JP2002208426A - Reforming device for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reforming device whose entity including auxiliaries is downsized, and which can prevent local heating, and drastically reduce heat radiation that is an energy loss by an internal combustion reforming method. SOLUTION: The reforming device of hydrocarbon gas by an internal combustion reforming method is equipped with a double pipe which consists of an inner pipe and an outer pipe arranged concentrically with spaces, where, an oxidative reaction tube filled with oxidative catalyst in the inner pipe, and a reforming reaction tube with reforming catalyst filled between the inner and the outer pipe are provided, and also a burner heating the inside of the reforming device at the time of driving is arranged at an upper end in the oxidant reaction tube, and hydrocarbon gas, steam, air are circulated from the upper end in the oxidant reaction tube for oxidative reaction, then circulated to the reforming reaction tube after turning back from a lower end, hydrocarbon gas is reformed to reforming gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for reforming hydrocarbon gas by an internal combustion type reforming method for producing hydrogen as a fuel for a polymer electrolyte fuel cell or a phosphoric acid fuel cell.

[0002]

2. Description of the Related Art A fuel cell is a polymer electrolyte fuel cell (P).
EFC), a phosphoric acid fuel cell (PAFC), and a solid oxide fuel cell are known. Among them, for example, PEFC has a low operating temperature of about 80 to 100 ° C., (1) has a high output density, and can be reduced in size and weight, and (2) the electrolyte is not corrosive and the operating temperature is low. Since it is low, there is no or little restriction on the battery constituent material from the viewpoint of corrosion resistance, so that cost reduction is easy. (3)
Since it can be started at room temperature, it has excellent features such as a short start-up time. For this reason, PEFC is expected to be applied not only to business and industrial use but also to general household use by utilizing the above features.

[0003] Hydrogen (hydrogen gas) is used as fuel for PEFC and PAFC. There are various methods for industrial production of hydrogen, such as water electrolysis and other methods. Examples of such methods include partial oxidation of hydrocarbon gas (partial combustion), steam reforming, or a combination of both (internal combustion reforming). ). In these reforming methods, methane, ethane, propane, butane, city gas, LP gas, and other hydrocarbon gases (including a mixed gas of two or more hydrocarbons) are reformed to contain hydrogen as a main component. A reformed gas is generated, and a reformer is used in each case.

[0004] Fig. 1 is a diagram showing an example of a mode from a hydrocarbon gas (raw material gas) to PEFC using a reformer based on an internal combustion type reforming method. The same applies to the case where the fuel cell is a PAFC, but in this case, a CO oxidizer is not required. Odorants such as mercaptans, sulfides, and thiophene are added to city gas and LP gas. Since the reforming catalyst is poisoned by these sulfur compounds and deteriorates in performance, the reforming catalyst is introduced into a desulfurizer to remove the sulfur compounds. Next, it is introduced into a reformer, and a hydrogen-rich reformed gas is generated by a reforming reaction in the reformer.

However, unreacted methane, unreacted water vapor, carbon dioxide, and carbon monoxide (CO) are produced as by-products in the generated reformed gas, which depends on the performance of the reformer. Is usually contained in an amount of about 8 to 15% (capacity, hereinafter the same). Therefore, the reformed gas is passed through a CO converter to remove the by-product CO. In the CO converter, CO is converted to carbon dioxide and hydrogen by a shift reaction (CO + H ₂ O → CO ₂ + H ₂ ). Here, a catalyst such as a copper-zinc system or a platinum catalyst is used.
A temperature of about 0 to 250 ° C is required.

[0006] The reformed gas emitted from the CO converter is composed of hydrogen and carbon dioxide gas except for unreacted methane and excess steam. Of these, hydrogen is the target component, but C
Also in the reformed gas obtained through the O shift converter, CO is not completely removed, but contains a trace amount of CO. PEF
CO content in fuel hydrogen supplied to C is 100ppm
(Capacity, hereinafter the same) is the limit, and if it exceeds this, the battery performance will be remarkably deteriorated. Therefore, it is necessary to remove the CO component as much as possible before introducing it into the PEFC.

For this reason, the reformed gas is converted into C by the CO converter.
After the O concentration is reduced to about 1% or less, it is subjected to a CO oxidizer (CO selective oxidizer). Here, an oxidizing gas such as air is added, and an oxidation reaction of CO (CO + ／ O _{2) is performed.}
= CO ₂ ) reduces CO to about 100 ppm or less, preferably 50 ppm or less, more preferably 10 ppm or less. The hydrogen thus purified is supplied to the fuel electrode of the PEFC.

