JP2001002401A - Carbon monoxide reducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently reduce carbon monoxide in a hydrogen enriched gas and to prevent the decrease of hydrogen content in the hydrogen enriched gas. SOLUTION: An air introducing stirrer 40 for introducing air as an oxygen- containing gas into the hydrogen enriched gas and stirring to mix the air with the hydrogen enriched gas and a polarizing plate 60 for stirring to mix air introduced from an air introducing pipe 56 with the hydrogen enriched gas are attached to the upstream side of the catalytic layers 32, 52. The stirring is performed by jetting the air from the blade of the air introducing stirrer 40 to energize turning force to stir in the air introducing stirrer 40 and giving force to polarize the flow of the hydrogen enriched gas to cause the action of whirling flow in the polarizing plate 60. Carbon monoxide contained in the hydrogen enriched gas is efficiently oxidized by oxygen on a catalyst and the oxidation of hydrogen by excess oxygen does not occur because the hydrogen enriched gas and the air are uniformly mixed by the air introducing stirrer 40 and the polarizing plate 60.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for reducing carbon monoxide, and more particularly to a device for reducing carbon monoxide in a hydrogen-rich gas.

[0002]

2. Description of the Related Art Heretofore, as this type of carbon monoxide reducing apparatus, there has been proposed an apparatus for reducing carbon monoxide in a hydrogen-rich reformed gas reformed by a steam reforming reaction of methanol ( For example, JP-A-10-302821 and the like. In this device, a reformed gas into which a predetermined ratio of air has been introduced is mixed by a mixing means and then supplied to a catalyst layer, and carbon monoxide in the reformed gas is oxidized with oxygen in the air to thereby form a gas in the reformed gas. Reduce carbon monoxide.

Further, as another carbon monoxide reducing device, a hydrogen-rich gas is allowed to flow linearly from vertically above to a catalyst layer filled with pellets or the like carrying a catalyst, and a flow path of cooling water is formed in the catalyst layer. The apparatus provided (for example, Japanese Patent Application Laid-Open No. 9-268001) or a catalyst layer filled with pellets and the like carrying a catalyst is divided into a plurality of layers, and a hydrogen-rich gas is caused to flow linearly and horizontally in each catalyst layer. A cooling device that supplies a cooling medium to each catalyst layer to cool it (for example, Japanese Patent Application Laid-Open No. 10-72202) has been proposed.

[0004]

However, in the apparatus described in Japanese Patent Application Laid-Open No. Hei 10-302821, it is difficult to sufficiently reduce the carbon monoxide in the reformed gas as a hydrogen-rich gas, or to reduce the hydrogen in the reformed gas. It may be done. According to the publication, the temperature of the reformed gas supplied to the carbon monoxide reduction device, that is, the temperature of the reformed gas from the reformer is 20
When the temperature is about 0 to 300 ° C. and the temperature of the air is room temperature, a difference occurs between the specific gravity of the reformed gas and the specific gravity of the air.
For this reason, simply mixing the reformed gas and air does not result in uniform mixing, and even if an appropriate amount of air is introduced with respect to the amount of carbon monoxide in the reformed gas, the reformed gas in the catalyst cannot be uniformly mixed. When a difference in velocity or density between carbon monoxide and oxygen occurs, carbon monoxide cannot be sufficiently reduced. If excess air is introduced with respect to the amount of carbon monoxide in the reformed gas, carbon monoxide in the reformed gas can be sufficiently reduced.However, excess oxygen causes combustion of hydrogen, and The hydrogen content is reduced.

In an apparatus such as the apparatus described in Japanese Patent Application Laid-Open No. 9-268001 or the apparatus described in Japanese Patent Application Laid-Open No. 10-72202, a device in which a hydrogen-rich gas flows linearly in one direction with respect to a catalyst layer is used. In some cases, carbon cannot be sufficiently reduced or the size of the apparatus increases. When the hydrogen-rich gas flows in a straight line through the catalyst layer, the turbulence of the flow of the hydrogen-rich gas is reduced, so the supply rates of carbon monoxide and oxygen in the hydrogen-rich gas to the catalyst are reduced, and the reduction rate of the carbon monoxide is reduced. Will decrease. In order to improve the reduction rate of carbon monoxide, the contact time between the catalyst and the gas may be increased. But,
If you try to increase the contact time without changing the gas flow rate,
The catalyst layer becomes long and the device becomes large. Also, if you try to increase the contact time without changing the length of the catalyst layer,
As the diameter increases, the size of the apparatus increases, and the flow velocity of the gas decreases, so that the turbulence of the gas flow further decreases and the desired reduction rate of carbon monoxide cannot be obtained.

Further, as in the apparatus described in Japanese Patent Application Laid-Open No. 9-268001 and the apparatus described in Japanese Patent Application Laid-Open No. 10-72202, a flow path for a cooling medium is provided in the catalyst layer, and the cooling medium is changed according to the temperature of the catalyst layer. In the flow-through device, the carbon monoxide reduction device may not be started quickly or the temperature of each part of the catalyst layer may not be adjusted to an appropriate temperature. When starting the carbon monoxide reduction device, it is necessary to quickly raise the temperature to the temperature at which the catalyst is activated. It takes time. Also, in order for the catalyst packed in the catalyst layer to function sufficiently, each part of the catalyst layer needs to be within the activation temperature range of the catalyst.However, depending on the shape and structure of the catalyst layer, temperature unevenness may occur in each part. In many cases, the catalyst will not function sufficiently.

The apparatus for reducing carbon monoxide of the present invention efficiently reduces carbon monoxide in a hydrogen-rich gas.
An object is to uniformly mix a hydrogen-rich gas and an oxygen-containing gas containing oxygen, and to adjust the temperature of each part of the catalyst layer to a temperature suitable for the catalyst. Another object of the present invention is to reduce the content of hydrogen in a hydrogen-rich gas. Further, another object of the present invention is to quickly start the apparatus for reducing carbon monoxide.

