JP4916138B2 - Power generation system - Google Patents

Description

  The present invention relates to a system for generating electric power from electric energy obtained by a fuel cell and recovering carbon dioxide as liquefied carbon dioxide from exhaust gas discharged from the fuel cell.

  Conventionally, a power generation system that generates power using a fuel cell and collects carbon dioxide discharged from the fuel cell has been developed (see, for example, Patent Documents 1 to 3).

However, in these systems, since the separation device for separating carbon dioxide and the liquefaction device for liquefying carbon dioxide are provided separately, the system cannot be reduced. In addition, these systems are not always satisfactory in terms of resource saving, energy saving, and efficient recovery of high-concentration liquefied carbon dioxide. However, there is a need for the development of a system that can be efficiently and efficiently collected.
JP-A-11-31527 JP 2004-186074 A JP 11-26004 A

  Then, an object of this invention is to provide the system which can collect | recover highly concentrated liquefied carbon dioxide efficiently with low energy, generating electric power with small resources.

  In order to solve the above problems, a power generation system according to the present invention removes moisture from a fuel cell and a first exhaust gas containing moisture, hydrogen, and carbon dioxide supplied from an anode electrode of the fuel cell. A dehumidifier that discharges the second exhaust gas as the second exhaust gas, and the second exhaust gas discharged by the dehumidifier is cooled to a first temperature that solidifies only the carbon dioxide, and the second exhaust gas The carbon dioxide contained therein was solidified, the third exhaust gas containing hydrogen from which the carbon dioxide was separated and removed from the second exhaust gas was discharged, the temperature was raised to liquefy the solidified carbon dioxide, and the liquid was liquefied A carbon dioxide separation and liquefaction device for discharging carbon dioxide, and a means for supplying the third exhaust gas discharged by the carbon dioxide separation and liquefaction device to the anode electrode of the fuel cell.

  In the power generation system according to the present invention, the first exhaust gas supplied from the anode electrode of the fuel cell to the dehumidifier using the cold heat of the third exhaust gas supplied to the anode electrode of the fuel cell. It is good also as including the heat exchanger which cools. In addition, the power generation system according to the present invention uses the cold heat of the third exhaust gas supplied to the anode electrode of the fuel cell to supply the second exhaust gas supplied from the dehumidifier to the carbon dioxide separation and liquefaction device. It is good also as including the heat exchanger which cools.

  Furthermore, the power generation system according to the present invention further includes a fuel gas reformer that reforms the fuel gas into a mixed gas containing hydrogen and carbon dioxide and supplies the mixed gas to the anode electrode of the fuel cell. Also good.

  Examples of the fuel cell include a molten carbonate fuel cell, a solid oxide fuel cell, a phosphoric acid fuel cell, and a solid polymer fuel cell. When the fuel cell is a molten carbonate fuel cell, a part of the first exhaust gas supplied from the molten carbonate fuel cell to the dehumidifier is burned and included in the first exhaust gas. A combustor that oxidizes carbon monoxide to carbon dioxide and supplies the carbon dioxide to the cathode of the molten carbonate fuel cell may be further included. Further, the power generation system according to the present invention includes a boiler that burns oil, coal, or fuel gas, a denitration device that removes nitrogen oxides contained in the fourth exhaust gas discharged from the boiler, and the denitration device. A dust removing device for removing solid components contained in the fourth exhaust gas from which nitrogen oxides have been removed, and a sulfur oxide contained in the fourth exhaust gas from which the solid components have been removed by the dust removing device. And a means for supplying the fourth exhaust gas from which the sulfur oxide has been removed by the desulfurization device to the cathode electrode of the molten carbonate fuel cell.

  Here, the liquefied carbon dioxide recovery device, for example, an exhaust gas inlet that receives the second exhaust gas supplied from the dehumidifier, cools the second exhaust gas, and removes carbon dioxide in the second exhaust gas. A pressure-resistant container having a refrigerant circulation pipe to be solidified and adhered to an outer surface, an exhaust gas outlet for discharging the third exhaust gas, and an opening / closing means for opening and closing the exhaust gas inlet and the exhaust gas outlet, and the pressure resistance Obtained by raising the temperature of the carbon dioxide solidified in a container, sealing the exhaust gas inlet and the exhaust gas outlet by the opening / closing means, and raising the temperature of the solidified carbon dioxide by the temperature raising means. And a discharge means for discharging liquefied carbon dioxide.

  In addition, the dehumidifying device cools the first exhaust gas supplied from the anode electrode of the fuel cell to a second temperature that does not solidify the carbon dioxide but liquefies or solidifies the water, for example. A cooling dehumidifier that liquefies or solidifies the moisture in one exhaust gas to remove the moisture from the first exhaust gas to form the second exhaust gas, and discharges the second exhaust gas; The first exhaust gas is passed through a first refrigerant and cooled to the second temperature, the moisture in the first exhaust gas is solidified to remove the moisture from the first exhaust gas, and A dehydration unit that discharges the second exhaust gas as a second exhaust gas, a separation unit that separates the solidified first refrigerant containing the moisture into the solidified moisture and the first refrigerant, and a separation Supplying the first refrigerant to the dehydrating unit It means that may be a device comprising a. When the dehumidifier is the cooling dehumidifier, the first exhaust gas is cooled to the second temperature by using the cold heat of the third exhaust gas supplied to the anode electrode of the fuel cell. It is good also as including the means to do.

  ADVANTAGE OF THE INVENTION According to this invention, the system which can collect | recover highly concentrated liquefied carbon dioxide with low energy efficiently can be provided, producing electric power with few resources.

  Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings.

== Configuration of power generation system according to the present invention ==
FIG. 1 shows a schematic configuration diagram of a power generation system described as an embodiment of the present invention. As shown in FIG. 1, a power generation system 1000 according to the present invention includes a fuel cell 100, a dehumidifier 200, a carbon dioxide (hereinafter referred to as “liquefied CO ₂ ”) separation liquefaction device 300, and the like.

