JP2005132712A - Microreactor for producing hydrogen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microreactor for producing hydrogen which has a small size and exhibits high efficiency. <P>SOLUTION: The microreactor has at least: a plurality of unit flow path members each having a flow path in its inside, an introducing port provided at one end part of the flow path and a discharge port provided at the other end part; and a connection member for holding the unit flow path members in a multistage state. The connection member has a plurality of connection parts for closely holding the unit flow path members at each position where the introducing port of each unit flow path member is located and at each position where the discharge port is located, a raw material introducing port, and a gas discharge port. At least one of the unit flow path members is a unit microreactor supporting a catalyst on the flow path. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a microreactor used for hydrogen production, and more particularly to a microreactor capable of performing a multistage reaction for producing hydrogen from a raw material.

In recent years, attention has been focused on using hydrogen as a fuel because no global warming gas such as carbon dioxide is generated from the viewpoint of protecting the global environment and energy efficiency is high. In particular, fuel cells are attracting attention because they can directly convert hydrogen into electric power and have high energy conversion efficiency in a cogeneration system that uses generated heat. Up to now, fuel cells have been adopted under special conditions such as space development and marine development, but recently they have been developed for use in automobiles and household distributed power supplies, and fuel cells for portable devices have also been developed. ing.
Among fuel cells, a fuel cell that takes out electricity by electrochemically reacting hydrogen gas obtained by reforming hydrocarbon fuels such as natural gas, gasoline, butane gas, and methanol and oxygen in the air is Generally, it is composed of a reformer that generates hydrogen gas by steam reforming a hydrocarbon-based fuel, and a fuel cell body that generates electricity.

In a reformer for obtaining hydrogen gas by steam reforming using methanol or the like as a raw material, a Cu—Zn-based catalyst is mainly used, and the steam reforming of the raw material is performed by an endothermic reaction. In an industrial fuel cell, start-up and stop are not frequently performed, so that the temperature fluctuation of the reformer hardly occurs. However, since fuel cells for automobiles and portable devices are frequently started and stopped, the start-up of the reformer is quick when starting from a stopped state (the time until the steam reforming temperature of methanol is reached). Short).
On the other hand, especially for portable devices, downsizing of the fuel cell is essential, and various downsizing of the reformer has been studied. For example, a microreactor in which a microchannel is formed on a silicon substrate or a ceramic substrate and a catalyst is supported in the microchannel has been developed (Patent Document 1).
JP 2002-252014 A

However, in conventional hydrogen production using a microreactor, a microreactor for each step of hydrogen production (mixing, reforming, CO removal) is prepared, and a plurality of these microreactors are connected by piping. When the space becomes large and the space allowed for the microreactor is severely limited, such as a fuel cell for portable devices, it has seriously hindered miniaturization.
In addition, when a catalyst is deactivated or deteriorated in a microreactor for one process during use and its function is lost, it is necessary to replace a plurality of microreactors including a normally functioning microreactor. There was a problem that the running cost was hindered.
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a small and highly efficient microreactor for hydrogen production.

  In order to achieve such an object, the present invention provides a microreactor for reforming a raw material to obtain hydrogen gas, and has a flow path inside, and one end of the flow path has an inlet. None, comprising at least a plurality of unit flow path members whose other end portion forms a discharge port, and a connection member for holding the unit flow path members in a multistage state, wherein the connection member is an inlet of the unit flow path member At least one unit having a plurality of connecting portions, a raw material introduction port, and a gas discharge port for adhering and holding the unit flow path member at the site where the discharge port is located The flow path member is a unit microreactor in which a catalyst is supported in the flow path, and the raw material is introduced from the raw material introduction port of the connecting member, and among the plurality of unit flow path members, a predetermined microreactor is used. React, from the gas outlet of the connecting member It was configured so as to obtain a Nozomu of the product gas.

  As another aspect of the present invention, there are n (n is an integer of 2 or more) unit flow path members, and the connection portion is connected to the introduction connection portion connected to the raw material introduction port, and the gas discharge port. It is composed of a connected discharge connecting portion and (n-1) sets of stage transition connecting portions connected to each other through an internal communication path. The first-stage unit flow path member has an introduction port at the introduction connecting portion. The discharge port is connected and held to the stage transition connecting portion, and the unit flow path members from the second stage to the (n-1) th stage are connected at the introduction port to the previous stage transition connecting part by the internal communication path. The discharge port is connected to and held by another set of stage transition connection parts, and the unit flow channel member of the nth stage connects the introduction port with the previous stage transition connection part through an internal communication path. It was set as the structure which the discharge port was connected and hold | maintained to the said discharge | emission connection part to the made stage transition connection part, respectively.

As another aspect of the present invention, the unit channel member is configured to be removable.
As another aspect of the present invention, the unit microreactor is configured such that a catalyst is supported on the inner wall surface of the unit channel member via a metal oxide film.
As another aspect of the present invention, each unit channel member has the same structure, and has a configuration in which a plurality of unit microreactors having different catalyst species supported in the channel are provided.
In another embodiment of the present invention, the unit microreactor including a heating element is provided.
As another aspect of the present invention, a configuration is adopted in which a space for heat insulation and / or a heat insulating material are interposed between unit flow path members at desired adjacent stages.
As another aspect of the present invention, the other end portions of the plurality of unit flow path members held in a multistage state by the connecting member are fixed with a fixing member.