The reforming by the internal combustion type reforming method is a combination of an exothermic partial oxidation reaction and an endothermic steam reforming reaction. When the raw material gas is methane, the reaction is represented by the following formula (1).
It is represented by (5). Pt, Pd, I
Metal catalysts such as r, Rh, Ru, Ni, etc. and catalysts comprising hexaaluminate compounds (Japanese Patent Laid-Open No. 2000-178006)
And the like, followed by a partial oxidation reaction of methane as shown in formula (1) and a partial oxidation reaction of methane as shown in formula (2), followed by the reactions of (3) and (4). And (2) ~
H ₂ and CO ₂ are finally generated through a shift reaction (5) in which CO generated by the reaction (4) reacts with water vapor.

[0009]

[Formula 1]

Of these, (1), (2) and (5) are exothermic reactions, (3) and (4) are endothermic reactions, and (1)
The heat generated in (2) and (5) is used for heating reactions (3) and (4). In the internal combustion type reforming method, a reformer is used. The reformer is generally constituted by a partial oxidation reactor in which an oxidation catalyst is arranged and a steam reforming reactor in which a reforming catalyst is arranged, and a raw material gas (hydrocarbon gas), Hydrogen-rich reformed gas is obtained from water and air.

FIG. 2 is a view showing some embodiments of a reformer using an internal combustion type reforming method. FIG. 2 (a) shows that the raw material gas, water and air, which are reaction components, are supplied to a partial oxidation reactor (partial oxidation section) to burn a part of the raw material gas to generate reaction heat (ΔH). Subsequently, the partial combustion gas is supplied to a steam reforming reactor (steam reforming section) together with the reaction components. Thus, a hydrogen-rich reformed gas is generated by utilizing the reaction heat (ΔH) (Japanese Patent Laid-Open No. Hei 10-291801).

FIG. 2B is a modification of FIG. 2A (JP-A-10-291801). The raw material gas, water (steam), and air, which are reaction components, are supplied to a partial oxidation reactor (partial oxidation section) to burn a part of the raw material gas to generate a reaction heat (Δ
H) is generated, and subsequently, the partial combustion gas is supplied to a steam reforming reactor (steam reforming section) together with a raw material gas and air as reaction components. The raw material gas is supplied to the steam reforming reactor, but water (steam) may be supplied together. Reaction heat (ΔH) thus generated in the partial oxidation reactor
To generate a hydrogen-rich reformed gas.

In FIG. 2C, a raw material gas and air are supplied to a partial oxidation reactor, in which a part of the raw material gas is burned by gas phase combustion or catalytic combustion to generate reaction heat (ΔH). On the other hand, a raw material gas and water are separately supplied to the steam reforming reactor. The heat of reaction (ΔH) generated in the partial oxidation reactor is used for heating in the steam reforming reactor, and the raw material gas is changed to a hydrogen-rich reformed gas. Since hydrogen is partially generated in the partial oxidation reactor, it is combined with the reformed gas generated in the steam reforming reactor.

[0014]

However, FIG.
In the apparatus of the type (b), the partial oxidation reaction and the steam reforming reaction need to be performed sequentially and continuously, so that a large temperature gradient occurs between the partial oxidation reactor and the steam reforming reactor,
Particularly, the high temperature portion (Hot Spot) causes deterioration of the catalyst and the furnace material. For this reason, Japanese Patent Application Laid-Open No. 11-1
In JP-A-99201, the temperature is reduced by introducing excessive water or dispersing air. However, this method has disadvantages such as excessive introduction of water and dispersion of air, resulting in poor efficiency and a complicated reactor. Further, in the apparatus of the type shown in FIG. 2 (c), it is necessary to control two reactions, that is, a partial oxidation reaction and a steam reforming reaction, so that the utility and the system itself are complicated, and the plant becomes large. Would.

The present invention has been made to solve the above-mentioned problems in a conventional reformer using an internal combustion type reforming method, and integrates a partial oxidation reactor and a steam reforming reactor. By doing so, the entire device including the auxiliary equipment can be made more compact, and the amount of heat radiation can be significantly reduced,
It is another object of the present invention to provide a new and useful reformer for an internal combustion reforming method for a fuel cell, which has an excellent effect such as a significantly shortened start-up time.

