JP2014114179A - Molded catalyst and hydrogen production apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded catalyst and a hydrogen production apparatus whereby, in the case of housing the molded catalyst and a hydrogen separation body in a reactor, the hydrogen separation body is hard to be broken.SOLUTION: A molded catalyst (3) is used in a reactor (9) that houses a cylindrical hydrogen separation body (5) equipped with a hydrogen separation metal layer (37) to selectively allow only hydrogen to permeate therethrough and a supporter (29) to support the hydrogen separation metal layer (37). The molded catalyst (3) is composed of a metal catalyst to produce hydrogen from a raw material gas and a carrier (4) to support the metal catalyst and has a cylindrical shape having a throughhole (15) for inserting the hydrogen separation body (5). The carrier (4) of the molded catalyst (3) and the supporter (29) of the hydrogen separation body (5) are made of almost the same constituent material in a volume ratio of 90% or higher.

Description

  The present invention relates to a forming catalyst for reforming a raw material gas, and a hydrogen production apparatus including a hydrogen separator that selectively separates the forming catalyst and hydrogen gas.

  Conventionally, for example, as an apparatus for producing hydrogen to be supplied to a fuel cell, a catalyst that reforms a raw material gas such as natural gas to generate hydrogen, and a metal hydrogen permeable membrane that allows only hydrogen to permeate (hydrogen separation metal) A hydrogen production apparatus in which a cylindrical hydrogen separator having a layer is disposed in a reactor (reaction vessel) has been developed.

  For example, in Patent Document 1 below, a hydrogen separator having a hydrogen permeable membrane on the outer surface is disposed inside a metal reaction tube, and a pellet (beads) is formed between the hydrogen separator and the inner wall of the reaction tube. A hydrogen production apparatus in which a large number of shaped catalysts are packed in a packed bed is disclosed.

In this hydrogen production apparatus, a raw material gas containing high-temperature steam comes into contact with the formed catalyst, and a steam reforming reaction or the like occurs to generate hydrogen gas or the like.
For example, in steam reforming of methane, it is decomposed into hydrogen, carbon monoxide, and carbon dioxide in accordance with the following reaction formulas (1) and (2).

CH ₄ + H ₂ O ← → CO + 3H ₂ O (reforming reaction) (1)
CO + H ₂ O ← → CO ₂ + H ₂ (shift reaction) (2)
Therefore, high-purity hydrogen can be obtained by selectively permeating hydrogen from the decomposed gas or the like through the hydrogen separator.

  In addition, the hydrogen production apparatus described above is characterized in that hydrogen production efficiency is high because the hydrogen permeable membrane and the shaped catalyst can be disposed close to each other by the configuration of filling the pellet shaped shaped catalyst.

JP 2005-58823 A

  However, since the hydrogen production apparatus is usually subjected to a heat cycle of high temperature when used and low temperature when not used, the reaction tube repeatedly expands and contracts. Therefore, the technology described in Patent Document 1 described above is used. Then, there was a problem that the hydrogen separator was damaged.

  In other words, when the metal reaction tube becomes hot and expands, the pellet-shaped forming catalyst descends to fill the expanded space, but when the reaction tube becomes low temperature and contracts, it is clogged underneath. Since the molded catalyst can hardly move, it is pushed inward by the reaction tube. As a result, the molding catalyst pressed inward presses the ceramic hydrogen separator, and the hydrogen separator may be damaged by the pressing.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a molded catalyst and a hydrogen which are difficult to damage the hydrogen separator when the molded catalyst and the hydrogen separator are accommodated in the reactor. It is to provide a manufacturing apparatus.

  (1) As a first aspect of the present invention, a reactor containing a cylindrical hydrogen separator including a hydrogen separation metal layer that selectively allows permeation of hydrogen and a support that supports the hydrogen separation metal layer The forming catalyst is a cylinder comprising a metal catalyst that generates hydrogen from a raw material gas and a carrier that supports the metal catalyst, and has a through-hole through which the hydrogen separator can be inserted. The constituent material of the support for the formed catalyst and the constituent material of the support for the hydrogen separator are the same in a volume ratio of 90% or more.

  Since the shaped catalyst of the first aspect has a cylindrical shape having a through-hole through which the hydrogen separator can be inserted, by passing the hydrogen separator through the through-hole of the molded catalyst (that is, the molded catalyst is formed in the hydrogen separator). ), The molded catalyst can be disposed on the outer peripheral side of the hydrogen separator.

  Therefore, in a hydrogen production apparatus in which a hydrogen separator fitted with this molded catalyst is accommodated in a reactor, a thermal cycle of a high temperature (for example, 550 ° C.) state and a low temperature (for example, room temperature) state is added, so that the reactor Even if the expansion and contraction are repeated, the hydrogen separator is not easily damaged.

  That is, even when the reactor expands at a high temperature, the formed catalyst remains fitted on the hydrogen separator, and is lower (expanded and expanded) like a conventional pellet-shaped formed catalyst. It does not move to fill the space. Therefore, even if the reactor shrinks at a low temperature, the formed catalyst is not pressed inward by the reactor, so that there is no problem that the hydrogen separator is damaged by being pressed by the formed catalyst.

  Further, in the first aspect, even when the reactor contracts, the formed catalyst is not pressed inward, so that the formed catalyst can be disposed close to (or in contact with) the hydrogen separator, and thus the hydrogen This has the advantage of improving the production efficiency.

  Thus, in the first aspect, it is possible to design the size of the formed catalyst so that it can be close to the hydrogen separator while ensuring a space with the inner wall of the reactor. It is possible to prevent the formed catalyst from being pressed against the hydrogen separator due to expansion and contraction of the reactor due to the thermal cycle at the time of stopping.

  Further, by making the support of the hydrogen separator and the support of the formed catalyst 90% or more identical in volume ratio, that is, at least 90% of the constituent material of the support of the hydrogen separator and the support of the formed catalyst By making 90% of the constituent materials of the same, the thermal expansion coefficient of the support and the support becomes substantially the same, and the expansion / contraction behavior of the hydrogen separator and the molded catalyst at the time of temperature increase and decrease substantially coincides. A predetermined distance is always maintained between the hydrogen separator and the formed catalyst, and a remarkable effect is obtained in that the hydrogen separator can be prevented from being damaged by the pressing of the formed catalyst during elevation.

