JP2017001006A - Composite wire type catalyst member, and catalyst reactor for hydrogen production using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite wire type catalyst member contributing to prevention of excessive diffusion and improvement of heat resistance life by setting up a diffusion suppressing layer between a core wire for heat generation and a clad layer as a barrier, and to provide a catalyst reactor for hydrogen production using the same.SOLUTION: A composite wire type catalyst member 1 comprises: a) a linear metallic heating wire 1A heated to a prescribed temperature by energization to generate heat; b) a clad layer 1B comprising a second metallic material encapsulating the heating wire 1A and being a type different from the heating wire 1A; and c) a catalyst carrier layer 1C carrying a prescribed catalytic substance X on the outer peripheral face of the clad layer 1B, and d) the catalyst member is composed including the catalytic substance X carried by the catalyst carrier layer 1C and also e) the boundary face of the heating wire 1A and the clad layer 1B has a diffusion suppressing layer Y suppressing excessive diffusion of the heating wire 1A and clad layer 1B formed with use along a circumferential direction in a nonsmooth irregular state. A catalyst reactor for hydrogen production equipped with plural catalyst members lamination-disposed in a multistage form and an electric heating circuit is also provided.SELECTED DRAWING: Figure 2

Description

Detailed Description of the Invention

  The present invention is a composite wire that, for example, is used as a catalyst member for a hydrogenation reaction to an aromatic compound, or a dehydrogenation reaction that is the reverse reaction thereof, particularly by conducting the reaction temperature by energization heating of the member and contributing to a longer life. The present invention relates to a catalyst member of a type and a catalytic reactor for hydrogen production using the same.

  In recent years, global warming affecting the global environment has been pointed out, and fuel cell systems are attracting attention as new clean energy alternatives to conventional fossil fuels. In this fuel cell, hydrogen is used as the fuel, and the demand for hydrogen as an energy source in other fields is increasing, and therefore, establishment of a stable and efficient hydrogen production technique is urgently required.

  Various methods have been tried for hydrogen production in the past, but the production system suitable for a large flow rate plant such as for a hydrogen station is still in development, mainly on a relatively small scale type. In the stage. Typical examples thereof include those based on electrolysis of water, those based on separation membranes that separate and produce only hydrogen from various mixed fluids containing hydrogen, and those based on other catalytic techniques. Further, as for the latter catalyst technology, for example, Patent Document 1 discloses a composite type catalyst wire that carries a catalytic substance by using a nichrome wire for electric heating as a core wire, and further coating the surface with an aluminum metal film to perform anodization. Is disposed along a separate flow path in the upper and lower molds.

  In addition, the applicants of the present invention have also proposed a coil wire body in which the wire is wound into a coil to improve the surface area of the composite wire in order to increase the amount of catalyst supported per unit volume ( Patent documents 2 to 4) are provided to improve the efficiency.

  JP 2005-246115 A   JP 2011-245475 A   International Publication WO2012-090326   JP 2012-236182 A

  As described above, each of the above prior patent documents is directed to a composite wire type catalyst member, and a heating wire for energization heating is arranged on the shaft core, and a porous alumite is provided on the surface via an aluminum coating layer. A layer is formed and encapsulated. That is, by making the composite wire structure of the three-layer structure including the heating wire, the aluminum layer, and the alumite layer supporting the catalyst material, the catalyst member has a heat responsiveness, that is, a control to a predetermined temperature and a response speed response. Sexuality will be promoted.

  However, the catalyst member carries a predetermined catalyst substance on the porous structure portion of the alumite layer, and the catalytic reaction is performed at a temperature of about 300 to 500 ° C., for example. Interdiffusion at the interface between the heating wire and the aluminum coating layer is inevitable. In particular, in the case of using the product while repeating heating and cooling continuously or intermittently over a long period of time such as 10,000 hours or more, preferably 3 years or more, the diffusion-affected zone increases and heat is generated. There is a concern that the current-carrying performance of the wire may be reduced, and sometimes delamination or disconnection may occur, and there is a need to prevent this problem.

  The present inventor, on the premise of such a use state, pays attention to the boundary surface between the core material for heat generation and the coating metal layer encapsulating the surface, and particularly prevents the excessive diffusion generated with use. We tried to improve the heat-resistant life to be suitable for long-term stable use. As a result, the present inventors have concluded that it is effective to form a diffusion suppressing layer in advance in order to prevent excessive diffusion formed in the use environment on the boundary surface.

