Greenhouse gas emission reduction devices for ships and ships or marine structures equipped with such devices

Abstract

The present invention discloses a greenhouse gas emission reduction device for a ship that includes a seawater supply unit 110 that supplies seawater, an absorbent circulation supply unit 120 that provides and circulates an absorbent that absorbs CO2, an absorption tower 130 including a CO2 removal unit 131 that reacts exhaust gas emitted from a ship engine 10 with seawater to cool it, and reacts the cooled exhaust gas with the absorbent to convert CO2 into a carbonate solution and capture CO2, an absorbent regeneration unit 140 that reacts the carbonate solution with a divalent metal oxide or a divalent metal hydroxide to regenerate the absorbent and generate a precipitate, and an overboard discharge unit 150 that separates the precipitate and discharges it overboard with seawater, mineralizing CO2 and discharging it overboard, thereby minimizing corrosion of a separator 152 by seawater.

Description

[Technical Field]

[0001] The present invention relates to a greenhouse gas emission reduction device for a ship and a ship or marine structure equipped with the same, and more particularly to a greenhouse gas emission reduction device for a ship that can mineralize CO2, discharge it overboard in accordance with overboard discharge conditions, and minimize corrosion of a separator due to seawater, and a ship or marine structure equipped with the same. [Background technology]

[0002] In recent years, greenhouse gas emissions caused by the indiscriminate use of fossil fuels have led to global warming and the resulting natural disasters.

[0003] For this reason, a series of technologies for capturing and storing carbon dioxide, a major greenhouse gas, without emitting it, is known as CCS (Carbon dioxide Capture and Storage) technology, which has attracted a great deal of attention in recent years. Of the CCS technologies, chemical absorption is the most advanced in commercialization due to its ability to process carbon dioxide on a large scale.

[0004] Furthermore, carbon dioxide emissions are regulated by the IMO's EEDI, which aims to reduce emissions by more than 50% compared to 2008 levels by 2050, and must also reduce emissions by 40% compared to 2008 levels by 2030. As a result, attention is being paid to technologies that do not emit CO2 or that capture CO2 that has been emitted.

[0005] Among CCS technologies that directly capture and store carbon dioxide, CO2 capture technology can be approached in a variety of ways depending on the CO2 generation conditions in the target process. The current representative technologies are absorption, adsorption, and membrane separation. Of these, wet absorption is the most mature technology for onshore plants and is easy to process large amounts of CO2, making it the capture technology closest to commercializing CCS technology. Amine and ammonia are mainly used as absorbents.

[0006] On the other hand, the aforementioned technologies for reducing carbon dioxide emissions or capturing the carbon dioxide produced have not yet been commercialized for ships, and methods for using hydrogen or ammonia as fuel are currently under development and have not yet reached the stage of commercialization.

[0007] In addition, ships equipped with scrubbers that use high-sulfur fuel oil have a disadvantage in that SOx has a high solubility and is first converted into a compound called NaSO3, making it difficult to remove CO2 until SOx is completely dissolved. In particular, the use of a separate, consumable absorbent material to remove CO2 increases the cost of removing greenhouse gases.

[0008] Therefore, there is a need to apply technology to ships that use fossil fuels, which can convert the CO2 in the exhaust gases emitted from the ship's engines into substances that do not have an impact on the environment and then emit them, or convert it into useful substances and store them, without having to provide a separate consumable absorbent raw material. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a greenhouse gas emission reduction device for a ship that can mineralize CO2 and discharge it overboard in accordance with the overboard discharge conditions, minimizing corrosion of the separator due to seawater, and a ship or marine structure equipped with the same. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, one embodiment of the present invention provides a greenhouse gas emission reduction device for a ship, including: an absorption tower including an absorption solution circulation supply unit that provides and circulates an absorption solution that absorbs CO2; an exhaust gas cooling unit that cools exhaust gas discharged from a ship engine; a CO2 removal unit that reacts the cooled exhaust gas with the absorption solution to convert CO2 into a carbonate aqueous solution and captures CO2; an absorption solution regeneration unit that reacts the carbonate aqueous solution with a regeneration reactant to regenerate the absorption solution and produce a precipitate; and an overboard discharge unit that separates the precipitate and discharges the precipitate overboard using seawater.

[0011] Here, the overboard discharge section performs a process of separating the sediment from the absorption liquid, a process of discharging the sediment using seawater, and can further perform a washing process using fresh water.

[0012] In this case, the overboard discharge section sucks in and separates the sediment and the absorption liquid from the absorption liquid regeneration section, dilutes the sediment with seawater so that the sediment meets the overboard discharge conditions, and discharges the sediment overboard.If the sediment does not meet the overboard discharge conditions, the sediment can be temporarily stored.

[0013] Specifically, the overboard discharge section may include a separation pump that sucks in the sediment and the absorption liquid from the absorption liquid regeneration section, a separator that separates the sediment and the absorption liquid transferred from the separation pump, discharges the sediment overboard, and returns the absorption liquid to the absorption liquid circulation supply section, and a discharge seawater pump that supplies seawater to the separator to dilute the sediment and discharge it overboard.

[0014] Here, the separator may be a filter-type separator or a centrifugal separator that separates the precipitate from the absorption liquid.

[0015] The overboard discharge unit may further include a fresh water supply valve that supplies the fresh water to the separator to clean the separator.

[0016] Here, the overboard discharge unit may further include a fresh water cooler that cools the seawater supplied to the discharge seawater pump into cooled fresh water.

[0017] At this time, the sediment discharged from the separator can be diluted by supplying seawater cooled through the fresh water cooler and then discharged overboard.

[0018] In addition, the overboard discharge unit includes a sensor for measuring one or more of the turbidity, pH, and oil content of the sediment separated from the separator, and can discharge the sediment overboard or temporarily store it depending on whether the overboard discharge conditions corresponding to the measured values ​​by the sensor are met.

[0019] Furthermore, the precipitate contains carbonate, and the absorption liquid is a monovalent alkali aqueous solution, which may include any one of an LiOH aqueous solution, an NaOH aqueous solution, an KOH aqueous solution, and an NH4OH aqueous solution.

