JP2016184456A - Gas manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable miniaturization of an off-gas tank while suppressing influence on a gas purification step.SOLUTION: A gas production apparatus includes a hydrogen separation unit 20 (gas purification unit) for separating impurities from supplied gas to purify the gas into product gas, and discharging off-gas containing the impurities, an off gas tank 21 for storing the off-gas discharged from the hydrogen separation unit 20, a solid oxide type fuel cell FC for generating electric power using the off-gas stored in the off-gas tank 21, and off-gas supply controller 34 for supplying off-gas from the off-gas tank 21 to the fuel cell FC. The off-gas supply controller 34 changes the supply quantity of the off-gas to the fuel cell FC based on at least one of process information relating to the purification of the product gas being conducted by the hydrogen separation unit 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas production apparatus having a gas purification unit that discharges off-gas.

  In recent years, hydrogen production apparatuses that produce hydrogen on-site using natural gas or city gas as a raw material gas have been developed. Such an apparatus for hydrogen production is used for industrial applications such as bright annealing of metals such as steel plates and glass production, and is installed in various places as hydrogen stations for supplying hydrogen to fuel cell vehicles.

  As an example of such a hydrogen production apparatus, a desulfurizer that desulfurizes the raw material gas fed by the pressure feeder, a reformer that obtains a reformed gas by heating the raw material gas after desulfurization in a mixed state with water vapor, A CO converter that obtains a hydrogen-rich gas by reacting carbon monoxide in the reformed gas from the reformer with water vapor, and a hydrogen purifier (PSA system) that purifies hydrogen by separating impurities other than hydrogen from the hydrogen-rich gas. (Apparatus used) is known (Patent Document 1).

Japanese Patent Laying-Open No. 2015-30655

  In the above-described hydrogen production apparatus, off-gas containing impurities is discharged along with the separation of impurities in the hydrogen purification unit. Conventionally, off gas discharged is stored in a tank or the like and used for heating a reformer of a hydrogen production apparatus. In order to smoothly transfer off-gas from the hydrogen purification unit to the tank, a large tank having a large capacity is used, which is a cause of increasing the installation area and installation cost of the hydrogen production apparatus.

  In order to reduce the installation cost of the hydrogen production apparatus, it is conceivable to reduce the size of the tank. However, when the tank is downsized, the pressure in the tank when the off-gas is transferred to the tank increases, which hinders the off-gas transfer and requires a longer time for the hydrogen purification process.

  The present invention has been made in view of the above-described problems, and an object thereof is to enable downsizing of a tank for storing off-gas while suppressing an influence on a gas purification process.

  In order to achieve the above object, the characteristic configuration of the gas production apparatus according to the present invention includes a gas purification unit that separates and purifies impurities from a supplied gas to obtain a product gas and discharges offgas containing the impurities, An offgas tank that stores the offgas discharged from the gas purification unit, a solid oxide fuel cell that generates electric power using the offgas stored in the offgas tank, and the offgas from the offgas tank to the fuel cell An off-gas supply control unit that supplies the pressure of the off-gas stored in the off-gas tank, a flow rate of the off-gas sent from the gas purification unit to the off-gas tank, and the gas purification Based on at least one of the process information relating to product gas purification performed in In terms of changing the supply amount of the gas.

  According to the above characteristic configuration, impurities are separated from the supplied gas and purified to obtain a product gas, and a gas purification unit that discharges offgas containing impurities, and an off gas that stores offgas discharged from the gas purification unit. A gas tank; a solid oxide fuel cell that generates power using off gas stored in the off gas tank; and an off gas supply control unit that supplies off gas from the off gas tank to the fuel cell. Offgas to the fuel cell based on at least one of the pressure of the offgas stored in the gas tank, the flow rate of the offgas sent from the gas purification unit to the offgas tank, and the process information on the purification of the product gas performed in the gas purification unit Since the supply amount of the gas is changed, when the offgas is transferred to the offgas tank, the pressure inside the offgas tank becomes excessive It is possible to suppress the occurrence of disturbed by resulting situation.

