JP2019112254A - Hydrogen generation apparatus and fuel cell system using the same - Google Patents

Abstract

To provide a hydrogen generation apparatus capable of reducing CO concentration in a hydrogen-containing gas with a temperature at a methanation reaction part of a CO remover being kept low.SOLUTION: A hydrogen generation apparatus 400 comprises: a modifier 100 that modifies a raw material to produce a hydrogen-containing gas; a CO remover 150 that is filled with the same catalyst and is formed from a selective oxidation reaction part 160 and a methanation reaction part and that reduces the concentration of carbon monoxide contained in a hydrogen-containing gas; and a selective oxidative air supplier 92 that supplies the hydrogen-containing gas flowing into the CO remover 150 with a selective oxidation air necessary for selective oxidation reaction. An upstream part 161 of the methanation reaction part is cooled by a cooler 62.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hydrogen generator that generates a hydrogen-containing gas and a fuel cell system using the same.

  A fuel cell cogeneration system (hereinafter simply referred to as "fuel cell system") capable of high-efficiency power generation even with a small-sized device has been developed as a power generation device of a distributed energy supply source.

  The fuel cell system includes a fuel cell as a main body of a power generation unit. As this fuel cell, for example, a phosphoric acid fuel cell, a molten carbonate fuel cell, an alkaline aqueous solution fuel cell, a polymer electrolyte fuel cell, a solid electrolyte fuel cell or the like is used.

  Among these fuel cells, a phosphoric acid fuel cell or a polymer electrolyte fuel cell (abbreviated as "PEFC") has a relatively low operating temperature during power generation operation, and thus the fuel cell constituting the fuel cell system Are preferably used. In particular, the polymer electrolyte fuel cell is particularly suitable for applications such as portable electronic devices and electric vehicles because the deterioration of the electrode catalyst is less and the electrolyte does not occur as compared with the phosphoric acid fuel cell. Used.

  Now, many fuel cells, for example, a phosphoric acid fuel cell and a polymer electrolyte fuel cell use hydrogen as a fuel during power generation operation. However, the hydrogen supply means required for power generation operation in these fuel cells has not yet been established as an infrastructure.

  Therefore, in order to obtain power by a fuel cell system including a phosphoric acid fuel cell or a polymer electrolyte fuel cell, it is necessary to generate hydrogen as a fuel at the installation site of the fuel cell system.

  For this reason, the fuel cell system usually comprises a hydrogen generator having a reformer. In the reformer, a hydrogen-containing gas is generated by a reforming reaction from town gas, natural gas or LPG, which is a common raw material infra gas. As the reforming reaction, a steam reforming reaction is generally used.

  In this steam reforming reaction, hydrogen is reacted by reacting city gas as a raw material with steam at a high temperature of about 600 ° C. to 700 ° C. using a Ni-based or Ru-based noble metal-based reforming catalyst. A hydrogen-containing gas, which is the main component, is generated.

  Although hydrogen is contained in the hydrogen-containing gas produced using the reforming catalyst, especially in polymer electrolyte fuel cells, electrode poisoning by CO tends to occur, so the concentration of CO in the supplied hydrogen-containing gas can be It is necessary to reduce to 10 volume ppm.

  Therefore, CO concentration is reduced by selectively oxidizing CO contained in the hydrogen-containing gas by adding selective oxidation air to the hydrogen-containing gas in a CO remover provided downstream of the reformer. In this selective oxidation reaction, a noble metal-based selective oxidation catalyst such as Pt or Ru is used.

  Further, a methanation catalyst is provided further downstream to methanate CO contained in the hydrogen-containing gas, thereby reducing the CO concentration. In this methanation reaction, a noble metal-based methanation catalyst such as Ru is used (see, for example, Patent Document 1).

In the methanation reaction of CO, although the CO concentration is reduced in the methanation reaction of CO shown in (Chem. 1), when the selective oxidation catalyst becomes high temperature, the reverse shift reaction of CO ₂ shown in (Chem. 2) is As it happens and the concentration of CO in the hydrogen-containing gas is high, it is necessary to keep the methanation catalyst at a suitable temperature.

JP 2005-67917 A

However, in the conventional configuration, in the process of reduction of the CO concentration in the hydrogen-containing gas by selective oxidation, the oxidation reaction of CO with oxygen in the selective oxidation reaction section at the front stage and methane of CO in the methanation reaction section at the rear stage since there is inverse shift reaction of the reaction and CO _2, when the methanation unit is hot due to the exothermic reaction of selective oxidation reaction unit, the reverse shift reaction of CO ₂ is promoted, a problem that the CO concentration becomes high It was

  An object of the present invention is to solve the conventional problems, and it is an object of the present invention to provide a hydrogen generator capable of reliably reducing the CO concentration in a hydrogen-containing gas.

  In order to solve the conventional problems, the hydrogen generator according to the present invention is charged with the same catalyst as the reformer that reforms the raw material to generate the hydrogen-containing gas, and the selective oxidation reaction unit and the methanation reaction And a CO remover for reducing the concentration of carbon monoxide contained in the hydrogen-containing gas, and a selective oxidation air supply for supplying the selective oxidation air necessary for the selective oxidation reaction to the hydrogen-containing gas flowing into the CO remover. And cooling the upstream portion of the methanation reaction unit.

By this, the temperature of the upstream portion of the methanation reaction portion of the CO remover is suppressed low, and the reverse shift reaction of CO ₂ promoted as the high temperature is suppressed to suppress the generation of CO, thereby containing the hydrogen-containing gas. The concentration of CO can be reliably reduced.

  According to the hydrogen generator of the present invention, since the generation of CO can always be suppressed, it is possible to provide a highly reliable hydrogen generator and a fuel cell system capable of reliably reducing the concentration of CO in a hydrogen-containing gas. Can.

