JP2006097526A - Temperature increasing device for on-vehicle type hydrogen production system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature increasing device for an on-vehicle type hydrogen production system for maintaining a temperature of reaction tubes of a hydrogen separation type reformer even during traveling without any loss of time for every destination. <P>SOLUTION: The temperature increasing device for an on-vehicle type hydrogen production system has a heater 3 started by the driving of engine power of a vehicle. The on-vehicle type hydrogen production system has the hydrogen separation type reformer 1, which has a reaction parts 11, 12. The reaction parts 11, 12 are constituted of reaction tubes filled with reforming catalysts, and provided with a hydrogen transmission part 14 partitioned by a hydrogen separation membrane and a combustion gas passage 15 heating the reaction pipes. The hydrogen separation type reformer 1 has a combustion part 13 generating combustion gas for heating the reaction pipe parts 11, 12, and the reaction pipes are preheated with a means utilizing the heat from the heater 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a temperature raising device for a vehicle-mounted hydrogen production system.

  In a hydrogen production system using a hydrogen separation reformer, a raw material gas obtained by adding steam to a hydrocarbon such as methane or methanol or a compound having a substituent containing oxygen in the hydrocarbon skeleton is steam-reformed in the presence of a reforming catalyst. It is supposed that hydrogen is obtained by selectively decomposing into hydrogen and carbon dioxide, and selectively separating only the generated hydrogen through a hydrogen separation membrane built in the hydrogen separation reformer. .

  Such a hydrogen separation type reformer is composed of a plurality of reaction tubes filled with a reforming catalyst, a multi-tube reaction tube portion having a hydrogen permeation portion separated by a hydrogen separation membrane, and combustion for obtaining reaction heat. Department. In such a hydrogen separation reformer, combustion gas is supplied to the surface of the reaction tube of the multi-tube reaction tube part, and heat necessary for the reaction is applied to the reaction tube by convection heat transfer in order to prevent the generation of hot spots. Yes.

However, since this type of hydrogen separation type reformer utilizes convective heat transfer, once it is stopped, it takes about 6 hours for the temperature raising time and cannot be restarted quickly.
Therefore, when applied to a vehicle-mounted hydrogen production system (Patent Document 1), there is a drawback that the operation efficiency is poor by the restart time for each destination.
A method of supplying fuel during movement, generating combustion gas, and preheating is also conceivable. However, such a method was practically impossible to implement due to legal restrictions.
JP 2004-079262 A

  The present invention provides a temperature raising device for a vehicle-mounted hydrogen production system that maintains the temperature of a reaction tube of a hydrogen separation reformer even during movement and eliminates time loss for each movement destination. With the goal.

  In order to achieve the above object, the present invention is a temperature raising device for a vehicle-mounted hydrogen production system, comprising a heater that is activated by driving vehicle engine power, and the vehicle-mounted hydrogen production system comprises: A hydrogen separation reformer, wherein the hydrogen separation reformer has a reaction tube portion, the reaction tube portion is constituted by a reaction tube filled with a reforming catalyst, and a hydrogen permeation portion partitioned by a hydrogen separation membrane; A combustion gas passage for heating the reaction tube, and the hydrogen separation reformer has a combustion part for generating combustion gas for heating the reaction tube part, and the heat obtained by the heater is obtained. A means for preheating the reaction tube is provided.

  In one embodiment, a temperature raising device for a vehicle-mounted hydrogen production system according to the present invention circulates at least a part of the combustion exhaust gas emitted from the hydrogen separation reformer via a blower means, and thus the combustion exhaust gas. A combustion exhaust gas circulation line for returning from the introduction port to the reformer is provided, and the circulating combustion exhaust gas is heated by the heater to preheat the reaction tube.

  Furthermore, in another embodiment, a temperature raising device for a vehicle-mounted hydrogen production system according to the present invention is provided with a hot air generator using the heater, and the hot air generated by the hot air generator is supplied from a combustion unit. The present invention is characterized in that the reaction tube is preheated by hot air supplied from a combustion section, provided with a blowing means for supplying.

  Furthermore, in another embodiment, a temperature raising apparatus for a vehicle-mounted hydrogen production system according to the present invention is provided with a hot air generator using the heater, and the hot air generated by the hot air generator is used as combustion exhaust gas. The reaction tube is preheated by the supplied hot air and provided with a blowing means for supplying from the outlet.

