SOE-SOFC-CCS Hybrid System

Abstract

The present invention relates to a hybrid system that combines a solid oxide electrolysis cell (SOE), a solid oxide fuel cell (SOFC), and a carbon capture system (CCS). More specifically, the present invention relates to an SOE-SOFC-CCS hybrid system in which a solid oxide electrolysis cell, a solid oxide fuel cell including a burner for burning exhaust gas, and carbon capture technology are operated in an organic relationship, and by-products and waste heat generated by the operation are recycled, thereby minimizing the fuel required for hydrogen and electricity production.

Description

Technical Field

[0001] The present invention relates to a hybrid system in which a solid oxide electrolysis cell (SOE), a solid oxide fuel cell (SOFC), and a carbon capture system (CCS) are combined. More specifically, the solid oxide electrolysis cell, the solid oxide fuel cell including a burner for burning exhaust gas, and carbon capture technology are organically related and driven, and by recycling the by-products and waste heat generated by the driving, the fuel required for hydrogen and power production is minimized, which relates to an SOE-SOFC-CCS hybrid system.

Background Art

[0002] A solid oxide fuel cell (SOFC) has a structure in which a plurality of electricity generation units each composed of a unit cell and a separator plate are stacked. The unit cell includes an electrolyte, an air electrode located on one surface of the electrolyte, and a fuel electrode located on the other surface of the electrolyte.

[0003] When oxygen is supplied to the air electrode and hydrogen is supplied to the fuel electrode, oxygen ions generated by the reduction reaction of oxygen at the air electrode move through the electrolyte membrane to the fuel electrode, and then react with the hydrogen supplied to the cathode, generating water. Here, in the process where electrons generated at the fuel electrode are transmitted to and consumed by the air electrode, electrons flow through the external circuit, and the unit cell uses such a flow of electrons to produce electrical energy.

[0004] A solid oxide electrolysis cell is a device that produces hydrogen by electrolyzing pure water using electrical energy, and generally operates at a temperature at which high-temperature electrolysis can occur at 500 to 850 °C.

[0005] Korean Patent Publication No. 10-2020-0110501 (Patent Document 1) discloses a technology for a solid oxide fuel cell to which an oxygen enrichment device is applied. However, Patent Document 1 does not burn the exhaust gas of the stack, so the carbon dioxide capture efficiency is low, and it does not present a plan for reusing the combustion heat, so it has the drawback of reduced operating efficiency.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] One of the technical problems to be solved by the present invention is to provide a solution for efficiently utilizing the exhaust gas of a solid oxide electrolysis cell without directly discharging it in a hybrid system of a solid oxide electrolysis cell and a solid oxide fuel cell.

[0008] Another one of the technical problems to be solved by the present invention is to provide a solution for effectively capturing carbon dioxide from unreacted hydrogen contained in the fuel electrode exhaust gas of the stack and the exhaust gas of the electrolysis cell in a hybrid system of a solid oxide electrolysis cell, a solid oxide fuel cell, and a carbon capture device.

[0009] Still another one of the technical problems to be solved by the present invention is to provide a solution for minimizing the consumed fuel by recycling the by-products and waste heat generated during the organic operation of a solid oxide fuel cell and a carbon capture device.

Means for Solving the Problems

[0010] As one of the technical solutions of the present invention, a solid oxide electrolyte (SOE), a reformer, a fuel heat exchanger (fuel HX) for heating the fuel produced by the reformer, a first air heat exchanger (air HX_A) for primary heating of external air (air), a second air heat exchanger (air HX_B) for secondary heating of the primary-heated external air, a stack including an anode that receives the fuel heated by the fuel heat exchanger and a cathode that receives the external air (air) heated by the first air heat exchanger and the second air heat exchanger, and a burner for burning the exhaust gas of the solid oxide electrolyte and the anode exhaust gas of the stack, a solid oxide fuel cell (SOFC) including, and a carbon capture system (CCS) for capturing carbon dioxide from the exhaust gas of the burner heat-exchanged by at least one of the reformer and the first air heat exchanger, a SOE-SOFC-CCS hybrid system is proposed.

[0011] Here, the exhaust gas of the burner can be heat-exchanged by the steam generator of the reformer.

[0012] In another embodiment, it can further include a first distributor (D1) that branches at least a part of the cathode exhaust gas of the stack to the second air heat exchanger and branches the remaining part to the fuel heat exchanger.