[0020] The ship may further include a seawater supply unit that supplies seawater from outside the ship, and the seawater supply unit may include a seawater pump that receives seawater from outside the ship via a sea chest and pumps it into the absorption tower, and a seawater control valve that adjusts the amount of seawater injected from the seawater pump to the absorption tower depending on the amount of exhaust gas.

[0021] Here, the exhaust gas cooling unit can cool the exhaust gas discharged from the ship engine by reacting it with the seawater supplied from the seawater supply unit.

[0022] The exhaust gas cooling section can cool the exhaust gas discharged from the marine engine by causing the exhaust gas to react with fresh water.

[0023] Furthermore, the exhaust gas cooling unit can cool the exhaust gas by circulating fresh water provided from an onboard cooling system through a heat exchange piping that encases the exhaust gas discharge pipe.

[0024] The exhaust gas cooling section may be provided inside the absorption tower.

[0025] Further, the absorbing liquid circulation supply unit may include an absorbing liquid storage tank that stores the absorbing liquid, an absorbing liquid pump that pumps and transfers the absorbing liquid from the absorbing liquid storage tank, an absorbing liquid circulation tank that mixes and stores the aqueous carbonate solution discharged from the absorption tower and the absorbing liquid supplied from the absorbing liquid pump, and an absorbing liquid circulation pump that supplies the absorbing liquid from the absorbing liquid circulation tank to an upper stage of the CO2 removal unit and circulates it.

[0026] Here, the absorbent pump can supply the absorbent to the absorbent circulation tank so as to make up for a shortage of the absorbent discharged overboard by the overboard discharge section.

[0027] The absorbent may be produced by electrolyzing seawater and fresh water, respectively, and stored in the absorbent storage tank.

[0028] The absorption tower further includes a seawater supply unit that supplies seawater from outside the ship, the exhaust gas cooling unit is provided inside the absorption tower, and the absorption tower further includes, as the exhaust gas cooling unit, an SOx absorption unit that reacts the exhaust gas with the seawater supplied from the seawater supply unit to cool it while dissolving and removing SOx, and the CO2 removal unit reacts the cooled exhaust gas from which SOx has been removed with absorbing liquid from the absorbing liquid circulation supply unit to convert it into a carbonate aqueous solution, thereby capturing CO2.

[0029] Alternatively, the absorption tower may further include a seawater supply unit that supplies seawater from outside the ship, and the absorption tower may further include a NOx absorption unit that absorbs and removes NOx from the exhaust gas, the exhaust gas cooling unit is provided inside the absorption tower, and the exhaust gas from which NOx has been removed is cooled by reacting it with the seawater supplied from the seawater supply unit, and the CO2 removal unit reacts the cooled exhaust gas with the absorbing liquid from the absorbing liquid circulation supply unit to convert it into a carbonate aqueous solution and capture CO2.

[0030] Alternatively, the absorption tower may further include a seawater supply unit that supplies seawater from outside the ship, and the exhaust gas cooling unit may be provided inside the absorption tower. The absorption tower may include a NOx absorption unit that absorbs and removes NOx from the exhaust gas, a SOx absorption unit that acts as the exhaust gas cooling unit by reacting the exhaust gas from which the NOx has been removed with the seawater supplied from the seawater supply unit to cool it while dissolving and removing SOx, and a CO2 removal unit that reacts the cooled exhaust gas from which the SOx has been removed with an absorbing solution from the absorbing solution circulating supply unit to convert it into a carbonate aqueous solution, which is then collected and used to remove CO2.

[0031] The NOx absorbing portion may include an SCR.

[0032] Here, the NOx absorption unit may further include a urea water storage tank that stores urea water, and a urea water supply pump that pumps the urea water from the urea water storage tank and supplies it to an injection nozzle recessed in a lower stage of the SCR.

[0033] The SOx absorption unit can also include a flow path through which the exhaust gas passes, and a multi-stage seawater injection nozzle that injects the seawater supplied from the seawater supply unit downward by opening and closing a seawater control valve to dissolve SOx, remove dust, and cool the exhaust gas.

[0034] Here, the SOx absorber includes a first temperature sensor and a second temperature sensor that measure the temperatures before and after the exhaust gas passing through the seawater injection nozzle, respectively, and can adjust the amount of seawater injected by the seawater injection nozzle according to the amount of exhaust gas or the measured temperature.

[0035] In addition, the flow path may be formed with a plurality of laminated plates spaced apart from one another, a structure forming a curved flow path, or an absorber filled with a filler, in which holes through which exhaust gas passes are alternately arranged, and a partition or umbrella-shaped blocking plate for preventing backflow of cleaning water may be formed.

[0036] Furthermore, the CO2 removal unit may include a first injection nozzle that injects the absorbing solution supplied from the absorbing solution regeneration unit, a first filler formed below the first injection nozzle and performing a primary reaction between the exhaust gas and the absorbing solution, a second injection nozzle that injects the absorbing solution provided and circulated from the absorbing solution circulation supply unit, and a second filler formed below the second injection nozzle and performing a secondary reaction between the exhaust gas and the absorbing solution.

[0037] Here, the CO2 remover may further include a mist removal plate having a curved multi-plate structure formed at an upper part of the second injection nozzle to block the discharge of the absorbing solution, and a partition or umbrella-shaped blocking plate to prevent backflow of the absorbing solution.

[0038] The CO2 removal section may include a cooling jacket that cools the heat generated in the first packing and the second packing.

[0039] Furthermore, the CO2 remover can adjust the injection amount of the absorption liquid by monitoring the pH corresponding to the degree of reaction in the first packing and the second packing.

[0040] The absorbent regeneration unit may include a regeneration reactant storage tank that stores the regeneration reactant, a transfer pump that pumps and transfers the carbonate aqueous solution, and a mixing tank that mixes and reacts the regeneration reactant with the carbonate aqueous solution to regenerate the absorbent and generate solid carbonate, and returns the regenerated absorbent to the absorption tower.

[0041] Here, the regeneration reactant may include a divalent metal oxide or a divalent metal hydroxide.

