JP3108269B2 - Fuel cell reforming system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel cell reforming system.

[0002]

2. Description of the Related Art A fuel cell is a device for generating electricity by electrochemically reacting a fuel gas composed mainly of hydrogen with oxygen in the air. A reformer is produced by reforming a fuel gas raw material such as gas, methanol, and naphtha using steam.

[0003] Incidentally, the above-mentioned fuel gas raw material contains a trace amount of sulfur. When this sulfur comes into contact with the catalyst used for the reforming reaction provided in the reformer, the catalytic ability of the catalyst decreases. Therefore, a sulfur component is removed using a desulfurizer before supplying the fuel gas raw material to the reformer. In addition, the fuel gas containing hydrogen as a main component generated by the reformer contains carbon monoxide. This carbon monoxide lowers the catalytic ability of the catalyst provided in the fuel cell. To avoid this, carbon monoxide in the fuel gas is converted into carbon dioxide by a converter before being supplied to the fuel cell.

[0004] As described above, the fuel gas supplied to the fuel cell is not simply generated and supplied by the reformer, but is supplied through a reformer system having a desulfurizer, a reformer, and a converter. It is. Here, a conventional reforming system will be described with reference to FIG. As shown in the figure, a conventional reforming system includes a desulfurizer 101 for removing a sulfur component present in a fuel gas raw material, and a desulfurizer 101.
A heater 102 for raising the temperature to 200 to 300 ° C.,
A reformer 103 for steam-reforming a fuel gas raw material from which a sulfur component has been removed by a desulfurizer 101 to generate a fuel gas containing hydrogen as a main component; A converter 104 for converting carbon oxide to carbon dioxide, and a converter temperature of 180 when the converter is started.
Heater 105 for raising the temperature to 200 ° C., and converter 1
A water pipe 106 for generating steam using heat released from the water pipe 04, a steam reservoir 107 for storing steam supplied from the water pipe 106 and the outside of the reforming system,
The heat exchanger 108 for transferring the heat of the fuel gas generated by the reformer 103 to steam, the steam supplied from the steam reservoir 107, and the fuel gas raw material passed through the desulfurizer 101 together with the reformer. And an ejector 109 that feeds the ejector 103.

[0005]

The above reforming system has the following problems. The reformer of the reforming system is 750-750 to reform the raw material.
Requires a temperature of 800 ° C. Therefore, as shown in FIG. 7, the fuel and air supplied to the burner 103a are burned, and the combustion gas is supplied to the reforming pipe 10 in the reformer.
3c is heated and maintained at this temperature.
3 is covered with a heat insulating material 110.

However, despite heat insulation using the heat insulating material 110, the wall surface 103b of the reformer provided along the main flow of heat in the reformer 103 indicated by the arrow A in the figure. The amount of heat released to the outside is large, and the heat loss of a reforming system using such a reformer is increased. The present invention
In view of the above problems, it is an object of the present invention to provide a fuel cell reforming system with less heat loss.

[0007]

To achieve SUMMARY OF to the above objects, the present invention includes a reformer for generating a fuel gas of hydrogen main component, carbon monoxide in the fuel gas generated by the reformer the in the reforming system for a fuel cell and a converter to convert to carbon dioxide, along the outer periphery of the wall of the reformer provided around the main heat flow before Kiaratameshitsu the apparatus, the reformer wherein the pre-Symbol converter via a heat insulating material is circumferentially provided between the.

[0008]

The converter is provided along the outer circumference of the wall of the reformer provided around the main heat flow in the reformer, so that the heat released to the outside as heat loss can be reduced. It can be used for heating at the start of the converter. Also, during operation of the converter, the heat of reaction always causes 180 to 20
It has a temperature of 0 ° C. By providing such a heat-generating material around the reforming device, heat is less likely to escape and heat loss can be reduced.

[0009]

Embodiments of the present invention will be described below. (Embodiment 1) Hereinafter, a reforming system of Embodiment 1 according to an example of the present invention will be described with reference to FIGS.