  Furthermore, the temperature raising apparatus for a vehicle-mounted hydrogen production system according to the present invention is characterized in that, in another embodiment, the reaction tube is directly preheated by the heater.

  According to the present invention, there is provided a temperature raising device for a vehicle-mounted hydrogen production system that maintains the temperature of the reaction tube of the hydrogen separation reformer even during movement and eliminates time loss for each movement destination. Is done.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

The present invention produces hydrogen by a steam reforming reaction using hydrocarbons such as city gas and steam as raw materials, and also produces high-purity hydrogen using a hydrogen separation membrane that selectively permeates only hydrogen. A temperature raising apparatus for a vehicle-mounted hydrogen production system using a separate reformer is provided. As the raw material gas, hydrocarbons such as city gas, methane, propane, kerosene and dimethyl ether are used as raw materials.
A hydrogen production system to which the present invention is applied includes a hydrogen separation reformer and a combustion exhaust gas circulation line for circulating a part of the combustion exhaust gas emitted from the hydrogen separation reformer through the blower means and returning it to the reformer. Is a hydrogen production system.

FIG. 1 schematically shows a vehicle-mounted hydrogen production system including a temperature raising device according to the present invention.
Reference numeral 1 denotes a hydrogen separation type reformer, and each reaction tube constituting the multi-tube reaction tube portion has a reforming catalyst layer 11 and a hydrogen separation membrane 12. The hydrocarbon that is the raw material of the reformer 1 is mixed with steam to form a mixed gas. The mixed gas is preheated by the heat exchanger 16 and heated to near the reaction temperature. The preheated mixed gas is introduced into the catalyst layer 11 of the hydrogen separation reformer 1 as a process gas.

In the reforming catalyst layer 11, hydrogen, carbon monoxide, and carbon dioxide are generated from the mixed gas by a steam reforming reaction. For example, when methane is used as a raw material, a steam reforming reaction is performed according to the following reaction formula.
CH ₄ + H ₂ O → 3H ₂ + CO (endothermic reaction) (1)
CO + H ₂ O → CO ₂ + H ₂ (exothermic reaction) (2)
Usually, this reaction is performed at 500 ° C. or higher, and is performed under steam rich conditions in which the S / C (steam / carbon ratio), which is the molar ratio of water to carbon C of methane, is 2 or more. Since the reaction (1) is an endothermic reaction, the higher the temperature, the more accelerated the reaction.
On the other hand, as described above, the use temperature of the hydrogen separation membrane 12 needs to be kept at 600 ° C. or lower, preferably 550 ° C. or lower. Therefore, a catalytic reaction is normally performed within the range of 500-600 degreeC.

Of the gas generated by the reformer 1, only hydrogen gas is separated into the permeation section 14 through the hydrogen separation membrane 12 made of palladium, palladium alloy or the like. The hydrogen gas collected in the permeation unit 14 is taken out of the system as high-purity hydrogen gas.
The remaining gas mainly composed of carbon dioxide from which hydrogen has been taken out is recovered as off-gas, cooled with cooling water or the like, and then introduced into the combustion section 13 together with air to be burned, and used as a fuel for the hydrogen separation reformer 1. The combustion gas introduced into the hydrogen separation reformer 1 from the combustion unit 13 passes through the combustion exhaust gas passage 15 in the vicinity of the reaction tube and supplies thermal energy for reacting to the catalyst layer 11.

Thereafter, after the combustion exhaust gas leaves the reformer 1, a part of the combustion exhaust gas is sent to the combustion exhaust gas a circulation line, and the remaining exhaust gas is discharged through the heat exchanger 16. The exhaust gas is circulated by providing a blower 17 as a blowing means in the circulation line. The ratio of the combustion exhaust gas sent to the circulation line can be arbitrarily determined according to the operating conditions, but is usually 50% by volume or more, preferably 60% by volume or more, more preferably 70% by volume or more. The higher the ratio, the lower the temperature of the combustion exhaust gas that has passed through the wake heat exchanger 16.
It is preferable that the multi-tube reaction tube section is generally heated within a range of 500 to 600 ° C. by the heat energy of the combustion gas and the combustion exhaust gas.