[0042] The system may further include a wash water treatment unit including a wash water tank for storing the wash water discharged from the absorption tower, a water treatment device including a filtering unit for adjusting the turbidity of the wash water transferred from the wash water tank so that it meets the overboard discharge requirements, a neutralizing agent injection unit for adjusting the pH, and a sludge storage tank for separating and storing solid waste.

[0043] The marine engine may further include an EGE formed between the NOx absorption section and the SOx absorption section, for exchanging heat between the waste heat of the marine engine and boiler water.

[0044] The steam generating unit may further include an auxiliary boiler that receives a mixture of heat-exchanged steam and saturated water, separates the steam, and supplies the steam to a steam consuming destination; a boiler water circulating pump that circulates boiler water from the auxiliary boiler to the EGE; a cascade tank that recovers condensed water from the steam consuming destination; and a supply pump and a control valve that adjust the amount of boiler water and supply it from the cascade tank to the auxiliary boiler.

[0045] In addition, the exhaust gas cooling unit branches and cools at least a portion of the exhaust gas emitted from the ship engine, and the CO2 removal unit reacts the cooled exhaust gas with the absorption liquid to convert CO2 into the carbonate aqueous solution and capture CO2.

[0046] Here, the exhaust gas cooling section may be provided with a blower that supplies at least a portion of the branched exhaust gas to the exhaust gas cooling section.

[0047] In this case, the air blowing means may be a blower.

[0048] In addition, the remaining exhaust gas discharged from the marine engine that is not branched to the exhaust gas cooling section is discharged through a main exhaust pipe, and at least a portion of the exhaust gas that is branched to the exhaust gas cooling section may be merged into the main exhaust pipe and discharged after CO2 is captured, or may be discharged through a separate exhaust pipe.

[0049] Meanwhile, in order to achieve the above-mentioned object, another embodiment of the present invention provides a ship or marine structure equipped with the above-mentioned greenhouse gas emission reduction device for a ship. [Effects of the Invention]

[0050] According to the present invention, carbonates separated by a separator are discharged overboard using seawater, and by washing with fresh water, corrosion of the separator due to seawater can be prevented. In addition, greenhouse gases can be mineralized to reduce environmental pollution. Since the material that has captured greenhouse gases is discharged into the ocean, separate storage facilities and loading / unloading facilities are not required. NOx, SOx, and CO2 can be removed simultaneously, and stored in a solid state with few impurities such as Na2CO3, NaHCO3, (NH4)2CO3, and NH4HCO3. CO2 is removed after SOx is removed, suppressing side reactions caused by SOx remaining in the exhaust gas, thereby improving the solubility of CO2 and the efficiency of CO2 removal. [Brief explanation of the drawings]

[0051] [Figure 1] 1 is a diagram showing the configuration of a greenhouse gas emission reduction device for a ship according to an embodiment of the present invention; [Figure 2] 2 is a diagram showing a system circuit diagram of the vessel greenhouse gas emission reduction device of FIG. 1. [Figure 3] FIG. 3 is a view showing the seawater supply section and the absorption tower of FIG. 2 in isolation. [Figure 4] FIG. 3 is a diagram showing an absorbent circulation supply unit and an absorbent regeneration unit in FIG. 2, separated from each other. [Figure 5] FIG. 3 is a view showing the overboard discharge section of FIG. 2 in isolation. [Figure 6] FIG. 3 is a view showing the cleaning water treatment section of FIG. 2 in isolation. [Figure 7] FIG. 3 is a view showing the steam generating unit of FIG. 2 in isolation. [Figure 8] FIG. 4 is a diagram showing the CO2 removal unit of FIG. 3. [Figure 9] FIG. 6 is a diagram showing a separation step among the steps of the overboard discharge section in FIG. 5. [Figure 10] FIG. 6 is a diagram showing a discharge step among the steps of the overboard discharge section of FIG. 5. [Figure 11] FIG. 6 is a diagram showing a cleaning process among the processes of the overboard discharge section in FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0052] Hereinafter, an embodiment of the present invention having the above-mentioned features will be described in more detail with reference to the accompanying drawings.

[0053] An apparatus for reducing greenhouse gas emissions from a ship according to one embodiment of the present invention includes a seawater supply unit 110 that supplies seawater, an absorbent circulation supply unit 120 that provides and circulates an absorbent that absorbs CO2, an absorption tower 130 including a CO2 removal unit 131 that reacts exhaust gas emitted from a ship engine 10 with seawater to cool it, and reacts the cooled exhaust gas with the absorbent to convert CO2 into a carbonate solution and capture CO2, an absorbent regeneration unit 140 that reacts the carbonate solution with a divalent metal oxide or a divalent metal hydroxide to regenerate the absorbent and generate a precipitate, and an overboard discharge unit 150 that separates the precipitate, discharges it overboard with seawater, and washes it with fresh water, thereby mineralizing CO2 and discharging it overboard, thereby minimizing corrosion of a separator 152 caused by seawater.

[0054] Here, depending on the type and specifications of the ship engine used as the main engine or the power generation engine (low-pressure engine or high-pressure engine) and the type of fuel supplied to the ship engine (HFO, MDO, LNG, MGO, LSMGO, ammonia, etc.), the absorption tower can be configured to selectively include a NOx absorption unit or a SOx absorption unit in addition to the CO2 removal unit, or to include both.

[0055] In particular, when LNG is used as fuel for ship engines, no SOx is generated, so there is no need to install a separate SOx absorption unit. However, when low-sulfur fuel oil (LSMGO) is used, a small amount of SOx may be generated, so it is possible to further install an SOx absorption unit that can simultaneously cool the exhaust gas and absorb SOx by dissolving it.

[0056] In the following, an embodiment will be described in which an NOx absorbing section, an SOx absorbing section as an exhaust gas cooling section, and a CO2 removing section are stacked in this order in an absorption tower, but the present invention is not limited to this.