As another aspect of the present invention, the unit flow path member is a joined body obtained by bonding a pair of metal substrates on which fine grooves for forming the flow path are formed so that the fine groove portions face each other, It was set as the structure which was the joined body which joined the metal cover member to the metal substrate surface in which the fine groove part for comprising a path | route was formed.
As another aspect of the present invention, the unit flow path member is a joined body obtained by bonding a pair of metal substrates on which fine grooves for forming the flow path are formed so that the fine groove portions face each other, It was set as the structure provided with the conjugate | zygote which joined the metal cover member to the metal substrate surface in which the fine groove part for comprising a path | route was formed.
As another embodiment of the present invention, the unit microreactor has a structure in which the catalyst is supported in the flow channel after forming the joined body, or a catalyst in which the catalyst is supported in the fine groove before joining. It was set as such a structure.

  According to the present invention, among the unit flow path members connected and held in a multistage state, the desired unit flow path member is a unit microreactor carrying a catalyst in the flow path. In addition, by selecting the number of unit microreactor stages and the type of catalyst supported on the unit microreactor, a microreactor for producing hydrogen having desired performance and characteristics can be obtained. Furthermore, by making each unit channel member removable, only the unit microreactor in which the catalyst is deactivated or deteriorated can be replaced, and the function of the entire microreactor can be maintained. In addition, by forming a unit microreactor by supporting a catalyst after forming a joined body, a unit microreactor carrying a catalyst corresponding to a required function using a unit flow path member (joined body) having the same structure. As a result, the manufacturing cost and running cost of the microreactor can be reduced. In addition, by providing a heating element in a desired unit microreactor, or by interposing a space for heat insulation or a heat insulating material between unit flow path members, it is possible to achieve an optimum temperature for each unit microreactor, thereby improving reaction efficiency. Improvement and effective use of heat are possible.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view showing an embodiment of the microreactor of the present invention, FIG. 2 is an enlarged longitudinal sectional view taken along line II of the microreactor shown in FIG. 1, and FIG. 3 is shown in FIG. It is a perspective view which shows the state which spaced apart the structural member of the microreactor. 1 to 3, a microreactor 1 according to the present invention has three unit channel members 2a, 2b, 2c connected and held by a connecting member 4 and a fixing member 6 in a multi-stage state of three stages. . A gap 7 is provided between the unit flow path members 2a, 2b, 2c.

  The unit flow path members 2a, 2b, and 2c have a flow path inside, and one end portion of the flow path forms an introduction port and the other end portion forms a discharge port. Of the three unit channel members 2a, 2b, and 2c, the unit channel members 2b and 2c are unit microreactors that carry a catalyst in the channel. That is, as shown in FIG. 2, each of the unit flow path members 2a, 2b, and 2c includes a metal substrate 11 on which the fine groove portion 12 is formed and a metal substrate 13 on which the fine groove portion 14 is formed. And the fine groove portion 14 are joined so as to face each other, and the joined body 10 is formed with a metal oxide film (insulating layer) 16 formed around it. Inside the joined body 10, a flow path 15 composed of opposed fine groove portions 12 and 14 is formed. In the unit flow path members (unit microreactors) 2b and 2c, the catalysts C1 and C2 are supported on the entire inner wall surface of the flow path 15 via the metal oxide film 16, respectively. In the illustrated example, the unit channel member 2a that does not carry a catalyst on the inner wall surface of the flow channel 15 also has the metal oxide film 16 on the inner wall surface of the flow channel 15 in the joined body 10. The metal oxide film 16 may not be provided.

  As shown in FIG. 3, the joined body 10 constituting the unit flow path members 2a, 2b, and 2c has a pair of protrusions 10a and 10b in the same direction. FIG. 4 is a perspective view for explaining the state of the channel 15 taking the unit channel member 2a as an example. As shown in FIG. 4, the flow path 15 has a shape that meanders continuously from an end located at the projecting portion 10 a to an end located at the projecting portion 10 b. And the edge part of the flow path 15 located in the protrusion part 10a comprises the inlet 3a, and the edge part of the flow path 15 located in the protrusion part 10b comprises the discharge port 3b. Specifically, in the unit flow channel member 2a and the unit flow channel member (unit microreactor) 2c, the end of the flow channel 15 located in the protruding portion 10a forms the introduction port 3a, and the flow channel located in the protruding portion 10b. 15 end portions form the discharge port 3b. In the unit channel member (unit microreactor) 2b, the end of the channel 15 located in the protruding portion 10a forms the discharge port 3b, and the end of the channel 15 positioned in the protruding portion 10b serves as the inlet 3a. There is no. Therefore, from the first stage unit flow path member to the third stage unit flow path member (unit microreactor), the projecting portion 10a side is arranged in the order of the introduction port 3a, the discharge port 3b, and the introduction port 3a. On the part 10b side, the discharge port 3b, the introduction port 3a, and the discharge port 3b are arranged in this order.

  Further, a heating element 17 is provided on one surface of the joined body 10 constituting each unit flow path member 2a, 2b, 2c, and electrodes 18, 18 are formed on the heating element 17, and the electrodes 18, A heating element protective layer 19 is provided so as to cover the heating element 17 so that a part of the heating element 18 is exposed. FIG. 3 shows a state where the heating element protective layer 19 of the unit flow path member 2a is separated. In the illustrated example, the heating element 17 and the electrodes 18 and 18 are also provided in the unit channel member 2a that is not a unit microreactor. However, the heating element 17 and the electrode 18 are provided only in the unit channel member that is a unit microreactor. , 18 may be provided.

