JP3663653B2 - Hydrogen generator - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a hydrogen generator.
[0002]
[Prior art]
As this type of prior art, an apparatus using a steam reforming method and a partial oxidation reforming method is known.
[0003]
In the former steam reforming method, methanol and water are mixed in a reaction tube, and heat is applied to the reaction tube to cause both to react as shown in the following equation to obtain hydrogen.
[0004]
CH3 OH + H2 O → CO2 + 3H2
The advantage of the steam reforming method is that the hydrogen concentration in the resulting reformed gas is high. However, the disadvantage is that (1) water storage means and heating means are required, so the structure is complicated and compact. And (2) heat is necessary because of the endothermic reaction. For this reason, if you want to temporarily increase the mountability of the device (the device becomes larger), startability (it takes time until sufficient hydrogen is obtained from the start of startup), and responsiveness It takes a long time until the necessary amount is generated).
[0005]
In view of such problems, the latter partial oxidation reforming method has been proposed. As an apparatus using this method, an apparatus disclosed in Japanese Patent Application Laid-Open No. 62-59501 is known. In this method, a mixture of methanol and oxygen (air) is caused to flow through a supply pipe into a housing in which a catalyst is accommodated, whereby both are reacted as in the following formula to obtain hydrogen.
[0006]
CH3 OH + 1 / 2O2 → CO2 + 2H2
The advantages of the partial oxidation reforming method are: (1) the structure is simple and the apparatus can be miniaturized; and (2) the exothermic reaction eliminates the need for a heat source for causing the reaction. Can be mentioned. For this reason, the mountability (that is, downsizing), startability, and response of the apparatus can be improved.
[0007]
In addition, in the hydrogen generator disclosed in Japanese Patent Application Laid-Open No. 62-59501, water and carbon monoxide are mixed by mixing water into methanol in order to reduce carbon monoxide generated due to incomplete reaction. The method of reducing by making it react like following Formula is employ | adopted.
[0008]
H2 O + CO → CO2 + H2
[0009]
[Problems to be solved by the invention]
The reaction between water and carbon monoxide is promoted at a low temperature (about 150 ° C.). However, in the method of mixing water in methanol as described above, the hot spot region (methanol and oxygen are active). Since water reacts with carbonized carbon in a normal operation, the temperature is 300 ° C. to 400 ° C.), so the effect of reducing carbon monoxide is small.
[0010]
This invention makes it a technical subject to provide the hydrogen generator with the large reduction effect of carbon monoxide.
[0011]
[Means for Solving the Problems]
In order to solve the above technical problem, the technical means taken in the invention of claim 1 includes a housing in which the internal space is filled with a catalyst, a first supply pipe that is opened upstream in the internal space, and A blowout pipe for the reformed gas generated by reaction in the internal space to flow out of the internal space, a methanol supply means connected to the first supply pipe, and an oxygen supply means connected to the first supply pipe The provided hydrogen generator includes a second supply pipe that opens to the downstream side in the internal space, and water supply means that supplies water to the second supply pipe.
[0012]
In order to further improve the reduction effect of carbon monoxide, the technical means taken in the invention of claim 2 is arranged such that the opening of the second supply pipe is disposed at a position facing the opening of the first supply pipe. It is that.
[0013]
In order to maintain the reduction effect of carbon monoxide, the technical means taken in the invention of claim 3 is provided with a heat exchange means disposed downstream in the internal space to lower the temperature of the catalyst. .
[0014]
[Action]
In the first aspect of the invention, the methanol and oxygen supplied from the methanol supply means and the oxygen supply means to the first supply pipe are blown into the catalyst from the opening of the first supply pipe. The mixed fluid of methanol and oxygen reacts by contacting the catalyst in the hot spot region (near the opening of the first supply pipe). The reformed gas (mixed gas of carbon dioxide and hydrogen) generated by this reaction is sequentially blown out from the blowing pipe.
[0015]
On the other hand, carbon monoxide generated due to partial incomplete reaction reacts with water flowing into the internal space from the water supply means through the second supply pipe in the low temperature region (about 150 ° C.) on the downstream side, It becomes carbon dioxide and hydrogen and is blown out from the blow-out tube. Thereby, carbon monoxide is reduced.