Block diagram showing the configuration of the hydrogen generation apparatus according to Embodiment 1 of the present invention Principal part longitudinal cross-sectional view showing a schematic configuration of a CO remover, a cooler, a reformer, and a heater in the hydrogen generator according to Embodiment 1 of the present invention Characteristic chart showing the relationship between the catalyst layer position and the catalyst layer temperature of the CO remover in the hydrogen generator of the first embodiment of the present invention Characteristic diagram showing the relationship between the catalyst layer position of the CO remover and the concentration of CO in the hydrogen-containing gas in the hydrogen generator of Embodiment 1 of the present invention Block diagram showing a configuration of a hydrogen generator in Embodiment 2 of the present invention Principal part longitudinal cross-sectional view showing a schematic configuration of a CO remover, an evaporator, a reformer and a heater in the hydrogen generator of the second embodiment of the present invention Characteristic diagram showing the relationship between the catalyst layer position and the catalyst layer temperature of the CO remover in the hydrogen generator of the second embodiment of the present invention Characteristic diagram showing the relationship between the catalyst layer position of the CO remover and the concentration of CO in the hydrogen-containing gas in the hydrogen generator of Embodiment 2 of the present invention Block diagram showing a configuration of a hydrogen generator in Embodiment 3 of the present invention Principal part longitudinal cross-sectional view showing a schematic configuration of a CO remover, a cooler, a reformer, and a heater in a hydrogen generator according to Embodiment 3 of the present invention Characteristic diagram showing the relationship between the catalyst layer position and the catalyst layer temperature of the CO remover in the hydrogen generator of the third embodiment of the present invention Characteristic diagram showing the relationship between the catalyst layer position of the CO remover and the concentration of CO in the hydrogen-containing gas in the hydrogen generator of Embodiment 3 of the present invention Block diagram showing a configuration of a fuel cell system according to Embodiment 4 of the present invention

  According to a first aspect of the present invention, a reformer for reforming a raw material to generate a hydrogen-containing gas, and a catalyst containing the same catalyst, comprising a selective oxidation reaction portion and a methanation reaction portion, which are contained in the hydrogen-containing gas A hydrogen generator comprising: a CO remover for reducing the concentration of carbon monoxide; and a selective oxidation air feeder for supplying selective oxidation air necessary for selective oxidation reaction to a hydrogen-containing gas flowing into the CO remover. The upstream portion of the methanation reaction portion is cooled.

As a result, the temperature of the upstream portion of the methanation reaction portion of the CO remover can be suppressed low, and the reverse shift reaction of CO ₂ promoted as the temperature increases can be suppressed to suppress the generation of CO. The CO concentration in the gas can be reliably reduced.

  In the second invention, in particular, in the first invention, an evaporator that exchanges heat with the CO remover to evaporate water necessary for reforming is provided.

By this, the upstream part of the methanation reaction part of the CO remover is cooled by the evaporator which evaporates the water necessary for reforming without providing a new cooling configuration, and the temperature of the upstream part of the methanation reaction part Can be suppressed low, and by suppressing the CO ₂ reverse shift reaction that is promoted as the temperature increases and suppressing the generation of CO, the CO concentration in the hydrogen-containing gas can be reliably reduced with a simpler configuration. be able to.

  The third invention is particularly characterized in that in the first invention or the second invention, the temperature of the catalyst in the selective oxidation reaction part is higher than the temperature of the catalyst in the methanation reaction part.

  Since the temperature of the catalyst in the selective oxidation reaction part of the CO remover is higher than the temperature of the catalyst in the methanation reaction by this, the reaction rate of the selective oxidation reaction can be sufficiently high, thereby promoting the reduction of the CO concentration. can do. Therefore, the amount of catalyst loaded in the CO remover can be reduced, and the hydrogen generator can be miniaturized.

A fourth invention is, in particular, a fuel cell system comprising the hydrogen generator according to any one of the first to third inventions, and a fuel cell that generates electric power using a hydrogen-containing gas generated by the hydrogen generator. is there.

As a result, the temperature of the upstream portion of the methanation reaction portion of the CO remover is suppressed low, the reverse shift reaction of CO ₂ promoted as the temperature increases is suppressed, and the generation of CO is suppressed, whereby CO in the hydrogen-containing gas The concentration can be reliably reduced, and a highly reliable fuel cell system can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited by the present embodiment. Moreover, below, the same referential mark is attached | subjected to the element which is the same or it corresponds through all the figures, and the overlapping description is abbreviate | omitted.

Embodiment 1
FIG. 1 is a block diagram showing a configuration of a hydrogen generator in Embodiment 1 of the present invention.

  As shown in FIG. 1, the hydrogen generator 400 of the present embodiment includes a reformer 100 which is a reactor that generates a hydrogen-containing gas, and a reformer temperature detector 80 which detects the temperature of the reformer 100. A raw material supply device 31 for supplying the raw material to the reformer 100, a raw material supply amount detector 30 for detecting the raw material supply amount, a desulfurizer 10 for removing a sulfur compound contained in the raw material, a reformer 100 Water supply unit 51 for supplying water to the water, a water supply amount detector 50 for detecting the supply amount of water, a heater 20 for heating the reformer 100, and a fuel supply unit 22 for supplying fuel to the heater 20 A fuel supply amount detector 21 for detecting the fuel supply amount, an air supply device 71 for supplying air to the heater 20, an air supply amount detector 70 for detecting the air supply amount, a reformer 100 Reactor that reduces the concentration of CO in the hydrogen-containing gas produced by The CO remover 150, a CO reducer temperature detector 90 for detecting the temperature of the CO remover 150, a cooler 62 for cooling the CO remover 150, and a controller 300 for controlling the hydrogen generator 400 The hydrogen-containing gas generated by the reformer 100 is supplied to the outside through the hydrogen supply path 41.

  The reformer 100 is made of a stainless steel structure, is filled with a reforming catalyst that causes the reforming reaction to proceed, and generates a hydrogen-containing gas by the reforming reaction using a raw material and steam. As the reforming catalyst, one obtained by supporting Ru with alumina beads as a carrier was used. The reforming reaction in the reformer 100 requires a temperature of 550 ° C. to 660 ° C., and is configured to be adjacent to the heater 20 for heating.

  As a raw material, city gas (13A) supplied from a gas company to each household through piping is used. In order to detect leakage, the city gas contains at least one or more odorant mainly composed of a sulfur compound, and odorant is performed. The sulfur compounds contained in these odorants poison the reforming catalyst and degrade it.

  Therefore, the raw material from which the sulfur compound has been removed in advance by the desulfurizer 10 is supplied to the reformer 100. In the desulfurizer 10, a desulfurization container having a stainless steel structure is filled with a zeolite ion-exchanged with silver, which is an adsorptive desulfurization agent for normal temperature, and used at normal temperature.