The combustion exhaust gas sent to the circulation line returns to the reformer 1 again from the reformer inlet (introduction line). At this time, the ratio between the combustion gas introduced from the combustion unit 13 of the reformer 1 and the combustion exhaust gas to be circulated and reused can be arbitrarily determined depending on the operating conditions and the configuration of the system. When the exhaust gas introduction port is provided, it can be used at a combustion gas of primary air: combustion exhaust gas = 1: 1 to 10, preferably 1: 2 to 8, for example 1: 5.
In the system of FIG. 1, the high-temperature combustion gas burned by the burner that is the combustion unit 13 is diluted with a part of the combustion exhaust gas that has exited the reformer 1, the temperature is lowered, and then the multi-tube reaction tube unit ( 11 and 12), the temperature distribution in the reformer 1 becomes uniform and stable.

Here, the embodiment of FIG. 1 further includes a heater 2. The heater 2 constitutes a characteristic part of the present invention and constitutes a temperature raising device in the embodiment of FIG. The heater 2 can exert an effect of heating the combustion exhaust gas by the heater 3. Further, the embodiment of FIG. 1 includes a damper 4.
In the embodiment of FIG. 1, when the reformer 1 stops the original hydrogen production and the vehicle is in a moving state, the temperature raising device is operated.
While the vehicle is moving, the raw material hydrocarbons and steam are not supplied. The damper 4 is closed, and the blower 17 circulates the combustion exhaust gas through the combustion exhaust gas circulation line. Here, the heater 3 of the heater 3 heats the combustion exhaust gas and keeps it at 500 ° C. or higher (however, 600 ° C. or lower). The combustion exhaust gas heats the reaction tube through the combustion exhaust gas passage 15. Thereby, the reaction tube can be preheated even when the vehicle is moving. Therefore, loss of time at startup can be avoided. The heater 3 generates electric power by driving the vehicle engine power, and is heated by the obtained electricity.

  Next, FIG. 2 shows in more detail the hydrogen separation reformer 1 to which the temperature raising device for the vehicle-mounted hydrogen production system according to the present invention is preferably applied. 2A is a cross-sectional view seen from the side, and FIG. 2B is a view showing a cross-section of the same reformer seen from the front.

  In the reformer 1, a plurality of reaction tubes 20 are provided with a hydrogen permeation section filled with a reforming catalyst and separated by a hydrogen separation membrane, thereby forming a multi-tube reaction tube section. In the vicinity of the reaction tube 20, a combustion gas passage 24 for heating the reaction tube is provided. Combustion gas is sent from the line burner 22 (combustion part) provided in the lower part of the reformer 1 to the reaction pipe in the upper multi-tubular reaction pipe part. At the same time, a secondary air introduction line 21 having combustion exhaust gas introduction ports every other row is provided near the line burner 22 at the lower part of the reformer 1. In addition, the burner installed in the combustion part 13 is not limited to a line burner, For example, various burners, such as a high flow rate burner and a flat flame burner, can be used.

  As described with reference to FIG. 1, when the flue gas heated by the heater 2 of FIG. 1 is introduced from the secondary air introduction line 21 and the vehicle is moving, a damper such as the damper 4 of FIG. By closing, high-temperature (500 ° C. or higher) combustion exhaust gas circulates and the reaction tube 20 is preheated.

On the other hand, in the reformer of FIG.
The lower part of this partition plate 25 becomes a combustion exhaust gas mixing part. In this combustion exhaust gas mixing section, the combustion gas emitted from the combustion section (line burner) 22 is mixed with the combustion exhaust gas supplied from the combustion exhaust gas inlet 21 before reaching the multi-tube reaction tube section. As a result, the temperature of the mixed gas passing through the upper reaction tube is made uniform, and it is possible to reliably prevent the high-temperature combustion gas from reaching the reaction tube 20 directly. Then, the catalyst layer can be uniformly heated to the reaction temperature, and the reaction can be advanced in the entire reaction tube 20.

  The temperature raising apparatus described with reference to FIG. 1 is not limited to the hydrogen separation reformer 1 shown in FIG. 2. In short, any apparatus provided with a combustion exhaust gas circulation line is applicable.