  The connecting member 4 holds the unit flow path members 2a, 2b, 2c in a multistage state, and has a structure 21 shaped so as to sandwich the block body 21c between the block bodies 21a, 21b. 5 is a view showing a surface on which the connecting portion of the connecting member 4 is formed, FIG. 6 is a cross-sectional view of the connecting member shown in FIG. 5, and (A) is a cross-sectional view taken along the line II-II, (B) is sectional drawing in the III-III line. As shown in FIGS. 5 and 6, the unit channel members 2 a, 2 b, 2 c are provided on one surface of the block bodies 21 a, 21 b, and the projection of the joined body 10 where the introduction port 3 a and the discharge port 3 b are located. A plurality of connecting portions 22 are provided to be held in close contact with the portions 10a and 10b. Further, a raw material introduction port 23 is provided on the opposite surface of the block body 21a, and a gas discharge port 24 is provided on the opposite surface of the block body 21b.

  The connecting portion 22 provided in the block body 21a includes an introduction connecting portion 22a connected to the raw material inlet 23 and the internal flow path 26, and a set of stage transition connecting portions connected to each other via the internal communication passage 25a. 22d and 22e, which are arranged in a line. The connecting portion 22 provided in the block body 21b is connected by a set of step transition connecting portions 22b and 22c connected to each other by an internal communication path 25b, a gas discharge inlet 24, and an internal flow path 27. The discharge connecting portions 22f are arranged in a line. And in each connection part 22 (22a, 22b, 22c, 22d, 22e, 22f), the protrusion parts 10a and 10b of the joined body 10 which comprises each unit flow path member 2a, 2b, 2c are airtight and liquid-tight. A packing 28 for tightly holding in the state is provided. In addition, the dimension of each connection body 22 is suitably set corresponding to the shape of the protrusions 10a and 10b of the unit flow path members to be connected and held.

  The above-mentioned connecting member 4 inserts the projecting portion 10a and the projecting portion 10b of the first-stage unit flow path member 2a into the introduction connecting portion 22a and the step transition connecting portion 22b, and keeps them in close contact with each other. The protrusion 10b and the protrusion 10a of the second stage unit flow path member (unit microreactor) 2b are inserted and held in close contact with 22d, and the third stage unit flow is supplied to the stage transition connection 22e and the discharge connection 22f. The protruding portion 10a and the protruding portion 10b of the path member (unit microreactor) 2c are inserted and held in close contact with each other. The packing 28 described above is for ensuring that the unit flow path members 2a, 2b, and 2c are in close contact with each other by the connecting member 4. For example, the packing 28 has elasticity such as an O-ring and silicon rubber. It can consist of the material which has. In addition, in order to ensure that the unit flow path members 2a, 2b, and 2c are closely held by the connecting member 4, an auxiliary member having elasticity such as silicon rubber is provided around the protruding portion 10a and the protruding portion 10b. It may be provided.

The fixing member 6 fixes other end portions of the unit flow path members 2a, 2b, and 2c held in a multistage state by the connecting member 4, and includes a frame body 31 and the inside of the frame body 31. Partition members 32a and 32b for partitioning in three stages are provided. The fixing member 6 is arranged in a multi-stage state by disposing the end portions of the unit flow path members 2a, 2b, 2c into the storage spaces 33a, 33b, 33c partitioned by the partition members 32a, 32b. Can be held fixed.
In the microreactor 1 as described above, the raw material introduced from the raw material introduction port 23 of the connecting member 4 passes through the internal flow path 26 and is introduced from the introduction connecting portion 22a to the first stage unit flow passage member 2a. Reach 3a. And after desired raw material mixing is performed in the flow path 15 of the unit flow path member 2a, the second stage from the stage transition connection part 22c via the discharge port 3b and the stage transition connection part 22b and the internal communication path 25b. To the inlet 3a of the unit flow path member (unit microreactor) 2b. Then, after passing through the flow path 15 in which the catalyst C1 of the unit microreactor 2b is carried, it is sent from the discharge port 3b to the stage transition connection part 22e via the stage transition connection part 22d and the internal communication path 25a. It reaches the inlet 3a of the stage unit flow path member (unit microreactor) 2c. Then, after passing through the flow path 15 on which the catalyst C2 of the unit microreactor 2c is carried, the discharge port 3b passes through the discharge connection portion 22f and the internal flow path 27 and reaches the gas discharge port 24.

In the microreactor 1 described above, the heating element 17 is disposed in each of the unit flow path members 2a, 2b, 2c, and the gap 7 exists between the unit flow path members. Thus, unnecessary conduction of heat in the unit microreactors 2b and 2c can be prevented, and optimum temperature settings can be made respectively.
Further, in the present invention, for example, as shown in FIG. 7, the unit microreactor having the heating element 17 is only the second-stage unit channel member (unit microreactor) 2b, and the first-stage unit channel member. 2a ′ and the third stage unit flow path member (unit microreactor) 2c ′ may not include the heating element 17. A space 7 for heat insulation is provided between the first-stage unit channel member 2a ′ and the second-stage unit channel member (unit microreactor) 2b, and the second-stage unit channel member (unit The heat insulating material 8 may be interposed between the microreactor 2b and the third-stage unit flow path member (unit microreactor) 2c ′. As the heat insulating material 8, for example, glass wool, a ceramic substrate, or the like can be used.