[0013] Here, it can further include a temperature sensor (A) for measuring the temperature of the external air passing through the first air heat exchanger, and a controller for transmitting a control signal including the distribution ratio to the second air heat exchanger and the fuel heat exchanger to the first distributor (D1) based on the measured value of the temperature sensor (A).

[0014] In another embodiment, a second distributor (D2) may be further included to branch at least a part of the burner exhaust gas passing through the first air heat exchanger to the burner and branch the remaining part to the carbon capturer.

[0015] Here, a temperature sensor (B) for measuring the temperature of the burner and a controller for transmitting a control signal including the distribution ratio to the burner and the carbon capturer to the second distributor (D2) based on the measured value of the temperature sensor (B) may be further included.

[0016] In another embodiment, a third distributor (D3) may be further included to branch at least a part of the exhaust gas of the solid oxide electrolytic cell to merge with the external air and branch the remaining part to the burner.

[0017] In another embodiment, a fourth distributor (D4) may be further included to branch at least a part of the burner exhaust gas to the solid oxide electrolytic cell and branch the remaining part to the reformer.

Advantages of the Invention

[0018] According to an embodiment of the present invention, in a hybrid system of a solid oxide electrolytic cell and a solid oxide fuel cell, by utilizing the exhaust gas of the solid oxide electrolytic cell as it is without discharging it directly, for example, for the combustion of the burner, the operating efficiency can be improved.

[0019] According to an embodiment of the present invention, in a hybrid system of a solid oxide electrolytic cell, a solid oxide fuel cell, and a carbon capturer, the carbon dioxide capture efficiency can be maximized by a method of removing impurities in advance from unreacted fuel contained in the fuel electrode exhaust gas of the stack and the exhaust gas of the electrolytic cell.

[0020] According to an embodiment of the present invention, by recycling by-products and waste heat generated during the organic operation of the solid oxide fuel cell and the carbon capturer, the consumption of fuel can be minimized.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0022] Hereinafter, several examples of the present invention will be described in detail based on the accompanying drawings. However, this is not intended to limit the present invention to a specific example, and it should be understood that all transformations, equivalents, and substitutions including the technical idea of the present invention are included in the scope of the present invention.

[0023] In this specification, the singular expression includes plural expressions unless otherwise clearly indicated in the context.

[0024] In this specification, when a certain configuration is described as "having" or "comprising or including" a certain sub - configuration, it means that, unless otherwise stated to the contrary, it does not exclude other configurations and can further include other configurations.

[0025] As used herein, the term "connected" can mean that two components are directly connected, but is not necessarily limited thereto, and can also mean being connected through one or more other components disposed between the components.

[0026] <Example 1>

[0027] FIG. 1 is a configuration diagram of an SOE-SOFC-CCS hybrid system according to Example 1.

[0028] The hybrid system of Example 1 includes a solid oxide electrolysis cell (SOE, Solid Oxide Electrolyte Cell) 10, a solid oxide fuel cell (SOFC, Solid Oxide Fuel Cell) 100, and a carbon capture system (CCS, carbon capture system) 20.

[0029] The solid oxide electrolysis cell 10 produces hydrogen by electrolyzing pure water using electrical energy. The solid oxide electrolysis cell 10 has a total of three ceramic layers composed of a porous hydrogen electrode, an oxygen electrode, and an impermeable electrolyte. In the solid oxide electrolysis cell 10, when water vapor flows into the cathode and a voltage is applied to the anode, water molecules are separated into hydrogen and oxygen by the decomposition reaction of water vapor.

[0030] The solid oxide electrolysis cell 10 supplies the oxygen obtained by the electrolysis of water to the burner 160 of the solid oxide fuel cell (SOFC) 100 through the oxygen electrode output terminal, and discharges hydrogen and other compositions to the hydrogen electrode output terminal.

[0031] The solid oxide fuel cell (SOFC) 100 is a fuel cell that uses an ion-conductive ceramic as an electrolyte, and includes a stack composed of an oxygen ion-conductive electrolyte and an air electrode (cathode) and a fuel electrode (anode) located on both sides thereof.

[0032] When air and hydrogen are supplied to the air electrode and the fuel electrode of the stack respectively, an oxygen reduction reaction occurs at the air electrode to generate oxygen ions. The oxygen ions that move to the fuel electrode through the electrolyte react again with the hydrogen supplied to the fuel electrode, generating water. Here, electrons are generated at the fuel electrode and consumed at the air electrode, so electricity is produced based on the principle that current flows through the two connected electrodes.

