Simultaneous Reducing Device For Carbon Dioxide And Nitrogen Oxides

Abstract

The objective of the present invention is to provide a device for simultaneously reducing carbon dioxide and nitrogen oxides, which reduces CO2 through a CO2 discharge plasma reactor and reduces NOx through a fuel-based in-situ reducing agent. The device for simultaneously reducing carbon dioxide and nitrogen oxides according to the present invention comprises: a plasma reactor that forms a CO2 plasma using a supplied discharge gas and removes CO2 while producing a reducing agent by reacting the supplied fuel with CO2 using the thermal energy of the CO2 plasma; a mixing unit that mixes the reducing agent produced in the plasma reactor with the supplied nitrogen oxide (NOx); and a hydrocarbon selective catalytic reduction (HC SCR) catalyst that removes NOx while emitting H2O, N2, and CO2 by passing the reducing agent and NOx mixed in the mixing unit through a catalyst.

Description

Technology Field

[0001] The present invention relates to a carbon dioxide and nitrogen oxide reduction device, and more specifically, to a carbon dioxide and nitrogen oxide simultaneous reduction device that simultaneously reduces carbon dioxide and nitrogen oxides. Background Technology

[0002] Exhaust gas emitted after burning fuel in a combustion device, combustion furnace, and engine contains nitrogen oxides (NOx). A method for treating NOx contained in exhaust gas is to remove it by reducing it to nitrogen (N2) through a selective catalytic reduction (SCR) process using ammonia or urea as a reducing agent. In this case, additional equipment and space are required to supply the reducing agent, ammonia or urea. The reducing agent may produce ammonium salts at low temperatures, and the reducing agent needs to be replaced periodically.

[0003] Meanwhile, CO2 reduction is necessary for carbon neutrality, and although much research has been conducted on HC SCR (hydrocarbon SCR) catalysts, there is little research on the generation of reducing agents for HC SCR catalysts. It has become necessary to generate reducing agents in-situ based on fuel to eliminate the need for additional reducing agents and to generate reducing agents for CO2 reduction and NOx reduction simultaneously. The problem to be solved

[0004] The objective of the present invention is to provide a device for the simultaneous reduction of carbon dioxide and nitrogen oxides that reduces CO2 through a CO2 discharge plasma reactor and reduces NOx through a fuel-based in-situ generated reducing agent. means of solving the problem

[0005] A device for simultaneously reducing carbon dioxide and nitrogen oxides according to one embodiment of the present invention comprises: a plasma reactor that forms a CO2 plasma using supplied CO2 discharge gas and removes CO2 while producing a reducing agent by reacting supplied fuel with CO2 using the thermal energy of the CO2 plasma; a mixing unit that mixes the reducing agent produced in the plasma reactor with supplied nitrogen oxides (NOx); and a hydrocarbon selective catalytic reduction (HC SCR) catalyst that removes NOx while emitting H2O, N2, and CO2 by passing the reducing agent and NOx mixed in the mixing unit through a catalyst.

[0006] The above plasma reactor can produce syngas, oxygenated hydrocarbons, and light hydrocarbons as reducing agents.

[0007] The above plasma reactor may include a high-voltage electrode and a ground electrode formed in the shape of mutually opposing truncated cones, which interpose an insulating material to form a discharge gap between each other on the wide side and discharge the CO2 plasma through respective outlets provided on the narrow side, a gas supply pipe connected to the insulating material to supply the discharge gas, and a fuel supply pipe connected to the insulating material to supply the fuel.

[0008] The insulating material is formed into a cylindrical shape placed between the high-voltage electrode and the ground electrode, and the gas supply pipe is connected tangentially to the inner surface of the insulating material to supply discharge gas tangentially.

[0009] The above fuel supply pipe is connected to the inner surface of the insulation material in the diametrical direction to supply fuel in the diametrical direction.

[0010] The outlet of the high-voltage electrode and the outlet of the ground electrode are connected to each other by a connecting line, and the connecting line is connected to the mixing unit to supply the generated reducing agent.

[0011] The CO2 plasma generated in the above plasma reactor may be 1000 to 2000K.

[0012] The above mixing unit may be placed between the plasma reactor and the HC SCR catalyst.

[0013] The above plasma reactor may include a high-voltage electrode and a ground electrode formed in the shape of mutually opposing truncated cones, which cause an arc discharge by interposing an insulating material that forms a discharge gap between them on the wide side and discharge the CO2 plasma through respective outlets provided on the narrow side, a gas supply pipe connected to the insulating material to supply the discharge gas, and a fuel injection pipe provided in front of each outlet to inject the fuel into the discharged CO2 plasma.