[0057] In particular, the exhaust gas cooling unit cools the exhaust gas emitted from the ship's engine, lowering the temperature of the exhaust gas and facilitating the absorption of CO2 by the absorption liquid. This role can be played by a SOx absorption unit using seawater, or the exhaust gas can be cooled using a heat exchange method with fresh water. Specifically, fresh water provided from an onboard cooling system (not shown) can be circulated through a heat exchange piping (not shown) surrounding an exhaust gas discharge pipe through which the exhaust gas flows, and the exhaust gas can be cooled to a temperature of 27°C to 33°C using a heat exchange method with the fresh water.

[0058] In this case, the water cooling method in which the exhaust gas is directly cooled by fresh water may lower the temperature of the absorbing solution due to the addition of fresh water, which may result in a decrease in the greenhouse gas absorption capacity. Therefore, it is preferable to cool the exhaust gas using a heat exchange method to prevent the concentration of the absorbing solution from decreasing and maintain a constant greenhouse gas absorption capacity.

[0059] The greenhouse gas emission reduction device for a ship having the above-described configuration will be described in detail below with reference to FIGS. 1 to 11.

[0060] First, the seawater supply unit 110 is configured to supply seawater to the absorption tower 130 and the overboard discharge unit 150, and specifically, as shown in Figures 2 and 3, may include a seawater pump 112 that receives seawater by drawing it in from outside the ship via a sea chest 111 and pumps it to the SOx absorber 132, and a seawater control valve 113 that adjusts the amount of seawater injected from the seawater pump 112 to the SOx absorber 132 depending on the amount of exhaust gas. In this case, the seawater pump 112 may preferably be a quenching seawater pump.

[0061] Depending on the water depth, seawater can be selectively supplied to the seawater pump 112 from a high sea chest that draws in upper seawater or a low sea chest that draws in lower seawater when the ship is docked or sailing. That is, when the ship is docked, the high sea chest is used because the upper seawater is cleaner than the lower seawater, and when the ship is sailing, the lower seawater is cleaner than the upper seawater, so the low sea chest can be used.

[0062] Here, the seawater control valve 113 is a manually operated diaphragm valve or solenoid valve that adjusts the flow rate of seawater, and can adjust the amount of seawater sprayed through the seawater spray nozzle according to the amount of exhaust gas.

[0063] Next, the absorbent circulation supply unit 120 is configured to provide an absorbent that absorbs CO2 contained in the exhaust gas and circulate it to the absorption tower 130. Specifically, as shown in Figures 2 and 4, it may include an absorbent storage tank 121 that stores the absorbent, an absorbent pump 122 that pumps the absorbent from the absorbent storage tank 121 and transfers it to an absorbent circulation tank 123, an absorbent circulation tank 123 that mixes and stores the carbonate aqueous solution discharged from the absorption tower 130 with the absorbent supplied from the absorbent pump 123, and an absorbent circulation pump 124 that provides the absorbent from the absorbent circulation tank 123 to the upper stage of the CO2 removal unit 131 and circulates it.

[0064] In this case, the absorbing liquid may be a monovalent alkali aqueous solution such as an aqueous LiOH (lithium hydroxide) solution, an aqueous NaOH (sodium hydroxide) solution, an aqueous KOH (potassium hydroxide) solution, or an aqueous NH4OH (ammonia) solution, and preferably an aqueous NaOH solution and / or an aqueous NH4OH solution.

[0065] Here, in the first stage, exhaust gas is converted into a carbonate aqueous solution by reacting with an absorbing solution, which is a monovalent alkali aqueous solution. CO2 in the exhaust gas reacts with water to produce H2CO3 (carbonate) according to the following formula 1. At this time, the water that reacts with CO2 may be water that coexists in the absorbing solution, which is a monovalent alkali aqueous solution.

[0066] [ka]

[0067] After the first step, if the monovalent alkali aqueous solution used as the absorption liquid is an NaOH aqueous solution, it will be converted into a carbonate aqueous solution by producing the carbonate salts NaHCO3 (sodium bicarbonate) or Na2CO3 (sodium carbonate) and water according to the following formula 2.

[0068] [ka]

[0069] Alternatively, after the first step, if the monovalent alkali aqueous solution used as the absorption liquid is an NH4OH aqueous solution, the carbonate NH4HCO3 (ammonium bicarbonate) or (NH4)2CO3 (ammonium carbonate) and water are produced according to the following formula 3, converting the solution into a carbonate aqueous solution.

[0070] [ka]

[0071] Furthermore, when solid-phase CaCO3 carbonate is separated and discharged overboard by the overboard discharge section 150, a portion of the absorption liquid is discharged overboard together with the carbonate, and therefore the absorption liquid pump 122 can be configured to supply a certain amount of absorption liquid to the absorption liquid circulation tank 123 to make up for any shortfall in the absorption liquid.

[0072] Meanwhile, the absorption solution of NaOH aqueous solution can be produced by electrolyzing seawater and fresh water, respectively, and stored in the absorption solution storage tank 121. Electricity can be generated through the reduction and oxidation of Na to supply a certain ratio of power applied for electrolysis, thereby reducing part of the electricity required for producing NaOH(aq).

[0073] In the absorption tower 130, the absorbing solution comes into contact with the exhaust gas and ionizes the CO2 into ions. The ionized absorbing solution flows into the absorbing solution circulation tank 123. The absorbing solution discharged from the CO2 removal unit 131 contains CO3 2- When all the CO2 absorption processes are completed, HCO3 - High concentration of ions, CO32- The concentration of CO2 is relatively low, and the temperature of the absorption liquid is relatively high, so the amount of precipitate is small and it is mostly in the form of ions. - The increased concentration of ions allows them to be continuously used to absorb CO2 until a certain concentration is reached.

[0074] Next, the absorption tower 130 includes a CO2 removal section 131 that reacts the exhaust gas emitted from the ship engine 10 with seawater to cool it, and then reacts the cooled exhaust gas with an absorption liquid to convert the CO2 into a carbonate aqueous solution and capture the CO2.

