JP5369656B2 - Hydrogen generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen generator capable of realizing the improvement of hydrogen generation efficiency. <P>SOLUTION: The hydrogen generator A1 which performs non-equilibrium hydrogen generation reaction is equipped with a reforming part 11 for reforming fuel by a reforming catalyst in flowing fuel in a fixed direction, a hydrogen separation film 12 for separating and extracting hydrogen gas from reformed gas which is reformed by the reforming part 11 and a permeation part 13 for flowing hydrogen gas separated and extracted by the hydrogen separation film 12 to the outside of the equipment. By equipping with a temperature dispersion suppression means 14 of the reforming catalyst in fuel flow direction of the reforming part 11, the reforming reaction heat is uniformly maintained over the whole fuel flow direction of the reforming part 11, and hydrogen generation efficiency is largely improved even if heating is at an upper limit temperature or less in the reformer. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a hydrogen generation apparatus including a hydrogen separation membrane, for example, a hydrogen generation apparatus used as a hydrogen supply source for apparatuses such as an internal combustion engine and a fuel cell.

  In recent years, the use of fuel cells has attracted attention due to the growing interest in global environmental problems. A fuel cell uses hydrogen as fuel and oxygen or air as an oxidant to generate electricity through an electrochemical reaction. When considering applications in automobiles, the volume of the fuel cell system as a whole should be as small as possible. Is important. For this reason, it is desirable that the fuel is a liquid rather than a gas, and a hydrogen generator for extracting hydrogen from the liquid fuel is required. In automobiles, a method of improving fuel consumption and exhaust gas by using hydrogen for engine and exhaust gas treatment has been considered.

As a conventional hydrogen generator, there is one that generates a hydrogen-rich fuel gas through a multi-stage process of steam reforming, shift reaction, and CO oxidation reaction on a hydrocarbon compound (see, for example, Patent Document 1). . This hydrogen generator once separates the hydrogen generated in the reforming reaction with a separation membrane, and promotes the reaction by performing a shift reaction using the remaining gas, improving the hydrogen generation efficiency and hydrogen partial pressure. It is a thing.
JP 2001-283890 A

  However, in the conventional hydrogen generator as described above, since the steam reforming that generates an endothermic reaction is performed, the temperature of the reforming catalyst is maintained between the inlet and the outlet of the reformer. However, there is a problem that the steam reforming reaction is delayed and the efficiency improvement of hydrogen generation is hindered. In addition, even if it is attempted to secure the reaction rate by increasing the overall temperature of the reaction field, an upper limit is set on the maximum temperature in the reformer from the viewpoint of the reformer reliability, and hydrogen generation efficiency is ensured throughout the reformer. However, there is a problem that there is a limit, and it was a problem to solve these problems.

  The present invention has been made paying attention to the above-mentioned conventional problems, and provides a hydrogen generator capable of improving the hydrogen generation efficiency even when heating is performed at a temperature lower than the upper limit temperature in the reformer. It is an object.

A hydrogen generator according to the present invention is attached to an internal combustion engine, and reforms the fuel with a reforming catalyst by flowing the fuel in a fixed direction, and hydrogen gas from the reformed gas reformed in the reforming unit. A hydrogen generation apparatus that includes a hydrogen separation membrane for separation and extraction, and a permeation section that allows hydrogen gas separated and extracted by the hydrogen separation membrane to flow outside the apparatus, and performs a non-equilibrium hydrogen generation reaction in a fuel flow direction of the reforming section A reforming catalyst temperature variation suppressing means is provided , and the temperature variation suppressing means uses the heating gas generated externally or internally as a heating source of the reforming catalyst of the reforming section, and with respect to the fuel flow direction of the reforming section. A gas flow path for flowing the heating gas in the reverse direction, and a gas flow path for flowing the heating gas in the direction along the fuel flow direction of the reforming section. Uses exhaust gas to detect the amount of residual oxygen in the exhaust gas That an oxygen detector, in accordance with the residual amount of oxygen detected by the oxygen detector has a structure having a fuel Add supplying fuel added supplier from the middle of the gas flow path, in order to solve the conventional problems with the above configuration As a means of.
Further, the hydrogen generator of the present invention includes a reforming unit that reforms the fuel with a reforming catalyst by flowing the fuel in a fixed direction, and a hydrogen that separates and extracts hydrogen gas from the reformed gas reformed in the reforming unit. A hydrogen generation apparatus that performs a non-equilibrium hydrogen generation reaction, comprising a separation membrane and a permeation section for flowing hydrogen gas separated and extracted by the hydrogen separation membrane to the outside of the apparatus, wherein the reforming catalyst in the fuel flow direction of the reforming section Temperature variation suppression means is provided, and the temperature variation suppression means uses the heating gas generated externally or internally as a heating source for the reforming catalyst of the reforming section and heats it in the direction opposite to the fuel flow direction of the reforming section. A gas flow path for flowing the working gas, and a gas flow path for flowing the heating gas in a direction along the fuel flow direction of the reforming section. Theory for heating gas and fuel and oxidant in gas flow path An air-fuel ratio regulator that supplies a mixture ratio equal to or greater than the fuel ratio, an oxygen detector that detects the amount of residual oxygen in the exhaust gas from the gas flow path, and a gas flow path that depends on the amount of residual oxygen detected by the oxygen detector. It is characterized by having an additional fuel supply device for supplying additional fuel from the middle.

  In the above configuration, the temperature variation suppressing means heats the reforming catalyst so that the temperature of the entire reforming catalyst becomes substantially equal. Therefore, the temperature variation suppressing means does not necessarily make the temperature of the entire reforming catalyst uniform, but suppresses variations in temperature distribution of the reforming catalyst as much as possible.