[0014] The above plasma reactor may include a conical high-voltage electrode, a ground electrode that encloses the high-voltage electrode to form a discharge gap between it and the high-voltage electrode and discharges the CO2 plasma through an outlet on one side, a gas supply pipe that supplies the discharge gas between the high-voltage electrode and the ground electrode, and a fuel supply pipe formed in the high-voltage electrode to supply the fuel to a fuel passage.

[0015] The above plasma reactor may include a conical high-voltage electrode, a ground electrode that incorporates the high-voltage electrode to form a discharge gap between it and the high-voltage electrode and discharges the CO2 plasma through an outlet on one side, a gas supply pipe that supplies the discharge gas between the high-voltage electrode and the ground electrode, and a fuel supply pipe that is positioned in front of the outlet and supplies the fuel to the CO2 plasma.

[0016] The discharge side of the HC SCR catalyst and the gas supply pipe of the plasma reactor are connected to a recirculation pipe so that the discharged CO2 can be supplied back to the plasma reactor. Effects of the invention

[0017] As such, one embodiment of the present invention generates CO2 plasma using a plasma reactor that uses CO2 as a discharge gas, thereby not only reducing CO2 but also simultaneously generating a reducing agent required for an HC-SCR (hydrocarbon SCR) catalyst by reacting the fuel and CO2 plasma in-situ, and can reduce NOx using the generated reducing agent with an HC-SCR catalyst. Brief explanation of the drawing

[0018] FIG. 1 is a diagram showing the configuration of a carbon dioxide and nitrogen oxide simultaneous reduction device according to the first embodiment of the present invention. Figure 2 is a perspective view of a plasma reactor applied to Figure 1. Figure 3 is a cross-sectional view taken along the line III-III of Figure 2. Figure 4 is a cross-sectional view taken along line IV-IV of Figure 2. Figure 5 is a schematic diagram of another plasma reactor that can be applied to Figure 1. Figure 6 is a schematic diagram of another plasma reactor that can be applied to Figure 1. Figure 7 is a schematic diagram of another plasma reactor that can be applied to Figure 1. FIG. 8 is a configuration diagram of a carbon dioxide and nitrogen oxide simultaneous reduction device according to a second embodiment of the present invention. Specific details for implementing the invention

[0019] Hereinafter, embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. In the drawings, parts unrelated to the explanation have been omitted to clearly explain the present invention, and the same reference numerals have been used throughout the specification for identical or similar components.

[0020] FIG. 1 is a diagram showing the configuration of a carbon dioxide and nitrogen oxide simultaneous reduction device according to a first embodiment of the present invention. Referring to FIG. 1, the carbon dioxide and nitrogen oxide simultaneous reduction device (100, hereinafter referred to as the "reduction device") of the first embodiment includes a plasma reactor (10), a mixing unit (20), and a hydrocarbon selective catalytic reduction (HC SCR) catalyst (30, hereinafter referred to as the "HC SCR catalyst").

[0021] The reduction device (100) is configured to simultaneously reduce CO2 and nitrogen oxides (NOx) through plasma reforming. For example, since nitrogen oxides (NOx) are contained in the exhaust gas emitted after combustion in a combustion device, combustion furnace, or engine, they are supplied through the exhaust pipe (40).

[0022] The first embodiment reduces CO2 in a plasma reactor (100) by using CO2 as a discharge gas. At the same time, the first embodiment can reduce NOx in a catalyst layer (31) by reacting fuel and CO2 plasma in-situ to produce a reducing agent required for an HC-SCR catalyst (30), and supplying the produced reducing agent and nitrogen oxides to the HC-SCR catalyst (30).

[0023] A plasma reactor (10) is configured to form a high-temperature CO2 plasma using CO2 as a discharge gas, and to produce a reducing agent by reacting the supplied fuel, diesel, with CO2 using the thermal energy of the CO2 plasma. The reducing agent produced using CO2 as the discharge gas and based on diesel fuel includes N2, H2O, and CO2. Diesel represents one example of fuel, and other petroleum-based fuels such as LNG and LPG are also included in the fuel.

[0024] That is, the plasma reactor (10) produces a reducing agent such as syngas of CO and H2, light hydrocarbons having C1 to C4, and oxygenated hydrocarbons. Oxygenated hydrocarbons include alcohols, aldehydes, and acids.