[0008]

Means for Solving the Problems and Actions and Effects The carbon monoxide reducing apparatus of the present invention employs the following means in order to achieve at least a part of the above object.

The first apparatus for reducing carbon monoxide of the present invention comprises a catalyst layer filled with a selective oxidation catalyst for oxidizing carbon monoxide in preference to hydrogen in the presence of oxygen. An oxygen introducing means for introducing an oxygen-containing gas containing oxygen into the hydrogen-rich gas, and the oxygen-containing gas and the hydrogen introduced by the oxygen introducing means. The gist is to provide a stirring means for stirring the rich gas.

In the first apparatus for reducing carbon monoxide of the present invention, since the oxygen-containing gas and the hydrogen-rich gas introduced by the oxygen introducing means are agitated by the agitating means, a more uniformly mixed gas is supplied to the catalyst layer. Can be supplied. As a result, the reduction rate of carbon monoxide can be improved, and a decrease in the hydrogen content due to oxidation of hydrogen in the hydrogen-rich gas by oxygen in the oxygen-containing gas can be prevented.

In the first apparatus for reducing carbon monoxide of the present invention, the stirring means may be a fan driven by the flow of the hydrogen-rich gas and / or the oxygen-containing gas. In this case, there is no need to provide an actuator such as a motor for driving the fan, and the apparatus can be simplified.

Further, in the first carbon monoxide reducing device of the present invention, the stirring means is formed integrally with the oxygen introduction means as a fan for obtaining a rotational force by ejecting the oxygen-containing gas from the blade. It can also be. In this case, the introduction of the oxygen-containing gas and the stirring of the oxygen-containing gas and the hydrogen-rich gas can be performed simultaneously and efficiently, and the apparatus can be simplified.

Further, in the first carbon monoxide reducing device according to the present invention, the stirring means may be a deflection plate for stirring by creating a turbulence in the flow of the hydrogen-rich gas. This makes it possible to stir the hydrogen-rich gas and the oxygen-containing gas with a simple configuration.

Further, in the first carbon monoxide reducing device of the present invention, the stirring means may be disposed downstream of the oxygen introducing means, or may be disposed upstream of the oxygen introducing means. It can also be.

Alternatively, in the first apparatus for reducing carbon monoxide according to the present invention, the catalyst layer may include at least two catalyst layers, ie, a first catalyst layer and a second catalyst layer.
And the oxygen introducing means is a former-stage introducing means for introducing the oxygen-containing gas upstream of the preceding stage of the catalyst layer and a latter-stage introducing the oxygen-containing means upstream of the latter stage of the catalytic layer. Introduction means, wherein the stirring means is a first-stage stirring means for stirring the oxygen-containing gas and the hydrogen-rich gas introduced by the first-stage introduction means, and the oxygen-containing gas and the hydrogen-rich gas introduced by the second-stage introduction means. And a subsequent-stage stirring means for stirring the mixture. This makes it possible to prevent combustion of hydrogen by oxygen contained in the oxygen-containing gas and to sufficiently reduce carbon monoxide in the hydrogen-rich gas. In the first apparatus for reducing carbon monoxide of the present invention according to this aspect, the pre-stage stirring means ejects the oxygen-containing gas from a fan or a blade driven by a flow of the hydrogen-rich gas and / or the oxygen-containing gas. It is a fan that obtains rotational force, and the post-stage stirring means can be a deflection plate that stirs by creating turbulence in the flow of the hydrogen-rich gas.

The second apparatus for reducing carbon monoxide of the present invention includes a catalyst layer filled with a selective oxidation catalyst that oxidizes carbon monoxide in preference to hydrogen in the presence of oxygen. A carbon monoxide reducing device for reducing carbon monoxide, comprising an oxygen introducing means for introducing an oxygen-containing gas containing oxygen into the hydrogen-rich gas, the catalyst layer,
The gist is that it is formed in a flow path that changes the flow direction of the hydrogen-rich gas into which the oxygen-containing gas has been introduced by the oxygen introduction means a plurality of times.

In the second apparatus for reducing carbon monoxide according to the second aspect of the present invention, the catalyst layer is formed in a flow path that changes the flow direction of the gas a plurality of times. The frequency of contact between the carbon oxide and oxygen with the catalyst can be increased. As a result, carbon monoxide in the hydrogen-rich gas can be efficiently reduced.

In the second apparatus for reducing carbon monoxide according to the second aspect of the present invention, the catalyst layer may be formed in a bypass channel, and a plurality of catalyst layers may be formed from the outer layer toward the center. A layer may be formed and the layer may be formed in a flow path from the outer layer to the center. Further, the catalyst layer may be formed in a spiral flow path.

A third carbon monoxide reducing device of the present invention is a carbon monoxide reducing device for reducing carbon monoxide in a hydrogen-rich gas, and oxidizes carbon monoxide in preference to hydrogen in the presence of oxygen. A catalyst layer filled with a selective oxidation catalyst to be heated, and a heat exchange channel capable of exchanging heat with the catalyst layer, and selectively using any one of a plurality of heat exchange media having different heat capacities to heat the catalyst layer. The gist of the present invention is to provide a heat exchange means for exchanging.

In the third apparatus for reducing carbon monoxide of the present invention, a plurality of heat exchange media having different heat capacities can be selectively used in accordance with the state of the catalyst layer to exchange heat with the catalyst layer.