According to the hydrogen generator of the present invention, the reforming reaction heat is evenly ensured over the entire fuel flow direction of the reforming section, and the hydrogen generation efficiency is greatly increased even when the heating is performed at the upper limit temperature or lower in the reformer. And can contribute to downsizing of the apparatus. Further, vehicle becomes easier with the downsizing of the device, making it possible to supply hydrogen to the internal combustion engine, which leads to an improvement of fuel consumption and exhaust. Furthermore, the hydrogen generator described above additionally heats the exhaust gas (heating gas) at the outlet side of the gas flow path by additionally supplying an amount of fuel calculated based on the amount of residual oxygen in the exhaust gas. It is possible to raise the temperature of the working gas, thereby making the temperature uniform throughout the reforming catalyst in the reforming section, improving the reforming efficiency, and increasing the amount of hydrogen produced.
Furthermore, according to the hydrogen generator of the present invention, the reforming reaction heat is evenly ensured over the entire fuel flow direction of the reforming section, and the hydrogen generation efficiency is greatly improved even when the heating is performed below the upper limit temperature in the reformer. And can contribute to downsizing of the apparatus. In addition, as the apparatus becomes smaller, the vehicle can be easily mounted, hydrogen can be supplied to the fuel cell vehicle and the internal combustion engine, and the fuel consumption and exhaust can be improved. Furthermore, the hydrogen generator described above is improved by reversing the supply ratio of fuel and oxidant (air) in the air-fuel ratio adjuster and performing additional supply of oxidant at a supply ratio below the stoichiometric air-fuel ratio. It is possible to make the temperature uniform throughout the reforming catalyst in the mass part, improve the reforming efficiency, and increase the amount of hydrogen generation.

1-3 is a figure explaining the reference example of the hydrogen generator of this invention.
A hydrogen generator A1 shown in FIG. 1 includes a reforming unit 11 that reforms the fuel in a cylindrical casing C by flowing the fuel in a certain direction and reforms the fuel with a reforming catalyst. A hydrogen separation membrane 12 that separates and extracts hydrogen gas from the gas and a permeation section 13 that allows the hydrogen gas separated and extracted by the hydrogen separation membrane 12 to flow outside the apparatus are arranged concentrically to perform a non-equilibrium hydrogen generation reaction. ing. The hydrogen generator A1 includes a reforming catalyst temperature variation suppressing means 14 in the fuel flow direction of the reforming unit 11 on the center line.

  It is desirable that the temperature variation suppressing means 14 has a structure capable of efficiently transferring heat to the reforming unit 11, and includes a gas flow path 15 adjacent to the reforming unit 11 as shown in FIG. In the gas flow path 15, an internal heating method can be employed in which the combustion gas resulting from the mixed combustion of fuel and oxidant (air) is the heating gas.

  Further, as shown in FIG. 2 (b), the temperature variation suppressing means 14 includes a gas flow path 15 adjacent to the reforming unit 11, and mixes and burns fuel and oxidant (air) in an external combustor 16. In addition, an external heating method in which the combustion gas is supplied to the gas flow path 15 as a heating gas can be employed.

  Further, as shown in FIG. 2C, the temperature variation suppressing means 14 includes a gas flow path 15 adjacent to the reforming unit 11 when the hydrogen generator A1 is attached to the internal combustion engine E. An external heating system that supplies exhaust gas of the internal combustion engine as a heating gas to the gas flow path 15 can also be employed.

  Further, a combustion catalyst can be provided in the gas flow path 15. A combustion catalyst is a catalyst that can burn a fuel or hydrogen to obtain a heating gas. For example, a noble metal such as platinum and palladium, or a transition metal such as copper, cobalt, and iron is converted into alumina, ceria, silica, and titania. It is carried on an inorganic porous material such as. The gas flow path 15 of the reforming section 11, the permeation section 13 and the temperature variation suppressing means 14 is provided with heat transfer fins or the like in order to reduce the deviation of the gas flow and increase the heat exchange rate. More desirable.

  Examples of the reforming catalyst of the reforming unit 11 include a fuel reforming catalyst, a dehydrogenation reaction catalyst, and a water gas shift reaction catalyst. Specifically, noble metals such as platinum, rhodium and ruthenium, and transition metals such as copper, cobalt and iron are supported on an inorganic porous material such as alumina, ceria, silica and titania. The reforming catalyst layer may be filled with a pellet-shaped catalyst. In addition, it is preferable to apply the slurry containing the catalyst component powder to the fins or the like in the reforming portion 11 by spraying or a wash coat method.

  As the fuel, various hydrocarbon fuels that can generate hydrogen by reaction, such as liquid hydrocarbons such as gasoline, alcohols such as ethanol, aldehydes, and natural gas can be used. In addition, when a fuel contains sulfur content, it is good to use the fuel desulfurized by providing a desulfurizer.

  The hydrogen separation membrane 12 may be a Pd-based alloy, V, Nb, or Zr-based alloy membrane, or a membrane using a silica-based or zeolite-based molecular sieve function. As the hydrogen separation membrane 12 is thinner, the amount of hydrogen permeation is increased, so that the thickness of the hydrogen separation membrane 12 is increasing. By using the thin hydrogen separation membrane 12 in the hydrogen generator A1 of the present invention as well, the entire device can be further miniaturized and the amount of Pd used can be suppressed.

  In order to reduce the size of the apparatus, a flat hydrogen separation membrane 12 is required. In order to manufacture the flat hydrogen separation membrane 12, there are a method of forming the hydrogen separation membrane 12 on the support plate, a method of securing the strength by placing the previously formed hydrogen separation membrane 12 on the support plate, and the like. .

