JPH07320763A - Power generating method, power generating device, and automobile loaded with power generating device - Google Patents

Abstract

PURPOSE:To provide a power generating device which is conformable to a sudden load fluctuation and requires no auxiliary device such as high output battery at starting by providing a buffer means and a means for supplying a fuel of fixed pressure from the buffer means to a fuel cell. CONSTITUTION:Methanol 1 is mixed with water 2 and evaporated in an evaporator 3, and the evaporated methanol and steam are guided into a reformer 4 to generate a reformed gas consisting of hydrogen, carbon monoxide, and carbon dioxide. The reformed gas is then supplied to a hydrogen separating device 5 consisting of a hydrogen separating film to separate only hydrogen gas from the other gases, and the resulting hydrogen gas is stored in a buffer device 8 through a pressure reducing device 6 and a pressure raising device 7. The hydrogen stored in the device 8 is supplied to a solid polymer electrolytic fuel cell 9, with a prescribed quantity and prescribed pressure, through a hydrogen supplying device 10 such as a pressure reducing valve as the fuel of the cell 9. Thus, the supplying gas pressure to the cell 9 is stabilized, and conformable to a sudden load fluctuation, and a high output battery at starting can be dispensed with.

Description

Detailed Description of the Invention

[0001]

The present invention relates to methane, propane,
Obtaining hydrogen from hydrocarbons such as methanol, ethanol, petroleum and / or hydrocarbons containing oxygen atoms,
The present invention relates to a power generation method including supplying the fuel cell to a fuel cell, a power generation device, and an automobile equipped with the power generation device.

[0002]

2. Description of the Related Art In recent years, fuel cells such as phosphoric acid fuel cells and solid polymer electrolyte fuel cells have been attracting attention from the viewpoint of pollution prevention. As an example of such a fuel cell, for example, in Japanese Patent Laid-Open No. 4-121973, only hydrogen is separated from a hydrogen-containing gas reformed in a fuel reformer and the hydrogen is provided in a bypass line. It is described to store in a hydrogen storage alloy system. In this example, at startup, the storage alloy is warmed to release hydrogen,
It is used as fuel and is used to maximize the startup speed.

Further, in Japanese Unexamined Patent Publication No. 4-325402, when hydrogen is produced by steam reforming a hydrocarbon or the like, hydrogen produced by steam reforming is sequentially permeated through a hydrogen separation membrane, and the hydrogen permeation side is A method for increasing the hydrogen separation rate and the hydrogen separation efficiency by suctioning under reduced pressure is described.

[0004]

However, in the technique described in Japanese Patent Laid-Open No. 4-121973, it is necessary to store hot water in order to take out hydrogen from the storage alloy, which is uneconomical. Since the weight of the alloy is large, the whole system needs to be large-scaled. In addition, the pressure of hydrogen supply gas to the fuel cell is unstable during normal operation, and it is not possible to cope with rapid load changes. There was a problem that I could not. For example, when this fuel cell is applied to an automobile, it cannot cope with sudden start or the like as it is, and a hybrid with a high output battery is required. Further, there is a problem that the hydrogen separation efficiency is low.

On the other hand, in the technique described in Japanese Patent Laid-Open No. 4-325402, similarly to the above, the hydrogen supply gas pressure to the fuel cell is unstable during normal operation, and rapid load fluctuations occur. There is a problem that we can not respond.

[0006]

Therefore, as a result of various studies to solve the above-mentioned problems of the prior art, the present inventors have found that in a power generation system (method, device) such as a fuel cell, a reformer and a fuel cell. The inventors have found that the problems of the above-mentioned conventional techniques can be solved by providing a buffer means for temporarily storing fuel during this period and a means for supplying fuel of a constant pressure from the buffer means to the fuel cell, and arrived at the present invention.

That is, according to the present invention, in the power generation method of reforming the fuel by the reforming means to obtain the hydrogen-containing gas and supplying the obtained hydrogen-containing gas to the fuel cell, the reforming means and the fuel There is provided a power generation method characterized in that a buffer means is provided between cells, the hydrogen-containing gas is temporarily stored in the buffer means, and then the hydrogen-containing gas having a predetermined pressure is supplied from the buffer means to the fuel cell. It Further, according to the present invention, in a power generation device including a reforming unit that reforms a fuel to produce a hydrogen-containing gas, and a fuel cell that uses the hydrogen-containing gas produced by the reforming unit as a fuel, There is provided a power generation device characterized in that a buffer means for temporarily storing a hydrogen-containing gas and a hydrogen supply means for supplying the hydrogen-containing gas of a predetermined pressure from the buffer means to the fuel cell are provided between the means and the fuel cell. To be done.