In the third apparatus for reducing carbon monoxide of the present invention, a heat exchange medium having a small heat capacity is sealed in the heat exchange flow path at the time of starting, and a heat exchange medium having a large heat capacity is supplied at the time of steady operation. Heat exchange control means for controlling the heat exchange means so that the heat flows through the heat exchange means. In this case, at the time of startup, it is only necessary to raise the temperature of the heat exchange medium having a small heat capacity together with the catalyst layer, so that the temperature can be raised quickly. Further, since this heat exchange medium having a small heat capacity is sealed, in the heat exchange flow path located at the outer peripheral portion of the catalyst layer, this flow path functions as a heat insulating layer and can prevent diffusion of heat to the outside. .

In the third carbon monoxide reduction device of the present invention, the heat exchange means is disposed in an outer layer of the catalyst layer and is capable of exchanging heat with the catalyst layer.
An internal heat exchange channel disposed inside the catalyst layer and capable of exchanging heat with the catalyst layer, a heat exchange medium flowing through the outer layer heat exchange channel and a heat exchange medium flowing through the internal heat exchange channel, May be used independently to selectively exchange heat with the catalyst layer. With this configuration, the temperature of the catalyst in the outer layer portion and the temperature of the catalyst in the inner portion of the catalyst layer can be respectively adjusted to appropriate levels, so that the rate of reduction of carbon monoxide in the hydrogen-rich gas can be improved.

In the third apparatus for reducing carbon monoxide of the present invention including the above-described embodiments, the plurality of heat exchange media having different heat capacities may be air and water.
This makes it possible to easily and inexpensively obtain heat exchange media having different heat capacities.

[0024]

Next, embodiments of the present invention will be described with reference to examples. FIG. 1 is a configuration diagram schematically showing the configuration of a carbon monoxide reduction device 20 according to one embodiment of the present invention. The carbon monoxide reduction device 20 of the embodiment oxidizes carbon monoxide contained in a hydrogen-rich gas containing hydrogen, for example, a reformed gas obtained by steam reforming a hydrocarbon-based fuel in preference to hydrogen. This is a device for reducing carbon monoxide, and includes a front-stage reducing unit 30 arranged at the front stage of the housing 22 and a rear-stage reducing unit 50 arranged at the rear stage as shown in the figure.

The pre-stage reduction section 30 includes a plurality of catalyst layers 32 carrying a selective oxidation catalyst for oxidizing carbon monoxide in preference to hydrogen in the presence of oxygen, for example, a catalyst such as platinum or ruthenium.
A plurality of cooling water passages 34 for cooling the catalyst layer 32 which generates heat as the carbon monoxide is oxidized; an air introduction pipe 36 for introducing air as an oxygen-containing gas containing oxygen into the hydrogen-rich gas; A plurality of air introduction stirrers 40 attached to the air introduction pipe 36 for introducing air into the hydrogen-rich gas and agitating the hydrogen-rich gas and air to form a uniform mixed state are provided. The plurality of catalyst layers 32 and the plurality of cooling water passages 34 are alternately stacked as shown in the drawing, so that all the catalyst layers 32 are cooled substantially uniformly.

FIG. 2 is an enlarged plan view of the air introduction stirrer 40, and FIG. 3 is a sectional view thereof. Air introduction stirrer 40
As shown in FIG. 2, the external appearance is configured as a fan having two blades 42, and a plurality of air outlets 44 are formed on the surface of the blades 42. The air outlet 44 is provided with an angle so as to blow out the air vigorously in the direction indicated by the arrow in the drawing, and gives a rotational force in the opposite direction to the wing 42 by the reaction force when blowing the air. I have. As shown in FIG. 3, the air introduction stirrer 40 is rotatably supported via a bearing 46 on a distribution pipe 38 arranged on the rotation shaft and connected to the air introduction pipe 36. The distribution pipe 38 has a through hole 4 formed inside the blade 42.
It is connected to the air outlet 44 via 3, so that air from the air inlet pipe 36 can be supplied to the outlet 44. Therefore, the air introduction stirrer 40
Is a state in which the air supplied from the air introduction pipe 36 is introduced into the hydrogen-rich gas from the plurality of outlets 44 and the air and the hydrogen-rich gas are introduced into the hydrogen-rich gas by the rotational force obtained by blowing the air from the outlets 44. And stir so that A plate 48 that is pressed against the friction material 47 by a push rod 49 via a friction material 47 is attached around the rotation axis on the back surface of the air introduction stirrer 40. The rotation of the air introduction stirrer 40 can be stopped or the number of rotations can be adjusted by adjusting the pressing force on the stirrer.

As shown in FIG. 1, the downstream reduction section 50 also includes a catalyst layer 32 and a cooling water passage 34 provided in the upstream reduction section 30.
Similarly to the above, a plurality of catalyst layers 52 and a plurality of cooling water passages 54 are alternately stacked, and all the catalyst layers 52 are cooled substantially uniformly. An air introduction pipe 56 for introducing air into the hydrogen-rich gas is provided upstream of the catalyst layer 52 of the post-stage reduction unit 50, and a deflection is performed to stir the introduced air and the hydrogen-rich gas to form a uniform mixed state. Board 60
Are provided.

As shown, a plurality of holes 58 are provided on the upstream side of the air introduction pipe 56.
Therefore, air is ejected toward the upstream side of the hydrogen-rich gas.

FIGS. 4 (a) and 4 (b) show the appearance of the deflection plate 60 as viewed from the upstream side and the appearance as viewed from the side. As shown in the figure, the deflecting plate 60 is formed by forming a plurality of blades 62 opened in the same rotational direction on a plate material by pressing or the like, and the plurality of blades 62 form a vortex in the flow of the hydrogen-rich gas. In this manner, the air introduced from the air introduction pipe 56 and the hydrogen-rich gas are stirred to form a uniform mixed state.

