JP6527398B2 - Composite wire type catalyst member and catalytic reactor for hydrogen production using the same - Google Patents

Description

Detailed Description of the Invention

  The present invention, for example, as a catalyst member for dehydrogenation reaction which is a hydrogenation reaction to an aromatic compound or its reverse reaction, particularly a composite wire which contributes to prolonging the life while performing the reaction temperature by electric heating of the member The present invention relates to a catalyst member of the type and a catalytic reactor for hydrogen production using the same.

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

  Various methods have been tried in the past for hydrogen production, but in terms of scale it is mainly of a relatively small amount type, and is still developed as a production system suitable for high flow rate plants such as for hydrogen stations. It is in the stage. As typical examples thereof, there may be mentioned, for example, those by electrolysis of water, those by a separation membrane which separates and generates only hydrogen from various mixed fluids containing hydrogen, and further by other catalyst technology. Also, as for the latter catalyst technology, for example, Patent Document 1 uses a Nichrome wire for electric heating as a core wire, and further coats the surface with an aluminum metal film to carry out anodizing treatment and support a catalyst substance. Are disposed along the flow path in the separate upper and lower formwork.

  In addition, the applicants of the present invention have a coil wire body in which the wire is formed into a coil shape to improve the surface area in order to further increase the catalyst loading amount per unit volume of such a composite type wire. Patent documents 2 to 4) are provided, and efforts are made to improve the efficiency.

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

  As described above, each of the prior patent documents is directed to a composite wire type catalyst member, in which an exothermic heating wire for electric heating is disposed on the axial core, and porous alumite through the aluminum coating layer on the surface It is intended to form and encapsulate a layer. That is, by using a composite wire structure of a three-layer structure provided with the heating wire, the aluminum layer, and the alumite layer supporting the catalyst substance, the catalyst member has a heating response, that is, a response to control and response speed to a predetermined temperature. Sex is promoted.

  However, since the catalyst member carries a predetermined catalyst substance on the porous structure portion of the alumite layer, the catalytic reaction is carried out, for example, at a temperature of about 300 to 500 ° C. Interdiffusion at the interface between the heating wire and the aluminum covering layer is inevitable. In particular, when the use is repeated while heating or cooling continuously or intermittently over a long period such as, for example, 10000 hours or more, preferably 3 years or more, the diffusion-affected zone is increased to generate heat. There is a concern that the current-carrying performance of the wire may be reduced, or delamination may occur at times or disconnection, and it is required to prevent this problem in advance.

  Based on such use condition, the present inventor pays attention to the interface between the heat generating core wire material and the covering metal layer that encapsulates the surface, and in particular, prevents the excessive diffusion generated with the use. We worked to improve the heat resistant life so as to be suitable for long-term stable use. As a result, in order to prevent the excessive diffusion formed in the use environment at the interface, it is concluded that it is effective to form a diffusion inhibiting layer in advance, and the present invention has been completed.

  Thus, according to the present invention, in the composite wire type catalyst member which is heated and used under a predetermined heating environment for a long period of time, a diffusion inhibiting layer for preventing the excessive diffusion in the structural interface portion in advance. By providing the diffusion preventing layer as a barrier to prevent excess diffusion beyond necessity, and to provide a catalyst member contributing to the improvement of the heat resistant life and a catalyst reactor for hydrogen production using the same. Do.

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

Further, in the present invention, the diffusion inhibiting layer is a third coating layer of a high melting point metal having a melting point of 1500 ° C. or more. The invention according to claim 2 is characterized in that the diffusion preventing layer contains molybdenum, vanadium, niobium, chromium or tantalum, and in the invention according to claim 3, the heating wire is nickel metal, and the coated metal is The layer is characterized by being composed of aluminum metal.

In the invention according to claim 4 , the diffusion inhibiting layer has a formation thickness of 60 μm or less, and according to the invention according to claim 5 , the apparent thickness calculated from the cross-sectional area drawn by the central position of the constituent thickness With respect to the upper circumference, it makes the above-mentioned concavo-convex shape provided with 1.02-1.4 times the actual circumference.

Furthermore, the invention of the catalyst member according to claim 6 further comprises a coil portion wound in a close contact manner by coiling, and in the invention according to claim 7 , the coil portion is 70 ° in plan view. It is also characterized in that it is obliquely wound in a fixed direction at the following inclination angle (α).