  As described above, the present invention provides a diffusion-inhibiting layer for preventing the excessive diffusion in the structural interface portion in advance in a composite wire-type catalyst member that is heated and used for a long time under a predetermined heating environment. In order to provide a catalyst member that contributes to the improvement of the heat-resistant life and a catalyst reactor for hydrogen production using the catalyst member, the diffusion inhibiting layer is used as a barrier to prevent excessive diffusion more than necessary. To do.

That is, the invention according to claim 1 of the present application is
a) a metal heating wire that generates heat by energization to a predetermined temperature;
b) a coating metal layer encapsulating the heating wire and made of a second metal material different from the heating wire;
c) A catalyst support layer for supporting a predetermined catalyst substance is provided on the outer peripheral surface of the coated metal layer, and
d) containing the catalyst material supported on the catalyst support layer;
e) The interface between the heating wire and the coating metal layer is provided with a diffusion suppressing layer that suppresses excessive diffusion between the heating wire and the coating metal layer formed in use in a non-smooth uneven state along the circumferential direction. This is a composite wire type catalyst member.

  In the invention according to claim 2, the diffusion suppression layer is a third diffusion layer of a refractory metal having a melting point of 1500 ° C. or higher, or a precursor diffusion formed in advance by mutual diffusion of the heating wire H and the coating metal layer C. According to a third aspect of the present invention, in the invention according to claim 3, the precursor diffusion layer is formed of an intermetallic compound that is formed in a layer form with a heat treatment in a production step of a coated composite wire of the heating wire and the coated metal layer. In the invention according to claim 4, the heating wire is made of nickel metal, the covering metal layer is made of aluminum metal, the precursor diffusion layer is made of heat of the nickel metal and the aluminum metal. It is characterized by being comprised by the Ni-Al type | system | group intermetallic compound layer produced | generated by reaction, respectively.

  In the invention according to claim 5, the diffusion suppressing layer has a thickness of 60 μm or less, and the invention according to claim 6 is an apparent calculation calculated from the cross-sectional area drawn by the center position of the constituent thickness. The concavo-convex shape having an actual circumferential length of 1.02 to 1.4 times the upper circumferential length.

  Furthermore, the invention of the catalyst member according to claim 7 further includes a coil portion wound tightly by coiling, and the invention according to claim 8 is that the coil portion is 70 ° in plan view. It is also characterized by being wound obliquely in a certain direction at the following inclination angle (α).

  On the other hand, claim 9 is directed to an invention of a catalytic reactor for hydrogen production using the same, and a flow direction of a fluid to be treated supplied to a plurality of catalyst members according to any one of the foregoing in a predetermined catalytic reaction chamber And an electric circuit for energizing and heating each of the heating lines of the catalyst member.

  According to the invention of claim 1 of the present application, as a composite wire type catalyst member that is energized and heated, a diffusion suppression layer is formed in advance on the boundary surface between the heating wire and the covering metal layer encapsulating the surface. Therefore, it is possible to prevent further excessive diffusion in the heating environment for the catalytic reaction when using this, and to form a non-smooth uneven surface on the boundary surface. Even when a thick diffusion layer is formed, the concavo-convex portions engage with each other to prevent partial peeling or disconnection of the surface coating layer.

  Moreover, according to the invention of Claims 2-8, while forming the said diffusion suppression layer suitably, while reducing the influence of the said excess diffusion, the engagement of both metal materials can be strengthened further. According to the invention of claim 9, the plurality of catalyst members are placed in a plurality of stages, and an electric circuit is formed so that each of the heating wires can be heated by energization. Can be provided.

  It is a perspective view which shows an example of the composite wire type | mold catalyst member which concerns on this invention.   It is an example of sectional drawing which expands the laminated structure of the composite wire in the catalyst member of FIG.   It is a top view which shows the catalyst member of another form as a shape article.   FIG. 3b is a side view of FIG. 3a.   It is sectional drawing which shows one form of a catalytic reactor.   It is a system diagram of hydrogen production.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
The composite wire-type catalyst member (hereinafter simply referred to as catalyst member) according to the present invention is a linear metal heating wire 1A (hereinafter also simply referred to as a heating wire) that heats and heats to a predetermined temperature when energized as described above. The composite metal wire 1B includes a covering metal layer 1B made of a second metal material different from the heating wire, and a catalyst support layer 1C formed on the surface of the coating metal layer 1B. A predetermined catalyst material X set in advance is supported on the surface of the support layer 1C.

  In such a composite wire type catalyst member 1, the present invention relates to the heating wire and the coating metal layer of the second metal material formed at the interface between the heating wire 1 </ b> A and the coating metal layer 1 </ b> B. In addition, a diffusion suppression layer Y that suppresses excessive diffusion is provided, and the suppression layer Y is formed in a non-smooth uneven shape along the circumferential direction.

