JP2010090425A - Hydrogen producing apparatus and method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogenn producing apparatus and a method thereof for producing hydrogen efficiently while reducing energy, in the production of hydrogen by high-temperature steam electrolysis. <P>SOLUTION: The hydrogenn producing apparatus for producing hydrogen includes: a water supply system 1; a water supply amount control device 24 for controlling the supply amount of water; a water evaporator-cum-produced gas cooler 2 for evaporating supplied water into steam; a hydrogen mixer 3 for mixing the steam, evaporated by the water evaporator-cum-produced gas cooler 2, and hydrogen to obtain a material gas; a material gas preheater 4 for preheating the material gas mixed in the hydrogen mixer 3; a cell container 6 into which the material gas preheated in the material gas preheater 4 is supplied; a cell 7 which is installed in the cell container 6 and includes a hydrogen pole, an oxygen pole and an electrolyte and in which hydrogen is produced by the electrolysis of the material gas; a cell performance monitoring device 23 for monitoring the performance of the cell 7; and a hydrogen flow rate control device 25 for controlling the flow rate of a portion of hydrogen that is produced in the cell 7 and circulated to the cell 7 through the hydrogen mixer 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hydrogen production apparatus and method for producing hydrogen by high-temperature steam electrolysis.

  As one vision of the future society, the realization of a hydrogen energy society using hydrogen as an energy medium is attracting attention, and several promising hydrogen production methods are considered. Among several hydrogen production methods, the high temperature steam electrolysis method includes a method of electrolyzing water vapor at a high temperature of about 900 ° C. Further, since the raw material is water, if a heat source that does not generate carbon dioxide is used, hydrogen can be produced without exhausting any carbon dioxide.

  In this high-temperature steam electrolysis method, the theoretical electrolysis voltage of water is 1.23V in water electrolysis at room temperature, whereas the theoretical decomposition voltage of water vapor at 900 ° C is 0.9V with a low power of about 30%. It is known as a hydrogen production method with high energy efficiency that can produce the same amount of hydrogen production (for example, see Non-Patent Document 1).

  In hydrogen production by high-temperature steam electrolysis, this minimum unit is called a cell. Basically, it has a three-layer structure in which an oxygen electrode (anode) and a hydrogen electrode (cathode) are arranged on both sides of the electrolyte layer in the middle of the electrolyte. Electrons are given at the hydrogen electrode to decompose water vapor into oxygen ions and hydrogen, the oxygen ions pass through the electrolyte layer, and electrons are released at the oxygen electrode to generate oxygen. The electrolyte layer, the oxygen electrode, and the hydrogen electrode are made of ceramics so as to withstand use at high temperatures.

  In addition, in order to electrolyze water vapor, a metal component contained on the surface of the hydrogen electrode acts as a catalyst, so that the metal molecule must be reduced. For this reason, in a hydrogen production system using high-temperature steam electrolysis, a system in which a part of the produced hydrogen is circulated and supplied to the cell together with the raw material steam is adopted.

Inventions relating to cell materials are known in connection with a hydrogen production apparatus that produces hydrogen by electrolyzing water vapor (see, for example, Patent Documents 1 and 2). Moreover, the invention regarding the structure of the hydrogen production apparatus using a flat cell is known (for example, refer patent document 3).
JP 2005-232525 A JP 7-109592 A JP-A-6-173053 Journal of the Atomic Energy Society of Japan, “Hydrogen production by hydrogen infrastructure and nuclear power”, vol. 48, no. 11 (2006), pages 835 to 851.

  The high temperature steam electrolysis method described above includes a method of electrolyzing water vapor at a high temperature of about 900 ° C. Further, since the raw material is water, if a heat source that does not generate carbon dioxide is used, hydrogen can be produced without exhausting any carbon dioxide. As an example of a heat source that does not generate carbon dioxide, there is a method of using the heat of a nuclear power plant or a HTGR. Here, it is assumed that the heat of the HTGR is used.