[0033] The solid oxide fuel cell 100 can also use pure hydrogen directly as fuel, or can use hydrogen obtained by reforming external fuels such as liquefied propane gas (LPG), pipeline transported natural gas (PNG), compressed natural gas (CNG), and hydrocarbon-based fuels (e.g., natural gas).

[0034] The solid oxide fuel cell 100 includes a stack 110, a reformer 120, a fuel heat exchanger 130, a first air heat exchanger 140, a second air heat exchanger 150, a burner 160, a first distributor D1, a first confluence C1, and a controller (not shown).

[0035] The stack 110 receives the external air heated by the first air heat exchanger (air heat exchanger_A; air HX_A) 140 at the air electrode, and receives the hydrogen generated by the reformer 120 at the fuel electrode.

[0036] The reformer 120 reforms the external fuel into hydrogen using any one of steam methane reforming, partial oxidation reaction, and auto-thermal reforming.

[0037] Steam methane reforming produces hydrogen by mixing steam with methane (or natural gas) at 700 - 1,100 °C and reacting it in a catalytic reactor at a pressure of 3 - 25 bar. The partial oxidation reaction supplies less oxygen than the amount required to oxidize natural gas to water and carbon dioxide, producing hydrogen, carbon monoxide, carbon dioxide, etc. Autothermal reforming reforms hydrogen by supplying the heat required for the endothermic steam reforming reaction by the exothermic reaction of partial oxidation itself.

[0038] In Example 1 and the following examples, the reformer 120 will be described assuming the use of steam methane reforming, but it is not necessarily limited to steam methane reforming.

[0039] Since steam methane reforming is an endothermic reaction overall, heat must be supplied from the outside, and a catalyst layer for promoting the conversion to hydrogen is provided in the subsequent stage. In the examples of the present invention, the reformer 120 can use a nickel-based catalyst.

[0040] The reformer 120 decomposes C2+ hydrocarbons contained in the reaction raw material (or fuel), that is, C2H6 (ethane) and C3H8 (propane), into CH4, CO, H2, etc., and reforms a part of CH4 (methane) into hydrogen. Coke formation (or carbon deposition) on the catalyst layer due to thermal decomposition of higher hydrocarbons can be suppressed by the decomposition process.

[0041] The fuel heat exchanger (fuel HX) 130 is arranged between the reformer 120 and the anode input of the stack 110. The fuel heat exchanger 130 preheats the hydrogen output from the reformer 120 to a preset temperature and supplies the preheated hydrogen to the anode input of the stack 110. The fuel heat exchanger 130 can also preheat the hydrogen produced in the reformer 120 with the thermal energy obtained by heat exchange with the cathode offgas of the stack 110. The exhaust gas heat-exchanged in the fuel heat exchanger 130 is discharged outside the solid oxide fuel cell 100.

[0042] The first air heat exchanger 140 preheats the external air to a preset temperature. The preheated external air is immediately input into the air electrode of the stack 110, or after being preheated secondly by the second air heat exchanger 150, it is input into the air electrode of the stack 110.

[0043] The first air heat exchanger 140 preheats the external air with the thermal energy obtained by exchanging heat with the high-temperature exhaust gas output from the burner 160.

[0044] All of the high-temperature exhaust gas output from the burner 160 is first heat-exchanged in the reformer 120 and then secondarily heat-exchanged in the first air heat exchanger 140. Alternatively, a part of the high-temperature exhaust gas output from the burner 160 can be branched to the reformer 120 and the remaining part can be branched to the first air heat exchanger 140 through a distributor (not shown) arranged at the outlet stage of the burner 160. In Example 1, the exhaust gas of the burner 160 is input into the carbon capture device 20 after being heat-exchanged in at least one of the reformer 120 and the first air heat exchanger 140.

[0045] The second air heat exchanger 150 is arranged between the first air heat exchanger 140 and the cathode input of the stack 110, and secondarily heats the external air that has been first heated by the first air heat exchanger 140 with the thermal energy obtained by exchanging heat with the cathode offgas of the stack 110. Since a considerable amount of thermal energy is taken away while the exhaust gas of the burner 160 is heat-exchanged in the reformer 120, the amount of heat to be heat-exchanged in the first air heat exchanger 140 may not be sufficient. If the external air passing through the first air heat exchanger 140 does not reach the reference temperature required for a smooth chemical reaction, additional heat exchange in the second air heat exchanger 150 can secure the thermal energy.