[0016]

SUMMARY OF THE INVENTION The present invention relates to (1) an apparatus for reforming hydrocarbon gas by an internal combustion type reforming method, comprising an inner pipe and an outer pipe which are arranged concentrically at intervals. Oxidation reaction tube, consisting of a double tube, filled with an oxidation catalyst in the inner tube,
A reforming reaction tube filled with a reforming catalyst is provided between the inner tube and the outer tube, and a burner that heats the inside of the reformer at the time of startup is arranged at the upper end of the oxidation reaction tube, and a hydrocarbon gas, Water vapor and air are circulated from the upper end of the oxidation reaction tube to cause an oxidation reaction, and after returning from the lower end, are circulated to the reforming reaction tube to reform hydrocarbon gas into a reformed gas. And a reformer for a fuel cell.

The present invention relates to (2) an apparatus for reforming hydrocarbon gas by an internal combustion type reforming method, which comprises a double pipe constituted by an inner pipe and an outer pipe which are arranged concentrically at intervals. The inside of the inner tube is a hollow oxidation reaction tube, a reforming reaction tube filled with a reforming catalyst is provided between the inner tube and the outer tube, and a premix burner is arranged at the upper end of the oxidation reaction tube. The hydrocarbon gas, water vapor, and air flow through the upper end of the oxidation reaction tube to cause an oxidation reaction, and after returning from the lower end, flow through the reforming reaction tube to reform the hydrocarbon gas into a reformed gas. A reformer for a fuel cell characterized by the above is provided.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The reformer of the present invention is a reformer for hydrocarbon gas by an internal combustion type reforming method, and comprises an inner pipe and an outer pipe which are arranged concentrically at intervals. An oxidation reaction tube filled with an oxidation catalyst in the inner tube, a reforming reaction tube filled with a reforming catalyst between the inner tube and the outer tube, and started at the upper end of the oxidation reaction tube Sometimes, a burner for heating the inside of the reformer is arranged. Then, the hydrocarbon gas, water vapor, and air are circulated from the upper end of the oxidation reaction tube to be oxidized, and are turned back from the lower end, and then are circulated to the reforming reaction tube to reform the hydrocarbon gas into the reformed gas. It becomes.

This reforming apparatus may be configured with its upside down, that is, its upside down. In this case, a burner for heating the inside of the reformer at the time of start-up is arranged at the lower end in the oxidation reaction tube, and hydrocarbon gas, water vapor, and air are circulated from the lower end in the oxidation reaction tube to cause an oxidation reaction, And then flow through the reforming reaction column to reform the hydrocarbon gas into a hydrogen-rich reformed gas. In the present invention, the oxidation catalyst is a partial oxidation catalyst,
Since it also functions as a combustion catalyst, in the present specification, the term “oxidation catalyst” includes a partial oxidation catalyst and a combustion catalyst, and the term “oxidation reaction tube” includes a meaning of a partial oxidation reaction tube.

Further, the reformer of the present invention can be configured as a hollow oxidation reaction tube without filling the inner tube with an oxidation catalyst. In this case, a premixing type partial oxidation burner is arranged at the upper end of the oxidation reaction tube. A mixed gas in which a raw material gas and air are previously mixed is introduced into the burner. In the partial oxidation burner, air is introduced so as to have an air ratio of about 0.5 to 0.95 to partially burn, and the generated partial combustion gas is
The mixture is mixed with a separately introduced raw material gas (+ water vapor) to control so that the air ratio λ = 0.15 to about 0.5. If the reformer is configured upside down,
The burner for partial oxidation is arranged at the lower end of the oxidation reaction tube.

According to the present invention, by adopting these basic structures, not only the reformer can be made more compact, but also the amount of heat released from the reformer to the outside can be reduced, and the reformer as a whole by the internal combustion type reforming method can be used. Can be significantly improved in thermal efficiency. According to the present invention, the source gas, water vapor,
As the air is heated, and the reforming reaction tube surrounds the oxidation reaction tube, the heat transfer area from the oxidation reaction tube to the reforming reaction tube increases, and the heat generated in the oxidation reaction tube passes through the inner tube wall efficiently. It can be transmitted to the reforming reaction tube well. In addition, since stainless steel or the like can be used as a constituent material of the inner tube, it is very advantageous in terms of cost.