  The power generation efficiency of the HTGR is 52.6% as shown in “The gas Turbine-Modular Helium Reactor” (Nuclear News October 2003). When hydrogen is produced by electrolyzing water by using electric energy generated in a high temperature gas furnace, the efficiency of hydrogen production is 52.6% or less because of the influence of electrolysis efficiency in addition to the power generation efficiency. This hydrogen production efficiency will be described with reference to FIG.

  FIG. 6 is a configuration diagram showing a schematic configuration of a conventional hydrogen production apparatus.

  The raw material water is vaporized into water vapor by the evaporator 31 and heated to a predetermined temperature by the heat exchanger 32 as a preheater via the supply line 35. The heated water vapor is electrolyzed in the cell 33 and becomes hydrogen. Since the hydrogen electrode of the cell 33 of the high-temperature steam electrolysis apparatus needs to be maintained in a reducing atmosphere, hydrogen must be supplied in addition to the steam. For this reason, part of the product hydrogen is recirculated to the supply line 35 via the circulation line 34 and supplied together with water vapor for reduction.

The hydrogen production efficiency is the combustion of product hydrogen relative to the sum of the energy input from the nuclear reactor (high temperature gas reactor) 36 (thermal energy E ₁ and E ₂ for heating the raw materials and system to about 900 ° C.) and the electrical energy used for electrolysis. Since it is heat, it is calculated as shown in the following equation (1).

The electric energy used for electrolysis is calculated by dividing the amount of power by the power generation efficiency of the HTGR as shown in the following equation (2).

  When hydrogen is produced by high-temperature steam electrolysis using the heat of a HTGR, if the hydrogen production efficiency exceeds the power generation efficiency, it is more efficient than hydrogen production by electrolysis of water using electric energy generated in the HTGR Therefore, there is a merit in hydrogen production by high temperature steam electrolysis. For this reason, how to increase the hydrogen production efficiency was a problem of the high temperature steam electrolysis method.

  There are the following two factors that affect the hydrogen production efficiency.

1) Water vapor utilization rate 2) Hydrogen amount for cell reduction This water vapor utilization rate is the amount of water vapor decomposed relative to the amount of water vapor supplied, that is, the amount of hydrogen produced. A high steam usage, since only a small amount of water vapor supplied per hydrogen production amount, the evaporator heat input E ₁ and the smaller the heat exchanger heat quantity E ₂ shown in FIG. 6, and supplies the heat energy is small Become. Since the denominator of the formula (1) is small, under the precondition that the amount of hydrogen production is constant, the higher the water vapor utilization rate, the higher the hydrogen production efficiency.

  By improving the water vapor utilization rate, waste of raw materials can be omitted, the amount of heat input is suppressed, the supplied heat energy is reduced, and the hydrogen production efficiency is improved.

The amount of hydrogen for cell reduction is the amount of hydrogen supplied together with the raw material water vapor. It is necessary to keep the hydrogen electrode of the high-temperature steam electrolysis apparatus in a reducing atmosphere. For this purpose, hydrogen must be supplied in addition to water vapor. Part of the product hydrogen is circulated to the supply line and supplied with steam for reduction. By reducing the amount of hydrogen circulation is suppressed heat exchanger heat input E ₂ shown in FIG. 6, supplies thermal energy decreases. Since the amount of hydrogen circulation is reduced, since the amount of hydrogen taken out as a product is increased, since fewer water vapor content supplied, the evaporator heat quantity E ₁ and the heat exchanger heat quantity E ₂ shown in FIG. 6 decreases , The heat energy to be supplied becomes smaller. Since the denominator of the formula (1) is small, under the precondition that the amount of hydrogen production is constant, it has been a problem to improve the hydrogen production efficiency by reducing the amount of hydrogen for cell reduction.