  The molded catalyst is sufficiently small in size with respect to the space to be filled, such as powder, liquid, or granular or pellet shape whose shape is not fixed (for example, the volume ratio with respect to the space to be filled is less than 1/100). ), Which is not capable of being densely packed in the filling space, and is formed into a predetermined shape (here, a cylinder) that can be introduced into the filling space while maintaining a predetermined gap that does not damage the hydrogen separator. It is a member. Therefore, for example, as the molded catalyst, a member having a volume of 1/100 or more with respect to the volume of the space to be filled can be employed.

Therefore, when arrange | positioning a shaping | molding catalyst in the to-be-filled space, it can arrange | position so that the wall surface (other than the lower part) around the to-be-filled space may not be pressed by own weight.
That is, the molded catalyst moves downward due to its own weight, such as powder or particles, even when the space to be filled is widened due to heat (that is, the interval between the side walls is widened). It is possible to stop at that position without pressing.

  In addition, it is desirable that the “materials are the same” as described above, but it is desirable that the materials be completely the same, but other materials may be included if the volume percentage of the constituent materials is up to 10%. The purpose of making the constituent materials the same is to match the thermal expansion coefficients. This is because even if 10% of other materials are mixed, the effect of the retention on the thermal expansion coefficient is limited, and the purpose of matching the expansion / contraction behavior due to the temperature rise and fall can be achieved.

(2) In the present invention, as a second aspect, the molding catalyst is a porous ceramic carrier supported by the metal catalyst.
The second aspect exemplifies the configuration of the molded catalyst. Thus, when using porous ceramics for the support, the heat resistance is high, the surface area of the support can be increased, and the metal catalyst can be highly dispersed and set in a large area, so that the reactivity is high. There is an advantage of high.

(3) In the present invention, as a third aspect, an unevenness for disturbing the gas flow is formed on the inner peripheral surface of the through hole of the molded catalyst.
In the third aspect, since the unevenness for disturbing the gas flow is formed on the inner peripheral surface of the through hole of the formed catalyst, there is a gap (due to the unevenness) between the formed catalyst and the hydrogen separator. Therefore, there is an advantage that the source gas easily flows along the gap and the reactivity is high.

  Further, due to the unevenness, it is possible to disturb the gas flow that flows essentially in parallel with the hydrogen separation metal layer (for example, the longitudinal direction of the cylindrical shape). By disturbing the gas flow, a gas flow perpendicular to the part of the hydrogen separation metal layer can be generated, and this effect can increase the hydrogen permeation amount.

In addition, as height of the unevenness (from the bottom to the top), 1 mm or more (the average value when there are a plurality of unevenness) is preferable.
Furthermore, in this third aspect, when hydrogen is generated from the raw material gas flowing along the gap, hydrogen is selectively separated by the adjacent hydrogen separator as it is, so that hydrogen is generated by hydrogen separation. The reaction is promoted, and there is an effect that hydrogen separation proceeds more efficiently.

(4) In the present invention, as a fourth aspect, the molded catalyst has a vent hole penetrating the molded catalyst itself in addition to the through hole.
In the fourth aspect, since there is a vent hole penetrating the molded catalyst itself in addition to the through hole, the raw material gas is also supplied to the vent hole. Disturbance of the gas flow can be caused by the gas flowing through the vent hole. In addition, there is an effect of increasing the contact area between the source gas and the metal catalyst, and hydrogen can be efficiently generated from the source gas.

Here, the air hole referred to here is a hole having a diameter larger than a communication hole (diameter of several μm to several tens of μm) in which the pores in the porous carrier communicate with each other.
(5) In the present invention, as a fifth aspect, a cylindrical hydrogen separator provided with a hydrogen separation metal layer that allows only hydrogen to permeate, and molding according to any one of claims 1 to 4 A hydrogen production apparatus in which a catalyst is accommodated in a reactor, wherein the molded catalyst is inserted into the through-hole of the hydrogen separator and is externally fitted to the hydrogen separator. To do.

  As described above, in a hydrogen production apparatus in which a hydrogen separator fitted with a molded catalyst is accommodated in a reactor, a thermal cycle of a high temperature state and a low temperature state is applied, so that expansion and contraction of the reactor are repeated. Even if this is done, the position of the formed catalyst does not change, so there is an effect that the formed catalyst does not press the hydrogen separator and the hydrogen separator is not damaged.

(6) In the present invention, as a sixth aspect, a plurality of the shaped catalysts are externally fitted to the hydrogen separator.
In the sixth aspect, a cylindrical shaped catalyst (having a shorter axial length than the axial length of the hydrogen separator) is fitted into the hydrogen separator sequentially, for example, in a stacked manner. . Therefore, even if the hydrogen separator is slightly inclined with respect to the central axis, there is an error in the radial dimension, or there is an error in the dimensional accuracy of the through hole of the forming catalyst (one long molding). Individual shaped catalysts can be easily fitted to the hydrogen separator (as compared to the case of fitting the catalyst).

  (7) In the present invention, as a seventh aspect, the hydrogen separator is fixed and fixed in the reactor by a fixing member, and the molded catalyst is placed on the hydrogen separator on the fixing member. It is characterized by being stacked along the vertical direction.

  The seventh aspect exemplifies a configuration in which the hydrogen separator is fixed to the reactor. Thereby, by sequentially fitting the formed catalyst from above the hydrogen separator, the formed catalyst can be stacked and disposed on the outer peripheral side of the hydrogen separator.

(8) In the present invention, as an eighth aspect, the molded catalysts having different inner diameters are alternately stacked.
In the eighth aspect, the hydrogen separator (stacked) having different inner diameters (cylindrical) is laminated alternately. By alternately arranging the formed catalysts having different inner diameters, the gas flow flowing between the formed catalyst inner peripheral surface and the hydrogen separator can be disturbed. By this effect, the hydrogen generation reaction and the hydrogen separation can be advanced efficiently.

  (9) In the present invention, as a ninth aspect, the adjacent formed catalysts are stacked, and a positioning portion for positioning the formed catalysts is provided on the surface of the stacked side.