Next, FIG. 3 shows another embodiment of a temperature raising device for a vehicle-mounted hydrogen production system according to the present invention.
In this form, the hydrogen separation reformer 1 is illustrated more conceptually than in FIG. Elements having the same reference numerals as those in FIGS. 1 and 2 perform substantially the same configuration and function, and thus a part of the description is omitted.
Also in this hydrogen separation type reformer 1, during the hydrogen production, the fuel can be burned by the burner 31 and the reaction tube 20 can be heated by the combustion exhaust gas. In addition, in order to avoid an excessive temperature rise in the reaction tube 20, the combustion exhaust gas can be appropriately introduced into the combustion unit 13.
This embodiment includes a blower 32 and is configured so that outside air can be introduced into the combustion unit 13 from the outside air (combustion exhaust gas) inlet 34 via the heater 33.

When hydrogen is not produced and the vehicle is moving, outside air is supplied from the blower 32 via the heater 33. The heater 35 of the heater 33 generates electric power by driving the vehicle engine power, and is generated by the obtained electricity. The outside air is heated to 500 ° C. or more (however, 600 ° C. or less), rises from the combustion section 13, heats the reaction tube 20 while passing through the combustion gas passage 24, passes through the combustion exhaust gas passage 36, and then exits the combustion exhaust gas. 37 is discharged. As a result, the reaction tube 20 is preheated, and the heating time at the place where hydrogen production is performed is greatly reduced. Here, the combustion gas passage 24 indicates a passage between the reaction tubes 20.
Furthermore, by supplying the outside air discharged from the combustion exhaust gas outlet 37 to the blower 32 and recirculating it, the load on the heater 33 can be reduced and the reaction tube 20 can be efficiently preheated. Moreover, this Embodiment can also be combined with the combustion exhaust gas circulation line shown in FIG. That is, the blower 32 that supplies the outside air between the blower 17 and the heater 2 in the combustion exhaust gas circulation line shown in FIG. 1 or the one that can simply take the outside air into the blower 17 may be used. Then, the blower 32, the heater 33, and the heater 35 can be omitted, and the reaction tube 20 can be preheated more efficiently.

Further, FIG. 4 shows another embodiment of a temperature raising apparatus for a vehicle-mounted hydrogen production system according to the present invention.
In this form, the hydrogen separation reformer 1 is illustrated more conceptually than in FIG. Elements having the same reference numerals as those in FIGS. 1 and 2 perform substantially the same configuration and function, and thus a part of the description is omitted.
Also in this hydrogen separation type reformer 1, during the hydrogen production, the fuel can be burned by the burner 31 and the reaction tube 20 can be heated by the combustion exhaust gas. In addition, in order to avoid an excessive temperature rise in the reaction tube 20, the combustion exhaust gas can be appropriately introduced into the combustion unit 13.
This embodiment includes a blower 42 and is configured so that outside air can be introduced from an original combustion exhaust gas outlet 44 via a heater 43.

  When hydrogen is not produced and the vehicle is moving, outside air is supplied from the blower 42 via the heater 33. The heater 45 of the heater 43 generates electric power by driving the vehicle engine power and generates heat by the obtained electricity. The outside air is heated to 500 ° C. or more (however, 600 ° C. or less), introduced from the combustion exhaust gas outlet 44, passes through the combustion exhaust gas passage 36, and descends while heating the reaction tube 20 while passing through the combustion gas passage 24. . Then, it is discharged from the combustion exhaust gas inlet 34 through the combustion exhaust gas passage 36. As a result, the reaction tube 20 is preheated, and the heating time at the place where hydrogen production is performed is greatly reduced. Furthermore, the external air discharged from the combustion exhaust gas inlet 34 is supplied to the blower 42 and recirculated, whereby the load on the heater 43 can be reduced and the reaction tube 20 can be preheated efficiently.

Furthermore, FIG. 5 shows another embodiment of a temperature raising device for a vehicle-mounted hydrogen production system according to the present invention.
In this form, the hydrogen separation reformer 1 has the same configuration as that shown in FIG. Elements having the same reference numerals as those in FIGS. 1 and 2 perform substantially the same configuration and function, and thus a part of the description is omitted.
Also in this hydrogen separation type reformer 1, during the hydrogen production, the fuel can be burned by the line burner 22 and the reaction tube 20 can be heated by the combustion exhaust gas. In addition, in order to avoid an excessive temperature rise in the reaction tube 20, the combustion exhaust gas can be appropriately introduced into the combustion unit 13.
In this embodiment, a heater 51 for heating each reaction tube 20 is wound around each reaction tube 20.