The operation of the apparatus 20 for reducing carbon monoxide thus constructed will be briefly described. In the pre-stage reduction section 30 of the carbon monoxide reduction device 20, air is introduced from the air introduction stirrer 40 into the supplied hydrogen-rich gas.
At this time, the amount of air introduced is adjusted to an appropriate amount of oxygen for oxidizing the amount of carbon monoxide in the hydrogen-rich gas, or to an amount of air that provides a smaller amount of oxygen. This is because if excessive air is introduced to oxidize all of the carbon monoxide in the hydrogen-rich gas in the pre-stage reduction unit 30, the hydrogen in the hydrogen-rich gas is also oxidized. The air introduced by the air introduction stirrer 40 is stirred by the hydrogen-rich gas at the same time as the introduction to form a substantially uniform mixed state, and is supplied to the plurality of catalyst layers 32. Is oxidized in preference to hydrogen.

The hydrogen-rich gas supplied from the plurality of catalyst layers 32 to the post-stage reduction unit 50 already has a low concentration of carbon monoxide. An appropriate amount or a slight excess of air is introduced from the air introduction pipe 56 to the hydrogen-rich gas having a low carbon monoxide concentration through the hole 58. The flow of the hydrogen-rich gas into which the air is introduced is disturbed by the deflecting plate 60 so that the gas is swirled, and is stirred to be supplied to the catalyst layer 52 in a substantially uniform mixed state. In the catalyst layer 52, carbon monoxide in the hydrogen-rich gas is oxidized on the catalyst by oxygen in the air in preference to hydrogen. As a result, a hydrogen-rich gas having a very low concentration of carbon monoxide is obtained.

According to the carbon monoxide reducing device 20 of the embodiment described above, the hydrogen-rich gas and the air introduced into the hydrogen-rich gas can be uniformly mixed. As a result, inconveniences caused by the non-uniform mixing state, such as a decrease in the reduction rate of carbon monoxide, which can reduce only a small amount of carbon monoxide with respect to the supply amount of air, and a decrease in the reduction rate of this carbon monoxide. Inconveniences such as an increase in the size of the apparatus and a reduction in the hydrogen content of the hydrogen-rich gas due to oxidation of hydrogen by partially excessive oxygen can be prevented. In addition, in the pre-stage reducing section 30, an air introduction stirrer 40 of a type in which the blades 42 are rotated and agitated by using the force at the time of injecting air into the hydrogen-rich gas is used.
Is used, there is no need to attach an electric motor or the like for rotating the wings 42. In addition, since the post-stage reducing unit 50 uses the deflecting plate 60 that gives a swirling effect to the flow of the introduced air and the hydrogen-rich gas, it is not necessary to obtain the power required for stirring, and the configuration is simple. Can be stirred. Naturally, the carbon monoxide reducing device 20 of the embodiment
According to this, a two-stage configuration of the pre-stage reduction unit 30 and the post-stage reduction unit 50 is adopted, and an appropriate amount of air is introduced in two stages, so that oxidation of hydrogen in the hydrogen-rich gas is reduced as much as possible to reduce carbon monoxide. Can be reduced.

In the apparatus for reducing carbon monoxide 20 of the embodiment, air is introduced and agitated by the air introduction stirrer 40 in the pre-stage reduction unit 30, and air is introduced by the air introduction pipe 56 in the post-stage reduction unit 50, and the deflection plate 60 However, both the pre-stage reduction unit 30 and the post-stage reduction unit 50 may be configured to introduce air by the air introduction stirrer 40 and stir the air.
Alternatively, air may be introduced by 6 and agitated by the deflecting plate 60.

In the apparatus for reducing carbon monoxide 20 in the embodiment, the deflecting plate 60 is disposed downstream of the air introducing pipe 56 to stir the introduced air and the hydrogen-rich gas. It may be arranged in the vicinity of the upstream side of the introduction pipe 56 so that air is introduced and stirred in a place where the flow of the hydrogen-rich gas is disturbed.

In the carbon monoxide reducing apparatus 20 of the embodiment, the deflecting plate 60 for stirring the introduced air and the hydrogen-rich gas is used.
However, the fan 40B illustrated in FIG. 5 and the fan 40C illustrated in FIG. 6 may be provided in place of the deflection plate 60 to stir the introduced air and the hydrogen-rich gas. In this case, air may be blown out to the fan 40B or the fan 40C so as to give a rotational force to the fan 40B or the fan 40C by this force, or the fan may be formed by a flow of a mixture of hydrogen-rich gas and introduced air. The rotational force may be applied to the fan 40C or the fan 40C. Further, an air introduction pipe may be arranged downstream of the fan 40B or the fan 40C, and air may be introduced and stirred when the flow of the hydrogen-rich gas is disturbed. In this case, a rotational force may be applied to the fans 40B and 40C by the flow of the hydrogen-rich gas. Further, these deflection plates 60 are connected to the fan 40B and the fan 4B.
In each of the embodiments replacing with 0C, an electric motor may be attached to the fan 40B or the fan 40C, and the motor may be used to apply a rotational force.

Next, a description will be given of a carbon monoxide reduction system 110 according to a second embodiment of the present invention. FIG.
FIG. 3 is a configuration diagram schematically showing a configuration of a carbon monoxide reduction device system 110 according to a second embodiment. As shown in the figure, a carbon monoxide reducing apparatus system 110 according to a second embodiment includes a blower 112 for introducing air as an oxygen-containing gas containing oxygen into a supplied hydrogen-rich gas, and a blower 112 for introducing hydrogen-rich gas into which air has been introduced. A carbon monoxide reducing device 120 for reducing the carbon monoxide, a cooling system 140 for cooling the carbon monoxide reducing device 120, and an electronic control unit 170 for controlling the entire system.

The blower 112 is connected to the electronic control unit 170 by a signal line, and is driven and controlled by the electronic control unit 170. The amount of air introduced into the hydrogen-rich gas by the blower 112 is an amount that is an appropriate amount or a slightly excessive amount of oxygen for oxidizing carbon monoxide contained in the supplied hydrogen-rich gas.