  The fuel cell 100 includes, for example, chemical energy possessed by fuels such as hydrogen, alcohols (eg, methanol, ethanol, etc.), hydrocarbons such as methane, ethane, propane, natural gas, city gas, LP gas, biogas, and digestion gas. Is a device that converts electricity directly into electrical energy to generate electricity. Examples of the fuel cell 100 include a molten carbonate fuel cell (MCFC), a solid oxide fuel cell (SOFC), and a phosphoric acid fuel cell (PAFC). And a polymer electrolyte fuel cell (PEFC). Note that air or oxygen (including carbon dioxide in the case of MCFC) is supplied to the cathode electrode of the fuel cell 100. On the other hand, hydrogen or the like (others may contain carbon monoxide in the case of MCFC and SOFC) is supplied to the anode electrode of the fuel cell 100.

  The dehumidifying device 200 removes moisture from the first exhaust gas containing moisture (for example, water vapor and water), hydrogen, and carbon dioxide supplied from the anode electrode of the fuel cell 100 to obtain a second exhaust gas. It is a device that discharges. The dehumidifier 200 may be, for example, an adsorption dehumidifier using a desiccant, an adsorbent (for example, activated carbon, zeolite, etc.), or the first exhaust gas supplied from the fuel cell 100 is converted into carbon dioxide. The first exhaust gas is cooled by cooling to an appropriate temperature (hereinafter referred to as “second temperature”) at which moisture can be liquefied or solidified without causing the moisture in the first exhaust gas to be liquefied or solidified. It may be a cooling dehumidifier that removes moisture from the water and discharges a second exhaust gas containing hydrogen and carbon dioxide, or may be a known dehumidifier.

The CO ₂ separation and liquefaction device 300 cools the second exhaust gas discharged by the dehumidification device 200 to an appropriate temperature at which only carbon dioxide can be solidified, and solidifies the carbon dioxide in the second exhaust gas to provide the first. This is an apparatus for discharging a third exhaust gas containing hydrogen from which carbon dioxide has been separated and removed from the exhaust gas of No. 2, raising the temperature to liquefy the solidified carbon dioxide, and discharging the liquefied carbon dioxide.

The power generation system 1000 according to the present invention includes means for supplying the third exhaust gas discharged by the CO ₂ separation and liquefaction device 300 to the anode electrode of the fuel cell 100. The means may be, for example, a pipe (may include a blower or the like), or a storage container that stores the third exhaust gas and supplies it to the anode electrode of the fuel cell 100.

As described above, by providing the power generation system 1000 including the fuel cell 100 with the dehumidifying device 200 and the CO ₂ separation and liquefaction device 300, it becomes possible to separate and collect high-concentration liquefied CO ₂ . In the CO ₂ separation and liquefaction apparatus 300, the solidified carbon dioxide is heated to evaporate in a sealed container to increase the pressure in the apparatus, thereby generating liquefied CO _2. Energy for liquefaction can be reduced. Further, by providing means for supplying the third exhaust gas separated by the CO ₂ separation and liquefaction apparatus 300 to the anode electrode of the fuel cell 100, electric energy can be effectively utilized by using hydrogen gas contained in the third exhaust gas. As a result, it is possible to save resources of hydrogen gas.

According to a preferred embodiment of the present invention, the power generation system 1000 according to the present invention uses the cold heat of the third exhaust gas discharged from the CO ₂ separation and liquefaction device 300 to cool the CO ₂ separation and liquefaction from the dehumidification device 200. A heat exchanger 400 that cools the second exhaust gas supplied to the apparatus 300, a heat exchanger 410 that cools the first exhaust gas supplied from the anode electrode of the fuel cell 100 to the dehumidifier 200, and the like may be further provided. Good. When the dehumidifying device 200 is a cooling type dehumidifying device, as shown in FIG. 1, the third exhaust gas discharged from the CO ₂ separation and liquefaction device 300 is passed through the cooling type dehumidifying device, A pipe or a heat exchanger for cooling the first exhaust gas using the cold heat of the exhaust gas may be provided in the cooling dehumidifier. As described above, energy consumption in the power generation system 1000 can be reduced by effectively using the cold heat of the third exhaust gas to cool the first and second exhaust gases.

  Note that the cooling of the first and second exhaust gases may be performed using cold heat of seawater or river water to a certain temperature. Further, the power generation system 1000 according to the present invention is provided with a refrigerator and a refrigerant pipe for circulating the refrigerant between the refrigerator and the heat exchangers 400 and 410 and the dehumidifier (cooling dehumidifier) 200, The refrigerant cooled in the refrigerator may be circulated through the heat exchangers 400 and 410 and the dehumidifier (cooled dehumidifier) 200, and the first and second exhaust gases may be cooled using the cold heat of the refrigerant. The schematic block diagram of the refrigerator demonstrated as one Embodiment of this invention in FIG. 2 is shown.

  As shown in FIG. 2, the refrigerator 500 includes a turbine-type compressor (including a turbine 520 and a booster 510), a compressor 530, a condenser 540, a heat exchanger 550, and the like. They are connected by a pipe 560.

  The compressor 530 is a device (low pressure side compressor) that compresses the refrigerant circulating in the pipe 560 to a predetermined pressure. The booster 510 is a device that boosts the refrigerant pressurized to a predetermined pressure by the compressor 530. The condenser 540 is a device that cools the refrigerant that has been brought to a high temperature and a high pressure by the compressors 510 and 530. The turbine 520 is a device that drives the compressor 510 by generating a rotational motion with the low-temperature and high-pressure refrigerant cooled by the condenser 540. The heat exchanger 550 uses the cold heat of the low-temperature and low-pressure refrigerant expanded by passing through the turbine 520, and circulates the refrigerant circulating between the heat exchanger 550 and the heat exchangers 400 and 410 and the cooling dehumidifier. A device for cooling. The refrigerant that has supplied the cold heat in the heat exchanger 550 is supplied to the compressor 530. The refrigerant included in the refrigerator 500 is circulated and used in the refrigerator 500 in the order of the compressor 530 → the booster 510 → the condenser 540 → the turbine 520 → the heat exchanger 550 → the compressor 530. In addition, any refrigerant that is circulated and used in the refrigerator 500 can be used as long as it has a lower melting point than the refrigerant circulated between the heat exchanger 550 and the heat exchangers 400 and 410 and the cooling dehumidifier. For example, liquid nitrogen, liquid oxygen, liquid helium, or the like can be used. For example, ethylene glycol, dimethyl ether, methanol, ethanol, toluene, carbon dioxide, ammonia, or the like is used as the refrigerant circulating between the heat exchanger 550 and the heat exchangers 400 and 410 or the cooling dehumidifier. it can.