  The reformer temperature detector 80 is constituted by a thermocouple and detects the temperature of the reformer 100. The reformer temperature detector 80 is installed in a sheath provided inside the reformer 100 to measure the catalyst temperature.

  The raw material supply unit 31 is configured by a combination of a pressure booster and a flow control valve, and supplies the raw material to the reformer 100. The raw material supply device 31 adjusts the supply amount of the raw material by the control of the controller 300 in accordance with the supply amount of the raw material detected by the raw material supply amount detector 30.

  The water supplier 51 is constituted by a combination of a pump and a flow control valve, and supplies water to the reformer 100. The water supplier 51 adjusts the water supply amount under the control of the controller 300 in accordance with the water supply amount detected by the water supply amount detector 50.

  The heater 20 is configured of a combustor and heats the reformer 100. For the fuel of the heater 20, city gas is used. The fuel supplier 22 is constituted by a combination of a booster and a flow control valve, and supplies fuel to the heater 20. The fuel supply device 22 adjusts the amount of supplied fuel under the control of the controller 300 in accordance with the amount of supplied fuel detected by the fuel supply amount detector 21.

  The air supplier 71 is constituted by a fan and supplies the heater 20 with air for combustion. The air supplier 71 adjusts the air supply amount under the control of the controller 300 in accordance with the air supply amount detected by the air supply amount detector 70.

  The CO remover 150 uses selective oxidation reaction and methanation reaction to reduce the concentration of CO in the hydrogen-containing gas discharged from the reformer 100 to 10 ppm or less. The CO remover 150 is filled with one type of catalyst supporting Ru with alumina beads as a carrier.

While O ₂ contained in the selective oxidation air upstream portion of the CO remover 150 is used to selective oxidation reactions, selective oxidation reactions in the portion where O ₂ is left, methanation downstream portion O ₂ does not remain Will occur. The selective oxidation reaction in the CO remover 150 requires a temperature of 150 ° C. to 200 ° C., and the methanation reaction requires a temperature of 100 ° C. to 150 ° C. It is set as the structure heated by heat.

  The selective oxidation air supplier 92 is constituted by a fan and supplies the CO remover 150 with selective oxidation air. The selective oxidation air supply device 92 adjusts the supply amount of the selective oxidation air under the control of the controller 300 in accordance with the supply amount of the selective oxidation air detected by the selective oxidation air supply amount detector 91.

  The CO reducer temperature detector 90 is constituted by a thermocouple and detects the temperature of the CO remover 150. Also, the CO reducer temperature detector 90 is installed in a sheath provided inside the CO remover 150 to measure the catalyst temperature.

  The cooler 62 is disposed adjacent to the CO remover 150 and exchanges heat with the CO remover 150 to cool the CO remover 150.

  The cooling air supplier 82 is constituted by a fan and supplies cooling air to the cooler 62. The cooling air supply device 82 adjusts the supply amount of the cooling air by the control of the controller 300 in accordance with the supply amount of the cooling air detected by the cooling air supply amount detector 81.

  The controller 300 that controls the hydrogen generator 400 includes an arithmetic unit 301 and a storage unit 302 that stores a control program. An MPU is used as the operation unit 301, and a memory is used as the storage unit 302. The storage unit 302 stores programs for controlling various operations of the hydrogen generation apparatus 400, and the operation unit 301 reads a necessary program from the storage unit 302 and executes the program to generate hydrogen. It controls various operations of the apparatus 400.

A raw material supply amount detector 30 for detecting the raw material supply amount is provided in the middle of the raw material supply path from the raw material supply device 31 to the reformer 100, and the detection output is input to the calculation unit 301. A water supply amount detector 50 for detecting the water supply amount is provided in the middle of the water supply path from the water supply device 51 to the reformer 100, and the detection output is inputted to the calculation unit 301. Raw material supply detector 3
The zero and water supply detector 50 is configured of a flow meter.

  A selective oxidation air supply amount detector 91 for detecting the supply amount of selective oxidation air is provided in the middle of the supply path of the selective oxidation air from the selective oxidation air supply device 92 to the CO remover 150, and the detection output thereof is calculated by the computing unit 301. Has been entered. The selective oxidation air supply amount detector 91 is configured of a flow meter.

  A fuel supply amount detector 21 for detecting the supply amount of fuel is provided in the middle of the fuel supply path from the fuel supply device 22 to the heater 20, and the detection output is inputted to the calculation unit 301. The fuel supply amount detector 21 is constituted by a flow meter.

  An air supply amount detector 70 for detecting the air supply amount is provided along the air supply path from the air supplier 71 to the heater 20, and the detection output is input to the calculation unit 301. The air supply detector 70 comprises a flow meter.

  FIG. 2 is a principal part longitudinal cross-sectional view showing a schematic configuration of a CO remover, a cooler, a reformer, and a heater in the hydrogen generator of Embodiment 1 of the present invention.

  As shown in FIG. 2, the cooler 62 for cooling the CO remover 150 has a configuration in which a space is formed by a cylinder 152 and a cylinder 157 whose central axes overlap and diameters are different, and cooling air is circulated in the space. There is. The cylinder 157 is smaller in diameter than the cylinder 152, the cylinder 157 is disposed inside the cylinder 152, and the cylinder 157 is surrounded by the cylinder 152.

  Cooling air is supplied to the cooler 62 from a pipe 156 connected to the upper portion of the cooler 62, and the cooling air for the cooler 62 is exhausted from a pipe 158 connected to the lower portion of the cooler 62.

  The CO remover 150 is formed between a cylinder 152 and a cylinder 159 whose central axes are different in overlapping diameter, and is disposed adjacent to the outer periphery of the cooler 62 via the cylinder 152. The cylinder 159 is larger in diameter than the cylinder 152, the cylinder 159 is disposed outside the cylinder 152, and the cylinder 159 surrounds the cylinder 152.

  The selective oxidation reaction portion 160 of the CO remover 150 is a portion where the selective oxidation reaction occurs in the CO remover 150, and the upstream portion 161 of the methanation reaction portion is an upstream portion of the site where the methanation reaction occurs in the CO remover 150 The downstream part 162 of the methanation reaction part is a downstream part of the site where the methanation reaction occurs in the CO remover 150.