The carbon monoxide reduction device 120 is a device for reducing carbon monoxide in a hydrogen-rich gas by oxidizing carbon monoxide in a hydrogen-rich gas in preference to hydrogen in the presence of oxygen. 8 and 9 illustrate cross sections of the carbon monoxide reduction device 120 along the flow of the hydrogen-rich gas, and FIG. 10 illustrates a cross section of the carbon monoxide reduction apparatus 120 for the flow of the hydrogen-rich gas. The cross section of FIG. 8 and the cross section of FIG.
Different degrees. As shown, as shown in FIG.
Is a three-layer catalyst inside and outside that carries a selective oxidation catalyst such as platinum or ruthenium that oxidizes carbon monoxide in hydrogen-rich gas in preference to hydrogen in the presence of oxygen in the presence of oxygen. (Hereinafter referred to as an outer catalyst layer, a middle catalyst layer, and an inner catalyst layer, respectively)
126, and a flow path (hereinafter, referred to as an outer flow path) 13 of the cooling medium disposed on the outer circumference of the three catalyst layers 122 to 126.
2 and a cooling medium flow path (hereinafter, referred to as a center flow path) 136 disposed on the center axis.

One end (the left end in FIGS. 8 and 9) of the outer catalyst layer 122 is connected to a hydrogen-rich gas supply port 121.
The other end (the right end in FIGS. 8 and 9) communicates with the middle catalyst layer 124. The other end of the middle catalyst layer 124, that is, the end that is not in communication with the outer catalyst layer 122 is connected to the inner catalyst layer 126.
The other end of the inner catalyst layer 126 (FIG. 8,
9 at the right end) communicates with the outlet 129 of the hydrogen-rich gas. Accordingly, the hydrogen-rich gas required at the supply port 121 flows from the left side to the right side in FIGS. 8 and 9 through the outer catalyst layer 122, and is turned 180 degrees at the right end to form the middle catalyst layer 1.
8 and 9 flows from right to left in FIGS. 8 and 9 again turns 180 degrees at the left end of the middle catalyst layer 124 and flows out from the outlet 129 through the inner catalyst layer 126. The reason why the hydrogen-rich gas is diverted over the three layers in this way is to increase the contact between the carbon monoxide and oxygen in the hydrogen-rich gas with the catalyst by disturbing the flow of the hydrogen-rich gas. This is because the contact time between the hydrogen-rich gas and the catalyst is extended without reducing the flow rate of the hydrogen-rich gas in each catalyst layer. In addition, the reason that the hydrogen-rich gas is caused to flow from the outer catalyst layer 122 to the inner catalyst layer 126 is that the oxidation reaction of carbon monoxide is often performed near the supply port of the hydrogen-rich gas having a high carbon monoxide concentration. This is because heat generated by this reaction is easily released.

The cooling system 140 includes the carbon monoxide reducing device 1
An outer peripheral system 150 for flowing a cooling medium through an outer peripheral passage 132
And a central system 160 through which a cooling medium flows through the central channel 136 of the carbon monoxide reduction device 120.

The outer peripheral system 150 includes a first supply pipe 153 connected to the supply port 133 of the outer peripheral flow path 132, and a first pump provided in the first supply pipe 153 for pumping water as one of the cooling media. 151, a three-way valve 152 also provided in the first supply pipe 153, and a branch pipe 154 connected to the first supply pipe 153 via the three-way valve 152 can supply air as one of the cooling media. A first discharge pipe 157 connected to the blower 155 and the outlet 134 of the outer peripheral flow path 132 and returning the cooling water to the water tank 142 via the heat exchanger 144
And a three-way valve 156 attached to the first discharge pipe 157
And the open pipe 1 opened to the atmosphere through the three-way valve 156.
58 and the outer peripheral flow path 1 of the carbon monoxide reduction device 120.
32 can be supplied with water or air as a cooling medium selectively to cool the carbon monoxide reduction device 120. That is, the first pump 151 is operated by operating the three-way valve 152 so that the branch pipe 154 does not communicate with the first supply pipe 153 and operating the three-way valve 156 so that the open pipe 158 does not communicate with the first discharge pipe 157. The water in the water tank 142 is pumped by the first pump 151 to
It flows through the supply pipe 153 and is supplied to the supply port 133 of the outer peripheral flow path 132, and is supplied to the outer catalyst layer 12 of the carbon monoxide reduction device 120.
2 is cooled by the outside air from the outlet 134 via the first discharge pipe 157 by the heat exchanger after the heat exchange with the water tank 1
It is returned to 42. On the other hand, the branch pipe 154 is connected to the first supply pipe 15.
3 and the three-way valve 156 so that the open pipe 158 communicates with the first discharge pipe 157.
By operating the blower 155, air is supplied to the supply port 1 of the outer peripheral flow path 132 through the first supply pipe 153.
33, and exchanges heat with the outer catalyst layer 122 of the carbon monoxide reduction device 120, and then through the outlet 134 to the first discharge pipe 1
It is opened to the atmosphere through 57 and the open pipe 158.

When the cooling medium of the outer peripheral system 150 is changed from water to air, the open pipe 158 is connected to the first discharge pipe 1.
The three-way valve 156 is operated so as not to be in communication with the outer tank 57 and the water in the outer peripheral flow path 132 and the pipe is returned to the water tank 142, and then the three-way valve 156 is operated to operate the open pipe 158 and the first discharge pipe 15.
7 is communicated. Further, in the outer peripheral system 150, the operation of the blower 155 is stopped in a state where the outer peripheral flow path 132 is filled with air, so that the outer peripheral flow path 132 can be a heat insulating layer using air as a heat insulating material. These operations will be described later.