  The present invention has been made to solve the above-mentioned problems. By increasing the steam utilization rate and reducing the amount of hydrogen for cell reduction, the energy required for hydrogen production by high-temperature steam electrolysis is reduced, and the hydrogen production efficiency is improved. An object of the present invention is to provide a hydrogen production apparatus and method capable of producing a good hydrogen.

  In order to achieve the above object, in the hydrogen production apparatus of the present invention, a water supply system to which water is supplied, a water supply control device for controlling the supply amount of water supplied from the water supply system, and the water supply system. A water evaporator / manufactured gas cooler that evaporates water supplied and controlled by a supply amount control device to produce water vapor, and a raw material obtained by mixing water vapor evaporated in the water evaporator / manufactured gas cooler and hydrogen A hydrogen mixer as a gas, a raw material gas preheater for preheating the raw material gas mixed in the hydrogen mixer, a cell container to which the raw material gas preheated by the raw material gas preheater is supplied, and the inside of the cell container A hydrogen electrode, an oxygen electrode, and an electrolyte formed between the hydrogen electrode and the oxygen electrode, wherein the source gas is electrolyzed to produce hydrogen, and the hydrogen is produced by electrolysis. A cell that monitors the performance of the manufactured cell. A performance monitoring device, and a part of hydrogen produced in the cell is circulated to the cell via the hydrogen mixer for reduction, and a hydrogen flow rate control device for controlling a flow rate of the part of hydrogen. It is characterized by this.

  In order to achieve the above object, in the hydrogen production method of the present invention, a water supply system to which water is supplied, a water supply amount control device for controlling the supply amount of water supplied from the water supply system, A water evaporator / manufactured gas cooler that evaporates the water supplied and controlled by the water supply amount control device to steam, and the steam and hydrogen evaporated by the water evaporator / manufactured gas cooler are mixed. A raw material gas hydrogen mixer, a raw material gas preheater for preheating the raw material gas mixed in the hydrogen mixer, a cell container to which the raw material gas preheated by the raw material gas preheater is supplied, and the cell A hydrogen electrode, an oxygen electrode, and an electrolyte formed between the hydrogen electrode and the oxygen electrode, and a cell in which the raw material gas is electrolyzed to produce hydrogen; Monitor the performance of the cell where hydrogen is produced A cell performance monitoring device, a part of the hydrogen produced in the cell is circulated to the cell via the hydrogen mixer for reduction, and a hydrogen flow rate control device for controlling the flow rate of this part of hydrogen, While adjusting the cell performance by the cell performance monitoring device, adjusting at least one of the water supply amount and the hydrogen amount supplied to the hydrogen mixer so that the performance of the cell becomes high It is characterized by driving.

  According to the hydrogen production apparatus and method of the present invention, by increasing the steam utilization rate and reducing the amount of hydrogen for cell reduction, the energy required for hydrogen production by high-temperature steam electrolysis is reduced, and the hydrogen production efficiency is good. Hydrogen production can be performed.

  Hereinafter, embodiments of a hydrogen production apparatus and method according to the present invention will be described with reference to the drawings. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

  FIG. 1 is a configuration diagram showing a schematic configuration of a hydrogen production apparatus 22 according to an embodiment of the present invention.

  First, as an example, a configuration of a hydrogen production apparatus 22 by high-temperature steam electrolysis using heat of a nuclear power plant will be described with reference to FIG.

  As shown in the figure, the hydrogen production device 22 includes a water supply system 1 to which water as a raw material is supplied, and a water supply amount control device 24 that is supplied from the water supply system 1 and controls the supply amount of water. Have.

  Water supplied in a state controlled by the water supply amount control device 24 is heated by the water evaporator / manufactured gas cooler 2 to generate water vapor. That is, in the water evaporator / manufactured gas cooler 2, the raw material water and the high-temperature hydrogen-containing gas produced by high-temperature steam electrolysis are heat-exchanged to evaporate the raw material water. In addition, the produced high-temperature hydrogen-containing gas is cooled.

