JP2010100481A - Membrane separation type hydrogen producing apparatus - Google Patents

Abstract

Provided is a membrane separation type hydrogen production apparatus capable of efficiently separating and purifying hydrogen while suppressing a decrease in hydrogen permeation amount in a hydrogen separation membrane while enhancing a reforming reaction in a steam reforming catalyst layer. To do.
SOLUTION: The upstream catalyst layer 2 disposed upstream from the inlet 1 of hydrocarbon and water vapor, the downstream catalyst layer 3 disposed downstream of the upstream catalyst layer 2, and the hydrogen permeability. The hydrogen separation membrane 4 is a membrane separation type hydrogen production apparatus including a first stage catalyst layer 2 composed of a steam reforming catalyst for steam reforming hydrocarbons, and the hydrogen separation membrane 4 is disposed on or in contact with the first stage catalyst layer 2. Without being disposed inside or outside the rear catalyst layer 3, the area S1 of the cross section by a plane perpendicular to the flow direction of the front catalyst layer 2 and the area S2 of the cross section of the rear catalyst layer 3 by a plane parallel to the cross section Is a membrane separation type hydrogen production apparatus characterized by satisfying the relationship of the formula: S1 ≧ 100/65 × S2.
[Selection] Figure 1

Description

  The present invention is a membrane separation type hydrogen production apparatus, in particular, using hydrogen such as methane, LPG, kerosene, naphtha, gasoline, etc. as a raw material, producing hydrogen by a steam reforming reaction, and separating hydrogen by a hydrogen separation membrane. The present invention relates to a membrane separation type hydrogen production apparatus used for purifying and taking out hydrogen.

  Conventionally, a hydrogen separation membrane steam reformer that generates a reformed gas containing hydrogen by a hydrocarbon reforming reaction and separates hydrogen from the reformed gas using a Pd-based hydrogen separation membrane is, for example, As described in Patent Document 1 (Japanese Patent Laid-Open No. 6-48701), a reforming catalyst is arranged around the hydrogen separation membrane.

  However, in such a configuration, the hydrogen concentration around the separation membrane is reduced by the amount of hydrogen separated and recovered by the hydrogen separation membrane, and the hydrogen concentration distribution is generated in the radial direction of the reforming catalyst layer. A sufficient hydrogen partial pressure difference for performing hydrogen separation could not be obtained, and the hydrogen separation efficiency was sometimes lowered.

Japanese Patent Laid-Open No. 6-48701

  In general, in order to separate and purify hydrogen using a hydrogen separation membrane, a pressure difference (hydrogen content) between the inlet side (reformed gas contact side) and the outlet side (product hydrogen recovery side) of the hydrogen separation membrane. It is advantageous to increase the pressure difference. In contrast, the steam reforming catalyst layer and the hydrogen separation membrane are integrated, a catalyst layer for the subsequent reaction is provided on the downstream side of the steam reforming catalyst layer, and the hydrogen separation membrane is built in the catalyst layer for the subsequent reaction. In the membrane separation type hydrogen production apparatus, the catalyst layer for the subsequent reaction is in contact with the inlet side of the hydrogen separation membrane, and the steam reforming catalyst layer in the previous stage is in contact with the catalyst layer for the subsequent reaction. Therefore, in order to increase the pressure difference between the inlet side and the outlet side of the hydrogen separation membrane, if the pressure on the inlet side of the hydrogen separation membrane is increased, the pressure of the steam reforming catalyst layer and the catalyst layer for the subsequent reaction is reduced. Get higher.

  In general, in the steam reforming reaction, the higher the reaction pressure, the lower the equilibrium composition becomes the lower the hydrogen partial pressure. Further, since the pressure is high, the flow rate (linear velocity) of the reformed gas containing hydrogen is reduced in the steam reforming catalyst layer. Here, if the flow rate of the reformed gas is not sufficiently high, in the region near the hydrogen separation membrane in the catalyst layer for the subsequent reaction, the hydrogen separation membrane is removed from the region at a speed at which the hydrogen separation membrane is removed. The rate at which hydrogen is supplied cannot catch up, and the hydrogen concentration in the region decreases, resulting in a hydrogen concentration distribution in the radial direction of the catalyst layer for the subsequent reaction. And since the hydrogen concentration in the vicinity of the hydrogen separation membrane is lowered, there is a problem that the difference in hydrogen partial pressure between the inlet side and the outlet side of the hydrogen separation membrane cannot be obtained sufficiently and the hydrogen separation efficiency is lowered. In addition, if the flow rate of the reformed gas is too high, the reformed gas that passes through the outer periphery of the catalyst layer for the subsequent reaction reaches the reactor outlet without contacting the hydrogen separation membrane, thus reducing the hydrogen separation efficiency. There was a problem.