  As an example, FIG. 1 shows that the fine wire W having the composite clad structure adjusted to have the predetermined equivalent wire diameter d is further adhered over the entire length so as to have an average coil diameter D of, for example, about 5 to 20 mm. The thing provided with the coil part 2 wound is shown. As can be understood from the above-mentioned prior patent documents 2 and 3, for example, the heating wire 1A disposed at the center of the shaft core, and the coated metal layer 1B made of a second metal material encapsulating the heating wire, For example, it is understood to be a wire-shaped catalyst member having a composite clad structure in which a metallic aluminum layer and a catalyst supporting layer 1C formed on the outer surface thereof are further provided, and the supporting material 1C supports a predetermined catalyst substance X. Is done. For example, when the coating metal layer is made of aluminum metal, the catalyst support layer 1C corresponds to an alumite layer obtained by anodic oxidation.

  The cross-sectional shape of the catalyst member 1 is not limited to a circular cross-sectional shape such as a normal metal wire, and may be a non-circular long strip material such as an ellipse, a square shape, a belt shape, Further, this is intended to be formed into a coil shape as shown in FIG. The wire diameter display can be represented by, for example, an equivalent wire diameter d calculated from an arbitrary cross-sectional area of the thin wire W. In this embodiment, the wire diameter d is set to about 0.3 to 2.0 mm, for example. .

  In the thin wire W having the above structure, the heating wire 1A is selected from a metal material having a relatively large electrical resistance that can be heated and heated to a predetermined temperature by energization. For example, nickel, chromium, iron, etc. Alloys, iron-chromium alloys, stainless steel, and other various alloy materials can also be employed. More preferably, those having an electrical resistivity of 5 μΩ · cm or more, for example, 5 to 200 μΩ · cm, are recommended. For example, electric wires such as Nichrome, Tungsten, and Molybdenum disclosed in each of the above-mentioned patent documents, Patent Document 2 , 3, a nickel metal wire is preferable.

  In particular, when the thin wire W as shown in FIGS. 1 and 2 is processed by the cladding method, if the heating wire 1A is made of nickel metal and the second metal material encapsulating the surface is made of aluminum metal, both processes It is suitable for narrowing the diameter. Not only this but 1 A of exothermic wires employ | adopt the said exemplary metal wire which has the characteristic which can carry out an electric heating easily about the reaction use temperature 300-500 degreeC.

  As for the covering metal layer 1B, a porous structure having a large number of micropores on its surface is formed by, for example, anodizing as the second metal material constituting the covering metal layer 1B, as disclosed in the above-mentioned prior patent document. The aluminum metal is preferred. However, the present invention is not limited to this, and those capable of forming micropores are also employed. For example, metal materials such as titanium, zinc, magnesium, and zirconium can be similarly employed depending on the treatment solution and conditions. Moreover, the formation thickness of this metal layer 1B is not specifically limited, It sets suitably by use conditions. For example, the volume of the exterior material 1X including the metal layer 1B and the outermost catalyst support layer 1C is 70% or less (for example, 20% or more) as a ratio (1X / A0) to the total volume (A0) of the catalyst member. Is set to be

  In the catalyst member 1 having such a composite structure, according to the present invention, as shown in FIG. 2, the diffusion suppressing layer Y is provided at the interface between the metal heating wire and the coated metal layer. The suppression layer Y has a function of suppressing, that is, preventing or reducing, the excessive diffusion generated by the thermal reaction between the heating wire 1A and the covering metal layer 1B with heating to the use temperature when using this. It has a non-smooth uneven shape along its circumferential direction.

  For example, as disclosed in each of the above-mentioned prior art documents, the unevenness is formed by applying a first metal wire for the heating wire 1A and a second metal material for the covering metal layer 1B on the surface thereof by metal plating or cladding. It is obtained by using composite wire coated by the method as a raw material and reducing it to the target wire diameter while reducing the size so as to enhance its adhesion, and further the porous structure on the outermost surface side by anodizing treatment A predetermined catalyst support layer Y can be supported in the pores. The surface treatment is performed by electrochemical treatment in a predetermined electrolyte solution (for example, sulfuric acid, oxalic acid, etc.) disclosed in various documents such as Japanese Patent Application Laid-Open Nos. 2-144154 and 8-246190. Generally, a heat baking treatment at about 350 to 600 ° C. is employed.

