JPH0769601A - Method and apparatus for detecting impure gas in hydrogen gas - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a method and apparatus for detecting impure gas in hydrogen gas. [Constitution] Using a container 1 containing a hydrogen storage alloy A,
A sufficient amount of hydrogen gas for detection is supplied into the container 1 in which the hydrogen storage alloy A is set to a first predetermined temperature to seal the container 1 and the inside of the container 1 is heated by a heating / cooling device 9. After setting the second predetermined temperature different from the first predetermined temperature, the internal pressure of the container 1 is detected by the pressure gauge 7, and the impurity gas content in the detection hydrogen gas is detected from the change in the internal pressure. [Effect] Introducing a hydrogen gas containing a trace amount of impure gas into a container, and easily detecting a trace amount of an impure gas component in hydrogen gas from the change in pressure or flow rate based on the change in performance of the hydrogen storage alloy due to this. You can Of course, since fire is not used when detecting the impure gas component, a trace amount of the impure gas component in the hydrogen gas can be safely detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for detecting impure gas in hydrogen gas.

[0002]

2. Description of the Related Art As a conventional method for detecting a minute amount of impure gas in hydrogen gas, a method using a gas chromatograph is known. With this type of impure gas content detection method, it is difficult to perform simple detection because the device becomes large.

Here, carbon dioxide, oxygen, etc. are known as impure gas components in hydrogen gas, and these impure gas components are poisonous gases for hydrogen storage alloys and are contained in hydrogen gas. In this case, when the hydrogen-absorbing alloy in the container cooled by the cooling device absorbs hydrogen gas, these poisonous gases chemically or physically bond with the hydrogen-absorbing alloy, so that hydrogen is absorbed in the hydrogen-absorbing alloy. When hydrogen is absorbed and released repeatedly, the hydrogen storage capacity gradually decreases.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional technical problems.
According to the configuration of the invention, the container 1 containing the hydrogen storage alloy A is used, and a sufficient amount of hydrogen gas for detection is supplied into the container 1 in which the hydrogen storage alloy A is set to the first predetermined temperature, After sealing the inside of the container 1 and setting the inside of the container 1 to a second predetermined temperature different from the first predetermined temperature by the heating / cooling device 9,
A method for detecting an impure gas content in hydrogen gas, comprising detecting the internal pressure of the container 1 with a pressure gauge 7 and detecting the impure gas content in the detection hydrogen gas from the change in the internal pressure. According to a second aspect of the invention, the opening / closing valve 3 accommodates the hydrogen storage alloy A.
A container 1 to which a pipe 5 for supplying and discharging hydrogen gas for detection is connected, a pressure gauge 7 for detecting the internal pressure of the container 1, and a heating / cooling device 9 for heating or cooling the hydrogen storage alloy A. And opening the on-off valve 3, and at the same time, the hydrogen storage alloy A
Is set to a first predetermined temperature by the heating / cooling device 9,
After supplying a sufficient amount of hydrogen gas for detection from the pipe 5 into the container 1, the opening / closing valve 3 is closed and the heating / cooling device 9 is connected.
Thus, the hydrogen storage alloy A is set to a second predetermined temperature different from the first predetermined temperature, the internal pressure of the container 1 is detected by the pressure gauge 7, and the impurity gas in the hydrogen gas for detection is detected from the change in the internal pressure. It is a device for detecting an impure gas in hydrogen gas, which is characterized by detecting a minute amount. According to a third aspect of the present invention, a container containing the hydrogen storage alloy A is used, and the hydrogen storage alloy A is first
A sufficient amount of hydrogen gas for detection is supplied into the container 1 set to a predetermined temperature to seal the container 1, and the inside of the container 1 is heated by the heating / cooling device 9 to a temperature higher than the first predetermined temperature. 2 After setting the temperature to a predetermined temperature, hydrogen gas for detection is caused to flow out from the container 1, the flow rate thereof is detected by a flow meter 17, and the impure gas content in the hydrogen gas for detection is detected from the amount of outflow. This is a method for detecting the impure gas content in the hydrogen gas. According to a fourth aspect of the invention, the hydrogen storage alloy A is housed in the first
First for supplying hydrogen gas for detection, which is provided with an on-off valve 15
A container 1 to which a second pipe 13 for discharging hydrogen gas for detection, which includes a pipe 11 and a second opening / closing valve 19, is connected;
A flow meter 17 for detecting the flow rate of the pipe 13 and a heating / cooling device 9 for heating or cooling the hydrogen storage alloy A are provided, and the hydrogen storage alloy A is set to the first predetermined temperature by the heating / cooling device 9. Then, the first opening / closing valve 15 is opened, and a sufficient amount of hydrogen gas for detection is supplied from the first pipe 11 into the container 1,
The first opening / closing valve 15 is closed, the inside of the container 1 is set to a second predetermined temperature higher than the first predetermined temperature by the heating / cooling device 9, and the second opening / closing valve 19 is opened.
The flowmeter 17 detects the flow rate of the second pipe 13 and detects the impure gas content in the hydrogen gas for detection from the outflow rate.