  On the other hand, in order to increase the reaction efficiency of the reforming reaction in the previous steam reforming catalyst layer, it is advantageous that the liquid space velocity is low, and the flow rate of the reformed gas containing hydrogen is low in the reforming catalyst layer. is there. In order to mitigate the influence of the temperature reduction of the reforming catalyst layer due to the endothermic reaction, it is advantageous that the flow rate of the reformed gas is low.

  Accordingly, an object of the present invention is to provide a membrane separation type capable of efficiently separating and purifying hydrogen while enhancing a reforming reaction in the steam reforming catalyst layer and suppressing a decrease in hydrogen permeation amount in the hydrogen separation membrane. The object is to provide a hydrogen production apparatus.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have arranged a rear catalyst layer downstream of the front catalyst layer made of the steam reforming catalyst, and further separated hydrogen inside or outside the rear catalyst layer. After arranging the membrane, the cross-sectional area of the latter catalyst layer on which the hydrogen separation membrane is arranged is made 65% or less of the sectional area of the former catalyst layer made of the steam reforming catalyst. It has been found that hydrogen can be efficiently separated and purified by reducing the hydrogen permeation amount in the hydrogen separation membrane while lowering the reformed gas flow rate to increase the efficiency of the reforming reaction, and the present invention has been completed. . That is, the present invention includes the following inventions.

(1) The upstream catalyst layer disposed upstream from the hydrocarbon and water vapor inlets upstream, the downstream catalyst layer disposed downstream of the upstream catalyst layer, and a hydrogen separation membrane having hydrogen permeability A membrane separation type hydrogen production apparatus comprising:
The preceding catalyst layer is composed of a steam reforming catalyst for steam reforming hydrocarbons,
The hydrogen separation membrane is arranged so as to be in contact with the catalyst layer inside or outside the latter catalyst layer without being arranged or in contact with the preceding catalyst layer,
An area S1 of a cross section by a plane perpendicular to the flow path direction of the front catalyst layer and an area S2 of a cross section of the rear catalyst layer by a plane parallel to the cross section are expressed by the following formula (I):
S1 ≧ 100/65 × S2 (I)
A membrane-separated hydrogen production system that satisfies the above relationship.

(2) The diameter D1 of the cylinder circumscribing the preceding catalyst layer and the diameter D2 of the cylinder circumscribing the latter catalyst layer are represented by the following formula (II):
D1> D2 (II)
The membrane-separated hydrogen production apparatus according to (1), wherein the relationship is satisfied. Here, it is assumed that the center axis of the cylindrical body circumscribing the front catalyst layer and the cylindrical body circumscribing the rear catalyst layer is parallel to the flow path direction of the front catalyst layer.

  According to the present invention, the reformed gas flow rate in the downstream catalyst layer in contact with the hydrogen separation membrane is increased while reducing the flow rate of the reformed gas in the upstream catalyst layer composed of the steam reforming catalyst to increase the efficiency of the reforming reaction. By increasing the flow rate, preventing a decrease in hydrogen concentration near the hydrogen separation membrane, and reducing the cross-sectional area of the rear catalyst layer to 65% or less of the cross-sectional area of the front catalyst layer, the hydrogen permeation efficiency in the hydrogen separation membrane is reduced. Therefore, hydrogen can be separated and purified efficiently. As a result, the hydrogen production efficiency can be greatly improved.