  The water vapor, which is the raw material evaporated in the water evaporator / manufactured gas cooler 2, is introduced into the cell reduction hydrogen mixer 3, which is a hydrogen mixer, and mixed with a part of the produced hydrogen to form a raw material gas.

  The raw material gas mixed in the cell reducing hydrogen mixer 3 is supplied to the raw material gas preheater 4. In the raw material gas preheater 4, the hydrogen-containing water vapor that is the raw material gas is preheated by the heat of the nuclear reactor 5 and is heated to a predetermined temperature.

  The raw material gas preheated by the raw material gas preheater 4 and heated to a high temperature is supplied into the cell container 6.

  In this cell container 6, a cell 7 in which the raw material gas is electrolyzed to produce hydrogen is installed. The cell 7 is formed of a hydrogen electrode, an oxygen electrode, and an electrolyte formed between the hydrogen electrode and the oxygen electrode. The shape of the cell 7 may be a shape suitable for the system, and examples thereof include a flat plate type, a cylindrical type, and a honeycomb type.

  That is, the hydrogen-containing water vapor preheated by the raw material gas preheater 4 and heated to a high temperature is supplied to the hydrogen electrode (cathode) side of the cell 7 installed in the cell container 6. When a voltage is applied to the cell 7, the water vapor is electrolyzed in the cell 7 to produce hydrogen.

  The electric power supplied at this time is supplied to the turbine 27 by the steam generator 26 as heat generated in the nuclear reactor 5 of the nuclear power plant, and a part of the electric power generated by the generator 8 by the rotational force of the turbine 27 is obtained. in use.

  Thereafter, the produced hydrogen flows out from the hydrogen side outlet of the cell container 6 together with undecomposed water vapor, and is cooled by the water evaporator / manufactured gas cooler 2. Undecomposed water vapor becomes water in the water evaporator / manufactured gas cooler 2 and is separated from hydrogen.

  The hydrogen separated from the undecomposed water vapor is supplied to the cell reduction hydrogen mixer 3 through the hydrogen flow rate control device 25 as a part of hydrogen for cell reduction at the hydrogen gas outlet 9, and the remaining gas is product hydrogen. As recovered.

  In addition, oxygen ions generated by electrolyzing water vapor in the cell 7 are released to the opposite side of the cell 7 to become oxygen, and an oxygen gas supply system is used to maintain the performance of the electrode surface on the opposite side of the cell 7. The oxygen-containing gas supplied from 10 is collected from the oxygen-side outlet of the cell container 6.

  In addition, a cell performance monitoring device 23 for monitoring the performance of the cell 7 that is electrolyzed to produce hydrogen is installed. A part of the hydrogen produced in the cell 7 is circulated to the cell 7 via the cell reducing hydrogen mixer 3 for reduction. A hydrogen flow rate control device 25 for controlling the flow rate of the part of the hydrogen that is circulated is provided.

  Here, the relationship between the hydrogen production efficiency and the water vapor utilization rate will be described with reference to FIG.

  FIG. 2 is a graph showing the relationship between the hydrogen production efficiency and the water vapor utilization rate of the present embodiment.

  The vertical axis represents the hydrogen production efficiency, and the horizontal axis represents the water vapor utilization rate. The water vapor utilization rate is the ratio of water decomposed into hydrogen with respect to the supplied water.

This water vapor utilization rate is calculated as follows. First, the amount of produced hydrogen is measured with a flow meter or the like. As shown in the following formula (3), since 1 mol of hydrogen is generated from 1 mol of water in water electrolysis, the measured hydrogen amount (volume or number of moles) is equal to the amount of decomposed water. .

  That is, the water vapor utilization rate is calculated by dividing the amount of produced hydrogen by the amount of water supplied.

