JP4727419B2 - Hydrogen generator using hydrocarbon, organic oxygen-containing compound as raw material, and discharge electrode used therefor - Google Patents

Description

  The present invention relates to a hydrogen generator.

Hydrogen is an important industrial gas and has been widely used for ammonia, methanol synthesis, hydrodesulfurization, hydrocracking, oil and fat hydrogenation, welding, semiconductor manufacturing, and the like. Recently, attention has been focused on new application fields such as reactants in fuel cells and fuels for automobiles, aircraft, power generation, kitchens, and the like.
As a method of generating hydrogen, a method of reacting alcohol or hydrocarbon with water vapor (steam reforming) is conventionally known. Steam reforming is also called steam reforming, and is specifically expressed by chemical reaction formulas such as (1) to (3).
CH ₃ OH + H ₂ O → 3H ₂ + CO ₂ (1)
C ₂ H ₅ OH + 3H ₂ O → 6H ₂ + 2CO ₂ (2)
CH ₄ + H ₂ O → 3H ₂ + CO (3)
This steam reforming has been conventionally performed under high temperature and high pressure conditions of about 1 to 50 atmospheres at 250 to 400 ° C. using a noble metal catalyst such as platinum with alumina as a carrier. However, this method requires an expensive catalyst, and since the reaction is carried out at a high temperature and a high pressure, it is necessary to use a robust reactor that can withstand the high temperature and pressure. In addition, various side reactions occur, and there are also problems that the reaction by-products are clogged and the catalyst is deteriorated.
Under such circumstances, it can be carried out at a lower temperature and atmospheric pressure than conventional methods, can be carried out without using an expensive catalyst, has a high conversion rate, and does not cause miscellaneous side reactions. A steam reforming method and apparatus have been developed and disclosed in Japanese Patent Laid-Open No. 2001-335302. This apparatus comprises a reactor, a pair of electrodes accommodated in the reactor, and a direct current power source for applying a voltage to the electrodes, and a gaseous chain hydrocarbon introduced into the reactor and water vapor. In this mixed gas, direct-current pulse discharge is performed to react chain hydrocarbons with water vapor to generate hydrogen.
Since the above apparatus can be implemented with a very low cost, small and portable reactor, it is expected to be mounted on, for example, an automobile and used to supply hydrogen to a fuel cell. For this purpose, it has been desired to further improve the efficiency of hydrogen generation.
On the other hand, the present applicant has proposed a new type of hydrogen generator in Japanese Patent Application No. 2002-227865. The invention according to this application includes a discharge electrode having a capillary for supplying a raw material containing one or more substances selected from hydrocarbons and organic oxygen-containing compounds and water, and performs pulse discharge with the discharge electrode, It is characterized in that hydrogen is generated by inducing a reaction of the raw material supplied by. That is, since the discharge electrode has a capillary for supplying the raw material, the raw material can be quickly supplied to the region where pulse discharge is performed according to the required amount, and as a result, hydrogen is efficiently produced. Can do. With respect to the present invention, it has been desired to generate discharge more stably and uniformly while having the various advantages described above.
Therefore, in view of the above-described conventional situation, the present invention provides a novel generation device that can generate pulse discharge stably and uniformly, and as a result, can generate hydrogen with higher efficiency, and a discharge electrode used in the device. For the purpose.

  In order to solve the above-mentioned problems, the present invention is such that a capillary for supplying a raw material containing one or more substances selected from hydrocarbons and organic oxygen-containing compounds and water is formed inside a pipe-shaped conductor. Provided is a hydrogen generation device that includes a discharge electrode, performs pulse discharge with the discharge electrode, and induces a reaction of a raw material supplied by the capillary to generate hydrogen.

FIG. 1 is a diagram showing a generation device in the embodiment (1).
FIG. 2 is a partially enlarged view of the discharge electrode in the embodiment (1).
FIG. 3 is a partially enlarged view of the discharge electrode in the embodiment (2).
FIG. 4 is a partially enlarged view of the discharge electrode in the embodiment (3).

The hydrogen generator of the present invention is a discharge electrode in which a capillary for supplying a raw material containing one or more substances selected from hydrocarbons and organic oxygen-containing compounds and water is formed inside a pipe-shaped conductor. The apparatus is characterized in that a pulse discharge is performed by the discharge electrode to induce a reaction of the raw material supplied by the capillary to generate hydrogen.