  Below, the membrane separation type | mold hydrogen production apparatus and hydrogen production method of this invention are demonstrated in detail using FIG. 1 and 2. FIG. FIG. 1 is a schematic view showing an example of a membrane separation type hydrogen production apparatus of the present invention. FIG. 2A is a sectional view taken along line IIA-IIA in FIG. 1, and FIG. FIG. 2 is a cross-sectional view taken along the line IIB-IIB in FIG. In the membrane separation type hydrogen production apparatus shown in FIG. 1, the upstream catalyst layer 2 made of a steam reforming catalyst is disposed upstream from the hydrocarbon and steam inlet 1, and the downstream side of the upstream catalyst layer 2. Is provided with a post-catalyst layer 3 made of a catalyst for the post-reaction of the reformed gas, and further, the hydrogen separation membrane 4 is not disposed or in contact with the pre-catalyst layer 2, and the downstream post-catalyst layer 3 Is arranged. Further, the membrane separation type hydrogen production apparatus shown in FIG. 1 is provided with a non-permeate gas outlet portion 5 on the downstream side of the rear catalyst layer 3, and further has a product hydrogen outlet portion 6 communicating with the hydrogen separation membrane 4. Prepare.

  In the membrane separation type hydrogen production apparatus shown in FIG. 1, hydrocarbons and steam are supplied to a pre-stage catalyst layer 2 made of a steam reforming catalyst through an inlet 1 to generate reformed gas by a steam reforming reaction. The generated reformed gas is supplied to the rear catalyst layer 3, passes through the hydrogen separation membrane 4 built in the rear catalyst layer 3, and is taken out of the apparatus through the outlet portion 6 as product hydrogen. The reformed gas that has not permeated the hydrogen separation membrane 4 undergoes a rear reaction in the rear catalyst layer 3, and the hydrogen generated in the rear reaction permeates the hydrogen separation membrane 4 disposed in the rear catalyst layer 3. Then, it is taken out of the apparatus through the outlet 6 as product hydrogen. On the other hand, the gas that has passed through the rear catalyst layer 3 without passing through the hydrogen separation membrane 4 is discharged out of the apparatus from the outlet 5 as a non-permeating gas.

[Raw material hydrocarbon]
As the hydrocarbon used as a raw material for producing hydrogen by the reforming reaction, a hydrocarbon having a boiling point of 300 ° C. or less and a mixture thereof can be used. For example, methane, ethane, propane, butane, pentane, natural gas, LP gas, etc., hydrocarbons in the gaseous state at room temperature, naphtha fraction, gasoline fraction, kerosene fraction, light oil fraction and petroleum equivalents thereof Petroleum hydrocarbons in a liquid state at room temperature such as a fraction can be used.

  A naphtha fraction is a fraction having a boiling point within a range of 30 ° C. to 180 ° C. as a boiling point range among fractions obtained by distillation separation of crude oil, natural gas condensate, and the like. Examples of the naphtha fraction include a light naphtha fraction having a boiling range of about 30 to 80 ° C, a heavy naphtha fraction having a boiling range of about 80 to 180 ° C, and a whole naphtha fraction having a boiling range of about 30 to 180 ° C. Etc. are included.

  The gasoline fraction is a fraction having a boiling point in the range of 30 ° C. to 200 ° C. as a boiling range, and the boiling point used for the preparation of automobile gasoline is within the above range in addition to commercial automobile gasoline and industrial gasoline. An intermediate product (also called a base material), an intermediate product having a boiling point in the above range, and a fraction corresponding to automobile gasoline are also included.

  A kerosene fraction is a fraction having a boiling point within a range of 140 ° C. to 270 ° C. as a boiling point among fractions obtained by distillation separation of crude oil, natural gas condensate, and the like. In addition to commercial kerosene such as for use, a fraction corresponding to kerosene having a boiling point within the above range is included.

  The light oil fraction is a fraction having a boiling point in the boiling range of 160 ° C. to 370 ° C. In addition to the commercially available light oil used for diesel engines, the fraction corresponding to the light oil having the boiling point in the above range is included. included.

  From the viewpoint of product distribution, cost, and availability, liquid hydrocarbons such as gaseous hydrocarbons such as methane and LPG, naphtha, gasoline, kerosene, light oil and their corresponding fractions are preferred. The corresponding fraction is preferred. Further, these hydrocarbons preferably have a low sulfur content, particularly those having a sulfur content of 50 mass ppb or less, from the viewpoint of poisoning the steam reforming catalyst.