In any of the above cases, fins may be provided on one or both of the inner wall of the inner tube (the inner wall of the inner tube) and the outer wall of the inner tube (the outer wall of the inner tube). it can. Thereby, the heat generated in the oxidation reaction tube can be more effectively transmitted to the reforming reaction tube. As a material of the fin, for example, a material having good heat conductivity such as stainless steel is used.

As the oxidation catalyst to be charged into the oxidation reaction tube,
For example, a noble metal catalyst such as palladium (Pd) or platinum (Pt) or a catalyst comprising a hexaaluminate compound is used. The noble metal catalyst is supported on a carrier such as alumina. As the reforming catalyst to be filled in the reforming reaction tube, for example, a suitable catalyst such as a Ni-based or Ru-based catalyst in which a metal such as Ni or Ru is supported on a carrier such as alumina is used. As the raw material gas, a hydrocarbon gas such as methane, ethane, propane, butane, or a mixed gas of these hydrocarbon gases, for example, natural gas, city gas, LP gas, or the like is used. Distilled water or ion-exchanged water is used as water for generating steam. As the air, in addition to air, oxygen-enriched air, oxygen, and the like can be used, and in the present specification, these are referred to as air.

In the present invention, since the oxidation reaction tube and the reforming reaction tube are integrated, the reformer itself can be made compact, and the amount of heat released during its operation can be remarkably reduced. Since the auxiliary devices are only water, raw material gas and air supply means, the entire apparatus including the auxiliary devices can be downsized. Further, according to the reforming apparatus of the present invention, at the time of startup, the combustion gas and the reforming catalyst are heated at the same time as the raw material gas is partially burned by the burner (pilot burner), and the generation of the reformed gas is started immediately. can do.

Further, in the reforming apparatus of the present invention, the air ratio with respect to the raw material gas is reduced to, for example, λ = 0.15 to 0.5, and the steam S (Steam) and the carbon number C ( (Carbon) molar ratio S / C =
Since the operation is performed within the range of 0.1 to 5.0, the raw material gas obtained by mixing air and water vapor has a composition out of the combustion range. Therefore, the raw material gas is not oxidized even when heated in the pipe. Also, by adding a large amount of water vapor with a low air ratio, a high temperature portion (Hot Spot) generated in the partial oxidation reactor of the conventional reformer can be suppressed to a low temperature. Life can be extended.

Further, according to the reforming apparatus of the present invention, the necessary reaction components, that is, the raw material gas, air and steam, can be mixed and supplied in their entirety after the start-up. The number of pipes can be reduced. Since the obtained reformed gas has a high temperature, the reformed gas exchanges heat with the process gas (raw material gas, air, and steam) to preheat them, and is cooled and supplied to the next step.

The reformer of the present invention is preferably used in connection with a fuel cell using hydrogen as a fuel, ie, PEFC or PAFC. Since the reforming apparatus of the present invention is compact and can reduce the startup time, it can be suitably used as a hydrogen production apparatus for PEFC, which is expected to be applied particularly to general households. When the reformed gas obtained by the present reformer is used as a fuel for PEFC, for example, it is sent to a CO converter to reduce CO to about 1%, and is further reduced to about 100 ppm or less and about 10 ppm or less by a CO selective oxidizer. After being reduced as described above, the fuel is supplied to the fuel electrode.

Hereinafter, the present invention will be described in more detail with reference to Examples, but it goes without saying that the present invention is not limited to these Examples.

<Embodiment 1> FIG. 3 is a diagram showing a reformer of the present embodiment in a longitudinal sectional view. The inner and outer tubes are spaced apart and configured as a double tube. The inner tube is filled with an oxidation catalyst to form an oxidation reaction tube. A perforated plate is arranged below the filled oxidation catalyst, whereby the oxidation catalyst is supported in a layered manner. The space between the inner tube and the outer tube is filled with a reforming catalyst, thereby forming a reforming catalyst tube. Perforated plates are arranged above and below the filled reforming catalyst, whereby the reforming catalyst is supported in layers. Instead of the perforated plates, a mesh or the like made of a heat-resistant material may be arranged.

A burner is arranged at the upper end in the inner tube, and a supply conduit for a mixed gas of raw material gas (hydrocarbon gas), steam and air (raw material mixed gas) faces the burner. An outlet pipe for the produced reformed gas is provided above the reforming catalyst cylinder. The raw material mixed gas is supplied to the burner through heat exchange with the reformed gas via the heat exchanger. The upper and lower portions of the double tube are covered, and each tube and cover can be made of stainless steel or the like.
It is desirable to dispose a heat insulating material such as alumina or perlite on the outer peripheral surface of the outer tube and the outer surface of the lid to prevent heat dissipation. These points are the same in the following embodiments.