[0016]
In the invention of claim 2, since the opening of the second supply pipe is disposed at a position opposite to the opening of the first supply pipe, the reformed gas generated by the reaction of methanol and oxygen is reduced. In the basin (the concentration of carbon monoxide is low), a high reaction probability is obtained with a high concentration of water, and the effect of reducing carbon monoxide can be further improved.
[0017]
In the invention of claim 3, the heat in the hot spot region is transferred to the catalyst on the downstream side of the internal space and the temperature of the catalyst on the downstream side of the internal space rises too much. The catalyst temperature on the downstream side of the internal space can be kept in a temperature range where water and carbon monoxide react actively, and the effect of reducing carbon monoxide is maintained. Can do.
[0018]
【Example】
Embodiments according to the present invention will be described with reference to the drawings.
[0019]
FIG. 1 is a configuration diagram of a hydrogen generator according to a first embodiment of the present invention. In the figure, the catalyst 11 is filled in the internal space 10 a of the housing 10. As the catalyst 11, a copper-based catalyst, a nickel-based catalyst, a noble metal-based catalyst, or the like is used.
[0020]
A first supply pipe 12 having an opening 12a opened in the internal space 10a of the housing is inserted into the upper surface of the housing 10 in the figure. The opening 12a of the first supply pipe 12 is located in the upper part (upstream side) of the internal space 10a in the figure.
[0021]
The first supply pipe 12 is connected to methanol supply means and oxygen supply means described later. The methanol supply means includes a methanol tank 20 for storing liquid methanol, a methanol pump 21 for sequentially supplying the methanol stored in the methanol tank 20 to the first supply pipe 12, and for vaporizing the liquid methanol. And the carburetor 22. The oxygen supply means includes an intake 30 for taking in oxygen (air), a filter 31 for removing oxygen dust sucked from the intake 30, and an air pump 32 for sequentially supplying oxygen to the first supply pipe 12. Has been.
[0022]
On the other hand, a blow-out pipe 14 is attached to the lower surface of the housing 10 in the figure to allow the reformed gas generated by reaction in the housing 10 to flow out. The reformed gas flowing through the blow-out pipe 14 is supplied to, for example, a fuel cell and used as a power generation source.
[0023]
A second supply pipe 15 connected to the water supply means is inserted into the blowing pipe 14. The opening 15 a of the second supply pipe 15 is disposed below the internal space 10 a and at a position facing the opening 12 a of the first supply pipe 12.
[0024]
The water supply means includes a water tank 40 for storing water, a water pump 41 for sequentially supplying water stored in the water tank 40 to the second supply pipe 15, and vaporization for vaporizing the water into steam. Unit 42.
[0025]
The operation control of the methanol pump 21, the air pump 32, and the water pump 41 is performed by a control device (not shown).
[0026]
The operation of the hydrogen generator of the first embodiment will be described.
[0027]
When the methanol pump 21, the air pump 32, and the water pump 41 are operated by the control device, a mixed fluid of methanol and oxygen is supplied from the first supply pipe 12 to the internal space 10 a and water vapor is supplied from the second supply pipe 15 to the inside. Supplied to the space.
[0028]
The mixed fluid supplied from the first supply pipe reacts by contacting the catalyst in the hot spot region HS to generate a reformed gas composed of hydrogen and carbon dioxide.
[0029]
At this time, carbon monoxide generated due to a partially incomplete reaction is steam (water) blown out upward in the figure from the second supply pipe 15 in the lower part (downstream) in the figure in the internal space 10a. Reacts to carbon dioxide and hydrogen.
[0030]
In the hydrogen generator of the first embodiment, since carbon monoxide and water are reacted in a low temperature region (about 150 ° C.) downstream of the internal space 10a, the reaction between water and carbon monoxide is accelerated. Therefore, the effect of reducing carbon monoxide is great.
[0031]
Further, in the hydrogen generator of the first embodiment, since the opening 15a of the second supply pipe 15 is disposed at a position facing the opening 12a of the first supply pipe 12, the reformed gas and the supply are supplied. The flow of the generated water vapor is opposed, and high density water vapor is hit in the region where the carbon monoxide concentration is low in the region downstream of the reformed gas, so that the effect of reducing carbon monoxide can be further improved.
[0032]
FIG. 2 is a configuration diagram of a housing and its surroundings of a hydrogen generator according to a second embodiment of the present invention. In the figure, only differences from the hydrogen generator of the first embodiment will be described.