In the present invention, it is preferable that a hydrogen separating unit is provided between the reforming unit and the buffer unit, and the hydrogen separating unit separates hydrogen from the hydrogen-containing gas generated by the reforming unit. Further, the hydrogen separating means, preferably comprising a palladium metal or an alloy containing palladium as a hydrogen separation membrane from the viewpoint of hydrogen separation ability, the hydrogen separated by the hydrogen separating means is decompressed by the decompressing means,
Next, it is preferable to increase the pressure of the hydrogen reduced by the pressure reducing means to the predetermined pressure by the pressure increasing means from the viewpoint of improving the hydrogen separation rate and improving the efficiency of the entire apparatus. Further, the hydrogen supply means for supplying hydrogen or hydrogen-containing gas from the buffer means to the fuel cell at a predetermined pressure is preferably a pressure reducing valve.

Further, a phosphoric acid type fuel cell and a solid polymer electrolyte type fuel cell can be used as the fuel cell, but a solid polymer electrolyte type fuel cell has an operating temperature of 10
The fuel is preferably hydrocarbon because it is as low as 0 ° C. or lower, and methanol and ethanol are more preferable because they are liquid and suitable for storage and transportation. As described above, the power generation device of the present invention has improved hydrogen separation speed and separability, the pressure of the hydrogen-containing gas or hydrogen gas to the fuel cell is stable, and it is possible to cope with rapid load changes. Very suitable for automobiles.

[0010]

In the present invention, the buffer means for temporarily storing the hydrogen-containing gas or hydrogen and the means for supplying the hydrogen-containing gas or hydrogen at a constant pressure from the buffer means to the fuel cell are provided between the reforming means and the fuel cell. Therefore, the pressure of the gas supplied to the fuel cell is stable, it is possible to cope with rapid load fluctuations, and an auxiliary device such as a high-power battery is not required at the time of startup. Further, when the hydrogen separating means is provided between the reforming means and the buffer means, the hydrogen separating efficiency is high and it is extremely suitable for automobiles.

[0011]

EXAMPLES Next, the present invention will be described in more detail based on the illustrated examples, but the present invention is not limited to these examples. FIG. 1 is a flow chart showing an embodiment of a power generator according to the present invention, in which methanol 1 as a fuel is mixed with water 2 and vaporized in a vaporizer 3. The methanol and steam vaporized in the vaporizer 3 are introduced into the reformer 4, and hydrogen,
A reformed gas composed of carbon monoxide and carbon dioxide is generated. Then, in the obtained reformed gas, only the hydrogen gas is separated from other gases by the hydrogen separation device 5 including the hydrogen separation membrane. The hydrogen gas is then stored in the buffer device 8 via the pressure reducing device 6 and the pressure increasing device 7. The hydrogen stored in the buffer device 8 is supplied to the fuel cell 9 as a fuel for the solid polymer electrolyte fuel cell 9 at a predetermined amount and a predetermined pressure via a hydrogen supply device 10 such as a pressure reducing valve.

In addition to hydrogen, air 11 is supplied to the fuel cell 9 as fuel. In addition, an appropriate amount of hydrogen is supplied from the buffer device 8 via the hydrogen supply device 10 to the line 1.
By passing through 2 and adding air 13 (burning) to this, it is possible to cover the required heat amount in the vaporizer 3, the reformer 4, or the hydrogen separation device 5.

Although the embodiment of the present invention has been described above, the present invention is not limited to this. For example, the fuel 1 may be hydrocarbons such as methane, ethane, ethanol and petroleum, instead of methanol. As the hydrogen separation membrane of the hydrogen separation device 5,
Palladium metal or an alloy containing palladium is preferable, and a structure in which a palladium metal film or the like is supported by a porous substrate is preferable.

The decompression device 6 for decompressing hydrogen on the downstream side of the hydrogen separation device 5 can improve the hydrogen separation speed and the separation efficiency of the hydrogen separation device 5.
For example, a rotary pump or the like is used. A compressor or the like can be used as the booster 7. Further, the buffer device 8 is not particularly limited as long as it can temporarily store the hydrogen-containing gas or hydrogen, and, for example,
A pressure vessel having a predetermined capacity, a hydrogen storage alloy, or the like is used.
A pressure vessel having a pressure of 2 to 9 atm and a volume of about 1 to 50 liters is preferable. As the hydrogen supply device 10 for supplying hydrogen (hydrogen-containing gas in the case of not having a hydrogen separation device) to the fuel cell 9 at a predetermined pressure, a normal pressure reducing valve, for example, a diaphragm type pressure reducing valve, or a piston type A pressure reducing valve, a relief type pressure reducing valve or the like can be used.