[0046] The burner 160 burns the anode offgas received from the fuel electrode output of the stack 110 by using the oxygen contained in the exhaust gas received from the solid oxide electrolysis cell. When the burner 160 burns the exhaust gas of the stack 110, most of the compositions contained in the exhaust gas, other than carbon dioxide and water, burn, resulting in higher concentrations of carbon dioxide (about 30%) and water (about 60%).

[0047] The high-temperature exhaust gas output from the burner 160 is heat-exchanged in at least one of the reformer 120 and the first air heat exchanger 140 and then supplied to the carbon capture device 20. As described above, since most of the exhaust gas of the burner 160 consists of carbon dioxide and water, it is easily separated into carbon dioxide and water by the carbon capture device 20.

[0048] The solid oxide fuel cell 100 can further include a first distributor D1 and a first mixer C1.

[0049] The first distributor D1 is disposed downstream of the air electrode output of the stack 110, branches a part of the cathode offgas of the stack 110 to the fuel heat exchanger 130, and the remainder is branched to the second air heat exchanger 150.

[0050] The first distributor D1 has one input end and two output ends, and can also be provided with a control valve (not shown) for automatically or manually adjusting the direction and flow rate of the fluid. Further, near the output end of the first air heat exchanger 140 or near the input end of the second air heat exchanger 150, a temperature sensor (not shown) for measuring the temperature of the external air heated by heat exchange with the first air heat exchanger 140 can also be provided.

[0051] The controller (not shown) determines how much of the cathode offgas of the stack is branched to the second air heat exchanger 150 by the first distributor D1 based on the measured value of the temperature sensor, and transmits a control signal including the determined value to the first distributor D1.

[0052] The exhaust gas from the air electrode, which is branched to the fuel heat exchanger 130 and the second air heat exchanger 150 by the first distributor D1, is discharged to the outside after merging at the first merger C1.

[0053] The carbon capture 20 captures carbon dioxide from the exhaust gas of the burner 160 that has been heat-exchanged in at least one of the reformer 120 and the first air heat exchanger 140.

[0054] The carbon capture 20 can also use any one of post combustion technology, pre-combustion technology, oxy-fuel combustion technology, and pressure swing adsorption.

[0055] FIG. 2 is a diagram showing an addition of the detailed configuration of the reformer of Example 1.

[0056] In FIG. 2, the remainder excluding the detailed configuration of the reformer 120 is the same as that in FIG. 1.

[0057] As shown in FIG. 2, the reformer 120 of one embodiment includes a steam generator 121, a mixer 122, and a pre-reformer 123.

[0058] The steam generator 121 heats the water supplied from the outside and converts it into steam. The steam generator 121 can also heat the water with the thermal energy obtained by heat-exchanging with the exhaust gas of the burner 160.

[0059] The high-temperature exhaust gas output from the burner 160 is heat-exchanged in the steam generator 121 and then moves to the first air heat exchanger 140, where it can be further heat-exchanged. The exhaust gas of the burner 160 heat-exchanged in the first air heat exchanger 140 is supplied to the carbon capture 20 and separated into carbon dioxide and water.

[0060] The mixer 122 mixes the natural fuel (e.g., natural gas) input from the outside with the steam generated by the steam generator 121.

[0061] The pre-reformer 123 produces hydrogen from the mixed gas of steam and natural gas. The hydrogen produced by the pre-reformer 123 is provided to the fuel heat exchanger 130, and after being heated up in the fuel heat exchanger 130, it is input to the fuel electrode of the stack 110.

[0062] <Example 2>

[0063] Example 2 relates to a technique for improving the carbon dioxide capture efficiency by recycling a part of the exhaust gas of the burner back to the burner to increase the purity of carbon dioxide, as compared with Example 1 in which the entire exhaust gas of the burner is supplied to the carbon capturer.

[0064] FIG. 3 is a configuration diagram of the SOE-SOFC-CCS hybrid system according to Example 2.