  If it explains, if the pressure (off gas pressure) of off gas stored in an off gas tank becomes high, possibility that the transfer of off gas (off gas transfer) from a gas refining part to an off gas tank will become high. Therefore, if the amount of off gas supplied to the fuel cell is changed based on the pressure of the off gas stored in the off gas tank, it is possible to suppress the off gas pressure from becoming excessive. For example, when the amount of off gas supplied to the fuel cell is increased, the amount of off gas flowing out of the off gas tank increases, which acts in the direction of decreasing the off gas pressure. Therefore, with the above-described characteristic configuration, it is possible to suppress the occurrence of a situation where off-gas transfer is hindered, and it is possible to smoothly transfer off-gas to the off-gas tank. Therefore, it is possible to reduce the size of the off-gas tank while suppressing the influence on the gas purification process.

  Moreover, when the flow rate of off gas sent to the off gas tank is large, an increase in off gas pressure is expected. Furthermore, the off-gas pressure may be expected to increase depending on the stage of the product gas purification performed in the gas purification unit (process information related to the product gas purification). For example, when a process in which a large amount of off gas is generated in the gas purification unit is started, it can be expected that the off gas pressure will increase. Therefore, it is possible to suppress the off gas pressure from becoming excessive by changing the off gas supply amount to the fuel cell based on the off gas flow rate or the above-described process information. Therefore, with the above-described characteristic configuration, it is possible to suppress the occurrence of a situation where off-gas transfer is hindered, and it is possible to smoothly transfer off-gas to the off-gas tank. Therefore, it is possible to reduce the size of the off-gas tank while suppressing the influence on the gas purification process.

  Another characteristic configuration of the gas manufacturing apparatus according to the present invention is that the off-gas supply control unit is configured so that when the pressure of the off-gas stored in the off-gas tank exceeds a preset threshold, the off-gas tank removes the fuel cell from the off-gas tank. It is in the point which increases the supply amount of the said off gas to.

  According to the above characteristic configuration, the off gas supply control unit increases the amount of off gas supplied from the off gas tank to the fuel cell when the pressure of the off gas stored in the off gas tank exceeds a preset threshold value. It is possible to more appropriately suppress an excessive increase in the offgas pressure, to suppress the occurrence of a situation in which the offgas transfer is hindered, and to smoothly transfer the offgas to the offgas tank. Therefore, it is possible to reduce the size of the off-gas tank while suppressing the influence on the gas purification process.

  Another characteristic configuration of the gas manufacturing apparatus according to the present invention is that the off-gas supply control unit is configured so that when the pressure of the off-gas stored in the off-gas tank exceeds a preset threshold, the off-gas tank removes the fuel cell from the off-gas tank. It is in the point which increases the supply amount of the said off gas to.

  According to the above characteristic configuration, the off gas supply control unit increases the amount of off gas supplied from the off gas tank to the fuel cell when the pressure of the off gas stored in the off gas tank exceeds a preset threshold value. It is possible to more appropriately suppress an excessive increase in the offgas pressure, to suppress the occurrence of a situation in which the offgas transfer is hindered, and to smoothly transfer the offgas to the offgas tank. Therefore, it is possible to reduce the size of the off-gas tank while suppressing the influence on the gas purification process.

  Another characteristic configuration of the gas manufacturing apparatus according to the present invention is that the off-gas supply control unit is configured to switch the off-gas tank when the flow rate of the off-gas sent from the gas purification unit to the off-gas tank exceeds a preset threshold value. From this point, the supply amount of the off gas to the fuel cell is increased.

  According to the above characteristic configuration, the off gas supply control unit increases the supply amount of the off gas from the off gas tank to the fuel cell when the flow rate of the off gas sent from the gas purification unit to the off gas tank exceeds a preset threshold value. Therefore, it is possible to more appropriately suppress the excessive increase in the offgas pressure based on the increasing tendency of the offgas flow rate, to suppress the occurrence of the situation in which the offgas transfer is hindered, and to smoothly transfer the offgas to the offgas tank. . Therefore, it is possible to reduce the size of the off-gas tank while suppressing the influence on the gas purification process.