[0025] The mixing section (20) is configured to mix the reducing agent generated in the plasma reactor (10) and the supplied nitrogen oxide (NOx) at the rear end of the plasma reactor (10). The mixing section (20) is configured separately as shown in FIG. 1 to enhance the mixing effect of the reducing agent and the nitrogen oxide (NOx). In this case, the exhaust pipe (40) supplying the nitrogen oxide (NOx) and the outlets (111, 121) of the plasma reactor (10) are connected to the mixing section (20).

[0026] The HC-SCR catalyst (30) passes the reducing agent and NOx mixed in the mixing section (20) through the catalyst, and the NOx and reducing agent react with the catalyst in the catalyst layer (31) to remove NOx while emitting H2O, N2, and CO2.

[0027] FIG. 2 is a perspective view of a plasma reactor applied to FIG. 1, FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2, and FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 2. Referring to FIG. 2 to FIG. 4, the plasma reactor (10) includes a high-voltage electrode (11), a ground electrode (12), an insulating material (13), a gas supply pipe (14), and a fuel supply pipe (15).

[0028] The high-voltage electrode (11) and the ground electrode (12) are formed in the shape of a truncated cone facing each other, and an insulating material (13) is interposed between them on the wide side of the truncated cone to form a discharge gap (G), and an arc discharge is generated in the discharge gap (G) to produce high-temperature CO2 plasma, i.e., high-temperature arc plasma (AP, arc plasma), and the CO2 plasma is discharged through each discharge port (111, 121) provided on the narrow side of the truncated cone.

[0029] Meanwhile, the outlet (111) of the high-voltage electrode (11) and the outlet (121) of the ground electrode (12) are connected to each other by a connecting line (17), and the connecting line (17) is connected to a mixing unit (20) to supply the generated reducing agent.

[0030] The insulating material (13) is formed as an electrical insulating material and enables the stable formation of a discharge gap (G) on the wide side of the high-voltage electrode (11) and the ground electrode (12). A gas supply pipe (14) is connected to the insulating material (13) to supply CO2 discharge gas to the discharge gap (G). A fuel supply pipe (15) is connected to the insulating material (13) to supply diesel fuel into the discharge gap (G) and the plasma reactor (10).

[0031] For example, the insulating material (13) is formed into a cylindrical shape placed between the high-voltage electrode (11) and the ground electrode (12). This cylinder may be formed into a circular shape corresponding to the wide area side of the truncated cone. The gas supply pipe (14) is connected tangentially to the inner surface of the insulating material (13) to supply discharge gas tangentially to the inner surface. That is, CO2, which is the discharge gas, is injected into the discharge gap (G) while rotating.

[0032] Therefore, the CO2 discharge gas causes arc ignition in the discharge gap (G) where the gap between the high-voltage electrode (11) and the ground electrode (12) is shortest, and forms a swirl gas flow (SGF) in the space inside the insulating material (13), the high-voltage electrode (11) and the ground electrode (12).

[0033] The swirl gas flow (SGF) acts on the arc plasma (AP) to form a rotating arc, and enables the generation of high-temperature CO2 plasma using the rotating arc. The swirl gas flow (SGF) enables the formation of high-temperature CO2 plasma over the entire internal space of the high-voltage electrode (11) and the ground electrode (12). Additionally, since the swirl gas flow (SGF) contacts the inner surface of the high-voltage electrode (11) and the ground electrode (12) in a tangential direction, it increases the lifespan of the high-voltage electrode (11) and the ground electrode (12).

[0034] The fuel supply pipe (15) is connected in the diametrical direction to the inner surface of the insulating material (13) to supply fuel in the diametrical direction. The fuel supply pipe (15) can inject fuel into the internal space of the high-voltage electrode (11) and the ground electrode (12) in a liquid, gaseous, or spray manner. For convenience, the spray method of liquid fuel is described below as an example. The fuel injected in the diametrical direction collides with and moves tangentially with the discharge gas CO2 of the swirl gas flow (SGF), and they mix with each other.

[0035] When a plasma reactor (10) applies a high voltage (HV) to a high voltage electrode (11) and supplies discharge gas and fuel to a gas supply pipe (14) and a fuel supply pipe (15), respectively, while the ground electrode (12) is grounded, it generates thermal energy as CO2 plasma inside the high voltage electrode (11) and the ground electrode (12).

[0036] A plasma reactor (10) uses thermal energy generated by CO2 plasma to react CO2 with fuel to produce various reducing agents such as syngas of formula 1, oxygenated hydrocarbon of formula 2, and light hydrocarbon of formula 3.