[0033]
In FIG. 2, the methanol passage 12 b of the first supply pipe 12 is inserted from below in the figure of the housing 10, and has a fin shape to efficiently transfer the heat in the catalyst 11 to the first supply pipe 12. A plurality of heat exchange members (heat exchange means) 50 are provided. On the other hand, the oxygen passage 12c of the first supply pipe 12 is inserted into the internal space 10a from below the housing 10 and is spirally disposed along the inner peripheral surface of the internal space 10a. In the vicinity of the center of the internal space 10a, both the methanol passage 12b and the oxygen passage 12c are connected, and the opening 12a is opened upward in the drawing.
[0034]
Next, the operation of the hydrogen generator of the second embodiment will be described.
[0035]
Methanol and oxygen supplied from the methanol pump 21 and the oxygen pump 32 are mixed through the passages 12b and 12c and supplied to the internal space 10a from the opening 12a of the first supply pipe 12. The mixed fluid supplied from the first supply pipe 12 reacts by contacting the catalyst in the hot spot region HS to generate a reformed gas composed of hydrogen and carbon dioxide.
[0036]
In the second embodiment, the methanol passage 12b of the first supply pipe 12 disposed in the internal space 10a absorbs the heat of the catalyst 11 via the heat exchange member 50, and the oxygen passage 12c directly covers the catalyst 11. The heat absorption is performed and the heat of the catalyst 11 located on the downstream side is taken away. For this reason, heat in the hot spot region HS is transmitted to the catalyst 11 on the downstream side of the internal space 10a, and the temperature of the catalyst 11 on the downstream side of the internal space 10a rises too much. Since it can be prevented by taking the temperature of the catalyst 11 downstream of the space 10a, the catalyst temperature downstream of the internal space 10a can be kept in a temperature region where water and carbon monoxide react actively. The effect of reducing carbon monoxide can be maintained.
[0037]
【The invention's effect】
In the first aspect of the invention, water is supplied to the downstream side of the internal space of the housing, and the water and carbon monoxide are reacted in a low temperature region on the downstream side, so that the reaction between water and carbon monoxide is accelerated. Therefore, the effect of reducing carbon monoxide is great.
[0038]
In the invention of claim 2, since the opening of the second supply pipe is disposed at a position opposed to the opening of the first supply pipe, the reformed gas and the flow of the supplied water vapor face each other, High density water vapor hits in the region of low carbon monoxide concentration in the reformed gas downstream region, and the effect of reducing carbon monoxide can be further improved.
[0039]
In the invention of claim 3, the heat in the hot spot region is transferred to the catalyst on the downstream side of the internal space and the temperature of the catalyst on the downstream side of the internal space rises too much. The catalyst temperature on the downstream side of the internal space can be kept in a temperature range where water and carbon monoxide react actively, and the effect of reducing carbon monoxide is maintained. Can do.
[Brief description of the drawings]
FIG. 1 shows a configuration diagram of a hydrogen generator according to a first embodiment of the present invention.
FIG. 2 shows a configuration diagram of a housing of a hydrogen generator according to a second embodiment of the present invention and its surroundings.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Housing 10a ... Internal space 11 ... Catalyst 12 ... 1st supply pipe 14 ... Blow-out pipe 15 ... 2nd supply pipe 20 ... Methanol tank (methanol supply means)
21 ... Methanol pump (methanol supply means)
22 ... Vaporizer (oxygen supply means)
30 ... Suction port (oxygen supply means)
31 ... Filter (oxygen supply means)
32 ... Oxygen pump (oxygen supply means)
40 ... Water tank (water supply means)
41 ... Water pump (water supply means)
42 ... vaporizer 50 ... heat exchange member (heat exchange means)

Claims (3)

A housing filled with catalyst in the internal space;
A first supply pipe that opens to the upstream side in the internal space;
A blowout pipe for the reformed gas generated by reaction in the internal space to flow out of the internal space;
Methanol supply means connected to the first supply pipe;
In a hydrogen generator comprising an oxygen supply means connected to the first supply pipe,
A second supply pipe opened to the downstream side in the internal space;
A hydrogen generator comprising water supply means for supplying water to the second supply pipe. The hydrogen generator according to claim 1, wherein the opening of the second supply pipe is disposed at a position facing the opening of the first supply pipe. The hydrogen generator according to claim 1, further comprising a heat exchange unit that is disposed downstream of the internal space and reduces the temperature of the catalyst.

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