JP2011143375A - Hydrogen separation system using 5a group metallic hydrogen separation membrane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen separation system providing a hydrogen recovery higher than in conventional reformers, by using both a Pd-based alloy hydrogen separation membrane and a 5A group metal alloy hydrogen separation membrane. <P>SOLUTION: In the hydrogen separation system, the hydrogen separation membrane is disposed on the outer peripheral face of a support body consisting of a casing-like or a cylindrical porous support body or a support body consisting of a perforated plate serving for supporting the hydrogen separation membrane, and a plurality of hydrogen separation reformers formed by arranging a reforming catalyst layer are serially arranged on the outer periphery of the hydrogen separation membrane. The hydrogen separation membrane uses the Pd-based alloy hydrogen separation membrane on the upstream of the treating object gas, and the 5A group metal alloy hydrogen separation membrane on the downstream of the treating object gas. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hydrogen separation system using a Group 5A metal-based hydrogen separation membrane, and more specifically, hydrogen using a Pd-based alloy hydrogen separation membrane and a periodic table of elements of Group 5A metal alloy hydrogen separation membrane. It relates to a separation system.

  As a hydrogen separation membrane of a conventional hydrogen separation reformer, a Pd-based alloy hydrogen separation membrane (Patent Document 1, etc.) is generally known and used. In a hydrogen separation reformer, if a large number of hydrogen separation membranes are mounted on the input raw material gas, that is, the hydrogen-containing treated gas (treated gas containing hydrogen obtained by steam reforming of hydrocarbons, etc.), the hydrogen separation type reformer is separated. Although the amount of hydrogen to be produced can be increased and hydrogen can be produced efficiently, the Pd-based alloy hydrogen separation membrane is expensive and the apparatus becomes large.

To selectively permeate and purify hydrogen through a hydrogen separation membrane made of a Pd-based alloy and perform efficient hydrogen production, for example, primary pressure (reaction side) = 0.8 MPaG, secondary pressure (permeation side) = -0.06 to 0 MPaG, 500 to 550 ° C., S / C = 2.5 to 3.5, raw material input amount is ^{2 to} 6 cc / min / cm ² , preferably about 3 to 4 cc / min / cm ² It is suitable to drive at.

  In a hydrogen separation reformer using only a Pd-based alloy hydrogen separation membrane, even if the area of the hydrogen separation membrane is increased or the mounting amount of the hydrogen separation membrane module is increased under such optimized operating conditions. Thus, the amount of hydrogen production that is equivalent to the increase in the hydrogen separation membrane cannot be obtained.

For example, the apparent hydrogen permeation coefficient during hydrocarbon reforming is 0.7 × 10 ⁻⁸ mol · m ⁻¹ · s ⁻¹ · Pa ^−1/2 , length 450 mm, width 120 mm, thickness 20 μm A Pd-based alloy hydrogen separation membrane of 95 NL / h (approximately 3 cc / min / cm ² ) of 13 A city gas and S / C (water vapor / carbon ratio) = 3 of water vapor on the primary side (reaction side) Considering the case where hydrogen was produced at 550 ° C. with a secondary pressure (permeation side) of −0.06 MPaG and the membrane area was increased by 33.3% by 0.8 MPaG. Hydrogen production increases only 20.7% from 294 NL / h to 355 NL / h.

  By the way, the periodic table 5A metal of an element such as Nb, V, or Ta or an alloy containing a 5A metal has a high hydrogen permeability coefficient Φ compared to a Pd-based alloy such as a Pd—Ag alloy. Since hydrogen embrittlement occurs, it is difficult to use as a hydrogen separation membrane. In order to suppress hydrogen embrittlement, methods for suppressing hydrogen embrittlement by adding additional elements have been proposed (Patent Documents 2 and 3). However, it is difficult to achieve both hydrogen embrittlement resistance and industrially important high hydrogen permeation rate by simply obtaining high solubility and hydrogen permeation coefficient by simply controlling what percentage of additive material is added. In addition to the addition amount, it is necessary to select an appropriate use temperature and use pressure (primary side and secondary side).