According to the above configuration, the raw material containing one or more substances selected from hydrocarbons and organic oxygen-containing compounds and water moves through the capillaries formed inside the pipe-shaped conductor and reacts by receiving pulse discharge. To produce the desired hydrogen. The generated hydrogen is usually discharged out of the system through a discharge port or the like. Here, the pipe-shaped conductor refers to a covering made of various metals, carbon, and the like, and includes a tube having a relatively high rigidity, a tube wound with a film, and the like. In addition, the side surface of the pipe is generally closed, but a partially open structure may be used as necessary. The capillary means a passage or gap formed along the inside of the pipe, and the raw material moves through the passage and gap to a region where pulse discharge is performed by means of a suction force by a capillary phenomenon or a pump. To do. And since the outer periphery is hold | maintained with a pipe-shaped conductor, the discharge electrode is maintained in shape and stable discharge is obtained. Further, the raw material is supplied to a region where pulse discharge is reliably and efficiently performed without leaking from the side surface of the discharge electrode. In addition, the hydrocarbon here includes an aliphatic hydrocarbon and an aromatic hydrocarbon. Furthermore, the organic oxygen-containing compound means an organic compound containing an oxygen atom in the molecule, and includes alcohol, ether, aldehyde, ketone, ester and the like.
According to the present invention, a capillary for supplying a raw material containing one or more substances selected from organic oxygen-containing compounds includes a discharge electrode formed inside a pipe-shaped conductor, and pulse discharge is performed by the discharge electrode. And a hydrogen generating device that generates hydrogen by inducing a reaction of the raw material supplied by the capillary.
According to the above configuration, the organic oxygenated compound that has moved through the capillary tube undergoes a pulse discharge, thereby causing a decomposition reaction mainly to generate hydrogen.
Further, the present invention is characterized in that in the above hydrogen generator, a plurality of conductive fibers are provided in a bundle in a pipe-shaped conductor, and a capillary is formed between the conductive fibers. And
According to the said structure, the bundle | flux of electroconductive fiber functions as a discharge electrode in the case of pulse discharge with the pipe-shaped conductor of the outer side. Moreover, a raw material moves through the space | gap (capillary) between a conductive fiber and another conductive fiber. As the conductive fibers, metal fibers such as stainless steel are used, and those having corrosion resistance are preferable.
The present invention is also characterized in that, in the hydrogen generator, the conductive fiber is a carbon fiber.
According to the above configuration, carbon fiber is particularly selected as the conductive fiber. Since carbon fiber is a good conductor and has corrosion resistance, it is suitable for the reaction system of the present invention. The carbon fiber referred to here includes any of PAN-based, rayon-based, and pitch-based, and further, a so-called graphite fiber obtained by treating the carbon fiber at a high temperature (1500 to 3000 ° C.) or activation treatment was performed. It is a concept that includes activated carbon fibers.
Further, the present invention is characterized in that in the above hydrogen generator, a dielectric is provided between the discharge electrodes where pulse discharge is performed.
According to the above configuration, since pulse discharge is performed through the dielectric, a so-called silent discharge generates uniform and stable pulse discharge in the plane provided with the dielectric.
Further, the present invention is characterized in that, in the above hydrogen generator, the dielectric is a ring-shaped dielectric provided along an end surface of the pipe-shaped conductor.
According to the above configuration, a uniform and stable pulse discharge is generated over the entire end face of the pipe-shaped conductor, and the raw material is efficiently supplied to the discharge region.
Further, the present invention provides the above hydrogen generator, wherein the dielectric is SiO. ₂ , CeO ₂ , LaO ₃ , Sm ₂ O ₃ , SiN, BN, and diamond.
According to the said structure, the specific substance which comprises a dielectric material is specified.
Furthermore, the present invention is characterized in that the hydrogen generation apparatus described above further comprises a reactor that houses a discharge electrode, and a power source that applies a voltage to the discharge electrode.
According to the above configuration, pulse discharge is generated by applying a voltage using a power source, and hydrogen is generated in the reactor.
Furthermore, this invention provides the various discharge electrodes used for the various production | generation apparatuses which have the above characteristics.
Hereinafter, the present invention will be described in detail based on embodiments.
First, an embodiment (1) of the present invention is shown in FIGS. 1 includes a reactor 10, and a pair of discharge electrodes 11 and 12 are provided in the reactor 10 so as to face each other. Between the discharge electrode 11 and the discharge electrode 12 is a discharge region 13 where pulse discharge is performed. The distance between the discharge electrode 11 and the discharge electrode 12 can be arbitrarily adjusted.
One discharge electrode 11 is schematically configured by forming a capillary for supplying the raw material A inside a pipe-shaped conductor. Here, the capillary means a passage or a gap formed along the inside of the pipe, and the raw material A can move in the capillary. The shape of the capillary can be appropriately set to a shape such as a tubular shape or a mesh shape.
A specific example of the capillary is shown in FIG. In FIG. 2, the discharge electrode 11 is configured by providing a plurality of good conductors such as carbon fibers 112 in an inside 111 of a pipe-shaped conductor 110. And between each carbon fiber 112 is functioning as the capillary 113 through which the raw material A passes.