  In the ninth aspect, since each molding catalyst is provided with a positioning portion, the molding catalysts are locked with each other and are not easily displaced, and a predetermined shape can be easily maintained.

It is sectional drawing which fractures | ruptures along the axial direction and shows typically the hydrogen production apparatus of Example 1. FIG. It is sectional drawing which fractures | ruptures and shows the hydrogen separator in Example 1 along an axial direction. It is explanatory drawing which fractures | ruptures and expands and shows a part of hydrogen separator in Example 1. FIG. 1 is a perspective view showing a molded catalyst of Example 1. FIG. It is sectional drawing which fractures | ruptures and shows the hydrogen production apparatus in Example 1 along an axial direction. FIG. 3 is an explanatory diagram illustrating the usage state of the hydrogen production apparatus according to the first embodiment. It is sectional drawing which fractures | ruptures along the axial direction and shows typically the hydrogen production apparatus of Example 2. FIG. (A) is a perspective view which shows the shaping | molding catalyst of Example 3, (b) is AA sectional drawing of (a), (c) is sectional drawing which fractures | ruptures and shows the shaping | molding catalyst of a modification along a central axis. It is. 6 is a plan view showing a molded catalyst of Example 4. FIG. (A) is a perspective view which shows the shaping | molding catalyst of Example 4, (b) is BB sectional drawing of (a), (c) is a cross section which fractures | ruptures and shows the shaping catalyst of Example 5 along a central axis. FIG. It is sectional drawing which fractures | ruptures along the axial direction and shows typically the hydrogen production apparatus of Example 6. FIG. (A) is a front view which shows the shaping | molding catalyst etc. of Example 7, (b) is a front view which shows the shaping | molding catalyst etc. of Example 8. FIG. It is sectional drawing which fractures | ruptures and shows another shaping | molding catalyst along a central axis.

Hereinafter, embodiments of the present invention will be described.
<Configuration of molded catalyst>
In the molded catalyst of the present invention, a part or the whole of the inner peripheral surface of the through hole may be disposed so as to contact the hydrogen separator, or may be disposed via a gap.

  Moreover, although the shaping | molding catalyst is a cylindrical member, the slit etc. which extend in an axial direction etc. are provided in this shaping | molding catalyst, and the location where the part is not connected in the circumferential direction may be sufficient. That is, it may be a cylindrical shape having a through-hole through which the hydrogen separator can be inserted.

  Examples of the metal catalyst supported on the forming catalyst include nickel, copper, iron, platinum, palladium, zinc, and mixtures and alloys thereof. In addition, a metal catalyst is a catalyst containing a metal.

  Examples of the carrier supporting the metal catalyst include porous ceramics, and examples of the porous ceramics include alumina, zirconia, stabilized zirconia, ceria, doped ceria, mullite, silica, and mixtures thereof.

  As a method for producing the above-described molded catalyst, for example, a material obtained by adding a binder to ceramic powder and a pore former is used to produce a molded body by extrusion molding or press molding, and then the molded body is degreased and fired. Later, a method of forming a molded catalyst can be employed by immersing in a solution containing a metal catalyst component, drying and heat treatment.

As another manufacturing method, a metal oxide, ceramics (for example, nickel oxide and zirconia) and a material obtained by adding a binder to a pore former are used to produce a molded body by extrusion molding or press molding. There is a method in which a metal catalyst is obtained by degreasing and firing the material and then performing a reduction treatment to reduce the metal oxide.
<Configuration of hydrogen separator>
As the hydrogen separator, it is possible to adopt a configuration such as a hydrogen separation metal layer and a support that supports it.

As the material for the support, ceramics can be used. As the structure of the support, a structure in which a part or the whole is made of porous ceramics can be adopted.
The part (porous part) made of this porous ceramic can permeate a gas containing hydrogen in whole or in part. Yttria-stabilized zirconia, stabilized zirconia, alumina, magnesia, ceria, Examples include doped ceria and mixtures thereof.

  Further, a hydrogen separator may be configured by joining a dense portion that does not transmit gas to, for example, an axial end portion of the porous portion. Here, “without gas permeability” is only required to prevent permeation of the raw material gas from which hydrogen is separated, and includes, for example, a density with a relative density of 70% or more.

  The material constituting the dense portion includes ceramics, and examples of the ceramics include yttria stabilized zirconia, stabilized zirconia, alumina, magnesia, ceria, doped ceria, and mixtures thereof.

  On the other hand, examples of the hydrogen separation metal (hydrogen permeable metal) constituting the hydrogen separation metal layer include Pd alone, Pd alloy (for example, PdAg alloy, PdCu alloy, PdAu alloy) and the like. From the viewpoint of suppressing hydrogen embrittlement, a PdAg alloy is preferable to Pd alone. In the case of a hydrogen production apparatus used at a high temperature (for example, 450 ° C. or higher), a PdAg alloy is desirable.

As this hydrogen separation metal layer, a configuration in which a hydrogen separation metal is disposed on the surface or inside of the support can be employed. For example, a hydrogen separation metal layer can be formed by filling the pores of a porous support with a hydrogen separation metal.
<Configuration of hydrogen production equipment>
In the hydrogen production apparatus, for example, one or a plurality of hydrogen separators and one or a plurality of formed catalysts are arranged in a cylindrical reactor or the like, and the hydrogen separator is attached to the reactor by a metal joint or the like, for example. It is attached.

  For example, when using a cylindrical hydrogen separator with a closed tip, the tip side is disposed in the reactor, and a metal joint is fixed to the rear end (base end side). The structure fixed to can be adopted.

  Examples of the reactor include metal containers made of stainless steel such as SUS316, SUS316L, and SUS430.

Below, the Example of the hydrogen production apparatus which can manufacture high purity hydrogen from raw material gas, such as natural gas, is described.
a) First, a schematic configuration of the hydrogen production apparatus according to the present embodiment will be described.

  As schematically shown in FIG. 1, the hydrogen production apparatus 1 of the present embodiment reforms a raw material gas into a hydrogen-rich reformed gas (rich in hydrogen) and selects hydrogen from the reformed gas. It is an apparatus that can be separated to obtain high-purity hydrogen.