The central system 160 has the same configuration as the outer system 150, and includes a second supply pipe 163 connected to the supply port 137 of the central flow path 136 and a second supply pipe provided in the second supply pipe 163. The pump 161 and the second supply pipe 163
, A blower 165 capable of supplying air to a branch pipe 164 connected to the second supply pipe 163 via the three-way valve 162, and an outlet 13 of the central flow path 136.
8, a second discharge pipe 167 for returning the cooling water to the water tank 142 via the heat exchanger 144, a three-way valve 166 attached to the second discharge pipe 167, and a three-way valve 1
An open pipe 168 that is opened to the atmosphere through the air 66, and selectively supplies water or air as a cooling medium to the central flow path 136 of the carbon monoxide reduction device 120 to cool the carbon monoxide reduction device 120. I can do it. Regarding the operation of each three-way valve and cooling by each cooling medium, the outer system 150
Since the operation is the same as that of the corresponding three-way valve, the description thereof is omitted. Also, in the central system 160, air is also supplied to the central channel 13.
It is also possible to stop the operation of the blower 165 when the condition of 6 is satisfied.

The electronic control unit 170 includes a CPU 172
And a RO that stores a processing program.
M 174 and RAM 176 for temporarily storing data
And an input / output port (not shown). The electronic control unit 170 includes an outer layer temperature sensor 178 attached to the outer catalyst layer 122 of the carbon monoxide reduction device 120.
From the temperature of the outer catalyst layer 122 to the inner catalyst layer 126
The temperature Ti and the like of the inner catalyst layer 126 from the inner layer temperature sensor 179 attached to the sensor are input via an input port. Further, the electronic control unit 170 outputs drive signals to the first pump 151 and the second pump 161, drive signals to the blowers 112, 155, 165, and the three-way valves 15.
2, 156, 162, 166 are output via output ports.

Next, the operation of the carbon monoxide reduction system 110 according to the second embodiment, particularly the operation at the time of starting, will be described. FIG. 11 shows the electronic control unit 1
30 is a flowchart illustrating an example of a start-time processing routine executed by a CPU 172 of FIG. This routine is executed when the carbon monoxide reduction device system 110 is started.

When the start-time processing routine is executed,
First, the CPU 172 of the electronic control unit 170 executes a process of draining the cooling water filled in the outer peripheral channel 132 and the central channel 136 (step S100). Specifically, the blower 155 is driven by operating the three-way valve 152 such that the branch pipe 154 and the first supply pipe 153 communicate with each other and the three-way valve 156 so that the open pipe 158 does not communicate with the first discharge pipe 157. To remove water from the outer peripheral flow path 132 so that the branch pipe 164 and the second supply pipe 163 communicate with each other.
Is operated and the three-way valve 166 is operated so that the open pipe 168 does not communicate with the second discharge pipe 167, and the blower 165 is driven to drain water from the central flow path 136. The reason why water is drained from the outer peripheral flow path 132 and the central flow path 136 and filled with air is that air has a smaller heat capacity than water.
That is, the heat capacity of the entire carbon monoxide reduction device 120 is reduced to quickly raise the temperature of the carbon monoxide reduction device 120. When the drainage processing of the outer peripheral channel 132 and the central channel 136 is completed, the operation of the blowers 155 and 165 is stopped (step S102). When the operation of the blowers 155 and 165 is stopped, the outer peripheral channel 132 functions as a heat insulating layer.

Subsequently, the temperature To of the outer catalyst layer 122 detected by the outer layer temperature sensor 178 and the inner layer temperature sensor 1
A process of reading the temperature Ti of the inner catalyst layer 126 detected by 79 is executed (step S104), and the read outer layer temperature To is compared with a threshold value Tr1 and the read inner layer temperature Ti is also compared with a threshold value Tr2 (step S104). S106, S110). In FIG. 11, step S110 is described after step S106 for convenience of displaying on paper, but both processes may be performed simultaneously in parallel or either may be performed first. Here, the threshold Tr
1 and the threshold Tr2 are determined by the outer catalyst layer 122 and the inner catalyst layer 12.
6 is set as an appropriate temperature in the steady operation state or a temperature slightly lower than this.
It is determined by an operation specification of 0 or the like. When the outer layer temperature To is greater than the threshold Tr1, the outer system 150
Is performed to switch the cooling of the central system 160 to the normal control when the inner layer temperature Ti is higher than the threshold Tr2 (step S112). Then, it is determined whether both the outer system 150 and the center system 160 have been switched to the normal cooling control (step S114), and if either or both are not switched, step S10 is performed.
Then, the process returns to the process of reading the outer layer temperature To and the inner layer temperature Ti, and ends this routine when both systems are switched to the normal cooling control.

The ordinary cooling control of the outer peripheral system 150 includes a control of cooling air having a small heat capacity as a cooling medium, a control of cooling water having a large heat capacity as a cooling medium, and a control of cooling air and water as a cooling medium. There is a control for cooling while switching the temperature, and any control can be performed based on the outer layer temperature To. Similarly, the normal cooling control of the central system 160 includes a control of cooling with air, a control of cooling with water, and a control of cooling while switching between air and water, and any control is performed based on the inner layer temperature Ti. Can do it. Moreover, since the outer system 150 and the center system 160 can be controlled independently, the number of combinations is nine. Which of these controls is to be used depends on the operating specifications of the carbon monoxide reduction device 120, the components of the supplied hydrogen-rich gas, and the like. While using a plurality of cooling media having different heat capacities as described above,
By providing a plurality of independent cooling systems, the temperature of each part of the carbon monoxide reduction device 120 can be adjusted to a more appropriate temperature.