Further, the positional relationship between the raw material inlet 23 and the gas outlet 24 of the connecting member 4 is not limited to the illustrated example. For example, the inner passage 27 is bent to form the raw material inlet 23 and the gas outlet 24. The outlet 24 may be arranged at the same height.
The above-described microreactor 1 has a three-stage structure in which two of the three unit channel members are unit microreactors. In the present invention, the number of unit channel members is two, or four or more. The number of unit microreactors among the unit flow path members is not particularly limited. And the number of the stage transition connection parts of the connection member 4 is set according to the number of steps of the unit flow path member. That is, in the present invention, when there are n (n is an integer of 2 or more) unit flow path members, among the connecting portions of the connecting members, the stage transition connecting portions connected to each other through the internal communication path (n− 1) A combination can be provided. The first stage unit flow path member is connected and held with the introduction port at the introduction connection part and the discharge port at the stage transition connection part, respectively, and the unit flow path member from the second stage to the (n-1) th stage. For, the inlet is connected to the stage transition connecting section connected to the previous stage transition connecting section through the internal communication path, and the discharge port is connected to another set of stage transition connecting sections. The path member constitutes the microreactor of the present invention by holding the inlet at the stage transition connecting portion connected to the previous stage transition connecting portion by the internal communication path and the discharge port at the discharge connecting portion, respectively. be able to.

Here, each member which comprises the above-mentioned microreactor 1 is demonstrated.
First, members constituting the unit flow path members 2a, 2b, and 2c will be described. For the metal substrates 11 and 13 constituting the joined body 10, a metal capable of forming a metal oxide film (insulating film) 16 by anodic oxidation can be used. Examples of such metals include Al, Si, Ta, Nb, V, Bi, Y, W, Mo, Zr, and Hf. Among these metals, Al is particularly preferably used from the viewpoint of processability, characteristics such as heat capacity and thermal conductivity, and unit price. In addition, as the metal substrates 11 and 13 constituting the bonded body 10, a material capable of forming the metal oxide film 16 by boehmite treatment such as Cu, stainless steel, Fe, and Al can be used. In this case, the metal oxide film 16 existing around the metal substrates 11 and 13 may be similarly formed by boehmite treatment, or a printing method such as screen printing using a paste containing an insulating material, or sputtering. Polyimide, ceramic (Al ₂ O ₃ , SiO ₂ ) or the like may be formed by a vacuum film formation method such as vacuum deposition.

The thickness of the metal substrates 11 and 13 takes into consideration the size of the unit flow path members 2a, 2b, and 2c, the characteristics of the heat capacity and thermal conductivity of the metal used, the size of the fine groove portions 12 and 14 to be formed, and the like. Although it can set suitably, it can set in the range of about 400-1000 micrometers, for example.
The fine groove portions 12 and 14 formed in the metal substrates 11 and 13 are not limited to the illustrated shape, and the amount of the catalyst carried in the fine groove portions 12 and 14 increases, and the raw material is the catalyst. It can be set as the arbitrary shapes that the flow path length to contact becomes long. The depth of the fine groove portions 12 and 14 can be set, for example, in the range of about 100 to 1000 μm, the width can be set in the range of about 100 to 1000 μm, and the flow path length can be set in the range of about 30 to 300 mm. it can.

In the present embodiment, since the metal oxide film 16 is formed on the inner wall surface of the flow path 15, the supported amount of the catalysts C 1 and C 2 is increased by the surface structure of the metal oxide film having micropores, and the stable catalyst. Support is possible.
As the catalysts C1 and C2, known catalysts conventionally used for hydrogen production can be used. For example, the raw material is mixed and vaporized in the first stage unit flow path member 2a, and the second stage unit flow path member (unit microreactor) 2b reforms the mixed gas. The third stage unit flow path When the member (unit microreactor) 2c removes impurities from the reformed gas, Cu—ZnO / Al ₂ O ₃ or the like can be used as the catalyst C1, and Pt / Al ₂ O ₃ or the like can be used as the catalyst C2.
The heating element 17 is for supplying heat necessary for each unit flow path member (unit microreactor), such as carbon paste, nichrome (Ni—Cr alloy), W (tungsten), Mo (molybdenum), and the like. Material can be used. For example, the heating element 17 may have a shape in which a thin wire having a width of about 10 to 200 μm is drawn around the entire surface of the joined body 10 corresponding to the region where the fine groove is formed.

On such a heating element 17, electrodes 18 and 18 for energization are formed. The energization electrodes 18 and 18 can be formed using a conductive material such as Au, Ag, Pd, and Pd—Ag.
The heating element protective layer 19 is disposed so as to expose a part of the electrodes 18 and 18 and cover the heating element 17. The heating element protective layer 19 can be formed of, for example, photosensitive polyimide, varnish-like polyimide, or the like. In addition, the thickness of the heating element protective layer 19 can be appropriately set in consideration of the material to be used, but can be set, for example, in the range of about 2 to 25 μm.