Another characteristic configuration of the gas production apparatus according to the present invention is that the gas purification unit has an adsorption tower that is purified by adsorbing the impurities from an supplied gas to an adsorbent to produce a product gas. Performing an off-gas discharge step of discharging the off-gas and sending it to the off-gas tank,
The offgas supply control unit is configured to increase the supply amount of the offgas from the offgas tank to the fuel cell when the gas purification unit receives the process information indicating that the offgas discharge process has started. .

  According to said characteristic structure, a gas refinement | purification part has an adsorption tower which makes an adsorbent adsorb | sucks impurities from the supplied gas, and makes it a product gas, discharges offgas from an adsorption tower, and sends it to an offgas tank The off gas discharge process is performed, and the off gas supply control unit increases the supply amount of the off gas from the off gas tank to the fuel cell when the gas purification unit receives process information indicating that the off gas discharge process has started. Therefore, an excessive increase in the offgas pressure accompanying the start of the desorption process can be more appropriately suppressed, and the occurrence of a situation in which the offgas transfer is hindered can be suppressed, and the offgas can be smoothly transferred to the offgas tank. Therefore, it is possible to reduce the size of the off-gas tank while suppressing the influence on the gas purification process.

Schematic of the hydrogen production apparatus according to the first embodiment Explanatory drawing of the operating state of the hydrogen separator Explanatory drawing of off gas supply operation concerning a 1st embodiment Schematic of the hydrogen production apparatus according to the second embodiment Explanatory drawing of off gas supply operation concerning a 3rd embodiment

<First Embodiment>
Hereinafter, a hydrogen production apparatus 100 as an example of a gas production apparatus will be described with reference to FIG. The hydrogen production apparatus 100 includes a reforming unit 10, a hydrogen separation unit 20, a fuel cell FC, a control device 30 that controls them, and the like. The control device 30 includes a reforming unit control unit 31 that controls the operation of the reforming unit 10, a hydrogen separation unit control unit 32 that controls the operation of the hydrogen separation unit 20, and a fuel cell control that controls the operation of the fuel cell FC. And an off-gas supply controller 34 that controls supply of off-gas to the fuel cell FC.

[Reformer]
The reforming unit 10 reforms a raw material gas containing hydrocarbon (for example, a city gas 13A mainly composed of methane) to obtain a reformed gas containing hydrogen. The reforming unit 10 includes a desulfurizer 12 that desulfurizes the raw material gas compressed by the compressor 11, and a reformer 13 that mixes and heats the desulfurized raw material gas with water vapor (pure water) to obtain a reformed gas. And a CO converter 17 for reacting carbon monoxide in the reformed gas from the reformer 13 with water vapor.

  The desulfurizer 12 is filled with a Ni—Mo-based, ZnO-based or other desulfurization catalyst, and sulfur components such as an odorant in the raw material gas are removed by the desulfurization catalyst. As a result, the raw material gas has a property that hardly degrades the reforming catalyst filled in the reformer 13.

  The reformer 13 heats the reforming catalyst by burning the supplied gas (fuel gas) in order to maintain the reforming catalyst (for example, nickel-based catalyst) filled in the reformer 13 at the catalyst activation temperature. A burner device 14 (heating means) is provided. The burner device 14 is supplied with off-gas generated in a hydrogen separator 20 (described later) as fuel gas. And the reformer 13 and the burner apparatus 14 are arrange | positioned inside the reforming furnace 13a. Combustion exhaust gas of about 900 ° C. is generated by the combustion of off-gas in the burner device 14. In the burner device 14, the supplied off gas and combustion air are mixed and burned with an appropriate air-fuel ratio.

  The flow path L2 for supplying the raw material gas to the reformer 13 is provided with a mixing unit 16 for mixing the vaporized water heated by the heat exchanger 15 for heating pure water with the heat of the exhaust gas and the raw material gas. It promotes the mixing of water vapor into the raw material gas.

  The CO converter 17 is filled with a carbon monoxide conversion catalyst, and carbon monoxide in the reformed gas reacts with water vapor and is converted into hydrogen and carbon dioxide. As the carbon monoxide shift catalyst, there are high temperature, medium temperature, and low temperature, and an appropriate one is used according to the operating temperature. Examples of the high temperature catalyst having an operating temperature of 300 to 450 ° C. include an iron-chromium-based catalyst, and the intermediate temperature catalyst having an operating temperature of 180 to 450 ° C. and the low temperature catalyst having a operating temperature of 190 to 250 ° C. For example, a copper-zinc catalyst can be mentioned. Moreover, these high temperature, medium temperature, and low temperature catalysts can be used in combination of two or more.