[0005]

According to the first aspect of the present invention, when a sufficient amount of the hydrogen gas for detection is supplied into the container 1, the hydrogen-absorbing alloy A is generated due to the poisonous impurities contained in the hydrogen gas for detection. Since it is poisoned, the hydrogen stored in the hydrogen storage alloy A decreases as compared with the case where pure hydrogen is supplied. Then, if the container 1 is closed and the inside of the container 1 is set to a second predetermined temperature different from the first predetermined temperature by the heating / cooling device 9, hydrogen is released or stored from the hydrogen storage alloy A, and the container 1 However, the amount of released hydrogen or the amount of stored hydrogen decreases as the hydrogen storage alloy A is poisoned. as a result,
The internal pressure becomes lower or higher than that in the case where pure hydrogen is supplied and the same temperature control is performed. This change in internal pressure is detected by the pressure gauge 7, and is compared with the change in internal pressure when pure hydrogen or hydrogen gas containing impure gas components of various concentrations is supplied to the container 1 to detect impurities in the hydrogen gas for detection. The gas content can be detected quantitatively.

The invention of claim 2 is an apparatus for carrying out the method of claim 1, wherein the opening / closing valve 3 is opened and the hydrogen storage alloy A is set to a first predetermined temperature by the heating / cooling device 9. Then, supply a sufficient amount of hydrogen gas for detection from the pipe 5 to the container 1.
After supplying the inside, the on-off valve 3 is closed and hydrogen is absorbed in the hydrogen storage alloy A. After that, the hydrogen storage alloy A is set to a second predetermined temperature different from the first predetermined temperature by the heating / cooling device 9 to release or store hydrogen from the hydrogen storage alloy A, and the pressure gauge 7 is used for the container 1 The internal pressure of is detected, and the impurity gas content in the detection hydrogen gas is quantitatively detected from the change in the internal pressure.

According to the third aspect of the present invention, when a sufficient amount of hydrogen gas for detection is supplied into the container 1, the hydrogen storage alloy A is poisoned by the impure gas contained in the hydrogen gas for detection. Therefore, the hydrogen stored in the hydrogen storage alloy A decreases as compared with the case of supplying pure hydrogen. After that, the container 1 is closed, and if the inside of the container 1 is set to a second predetermined temperature higher than the first predetermined temperature by the heating / cooling device 9, hydrogen is released from the hydrogen storage alloy A. The hydrogen gas for detection containing the released hydrogen is caused to flow out of the container 1, and the flow rate is measured by the flow meter 1
Detected at 7. This outflow amount is reduced by the amount of poisoning of the hydrogen storage alloy A, so compare with the outflow amount when pure hydrogen is supplied or when hydrogen gas containing impure gas components of various concentrations is supplied. Therefore, the impure gas content in the detection hydrogen gas can be quantitatively detected.

The invention of claim 4 is an apparatus for carrying out the method of claim 3, in which the hydrogen storage alloy A is set to a first predetermined temperature by the heating / cooling device 9 and the first opening / closing valve 15 is opened. Open and supply a sufficient amount of hydrogen gas for detection from the first pipe 11 into the container 1. At that time, since the hydrogen storage alloy A is poisoned by the impure gas contained in the hydrogen gas for detection,
The hydrogen stored in the hydrogen storage alloy A decreases as compared with the case of supplying pure hydrogen. After that, the first opening / closing valve 15 is closed, and the inside of the container 1 is set to the second predetermined temperature higher than the first predetermined temperature by the heating / cooling device 9. As a result, hydrogen is released from the hydrogen storage alloy A,
The second on-off valve 19 is opened, and the flow rate of the detection hydrogen gas containing hydrogen released from the second pipe 13 is detected by the flow meter 17. Thereby, the impurity gas content in the detection hydrogen gas can be quantitatively detected by comparison with the outflow amount obtained when pure hydrogen or hydrogen gas containing impure gas content of various concentrations is supplied. .

