JP3473896B2 - Hydrogen purification equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for removing carbon monoxide in a reformed gas containing hydrogen monoxide as a main component and containing carbon monoxide for use in a fuel such as a fuel cell.

[0002]

2. Description of the Related Art As a hydrogen source for a fuel cell or the like, a reformed gas obtained by reforming a hydrocarbon or alcohol is used. In the case of a polymer electrolyte fuel cell operating at a low temperature of 100 ° C. or lower, The platinum catalyst used for the electrode is poisoned by carbon monoxide contained in the reformed gas. When poisoning of the platinum catalyst occurs, the reaction of hydrogen is hindered, and the power generation efficiency of the fuel cell is significantly reduced.
m or less, preferably 10 ppm or less.

Usually, in order to remove carbon monoxide, a shift reaction in which a shift catalyst is installed is subjected to a shift reaction, that is, carbon monoxide and steam are reacted to convert into carbon dioxide and hydrogen, and from several thousands ppm to 1%. Decrease carbon monoxide concentration to the extent.
Then, a small amount of air is added to remove carbon monoxide by the selective oxidation catalyst to a level of several ppm which does not adversely affect the fuel cell. In order to sufficiently remove carbon monoxide, it is necessary to supply oxygen at 1 to 3 times the carbon monoxide concentration, but hydrogen is also oxidized corresponding to the amount of oxygen. At this time, when the carbon monoxide concentration is high, the amount of hydrogen consumed increases, so that the overall efficiency significantly decreases. Therefore, it is necessary to sufficiently reduce the carbon monoxide concentration in the metamorphic part.

Conventionally, as the shift catalyst, a copper-zinc catalyst, a copper-chromium catalyst or the like which can be used at 150 ° C to 300 ° C as a medium / low temperature catalyst has been used, and an iron / chromium which functions as a high temperature catalyst at 300 ° C or higher. A catalyst or the like is used. Depending on the application such as a chemical plant or a hydrogen generator for a fuel cell, these catalysts have been used only as a medium / low temperature catalyst or a combination of a high temperature catalyst and a medium / low temperature catalyst.

[0005]

As described above, when a copper-based catalyst is mainly used, the activity of the catalyst is very high.
Before use, it is necessary to carry out a reduction treatment to activate it. At this time, since heat is generated during the activation treatment, it is necessary to perform treatment for a long time while circulating a reducing gas so as not to exceed the heat resistant temperature of the catalyst. Further, once activated, the catalyst may be reoxidized and deteriorated due to mixing of oxygen when the apparatus is stopped. Therefore, it is necessary to take measures such as preventing oxidation. Further, since the catalyst for low temperature has low heat resistance, the catalyst cannot be rapidly heated at the time of starting the apparatus, and it is necessary to take measures such as gradually increasing the temperature.

On the other hand, when only the high temperature catalyst is used,
Although heating at the time of start-up becomes easy, the CO conversion reaction is an equilibrium reaction that depends on temperature, and it was difficult to reduce the carbon monoxide concentration to 1% or less. Therefore, C to connect later
The efficiency in the O purification unit was reduced.

As described above, in the conventional method, there are many problems in the application in which it takes time to start the shift conversion section, the reactor becomes large, and the operation is stopped and the operation is repeated.

[0008]

SUMMARY OF THE INVENTION In consideration of the above problems of the hydrogen purifier, the present invention facilitates the activation treatment of the shift catalyst and eliminates the influence of oxygen mixture when the operation is stopped or repeated. An object of the present invention is to provide a hydrogen purification device that operates stably over a long period of time .

[0009] Therefore, the hydrogen purifying apparatus of the present invention, hydrogen
And comprising a supply of the reformed gas containing carbon monoxide and water, and a reaction chamber equipped with a CO shifting catalyst body downstream of said reformed gas supply portion, the CO shifting catalyst body, Pt, Ru , R
at least one selected from h and Pd and Ce
And a small amount selected from Ru, Pt, Pd, Rh
Equipped with a catalyst containing at least one precious metal element as the active ingredient
Connecting the reforming section to the upstream side of the reforming gas supply section,
At least one selected from Ru, Pt, Pd, and Rh
CO equipped with a catalyst containing one precious metal element as an active ingredient
The purification unit is connected to the downstream side of the CO shift catalyst body .

At this time, it is effective that the CO conversion catalyst body contains Ce together with the noble metal.