  The hydrogen production efficiency is the ratio of the combustion heat of the produced hydrogen to the input energy (heat and electricity), as shown in equation (1).

  Here, the same amount of hydrogen as the amount of water supplied as a raw material was circulated and returned, and the gas composition at the inlet was calculated as a water vapor concentration of 50% and a hydrogen concentration of 50%. As a result, as shown in FIG. 2, it is understood that in order for the hydrogen production efficiency to exceed the power generation efficiency 52.6% of the HTGR, the steam utilization rate must be 60% or more.

  Next, a flow during a test of the hydrogen production apparatus will be described with reference to FIG.

  FIG. 3 is an explanatory diagram showing a flow during a test of the hydrogen production apparatus of the present embodiment.

  As shown in this figure, the flow rate of raw material water is controlled by a metering pump 11, evaporated by an evaporator 12, and supplied to the hydrogen electrode side of a cell 13.

  Part of the produced hydrogen becomes hydrogen for reduction. Instead of returning to the inlet, the flow rate is controlled by the mass flow controller 14, preheated by the preheater 15, mixed with water vapor, and supplied to the hydrogen electrode side of the cell 13. Is done.

  On the other hand, oxygen is flow controlled at the oxygen electrode side of the cell 13 by the mass flow controller 16, nitrogen is flow controlled by the mass flow controller 17, mixed, and preheated by the preheater 18. The supplied gas composition is a mixed gas of oxygen 20% and nitrogen 80%.

  The cell 13 is heated to an arbitrary temperature in the electric furnace 19. Hydrogen produced by being decomposed at the hydrogen electrode of the cell 13 is recovered after being cooled by the cooler 20. The oxygen produced at the oxygen electrode of the cell 13 is recovered after being cooled by the cooler 21.

Using a cylindrical cell with a length of 300 mm and an electrode area of 75 cm ² , the water vapor concentration supplied to the hydrogen electrode was 50%, the hydrogen concentration was 50%, and the oxygen electrode was adjusted to 20% oxygen and 80% nitrogen. A test was conducted in which the gas flow rate was supplied at the same flow rate as that of the hydrogen electrode, and the water vapor utilization rate was changed by changing the amount of water vapor supplied at a cell temperature of 800 ° C. and a cell voltage of 1.3 V, and the cell performance was compared.

  The relationship between the water vapor utilization rate and the cell performance will be described with reference to FIG.

  FIG. 4 is a graph showing the relationship between the water vapor utilization rate and the cell performance of the present embodiment.

  The cell performance is a relative value where the value of the current flowing through the cell when the water vapor utilization rate is 20% is 1.

  As shown in this graph, when the water vapor supply rate is reduced and the water vapor utilization rate is increased, the current value is constant up to the water vapor utilization rate of 60%, but the raw material water vapor is insufficient when the water vapor utilization rate is 60% or more. It can be seen that the cell performance decreases. By increasing the water vapor utilization rate, the heat to raise the raw material water vapor can be reduced and the hydrogen production efficiency will increase, so by adjusting the water supply amount and making the system operating at the highest cell performance Efficient hydrogen production becomes possible.

  According to the present embodiment, while monitoring the performance of the cell 7 by the cell performance monitoring device 23 shown in FIG. 1, the water vapor supply rate is reduced, thereby increasing the water vapor utilization rate and reducing the performance of the cell 7. It is possible to increase the water vapor utilization rate to the point where it does not exist. During operation, the cell performance monitoring device 23 monitors the cell performance, adjusts the water vapor supply rate, changes the water vapor utilization rate, and confirms that the performance of the cell 7 is maximum. can do. The cell performance referred to here only needs to know the hydrogen production capacity of the cell 7 and indicates, for example, the value of the current flowing through the cell 7 and the amount of hydrogen produced.