As the pipe-shaped conductor 110, any material having high conductivity can be selected and used as appropriate. Moreover, it is preferable to have corrosion resistance with respect to water. Specific examples of the material include metal materials such as SUS, nickel, copper, aluminum, and iron, and materials such as carbon. Among them, SUS, carbon, and the like are more preferable because they hardly corrode. Note that the shape of the pipe-shaped conductor 110 is not limited to the cylindrical shape as shown in FIG. 2, and can be various shapes such as a quadrangular prism shape and a polygonal prism shape. The thickness of the pipe-shaped conductor 110 (difference between the outer diameter and the inner diameter) can be set as appropriate.
As shown in FIG. 2, the bundle of carbon fibers 112 is provided at a position slightly retracted into the pipe-shaped conductor 110 or is aligned with the position of the end surface 114 of the pipe-shaped conductor 110. Is preferred.
Further, in FIG. 2, for convenience, the carbon fibers 112 are schematically shown as having a certain thickness and a bundle of about several tens, but generally the thickness of the carbon fibers 112 is on the order of micrometers ( Specifically, the number is about 1 μm to 1 mm, and the number is also large (for example, tens of thousands or more) according to the thickness of the discharge electrode 11. However, depending on the scale of the production apparatus 1 and the type of the raw material A, it is possible to use a thicker and smaller number of carbon fibers, which is not limited to the above numerical range.
As the carbon fiber 112, conventionally known various carbon fibers can be used. Specific examples include carbon fibers made from polyacrylonitrile (PAN), pitch-based carbon fibers made from petroleum, petroleum tar, liquefied coal, etc., and rayon-based carbon fibers. For example, the PAN-based carbon fiber can be obtained by heat-treating a special acrylic fiber (precursor) in air and firing the obtained flame-resistant fiber at 1000 to 1800 ° C. in an inert gas. Further, graphite fibers obtained by firing this carbon fiber at a higher temperature of 2000 to 3000 ° C., activated carbon fibers activated in an activation gas (mixed gas such as water vapor, carbon dioxide gas, nitrogen gas) can be applied. is there. Since carbon fiber is chemically stable, there is an advantage that it is not corroded by water or the like used in the present invention.
Further, the end face 115 of the carbon fiber 112 is preferably formed in an edge shape. In this way, when pulse discharge is performed, current is concentrated at the tip of the edge, so that discharge is likely to occur, and as a result, hydrogen generation efficiency is improved. In addition, when the carbon fiber 112 is sufficiently thin (on the order of micrometers), the end face 115 itself becomes an edge shape without being processed. Further, when the carbon fiber 112 has a thickness of about millimeters, it may be appropriately processed by means such as cutting and cutting so that the end face 115 has an edge shape.
As the other discharge electrode 12, a general one such as a cylindrical electrode rod can be used. As the material of the discharge electrode 12, general materials such as SUS, nickel, copper, aluminum, iron, and carbon can be used. Among them, materials that are difficult to corrode such as SUS and carbon are more preferable. Further, the shape of the discharge electrode 12 is not limited to the above-described columnar shape, and may be various shapes such as a needle shape and a flat plate shape. Also, in the same manner as the discharge electrode 11 described above, You may comprise from the shape-like conductor 110, carbon fiber 112 grade | etc.,. The end face of the discharge electrode 12 facing the discharge region 13 is preferably parallel to the end faces 114 and 115 of one discharge electrode 11.
In FIG. 1, a reactor 10 is made of quartz, other glass, ceramic, synthetic resin, or the like. A direct current power source 14 for applying a negative high voltage is connected to the discharge electrode 11 extending outside the reactor 10, and a digital oscilloscope 15 is connected between the direct current power source 14 and the discharge electrode 11. On the other hand, a three-way port 16 is connected to the reactor 10, and a discharge electrode 12 extending outward from the reactor 10 passes through one of the three-way ports 16 and is grounded. The other port of the three-way port 16 is a discharge port 17 for discharging hydrogen H2 generated by pulse discharge. Further, the discharge electrode 11 is connected to an introduction path 18 for introducing the raw material A into the capillary 113 of the discharge electrode 11.
When using the above production | generation apparatus 1, it is performed as follows roughly. First, a raw material A containing one or more substances selected from hydrocarbons and organic oxygen-containing compounds and water is supplied into the discharge electrode 11 through the introduction path 18. The supplied raw material A moves through the capillary 113 formed in the inside 111 of the discharge electrode 11, and finally leaches out from the end face 115 of the discharge electrode 11, for example, to discharge the region 13 ( Or its vicinity).
Subsequently, when a negative voltage is applied to the discharge electrode 11 by the DC power supply 14, between the discharge electrodes 11 and 12, that is, between the pipe-shaped conductor 110 and the discharge electrode 12, or between the carbon fiber 112 and the discharge electrode 12. A pulse discharge occurs between them to induce a reaction, and hydrogen H ₂ Produces. Generated hydrogen H ₂ Is discharged from the outlet 17 for various uses. The raw material A that moves through the capillary 111 and reacts by pulse discharge may be in a liquid state or in a gaseous state. When the raw material A is a liquid, the raw material A is vaporized by slight Joule heat generated by pulse discharge, and the vaporized raw material A may react.
