JP2000226201A - Improver for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an improver for a fuel cell capable of forming a high- purity hydrogen. SOLUTION: This improver 2 is constituted of an improver body 13 composed of a catalyst retainer 11 and a retention sealing member 12 and a metal pipe 14 for holding the improver body 13. A catalyst such as platinum is supported on the catalyst retainer 11. For example, a cordierite carrier molded into a honeycomb shape is used as the catalyst retainer 11. The retention sealing member 12 is of a mat substance. The sealing member 12 is constituted of an inorganic fiber material such as crystalline alumina fiber or silica-alumina fiber and the contents of chlorine, sulfur and phosphorus are set to <=10 ppm, respectively. Namely, the retention sealing member 12 is of an inorganic fiber material having a low impurity concentration. The metal pipe 14 has a cylindrical shape and is formed by using a material having excellent corrosion resistance such as stainless steel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a reformer for a fuel cell mounted on a vehicle, for example.

[0002]

2. Description of the Related Art Conventionally, a reformer for a fuel cell mainly comprises a catalyst holder, a metal pipe for covering the outer periphery of the holder, and a holding seal material disposed between the two.

A catalyst such as platinum is supported on a catalyst holder. As the catalyst holder, for example, a cordierite carrier formed in a honeycomb shape is used. The catalyst holder generates hydrogen by passing a hydrocarbon compound such as methanol.

[0004] As the holding sealing material, one made of only inorganic fibers such as ceramic fibers is usually used. This holding sealing material is used to prevent the catalyst holding body from being damaged when the catalyst holding body comes into contact with the metal pipe during driving of an automobile or the like, and also to prevent hydrocarbon compounds from leaking from between the metal shell and the catalyst holding body. Used for

[0005]

By the way, impurities such as chlorine, phosphorus, and sulfur are contained in a general holding sealing material.
It has been confirmed by the inventor that it is contained at a concentration of 以上 3 wt% or more.

[0006] Further, the holding seal material impregnated with an organic binder such as NBR or SBR at about 1 to 10 wt% has a higher impurity concentration. However, when a holding sealing material containing a large amount of impurities is used, chlorine, phosphorus, sulfur, and the like are mixed into hydrogen generated by the reformer, and the purity of hydrogen is reduced. When the purity of hydrogen is reduced in this way, it is expected that inconveniences such as a decrease in power generation efficiency of the fuel cell and a shortened life of the device will occur.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a reformer for a fuel cell capable of producing high-purity hydrogen.

[0008]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, there is provided a catalyst holder for holding a catalyst for producing hydrogen by reacting with a hydrocarbon compound;
A fuel cell reformer, comprising: a metal pipe for accommodating the catalyst holder; and a holding sealer disposed between the catalyst holder and the metal pipe for holding the catalyst holder. The gist is that the sealing material is made of an inorganic fiber material having a low impurity concentration and is a resin-impregnated mat-like material.

According to a second aspect of the present invention, in the fuel cell reformer according to the first aspect, an impurity concentration in the mat-like material is less than 1%.
According to a third aspect of the present invention, in the fuel cell reformer according to the first or second aspect, the concentration of chlorine, sulfur, and phosphorus in the mat-like material is 300 ppm or less. I do.

Hereinafter, the "action" of the present invention will be described. According to the first aspect of the invention, a mat-like material made of an inorganic fiber material having a low impurity concentration and not impregnated with a resin is used as a holding sealing material. That is, since the content of impurities is originally small, the amount of impurities mixed into the generated hydrogen is also reduced. Therefore, the generated hydrogen can be maintained at a high purity. As a result, it is possible to reliably prevent a decrease in the power generation efficiency of the fuel cell due to a decrease in the hydrogen purity.

According to the second aspect of the present invention, by setting the concentration of impurities contained in the holding sealing material to less than 1%, the generated hydrogen can be reliably maintained at a high purity.

According to the third aspect of the present invention, the concentration of chlorine, sulfur and phosphorus contained in the holding sealing material is set to 300 pp.
By setting it to m or less, the generated hydrogen can be more reliably maintained at a high purity.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS.

As shown in FIG. 1, a fuel cell 1 is connected to a reformer 2. In the present embodiment, the fuel cell 1 and the reformer 2 are mounted on a vehicle or the like, and the fuel cell 1 is connected to a motor 3 used for running the vehicle, driving vehicle electric components, and the like.

[0015] As shown in FIG.
And a metal pipe 14 for accommodating the main body 13 thereof. The main body 13 has a cylindrical catalyst holder 11.
And a holding sealing material 12 wound around the outer peripheral surface of the holding body 11.

The catalyst holder 11 carries a catalyst such as platinum. As the catalyst holder 11, a porous body made of, for example, cordierite or alumina formed into a honeycomb shape is used. In this embodiment, the catalyst holder 11 has a substantially perfect circular cross section. Further, the impurity concentration in the catalyst holder 11, that is, the concentration of chlorine, sulfur, and phosphorus is extremely low.