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of a device for detecting an impure gas content in hydrogen gas. In the figure, reference numeral 1 indicates a container that can be closed. The container 1 contains a hydrogen storage alloy A (metal hydride) at the bottom thereof and an opening / closing valve 3
The pipe 5 for supplying and discharging the hydrogen gas for detection, which is equipped with, is connected.
Further, a pressure gauge 7 for detecting the internal pressure of the container 1 and a heating / cooling device 9 for heating or cooling the hydrogen storage alloy A in the container 1 are attached to the container 1. A hydrogen utilization device (not shown) is connected to such a pipe 5, and hydrogen gas is used in the hydrogen utilization device.

The hydrogen storage alloy A reacts with hydrogen gas to reversibly store or release hydrogen gas. This reaction is based on the hydrogen equilibrium pressure-temperature characteristic (PT characteristic) in the plateau region. From the temperature condition at equilibrium pressure,
When cooled to a low temperature, it occludes hydrogen gas, and when heated to a high temperature, it releases hydrogen gas. The hydrogen storage alloy A here is
Since it is used as a material for detecting an impure gas content, an impure gas content, for example, a material covered with carbon dioxide and easily poisoned is used. A TiZrCrFeMnCu-based alloy is known as a hydrogen storage alloy A that is easily poisoned by carbon dioxide.

The cooling device of the heating / cooling device 9 supplies a heat medium from a heat medium supplying device (not shown), for example, cold water to cool the hydrogen storage alloy A to a temperature at which hydrogen gas can be satisfactorily stored. Good. Further, the heating device of the heating / cooling device 9 may be one that guides the heat medium from the heat medium supply device, for example, hot water or steam, and heats the hydrogen storage alloy A to a temperature at which hydrogen is favorably released. The heating device can also be configured with an electric heater.

Next, the operation of the above embodiment will be described. First, the open / close valve 3 is opened, and the hydrogen gas for detection having a predetermined pressure is sufficiently supplied from the pipe 5 into the container 1. The temperature of the hydrogen storage alloy A in the container 1 is previously cooled by the heating / cooling device 9 and set to the first predetermined temperature at which hydrogen can be stored. If the hydrogen gas for detection is supplied into the container 1 and a sufficient amount is stored in the hydrogen storage alloy A, the inside of the container 1 will have a stable predetermined pressure.
Is closed. It should be noted that the fact that a sufficient amount of hydrogen gas for detection has been supplied to the container 1 can be understood by attaching a flow meter (not shown) to the pipe 5 and detecting the zero flow rate.

Next, with the opening / closing valve 3 closed, the hydrogen storage alloy A in the container 1 is heated or cooled to a temperature different from the first predetermined temperature by the heating / cooling device 9, and the second predetermined temperature is set. To do. As a result, hydrogen is released from the hydrogen storage alloy A, or hydrogen in the container 1 is stored in the hydrogen storage alloy A, and the internal pressure of the container 1 changes. Waiting for the pressure in the container 1 to stabilize, the internal pressure of the container 1 is detected by the pressure gauge 7. In this way, the internal pressure of the container 1 is changed by utilizing the difference in the storage capacity based on the difference between the first predetermined temperature and the second predetermined temperature of the hydrogen storage alloy A, and the changed internal pressure is
Compared with the case where pure hydrogen or hydrogen gas containing impure gas components of various concentrations is supplied to the container 1 and the same temperature change is given, a trace amount of impurities contained in the hydrogen gas for detection introduced from the pipe 5 It is possible to know the presence or absence of a gas component and the amount of a specific type of impure gas.