On the other hand, the invention according to claim 8 is directed to the invention of a catalytic reactor for producing hydrogen, and the flow direction of the to-be-treated fluid supplied to a predetermined catalytic reaction chamber with a plurality of catalyst members described in any of the above. And an electric circuit for electrically heating each of the heating wires of the catalyst member.

  According to the invention of claim 1 of the present application, as the composite wire type catalyst member to be electrically heated, a layer for preventing diffusion is formed in advance on the boundary surface between the heating wire and the covering metal layer covering the surface thereof. By setting the layer, it is possible to prevent the progress of excess diffusion further in the heating environment for the catalytic reaction when using it, and to form the boundary surface in a non-smooth uneven shape, so that the layer temporarily exceeds a predetermined level. Also in the case where a thick diffusion layer is produced, the uneven portions are engaged with each other to prevent partial peeling or breakage of the surface coating layer.

According to the inventions of claims 2 to 7 , by suitably forming the diffusion inhibiting layer, the influence of the excessive diffusion can be reduced and the engagement between the two metal materials can be further strengthened. Further, according to the invention of claim 8 , a plurality of the catalyst members are mounted in a plurality of stages, and an electric circuit is formed so that each of the heating wires can be energized and heated. It is possible to provide a space-saving catalytic reactor.

  It is a perspective view showing an example of a composite wire type catalyst member concerning the present 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 shaped 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 attached drawings.
The catalyst member of the composite wire type according to the present invention (hereinafter referred to simply as the catalyst member) is a linear metal heating wire 1A (hereinafter referred to simply as the heating wire) which heats to heat to a predetermined temperature by energization. A composite metal wire including a covering metal layer 1B which is encapsulated and is made of a second metal material different from the heating wire, and a catalyst supporting layer 1C laminated on the surface side of the covering metal layer 1B; The support layer 1C is loaded with a predetermined catalyst substance X set in advance on the surface thereof.

  In the composite wire type catalyst member 1 as described above, the present invention relates to the heating wire and the covering metal layer of the second metal material formed along with the use at the interface between the heating wire 1A and the covering metal layer 1B. And the suppression layer Y is formed in a non-smooth concavo-convex shape along the circumferential direction.

  As an example, FIG. 1 is in close contact with the thin wire material W of the composite clad structure adjusted to have the predetermined equivalent wire diameter d so as to have an average coil diameter D of, for example, about 5 to 20 mm over the entire length. It shows what is provided with the wound coil part 2. As the configuration can be understood by the above-mentioned Patent Documents 2 and 3, for example, the heating wire 1A disposed at the center of the axial core, and the covering metal layer 1B made of a second metal material for covering the heating wire, For example, it is understood as a wire-like catalyst member having a composite clad structure comprising a metal aluminum layer and a catalyst supporting layer 1C formed on the outer surface of the metal supporting layer 1C and supporting the catalyst substance X set in advance on the supporting layer 1C. Be done. The catalyst supporting layer 1C corresponds to, for example, an alumite layer obtained by anodic oxidation when the covering metal layer is made of aluminum metal.

  The cross-sectional shape of the catalyst member 1 is not limited to a circular cross-sectional shape like a normal metal wire, but may be a long strip material having a non-circular shape such as an oval, square or band. Moreover, it shape | molds this in coil shape like FIG. 1 is made into object. The wire diameter indication can be indicated by, for example, an equivalent wire diameter d calculated from an arbitrary cross-sectional area of the thin wire W, and in the present embodiment, the wire diameter d is, for example, about 0.3 to 2.0 mm. .

  In the thin wire material W of the above-mentioned structure, the heating wire 1A is selected from a metal material having a relatively large electric resistance which can heat and generate heat to a predetermined temperature by energization. For example, nickel chromium and metal materials such as nickel, chromium and iron Alloys, iron-chromium alloys, stainless steels, and various other alloy materials may also be employed. More preferably, one having an electric resistivity of 5 μΩ · cm or more, for example, 5 to 200 μΩ · cm is recommended, and for example, a wire material for electroheating such as nichrome, tungsten, molybdenum disclosed in each of the above patent documents is disclosed Nickel metal wire is preferred as shown in.

  In particular, in the case where the fine wire material W as shown in FIGS. 1 and 2 is processed by the cladding method, when the heating wire 1A is made of nickel metal and the second metal material which encapsulates the surface is made of aluminum metal The characteristics are similar and suitable for reduction in diameter. The heating wire 1A is not limited to this, and the metal wire of the above-described example having a characteristic that can be easily heated by current to a reaction use temperature of about 300 to 500 ° C. is adopted.