  The cooler 62 is disposed adjacent to the upstream portion 161 of the methanation reaction unit. The reformer 100 is formed between the cylinder 152 and the cylinder 159 and is disposed upstream of the CO remover 150. The heater 20 is disposed at the central position of the cylinder 152 and the cylinder 159 and heats the reformer 100.

  The operation and action of the hydrogen generator 400 of the present embodiment configured as described above will be described. The following operations and actions are performed by the controller 300 controlling the hydrogen generator 400.

  The hydrogen generator 400 changes the supply amount of the raw material according to the flow rate of hydrogen to be generated to generate a hydrogen-containing gas. A hydrogen generator 400 capable of supplying the flow rate of hydrogen in the hydrogen-containing gas from 3NLM to 9NLM will be described.

When a request for starting operation of hydrogen generator 400 is generated, controller 300 generates hydrogen generator 40.
0 starts driving. When the hydrogen generator 400 is activated, fuel and air for combustion are supplied to the heater 20 by the operation start of the fuel supplier 22 and the air supplier 71.

  In the heater 20, an ignition operation is performed by an ignition electrode (not shown) to burn fuel using combustion air. Thus, the heat of combustion supplied from the heater 20 heats the reformer 100.

  When the reformer 100 (the temperature detected by the reformer temperature detector 80) reaches a predetermined temperature, the raw materials and water are supplied to the reformer 100 by the operation start of the raw material feeder 31 and the water feeder 51, and the steam is improved. The hydrogen-containing gas produced by the quality reaction is supplied.

  According to the flow rate of hydrogen to be generated, the supply amount of the raw material is increased or decreased. At this time, as shown in (Equation 1), the supply amount (Fa) of the selective oxidation air is set according to the supply amount (Fi) of the raw material Control.

水素含有ガス中の水素の流量を９ＮＬＭ生成とするとき、原料の供給量を３ＮＬＭ、選択酸化空気の供給量を０．６４ＮＬＭ供給する。

Assuming that the flow rate of hydrogen in the hydrogen-containing gas is 9NLM, the supply amount of the raw material is 3NLM, and the supply amount of the selective oxidation air is 0.64NLM.

  FIG. 3 is a characteristic diagram showing the relationship between the catalyst layer position and the catalyst layer temperature in the CO remover in the hydrogen generator of Embodiment 1 of the present invention. FIG. 4 is a characteristic diagram showing the relationship between the catalyst layer position of the CO remover and the concentration of CO in the hydrogen-containing gas in the hydrogen generator of Embodiment 1 of the present invention.

  Assuming that the flow rate of hydrogen in the hydrogen-containing gas is 9NLM, 13NLM of hydrogen-containing gas having a CO concentration of 0.5% is supplied to the CO remover 150. By placing the cooler 62 adjacent to the upstream portion 161 of the methanation reaction portion of the CO remover 150, the upstream portion 161 of the methanation reaction portion is reliably confirmed because the effect of cooling the upstream portion 161 of the methanation reaction portion is high. Can be kept at a low temperature.

  At that time, as shown in FIG. 3, the inlet of the catalyst layer of the selective oxidation reaction part 160 of the CO remover 150 is 180 ° C., the maximum temperature of the upstream part 161 of the methanation reaction part is 154 ° C., and the minimum temperature is 134 ° C. The maximum temperature of the downstream part 162 of the chemical reaction part is 134.degree. C., and the minimum temperature is 130.degree.

  In addition, as shown in FIG. 4, the CO concentration at the outlet of the catalyst layer in the selective oxidation reaction unit 160 is 800 ppm, the CO concentration at the outlet of the catalyst layer in the upstream portion 161 of the methanation reaction unit is 500 ppm, and the downstream portion 162 of the methanation reaction unit The concentration of CO at the outlet of the catalyst bed is 4 ppm.

  Thus, the cooler 62 is adjacent to the upstream portion 161 of the methanation reaction portion, and the temperature of the upstream portion 161 of the methanation reaction portion is lowered by heat exchange with the cooling air, whereby the downstream portion of the methanation reaction portion The CO concentration at the catalyst layer outlet 162, that is, the outlet of the CO remover 150 can be reduced to 4 ppm.

As described above, in the hydrogen generator 400 of the present embodiment, the temperature of the upstream portion of the methanation reaction portion of the CO remover 150 is kept low by the cooler 62 that cools the CO remover 150, so that high temperature is achieved. Thus, it is possible to suppress the reverse shift reaction of CO ₂ , which is further promoted, to suppress the generation of CO, and to surely reduce the CO concentration in the hydrogen-containing gas.

Although a CO remover 150 is provided downstream of the reformer 100 to perform CO removal by selective oxidation reaction using selective oxidation air, the aqueous shift between the reformer 100 and the CO remover 150 is performed. It is also possible to provide a CO converter (not shown) for reducing the concentration of CO in the hydrogen-containing gas by reaction. In this case, the CO shift converter is filled with a shift catalyst.

  Further, although the supply amount (Fa) of the selective oxidation air is controlled according to the supply amount (Fi) of the raw material as in the equation (Equation 1), other expressions may be used.

Second Embodiment
FIG. 5 is a block diagram showing a configuration of a hydrogen generator in Embodiment 2 of the present invention.

  In the hydrogen generator 401 of the second embodiment shown in FIG. 5, the same components as those of the hydrogen generator 400 of the first embodiment shown in FIG.

  The hydrogen generator 401 of the second embodiment differs from the hydrogen generator 400 of the first embodiment in that, in the first embodiment, the CO remover 150 is cooled by the cooler 62. In the second embodiment, the CO remover 150 is cooled by the evaporator 61, and the hydrogen generator 400 is controlled by the controller 300 in the first embodiment. However, in the second embodiment, the hydrogen generator is controlled by the controller 303. The point of controlling 401 and the point of controlling the hydrogen generator 401 of the second embodiment are that the hydrogen containing gas is supplied to the hydrogen utilizing device 201 through the hydrogen supply path 41.

  The evaporator 61 is for evaporating water necessary for reforming in the reformer 100, is disposed adjacent to the CO remover 150, and exchanges heat with the CO remover 150, whereby the water supplier 51 is provided. Simultaneously with the vaporization of the water supplied thereto, and the cooling of the CO remover 150 is performed.

  FIG. 6 is an essential part longitudinal cross sectional view showing a schematic configuration of a CO remover, an evaporator, a reformer and a heater in the hydrogen generator of the second embodiment of the present invention.