[0065] The hybrid system of Example 2 includes a solid oxide electrolysis cell 10, a solid oxide fuel cell 200, and a carbon capturer 20. The solid oxide fuel cell 200 includes a stack 210, a reformer 220, a fuel heat exchanger 230, a first air heat exchanger 240, a second air heat exchanger 250, a burner 260, a first distributor D1, a second distributor D2, a first mixer C1, a second mixer C2, and a controller (not shown).

[0066] In Example 2, the technical configurations of the solid oxide electrolysis cell 10, the stack 210, the reformer 220, the fuel heat exchanger 230, the first air heat exchanger 240, the second air heat exchanger 250, the burner 260, the first distributor D1, the first mixer C1, the controller (not shown), and the carbon capturer 20 are basically the same as those of the electrolysis cell 10, the stack 110, the reformer 120, the fuel heat exchanger 130, the first air heat exchanger 140, the second air heat exchanger 150, the burner 160, the first distributor D1, the first mixer C1, the controller (not shown), and the carbon capturer 20 in Example 1. Therefore, only the differences will be additionally explained here.

[0067] The second distributor D2 is arranged downstream of the first air heat exchanger 240, so that a part of the exhaust gas of the burner 260 that has undergone heat exchange in the reformer 220 and the first air heat exchanger 240 is branched to the carbon capturer 20, and the remaining part is branched to the burner 260.

[0068] The second confluence unit C2 merges a part of the burner exhaust gas that remains after being branched to the burner 260 and the fuel electrode exhaust gas of the stack 210. The gas merged by the second confluence unit C2 is input to the burner 260 again.

[0069] In this way, by recycling a part of the exhaust gas of the burner 260 to the burner 260 again, three effects can be expected.

[0070] First, basically, the exhaust gas of the burner 260 is a gas rich in CO2 with a high concentration of carbon dioxide due to the combustion reaction, but there is still a small amount of unreacted fuel (for example, H2, CO, etc.) remaining therein. Therefore, by sending a part of the burner exhaust gas that has passed through the reformer 220 and the first air heat exchanger 240 back to the burner to pass through the combustion process, the residual unreacted fuel is additionally converted into carbon dioxide. That is, each time the burner exhaust gas is recycled, the burner exhaust gas becomes a gas richer in CO2. And the carbon capturer 20 can more easily capture carbon dioxide for a gas richer in CO2.

[0071] Second, the exhaust gas of the burner 260 is cooled by heat exchange while passing through the reformer 220 and the first air heat exchanger 240. Therefore, by recycling the inert gas such as carbon dioxide contained in the exhaust gas of the burner 260 to the burner 260, the effect of adjusting the temperature of the burner 260 or preventing overheating can be expected.

[0072] Third, compared with the case where the exhaust gas of the SOE and the exhaust gas of the fuel electrode of the stack are input as fuel to the burner 160 of Example 1, in the burner 260 of Example 2, in addition to the exhaust gas of the SOE and the exhaust gas of the fuel electrode of the stack, the burner exhaust gas branched by the second distributor D2 is further input. Therefore, due to the recirculation of the burner exhaust gas, the flow rate (mass) flowing from the burner 260 into the reformer 220 and the first air heat exchanger 240 increases, so the heat exchange efficiency is increased.

[0073] <Example 3>

[0074] Example 3 is not about sending all the exhaust gas (oxygen) of the solid oxide electrolysis cell 10 to the burner as compared with Example 1 or Example 2. Instead, it relates to a technique in which a part of the exhaust gas of the electrolysis cell 10 is sent to the burner 360, and the rest is merged with the external air flowing into the air electrode of the stack. According to Example 3, by increasing the concentration of oxygen flowing into the air electrode of the stack, the electrical production efficiency of the solid oxide fuel cell can be increased.

[0075] Example 3 can also be understood as a modified example further including a third distributor D3 and a third confluence C3 in Example 1, and can also be understood as a modified example further including a third distributor D3 and a third confluence C3 in Example 2. FIG. 4 is a diagram showing a modified example further including a third distributor D3 and a third confluence C3 in Example 1.

[0076] As shown in FIG. 4, the hybrid system of Example 3 includes a solid oxide electrolysis cell 10, a solid oxide fuel cell 300, and a carbon capture device 20. The solid oxide fuel cell 300 includes a stack 310, a reformer 320, a fuel heat exchanger 330, a first air heat exchanger 340, a second air heat exchanger 350, a burner 360, a first distributor D1, a third distributor D3, a first confluence C1, a third confluence C3, and a controller (not shown).