  In addition, as the second metal material constituting the covering metal layer 1B, as disclosed in the prior patent document, a porous structure having a large number of micropores is formed on the surface, for example, by anodizing treatment. Said aluminum metal is preferred. However, the present invention is not limited to this, and similarly, one capable of forming micropores is adopted. For example, metallic materials such as titanium, zinc, magnesium, zirconium and the like may be adopted similarly depending on the processing solution and conditions. Moreover, the formation thickness of the metal layer 1B is not particularly limited, and is appropriately set according to the use conditions. For example, the volume of the exterior material 1X including the metal layer 1B and the outermost catalyst supporting layer 1C is 70% or less (eg, 20% or more) in 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, as shown in FIG. 2, the present invention includes the diffusion inhibiting layer Y at the interface between the metal heating wire and the covering metal layer. The suppression layer Y suppresses, that is, prevents or reduces the excessive diffusion generated by the thermal reaction between the heating wire 1A and the covering metal layer 1B when it is heated to the use temperature at the time of using it. It is formed in a non-smooth uneven shape along the circumferential direction.

  For example, as disclosed in the respective prior documents, this uneven shape is formed by metal plating or cladding a first metal wire for the heating wire 1A, and a second metal material for the covering metal layer 1B on the surface thereof. Obtained by using a composite wire coated by the method as a raw material and reducing the diameter to a target wire diameter while performing reduction processing so as to enhance the adhesion, and further, the porous structure on the outermost surface side by anodizing treatment Also, a predetermined catalyst supporting layer Y can be supported in the pores. The surface treatment is carried out by electrochemical treatment in a predetermined electrolytic solution (eg, sulfuric acid, oxalic acid, etc.) disclosed in various documents including, for example, JP-A-2-144154 and JP-A-8-246190. Generally, a heating and baking process at about 350 to 600 ° C. is employed.

  Further, the diffusion inhibiting layer Y is a clad structure in which a film material of high melting point metal having a melting point of 1500 ° C. or more is disposed at the interface between the heating wire 1A and the covering metal layer 1B at the material stage. It can be comprised by the precursor diffusion layer by the layered intermetallic compound produced | generated by the heat processing in the intermediate | middle thru | or the last step of the coated composite wire of the said exothermic wire 1A and the coating metal layer 1B.

  The thickness of the diffusion inhibiting layer Y is preferably, for example, 60 μm or less. In the case of a thick coating state exceeding this, there is concern that delamination may occur, the processability may be reduced, and the product function of the catalyst member 1 may be affected. If the thickness is thinner than necessary, the effect can not be obtained, and more preferably 1 to 30 μm.

  In the case of the former high melting point metal film material, in addition to various metal materials such as molybdenum, vanadium, niobium, chromium and tantalum, some third elements (for example, W, Y2O3 of 10 mass% or less, etc.) ) Are selected. In particular, chromium, molybdenum and the like which are excellent in processability preferably have a relatively high melting point.

  When the heating wire 1A is a metal wire of Ni, for example, and the covering metal layer 1B is made of aluminum metal, the latter due to the precursor diffusion layer is, for example, 400.degree. The relatively stable compound layer can be formed by treating under the above-mentioned excessive heat treatment conditions (temperature and heating time). As an example, Ni-Al based intermetallic compounds such as NiAl, Ni3Al, Ni5Al3, Ni2Al3 etc. are illustrated. According to the diffusion inhibiting layer Y by these intermetallic compounds, the diffusion state is obtained by thermal reaction above the normal use temperature, and the actual use temperature is maintained at a temperature environment lower than this. The diffusion inhibiting layer acts as a relatively stable barrier layer, and the increase of the substantial diffusion phenomenon is suppressed. Therefore, for example, the heating wire 1A is prevented from reducing the heat generation function by the diffusion.

  It is effective that the diffusion inhibiting layer Y is formed in a non-smooth uneven shape along the interface between the two metals as seen in FIG. The concavo-convex portion mutually engages between the heating wire 1A and the aluminum layer 1B located on the both sides to provide an integral and strong composite wire, which contributes to prolonging the life.