  As shown in FIG. 6, the evaporator 61 for cooling the CO remover 150 has a configuration in which a space is formed by a cylinder 152 and a cylinder 172 whose central axes overlap with different diameters, and water is circulated in the space. . The cylinder 172 is smaller in diameter than the cylinder 152, the cylinder 172 is disposed inside the cylinder 152, and the cylinder 172 is surrounded by the cylinder 152.

  Water is supplied to the evaporator 61 from a pipe 171 connected to the upper portion of the evaporator 61 and water vapor is discharged from a pipe 173 connected to the lower portion of the evaporator 61.

  The CO remover 150 is formed between a cylinder 152 and a cylinder 159 whose central axes are different in overlapping diameter, and is disposed adjacent to the outer periphery of the evaporator 61 via the cylinder 152. The cylinder 159 is larger in diameter than the cylinder 152, the cylinder 159 is disposed outside the cylinder 152, and the cylinder 159 surrounds the cylinder 152.

  The selective oxidation reaction portion 160 of the CO remover 150 is a portion where the selective oxidation reaction occurs in the CO remover 150, and the upstream portion 161 of the methanation reaction portion is an upstream portion of the site where the methanation reaction occurs in the CO remover 150 The downstream part 162 of the methanation reaction part is a downstream part of the site where the methanation reaction occurs in the CO remover 150.

  The evaporator 61 is disposed adjacent to the upstream portion 161 of the methanation reaction portion. The reformer 100 is formed between the cylinder 152 and the cylinder 159 and is disposed upstream of the CO remover 150. The heater 20 is disposed at the central position of the cylinder 152 and the cylinder 159 and heats the reformer 100.

  The operation and action of the hydrogen generator 401 of the present embodiment configured as described above will be described. The following operations and actions are performed by the controller 303 controlling the hydrogen generator 401.

  As shown in (Equation 1), the supply amount (Fa) of the selective oxidation air is controlled according to the supply amount (Fi) of the raw material. When the flow rate of hydrogen in the hydrogen-containing gas is required to be 9 NLM, the feed amount of the raw material is 3 N LM, and the feed amount of the selective oxidation air is 0.64 N LM. At this time, the temperature of the selective oxidation catalyst was 185 ° C. The CO concentration in the hydrogen-containing gas at that time was 1 ppm.

  FIG. 7 is a characteristic diagram showing the relationship between the catalyst layer position and the catalyst layer temperature in the CO remover in the hydrogen generator of Embodiment 2 of the present invention. FIG. 8 is a characteristic diagram showing the relationship between the catalyst layer position of the CO remover and the concentration of CO in the hydrogen-containing gas in the hydrogen generator of Embodiment 2 of the present invention.

  To the CO remover 150, 13 NLM of hydrogen-containing gas with a CO concentration of 0.5% is supplied. Since water is supplied from the pipe 171 to the evaporator 61 adjacent to the upstream portion 161 of the methanation reaction portion of the CO remover 150 and the cooling effect is high, the upstream portion 161 of the methanation reaction portion is It can be kept at low temperature surely.

  At that time, as shown in FIG. 7, the inlet of the catalyst bed of the selective oxidation reaction part 160 of the CO remover 150 is 180 ° C., the maximum temperature of the upstream part 161 of the methanation reaction part is 150 ° C., and the minimum temperature is 134 ° C. The maximum temperature of the downstream part 162 of the chemical reaction part is 134.degree. C., and the minimum temperature is 130.degree.

  Further, as shown in FIG. 8, the CO concentration at the outlet of the catalyst layer in the selective oxidation reaction unit 160 is 800 ppm, the CO concentration at the outlet of the catalyst layer in the upstream portion 161 of the methanation reaction unit is 300 ppm, and the downstream portion 162 of the methanation reaction unit The concentration of CO at the outlet of the catalyst bed is 1 ppm.

  Thus, water is supplied to the evaporator 61 adjacent to the upstream portion 161 of the methanation reaction portion, and heat exchange between the upstream portion 161 of the methanation reaction portion and the evaporator 61 causes the upstream portion 161 of the methanation reaction portion The CO concentration at the catalyst layer outlet of the downstream portion 162 of the methanation reaction portion, that is, the outlet of the CO remover 150 can be reduced to 1 ppm.

As described above, in the hydrogen generator 401 of the present embodiment, it is disposed adjacent to the CO remover 150 and exchanges heat with the CO remover 150 to vaporize the water supplied from the water supplier 51. Lower the temperature of the upstream part of the methanation reaction part of the CO remover 150 by the evaporator 61 for cooling the CO remover 150 at the same time, thereby suppressing the CO ₂ reverse shift reaction promoted at high temperature As a result, the generation of CO can be suppressed, and the CO concentration in the hydrogen-containing gas can be reliably reduced.

Further, in the hydrogen generator 401 of the present embodiment, the upstream portion 161 of the methanation reaction portion can be made efficient by using the evaporator 61 that vaporizes the water necessary for the steam reforming reaction in the reformer 100. To cool down and lower the temperature of the upstream portion 161 of the methanation reaction portion, thereby suppressing the reverse shift reaction of CO ₂ occurring at high temperature and suppressing the generation of CO without providing a new cooling configuration. it can.

  As a result, since the generation of CO can always be suppressed, it is possible to provide the hydrogen generator 401 capable of reliably reducing the concentration of CO in the hydrogen-containing gas with a simpler configuration.

Further, in the hydrogen generator 401 of the present embodiment, in particular, the amount of heat exchange between the selective oxidation reaction unit 160 and the evaporator 61 of the CO remover 150 is reduced to reduce the temperature of the catalyst layer of the selective oxidation reaction unit 160 to methane. Since the reaction rate of the selective oxidation reaction unit 160 of the CO remover 150 can be made sufficiently high by making the temperature higher than the temperature of the catalyst layer of the oxidation reaction unit, the reduction of the CO concentration can be promoted.

  Therefore, the amount of catalyst loaded in the CO remover 150 can be reduced, and a small-sized hydrogen generator 401 can be provided. As a result, since the generation of CO can always be suppressed, it is possible to provide the hydrogen generator 401 capable of reliably reducing the concentration of CO in the hydrogen-containing gas.