  By the reaction in the CO converter 17, the reformed gas contains hydrogen, carbon monoxide, carbon dioxide, and methane, and the hydrogen concentration becomes a mixed gas of 64 to 96% by volume. After being discharged from 17 and heat-cooled with cooling water in the heat exchanger 18 and cooled down, the water-vapor separation unit 19 removes water vapor and the like, and then is guided to the hydrogen separation unit 20.

  That is, in the hydrogen production apparatus 100, as shown in FIG. 1, after the raw material gas passes through the valve V1, it is pumped by the compressor 11, flows through the flow path L1, and is led to the desulfurizer 12 for desulfurization. Then, it is led to the reformer 13 through the flow path L2 in which the mixing section 16 for mixing the steam is provided and reformed, and is converted by the CO converter 17 through the flow path L3. After being led to the gas-liquid separation part 19 through the arranged flow path L4, it is led to the hydrogen separation part 20 via the flow path L5.

  The combustion exhaust gas generated by the combustion of the off gas in the burner device 14 is discharged from the reforming furnace 13a through the flow passage L13 (combustion exhaust gas passage) and sent to the fuel cell FC described later. The combustion exhaust gas contains hydrogen, carbon monoxide, hydrocarbons, and the like that can be used for power generation in the fuel cell FC.

(Hydrogen separation part)
The hydrogen separation unit 20 (gas purification unit) may be abbreviated as a pressure swing adsorption method (hereinafter referred to as PSA method) in order to separate impurities other than hydrogen from the reformed gas reformed by the reforming unit 10. ) Can be implemented. That is, the hydrogen separation unit 20 (gas purification unit) is a pressure fluctuation adsorption type gas purification device. The hydrogen separation unit 20 includes a plurality (three in this embodiment) of adsorption towers 20 a, 20 b, and 20 c and an offgas tank 21.

  Each of the adsorption towers 20a, 20b, and 20c is filled with a combination of a zeolite-based adsorbent, activated carbon, silica gel, or the like as an adsorbent. In each of the adsorption towers 20a, 20b, and 20c, the adsorption process, the pressure equalization process, the pressure reduction process, the cleaning process, and the pressure increase process are executed with different phases in the plurality of adsorption towers 20a, 20b, and 20c, The hydrogen-rich gas can be supplied as product hydrogen (product gas). Although detailed explanation is omitted, the above-described process is sequentially executed by opening and closing a plurality of valves (not shown) provided in the flow passage. The hydrogen-rich gas having a hydrogen concentration of 99.999% by volume purified by the hydrogen separation unit 20 is supplied as product hydrogen via the valve V5 of the flow path L6.

  On the other hand, the off-gas after the hydrogen is separated by the hydrogen separator 20 is temporarily stored in an off-gas tank 21 connected to each adsorption tower 20a, 20b, 20c via a valve V2. Since the off gas stored in the off gas tank 21 contains a combustible gas such as hydrogen or methane, the off gas is led to the burner device 14 through the flow path L8 and used as a fuel gas for heating the reformer 13.

  The off gas stored in the off gas tank 21 includes fuel components that can be used for power generation in a fuel cell such as hydrogen, carbon monoxide, and hydrocarbons. Therefore, in the present embodiment, the off-gas is led to the fuel cell FC via the flow path L17 and the valve V14 and used for the power generation reaction in the fuel cell FC.

  The off gas tank 21 is provided with a pressure sensor P that measures the pressure of the off gas stored in the off gas tank 21. Then, the off-gas supply control unit 34 of the control device 30 adjusts the opening of the valve V14 based on the off-gas pressure measured by the pressure sensor P, thereby controlling the off-gas supply amount to the fuel cell FC.

[Operating state of hydrogen separator]
Here, with reference to FIG. 2, the details of the operating state of the hydrogen separator 20 and the timing at which the off-gas is discharged from the hydrogen separator 20 will be described.

