JPH0582149A - Fuel supply device for fuel cell power generation device - Google Patents

Abstract

(57) [Abstract] [Purpose] A fuel cell for a fuel cell power generator that uses methanol as a raw fuel, and an aqueous methanol solution prepared as a raw fuel can be used as a combustion fuel for a methanol reformer without any inconvenience. A fuel supply device for a power generator is provided. [Structure] Methanol reformer 2 with methanol as raw fuel
In the fuel cell power generator that supplies the hydrogen reformed in 1 to the fuel cell 1 to generate electric power, a methanol aqueous solution in which methanol and water are mixed at a predetermined ratio is stored in the raw fuel tank and extracted from the raw fuel tank. While introducing the aqueous methanol solution into the reforming pipe 2b of the methanol reformer to reform the fuel, on the other hand, a part of the aqueous methanol solution extracted from the raw fuel tank is used as an organic solvent separation membrane (for example, an aromatic polyimide hollow fiber membrane). To separate into high concentration methanol and water,
The methanol obtained here is temporarily stored in the methanol reservoir 13
It is stored in and is supplied to the burner of the methanol reformer as fuel for combustion when necessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell power generator for generating power using methanol as a raw fuel, and more particularly to a fuel supply device for a methanol reformer.

[0002]

2. Description of the Related Art Methanol, which is easy to handle, is often used as a raw fuel for fuel cells in small-scale fuel cell power generators for vehicles. Next, FIG. 2 shows a conventional system flow of a fuel cell power generator using methanol as a raw fuel. In the figure, 1 is a fuel cell, and 2 is a methanol reformer for steam reforming methanol to convert it into hydrogen. Here, methanol and water (pure water), which are raw fuels, are individually stored in the methanol tank 3 and the water tank 4, respectively.
The methanol extracted from the tank is supplied to the burner 2a of the methanol reformer 2 as a combustion fuel for combustion, while the methanol and water extracted from the methanol tank 2 and the water tank 3 are mixed in a blender 5 at a predetermined ratio. Then, the aqueous methanol solution obtained here is passed through the fuel vaporizer 6 to the reforming pipe of the methanol reformer 2 (filled with the reforming catalyst).
2b is introduced and converted into hydrogen-rich gas, and the hydrogen gas obtained in the methanol reformer 2 is supplied to the fuel cell 1 to generate electricity. Reference numeral 7 indicates a start burner provided in the cooling system line of the fuel cell 1. In addition, off gas (unreacted gas) emitted from the fuel cell 1 after the operation of the power generator is established.
Is supplied to the burner 2a of the methanol reformer 2. The operating principle of such a fuel cell power generator is well known, and its explanation is omitted here.

[0003]

By the way, in the system in which the raw fuel methanol and water are separately stored in the methanol tank 3 and the water tank 4 and supplied to the reformer 2 as described above, the handling will be described below. There are some difficulties. That is, since the freezing point of water is 0 ° C., the water stored in the water tank 4 may be frozen in the low ambient temperature such as in winter, which may result in the inoperability of the power generator. Therefore, it is necessary to take measures against cold, such as using a heater to keep the temperature warm, which makes maintenance difficult. In addition, it is actually difficult in practice to adjust the mixing ratio of methanol and water with the blender 5 to an optimum value.

On the other hand, the freezing temperature of the aqueous methanol solution obtained by mixing water and methanol is lower than that of water alone. Therefore, as a measure to prevent the freezing of water, the aqueous methanol solution is prepared by mixing methanol and water in a predetermined ratio. It is considered that the raw fuel tank is stored and the aqueous methanol solution extracted from the raw fuel tank is supplied to the reforming pipe of the methanol reformer. However, if the methanol aqueous solution having a low methanol concentration extracted from the raw fuel tank is used as it is as the fuel for combustion of the methanol reformer and burned in the burner 2a, it is difficult to ignite the fuel and incomplete combustion occurs. Therefore, there is a problem of environmental pollution such as an increase in the concentration of carbon monoxide in the combustion exhaust gas. In this respect, a combustion fuel tank containing methanol may be prepared separately from the raw fuel tank containing the aqueous methanol solution. However, this method not only enlarges the size of the power generator but also refuels the fuel tank. There is a problem that the maintenance of is complicated.

The present invention has been made in view of the above points, and an object thereof is to implement a fuel cell power generator using methanol as a raw fuel, and to use an aqueous methanol solution prepared as a raw fuel for combustion in a methanol reformer. It is an object of the present invention to provide a fuel supply device of a fuel cell power generation device which can be used as a fuel for a vehicle without inconvenience.