According to the carbon monoxide reducing device system 110 of the second embodiment described above, the carbon monoxide reducing device 12
0, the flow of the hydrogen-rich gas can be disturbed to enhance the contact of the carbon monoxide and oxygen in the hydrogen-rich gas with the catalyst, and the flow rate of the hydrogen-rich gas in each catalyst layer can be reduced. The contact time between the hydrogen-rich gas and the catalyst can be lengthened without lowering. As a result, the reduction rate of carbon monoxide can be improved, and the entire device can be downsized. Further, by causing the hydrogen-rich gas to flow from the outer catalyst layer 122 to the inner catalyst layer 126, the heat generated due to the oxidation reaction of carbon monoxide that is frequently performed near the supply port of the hydrogen-rich gas having a high carbon monoxide concentration is reduced. Cooling properties can be improved. As a result, the carbon monoxide reduction device 120 can be maintained at a more appropriate temperature.

Further, according to the carbon monoxide reducing apparatus system 110 of the second embodiment, the temperature of the carbon monoxide reducing apparatus 120 can be made more appropriate by using a plurality of cooling media having different heat capacities. Further, by providing a plurality of cooling systems using a plurality of cooling media having different heat capacities, the temperature of each part of the carbon monoxide reduction device 120 can be adjusted to a more appropriate temperature. Further, when the system is started, air as a cooling medium having a small heat capacity is supplied to the outer peripheral passage 132 and the central passage 1 of the carbon monoxide reduction device 120.
By reducing the heat capacity of the carbon monoxide reducing device 120 by filling the carbon dioxide into the 36, the temperature of the carbon monoxide reducing device 120 can be quickly raised, and the system can be quickly brought into a steady state.

In the carbon monoxide reduction system 110 of the second embodiment, a hydrogen-rich gas flows from the outer periphery to the center using the columnar carbon monoxide reduction device 120, as shown in FIGS. 12 and 13. As shown in a modified example of the carbon monoxide reduction device 120B, the appearance is a prismatic shape,
The outer catalyst layer 122 is deflected inward in a layered manner.
B, the middle catalyst layer 124B and the inner catalyst layer 126B may be formed. FIG. 12 is a cross-sectional view showing an example of a cross section of the modified carbon monoxide reduction device 120B along the flow of the hydrogen-rich gas. FIG. 13 is a cross-sectional view of the modified carbon monoxide reduction device 120B with respect to the flow of the hydrogen-rich gas. It is sectional drawing which shows an example of a cross section.

Further, in the carbon monoxide reducing device system 110 of the second embodiment, the carbon monoxide reducing device 120 is configured so that the hydrogen-rich gas bypasses. However, the flow of the hydrogen-rich gas may be disturbed. As illustrated in the carbon monoxide reduction device 120C of the modification of FIG. 14, the catalyst layer 122C may be arranged in a spiral.

In the carbon monoxide reducing apparatus system 110 of the second embodiment, air and water are used as cooling media having different heat capacities, but other cooling media such as oil may be used. Alternatively, three or more cooling media may be used.

The carbon monoxide reduction system 110 of the second embodiment has two independent cooling systems, the outer system 150 and the center system 160. However, if a plurality of cooling media having different heat capacities are used, one system is used. The cooling system may include only the cooling system, or may include three or more independent or dependent cooling systems.

In the carbon monoxide reduction system 110 of the second embodiment, the outer peripheral passage 132 and the central
Although the drainage is performed from the beginning, the drainage may be performed at the time of stop.

The embodiments of the present invention have been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various embodiments may be made without departing from the gist of the present invention. Of course, it can be carried out.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing the configuration of a carbon monoxide reduction device 20 according to one embodiment of the present invention.

FIG. 2 is an enlarged plan view of the air introduction stirrer 40.

FIG. 3 is an enlarged cross-sectional view of the air introduction stirrer 40.

FIG. 4 is an explanatory view illustrating the appearance of the deflection plate 60 viewed from the upstream side and the appearance viewed from the side.

FIG. 5 is an explanatory view showing an example of a fan 40B as a stirring means of a modified example.

FIG. 6 is an explanatory view showing an example of a fan 40C as a stirring means of a modified example.

FIG. 7 is a carbon monoxide reduction system 1 according to a second embodiment.
It is a block diagram which shows the outline of a 10 structure.

FIG. 8 is a cross-sectional view illustrating a cross section along a flow of a hydrogen-rich gas of the carbon monoxide reduction device 120 of the second embodiment.

FIG. 9 is a cross-sectional view illustrating a cross section of the carbon monoxide reduction device 120 along the flow of the hydrogen-rich gas in the second embodiment, which is different from the cross section of FIG. 8 by an angle of 90 degrees.

FIG. 10 is a cross-sectional view illustrating a cross section of the carbon monoxide reduction device 120 according to the second embodiment with respect to the flow of a hydrogen-rich gas.

FIG. 11 is a flowchart illustrating an example of a startup processing routine executed by the electronic control unit 170 according to the second embodiment.

FIG. 12 is a cross-sectional view showing an example of a cross section of a carbon monoxide reduction device 120B according to a modification along a flow of a hydrogen-rich gas.

FIG. 13 is a cross-sectional view showing an example of a cross section of a carbon monoxide reduction device 120B according to a modified example with respect to the flow of a hydrogen-rich gas.

FIG. 14 is a configuration diagram schematically showing a configuration of a carbon monoxide reduction device 120C according to a modification.