  The left, center, and right diagrams in the upper part of FIG. 2 show the states of the adsorption towers 20a, 20b, and 20c in steps 1, 2, and 3, respectively. The table in the lower part of FIG. 2 represents the process and pressure transition performed in the adsorption towers 20a, 20b, and 20c in steps 1 to 9.

  In step 1, the adsorption step is performed in the adsorption tower 20a for a time t1. Specifically, the reformed gas is supplied to the adsorption tower 20a, and impurities (water, carbon dioxide, carbon monoxide, methane, nitrogen, etc.) contained in the reformed gas are adsorbed by the adsorbent. The gas in the adsorption tower 20a, which has been purified to high purity due to the adsorption of impurities onto the adsorbent, is discharged as product hydrogen (product gas) from the flow path L6.

  At this time, a pressure equalization step is performed in the adsorption towers 20b and 20c. Specifically, the adsorption tower 20b immediately after the completion of the cleaning process and the adsorption tower 20c immediately after the completion of the adsorption process are connected, gas moves from the adsorption tower 20c to the adsorption tower 20b, and the pressure becomes uniform.

  In step 2, during the time t2, the adsorption step is continued in the adsorption tower 20a. A pressure increasing step is performed in the adsorption tower 20b. Specifically, the outlet side of the adsorption tower 20a and the adsorption tower 20b are connected, product hydrogen is supplied to the adsorption tower 20b, and the pressure in the adsorption tower 20b increases.

  At this time, the depressurization step is performed in the adsorption tower 20c. Specifically, the adsorption tower 20c is depressurized, the impurities adsorbed on the adsorbent are desorbed, and off-gas is generated. The generated off gas is stored in the off gas tank 21.

  In step 3, during the time t3, the adsorption process is continued in the adsorption tower 20a and the pressure increasing process is continued in the adsorption tower 20b.

  At this time, a cleaning process is performed in the adsorption tower 20c. Specifically, product hydrogen is supplied into the adsorption tower 20c, and the remaining impurities are desorbed from the adsorbent. The gas in the adsorption tower 20c containing the desorbed impurities is stored in the offgas tank 21 as offgas.

  In subsequent steps 4 to 6, the adsorption process is performed in the adsorption tower 20b, the pressure equalizing process to the pressure increasing process is performed in the adsorption tower 20c, and the pressure equalizing process, the pressure reducing process, and the washing process are performed in the adsorption tower 20a. In steps 7 to 9, the same process is performed by changing the role between the adsorption towers 20a, 20b, and 20c, and the process returns to step 1 thereafter.

  Thus, product hydrogen is continuously produced | generated by repeating steps 1-9 in adsorption tower 20a, 20b, 20c. Then, off-gas is generated in the decompression process in steps 2, 5, 8, and the washing process in steps 3, 6, 9. The off-gas is discharged from the hydrogen separator 20, sent to the off-gas tank 21, and stored.

〔Fuel cell〕
The fuel cell FC is a solid oxide fuel cell that generates electric power using off-gas discharged from the hydrogen separation unit 20 (gas purification unit). In the present embodiment, the off gas is supplied from the off gas tank 21 to the fuel cell FC through the flow paths L17 and L18.

The fuel cell FC used in the present embodiment is in the form of a solid oxide, and on one side of an electrolyte membrane composed of a solid oxide dense body having oxide ion conductivity, an oxide ion and electron conductive porous A plurality of single cells are formed by joining an air electrode made of a body and joining a fuel electrode made of an electron conductive porous body on the other side. Then, air (oxygen-containing gas) is supplied to the air electrode, and a gas containing fuel such as hydrogen, carbon monoxide, or hydrocarbon is supplied to the fuel electrode and operated at an operating temperature of about 700 ° C. Then, oxygen molecules O ₂ in the air electrode is an electron e ^- is reacted with ^2-oxygen molecular ion O and generated, the oxygen molecular ion O ^2- passes through the electrolyte membrane to move to the fuel electrode, supplying the fuel electrode The generated fuel molecules react with the oxygen molecular ions O ²⁻ , whereby an electromotive force E is generated between the fuel electrode and the air electrode, and the electromotive force E can be taken out and used.