  In addition, since the cell used for hydrogen production by high-temperature steam electrolysis requires that the hydrogen electrode (cathode) side be in a reduced state, a part of the produced hydrogen is recovered from the outlet of the hydrogen production system, and then the inlet of the hydrogen production system. , And mixed with the raw material water vapor and supplied to the cell 7. By reducing this circulating hydrogen, the amount of hydrogen that can be taken out as a product increases and the efficiency of hydrogen production increases. However, if this circulating hydrogen is reduced and the hydrogen concentration for cell reduction on the inlet side is lowered, the reduced state on the surface of the hydrogen electrode (cathode) cannot be maintained.

A cylindrical cell with a length of 300 mm and an electrode area of 75 cm ² is used, and a mixed gas adjusted to have a water vapor utilization rate of 60%, oxygen of 20% and nitrogen of 80% is supplied to the oxygen electrode at the same flow rate as the hydrogen electrode. Instead of returning the produced hydrogen to the inlet under the conditions of a cell temperature of 800 ° C. and a cell voltage of 1.3 V, the cell performance was tested by supplying the hydrogen electrode to change the amount of hydrogen and changing the hydrogen concentration. .

  The relationship between the cell reducing hydrogen concentration and the cell performance will be described with reference to FIG.

  FIG. 5 is a graph showing the relationship between the cell reducing hydrogen concentration and the cell performance according to the present embodiment.

  The cell performance is a relative value with the value of the current flowing through the cell at a hydrogen concentration of 50% being 1.

  As shown in this graph, the current value is constant until the hydrogen concentration is higher than 10%, but the cell performance decreases when the hydrogen concentration is 10% or less. It can be seen that the cell performance declines because the hydrogen for reduction is insufficient and the metal component contained on the surface of the hydrogen electrode is oxidized and no longer acts as a catalyst.

  Therefore, by adjusting the hydrogen concentration for cell reduction and setting the system to operate where the cell performance is the highest, this circulating hydrogen can be reduced, the amount of hydrogen that can be taken out as a product increases, and the circulation Thus, the heat for raising the temperature of the hydrogen can be reduced, the hydrogen production efficiency is increased, and efficient hydrogen production becomes possible.

  For this purpose, by reducing the amount of hydrogen circulated to the inlet side of the hydrogen produced by high-temperature steam electrolysis while monitoring the cell performance, the hydrogen concentration for cell reduction is lowered until the cell performance does not decrease. I will do it.

  According to the present embodiment, the hydrogen flow rate control device 25 changes the amount of hydrogen circulated during operation, and the cell performance monitoring device 23 operates while confirming that the cell performance is maximum. The cell performance described here only needs to know the hydrogen production capacity of the cell, and indicates, for example, the value of the current flowing through the cell 7 and the amount of hydrogen produced.

  Further, while monitoring the cell performance by the cell performance monitoring device 23, the most efficient operation is possible by operating at the highest water vapor utilization rate and the lowest hydrogen concentration for reduction. Hydrogen production by electrolysis becomes possible.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and departs from the gist of the present invention by combining the configurations of the embodiments. Various modifications can be made without departing from the scope.

The block diagram which shows schematic structure of the hydrogen production apparatus of embodiment of this invention. The graph which shows the relationship between the hydrogen production efficiency and water vapor utilization rate of this Embodiment. Explanatory drawing which shows the flow at the time of the test of the hydrogen production apparatus of this Embodiment. The graph which shows the relationship between the water vapor utilization rate of this Embodiment, and cell performance. The graph which shows the relationship between the hydrogen concentration for cell reduction of this Embodiment, and cell performance. The block diagram which shows schematic structure of the conventional hydrogen production apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Water supply system, 2 ... Water evaporator and production gas cooler, 3 ... Hydrogen mixer for cell reduction, 4 ... Raw material gas preheater, 5 ... Reactor, 6 ... Cell container, 7 ... Cell, 8 ... Electric power generation 9 ... Hydrogen gas outlet, 10 ... Oxygen gas supply system, 11 ... Metering pump, 12 ... Evaporator, 13 ... Cell, 14 ... Mass flow controller, 15 ... Preheater, 16 ... Mass flow controller, 17 ... Mass flow controller, 18 DESCRIPTION OF SYMBOLS ... Preheater, 19 ... Electric furnace, 20 ... Cooler, 21 ... Cooler, 22 ... Hydrogen production device, 23 ... Cell performance monitoring device, 24 ... Water supply amount control device, 25 ... Hydrogen flow rate control device.