[Explanation of symbols]

20 Carbon monoxide reduction device, 30 Pre-stage reduction unit, 32
Catalyst layer, 34 cooling water passage, 36 air introduction pipe, 38
Distribution pipe, 40 air introduction stirrer, 40B, 40C fan, 42 blades, 43 through hole, 44 air outlet, 46 bearing, 47 friction material, 48 plate, 49 push rod, 50 post-stage reduction unit, 52 catalyst layer, 54
Cooling water passage, 56 air introduction pipe, 58 hole, 60 deflection plate, 62 blades, 110 carbon monoxide reduction system,
112 blower, 120, 120B carbon monoxide reduction device, 121, 121B supply port, 122, 122B outer layer catalyst layer, 122C catalyst layer, 124, 124B middle layer catalyst layer, 126, 126B inner layer catalyst layer, 129, 129
B outlet, 132, 132B, 132C Outer channel, 1
33 supply port, 134 outlet, 136, 136B, 13
6C central channel, 137 supply port, 138 outlet, 14
0 cooling system, 142 water tank, 144 heat exchanger, 1
50 peripheral system, 151 first pump, 152, 15
6,162,166 Three-way valve, 153 First supply pipe, 1
54,164 Branch pipe, 155,165 Blower, 15
7 1st discharge pipe, 158, 168 open pipe, 160 central system, 161 second pump, 163 second supply pipe, 1
67 second discharge pipe, 170 electronic control unit, 172
CPU, 174 ROM, 176 RAM, 178 outer layer temperature sensor, 179 inner layer temperature sensor.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshitake Suzuki 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Masahiro Inoue 1 Toyota Town Toyota City, Aichi Prefecture Toyota Motor Corporation ( 72) Inventor Satoshi Aoyama 1 Toyota Town, Toyota City, Aichi Prefecture F-term in Toyota Motor Corporation (reference) 4G040 EA02 EA06 EB31 EB33 EB41 EB46 FA02 FB04 FC07 FE01

Claims (16)

[Claims] 1. A catalyst layer filled with a selective oxidation catalyst for oxidizing carbon monoxide in preference to hydrogen in the presence of oxygen,
A carbon monoxide reducing device for reducing carbon monoxide in a supplied hydrogen-rich gas, comprising: an oxygen introduction unit for introducing an oxygen-containing gas containing oxygen into the hydrogen-rich gas; An apparatus for reducing carbon monoxide, comprising: a stirring means for stirring an oxygen-containing gas and the hydrogen-rich gas. 2. The apparatus for reducing carbon monoxide according to claim 1, wherein said stirring means is a fan driven by a flow of said hydrogen-rich gas and / or said oxygen-containing gas. 3. The carbon monoxide reduction device according to claim 1, wherein said stirring means is integrally formed with said oxygen introducing means as a fan for obtaining a rotational force by ejecting said oxygen-containing gas from a blade. 4. The apparatus for reducing carbon monoxide as claimed in claim 1, wherein said stirring means is a deflection plate for stirring by creating turbulence in the flow of said hydrogen-rich gas. 5. The carbon monoxide reduction device according to claim 1, wherein said stirring means is disposed downstream of said oxygen introducing means. 6. The apparatus for reducing carbon monoxide according to claim 1, wherein said stirring means is disposed upstream of said oxygen introducing means. 7. The carbon monoxide reduction device according to claim 1, wherein the catalyst layer is divided into at least two stages, a former stage and a latter stage, and the oxygen introducing means includes a catalyst. A pre-introduction means for introducing the oxygen-containing gas upstream of a pre-stage of the layer, and a post-introduction means for introducing the oxygen-containing means upstream of a post-stage of the catalyst layer; A first stage stirring unit for stirring the oxygen-containing gas and the hydrogen-rich gas introduced by a second stage, and a second stage stirring unit for stirring the oxygen-containing gas and the hydrogen-rich gas introduced by the second stage introduction unit. Carbon reduction equipment. 8. The carbon monoxide reduction device according to claim 7, wherein the first-stage stirring unit is the fan according to claim 2 or 3, and the second-stage stirring unit is the deflection plate according to claim 4. A carbon monoxide reduction device. 9. A catalyst layer filled with a selective oxidation catalyst for oxidizing carbon monoxide in preference to hydrogen in the presence of oxygen,
A carbon monoxide reduction device for reducing carbon monoxide in a supplied hydrogen-rich gas, comprising: an oxygen introduction unit for introducing an oxygen-containing gas containing oxygen into the hydrogen-rich gas; A carbon monoxide reduction device formed in a flow path that changes the flow direction of a hydrogen-rich gas into which an oxygen-containing gas has been introduced by means a plurality of times. 10. The carbon monoxide reduction device according to claim 9, wherein the catalyst layer is formed in a bypass channel. 11. The carbon monoxide according to claim 9, wherein the catalyst layer is formed in a plurality of layers from an outer layer portion to a center portion, and the layers are formed in a flow path from the outer layer portion to the center portion. Reduction device. 12. The carbon monoxide reduction device according to claim 9, wherein the catalyst layer is formed in a spiral flow path. 13. A carbon monoxide reduction device for reducing carbon monoxide in a hydrogen-rich gas, comprising: a catalyst layer filled with a selective oxidation catalyst for oxidizing carbon monoxide in preference to hydrogen in the presence of oxygen; A carbon monoxide having a heat exchange channel capable of exchanging heat with the catalyst layer, and heat exchange means for exchanging heat with the catalyst layer by selectively using any one of a plurality of heat exchange media having different heat capacities. Reduction device. 14. A heat exchange means for controlling the heat exchange means so that a heat exchange medium having a small heat capacity is sealed in the heat exchange flow path at the time of starting, and a heat exchange medium having a large heat capacity flows through the heat exchange flow path during a normal operation. 14. The carbon monoxide reduction device according to claim 13, further comprising a control unit. 15. The heat exchange means is disposed in an outer layer of the catalyst layer and is capable of exchanging heat with the catalyst layer. An exchangeable internal heat exchange flow path, wherein the heat exchange medium flowing through the outer heat exchange flow path and the heat exchange medium flowing through the internal heat exchange flow path are selectively used independently and selectively. The carbon monoxide reduction device according to claim 13 or 14, which is a replacement means. 16. The apparatus for reducing carbon monoxide according to claim 13, wherein the plurality of heat exchange media having different heat capacities are air and water.