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

  Such a concavo-convex state uses, for example, a relatively large diameter clad in the forming process of the composite wire, and a wire drawing process 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 process, since the processing strain is narrowed in the axial direction, the boundary surface forms an irregular asperity surface along with the processing degree.

  Therefore, even in the case of the former high melting point metal, the same concavo-convex state can be obtained by interposing a predetermined metal film material in advance in the interface at the material stage, and in the case of the latter diffusion inhibiting layer Y, In the heat treatment in the middle to the final stage, it is recommended to enhance the thermochemical reaction of the both by raising the heating temperature higher than the normal processing temperature or prolonging the heating time.

  The heating conditions are appropriately set according to the type and shape of the material to be used. For example, in the case of nickel and aluminum, they are set at a set temperature of about 400 to 650.degree. C. below the melting point and in the range of about 0.1 to 30 minutes. Be done. In particular, high temperature heating where the heating temperature exceeds 650 ° C. substantially approaches the melting point of aluminum, causing problems such as eccentricity, making it difficult to obtain a satisfactory composite wire. On the other hand, low-temperature heat treatment at less than 400 ° C. can not achieve sufficient softening, and the formation of the diffusion inhibiting layer Y also requires a long time. Preferably, it is set to 70 to 98% of the melting point of the low melting point side metal material, 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 including fine bottomed pores in its surface layer by oxidation treatment, for example, anodizing treatment, in the present embodiment, the aluminum coating The layer is described as an alumite layer. The pores are, for example, provided with micropores of a bottomed shape with 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 (mesoporous structure of turtle shell), if necessary The aspect ratio (depth / opening diameter) of the pores can be set to about 50 to 2000 by post-processing of the pore wide ring process or the baking process. The details thereof can be understood, for example, by the above-mentioned prior documents 2 to 4.

  With such a porous structure, a predetermined catalyst substance X can be supported at a high density in its pores, the amount of supported catalyst per unit area can be increased, and catalytic reaction is promoted. Further, since the alumite layer 1C is obtained by the oxidation treatment of the reaction base material, it is firmly bonded and formed with the base aluminum layer 1B. The fine pores can be appropriately adjusted, for example, by voltage control during anodizing treatment, and the above-mentioned example of the dimensions is an example thereof.

  The carrier layer 1C is an electrically nonconductive insulating film. Thus, the catalyst member 1 made of the composite wire covered with the insulating film can prevent an electrical short circuit due to contact with other members (housing container etc.) at the time of use, and its porous structure is very Since the catalyst is fine and hard, it is possible to properly support the predetermined catalyst substance X by preventing deformation and sealing of the fine opening. The catalyst substance X contained can be prevented from coming off or coming off due to contact with another member at the time of use, friction or the like.

  The catalyst substance X may be variously selected depending on the purpose of use, and is not particularly limited. For example, platinum (including platinum group metals and their alloys) is preferable. In addition to platinum, at least one transition metal selected from the group consisting of rhodium, rhenium, nickel, titanium, magnesium, zinc, zirconium, molybdenum and tungsten is preferable.

  In the supporting treatment of the catalyst substance X, a platinum solution containing the metal, for example, platinum, is applied to the alumite layer 1C having a porous structure, and pressure is applied to cause penetration into the bottomed pores H. Carried by As the platinum solution, for example, hexachloroplatinate (IV) hexahydrate solution, dinitrodiammineplatinum (II) nitric acid solution, hexaammineplatinum (IV) chloride solution, tetraammineplatinum (II) hydrate solution, etc. are suitably used. Be The platinum and / or the transition metal salt solution may be simultaneously or sequentially supported by a method such as immersion, dropping, coating or spraying in a predetermined temperature range while the wire body W is energized or electromagnetically heated. Furthermore, although the alumite layer is laminatedly formed on the outermost surface side of aluminum by lamination to form micropores, and the catalyst supporting layer supporting the catalyst substance on the micropores has been described, the present invention is not limited thereto. A fine cut may be made on the surface of the film to form pores, and a catalyst support layer may be used to support the catalyst material on the pores.

Besides this, 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 etc. by Chemical Vapor Deposition, and after loading, stepwise calcination 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 the coil portion 2 wound with the winding diameter D, and both ends of the coil wire (in the present embodiment, non-coiled portions) The supporting layer 1C is not provided and the connecting portions 3a and 3b to which the metal heating wire 1A is exposed are provided. The connection portions 3a and 3b are further connected to an external power supply outside the system and heated to a predetermined temperature by energization.