The CO shift catalyst body has a honeycomb structure,
Alternatively, it is effective that a catalyst component is supported on a carrier substrate having a foam structure having communicating holes.

At this time, it is effective that the carrier base material is made of a metal base material .

Further, the hydrogen purifying apparatus of the present invention is compatible with hydrogen.
A reformed gas supply unit containing carbon oxide and water;
A reaction chamber equipped with a CO conversion catalyst body on the downstream side of the gas supply section;
And the CO shift catalyst body contains Pt, Ru, Rh, P
In a hydrogen purification device containing at least one selected from
There are, set the air supply to the upstream side of the CO shifting catalyst body
It is characterized by being placed.

At this time, it is effective that the flow rate of the air supplied from the air supply unit is controlled in conjunction with the temperature of the CO shift catalyst body.

At this time, it is effective that the air flow rate is controlled so as to increase when the temperature of the CO shift catalyst body decreases and to decrease when the temperature of the CO shift catalyst body rises.

Further, Ru, on the upstream side of the reformed gas supply section,
It is effective that a reforming section equipped with a noble metal catalyst containing one or more noble metal elements selected from Pt, Pd, and Rh as an active component is connected.

Further, Ru, Ru, is provided on the downstream side of the CO shift catalyst body.
It is effective that a CO purifying section equipped with a noble metal catalyst containing one or more noble metal elements selected from Pt, Pd, and Rh as an active component is connected.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a configuration diagram showing a cross section of a hydrogen purifier according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 is a catalyst body, which is filled in the reaction chamber 2. Reference numeral 3 is a reformed gas inlet from which reformed gas is introduced. A catalyst supporting net 4 is installed in the reaction chamber 2 so that the reformed gas comes into uniform contact with the upstream portion of the catalyst body 1,
A space was provided on the upstream side of the catalyst body 1. The reformed gas that has finished the reaction on the catalyst body 1 is discharged from the reformed gas outlet 5.

Further, in order to keep the reactor at a constant temperature, the outer periphery of the reaction chamber 2 was covered with a heat insulating material 6 made of ceramic wool. Here, the catalyst body 1 is prepared by supporting Ce and Pt on a spherical porous alumina pellet having a diameter of 6 mm.

Next, the principle of the present embodiment will be described. As the fuel used to generate the reformed gas to be supplied to the hydrogen purifier of the present invention, natural gas, methanol,
There are gasoline, etc., and there are reforming methods such as steam reforming that adds steam and partial reforming that adds air,
In this embodiment, a case where a reformed gas obtained by steam reforming natural gas is used will be described.

The reformed gas produced by mixing natural gas with steam and bringing it into contact with the reforming catalyst contains carbon dioxide and carbon monoxide as byproducts as well as hydrogen, and steam added before reforming. The rest is included. The composition of this reformed gas varies somewhat depending on the catalyst temperature at the time of reforming, but as an average value excluding steam, about 80% of hydrogen, about 10% of carbon dioxide and about 10% of carbon monoxide are contained. 5 reforming reactions of natural gas
On the other hand, the transformation reaction in which carbon monoxide and steam react is performed at about 150 ° C to 300 ° C, whereas the reformed gas is fed to the heat exchanger before the reformed gas inlet 3 because the conversion reaction where carbon monoxide and steam react is performed at about 150 ° C to 300 ° C. Supply after cooling by passing.

The CO conversion reaction is an equilibrium reaction that depends on temperature, and the CO concentration can be reduced as the temperature is lowered.
On the other hand, as the temperature decreases, the reaction rate on the catalyst decreases, so a catalyst that can react at a low temperature is more effective. Normal,
Copper-based conversion catalysts such as copper-zinc catalysts and copper-chromium catalysts used as conversion catalysts can perform CO conversion reaction at a low temperature of about 150 ° C to 250 ° C, and have a CO concentration of several hundreds to several thousands ppm. Can be reduced to However, after filling the reactor with the copper-based catalyst, it is necessary to circulate and activate a reducing gas such as hydrogen or a reformed gas. Since the heat resistance of the copper-based catalyst is as low as around 300 ° C., it is necessary to dilute the reducing gas or supply it gradually at a small flow rate so that the heat of reaction during activation does not exceed the heat resistant temperature. Further, the content of copper in the catalyst also affects the time required for activation, but about several 10% by weight is necessary for ensuring life reliability, and long time is required for activation. .