  In addition to the function of reinforcing the hydrogen separation membrane 12, the support plate needs to have a function of preventing the flow of permeated hydrogen from flowing. For example, a support plate made of a porous material can be used. The porous body is made of ceramic or metal. However, when a metal porous body is used, since it may contain a component that may form an alloy with the hydrogen separation membrane 12, an alloy with the hydrogen separation membrane 12 is formed on the surface of the support plate. It is necessary to provide a protective layer for preventing the formation. Specifically, a protective layer such as alumina or zirconia is formed on the surface of the metal porous body.

  The permeation part 13 is a part that draws out hydrogen in the reformed gas through the hydrogen separation membrane 12 and flows it outside the apparatus.

Here, Fig.3 (a) is a graph which shows the relationship between steam reforming temperature and a methane conversion rate. That is, when steam reforming methane, generally, if there is a reaction temperature of about 800 ° C. to 900 ° C., nearly 100% of methane can be converted into hydrogen and CO ₂ in equilibrium.

  However, when designing a reformer in such a temperature environment, it is difficult to give sufficient reliability to the reactor itself, the catalyst, and other components. In view of the reforming reaction, it is not easy to create a reaction temperature close to 1000 ° C. on a daily basis. Furthermore, although steam reforming of methane occurs even at temperatures of about 500 ° C. to 600 ° C., since the conversion rate generally remains at about 20%, the overall hydrogen yield in the reforming reaction involving by-production of methane is reduced. If you think about it, its value is generally not high.

  On the other hand, for example, when a hydrogen generation apparatus A1 provided with the reforming unit 11, the hydrogen permeation unit 13, and the temperature variation suppressing means 14 is used to extract the generated hydrogen from the reaction field to create a non-equilibrium state, The reforming reaction can be promoted even in a low temperature range.

  In addition, when a reforming reaction accompanied by an endothermic reaction such as steam reforming occurs, for example, as shown by a broken line in FIG. descend. For this reason, it is necessary to ensure the amount of heat required for the reaction over the entire fuel flow direction of the reforming section 11. Considering the compatibility between the reforming reaction process with high hydrogen yield from reforming reaction to methane steam reforming and reformer design, the temperature from the inlet to the outlet of the hydrogen generator is improved. It is important to keep the temperature of the quality catalyst almost constant.

  Therefore, the hydrogen generation apparatus A1 includes the reforming unit 11, the hydrogen separation membrane 12, and the permeation unit 13, and performs a non-equilibrium hydrogen generation reaction. The entire reforming catalyst is heated evenly in the flow direction. Thereby, even if the temperature of the reforming catalyst of the reforming unit 11 is lowered, the conversion rate of methane is improved, and as shown in FIG. 3B, the hydrogen generation amount increases and the methane generation amount decreases. Will be.

( Reference Example 1)
In the hydrogen generator A1 shown in FIG. 1, Rh / Al 2 O 3 was used as the reforming catalyst in the reforming unit 11, and the temperature of the reforming catalyst was maintained at 540 ° C. to 580 ° C. Ethanol and water vapor are supplied to the reforming section 11 so that S / C = 2, and the temperature of the reforming section 11 is set to the above temperature in the gas flow path 15 section of the temperature variation suppressing means 14. Gas for heating was supplied. A hydrogen separation membrane 12 was provided between the reforming unit 11 and the permeation unit 13 and adjusted so that the hydrogen partial pressure difference between the reforming unit 11 and the permeation unit 13 was 0.9 MPa. Thereby, a large amount of hydrogen was able to be produced effectively.

(Comparative Example 1)
In a hydrogen generator equipped with a reforming unit, a hydrogen separation membrane, and a permeation unit, the temperature of the reforming catalyst in the reforming unit is maintained at 450 ° C. to 590 ° C., and the steam reforming reaction in the reforming unit and the hydrogen separation membrane Hydrogen abstraction was performed. As a result, the hydrogen generator of Comparative Example 1 was able to obtain only a hydrogen permeation amount corresponding to 75% of the hydrogen generation amount of the hydrogen generator A1 of the reference example .

FIG. 4 is a diagram for explaining another reference example of the hydrogen generator of the present invention. Note that the same components as those in the previous reference example are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 4A is a horizontal sectional view of the reforming unit 11 of the hydrogen generator A2. Therefore, the illustrated hydrogen generator A2 includes a reforming unit 11, a hydrogen separation membrane, and a permeation unit in a direction perpendicular to the paper surface. This hydrogen generator A2 includes two parallel reforming sections 11 that allow fuel to flow in a fixed direction (right direction in the drawing), and means for suppressing temperature variation of the reforming catalyst in the fuel flow direction of the reforming section 11. 14 is provided.

Temperature variation suppression means 14, as described with reference to FIG. 2 above, the heating gas generated in the external or internal heating source for the reforming catalyst of the reforming section, in this reference example, the reforming section The three gas flow paths 15 for flowing the heating gas in the direction opposite to the fuel flow direction 11 are provided. These gas flow paths 15 are disposed between the reforming sections 11 and on both sides.

  Here, in the above hydrogen generator A2, if the fuel of the reforming unit 11 and the heating gas are caused to flow in the same direction, the reforming reaction in the reforming unit 11 is an endothermic reaction. ), The temperature decreases on the outlet side of the reforming section 11, and the reforming efficiency also decreases.

  In view of this, the hydrogen generator A2 is adapted to flow the heating gas in each gas flow path 15 in the reverse direction with respect to the fuel flow direction of the reforming unit 11, thereby improving the reforming as shown by the solid line in FIG. The peak temperature of the mass part 11 can be shifted to the outlet side. As a result, the hydrogen generator A2 ensures the reaction temperature on the outlet side while maintaining the reaction temperature on the inlet side of the reforming catalyst, substantially equalizes the temperature of the entire reforming catalyst, as shown in FIG. 4 (b). As a result, the amount of hydrogen produced increases and the amount of methane produced decreases.