Moreover, the material of the connection member 4 can be stainless steel, Al, Fe, Cu, or the like, and can be formed into a desired structure shape by machining, diffusion bonding, brazing, or the like. For example, as shown in FIGS. 6A and 6B, the structure 21 forming the connecting member 4 can be composed of six members divided by five alternate long and short dash lines L1 to L5. . And in six members, the groove part and through-hole for comprising the connection part 22, internal communication path 25a, 25b, internal flow path 26, 27 grade | etc., Are previously formed in one surface. The connecting member 4 can be formed by diffusing and integrating these six members in a predetermined order.
Further, the packing 28 can be made of an O-ring, silicon rubber or the like made of various conventionally known materials.
The material of the fixing member 6 can be the same as that of the connecting member 4.

The above-described embodiment of the microreactor is an example, and the present invention is not limited to these.
For example, the structure of the unit flow path members 2a, 2b, 2c has a flow path capable of carrying a catalyst therein, and one end of this flow path serves as an inlet, and the other end is There is no particular limitation as long as it forms a discharge port. Therefore, as shown in FIG. 8A, as a unit flow path member (unit microreactor) 2b, a metal substrate 42 having a fine groove 43 formed on one surface, and a metal substrate so as to cover the fine groove 43 The metal cover member 44 bonded to 42 and the bonded body 41 including the metal oxide film 46 around the metal cover member 44 may be used. Inside the joined body 41, a flow path 45 composed of the fine groove portion 43 and the metal cover member 44 is formed, and the catalyst C1 is formed on the entire inner wall surface of the flow path 45 via the metal oxide film 46. It is supported. Further, as shown in FIG. 8B, as the unit flow path member (unit microreactor) 2b, a fine groove portion 53 in which the catalyst C1 is supported is formed on one surface via the metal oxide film 56. You may have the joined body 51 which consists of the metal substrate 52 and the metal cover member 54 joined to the metal substrate 52 so that the fine groove part 53 may be covered. Inside the joined body 51, a flow path 55 composed of a fine groove 53 and a metal cover member 54 is formed, and a metal oxide film (insulating film) 56 is formed around the metal substrate 52. ing.

Next, a manufacturing method will be described with reference to FIG. 9, taking the unit channel member (unit microreactor) 2b including the above-described joined body 10 as an example.
In FIG. 9, the fine groove portion 12 is formed on one surface of the metal substrate 11, and the fine groove portion 14 is formed on one surface of the metal substrate 13 (FIG. 9A). The fine groove portions 12 and 14 can be formed by forming a resist having a predetermined opening pattern on the metal substrates 11 and 13 by wet etching using the resist as a mask, and processing by a micromachine can be made unnecessary. .
Next, the metal substrates 11 and 13 are joined so that the fine groove portions 12 and the fine groove portions 14 face each other, thereby forming the joined body 10 (FIG. 9B). Thereby, the fine groove part 12 and the fine groove part 14 oppose, and the flow path 15 is formed. The metal substrates 11 and 13 can be bonded by, for example, diffusion bonding or brazing.

Next, the joined body 10 is anodized to form a metal oxide film (insulating film) 16 on the entire surface including the inner wall surface of the flow path 15 to form the unit flow path member 2b (FIG. 9C). The metal oxide film (insulating film) 16 can be formed by immersing the joined body 10 in the state of being connected to the anode of the external electrode and immersing it in an anodic oxidation solution so as to face the cathode and energizing it. When a metal material that cannot be anodized and can be subjected to boehmite treatment is used as the metal substrates 11 and 13, the metal oxide film 16 is formed by boehmite treatment.
Next, the catalyst C1 is supported on the entire inner wall surface of the channel 15 of the unit channel member 2b via the metal oxide film (insulating film) 16 to form the unit microreactor 2b (FIG. 9D). For example, the catalyst C1 is supported on the metal oxide film (insulating film) 16 by filling the flow path 15 of the joined body 10 with the catalyst suspension or filling the joined body 10 in the catalyst suspension. It can be carried out by immersing and then removing the catalyst suspension from the channel 15 and drying.

  In addition, after forming the fine groove parts 12 and 14 in the metal substrates 11 and 13, the metal substrates 11 and 13 are anodized to form a metal oxide film, and then the metal oxide film present on the surface to be the bonding surface Then, the metal substrates 11 and 13 may be joined, and then the catalyst C1 may be supported on the metal oxide film.

Next, a heating element is provided on the metal oxide film (insulating film) 16 on the metal substrate 11 side, an electrode for energization is formed, a heating element protection layer is formed on the heating element, and the unit microreactor 2b is formed. Can be obtained.
As a method of forming the heating element, a method of forming by screen printing using a paste containing the above-mentioned material, a method of forming a coating film using a paste containing the above-mentioned material, and then patterning by etching or the like, Examples thereof include a method of forming a thin film by a vacuum film formation method using the above materials and then patterning by etching or the like. Moreover, the electrode for electricity supply can be formed by screen printing using the paste containing the above-mentioned electrically-conductive material, for example. Further, the heating element protective layer can be formed in a predetermined pattern by screen printing using a paste containing the above-described material, for example.