On the other hand, in the hydrogen purifying apparatus of the present invention, since the noble metal catalyst is used for the catalyst body 1 and it has much higher heat resistance than the copper-based catalyst, the carrier such as alumina has a weight ratio of 0. It is only necessary to carry about 1% to several% of noble metal.
Therefore, it can be used by performing activation treatment with a reducing gas for a short time or simply by passing the reformed gas.

An outline of the characteristics of the noble metal catalyst used for the catalyst body 1 in this example is shown in FIG. For comparison, the characteristics of the copper-zinc catalyst, which is a shift catalyst for low temperature, and the iron-chromium catalyst, which is a shift catalyst for high temperature, are shown. The noble metal catalyst used in this example has an intermediate performance between the high temperature catalyst and the low temperature catalyst. It is difficult to reduce the CO concentration to 1% or less with the high temperature shift catalyst alone, and it is often used in combination with the low temperature shift catalyst. Although the noble metal catalyst of this example is inferior to the low-temperature shift conversion catalyst, it can reduce carbon monoxide to a concentration of about several thousand ppm, and the noble metal catalyst alone can be applied to the hydrogen purification device for a fuel cell.

In the CO shift conversion reaction, the gas flow rate per unit catalyst volume (space velocity SV) is usually 1000 or less per hour, and a large amount of catalyst is required to increase the heat capacity. It takes a long time to do. Therefore, it is conceivable to use heating from the outside of the reaction chamber together with an electric heater or to raise the temperature of the supplied reformed gas to accelerate the rate of temperature rise. However, since the copper-based catalyst has a low heat resistant temperature, rapid heating that locally raises the temperature is not desirable. On the other hand, since the noble metal catalyst with high heat resistance is used in the hydrogen refining apparatus of this example, there is no problem even if a high temperature part of about 500 ° C. is locally generated, and by supplying the high temperature reformed gas, Therefore, the device can be quickly started.

Further, when the apparatus is stopped, the pressure inside the reaction chamber decreases with a decrease in the temperature of the apparatus, and a small amount of external air is mixed. Therefore, when the apparatus is repeatedly stopped and started over a long period of time, the copper-based catalyst gradually deteriorates. Therefore, a means for preventing oxygen from entering is required, and the apparatus becomes complicated. On the other hand, since the noble metal catalyst is used in the hydrogen purification apparatus of this example, it is not necessary to take measures against a slight amount of oxygen mixed in, and the apparatus can be stopped and started very easily.

In this embodiment, the catalyst body 1 has a diameter of 6 mm.
The spherical porous alumina pellets of No. 2 prepared by supporting Ce and Pt were used.
Even if a noble metal element selected from d and Rh is used, it can be used without a long-term activation treatment such as a copper-based catalyst, and at the same time, there is no problem in heat resistance. The shape of the catalyst body may be spherical, conical, or foam-shaped,
There is no problem if the pressure loss for the gas flow is small enough for the application.

Further, Ce has an effect as a co-catalyst for accelerating the transformation reaction, and it is preferable to add it in order to carry out the reaction at a low temperature.

Further, although the reformed gas obtained by steam reforming the natural gas was used in this example, there is no particular difference in other fuels, as the ratio of carbon monoxide and carbon dioxide slightly changes.

When a partial reformed gas to which air is added instead of steam is used, it is necessary to add water before entering the reaction chamber 2 because the proportion of steam is small. It is essentially no different from quality gas.

(Second Embodiment) The second embodiment of the present invention will be described. As shown in FIG. 3, this embodiment uses a cordierite honeycomb carrying a noble metal catalyst as the catalyst body 11, and most of the operational effects are similar to those of the first embodiment. Therefore, the present embodiment will be described focusing on different points.

FIG. 3 is a sectional view of the configuration of this embodiment.
By forming the catalyst body 11 in the honeycomb structure, the contact area between the catalyst and the reformed gas is increased, the volume of the catalyst can be reduced, and the heat capacity can be reduced, so that the time for starting the apparatus can be shortened. In addition, since the noble metal catalyst having high heat resistance is used, even when the amount of the catalyst is reduced by supporting it on the honeycomb, the characteristics can be stably maintained for a long time without deterioration.

In this example, the carrier base material has a honeycomb shape. However, the shape is not limited to the honeycomb shape, and if the shape is such that the pressure loss is small and the contact area between the catalyst and the gas is large, even if it is like a foam shape, the heat-resistant fibers carry the catalyst. It doesn't matter.