FIG. 5 is a diagram for explaining still another reference example of the hydrogen generator of the present invention. Note that the same components as those in the previous reference example are denoted by the same reference numerals, and detailed description thereof is omitted.

The hydrogen generator A3 illustrated in FIG. 5A includes a reforming unit 11, a hydrogen separation membrane 12, a permeating unit 13, and a temperature variation suppressing unit 14. The temperature variation suppression means 14 of this reference example uses heating gas generated outside or inside as a heating source of the reforming catalyst of the reforming unit 11 and is used for heating in a direction along the fuel flow direction of the reforming unit 11. A gas flow path 15 for flowing gas and a gas flow rate regulator 17 for increasing and decreasing the flow rate of the heating gas are provided.

  Here, the gas flow rate regulator 17 increases or decreases the flow rate of the heating gas in the case of the external heating method (see FIGS. 2b and 2c) in which the heating gas generated outside is supplied to the gas flow path 15. In the case of the internal heating system (see FIG. 2a) in which the fuel and oxidant are mixed and burned inside and the combustion gas is supplied to the gas passage 15 as a heating gas, the fuel and oxidant are The flow rate of the combustion gas (heating gas) is increased or decreased by increasing or decreasing the flow rate.

In the hydrogen generation device A3, when the flow rate of the heating gas is increased, the flow velocity of the heating gas in the gas flow path 15 is also increased . As shown in FIG. The temperature rises on the exit side. Thereby, in the hydrogen generator A3, as shown in FIG. 5B, the peak temperature of the reforming section 11 heated by the heating gas is shifted to the outlet side, and the reforming catalyst outlet in the reforming section 11 The temperature of the portion on the side can be raised, and as a result, the reforming efficiency is improved and the amount of hydrogen generation is increased.

  Further, the hydrogen generator A3 includes, for example, a temperature sensor 18 that detects the exhaust gas temperature on the outlet side of the reforming unit 11, and controls the gas flow rate regulator 17 based on the detected value of the temperature sensor 18. Thus, the temperature of the reforming unit 11 can be automatically adjusted.

That is, as shown in FIG. 5 (d) , when the hydrogen generator A3 receives the temperature increase instruction signal when the detected value of the temperature sensor 18 is equal to or lower than the predetermined value in step S1, the heating gas is detected in step S2. The gas flow rate regulator 17 is driven so that the flow rate increases. As a result, the exhaust temperature of the reforming unit 11 also increases. In step S3, it is determined whether or not the detected value of the temperature sensor 18 is equal to or greater than a predetermined value (whether or not a temperature increase completion signal has been received). Returning to step S4, when the predetermined value or more is reached (Yes), the control is terminated.

6 and 7 are diagrams for explaining an embodiment of the hydrogen generator of the present invention , and FIG. 8 is a diagram for explaining still another reference example . Note that the same components as those in the previous reference example are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 6 is a horizontal sectional view of the reforming unit 11 of the hydrogen generator A4. Accordingly, the illustrated hydrogen generator A4 includes a reformer 11, a hydrogen separation membrane, and a permeate layer in a direction perpendicular to the paper surface. This hydrogen generator A2 includes two parallel reforming sections 11 that allow fuel to flow in a fixed direction (right direction in the drawing), and means for suppressing temperature variation of the reforming catalyst in the fuel flow direction of the reforming section 11. 14 is provided.

  The temperature variation suppressing means 14 uses heating gas generated externally or internally as a heating source of the reforming catalyst of the reforming section, and in this embodiment, heats in the direction opposite to the fuel flow direction of the reforming section 11. The central gas flow path 15A for flowing the working gas and the gas flow paths 15B and 15B on both sides for flowing the heating gas in the direction along the fuel flow direction of the reforming section 11 are provided.

  FIG. 7 is a horizontal sectional view of the temperature variation suppressing means 14 of the hydrogen generator A5. Therefore, the illustrated hydrogen generator A5 includes a reforming unit that polymerizes on the temperature variation suppressing means 14, a hydrogen separation membrane, and a permeating unit in a direction perpendicular to the paper surface.

  The temperature variation suppressing means 14 uses the heating gas generated externally or internally as a heating source of the reforming catalyst of the reforming section. In this embodiment, the temperature variation suppressing means 14 extends in the fuel flow direction of the reforming section indicated by a thick arrow in the figure. On the other hand, two gas flow paths 15A for flowing the heating gas in the reverse direction and two gas flow paths 15B for flowing the heating gas in the direction along the fuel flow direction of the reforming unit 11 are provided. The gas flow paths 15A and 15B are arranged such that the flow directions of the heating gas between the adjacent flow paths are opposite to each other.

 FIG. 8 is a horizontal sectional view of a portion of the temperature variation suppressing means 14 of the hydrogen generator A6. Therefore, the illustrated hydrogen generator A6 includes a reforming unit that polymerizes in the temperature variation suppressing means 14, a hydrogen separation membrane, and a permeation unit in a direction perpendicular to the paper surface.

The temperature variation suppressing means 14 uses the heating gas generated outside or inside as a heating source of the reforming catalyst of the reforming section. In this reference example , in the fuel flow direction of the reforming section indicated by a thick arrow in the figure. On the other hand, the four gas flow paths 15 which flow the heating gas in the orthogonal direction are provided. Each gas flow path 15 is arrange | positioned so that the flow direction of the gas for heating of adjacent flow paths may become a mutually reverse direction.

