JP2020030892A - Carbon recovery type fuel battery power generation system - Google Patents

Abstract

To provide a carbon recovery type fuel battery power generation system capable of greatly simplifying a transport and fixation process for high efficiency by inhibiting discharge of carbon dioxide gas by converting carbon dioxide generated due to power generation of a fuel battery to carbon.SOLUTION: A fuel battery power generation system 10 includes: a first fuel battery cell stack 12 and a second fuel battery cell stack 14 that generate power using fuel gas containing a carbon compound and supplied to a fuel electrode and oxidant gas containing oxygen and supplied to an air electrode and discharge off-gas; a condenser 26 for separating carbon dioxide gas from the off-gas; a water electrolysis device 70 for performing electrolysis on water to generate hydrogen gas; and a powder carbon generator 78 for making the carbon dioxide gas from the condenser 26 react with the hydrogen gas from the water electrolysis device 70 on a catalyst to generate carbon.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a carbon-recovery fuel cell power generation system, and more particularly to a carbon-recovery fuel cell power generation system capable of generating power using a carbon compound fuel and recovering carbon dioxide generated as a result of the power generation into carbon.

  When a carbon compound fuel is used in a fuel cell power generation system, the exhaust gas discharged from the fuel cell contains carbon dioxide gas. Since carbon dioxide gas is one of the causes of global warming, it has been considered to separate and collect carbon dioxide gas from exhaust gas and store it so that it is not released into the atmosphere.

  As for the storage of carbon dioxide gas, CCS (Carbon Capture and Storage) which collects carbon dioxide gas and stores and fixes the collected carbon dioxide gas in the ground etc., and stores the collected carbon dioxide gas in the ground etc. While fixed, EOR (Enhanced Oil Recovery) to increase crude oil recovery from depleted oil fields, EGR (Enhanced Gas Recovery) to increase natural gas recovery from depleted gas fields, and injection of methane by injection into coal seams It is known to use it for ECBM (Enhanced Coal Bed Methane) for free recovery.

  A method of burying carbon dioxide gas in the ground or injecting it into the sea floor for treatment is described in Patent Document 1, for example.

JP 2013-196890 A

  However, in any of the above-mentioned CCSs including EOR, EGR, ECBM, etc., the transport of carbon dioxide to the storage site is performed by transporting carbon dioxide gas by pipeline or by converting carbon dioxide gas into liquefied carbon dioxide and transporting it by lorry. In order to construct a power generation system compatible with CCS, a system capable of efficiently separating and recovering carbon dioxide gas generated during power generation and storing the recovered carbon dioxide gas efficiently is also assumed to be transported by It is desirable to construct

In addition, for CCS and BECCS, locations where carbon dioxide gas can be injected and stored are limited (for example, in Japan, there are few oil and gas fields suitable for EOR and EGS, so liquefaction to overseas storage sites such as Australia) (It is assumed that carbon dioxide will be transported and carbon dioxide gas will be injected and stored underground by injection pumps.) In addition, in the case of aquifer storage, there is a risk of aquifer pollution and release risks associated with earthquakes and nearby fluctuations. Even in the case of marine storage, there are concerns about the impact on the marine ecosystem and the risk of releasing stored carbon dioxide gas due to crustal deformation, and there is room for improvement.
Transporting and injecting and storing carbon dioxide gas and liquefied carbon dioxide consumes a great deal of energy and increases costs. In the fields of carbon dioxide gas separation and recovery, fixation and effective utilization, it is said that CO ₂ separation and recovery accounts for 60 to 70% of the total CCS cost, and CO ₂ fixation cost accounts for 30 to 40%. Therefore, simplification and high efficiency in each of the separation and recovery of carbon dioxide gas and immobilization are extremely important technical issues.

  The present invention has been made in consideration of the above facts, and efficiently separates and recovers carbon dioxide generated by power generation of a fuel cell, converts the carbon dioxide into carbon that can be easily transported and fixed, and converts the carbon dioxide gas into the atmosphere. It is an object of the present invention to provide a carbon-recovery-type fuel cell power generation system capable of suppressing the emission of carbon.

  According to the first aspect of the present invention, the fuel cell power generation system generates power by using a fuel gas containing a carbon compound and supplied to a fuel electrode and an oxidizing gas containing oxygen and supplied to an air electrode to discharge off-gas. A fuel cell, a carbon dioxide gas separation unit that separates carbon dioxide gas from the off-gas, a water electrolysis device that electrolyzes water to generate hydrogen gas, and the carbon dioxide gas from the carbon dioxide gas separation unit, A carbon generating unit that reacts the hydrogen gas from the water electrolysis device on a catalyst to generate carbon and water vapor.

In the carbon-recovery fuel cell power generation system according to claim 1, the fuel cell generates power by the fuel gas supplied to the fuel electrode and the oxidant gas supplied to the air electrode, and discharges off-gas.
The carbon dioxide gas is separated from the off gas discharged from the fuel cell in the carbon dioxide gas separation unit.
The water electrolysis device electrolyzes water to generate hydrogen gas.
The carbon generator reacts the carbon dioxide gas separated by the carbon dioxide gas separator with the hydrogen gas generated by the water electrolysis device on a catalyst to generate carbon (solid) and water vapor.
Thus, in the carbon recovery fuel cell power generation system according to the first aspect, carbon dioxide gas generated by power generation can be recovered as solid carbon.
Capturing with solid carbon reduces carbon dioxide emissions to the atmosphere, greatly simplifies the process of transporting and immobilizing, and increases efficiency compared to capturing carbon dioxide as is. Can be.

  According to a second aspect of the present invention, in the carbon recovery fuel cell power generation system according to the first aspect, the water electrolysis device is configured to generate electric power generated by a renewable energy power generation device and electric power generated by the fuel cell. The water is electrolyzed by at least one of the following.

  In the carbon recovery fuel cell power generation system according to claim 2, the water electrolyzer electrolyzes water by at least one of the power generated by the renewable energy power generation device and the power generated by the fuel cell, It is not necessary to use the electric power generated by the power generation device that emits carbon dioxide gas in association with the power generation, and the emission of carbon dioxide gas into the atmosphere can be suppressed.

  According to a third aspect of the present invention, in the carbon recovery fuel cell power generation system according to the first or second aspect, the carbon dioxide gas separation unit separates the carbon dioxide gas and water from the off-gas, In the water electrolysis device, the water separated by the carbon dioxide gas separation unit is used.

  In the carbon-recovery fuel cell power generation system according to claim 3, since the water electrolyzer uses the water separated by the carbon dioxide gas separation unit for electrolysis, there is no need to supply water from an external water supply or the like. External dependence can be reduced.

  According to a fourth aspect of the present invention, in the carbon recovery type fuel cell power generation system according to any one of the first to third aspects, a fuel gas containing a carbon compound and supplied to the first fuel electrode, A first fuel cell that generates electric power by using an oxidizing gas supplied to the first air electrode and supplies the first fuel electrode off-gas from the first fuel electrode to the first fuel electrode off-gas flow path; Electric power is generated using the first fuel electrode off gas supplied to the electrode and the oxidant gas supplied to the second air electrode, and the second fuel electrode off gas is supplied from the second fuel electrode to the second fuel electrode off gas flow path. A fuel cell including a second fuel cell for sending out, an air electrode off gas flow path for sending out an air electrode off gas from at least one of the first air electrode and the second air electrode, and the air electrode off gas The air electrode off-gas is supplied And an oxygen separator for separating oxygen from the air electrode off-gas, and the second fuel electrode off-gas is supplied, and the oxygen separated by the oxygen separator is supplied, and the second fuel electrode off-gas is A combustion unit for performing a combustion reaction by oxygen, and an exhaust heat input type absorption refrigerator or an adsorption refrigerator for cooling water by using the off-gas as a heat source to generate cooling water, and the carbon dioxide gas separation. The unit cools the combustion off-gas sent from the combustion unit with the cooling water to separate carbon dioxide gas and water.

In the fuel cell power generation system according to the fourth aspect, the fuel cell includes the first fuel cell and the second fuel cell.
In the first fuel cell, power is generated by the fuel gas supplied to the first fuel electrode and the oxidant gas supplied to the first air electrode. In the second fuel cell, power generation is performed by the first fuel electrode off-gas supplied from the first fuel electrode to the second fuel electrode and the oxidant gas supplied to the second air electrode.

  At least one of the first air electrode and the second air electrode sends out the air electrode off-gas to the air electrode off-gas flow path, and supplies the air electrode off-gas to the oxygen separation unit via the air electrode off-gas flow path. In the oxygen separation section, oxygen is separated from the air electrode off-gas, and the separated oxygen is supplied to the combustion section.

  Further, the second fuel electrode sends the second fuel electrode off-gas to the fuel electrode off-gas flow path, and supplies the second fuel electrode off-gas to the combustion unit via the fuel electrode off-gas flow path. In the combustion section, a combustion reaction occurs between the combustible component in the second fuel electrode off-gas and oxygen, and the combustion off-gas is delivered from the combustion section.

  The combustion off-gas is sent to the carbon dioxide separation unit, and carbon dioxide is separated from the combustion off-gas.

  In the fuel cell power generation system according to the fourth aspect, since the second fuel electrode off-gas after being sent from the second fuel cell is burned in the combustion unit, the first fuel electrode off-gas is supplied to the first fuel cell before being used for power generation by the second fuel cell. The amount of unreacted fuel gas supplied to the second fuel cell is larger than in the case where the fuel electrode off-gas is burned. Therefore, the power generation efficiency of the second fuel cell can be improved.