For example, when the impure gas is carbon dioxide and the hydrogen storage alloy A is a TiZrCrFeMnCu type alloy, the hydrogen storage alloy A is stored at the first predetermined temperature (eg 25 ° C.) and the container 1 is closed. Second predetermined temperature (eg 95 ° C)
If the hydrogen storage alloy A is released, the internal pressure of the container 1 rises due to the release, but the rise in pressure decreases as much as the hydrogen storage alloy A is poisoned by carbon dioxide. The internal pressure after this rise,
Compared with the internal pressure when pure hydrogen was supplied to the container 1 or when hydrogen gas containing carbon dioxide of various concentrations was supplied to the container 1, from the insufficient rise in pressure, the minute amount of hydrogen contained in the hydrogen gas for detection was detected. The amount of carbon dioxide gas can be estimated.

2 to 4 show a second embodiment of a device for detecting an impure gas content in hydrogen gas, and the parts substantially the same as those in the first embodiment are designated by the same reference numerals and their description will be given. Is omitted. In this embodiment, a first pipe 11 for supplying hydrogen gas for detection is provided in a container 1 which contains a hydrogen storage alloy A and is provided with a heating / cooling device 9 for heating or cooling the hydrogen storage alloy A.
And a second pipe 13 for discharging the hydrogen gas for detection, respectively. The first pipe 11 is provided with a first opening / closing valve 15, and the second pipe 13 is provided with a flow meter 1 for detecting a flow rate.
7 and a second opening / closing valve 19 are provided.

Next, the operation of the above-mentioned impure gas content detecting device in hydrogen gas will be described. First, similarly to the first embodiment, the hydrogen storage alloy A is brought to the first predetermined temperature, the first opening / closing valve 15 is opened, and a sufficient amount of hydrogen gas for detection is supplied from the first pipe 11 into the container 1. The first predetermined temperature in the container 1 is set by cooling the hydrogen storage alloy A by the heating / cooling device 9. When a sufficient amount of hydrogen gas for detection is supplied into the container 1 and sufficient hydrogen is stored in the hydrogen storage alloy A, the first opening / closing valve 15 is closed and the container 1 is sealed.

Next, the container 1 is heated by the heating / cooling device 9.
The hydrogen storage alloy A therein is heated to a second predetermined temperature higher than the first predetermined temperature, and the second opening / closing valve 19 is opened. As a result, the hydrogen gas for detection released from the hydrogen storage alloy A flows out from the second pipe 13, and the total outflow amount is detected by the flow meter 17. For detection hydrogen gas containing impure gas, the
There is a difference in the outflow amount of the hydrogen gas for detection based on the difference between the predetermined temperature and the second predetermined temperature. Since this difference is obtained depending on the content of the impure gas, that is, the degree of poisoning of the hydrogen storage alloy A, the amount of outflow when pure hydrogen is supplied in advance and the impure gas of various concentrations. If the outflow amount of the hydrogen gas including the content is obtained, the impure gas content of the detection hydrogen gas can be quantitatively known. However, the outflow amount of the hydrogen gas including the impure gas component gradually decreases according to the number of times the hydrogen storage alloy A is poisoned.

For example, the impure gas is carbon dioxide (concentration 60
00 ppm) and the hydrogen storage alloy A is a TiZrCrFeMnCu-based alloy, the hydrogen storage alloy A is stored at a temperature of 25 ° C. (first predetermined temperature) -95 ° C. (second predetermined temperature) in a 10-minute cycle. By repeating the release, the absorption / release amount characteristic shown by the curve L in FIG. 3 is obtained.

As is known from the figure, as the number of repetitions (times) increases, the hydrogen storage alloy A is gradually poisoned, and the amount of hydrogen absorption / release per unit weight of the hydrogen storage alloy A (l
/ Kg) gradually decreases. The straight line P shows the case where the hydrogen gas for detection is pure hydrogen, and the absorbed / released amount (l / Kg)
Does not change. The curve O shows that the hydrogen storage alloy A has CaNi
It is known that the MnAl-based alloy shows absorption / desorption amount characteristics, is hardly poisoned by carbon dioxide, and the absorption / desorption amount (l / Kg) hardly changes.

In FIG. 4, the impure gas is carbon dioxide (concentration 39
In the case of (00 ppm), the same characteristic as FIG. 3 is shown, and a line showing the same characteristic as FIG. Therefore, if the carbon dioxide concentration varies,
By obtaining the release amount characteristic in advance, it is possible to estimate the minute amount of impure gas contained in the hydrogen gas for detection.