As described above, after the joined body 10 including the flow path 15 is formed, the catalyst C1 is supported to form the unit microreactor 2b, so that there is no risk of catalyst deactivation due to heat in the joining process. The selection range becomes wider. Further, by preparing a plurality of unit flow path members in which the metal oxide film (insulating film) 16 is completed up to the formation process, a unit microreactor having a function required only by supporting a desired catalyst, can do.
The unit flow path member (unit microreactor) 2b including the above-described joined body 41 is the same as that in the above production example by joining the metal cover member 44 to the metal substrate 11 instead of the metal substrate 13. Can be produced.

Next, a manufacturing method will be described with reference to FIG. 10 by taking the unit channel member (unit microreactor) 2b including the above-described joined body 51 as an example.
In FIG. 10, first, a fine groove 53 is formed on one surface of a metal substrate 52 (FIG. 10A). The formation of the fine groove portion 53 can be performed in the same manner as the formation of the fine groove portions 12 and 14 described above.
Next, the metal substrate 52 is anodized to form a metal oxide film 56 on the entire surface including the inside of the fine groove 53 (FIG. 10B). When a metal material that cannot be anodized and can be treated with boehmite is used as the metal substrate 52, a metal oxide film 56 is formed by boehmite treatment.
Next, the catalyst C1 is supported in the fine groove portion 53 (FIG. 10C). This catalyst loading can be performed by immersing the surface of the metal substrate 52 on which the fine groove 53 is formed in a desired catalyst suspension and drying it.

Next, the surface of the metal substrate 52 on which the fine groove 53 is formed is polished to expose the surface to be a joint surface with the metal cover member 54 (FIG. 10D). Thereafter, the metal substrate 52 and the metal cover member 54 are bonded to form a bonded body 51 (FIG. 10E). By this joining, a flow path 55 is formed in the joined body 51.
Next, a heating element is provided on the metal oxide film (insulating film) 56 of the metal substrate 52, an electrode for energization is further formed, and a heating element protection layer is formed on the heating element. Microreactor) 2b can be obtained.

Next, the present invention will be described in more detail by showing more specific examples.
Example 1
[Preparation of joined body]
A 1000 μm thick Al substrate (250 mm × 250 mm) was prepared as a metal substrate, and a photosensitive resist material (OFPR manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied to both surfaces of this Al substrate by a dipping method (film thickness 7 μm (when dry)) )did. Next, a photomask having a shape in which stripe-shaped light-shielding portions having a width of 1500 μm alternately extend from the left and right at a pitch of 2000 μm (length 30 mm) was disposed on the resist coating film on the side where the fine groove portions of the Al substrate are to be formed. . Next, the resist coating film was exposed through this photomask and developed using a sodium hydrogen carbonate solution. Thereby, on one surface of the Al substrate, stripe-shaped openings having a width of 500 μm are arranged at a pitch of 2000 μm, and adjacent stripe-shaped openings have a meandering pattern alternately and continuously at the end thereof, and A resist pattern was formed in which both end portions faced in the same direction and were 5 mm longer than other striped openings.

Next, using the resist pattern as a mask, the Al substrate was etched (for 3 minutes) under the following conditions.
(Etching conditions)
・ Temperature: 20 ℃
Etching solution (HCl) concentration: 200 g / L
(Dissolve 200 g of 35% HCl in pure water to make 1 L)
After the etching treatment was completed, the resist pattern was removed using a sodium hydroxide solution and washed with water. As a result, stripe-shaped microgrooves having a width of 1000 μm, a depth of 650 μm, and a length of 30 mm are formed on one surface of the Al substrate at a pitch of 2000 μm, and the shape is such that the end portions of adjacent microgrooves are alternately continuous. A fine groove (flow path length of 300 mm) having a shape meandering continuously while being folded by 180 degrees as shown in FIG. 4 was formed.

Next, an Al plate having a thickness of 100 μm was prepared as a metal cover member, and this Al plate was diffusion bonded to the Al substrate on which the fine groove portion was formed as described above under the following conditions so as to cover the fine groove portion.
(Diffusion bonding conditions)
-Atmosphere: in vacuum-Joining temperature: 300 ° C
Joining time: 8 hours Thereby, a joined body having an outer shape as shown in FIG. 3 was formed. The dimensions of this joined body are 25 mm × 35 mm and a thickness of 1.4 mm, and two protruding portions (length 5 mm, width 5 mm) are separated by a distance of 15 mm in the same direction. The inlet and outlet of the channel were located.

Three such joined bodies are prepared, and each joined body is connected to the anode of the external electrode, immersed in an anodic oxidation solution (4% oxalic acid solution) to face the cathode, and energized under the following conditions. A unit channel member in which an aluminum oxide thin film (insulating film) was formed on the surface of the joined body including the inside of the channel was used. In addition, as a result of measuring the thickness of the formed aluminum oxide thin film with an ellipsometer, it was about 30 μm.
(Conditions for anodization)
・ Bath temperature: 25 ℃
・ Voltage: 25V (DC)
・ Current density: 100 A / m ²

[Unit flow path member for the first stage]
A heating element paste having the following composition was printed on an aluminum oxide thin film of one unit channel member by screen printing and cured at 200 ° C. to form a heating element. The formed heating element was shaped such that a fine line having a width of 100 μm was drawn on an Al substrate at a line interval of 100 μm so as to cover the entire area (35 mm × 25 mm) corresponding to the area where the fine groove was formed.
(Composition of paste for heating element)
Carbon powder: 20 parts by weight Fine powder silica: 25 parts by weight Xylene phenol resin: 36 parts by weight Butyl carbitol: 19 parts by weight