[Steam reforming catalyst, pre-catalyst layer]
As the steam reforming catalyst used in the present invention, a normal steam reforming catalyst can be used. For example, at least one catalytically active component selected from Fe, Co, Ni, Ru, Rh, Pd, Ir, and Pt is used as an oxide of Mg, Al, Si, Ti, Zr, Ba, La and / or Those supported on a carrier containing at least one carrier component selected from hydrated oxides can be used. From the viewpoint of suppressing the occurrence of coking, it is preferable to use Ru or Rh as the catalyst active component.

  These steam reforming catalysts are arranged on the most upstream side with respect to the supply direction of the mixed gas of hydrocarbon and steam as the pre-stage catalyst layer 2. The amount of the steam reforming catalyst contained in the pre-stage catalyst layer 2 can be appropriately determined depending on the type of hydrocarbon as the raw material, the reforming reaction temperature, the steam / carbon ratio, and the like.

[Catalyst for post reaction, post catalyst layer]
Further, a downstream catalyst layer 3 made of a catalyst for the subsequent reaction (may be the same as the steam reforming catalyst) is disposed downstream of the upstream catalyst layer 2 made of the steam reforming catalyst. The reformed gas from which hydrogen is separated by the hydrogen separation membrane 4 to be described later and the hydrogen partial pressure is reduced further generates hydrogen by a subsequent reaction (a further steam reforming reaction and a reaction that shifts the equilibrium state to the hydrogen generation side) by the catalyst. By doing so, hydrogen can be produced with higher efficiency by further separating hydrogen by the hydrogen separation membrane 4 without lowering the hydrogen concentration. In addition, it is preferable that the temperature of the back | latter stage catalyst layer 3 shall be 350 degreeC or more and less than 650 degreeC, and it is still more preferable to set it as 450-600 degreeC.

  Furthermore, if hydrogen is not sufficiently diffused in the post-catalyst layer 3 in contact with the hydrogen separation membrane 4, the hydrogen concentration in the region of the post-catalyst layer 3 in the vicinity of the hydrogen separation membrane 4 also decreases, thereby reducing the hydrogen separation efficiency. Therefore, it is preferable that the thickness of the catalyst filling portion of the rear catalyst layer 3 is thinner. Here, the area S1 of the cross section by the plane perpendicular to the flow path direction of the front catalyst layer 2 and the area S2 of the cross section of the rear catalyst layer 3 by the plane parallel to the cross section satisfy the relationship of the above formula (I). That is, the cross-sectional area S2 of the rear catalyst layer 3 needs to be 65% or less of the cross-sectional area S1 of the front catalyst layer 2, as shown in FIG. It is in the range of 65 to 1% of the cross-sectional area S1, more preferably in the range of 50 to 1%, and particularly preferably in the range of 50 to 5%. By making the cross-sectional area S2 of the post-catalyst layer 3 65% or less of the cross-sectional area S1 of the pre-catalyst layer 2, the difference in hydrogen concentration in the post-catalyst layer 3 can be reduced and without contacting the hydrogen separation membrane 4 The reformed gas passing through the reactor can be reduced. Further, if the cross-sectional area S2 of the post-catalyst layer 3 is 1% or more of the cross-sectional area S1 of the pre-catalyst layer 2, the post-catalyst layer 3 for further generating hydrogen by the post-reaction by the amount of permeated hydrogen can be secured.