  As will be described in detail later, the hydrogen production apparatus 1 includes a cylindrical shaped catalyst 3 for reforming a raw material gas, a test tube-shaped hydrogen separator 5 for separating hydrogen from the reformed gas, and a hydrogen separator 5. The cylindrical metal joint 7 attached to the base end side (upper side of the figure) and the reactor (reaction vessel) 9 which is a cylindrical vessel for accommodating the molded catalyst 3 and the hydrogen separator 5 are provided. .

  Specifically, the hydrogen separator 5 is fixed to a substrate (upper substrate) 11 at the upper end of the reactor 9 by a metal joint 7 (with the front end side of the hydrogen separator 5 facing downward). A plurality of molded catalysts 3 are arranged so as to fit externally.

  That is, each molded catalyst 3 is formed by coaxially stacking each molded catalyst 3 on a lower substrate (lower substrate) 13 of the reactor 9, and hydrogen is placed in each through-hole 15 of each stacked molded catalyst 3. A separator 5 is inserted.

  Further, a raw material introduction hole 17 through which a raw material gas is introduced is formed in the upper part of the reactor 9, and a gas discharge hole 19 through which off gas after the reaction is discharged is formed in the lower part of the reactor 9. . Further, the center hole 21 of the hydrogen separator 5 is in communication with the center hole 23 of the metal joint 7, and the hydrogen separated by the hydrogen separator 5 is separated from the center hole 21 of the hydrogen separator 5 and the center hole of the metal joint 7. It is configured to be taken out from the reactor 9 through 23.

b) Next, the hydrogen separator 5 and the molded catalyst 3 which are the main parts of the present embodiment will be described.
<Hydrogen separator 5>
As shown in FIG. 2, the hydrogen separator 5 is provided with a test tube-shaped hydrogen separator 25 mainly made of porous ceramics and having a function of separating hydrogen on the closed tip side (upper side in the figure). On the open base end side (the lower side in the figure), a cylindrical dense portion 27 made of dense ceramics having no gas permeability and high strength is provided.

Each configuration will be described below. 2, 3, and 5 below are upside down from FIG. 1.
The dense portion 27 is a cylindrical ceramic body made of YSZ and is sufficiently dense to prevent gas permeation, and its strength is greater than that of the hydrogen separation portion 25.

  The hydrogen separator 25 selectively separates hydrogen from the gas introduced from the outer periphery thereof (reformed gas reformed by the shaping catalyst 3 here), and the center of the axial center of the hydrogen separator 25 is obtained. A member to be supplied to the hole 21.

  As shown in an enlarged view in FIG. 3, the hydrogen separation unit 25 is integrally formed from a test tubular porous part 29 whose one end is closed and a porous layer 31 covering the outer surface of the porous part 29. Has been. A ceramic support 30 (see FIG. 2) is composed of the dense portion 27 and the porous portion 29.

  Among these, the porous portion 29 is a porous ceramic support made of yttria-stabilized zirconia (YSZ), that is, a support having a role of supporting the porous layer 31 while having air permeability. The porous part 29 has a porosity of 40%, for example, and has a structure capable of transmitting gas (hydrogen). The support material may be the same as the support material of the forming catalyst 3, and alumina, magnesia, mullite, or the like can be used in addition to YSZ.

The porous layer 31 is a porous ceramic coating layer made of YSZ and has a gas-permeable structure.
Specifically, the porous layer 31 covers the outer surface of the porous portion 29 (permeable with hydrogen gas) and the outer surface of the first porous layer 33 (permeated with hydrogen gas). The second porous layer 35 (possible) and the porous protective layer 37 that covers the outer surface of the second porous layer 35 (the reformed gas is permeable) are integrally formed.

The first and second porous layers 33 and 35 have the same porous structure, and hereinafter, this ceramic portion is referred to as an inner porous layer 36.
In particular, a part of the inside of the pores of the second porous layer 35 is filled with a hydrogen permeable metal such as Pd, and this hydrogen permeable metal selects only hydrogen from the reformed gas. It is a metal that separates hydrogen from the reformed gas by permeation.

  That is, the portion inside the second porous layer 35 that is filled with the hydrogen permeable metal and covers the entire outside of the porous portion 29 (specifically, the first porous layer 33) in a layered manner is the hydrogen separation metal layer ( Hydrogen permeable membrane) 39.

The porous protective layer 37 prevents contaminants (eg, Fe) that damage the hydrogen separation metal layer 39 from the outside from adhering to the hydrogen separation metal layer 39.
<Molded catalyst>
As shown in FIG. 4, the molded catalyst 3 has a cylindrical shape with a predetermined thickness, with both axial end faces (that is, upper and lower end faces in the figure) 41 and 43 being parallel, and its length (axis The length in the direction) is sufficiently shorter than the length of the hydrogen separator 5 so that a plurality of the lengths can be fitted to the hydrogen separator 5 (for example, half or less of the portion of the hydrogen separator 5 in contact with the source gas) Is set to

  Further, the inner diameter of the through hole 15 of the molded catalyst 3 is set to be slightly larger than the outer diameter of the hydrogen separator 5 so that it can be fitted to the hydrogen separator 5. The inner diameter of the formed catalyst 3 may be set so as to have a gap (for example, 2 mm or less) with the hydrogen separator 5 or may be set so as to contact the hydrogen separator 5.

  The molded catalyst 3 uses a porous ceramic made of, for example, yttria-stabilized zirconia (YSZ) as a support (porous support) 4 so that the reformed gas can pass through. The metal catalyst which consists of is supported. The support material may be any material that is substantially the same as the support of the hydrogen separator 5 (ie, the porous portion 29) (ie, the volume ratio is 90% or more), and besides YSZ, alumina, magnesia, etc. Mullite and the like can be used.

c) Next, a configuration for attaching the hydrogen separator 5 to the reactor 9 will be briefly described.
As shown in FIG. 5, a metal joint 7 is attached to the base end side of the hydrogen separator 5.
This metal joint 7 is a cylindrical mounting bracket 51 into which the open end side of the hydrogen separator 5 is inserted, and a cylindrical shape disposed between the outer peripheral surface of the hydrogen separator 5 and the inner peripheral surface of the mounting bracket 51. A seal member 53 (made of expanded graphite), a cylindrical pressing metal 55 that is externally fitted to the hydrogen separator 5 and presses the sealing member 53, and is externally fitted to the pressing metal 55 (screwed into the mounting metal 51). And a cylindrical fixing fitting 57 for pressing the pressing fitting 55.