When starting and operating the reforming apparatus, the raw material mixed gas is supplied to the burner via a heat exchanger, where the raw material gas is partially burned, and is caused to flow into the oxidation reaction column with heat of reaction. Here, the raw material gas is further partially burned by the catalytic reaction by the oxidation catalyst, and is returned from the lower end thereof with the reaction heat, and then flows through the reforming reaction tube. In this reformer, since the inner tube and the outer tube are configured as a double tube with a space therebetween, heat generated in the partial oxidation reaction tube is transmitted to the reforming catalyst tube through the inner tube. The gas is converted into a hydrogen-rich reformed gas by a contact reaction of the reforming catalyst in the reforming catalyst tube, and is led out from an upper portion of the reforming catalyst tube. The reformed gas is 50
Since the temperature is as high as about 0 to 700 ° C., the heat is passed through a heat exchanger and the heat is used for preheating the raw material mixed gas.

<< Embodiment 2 >> FIG. 4 is a longitudinal sectional view showing a reformer of this embodiment. As shown in the figure, the present reformer is constituted by four tubes of tubes 1 to 4, in which an inner tube 1 is filled with a combustion catalyst (oxidation reaction tube), and an inner tube 1 and a tube 2 surrounding the inner tube 1.
Is filled with a reforming catalyst (a reforming catalyst tube), and a tube 3 is arranged on the outer periphery of the tube 2 with an interval (gap) therebetween.
The outer jacket 4 is arranged at an interval (gap) on the outer periphery of the casing. The reformed gas flows through the gap between the pipe 2 and the pipe 3, and the raw material mixed gas flows through the gap between the pipe 3 and the mantle 4, thereby preheating the raw material mixed gas. Since only a low-temperature raw material mixed gas flows inside the mantle 4, the outer peripheral surface of the mantle 4 is kept at a low temperature, and heat dissipation can be prevented.

The inner tube 1 and the inner tube 2 are made of stainless steel (SUS 3
10), and the tube 3 and the mantle 4 are made of stainless steel (SUS
304). The inner diameter of the inner tube 1 is 50 mmφ, the inner diameter of the tube 2 is 65 mmφ, the inner diameter of the tube 3 is 72 mmφ, the inner diameter of the jacket 4 is 79 mmφ, and the height is 150 mm. A catalyst in which palladium is supported on alumina (granular) was used as the oxidation catalyst, and a catalyst in which nickel was supported on alumina (granular) was used as the reforming catalyst. The filling amounts of the oxidation catalyst and the reforming catalyst are 50 cc and 300 cc, respectively. Granular alumina was arranged on the outer peripheral surface of the outer tube and the outer surface of the lid to insulate and prevent heat dissipation. Using 5.7 NL / min of city gas (desulfurized) as raw material gas, 19 NL / m of air
in (air ratio λ = 0.3), water addition amount 15 cc / mi
n (18.7 NL / min with steam).
As a result, the methane of the raw material gas was 99.3%, that is, 9%.
More than 9% could be converted to hydrogen. It also worked well in endurance tests for 1000 hours and longer, and no problems were found.

<Embodiment 3> FIG. 5 is a view showing a reformer of this embodiment as a longitudinal sectional view. This is the same as Example 1 except that the reforming apparatus of Example 1 (FIG. 3) was turned upside down. In this reformer also, since the inner tube and the outer tube are configured as a double tube with an interval, the heat generated in the oxidation reaction tube is transmitted to the reforming catalyst tube through the inner tube, but the inner wall of the inner tube Alternatively, by providing fins on the outer wall or on both walls, heat generated in the oxidation reaction tube can be more effectively transmitted to the reforming catalyst tube. As a material of the fin, for example, a material having good heat conductivity such as stainless steel is used. The provision of these fins is similarly applied to the reformers of the first and fourth embodiments.

The fins can be arranged in various ways.
Is a diagram showing an example thereof. FIG. 6A shows a case where fins are spirally provided on the outer wall of the inner tube, and FIG. 5B shows a case where fins are provided parallel to the tube axis on the outer wall of the inner tube. The reforming catalyst is filled between these fins. These fins can likewise be provided on the inner wall of the inner tube. Thus, the heat generated in the oxidation reaction tube is more effectively transmitted to the reforming catalyst tube through the fins.