  Further, the pre-stage catalyst layer 2 and the post-stage catalyst layer 3 preferably satisfy the relationship of the above formula (II), that is, a cylinder that circumscribes the pre-stage catalyst layer 2 and a cylinder that circumscribes the post-stage catalyst layer 3 are considered. In this case, the diameter D2 of the cylindrical body circumscribing the rear catalyst layer 3 is preferably smaller than the diameter D1 of the cylindrical body circumscribing the front catalyst layer 2, as shown in FIG. Is in the range of 80 to 10%, more preferably in the range of 70 to 10%, and particularly preferably in the range of 70 to 20% (see FIGS. 1 and 2). In the membrane-separated hydrogen production apparatus shown in FIG. 2, since the front catalyst layer 2 and the rear catalyst layer 3 are cylindrical, the diameter of the cylindrical body circumscribing the front catalyst layer 2 is equal to the diameter of the front catalyst layer 2, and the rear catalyst layer The diameter of the cylindrical body circumscribing 3 is the diameter of the latter catalyst layer 3 Shii). By making the diameter D2 of the cylindrical body circumscribing the rear catalyst layer 3 smaller than the diameter D1 of the cylindrical body circumscribing the front catalyst layer 2, the hydrogen concentration difference in the rear catalyst layer 3 can be reduced, and further, the rear catalyst layer The diameter D2 of the cylinder circumscribing 3 is 80% or less of the diameter D1 of the cylinder circumscribing the front catalyst layer 2, so that the hydrogen concentration difference in the rear catalyst layer 3 can be sufficiently reduced, and hydrogen separation is performed. The reformed gas that passes through the reactor without contacting the membrane 4 can be greatly reduced. Further, if the diameter D2 of the cylinder circumscribing the rear catalyst layer 3 is 10% or more of the diameter D1 of the cylinder circumscribing the front catalyst layer 2, the amount of permeated hydrogen is used to further generate hydrogen by the rear reaction. The latter stage catalyst layer 3 can be secured.

  In the membrane separation type hydrogen production apparatus shown in FIG. 1 and FIG. 2 described above, the front catalyst layer 2 and the rear catalyst layer 3 are cylindrical, and one hydrogen separation membrane 4 is built in the rear catalyst layer 3. The shape of the membrane separation type hydrogen production apparatus of the present invention is not limited to this, and it is sufficient that the hydrogen separation membrane 4 is disposed so as to contact the subsequent catalyst layer 3 without contacting the previous catalyst layer 2, for example, FIG. 4 and FIG. 4, the front catalyst layer 2 and the rear catalyst layer 3 may be cylindrical, and a plurality of hydrogen separation membranes 4 may be built in the rear catalyst layer 3, as shown in FIG. 5 and FIG. 6. In addition, the front catalyst layer 2 and the rear catalyst layer 3 may have a rectangular parallelepiped shape, and the hydrogen separation membrane 4 may be built in the rear catalyst layer 3, or as shown in FIGS. The rear catalyst layer 3 may be cylindrical, and the hydrogen separation membrane 4 may be disposed on the outer periphery of the rear catalyst layer 3. 4A is a sectional view taken along line IVA-IVA in FIG. 3, FIG. 4B is a sectional view taken along line IVB-IVB in FIG. 3, and FIG. (A) in FIG. 5 is a cross-sectional view taken along line VIA-VIA in FIG. 5, (B) in FIG. 6 is a cross-sectional view taken along line VIB-VIB in FIG. 5, and (A) in FIG. ) Is a cross-sectional view taken along line VIIIA-VIIIA in FIG. 7, and FIG. 8B is a cross-sectional view taken along line VIIIB-VIIIB in FIG. 7.

As the post-reaction catalyst used for the downstream post-catalyst layer 3 in the present invention, a conventionally known catalyst can be used, which may be the same as the steam reforming catalyst. For example, examples of the catalytically active component include those of noble metals such as Fe ₂ O ₃ , Cu—ZnO, Ru, Pt, and Au. What carried these catalyst active components in magnesia, magnesia-calcium oxide-silica, magnesia-silica, alumina, silica-alumina, silica, etc. can be used as a catalyst. The amount of the catalyst to be included in the downstream downstream catalyst layer 3 can be appropriately determined depending on the type of raw material hydrocarbon used, the downstream reaction temperature, and the like.

[Hydrogen separation membrane]
Further, a hydrogen separation membrane 4 is disposed inside or outside the downstream downstream catalyst layer 3 so as to be in contact with the downstream catalyst layer 3 without being disposed on or in contact with the upstream catalyst layer 2. The hydrogen separation membrane used in the present invention is not particularly limited as long as it is a material having selective hydrogen permeability, but is preferably a palladium membrane or palladium alloy membrane having high hydrogen permeability, such as palladium / copper, palladium / silver. A palladium alloy film such as is more preferable.