[0075] For example, the absorption tower 130 further includes an SOx absorption section 132 that reacts the exhaust gas with seawater supplied from the seawater supply section 110 to cool it while dissolving and removing SOx, and the CO2 removal section 131 reacts the exhaust gas from which SOx has been removed with seawater supplied from the seawater supply section 110 to cool it, and reacts the cooled exhaust gas with the absorbing liquid from the absorbing liquid circulation supply section 120 to convert it into a carbonate aqueous solution, thereby capturing CO2.

[0076] Alternatively, the absorption tower 130 may further include a NOx absorption section 133 that absorbs and removes NOx from the exhaust gas, and the CO2 removal section 131 may react the exhaust gas from which NOx has been removed with seawater supplied from the seawater supply section 110 to cool it, and may react the cooled exhaust gas with the absorbing liquid from the absorbing liquid circulation supply section 120 to convert it into a carbonate aqueous solution, thereby capturing CO2.

[0077] Alternatively, the absorption tower 130 may be formed by sequentially stacking a NOx absorption section 133 that absorbs and removes NOx from the exhaust gas, a SOx absorption section 132 that reacts the exhaust gas from which NOx has been removed with seawater supplied from the seawater supply section 110 to cool it and dissolve and remove SOx, and a CO2 removal section 131 that reacts the exhaust gas from which SOx has been removed with the absorbing solution from the absorbing solution circulation supply section 120 to convert it into a carbonate aqueous solution, which is then captured and removed.

[0078] Specifically, referring to FIG. 3, the CO2 removal unit 131 may include a first injection nozzle 131a that injects the absorbing solution supplied from the absorbing solution regeneration unit 140, a first filler 131b formed below the first injection nozzle 131a and causing a primary reaction between the exhaust gas and the absorbing solution, a second injection nozzle 131c that injects the absorbing solution provided and circulated from the absorbing solution circulation supply unit 120, and a second filler 131d formed below the second injection nozzle 131c and causing a secondary reaction between the exhaust gas and the absorbing solution.

[0079] Here, the second injection nozzles 131c may be formed to branch off from the upper portions of the first filler 131b and the second filler 131d, respectively, to inject the absorbing liquid downward.

[0080] In addition, as shown in FIG. 8, the CO2 removal unit 131 may further include a mist removal plate 131e having a curved multi-plate structure that is formed on the upper part of the second injection nozzle 131c and forms droplets to block the external discharge of the absorbing solution, and a partition wall 131f or an umbrella-shaped blocking plate 131g that prevents the absorbing solution from flowing back into the exhaust gas piping.

[0081] Furthermore, the CO2 removal unit 131 may include a cooling jacket (not shown) for cooling the heat generated in the first filler 131b and the second filler 131d, thereby maintaining the temperature of the exhaust gas at 80 to 100°C, or by lowering the temperature of the absorbing solution supplied from the first injection nozzle 131a and the second injection nozzle 131c by 10 to 20°C, thereby increasing the absorption rate during the heat generation process in which CO2 is absorbed into the absorbing solution and minimizing loss of H2O due to evaporation.

[0082] In addition, the first filler 131b and the second filler 131d may be formed in a multi-stage configuration of distillation column packing designed to increase the contact area per unit volume. An appropriate distillation column packing may be selected in consideration of the contact area per unit area, gas pressure drop, and flooding velocity. A solution redistributor may be formed between the multi-stage distillation column packing to prevent solution channeling.

[0083] Furthermore, the CO2 removal unit 131 can monitor the pH corresponding to the degree of reaction in the first filler 131b and the second filler 131d via the pH sensor P and adjust the amount of absorbent sprayed through the first spray nozzle 131a and the second spray nozzle 131c.

[0084] Specifically, referring to FIG. 3, the SOx absorption unit 132 includes a flow path 132a through which the exhaust gas passes, and a multi-stage seawater injection nozzle 132b that injects seawater supplied from the seawater supply unit 110 downward by opening and closing the seawater control valve 113 to dissolve SOx, remove dust such as soot, and cool the exhaust gas.

[0085] The SOx absorber 132 also includes a first temperature sensor T1 and a second temperature sensor T2 that measure the temperatures before and after the exhaust gas passing through the seawater injection nozzle 132b, respectively, and can adjust the amount of seawater injected by the seawater injection nozzle 132b according to the amount of exhaust gas or the measured temperature.

[0086] Furthermore, the flow path 132a may be provided with a plurality of stacked plates spaced apart from one another, a structure forming a curved flow path, or an absorber filled with a filler, in which holes through which the exhaust gas passes are arranged alternately, thereby increasing the contact area between the seawater and the exhaust gas and facilitating cooling and absorption, and a partition wall 132c or an umbrella-shaped blocking plate 132d may be provided to prevent backflow of cleaning water.

[0087] As a result, SOx is first removed through the SOx absorption unit 132, and then CO2 is removed through the CO2 removal unit 131. This solves the problem that it is difficult to remove CO2 until all SOx is dissolved because SOx has a high solubility and is first converted into compounds such as Na2SO4, and therefore CO2 removal efficiency can be improved.

[0088] The wash water discharged from the lower stage of the SOx absorber 132 contains SO3 - , SO4 2- , soot, NaSO3, Na2SO4, MgCO3, MgSO4 and other ionic compounds may be included together.

[0089] Meanwhile, the NOx absorption unit 133 includes an SCR (Selective Catalyst Reduction) 133c, and may include a urea water storage tank 133a for storing urea water, and a urea water supply pump 133b for pumping urea water from the urea water storage tank 133a and supplying it to an injection nozzle located at the lower stage of the SCR 133c.

[0090] The system may further include an EGE 134 formed between the NOx absorbing section 133 and the SOx absorbing section 132 for heat exchange between the waste heat of the marine engine 10 and the boiler water.

[0091] Furthermore, as shown in FIG. 3, the absorption tower 130 diverts (branches) at least a portion of the exhaust gas emitted from the marine engine 10, reacts it with seawater to cool it, and reacts the cooled exhaust gas with an absorption liquid to convert CO2 into a carbonate aqueous solution, thereby capturing CO2.