Further, at this time, since the outer periphery of the discharge electrode 11 is held by the pipe-shaped conductor 110, the form of the discharge electrode 11 as a whole is maintained, and stable discharge can be obtained. Further, if the tips of the carbon fibers 112 are microscopically irregular, if there is no pipe-shaped conductor 110, there is a possibility that discharge occurs locally and the hydrogen generation efficiency decreases, By providing the conductor 110, a uniform pulse discharge can be generated mainly in the end face 114 of the pipe-shaped conductor 110, and as a result, the reaction can proceed efficiently. Furthermore, the raw material A can be reliably and efficiently supplied to the discharge region 13 without leaking from the side surface of the discharge electrode 11.
As means for moving the raw material A through the capillary tube 113, various physical phenomena can be used, or forced delivery means can be used, and it is not particularly limited. Specifically, as a suitable example, by appropriately setting the inner diameter of the capillary 113, the raw material A can be naturally sucked in the direction of the discharge region 13 by utilizing the capillary phenomenon. When the sucked raw material A is lost due to the reaction, new raw material A is sucked to make up for it. Thereby, since the raw material A can be naturally supplied to the discharge area | region 13 without using sending means, such as a pump, for example, it is preferable from a viewpoint of production | generation efficiency. The appropriate value of the inner diameter of the capillary tube 113 can be obtained by comprehensively considering the length of the capillary tube 113, the density of the raw material A, the surface tension of the raw material A, the contact angle of the raw material A with respect to the discharge electrode surface, and the like. For example, in the case of 100,000 bundles of carbon fibers having a diameter of 7 μm (the inner diameter of the formed capillary is several μm), it is possible to suck about 30 ml of raw material having a volume equivalent ratio of ethanol and water per minute. I know that.
In addition, the material A can be forcibly supplied into the capillary 113 by, for example, connecting a normal pump or the like to the introduction path 18 regardless of the method using the capillary phenomenon. Moreover, you may combine suitably the method using a pump etc. and the above-mentioned capillary phenomenon.
Furthermore, the raw material A can be moved along with the pulse discharge. That is, the raw material A is ionized by a high voltage at the time of pulse discharge. By using this, the ionized raw material A is subjected to a phenomenon such as electrophoresis in the direction of the other discharge electrode 12 every time the pulse discharge occurs. It can be moved using. Also in this case, similarly to the above-described capillary phenomenon, since no delivery means such as a pump is required, hydrogen can be generated efficiently and at low cost. Moreover, since the supply of the raw material A is performed corresponding to the voltage at the time of pulse discharge, the responsiveness of hydrogen generation is improved.
Next, the raw material A will be described. First, the hydrocarbon to be reacted is not particularly limited, and can be appropriately selected from various hydrocarbons. Examples include aliphatic hydrocarbons such as linear, branched, or cyclic alkanes, alkenes, alkynes, various aromatic hydrocarbons, or a mixture of two or more thereof. Natural gas, petroleum naphtha, gasoline, kerosene, etc., and mixtures thereof can be used as they are. Moreover, the hydrocarbon obtained from biomass is also applicable. Examples of this include methane obtained by fermentation or thermal decomposition of waste, garbage, manure, grass / pruned branches, woody biomass, etc. discharged from food factories.
The organic oxygen-containing compound is an organic compound containing an oxygen atom in the molecule, and can be appropriately selected from various substances in the same manner as the hydrocarbon. Examples include alcohols such as methanol, ethanol, propanol and butanol, ethers such as dimethyl ether, diethyl ether, methyl ethyl ether and methyl tertiary butyl ether, aldehydes such as acetaldehyde and formaldehyde, ketones such as acetone and methyl ethyl ketone, ethyl acetate and ethyl formate. And esters such as dimethyl carbonate, or a mixture of two or more thereof. The organic oxygen-containing compound may be derived from biomass. Examples include alcohol produced by hydrolyzing cellulose such as weeds to glucose using microorganisms / enzymes. In the present invention, the above-mentioned hydrocarbon and an organic oxygen-containing compound can be used in combination as appropriate.
The water is H ₂ It means a liquid containing excessive O or water vapor, and can be applied to general water. In addition, distilled water, ion-exchanged water, and so-called “hot water” are naturally included in the concept of water of the present invention.
The apparatus of the present invention is characterized in that a pulse discharge is performed after supplying a raw material A containing one or more substances selected from the hydrocarbons and organic oxygen-containing compounds and water to the discharge region 13 or the vicinity thereof. To do. Here, the pulse discharge is a flow of a pulse current between the discharge electrodes. For example, since the electron irradiation is repeated within a minute time of 1 μs or less, the gas phase temperature does not rise and the reaction is performed at a very low temperature. Can do. The pulse discharge is usually performed at regular intervals, but may be intermittent.