Further, an electrode paste having the following composition was formed by screen printing so as to reach the side surface of the joined body at two predetermined locations of the heating element.
(Composition of electrode paste)
・ Silver plated copper powder: 90 parts by weight ・ Phenolic resin: 6.5 parts by weight ・ Butyl carbitol: 3.5 parts by weight

Next, a heating element protective layer (thickness 20 μm) is formed on the heating element by screen printing using a protective layer paste having the following composition so as to expose the ends of the two electrodes formed on the heating element. Formed.
(Composition of protective layer paste)
Resin content concentration: 30 parts by weight Silica filler: 10 parts by weight Lactone solvent (penta-4-lactone): 60 parts by weight Thus, a first-stage unit channel member was obtained.

[Second-stage unit channel member (unit microreactor)]
Fill the flow path of another unit flow path member with a catalyst suspension having the following composition and leave it for 15 minutes. Then, remove the catalyst suspension and perform a dry reduction treatment at 120 ° C. for 3 hours. The catalyst C1 was supported on the entire surface in the flow path.
(Composition of catalyst suspension)
・ Al: 41.2% by weight
Cu: 2.6% by weight
Zn: 2.8% by weight
Next, a heating element, an electrode, and a heating element protective layer are formed on the aluminum oxide thin film of the Al substrate in the same manner as the first-stage unit flow path member, and the second-stage unit flow path member (unit micro-channel member) is formed. Reactor) was prepared.

[Unit flow member for the third stage (unit microreactor)]
Fill the flow path of another unit flow path member with a catalyst suspension having the following composition and leave it for 15 minutes. Then, remove the catalyst suspension and perform a dry reduction treatment at 120 ° C. for 3 hours. The catalyst C2 was supported on the entire surface of the flow path.
(Composition of catalyst suspension)
・ Pt: 0.4% by weight
・ Fe: 0.2% by weight
・ Mordenite (Na ₈ (Al ₈ Si ₄₀ O ₉₆ ) / 24H ₂ O): 9.4 wt%
Next, a heating element, an electrode, and a heating element protective layer are formed on the aluminum oxide thin film of the Al substrate in the same manner as the first-stage unit flow path member, and the third-stage unit flow path member (unit micro-channel member) is formed. Reactor) was prepared.

[Production of connecting member]
Prepare 6 stainless steel plate materials with flat surfaces (30mm x 20mm), and machine predetermined grooves and through holes on one flat surface of each stainless steel substrate to form connecting parts, internal communication paths, internal flow paths, etc. Formed by processing. These six stainless steel substrates were joined by diffusion bonding in a predetermined stacking order to produce a connecting member of 30 mm × 20 mm × 12 mm. This connecting member has six connecting portions (width 5.1 mm, height 1.41 mm, depth 5 mm) on a 30 mm × 12 mm surface, and has a raw material inlet and a gas outlet on the opposite surface. And it was the structure as shown in FIG. 5 and FIG. 6 with the internal communication path and the internal flow passage inside (the outer shape of the structure is a rectangular parallelepiped and different from FIG. 5 and FIG. 6). In this connecting member, the pitch of each of the three connecting portions arranged in a row (corresponding to the multi-step pitch of the unit channel member) is 2 mm, and the distance between each array (the inlet and outlet of the unit channel member) Was equivalent to a distance of 20 mm. Each connecting portion was provided with a silicone rubber packing.

[Fabrication of fixing member]
A stainless steel material was used to produce a fixing member having three storage spaces with a frontage of 25 mm × 1.41 mm at a pitch of 2 mm.
[Production of microreactor]
Insert the protruding part of each unit flow channel member (the second and third stages are unit microreactors) into the connecting member produced as described above in order from the first stage to the third stage. In addition, the end of the unit channel member opposite to the connection end was fixed by a fixing member.
Thereby, the microreactor of the present invention could be obtained.

Example 2
[Preparation of joined body]
First, in the same manner as in [Production of bonded body] in Example 1, an Al substrate in which stripe-shaped fine grooves having a width of 1000 μm, a depth of 650 μm, and a length of 30 mm were formed at a pitch of 2000 μm was produced.
Next, this Al substrate was connected to the anode of the external electrode and anodized under the same conditions as in Example 1 to form an aluminum oxide thin film (insulating film) on the Al substrate surface including the fine groove. Next, the surface on which the fine groove portion was formed was polished with alumina powder to remove the aluminum oxide thin film, and the Al substrate surface (joint surface) was exposed.

Next, an Al plate having a thickness of 100 μm was prepared as a metal cover member, and this Al plate was brazed under the same conditions as in Example 1 so as to cover the fine groove portion on the Al substrate on which the fine groove portion was formed as described above. Joined. As a result, three joined bodies having an outer shape as shown in FIG. 3 were produced and used as unit channel members. The dimensions of this joined body are 25 mm × 35 mm and a thickness of 1.4 mm, and two protruding portions (length 5 mm, width 5 mm) are separated by a distance of 15 mm in the same direction. The inlet and outlet of the channel were located.
Using the above three unit flow path members, similarly to Example 1, a unit flow path member for the first step surface, a unit flow path member for the second step surface, and a unit flow path member for the third step surface The microreactor of the present invention was manufactured.