In this example, cordierite honeycomb was used as the carrier substrate. However, when a base material having good thermal conductivity such as a metal honeycomb is used, the temperature difference from the upstream part to the downstream part of the catalyst body becomes small, and the reaction heat on the catalyst body 11 can be quickly radiated, Stable characteristics can be obtained.

(Third Embodiment) A third embodiment of the present invention will be described. In this embodiment, as shown in FIG. 4, the CO conversion catalyst body is a first catalyst body 2 composed of a noble metal catalyst.
1 and a second catalyst body 22 composed of a copper-based catalyst, and most of the operational effects are similar to those of the first embodiment. Therefore, the present embodiment will be described focusing on different points.

FIG. 4 is a sectional configuration diagram of the present embodiment.
As the first catalyst body 21, a catalyst body in which a noble metal-based catalyst is carried on a cordierite honeycomb is used, and the temperature of the reforming gas to be supplied is controlled so as to react at about 300 ° C. As the second catalyst body 22, a copper-based catalyst supported on a cordierite honeycomb is used, and the reaction is performed in a temperature range of about 150 ° C to 250 ° C. Normally, about 90% of carbon monoxide reacts in the upstream portion of the CO conversion catalyst body. Further, even when the temperature is raised when the apparatus is started up, the upstream portion of the CO shift catalyst body is exposed to the high temperature reformed gas. Therefore, catalyst deterioration is more likely to proceed in the upstream portion of the shift catalyst. Here, in the hydrogen purification apparatus of the present invention, since the noble metal catalyst having high heat resistance is used for the first catalyst body 21, it is possible to eliminate the above influence. Further, since the second catalyst body 22 uses a copper-based catalyst, it is possible to characteristically reduce the CO concentration to several hundreds to several thousands ppm, which is equivalent to the case where the copper-based catalyst is used alone. Further, instead of the noble metal catalyst of the first catalyst body 21,
When a high temperature shift catalyst is used, deterioration of the low temperature shift catalyst can be suppressed in the same manner. However, the high temperature shift catalyst requires a temperature of around 400 ° C. In order to use the two-catalyst body 22 in combination with the low-temperature shift conversion catalyst, a heat exchanger for cooling is required between the two catalysts, and the apparatus becomes large.

(Embodiment 4) A fourth embodiment of the present invention will be described. In the present embodiment, as shown in FIG. 5 , an air supply unit is provided on the upstream side of the catalyst body 31, and most of the operational effects are similar to those of the first embodiment. Therefore, the present embodiment will be described focusing on different points.

FIG. 5 is a sectional configuration diagram of this embodiment.
When the CO shift section is connected to the reforming section and the CO purifying section,
Since the heat capacity is large at the time of start-up as compared with the reforming section and the CO purifying section, the CO shift section requires the most time to raise the temperature.
Heating by electric heater or combustion is considered,
It requires extra energy and is not efficient. Here, in this example, an air supply unit is provided on the upstream side of the catalyst body 31, and the air is supplied so that the oxygen concentration is about 1 to 2%, whereby hydrogen or carbon monoxide in the reformed gas is supplied. Can be combusted and heated on the shift catalyst. The reformed gas while the temperature of the shift catalyst has not risen sufficiently has a high carbon monoxide concentration and cannot be supplied to the fuel cell. Therefore, burning this gas does not require extra energy and is efficient. The metamorphic part can be heated. Further, even during steady operation, the shift catalyst can be stably operated by supplying air when the temperature of the shift catalyst has dropped. In the case of a copper-based catalyst, it is not preferable to add air to the shift conversion part because it deteriorates the catalyst. However, in this example, since the noble metal catalyst is used for the catalyst body 31, there is no deterioration due to oxidation.

Further, by detecting the temperature of the catalyst body 31 and controlling the air amount so as to keep the catalyst temperature constant, a more stable operation becomes possible.

The consumption of the supplied oxygen is an oxidation reaction with a high reaction rate, is completed in the upstream portion of the catalyst body 31, and oxygen does not reach the downstream portion. Therefore, in this example, only the noble metal catalyst was used for the catalyst body 31, but even if a copper-based catalyst was used for the downstream portion, it did not deteriorate, and higher characteristics could be obtained.