  The present inventors have first developed a method for obtaining an optimum condition for realizing a high hydrogen concentration difference while suppressing the amount of hydrogen solid solution by adding other components by using a PCT curve (= pressure composition temperature curve). (Patent Documents 4 and 5). According to this method, it was shown that pure Nb and Nb-W alloys can be used at low hydrogen partial pressure and low pressure difference by clarifying the conditions that do not cause brittle fracture. However, the maximum working pressure is below atmospheric pressure of 0.05 MPa (absolute pressure) and cannot be used at a high hydrogen partial pressure.

U.S. Pat. No. 2,773,561 JP 2001-170460 A JP 2006-000722 A Japanese Patent Application No. 2008-072607 (filed on Mar. 19, 2008) Japanese Patent Application No. 2008-072609 (filed on Mar. 19, 2008)

  The present inventors have newly found a group 5A metal alloy hydrogen separation membrane that can be used even at a hydrogen partial pressure of atmospheric pressure or higher. That is, for example, at 500 ° C., a VW alloy hydrogen separation membrane can be used up to 0.3 MPa (absolute pressure), and a Ta—W alloy hydrogen separation membrane can be used up to 0.15 MPa (absolute pressure). It can be used. Then, it was clarified that the apparent hydrogen permeation coefficient at 500 ° C. is 5 times as large as that of the Pd—Ag alloy (FIGS. 1 to 4).

  In the present invention, for example, a VW alloy hydrogen separation membrane that can be used up to 0.3 MPa [= 3 atm (absolute pressure)] at 500 ° C., 0.15 MPa [= 1.5 atm (absolute pressure), for example. )]] By using Ta-W alloy hydrogen separation membranes that can be used up to and using them together with Pd alloy hydrogen separation membranes, that is, using both Pd alloy hydrogen separation membranes and Group 5A metal alloy hydrogen separation membranes Thus, an object of the present invention is to provide a hydrogen separation system that can obtain a higher hydrogen recovery rate than a conventional reformer.

  In the present invention (1), a hydrogen separation membrane is arranged on the outer peripheral surface of a cylindrical porous support or a porous plate supporting the hydrogen separation membrane, and reformed on the outer periphery of the hydrogen separation membrane. A hydrogen separation system in which a plurality of hydrogen separation type reformers each having a catalyst layer are arranged in series, wherein the hydrogen separation membrane uses a Pd-based alloy hydrogen separation membrane on the upstream side of the gas to be treated The two-stage hydrogen separation reformer is characterized in that a 5A group metal alloy hydrogen separation membrane is used on the downstream side of the gas to be treated.

  The present invention (2) is a hydrogen separation type in which a hydrogen separation membrane is disposed on the outer peripheral surface of a cylindrical reforming catalyst / porous support that simultaneously serves as a reforming catalyst and supports a hydrogen separation membrane. A hydrogen separation system comprising a plurality of reformers arranged in series, wherein the hydrogen separation membrane uses a Pd-based alloy hydrogen separation membrane on the upstream side of the gas to be treated and 5A on the downstream side of the gas to be treated. Is a hydrogen separation system using a group III metal alloy hydrogen separation membrane.

  In the present invention (3), a hydrogen separation membrane is arranged on the outer peripheral surface of a cage-like porous support or a porous plate that plays a role of supporting the hydrogen separation membrane, and the reforming is performed on the outer periphery of the hydrogen separation membrane. A hydrogen separation system in which a plurality of hydrogen separation type reformers each having a catalyst layer are arranged in series, wherein the hydrogen separation membrane uses a Pd-based alloy hydrogen separation membrane on the upstream side of the gas to be treated The two-stage hydrogen separation reformer is characterized in that a 5A group metal alloy hydrogen separation membrane is used on the downstream side of the gas to be treated.

  The present invention (4) is a hydrogen separation reforming in which a hydrogen separation membrane is disposed on the outer peripheral surface of a bowl-shaped reforming catalyst / support that simultaneously serves as a reforming catalyst and supports a hydrogen separation membrane. A hydrogen separation system comprising a plurality of reactors arranged in series, wherein the hydrogen separation membrane uses a Pd-based alloy hydrogen separation membrane on the upstream side of the gas to be treated, and a group 5A metal on the downstream side of the gas to be treated A hydrogen separation system comprising an alloy hydrogen separation membrane.