  It is preferable to carry out the processing or winding shape, molding dimension, etc. of the coil portion 2 in consideration of the wire diameter d of the catalyst member 1 and the catalyst supporting layer 1C on the surface, and the Patent Documents 2 and 3 Disclosed is a coiled product wound tightly around its entire length. In that case, since the coil portion 2 has a width and a coil height of approximately the same diameter and the inside of the coil portion is substantially hollow, it is possible to make the catalyst material sufficiently effective storage ratio Can not. Further, as in Patent Document 3, in the case of inserting coil wires of different sizes, the number of points is increased and it becomes complicated in inventory control, and as such a point is eliminated, for example, as shown in FIGS. 3a and 3b. A coil wire wound obliquely in a state of being inclined in the direction is suitable. FIG. 3a shows its plan view and FIG. 3b shows a side view.

  The catalyst member is configured to be inclined in a fixed direction having an inclination angle (α) in plan view, and the inclination angle α is set to, for example, 70 ° or less, preferably about 30 to 60 °. . In the coil wire body 2 thus inclined, the height h of the structure can be made smaller than the width, that is, it can be formed thin, so when using it stacked in multiple stages, for example, its entire thickness is greatly increased As a result, the entanglement between the coil portions 2 can be prevented, and a gap flow path through which the fluid to be treated can sufficiently flow can be obtained between the respective windings, which leads to a good catalytic reaction.

  Regarding the winding shape, for example, it is described that the coil portion 2 which is wound in a normal close-contact perfect circular shape using the composite wire is further squeezed in the oblique direction so as to be the predetermined angle α. Can. It is desirable that such winding formation be performed before the surface treatment of the alumite layer 1C. Further, in the coil portion 2 thus flattened, the average coil diameter D corresponding to the winding width is 3 times or more, for example 3 to 20 times, preferably 5 to 5 times the equivalent wire diameter d of the composite wire. It is set so as to be relatively large, such as 15 times, and is diagonally wound so as to have the inclination angle (α). The length of the coil portion is not particularly limited and can be set arbitrarily, but generally about 100 cm or less, for example, about 5 to 50 cm, for example, can be used relatively favorably in view of the usage of electric heating.

  With regard to the material for the catalyst reactor for hydrogen production of the catalyst member 1, for example, a plurality thereof can be disposed in multiple stages along the flow direction of the fluid to be treated supplied into a predetermined reaction chamber, The electric circuit which electrically heats the said exothermic line 1A of the catalyst member 1, respectively is comprised and used. For example, in addition to the above-mentioned patent documents, JP-A-2014-177360 shows its use form, and one having a multi-stage laminated type as shown in FIGS. 4 and 5 is preferable.

  As a representative example, FIG. 4 shows that the reactor 10 has a slightly small diameter middle container 13 in a large diameter housing container 12 provided with piping flanges 11A and 11B at the upper and lower end surfaces, for example, As a cassette type using, for example, a flat-plate-like accommodation holder 14 in which a plurality of coil wires 15 of the catalyst member are sequentially accommodated, it is configured by arranging it in multiple stages.

  Each coil wire body 15 is connected to an external power supply 27 (Dw) outside the system, and forms an electric circuit capable of conducting heating to a predetermined temperature, and if necessary, the housing container 12 and the middle container 13 It can also be used as an indirect heating type that supplies a heating fluid that has been heated to a predetermined temperature in advance by the supply port 16A and the outlet 16B in the empty space between them.

  Further, as shown in the system flow diagram of FIG. 5, for example, methylcyclohexane (MCH) solution is used as the raw fluid to be treated, and the fluid to be treated for hydrogen production is preheated and atomized by the vaporizer 23 on the upstream side. The catalyst reaction occurs by feeding the catalyst into the reactor 20. That is, in the line, the reaction gas generated in the catalytic reactor 24 through the storage tank 21 storing the MCH, the feed pump 22 and the vaporizer 23 is separated into gas and liquid by the next cooler 25 to separate and generate In the system, the recovered gas is recovered as hydrogen and the liquid as, for example, toluene in the recovery layer 30. In this embodiment, the vaporizer 23 uses a reducing back pressure gas such as hydrogen for preventing the supply back pressure of MCH and the oxidation deterioration of the catalyst substance of the reaction apparatus.