  Further, in the combustion section, carbon dioxide and water vapor are generated by a combustion reaction between the combustible component contained in the second fuel electrode offgas and oxygen. Therefore, the combustible gas can be reduced from the second fuel electrode off-gas, and high-concentration carbon dioxide can be recovered.

  Further, the amount of unreacted fuel gas contained in the second fuel electrode offgas is smaller than that of the first fuel electrode offgas, and the carbon dioxide content is higher. Therefore, it is possible to reduce the amount of burning the unreacted fuel gas in the combustion section, and to reduce the amount of oxygen required to burn the unreacted fuel gas.

  In addition, since the exhaust heat input type absorption refrigerator or the adsorption refrigerator is driven by using the air electrode off-gas discharged from the fuel cell as a driving heat source to cool water, the exhaust heat of the off-gas is effectively used. be able to. An exhaust heat absorption type absorption chiller or adsorption chiller can effectively use exhaust heat to supply cold heat, so a compressor that is driven by a motor to compress and expand the refrigerant to generate cold heat. Water can be efficiently cooled with less electric power and used as cooling water as compared with the case of generating water.

  According to a fifth aspect of the present invention, in the carbon recovery type fuel cell power generation system according to the fourth aspect, the first fuel cell and the second fuel cell are a hydrogen ion conductive solid oxide fuel cell (PCFC). : Proton Conducting Solid Oxide Fuel Cell).

  In a hydrogen ion conductive solid oxide fuel cell, water vapor is generated by a power generation reaction on the air electrode side. Therefore, since the amount of water vapor contained in the first fuel electrode off-gas is reduced, the decrease in the concentration of the fuel gas supplied to the second fuel electrode is small, and the power generation efficiency in the second fuel cell can be improved. Further, since the amount of water vapor contained in the second fuel electrode off-gas is also reduced, the amount of water vapor removed from the second fuel electrode off-gas can be reduced.

  According to a sixth aspect of the present invention, in the carbon recovery fuel cell power generation system according to the fourth or fifth aspect, the water separated by the carbon dioxide gas separation unit is subjected to the exhaust heat input type absorption refrigeration. A supply unit for supplying the cooling water path of the cooling machine or the cooling water path of the adsorption refrigerator to constitute the cooling water of the exhaust heat input absorption refrigerator or the exhaust heat input absorption refrigerator. Part of the cooling water supplementary water of the cooling tower, or part of the cooling water of the adsorption chiller or part of the cooling water supplementary water of the cooling tower constituting the adsorption chiller was separated by the carbon dioxide gas separation unit. The water is used.

  In the carbon-recovery fuel cell power generation system according to claim 6, the water separated by the carbon dioxide gas separation unit is transferred to a cooling water path of an exhaust heat input type absorption refrigerator or a cooling water path of an adsorption refrigerator. It can be supplied by the supply unit. Therefore, when there is a shortage of cooling water in the cooling water path, there is no need to supply water from an external water supply or the like, and the amount of external dependence on water can be reduced.

  According to a seventh aspect of the present invention, in the carbon recovery fuel cell power generation system according to any one of the fourth to sixth aspects, the oxygen separation unit includes an oxygen permeable membrane that selectively transmits oxygen. The combustion section has a combustion space disposed on the permeation side of the oxygen permeable membrane and is integrated with the oxygen separation section.

  According to the carbon recovery type fuel cell power generation system of the seventh aspect, the combustion section can be arranged adjacent to the oxygen permeable membrane of the oxygen separation section, and the combustion section and the oxygen separation section can be made compact.

  The invention according to claim 8 is the carbon recovery type fuel cell power generation system according to any one of claims 4 to 6, wherein the oxygen separation unit includes the first fuel cell and the second fuel. It has a high-temperature PSA device driven by electric power generated by a battery.

  According to the carbon recovery fuel cell power generation system according to claim 8, the oxygen separation unit separates oxygen from high-temperature air electrode off-gas by the high-temperature PSA device, so that oxygen can be efficiently separated.

  According to a ninth aspect of the present invention, in the carbon recovery type fuel cell power generation system according to any one of the first to eighth aspects, the carbon dioxide gas separation unit cools the off-gas to produce the carbon dioxide. Gas and water are generated, and the steam generated in the carbon generation unit is supplied to the carbon dioxide gas separation unit via a supply path.

According to the carbon-recovery fuel cell power generation system of the ninth aspect, the off-gas is cooled by the carbon dioxide gas separation unit to generate carbon dioxide gas and water.
The water vapor generated by the carbon generation unit is supplied to the carbon dioxide gas separation unit via the supply path, and the water vapor is cooled by the carbon dioxide gas separation unit to generate water.
Therefore, in the carbon dioxide gas separation unit, water generated by the off-gas and water generated by cooling the steam are obtained, and the amount of water generated in the system can be increased. The amount of hydrogen gas generated in the water splitter can also be increased.

  According to a tenth aspect of the present invention, in the carbon recovery type fuel cell power generation system according to any one of the first to ninth aspects, the carbon generated in the carbon generation unit is made of graphite, carbon nanotube, or diamond. And a carbon product manufacturing apparatus.

  In the carbon-recovery fuel cell power generation system according to claim 10, the carbon generated by the carbon generation unit is harder to burn than carbon, and can be used for commercial and industrial purposes while being stably fixed for a long period of time. Nanotubes or diamonds can be used, and safe and long-term stable effective utilization and immobilization of carbon dioxide gas can be realized.

  ADVANTAGE OF THE INVENTION According to the carbon-recovery-type fuel cell power generation system according to the present invention, carbon dioxide generated during power generation of the fuel cell can be converted into carbon, and carbon can be fixed more easily and for a longer period of time than carbon dioxide gas storage. it can.

1 is a schematic diagram of a fuel cell power generation system according to a first embodiment. It is a block diagram of a control system of the fuel cell power generation system according to the first embodiment. It is a flowchart of the flow rate adjustment processing of the first embodiment. It is a flow chart of cooling water temperature adjustment processing of a 1st embodiment. It is a schematic diagram of a fuel cell power generation system according to a second embodiment. It is a schematic diagram of a fuel cell power generation system according to a third embodiment. It is a schematic diagram of a fuel cell power generation system according to a fourth embodiment. It is a schematic diagram of a fuel cell power generation system according to a fifth embodiment. It is a schematic diagram of a fuel cell power generation system according to a sixth embodiment. It is a schematic diagram of a fuel cell power generation system according to a seventh embodiment. It is a schematic diagram of a fuel cell power generation system according to an eighth embodiment. It is a schematic diagram of a fuel cell power generation system according to a ninth embodiment. It is a schematic diagram of a fuel cell power generation system according to a modification of the first embodiment.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 shows a fuel cell power generation system 10A according to a first embodiment as an example of a carbon dioxide capture type fuel cell power generation system of the present invention. The fuel cell power generation system 10A mainly includes a first fuel cell stack 12, a second fuel cell stack 14, a combustor 20 with an oxygen permeable membrane, a condenser 26, a first heat exchanger 30, and a second heat exchanger. An exchanger 32, an exhaust heat input type absorption refrigerator 36, a water tank 27, a carbon production section 66, and the like are provided, and these are provided on-site. Further, as shown in FIG. 2, the fuel cell power generation system 10A includes a control unit 40 for controlling the fuel cell power generation system 10A.

  As shown in FIG. 1, the first fuel cell stack 12 is a proton-conducting solid oxide fuel cell (PCFC), which is an electrolyte layer 12 </ b> C and a table of the electrolyte layer 12 </ b> C. It has a first fuel electrode (fuel electrode) 12A and a first air electrode (air electrode) 12B that are respectively stacked on the back surface.

  The basic configuration of the second fuel cell stack 14 is the same as that of the first fuel cell stack 12, and the second fuel electrode 14A corresponding to the first fuel electrode 12A and the second fuel electrode 14B corresponding to the first air electrode 12B. It has two air electrodes 14B and an electrolyte layer 14C corresponding to the electrolyte layer 12C.

  One end of a fuel gas pipe P1 is connected to the first fuel electrode 12A of the first fuel cell stack 12, and the other end of the fuel gas pipe P1 is connected to a fuel gas source (not shown). From the fuel gas source, fuel gas is delivered to the first fuel electrode 12A by the fuel supply blower B1. In this embodiment, methane is used as the fuel gas. However, the fuel gas is not particularly limited as long as it can generate hydrogen by reforming, and a hydrocarbon fuel can be used. Examples of the hydrocarbon fuel include natural gas, LP gas (liquefied petroleum gas), biogas, coal reformed gas, and lower hydrocarbon gas. Examples of the lower hydrocarbon gas include lower hydrocarbons having 4 or less carbon atoms, such as methane, ethane, ethylene, propane, and butane. Methane used in the present embodiment is preferable. The hydrocarbon fuel may be a mixture of the above-mentioned lower hydrocarbon gas, and the above-mentioned lower hydrocarbon gas may be a gas such as natural gas, city gas, or LP gas. If the source gas contains impurities, a desulfurizer or the like is required, but is omitted in the figure.

  A steam pipe P2 is connected to the fuel gas pipe P1 so that steam is appropriately fed from a steam source (not shown) at the time of starting or stopping. Methane and water vapor are combined at the fuel gas pipe P1 and supplied to the first fuel electrode 12A. In the present embodiment, since a part of the second fuel electrode off-gas is returned to the first fuel electrode 12A and the steam is reused as described later, the steam from the steam pipe P2 is discharged from the fuel cell power generation system 10A. In the start-up and stop processes, the water is supplementarily supplied when necessary.