FIG. 1 is a schematic configuration diagram of a reforming system of the present embodiment, FIG. 2 is a top view of a reforming apparatus and a converter of the reforming system, and FIG. FIG. As shown in FIG. 1, the reforming system of the present invention includes a desulfurizer 1 for removing a sulfur component from a raw material of a fuel gas,
A heater 2 for maintaining the temperature at 300 ° C., a reformer 3 for steam reforming the raw material from which the sulfur content has been removed by the desulfurizer 1 to generate a fuel gas mainly composed of hydrogen, and a reformer 3 provided around the reformer 3 And a converter 4 for converting carbon monoxide present in the fuel gas generated in the reformer 3 into carbon dioxide, and provided along the outer wall surface of the converter 4 and discharged from the converter 4. A water pipe 5 for generating steam using heat, a water reservoir 6 for accumulating steam supplied from outside the water pipe 5 and the fuel cell reforming system, and a fuel gas generated from the reformer 3 Heat exchanger 7 for transferring the heat of steam to steam, an ejector 8 for sending steam supplied from steam reservoir 6 and natural gas passed through desulfurizer 1 to reformer 3 together.
And a pipe A connecting the ejector 8 and the reformer 3;
A pipe B connecting the reformer 3 and the converter 4 and a heat exchanger 7 provided in the middle thereof, a pipe C connecting one end of the water pipe 5 to the steam reservoir 6, a steam reservoir 6 and an ejector 8
And a pipe D in which a heat exchanger 7 is provided on the way.
And

Further, as shown in FIGS. 2 and 3, the converter 4 includes a heat insulating material 9 on the outer periphery of a wall provided so as to surround a main heat flow (arrow A) of the reformer 3. And an outer surface thereof is covered with a heat insulating material 10. At this time, the catalyst portion 4a of the converter 4
It is preferable to provide the catalyst portion 4a of the converter 4 in such a manner as to face the catalyst portion 3a.
Preferably, the thickness is such that a temperature gradient does not occur inside the catalyst 4a of the converter 4. Further, it is preferable that the heat insulating material 9 between the reformer 3 and the converter 4 be made of a material and a thickness that allows the converter 4 to maintain heat at 180 ° C. to 200 ° C. and transmits heat from the reformer 3.

The above-structured reforming system operates as follows. At the start of the reforming system, the desulfurizer 1
, The fuel gas raw material is supplied from a supply source (not shown) to the desulfurizer 1 in this state, and the desulfurization reaction is started. The reformer 3 is heated to 750 to 800 ° C. by a burner provided inside. Subsequently, the steam supplied from the steam reservoir 6 through the pipe D and the fuel gas raw material from which the sulfur component has been removed by the desulfurizer 1 are supplied to the reformer 3 through the pipe A by the ejector 8. The reforming apparatus 3 performs a reforming reaction using the supplied fuel gas raw material and steam, and generates fuel. The fuel gas generated by the reformer 3 is supplied to the pipe B
And supplied to the converter 4. At this time, the converter 4
Is capable of starting the conversion reaction by the heat release of the reformer 3.
Since it is heated to 0 to 200 ° C., the conversion reaction starts. The fuel gas in which the carbon monoxide component is converted into carbon dioxide by the converter 4 is supplied to a fuel cell (not shown).

A water pipe 5 is provided around the converter 4, and the water passing through the water pipe 5 generates steam by heat released from the converter 4, and generates the steam. Is supplied to the steam reservoir 6 through the pipe C. As described above, by providing the converter around the reformer, the heat released from the reformer, which has been a heat loss, can be used for heating the converter at the start of the reaction. it can.

Further, since the reformer is always covered with a converter whose temperature is kept at 180 ° C. to 200 ° C., the amount of heat released from the reformer is reduced. Further, the heat of the reformer transmitted to the converter can be used for steam generation. In addition, there is no need to provide a heater for heating the converter, and the reformer and the converter, which were conventionally separately provided, can be integrated, so that the system can be made more compact. did it.

Here, the following experiment 1 was performed in order to confirm that the amount of heat released from the reformer was reduced. (Experiment 1) Combustion calorie of the burner of the reformer of the reforming system of the present invention, and the burner of the reformer of the reforming system in which the reformer and the converter as shown in FIG. Table 1 shows the results.

As the reforming system of the present invention, the following 3 kW class reformer and a converter were used. Reformer: Outside diameter about 150 mm Height about 500 mm (catalyst layer height about 300 mm) Converter: Height about 300 mm (catalyst layer height is 200
mm, which is provided so as to face the catalyst layer of the reformer.) Width: about 25 mm (a value corresponding to m in FIG. 3).
A kW class reformer and a converter were used.

Reformer: Outside diameter: about 250 mm Height: about 500 mm (height of catalyst layer: about 300 mm) Converter: A converter having the same shape as above was used. However,
Separately from the reformer, a heat insulating material was provided on the inner outer surface of the donut to prevent heat radiation.