Further, if necessary, the 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. Thus, the fluid to be treated is rectified and adjusted from the upper side of FIG. 4 so that the supply amount can be substantially averaged over the entire surface through the dispersed porous plate 17, and catalytic reactions occur sequentially as it flows down.
Hereinafter, the present invention will be further described by the following examples.

[Production of aluminum clad coil fine wire]
A nickel wire (purity 99%) having an electric heating function was encapsulated with a band material of aluminum (purity 99.9%), and a base material of an aluminum clad wire (composite wire) with a wire diameter of 12 mm was used as a starting material. Then, after intermediate heat treatment under the conditions of a temperature of 620 ° C. × 5 min, the base wire is reduced in diameter by cold drawing at a final working ratio of 88%, and finally a composite fine wire having a wire diameter of 0.7 mmφ is obtained. Obtained.

  The composite thin line has an average thickness of 100 μm of the packaging material 1X including the aluminum layer, and the cross section thereof is microscopically observed to have an average thickness of 23 μm on the interface between the core material Ni and the cladding material aluminum layer. The compound layer was observed and X-ray diffraction of the compound layer confirmed that it was substantially NiAl.

  In this embodiment, the compound layer is presumed to be caused by heating for a long time more than the heat treatment in the prior art, and the boundary surface thereof is uneven with a non-circular cross section as shown in FIG. The peripheral length is a non-smooth uneven portion having a peripheral length of a reduced equivalent circle equivalent to the area of the sectioned area drawn by the middle point of the compound layer, that is, a length of about 1.08 times the apparent peripheral length. The two were firmly integrated together.

  Next, this composite fine wire was set in a coiling machine to obtain a tightly wound coil wire body having a winding average diameter D of 10 mm and a length of 300 mm. The coil wire was a close contact coil wire closely attached to about 1.01 times the wire diameter d of the composite fine wire, and no defect such as peeling was observed in the aluminum layer, and the coil had a good coil state. .

[Alumite treatment of composite thin line]
Next, the coil wire was subjected to anodizing treatment under the conditions of a 4 wt% aqueous solution of oxalic acid at a temperature of 35 ° C. and a current density of 60 A / m ² . Then, it was acid-treated while being immersed in the same type of oxalic acid-treated solution for 6 hours, and the pore size was broadened and dried in the air. Next, after baking treatment at 400 ° C. for about 1 hour, hydration treatment was carried out at 80 ° C. or more for about 2 hours and dried. Thereafter, it is further calcined at 500 ° C. for 3 hours to form an alumite clad metal fine wire provided with an alumite layer having a porous structure having pores on the surface, and this is further subjected to the following catalyst treatment to support platinum catalyst substance on the surface. The

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

[Reactor]
Next, eight of the coiled wire bodies are connected in series to form a unit block, and the three sets are sequentially incorporated into separate support holders to form a catalyst unit having a total of 24 coiled wire bodies.

  The support holder is a plate-shaped molded product of 300 × 300 mm in size by extrusion of aluminum alloy, and 10 mm high partition walls are provided in parallel at intervals of 12 mm on one side of the support holder. The coil wire body is sequentially incorporated along the circuit, and both terminals of each circuit block are respectively connected to relay terminals attached in an insulated state to one end of the holder and receive power supplied from outside the system. In the bottom surface, there are provided through holes at a distance of 5 mm, with a hole diameter of 10 mm, for passing the processing fluid.

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

  The fluid to be treated is supplied methylcyclohexane from the upstream side from a pulse spray nozzle 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 reaction was evaluated for performance over 2000 hours for hydrogen generation, 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, the conversion of methylcyclohexane showing the purity in the by-products, and the selectivity to toluene, and the conversion to methylcyclohexane is 92% on average, 98% on toluene selectivity The average hydrogen production amount was 147 L / min, and it was confirmed that hydrogen production was effective.

  Moreover, also about the influence investigation of the material diffusion accompanying the said long-time current heating, in the catalyst member after use, it extract | collected arbitrarily and performed microscopic observation of the cross section each using five samples, The structure of the boundary part between the core material (Ni wire) and the coated aluminum layer was observed, and the increase or absence of the diffusion layer was compared with that of the unused original wire state. However, in the material of this example, the NiAl phase formed by the relatively high temperature treatment in the processing step becomes a barrier layer, and further metal reactions can be suppressed, and the change with time is small, and sufficient effectiveness is obtained. It was done.