  As described above, in the power generation system 1000 according to the present invention, the refrigerant is circulated between the refrigerator 500, the refrigerator 500, the heat exchangers 400 and 410, and the dehumidifier (cooling dehumidifier) 200. By providing the pipe, the refrigerant circulated between the heat exchanger 550 and the heat exchangers 400 and 410 and the dehumidifier (cooling dehumidifier) 200 using the cold heat of the refrigerant circulating in the refrigerator 500. Can be cooled.

  Moreover, according to one embodiment of the present invention, the fuel gas reformer 700 may be further provided in the power generation system 1000 according to the present invention. As a result, the fuel gas reformer 700 can reform the fuel gas into a mixed gas containing hydrogen and carbon dioxide, and supply the reformed mixed gas to the anode electrode of the fuel cell 100 as fuel. Examples of the fuel gas include alcohols such as methanol, ethanol, and propanol, hydrocarbon gases such as methane, ethane, propane, and butane, natural gas, city gas, and LP gas, or liquefied gases thereof. Can be used. FIG. 3 is a diagram showing a process of generating a mixed gas to be supplied from liquefied natural gas (LNG) to the anode electrode of the fuel cell 100 in one embodiment of the present invention.

  As shown in FIG. 3, the LNG stored in the LNG storage tank 600 is supplied to the fuel gas reformer 700 through the heat exchanger 420. In the heat exchanger 420, refrigerant that circulates between the heat exchanger 420 and the heat exchangers 400 and 410 and the dehumidifier (cooling dehumidifier) 200 using the cold heat of LNG supplied from the LNG storage tank 600. Is cooled. The LNG that has supplied cold heat in the heat exchanger 420 is vaporized, supplied to the fuel gas reformer 700, reformed into a mixed gas containing hydrogen and carbon dioxide, and supplied to the anode electrode of the fuel cell 100.

  As described above, by providing the heat exchanger 420 and the fuel gas reformer 700 in the power generation system 1000 according to the present invention, the heat exchanger 420 and the heat exchanger 400 are utilized using the cold heat of the liquid fuel gas. , 410 and the cooling type dehumidifying device can be cooled, so that the energy required for the entire system can be reduced.

<About the CO ₂ separation and liquefaction apparatus 300>
Next, the configuration and processing procedure of the CO ₂ separation and liquefaction apparatus 300 included in the power generation system 1000 according to the present invention will be described in detail. FIG. 4 shows a schematic configuration of a CO ₂ separation and liquefaction apparatus 300 described as an embodiment of the present invention.

As shown in FIG. 4, the CO ₂ separation and liquefaction apparatus 300 is composed of a substantially rectangular parallelepiped metal (for example, stainless steel) pressure vessel 310 having a vertical, horizontal, and height of about several meters each. An exhaust gas inlet 321 for receiving the second exhaust gas supplied from the dehumidifier 200 is provided at a predetermined position on the upper surface of the pressure vessel 310. On the other hand, at a predetermined position on the lower surface of the pressure vessel 310, there are an exhaust gas outlet 322 for discharging the third exhaust gas from which the carbon dioxide has been removed from the second exhaust gas from the pressure vessel 310, and liquefied CO ₂ accumulated at the bottom of the pressure vessel 310. A liquid discharge port 323 for discharging is provided. The exhaust gas outlet 322 is provided at a position separated from the exhaust gas inlet 321 by a predetermined distance so that the second exhaust gas received from the exhaust gas inlet 321 stays in the pressure vessel 310 for a predetermined time or longer.

A pipe (gas inflow pipe 331) connected to the exhaust gas inlet 321 is provided with a control valve 341 for adjusting the amount of inflow of exhaust gas. In addition, a control valve 342 for adjusting the outflow amount of exhaust gas is provided in a pipe (gas exhaust pipe 332) connected to the exhaust gas outlet 322. In addition, a control valve 343 that adjusts the amount of liquefied CO ₂ to be discharged is provided in a pipe (liquid discharge pipe 333) connected to the liquid discharge port 323. By closing all of these control valves 341, 342, and 343, the inside of the pressure vessel 310 is completely sealed. In addition, the second exhaust gas can flow into the pressure vessel 310 by opening the control valve 341, and the third exhaust gas in the pressure vessel 310 can be discharged by opening the control valve 342, By opening the control valve 343, the liquefied CO ₂ can be discharged from the pressure vessel 310 and recovered.

Inside the pressure vessel 310, a refrigerant circulation pipe 312 made of metal (for example, copper or stainless steel) through which liquid nitrogen (LN ₂ ), which is a refrigerant, circulates is provided. The LN ₂ may be supplied from an LN ₂ cylinder, but a pipe that can circulate between the heat exchanger 550 of the refrigerator 500 and the pressure vessel 310 through the refrigerant circulation pipe 312. The LN _{2 that} is provided and cooled by the cold heat of the refrigerant circulating in the refrigerator 500 in the heat exchanger 550 may be supplied to the refrigerant flow pipe 312. In the case of such a configuration, it is necessary to use liquid nitrogen, liquid helium, or the like as a refrigerant circulating in the refrigerator 500.

  A control valve 344 for controlling the flow rate of the refrigerant is provided upstream of the refrigerant flow pipe 312. The refrigerant flow pipe 312 branches into two inside the pressure vessel 310 and is meandered inside the pressure vessel 310 in order to increase the contact efficiency with the exhaust gas flowing inside the pressure vessel 310.