  In the hydrogen separation system of the present invention (1) to (4), the 5A group metal alloy hydrogen separation membrane used downstream of the gas to be treated includes a VW alloy hydrogen separation membrane and a Ta-W alloy hydrogen separation membrane. Etc. can be used.

According to the present invention, the following effects (1) to (4) can be obtained.
(1) A hydrogen separation type reformer that can obtain a higher hydrogen recovery rate than a conventional reformer from a raw fuel such as natural gas can be realized.
(2) By reducing the amount of noble metal used such as Pd, the cost of the hydrogen separation membrane can be reduced. If the same amount of hydrogen production as before is required, a group 5A metal alloy hydrogen separation membrane can be provided in the subsequent stage to reduce the amount of the Pd-based alloy hydrogen separation membrane in the previous stage.
(3) With the two-stage hydrogen separation membrane, a hydrogen production amount equivalent to that at 550 ° C. can be obtained only at the Pd-based alloy hydrogen separation membrane even at 500 ° C. For this reason, it is possible to lower the operating temperature of the reactor, leading to higher efficiency.
(4) Since hydrogen is extracted at a high recovery rate, the CO ₂ concentration in the reformer off-gas increases, and efficient CO ₂ separation and recovery from the off-gas by compression liquefaction becomes possible.

FIG. 1 is a graph plotting the relationship between the hydrogen pressure P of the atmosphere and the amount of dissolved hydrogen C at temperatures of 400 ° C., 450 ° C., and 500 ° C. for the VW type alloy film. FIG. 2 is a diagram showing test conditions and results of a hydrogen permeation rate test for Pd-26Ag alloy, Nb-5W alloy, and V-5W alloy. FIG. 3 is a graph plotting the relationship between the hydrogen pressure P of the atmosphere and the amount C of solute hydrogen at temperatures of 400 ° C., 450 ° C., and 500 ° C. for the Ta—W alloy film. FIG. 4 is a diagram showing test conditions and results of a hydrogen permeation rate test for a Pd-26Ag alloy and a Ta-5W alloy. FIG. 5 is a diagram for explaining a configuration example of the present invention (1) to (2). FIG. 6 is a diagram for explaining a configuration example of the present invention (3) to (4). FIG. 7 is a view for explaining the hydrogen separator 1 and the like provided with a Pd-based alloy hydrogen separation membrane.

  In the present invention (1), a hydrogen separation membrane is arranged on the outer peripheral surface of a cylindrical porous support or a porous plate supporting the hydrogen separation membrane, and reformed on the outer periphery of the hydrogen separation membrane. This is a hydrogen separation system in which a plurality of hydrogen separation type reformers each having a catalyst layer are arranged in series. The hydrogen separation membrane is characterized in that a Pd-based alloy hydrogen separation membrane is used on the upstream side of the gas to be processed, and a 5A group metal alloy hydrogen separation membrane is used on the downstream side of the gas to be processed.

  The present invention (2) is a hydrogen separation type in which a hydrogen separation membrane is disposed on the outer peripheral surface of a cylindrical reforming catalyst / porous support that simultaneously serves as a reforming catalyst and supports a hydrogen separation membrane. This is a hydrogen separation system in which a plurality of reformers are arranged in series. The hydrogen separation membrane is characterized in that a Pd-based alloy hydrogen separation membrane is used on the upstream side of the gas to be processed, and a 5A group metal alloy hydrogen separation membrane is used on the downstream side of the gas to be processed.

  In the present invention (3), a hydrogen separation membrane is arranged on the outer peripheral surface of a cage-like porous support or a porous plate that plays a role of supporting the hydrogen separation membrane, and the reforming is performed on the outer periphery of the hydrogen separation membrane. This is a hydrogen separation system in which a plurality of hydrogen separation type reformers each having a catalyst layer are arranged in series. The hydrogen separation membrane is characterized in that a Pd-based alloy hydrogen separation membrane is used on the upstream side of the gas to be processed, and a 5A group metal alloy hydrogen separation membrane is used on the downstream side of the gas to be processed.