  The mounting bracket 51 includes a distal end side tubular portion 59, a flange portion 61, and a screw portion 63, and a through hole (hollow portion) 65 serving as a gas (hydrogen) flow path is formed at the center of the shaft. The hollow portion 65 accommodates an end portion on the proximal end side of the hydrogen separator 5.

  When the metal joint 7 is fixed to the hydrogen separator 5, the fixing fitting 57 that is screwed to the attachment fitting 51 is tightened to press the pressing fitting 55. As a result, the seal member 53 is pressed and compressed in the axial direction and expanded in the radial direction, so that sealing (airtight) and fixing between the hydrogen separator 5 and the metal joint 7 are performed. An apparatus in which the metal joint 7 is attached to the hydrogen separator 5 is referred to as a hydrogen separator 67.

  In the hydrogen production apparatus 1, the hydrogen separation device 67 is attached to the reactor 9, but the hydrogen separation device 67 is configured such that the screw portion 63 of the metal joint 7 is screwed into the screw hole (not shown) of the reactor 9. It is fixed by combining.

d) Next, the manufacturing method of the hydrogen production apparatus 1 of the present embodiment will be described.
<Method for producing hydrogen separator 5>
Although not shown in the figure, first, a rubber mold is filled with yttria-stabilized zirconia granulated powder, then yttria-stabilized zirconia granulated powder added with 48% by volume organic beads as a pore former, and then pressed. The molded body was produced by molding into a cylindrical bottomed tube shape (test tube shape) by a molding method.

  Next, this molded body was degreased and sintered at 1400 ° C. to produce a ceramic support 30 in which the dense portion 27 and the porous portion 29 having an outer diameter of 10 mm × length of 300 mm were integrated.

  Next, a slurry in which yttria-stabilized zirconia powder is dispersed in an organic solvent is prepared, and the inner porous layer (which becomes the inner porous layer 36) is formed on the porous portion 29 of the ceramic support 30 by dip coating. A quality forming layer (not shown) was prepared.

  Next, the inner porous forming layer is baked by heating to 1200 ° C., and the inner porous layer 36 (corresponding to the first and second porous layers 33 and 35) is provided on the surface of the porous portion 29. A ceramic support 30 was formed.

  Next, after performing a well-known Pd nucleation process on the surface of the inner porous layer 36, dip coating of yttria-stabilized zirconia slurry on the inner porous layer 36 (with the porous protective layer 37 and A protective layer forming layer (not shown) was prepared.

Next, the porous protective layer 37 was formed on the inner porous layer 36 by baking in the same manner as described above.
Next, Pd nuclei inside the inner porous layer 36 were grown by electroless plating to form a hydrogen separation metal layer 39 made of Pd having a thickness of 3.0 μm. Of the inner porous layer 36, the portion where the hydrogen separation metal layer 39 is formed is the second porous layer 35, and the portion where the inner hydrogen separation metal layer 39 is not formed is the first porous layer 35. Layer 33. Thereby, the hydrogen separator 5 was completed.

Thereafter, a metal joint 7 was attached to the hydrogen separator 5 to obtain a hydrogen separator 67.
<Method for producing molded catalyst 3>
Although not shown, first, yttria-stabilized zirconia powder, 60% by volume of organic beads as a pore former, and an organic binder are mixed, and then a cylinder having an outer diameter of φ30 mm, an inner diameter of φ15 mm, and a length of 30 mm is obtained by extrusion molding. Molded into a shape to produce a molded body.

Next, this molded body was degreased and then sintered at 1400 ° C. to produce a porous carrier 4 having an outer diameter of φ24 mm × inner diameter of φ12 mm × length of 24 mm.
Next, the porous carrier 4 was immersed in an aqueous nickel nitrate solution and dried.

Next, the dried porous carrier 4 is heat-treated in the atmosphere at 600 ° C., and then subjected to a reduction treatment in hydrogen at 600 ° C. to form the cylindrical shaped catalyst 3 as shown in FIG. did.
That is, a molded catalyst 3 in which nickel (Ni) was supported as a metal catalyst on a porous support 4 made of yttria-stabilized zirconia porous ceramics was produced.
<Assembly method of hydrogen production apparatus 1>
As shown in FIG. 1, the hydrogen separator 5 and the molded catalyst 3 produced by the above-described method were placed in a cylindrical reactor 9 having an outer diameter of 30 mm, an inner diameter of 25 mm, and a length of 400 mm, for example.

Specifically, the hydrogen separator 5 was disposed in the reactor 9 so that a plurality of the shaped catalysts 3 were coaxially stacked and inserted into the through holes 15.
At this time, the hydrogen separator 5 is fixed to the upper substrate 11 of the reactor 9 through the metal joint 7. The upper substrate 11 and the hydrogen separator 67 are configured to be detachable from the reactor 9 (lower part other than the upper substrate 11).

  Therefore, in the hydrogen production apparatus 1 configured as described above, when a raw material gas (including steam) is supplied from the raw material introduction hole 17, steam reforming is performed in the molded catalyst 3 to generate a reformed gas. Is done. Then, the reformed gas is separated into hydrogen by the hydrogen separation metal layer 39 of the hydrogen separator 5 and discharged into the center hole 21, and this hydrogen is further discharged from the center hole 21 of the hydrogen separator 5 to the metal joint. 7 is taken out of the reactor 9 through the central hole 23.

e) Next, the effect of the present embodiment will be described.
Since the shaped catalyst 3 of this embodiment has a cylindrical shape having a through hole 15 into which the hydrogen separator 5 can be inserted, the hydrogen separator 5 is passed through the through hole 15 of the shaped catalyst 3 (that is, hydrogen). By externally fitting the molded catalyst 3 to the separator 5, the molded catalyst 3 can be arranged on the outer peripheral side of the hydrogen separator 5.