(Fifth Embodiment) A fifth embodiment of the present invention will be described. In the present embodiment, the hydrogen purification apparatus shown in the first embodiment is connected to a reforming section using a noble metal catalyst and a CO purifying section using a noble metal catalyst.

Usually, a catalyst such as Ni or a catalyst mainly composed of Pt or Ru is used as a reforming catalyst for natural gas or the like, but a transition metal catalyst such as Ni is subjected to a reduction treatment in advance, It is necessary to activate it, and if it is oxidized even after the device is stopped, the activation process is required again, so it is necessary to be careful about the inclusion of air. On the other hand, noble metal catalysts such as Ru require almost no activation treatment, and there is no problem even if no measures are taken against air inclusion even after the apparatus is stopped. Further, the CO purification unit also uses a noble metal catalyst such as a ruthenium catalyst or a platinum catalyst, thereby eliminating the need for activation treatment with a reducing gas. Therefore, a reforming section having a noble metal catalyst, a reforming section having the same precious metal catalyst, and a CO
By connecting the purification unit,
When the apparatus is repeatedly stopped and started, the influence of air mixing is eliminated, and stable performance can be obtained for a long period of time.

[0044]

Example 1 A spherical porous alumina pellet having a diameter of 6 mm was impregnated with a mixed solution of cerium nitrate and a platinum salt, and fired at 500 ° C. in an electric furnace to prepare a catalyst body 1. This catalyst body 1 is used in the reaction chamber 2 of the hydrogen purifier shown in FIG.
The reformed gas containing 8% of carbon monoxide, 8% of carbon dioxide, 20% of steam and the rest of hydrogen is cooled to 350 ° C. and introduced at a flow rate of 10 liters per minute through the reformed gas inlet 3. did. When the composition of the reaction gas discharged from the reformed gas outlet 5 was measured by gas chromatography after removing the steam, the carbon monoxide concentration was 3 after 30 minutes from the introduction of the reformed gas.
It became 500 ppm. After that, the inside of the reaction chamber 2 was replaced with nitrogen, and then air was supplied and reformed gas was supplied again to measure the composition of the reaction gas.
It was 00 ppm. The same operation was repeated 50 times, and the characteristics were examined in the same manner. The carbon monoxide concentration was found to be 36.
It was 00 ppm.

Example 2 After the reformed gas was once reacted in Example 1, the supply of the reformed gas was stopped and the hydrogen purifier was cooled to room temperature. Then, the reformed gas cooled to a predetermined temperature is first supplied again, and when the catalyst temperature rises to 300 ° C., the supplied reformed gas temperature is set to 350 ° C. and the reaction gas discharged from the reformed gas outlet 5 is discharged. It was measured. In order to know the time required for rising, the time until the CO concentration fell below 5000 ppm was measured. The temperature of the reformed gas supplied first is 350 ° C, 400 ° C, 450
The rise time of the device is
They were 29 minutes, 25 minutes, 18 minutes, and 12 minutes, respectively.

(Example 3) Alumina powder was impregnated with a mixed solution of a cerium nitrate solution and a platinum salt, and the mixture was placed in an electric furnace at 500 ° C.
It was baked in. Disperse this in water to make a slurry,
A catalyst body 11 was prepared by supporting a cordierite honeycomb having 400 cells per square inch. When the catalyst body 11 was installed in the hydrogen purifier shown in FIG. 3, the reformed gas was supplied from the reformed gas inlet 13 and the reaction gas discharged from the reformed gas outlet 15 was measured as in Example 1. The carbon monoxide concentration was 2800 ppm. In addition, as in Example 2, 3
Supplying reformed gas at 50 ℃, CO concentration is 5000ppm
It was 20 minutes when the time until it fell below was measured.

(Example 4) The same cordierite honeycomb as that used in Example 3 was divided into two in the length direction. One of the honeycombs was loaded with the platinum catalyst slurry used in Example 3 to form a first catalyst body, and the other was loaded with a slurry of copper-zinc catalyst powder to form a second catalyst body. . These catalyst bodies were installed in the hydrogen purifier shown in FIG. When the reformed gas cooled to 350 ° C. was supplied in the same manner as in Example 1 and the reaction gas discharged from the reformed gas outlet 26 was measured, the carbon monoxide concentration was 1000 ppm. After that, the supply of the reformed gas was stopped, and the hydrogen purifier was cooled to room temperature. Further, the reformed gas initially cooled to the predetermined temperature is supplied again, and when the catalyst temperature rises to 300 ° C., the supplied reformed gas temperature is set to 350 ° C., and the reaction gas discharged from the reformed gas outlet 5 is discharged. It was measured. The time until the CO concentration fell below 5000 ppm was measured. The temperature of the reformed gas supplied first is 350 ° C., 4
When the temperature was set to 00 ° C, 450 ° C, and 500 ° C, the rise times of the device were 27 minutes, 23 minutes, 16 minutes, and 10 minutes, respectively. The initial reformed gas temperature was set to 500 ° C, and after repeatedly rising 50 times, 350 ° C again.
The reformed gas was supplied to measure the CO concentration.
It was 50 ppm.