[0018]

[Table 1]

As can be seen from Table 1, the reforming system of the present invention has a 15% lower combustion heat than the comparative example. This is because the amount of heat released from the reformer was reduced by spreading the converter around the reformer, and the combustion amount of the burner of the reformer was reduced. Further, the amount of generated steam of the reforming system of the present invention was also examined. (Experiment 2) Using the reforming system of the present invention used in the above Experiment 1 and the reforming system of the comparative example, the amount of steam generated by the heat generated by the converter was examined. The results are shown in Table 2.

The experimental conditions were the same as those used in Experiment 1 above.
When the load is reduced to 1/2 load or less using the quality system
And per unit time when it is larger than 1/2 load
The amount of generated steam was examined. However, take it out during this experiment
Ta steam is about 3kg / cm ^TwoG saturated water vapor
You.

[0021]

[Table 2]

As is clear from Table 2, the present invention was able to generate more steam. Such a result was obtained for the following reason. In the case of the conventional converter, the heat used for steam generation utilizes only the reaction heat of the converter.

On the other hand, in the case of the present invention, since the heat released from the reformer is also transmitted to the converter as described above, steam is generated by the combined heat of the reaction of the converter and the heat transmitted from the reformer. Generated. Therefore, the steam generation amount of the present invention can generate a larger amount of steam than the conventional one. (Embodiment 2) A reforming system according to Embodiment 2 of the present invention will be described below with reference to FIGS.

FIG. 4 is a schematic configuration diagram of the reforming system of the present embodiment, and FIG. 5 is a diagram showing a desulfurizer of the reforming system.
However, in the figure, components having the same functions as those of the first embodiment are denoted by the same reference numerals, and the description of the configuration operation is omitted.
As shown in the figure, the reforming system of this embodiment is the same as that of the first embodiment.
A hollow burner exhaust gas passage 41 provided to cover the outer periphery of the desulfurizer 1 instead of the heater 2 for raising the temperature of the desulfurizer 1 used in A pipe E for connecting a burner exhaust gas outlet (not shown) of the reformer 3 to a burner exhaust gas passage; and a pipe provided in the middle of the pipe E for discharging a part of the burner exhaust gas passing through the pipe E to the atmosphere. F, a burner exhaust gas which is provided at a connecting portion between the pipes E and F and is discharged from the reformer 3 through the pipe F and supplied to the exhaust gas passage 41. And a damper 42 for adjusting the distribution ratio of

The above-structured reforming system operates as follows. When combustion of the burner is started for heating the air in the reformer 3, high-temperature burner exhaust gas is discharged from the burner exhaust gas outlet. The released burner exhaust gas is supplied to the exhaust gas passage 41 through the pipe E. The desulfurizer 1 is heated to a temperature (200 to 300 ° C.) at which the desulfurization reaction can be started by the burner exhaust gas, and the desulfurization reaction is started. it can. Further, during normal operation of the system, the amount of exhaust gas supplied to the exhaust gas passage 41 by the damper 42 is adjusted so that the temperature of the desulfurizer 1 is maintained at 200 to 300 ° C.

As described above, according to this embodiment, in addition to the effects of the first embodiment, the burner exhaust gas can be used for heating the desulfurizer 1, and the energy of the reforming system can be effectively used. did it.

[0027]

As described above, according to the present invention,
The heat released from the reformer can be used for heating when the converter is started, and the heat of the reformer is less likely to escape due to the reaction heat during the operation of the converter. Therefore, a reforming system with less heat loss could be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a reforming system according to an example of the present invention.

FIG. 2 is a top view of a reformer and a converter of a reforming system according to an example of the present invention.

FIG. 3 is a sectional view of a reformer and a converter of a reforming system according to an example of the present invention.

FIG. 4 is a schematic configuration diagram of a reforming system according to an example of the present invention.

FIG. 5 is a diagram showing a desulfurizer of a reforming system according to an example of the present invention.

FIG. 6 is a diagram showing a conventional reforming system.

FIG. 7 is a cross-sectional view of a reforming device of a conventional reforming system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Desulfurizer 3 Reformer 4 Converter 41 Exhaust gas passage

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-237002 (JP, A) JP-A-4-170301 (JP, A) JP-A-6-1601 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01M 8/00-8/24 C01B 3/32-3/48

Claims (1)

(57) [Claims] 1. A reformer for a fuel cell, comprising: a reformer for producing a fuel gas containing hydrogen as a main component; and a converter for converting carbon monoxide in the fuel gas produced by the reformer to carbon dioxide. in the system, along the outer periphery of the wall of the reformer provided around the main heat flow before Kiaratameshitsu the device, thermal insulation between the reformer
Reforming system for a fuel cell Ru features and to <br/> that pre Symbol converter through the wood is circumferentially provided.