  INDUSTRIAL APPLICABILITY The present invention can be used for hydrogen production including reactions such as methanol reforming and carbon monoxide oxidation.

It is a perspective view which shows one Embodiment of the microreactor of this invention. It is an expanded longitudinal cross-sectional view in the II line of the microreactor shown by FIG. It is a perspective view which shows the state which spaced apart the structural member of the microreactor shown by FIG. It is a perspective view for demonstrating the example of the flow path in the unit flow path member which comprises the microreactor of this invention. It is a figure which shows the surface in which the connection part of the connection member was formed. It is sectional drawing of the connection member shown by FIG. 5, Comprising: (A) is sectional drawing in the II-II line, (B) is sectional drawing in the III-III line. It is a longitudinal cross-sectional view equivalent to FIG. 2 for demonstrating the other example of the microreactor of this invention. It is a longitudinal cross-sectional view which shows the other example of the unit flow-path member (unit microreactor) which comprises the microreactor of this invention. It is process drawing which shows an example of the manufacturing method of a unit microreactor. It is process drawing which shows the other example of the manufacturing method of a unit microreactor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Microreactor 2a, 2b, 2c, 2a ', 2c' ... Unit flow path member 2b, 2c, 2c '... Unit microreactor 3a ... Introduction port 3b ... Discharge port 4 ... Connecting member 6 ... Fixing member 7 ... Air gap 8 ... Heat insulation 10,41,51 ... Joint body 10a, 10b ... Protrusion 11,13,42,52 ... Metal substrate 12,14,43,53 ... Fine groove 15,45,55 ... Flow path 16,46,56 ... Metal oxide film (insulating film)
DESCRIPTION OF SYMBOLS 17 ... Heating body 18 ... Electrode 19 ... Heating body protective layer 21 ... Structure 21a, 21b, 21c ... Block body 22 (22a, 22b, 22c, 22d, 22e, 22f) ... Connection part 22a ... Introduction connection part 22b, 22c 22d, 22e ... stage transition connecting portion 22f ... discharge connecting portion 23 ... raw material introduction port 24 ... gas discharge port 25a, 25b ... internal communication passage 26,27 ... internal flow channel 31 ... frame body 41, 51 ... joint body 42, 52 ... Metal substrate 43, 53 ... Fine groove 44, 54 ... Metal cover member 45, 55 ... Flow path 46, 56 ... Metal oxide film (insulating film)
C1, C2 ... Catalyst

Claims (11)

In a microreactor for reforming raw materials to obtain hydrogen gas,
A plurality of unit flow path members having a flow path inside, one end of the flow path serving as an introduction port and the other end serving as a discharge port, and the unit flow path members are held in a multistage state And at least a connecting member
The connecting member includes a plurality of connecting portions for closely holding the unit channel member at a site where the inlet of the unit channel member is located and a site where the outlet is located, a raw material inlet, a gas exhaust And an exit
At least one of the unit channel members is a unit microreactor supporting a catalyst in the channel,
A raw material is introduced from the raw material inlet of the connecting member, a predetermined reaction is performed in the unit microreactor among the plurality of unit flow path members, and a desired product gas is obtained from the gas outlet of the connecting member. A microreactor characterized by that. n (n is an integer of 2 or more) unit channel members,
The connecting part includes (n-1) sets of stage transition connections that are connected to the raw material inlet, the discharge connecting part that is connected to the gas outlet, and the internal communication path. And consists of
The first stage unit flow path member is connected and held with the introduction port at the introduction connection part and the discharge port at the stage transition connection part,
From the second stage to the (n-1) th stage unit flow path member, the introduction port is connected to the stage transition connection part connected to the previous stage transition connection part by an internal communication path, and the discharge port is moved to another stage. Each of the connecting parts is connected and held,
The n-th unit flow path member is connected and held with the introduction port connected to the previous stage transition connection portion and the internal passage, and the discharge port connected to the discharge connection portion. The microreactor according to claim 1, wherein The microreactor according to claim 1 or 2, wherein the unit channel member is removable. The microreactor according to any one of claims 1 to 3, wherein the unit microreactor has a catalyst supported on the inner wall surface of the unit channel member via a metal oxide film. The microreactor according to any one of claims 1 to 4, wherein each unit flow path member has a plurality of unit microreactors having the same structure and different catalyst species carried in the flow path. 6. The microreactor according to claim 1, further comprising a unit microreactor provided with a heating element. The microreactor according to any one of claims 1 to 6, wherein a gap and / or a heat insulating material for heat insulation are interposed between the unit flow path members of desired adjacent stages. The microreactor according to any one of claims 1 to 7, wherein the other ends of the plurality of unit flow path members held in a multistage state by the connecting member are fixed by a fixing member. The unit flow path member is a joined body in which a set of metal substrates on which fine grooves for forming a flow path are formed are joined so that the fine groove portions face each other, or a fine groove for forming a flow path The microreactor according to any one of claims 1 to 8, further comprising a joined body in which a metal cover member is joined to a metal substrate surface on which is formed. The microreactor according to claim 9, wherein the unit microreactor is one in which a catalyst is supported in a flow path after forming the joined body. The microreactor according to claim 9, wherein the unit microreactor has a catalyst supported in a fine groove before joining.

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