  At the first fuel electrode 12A, as shown in the following equation (1), the fuel gas is subjected to steam reforming to generate hydrogen and carbon monoxide. Further, as shown in the following equation (2), carbon dioxide and hydrogen are generated by a shift reaction between the generated carbon monoxide and water vapor.

CH ₄ + H ₂ O → 3H ₂ + CO (1)
CO + H ₂ O → CO ₂ + H ₂ (2)

  Then, at the first fuel electrode 12A, hydrogen is separated into hydrogen ions and electrons as shown in the following equation (3).

(Fuel electrode reaction)
H ₂ → 2H ⁺ + 2e ⁻ (3)

  The hydrogen ions move to the first air electrode 12B through the electrolyte layer 12C. The electrons move to the first cathode through an external circuit (not shown). Thereby, power is generated in the first fuel cell stack 12. During power generation, the first fuel cell stack 12 generates heat.

  The oxidizing gas (air) is supplied to the first air electrode 12B of the first fuel cell stack 12 from the oxidizing gas pipe P5. Air is introduced into the oxidizing gas pipe P5 by an oxidizing gas blower B2. The oxidizing gas pipe P5 is provided with a second heat exchanger 32, and the air flowing through the oxidizing gas pipe P5 is heated by heat exchange with an air electrode off-gas flowing through an air electrode off-gas pipe P6 described later. The heated air is supplied to the first air electrode 12B.

  At the first air electrode 12B, as shown in the following equation (4), hydrogen ions that have moved from the first fuel electrode 12A through the electrolyte layer 12C and electrons that have moved from the first fuel electrode 12A through the external circuit are: Reacts with oxygen in the oxidant gas to generate water vapor.

(Air cathode reaction)
2H ⁺ + 2e ⁻ + ＯO ₂ → H ₂ O (4)

  An air electrode off-gas pipe P6 is connected to the first air electrode 12B. The air electrode off-gas is discharged from the first air electrode 12B to the air electrode off-gas pipe P6. Note that the oxidizing gas pipe P5 and the air electrode off-gas pipe P6 are similarly connected to the second air electrode 14B, and the first air electrode 12B and the second air electrode 14B are connected in parallel.

  One end of a first fuel electrode off-gas pipe P7 is connected to the first fuel electrode 12A of the first fuel cell stack 12, and the other end of the first fuel electrode off-gas pipe P7 is connected to the first fuel electrode off-gas pipe P7. Two fuel electrodes 14A are connected. The first fuel electrode off-gas is sent from the first fuel electrode 12A to the first fuel electrode off-gas pipe P7. The fuel electrode off-gas contains unreformed fuel gas components, unreacted hydrogen, unreacted carbon monoxide, carbon dioxide, water vapor, and the like.

  One end of a second fuel electrode off-gas pipe P7-2 is connected to the second fuel electrode 14A of the second fuel cell stack 14, and the second fuel electrode off-gas is delivered from the second fuel electrode 14A. The other end of the second fuel electrode off-gas pipe P7-2 is connected to the combustor 20 with the oxygen permeable membrane. A circulating gas pipe P3 is branched from the second fuel electrode off-gas pipe P7-2, and the circulating gas pipe P3 is connected to a fuel gas pipe P1 connected to the first fuel electrode 12A. A circulation gas blower B3 is provided in the circulation gas pipe P3.

  In the second fuel cell stack 14, a power generation reaction similar to that of the first fuel cell stack 12 is performed, and the air electrode off-gas is sent from the second air electrode 14B to the air electrode off-gas pipe P6. The air electrode off-gas pipe P6 connected to the second air electrode 14B is branched upstream from a junction with the air electrode off-gas pipe P6 connected to the first air electrode 12B, and the branched air electrode off-gas pipe P6 is formed. -2 is formed. The branch air electrode off-gas pipe P6-2 is provided with a flow rate adjusting valve 42 capable of adjusting the flow rate. The flow control valve 42 is connected to the control unit 40. The flow rate adjusting valve 42 is controlled by the control unit 40, and adjusts the flow rate of the air electrode off-gas branched to the branch air electrode off-gas pipe P6-2. The downstream end of the branch air electrode off-gas pipe P6-2 is connected to the combustor 20 with an oxygen permeable membrane.

(Combustor with oxygen permeable membrane)
The combustor 20 with an oxygen permeable membrane has a multi-cylindrical shape, and has a combustion part 22 forming an outer peripheral cylinder of the multi-cylinder, and an oxygen separation part 24 arranged radially inside the combustion part 22. . A combustion space 22 </ b> A is formed in the combustion section 22.

  The oxygen separation unit 24 is disposed radially inside the combustion unit 22 and has an air flow passage 24A formed adjacent to the combustion space 22A. The air passage 24A and the combustion space 22A are separated by an oxygen permeable film 23. As the oxygen permeable film 23, for example, a mixed conductive ceramic of electrons and oxygen ions such as LSCF or a dense ceramic film of oxygen ions conductive such as YSZ can be used. The other end of the second fuel electrode off-gas pipe P7-2 is connected to the inlet of the combustion space 22A, and the downstream end of the branch air electrode off-gas pipe P6-2 is connected to the inlet of the air flow path 24A. An oxidation catalyst is arranged inside the combustion space 22A. As the oxidation catalyst, for example, nickel or ruthenium can be used.

  The second air electrode off-gas is supplied to the air flow path 24A, and oxygen contained in the second air electrode off-gas passes through the oxygen permeable membrane 23 and moves to the combustion space 22A. The second air electrode off-gas that does not move to the combustion space 22A is exhausted to the outside from an exhaust pipe P12 connected to the outlet side of the air flow path 24A.

  The second fuel electrode off-gas is supplied to the combustion space 22A, and is mixed with the oxygen that has passed through the oxygen permeable membrane 23 from the oxygen separator 24 and moved. Thus, a combustion reaction occurs between the combustible gas components (unreformed methane, unreacted hydrogen, unreacted carbon monoxide, etc.) and oxygen in the second fuel electrode off-gas via the oxidation catalyst, and carbon dioxide is generated. And steam are generated. The combustion off-gas pipe P8 is connected to the outlet side of the combustion space 22A, and the combustion off-gas is discharged from the combustion space 22A.

  The other end of the combustion off-gas pipe P8 is connected to the condenser 26 via the first heat exchanger 30. In the first heat exchanger 30, the fuel gas is heated by heat exchange between the fuel gas and the combustion off-gas. The condenser 26 is provided with a cooling water circulation flow path 26A, and cooling water from an exhaust heat input type absorption refrigerator 36 to be described later is circulated and supplied by driving a pump 26P to cool the combustion off-gas. Thereby, the water vapor in the combustion off-gas condenses. The condensed water is sent out to the water tank 27 via the water pipe P9.

  The combustion off-gas from which the water vapor has been separated and removed is sent to a carbon dioxide gas pipe P10. The combustion offgas from which water (liquid phase) has been removed by the condenser 26 is a gas having a high carbon dioxide concentration, and the combustion offgas is referred to as a carbon dioxide rich gas. A composition detector 44 is provided in the carbon dioxide gas pipe P10. The composition detecting section 44 detects the composition of the carbon dioxide-rich gas sent from the condenser 26. Specifically, at least one of the concentrations of combustible gas such as methane, carbon monoxide, and hydrogen, carbon dioxide, and oxygen is detected. The composition detection unit 44 is connected to the control unit 40, and the composition information of the detected carbon dioxide-rich gas is transmitted to the control unit 40. The control unit 40 performs various controls to increase the concentration of the carbon dioxide gas.

  In addition, a carbon production unit 66 described below is provided downstream of the carbon dioxide gas pipe P10.

  A second heat exchanger 32 is provided downstream of the junction where the air electrode off-gas pipes P6 from the first air electrode 12B and the second air electrode 14B are merged. In the second heat exchanger 32, heat exchange is performed between the air electrode off-gas flowing through the air electrode off-gas pipe P6 and the oxidizing gas flowing through the oxidizing gas pipe P5, the oxidizing gas is heated, and the air electrode off-gas is generated. Cooled. The air electrode off-gas is supplied to the exhaust heat input type absorption refrigerator 36 through the second heat exchanger 32.

(Exhaust heat absorption type absorption refrigerator)
The exhaust heat input type absorption refrigerator 36 is a heat pump that generates cold heat using the exhaust heat, and for example, a steam / exhaust heat input type absorption refrigerator can be used. In a steam / exhaust heat input absorption refrigerator, the absorption liquid (for example, aqueous lithium bromide solution or aqueous ammonia solution) that has absorbed water vapor is heated by the heat of the air electrode off-gas to separate water from the absorption liquid and regenerate it. I do. Water vapor is condensed in the air electrode off-gas cooled by heating the absorbing liquid, and the condensed water is supplied to the water tank 27 through the water pipe P36-2. The air electrode off-gas from which the water vapor has been condensed and removed is sent to the exhaust pipe P36-1, and is exhausted to the outside of the exhaust heat input type absorption refrigerator 36.

  A pump for circulating the absorbing liquid and a pump for circulating the water separated from the absorbing liquid (both not shown) are provided inside the exhaust heat input type absorption refrigerator 36. These pumps are driven by a DC motor, and the DC motor can be driven by the DC power generated by the first fuel cell stack 12 and the second fuel cell stack 14.