The holding sealing material 12 is a mat-like material. At one end of the holding sealing material 12, a convex portion 12a is formed, and at the other end, a concave portion 12b corresponding to the convex portion 12a is formed. The holding sealing material 12 is made of an inorganic fiber material such as a crystalline alumina fiber or a silica-alumina fiber, and the concentrations of impurities of chlorine, sulfur and phosphorus are set to 100 ppm or less, respectively. The holding sealing material 12 is not impregnated with an organic binder such as NBR or SBR. That is, the holding sealing material 12 is an inorganic fiber material having a low impurity concentration.

The metal pipe 14 has a cylindrical shape and is formed of a material having excellent corrosion resistance, such as stainless steel. The inner diameter L2 of the metal pipe 14 is set to be several mm to several tens mm larger than the diameter L1 of the main body 13.

Next, a method of assembling the reformer 2 configured as described above will be briefly described. First, after the holding sealing material 12 is wound around the catalyst holding body 11, the convex portions 12a and the concave portions 12b are formed.
Are fixed with tape 15 at both ends.

Subsequently, as shown by an arrow in FIG.
3 is pressed into a metal pipe 14. As a result, the main body 13 is inserted into the metal pipe 14 without any gap. Therefore, it is possible to prevent the later-described methanol from flowing out between the holding sealing material 12 and the metal pipe 14.

Then, one end of the metal pipe 14 is connected to a methanol storage tank (not shown), and the other end is connected to the fuel cell 1. Next, the operation of the fuel cell 1 and the reformer 2 configured as described above will be described.

As shown in FIG. 1, first, methanol, which is a kind of hydrocarbon compound, is sent to the reformer 2 in a vaporized state. Then, the reformer 2 reacts the methanol with the catalyst in the catalyst holder 11 to generate hydrogen, and sends the hydrogen to the fuel cell 1 side. The fuel cell 1 reacts generated hydrogen with oxygen, and converts energy obtained by the reaction into electric power. The motor 3 is driven by this electric power. Note that water generated by the reaction between hydrogen and oxygen is discharged outside the vehicle.

[0023]

EXAMPLES AND COMPARATIVE EXAMPLES In the present embodiment, the following Table 1 is used according to the impurity concentration contained in the holding sealing material 12.
As shown in FIG. 7, the purity of hydrogen generated by the reformer 2 changed.

In the present embodiment, the following is used as the reformer 2. -Catalyst holder 11: Cordierite monolith having an outer diameter of 130 mm and a length of 100 mm.

Holding sealing material 12: A mat-like material of crystalline alumina fiber having a thickness of 25 mm.・ Metal pipe 14: Outside diameter φ141mm, thickness 1.5mm
Made of SUS304. Further, the vaporized methanol at about 500 ° C. is passed through the inflow side of the reformer 2 at a predetermined flow rate of about 0.05 (m ³ / min). Then, hydrogen gas discharged from the outlet side of the reformer 2 was sampled, the impurity concentration was measured according to a conventional method, and the average value was obtained.

[0026]

[Table 1] As shown in Table 1, in "Example 1," the purity of hydrogen was measured using the holding sealing material 12 containing 50 ppm of chlorine, sulfur, and phosphorus as impurities. That is, in the “Example 1”, the impurities were
The holding sealing material 12 containing 0 ppm was used. as a result,
The purity of the generated hydrogen was 99.8%.

In "Example 2," 135 ppm of chlorine was added.
The hydrogen purity was measured using a holding sealing material 12 containing m, 50 ppm of sulfur and 100 ppm of phosphorus. That is, in the “Example 2”, the holding sealing material 12 containing a total of 285 ppm of impurities was used. As a result, the purity of the generated hydrogen became 98.7%.

By the way, in "Comparative Example", hydrogen purity was measured using a holding sealing material 12 containing 1.2% of chlorine, 0.6% of sulfur and 0.4% of phosphorus. That is, the holding sealing material 12 in this comparative example is a holding sealing material 12 conventionally used, and is 2200 ppm.
(2.2%) impurities. As a result, the purity of the generated hydrogen was 80.3%.

As a result, in Examples 1 and 2, it is found that the purity of generated hydrogen is kept high by using an inorganic fiber material having a low impurity concentration as the holding sealing material 12. .

In particular, from the results of "Example 1", it can be seen that almost pure hydrogen is produced by setting the concentration of chlorine, sulfur and phosphorus to 100 ppm or less, respectively.
Further, from the results of “Example 2”, it can be seen that even when the total concentration of chlorine, sulfur and phosphorus is 300 ppm or less, highly pure hydrogen is generated.

In the comparative example, the holding sealing material 12 having an impurity concentration of 2.2% was used.
0.3% pure hydrogen has been produced. For this reason,
If the holding sealing material 12 having an impurity concentration of less than 1% is used,
It is speculated that hydrogen with a purity of 90% or more can be produced.