  Using a nickel wire (purity 99%) with a wire diameter of 8 mm having a current-carrying heating function as a core material, this is used to form a 50 μm-thick chromium layer by electrochromic plating and further inserted into an Al pipe, A three-layered composite wire was provided.

  Then, the base wire material is reduced in diameter through cold drawing at a final working ratio of 88% and intermediate heat treatment under conditions of a temperature of 620 ° C. × 1 min, and finally a composite fine wire with a wire diameter of 0.9 mmφ. I got

  When the average thickness of the aluminum layer is 100 μm, and the cross section of the composite fine wire is observed microscopically, the chromium layer with a thickness of 5 μm is formed at the interface between the core Ni material and the clad aluminum layer. The chromium layer has a concavo-convex shape having a substantial circumferential length of 1.04 times the calculated circumferential length in the cross-sectional view due to the cold working.

  By using this composite wire, a coiled wire wound with a close-contact coil and having an outer diameter of 10 mm is obtained in the same manner as in Example 1 and incorporated into a catalytic reactor to carry out continuous current heating for 1500 hours. The tissue condition of the cross section was similarly observed with a microscope. The heating temperature is set to 340 ° C. in a reducing atmosphere as in use conditions, but no substantial diffusion is observed at that heating temperature, and the chromium layer has a sufficient barrier effect. Was confirmed.

The heating wire and the coated metal layer were further evaluated in the case of other metal materials.
Here, the heating wire is a Nichrome (Ni-Cr alloy) wire of 0.6 mm and the covering metal layer is a titanium metal covering 0.1 mm in thickness, and the interface thereof is the same as in Example 1. A precursor compound layer of TiNi was intervened by intermediate heat treatment, and further, the same was applied to catalyst loading and the like.
The evaluation was made by heating this to the use assumed temperature of 380 ° C. and observing the change in the interface between the exothermic line and the coated metal layer during the continuous treatment for 800 hours, and the results were good.

Industrial application field

  The catalyst member according to the present invention can reduce the influence on the material characteristics especially due to metal diffusion as a catalyst wire of electric heating type, and aim at the improvement of the product life, and is particularly wide as a maintenance-free catalyst member. It can be expected for applications and can be widely used in the energy field of hydrogen fueled cars, ships and the like.

Reference Signs List 1 catalyst member 2 coil portion 1A heating wire 1B coating metal layer 1C catalyst supporting layer X catalyst substance Y diffusion inhibiting layer

Claims (8)

A metal heating wire that generates heat by heating to a predetermined temperature by energization;
A coated metal layer which encapsulates the heating wire and which is made of a second metal material different from the heating wire;
A catalyst supporting layer for supporting a predetermined catalyst substance on the outer peripheral surface of the coated metal layer ;
And a said catalytic material supported on the catalyst supporting layer,
The interface of the heating wire and the covering metal layer is provided with a diffusion inhibiting layer for suppressing excessive diffusion of the heating wire and the covering metal layer formed along with use in a non-smooth uneven shape along the circumferential direction ,
The composite wire type catalyst member characterized in that the diffusion inhibiting layer is a third covering layer made of a high melting point metal material having a melting point of 1500 ° C. or higher . The composite wire type catalyst member according to claim 1, wherein the diffusion inhibiting layer contains molybdenum, vanadium, niobium, chromium or tantalum. The heating wire is a nickel metal, the coating metal layer is a composite wire catalyst member according to claim 1 or 2 are those that consists of aluminum metal. The composite wire type catalyst member according to any one of claims 1 to 3, wherein the diffusion inhibiting layer has a thickness of 60 μm or less. The diffusion inhibiting layer has the concavo-convex shape having an actual circumferential length of 1.02 to 1.4 times the apparent circumferential length calculated from the cross sectional area drawn by the central position of the constituent thickness. The composite wire type catalyst member according to any one of claims 1 to 4. The composite wire type catalyst member according to any one of claims 1 to 5, wherein the catalyst member further comprises a coil portion wound tightly in a coiled manner. The composite wire type catalyst member according to claim 6, wherein the coil portion is obliquely wound in a predetermined direction at an inclination angle (α) of 70 ° or less in a plan view thereof. A plurality of catalyst members according to any one of claims 1 to 7 are stacked and arranged in a plurality of stages along the flow direction of the fluid to be treated supplied into a predetermined catalytic reaction chamber, and the heating wire of the catalyst member A catalytic reactor for hydrogen production, comprising:

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