JPH10189022A - Fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell using dimethyl ether. SOLUTION: In the fuel cell, dimethyl ether 4 used as a raw fuel is supplied to a reformer 6 together with steam 5, and is supplied to an anode of a fuel cell 1 after reforming, and an oxidizing agent gas such as air 3 is supplied to a cathode of the fuel cell 1. In the solid electrolyte fuel cell, dimethyl ether 4 is supplied to an anode of a solid electrolyte fuel cell 2 together with steam 5, and the oxidizing agent gas such as the air 3 is supplied to a cathode of the solid electrolyte fuel cell 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel cell, and more particularly to a fuel cell using dimethyl ether.

[0002]

2. Description of the Related Art In recent years, power generation by a fuel cell has attracted attention because it has low pollution, low noise, low energy loss, and is advantageous in terms of installation conditions and operability.

[0003] A fuel cell is an energy conversion device that in principle converts the chemical energy of hydrogen, which is a fuel gas, directly into electric energy, and therefore requires a stable and large supply of hydrogen. Mass supply of hydrogen is described in, for example,
As described in Japanese Patent No. 48101, hydrocarbon gas such as methane or natural gas, propane, butane or petroleum gas, naphtha, kerosene, light oil, synthetic petroleum, etc. It is used as a fuel and reformed into hydrogen and carbon dioxide or carbon monoxide by a reformer (reformer).

[0004]

When such a raw fuel is used for a portable power source of an electric vehicle or a fuel cell for a power plant in a remote place where city gas cannot be used, transportation, storage place, safety and the like are considered. Liquid or easily liquefiable propane, butane, naphtha, kerosene, light oil,
Preferred are synthetic petroleum, methanol and the like. However, when heavy hydrocarbons such as propane, butane, naphtha, kerosene, gas oil, and synthetic petroleum are used, carbon precipitation occurs on the catalyst surface during reforming, so reforming conditions must be carefully controlled unless reformer conditions are carefully controlled. There is a problem that causes a decrease in
Methanol containing oxygen does not have the problem of carbon deposition, but it causes corrosion of the reformer due to the generation of highly corrosive formic acid in the reforming process.

On the other hand, a national project is planned to synthesize dimethyl ether, which is clean and easy to handle, containing no ash or sulfur from low-grade coal in large quantities at low cost and uses it as fuel. Dimethyl ether is easily liquefied when pressurized to a few atmospheres.
It is expected to be used in new applications such as fuel cells from the viewpoint of safety and environmental protection.

[0006] However, no example in which dimethyl ether is applied to a fuel cell has been disclosed.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a fuel cell using dimethyl ether.

[0008]

The above object is achieved by a fuel cell using dimethyl ether as a raw fuel.

The present inventors have examined whether dimethyl ether can be reformed as a fuel gas without any problem by using a reformer that reforms a raw fuel for a normal fuel cell into a fuel gas.

Table 1 shows the gas composition after reforming in comparison with the case of natural gas (methane). It can be seen that dimethyl ether can be reformed to hydrogen, carbon monoxide, and water vapor in the same manner as natural gas, even if reformed with a normal reformer.

Therefore, dimethyl ether can be used as a raw fuel for a fuel cell without any problem.

[0012]

[Table 1]

In the case of a solid oxide fuel cell, the operating temperature is as high as about 1000 ° C., so that methane and water vapor are supplied directly to the fuel electrode (anode) as fuel gas without passing through a reformer, and A technology for reducing the cost of a solid oxide fuel cell by reforming with a fuel cell is already known. However, even if a mixed gas containing dimethyl ether and water vapor was directly supplied as a fuel gas, power generation was possible without any problem. .

[0014]

FIG. 1 shows a configuration diagram of a fuel cell having a reformer according to one embodiment of the present invention. In the figure, 1 is a fuel cell, 3 is air, 4 is dimethyl ether,
5 represents steam and 6 represents a reformer.

Using dimethyl ether 4 as a raw fuel,
The power is supplied to the reformer 6 together with the water vapor 5 and reformed into hydrogen and carbon monoxide or carbon dioxide, and then supplied to the anode of the fuel cell 1 and the air 3 as the oxidizing gas to the cathode of the fuel cell 1 to generate power. Becomes possible.

FIG. 2 shows a configuration diagram of a solid oxide fuel cell according to one embodiment of the present invention. In the drawing, reference numeral 2 denotes a solid oxide fuel cell, and the same reference numerals as those in FIG. 1 denote the same components as those in FIG.

When a mixed gas containing dimethyl ether 4 and water vapor 5 is supplied directly to the anode of the solid oxide fuel cell 2 without passing through a reformer, the mixed gas comes into contact with an electrode material having a catalytic action at a high temperature near 1000 ° C. Is reformed into hydrogen and carbon monoxide or carbon dioxide at the anode, so that if the air 3 as the oxidizing gas is supplied to the cathode of the solid oxide fuel cell 2, power generation becomes possible.

There is no problem if the mixed gas containing dimethyl ether 4 and water vapor 5 contains an inert gas such as argon.

[0019]

EXAMPLE Porous lanthanum calcium manganite L
a _0.75 Ca _0.25 Using a cathode substrate made of MnO ₃ ,
On the substrate, stabilized zirconia 8 mol% Y ₂ O ₃ -Z
A solid electrolyte fuel cell in which a solid electrolyte membrane of rO ₂ is formed, and a platinum anode is provided on the electrolyte membrane, at 1000 ° C.
, And a mixed gas of 4.7% dimethyl ether, 2.6% water vapor and the remaining Ar gas is supplied directly to the anode electrode, and oxygen as an oxidizing gas is supplied to the cathode electrode, and galvanostat is applied to both electrodes. And the power generation characteristics were investigated. For comparison, the power generation characteristics when hydrogen, which is generally used instead of the mixed gas, was supplied to the anode electrode were also investigated.

FIG. 3 shows the results. DME in the figure represents dimethyl ether. Even if dimethyl ether and water vapor are directly supplied to the anode electrode, the power generation efficiency is slightly inferior to the case of hydrogen, but it is understood that power generation is performed to the extent that there is no problem as a solid oxide fuel cell. Also, there was almost no problem such as deterioration of the electrodes.

[0021]

The present invention is configured as described above, so that a fuel cell using dimethyl ether can be provided.

Since dimethyl ether can be easily liquefied, it can be easily transported and stored, and is a clean fuel. Therefore, a fuel cell using the dimethyl ether is particularly suitable for a portable power source of an electric vehicle or a remote power plant where city gas cannot be used. It is valid.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram of a solid oxide fuel cell according to an embodiment of the present invention.

FIG. 3 is a diagram showing power generation characteristics of a solid oxide fuel cell using dimethyl ether.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Solid oxide fuel cell 3 Air 4 Dimethyl ether 5 Water vapor 6 Reformer

Continued on the front page (72) Inventor Masatsugu Mizuguchi 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd.

Claims (2)

[Claims] 1. A fuel cell using dimethyl ether as a raw fuel. 2. A solid oxide fuel cell using a mixed gas containing dimethyl ether and water vapor as a fuel gas.