  As the hydrogen separation membrane, as shown in FIG. 9, a barrier layer 9 is provided on the sintered filter portion 7 of the metal tube 8 having the sintered filter portion 7, and a palladium alloy plating film is formed on the barrier layer 9. It is preferable to use a hydrogen separation membrane in which 10 is arranged. Here, the sintered filter portion 7 and the metal tube 8 are preferably made of stainless steel, and the barrier layer 9 is preferably made of zirconia, alumina, or the like, and the palladium alloy plating film 10 includes a palladium-copper alloy. And a palladium-silver alloy plating film are preferred, and a palladium-copper alloy plating film is particularly preferred. The barrier layer 9 prevents the metal component of the sintered filter portion 7 from diffusing into the palladium alloy plating film 10 to deteriorate the hydrogen permeability of the plating film 10 and increases the surface smoothness. It has the effect of preventing defects in the palladium alloy plating film 10.

[Hydrogen production method]
The hydrogen production method using the membrane separation type hydrogen production apparatus of the present invention is performed as follows. First, the mixed gas of hydrocarbon and steam is supplied to the pre-stage catalyst layer 2 made of the steam reforming catalyst, and a steam reforming reaction is performed to generate a reformed gas containing hydrogen as a main component. Here, the ratio of hydrocarbon to water vapor is preferably in the range of 2.5 to 4.0 as the steam / carbon ratio (S / C ratio), and more preferably in the range of 2.8 to 3.5. When the S / C ratio is low, coking occurs and the activity of the steam reforming catalyst is reduced. Further, when the S / C ratio is higher than necessary, the efficiency is lowered.

  The temperature of the pre-catalyst layer 2, that is, the reforming reaction temperature is preferably 400 to 800 ° C, more preferably 450 to 750 ° C. When the temperature of the reforming reaction is less than 400 ° C., the hydrogen fraction is 10 vol% or less (under the condition of a reaction pressure of 0.9 MPaG with a methane raw material), and a sufficient hydrogen permeation amount cannot be obtained. If it exceeds, a heat-resistant material (such as Kanthal, Inconel, Hastelloy, etc.) is required as the material of the reaction tube and the cost becomes high.

  The pressure for the reforming reaction is preferably 0.5 to 1.5 MPaG, more preferably 0.7 to 1.2 MPaG. When the reaction pressure is too low, a sufficient amount of hydrogen permeation cannot be obtained, and when the reaction pressure is too high, the hydrocarbon reaction (reaction toward the hydrogen generation side) is difficult to proceed.

When kerosene is used as the raw material hydrocarbon, SV (kerosene-based LHSV) is preferably in the range of 0.3 to 3.0 h ^{−1 in} the current catalyst, and in the range of 0.3 to 1.7 h ⁻¹ . More preferred.

  Next, the reformed gas is supplied to the subsequent catalyst layer 3 arranged on the downstream side of the previous catalyst layer 2, and then hydrogen is permeated and separated by the hydrogen separation membrane 4.

  Further, the reformed gas from which the hydrogen has been separated by the hydrogen separation membrane 4 causes the rear catalyst layer 3 to further generate hydrogen by the rear reaction, and the hydrogen separation membrane 4 disposed in contact with the rear catalyst layer 3 The generated hydrogen is separated. Since hydrogen is separated by the hydrogen separation membrane 4 and the hydrogen partial pressure is reduced, hydrogen is produced by the subsequent reaction. Therefore, the amount of hydrogen produced can be increased and hydrogen can be produced with high efficiency.

  As described above, according to the present invention, it is possible to provide a membrane separation type hydrogen production apparatus capable of recovering hydrogen with high efficiency. The membrane-separated hydrogen production apparatus of the present invention can produce high-purity hydrogen gas in a compact configuration with high efficiency and a high recovery amount. Therefore, a hydrogen production apparatus for a polymer electrolyte fuel cell (PEFC), or It can be suitably used as an on-site type hydrogen production apparatus used in a hydrogen station.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