  A heat transfer tube 313 is embedded in the wall surface of the pressure vessel 310. A control valve that controls the flow rate of the heat medium that flows through the heat transfer tube 313 is provided upstream of the heat transfer tube 313 (not shown). The heat medium is, for example, dry air, and the heat medium is transported from the heat source 314 to the heat transfer tube 313. As described above, the heat medium flows through the heat transfer tube 313, so that the inside of the pressure vessel 310 is heated. The heat medium may be a third exhaust gas that is discharged from the apparatus 300 and provides cold heat in the heat exchangers 400 and 410 and the dehumidifier (cooling dehumidifier) 200, or the refrigerator 500. The refrigerant may circulate between the heat exchanger 550 and the heat exchangers 400 and 410 and the dehumidifying device (cooling dehumidifying device) 200. By using the third exhaust gas or the refrigerant as a heat medium in this way, it is possible to absorb the cold heat in the pressure vessel 310, so that the heat exchangers 400 and 410 and the dehumidifier (cooling dehumidifier) 200 again. It becomes possible to provide cold heat. Thereby, the effective use of the energy as the whole system is achieved. The heat transfer tube 313 may be provided inside the pressure vessel 310 instead of being embedded in the wall surface of the pressure vessel 310. Instead of the heat transfer tube 313, an electrothermal heater (for example, a silicon rubber heater or a fluororesin heater) may be used.

  The pressure vessel 310 may be provided with various sensors such as a sensor that measures the temperature in the pressure vessel 310 and a sensor that measures the temperature of the outer surface of the refrigerant flow pipe 312. When various sensors are provided in this way, the output value of each sensor may be input to a measuring device or a computer (not shown) so that it can be monitored by an operator. Thereby, it becomes possible to grasp the temperature in the pressure vessel 310 and the temperature of the outer surface of the refrigerant flow pipe 312, and the carbon dioxide contained in the second exhaust gas can be efficiently processed.

  In the present embodiment, the pressure vessel 310 may be further provided with a small window through which the inside of the pressure vessel 310 can be visually observed. Thereby, the change of the carbon dioxide in the pressure vessel 310 can be confirmed.

Next, the processing procedure of the CO ₂ separation and liquefaction apparatus 300 will be described.
The second exhaust gas flowing into the pressure vessel 310 by opening the control valve 341 is cooled by the cold heat of the refrigerant flowing through the refrigerant flow pipe 312 provided in the pressure vessel 310. As a result, only carbon dioxide in the second exhaust gas is solidified and attached to the outer surface of the refrigerant flow pipe 312. The third exhaust gas from which carbon dioxide has been removed from the second exhaust gas by solidifying and adhering the carbon dioxide in the second exhaust gas is opened through the gas exhaust pipe 332 from the exhaust gas outlet 322 by opening the control valve 342. Discharged through.

  When the amount of dry ice adhering to the outer surface of the refrigerant flow pipe 312 reaches a predetermined amount by visually observing a small window provided in the pressure vessel 310 or after a predetermined time has passed, the control valves 341 and 342 are controlled. Is closed and the pressure vessel 310 is sealed. Further, the control valve 344 is closed to stop the refrigerant flow in the refrigerant flow pipe 312.

Next, the control valve is opened, the heat medium is circulated through the heat transfer tube 313, and the temperature in the pressure vessel 310 is raised. As the temperature in the pressure vessel 310 rises, dry ice attached to the outer surface of the refrigerant flow pipe 312 sublimates. Thereby, the pressure in the pressure vessel 310 is increased, and the vaporized carbon dioxide is liquefied. The liquefied CO ₂ accumulated at the bottom of the pressure vessel 310 is discharged through the liquid discharge pipe 333 and collected by opening the control valve 343. The determination of whether or not the dry ice is completely vaporized and liquefied can be made, for example, by looking through a small window provided in the pressure resistant vessel 310 or when a predetermined time has elapsed. Further, by setting the inside of the liquid discharge pipe 333 connected to the liquid discharge port 323 to a pressure and temperature at which carbon dioxide can be discharged in a liquid state, all of the liquefied CO ₂ can be recovered.

  After the recovery, the heat medium control valve is closed and the refrigerant control valve 344 is opened to cool the inside of the pressure vessel 310. After the pressure vessel 310 is cooled to a predetermined temperature, the control valves 341 and 342 are opened, and the second exhaust gas flows into the pressure vessel 310.

As described above, according to the CO ₂ separation and liquefaction apparatus 300 in one embodiment of the present invention, carbon dioxide contained in the second exhaust gas is efficiently separated, and liquefied CO ₂ that is convenient for transportation and storage can be obtained. It becomes possible to collect at a high concentration. In addition, since no special liquefaction device is required, the system can be reduced. Further, by providing a plurality of the CO ₂ separation and liquefaction apparatus 300 as described above in the power generation system 1000 according to the present invention and making it possible to select the CO ₂ separation and liquefaction apparatus 300 that supplies the second exhaust gas by a switching bubble or the like, dehumidification It becomes possible to continuously process the second exhaust gas supplied from the apparatus 200.

Moreover, according to the above-mentioned CO ₂ separation and liquefaction apparatus 300, since the apparatus configuration is simple as described above, it can be implemented at low cost. The control valves 341, 342, 343, and 344 and the heat medium control valve in the above-described CO ₂ separation and liquefaction apparatus 300 are electromagnetic valves, and a control line for controlling each electromagnetic valve is connected to a computer. The electromagnetic valve may be remotely controlled by computer hardware or control software operating on the hardware. Further, all or part of the above-described process may be automatically executed based on the output values of the various sensors. By controlling the computer hardware and control software in this way, the carbon dioxide is solidified and separated from the second exhaust gas, and the solidified carbon dioxide is liquefied by raising the temperature, and the liquefied CO ₂ is automatically converted. It can be recovered.