Claims (8)

A water supply system to which water is supplied;
A water supply amount control device for controlling the amount of water supplied from this water supply system;
A water evaporator / manufactured gas cooler that evaporates water supplied and controlled by this water supply amount control device;
A hydrogen mixer that mixes water vapor and hydrogen evaporated in this water evaporator and production gas cooler into raw gas,
A raw material gas preheater for preheating the raw material gas mixed in the hydrogen mixer;
A cell container to which the source gas preheated by the source gas preheater is supplied;
A cell installed in the cell container, including a hydrogen electrode, an oxygen electrode, and an electrolyte formed between the hydrogen electrode and the oxygen electrode, wherein the source gas is electrolyzed to produce hydrogen; and
A cell performance monitoring device that monitors the performance of the cell that is electrolyzed to produce the hydrogen;
A part of the hydrogen produced in the cell is circulated to the cell via the hydrogen mixer for reduction, and a hydrogen flow rate control device for controlling the flow rate of the part of hydrogen,
The hydrogen production apparatus characterized by having.   The hydrogen production apparatus according to claim 1, wherein a part of hydrogen produced by electrolyzing the water vapor is used as hydrogen mixed with water vapor in the hydrogen mixer.   The hydrogen production apparatus according to claim 1, wherein heat generated in a nuclear reactor including a high-temperature gas reactor and a fast breeder reactor is used as a heat source of the source gas preheater. A water supply system to which water is supplied;
A water supply amount control device for controlling the amount of water supplied from this water supply system;
A water evaporator / manufactured gas cooler that evaporates water supplied and controlled by this water supply amount control device;
A hydrogen mixer that mixes water vapor and hydrogen evaporated in this water evaporator and production gas cooler into raw gas,
A raw material gas preheater for preheating the raw material gas mixed in the hydrogen mixer;
A cell container to which the source gas preheated by the source gas preheater is supplied;
A cell installed in the cell container, comprising a hydrogen electrode, an oxygen electrode, and an electrolyte formed between the hydrogen electrode and the oxygen electrode, wherein the source gas is electrolyzed to produce hydrogen; and
A cell performance monitoring device that monitors the performance of the cell that is electrolyzed to produce the hydrogen;
A part of the hydrogen produced in the cell is circulated to the cell through the hydrogen mixer for reduction, and a hydrogen flow rate control device for controlling the flow rate of the part of hydrogen,
With
While the cell performance is monitored by the cell performance monitoring device, the operation is performed while adjusting at least one of the water supply amount and the hydrogen amount supplied to the hydrogen mixer so that the performance of the cell becomes high. A method for producing hydrogen.   The hydrogen production method according to claim 4, wherein a part of hydrogen produced by electrolyzing the water vapor is used as the hydrogen mixed with the water vapor in the hydrogen mixer.   The operation is performed while the cell performance monitoring device monitors the performance of the cell by changing at least one of the water supply amount and the hydrogen amount supplied to the hydrogen mixer during operation. The method for producing hydrogen according to claim 4.   5. The hydrogen according to claim 4, wherein the performance of the cell monitored by the cell performance monitoring device is at least one of a current value flowing through the cell and a hydrogen production amount under a constant applied voltage. Production method.   The method for producing hydrogen according to claim 4, wherein heat generated in a nuclear reactor including a high-temperature gas reactor and a fast breeder reactor is used as a heat source of the source gas preheater.

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