For example, when a mixed gas of methane and water vapor is used as the raw material A by pulse discharge, the reaction proceeds as shown in the following formula (4) to generate target hydrogen. Further, when a mixed liquid of ethanol and water is used as the raw material A, it proceeds as shown in the following formula (5) to generate hydrogen. At that time, no by-product such as acetylene is produced.
CH ₄ + H ₂ O → 3H ₂ + CO (4)
C ₂ H ₅ OH + H ₂ O → 4H ₂ + 2CO (5)
In the present invention, an organic oxygen-containing compound can be used alone as the raw material A. That is, an organic oxygen-containing compound such as an alcohol typified by methanol or ethanol is not necessarily used in combination with water, and can be used alone. In that case, for example, as shown in (Chemical Formula 6), a decomposition reaction of the organic oxygen-containing compound itself occurs to generate hydrogen.
CH ₃ OH → 2H ₂ + CO (6)
It is considered that the above various reactions generate radicals when a discharge current, that is, an electron beam is irradiated from the discharge electrode, and these radicals cause reactions. Therefore, as the discharge current is increased and the distance between the discharge electrodes is increased, the number of molecules colliding with the electron beam is increased, so that the reaction rate is increased and the conversion rate within a unit time is increased. Tend.
In performing the discharge, a pulse power source can be used. However, a direct current self-excited pulse discharge in which a constant voltage is applied between the discharge electrodes and the self-excited pulse discharge is performed is preferably employed. In this case, the number of pulse discharges per second (hereinafter sometimes referred to as “pulse generation frequency”) is suitably about 5 to 1000 times, and particularly preferably about 50 to 100 times. The pulse generation frequency increases as the current increases under a constant voltage, and decreases as the distance between the discharge electrodes increases. Therefore, preferable voltage, current, and discharge electrode distance are set by adjusting the voltage, current, and discharge electrode distance so that the above-described pulse generation frequency is achieved. For example, when a small reactor having an inner diameter of about 5 mm is used, it is preferable that the applied voltage is about 1 kV to 10 kV, the current is about 1 to 20 mA, and the distance between the discharge electrodes is about 2 mm to 10 mm. Of course, the applied voltage, current, and discharge electrode distance are not limited to the above ranges, and when using a large reactor having a higher production capacity, the discharge electrode distance is increased to generate the pulse. In order to achieve the frequency, the applied voltage and current can be increased accordingly.
The raw material A to be reacted may be in a liquid or gas state. In particular, when reacting the raw material A in a gaseous state, the reaction temperature is not particularly limited, but it is preferable to perform the reaction at as low a temperature as possible because energy costs are low. For example, when methanol, ethanol, propanol or the like and water vapor are used as raw materials, the reaction temperature is preferably about 80 ° C. to 150 ° C. (under normal pressure conditions). Here, the reason why the low temperature side of the above range is lower than 100 ° C. is that alcohol and water may be vaporized by an azeotropic phenomenon. Since water vapor tends to be concentrated, when the boiling point of the hydrocarbon or organic oxygen-containing compound is lower than that of water, the raw material A is preheated at a temperature higher than the reaction temperature in advance, and then the reaction zone 13 It is preferable to supply to.
The total pressure in the reactor 10 when supplying the raw material A in a gaseous state is not particularly limited, and can be performed, for example, at about 0.1 to 10 atm. However, since the reaction proceeds sufficiently at normal pressure and a robust reaction apparatus is not required at that time, it can be said that it is particularly preferable in the industry to carry out at normal pressure. The mixing ratio of the hydrocarbon or organic oxygen-containing compound and water may be a stoichiometric amount, but if desired, one substance is increased or decreased to about 1/2 to 2 times the stoichiometric amount or more. It is also possible.
When the raw material A is configured so as to be continuously supplied into the reactor 10, it is efficient and industrially excellent. In the case of continuous operation, the feed rate of the raw material A is hydrogen H discharged from the discharge port 17. ₂ Is preferably set to a value such that the conversion rate of the raw material A is a certain value or more, for example, 60% or more. For example, when using a reactor having an inner diameter of 5 mm, a distance between the discharge electrodes is set to about 1 mm to 10 mm, an applied voltage is set to about 1 to 5 kV, and a mixed gas containing alcohol and water vapor is used as the raw material A, About 10 to 1000 ml / min, especially 50 to 100 ml / min is suitable. In addition, it is also possible to carry out by a batch type instead of the continuous type as shown in FIG.
Furthermore, in the generating apparatus 1 of FIG. 1, the DC power source 14 is used as the power source connected to the discharge electrode 11, but any other power source capable of pulse discharge is applicable. For example, the AC power source In addition, a power source in which a diode bridge circuit, a load, and the like are appropriately combined, or a power source in which a direct current voltage is superimposed on the power source can be appropriately employed. Further, the voltage applied to the discharge electrode is preferably unipolar as described above, but is not limited thereto, and an alternating voltage can be applied.
Moreover, the discharge electrodes accommodated in the reactor 10 are not limited to a pair, and a plurality of discharge electrodes may be used as necessary.