  The absorbing liquid regenerated by heating absorbs water vapor to promote the evaporation of water and contributes to the generation of cold. The exhaust heat input type absorption refrigerator 36 is connected to a cooling tower 38 via a heat radiation circuit 37. A pump 37P is provided in the heat radiation circuit 37, and the pump 37P supplies cooling water to the heat radiation circuit 37. Absorbed heat generated when the absorbing liquid absorbs water vapor in the exhaust heat input type absorption refrigerator 36 is released from the cooling tower 38 to the atmosphere via cooling water flowing through the heat radiation circuit 37.

  The cold generated by the exhaust heat input type absorption refrigerator 36 is sent to the condenser 26 through the cooling water flowing through the cooling water circulation channel 26A, and the combustion off-gas is cooled by the condenser 26. Water vapor is condensed and removed.

  The water tank 27 is connected to a cooling water circulation flow path 26A, a heat radiation circuit 37, and a heat medium flow path (not shown) through which water as a heat medium of the exhaust heat input type absorption refrigerator 36 flows. In the cooling water circulation flow path 26A, the heat radiation circuit 37, and the heat medium flow path, when water is insufficient, water is appropriately replenished from the water tank 27.

(Carbon production department 66)
The carbon dioxide-rich gas sent to the carbon dioxide gas pipe P10 is sent to the carbon production unit 66.
The carbon production unit 66 includes a water electrolysis device 70, a pipe P14, a hydrogen blower 72, a pipe P15, an oxygen blower 74, an oxygen tank 76, a powdered carbon generator 78, and the like.

  The water in the water tank 27 via the pipe P16, the pump 80, and the water purification device 82 is supplied to the water electrolysis device 70. The water purification device 82 purifies water from the water tank 27 (removal of foreign substances, pH adjustment, and the like). The water electrolysis device 70 can generate hydrogen gas and oxygen gas by electrolyzing purified water using electric power obtained in the first fuel cell stack 12 and the second fuel cell stack 14. . The water electrolysis device 70 can also electrolyze water using electric power (so-called “clean energy”) obtained by renewable energy power generation (not shown). Examples of renewable energy power generation include photovoltaic power generation, solar thermal power generation, hydroelectric power generation, wind power generation, geothermal power generation, wave power generation, temperature difference power generation, biomass power generation, and the like. Good. That is, from the viewpoint of reducing the carbon dioxide in the atmosphere or suppressing the emission of carbon dioxide to the atmosphere, the DC power obtained by the first fuel cell stack 12 and the second fuel cell It is preferable to use electric power obtained by possible energy generation.

  The water electrolysis device 70 electrolyzes water using the DC power obtained by the first fuel cell stack 12 and the second fuel cell stack 14 and the power obtained by renewable energy power generation. In addition, water can be efficiently electrolyzed as compared with a case where AC power of a power generation device that emits carbon dioxide gas is converted into DC power and used for electrolysis. The water electrolysis device 70 is controlled by a control unit 40 described later.

  The hydrogen gas generated in the water electrolysis device 70 is sent to a powdered carbon generator 78 via a pipe P14 and a hydrogen blower 72, and the oxygen gas is sent to an oxygen tank 76 via a pipe P15 and an oxygen blower 74. It is stored in a tank 76. The hydrogen blower 72 and the oxygen blower 74 are controlled by a control unit 40 described later.

(Configuration of powder carbon generator)
As one example, the powdered carbon generator 78 has a multi-cylindrical shape, a gas flow path 78A formed in an annular shape in plan view, and a carbon fixing portion 78B disposed radially inside the gas flow path 78A. have.
In the carbon fixing section 78B, the carbon dioxide gas sent from the condenser 26 and the hydrogen gas sent from the water electrolysis device 70 are supplied. In the carbon fixing section 78B, a reduction reaction as shown in the following equation (5) is caused by using a catalyst for carbon dioxide gas and hydrogen gas.
CO ₂ + 2H ₂ → C + 2H ₂ O (5)

C generated by the reduction reaction is powdered carbon, and can be discharged from the lower portion of the carbon fixing section 78B. Moreover, H _{2 0} produced in the above reduction reaction is steam Specifically, water vapor is fed to the condenser 26 through a pipe P17.

(Control unit)
The control unit 40 controls the entire fuel cell power generation system 10A, and includes a CPU, a ROM, a RAM, a memory, and the like. The memory stores data, procedures, and the like necessary for a flow rate adjustment process, a cooling water temperature adjustment process, and a process during normal operation, which will be described later. As shown in FIG. 2, the control unit 40 is connected to the flow control valve 42, the composition detection unit 44, the exhaust heat input type absorption refrigerator 36, and the like. The control unit 40 controls the flow control valve 42, the composition detecting unit 44, the exhaust heat input type absorption refrigerator 36, and the like. FIG. 2 shows a part of the connection relationship of the control unit 40 in the fuel cell power generation system 10A, and the control unit 40 is also connected to other devices not shown in FIG.

  In the fuel cell power generation system 10A, a pump, a blower, and other accessories are driven by the power generated by the fuel cell power generation system 10A. In order to efficiently use the electric power generated by the fuel cell power generation system 10A without converting it into a direct current, the auxiliary machine is preferably driven by a direct current.

(Action, effect)
Next, the operation of the fuel cell power generation system 10A of the present embodiment will be described.

  In the fuel cell power generation system 10A, methane is sent from the gas source to the fuel gas pipe P1 by the fuel supply blower B1, is heated by passing through the first heat exchanger 30, and is supplied to the first fuel electrode 12A. From the steam pipe P2, steam for steam reforming is supplied to the first fuel electrode 12A via the fuel gas pipe P1. The supply of steam is performed at the time of startup and at the time of shortage. At the time of rated operation, the steam in the second fuel electrode off-gas returned from the circulation gas pipe P3 is used as described later.

  At the first fuel electrode 12A of the first fuel cell stack 12, the fuel gas is subjected to steam reforming to generate hydrogen and carbon monoxide. In addition, carbon dioxide and hydrogen are generated by a shift reaction between the generated carbon monoxide and water vapor.

  Air is supplied to the first air electrode 12B of the first fuel cell stack 12 via the oxidizing gas pipe P5. In the first fuel cell stack 12, hydrogen ions move in the first fuel electrode 12A and the first air electrode 12B, and the above-described reaction occurs to generate power. From the first fuel electrode 12A of the first fuel cell stack 12, the first fuel electrode off-gas is delivered to the first fuel electrode off-gas pipe P7. Further, the air electrode off-gas is sent from the first air electrode 12B to the air electrode off-gas pipe P6.

  The first fuel electrode off-gas sent from the first fuel electrode 12A is guided to the first fuel electrode off-gas pipe P7 and supplied to the second fuel electrode 14A of the second fuel cell stack 14. Air is supplied to the second air electrode 14B of the second fuel cell stack 14 via the oxidizing gas pipe P5. The second fuel cell stack 14 also generates power similarly to the first fuel cell stack 12. The second fuel electrode off-gas is delivered from the second fuel electrode 14A of the second fuel cell stack 14 to the second fuel electrode off-gas pipe P7-2. Further, the air electrode off-gas is sent from the second air electrode 14B to the air electrode off-gas pipe P6. A part of the air electrode off-gas sent from the second air electrode 14B is branched to the branch air electrode off-gas pipe P6-2, and the other part is combined with the air electrode off-gas sent from the first air electrode 12B.

  The air electrode off-gas is supplied to the exhaust heat input type absorption refrigerator 36 through the second heat exchanger 32. In the second heat exchanger 32, heat exchange is performed between the air electrode off-gas and the oxidizing gas, and the oxidizing gas is heated by the air electrode off-gas. In the exhaust heat input type absorption refrigerator 36, as described above, cold heat is generated using the heat of the air electrode off-gas.

  A part of the second fuel electrode off-gas branches to the circulation gas pipe P3, and is returned to the first fuel electrode 12A. The other second fuel electrode off-gas is supplied to the combustion section 22 of the combustor 20 with the oxygen permeable membrane, and flows through the combustion space 22A.

  The air electrode off-gas branched to the branch air electrode off-gas pipe P6-2 is supplied to the oxygen separator 24 of the combustor 20 with the oxygen permeable membrane. The air electrode off-gas supplied to the oxygen separation unit 24 flows through the air flow path 24A. In the air passage 24A, oxygen contained in the air electrode off-gas passes through the oxygen permeable membrane 23 and moves to the combustion space 22A side. In the combustion space 22A, a combustion reaction of combustible gas (methane, hydrogen, carbon monoxide, etc.) in the second fuel electrode off-gas and oxygen occurs, and carbon dioxide and water vapor are generated. The combustion off-gas containing carbon dioxide and water vapor is sent from the combustion space 22A to the combustion off-gas pipe P8. The combustion off-gas sent to the combustion off-gas pipe P8 is supplied to the condenser 26 via the first heat exchanger 30.

  The combustion off-gas supplied to the condenser 26 is cooled by the cooling water from the exhaust heat input type absorption refrigerator 36 circulated and supplied through the cooling water circulation passage 26A, and the steam in the combustion off-gas is condensed. The condensed water is sent out to the water tank 27 via the water pipe P9 and stored in the water tank 27.

  The combustion off-gas from which the water vapor has been removed by the condenser 26 becomes a carbon dioxide-rich gas having a high carbon dioxide concentration, is sent out to the carbon dioxide gas pipe P10 by the carbon dioxide blower B4, and is sent to the composition detecting section 44. The composition detector 44 detects the composition of the carbon dioxide-rich gas, and transmits the detected information to the controller 40.