Example 1
A membrane separation type hydrogen production apparatus having the structure shown in FIG. 1 was prepared. The upstream steam reforming section of the apparatus has a reaction tube diameter (that is, the diameter of the upstream catalyst layer (= the diameter of the cylindrical body circumscribing the upstream catalyst layer) D1) of 43 mmφ, and the upstream catalyst layer made of the steam reforming catalyst. The cross-sectional area S1 is 1452 mm ² , the length is 30 mm, and the hydrogen separation and downstream reaction section has a pipe diameter (that is, the downstream downstream catalyst layer diameter (= the cylindrical body circumscribing the downstream catalyst layer). The diameter D2) is 22 mmφ, the cross-sectional area S2 of the rear catalyst layer is 300 mm ² , the length is 45 mm, and the area of the hydrogen separation membrane is about 15 cm ² .

  In addition, as a hydrogen separation membrane module, on the support body which arranged the stabilized zirconia layer (30 micrometers) as a barrier layer on the sintered filter part of the SUS pipe | tube with a diameter of 10.1 mmphi which has a sintered filter part made from SUS. Pd and Cu [Pd: Cu = 60: 40 (wt%)] were sequentially plated to a film thickness of 3 μm, and a module that was alloyed at 400 ° C. for 60 hours under a nitrogen atmosphere was used.

  Further, a general steam reforming catalyst (Ru system, size 2 mmφ) was used for the front catalyst layer and the rear catalyst layer.

Using methane (0.811 mol / hr) as a raw material hydrocarbon, reaction temperature 500 ° C., reaction pressure 0.9 MPaG, steam / carbon ratio (S / C) = 3.0, GHSV (methane + steam) = 3000 h ^{− The} reforming reaction was performed under the condition of ¹ . Table 1 shows the hydrogen recovery rate and the methane conversion rate.

(Comparative Example 1)
A membrane separation type hydrogen production apparatus having the structure shown in FIG. 10 was prepared. The upstream steam reforming section of the apparatus has a reaction tube diameter (that is, the diameter of the upstream catalyst layer (= the diameter of the cylindrical body circumscribing the upstream catalyst layer) D1) of 43 mmφ, and the upstream catalyst layer made of the steam reforming catalyst. The cross-sectional area S1 is 1452 mm ² and the length is 30 mm, and the hydrogen separation and rear reaction part has a pipe diameter (that is, the diameter of the rear catalyst layer (= the diameter of the cylinder circumscribing the rear catalyst layer) D2. ) Is 43 mmφ, the cross-sectional area S2 of the rear catalyst layer is 1373 mm ² , the length is 45 mm, and the area of the hydrogen separation membrane is about 15 cm ² .

  In addition, as a hydrogen separation membrane module, on the support body which arranged the stabilized zirconia layer (30 micrometers) as a barrier layer on the sintered filter part of the SUS pipe | tube with a diameter of 10.1 mmphi which has a sintered filter part made from SUS. Pd and Cu [Pd: Cu = 60: 40 (wt%)] were sequentially plated to a film thickness of 3 μm, and a module that was alloyed at 400 ° C. for 60 hours under a nitrogen atmosphere was used.

  Further, a general steam reforming catalyst (Ru system, size 2 mmφ) was used for the front catalyst layer and the rear catalyst layer.

Using methane (1.352 mol / hr) as a raw material hydrocarbon, reaction temperature 500 ° C., reaction pressure 0.9 MPaG, steam / carbon ratio (S / C) = 3.0, GHSV (methane + steam) = 3000 h ^{− The} reforming reaction was performed under the condition of ¹ . Table 1 shows the hydrogen recovery rate and the methane conversion rate.

(Comparative Example 2)
A membrane separation type hydrogen production apparatus having the structure shown in FIG. 10 was prepared. The upstream steam reforming section of the apparatus has a reaction tube diameter (that is, the diameter of the upstream catalyst layer (= the diameter of the cylindrical body circumscribing the upstream catalyst layer) D1) of 43 mmφ, and the upstream catalyst layer made of the steam reforming catalyst. The cross-sectional area S1 is 1452 mm ² and the length is 30 mm, and the hydrogen separation and rear reaction part has a pipe diameter (that is, the diameter of the rear catalyst layer (= the diameter of the cylinder circumscribing the rear catalyst layer) D2. ) Is 43 mmφ, the cross-sectional area S2 of the rear catalyst layer is 1373 mm ² , the length is 45 mm, and the area of the hydrogen separation membrane is about 15 cm ² .