  Therefore, in the hydrogen production apparatus 1 in which the hydrogen separator 5 fitted with the molded catalyst 3 is accommodated in the reactor 9, a thermal cycle of a high temperature state and a low temperature (room temperature) state is added, so that the reactor 9 Even if the expansion and contraction are repeated, the hydrogen separator 5 is not easily damaged.

  That is, even when the reactor 9 becomes hot and expands, the molded catalyst 3 remains fitted on the hydrogen separator 5 and does not move in the radial direction. Therefore, even if the reactor 9 becomes low temperature and shrinks, the molded catalyst 3 is not pressed inward by the reactor 9, so the problem that the hydrogen separator 5 is damaged by being pressed by the molded catalyst 3 Does not occur.

  Further, the porous carrier 4 of the molded catalyst 3 and the support (porous portion 29) of the hydrogen separator 5 are composed of the same material, in this case completely the same material, in the volume ratio of 90% or more. Expansion / contraction behavior is consistent. For this reason, the hydrogen separator 5 is not pressed by the molded catalyst 3 due to the contraction of the molded catalyst 3 itself or the expansion of the hydrogen separator 5, and the hydrogen separator 5 is not damaged.

  In the present embodiment, a plurality of cylindrical shaped catalysts 3 are fitted on the hydrogen separator 5. Therefore, even if the hydrogen separator 5 is slightly inclined with respect to the central axis, there is an error in the radial dimension, or there is an error in the dimensional accuracy of the through hole 15 of the molding catalyst 3, 3 can be easily fitted to the hydrogen separator 5.

In addition, as shown in FIG. 6, each of the molded catalysts 3 may be slightly shifted in the radial direction with respect to the axial center of the hydrogen separator 5.
Furthermore, in this example, even when the reactor 9 contracts, the molded catalyst 3 is not pressed inward, so that the molded catalyst 3 can be disposed close to (or in contact with) the hydrogen separator 5, Therefore, there is an advantage that the production efficiency of hydrogen is high.

f) Next, experimental examples conducted for confirming the effects of the present invention will be described.
In this experimental example, the degree of damage of the hydrogen separator 5 when a heat cycle is applied is produced using the hydrogen production apparatus 1 of Example 1 which is an example of the present invention and the hydrogen production apparatus of the comparative example. It was investigated by the purity of hydrogen.

  First, using the hydrogen production apparatus 1 of Example 1, the temperature was raised from room temperature (25 ° C.) to 550 ° C., and the raw material gas (natural gas + water vapor) was introduced to the side of the molded catalyst 3 as in Example 1. Then, a hydrogen production test for extracting hydrogen into the central hole 21 of the hydrogen separator 5 was performed. As a result, the purity of the obtained hydrogen was 99.99 volume% or more.

In addition, after the test, the temperature was lowered to room temperature, and then the temperature was raised again to 550 ° C. to produce hydrogen, that is, the start / stop test of the hydrogen production apparatus 1 was repeatedly performed.
As a result, the hydrogen purity was maintained at 99.99% by volume or more even after starting and stopping 100 times or more, indicating the effectiveness of the present invention.

  On the other hand, a hydrogen production apparatus (not shown) of a comparative example was produced. In this hydrogen production apparatus, similarly to the above-described prior art, a hydrogen separator was installed in a cylindrical metal reactor, and a granular catalyst having a diameter of 2 mm was filled between the reactor and the hydrogen separator.

  And it heated up from room temperature to 550 degreeC, the raw material gas was introduce | transduced into the granular catalyst side, and the hydrogen production test which extracts hydrogen in a hydrogen separator was done. As a result, the obtained hydrogen purity was 99.99% by volume or more.

  Moreover, when the hydrogen production test was carried out by repeating the start / stop five times, the hydrogen purity was less than 99.99% by volume. After that, the hydrogen purity gradually decreased each time starting and stopping were repeated.

  When the temperature was lowered and the hydrogen separator was taken out after starting and stopping five times, particulate catalyst traces were observed on the surface, and damage to the hydrogen separator was confirmed.

Next, the second embodiment will be described, but the description of the same contents as the first embodiment will be omitted.
As shown in FIG. 7, in the hydrogen production apparatus 71 of the present embodiment, the same hydrogen separator 73 as in the first embodiment is used, but the orientation of the hydrogen separator 73 is opposite to that in the first embodiment. It is.

  Specifically, the hydrogen separator 73 is erected vertically with the closed tip side facing upward. A metal joint 75 similar to that of the first embodiment is attached to the base end side of the hydrogen separator 73, and the metal joint 75 is fixed to the lower substrate 79 of the reactor 77.

In the hydrogen separator 73, a plurality of molded catalysts 81 similar to those in the first embodiment are sequentially stacked.
Also in the present embodiment, the same effects as in the first embodiment can be obtained, and when the formed catalyst 81 is arranged, the formed catalyst 81 may be sequentially fitted into the hydrogen separator 73 standing vertically. Therefore, there exists an advantage that the manufacture is easy.

Next, the third embodiment will be described, but the description of the same contents as the first embodiment will be omitted.
In this embodiment, the shape of the formed catalyst is different from that of the first embodiment, and therefore the formed catalyst will be described.

a) First, the configuration of the molded catalyst of this example will be described.
As shown in FIGS. 8A and 8B, the molded catalyst 91 of this example has the same cylindrical shape as that of Example 1, but the shape of the inner peripheral surface of the through-hole 93 is the same. Is different.

Specifically, a protruding portion 95 is formed on the inner peripheral surface of the through hole 93 of the molded catalyst 91 so that the central portion protrudes in a mountain shape toward the inner side (through hole 93 side).
As a modification, as shown in FIG. 8 (c), toward one opening end (downward in the figure) of the through-hole 103 of the molded catalyst 101, from the other opening end (upward in the figure). Protruding portions 105 that protrude (inclined) may be provided.

b) Next, the manufacturing method of the shaping | molding catalyst 91 of a present Example is demonstrated.
Although not shown, first, yttria-stabilized zirconia powder, 60% by volume of organic beads as a pore former, and an organic binder were mixed, and then granulated by spray drying.

  Next, the obtained granulated powder is pressed into a cylindrical shape having an outer diameter φ30 mm × inner diameter φ15 mm × length 30 mm, and an inner peripheral surface with irregularities (the shape of the protruding portion 95 shown in FIG. 8B). Molded.