[0092] That is, by providing a blower (not shown) that branches off at least a portion of the exhaust gas and supplies it to the SOx absorber 132, and by minimizing the back pressure generated by the piping system of the absorber tower 130, the diameter of the absorber tower 130 can be minimized and the height can be designed to be large, thereby overcoming the constraints on installation space.

[0093] Here, the blowing means can be constituted by a blower, and if the SOx absorption section 132 is provided, the blower is preferably designed to blow or pressurize and transfer exhaust gas at 40°C to 50°C, and if the SOx absorption section 132 is not provided, it is preferably designed to blow or pressurize and transfer exhaust gas at around 300°C.

[0094] In this case, the remaining exhaust gas discharged from the marine engine that is not branched to the absorption tower 130 is discharged through the main exhaust pipe, and at least a portion of the exhaust gas that is branched to the absorption tower 130 can be discharged by joining the main exhaust pipe after CO2 is captured, or can be discharged through a separate exhaust pipe.

[0095] Next, the absorbent regenerating section 140 reacts the carbonate aqueous solution with a divalent metal oxide or a divalent metal hydroxide to regenerate the absorbent and produce a precipitate.

[0096] Specifically, referring to FIG. 4, the absorbent regeneration unit 140 may include a regeneration reactant storage tank 141 that stores a regeneration reactant of divalent metal oxide (CaO) or divalent metal hydroxide (Ca(OH)2), a transfer pump 142 that pumps the carbonate aqueous solution from the absorbent circulation tank 123 and transfers it to a mixing tank 143, and the mixing tank 143 that mixes and reacts the regeneration reactant with the carbonate aqueous solution to regenerate the absorbent and generate solid carbonate (CaCO3(s)), and returns the regenerated absorbent to the absorption tower 130 for reuse.

[0097] First, when NaOH and CO2 react to produce the carbonate NaHCO3 (sodium bicarbonate) or Na2CO3 (sodium carbonate), the carbonate NaHCO3 (sodium bicarbonate) or Na2CO3 (sodium carbonate) reacts with CaO (calcium oxide) according to the following equation 4 to produce the carbonate CaCO3 while regenerating NaOH, or reacts with Ca(OH)2 (calcium hydroxide) according to the following equation 5 to produce the carbonate CaCO3 while regenerating NaOH.

[0098] [ka]

[0099] [ka]

[0100] Alternatively, when NH4OH and CO2 react to produce NH4HCO3 (ammonium bicarbonate) or (NH4)2CO3 (ammonium carbonate), the carbonate NH4HCO3 (ammonium bicarbonate) or (NH4)2CO3 (ammonium carbonate) reacts with CaO (calcium oxide) according to the following equation 6 to produce the carbonate CaCO3 while regenerating NH4OH, or reacts with Ca(OH)2 (calcium hydroxide) according to the following equation 7 to produce the carbonate CaCO3 while regenerating NH4OH.

[0101] [ka]

[0102] [ka]

[0103] Here, the HCO3 in the absorption liquid circulation tank 123 - When the ion concentration becomes high, the absorbing solution is transferred to the mixing tank 143 via the transfer pump 142, so that the absorbing solution can be transferred at a concentration that allows it to continuously absorb CO2 even during the mineralization process in the subsequent process.

[0104] The mixing tank 143 also regenerates the absorbing solution by reacting the absorbing solution in which CO2 is ionized with CaO or Ca(OH)2, converting CO2 into CaCO3, and converting CaO or Ca(OH)2 into OH through the reactions of [Chemical Formula 4] to [Chemical Formula 7]. - Ions are supplied, and CO3 2- The ion is Ca 2+It can combine with ions to produce solid, insoluble CaCO3.

[0105] Next, the overboard discharge unit 150 separates the CaCO3(s) sediment and discharges it overboard in the form of sediment that is basically contained in the marine environment using seawater, and then washes it with fresh water.

[0106] That is, the overboard discharge section 150 can sequentially perform a process of separating sediments and absorption liquid along the path P1 shown in FIG. 9, a process of discharging sediments using seawater along the path P2 shown in FIG. 10, and a cleaning process using fresh water along the path P3 shown in FIG. 11.

[0107] Meanwhile, the overboard discharge section 150 sucks in and separates the sediment and absorbent from the absorbent regeneration section 140, dilutes the sediment with seawater so that the sediment meets the overboard discharge conditions, and discharges it overboard.If the sediment does not meet the overboard discharge conditions, the sediment can be temporarily stored in a separate storage tank (not shown).

[0108] For example, the overboard discharge unit 150 may include sensors (not shown) for measuring the turbidity, pH, and oil content of the sediment separated from the separator 152, and may discharge the sediment overboard or temporarily store it depending on whether the overboard discharge conditions corresponding to the sensor measurements are met.

[0109] Specifically, referring to FIG. 5, the overboard discharge unit 150 may include a separation pump 151 that sucks in the sediments and the absorbing solution from the absorbing solution regeneration unit 140, a separator 152 that separates the sediments and the absorbing solution transferred from the separation pump 151 and discharges the sediments overboard while returning the absorbing solution to the absorbing solution circulation supply unit 120, a discharge seawater pump 153 that supplies cooled seawater to the separator 152 to dilute the sediments and discharge them overboard, and a cooling seawater pump 154 ​​that supplies cooling seawater from the sea chest 111 to the discharge seawater pump 153.

[0110] Here, the separator 152 may be a filter-type separator or a centrifugal separator that separates the sediment from the absorption liquid.

[0111] In addition, the overboard discharge section 150 may further include a fresh water supply valve 155 that supplies fresh water to the separator 152 to clean the separator 152, thereby preventing corrosion by seawater and mixing of seawater with the regenerated absorption liquid.

[0112] Furthermore, the overboard discharge section 150 further includes a fresh water cooler 156 that cools the seawater supplied to the discharge seawater pump 153 into cooled fresh water, and the cooled seawater from the fresh water cooler 156 can be supplied to the sediment discharged from the separator 152 to dilute it and discharge it overboard.