The hydrogen generators A4 to A6 of the above three examples can uniformly heat the reforming catalyst over the entire fuel flow direction of the reforming unit 11 by the temperature variation suppressing means 14, and thereby each of the above references Similar to the example , the reforming efficiency can be improved and the amount of hydrogen generation can be increased.

FIG. 9 is a diagram illustrating still another embodiment of the hydrogen generator of the present invention. Note that the same components as those in the previous reference example and embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

A hydrogen generation apparatus A7 shown in FIG. 9A is an apparatus attached to the internal combustion engine E, and is similar to the previous reference example and embodiment, the reforming section, the hydrogen separation membrane, the permeation section, and the temperature variation suppressing means. 14 is provided. The temperature variation suppressing means 14 of this embodiment is an external heating system that uses the exhaust gas of the internal combustion engine E as a heating gas, and an oxygen detector 19 that detects the amount of residual oxygen in the exhaust gas, and an oxygen detector 19. An additional fuel supply device 20 for supplying additional fuel from the middle of the gas flow path 15 in accordance with the amount of residual oxygen detected in FIG. For the oxygen detector 19, an oxygen sensor, an air-fuel ratio sensor, or the like can be used.

  Further, the hydrogen generator A7 is configured to exhaust the internal combustion engine E with respect to the fuel supply unit 21 and the water vapor supply unit 22 that supply fuel and an oxidant to the reforming unit, and the gas flow path 15 of the temperature variation suppressing unit 14. A gas flow rate regulator 23 for adjusting and increasing the gas flow rate, and a controller 24 for controlling the additional fuel supply device 20 and the gas amount regulator 23 based on the detection value of the oxygen detector 19 are provided. Fuel is supplied to the previous fuel additional supply device 20 from a fuel supply device 21 that supplies fuel to the reforming unit.

The above hydrogen generator A7, by the internal combustion engine E is lean combustion because it contains residual oxygen in the exhaust gas (heating gas), as shown in FIG. 9 (c), the residual exhaust gas The additional supply amount of fuel is calculated based on the oxygen amount. Then, by additionally supplying the calculated amount of fuel from the middle of the gas flow path 15, exhaust gas (heating gas) is completely burned on the outlet side of the gas flow path 15 to raise the temperature of the heating gas. Thus, as shown in FIG. 9 (b), the temperature is made uniform throughout the reforming catalyst in the reforming unit 11, it is possible to increase the amount of hydrogen generated to improve the reforming efficiency.

  Further, the hydrogen generator A7 can automatically adjust the temperature of the reforming unit. That is, as shown in FIG. 9 (d), when the hydrogen detector A7 receives the temperature increase instruction signal when the detected value of the oxygen detector 19 reaches or exceeds a predetermined value in step S11, in step S12, The additional supply amount is calculated, and fuel is additionally supplied from the middle of the gas flow path 15 by the additional fuel supplier 20 in step S13. In step S14, it is determined whether or not the detection value of the oxygen detector 19 is equal to or less than a predetermined value (whether or not a temperature increase completion signal is received). Since there is a sufficient amount of residual oxygen in the exhaust gas, the process returns to step S13, and when it is equal to or less than the predetermined value (Yes), the control is terminated because the amount of residual oxygen in the exhaust gas is insufficient.

Even when it is determined that the residual oxygen amount is insufficient, the hydrogen generator A7 includes the gas flow rate regulator 23 as in the reference example shown in FIG. The temperature can be equalized over the entire reforming catalyst in the reforming section by increasing or decreasing the flow rate of the exhaust gas (heating gas) to the gas flow path 15.

  FIG. 10 is a diagram illustrating still another embodiment of the hydrogen generator of the present invention. Note that the same components as those of the previous embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

The hydrogen generator A8 shown in FIG. 10A includes a reforming unit, a hydrogen separation membrane, a permeation unit, and a temperature variation suppressing unit 14 as in the previous embodiment. The temperature variation suppressing means 14 of this embodiment is an internal heating method in which the combustion gas resulting from the mixed combustion of fuel and oxidant is used as a heating gas, and the fuel and oxidant are mixed in the gas flow path 15 at a theoretical air fuel ratio or higher. and air-fuel ratio regulator 25 supplies a ratio, the oxygen detector for detecting the residual oxygen amount in the exhaust gas from the gas flow channel 15 (the reference numeral 19 in FIG. 9), detected by the oxygen detector (19) An additional fuel supply device 20 for supplying additional fuel from the middle of the gas flow path 15 according to the residual oxygen amount is provided.

The hydrogen generating device A8 is provided with a fuel supply device 21 and the steam supply unit 22 for supplying the fuel and oxidant from the fuel supply 21 through the air-fuel ratio regulator 25 the gas stream relative to the reformer Fuel is supplied to the passage 15.

The above hydrogen generator A8 is a step for supplying the fuel to the gas flow path 15 of the temperature variation suppressing means 14, may be set fuel and oxidant (air) to the stoichiometric air-fuel ratio than the air-fuel ratio regulator 25 The oxygen detector (19) detects the amount of residual oxygen in the exhaust gas from the gas flow path 15 so that it becomes close to the stoichiometric air-fuel ratio at the outlet side of the gas flow path 15 as shown in FIG. 10 (c). In addition, additional fuel is supplied from the middle of the gas flow path 15 by the additional fuel supplier 20. Such control can be automatically performed in the same process as the flowchart shown in FIG.

  Thereby, as shown in FIG.10 (b), hydrogen generator A8 can make temperature uniform throughout the reforming catalyst in a reforming part, can improve reforming efficiency, and can increase the amount of hydrogen production. .

Also, the above hydrogen generator A8 reverses the supply ratio of the fuel and oxidant (air) in the air-fuel ratio regulator 25, and then add the supply of the oxidizing agent at the following feed ratio the stoichiometric air-fuel ratio Similar effects can be obtained.