  Note that when the control valves 341 and 342 are opened, the temperature value in the pressure-resistant vessel 310 is changed via a storage device built in the personal computer, or a personal computer and a network (for example, a local area network (LAN)). For example, hardware (for example, a CPU) may determine that the threshold value is lower than the threshold value stored in the connected storage device. The control valves 341 and 342 are closed by, for example, measuring a difference between the pressure of the second exhaust gas flowing in from the exhaust gas inlet 321 and the pressure of the third exhaust gas discharged from the exhaust gas outlet 322 with a differential pressure gauge. For example, hardware (for example, a CPU or the like) may determine that the differential pressure has become larger than a predetermined value.

  The control valve 344 is closed by, for example, hardware (for example, a CPU) determining that the control valves 341 and 342 have started to be closed or the control valves 341 and 342 have been closed. It is good as well. On the other hand, when the control valve 344 is opened, the temperature in the pressure-resistant container 310 is measured by the above-described sensor, and the hardware (for example, CPU or the like) indicates that the measured temperature value is higher than a predetermined value. It is good also as judging and performing.

For opening the control valve 343, for example, hardware (for example, a CPU or the like) determines that the temperature in the pressure-resistant container 310 is measured by the above-described sensor and the measured temperature value is higher than a predetermined value. It may be done. On the other hand, the control valve 343 is closed when the liquefied CO ₂ does not remain in the pressure-resistant vessel 310 by, for example, a sensor that senses the discharge of the liquefied CO ₂ provided in the liquid discharge pipe 333, the liquid discharge port 323, or the like. When the determination is made, the sensor may notify the hardware (for example, a CPU or the like), and the hardware may receive the notification.

  The control valve for the heat medium may be opened when, for example, hardware (for example, a CPU) recognizes that the control valves 341, 342, and 344 are closed. Further, when the control valve for the heat medium is closed, the temperature in the pressure-resistant container 310 is measured by the above-described sensor. ) May be performed after judgment.

<About dehumidifying apparatus 200>
Next, the configuration and processing procedure of the dehumidifying device 200 included in the power generation system 1000 according to the present invention will be described in detail. FIG. 5 shows a schematic configuration diagram of a dehumidifying device 200 described as an embodiment of the present invention.

As shown in FIG. 5, the dehumidifying apparatus 200 includes a dehydrating tower 210, a separation tower 220, a cooling tower 230, and the like. The dehydration tower 210 includes a refrigerant, and the first exhaust gas supplied from the anode electrode of the fuel cell 100 is bubbled to the refrigerant, whereby the first exhaust gas is cooled to the second temperature and the first exhaust gas is cooled. It is a tower that liquefies or solidifies only the water therein, removes the water from the first exhaust gas to form the second exhaust gas, and discharges the second exhaust gas. The second exhaust gas from which moisture has been removed from the first exhaust gas in the dehydration tower 210 is supplied to the CO ₂ separation and liquefaction apparatus 300. The refrigerant provided in the dehydration tower 210 is, for example, dimethyl ether.

Separation tower 220 is a tower that separates ice, water, and refrigerant by elevating the temperature of a refrigerant containing ice and water using the heat of seawater to vaporize only the refrigerant. The cooling tower 230 cools the third exhaust gas supplied from the CO ₂ separation and liquefaction apparatus 300 to the anode electrode of the fuel cell 100 in order to liquefy the refrigerant separated by the separation tower 220, or the refrigerator 500 and the cooling tower. 230 is a tower that cools by using the cold heat of the refrigerant circulating through 230. Note that the refrigerant liquefied by cooling in the cooling tower 230 is supplied from the cooling tower 230 to the dehydrating tower 210 and reused in the dehydrating tower 210.

  As described above, by providing the power generation system 1000 according to the present invention with the dehumidifying device 200 as described above, the first exhaust gas can be cooled and moisture in the first exhaust gas can be removed. It is possible to efficiently use the refrigerant that cools the battery.

  In the present embodiment, the refrigerant including ice and water is supplied to the separation tower 220 in the dehydration tower 210. However, when the water is completely solidified in the dehydration tower 210, the separation tower 220 is used. Instead of this, a solid-liquid separation device (not shown) may be used to separate the solid (ice) and the liquid (refrigerant) by the solid-liquid separation device, and the separated liquid may be supplied to the cooling tower 230. As described above, by further providing the solid-liquid separation device in the dehumidifying device 200, the cooling tower 230 can quickly cool the refrigerant, so that the energy for cooling the refrigerant can be reduced. Note that the refrigerant separated by the solid-liquid separation device may be supplied to the dehydration tower 210 through a pipe connecting the solid-liquid separation device and the dehydration tower 210, for example. Moreover, when the liquid separated into the solid isolate | separated with the solid-liquid separator is good also as separating column 220, it is good also as collect | recovering liquids. As a result, the refrigerant can be prevented from decreasing and the refrigerant can be used effectively.

== Processing method of power generation system according to the present invention ===
<Power generation system with MCFC>
As an embodiment of the present invention, a processing method of the power generation system 1000 when the fuel cell 100 is a molten carbonate fuel cell (MCFC) will be described with reference to FIG.

As shown in FIG. 6, the power generation system 1000 according to the present embodiment includes a boiler 10, a denitration device 20, and a dust removal device 30 in addition to the MCFC 100 a, the cooler 410, the dehumidification device 200, and the CO ₂ separation and liquefaction device 300. , A desulfurization apparatus 40, a precision desulfurization apparatus 50, and a combustor 800.

  The boiler 10 is an apparatus that burns fuel such as petroleum, coal, and LNG to produce high-temperature and high-pressure steam and exhaust gas necessary for power generation by a gas turbine. The boiler 10 may be, for example, a pressurized fluidized bed boiler or a pulverized coal boiler. The denitration device 20 is a device that removes nitrogen oxides from the exhaust gas produced in the boiler 10. The denitration device 20 may be, for example, a dry denitration device that reduces nitrogen oxides to nitrogen and water using ammonia and a denitration catalyst (for example, zeolite, activated carbon, etc.), or a nitrogen oxide solution using a sodium peroxide aqueous solution. It may be a wet denitration apparatus that absorbs and removes water.