  The control unit 40 controls the flow rate adjustment valve 42 based on the composition information transmitted from the composition detection unit 44 to adjust the amount of the air electrode off-gas branched to the branch air electrode off-gas pipe P6-2 and to input the exhaust heat. The temperature of the cooling water sent to the cooling water circulation flow path 26A is controlled by the type absorption refrigerator 36. Specifically, the control unit 40 executes the following flow rate adjustment processing and cooling water temperature adjustment processing.

  As shown in FIG. 3, in the flow rate adjustment processing, in step S10, it is determined whether or not the concentration of the combustible gas is within the threshold value G1 in the composition information of the carbon dioxide-rich gas detected by the composition detection unit 44. Here, the threshold value G1 is a sufficiently low concentration in the carbon dioxide-rich gas, and can be set to about 0.1 to 5 vol%, and more preferably 0.1 to 1 vol%. If the concentration of the combustible gas is higher than the threshold value G1, the flow control valve 42 is controlled in step S12 to increase the flow rate of the air electrode off-gas branched to the branch air electrode off-gas pipe P6-2. Thereby, the amount of oxygen that permeates the oxygen permeable membrane 23 and moves to the combustion space 22A increases, and the combustion reaction in the combustion space 22A can reduce the combustible gas contained in the carbon dioxide-rich gas.

  If the combustible gas concentration is equal to or less than the threshold value G1 in step S10, it is determined in step S14 whether the oxygen concentration is within the threshold value O1 in the composition information of the carbon dioxide-rich gas detected by the composition detection unit 44. Here, the threshold O1 is a sufficiently low concentration in the carbon dioxide-rich gas, and can be set to about 0.1 to 5 vol%, and more preferably 0.1 to 1 vol%. If the oxygen concentration is higher than the threshold value O1, the flow control valve 42 is controlled in step S16 to reduce the flow rate of the air electrode off-gas branched to the branch air electrode off-gas pipe P6-2. Thus, the amount of oxygen that permeates the oxygen permeable film 23 and moves to the combustion space 22A decreases, and oxygen remaining without being subjected to the combustion reaction in the combustion space 22A can be reduced.

  After steps S12, S14, and S16, the process returns to step S10, and the above-described processing is repeated. This flow adjustment process is started when the operation of the fuel cell power generation system 10A is started, is continued during the operation, and ends when the operation is stopped.

  Further, as shown in FIG. 4, in the condensation amount adjustment processing, it is determined in step S20 whether or not the concentration of water vapor is within the threshold M in the composition information of the carbon dioxide rich gas detected by the composition detection unit 44. Here, the threshold value M is a sufficiently low concentration in the carbon dioxide-rich gas, and can be set to about 0.1 to 5 vol%, and more preferably 0.1 to 1 vol%. When the concentration of the water vapor is higher than the threshold value M, in step S22, the condensation is strengthened. Specifically, the exhaust heat input type absorption refrigerator 36 is controlled to lower the temperature of the cooling water sent to the cooling water circulation channel 26A, or to increase the circulation flow rate of the cooling water. As a result, the amount of water separated from the combustion off-gas by condensation in the condenser 26 increases, and the proportion of water vapor contained in the carbon dioxide-rich gas can be reduced.

  After steps S20 and S22, the process returns to step S20, and the above-described processing is repeated. This condensed amount adjustment processing is started when the operation of the fuel cell power generation system 10A is started, is continued during the operation, and ends when the operation is stopped.

The water electrolyzer 70 electrolyzes the water sent from the water purifier 82 to generate hydrogen gas and oxygen gas. The carbon dioxide-rich gas sent to the carbon dioxide gas pipe P10 is sent to the powdered carbon generator 78.
In the carbon fixing section 78B, the carbon dioxide gas sent from the condenser 26 and the hydrogen gas sent from the water electrolysis device 70 are supplied to cause a reduction reaction as shown in the following equation (6).
CO ₂ + 2H ₂ → C + 2H ₂ O (6)

  In order to start the above reaction, it is necessary to raise the ambient temperature to a high temperature. However, since the reaction generates heat, it is not necessary to apply heat from the outside once the reaction is started. When starting the powdered carbon generator 78, first, hydrogen gas and oxygen gas are supplied to the gas flow path 78A to ignite. After the ignition, if heat is generated by the reaction of the formula (6), the supply of the oxygen gas and the hydrogen gas is stopped.

In the carbon fixing section 78B, by continuously supplying carbon dioxide gas and hydrogen gas, powdered carbon (“C” in the expression (6)) can be continuously generated. The generated powdered carbon can be taken out from below the carbon fixing section 78B. Water vapor (H ₂ O in the formula (6)) generated by the reaction between the carbon dioxide gas and the hydrogen gas is discharged from below the carbon fixing unit 78B. The water vapor discharged from the carbon fixing section 78B is sent to the condenser 26 via the pipe P17, and is cooled by the condenser 26 to become water.

In the fuel cell power generation system 10A of the present embodiment, since the first fuel cell stack 12 and the second fuel cell stack 14 to the carbon production unit 66 are continuously connected and provided on-site, power generation is performed during power generation. Can efficiently produce powdered carbon continuously.
As long as the carbon powder is not ignited and burned, it is not released into the atmosphere as carbon dioxide gas, and the emission of carbon dioxide gas to the atmosphere can be suppressed.
In addition, powdered carbon can be easily transported to storage sites, and long-term stable carbon fixation can be achieved by landfill disposal underground or storage on the ground unless the ignition source and oxygen are kept in a condition. Is possible. The produced powdered carbon can also be used for commercial and industrial purposes as carbon black or the like.

In the fuel cell power generation system 10A of the present embodiment, the powdered carbon is generated from the carbon dioxide gas. However, a carbon product manufacturing apparatus 84 for converting the powdered carbon into graphite, carbon nanotube, diamond, or the like may be further added. In the carbon product manufacturing apparatus 84, for example, the recovered powdered carbon is subjected to high temperature (electric heater heating) and high pressure (electric high-pressure press) by utilizing the power generated by the fuel cell power generation system 10A or the power from renewable energy. ) By putting it in an environment, synthetic diamond powder can be obtained by a known technique. Further, for example, the recovered powdered carbon is converted into carbon by a known technique such as an arc discharge method, a laser ablation method, a CVD method, or the like by utilizing the power generated by the fuel cell power generation system 10A or the power from renewable energy. Nanotubes can be obtained. Further, graphite can be obtained from the recovered powdered carbon by a known technique using electric power generated by the fuel cell power generation system 10A or electric power by renewable energy.
By using graphite, carbon nanotubes or diamond powder as carbon powder, it does not easily burn even if there is an ignition source or oxygen, and even if it is piled on the ground, it fixes carbon safely and long-term stably This makes it possible to eliminate restrictions on storage locations and reduce energy loss and costs for transportation and injection. In addition, graphite can be used for commercial purposes such as pencil cores and brake pads for automobiles, carbon nanotubes can be used as semiconductors and structural materials, and synthetic diamond powder can be used for construction and blade materials for diamond cutters for machine tools. it can.
The carbon product manufacturing device 84 is also a part of the carbon manufacturing unit 66, and is provided on-site in the fuel cell power generation system 10A. In addition, products manufactured using powdered carbon are not limited to the above-mentioned carbon products, and carbon materials such as carbon nanohorns and fullerenes may be manufactured by a known technique and used for commercial and industrial purposes.

  Furthermore, in the fuel cell power generation system 10A of the present embodiment, the second fuel cell off-gas sent from the second fuel electrode 14A of the second fuel cell stack 14 is burned in the combustion section 22, so that the second fuel cell cell The amount of unreacted fuel gas used for power generation by the second fuel cell stack 14 is greater than when the first fuel electrode off-gas is burned before being used for power generation in the stack 14. Therefore, the power generation efficiency of the second fuel cell stack 14 can be improved.

  Further, in the combustion section 22, carbon dioxide and water vapor are generated by a combustion reaction between the combustible gas contained in the second fuel electrode off-gas and oxygen. Therefore, the combustible gas can be reduced from the second fuel electrode off-gas, and high-concentration carbon dioxide can be recovered. Further, only oxygen in the air electrode off-gas is supplied to the combustion unit 22. The amount of unreacted fuel gas contained in the second fuel electrode off-gas is smaller than that of the first fuel electrode off-gas. Is high. Therefore, it is possible to reduce the amount of burning the unreacted fuel gas in the combustion section 22 and the amount of oxygen required to burn the unreacted fuel gas.

  Further, since the fuel cell power generation system 10A of the present embodiment has the branch air electrode off-gas pipe P6-2 branched from the air electrode off-gas pipe P6, the composition of the carbon dioxide rich gas detected by the composition detection unit 44 Based on the information, the flow rate of the air electrode off-gas branched to the branch air electrode off-gas pipe P6-2 can be easily adjusted. Thereby, the amount of oxygen flowing into the combustion space 22A of the combustion part 22 can be adjusted so that the amounts of combustible gas and oxygen contained in the combustion off-gas become lower than the predetermined threshold.

  Further, in the fuel cell power generation system 10A of the present embodiment, the amount of water condensed in the condenser 26 is adjusted based on the composition information of the carbon dioxide rich gas detected by the composition detection unit 44, so that the carbon dioxide rich gas Carbon dioxide concentration can be increased.