  Although a CO remover 150 is provided downstream of the reformer 100 to perform CO removal by selective oxidation reaction using selective oxidation air, the aqueous shift between the reformer 100 and the CO remover 150 is performed. It is also possible to provide a CO converter (not shown) for reducing the concentration of CO in the hydrogen-containing gas by reaction. The CO shift converter is filled with a shift catalyst.

Third Embodiment
FIG. 9 is a block diagram showing a configuration of a hydrogen generator in Embodiment 3 of the present invention.

  In the hydrogen generator 402 of Embodiment 3 shown in FIG. 9, the same components as those of the hydrogen generator 401 of Embodiment 2 shown in FIG.

  The hydrogen generator 402 of the third embodiment differs from the hydrogen generator 401 of the second embodiment in that, in the second embodiment, the CO remover 150 is cooled by the evaporator 61. In the second embodiment, the CO remover 150 is cooled by the evaporator 63, and the hydrogen generator 401 is controlled by the controller 303 in the second embodiment. However, in the third embodiment, the hydrogen generator in the controller 304 The point is to control 402.

  FIG. 10 is an essential part longitudinal cross sectional view showing a schematic configuration of a CO remover, a cooler, a reformer and a heater in the hydrogen generator of Embodiment 3 of the present invention.

  The evaporator 63 forms a space between the round bars 153 by sandwiching the metal round bar 153, which is a spiral-shaped partition, between the outer peripheral surface of the cylinder 151 and the inner peripheral surface of the cylinder 152. Water is distributed along the round bar 153.

  Therefore, a space surrounded by the outer peripheral surface of the cylinder 151 of the evaporator 63 and the inner peripheral surface of the cylinder 152 is partitioned in the central axis direction of the cylinder 151 and the cylinder 152 by the spiral shaped round rod 153. It is formed as a spiral-shaped flow channel surrounding along.

  The CO remover 150 is formed between the cylinder 152 and the cylinder 159, and is disposed adjacent to the outer periphery of the evaporator 63 via the cylinder 152.

  The selective oxidation reaction portion 160 of the CO remover 150 is a portion where the selective oxidation reaction occurs in the CO remover 150, and the upstream portion 161 of the methanation reaction portion is an upstream portion of the site where the methanation reaction occurs in the CO remover 150 The downstream part 162 of the methanation reaction part is a downstream part of the site where the methanation reaction occurs in the CO remover 150.

  The helical pitch width of the round bar 153 was 20 mm in the selective oxidation reaction part 160 and the part adjacent to the downstream part 162 of the methanation reaction part, and 10 mm in the part adjacent to the upstream part 161 of the methanation reaction part.

The reformer 100 is formed between the cylinder 152 and the cylinder 159 and is disposed upstream of the CO remover 150. The heater 20 is disposed at the central position of the cylinder 152 and the cylinder 159 and heats the reformer 100.

  The operation and action of the hydrogen generator 402 of the present embodiment configured as described above will be described. The following operations and actions are performed by the controller 304 controlling the hydrogen generator 402.

  As shown in (Equation 1), the supply amount (Fa) of the selective oxidation air is controlled according to the supply amount (Fi) of the raw material, and the flow rate of hydrogen in the hydrogen-containing gas needs 9NLM. The selective oxidation catalyst was supplied at a temperature of 185 ° C. by supplying 3 NLM of the amount and 0.64 NLM of the selective oxidation air supply amount. The CO concentration in the hydrogen-containing gas at that time was 2 ppm.

  FIG. 11 is a characteristic diagram showing the relationship between the catalyst layer position and the catalyst layer temperature in the CO remover in the hydrogen generator of Embodiment 3 of the present invention. FIG. 12 is a characteristic diagram showing the relationship between the catalyst layer position of the CO remover and the concentration of CO in the hydrogen-containing gas in the hydrogen generator of Embodiment 3 of the present invention.

  The CO remover 150 is supplied with 13 NLM of hydrogen-containing gas with a CO concentration of 0.5%. In the evaporator 63 adjacent to the upstream portion 161 of the methanation reaction part of the CO remover 150, the helical pitch width of the round bar 153 is small, and the flow rate of water is slow, so the cooling effect is high. The upstream portion 161 of the methanation reaction portion can be maintained at a low temperature more reliably.

  As shown in FIG. 11, the inlet of the catalyst layer of the selective oxidation reaction part 160 of the CO remover 150 is 175 ° C., the maximum temperature of the upstream part 161 of the methanation reaction part is 152 ° C., the minimum temperature is 134 ° C., the methanation reaction part The maximum temperature of the downstream portion 162 of the lower portion is 134.degree. C., and the minimum temperature is 130.degree.

  Further, as shown in FIG. 12, the CO concentration at the outlet of the catalyst layer of the selective oxidation reaction unit 160 is 800 ppm, the CO concentration at the outlet of the catalyst layer at the upstream portion 161 of the methanation reaction unit is 400 ppm, and the downstream portion 162 of the methanation reaction unit The concentration of CO at the outlet of the catalyst bed is 2 ppm.

  Thus, water is supplied to the evaporator 63 adjacent to the upstream portion 161 of the methanation reaction portion, and heat exchange between the upstream portion 161 of the methanation reaction portion and the evaporator 63 causes the upstream portion 161 of the methanation reaction portion The CO concentration at the catalyst layer outlet of the downstream portion 162 of the methanation reaction portion, that is, the outlet of the CO remover 150 can be reduced to 2 ppm.

As described above, in the hydrogen generator 402 of the present embodiment, it is disposed adjacent to the CO remover 150 and exchanges heat with the CO remover 150 to vaporize the water supplied from the water supplier 51. And the temperature of the upstream portion of the methanation reaction part of the CO remover 150 is lowered by the evaporator 63 which cools the CO remover 150 at the same time to suppress the reverse shift reaction of CO ₂ more promoted at high temperature Thus, the generation of CO can be suppressed, and the CO concentration in the hydrogen-containing gas can be reliably reduced.

Further, in the present embodiment, the upstream portion 161 of the methanation reaction portion is efficiently cooled using the evaporator 63 that vaporizes water necessary for the steam reforming reaction in the reformer 100. By lowering the temperature of the upstream portion 161 of the methanation reaction portion, it is possible to suppress the reverse shift reaction of CO ₂ occurring at high temperature and to suppress the generation of CO without providing a new cooling configuration.