Example 5 A spherical porous alumina pellet having a diameter of 6 mm was impregnated with a mixed solution of cerium nitrate and a platinum salt and fired at 500 ° C. in an electric furnace to prepare a catalyst body 31. The catalyst body 31 was filled in the reaction chamber 32 of the hydrogen purifier shown in FIG. 5, and carbon monoxide 8%, carbon dioxide 8%,
The reformed gas containing 20% steam and the rest hydrogen was cooled to 350 ° C. and introduced from the reformed gas inlet 33 at a flow rate of 10 liters per minute. At this time, the oxygen concentration from the air supply unit 37 is 2
Air was supplied so that it became%. Catalyst temperature is 300 ℃
The temperature of the reaction gas discharged from the reformed gas outlet 35 was measured after the air supply was stopped when the temperature rose. It was 15 minutes when the time until the CO concentration at this time fell below 5000 ppm was measured. Then, in the same way, 50
The temperature was raised, a reformed gas at 350 ° C. was supplied, and the CO concentration was measured and found to be 3500 ppm.

(Comparative Example 1) A copper-zinc catalyst having a diameter of 6 mm was filled in the reaction chamber 2 of the hydrogen purifier shown in FIG. 1 as in Example 1, and carbon monoxide 8%, carbon dioxide 8% and water vapor 2
When the reformed gas with 0% and the remaining hydrogen was cooled to 200 ° C. and introduced from the reformed gas inlet 3 at a flow rate of 10 liters / min, the catalyst temperature temporarily rose to 500 ° C. After the reduction was completed and the catalyst temperature was lowered, the carbon monoxide concentration did not fall below 3% even if the temperature of the reformed gas supplied was changed.

Comparative Example 2 A copper-zinc catalyst having a diameter of 6 mm was filled in the reaction chamber 2 of the hydrogen purifier shown in FIG. 1 as in Example 1, and carbon monoxide 8%, carbon dioxide 8% and water vapor 2
When the reformed gas with 0% and the remaining hydrogen was cooled to 200 ° C. and introduced from the reformed gas inlet 3 at a flow rate of 1 liter / min, the catalyst temperature reached a steady state at 290 ° C. and the activation was completed. It took 50 hours for the catalyst temperature to drop. After that, the reformed gas flow rate was set to 10 liters per minute,
The reaction gas discharged from the reformed gas outlet 5 was measured and found to be 1000 ppm. After that, the inside of the reaction chamber 2 was replaced with nitrogen, air was supplied, and the above activation treatment was performed again for 50 hours, and the composition of the reaction gas was measured in the same manner. The carbon monoxide concentration was 8000 ppm. there were.
The same operation was repeated 5 times, and the characteristics were examined in the same manner. As a result, the CO concentration did not reach 2% or less even if the temperature condition was changed.

Comparative Example 3 After activating the catalyst in Comparative Example 2, the reformed gas was stopped and the hydrogen purifier was cooled to room temperature. After that, the reformed gas cooled to a predetermined temperature was first supplied again, and when the catalyst temperature rose to 200 ° C., the supplied reformed gas temperature was set to 250 ° C. and the reaction gas discharged was measured. The time until the CO concentration fell below 5000 ppm was measured. The temperature of the reformed gas initially supplied is 250 ° C, 300 ° C, 350 ° C, and 400 ° C.
When the temperature is set to ℃, the rise time of the device is 50
Minutes, 40 minutes, 30 minutes, and 20 minutes. Also, when the temperature of the reformed gas was set to 350 ° C. and the temperature was raised 50 times to examine the characteristics, the CO concentration did not become 2% or less even if the temperature conditions were changed.