Furthermore, the production | generation apparatus 1 of this invention produces | generates by-product carbon monoxide with the target hydrogen. Therefore, it is possible to finally produce hydrogen gas and carbon dioxide by separately reacting the produced hydrogen and carbon monoxide with water vapor. This reaction is known as the water gas shift reaction. The water gas shift reaction itself is well known in this field and has the advantage of proceeding at a low temperature and normal pressure. When this water gas shift reaction is incorporated in the production apparatus 1 of the present invention, for example, a catalyst for a water gas shift reaction such as a zinc oxide copper monoxide-based solid catalyst is charged on the outlet 17 side of the reactor 10 in FIG. By doing so, the carbon monoxide produced | generated by pulse discharge is further made to react with water vapor | steam, and it can be set as hydrogen and a carbon dioxide, and, thereby, the production efficiency of hydrogen can be improved significantly.
Then, the catalyst 20 can be attached to the discharge electrode 11 as shown in FIG. The catalyst 20 is applicable as long as it can improve the efficiency of the hydrogen generation reaction by pulse discharge or reduce the by-products such as C2 compounds. Examples include palladium or platinum catalysts using alumina as a support, nickel catalysts, Lindlar catalysts, and the like. These catalysts can particularly suppress the production of C2 compounds such as acetylene. In addition, the catalyst 20 is activated by receiving pulse discharge, and it has been found that the catalytic ability is higher than usual.
In particular, it was found that when the catalyst 20 in the reaction system of the present invention is ruthenium, a multi-component catalyst of ruthenium and another catalyst, fullerene, or fullerene carrying ruthenium, the hydrogen generation efficiency is maximized. As the fullerene, various conventionally known fullerenes can be applied. ₆₀ , C ₇₀ , C ₇₆ , C ₈₀ , C ₈₂ , C ₈₄ , C ₈₆ , C ₈₈ , C ₉₀ , C ₉₂ , C ₉₄ , C ₉₆ , C ₁₂₀ , C ₂₄₀ , C ₅₆₀ Or a mixture thereof. Among them, C ₂₄₀ Is known to have the highest effect. This is C ₂₄₀ This is thought to be due to the high hydrogen storage capacity. C ₆₀ C containing ₂₄₀ (Hereinafter C ₆₀ @C ₂₄₀ ), C ₂₄₀ @C ₅₆₀ , C ₈₀ @C ₂₄₀ @C ₅₆₀ A fullerene having a shell having a plurality of layers is also preferably used. The method of supporting ruthenium on fullerene is not particularly limited. For example, ruthenium is supported by plating, vapor deposition, sputtering, etc. on fullerene, or when ruthenium is prepared by laser evaporation. A method of evaporating and supporting at the same time can be appropriately employed. Note that ruthenium supported on fullerene is very fine particles and is in an activated state. The reason why the ruthenium particles become fine is not clear, but it is considered that the contact between the ruthenium particles and the grain growth are inhibited by the fullerene.
As a method for attaching the catalyst 20 to the discharge electrode 11, a method such as vapor deposition, sputtering, or plating of the catalyst 20 on the surface of the carbon fiber 112 or the like of the discharge electrode 11 can be appropriately employed. Alternatively, the discharge electrode 11 may be manufactured by attaching the catalyst 20 to the surface of the carbon fiber 112 before being bundled in advance by vapor deposition or the like, and then bundling them to be provided inside the pipe-shaped conductor 110.
However, since the apparatus according to the present invention can generate hydrogen without using a catalyst, it may be carried out without using any catalyst. The production apparatus of the present invention is characterized in that it can be carried out at a much lower temperature and lower pressure and is lower in cost than the conventional method of reforming at a high temperature and high pressure using a catalyst.
Next, an embodiment (2) of the present invention will be described.
FIG. 3 is a partially enlarged view of the discharge electrode 11. This embodiment (2) is characterized in that a dielectric is provided between the discharge electrodes where pulse discharge is performed. Specifically, a ring-shaped dielectric 23 is provided along the end surface 114 of the pipe-shaped conductor 110. In this way, a uniform pulse discharge can be generated over the entire end face 230 of the ring-shaped dielectric 23 by the action of so-called silent discharge. Therefore, the reaction efficiency of hydrogen generation can be improved. Note that the thickness of the ring-shaped dielectric 23 can be appropriately set in consideration of the distance between the discharge electrodes, the voltage, and the like. Further, the shape of the dielectric 23 is not limited to the ring shape, and may be various shapes provided that it is located between the discharge electrodes, but does not hinder the movement of the raw material A to the discharge region 13. To do. The dielectric 23 may be provided in contact with the other discharge electrode 12 instead of the discharge electrode 11.
As the dielectric 23, any material that has high crystallinity and is non-conductive can be used. Specifically, quartz (SiO ₂ ), CeO ₂ , LaO ₃ , Sm ₂ O ₃ , SiN, BN, diamond and the like, but are not limited thereto.