  The present invention (4) is a hydrogen separation reforming in which a hydrogen separation membrane is disposed on the outer peripheral surface of a bowl-shaped reforming catalyst / support that simultaneously serves as a reforming catalyst and supports a hydrogen separation membrane. This is a hydrogen separation system in which a plurality of vessels are arranged in series. The hydrogen separation membrane is characterized in that a Pd-based alloy hydrogen separation membrane is used on the upstream side of the gas to be processed, and a 5A group metal alloy hydrogen separation membrane is used on the downstream side of the gas to be processed.

  In the hydrogen separation system of the present invention (1) to (4), as a 5A group metal alloy hydrogen separation membrane used on the downstream side of the gas to be treated, a VW alloy hydrogen separation membrane (alloy added with W to an alloy) Hydrogen separation membrane made of alloyed alloy), Ta-W alloy hydrogen separation membrane (hydrogen separation membrane made of alloy formed by adding W to Ta) and the like can be used.

For example, in hydrogen separation using a Pd-based alloy hydrogen separation membrane, the Sievert's law (C = KP ^1/2, hereinafter abbreviated as “Siebert's law”) is used, so a high hydrogen permeation amount J (J = D · ΔC / d, D is a diffusion coefficient, ΔC is a solid solution hydrogen amount difference, and d is a film thickness), but a certain hydrogen partial pressure difference (ΔP) is required, but Nb does not follow the Siebelz rule I found that there was a region. For this reason, if a hydrogen pressure difference or a hydrogen partial pressure difference occurs even at a low hydrogen concentration, a high solid solution hydrogen amount difference (ΔC) can be obtained, and a high hydrogen permeation amount (J) can be obtained.

  By measuring the PCT curve at the operating temperature, the usable hydrogen pressure of the alloy can be determined. For example, at 500 ° C., the hydrogen partial pressure is 0.3 MPa (= 3 atmospheres (absolute pressure)) or less for V-W alloys and 0.15 MPa (= 1.5 atmospheres (absolute pressure)) for Ta-W alloys. Can be used as a hydrogen separation membrane (FIGS. 1 and 3).

  Also, depending on the pressure condition from the evaluation of the J · d value, which is the product of the hydrogen permeation flux J and the film thickness d of the alloy, the VW alloy and the Ta—W alloy may be compared with the Pd—Ag alloy. It was found that a high hydrogen permeation rate was obtained (FIGS. 2 and 4).

As shown in FIG. 2, at 500 ° C., when hydrogen permeation condition, process side (primary side) / permeation side (secondary side) = 0.20 MPa / 0.01 MPa, the apparent hydrogen permeation capacity Φ is Pd-26Ag alloy Is 2.3 × 10 ⁻⁸ (mol ⁻¹ · m ⁻¹ · s ⁻¹ · Pa ^−1/2 ), whereas V-5W alloy film 1.2 × 10 ⁻⁷ (mol ⁻¹ · m ⁻¹ · s ⁻¹ · Pa ^−1/2 ) and about 5 times as long as a separation membrane having the same area and thickness, a hydrogen permeation amount of about 5 times can be obtained.

For example, the apparent hydrogen permeation coefficient during reforming is 0.7 × 10 ⁻⁸ (mol ⁻¹ · m ⁻¹ · s ⁻¹ · Pa ^−1/2 ), length 450 mm, width 120 mm, thickness To a 20 μm Pd-based alloy hydrogen separation membrane, 95 NL / h (approximately 3 cm ³ / min / cm ² ) of 13 A city gas and S / C (water vapor / carbon ratio) = 3 water vapor are added to the primary side (reforming side). ) At 0.8 MPa, the secondary side (permeation side) at −0.06 MPaG, and hydrogen production at 550 ° C., the hydrogen production amount is 294 L / h, and the raw material conversion rate is 80 4%.

At this time, the gas composition at the outlet of the reaction tube is 550 ° C., CH ₄ = 7.0%, H ₂ O = 51.6%, CO = 1.9%, CO ₂ = 26.9%, H ₂ = 12. Since the hydrogen partial pressure at the outlet portion is 0.11 MPa (absolute pressure), even if the pressure on the process gas side is 0.8 MPaG, V-W It is possible to use a hydrogen-based alloy hydrogen separation membrane or a Ta-W alloy hydrogen separation membrane.