(Comparative Example 4) A copper-zinc catalyst having a diameter of 6 mm was used in the reaction chamber 32 of the hydrogen purifier shown in FIG.
The reformed gas containing 8% of carbon monoxide, 8% of carbon dioxide, 20% of steam and the rest of hydrogen was cooled to 250 ° C. and introduced from the reformed gas inlet 33 at a flow rate of 10 liters / min. . At this time, the oxygen concentration from the air supply unit 37 is 2%
The air was supplied so that When the catalyst temperature increased to 200 ° C., the air supply was stopped and the reaction gas discharged from the reformed gas outlet 35 was measured. C at this time
It was 15 minutes when the time until the O concentration fell below 5000 ppm was measured. Subsequently, the same method was used to start up 50 times and the characteristics were examined. As a result, even if the temperature was changed, the CO concentration did not become 2% or less.

[0053]

As is apparent from the comparison of the evaluation results of the apparatus of the above-mentioned example and the comparative example, according to the present invention, the start-up time of the apparatus can be shortened, and the oxygen when the operation of the apparatus is stopped and the operation is repeated is repeated. It has been possible to provide a hydrogen purifier that suppresses the influence of contamination and operates stably over a long period of time.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a cross section of a hydrogen purifier according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the operating temperature of the shift conversion catalyst used in the hydrogen purifying apparatus according to the first embodiment of the present invention and the concentration of carbon monoxide after passing through the catalyst.

FIG. 3 is a configuration diagram showing a cross section of a hydrogen purifier according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram showing a cross section of a hydrogen purifier according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram showing a cross section of a hydrogen purifier which is a fourth embodiment of the present invention.

[Explanation of symbols]

1,11,31 catalyst 2,12,23,32 Reaction chamber 3,13,24,33 Reformed gas inlet 4,14,25,34 Catalyst support network 5,15,26,35 Reformed gas outlet 6,16,27,36 insulation 21 First catalyst body 22 Second catalyst body 37 Air supply unit

Front page continued (72) Inventor Takeshi Tomizawa 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Toshiyuki Shono 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72 ) Inventor Koichiro Kitagawa 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP 58-161901 (JP, A) JP 9-320624 (JP, A) JP 9-180749 (JP, A) JP-A-8-119602 (JP, A) JP-A-62-250095 (JP, A) JP-B-39-29435 (JP, B1) J. CATAL. , 1985, 96, pp. 285-287 Journal of Japan Petroleum Institute, 1977, 20, 2, pp. 109-114 (58) Fields investigated (Int. Cl. ⁷ , DB name) C01B 3/40 C01B 3/58

Claims (6)

(57) [Claims] 1. A CO conversion catalyst comprising: a reformed gas supply part containing hydrogen, carbon monoxide, and water; and a reaction chamber provided with a CO conversion catalyst body on the downstream side of the reformed gas supply part. The medium is selected from Pt, Ru, Rh, and Pd.
At least one selected from Ce and Ce, and at least selected from Ru, Pt, Pd, and Rh.
Is also equipped with a catalyst containing one precious metal element as the active ingredient.
A quality part connected to the upstream side of the reformed gas supply part, and at least selected from Ru, Pt, Pd, and Rh.
C, which is equipped with a catalyst containing one precious metal element as an active ingredient
The O purification section was connected to the downstream side of the CO shift catalyst body.
Hydrogen purifier characterized by. 2. A honeycomb structure or a honeycomb structure having communicating holes.
Supporting a CO conversion catalyst body on a carrier substrate having a foam structure
The hydrogen purifier according to claim 1, characterized in that. 3. The carrier substrate is a metal substrate.
The hydrogen purifier according to claim 2, which is used as a characteristic. 4. A reformed gas containing hydrogen, carbon monoxide, and water.
And a CO conversion catalyst on the downstream side of the reformed gas supply section.
A reaction chamber provided with a medium, and the CO shift catalyst body
Is at least selected from Pt, Ru, Rh, and Pd
A hydrogen refining device including a kind, An air supply unit is installed on the upstream side of the CO shift catalyst body.
A hydrogen purifier characterized by: 5. The flow rate of air supplied from the air supply unit is C
The hydrogen purifying apparatus according to claim 4, wherein the hydrogen purifying apparatus is controlled in association with the temperature of the O-shifting catalyst body. 6. The air flow rate increases as the temperature of the CO shifting catalyst body is reduced, the CO shifting catalyst body hydrogen purification device according to claim 5, wherein the temperature is and decreases with increase of.