[0113] Next, as shown in FIG. 6, the wash water treatment unit 160 includes a wash water tank 161 for storing the wash water discharged from the absorption tower 130, a water treatment device 162 equipped with a filtering unit for adjusting the turbidity of the wash water transferred from the wash water tank 161 so that it meets the overboard discharge conditions and a neutralizing agent injection unit for adjusting the pH, and a sludge storage tank 163 for separating and storing solid waste.

[0114] 3, the steam generating unit 170 may further include an EGE 134 formed between the NOx absorbing unit 133 and the SOx absorbing unit 132, for heat exchange between waste heat from the ship engine and boiler water. Specifically, as shown in FIG. 7, the steam generating unit 170 includes an auxiliary boiler 171 that receives a mixture of steam and saturated water that has been heat exchanged through the EGE 134, separates the steam using a steam drum (not shown), and supplies the steam to steam-consuming devices on the ship, a boiler water circulating pump 172 that circulates boiler water from the auxiliary boiler 171 to the EGE 134, a cascade tank 173 that collects condensed water that has changed phase after being consumed by the steam-consuming devices, and a supply pump 174 and a control valve 175 that adjust the amount of boiler water supplied from the cascade tank 173 to the auxiliary boiler 171, thereby generating and supplying steam required for heating devices on the ship.

[0115] Here, when the load of the ship engine 10 is heavy, the amount of heat that can be provided from the exhaust gas is high and the amount of steam required on board can be sufficiently produced through the EGE 134, but if this is not the case, the required steam can be produced by burning fuel in the auxiliary boiler 171 itself.

[0116] Meanwhile, another embodiment of the present invention provides a ship or marine structure equipped with the above-described greenhouse gas emission reduction device for a ship.

[0117] Therefore, according to the configuration of the embodiment of the present invention, the carbonate separated by the separator is discharged overboard using seawater, and by washing with fresh water, corrosion of the separator due to seawater can be prevented. In addition, greenhouse gases can be mineralized to reduce environmental pollution. Since the material that has captured greenhouse gases is discharged into the ocean, separate storage facilities and loading / unloading facilities are not required. NOx, SOx, and CO2 can be removed simultaneously, and stored in a solid state with few impurities such as Na2CO3, NaHCO3, (NH4)2CO3, and NH4HCO3. CO2 is removed after SOx is removed, thereby suppressing side reactions caused by SOx remaining in the exhaust gas, thereby improving the solubility of CO2 and the efficiency of CO2 removal.

[0118] The embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, so it should be understood that various equivalents and modifications may exist in place of them at the time of filing this application.

Claims

1. CO ２ an absorbent circulation supply unit that provides and circulates an absorbent that absorbs the an exhaust gas cooling unit that cools exhaust gas discharged from the ship engine; The cooled exhaust gas is reacted with the absorption liquid to produce CO ２ is converted into a carbonate solution and CO ２ CO ２ an absorption tower including a removal section; an absorbent regeneration unit that reacts the carbonate aqueous solution with a regeneration reactant to regenerate the absorbent and generate a precipitate; an overboard discharge unit that separates the sediment and discharges the sediment overboard using seawater; and greenhouse gas emission reduction devices for ships, including:

2. The overboard discharge section is 2. The greenhouse gas emission reduction device for a ship according to claim 1, further comprising a step of separating the sediment from the absorption liquid, a step of discharging the sediment using seawater, and a step of washing the sediment using fresh water.

3. The overboard discharge section is 3. A greenhouse gas emission reduction device for a ship as described in claim 2, characterized in that the sediment and the absorption liquid from the absorption liquid regeneration section are sucked in and separated, the sediment is diluted with seawater and discharged overboard so that the sediment meets the overboard discharge conditions, and if the sediment does not meet the overboard discharge conditions, the sediment is temporarily stored.

4. The overboard discharge section is a separation pump that sucks the sediment and the absorbing liquid from the absorbing liquid regeneration unit; a separator that separates the sediment and the absorption liquid transferred from the separation pump, discharges the sediment overboard, and returns the absorption liquid to the absorption liquid circulation supply section; a discharge seawater pump that supplies the seawater to the separator to dilute the sediment and discharge it overboard; 4. The greenhouse gas emission reduction device for a ship according to claim 3, further comprising:

5. The separator comprises:

5. The greenhouse gas emission reduction device for a ship according to claim 4, wherein the separator for separating the sediment and the absorbing liquid from each other is a filter-shaped separator or a centrifugal separator.

6. The overboard discharge section is The greenhouse gas emission reduction device for a ship according to claim 4, further comprising a fresh water supply valve that supplies the fresh water to the separator to wash the separator.

7. The overboard discharge section is 7. The greenhouse gas emission reduction device for a ship according to claim 6, further comprising a fresh water cooler that cools the seawater supplied to the discharge seawater pump into cooled fresh water.

8. The greenhouse gas emission reduction device for a ship as described in claim 7, characterized in that the sediment discharged from the separator is supplied with seawater cooled through the fresh water cooler, diluted, and discharged overboard.

9. The overboard discharge section is The greenhouse gas emission reduction device for a ship as described in claim 4, characterized in that it includes a sensor for measuring one or more of the turbidity, pH, and oil content of the sediment separated from the separator, and the sediment is discharged overboard or temporarily stored depending on whether the overboard discharge conditions corresponding to the measured values ​​by the sensor are met.

10. the precipitate comprises carbonate; The absorption liquid is a monovalent alkali aqueous solution, and may be an aqueous solution of LiOH, NaOH, KOH, or NH ４ 4. The greenhouse gas emission reduction device for a ship according to claim 3, wherein the greenhouse gas emission reduction device for a ship includes any one of an aqueous solution of OH.

11. Further including a seawater supply unit that supplies seawater from outside the ship; The seawater supply unit includes: a seawater pump that receives the seawater from outside the ship via a sea chest and pumps it into the absorption tower; a seawater control valve that adjusts the injection amount of the seawater supplied from the seawater pump to the absorption tower in accordance with the amount of exhaust gas; 2. The greenhouse gas emission reduction device for a ship according to claim 1, further comprising:

12. The exhaust gas cooling section 12. The greenhouse gas emission reduction device for a ship according to claim 11, wherein exhaust gas discharged from the ship engine is cooled by reacting it with the seawater supplied from the seawater supply unit.