  The off gas supplied to the fuel electrode of the fuel cell FC is sent from the off gas tank 21 to the heat exchanger 27 through the flow path L17, and is discharged from the fuel cell FC in the heat exchanger 27 (fuel cell exhaust gas). ) Receive heat from and be heated. The off-gas that has become high temperature in the heat exchanger 27 is sent to the mixing valve V16 (off-gas mixing unit) through the flow path L18, and is mixed with the combustion exhaust gas from the reforming furnace 13a by the mixing valve V16.

  The off-gas mixed with the combustion exhaust gas is heat-exchanged with the air from the blower 24 by the heat exchanger 26 and then supplied to the fuel electrode of the fuel cell FC. Then, after being used for the power generation reaction in the fuel cell FC, it is discharged as anode exhaust gas from the flow passage L14.

  Air from the blower 24 is supplied to the air electrode of the fuel cell FC through the flow path L15. A heat exchanger 25 and a heat exchanger 26 are provided in the flow path L15. The air from the blower 24 is heated by exchanging heat with the cathode exhaust gas discharged from the fuel cell FC in the heat exchanger 25, and in the heat exchanger 26, the mixed gas of the combustion exhaust gas and off-gas in the burner device 14. Heated with heat exchange. Then, after being used for the power generation reaction in the fuel cell FC, the heat from the blower 24 is given heat by the heat exchanger 25 and then discharged as cathode exhaust gas through the flow passage L16.

[Off gas supply operation]
As described above, in the hydrogen production device 100 according to the first embodiment, the off gas supply control unit 34 of the control device 30 adjusts the opening degree of the valve V14 based on the off gas pressure p measured by the pressure sensor P of the off gas tank 21. Thus, the supply amount of the off gas to the fuel cell FC is controlled. Specifically, when the off-gas pressure p increases and exceeds a preset pressure threshold value SP, the valve V14 is opened to increase the supply amount of off-gas to the fuel cell FC from zero to a predetermined value. . Thereafter, the opening degree of the valve V14 is increased or decreased according to the off-gas pressure p, and the off-gas supply control unit 34 controls the off-gas supply to the fuel cell FC so that the off-gas pressure p in the off-gas tank 21 does not exceed the pressure threshold value SP. Control the supply amount.

  FIG. 3 shows an example of an off-gas supply operation to the fuel cell FC performed by the hydrogen production apparatus 100 according to the first embodiment. The transition of the off gas pressure p when the off gas supply operation is not performed is indicated by a thin line in the graph. In this case, when the degassing step is started in the adsorption tower and the off gas is supplied from the adsorption tower to the off gas tank 21, the off gas pressure p rises and a high pressure peak occurs.

  On the other hand, when the off gas supply operation according to the present embodiment is performed (thick line), when the off gas pressure p increases and reaches the pressure threshold value SP, the off gas is supplied from the off gas tank 21 to the fuel cell FC. Further, the off-gas pressure p does not increase. For a while, the off-gas pressure p is maintained at the same level as the pressure threshold SP. Thereafter, the amount of off-gas transferred from the adsorption tower to the off-gas tank 21 decreases, and the off-gas pressure p in the off-gas tank 21 decreases accordingly, and the supply of off-gas from the off-gas tank 21 to the fuel cell FC is also stopped. Then, when the next decompression process in another adsorption tower starts, the same operation is repeated. Thus, when the off gas supply operation according to the present embodiment is performed, an excessive increase in the off gas pressure p in the off gas tank 21 is suppressed.

  As described above, the hydrogen production apparatus 100 according to the first embodiment separates and purifies impurities from the supplied gas to produce a product gas, and discharges offgas containing impurities (gas purification unit 20). ), An offgas tank 21 for storing offgas discharged from the hydrogen separator 20, a solid oxide fuel cell FC that generates power using the offgas stored in the offgas tank 21, and a fuel cell FC from the offgas tank 21. The off-gas supply control unit 34 supplies off-gas to the fuel cell FC based on the off-gas pressure stored in the off-gas tank 21. The offgas supply control unit 34 increases the supply amount of offgas from the offgas tank 21 to the fuel cell FC when the pressure of the offgas stored in the offgas tank 21 exceeds a preset pressure threshold value SP.