  Further, in the fuel cell power generation system 10A of the present embodiment, since the hydrogen ion conductive solid oxide fuel cell is used for the fuel cell stack, no water vapor is generated at the first fuel electrode 12A. Therefore, the amount of water vapor contained in the first fuel electrode off-gas is reduced, so that the power generation efficiency of the second fuel cell can be improved. Further, since the amount of water vapor contained in the second fuel electrode off-gas is also reduced, the amount of water vapor removed from the second fuel electrode off-gas can be reduced.

  Further, the fuel cell power generation system 10A of the present embodiment includes a circulating gas pipe P3 that supplies a part of the second fuel electrode off-gas to the first fuel electrode 12A from the upstream side of the combustion unit 22. Therefore, a part of the unreacted fuel gas and the steam in the second fuel electrode off-gas can be reused for power generation and steam reforming of the fuel gas, respectively.

  Further, in the fuel cell power generation system 10A of the present embodiment, by arranging the combustion section 22 adjacent to the oxygen permeable membrane 23 of the oxygen separation section 24, a compact oxygen transmission section in which the combustion section 22 and the oxygen separation section 24 are integrally formed. The combustor 20 with a film can be constituted.

  Further, in the fuel cell power generation system 10A of the present embodiment, since the heat of the air electrode off-gas is used for generating cold heat in the exhaust heat input type absorption refrigerator 36, the first fuel cell stack 12, the second fuel cell stack The exhaust heat from 14 can be used effectively. Further, since the air electrode off-gas contains a large amount of water vapor, the water vapor is condensed at the time of heat exchange in the exhaust heat input type absorption refrigerator 36, so that the heat of condensation can also be used effectively.

  In the present embodiment, the carbon dioxide is separated from the combustion off-gas by condensing and removing the water vapor in the combustion off-gas in the condenser 26. However, other means, for example, carbon dioxide is separated by a carbon dioxide separation membrane. Alternatively, carbon dioxide may be separated by a PSA device.

[Second embodiment]
Next, a second embodiment of the present invention will be described. In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the detailed description is omitted.

  As shown in FIG. 5, the fuel cell power generation system 10B of the present embodiment includes a high-temperature oxygen production device 50 and a combustor 52 instead of the combustor 20 with the oxygen-permeable membrane of the first embodiment. The configuration other than the high-temperature oxygen production device 50 and the combustor 52 is the same as that of the first embodiment.

  The downstream end of the branch air electrode offgas pipe P6-2 is connected to the inlet side of the high-temperature oxygen production device 50. The high-temperature oxygen production device 50 is a device that separates oxygen from the air electrode off-gas, and as an example, a high-temperature (for example, an operating temperature of 600 to 900 ° C.) PSA device that performs adsorption and desorption at a high temperature can be used. One end of an oxygen supply pipe PO is connected to the oxygen outlet side of the high-temperature oxygen production device 50. An exhaust pipe P13 is connected to the air electrode off-gas outlet side of the high-temperature oxygen production device 50 after oxygen is separated. The other end of the oxygen supply pipe PO is connected to the inlet side of the combustor 52. The exhaust pipe P13 is open to the outside of the fuel cell power generation system 10B. The high-temperature oxygen production apparatus 50 can efficiently produce oxygen using high-temperature air electrode off-gas. Further, the high-temperature oxygen production apparatus 50 can be driven by the DC power generated by the first fuel cell stack 12 and the second fuel cell stack 14.

  The other end of the oxygen supply pipe PO and the downstream end of the second fuel electrode offgas pipe P7-2 are connected to the inlet side of the combustor 52. Inside the combustor 52, the combustible gas components (unreformed methane, unreacted hydrogen, unreacted carbon monoxide, etc.) in the second fuel electrode off-gas are mixed with oxygen supplied from the oxygen supply pipe PO. A combustion reaction occurs, producing carbon dioxide and water vapor. The combustion off-gas pipe P8 is connected to the outlet side of the combustor 52, and the combustion off-gas is delivered from the combustor 52.

  Next, the operation of the fuel cell power generation system 10B of the present embodiment will be described.

  Also in the present embodiment, power generation is performed in the first fuel cell stack 12 and the second fuel cell stack 14, similarly to the fuel cell power generation system 10A of the first embodiment. The second air electrode off-gas sent from the second air electrode 14B and branched to the branch air electrode off-gas pipe P6-2 is supplied to the high-temperature oxygen production device 50. In the high-temperature oxygen production device 50, oxygen is separated from the second air electrode off-gas, and the separated oxygen is supplied to the combustor 52 via the oxygen supply pipe PO. The air electrode off-gas from which oxygen has been separated is discharged to the outside from the exhaust pipe P13.

  In the combustor 52, a combustion reaction occurs between the combustible gas components (unreformed methane, unreacted hydrogen, unreacted carbon monoxide, etc.) in the second fuel electrode off-gas and oxygen, and carbon dioxide and water vapor are generated. Generated. The combustion off-gas is sent to the combustion off-gas pipe P8, water is separated by the condenser 26 in the same manner as in the first embodiment, the separated water is collected in the water tank 27, and the carbon dioxide-rich gas is supplied to the carbon production unit 66. Supplied to.

  Also in the present embodiment, in the combustor 52, carbon dioxide and water vapor are generated by a combustion reaction between the combustible gas contained in the second fuel electrode off-gas and oxygen. Therefore, combustible gas can be reduced from the second fuel electrode off-gas, high concentration carbon dioxide can be recovered, and powdered carbon can be obtained efficiently.

[Third embodiment]
Next, a third embodiment of the present invention will be described. In the present embodiment, the same parts as those in the first and second embodiments are denoted by the same reference numerals, and detailed description is omitted.

  The fuel cell power generation system 10C of the present embodiment mainly includes the reformer 54, the point that the circulating gas pipe P3 is not provided, and the pipe flow paths related to these configurations according to the first embodiment. Is different. Other configurations are the same as those of the first embodiment.

  As shown in FIG. 6, the fuel cell power generation system 10C includes a reformer 54. One end of a fuel gas pipe P1-1 is connected to the inlet side of the reformer 54. One end of a water supply pipe P2-2 is connected to the inlet side of the reformer 54. The other end of the water supply pipe P2-2 is connected to the water tank 27. The water supply pipe P2-2 is provided with an ion exchange resin 56 and a pump 27B. By driving the pump 27B, the water stored in the water tank 27 is supplied to the reformer 54 via the ion exchange resin 56.

  One end of a reformed gas pipe P1-2 is connected to the outlet side of the reformer 54. The other end of the reformed gas pipe P1-2 is connected to the first fuel electrode 12A of the first fuel cell stack 12.

  Next, the operation of the fuel cell power generation system 10C of the present embodiment will be described.

  In the reformer 54, the mixed gas of the fuel gas and the steam is heated by heat exchange with the combustion off-gas, and hydrogen and carbon monoxide are generated by the steam reforming reaction. In addition, carbon dioxide and hydrogen are generated by a shift reaction between the generated carbon monoxide and water vapor. A reformed gas containing unreacted fuel gas (methane), hydrogen, carbon monoxide, and carbon dioxide is supplied to the first fuel electrode 12A through the reformed gas pipe P1-2. The first fuel cell stack 12 and the second fuel cell stack 14 generate electric power in the same manner as in the first embodiment.

  The second fuel electrode off-gas is sent from the second fuel electrode 14A to the second fuel electrode off-gas pipe P7-2. The second fuel electrode off-gas is supplied to the combustion section 22 of the combustor 20 with an oxygen permeable membrane without branching. From the second air electrode 14B, the air electrode off-gas is sent to the air electrode off-gas pipe P6, and a part of the air electrode off-gas is branched to the branch air electrode off-gas pipe P6-2, as in the first embodiment, and the others are It merges with the air electrode off-gas sent from the first air electrode 12B.

  In the combustor 20 with the oxygen permeable membrane and the condenser 26, the same processing as in the first embodiment is performed, and the carbon dioxide-rich gas is supplied to the carbon production unit 66.

  Also in the present embodiment, in the combustor 20 with the oxygen-permeable membrane, carbon dioxide and water vapor are generated by a combustion reaction between the combustible gas contained in the second fuel electrode offgas and oxygen. Therefore, combustible gas can be reduced from the second fuel electrode off-gas, high concentration carbon dioxide can be recovered, and powdered carbon can be obtained efficiently.

[Fourth embodiment]
Next, a fourth embodiment of the present invention will be described. In the present embodiment, the same parts as those in the first to third embodiments are denoted by the same reference numerals, and detailed description is omitted.

  The fuel cell power generation system 10D of the present embodiment includes a high-temperature oxygen production device 50 and a combustor 52 of the second embodiment, instead of the combustor 20 with an oxygen-permeable membrane of the third embodiment. The configuration other than the high-temperature oxygen production device 50 and the combustor 52 is the same as that of the third embodiment.

  As shown in FIG. 7, the downstream end of the branch air electrode off-gas pipe P6-2 is connected to the inlet side of the high-temperature oxygen production apparatus 50, and the oxygen supply pipe PO is connected to the oxygen exit side of the high-temperature oxygen production apparatus 50. One end is connected. An exhaust pipe P13 is connected to the air electrode off-gas outlet side of the high-temperature oxygen production device 50 after oxygen is separated. The other end of the oxygen supply pipe PO is connected to the inlet side of the combustor 52. The exhaust pipe P13 is open to the outside of the fuel cell power generation system 10D.

  The other end of the oxygen supply pipe PO and the downstream end of the second fuel electrode offgas pipe P7-2 are connected to the inlet side of the combustor 52. Inside the combustor 52, the combustible gas components (unreformed methane, unreacted hydrogen, unreacted carbon monoxide, etc.) in the second fuel electrode off-gas are mixed with oxygen supplied from the oxygen supply pipe PO. A combustion reaction occurs, producing carbon dioxide and water vapor. The combustion off-gas pipe P8 is connected to the outlet side of the combustor 52, and the combustion off-gas is delivered from the combustor 52.

