and the magnesium hydroxide aqueous solution is 2% by weight or less based on the total reaction solution. The method for purifying marine exhaust gas according to claim 7.

10. The reaction solution is prepared using pure water or seawater. The method for purifying marine exhaust gas according to claim 5.

11. The divalent metal oxide is calcium oxide or magnesium oxide. The method for purifying marine exhaust gas according to claim 5.

12. The divalent metal hydroxide is calcium hydroxide or magnesium hydroxide. The method for purifying marine exhaust gas according to claim 5.

13. The divalent metal oxide or hydroxide is provided in the form of a powder, an aqueous solution or a sludge. The method for purifying marine exhaust gas according to claim 5.

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