  The dedusting device 30 is a device that removes solid components (for example, dust) from the exhaust gas from which nitrogen oxides have been removed in the denitration device 20. The dust removing device 30 is, for example, an electric dust collector, a bag filter, a ceramic filter, or a cyclone. The desulfurization device 40 is a device that removes sulfur oxide from the exhaust gas dedusted in the dedusting device 30. The desulfurization device 40 may be, for example, a wet desulfurization device using a sulfur oxide absorbent such as lime water, limestone, magnesium hydroxide, calcium carbonate, or a sulfur oxide in a metal oxide such as iron oxide. It may be a dry desulfurization apparatus that adsorbs and removes the sulfur oxide with hydrogen sulfide.

  In the present embodiment, the exhaust gas is treated in the order of the denitration device 20, the dust removal device 30, and the desulfurization device 40, but the treatment of the exhaust gas by these devices 20, 30, 40 may be performed in any order. I do not care. In addition, when the above-described desulfurization apparatus 40 cannot sufficiently remove sulfur oxides, a precision desulfurization apparatus 50 may be further provided in the power generation system 1000 according to the present invention as shown in FIG. Thereby, sulfur oxide can be sufficiently removed. The precision desulfurization apparatus 50 is, for example, an apparatus that adsorbs and removes sulfur oxide using zinc.

  The combustor 800 burns a part of the first exhaust gas supplied from the anode electrode of the MCFC 100a to the dehumidifier 200 to convert carbon monoxide contained in the first exhaust gas into carbon dioxide, and converts the carbon dioxide into the MCFC 100a. This is a device that supplies the cathode electrode.

First, exhaust gas (including nitrogen oxides, dust, sulfur oxides, carbon dioxide, oxygen, nitrogen, etc.) discharged by burning petroleum, coal, or fuel gas in the boiler 10 By sequentially supplying the apparatus 30, the desulfurization apparatus 40, and the precision desulfurization apparatus 50, nitrogen oxides, dust, and sulfur oxides in the exhaust gas are removed, and the remaining carbon dioxide, oxygen, nitrogen, and the like are air (N ₂ and O ₂ ) to the cathode of MCFC 100a. On the other hand, hydrogen, carbon dioxide, carbon monoxide and the like are supplied to the anode electrode of the MCFC 100a.

In the MCFC 100a, carbon dioxide and oxygen supplied to the cathode electrode react with electrons energized through the power load to become carbonate ions (CO ₃ ²⁻ ), move to the anode electrode side, and hydrogen and oxygen supplied to the anode electrode Reacts with carbon monoxide to produce water, carbon dioxide, and electrons (electrical energy). Electrons generated at the anode electrode generate electricity by energizing a power load and moving to the cathode electrode.

  A part of the exhaust gas including hydrogen, carbon dioxide, and carbon monoxide that was not used at the anode electrode of the MCFC 100a, and moisture and carbon dioxide generated at the anode electrode are supplied to the combustor 800, and the rest is the cooler 410. And is supplied to the dehumidifier 200.

  The exhaust gas supplied to the combustor 800 is combusted by the combustor 800, whereby hydrogen contained in the exhaust gas is oxidized into water and carbon monoxide is oxidized into carbon dioxide. The exhaust gas containing oxidized carbon dioxide and moisture is cooled and supplied to the cathode electrode of the MCFC 100a. Thus, by converting carbon monoxide into carbon dioxide by the combustor 800, it becomes possible to provide carbon dioxide required at the cathode electrode of the MCFC 100a at a high concentration. Note that nitrogen, oxygen, carbon dioxide, and moisture that are not used in the cathode electrode of the MCFC 100a are discharged from the cathode electrode of the MCFC 100a.

On the other hand, the exhaust gas containing moisture, carbon dioxide, hydrogen, and carbon monoxide supplied to the dehumidifying device 200 is dehydrated in the dehumidifying device 200 and supplied to the CO ₂ separation and liquefaction device 300 as described above. CO ₂ was fed to a separation liquefier 300, carbon dioxide, hydrogen, and an exhaust gas containing carbon monoxide, in the CO ₂ separation liquefier 300, as described above, is separated into carbon dioxide and other components, dioxide Carbon will be recovered as liquefied CO ₂ .

In addition, components other than carbon dioxide (including hydrogen and carbon monoxide) separated in the CO ₂ separation and liquefaction device 300 are supplied to the cooler 410, and the dehumidification device 200 is removed from the anode electrode of the MCFC 100a by the cold heat of those components. The exhaust gas supplied to is cooled. Components other than carbon dioxide that has absorbed heat are supplied to the anode electrode of the MCFC 100a and used.

With the power generation system 1000 as described above, it is possible to generate power by effectively using carbon dioxide and oxygen in the exhaust gas discharged from the boiler 10, and to recover high-concentration liquefied CO _2. Become. Further, not only can the hydrogen and carbon monoxide separated in the CO ₂ separation and liquefaction apparatus 300 be used effectively, but also the cold heat that they have can be used effectively.

<Power generation system with SOFC>
Next, as an embodiment of the present invention, a processing method of the power generation system 1000 when the fuel cell 100 is a solid oxide fuel cell (SOFC) will be described with reference to FIG.

First, the mixed gas containing hydrogen, carbon dioxide, and carbon monoxide reformed from the fuel gas in the fuel gas reformer 700 is supplied to the anode electrode of the SOFC 100b. On the other hand, air (N ₂ and O ₂ ) is supplied to the cathode electrode of the SOFC 100b.

In the SOFC 100b, oxygen supplied to the cathode electrode reacts with electrons energized through the power load to become oxygen ions (O ²⁻ ), moves to the anode electrode side, and supplies hydrogen and carbon monoxide supplied to the anode electrode. It reacts to produce water, carbon dioxide, and electrons (electric energy). Electrons generated at the anode electrode generate electricity by energizing a power load and moving to the cathode electrode.