FIG. 11 is a diagram for explaining still another reference example of the hydrogen generator of the present invention. Note that the same components as those in the previous reference example and embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 11A is a horizontal sectional view of a portion of the temperature variation suppressing means 14 of the hydrogen generator A9. The temperature variation suppressing means 14 of this reference example is an internal heating system in which the combustion gas resulting from the mixed combustion of fuel and oxidant is a heating gas, and includes a large number of heat transfer fins 26 inside the gas flow path 15. At the same time, the installation density of the heat transfer fins 26 is varied in the gas flow direction of the gas flow path 15. More specifically, the installation density of the heat transfer fins 26 on the outlet side is larger than the installation density of the heat transfer fins 26 on the inlet side of the gas flow path 15. That is, the number of heat transfer fins 26 in the latter half is larger than the number of heat transfer fins 26 in the first half of the gas flow path 15.

  The hydrogen generating device A9 described above has a flow passage area in the second half of the gas flow passage 15 by increasing the installation density of the heat transfer fins 26 on the outlet side than the installation density of the heat transfer fins 26 on the inlet side. Is increased to increase the thermal conductivity, and the fuel conversion rate is also improved on the outlet side of the gas flow path 15 as shown in FIG. As a result, as shown in FIG. 11B, the hydrogen generator A9 can make the temperature uniform over the entire reforming catalyst in the reforming section, improve the reforming efficiency, and increase the hydrogen generation amount. .

FIG. 12 is a diagram for explaining still another reference example of the hydrogen generator of the present invention. Note that the same components as those in the previous reference example and embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 12A is a horizontal sectional view of a portion of the temperature variation suppressing means 14 of the hydrogen generator A10. The temperature variation suppressing means 14 of this reference example is an internal heating method in which the combustion gas produced by the mixed combustion of fuel and oxidant is a heating gas, and is provided at a plurality of locations in the gas flow direction of the gas flow path 15 (two in the illustrated example). The combustion catalyst 27 is disposed at a location).

  The hydrogen generator A10 described above is an internal heating method in which the temperature variation suppressing means 14 uses a fuel and an oxidant, so that it can be burned at a low temperature by using the combustion catalyst 27. In this case, since the oxidation reaction is mainly caused by the combustion catalyst 27, by arranging the combustion catalyst 27 at a plurality of locations as described above, as shown in FIG. Fuel conversion rate is also improved.

  Thereby, the hydrogen generator A10 can disperse the heat of the gas flow path 15, and as shown in FIG. 12B, the temperature can be made uniform over the entire reforming catalyst in the reforming section. The reforming efficiency can be improved and the amount of hydrogen generation can be increased.

FIG. 13 is a diagram for explaining still another reference example of the hydrogen generator of the present invention. Note that the same components as those in the previous reference example and embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 13A is a horizontal sectional view of a portion of the temperature variation suppressing means 14 of the hydrogen generator A11. The temperature variation suppressing means 14 of this reference example is an internal heating system in which the combustion gas resulting from the mixed combustion of fuel and oxidant is a heating gas, and there are a plurality of (two in the illustrated example) in the gas flow direction of the gas flow path 15. ) Combustion catalysts 27A and 27B are disposed.

  Then, the temperature variation suppressing means 14 combusts at the outlet side of the gas flow path 15 more than the combustion catalyst 27A at the inlet side of the gas flow path 15 in the combustion catalysts 27A and 27B adjacent in the gas flow direction of the gas flow path 15. At least one of the coating amount of the catalyst 27B and the base metal loading amount is increased.

  As shown in FIG. 13C, the hydrogen generation device A11 separates the combustion catalysts 27A and 27B so that the fuel conversion rate becomes 100% in the latter half of the gas flow path 15, as shown in FIG. The generation of heat at the two stages becomes two-stage, and the temperature of the latter half of the reforming catalyst in the reforming section can be secured by preventing the bias of heat transmitted to the reforming section.

  Thereby, the hydrogen generator A11 can disperse the heat of the gas flow path 15, and as shown in FIG. 13B, the temperature can be made uniform over the entire reforming catalyst in the reforming section. Improve reforming efficiency and increase hydrogen production

FIG. 14 is a diagram for explaining still another reference example of the hydrogen generator of the present invention. Note that the same components as those in the previous reference example and embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The temperature variation suppressing means 14 in the hydrogen generator A12 shown in the figure is an internal heating method in which the combustion gas obtained by the mixed combustion of fuel and oxidant is a heating gas, and an electric heater is provided on the outlet side of the gas flow path 15. (Heater) 28 is provided.

The hydrogen generator A12 described above has a gas flow when the temperature of the reforming section cannot be kept almost even from the inlet to the outlet only by the mixed combustion heat of the fuel and oxidant (air) supplied to the gas flow path 15. In the latter half of the path 15, the heating gas is heated by the heater 28. Thereby, the hydrogen generator A12 can make the temperature uniform over the entire reforming catalyst in the reforming section, and can improve the reforming efficiency and increase the hydrogen generation amount.

FIG. 15 is a diagram for explaining still another reference example of the hydrogen generator of the present invention. Note that the same components as those in the previous reference example and embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

The hydrogen generator A13 shown in FIG. 15A includes the reforming unit 11, the hydrogen separation membrane 12, the permeating unit 13, and the temperature variation suppressing means 14 as in the previous reference examples . The temperature variation suppressing means 14 of this embodiment includes a gas flow path 15 for flowing a heating gas generated outside or inside, an inlet temperature detector 29A for detecting the inlet temperature of the reforming unit 11, and reforming. An outlet temperature detector 29 </ b> D that detects the outlet temperature of the part 11, catalyst temperature detectors 29 </ b> B and 29 </ b> C that detect temperatures at a plurality of locations of the reforming catalyst of the reforming part 11, and a controller 30 are provided.