  As a result, since the generation of CO can always be suppressed, it is possible to provide the hydrogen generator 402 capable of reliably reducing the CO concentration in the hydrogen-containing gas with a simpler configuration.

Further, in the present embodiment, in particular, the amount of heat exchange between the selective oxidation reaction unit 160 of the CO remover 150 and the evaporator 63 is reduced to reduce the temperature of the catalyst layer of the selective oxidation reaction unit 160 to the catalyst of the methanation reaction unit. By setting the temperature higher than the temperature of the layer, the reaction rate of the selective oxidation reaction portion 160 of the CO remover 150 can be made sufficiently high, and thus the reduction of the CO concentration can be promoted.

  Therefore, the amount of catalyst loaded in the CO remover 150 can be reduced, and a compact hydrogen generator can be provided. As a result, since the generation of CO can always be suppressed, it is possible to provide the hydrogen generator 402 capable of reliably reducing the concentration of CO in the hydrogen-containing gas.

  Although a CO remover 150 is provided downstream of the reformer 100 to perform CO removal by selective oxidation reaction using selective oxidation air, the aqueous shift between the reformer 100 and the CO remover 150 is performed. It is also possible to provide a CO converter (not shown) for reducing the concentration of CO in the hydrogen-containing gas by reaction. The CO shift converter is filled with a shift catalyst.

  In addition, although the helical pitch width of the round bar 153 is 20 mm in the selective oxidation reaction unit 160 and the downstream portion 162 of the methanation reaction unit and 10 mm in the upstream portion 161 of the methanation reaction unit, it is not limited to these dimensions. Other dimensions may be used as long as the helical pitch width of the upstream portion 161 of the methanation reaction portion is narrower than the other portions.

Embodiment 4
FIG. 13 is a block diagram showing a configuration of a fuel cell system according to Embodiment 4 of the present invention.

  As shown in FIG. 13, a fuel cell system 500 according to Embodiment 4 of the present invention includes a hydrogen generator 403 and a fuel cell 200.

  The fuel cell 200 causes the hydrogen-containing gas supplied from the hydrogen generator 403 to react with the oxidant gas to generate power. For the fuel cell 200, a polymer electrolyte fuel cell (PEFC) is used.

  In the hydrogen generator 403 of the fuel cell system 500 of Embodiment 4 shown in FIG. 13, the same components as those of the hydrogen generator 402 of Embodiment 3 shown in FIG. Do.

  The hydrogen generator 403 of the fuel cell system 500 of the fourth embodiment differs from the hydrogen generator 402 of the third embodiment in the hydrogen generator 403 of the fourth embodiment from the hydrogen generator 403 to the fuel cell 200. A sealing device 40 for opening and closing the hydrogen supply path 41 is installed in the middle of the hydrogen supply path 41, and the fuel supply path 42 and the hydrogen supply path 41 from the fuel cell 200 to the heater 20 are bypassed by a bypass path 43. A bypass sealing device 45 for opening and closing the bypass path 43 is installed in the middle of the bypass path 43.

  The hydrogen generator 402 of the third embodiment supplies the hydrogen-containing gas to the hydrogen utilizing device 201, but the hydrogen generator 403 of the fourth embodiment supplies the hydrogen-containing gas to the fuel cell 200.

  The operation and action of fuel cell system 500 of the present embodiment configured as described above will be described. The following operations and actions are performed by the controller 305 controlling the hydrogen generator 403.

The hydrogen generator 403 changes the supply amount of the raw material according to the flow rate of hydrogen required by the fuel cell 200 to generate a hydrogen-containing gas. As a fuel cell system 500, a hydrogen generator 403 capable of supplying a flow rate of hydrogen in a hydrogen-containing gas from 3NLM to 9NLM, which is necessary for power generation from 200 W to 700 W, will be described. In addition, city gas 13A is used as a raw material.

  The controller 305 starts the operation of the hydrogen generator 403 when the operation start request of the hydrogen generator 403 is generated. When the hydrogen generator 403 is activated, combustion in the heater 20 is started.

  At this time, the hydrogen supply passage 41 from the hydrogen generator 403 to the fuel cell 200 is closed by the sealer 40, and the bypass passage 43 bypassing the fuel supply passage 42 and the hydrogen supply passage 41 is opened by the bypass sealer 45. Do.

  Therefore, when the raw material is supplied to the reformer 100 by the start of operation of the raw material feeder 31, the raw material which has passed through the reformer 100 passes from the hydrogen supply path 41 through the bypass path 43 and the fuel supply path 42 to the heater. Supplied to 20. At the same time, the air for combustion is supplied to the heater 20 by the start of the operation of the air supplier 71.

  In the heater 20, an ignition operation is performed by an ignition electrode (not shown), and the raw material as fuel is burned using the air for combustion. Thus, the heat of combustion supplied from the heater 20 heats the reformer 100.

  Next, water is supplied to the reformer 100 by the start of operation of the water supplier 51. After the supply of water is started, when the composition of the hydrogen-containing gas generated by the hydrogen generator 403 becomes a composition suitable for supply to the fuel cell 200, the hydrogen supply path 41 is opened by opening the sealer 40. The fuel cell 200 is supplied with the hydrogen-containing gas by closing the bypass passage 43 by closing the bypass sealer 45 while opening the fuel cell 200.

  The fuel cell 200 generates electric power by reacting an oxidant gas supplied from an oxidant supply path (not shown) with a hydrogen-containing gas. Then, a hydrogen-containing gas not used for power generation in the fuel cell 200 is supplied to the heater 20 through the fuel supply path 42 and burned in the heater 20.

  The supply amount of the raw material of the raw material supply device 31 is controlled according to the flow rate of hydrogen required by the fuel cell 200. At this time, as shown in (Equation 1), the supply amount (Fa) of the selective oxidation air is controlled according to the supply amount (Fi) of the raw material. When the fuel cell 200 requires 9 NLM of the flow rate of hydrogen in the hydrogen-containing gas, the supply amount of the raw material is 3 NLM, and the supply amount of the selective oxidation air is 0.64 NLM.

  The relationship between the catalyst layer position of the CO remover 150 in the fuel cell system 500 of the fourth embodiment and the catalyst layer temperature is the catalyst layer position of the CO remover 150 in the hydrogen generator 402 of the third embodiment shown in FIG. It is similar to the relationship between the temperature of the catalyst bed and the temperature of the catalyst bed.