Next, an embodiment (3) of the present invention will be described.
FIG. 4 is a partially enlarged view of the discharge electrode 11. This embodiment (3) is characterized in that a bundle of bent carbon fibers 112 is provided in an interior 111 of a pipe-shaped conductor 110 as shown in FIG. Specifically, the carbon fiber 112 is bent in two, and the folded portion 116 is provided so as to be positioned on the end surface 114 side of the conductor 110.
If it does in this way, it will become possible to hold end face 115 as folding part 116 only by bending carbon fiber 112. Thereby, the carbon fiber 112 can be easily provided in the inside 111 of the conductor 110 with the end faces 115 aligned. In particular, even when the carbon fibers 112 are thin (on the order of micrometers), the end faces 115 of the carbon fibers 112 can be easily aligned. In addition, since the end faces 115 of the carbon fibers 112 are in a uniform state, it is possible to generate a stable pulse discharge.
In addition, in the hydrogen generator shown in the above embodiments (1) to (3), a storage unit for storing the raw material A reaching the outside of the discharge electrode 11 through the capillary tube 113 can be provided. The storage part can be configured by, for example, a method of attaching a powder of metal, ceramic, resin, or the like to the surface of the carbon fiber 112. In this way, the raw material A that has oozed out of the bundle of capillaries 113 is stored by being held in the gap between the powders by surface tension. Accordingly, the amount of the raw material A that can be reacted by the pulse discharge increases, and the hydrogen generation efficiency can be improved. Moreover, since the raw material A can always be present in the vicinity of the discharge region, the responsiveness of hydrogen generation to pulse discharge can be improved.
About a storage part, various structures are employable besides the method of attaching the above-mentioned powder. For example, the surface of the carbon fiber 112 is roughened by sandblasting or the like, or the volume of the reactor 10 is expanded near the discharge region 13 (the outer diameter of the reactor 10 is increased near the discharge region 13). A method of increasing the amount of the raw material A to be used for the reaction by retaining the raw material A supplied from the capillary tube 113 in the expanded portion can be exemplified.
In the hydrogen generator shown in the above embodiments (1) to (3), a heating unit for heating and vaporizing the raw material A moving in the capillary 113 can be provided. The raw material A vaporized by the heating part evaporates out of the discharge electrode 11, reaches the discharge region 13, and reacts by pulse discharge to generate hydrogen. The specific configuration of the heating unit includes, for example, supplying current to the discharge electrode 11 itself and heating it using Joule heat generated, or arranging a general heater such as nichrome wire around the discharge electrode 11. A means for directly heating the raw material A moving the capillary 113 by embedding a nichrome wire or the like between the carbon fibers 112 can be appropriately used.
Further, in the above-described embodiments (1) to (3), the discharge electrode 11 is described as being composed of a pipe-shaped conductor 110 and a bundle of a plurality of carbon fibers 112. Any structure may be used as long as it is a structure in which A is movable so that A can move.
For example, the discharge electrode 11 can be configured by using a plurality of conductive fibers instead of the carbon fiber and providing a bundle of them in a pipe-shaped conductor. In this case, the space between the conductive fibers and the other conductive fibers functions as a capillary to which the raw material is supplied. As the conductive fibers, those having corrosion resistance are preferably used. Specifically, metal fibers such as stainless steel are preferably used.
A plurality of non-conductive fibers can be used instead of the carbon fibers. Even in this case, the space between the non-conductive fibers and the other non-conductive fibers functions as a capillary to which the raw material is supplied. The nonconductive fiber does not act as an electrode, and pulse discharge is generated between the pipe-shaped conductor 110 and the discharge electrode 11. As the non-conductive fiber, those having corrosion resistance are preferably used. Specifically, silicon, glass, SiO ₂ Etc. are preferably used.
Furthermore, in the said embodiment (1)-(3), it is also possible to provide a core material in the center part of the bundle of fibers. In this way, the shape of the fiber bundle is supported by the core material. In addition, the discharge is stably performed not only in the pipe-shaped conductor 110 but also in the core portion. In addition, it does not specifically limit as a material of a core material, Various metals, such as SUS, aluminum, copper, carbon, etc. can be used suitably. It is also possible to provide a plurality of core materials for a bundle of fibers.
As another example of the discharge electrode 11, a capillary is formed by cutting a normal carbon or metal material using a drilling machine, a laser, or the like, and the outer periphery of the material forming the capillary is piped. Pressurize and heat by laminating multiple sheets covered with a conductive material or carbon fiber woven fabric impregnated with a thermosetting synthetic resin such as phenol resin or a binder such as petroleum pitch. The porous material produced by curing the binder and then baking at high temperature in an inert atmosphere to carbonize the binder, or the fine particles of graphite precursor having sinterability such as raw coke, while pressure forming Examples include a porous material fired at a high temperature and the outer periphery of the porous material covered with a pipe-shaped conductor.
The hydrogen produced by the production apparatus of the present invention as described above can be effectively used for ammonia, methanol synthesis, hydrodesulfurization, hydrocracking, oil and fat hydrogenation, welding, semiconductor production, and the like. . In consideration of utilization as a turbine fuel, there is an advantage that the amount of heat generated is larger when the alcohol or the like is combusted as it is than when the alcohol is combusted as it is. Furthermore, since it can be a small and portable device, it is suitable as a device for supplying hydrogen to a fuel cell mounted on an automobile or the like.
EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, it is not limited to these.

The apparatus shown in FIG. 1 was produced as a generating apparatus. A quartz tube having an outer diameter of 10 mm, an inner diameter of 9 mm, and a length of 200 mm was used as the reactor, and one of the opposed discharge electrodes was bundled with 84,000 carbon fibers having a diameter of 7 μm inside a pipe made of SUS306. It was constructed by inserting a bowl (7 bundles of Besfight HTA-12K (trade name) manufactured by Toho Rayon Co., Ltd.). The diameter of the carbon fiber bundle portion is about 3 mm. Moreover, the rod-shaped discharge electrode which consists of SUS306 was used for the other discharge electrode.
Subsequently, a mixture of water and ethanol (volume ratio of 1: 1) was supplied from the introduction path into the discharge electrode by utilizing capillary action, and a constant voltage was applied between the discharge electrodes to perform direct current pulse discharge. . The discharge conditions are that the frequency of pulse generation is 50 times per second, the voltage is 5 kV, and the current is 10 mA at maximum. Moreover, the temperature in the reactor was maintained at 100 ° C. at which the raw material can be evaporated.
The amount of gas produced per minute discharged from the outlet was measured by gas chromatography. As a result, it was found that the target hydrogen was obtained in a high yield. Moreover, the state of pulse discharge was very stable.

As described above, since the generation apparatus of the present invention includes the discharge electrode in which the capillary for supplying the raw material is formed inside the pipe-shaped conductor, the discharge electrode form is maintained and stable pulse discharge is performed. The target hydrogen supplied through the capillary can be induced to efficiently generate the target hydrogen.
Further, by providing a dielectric such as quartz between the discharge electrodes, pulse discharge can be performed uniformly and stably via the dielectric.
The production apparatus of the present invention can be suitably used as, for example, a production apparatus for hydrogen to be supplied to a fuel cell, taking advantage of the fact that it can be implemented at low pressure, low temperature, and at low cost, and does not produce by-products. can do.

Claims (10)

A capillary for supplying a raw material containing one or more substances selected from hydrocarbons and organic oxygen-containing compounds and water comprises a discharge electrode formed inside a pipe-shaped conductor,
A plurality of conductive fibers are provided in a bundle inside the pipe-shaped conductor, and the capillary is formed between the conductive fibers,
A hydrogen generator that generates hydrogen by performing a pulse discharge with the discharge electrode and inducing a reaction of a raw material supplied by the capillary. A capillary for supplying a raw material containing one or more substances selected from organic oxygenated compounds comprises a discharge electrode formed inside a pipe-shaped conductor,
A plurality of conductive fibers are provided in a bundle inside the pipe-shaped conductor, and the capillary is formed between the conductive fibers,
A hydrogen generator that generates hydrogen by performing a pulse discharge with the discharge electrode and inducing a reaction of a raw material supplied by the capillary. 3. The hydrogen generator according to claim 1 , wherein the conductive fiber is a carbon fiber. The hydrogen generator according to any one of claims 1 to 3, wherein a dielectric is provided between discharge electrodes where pulse discharge is performed. 5. The hydrogen generator according to claim 4, wherein the dielectric is a ring-shaped dielectric provided along an end face of the pipe-shaped conductor. 6. The hydrogen generator according to claim 4 , wherein the dielectric is made of one material selected from SiO ₂ , CeO ₂ , LaO ₃ , Sm ₂ O ₃ , SiN, BN, and diamond. A hydrogen generator. The hydrogen generator according to any one of claims 1 to 6 , further comprising a reactor that houses a discharge electrode, and a power source that applies a voltage to the discharge electrode. Generator. Used in a device that generates hydrogen by inducing a reaction of the raw material in a raw material containing one or more substances selected from hydrocarbons and organic oxygen-containing compounds and water, and can supply the raw material A capillary tube is formed inside the pipe-shaped conductor, a plurality of conductive fibers are bundled inside the pipe-shaped conductor, and the capillary is formed between the conductive fibers. electrode. In a raw material containing one or more substances selected from organic oxygenated compounds, a pulse discharge is used in an apparatus for generating hydrogen by inducing a reaction of the raw material. A discharge electrode in which a plurality of conductive fibers are provided in a bundle inside the pipe-shaped conductor, and the capillary is formed between the conductive fibers . 10. The discharge electrode according to claim 8 , wherein the conductive fiber is a carbon fiber.

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