  The diffusion suppression layer Y has a clad structure in which, for example, a refractory metal film material having a melting point of 1500 ° C. or higher is arranged at the interface between the heating wire 1A and the covering metal layer 1B at the material stage, or It can be composed of a precursor diffusion layer made of a layered intermetallic compound that is generated by heat treatment in the middle or final stage of the coated composite wire of the heating wire 1A and the coated metal layer 1B.

  The constituent thickness of the diffusion suppressing layer Y is preferably 60 μm or less, for example. In the case of a thick coating state exceeding this, there is a concern that delamination may occur, workability may be reduced, and the product function of the catalyst member 1 may be affected. Moreover, the effect is not acquired in the thing thinner than necessary, More preferably, it is 1-30 micrometers.

  In the former case of the refractory metal film material, in addition to various metal materials such as molybdenum, vanadium, niobium, chromium and tantalum, there are some third elements (for example, W, Y 2 O 3 of 10% by mass or less). ) Are selected. In particular, chromium, molybdenum, and the like excellent in workability are preferable because of their relatively high melting points.

  Further, as the latter due to the precursor diffusion layer, for example, when the heating wire 1A is a Ni metal wire and the covering metal layer 1B is made of aluminum metal, when it is used, for example, 400 ° C. or higher By treating under the excessive heat treatment conditions (temperature and heating time), a relatively stable compound layer can be formed. As an example, Ni-Al based intermetallic compounds such as NiAl, Ni3Al, Ni5Al3, Ni2Al3 are exemplified. According to the diffusion suppression layer Y by these intermetallic compounds, the diffusion state is obtained by a thermal reaction at a temperature higher than the normal use temperature, and the actual use temperature is maintained in a temperature environment state lower than this, The diffusion inhibiting layer acts as a relatively stable barrier layer, and a substantial increase in the diffusion phenomenon is suppressed. For this reason, for example, the heating wire 1A is prevented from deteriorating the heating function due to the diffusion.

  As shown in FIG. 2, it is effective that these diffusion suppression layers Y are formed in a non-smooth uneven shape along the boundary surface between the two metals. The concavo-convex portions engage with each other between the heating wire 1A and the aluminum layer 1B located on both sides of the concavo-convex portion to provide a solid composite wire, which contributes to a long life.

  The uneven state can be indicated by, for example, the ratio of the apparent circumferential length and the actual circumferential length indicated by the virtual equivalent circle corresponding to the center position of the thickness of the diffusion suppression layer Y, that is, the area of the partition region drawn by the midpoint. it can. In the present invention, due to the unevenness, the actual circumference is 1.02 to 1.4 times, preferably 1.05 to 1.35 times, more preferably 1.08 to 1.3 times the apparent circumference. To do.

  Such a concavo-convex state uses, for example, a material that is clad at a relatively large diameter in the forming process of the composite wire, and this is subjected to wire drawing with a processing rate of 80% or more, more preferably 85% or more. It can be obtained by doing. That is, in the wire drawing, the processing strain is reduced in the axial direction, so that the boundary surface forms an irregular concavo-convex surface with the degree of the processing.

  Therefore, also in the case of the former refractory metal, a similar uneven state can be obtained by interposing a predetermined metal film material in advance at the interface at the material stage, and in the case of the latter diffusion suppression layer Y, In the heat treatment in the middle or final stage, it is recommended to increase the thermochemical reaction between the two by increasing the heating temperature above the normal processing temperature or extending the heating time.

  The heating condition is appropriately set depending on the type and shape of the material used. For example, in the case of nickel and aluminum, the heating condition is set at a set temperature of, for example, about 400 to 650 ° C. below the melting point and in the range of about 0.1 to 30 minutes. Is done. In particular, when the heating temperature is higher than 650 ° C., the temperature substantially approaches the melting point of aluminum, causing problems such as eccentricity and it is difficult to obtain a satisfactory composite wire. On the other hand, sufficient softening cannot be obtained by low-temperature heat treatment at less than 400 ° C., and the formation of the diffusion suppressing layer Y takes a long time. Preferably, it is set at 70 to 98% of the melting point of the metal material on the low melting point side, for example, at a temperature of 500 to 630 ° C.

  On the other hand, in the present embodiment, the catalyst-supporting layer 1C has a porous structure having fine bottomed pores on its surface layer by oxidizing the coated metal layer 1B, for example, anodizing treatment. The layer is described as an alumite layer. The pores have, for example, micropores with a bottomed shape having a pore diameter of 1 to 200 nm and a depth of 0.1 to 500 μm (preferably 300 μm or less) in a honeycomb shape (tortoise shell mesoporous structure). The pore aspect ratio (depth / opening diameter) can be set to about 50 to 2000 by the pore wide ring treatment or post-treatment of the firing treatment. The details can be understood from, for example, the above-mentioned prior art documents 2 to 4.