  Exhaust gas containing hydrogen, carbon dioxide, and carbon monoxide that are not used at the anode electrode of the SOFC 100b, and moisture and carbon dioxide generated at the anode electrode are cooled by the cooler 410 and supplied to the dehumidifier 200.

As described above, the exhaust gas containing moisture, carbon dioxide, hydrogen, and carbon monoxide supplied to the dehumidifier 200 is removed by the dehumidifier 200 and supplied to the CO ₂ separation and liquefaction device 300. CO ₂ was fed to a separation liquefier 300, carbon dioxide, hydrogen, and an exhaust gas containing carbon monoxide, in the CO ₂ separation liquefier 300, as described above, is separated into carbon dioxide and other components, dioxide Carbon will be recovered as liquefied CO ₂ .

In addition, components other than carbon dioxide (including hydrogen and carbon monoxide) separated in the CO ₂ separation and liquefaction device 300 are supplied to the cooler 410, and the dehumidification device 200 from the anode electrode of the SOFC 100b by the cold heat of those components. The exhaust gas supplied to is cooled. In addition, components other than carbon dioxide that has absorbed heat are supplied to the anode electrode of the SOFC 100b and used.

The power generation system 1000 as described above can not only generate power by effectively using the hydrogen and carbon monoxide separated in the CO ₂ separation and liquefaction apparatus 300, but also effectively utilize the cold heat that they have. In addition, a high concentration of liquefied CO ₂ can be recovered.

<Power generation system with PAFC>
Next, as an embodiment of the present invention, a processing method of the power generation system 1000 when the fuel cell 100 is a phosphoric acid fuel cell (PAFC) will be described with reference to FIG.

First, the mixed gas containing hydrogen, carbon dioxide, and carbon monoxide reformed from the fuel gas in the fuel gas reformer 700 is supplied to the anode electrode of the PAFC 100c. On the other hand, air (N ₂ and O ₂ ) is supplied to the cathode electrode of the PAFC 100c.

In the PAFC 100c, hydrogen supplied to the anode electrode is decomposed into hydrogen ions (H ⁺ ) and electrons (electric energy), and the electrons generate electricity by energizing a power load and moving to the cathode electrode. On the other hand, hydrogen ions move to the cathode electrode and are converted to water by oxygen and electrons supplied to the cathode electrode. Note that water generated at the cathode electrode, and nitrogen and oxygen not used at the cathode electrode are discharged from the cathode electrode.

  Exhaust gas containing hydrogen, carbon dioxide, carbon monoxide, and moisture (surplus of fuel reforming steam) that has not been used at the anode electrode of the PAFC 100c is cooled by the cooler 410 and supplied to the dehumidifier 200.

As described above, the exhaust gas containing moisture, carbon dioxide, hydrogen, and carbon monoxide supplied to the dehumidifier 200 is removed by the dehumidifier 200 and supplied to the CO ₂ separation and liquefaction device 300. CO ₂ was fed to a separation liquefier 300, carbon dioxide, hydrogen, and an exhaust gas containing carbon monoxide, in the CO ₂ separation liquefier 300, as described above, is separated into carbon dioxide and other components, dioxide Carbon will be recovered as liquefied CO ₂ .

In addition, components other than carbon dioxide (including hydrogen and carbon monoxide) separated in the CO ₂ separation and liquefaction device 300 are supplied to the cooler 410, and the dehumidifying device 200 is supplied from the anode electrode of the PAFC 100c by the cold heat of those components. The exhaust gas supplied to is cooled. In addition, components other than carbon dioxide that has absorbed heat are supplied to the anode electrode of the PAFC 100c and used.

The power generation system 1000 as described above can not only generate power by effectively using the hydrogen and carbon monoxide separated in the CO ₂ separation and liquefaction apparatus 300, but also effectively utilize the cold heat that they have. In addition, a high concentration of liquefied CO ₂ can be recovered.

<Power generation system with PEFC>
Next, as one embodiment of the present invention, a processing method of the power generation system 1000 when the fuel cell 100 is a polymer electrolyte fuel cell (PEFC) will be described with reference to FIG.

First, the mixed gas containing hydrogen and carbon dioxide reformed from the fuel gas in the fuel gas reformer 700 is supplied to the anode electrode of the PEFC 100d. On the other hand, air (N ₂ and O ₂ ) is supplied to the cathode electrode of the PEFC 100d.

In the PEFC 100d, hydrogen supplied to the anode electrode is decomposed into hydrogen ions (H ⁺ ) and electrons (electric energy), and the electrons generate electricity by energizing a power load and moving to the cathode electrode. On the other hand, hydrogen ions move to the cathode electrode and are converted to water by oxygen and electrons supplied to the cathode electrode. Note that water generated at the cathode electrode, and nitrogen and oxygen not used at the cathode electrode are discharged from the cathode electrode.

  Exhaust gas containing hydrogen, carbon dioxide, and moisture (surplus of fuel reforming steam) not used at the anode electrode of the PEFC 100d is cooled by the cooler 410 and supplied to the dehumidifier 200.

As described above, the exhaust gas containing hydrogen, carbon dioxide, and moisture supplied to the dehumidifying device 200 is dehydrated in the dehumidifying device 200 and supplied to the CO ₂ separation and liquefaction device 300. Supplied to the CO ₂ separation liquefier 300, exhaust gas containing hydrogen and carbon dioxide, is separated into carbon dioxide and other components in the CO ₂ separation liquefier 300, as described above, carbon dioxide as the liquefied CO ₂ It will be collected.

Further, components other than carbon dioxide (including hydrogen and the like) separated in the CO ₂ separation and liquefaction device 300 are supplied to the cooler 410, and are supplied to the dehumidifying device 200 from the anode electrode of the PEFC 100d by the cold heat of those components. The exhaust gas is cooled. In addition, components other than carbon dioxide that has absorbed heat are supplied to the anode electrode of PEFC 100d and used.