[0021]

As can be understood from the above description,
According to the impure gas content detection device in the hydrogen gas according to the present invention, hydrogen gas containing a trace amount of impure gas content is introduced into the container,
From this change in pressure or flow rate based on the change in performance of the hydrogen storage alloy, a trace amount of impure gas component in hydrogen gas can be easily detected. Of course, since fire is not used when detecting the impure gas component, a trace amount of the impure gas component in the hydrogen gas can be safely detected.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a device for detecting an impure gas content in hydrogen gas according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a device for detecting impure gas in hydrogen gas according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a similar absorption / release amount-repetition number characteristic.

FIG. 4 is a diagram similarly showing absorption / release amount-repetition number characteristics.

[Explanation of symbols]

1: container, 3: open / close valve, 5: piping, 7: pressure gauge,
9: heating / cooling device, 11: first pipe, 13: second pipe, 15: first opening / closing valve, 17: flow meter, 19: second
Open / close valve, A: Hydrogen storage alloy.

Claims (4)

[Claims] 1. A container (1) containing a hydrogen storage alloy (A) is used, and a sufficient amount of hydrogen gas for detection is stored in the container (1) in which the hydrogen storage alloy (A) is set to a first predetermined temperature. Is supplied to the container (1) to close the container (1) and the inside of the container (1) is set to a second predetermined temperature different from the first predetermined temperature by a heating / cooling device (9). A method for detecting an impure gas content in hydrogen gas, which comprises detecting the internal pressure of the container (1) in 7) and detecting the impure gas content in the hydrogen gas for detection from the change in the internal pressure. 2. A pipe (5) for accommodating a hydrogen storage alloy (A) and having an opening / closing valve (3) for supplying and discharging hydrogen gas for detection.
A container (1) to which is connected, a pressure gauge (7) for detecting the internal pressure of the container (1), and a heating / cooling device (9) for heating or cooling the hydrogen storage alloy (A), While opening the on-off valve (3), heating the hydrogen storage alloy (A)
After setting the first predetermined temperature by the cooling device (9) and supplying a sufficient amount of hydrogen gas for detection from the pipe (5) into the container (1), the on-off valve (3) is closed, The hydrogen storage alloy (A) is set to a second predetermined temperature different from the first predetermined temperature by the heating / cooling device (9), and the internal pressure of the container (1) is adjusted by the pressure gauge (7). A device for detecting an impure gas in hydrogen gas, which detects and detects an impure gas content in hydrogen gas for detection based on a change in internal pressure. 3. A container containing a hydrogen storage alloy (A) is used, and a sufficient amount of hydrogen gas for detection is supplied into the container (1) in which the hydrogen storage alloy (A) is set to a first predetermined temperature. And, by sealing the container (1) and heating the inside of the container (1) by a heating / cooling device (9) to a second temperature higher than the first predetermined temperature.
After setting to a predetermined temperature, hydrogen gas for detection is caused to flow out from the container (1), and the flow rate thereof is detected by a flow meter (17),
A method for detecting an impure gas content in hydrogen gas, which comprises detecting an impure gas content in hydrogen gas for detection from an outflow amount. 4. A first for supplying hydrogen gas for detection, which contains a hydrogen storage alloy (A) and is provided with a first opening / closing valve (15).
Flow rate for detecting the flow rate of the container (1) to which the second pipe (13) for discharging the hydrogen gas for detection, which is provided with the pipe (11) and the second opening / closing valve (19), and the flow rate of the second pipe (13) are detected. A heating / cooling device (9) for heating or cooling the hydrogen storage alloy (A);
The hydrogen storage alloy (A) is set to a first predetermined temperature to open the first opening / closing valve (15), and a sufficient amount of hydrogen gas for detection is supplied from the first pipe (11) into the container (1). And then the first opening / closing valve (15) is closed and the inside of the container (1) is set to a second predetermined temperature higher than the first predetermined temperature by the heating / cooling device (9). Then, the second opening / closing valve (19) is opened, the flow rate of the second pipe (13) is detected by the flow meter (17), and the impurity gas content in the detection hydrogen gas is detected from the outflow amount. Detecting device for impure gas in hydrogen gas.