  Further, the relationship between the catalyst layer position of the CO remover 150 in the fuel cell system 500 of the fourth embodiment and the CO concentration in the hydrogen-containing gas is the CO removal in the hydrogen generator 402 of the third embodiment shown in FIG. It is similar to the relationship between the catalyst layer position of the vessel 150 and the CO concentration in the hydrogen-containing gas.

  The CO remover 150 is supplied with 13 NLM of hydrogen-containing gas with a CO concentration of 0.5%. At that time, as shown in FIG. 11, the inlet of the catalyst bed of the selective oxidation reaction part 160 of the CO remover 150 is 175 ° C., the maximum temperature of the upstream part 161 of the methanation reaction part is 152 ° C., and the minimum temperature is 134 ° C. The maximum temperature of the downstream part 162 of the chemical reaction part is 134.degree. C., and the minimum temperature is 130.degree.

  Further, as shown in FIG. 12, the CO concentration at the outlet of the catalyst layer of the selective oxidation reaction unit 160 is 800 ppm, the CO concentration at the outlet of the catalyst layer at the upstream portion 161 of the methanation reaction unit is 400 ppm, and the downstream portion 162 of the methanation reaction unit The concentration of CO at the outlet of the catalyst bed is 2 ppm.

  Thus, the concentration of CO in the hydrogen-containing gas supplied from the hydrogen generator 403 to the fuel cell 200 can be reduced to 2 ppm by narrowing the helical pitch width of the upstream portion 161 of the methanation reaction portion and lowering the temperature. it can.

As described above, in the fuel cell system 500 according to the present embodiment, the fuel cell system 500 is disposed adjacent to the CO remover 150 and exchanges heat with the CO remover 150 to vaporize the water supplied from the water supplier 51. And the temperature of the upstream portion of the methanation reaction part of the CO remover 150 is lowered by the evaporator 63 which cools the CO remover 150 at the same time to suppress the reverse shift reaction of CO ₂ more promoted at high temperature Thus, the generation of CO can be suppressed, the CO concentration in the hydrogen-containing gas can be reliably reduced, and a highly reliable fuel cell system 500 in which the deterioration of the fuel cell 200 is suppressed can be provided.

  Further, in the present embodiment, the upstream portion 161 of the methanation reaction portion is efficiently cooled using the evaporator 63 that vaporizes water necessary for the steam reforming reaction in the reformer 100. By lowering the temperature of the upstream portion 161 of the methanation reaction portion, it is possible to suppress the reverse shift reaction of CO 2 occurring at high temperature and to suppress the generation of CO without providing a new cooling configuration.

  As a result, since the generation of CO can always be suppressed, the CO concentration in the hydrogen-containing gas can be reliably reduced with a simpler configuration, and a highly reliable fuel cell system 500 that suppresses the deterioration of the fuel cell 200. Can be provided.

  Further, in the present embodiment, in particular, the temperature of the catalyst layer of the selective oxidation reaction unit 160 of the CO remover 150 is made higher than the temperature of the catalyst layer of the methanation reaction unit, whereby the selective oxidation reaction of the CO remover 150 is performed. In the part 160, since the reaction rate can be sufficiently high, reduction of the CO concentration can be promoted.

  Therefore, the amount of catalyst loaded in the CO remover 150 can be reduced, and a compact hydrogen generator can be provided. As a result, since the generation of CO can always be suppressed, the concentration of CO in the hydrogen-containing gas can be reliably reduced, and a highly reliable fuel cell system 500 in which the deterioration of the fuel cell 200 is suppressed can be provided. .

  Although a polymer electrolyte fuel cell (PEFC) is used for the fuel cell 200, any type of fuel cell may be used. In addition, for example, a phosphoric acid fuel cell or a molten carbonate fuel is used. A battery or the like may be used.

  As described above, the hydrogen generator according to the present invention can sufficiently reduce the concentration of CO in the hydrogen-containing gas, and therefore, the use in which the hydrogen-containing gas with sufficiently reduced CO concentration is required, in particular, It is suitable for a fuel cell system using a polymer electrolyte fuel cell (PEFC).

DESCRIPTION OF SYMBOLS 10 Desulfurizer 20 Heater 21 Fuel supply amount detector 22 Fuel supply device 30 Raw material supply amount detector 31 Raw material supply device 40 Sealer 41 Hydrogen supply path 42 Fuel supply path 43 Bypass path 45 Bypass sealer 50 Water supply amount Detector 51 Water supply device 61 Evaporator 62 Cooler 63 Evaporator 70 Air supply amount detector 71 Air supply device 80 Reformer temperature detector 81 Cooling air supply amount detector 82 Cooling air supply device 91 Selective oxidation air supply amount Detector 92 selective oxidation air supply unit 100 reformer 150 CO remover 151 cylinder 152 cylinder 153 round bar 156 pipe 157 cylinder 158 pipe 159 cylinder 160 selective oxidation reaction unit 161 upstream of methanation reaction unit 162 of methanation reaction unit Downstream part 171 pipe 172 cylinder 173 pipe 200 fuel cell 201 hydrogen utilization equipment 300 controller 301 computing unit 302 storage unit 303 controller 304 controller 305 controller 400 hydrogen generator 401 hydrogen generator 402 hydrogen generator 403 hydrogen generator 500 fuel cell system

Claims (4)

  A reformer which reforms the raw material to generate a hydrogen-containing gas, and the same catalyst are charged, and comprises a selective oxidation reaction part and a methanation reaction part, wherein the concentration of carbon monoxide contained in the hydrogen-containing gas is A hydrogen generator comprising: a CO remover to be reduced; and a selective oxidation air feeder which supplies selective oxidation air necessary for selective oxidation reaction to the hydrogen-containing gas flowing into the CO remover, the methane generating apparatus comprising: A hydrogen generator characterized in that the upstream part of the chemical reaction part is cooled.   The hydrogen generator according to claim 1, further comprising an evaporator that exchanges heat with the CO remover to evaporate water necessary for the reforming.   The hydrogen generator according to claim 1 or 2, wherein the temperature of the catalyst in the selective oxidation reaction part is higher than the temperature of the catalyst in the methanation reaction part.   A fuel cell system comprising: the hydrogen generator according to any one of claims 1 to 3; and a fuel cell that generates electric power using the hydrogen-containing gas generated by the hydrogen generator.

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