[0077] The technical configurations of the solid oxide type electrolytic cell 10, stack 310, reformer 320, fuel heat exchanger 330, first air heat exchanger 340, second air heat exchanger 350, burner 360, first distributor D1, first confluence unit C1, controller (not shown), and carbon capturer 20 of Example 3 are fundamentally the same as those of the electrolytic cell 10, stack 110, reformer 120, fuel heat exchanger 130, first air heat exchanger 140, second air heat exchanger 150, burner 160, first distributor D1, first confluence unit C1, controller (not shown), and carbon capturer 20 of Example 1. Therefore, only the differences will be additionally described here.

[0078] The third distributor D3 is arranged at the outlet end of the solid oxide type electrolytic cell 10, branches a part of the exhaust gas (SOE offgas) of the solid oxide type electrolytic cell 10 to the burner 360, and merges the remainder with the external air flowing into the air electrode of the stack.

[0079] The third confluence unit C3 is arranged between the first air heat exchanger 340 and the second air heat exchanger 350, and merges the external air passing through the first air heat exchanger 340 and the exhaust gas (SOE offgas) of the solid oxide type electrolytic cell 10 branched by the third distributor D3. Then, the merged mixed gas is input to the air electrode of the stack 310 via the second air heat exchanger 350.

[0080] As a modified example, the third confluence unit C3 can also be arranged between the second air heat exchanger 350 and the air electrode of the stack 310. In this case, the external air heated by the second air heat exchanger 350 and the exhaust gas of the electrolytic cell 10 branched by the second distributor D2 merge at the third confluence unit C3 and are input to the air electrode of the stack 310.

[0081] Since the exhaust gas of the electrolytic cell 10 contains oxygen, the more the electrolytic cell exhaust gas is distributed from the third distributor D3 to the burner 360 by the burner 360, the more the combustion of the burner is activated, and the higher the purity of the carbon dioxide contained in the burner exhaust gas becomes. Therefore, the carbon dioxide capture rate of the carbon capture device 20 increases. The more the electrolytic cell exhaust gas is distributed to the air heat exchanger 340 or 350 side by the third distributor D3, the more the amount of oxygen input to the air electrode of the stack increases, so the electrical output of the stack increases.

[0082] Therefore, the controller (not shown) determines the distribution ratio to the burner 360 or the air heat exchanger 340 or 350 according to the carbon dioxide capture amount or the electrical output set in the hybrid system, and transmits a control signal including the determined distribution ratio to the third distributor D3.

[0083] <Example 4>

[0084] Example 4 relates to a technique in which, compared with Examples 1 to 3, not all of the exhaust gas of the burner is sent to the reformer, but a part of the exhaust gas of the burner is recycled to the solid oxide electrolytic cell, and the rest is sent to the reformer.

[0085] Example 4 can also be understood as a modified example further including a fourth distributor D4 in Example 1, and can also be understood as a modified example further including a fourth distributor D4 in Example 2. FIG. 5 is a diagram showing a modified example further including a fourth distributor D4 in Example 1.

[0086] As shown in FIG. 5, the hybrid system of Example 4 includes a solid oxide electrolytic cell 10, a solid oxide fuel cell 400, and a carbon capture device 20. The solid oxide fuel cell 400 includes a stack 410, a reformer 420, a fuel heat exchanger 430, a first air heat exchanger 440, a second air heat exchanger 450, a burner 460, a first distributor D1, a fourth distributor D4, a first confluence unit C1, and a controller (not shown).

[0087] The technical configurations of the solid oxide electrolysis cell 10, stack 410, reformer 420, fuel heat exchanger 430, first air heat exchanger 440, second air heat exchanger 450, burner 460, first distributor D1, first confluence C1, controller (not shown), and carbon capturer 20 in Example 4 are basically the same as those of the electrolysis cell 10, stack 110, reformer 120, fuel heat exchanger 130, first air heat exchanger 140, second air heat exchanger 150, burner 160, first distributor D1, first confluence C1, controller (not shown), and carbon capturer 20 in Example 1. Therefore, only the differences will be additionally described here.

[0088] The fourth distributor D4 is arranged downstream of the burner 460.

[0089] The fourth distributor D4 recirculates a part of the exhaust gas of the burner 460 back to the solid oxide electrolysis cell 10 and branches the rest to the reformer 420.