  With such a porous structure, the predetermined catalyst substance X can be supported in the pores at a high density, the amount of catalyst supported per unit area is increased, and the catalytic reaction is promoted. Since the alumite layer 1C is obtained by oxidizing the reaction base material, the alumite layer 1C is strongly bonded to the base aluminum layer 1B. The fine holes can be adjusted as appropriate by voltage control during anodizing, for example, and the above dimensions are an example.

  The carrier layer 1C becomes an electrically non-conductive insulating film. Thus, the catalyst member 1 composed of a composite wire covered with an insulating film can prevent an electrical short circuit due to contact with other members (such as a housing container) during use, and the porous structure is extremely Therefore, the predetermined catalytic substance X can be properly supported by preventing deformation and sealing of the fine openings. The accommodated catalyst substance X can prevent detachment and dropout due to contact with other members or friction during use.

  Various catalyst materials X are selected according to the purpose of use, and are not particularly limited. For example, platinum (including platinum group metals and alloys thereof) is preferable. In addition to platinum, one or more transition metals selected from the group consisting of rhodium, rhenium, nickel, titanium, magnesium, zinc, zirconium, molybdenum and tungsten are suitable.

  The catalyst material X is supported by applying a platinum solution containing the metal, for example, platinum, to the porous alumite layer 1C and applying pressure to the bottomed pores H so as to infiltrate into the bottomed pores H. It is carried on. As the platinum solution, for example, hexachloroplatinic (IV) acid hexahydrate, dinitrodiammine platinum (II) nitric acid solution, hexaammine platinum (IV) chloride solution or tetraammine platinum (II) hydrochloride solution is preferably used. It is done. Moreover, platinum and / or the said transition metal salt solution can also be simultaneously or sequentially carried | supported by methods, such as immersion, dripping, application | coating, or spraying, in a predetermined temperature range, energizing or electromagnetic induction heating the wire main body W. Furthermore, an alumite layer is laminated on the outermost surface side of aluminum to form micropores, and a catalyst support layer for supporting a catalyst substance in this microscopic opening has been described. A method may be used in which fine cuts are made on the surface of the film to form pores, and a catalyst-carrying layer that carries a catalyst substance in the pores.

In addition, the catalyst substance X may be a metal carbonyl compound such as Pt (CO) ₂ Cl, Rh ₄ (CO ₁₂ , Ni (CO) ₄ , Re ₂ (CO) ₇ , or CpTiCl ₂ (Cp = cyclopentadienyl). ), Mo (CO) ₆ or the like, which is appropriately supported by a chemical vapor deposition method, and if necessary, stepwise firing in a temperature range of 250 to 600 ° C. in an oxygen-containing atmosphere if necessary. Furthermore, it is preferable to perform the activation treatment by raising the temperature stepwise in a temperature range of 100 to 450 ° C. in a hydrogen gas atmosphere.

  Thus, as shown in FIG. 1, the composite wire 1 has a coil portion 2 wound with the winding diameter D, and both ends of the coil wire (non-coiled portion in this embodiment) The support layer 1C is not provided, but the connection portions 3a and 3b from which the metal heating wire 1A is exposed are provided. The connecting portions 3a and 3b are further connected to an external power source outside the system and heated to a predetermined temperature by energization.

  It is desirable that the processing, winding shape, molding size, and the like of the coil portion 2 be performed in consideration of the wire diameter d of the catalyst member 1 and the catalyst support layer 1C on the surface. A coil product wound in close contact over the entire length is disclosed. In this case, the coil portion 2 has a width and a coil height that are substantially the same diameter, and the inside of the coil portion is substantially in a hollow state. Can not. Further, in the case where the coil wires having different sizes are inserted as in Patent Document 3, the number of points increases and the inventory management becomes complicated. For example, as shown in FIGS. A coil wire wound obliquely in a state inclined in the direction is suitable. FIG. 3a shows the top view and FIG. 3b shows the side view.

  The catalyst member is formed by inclining in a certain direction having an inclination angle (α) in a plan view, and the inclination angle α is set to a range of, for example, 70 ° or less, preferably about 30 to 60 °. . In the coil wire body 2 tilted in this way, the configuration height h is smaller than the width dimension, that is, it can be formed thin, so that, for example, when it is used by being stacked in multiple stages, the overall thickness is greatly increased. This reduces the entanglement between the coil portions 2 and provides a gap flow path through which the fluid to be treated sufficiently circulates between the windings, thereby providing a good catalytic reaction.