Therefore, according to the present embodiment, the following effects can be obtained. (1) By using an inorganic fiber material having a low concentration of impurities of chlorine, sulfur and phosphorus as the holding sealing material 12, hydrogen generated from the reformer 2 can be maintained at high purity. Therefore, a decrease in the power generation efficiency of the fuel cell 1 can be reliably prevented.

(2) By setting the concentration of chlorine, sulfur and phosphorus impurities contained in the holding sealing material 12 to less than 1%, the hydrogen generated from the reformer 2 is maintained at a high purity. can do.

(3) The concentration of chlorine, sulfur and phosphorus impurities contained in the holding sealing material 12 is set to 10
By setting the content to 0 ppm or less, the hydrogen generated from the reformer 2 can be more reliably maintained at a high purity. Similar effects can be obtained by setting the concentration of the impurities to 300 ppm or less in total.

The embodiment of the present invention may be modified as follows. -The hydrocarbon compound is not limited to methanol. That is, like ethanol, propanol, butanol, methane, ethane, propane, butane, etc.
Various hydrocarbon compounds which do not contain halogen such as chlorine, sulfur, phosphorus and the like in the molecular structure may be used.

The catalyst support 11 is made of cordierite,
It is not limited to alumina. That is, silicon carbide, silicon nitride, and the like are also applicable. The catalyst support 11 is not limited to a honeycomb shape, but may be porous.

The metal pipe 14 is not limited to a cylinder made of a single member. That is, it may be formed by combining a plurality of members, that is, two-piece shell-shaped pipe pieces. Further, the cross-sectional shape of the metal pipe 14 is not limited to a perfect circular shape as in the above embodiment, and may be, for example, an elliptical shape or a polygonal shape. Of course, the outer shape of the catalyst holder 11 may be changed according to the shape of the metal pipe.

In the above embodiment, the concentrations of chlorine, sulfur and phosphorus are set to be 100 ppm or less, respectively. However, these may be 300 ppm or less in total. Next, in addition to the technical ideas described in the claims, technical ideas grasped by the above-described embodiments will be listed below.

(1) The fuel cell reformer according to claim 1 or 2, wherein the concentrations of chlorine, sulfur and phosphorus in the mat-like material are each 100 ppm or less. Battery reformer.

According to the invention described in the technical concept (1), the purity of hydrogen generated from the reformer can be maintained even higher. (2) Any one of claims 1 to 3 and the technical idea (1)
The fuel cell reformer according to claim 1, wherein the mat-like material is at least one kind of inorganic fiber material selected from crystalline alumina fibers and silica-alumina fibers. vessel.

(3) In the reformer for a fuel cell according to any one of claims 1 to 3, and the technical ideas (1) and (2), the catalyst holder is made of cordierite, alumina, carbonized A reformer for a fuel cell, which is a porous ceramic sintered body made of silicon or silicon nitride.

(4) Claims 1 to 3, Technical idea (1)
The reformer for a fuel cell according to any one of claims 1 to 3, wherein the catalyst holder is formed in a honeycomb shape, and an outer shape thereof is substantially cylindrical. Porcelain.

(5) Claims 1 to 3, Technical idea (1)
The reformer for a fuel cell according to any one of (1) to (4), wherein the metal pipe is formed of a tubular or two-piece shell-shaped pipe piece. vessel.

(6) A catalyst holder for holding a catalyst which reacts with a hydrocarbon compound to generate hydrogen and a metal pipe for holding the catalyst holder for holding the catalyst holder. The holding sealing material for a fuel cell reformer, wherein the holding sealing material is made of an inorganic fiber material having a low impurity concentration, and is a resin-impregnated mat-like material. Holding sealing material.

[0045]

As described in detail above, according to the first aspect of the present invention, the generated hydrogen can be maintained at a high purity. Therefore, it is possible to reliably prevent a decrease in the power generation efficiency of the fuel cell due to a decrease in the hydrogen purity.

According to the second aspect of the present invention, the generated hydrogen can be more reliably maintained at a high purity. According to the third aspect of the invention, the generated hydrogen can be more reliably maintained at a high purity.

[Brief description of the drawings]

FIG. 1 is a block diagram of a fuel cell according to an embodiment using a fuel cell reformer according to the present invention.

FIG. 2 is a perspective view showing the fuel cell reformer of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuel cell, 2 ... Reformer, 11 ... Catalyst holder, 12 ...
Holding seal material, 13: body, 14: metal pipe.

Claims (3)

[Claims] 1. A catalyst holder for holding a catalyst for producing hydrogen by reacting with a hydrocarbon compound, a metal pipe for housing the catalyst holder, and a metal pipe disposed between the catalyst holder and the metal pipe. And a holding seal material holding the catalyst holding body, wherein the holding seal material is made of an inorganic fiber material having a low impurity concentration and is a resin-impregnated mat-like material. A reformer for a fuel cell, comprising: 2. The reformer for a fuel cell according to claim 1, wherein an impurity concentration in the mat-like material is less than 1%. 3. The fuel cell reformer according to claim 1, wherein the concentration of chlorine, sulfur and phosphorus in the mat-like material is 300 ppm or less. Reformer.