[0090] The solid oxide electrolysis cell 10 receives thermal energy by sending the high-temperature burner exhaust gas branched by the fourth distributor D4 to at least one heat exchanger included in the electrolysis cell.

[0091] The more burner exhaust gas is distributed to the electrolysis cell 10 by the fourth distributor D4, the more the electrolysis cell is activated and the higher the hydrogen production amount. The more burner exhaust gas is distributed to the reformer 420 side by the fourth distributor D4, the higher the efficiency of the fuel cell 400, and thus the higher the electrical output.

[0092] Therefore, the controller (not shown) determines the distribution ratio to the electrolysis cell 10 or the reformer 420 according to the hydrogen production amount or electrical output set for the hybrid system, and transmits a control signal including the determined distribution ratio to the fourth distributor D4.

[0093] <Example 5>

[0094] Example 5 relates to the technology that combines all of Examples 1 to 4.

[0095] As shown in FIG. 6, the hybrid system of Example 5 includes a solid oxide electrolysis cell 10, a solid oxide fuel cell 500, and a carbon capturer 20. The solid oxide fuel cell 500 includes a stack 510, a reformer 520, a fuel heat exchanger 530, a first air heat exchanger 540, a second air heat exchanger 550, a burner 560, a first distributor D1, a second distributor D2, a third distributor D3, a fourth distributor D4, a first mixer C1, a second mixer C2, a third mixer C3, and a controller (not shown).

[0096] The technical configurations of the solid oxide electrolysis cell 10, stack 510, reformer 520, fuel heat exchanger 530, first air heat exchanger 540, second air heat exchanger 550, burner 560, first distributor D1, first mixer C1, controller (not shown), and carbon capturer 20 of Example 5 are the same as those of the electrolysis cell 10, stack 110, reformer 120, fuel heat exchanger 130, first air heat exchanger 140, second air heat exchanger 150, burner 160, first distributor D1, first mixer C1, controller (not shown), and carbon capturer 20 of Example 1.

[0097] Also, the second distributor D2, second mixer C2, and controller (not shown) of Example 5 are the same as those of the second distributor D2, second mixer C2, and controller (not shown) of Example 2. The third distributor D3, third mixer C3, and controller (not shown) of Example 5 are the same as those of the third distributor D3, third mixer C3, and controller (not shown) of Example 3. The fourth distributor D4 and controller (not shown) of Example 5 are the same as those of the fourth distributor D4 and controller (not shown) of Example 4.

[0098] Above, several embodiments of the present invention have been described with reference thereto. However, it will be understandable to those having ordinary knowledge in the relevant technical field that the present invention can be variously modified and changed without departing from the spirit and scope of the present invention described in the following claims.

Claims

1. A solid oxide electrolytic cell (Solid Oxide Electrolyte, SOE), A reformer, a fuel heat exchanger (fuel HX) for heating the fuel produced by the reformer, a first air heat exchanger (air HX_A) for primary heating of external air (air), a second air heat exchanger (air HX_B) for secondary heating of the primary heated external air, an anode receiving the fuel heated by the fuel heat exchanger, and a cathode receiving the external air (air) heated by the first air heat exchanger and the second air heat exchanger, including a stack, and a burner for burning all of the fuel electrode exhaust gas of the stack by using oxygen contained in the exhaust gas of the solid oxide electrolytic cell, a solid oxide fuel cell (Solid Oxide Fuel Cell, SOFC) including; A carbon capture system (CCS) for capturing carbon dioxide from the exhaust gas of the burner heat-exchanged by the reformer and the first air heat exchanger; A first distributor for branching at least a part of the air electrode exhaust gas of the stack to the second air heat exchanger and branching the remaining part to the fuel heat exchanger; An SOE-SOFC-CCS hybrid system including.

2. The exhaust gas of the burner is heat-exchanged by a steam generator of the reformer, and the SOE-SOFC-CCS hybrid system according to claim 1.

3. A temperature sensor (A) for measuring the temperature of the external air passing through the first air heat exchanger; A controller for transmitting a control signal including a distribution ratio to the second air heat exchanger and the fuel heat exchanger to the first distributor based on the measured value of the temperature sensor (A), and the SOE-SOFC-CCS hybrid system according to claim 1.