Second Embodiment
As shown in FIG. 4, in the hydrogen production apparatus 100 according to the second embodiment, a flow rate sensor FM is provided in the flow path L <b> 21 between the adsorption towers 20 a, 20 b, 20 c and the offgas tank 21 instead of the pressure sensor P. It is done. Then, based on the off-gas flow f measured by the flow sensor FM, the off-gas supply controller 34 of the control device 30 adjusts the opening of the valve V14, thereby controlling the amount of off-gas supplied to the fuel cell FC. In addition, the same code | symbol is attached | subjected about the structure similar to 1st Embodiment.

  The off gas supply operation from the off gas tank 21 to the fuel cell FC according to the second embodiment will be specifically described. When the depressurization process starts in the adsorption tower and the off gas is supplied from the adsorption tower to the off gas tank 21, the flow rate f of the off gas in the flow path L21 increases. When the flow rate f exceeds a preset threshold value, the off gas supply control unit 34 opens the valve V14 to increase the supply amount of the off gas to the fuel cell FC from zero to a predetermined value. Thereafter, the opening degree of the valve V14 is increased or decreased according to the flow rate f, and the offgas supply control unit 34 controls the supply amount of the offgas to the fuel cell FC so that the offgas flow rate f in the flow path L21 does not exceed the threshold value. . By performing the above supply operation, an excessive increase in the pressure of the off gas in the off gas tank 21 is suppressed.

  As described above, the hydrogen production apparatus 100 according to the second embodiment separates and purifies impurities from the supplied gas to produce a product gas, and discharges offgas containing impurities (gas purification unit 20). ), An offgas tank 21 for storing offgas discharged from the hydrogen separator 20, a solid oxide fuel cell FC that generates power using the offgas stored in the offgas tank 21, and a fuel cell FC from the offgas tank 21. An off-gas supply control unit 34 for supplying off-gas to the fuel cell FC based on the flow rate of the off-gas sent from the hydrogen separation unit 20 to the off-gas tank 21. To do. Then, the off gas supply control unit 34 increases the supply amount of the off gas from the off gas tank 21 to the fuel cell FC when the flow rate of the off gas sent from the hydrogen separation unit 20 to the off gas tank 21 exceeds a preset threshold value.

<Third Embodiment>
The hydrogen production apparatus 100 according to the third embodiment has the same configuration as that of the first embodiment, and is based on the process information relating to the purification of the product gas performed in the hydrogen separator 20, and is off-gas to the fuel cell FC. The supply amount is controlled. Specifically, when the depressurization process is started in any of the adsorption towers 20a, 20b, and 20c, the hydrogen separator control unit 32 sends process information indicating that the depressurization process has started to the off-gas supply control unit 34. The off gas supply control unit 34 that has received the process information opens the valve V14 and supplies the off gas from the off gas tank 21 to the fuel cell FC. Then, after the elapse of a preset time T, the off-gas supply controller 34 closes the valve V14 and stops the supply of off-gas to the fuel cell FC.

FIG. 5 shows an example of an off-gas supply operation to the fuel cell FC performed by the hydrogen production apparatus 100 according to the third embodiment. Similarly to FIG. 3, the transition of the offgas pressure in the offgas tank 21 when the offgas supply operation is not performed is indicated by a thin line in the graph. At time t1, the depressurization process starts in the adsorption tower, off gas is supplied from the adsorption tower to the off gas tank 21, the off gas pressure p in the off gas tank 21 increases, and a high pressure peak occurs.
On the other hand, when the off gas supply operation according to the present embodiment is performed (thick line), when the depressurization process is started in the adsorption tower at time t1, the supply of the off gas to the fuel cell FC is started and the off gas is supplied from the off gas tank 21. Leaks. As a result, an increase in off-gas pressure is suppressed compared to a case where no off-gas supply operation is performed (thin line). When the valve V14 is closed and the supply of the off gas to the fuel cell FC is stopped at time t2 after the time T has elapsed, the off gas pressure rises again. Thereafter, the same operation is repeated at times t3, t5, t7, and t9.