  When the vehicle is moving without producing hydrogen, the reaction tube 20 is directly heated by the heater 51, and the reaction tube 20 is heated to 500 ° C. or higher (however, 600 ° C. or lower). The heater 51 generates electric power by driving the vehicle engine power, and is heated by the obtained electricity. As a result, the reaction tube 20 is preheated, and the heating time at the place where hydrogen production is performed is greatly reduced.

  In addition, in embodiment described about FIG.1, FIG.3, FIG.4, FIG.5, the surplus electric power obtained by the traveling engine in movement of a vehicle can be utilized exclusively, and it has the advantage which does not accompany a special additional facility in power generation. .

FIG. 1 is a block diagram showing an embodiment of a vehicle-mounted hydrogen production system to which a temperature raising device for a vehicle-mounted hydrogen production system according to the present invention is applied. FIG. 2 is a view for explaining an embodiment of a hydrogen separation reformer employed in the vehicle-mounted hydrogen production system of FIG. 1, wherein (a) is a sectional view seen from the side, and (b) It is a figure which shows the cross section which looked at the same reformer from the front. FIG. 3 is a conceptual diagram illustrating another embodiment of a temperature raising device for a vehicle-mounted hydrogen production system according to the present invention. FIG. 4 is a conceptual diagram for explaining still another embodiment of the temperature raising device for the vehicle-mounted hydrogen production system according to the present invention. FIG. 5 is a conceptual diagram illustrating another embodiment of the temperature raising device according to the present invention applied to the hydrogen separation reformer described with reference to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrogen separation type reformer 2 Heater 3 Heater 4 Damper 11 Reforming catalyst layer 12 Hydrogen separation membrane 13 Combustion part 14 Permeation part 15 Combustion exhaust gas passage 16 Heat exchanger 17 Blower 20 Reaction pipe 21 Secondary air introduction line 22 Line burner 24 Combustion exhaust gas passage 31 Burner 32 Blower 33 Heater 34 Outside air (combustion exhaust gas) inlet 35 Heater 36 Combustion exhaust gas passage 37 Combustion exhaust gas outlet 42 Blower 43 Heater 44 Combustion exhaust gas outlet 45, 51 Heater

Claims (5)

A temperature raising device for a vehicle-mounted hydrogen production system,
A heater that is activated by driving vehicle engine power;
The vehicle-mounted hydrogen production system includes a hydrogen separation reformer,
The hydrogen separation reformer has a reaction tube part,
The reaction tube portion is composed of a reaction tube filled with a reforming catalyst, and includes a hydrogen permeation portion partitioned by a hydrogen separation membrane, and a combustion gas passage for heating the reaction tube,
Further, the hydrogen separation reformer has a combustion part that generates combustion gas for heating the reaction tube part,
A temperature raising device for a vehicle-mounted hydrogen production system, comprising means for preheating the reaction tube using heat obtained by the heater. A combustion exhaust gas circulation line is provided for circulating at least a part of the combustion exhaust gas emitted from the hydrogen separation reformer through a blowing means and returning the combustion exhaust gas from the combustion exhaust gas inlet to the reformer. 2. A temperature raising apparatus for a vehicle-mounted hydrogen production system according to claim 1, wherein the reaction tube is heated to preheat. A hot air generator using the heater is provided, provided with a blowing means for supplying hot air generated by the hot air generator from the combustion section, and the reaction tube is preheated by the hot air supplied from the combustion section. The temperature raising apparatus for a vehicle-mounted hydrogen production system according to claim 1. A hot air generator using the heater was provided, provided with a blowing means for supplying hot air generated by the hot air generator from the outlet of the combustion exhaust gas, and the reaction tube was preheated with the supplied hot air. The temperature raising device for a vehicle-mounted hydrogen production system according to claim 1. 2. The temperature raising device for a vehicle-mounted hydrogen production system according to claim 1, wherein the reaction tube is directly preheated by the heater.

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