[0037] At this time, CO2 is used as an oxygen source (O source) in the generated CO2 plasma, and compared to plasma using other gases, CO2 is a discharge gas that is advantageous for generating high-temperature plasma. Through this, the plasma reactor (10) can generate high-temperature plasma of 1000 to 2000K.

[0038]

[0039]

[0040]

[0041] Various embodiments of the present invention are described below. When comparing the various embodiments with the first embodiment or the previously described embodiment, descriptions of identical configurations are omitted, and different configurations are described.

[0042] FIG. 5 is a schematic diagram of another plasma reactor that can be applied to FIG. 1. Referring to FIG. 5, play In the plasma reactor (210), fuel injection pipes (151, 152) are provided in front of the respective outlets (111, 121) of the high-voltage electrode (11) and the ground electrode (12) to inject fuel into the high-temperature CO2 plasma (P) being discharged.

[0043] The fuel injected from the fuel injection pipes (151, 152) is mixed with the CO2 plasma (P) without obstructing the swirl gas flow (SGF) caused by the discharge gas. In this case, the connecting line (17) is connected to each other after the CO2 plasma (P) and connected to the mixing section (20) in a connected state.

[0044] The plasma reactor (210) uses the thermal energy of the discharged CO2 plasma (P) to react CO2 with the injected fuel to produce various reducing agents. The injected fuel is mixed with the CO2 plasma (P) and supplied to the mixing unit (30).

[0045] FIG. 6 is a diagram of another plasma reactor that can be applied to FIG. 1. Referring to FIG. 6, in the plasma reactor (310), the high-voltage electrode (311) is formed in a conical shape, and the ground electrode (312) incorporates the high-voltage electrode (311) to form a discharge gap (G3) between it and the high-voltage electrode (311), and discharges CO2 plasma (P) through an outlet (313) on one side.

[0046] The gas supply pipe (14) supplies the discharge gas between the high-voltage electrode (311) and the ground electrode (312). For example, the gas supply pipe (14) can supply CO2 discharge gas tangentially to the ground electrode (312) to form a swirl gas flow (SGF2) within the ground electrode (312).

[0047] The fuel supply pipe (15) is formed in the high-voltage electrode (311) and supplies fuel to the fuel passage (314). For example, the fuel passage (314) can spray fuel into the internal space of the ground electrode (312) in a spray manner within the high-voltage electrode (311). An arc discharge is generated in the discharge gap (G3) to produce high-temperature CO2 plasma (P), and the CO2 plasma (P) is discharged through the outlet (313).

[0048] FIG. 7 is a diagram of another plasma reactor that can be applied to FIG. 1. Referring to FIG. 7, in the plasma reactor (410), the high-voltage electrode (411) is formed in a conical shape, and the fuel supply pipe (415) is positioned in front of the outlet (313) to inject fuel into the CO2 plasma (P) that is discharged.

[0049] Fuel injected from the fuel supply pipe (415) is mixed with CO2 plasma (P) without obstructing the swirl gas flow (SGF2) within the ground electrode (312). In this case, the plasma reactor (410) uses the thermal energy of the discharged CO2 plasma (P) to react CO2 with the injected fuel to produce various reducing agents. The injected fuel is mixed with CO2 plasma (P) and supplied to the mixing section (30).

[0050] FIG. 8 is a configuration diagram of a carbon dioxide and nitrogen oxide simultaneous reduction device according to a second embodiment of the present invention. Referring to FIG. 8, the carbon dioxide and nitrogen oxide simultaneous reduction device (200) of the second embodiment further includes a recirculation pipe (250).

[0051] The recirculation pipe (250) connects the discharge side of the HC SCR catalyst (30) and the gas supply pipe (14) of the plasma reactor (10) to each other, thereby supplying the discharged CO2 back to the discharge gas of the plasma reactor (10).

[0052] By recovering CO2 that has passed through the catalyst layer (31) of the HC SCR catalyst (30) and recycling it as a discharge gas, it is possible to generate a higher temperature CO2 plasma in the plasma reactor (10).