The molded body was degreased and sintered at 1400 ° C. to prepare a porous carrier (not shown) having an outer diameter of φ24 mm × inner diameter of φ12 mm × length of 24 mm.
Next, the porous carrier was immersed in an aqueous nickel nitrate solution and dried.

  Thereafter, the dried porous carrier is heat treated in the atmosphere at 600 ° C., and then reduced in hydrogen at 600 ° C. to form the cylindrical shaped catalyst shown in FIGS. 8 (a) and 8 (b). 91.

  c) This embodiment has the same effects as the first embodiment, and the inner peripheral surface of the through-hole 93 has a protruding portion 95 protruding inward, so that the gas flow can be disturbed. , There is an advantage that the raw material gas is easy to come into contact with the forming catalyst 91 and has high reactivity.

  In addition, when hydrogen is generated by reforming the raw material gas flowing through the through hole 93, hydrogen is selectively separated by the adjacent hydrogen separator 5 as it is, so that hydrogen production performance is high. There is an effect.

d) Next, experimental examples will be described.
The molded catalyst 91 of this example and the hydrogen separator 5 of Example 1 were accommodated in the reactor 9 of Example 1 to produce a hydrogen production apparatus (not shown) used for the experiment.

  And when this start-up / stop test was carried out under the same conditions as in the experimental example using this hydrogen production apparatus, the hydrogen purity was 99.99% by volume or more after 100 start-ups / stops. Maintained.

Next, the fourth embodiment will be described, but the description of the same contents as the first embodiment will be omitted.
In this embodiment, the shape of the formed catalyst is different from that of the first embodiment, and therefore the formed catalyst will be described.

As shown in FIG. 9, the molded catalyst 111 of the present example has a cylindrical shape similar to that of Example 1, except that the vent hole 115 is provided in addition to the through hole 113. Yes.
Specifically, the molded catalyst 111 has ventilation holes 115 that penetrate the molded catalyst 111 in the axial direction at a plurality of locations (for example, at four locations) in parallel with the through holes 113.

  Therefore, in this embodiment, the same effect as in the first embodiment is obtained, and since the air hole 115 is provided, the source gas is also supplied to the air hole 115. Therefore, since the source gas is easily in contact with the metal catalyst, hydrogen is efficiently generated from the source gas.

Next, although Example 5 is demonstrated, description of the content similar to the said Example 1 is abbreviate | omitted.
In this embodiment, the shape of the formed catalyst is different from that of the first embodiment, and therefore the formed catalyst will be described.

  As shown in FIGS. 10A and 10B, the molded catalyst 121 of this example has a cylindrical shape similar to that of Example 1, but both end faces in the axial direction (upper end face 123 and The structure of the lower end face 125) is different.

  Specifically, the upper end surface 123 of the molded catalyst 121 protrudes toward one side of the axial direction (here, upward in the figure) as the through hole 127 side. Similarly, the lower end surface 125 also extends toward the through hole 127 side. Projects upward. The upper end surface 123 and the lower end surface 125 are parallel.

  Therefore, in this embodiment, the same effects as in the first embodiment are obtained, and the upper end surface 123 and the lower end surface 125 protrude upward, and therefore, it is difficult to shift the position when stacking the plurality of molded catalysts 121. There is.

That is, since positioning can be performed by the structure in which the upper end surface 123 and the lower end surface 125 protrude upward, there is an advantage that the axial directions of the plurality of molded catalysts 121 can be aligned.
FIG. 10C shows a molded catalyst 131 according to a modification of the present embodiment.

  In this modification, a plurality of convex portions 135 are provided on one end surface (here, upper end surface 133) in the axial direction of the molded catalyst 131, and the convex portion 135 is formed on the other end surface (here, lower end surface 137). A recessed portion 139 to be fitted is provided.

  That is, since positioning can be performed by a structure in which the convex portions 135 and the concave portions 139 facing each other are fitted, there is an advantage that the axial directions of the plurality of molded catalysts 131 can be aligned and easily arranged.

Next, the sixth embodiment will be described, but the description of the same contents as the second embodiment will be omitted.
As shown in FIG. 11, in the hydrogen production apparatus 140 of the present embodiment, as in the second embodiment, a hydrogen separator 145 with a metal joint 143 attached is erected in the reactor 141, and the hydrogen A plurality of cylindrical shaped catalysts 147 are fitted on the separator 145.

  In particular, in this embodiment, as the molded catalyst 147, two types of molded catalysts 147a and 147b having the same outer diameter but different inner diameters are laminated. That is, the molding catalyst 147a having a large inner diameter and the molding catalyst 147b having a small inner diameter are alternately stacked.

  According to the present embodiment, the same effects as those of the second embodiment can be obtained, and by disturbing the gas flow, there is an advantage that the raw material gas can be efficiently reformed to generate hydrogen and hydrogen can be separated.

Next, although Example 7 is demonstrated, description of the content similar to the said Example 2 is abbreviate | omitted. The same members as those in the second embodiment will be described using the same numbers.
As shown in FIG. 12A, in this embodiment, as in the second embodiment, a hydrogen separator 73 to which a metal joint 75 is attached is erected. Similar to Example 2, a plurality of cylindrical shaped catalysts 81 are externally fitted.

  In particular, in this embodiment, a cup-shaped molded catalyst 151 (with a bottom) is placed on the uppermost cylindrical molded catalyst 81. That is, the formed catalyst 151 is disposed so as to cover the front end of the hydrogen separator 73 exposed from the front end of the cylindrical formed catalyst 81.

  Also according to the present embodiment, there are advantages that the same effects as those of the second embodiment are obtained and the performance of reforming the raw material gas is high.

Next, Example 8 will be described, but the description of the same contents as Example 2 will be omitted. The same members as those in the second embodiment will be described using the same numbers.
As shown in FIG. 12B, in this embodiment, as in the second embodiment, a hydrogen separator 73 to which a metal joint 75 is attached is erected, and one hydrogen separator 73 is provided on the hydrogen separator 73. The cylindrical molding catalyst 161 is externally fitted.