  Next, the operation of the fuel cell power generation system 10D of the present embodiment will be described.

  Also in the present embodiment, similarly to the fuel cell power generation system 10C of the third embodiment, the reformer 54 steam-reforms the fuel gas to generate a reformed gas, and the first fuel cell stack 12 and the second Power generation is performed in the fuel cell stack 14. The second air electrode off-gas sent from the second air electrode 14B and branched to the branch air electrode off-gas pipe P6-2 is supplied to the high-temperature oxygen production device 50. In the high-temperature oxygen production device 50, oxygen is separated from the second air electrode off-gas, and the separated oxygen is supplied to the combustor 52 via the oxygen supply pipe PO. The air electrode off-gas from which oxygen has been separated is discharged to the outside from the exhaust pipe P13.

  In the combustor 52, a combustion reaction occurs between the combustible gas components (unreformed methane, unreacted hydrogen, unreacted carbon monoxide, etc.) in the second fuel electrode off-gas and oxygen, and carbon dioxide and water vapor are generated. Generated. The combustion off-gas is sent to the combustion off-gas pipe P8, water is separated by the condenser 26 in the same manner as in the first embodiment, the separated water is collected in the water tank 27, and the carbon dioxide-rich gas is supplied to the carbon production unit 66. Supplied to.

  Also in the present embodiment, in the combustor 52, carbon dioxide and water vapor are generated by a combustion reaction between the combustible gas contained in the second fuel electrode off-gas and oxygen. Therefore, combustible gas can be reduced from the second fuel electrode off-gas, high concentration carbon dioxide can be recovered, and powdered carbon can be obtained efficiently.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described. In the present embodiment, the same parts as those in the first to fourth embodiments are denoted by the same reference numerals, and detailed description will be omitted.

  The fuel cell power generation system 10E of the present embodiment is different from the first embodiment in that a third heat exchanger 34 and a condenser 35 are provided in the path of the first fuel electrode off-gas pipe P7.

  As shown in FIG. 8, the first fuel electrode offgas pipe P7 extends from the first fuel electrode 12A and is connected to the condenser 35 via the third heat exchanger 34. A first fuel electrode off-gas pipe P7 from the first fuel electrode 12A to the condenser 35 is indicated by a symbol P7A. The first fuel electrode off-gas pipe P7A extends from the gas-side outlet of the condenser 35, and is connected to the second fuel electrode 14A via the third heat exchanger 34. A first fuel electrode off-gas pipe P7 from the condenser 35 to the second fuel electrode 14A is indicated by a symbol P7B. One end of a water pipe P9-2 is connected to a liquid-side outlet of the condenser 35. The other end of the water pipe P9-2 is connected to the water tank 27. The condenser 35 is provided with a cooling water circulation passage 35A, and cooling water from an exhaust heat input type absorption refrigerator 36 is circulated and supplied by driving a pump 35P. Thereby, the first fuel electrode off-gas is cooled, and the water vapor in the first fuel electrode off-gas is condensed. The condensed water is sent out to the water tank 27 via the water pipe P9-2.

  Next, the operation of the fuel cell power generation system 10E of the present embodiment will be described.

  Also in the present embodiment, power generation is performed in the first fuel cell stack 12 as in the fuel cell power generation system 10A of the first embodiment. The first fuel electrode off-gas sent from the first fuel electrode 12A to the first fuel electrode off-gas pipe P7-1 is cooled by heat exchange with a regenerated fuel gas described later in the third heat exchanger 34 and supplied to the condenser 35. Is done. In the condenser 35, the first fuel electrode off-gas is further cooled by the cooling water circulating through the cooling water circulation channel 35A, and the water vapor in the first fuel electrode off-gas is condensed. Here, the temperature of the cooling water circulating through the cooling water circulation channel 35A is set to a value such that the amount of water vapor remaining in the regenerated fuel gas improves the power generation efficiency in the second fuel cell stack 14 so that the water vapor in the first fuel electrode off-gas is improved. Is set to condense. The condensed water is sent out to the water tank 27 via the water pipe P9-2.

  The first fuel electrode off-gas from which the condensed water has been separated is sent out to the first fuel electrode off-gas pipe P7B as a regenerated fuel gas, and the heat with the first fuel electrode off-gas before water is separated by the third heat exchanger 34. It is heated by the exchange and supplied to the second fuel electrode 14A. In the second fuel cell stack 14, power is generated in the same manner as in the fuel cell power generation system 10A of the first embodiment.

  In the present embodiment, since the regenerated fuel gas generated by separating a part of the water vapor from the first fuel electrode off-gas is supplied to the second fuel electrode 14A, the power generation efficiency in the second fuel cell stack 14 is improved. Can be.

  Also in the present embodiment, in the combustion section 22 of the combustor 20 with the oxygen permeable membrane, carbon dioxide and water vapor are generated by a combustion reaction between the combustible gas contained in the second fuel electrode offgas and oxygen. Therefore, combustible gas can be reduced from the second fuel electrode off-gas, high concentration carbon dioxide can be recovered, and powdered carbon can be obtained efficiently.

[Sixth embodiment]
Next, a sixth embodiment of the present invention will be described. In the present embodiment, the same parts as those in the first to fifth embodiments are denoted by the same reference numerals, and detailed description is omitted.

  As shown in FIG. 9, in the fuel cell power generation system 10F of the present embodiment, the first fuel cell stack 62 and the second fuel cell stack 64 are the hydrogen ion conductive solid oxide fuel cell of the first embodiment. Instead, a solid oxide fuel cell (SOFC) is used. Therefore, reactions occur at the first fuel electrode 62A (fuel electrode) and the first air electrode 62B (air electrode) as follows. The same applies to the second fuel electrode 64A and the second air electrode 64B.

  At the first air electrode 62B, as shown in the following equation (5), oxygen in the oxidizing gas reacts with electrons to generate oxygen ions. The generated oxygen ions reach the first fuel electrode 62A of the first fuel cell stack 62 through the electrolyte layer 62C.

(Air cathode reaction)
1 / 2O ₂ + 2e ⁻ → O ² -... (5)

  On the other hand, at the first fuel electrode 62A of the first fuel cell stack 62, as shown in the following equations (6) and (7), oxygen ions passing through the electrolyte layer 62C are converted into hydrogen and monoxide in the fuel gas. Reacts with carbon to produce water vapor, carbon dioxide and electrons. Electrons generated at the first fuel electrode 62A move from the first fuel electrode 62A to the first air electrode 62B through an external circuit to generate power.

(Fuel electrode reaction)
H ₂ + O ²⁻ → H ₂ O + 2e ⁻ (6)
CO + O ²⁻ → CO ₂ + 2e ⁻ (7)

  In the solid oxide fuel cell, since the first fuel electrode 62A and the second fuel electrode 64A generate water vapor, the first fuel electrode off-gas and the second fuel electrode (2) The amount of water vapor contained in the fuel electrode off-gas is large. On the other hand, no water vapor is generated at the first air electrode 62B and the second air electrode 64B. The air electrode off-gas supplied to the exhaust heat input type absorption refrigerator 36 is exhausted from the exhaust pipe P36-1 after heat exchange.

  The other configuration of the fuel cell power generation system 10F of the present embodiment is the same as that of the fifth embodiment, and the third heat exchanger 34 and the condenser 35 are provided in the path of the first fuel electrode offgas pipe P7. ing. Here, since the amount of water vapor contained in the first fuel electrode off-gas and the second fuel electrode off-gas is larger than that in the fuel cell power generation system 10E, the amount of water vapor removed by condensation in the condenser 35 is increased. The temperature of the cooling water circulating through the cooling water circulation channel 35A is set. The condensed water is sent out to the water tank 27 via the water pipe P9-2.

  In the present embodiment, since the regenerated fuel gas generated by separating a part of the water vapor from the first fuel electrode off-gas is supplied to the second fuel electrode 14A, the power generation efficiency in the second fuel cell stack 14 is improved. Can be.

  Also in the present embodiment, in the combustion section 22 of the combustor 20 with the oxygen permeable membrane, carbon dioxide and water vapor are generated by a combustion reaction between the combustible gas contained in the second fuel electrode offgas and oxygen. Therefore, combustible gas can be reduced from the second fuel electrode off-gas, high concentration carbon dioxide can be recovered, and powdered carbon can be obtained efficiently.

[Seventh embodiment]
Next, a seventh embodiment of the present invention will be described. In the present embodiment, the same parts as those in the first to sixth embodiments are denoted by the same reference numerals, and detailed description is omitted.

  As shown in FIG. 10, in the fuel cell power generation system 10G of the present embodiment, instead of the combustor 20 with an oxygen-permeable membrane of the sixth embodiment, a high-temperature oxygen production device 50 and a combustion system similar to those of the second embodiment are used. The container 52 is provided. The configuration other than the high-temperature oxygen production device 50, the combustor 52, and the piping related thereto is the same as in the sixth embodiment.

  Also in the present embodiment, since the regenerated fuel gas generated by separating a part of the water vapor from the first fuel electrode off-gas is supplied to the second fuel electrode 14A, the power generation efficiency in the second fuel cell stack 14 is improved. be able to.