The power generation system 1000 as described above can not only generate power by effectively using the hydrogen separated in the CO ₂ separation and liquefaction apparatus 300, but also can effectively use the cold heat that they have, A high concentration of liquefied CO ₂ can be recovered.

It is a figure which shows schematic structure of the electric power generation system 1000 demonstrated as one Embodiment of this invention. It is a figure which shows schematic structure of the refrigerator for cooling the refrigerant | coolant which circulates through the dehumidification apparatus 200 and the heat exchangers 400 and 410 demonstrated as one Embodiment of this invention. It is a figure which shows the production | generation process of the mixed gas supplied to the anode electrode of the fuel cell 100 demonstrated as one Embodiment of this invention. It is a diagram showing a schematic configuration of a CO ₂ separator liquefier 300 to be described as an embodiment of the present invention. It is a figure which shows schematic structure of the dehumidification apparatus 200 demonstrated as one Embodiment of this invention. In one Embodiment of this invention, it is a figure which shows schematic structure of the electric power generation system whose fuel cell is a molten carbonate fuel cell (MCFC). In one Embodiment of this invention, it is a figure which shows schematic structure of the electric power generation system whose fuel cell is a solid oxide fuel cell (SOFC). In one Embodiment of this invention, it is a figure which shows schematic structure of the electric power generation system whose fuel cell is a phosphoric acid fuel cell (PAFC). In one Embodiment of this invention, it is a figure which shows schematic structure of the electric power generation system whose fuel cell is a polymer electrolyte fuel cell (PEFC).

Claims (10)

A fuel cell;
A dehumidifier that removes moisture from the first exhaust gas containing moisture, hydrogen, and carbon dioxide supplied from the anode electrode of the fuel cell to form a second exhaust gas, and discharges the second exhaust gas;
The second exhaust gas discharged by the dehumidifying device is cooled to a first temperature for solidifying only the carbon dioxide, and the carbon dioxide in the second exhaust gas is solidified to form the carbon dioxide from the second exhaust gas. A carbon dioxide separation and liquefaction device for discharging a third exhaust gas containing hydrogen separated and removed, raising the temperature to liquefy the solidified carbon dioxide, and discharging the liquefied carbon dioxide;
Means for supplying the third exhaust gas discharged by the carbon dioxide separation and liquefaction device to the anode electrode of the fuel cell;
Only including,
The carbon dioxide separation and liquefaction device is
An exhaust gas inlet for receiving the second exhaust gas supplied from the dehumidifier;
A refrigerant circulation pipe that cools the second exhaust gas and solidifies carbon dioxide in the second exhaust gas to adhere to the outer surface;
An exhaust gas outlet for discharging the third exhaust gas;
Opening and closing means for each of opening and closing the exhaust gas inlet and the exhaust gas outlet,
A pressure vessel having
A temperature raising means for raising the temperature of the carbon dioxide solidified in the pressure vessel;
An exhaust means for discharging the liquefied carbon dioxide obtained by sealing the exhaust gas inlet and the exhaust gas outlet by the opening and closing means and raising the temperature of the solidified carbon dioxide by the temperature raising means,
Power generation system characterized by including Mukoto a. And further comprising a heat exchanger that cools the first exhaust gas supplied from the anode electrode of the fuel cell to the dehumidifier using the cold heat of the third exhaust gas supplied to the anode electrode of the fuel cell. The power generation system according to claim 1 . It further includes a heat exchanger that cools the second exhaust gas supplied from the dehumidifier to the carbon dioxide separation and liquefaction device using the cold heat of the third exhaust gas supplied to the anode electrode of the fuel cell. The power generation system according to claim 1 or 2 . Reformed fuel gas to the mixed gas containing hydrogen and carbon dioxide, one of the claims 1-3, characterized in that it further includes a fuel gas reformer for supplying the mixed gas to the anode of the fuel cell The power generation system according to Crab. The dehumidifier cools the first exhaust gas supplied from the anode electrode of the fuel cell to a second temperature that does not solidify the carbon dioxide but liquefies or solidifies the water, and in the first exhaust gas 2. A cooling type dehumidifier that liquefies or solidifies the water to remove the water from the first exhaust gas to form the second exhaust gas, and discharges the second exhaust gas. The power generation system according to any one of to 4 . The dehumidifier further includes means for cooling the first exhaust gas to the second temperature by using the cold heat of the third exhaust gas supplied to the anode electrode of the fuel cell. Item 6. The power generation system according to Item 5 . The dehumidifying device is
The first exhaust gas is passed through a first refrigerant and cooled to the second temperature, the moisture in the first exhaust gas is solidified to remove the moisture from the first exhaust gas, and A dehydration unit that discharges the second exhaust gas,
A separation unit that separates the solidified first refrigerant containing the moisture into the solidified moisture and the first refrigerant;
Means for supplying the separated first refrigerant to the dewatering unit;
Power generation system according to any one of claims 1 to 4, characterized in that it comprises a. The fuel cell is any one device selected from the group consisting of a molten carbonate fuel cell, a solid oxide fuel cell, a phosphoric acid fuel cell, and a solid polymer fuel cell. Item 8. The power generation system according to any one of Items 1 to 7 . Combusting a part of the first exhaust gas supplied from the molten carbonate fuel cell to the dehumidifying device to oxidize carbon monoxide contained in the first exhaust gas into carbon dioxide, and converting the carbon dioxide into the carbon dioxide The power generation system according to claim 8 , further comprising a combustor that supplies the cathode of the molten carbonate fuel cell. A boiler that burns oil, coal, or fuel gas;
A denitration device for removing nitrogen oxides contained in the fourth exhaust gas discharged from the boiler;
A dedusting device for removing solid components contained in the fourth exhaust gas from which nitrogen oxides have been removed by the denitration device;
A desulfurization device for removing sulfur oxides contained in the fourth exhaust gas from which the solid component has been removed by the dedusting device;
Means for supplying the fourth exhaust gas from which the sulfur oxide has been removed by the desulfurizer to the cathode electrode of the molten carbonate fuel cell;
The power generation system according to claim 8 or 9 , further comprising: