JP5398367B2 - Hydrogen generator - Google Patents

Description

  The present invention relates to a hydrogen generator, and more particularly, to a hydrogen generator using a hydrogen catalyst member made of a catalyst carrier having a metal catalyst supported on an oxide film.

  In recent years, organic hydride systems using hydrocarbons such as cyclohexane and decalin have attracted attention as hydrogen storage methods that are excellent in safety, transportability and storage capacity. Since these hydrocarbons are liquid at room temperature, they are excellent in transportability and storage properties.

  For example, benzene and cyclohexane are cyclic hydrocarbons having the same carbon number, whereas benzene is an unsaturated hydrocarbon in which the bond between carbons is a double bond, whereas cyclohexane has a double bond. There are no saturated hydrocarbons. Cyclohexane is obtained by the hydrogenation reaction of benzene, and benzene is obtained by the dehydrogenation reaction of cyclohexane. That is, hydrogen can be stored and supplied by utilizing hydrogenation and dehydrogenation of these hydrocarbons.

  By the way, Patent Document 1 discloses a medium in which the surface of an aluminum plate is anodized, a porous oxide film is provided, a metal catalyst is supported on the porous oxide film as a catalyst carrier, and hydrogen storage and supply are chemically repeated. It has been proposed to obtain a hydrogen catalyst member for taking out hydrogen by using the. It has also been proposed to improve the efficiency of hydrogen separation by stacking the aluminum flat plate hydrogen catalyst members via spacers.

JP 2007-326000 A

It is necessary to design the hydrogen reaction vessel in accordance with the hydrogen reaction system for taking out hydrogen, and to design the hydrogen catalyst member to be put in the hydrogen reaction vessel accordingly.
In Patent Document 1 in which a porous oxide film is provided on an aluminum flat plate, the thermal diffusion from the heat exchanger relies on the thermal conductivity of the aluminum flat plate. Here, in order to increase the volume ratio of the catalyst support, it is necessary to increase the thickness of the porous oxide film. However, since the porous oxide film has poor thermal conductivity, if the porous oxide film is too thick, the hydrogen conversion rate is conversely increased. descend.
That is, the aluminum metal portion having high thermal conductivity and the porous oxide film portion having low thermal conductivity must be thin and dense, and a gap such as a gas flow path must be formed. In a laminated structure, there is a limit to thinning in order to maintain strength.
Since the dehydrogenation reaction for extracting hydrogen is an endothermic reaction, the hydrogen reaction vessel needs to be heated. However, engine waste heat can be used in automobile applications. However, since the heat conduction length by the aluminum flat plate is long and the heat resistance is large, heat exchange is insufficient and a large heat exchanger is required. As described above, with the conventional technology, it has been difficult to obtain a small and lightweight hydrogen generator.

In order to solve the above-described problems, the present invention provides a lightweight, small, and inexpensive hydrogen generator that can easily obtain an optimum structure as a hydrogen generator.

In order to solve the above problems, the present invention provides the following hydrogen catalyst member.
(1) In a hydrogen generating apparatus for extracting hydrogen by a chemical reaction using an organic hydride as a hydrogen supply medium using a hydrogen catalyst member supporting a metal catalyst, the hydrogen catalyst member is dispersed and provided in the first pipe. a second pipe through which combustion exhaust gases or inwardly so as to surround the outer side of the first pipe is provided, of the first pipe and the second double pipe and the pipe is serpentine similarly A hydrogen generator characterized by a structure .
(2) In the above (1), the hydrogen catalyst member is any one of an aluminum fiber, an aluminum powder or an aluminum foil, a porous oxide film, or an alumina nanotube provided with a porous oxide film. The hydrogen generator characterized by being .
(3) The hydrogen generator according to (1) or (2) , wherein the double pipe meanders spirally.
(4) In any one of (1) to (3), in the length direction of the double pipe, in the region where the temperature of the chemical reaction section is 250 ° C. or less and characterized in that without the hydrogen catalyst member either hydrogen generating apparatus of claims 1 to 3.
(5) In any one of the above (1) to (4), in order to obtain a constant clearance space between the pipes of the double pipe, hydrogen is provided with intermittent dents on the outer pipe Generator.
(6) In any one of (1) to (5), wherein the metal catalyst is a two or more, the chemical temperature of the reaction portion, at 700 ° C. from 250 ° C. platinum, 700 ° C. or higher, the upper limit of the hydrogen generating apparatus The hydrogen generator is characterized in that it is nickel below the temperature and is selectively used depending on the temperature at which the hydrogen catalyst member is disposed.

According to the present invention, the hydrogen catalyst member is dispersed and provided in the first pipe, and the second pipe for passing the combustion waste gas is provided outside or inside in the longitudinal direction of the first pipe. Since the shape has a higher strength against pressure stress than the plate shape, it can be made thin, so that the thermal resistance can be lowered.
In addition, since the hydrogen catalyst member of the present invention can be deformed to fit the storage container, the pipe can freely meander and the contact area with the combustion waste gas can be increased, so that the heat exchange efficiency is high and the reaction efficiency and heat exchange as a hydrogen generator. It is easy to obtain an optimal structure that can improve efficiency. Therefore, a small, lightweight, and inexpensive hydrogen generator can be provided.

The example of the schematic of the hydrogen catalyst member of the form of this invention and the hydrogen reaction unit using the same is shown. 1 schematically illustrates a hydrogen generator according to an embodiment of the present invention. Fig. 3 conceptually shows another hydrogen generator in the form of the present invention. 2 shows a double structure of an outer pipe and an inner pipe in the form of the present invention. 1 shows a hydrogen generator in the form of the present invention. 3 shows another hydrogen generator in the form of the present invention.

The metal catalyst described in the present invention is a metal for a hydrogen catalyst, such as nickel, palladium, platinum, rhodium, iridium, rhenium, ruthenium, molybdenum, tungsten, vanadium, osmium, chromium, cobalt, iron, and alloys thereof. Can be used.
Platinum as a metal catalyst has a low minimum temperature of the dehydrogenation catalytic reaction of about 300 ° C., and although high efficiency is obtained, it is rare and expensive. As a metal catalyst that is cheaper than platinum, for example, nickel has a high minimum temperature of about 700 ° C. for the dehydrogenation catalytic reaction. Therefore, in order to reduce the amount of rare platinum used, in the hydrogen generator, for example, there is no metal catalyst at 250 ° C. or lower, and the portion of 250 to 700 ° C. is platinum, at 700 ° C. or higher and below the upper limit temperature of the hydrogen generator. There is a way to use nickel.

The hydrogen catalyst member described in the present invention is a hydrogen generation catalyst member carrying a metal catalyst, and is provided with a porous oxide film, an aluminum fiber, an aluminum powder, an aluminum foil pulverized body, or a porous oxide film pulverized body Or it aggregates and uses by small shape bodies, such as an alumina nanotube. One small body has a size of about 10 nm to 10 mm.
Moreover, as a hydrogen catalyst member, you may make it the small-shaped body which sintered these catalyst members, metal fiber, and metal powder, or you may make it a mixture.
As the metal fibers and metal powders to be mixed or mixed and sintered with these catalyst members, those corresponding to the application temperature are selected, and aluminum is suitable when sufficiently lower than 660 ° C., and high at high temperatures. A melting point metal is selected. The selected metal fiber or metal powder is mixed with any one of aluminum fiber, aluminum powder, aluminum foil pulverized body, porous oxide film pulverized body or alumina nanotube provided with a porous oxide film, preferably baked. As a result, metal fibers or metal powders are bonded together to form a support.

  The method of providing a porous oxide film is performed in the order of an anodic oxidation process, acidic aqueous solution treatment, boehmite treatment, and firing, and then a metal catalyst is supported.

The anodizing step is a step of forming an oxide film on the aluminum surface, and the oxide film is classified into a barrier type film and a porous oxide film. Of these, the porous oxide film has a shape having pores on the surface, has a large surface area, and can increase the surface area of the metal catalyst, so that the anodization method of the porous oxide film is optimal as the hydrogen catalyst support. For example, phosphoric acid, chromic acid, oxalic acid, aqueous sulfuric acid, etc. can be used as the anodizing chemical. The pore spacing, film thickness and pore diameter depend on conditions such as applied voltage, treatment temperature, and treatment time. Can be set as appropriate.
However, when trying to enlarge the pore diameter only under the chemical conversion conditions, the pore spacing may increase and the optimal catalyst loading density may not be obtained. Therefore, the pore diameter in anodic oxidation is kept small, and the subsequent acidic solution treatment is performed. It is good to adjust the pore diameter. The optimum film thickness varies depending on the applied aluminum powder diameter and sintered density. When the film thickness is thick with respect to the powder diameter, the sintered joint portion between the powders disappears, the voids are filled with the film, or cracks are generated due to stress in the film growth. The treatment liquid temperature for anodization is preferably 0 ° C. to 50 ° C., particularly 30 ° C. to 40 ° C. The treatment time of this anodization varies depending on the treatment conditions and the film thickness to be formed. For example, when an anodic acid solution of 20% at 4 ° C. and 15 V for 40 minutes is formed, an anodized layer of about 1.5 μm is formed. it can. After this step, it is washed with water and then treated with an acidic aqueous solution.

  The acidic aqueous solution treatment is intended to expand the pores of the film obtained by the anodization to a diameter suitable for supporting the catalyst, and is applied when the pores in the anodization are thin. For example, in the case of phosphoric acid, the acidic aqueous solution is preferably 5 to 20% by mass, and is treated at 10 to 30 ° C. for 10 minutes to 2 hours until the pore diameter is appropriately expanded. After this step, it is washed with water and then subjected to boehmite treatment.

Boehmite treatment is a step of forming feathered aluminum hydroxide, which is a nanoscale structure, on the surface of the film. The surface area is further increased by the surface becoming feathery. This feather-like shape is formed on the outer surface of the film and the inner wall of the pore, but is also formed on the pulverized surface in the crushed aluminum foil provided with the porous oxide film. The boehmite treatment is performed at 50 ° C. to 200 ° C. in water of pH 6 to pH 8, preferably pH 7 to pH 8, dried, and then fired.
The treatment time of the boehmite treatment varies depending on the pH and treatment temperature, but is preferably 1 hour or longer. For example, when processing in water at pH 7 and about 100 ° C., it is processed for about 5 hours.

  Firing is intended to make the film have an optimum water content for the catalytic reaction, and is intended to convert aluminum hydroxide into γ-alumina. Usually, it is performed at 300 to 550 ° C. for 0.1 to 5 hours.

The metal catalyst is supported after the acidic aqueous solution treatment, the boehmite treatment, or the calcination. The method for supporting the metal catalyst on the porous oxide film is performed by immersing the catalyst metal in a colloidal dispersion or electroless plating of the catalyst metal.

As the aluminum fiber, aluminum is used in a fiber shape, and the size and the cross-sectional shape vary depending on the manufacturing method. The diameter is about 20 μm to 1500 μm, and the length is about 0.5 mm to several hundreds m. The purity is not particularly limited, but at least 99%, preferably 99.9% or more is suitable. Moreover, the manufacturing method can be used without limitation, such as a conventional drawing method, cutting method, melt spinning method, or powder drawing method.
In the wire drawing method, a wire is drawn through a die. In the cutting method, an aluminum block is cut with a blade to make short fibers. The melt spinning method melts aluminum metallurgy and thins it from a molten state at once. In the powder drawing method, a mixture of aluminum powder and salts is drawn by extrusion or rolling. Of the cutting methods, a method of cutting an aluminum foil into a fiber shape can be used, for example, a coil cutting method in which a coil tool is wound and rotated, and a cutting tool is applied to the end face for cutting. The aluminum fiber can be used as it is or after being cut into a required length, or a plurality of aluminum fibers can be bundled in the length direction of the fiber, or can be sintered after being entangled in a felt shape. This aluminum fiber is subjected to anodization, acidic aqueous solution treatment, boehmite treatment, firing and catalyst support.

As aluminum powder, what was manufactured by the well-known method can be used. For example, when the particle size is about 50 μm to 200 μm, the gas atomizing method can be used. When the particle size is smaller than that, the centrifugal atomizing method can be used, and when larger, the mechanical process stamp mill, ball mill, etc. A grinding method or the like can be used.
This aluminum powder is subjected to anodization, acidic aqueous solution treatment, boehmite treatment, firing and catalyst support. However, since it is difficult to energize the aluminum powder, the aluminum powder is once made into a porous sintered body and then divided into the required size again after the anodizing step.

  Alumina nanotubes are columnar with a pore at the center, and the cross-sectional shape of the column is indefinite, but a hexagonal column is a representative shape. For example, alumina nanotubes formed by decomposing cells by dissolving a porous oxide film with high-concentration sulfuric acid from the aluminum metal side can be used. As another method, it is known that alumina nanotubes can be obtained by a two-stage chemical conversion treatment, followed by conversion with an aqueous solution of ammonium borate and then conversion with an aqueous sulfuric acid solution. This alumina nanotube is subjected to acidic aqueous solution treatment, boehmite treatment, firing, and catalyst support.

  The pulverized body of aluminum foil is obtained by providing a porous oxide film on the surface of the aluminum foil by anodic oxidation and pulverizing. The thickness ratio of the film to the metal (film thickness / metal thickness) is 1 As described above, it is particularly preferable to use a powder obtained by pulverizing after the pore diameter expansion by acidic aqueous solution treatment until it becomes 5 or more.

  As the pulverized body of the porous oxide film, a porous oxide film is formed by anodic oxidation on the surface of the aluminum base, and after increasing the pore diameter by the acid aqueous solution treatment, a reverse voltage is applied in the acid aqueous solution, or the acid or The porous oxide film is peeled off by immersing in an alkaline aqueous solution and pulverized.

  By crushing the two pulverized bodies, the pulverized surface can also be used as the surface area for supporting the metal catalyst. Although the above-mentioned alumina nanotubes have the highest metal catalyst loading density, a high loading density can be achieved at a lower cost than alumina nanotubes. In order to increase the surface area, it is better to crush as finely as possible. The method of the anodic oxidation and the acidic aqueous solution treatment is as described later, and after pulverization, the boehmite treatment, firing, and catalyst support described later are performed.

Thus, the hydrogen catalyst member used in the present invention is a small-shaped body having a large surface area, unlike the case of a plate. Since the (surface area / volume) of the structure can be increased as the structure is smaller, the storage efficiency of the catalyst carrier is higher than in the case of a flat plate.
In addition, when a medium such as cyclohexane is circulated through the catalyst member, a laminar flow is generated in the flat flow path, and a region that does not contribute to the reaction is formed. However, in the present invention, the medium circulates through the voids of the small-shaped body. Since the flow is disturbed, it is difficult to generate an unreacted region.
In addition, the hydrogen catalyst member is not a monolithic shape as in the patent document, but is a microstructure and used by mixing with metal fibers or metal powders, adjusting the mixing ratio thereof, or adjusting the adjusted metal fibers or metal powders. It is also possible to sinter them.
Since the dehydrogenation reaction is endothermic, a temperature distribution is generated in the reaction vessel, but the dehydrogenation reaction is temperature dependent. Increasing the volume fraction of the metal fiber or metal powder improves the heat conduction, but decreases the amount of porous alumina. Conversely, if the volume ratio of the metal fiber or metal powder sintered body is reduced, the amount of porous alumina can be increased, but the heat conduction is insufficient. By adjusting the ratio of metal fiber, metal powder and porous alumina group in the container according to the container shape, size, heat exchanger arrangement, performance, etc., the reaction container does not become lower than the reaction lower limit temperature High efficiency can be obtained.

The medium described in the present invention is a hydrogen medium that releases and stores hydrogen, and a hydrogen supplier that is a hydrogen medium that releases hydrogen is stable and dehydrogenated into stable aromatics. It is not particularly limited as long as it is, but preferably monocyclic hydrogenated aromatics such as cyclohexane, methylcyclohexane and dimethylcyclohexane, bicyclic hydrogenated aromatics such as tetralin, decalin and methyldecalin, Examples include tricyclic hydrogenated aromatics such as tetradecahydroanthracene, more preferably monocyclic hydrogenated aromatics such as cyclohexane, methylcyclohexane, dimethylcyclohexane, tetralin, decalin, methyldecalin, etc. These bicyclic hydrogenated aromatics.
The hydrogen medium for storing hydrogen is the above-described hydrogen storage body from which hydrogen has been released, such as benzene, toluene, xylene, mesitylene, naphthalene, methylnaphthalene, and anthracene.
Hereinafter, the entire hydrogen medium is referred to as organic hydride. These organic hydrides store hydrogen by adding hydrogen to a double bond between carbon atoms. The hydrogen supply body after hydrogen addition releases hydrogen and returns to the original hydrogen storage body. That is, the above-described fuel is a carrier suitable for hydrogen recycling. On the other hand, as the catalyst used in the hydrogenation reaction and dehydrogenation reaction of the above-mentioned fuel, a catalyst that has already been researched and developed and is well known is applicable and practical. In the present invention, it is preferable to use a catalyst capable of storing and supplying hydrogen at a lower temperature, and the efficiency of the entire system can be improved.

The pipe described in the present invention is a cylindrical body having an inlet and an outlet, and at least the inner pipe meanders. The hydrogen generator described in the present invention has a structure in which another pipe is accommodated in a pipe, and is either a space sandwiched between the inner wall of the outer pipe and the outer wall of the inner pipe, or one of the spaces in the inner pipe. The hydrogen catalyst member is dispersed and held on the surface. As the combustion waste gas passes through the space where there is no hydrogen catalyst member, the space where the other hydrogen catalyst member is located is heated. A hydrogen medium passes through the space where the hydrogen catalyst member is present, and hydrogen is generated by a chemical reaction by the catalyst at a site exceeding the lower reaction temperature for dehydrogenation.
In any case, the inner pipe is meandered to circulate the space between the outer pipe and the inner pipe. Further, the space between the outer pipe and the inner pipe may be narrowed and meandered integrally. The meandering method is not particularly limited, such as spiral, wavy, or U-shaped, but is selected according to the shape constraint, pressure loss, and heat exchange efficiency of the hydrogen generator. Here, especially when it is spiral, processing stress and pressure stress during operation can be distributed throughout and thinned, and even when only the inner pipe is spiral, it is sandwiched between the inner wall of the outer pipe and the inner pipe The space is spiral, and the flow path length of the fluid (combustion waste gas or hydrogen medium) flowing through this space is increased, which is preferable because the heat exchange efficiency can be increased.
The material of the pipe is preferably heat resistant and has good workability, and heat resistant metals such as copper, nickel, iron, and stainless steel are preferable. In particular, a pipe through which combustion exhaust gases, in particular requires a combustion exhaust gas temperature above the melting point and high thermal conductivity, when using the combustion exhaust gas of an internal combustion engine, it requires melting and high thermal conductivity on the 800 ° C. or more And copper is preferable.
The cross-sectional shape of the pipe is not particularly limited, but a round pipe is preferable because of versatility and ease of meandering. The size is determined from the flow rate, the required heat exchange efficiency, and the like. For example, the outer diameter of the inner pipe is about 5 mm to 20 mm, and the wall thickness is about 0.4 mm to 2 mm.

The hydrogen catalyst member may be inserted before the pipe meandering process, but can be inserted after the meandering process, especially when the hydrogen medium is powder or short fiber, and even in the case of sintering, Sintering allows insertion after serpentine processing. In the meandering process of a pipe, sand is inserted into the pipe or water is frozen to prevent bending by the process. As an alternative to these, a hydrogen catalyst member may be used. However, if the optimum filling amount / packing density for bending does not match the final filling amount / packing density of the hydrogen catalyst member, sand or frozen water It is convenient that the hydrogen catalyst member be inserted after processing.
In addition, when platinum is used as the metal catalyst, the lower limit temperature of the dehydrogenation reaction is about 300 ° C., so the hydrogen catalyst member is not disposed in the portion not reaching 250 ° C. on the hydrogen medium introduction side, and the hydrogen medium is preheated. . In this region, nothing is inserted, or metal powder, metal fiber or a sintered body thereof is inserted to increase the preheating efficiency. Further, in the region where the temperature exceeds 700 ° C., nickel which is cheaper than platinum can be used as a catalyst, and the amount of rare / expensive platinum used can be reduced.
In addition, it is more efficient to use the high temperature part of the combustion waste gas as a dehydrogenation reaction and the low temperature part to preheat the hydrogen medium. The hydrogen medium discharge side should be the combustion waste gas introduction side.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an example of a schematic diagram of a hydrogen generator and a hydrogen reaction system, and shows a hydrogen engine.
The hydrogen generator 1 is provided with a reaction vessel portion 2 and a heat exchange portion 3 for combustion waste gas which is a heat source for this reaction.
In the reaction vessel part 2, a hydrogen catalyst carrier in which a metal catalyst such as platinum is supported on a porous oxide film is arranged, and a medium added with hydrogen such as methylcyclohexane sent from a medium tank by piping is hydrogen and toluene. It chemically reacts with the medium from which the hydrogen has been released and is sent to a gas-liquid separation container to be separated. A liquefied product of a medium from which hydrogen has been released such as toluene and a medium to which hydrogen has been added such as unreacted methylcyclohexane is stored in a waste tank. On the other hand, hydrogen is sent to the engine and becomes fuel.
Further, in the heat exchange portion 3 of the combustion waste gas, since the chemical reaction of the dehydrogenation reaction of the hydrogen generation is an endothermic reaction, heat is required, and this heat is used by using the combustion waste gas that is exhaust gas from the engine. It is obtained by the heat exchange part 3 of the combustion waste gas of the hydrogen generator 1.

FIG. 2 conceptually shows a hydrogen generator according to the embodiment of the present invention.
In FIG. 2A, the hydrogen catalyst member 4 is dispersed and held, and the hydrogen that is generated by dehydrogenation through the medium is defined as the first pipe 5, and the first pipe 5 is surrounded on the outside so as to surround the first pipe 5. 2 shows a structure in which a second pipe 6 having a diameter larger than that of one pipe 5 is provided and combustion waste gas is passed through a space between the first pipe 5 and the second pipe 6.
FIG. 2B shows a structure in which the combustion waste gas is passed through the inner second pipe 6 and the hydrogen catalyst member 4 is provided in the space between the outer first pipe 5 and the inner second pipe 6. Is shown.
Since the hydrogen catalyst member 4 is a small-shaped body, in FIG. 2 (a), it conforms to the shape of the meandering first pipe 5 and in FIG. 2 (b), the meandering second pipe. And accommodated in a shape between the first pipe and the outer first pipe.
When the first pipe 5 is formed in a spiral shape, the fluid flowing outside the main pipe is also formed in a spiral shape along the main pipe, so that high heat exchange efficiency is obtained. In addition, it is better to wrap the winding more than the heat exchange efficiency. In the case of a spiral shape, it is preferable to wind the pipe around a winding rod. In order to make the fluid flowing outside the first pipe 5 spiral, the inner diameter of the second pipe 6 must be matched with the outer diameter of the spiral of the first pipe, and the pitch of the spiral is the necessary heat exchange. Determined from efficiency, fluid pressure loss.
Further, in order to prevent the hydrogen catalyst member 4 in the pipe from moving due to the passage of the medium, a filter 7 such as an aggregate of metal fibers or ceramic fibers is packed at the boundary between the storage portion and the non-storage portion, and this is fixed. Concave and convex processing 8 may be performed on the pipe. The outer surface of the outer pipe is preferably covered with a heat insulating material 9 in order to suppress heat dissipation.
A filter, a silencer, and the like are arranged on the rear side of the combustion exhaust gas exhaust of the hydrogen generator as in a normal engine.

FIG. 3 conceptually shows another hydrogen generator according to the embodiment of the present invention.
A double pipe structure is shown in which the space between the outer pipe and the inner pipe is made smaller and meandered integrally.
In FIG. 3A, the hydrogen catalyst member 4 is dispersed and held in the first inner pipe 5 to allow the medium to pass therethrough, and the inner first pipe 5 is surrounded on the outer side by the inner first pipe 5. 2 shows a structure in which a second pipe 6 having a diameter larger than that of one pipe 5 is provided, and combustion waste gas is passed through a space between the outer second pipe 6 and the inner first pipe 5.
FIG. 3B shows a structure in which the combustion waste gas is passed through the inner second pipe 6 and the hydrogen catalyst member 4 is provided in the space between the outer first pipe 5 and the inner second pipe 6. Is shown.
These double pipes are preferably made compact by winding and bending, and the space is preferably covered with a heat insulating material 9. Further, as shown in FIG. 4, intermittent dent processing 11 may be performed on the outer pipe so that the gap space of the double pipe 10 becomes constant to some extent.

As described above, when the hydrogen catalyst member is any one of aluminum fiber, aluminum powder or aluminum foil pulverized body, porous oxide film pulverized body, or alumina nanotube provided with a porous oxide film, a small shape Because it is a body, it is easy to disperse in the pipe.
Further, when the meandering is spiral, the pressure loss of the fluid passing therethrough is small and the stress in pipe processing can be dispersed.
Further, in the longitudinal direction of the pipe, if the hydrogen catalyst member is not provided in a region where the temperature of the chemical reaction portion is 250 ° C. or less, material waste of the hydrogen catalyst member is saved.
Further, if the medium introduction side is opposite to the combustion waste gas introduction port of the internal combustion engine, the medium is sufficiently heated and the reaction efficiency is easily improved.
Further, the catalyst metal is made of two or more types, and the temperature of the chemical reaction portion is platinum when the temperature is 700 ° C. or lower, and nickel when the temperature is 700 ° C. or higher. be able to.

(Production of hydrogen generator 1)
A copper pipe 20 having an outer diameter of 8 mm and a wall thickness of 0.8 mm is spirally wound around a rod 21 having a diameter of 15 mm and a length of 220 mm. The winding pitch was set to about 13 mm, and it was wound three times (1.5 reciprocations) (FIG. 5A).
Next, a hydrogen catalyst member is accommodated in the copper pipe 20. Note that the storage of the hydrogen catalyst member is only a portion where the temperature is 250 ° C. or more, thus saving the hydrogen catalyst member.
A medium to which hydrogen is added flows from the medium inlet 20 b side to the copper pipe 20, and the filter 7 is inserted on the medium outlet 20 a side so that the hydrogen catalyst member is not pushed away by this flow, and is fixed by the unevenness processing 8.
Next, the semi-cylindrical body 22 is formed in a pipe shape with the copper pipe 20 sandwiched between the pair of semi-cylindrical bodies 22, and an end face material 23 and a combustion waste gas lead-in / out pipe 24 provided to protrude outward from the end face material 23 are provided on both end faces thereof. The hydrogen generator is assembled (FIG. 5B) and welded (FIG. 5C). The inlet and outlet portions of the copper pipe 20 are led out from a hole 25 provided in the half cylinder 22.
Although not shown in FIG. 5, the entire hydrogen generator is covered with a heat insulating material. The combustion waste gas is inserted from the combustion waste gas inlet / outlet 24a side of the combustion waste gas lead-in / out pipe 24, and goes out to the combustion waste gas outlet / 24b side of the combustion waste gas lead-in / out pipe 24.
The medium to which hydrogen is added is injected from the medium inlet 20b of the copper pipe, preheated at the low temperature part where there is no hydrogen catalyst member, passes through the high temperature part where the hydrogen catalyst member is present, spirally along the pipe, and is dehydrogenated. The hydrogen, the dehydrogenated medium, and the unreacted medium are discharged from the medium outlet 20a side of the copper pipe. These are separated in a gas-liquid separation container as shown in FIG. 1, and liquid is led to a waste liquid tank and hydrogen is led to an engine.