  Regarding the winding shape, for example, the coil portion 2 that is wound in a normal close-fitting circular shape using the composite wire is described as being further crushed to the predetermined angle α in an oblique direction. Can do. Such winding molding is desirably performed before the surface treatment of the alumite layer 1C. Further, the coil portion 2 thus flattened has an average coil diameter D corresponding to the winding width of 3 times or more, for example 3 to 20 times, more preferably 5 to the equivalent wire diameter d of the composite wire. It is set to a comparatively large value of 15 times and is wound obliquely so as to have the inclination angle (α). The length of the coil portion is not particularly limited and can be set arbitrarily. However, from the viewpoint of the use form of energization heating, a length of about 100 cm or less, for example, about 5 to 50 cm can be used relatively well.

  Regarding the use of the catalyst member 1 as a material for a catalytic reactor for hydrogen production, for example, a plurality of the catalyst members 1 can be arranged in multiple stages along the flow direction of the fluid to be treated supplied into a predetermined reaction chamber, An electric circuit for energizing and heating each of the heating wires 1A of the catalyst member 1 is configured and used. For example, JP-A-2014-177360 shows a usage pattern other than those described in the above-mentioned patent documents, and a multi-layered type as shown in FIGS. 4 and 5 is suitable.

  FIG. 4 shows a typical example of the reactor 10. For example, the reactor 10 is provided with a small-diameter medium container 13 in a large-diameter housing container 12 provided with piping flanges 11A and 11B on the upper and lower end surfaces. For example, it is configured as a cassette type that uses a flat-shaped accommodation holder 14 that sequentially accommodates a plurality of coil members 15 of the catalyst member, and is arranged in multiple stages.

  Each coil wire 15 is connected to an external power supply 27 (Dw) outside the system, and forms an electric circuit so that it can be heated to a predetermined temperature. If necessary, the housing container 12 and the intermediate container 13 are formed. It can also be used as an indirect heating type in which a heating fluid heated to a predetermined temperature in advance by the supply port 16A and the discharge port 16B is supplied into the empty space between the two.

  Further, as shown in the system flow diagram of FIG. 5, the fluid to be processed for hydrogen production is preliminarily heated and atomized by the upstream vaporizer 23 using, for example, a methylcyclohexane (MCH) liquid as a raw material to be processed. Is fed into the reactor 20 to cause a catalytic reaction. That is, the line separates the reaction gas generated in the catalytic reactor 24 through the storage tank 21 for storing the MCH, the feed pump 22 and the vaporizer 23 by the next cooler 25, and separates the generated gas. In this system, the gas body is recovered as hydrogen, and the liquid component is recovered in the recovery layer 30 as, for example, toluene. In this embodiment, the vaporizer 23 uses a reducing accompanying gas such as hydrogen for preventing the MCH supply back pressure and the oxidative deterioration of the catalytic material of the reactor.

If necessary, a thermocouple Th is installed at a predetermined position so that each catalyst member in the reactor 24 always has a predetermined temperature, and the temperature is controlled by a thermometer Tm. In this way, the fluid to be treated is rectified and adjusted from the upper side of FIG. 4 through the dispersed perforated plate 17 so that the supply amount can be almost averaged over the entire surface, and a catalytic reaction occurs sequentially as it flows down.
The following examples further illustrate the present invention.

[Manufacture of aluminum clad coil wire]
A nickel wire (purity 99%) having an electric heating function was encapsulated with a strip of aluminum (purity 99.9%), and a base wire of an aluminum clad wire (composite wire) having a wire diameter of 12 mm was used as a starting material. Then, after the intermediate heat treatment under the condition of a temperature of 620 ° C. × 5 min, the bus wire is thinned by cold wire drawing with a final working rate of 88%, and finally a composite thin wire having a wire diameter of 0.7 mmφ is formed. Obtained.

  The composite thin wire has an average thickness of 100 μm of the exterior material 1X including the aluminum layer, and when the cross section is observed with a microscope, an average thickness of 23 μm is obtained at the interface between the core material Ni material and the clad material aluminum layer. A compound layer was observed, and X-ray diffraction of the compound layer was confirmed to be substantially NiAl.

  In this embodiment, this compound layer is presumed to be caused by heating for a long time after the heat treatment as before, and the boundary surface has a non-circular uneven shape as shown in FIG. The perimeter is a non-smooth concavo-convex portion having a length of a converted equivalent circle corresponding to the area of the partition region drawn by the middle point of the compound layer, that is, a length of about 1.08 times the apparent perimeter. Both of them were firmly combined and integrated.