[0006]

In order to solve the above problems, the fuel supply apparatus of the present invention stores an aqueous methanol solution in which methanol and water are mixed at a predetermined ratio in a raw fuel tank, The extracted methanol aqueous solution is introduced into the reforming tube of the methanol reformer for fuel reforming, and part of the methanol aqueous solution extracted from the raw fuel tank is passed through the organic solvent separation membrane to produce high-concentration methanol and water. And the methanol obtained here is supplied to the burner of the methanol reformer as a fuel for combustion.

Here, an aromatic polyimide hollow fiber membrane can be used as the organic solvent separation membrane. Further, as an embodiment of the fuel supply device, a methanol reservoir for storing methanol obtained through an organic solvent separation membrane is provided in a combustion fuel supply line, and methanol is supplied from the reservoir to a burner of a methanol reformer when necessary. There is a supply structure.

[0008]

In the above structure, when the aqueous methanol solution extracted from the raw fuel tank is vaporized and passed through the organic solvent separation membrane (aromatic polyimide hollow fiber membrane), it is separated into high-concentration methanol and water vapor. The dehydration technology using a solvent separation membrane has already been announced in Japan and is well known.)
Therefore, the high-concentration methanol obtained here can be used as it is as the combustion fuel of the methanol reformer.

[0009]

Embodiment An embodiment of the present invention will be described below with reference to FIG. It should be noted that in the figure, members corresponding to those in FIG. 2 are denoted by the same reference numerals. That is, in the embodiment of FIG. 1, an aqueous methanol solution prepared by mixing methanol and water as raw fuel at an optimum ratio for fuel reforming is stored in the raw fuel tank 8 and prepared. During operation, the aqueous methanol solution extracted from the raw fuel tank 8 is directly supplied to the reforming pipe 2b via the pump 9 and the fuel vaporizer 6.

On the other hand, between the burner 2a of the reformer 2 and the raw fuel tank 8, a pump 10, a fuel vaporizer 6, and an organic solvent separation membrane as an aromatic polyimide hollow fiber membrane are provided. Organic solvent separator 11, cooler 12 for returning methanol vapor to liquid, methanol reservoir 13, pump 1
A combustion fuel supply line 14 including 4 is connected.

The aqueous methanol solution extracted from the raw fuel tank 8 is separated into high-concentration methanol and water vapor through the organic solvent separation membrane of the organic solvent separator 11.
The methanol obtained here is temporarily stored in the methanol reservoir 13 after being reconstituted into the liquid, and from here, when necessary (for example, when the power generator is started), the methanol is supplied to the burner 2a of the methanol reformer 2 via the pump 14. Supplied. In addition, the power generated by the fuel cell 1 is used as the power source for each pump described above. In the figure, reference numeral 16 indicates inverters 16 and 17 for power conversion, and control units for auxiliary machines such as pumps.

[0012]

As described above, according to the fuel supply device of the fuel cell power generator of the present invention, a part of the aqueous methanol solution prepared as the raw fuel of the fuel cell is used to burn the fuel for the methanol reformer. As a result, there is no need for special cold protection measures against freezing of water, and there is no need to separate the fuel for combustion of the methanol reformer into a separate tank from the fuel for the fuel cell, A fuel supply device advantageous in terms of maintenance can be provided.

[Brief description of drawings]

FIG. 1 is a system flow chart of an embodiment of the present invention.

FIG. 2 is a system flow diagram of a conventional fuel cell power generator.

[Explanation of symbols]

 1 Fuel cell 2 Methanol reformer 2a Burner 2b Reformer tube 8 Raw fuel tank 11 Organic solvent separator 13 Methanol reservoir

Claims (3)

[Claims] 1. A fuel cell power generator that uses methanol as a raw fuel and supplies hydrogen reformed by a methanol reformer to a fuel cell to generate electricity. An aqueous methanol solution obtained by mixing methanol and water at a predetermined ratio is used as a raw material. Stored in the fuel tank, while introducing the methanol aqueous solution extracted from the raw fuel tank into the reforming tube of the methanol reformer to perform fuel reforming,
Part of the aqueous methanol solution extracted from the raw fuel tank is passed through an organic solvent separation membrane to separate it into high-concentration methanol and water, and the methanol obtained here is supplied to the burner of the methanol reformer as combustion fuel. A fuel supply device for a fuel cell power generator. 2. The fuel supply device according to claim 1, wherein the organic solvent separation membrane is an aromatic polyimide hollow fiber membrane. 3. The fuel supply device according to claim 1, further comprising a methanol reservoir for storing methanol obtained through an organic solvent separation membrane in a combustion fuel supply line, and a methanol reformer from the reservoir when necessary. A fuel supply device for a fuel cell power generator, which supplies methanol to a burner.