Embodiment 4 The present embodiment is an example in which an inner tube is not filled with an oxidation catalyst and a hollow oxidation reaction tube is formed. FIG. 7 is a diagram showing a main point portion in the inner tube of the present reformer,
Other points are the same as those of the first embodiment (FIG. 3). Premixed burner (burner for partial oxidation) at the top of the oxidation reaction tube
And a mixed gas obtained by mixing a raw material gas and air in advance is introduced into the burner. As shown in FIG. 7, the air to the burner for partial oxidation is introduced at an air ratio of about 0.5 to 0.95 to partially burn, and the raw material gas (+
(Water vapor) and the air ratio λ is controlled so as to be about 0.15 to 0.5.

[0037]

According to the present invention, in the reforming apparatus using the internal combustion type reforming method, by integrating the oxidation reactor and the steam reforming reactor, the entire apparatus including the auxiliary equipment can be made compact, Local heating can be prevented, and the amount of heat radiation resulting in energy loss can be significantly reduced. Also, various excellent effects can be obtained, such as reducing the number of accessories and greatly shortening the startup time.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a mode from a hydrocarbon gas (raw material gas) to PEFC using a reformer.

FIG. 2 is a diagram showing some examples of a reformer using an internal combustion type reforming method.

FIG. 3 is a view showing the first embodiment of the present invention (longitudinal sectional view).

FIG. 4 shows a second embodiment of the present invention (longitudinal sectional view).

FIG. 5 shows a third embodiment of the present invention (longitudinal sectional view).

FIG. 6 is a diagram showing an example in which fins are provided on the outer wall of the inner pipe in the reforming apparatus of the present invention.

FIG. 7 is a diagram showing a fourth embodiment of the present invention.

Claims (6)

[Claims] An apparatus for reforming hydrocarbon gas by an internal combustion type reforming method, comprising a double pipe composed of an inner pipe and an outer pipe which are arranged concentrically at intervals, wherein An oxidation reaction tube filled with an oxidation catalyst, a reforming reaction tube filled with a reforming catalyst between an inner tube and an outer tube are provided, and a burner that heats the inside of the reformer at the time of startup is provided at the upper end of the oxidation reaction tube. Hydrocarbon gas, water vapor, and air are circulated from the upper end of the oxidation reaction tube to cause an oxidation reaction, and after being turned back from the lower end, are passed through the reforming reaction tube to convert the hydrocarbon gas into a reformed gas. A reforming apparatus for a fuel cell, characterized in that the reforming apparatus for a fuel cell is manufactured. 2. The fuel cell reforming apparatus according to claim 1, wherein the oxidation catalyst filled in the oxidation reaction cylinder is a noble metal catalyst such as palladium or platinum or an oxidation catalyst comprising a hexaaluminate compound. 3. An apparatus for reforming hydrocarbon gas by an internal combustion type reforming method, comprising a double pipe comprising an inner pipe and an outer pipe which are arranged concentrically at intervals, wherein the inner pipe is It is a hollow oxidation reaction tube, a reforming reaction tube filled with a reforming catalyst is provided between the inner tube and the outer tube, and a premix burner is arranged at the upper end in the oxidation reaction tube to form a hydrocarbon. Gas, water vapor, and air are circulated from the upper end of the oxidation reaction tube to cause an oxidation reaction, and after returning from the lower end, are circulated to the reforming reaction tube to reform hydrocarbon gas into a reformed gas. A reformer for a fuel cell, comprising: 4. The reformer for a fuel cell according to claim 1, wherein pipes are arranged concentrically around the outer circumference of the outer pipe, and concentric with the outer circumference of the pipe. An outer jacket is arranged at an interval in a shape, and a reformed gas from a reforming reaction tube is caused to flow between the outer tube and the tube, and a raw material mixed gas is caused to flow between the outer tube and the jacket, thereby reducing the raw material. A reformer for a fuel cell, wherein a mixed gas is preheated. 5. The fuel cell reforming apparatus according to claim 1, wherein the fuel cell reforming apparatus is turned upside down. 6. A fin provided on one or both of an inner wall and an outer wall of the inner tube.
The reformer for a fuel cell according to any one of claims 1 to 5.