  In addition, as a hydrogen separation membrane module, on the support body which arranged the stabilized zirconia layer (30 micrometers) as a barrier layer on the sintered filter part of the SUS pipe | tube with a diameter of 10.1 mmphi which has a sintered filter part made from SUS. Pd and Cu [Pd: Cu = 60: 40 (wt%)] were sequentially plated to a film thickness of 3 μm, and a module that was alloyed at 400 ° C. for 60 hours under a nitrogen atmosphere was used.

  Further, a general steam reforming catalyst (Ru system, size 2 mmφ) was used for the front catalyst layer and the rear catalyst layer.

Using methane (0.811 mol / hr) as a raw material hydrocarbon, reaction temperature 500 ° C., reaction pressure 0.9 MPaG, steam / carbon ratio (S / C) = 3.0, GHSV (methane + steam) = 1800 h ^{− The} reforming reaction was performed under the condition of ¹ . Table 1 shows the hydrogen recovery rate and the methane conversion rate.

  It can be seen from Table 1 that the hydrogen recovery rate and the methane conversion rate can be improved by using the membrane separation type hydrogen production apparatus of the example.

It is a schematic diagram which shows an example of the membrane separation type | mold hydrogen production apparatus of this invention. It is sectional drawing of the membrane separation type | mold hydrogen production apparatus shown in FIG. It is a schematic diagram which shows another example of the membrane separation type | mold hydrogen production apparatus of this invention. It is sectional drawing of the membrane separation type | mold hydrogen production apparatus shown in FIG. It is a schematic diagram which shows another example of the membrane separation type | mold hydrogen production apparatus of this invention. It is sectional drawing of the membrane separation type | mold hydrogen production apparatus shown in FIG. It is a schematic diagram which shows another example of the membrane separation type | mold hydrogen production apparatus of this invention. It is sectional drawing of the membrane separation type | mold hydrogen production apparatus shown in FIG. It is a fragmentary sectional view of the suitable example of the hydrogen separation membrane used for the membrane separation type | mold hydrogen production apparatus of this invention. It is a schematic diagram of the membrane separation type | mold hydrogen production apparatus used by the comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Entrance part of hydrocarbon and water vapor | steam 2 Front stage catalyst layer 3 Back stage catalyst layer 4 Hydrogen separation membrane 5 Outlet part of non-permeate gas 6 Outlet part of product hydrogen 7 Sintering filter part 8 Metal pipe 9 Barrier layer 10 Palladium alloy plating film S1 Cross-sectional area of the front catalyst layer perpendicular to the flow path direction S2 Cross-sectional area of the rear catalyst layer parallel to the surface perpendicular to the flow path direction of the front catalyst layer D1 Cylindrical body circumscribing the front catalyst layer Diameter D2 Diameter of the cylinder circumscribing the latter catalyst layer

Claims (2)

A membrane comprising an upstream catalyst layer disposed upstream from a hydrocarbon and water vapor inlet, upstream a downstream catalyst layer disposed downstream of the upstream catalyst layer, and a hydrogen separation membrane having hydrogen permeability A separation-type hydrogen production apparatus,
The preceding catalyst layer is composed of a steam reforming catalyst for steam reforming hydrocarbons,
The hydrogen separation membrane is arranged so as to be in contact with the catalyst layer inside or outside the latter catalyst layer without being arranged or in contact with the preceding catalyst layer,
An area S1 of a cross section by a plane perpendicular to the flow path direction of the front catalyst layer and an area S2 of a cross section of the rear catalyst layer by a plane parallel to the cross section are expressed by the following formula (I):
S1 ≧ 100/65 × S2 (I)
A membrane-separated hydrogen production system that satisfies the above relationship. The diameter D1 of the cylinder circumscribing the preceding catalyst layer and the diameter D2 of the cylinder circumscribing the latter catalyst layer are represented by the following formula (II):
D1> D2 (II)
The membrane separation type hydrogen production apparatus according to claim 1, wherein the relationship is satisfied.

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