  This shaped catalyst 161 has a longer axial dimension than the shaped catalyst of Example 2, and almost covers the outer peripheral portion of the hydrogen separator 73 (excluding the tip portion) by one shaped catalyst 161. For example, the length of the formed catalyst 161 covers more than half of the exposed portion of the hydrogen separator 73.

  The present embodiment has the advantages that the same effects as those of the second embodiment can be obtained and the configuration can be simplified.

Next, the ninth embodiment will be described, but the description of the same contents as the first embodiment will be omitted.
Although not shown, alumina was used as a support material for the hydrogen separator. The rubber mold is filled with alumina granulated powder and then alumina granulated powder with 48% by volume of organic beads added as a pore former, and after that, a cylindrical bottomed tube shape ( After forming into a test tube shape), firing at 1500 ° C. gave a ceramic support in which the dense portion and the porous portion were integrated. Thereafter, in the same manner as in Example 1, a hydrogen separation metal layer and the like were formed to obtain a hydrogen separator.

  After mixing alumina powder, 60% by volume of organic beads, and an organic binder as a catalyst carrier, it is molded into a cylindrical shape having an outer diameter of 30 mm, an inner diameter of 15 mm, and a length of 30 mm by an extrusion molding method. Produced. Thereafter, in the same manner as in Example 1, it was fired to obtain a porous carrier, and a catalyst metal was carried to obtain a molded catalyst.

Therefore, in this embodiment, the constituent materials of the ceramic support (specifically, the porous portion) and the porous support are completely the same (100%).
And the hydrogen separator and the said shaping | molding catalyst were combined, and it was set as the hydrogen production apparatus like 1st Example.

  Also in this example, the same effect as in Example 1 was obtained.

Next, the tenth embodiment will be described, but the description of the same contents as the ninth embodiment will be omitted.
The hydrogen separator was produced in the same manner as in Example 1.
Further, as a catalyst support, 40% by volume of a mixed powder of 90:10 (volume ratio) of yttria-stabilized zirconia and alumina, 60% by volume of organic beads, and an organic binder are mixed and then extruded. According to the above method, it was molded into a cylindrical shape having an outer diameter of 30 mm, an inner diameter of 15 mm, and a length of 30 mm to produce a molded body. Thereafter, in the same manner as in Example 1, it was fired to obtain a porous carrier, and a catalyst metal was carried to obtain a molded catalyst.

Therefore, in this embodiment, 90% of the constituent materials of the ceramic support (specifically, the porous portion) and the porous support are the same.
Then, a hydrogen production apparatus was formed as in the first example using the molded catalyst.
Also in this example, the same effect as in Example 1 was obtained.

In addition, this invention is not limited to the said embodiment and Example at all, and it cannot be overemphasized that it can implement with a various aspect in the range which does not deviate from this invention.
(1) For example, as shown in FIG. 13, annular irregularities extending in the circumferential direction may be formed on the inner peripheral surfaces of the cylindrical shaped catalysts 171 and 173.

  (2) Moreover, when forming a hydrogen separation metal layer, you may perform electrolytic plating after the said electroless plating. As this electrolytic plating, an internal power feeding method can be adopted in addition to normal electrolytic plating. In this internal power feeding method, the electrolytic solution is supplied to the inside (or outside) of the ceramic support, and the electrolytic plating solution is supplied to the outside (or inside), which is the opposite side, and the plating metal is supplied from the outside (or inside). It may be deposited.

  (3) Further, when a Pd alloy is used as the hydrogen separation metal layer, each alloy material (for example, Pd and Ag) may be sequentially formed by electroless plating or electrolytic plating, and then heated to be alloyed. .

DESCRIPTION OF SYMBOLS 1, 71, 140 ... Hydrogen production apparatus 3, 81, 91, 101, 111, 121, 131, 141, 147, 147a, 147b, 151, 161, 171, 173 ... Molding catalyst 4 ... Support body (porous support body) )
5, 73, 145 ... Hydrogen separator 9, 77, 141 ... Reactor 15, 65, 93, 103, 113, 127 ... Through hole 29 ... Porous part (support)
31 ... Porous layer 39 ... Hydrogen separation metal layer (hydrogen permeable membrane)
67 ... Hydrogen separator 95, 105 ... Projection 115 ... Vent 135 ... Convex 139 ... Concave

Claims (9)

A molded catalyst used in a reactor containing a cylindrical hydrogen separator comprising a hydrogen separation metal layer that selectively permeates hydrogen and a support that supports the hydrogen separation metal layer,
The molded catalyst is composed of a metal catalyst that generates hydrogen from a raw material gas and a carrier that supports the metal catalyst, and has a cylindrical shape having a through-hole into which the hydrogen separator can be inserted.
The forming catalyst is characterized in that the forming material of the forming catalyst carrier and the supporting material of the hydrogen separator have the same volume ratio of 90% or more.   The shaped catalyst according to claim 1, wherein the shaped catalyst is a porous ceramic carrier supported by the metal catalyst.   3. The shaped catalyst according to claim 1, wherein unevenness for disturbing a gas flow is formed on an inner peripheral surface of the through hole of the shaped catalyst.   The shaped catalyst according to any one of claims 1 to 3, wherein the shaped catalyst has a vent hole penetrating the shaped catalyst itself in addition to the through hole. A cylindrical hydrogen separator having a hydrogen separation metal layer that allows only hydrogen to permeate, and
The molded catalyst according to any one of claims 1 to 4,
A hydrogen production apparatus containing the
The hydrogen producing apparatus is characterized in that the molded catalyst is fitted into the hydrogen separator by inserting the hydrogen separator into a through hole of the molded catalyst.   The hydrogen production apparatus according to claim 5, wherein a plurality of the formed catalysts are fitted on the hydrogen separator.   The hydrogen separator is fixed in a standing manner in the reactor by a fixing member, and the molded catalyst is stacked on the fixing member in the vertical direction along the hydrogen separator. The hydrogen production apparatus according to claim 6.   The hydrogen production apparatus according to claim 6 or 7, wherein the molded catalysts having different inner diameters are alternately stacked.   The hydrogen according to any one of claims 6 to 8, further comprising a positioning portion that stacks adjacent molding catalysts and positions the molding catalysts on a surface of the stacking side. manufacturing device.

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