(Production of hydrogen generator 2)
In a double pipe 28 structure consisting of a copper inner pipe 26 having an outer diameter of 8 mm and a wall thickness of 0.8 mm and a copper outer pipe 27 having an outer diameter of 12 mm and a wall thickness of 0.8 mm, a slit 29 is formed on the side surface of the end portion of the outer pipe 27. From which the inner pipe 26 protrudes at a right angle to the outer pipe 27 (FIG. 6A). Further, the outer pipe 27 is provided with a plurality of intermittent dents so that the inner pipe 26 is arranged at substantially the center of the outer pipe 27.
Next, a hydrogen catalyst member is inserted into the inner pipe 26, and the double pipe 28 is wound into a triple-turn coil shape in the order of FIGS. 6 (a), 6 (b), and 6 (c). A slit 29 is provided on the side face of the end of the outer pipe 27 in the rear part after the winding as in the case of the starting part, and the inner pipe 26 is projected at a right angle therefrom (FIG. 6C).
Next, a pair of semi-cylindrical welding pieces 30 are welded to both ends of the double pipe 28 so as to close the slits 29 (FIGS. 6D and 6E). Although not shown in the figure, the whole is covered with a heat insulating material.
Combustion waste gas from the engine is inserted from the inlet 27 a side of the outer pipe of the double pipe 28, passes through the gap between the outer pipe 27 and the inner pipe 26, and escapes to the outlet 27 b side of the outer pipe of the double pipe 28. On the other hand, the medium to which hydrogen is added is supplied from the inlet 26b side of the inner pipe 26, and hydrogen, the dehydrogenated medium, and the unreacted medium are discharged from the outlet 26a side of the inner pipe.
The temperature of the pipe is high on the inlet 27a side of the outer pipe of the double pipe 28 and low on the outlet 27b side of the outer pipe of the double pipe 28. As in the case of Example 1, the hydrogen catalyst member is disposed only in the high temperature part, and is used as a preheating of the medium added with hydrogen in the region of 250 ° C. or lower.

  DESCRIPTION OF SYMBOLS 1 ... Hydrogen generator, 2 ... Reaction container part, 3 ... Heat exchange part of combustion waste gas, 4 ... Hydrogen catalyst member, 5 ... 1st pipe, 6 ... 2nd pipe, 7 ... Filter, 8 ... Concavity and convexity processing , 9 ... Insulating material, 10 ... Double pipe, 11 ... Indentation, 20 ... Copper pipe, 20a ... Copper pipe medium outlet, 20b ... Copper pipe medium inlet, 21 ... Bar, 22 ... Half cylinder, 23 ... End face material, 24 ... Combustion waste gas outlet / inlet pipe, 24a ... Combustion waste gas inlet of the combustion waste gas outlet / inlet pipe, 24b ... Combustion waste gas outlet of the combustion waste gas outlet / inlet pipe, 25 ... Hole, 26 ... Inner pipe, 26a ... Inner pipe 26b ... inner pipe inlet 27 ... outer pipe 27a ... outer pipe inlet 27b ... outer pipe outlet 28 ... double pipe 29 ... slit 30 ... welded piece

Claims (6)

In a hydrogen generating apparatus for extracting hydrogen by a chemical reaction using an organic hydride as a hydrogen supply medium by a hydrogen catalyst member supporting a metal catalyst, the hydrogen catalyst member is dispersed and provided in a first pipe. a second pipe through which combustion exhaust gases or inwardly so as to surround the outer side is provided in the pipe, is the structure of the double pipe and the first pipe and the second pipe is serpentine similarly A hydrogen generator characterized by that . Claims wherein the hydrogen catalyst member, provided a porous oxide film, grinding bodies of aluminum fibers, aluminum powder or aluminum foil, or grinding bodies of porous oxide film, or is characterized in that any one of alumina nanotube 1. Hydrogen generator. The hydrogen generator according to claim 1 or 2 , wherein the double pipe meanders spirally. In the length direction of the double pipe, one of the hydrogen generating apparatus of claims 1-3 in which the temperature of the chemical reaction section is in a region to be 250 ° C. or less, characterized in that it is provided with a hydrogen catalyst member. 5. The hydrogen generator according to claim 1, wherein an intermittent dent is provided in an outer pipe in order to obtain a constant gap space between the pipes of the double pipe . The metal catalyst may be at least two kinds, platinum at a chemical reaction portion of 250 ° C. to 700 ° C., nickel at a temperature of 700 ° C. or higher, and lower than the upper limit temperature of the hydrogen generator, depending on the temperature at which the hydrogen catalyst member is disposed. The hydrogen generator according to any one of claims 1 to 5 , wherein:

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