  As described above, the hydrogen production apparatus 100 according to the third embodiment separates and purifies impurities from the supplied gas to produce a product gas and discharges offgas containing impurities (gas purification unit 20). ), An offgas tank 21 for storing offgas discharged from the hydrogen separator 20, a solid oxide fuel cell FC that generates power using the offgas stored in the offgas tank 21, and a fuel cell FC from the offgas tank 21. An off-gas supply control unit 34 for supplying off-gas to the fuel cell FC based on at least one of the process information relating to the purification of the product gas performed in the hydrogen separation unit 20. Change the off gas supply amount. The hydrogen separation unit 20 has adsorption towers 20a, 20b, and 20c for adsorbing impurities from the supplied gas to the adsorbent and purifying product hydrogen (product gas). The off-gas tank is configured to discharge off-gas from the adsorption tower. The off-gas supply control unit 34 performs a decompression step (off-gas discharge step) to be sent to the fuel cell 21 and the off-gas supply control unit 34 receives fuel cell FC from the off-gas tank 21 when it receives process information indicating that the decompression step has started in the gas purification unit. Increase the supply of off-gas to

<Another embodiment>
(1) In the above-described embodiment, off gas is supplied from the off gas tank 21 to the fuel cell FC through the flow paths L17 and L18. However, the flow path is provided in the middle of the flow path L8 for supplying off gas from the off gas tank 21 to the burner device 14. It may be configured to branch off and supply off gas to the fuel cell FC.

(2) In the off gas supply operation of the above-described embodiment, the valve V14 is opened to start the supply of the off gas to the fuel cell FC, that is, the off gas supply amount is changed (increased) from zero to a predetermined amount. It was. This may be configured to change (increase) from a predetermined first flow rate that is not zero to a second flow rate that is greater than the first flow rate.

(3) In the above-described third embodiment, after receiving the process information indicating that the decompression process has started, the offgas supply control unit 34 opens the valve V14, and then closes the valve V14 after the time T has elapsed, thereby fueling The supply of off gas to the battery FC was stopped. The valve V14 may be opened after a predetermined time has elapsed since the start of the pressure reduction process, or may be configured to start when a cleaning process for generating off-gas is started in the same manner as the pressure reduction process. . Further, the valve V14 may be closed when the process information indicating that the decompression process is completed, or the process information indicating that the cleaning process that is the next process of the decompression process is started. You may comprise so that it may be performed when received.

  Note that the configurations disclosed in the above-described embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in the other embodiments as long as no contradiction arises. The embodiment disclosed in this specification is an exemplification, and the embodiment of the present invention is not limited to this. The embodiment can be appropriately modified without departing from the object of the present invention.

20: Hydrogen separation part (gas purification part)
21: Off-gas tank 34: Off-gas supply control unit 100: Hydrogen production device (gas production device)
FC: Fuel cell

Claims (4)

A gas purification unit that separates and purifies impurities from the supplied gas to obtain a product gas and discharges offgas containing the impurities, an offgas tank that stores the offgas discharged from the gas purification unit, and the off gas A solid oxide fuel cell that generates electric power using the off gas stored in a gas tank; and an off gas supply control unit that supplies the off gas from the off gas tank to the fuel cell;
The off gas supply control unit is a step related to the pressure of the off gas stored in the off gas tank, the flow rate of the off gas sent from the gas purification unit to the off gas tank, and the purification of the product gas performed in the gas purification unit. A gas manufacturing apparatus that changes a supply amount of the off gas to the fuel cell based on at least one of the information.   The off gas supply control unit increases the supply amount of the off gas from the off gas tank to the fuel cell when the pressure of the off gas stored in the off gas tank exceeds a preset threshold value. The gas manufacturing apparatus as described.   The off gas supply control unit increases the supply amount of the off gas from the off gas tank to the fuel cell when a flow rate of the off gas sent from the gas purification unit to the off gas tank exceeds a preset threshold value. The gas production apparatus according to claim 1 or 2. The gas purification unit has an adsorption tower that is purified by adsorbing the impurities from the supplied gas to an adsorbent to produce a product gas, and the off-gas discharge step of discharging the off-gas from the adsorption tower and sending it to the off-gas tank Which performs
The off gas supply control unit increases the supply amount of the off gas from the off gas tank to the fuel cell when the gas purification unit receives the process information indicating that the off gas discharge process has started. The gas manufacturing apparatus of any one of -3.

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