  Also in the present embodiment, in the combustor 52, carbon dioxide and water vapor are generated by a combustion reaction between the combustible gas contained in the second fuel electrode offgas and oxygen. Therefore, combustible gas can be reduced from the second fuel electrode off-gas, high concentration carbon dioxide can be recovered, and powdered carbon can be obtained efficiently.

[Eighth Embodiment]
Next, an eighth embodiment of the present invention will be described. In the present embodiment, the same parts as those in the first to seventh embodiments are denoted by the same reference numerals, and detailed description is omitted.

  As shown in FIG. 11, in the fuel cell power generation system 10H of the present embodiment, similarly to the third embodiment, the point that the reformer 54 is provided, the point that the circulating gas pipe P3 is not provided, and The piping flow path related to the configuration is different from that of the sixth embodiment. Other configurations are the same as in the sixth embodiment.

  Also in the present embodiment, since the regenerated fuel gas generated by separating a part of the water vapor from the first fuel electrode off-gas is supplied to the second fuel electrode 14A, the power generation efficiency in the second fuel cell stack 14 is improved. be able to.

  Also in the present embodiment, carbon dioxide and water vapor are generated by the combustion reaction between the combustible gas contained in the second fuel electrode offgas and oxygen in the combustion section 22. Therefore, combustible gas can be reduced from the second fuel electrode off-gas, high concentration carbon dioxide can be recovered, and powdered carbon can be obtained efficiently.

[Ninth embodiment]
Next, a ninth embodiment of the present invention will be described. In the present embodiment, the same parts as those in the first to eighth embodiments are denoted by the same reference numerals, and detailed description will be omitted.

  As shown in FIG. 11, in the fuel cell power generation system 10I of the present embodiment, a high-temperature oxygen production device 50 and a combustor 52 of the seventh embodiment are used instead of the combustor 20 with an oxygen-permeable membrane of the eighth embodiment. It has. The configuration other than the high-temperature oxygen production device 50 and the combustor 52 is the same as that of the eighth embodiment.

  Also in the present embodiment, since the regenerated fuel gas generated by separating a part of the water vapor from the first fuel electrode off-gas is supplied to the second fuel electrode 14A, the power generation efficiency in the second fuel cell stack 14 is improved. be able to.

  Also in the present embodiment, in the combustor 52, carbon dioxide and water vapor are generated by a combustion reaction between the combustible gas contained in the second fuel electrode offgas and oxygen. Therefore, combustible gas can be reduced from the second fuel electrode off-gas, high concentration carbon dioxide can be recovered, and powdered carbon can be obtained efficiently.

[Other Embodiments]
As described above, one embodiment of the carbon recovery fuel cell power generation system of the present invention has been described. However, the present invention is not limited to the above, and other than the above, various modifications may be made without departing from the gist of the present invention. Of course, it can be implemented.

  As the fuel cell of the present invention, other fuel cells such as a molten carbonate fuel cell (MCFC), a phosphoric acid fuel cell (PAFC), and a polymer electrolyte fuel cell (PEFC) can also be used.

  In the first to ninth embodiments, the cold heat is generated by using the exhaust heat input type absorption refrigerator 36, but other exhaust heat is used instead of the exhaust heat input absorption refrigerator 36. Cold heat may be generated using a heat pump, for example, an adsorption refrigerator.

  Further, instead of the exhaust heat input type absorption refrigerator 36, a fuel cell power generation system 10J using an electric turbo refrigerator 60 that generates cold heat by using electric power without using exhaust heat may be used. FIG. 13 shows, as an example, a configuration in which the exhaust heat input type absorption refrigerator 36 is replaced with an electric turbo refrigerator 60 in the fuel cell power generation system 10A of the first embodiment. The same applies to the second to ninth embodiments. In the fuel cell power generation system 10J, the air electrode off-gas is exhausted out of the system after heat exchange in the second heat exchanger 32. The electric turbo refrigerator 60 can be driven by the electric power generated by the fuel cell power generation system 10J. Since the electric turbo chiller 60 generally has high cooling efficiency, the fuel cell power generation system 10J can be operated with high efficiency even by using the generated power. Also in this case, it is preferable to drive the electric centrifugal chiller 60 with a direct current in order to efficiently use the generated power without converting it into an alternating current.

10A-10J Fuel cell power generation system (Carbon recovery type fuel cell power generation system)
12, 62 First fuel cell stack (first fuel cell)
12A, 62A First fuel electrode 12B, 62B First air electrode 14, 64 Second fuel cell cell stack (second fuel cell)
14A, 64A second fuel electrode 14B, 64B second air electrode 20 combustor 22 with oxygen permeable membrane combustion section,
22A combustion space 23 oxygen permeable membrane,
24 Oxygen separation unit 26 Condenser (carbon dioxide separation unit)
35 Condenser (fuel regeneration unit)
36 Exhaust heat absorption type absorption refrigerator 50 High temperature oxygen production equipment (oxygen separation unit)
52 combustor (combustion unit),
54 reformer,
70 water electrolysis device 78 powder carbon generator (carbon generator)
84 Carbon Product Manufacturing Equipment
P3 Circulating gas pipe (circulating flow path)
P6 Air electrode off gas pipe (Air electrode off gas flow path)
P6-2 Branch air electrode off-gas pipe (branch air electrode off-gas flow path)
P7 Second fuel electrode off-gas pipe (second fuel electrode off-gas flow path)

Claims (10)

A fuel cell that includes a carbon compound and is supplied to the fuel electrode, and an oxidant gas that includes oxygen and is supplied to the air electrode, generates power, and discharges off-gas,
A carbon dioxide gas separation unit that separates carbon dioxide gas from the off-gas,
A water electrolysis device that electrolyzes water to produce hydrogen gas,
A carbon generation unit that reacts the carbon dioxide gas from the carbon dioxide gas separation unit and the hydrogen gas from the water electrolysis device on a catalyst to generate carbon and water vapor,
A carbon recovery fuel cell power generation system equipped with   The carbon capture fuel cell power generation system according to claim 1, wherein the water electrolysis device electrolyzes the water by at least one of a power generated by a renewable energy power generation device and a power generated by the fuel cell. . The carbon dioxide gas separation unit separates the carbon dioxide gas and water from the off gas,
The fuel cell power generation system according to claim 1, wherein the water separated by the carbon dioxide gas separation unit is used in the water electrolysis device. Electric power is generated by a fuel gas containing a carbon compound and supplied to the first fuel electrode and an oxidizing gas containing oxygen and supplied to the first air electrode, and the first fuel electrode off-gas is discharged from the first fuel electrode to the first fuel electrode. The first fuel cell to be delivered to the fuel electrode off-gas flow path, and the first fuel electrode off gas supplied to the second fuel electrode and the oxidant gas supplied to the second air electrode generate power, and A second fuel cell configured to send a second fuel electrode off-gas from the fuel electrode to a second fuel electrode off-gas flow path;
An air electrode off-gas flow path for sending air electrode off-gas from at least one of the first air electrode and the second air electrode;
An oxygen separator connected to the air electrode off-gas flow path, supplied with the air electrode off-gas, and separating oxygen from the air electrode off-gas;
A combustion unit for supplying the second fuel electrode off-gas and for supplying the oxygen separated by the oxygen separation unit, and for causing a combustion reaction of the second fuel electrode off-gas with the oxygen;
An exhaust heat input absorption refrigerator that cools water using the off-gas as a heat source to generate cooling water, or an adsorption refrigerator,
With
The carbon dioxide gas separation unit according to any one of claims 1 to 3, wherein the combustion offgas sent from the combustion unit is cooled by the cooling water to separate carbon dioxide gas and water. Carbon recovery fuel cell power generation system.   The carbon capture fuel cell power generation system according to claim 4, wherein the first fuel cell and the second fuel cell are hydrogen ion conductive solid oxide fuel cells. The water separated by the carbon dioxide gas separation unit, a cooling water path of the exhaust heat input type absorption refrigerator or a cooling water replenishment path of a cooling tower constituting the exhaust heat input absorption refrigerator, or A supply unit for supplying to a cooling water path of an adsorption refrigerator or a cooling water rehydration path of a cooling tower constituting the adsorption refrigerator,
Part of the cooling water of the exhaust heat input type absorption refrigerator or the supplementary cooling water of the cooling tower constituting the exhaust heat input absorption refrigerator, or the cooling water or the adsorption type of the adsorption type refrigerator The carbon recovery type fuel cell power generation system according to claim 4 or 5, wherein the water separated by the carbon dioxide gas separation unit is used as a part of the cooling water supplementary water of a cooling tower constituting a refrigerator. The oxygen separation unit has an oxygen permeable membrane that selectively allows oxygen to pass therethrough,
7. The carbon capture fuel cell power generator according to claim 4, wherein the combustion unit has a combustion space disposed on a permeation side of the oxygen permeable membrane and is integrated with the oxygen separation unit. 8. system.   The said oxygen separation part has the high temperature PSA apparatus made drivable with the electric power generated by the said 1st fuel cell and the said 2nd fuel cell, any one of Claims 4-6. A carbon recovery type fuel cell power generation system according to item 1. The carbon dioxide gas separation unit cools the off gas to generate the carbon dioxide gas and water,
The water vapor generated in the carbon generation unit is supplied to the carbon dioxide gas separation unit via a supply path,
The carbon recovery type fuel cell power generation system according to any one of claims 1 to 8.   The carbon recovery type fuel cell power generation system according to any one of claims 1 to 9, further comprising a carbon product manufacturing apparatus that converts the carbon generated by the carbon generation unit into graphite, carbon nanotubes, or diamond.