  Next, the composite thin wire was set in a coiling machine to obtain a coiled wire wound in close contact with a winding average diameter D of 10 mm and a length of 300 mm. The coil wire was a tightly coiled wire that was in close contact with the wire diameter d of the composite thin wire about 1.01 times, and the aluminum layer had no defects such as peeling and had a good coil state. .

[Alumite treatment of composite thin wire]
Next, the coil wire was anodized under the conditions of a 4 wt% oxalic acid aqueous solution at a temperature of 35 ° C. and a current density of 60 A / m ² . Then, the acid treatment was performed while immersed in the same kind of oxalic acid treatment solution for 6 hours, and the pore size was widened and dried in the atmosphere. Next, after baking at 400 ° C. for about 1 hour, hydration was performed at 80 ° C. or higher for about 2 hours and dried. After that, it is further calcined at 500 ° C. for 3 hours to form an alumite clad metal fine wire having a porous anodized layer with pores on the surface, and further, this is supported on the surface by a platinum catalyst material by the following catalyst treatment. It was.

The catalyst treatment was performed by immersing the alumite clad fine wire in a chloroplatinic acid solution dissolved in ethanol using a platinum salt of a catalyst substance and using chloroplatinic acid H ₂ PtCl ₆ 6H ₂ O, respectively. The amount was detected to be 3 g Pt / m 2 from the amount of ions in the lysis solution.

[Reactor]
Next, eight of these coil wires are connected in series to form a unit block, and the three sets are sequentially incorporated into separate support holders, thereby forming a catalyst unit having a total of 24 coil wires.

  The support holder is a 300 × 300 mm plate-shaped product made by extrusion molding made of an aluminum alloy, and 10 mm high partition walls are provided in parallel at 12 mm intervals on one side, and the chamber between the partition walls The coil wire bodies are sequentially assembled along the two terminals, and both terminals of each circuit block are respectively connected to a relay terminal provided in an insulated state at one end portion of the holder, and receive power supplied from outside the system. The flow holes for flowing the processing fluid are provided at intervals of 5 mm at a hole diameter of 10 mm.

A total of 10 stages of the obtained catalyst units were prepared, and each was electrically wired to constitute a catalyst reactor, and a hydrogen production test was conducted by the hydrogen production system of FIG.
In the test, the quality of dehydrogenation using methylcyclohexane (MCH) as the fluid to be treated is analyzed and measured by gas chromatography of hydrogen generation amount and toluene conversion rate of methylcyclohexane. The body was able to be heated to the target temperature of 350 ° C. in about 3 minutes by adding an amount of electricity of 500 W through the power receiving unit. The temperature measurement is automatically controlled by a temperature sensor provided for each unit block.

  The fluid to be treated is supplied from the upstream side from a pulse type spray nozzle with methylcyclohexane in a hydrogen stream at a flow rate of 12 L / min, a spray time of 0.5 seconds (a single spray amount of 30 gr), and a spray interval of 10 and 20 seconds. The catalyst produced a hydrogen, and its catalytic reaction was evaluated for 2000 hours, and the state of material diffusion of the catalyst member accompanying the heating was investigated.

  The evaluation is based on the amount of hydrogen produced by the reaction, methylcyclohexane conversion indicating the purity of by-products, and toluene selectivity, with an average methylcyclohexane conversion of 92% and toluene selectivity of 98%. As a result, an average hydrogen production amount of 147 L / min was obtained, and it was confirmed that hydrogen was effectively produced.

  In addition, for the investigation of the influence of material diffusion associated with the long-time energization heating, a sample of the catalyst member after use was arbitrarily sampled and five points of samples were used, and the respective cross sections were observed with a microscope. The structure of the boundary portion between the core material (Ni wire) and the coated aluminum layer was observed, and the presence or absence of increase in the diffusion layer was compared with that in the unused original wire state. However, in this example material, the NiAl phase formed by the relatively high temperature treatment at the processing stage becomes a barrier layer, and further metal reaction can be suppressed, and sufficient effectiveness is obtained with little change over time. It was.

  A nickel wire (purity 99%) having a wire diameter of 8 mm having a current heating function is used as a core material, and a chromium layer having a thickness of 50 μm is formed by an electrochrome plating method, and further inserted into an Al pipe. A three-layer composite wire was prepared.