4. The SOE - SOFC - CCS hybrid system according to claim 1, further comprising a second distributor that branches at least a part of the exhaust gas of the burner via the first air heat exchanger to the burner and branches the remaining part after branching to the carbon capturer.

5. A temperature sensor (B) for measuring the temperature of the burner, The SOE - SOFC - CCS hybrid system according to claim 4, further comprising a controller that transmits a control signal including a distribution ratio to the burner and the carbon capturer to the second distributor based on the measured value of the temperature sensor (B).

6. A solid oxide electrolytic cell (Solid Oxide Electrolyte, SOE), A reformer, a fuel heat exchanger (fuel HX) for heating the fuel produced by the reformer, a first air heat exchanger (air HX_A) for primarily heating external air (air), a second air heat exchanger (air HX_B) for secondarily heating the primarily heated external air, a stack including an anode that receives the fuel heated by the fuel heat exchanger and a cathode that receives the external air (air) heated by the first air heat exchanger and the second air heat exchanger, and a burner (burner) that burns the fuel electrode exhaust gas of the stack using oxygen contained in the exhaust gas of the solid oxide electrolytic cell, a solid oxide fuel cell (Solid Oxide Fuel Cell, SOFC) including; A carbon capturer (carbon capture system, CCS) that captures carbon dioxide from the exhaust gas of the burner heat - exchanged by at least one of the reformer and the first air heat exchanger, A second distributor that branches at least a part of the exhaust gas of the burner via the first air heat exchanger to the burner and branches the remaining part after branching to the carbon capturer, A temperature sensor (B) for measuring the temperature of the burner, A SOE-SOFC-CCS hybrid system comprising a controller that transmits a control signal including a distribution ratio to the burner and the carbon capturer to the second distributor based on the measured value of the temperature sensor (B). **Claim 7** The SOE-SOFC-CCS hybrid system according to claim 1, further comprising a third distributor configured to branch at least a part of the exhaust gas of the solid oxide electrolytic cell to merge with external air and branch the remaining part to the burner. **Claim 8** A solid oxide electrolytic cell (Solid Oxide Electrolyte, SOE), a reformer, a fuel heat exchanger (fuel HX) for heating the fuel produced by the reformer, a first air heat exchanger (air HX_A) for primarily heating external air (air), a second air heat exchanger (air HX_B) for secondarily heating the primarily heated external air, a stack including an anode that receives the fuel heated by the fuel heat exchanger and a cathode that receives the external air (air) heated by the first air heat exchanger and the second air heat exchanger, and a burner (burner) that burns the fuel electrode exhaust gas of the stack using oxygen contained in the exhaust gas of the solid oxide electrolytic cell, a solid oxide fuel cell (Solid Oxide Fuel Cell, SOFC) including: a carbon capture system (carbon capture system, CCS) that captures carbon dioxide from the exhaust gas of the burner heat-exchanged by at least one of the reformer and the first air heat exchanger; A SOE-SOFC-CCS hybrid system comprising a third distributor configured to branch at least a part of the exhaust gas of the solid oxide electrolytic cell to merge with the external air and branch the remaining part to the burner. **Claim 9** The SOE-SOFC-CCS hybrid system according to claim 1, further comprising a fourth distributor that branches at least a part of the exhaust gas of the burner to the solid oxide electrolytic cell and branches the remaining part after branching to the reformer.

10. A solid oxide electrolytic cell (Solid Oxide Electrolyte, SOE), a reformer, a fuel heat exchanger (fuel HX) that heats the fuel produced by the reformer, a first air heat exchanger (air HX_A) that primarily heats external air (air), a second air heat exchanger (air HX_B) that secondarily heats the primarily heated external air, an anode that receives the fuel heated by the fuel heat exchanger, and a stack including a cathode that receives the external air (air) heated by the first air heat exchanger and the second air heat exchanger, and a burner that burns the fuel electrode exhaust gas of the stack using oxygen contained in the exhaust gas of the solid oxide electrolytic cell. A solid oxide fuel cell (Solid Oxide Fuel Cell, SOFC) including: A carbon capture system (carbon capture system, CCS) that captures carbon dioxide from the exhaust gas of the burner heat-exchanged by at least one of the reformer and the first air heat exchanger; An SOE-SOFC-CCS hybrid system comprising a fourth distributor that branches at least a part of the exhaust gas of the burner to the solid oxide electrolytic cell and branches the remaining part after branching to the reformer.

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