The concrete results of the present invention will be described below. (Example) The power generator having the configuration shown in FIG. 1 was used. Capacity 6
Using a 0 liter methanol fuel tank, methanol 1 and water 2 were introduced into the vaporizer 3 and vaporized at 300 ° C.
The mixed gas of methanol and water vaporized in the vaporizer 3 has an inner diameter of 9 mmφ, an outer diameter of 11 mmφ and a length of 500 mm, and has a built-in hydrogen separation device 5 consisting of 50 porous alumina tubes covered with a palladium membrane. It was introduced into the reformer 4. Hydrogen separator 5 and reformer 4 are 300 ° C, 10 atm
Held in. Next, the hydrogen separated from the hydrogen separator 5 is depressurized to 0.2 atm by the rotary pump 6, then boosted to 5 atm by the compressor 7, and stored in a pressure vessel (buffer device) 8 having a capacity of 10 liters and a pressure of 5 atm. did. The hydrogen stored in the pressure vessel 8 was depressurized to 3 atm by the diaphragm type pressure reducing valve 9 and supplied to the solid polymer electrolyte fuel cell 9.

When the fuel cell was operated under the above conditions, the output was stable at 4 ± 0.1 kW during normal operation. Also, the output could reach from 20% to 100% in 3 seconds. Further, it can be started without requiring any auxiliary device such as a high-power battery, and can be started in 1 second.

(Comparative Example) A fuel cell was operated under the same apparatus and conditions as in Example except that the buffer device 8 was omitted from the power generator shown in FIG. As a result, the output was stable at 4 ± 0.1 kW during normal operation, but the output was 20% to 10%.
It took 30 seconds to reach 0%. Further, at the time of starting, a starting battery is required, and even when the starting battery is used, it took 20 seconds to start.

[0018]

As described above, according to the present invention, the buffer means for temporarily storing the hydrogen-containing gas or hydrogen between the reforming means and the fuel cell, and the hydrogen-containing gas or hydrogen having a constant pressure from the buffer means. Since the means for supplying the fuel cell to the fuel cell is provided, the gas pressure supplied to the fuel cell is stable,
It has an advantage that it can cope with a rapid load change. Further, at the time of startup, an auxiliary device such as a high output battery is unnecessary. Therefore, by applying or mounting the power generation method and power generation device of the present invention to a vehicle, a vehicle with less harmful substances in the exhaust gas can be obtained, which is extremely significant in terms of the environment.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of a power generator according to the present invention.

[Explanation of symbols]

1: Methanol, 2: Water, 3: Vaporizer, 4: Reformer,
5: hydrogen separator, 6: depressurizer, 7: booster, 8:
Buffer device, 9: solid polymer electrolyte fuel cell, 1
0: Hydrogen supply device, 11: Air, 12: Line, 13:
air.

Claims (14)

[Claims] 1. A power generation method for reforming a fuel by a reforming means to obtain a hydrogen-containing gas and supplying the obtained hydrogen-containing gas to a fuel cell, wherein a buffer means is provided between the reforming means and the fuel cell. Is provided, the hydrogen-containing gas is temporarily stored in the buffer means, and then the hydrogen-containing gas having a predetermined pressure is supplied from the buffer means to the fuel cell. 2. A hydrogen separating unit is provided between the reforming unit and the buffer unit, the hydrogen separating unit separates hydrogen from the hydrogen-containing gas produced by the reforming unit, and the hydrogen is transferred to the fuel cell. The power generation method according to claim 1, wherein the power is supplied. 3. The power generation method according to claim 2, wherein the hydrogen separation means comprises palladium metal or an alloy containing palladium as a hydrogen separation membrane. 4. The power generation method according to claim 2, wherein the hydrogen separated by the hydrogen separating means is depressurized and then pressurized. 5. The power generation method according to claim 1, wherein the fuel cell is a solid polymer electrolyte fuel cell. 6. The fuel is methanol as claimed in claim 1.
The power generation method according to any one of 1 to 5. 7. A power generation device comprising a reforming means for reforming a fuel to produce a hydrogen-containing gas, and a fuel cell using the hydrogen-containing gas produced by the reforming means as a fuel. A power generator comprising a buffer means for temporarily storing a hydrogen-containing gas between the fuel cells and a hydrogen supply means for supplying the hydrogen-containing gas at a predetermined pressure from the buffer means to the fuel cell. 8. The power generator according to claim 7, further comprising hydrogen separating means provided between the reforming means and the buffer means. 9. The power generator according to claim 8, wherein the hydrogen separation means comprises palladium metal or an alloy containing palladium as a hydrogen separation membrane. 10. The power generator according to claim 7, wherein the hydrogen supply unit is composed of a pressure reducing valve. 11. A depressurizing unit for depressurizing the hydrogen separated by the hydrogen separating unit, and a boosting unit for boosting the hydrogen depressurized by the depressurizing unit to a predetermined pressure.
The power generation device according to any one of 0. 12. The power generator according to claim 7, wherein the fuel cell is a solid polymer electrolyte fuel cell. 13. The fuel of claim 7, wherein the fuel is methanol.
The power generator according to any one of to 12. 14. An automobile equipped with the power generation device according to claim 7.