[0053] Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto and can be implemented with various modifications within the scope of the claims, the description of the invention, and the attached drawings, and it is obvious that such modifications also fall within the scope of the present invention. Explanation of the symbols

[0054] 10, 210, 310, 410: Plasma reactor 11, 311, 411: High-voltage electrodes 12, 312: Ground electrodes 13: Insulating material 14: Gas supply pipe 15, 415: Fuel supply pipe 17: Connection line 20: Mixing section 30: HC SCR catalyst 31: Catalytic layer 100, 200: Reduction device 111, 121, 313: Outlets 151, 152: Fuel injectors 250: Recirculation pipe 314: Fuel passage AP: Arc Plasma G: Discharge Gap P: Plasma SGF, SGF2: Swirl gas flow

Claims

Claim 1 A plasma reactor that reduces CO2 through plasma reforming to form CO2 plasma using supplied CO2 discharge gas, and removes CO2 while producing a reducing agent through the reaction of supplied fuel and CO2 using the thermal energy of said CO2 plasma; a mixing unit that mixes the reducing agent produced in said plasma reactor with supplied nitrogen oxides (NOx); A device for simultaneous reduction of carbon dioxide and nitrogen oxides, comprising a hydrocarbon selective catalytic reduction (HC SCR) catalyst that removes NOx while emitting H2O, N2, and CO2 by passing the reducing agent and NOx mixed in the mixing section through a catalyst, wherein the plasma reactor forms a discharge gap between a high-voltage electrode and a ground electrode, wherein the ground electrode is formed in the shape of a truncated cone to cause an arc discharge on the wide side and discharge the CO2 plasma through an outlet provided on the narrow side, wherein the high-voltage electrode is formed to face the ground electrode and causes an arc discharge by interposing an insulating material formed in the shape of a truncated cone to form a discharge gap between them on the wide side and discharges the CO2 plasma through an outlet provided on the narrow side, and wherein the plasma reactor further comprises a gas supply pipe connected to the insulating material to supply the discharge gas, and a fuel supply pipe connected to the insulating material to supply the fuel. Claim 2 In claim 1, the plasma reactor is a carbon dioxide and nitrogen oxide simultaneous reduction device that produces syngas, oxygenated hydrocarbons, and light hydrocarbons as reducing agents. Claim 3 delete Claim 4 A carbon dioxide and nitrogen oxide simultaneous reduction device according to claim 1, wherein the insulating material is formed in a cylindrical shape disposed between the high-voltage electrode and the ground electrode, and the gas supply pipe is connected tangentially to the inner surface of the insulating material to supply discharge gas tangentially. Claim 5 In paragraph 4, the fuel supply pipe is connected in the diametrical direction to the inner surface of the insulating material to supply fuel in the diametrical direction, a device for simultaneously reducing carbon dioxide and nitrogen oxides. Claim 6 A carbon dioxide and nitrogen oxide simultaneous reduction device according to claim 1, wherein the outlet of the high-voltage electrode and the outlet of the ground electrode are connected to each other by a connecting line, and the connecting line is connected to the mixing unit to supply a generated reducing agent. Claim 7 A carbon dioxide and nitrogen oxide simultaneous reduction device according to claim 1, wherein the CO2 plasma generated in the plasma reactor is 1000 to 2000K. Claim 8 A carbon dioxide and nitrogen oxide simultaneous reduction device according to claim 1, wherein the mixing unit is disposed between the plasma reactor and the HC SCR catalyst. Claim 9 A plasma reactor that reduces CO2 through plasma reforming to form CO2 plasma using supplied CO2 discharge gas, and removes CO2 while producing a reducing agent through the reaction of supplied fuel and CO2 using the thermal energy of said CO2 plasma; a mixing unit that mixes the reducing agent produced in said plasma reactor with supplied nitrogen oxides (NOx); A device for simultaneous reduction of carbon dioxide and nitrogen oxides, comprising a hydrocarbon selective catalytic reduction (HC SCR) catalyst that removes NOx while emitting H2O, N2, and CO2 by passing the reducing agent and NOx mixed in the mixing section through a catalyst, wherein the plasma reactor is formed in the shape of mutually opposing truncated cones, and includes a high-voltage electrode and a ground electrode that generate an arc discharge by interposing an insulating material that forms a discharge gap between them on the wide side and discharges the CO2 plasma through respective outlets provided on the narrow side, a gas supply pipe connected to the insulating material to supply the discharge gas, and a fuel injection pipe provided in front of each outlet to inject the fuel into the discharged CO2 plasma. Claim 10 delete Claim 11 delete Claim 12 A carbon dioxide and nitrogen oxide simultaneous reduction device according to claim 1, wherein the discharge side of the HC SCR catalyst and the gas supply pipe of the plasma reactor are connected to a recirculation pipe to supply the discharged CO2 back to the plasma reactor.

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