13. The exhaust gas cooling section 2. The greenhouse gas emission reduction device for a ship according to claim 1, wherein the exhaust gas discharged from the ship engine is cooled by reacting it with fresh water.

14. The exhaust gas cooling section 2. The greenhouse gas emission reduction device for a ship according to claim 1, wherein the exhaust gas is cooled by circulating fresh water provided from an onboard cooling system through a heat exchange piping surrounding the exhaust gas discharge pipe.

15. 2. The greenhouse gas emission reduction device for a ship according to claim 1, wherein the exhaust gas cooling unit is provided inside the absorption tower.

16. The absorption liquid circulation supply unit an absorption liquid storage tank that stores the absorption liquid; an absorbent pump that pumps and transfers the absorbent from the absorbent storage tank; an absorption liquid circulation tank that mixes and stores the carbonate aqueous solution discharged from the absorption tower and the absorption liquid supplied from the absorption liquid pump; The absorption liquid is transferred from the absorption liquid circulation tank to the CO ２ an absorbent circulation pump for supplying and circulating the absorbent to the upper stage of the removal section; 2. The greenhouse gas emission reduction device for a ship according to claim 1, further comprising:

17. The absorption liquid pump 17. The greenhouse gas emission reduction device for a ship according to claim 16, wherein the absorption liquid is supplied to the absorption liquid circulation tank so as to make up for a shortage of the absorption liquid discharged overboard by the overboard discharge section.

18. The absorption liquid is 17. The greenhouse gas emission reduction device for a ship according to claim 16, wherein seawater and fresh water are produced by electrolysis and stored in the absorption liquid storage tank.

19. a seawater supply unit that supplies seawater from outside the ship, the exhaust gas cooling unit being provided inside the absorption tower; The absorption tower comprises: The exhaust gas cooling unit further includes a SOx absorption unit that reacts the exhaust gas with the seawater supplied from the seawater supply unit to cool the exhaust gas and dissolves and removes SOx, The CO ２ The removal section is The cooled exhaust gas from which SOx has been removed is reacted with the absorbing solution from the absorbing solution circulation supply unit to convert it into a carbonate aqueous solution, thereby producing CO ２ 2. The greenhouse gas emission reduction device for a ship according to claim 1, wherein the greenhouse gas is collected.

20. Further including a seawater supply unit that supplies seawater from outside the ship; The absorption tower comprises: Further comprising a NOx absorption section that absorbs and removes NOx from the exhaust gas, the exhaust gas cooling unit is provided inside the absorption tower, and cools the exhaust gas from which NOx has been removed by reacting it with the seawater supplied from the seawater supply unit; The CO ２ The removal section is The cooled exhaust gas is reacted with the absorbing solution from the absorbing solution circulation supply unit to convert it into a carbonate aqueous solution, thereby CO ２ 2. The greenhouse gas emission reduction device for a ship according to claim 1, wherein the greenhouse gas is collected.

21. Further including a seawater supply unit that supplies seawater from outside the ship; the exhaust gas cooling section is provided inside the absorption tower, The absorption tower comprises: a NOx absorption section that absorbs and removes NOx from the exhaust gas; an SOx absorption unit as the exhaust gas cooling unit that reacts the exhaust gas from which the NOx has been removed with the seawater supplied from the seawater supply unit to cool the exhaust gas while dissolving and removing SOx; The cooled exhaust gas from which SOx has been removed is reacted with the absorbing solution from the absorbing solution circulation supply unit to convert it into a carbonate aqueous solution, which is then collected and CO ２ The CO ２ 2. The greenhouse gas emission reduction device for a vessel according to claim 1, wherein the removal portions are formed by stacking them in order.

22. 22. The greenhouse gas emission reduction device for a vessel according to claim 20 or 21, wherein the NOx absorption section includes an SCR.

23. The absorption liquid regeneration unit a regeneration reactant storage tank for storing the regeneration reactant; a transfer pump that pumps and transfers the carbonate aqueous solution; a mixing tank for mixing and reacting the regenerated reactant with the carbonate aqueous solution to regenerate the absorption solution, generating solid carbonate, and returning the regenerated absorption solution to the absorption tower; 2. The greenhouse gas emission reduction device for a ship according to claim 1, further comprising:

24. The regeneration reactant is 24. The greenhouse gas emission reduction device for a ship according to claim 23, characterized in that it contains a divalent metal oxide or a divalent metal hydroxide.

25. a wash water tank for storing wash water discharged from the absorption tower; a water treatment device including a filtering unit for adjusting turbidity of the wash water transferred from the wash water tank so that the wash water meets the overboard discharge requirements, and a neutralizing agent injection unit for adjusting pH; a wash water treatment section including a sludge storage tank for separate storage of solid effluent; 2. The vessel greenhouse gas emission reduction device according to claim 1, further comprising:

26. The exhaust gas cooling section At least a portion of the exhaust gas discharged from the marine engine is branched and cooled; The CO ２ The removal section is The cooled exhaust gas is reacted with the absorption liquid to produce CO ２ is converted into the carbonate aqueous solution and CO ２ 2. The greenhouse gas emission reduction device for a ship according to claim 1, wherein the greenhouse gas is collected.

27. 27. The greenhouse gas emission reduction device for a ship according to claim 26, further comprising a blower means for supplying at least a portion of the branched exhaust gas to the exhaust gas cooling section.

28. 28. The greenhouse gas emission reduction device for a vessel according to claim 27, wherein the air blowing means is a blower.

29. Residual exhaust gas that is not branched to the exhaust gas cooling section out of the exhaust gas discharged from the marine engine is discharged through a main exhaust pipe, The at least part of the exhaust gas that is branched to the exhaust gas cooling section is ２ 27. The greenhouse gas emission reduction device for a ship as described in claim 26, wherein the collected exhaust gas is discharged by joining the main exhaust pipe or via a separate exhaust pipe.

30. A ship or marine structure equipped with the greenhouse gas emission reduction device for a ship according to any one of claims 1 to 21.

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