  Then, the wire rod is thinned through a cold wire drawing with a final working rate of 88% and an intermediate heat treatment under conditions of a temperature of 620 ° C. × 1 min, and finally a composite thin wire with a wire diameter of 0.9 mmφ Got.

  The composite thin wire has an average thickness of the aluminum layer of 100 μm, and the cross section thereof was observed with a microscope. As a result, the chromium layer having a thickness of 5 μm was formed on the boundary surface between the core material Ni material and the clad material aluminum layer. The chrome layer has an uneven shape having a substantial circumferential length of 1.04 times the calculated circumferential length in a cross-sectional view by the cold working.

  Using this composite wire, a coiled wire wound with a tightly wound coil having an outer diameter of 10 mm was obtained in the same manner as in Example 1, and this was incorporated into a catalytic reactor and subjected to continuous energization heating for 1500 hours. The structure of the cross section was similarly observed with a microscope. The heating temperature is set to a heating temperature of 340 ° C. in a reducing atmosphere according to the use state, but no substantial diffusion is observed at that heating temperature, and the chromium layer has a sufficient barrier effect. It was confirmed that there is.

The exothermic wire and the coated metal layer were further evaluated for other metal materials.
Here, the heating wire is a 0.6 mm nichrome (Ni—Cr alloy) wire, and the coated metal layer is coated with a titanium metal to a thickness of 0.1 mm, and the interface is the same as in the first embodiment. A TiNi precursor compound layer was interposed by an intermediate heat treatment, and the same catalyst loading was used.
In the evaluation, while heating this to an expected use temperature of 380 ° C., the change in the interface between the heating wire and the coating metal layer accompanying the continuous treatment for 800 hours was observed, and the result was good.

Industrial application fields

  The catalyst member according to the present invention can reduce the influence on the material properties particularly due to metal diffusion as an electrically heated catalyst wire, and can improve the product life, and is particularly wide as a maintenance-free catalyst member. It can be expected for use, and can be widely used in the energy field such as automobiles and ships using hydrogen as fuel.

DESCRIPTION OF SYMBOLS 1 Catalyst member 2 Coil part 1A Heating wire 1B Coated metal layer 1C Catalyst support layer X Catalyst substance Y Diffusion suppression layer

Claims (9)

A metal heating wire that heats up to a predetermined temperature when energized,
A coating metal layer encapsulating the heating wire and made of a second metal material different from the heating wire;
On the outer peripheral surface of the coated metal layer is provided with a catalyst supporting layer for supporting a predetermined catalyst substance,
Including the catalyst material supported on the catalyst support layer;
The interface between the heating wire and the coating metal layer is provided with a non-smooth uneven shape along the circumferential direction, which includes a diffusion suppression layer that suppresses excessive diffusion between the heating wire and the coating metal layer that are formed with use. A composite wire-type catalyst member.   The diffusion-inhibiting layer is either a third coating layer made of a refractory metal material having a melting point of 1500 ° C. or higher, or a precursor diffusion layer formed in advance by mutual diffusion of the heating wire and the coating metal layer. The composite wire-type catalyst member according to claim 1.   3. The composite wire type catalyst member according to claim 2, wherein the precursor diffusion layer is made of an intermetallic compound formed in a layer shape in accordance with a heat treatment in a production stage of a coated composite wire of the heating wire and the coated metal layer.   The heating wire is made of nickel metal, the covering metal layer is made of aluminum metal, and the precursor diffusion layer is made of a Ni—Al intermetallic compound generated by a thermal reaction between the nickel metal and the aluminum metal. The composite wire-type catalyst member according to claim 3, which is a thing.   The composite wire type catalyst member according to any one of claims 1 to 4, wherein the diffusion inhibiting layer has a constituent thickness of 60 µm or less.   The diffusion-inhibiting layer has the concavo-convex shape having an actual circumference of 1.02 to 1.4 times the apparent circumference calculated from the cross-sectional area drawn by the center position of the constituent thickness. The composite wire-type catalyst member according to any one of claims 1 to 5.   The composite wire type catalyst member according to claim 6, wherein the catalyst member further includes a coil portion wound in close contact by coiling.   The composite wire-type catalyst member according to claim 7, wherein the coil portion is wound obliquely in a fixed direction at an inclination angle (α) of 70 ° or less in plan view.   A plurality of catalyst members according to any one of claims 1 to 8 are stacked in a plurality of stages along a flow direction of a fluid to be treated supplied into a predetermined catalyst reaction chamber, and the heating wire of the catalyst member A catalytic reactor for producing hydrogen, characterized by comprising an electric circuit for heating and heating each.

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