  Then, the controller 30 determines that the outlet temperature of the reforming unit 11 detected by the outlet temperature detector 29D is three times the average temperature of the reforming catalyst and its standard deviation based on the detected values of the temperature detectors 29A to 29D. If it is less than the above, the reforming catalyst of the reforming unit 11 is heated.

The heating to the reforming catalyst is, for example, increase / decrease in the flow rate of the heating gas in the reference example shown in FIG. 5, additional supply of fuel to the gas flow path 15 in the embodiment shown in FIGS. 9 and 10, and FIG. It is control, such as an action | operation of the heater 28 in the reference example shown.

  As shown in FIG. 15 (b), the hydrogen generator A13 described above, in step S21, based on the detected values from the temperature detectors 29A to 29D, the average temperature of the reforming catalyst of the reforming unit 11 and its standard. The deviation is calculated, and in step S22, it is determined whether or not the outlet temperature of the reforming unit 11 by the outlet temperature detector 29D is equal to or higher than the average temperature of the reforming catalyst and the standard deviation thereof. The reason why the value is triple the standard deviation is that the inflection point where the yield of hydrogen increases is experimentally around the triple value.

  Then, in Step S22, when the outlet temperature of the reforming unit 11 is equal to or more than three times the average temperature of the reforming catalyst and its standard deviation (Yes), the hydrogen generator A13 determines the temperature variation in Step S23. The temperature increase instruction signal for the suppression means 14 is canceled and the control is terminated. In step S22, when the outlet temperature of the reforming unit 11 is less than the average temperature of the reforming catalyst and three times the standard deviation (No), in step S24, the temperature rise for the temperature variation suppressing means 14 is increased. An instruction signal is transmitted, and temperature control is performed in step S25.

  That is, the temperature of the entire reforming catalyst of the reforming unit 11 is equalized by increasing the flow rate of the heating gas, supplying additional fuel to the gas flow path 15, operating the heater 28, and the like. It is possible to improve the quality efficiency and increase the amount of hydrogen produced.

  In the above hydrogen generator A13, when a hydrocarbon or alcohol is steam reformed, a reforming temperature of approximately 400 ° C. or higher is required, although depending on the reforming catalyst used. Above this reforming temperature, the reformed fuel undergoes decomposition, dehydrogenation, shift reaction, steam reforming, and the like, and is sequentially decomposed and reformed to those having a light molecular weight such as methane and CO.

  In the case where a non-equilibrium hydrogen generation reaction is taking place, if the average temperature of the reforming catalyst is maintained at 400 ° C. or higher, methane and CO compounded by the reforming reaction are also converted into methane steam reforming and CO. The aquatic gas shift reaction can occur and higher hydrogen production efficiency can be obtained. Therefore, the hydrogen generation apparatus can realize highly efficient hydrogen generation from a non-equilibrium hydrogen generation reaction by maintaining the outlet temperature of the reforming unit 11 at about 400 ° C. to 600 ° C.

The configuration of the hydrogen generator of the present invention is not limited to the above embodiments, and the specific configuration of the temperature variation suppressing means of each embodiment and each reference example can be appropriately combined. The details of the configuration can be changed without departing from the scope of the present invention.

It is sectional drawing explaining the reference example of the hydrogen generator of this invention. FIG. 4 is a cross-sectional view (a) illustrating temperature variation suppressing means of the internal heating method, and cross-sectional views (b) and (c) illustrating temperature variation suppressing means of the external heating method. It is the graph (a) which shows the relationship between steam reforming temperature and the conversion rate of methane, the graph (b) which shows the production amount of the substance in a reforming part, and the graph (c) which shows the temperature in a reforming part. It is the horizontal sectional view (a) explaining the other reference example of the hydrogen generator of this invention, the graph (b) which shows the production amount of the substance in a reforming part, and the graph (c) which shows the temperature in a reforming part. . Sectional drawing (a) explaining the further another reference example of the hydrogen generator of this invention, the graph (b) which shows the temperature in a reforming part, the graph (c) which shows the flow velocity of the gas for heating, and the temperature of a gas flow path And FIG. 6 is a flowchart (d) illustrating a control process. It is a horizontal sectional view explaining one embodiment of the hydrogen generator of the present invention. It is a horizontal sectional view explaining other embodiments of the hydrogen generator of the present invention. It is a horizontal sectional view explaining the other reference example of the hydrogen generator of the present invention. Further block diagram illustrating another embodiment of a hydrogen generator of the present invention (a), a graph showing the temperature in the reformer unit (b), a graph showing the amount of fuel supplied to the gas flow path (c), and the control It is a flowchart (d) explaining a process. Further block diagram illustrating another embodiment of a hydrogen generator of the present invention (a), is a graph showing the temperature in the reformer unit (b), and a graph showing the air-fuel ratio with respect to the gas flow path (c). It is the horizontal sectional view (a) explaining the other reference example of the hydrogen generator of this invention, the graph (b) which shows the temperature in a reforming part, and the graph (c) which shows the fuel conversion rate with respect to a gas flow path. . It is the horizontal sectional view (a) explaining the other reference example of the hydrogen generator of this invention, the graph (b) which shows the temperature in a reforming part, and the graph (c) which shows the fuel conversion rate with respect to a gas flow path. . It is the horizontal sectional view (a) explaining the other reference example of the hydrogen generator of this invention, the graph (b) which shows the temperature in a reforming part, and the graph (c) which shows the fuel conversion rate with respect to a gas flow path. . It is a horizontal sectional view explaining the other reference example of the hydrogen generator of the present invention. It is sectional drawing (a) explaining the further reference example of the hydrogen generator of this invention, and the flowchart (b) explaining a control process.

Explanation of symbols

A1 to A13 Hydrogen generator E Internal combustion engine 11 Reforming unit 12 Hydrogen separation membrane 13 Permeating unit 14 Temperature variation suppressing means 15 Gas flow channel 15A Gas flow channel 15B Gas flow channel 17 Gas flow rate regulator 19 Oxygen detector 20 Fuel supply vessel 23 gas flow regulator 24 controller 25 air-fuel ratio regulator 26 the heat transfer fins 27 combustion catalyst 27A combustion catalyst 27B combustion catalyst 28 heater 29A inlet temperature detector 29B catalyst temperature detector 29C catalyst temperature detector 29D outlet temperature Detector

Claims (9)

A reforming unit attached to the internal combustion engine, for flowing the fuel in a fixed direction and reforming the fuel with a reforming catalyst, a hydrogen separation membrane for separating and extracting hydrogen gas from the reformed gas reformed in the reforming unit, A hydrogen generation apparatus that includes a permeation section that allows hydrogen gas separated and extracted by a hydrogen separation membrane to flow outside the apparatus, and performs a non-equilibrium hydrogen generation reaction,
Provided with means for suppressing temperature variation of the reforming catalyst in the fuel flow direction of the reforming section ,
A gas flow path in which the temperature variation suppressing means uses the heating gas generated outside or inside as a heating source of the reforming catalyst of the reforming section and flows the heating gas in a direction opposite to the fuel flow direction of the reforming section. And a gas flow path for flowing a heating gas in a direction along the fuel flow direction of the reforming section,
Further, the temperature variation suppressing means uses the exhaust gas of the internal combustion engine as the heating gas, detects an amount of residual oxygen in the exhaust gas, and a gas flow path according to the amount of residual oxygen detected by the oxygen detector A hydrogen generator comprising an additional fuel supply device for additionally supplying fuel from the middle of the fuel . A reforming unit that reforms the fuel with a reforming catalyst by flowing the fuel in a certain direction, a hydrogen separation membrane that separates and extracts hydrogen gas from the reformed gas reformed in the reforming unit, and a separation separation and extraction with the hydrogen separation membrane A hydrogen generation apparatus that includes a permeation section that allows the hydrogen gas to flow outside the apparatus to perform a non-equilibrium hydrogen generation reaction,
Provided with means for suppressing temperature variation of the reforming catalyst in the fuel flow direction of the reforming section,
A gas flow path in which the temperature variation suppressing means uses the heating gas generated outside or inside as a heating source of the reforming catalyst of the reforming section and flows the heating gas in a direction opposite to the fuel flow direction of the reforming section. And a gas flow path for flowing a heating gas in a direction along the fuel flow direction of the reforming section,
Further, the temperature variation suppression means uses an air-fuel ratio regulator that supplies combustion gas from a mixed combustion of fuel and oxidant as a heating gas, and supplies the fuel and oxidant to the gas flow path at a mixture ratio equal to or higher than the theoretical air-fuel ratio; An oxygen detector that detects the amount of residual oxygen in the exhaust gas from the flow path and an additional fuel supply device that additionally supplies fuel from the middle of the gas flow path according to the amount of residual oxygen detected by the oxygen detector A hydrogen generator characterized by this. A reforming unit that reforms the fuel with a reforming catalyst by flowing the fuel in a certain direction, a hydrogen separation membrane that separates and extracts hydrogen gas from the reformed gas reformed in the reforming unit, and a separation separation and extraction with the hydrogen separation membrane A hydrogen generation apparatus that includes a permeation section that allows the hydrogen gas to flow outside the apparatus to perform a non-equilibrium hydrogen generation reaction,
Provided with means for suppressing temperature variation of the reforming catalyst in the fuel flow direction of the reforming section,
A gas flow path in which the temperature variation suppressing means uses the heating gas generated outside or inside as a heating source of the reforming catalyst of the reforming section, and flows the heating gas in a direction along the fuel flow direction of the reforming section; A hydrogen generating apparatus comprising: a gas flow path for flowing a heating gas in a direction opposite to a fuel flow direction of the reforming unit; and a gas flow rate regulator for increasing or decreasing the flow rate of the heating gas.   The gas flow path in which the temperature variation suppression means uses the heating gas generated externally or internally as the heating source of the reforming catalyst of the reforming section and flows the heating gas in a direction orthogonal to the fuel flow direction of the reforming section The hydrogen generator according to any one of claims 1 to 3, wherein the hydrogen generator is provided.   The temperature variation suppressing means comprises a large number of heat transfer fins inside the gas flow path, and the installation density of the heat transfer fins is varied in the gas flow direction of the gas flow path. 5. The hydrogen generator according to any one of 4 above.   6. The hydrogen generator according to claim 5, wherein the installation density of the heat transfer fins on the outlet side is larger than the installation density of the heat transfer fins on the inlet side of the gas flow path.   6. The temperature variation suppressing means uses a combustion gas produced by mixed combustion of fuel and oxidant as a heating gas, and combustion catalysts are arranged at a plurality of locations in the gas flow direction of the gas flow path. The hydrogen generator according to any one of the above.   In the combustion catalyst adjacent to the gas flow direction of the gas flow path, at least one of the coating amount of the combustion catalyst on the outlet side of the gas flow path and the support amount of the base metal is larger than the combustion catalyst on the inlet side of the gas flow path. 8. The hydrogen generator according to claim 7, wherein   The hydrogen generator according to any one of claims 1 to 8, wherein the temperature variation suppressing means includes an electric heater on the outlet side of the gas flow path.

Images