  If a hydrogen separation membrane module using a V-W type alloy membrane or a Ta-W type alloy membrane is installed at a position subsequent to the Pd type alloy hydrogen separation membrane and at a temperature above the reformer, the Pd type A hydrogen separation reformer that can further separate hydrogen from the process gas side off-gas of the alloy hydrogen separation membrane to obtain a high hydrogen production amount can be realized.

  In Patent Document 6, by connecting the units in series, the linear flow rate of the source gas in the unit is increased and the direction orthogonal to the flow is compared to the case where the source gas is uniformly connected and supplied simultaneously. Has been proposed to promote mixed diffusion of hydrogen reacted on the reforming catalyst and increase the amount of hydrogen produced.

JP 2004-182297 A

In order to perform efficient hydrogen production, for example, primary pressure (reaction side) = 0.8 MPaG, secondary pressure (permeation side) = − 0.06 to 0 MPaG, 500 to 550 ° C., S / C = 2.5 It is appropriate to operate at a raw material input amount of ^{2 to 6} cm ³ / min / cm ² , ideally about ³ to 4 cm ³ / min / cm ^{2 under} the conditions of ˜3.5. For the same unit area and raw material input per unit time, when connecting reaction tubes in series, double when two reaction tubes are connected in series, 4 when connecting four reaction tubes in series Double the linear velocity in proportion to the number of connected reaction tubes.

Two reaction tubes using the above-mentioned Pd alloy hydrogen separation membrane are connected, and the same raw material per membrane area, 189 NL / h (approximately 3 cm ³ / min / cm ² ) is charged, and ideally the whole is 550 ° C. Assuming that, the raw material conversion is 80.4% and the hydrogen production is 588 NL / h. One reaction tube using a Pd-based alloy hydrogen separation membrane in the high temperature part (up to 550 ° C) in the former stage, and a 5A metal alloy hydrogen separation membrane in a place where the temperature in the latter stage (upper part) is low and around 500 ° C. When one reaction tube used is installed and 3 cm ³ / min / cm ² is charged, the hydrogen partial pressure at the outlet portion of the reaction tube using the first Pd-based alloy hydrogen separation membrane is 0.152 MPa ( Absolute pressure), a Ta—W alloy film cannot be used, but a V—W alloy film can be used.

  When a 5A group metal alloy hydrogen separation membrane having a length of 450 mm, a width of 120 mm, and a thickness of 40 μm (because workability is lower than that of a Pd alloy) is used instead of the second Pd alloy hydrogen separation membrane, the raw material conversion at the outlet is performed. The rate is 85.8% and the hydrogen production amount is 679 NL / h, which is 15.5% higher than the hydrogen production amount 588 NL / h when only two Pd alloy hydrogen separation membranes are used.

Similarly, three reaction tubes using the above-mentioned Pd-based alloy hydrogen separation membrane are connected, and the same raw material, 284 NL / h (approximately 3 cm ³ / min / cm ² ), is charged per membrane area. Is assumed to be 550 ° C., the raw material conversion is 80.4%, and the hydrogen production is 883 NL / h. Two reaction tubes using a Pd-based alloy hydrogen separation membrane in the high temperature part (up to 550 ° C) in the former stage, and a 5A metal alloy hydrogen separation membrane in a place where the temperature in the latter stage (upper part) is low and around 500 ° C When installing one reaction tube using Pd, the hydrogen partial pressure at the outlet of the reaction tube using the Pd-based alloy hydrogen separation membrane is 0.138 MPa (absolute pressure), and the Ta-W-based alloy membrane is also V A -W alloy film can also be used.

  At this time, if a group 5A metal alloy hydrogen separation membrane having the same dimensions as described above is used instead of the third Pd alloy hydrogen separation membrane, the raw material conversion rate at the third outlet is 82.8%, and the hydrogen production amount is 974 NL. / H and 10.3% increase. Thus, by replacing a part of the reaction tube using the Pd-based alloy hydrogen separation membrane with a reaction tube using the 5A group metal alloy hydrogen separation membrane, a low-cost and high-efficiency hydrogen separation reformer is realized. it can.

  Further, it is possible to bring the entire reactor to a substantially uniform temperature, and when operating at 500 ° C., if there is a Pd-based alloy hydrogen separation membrane only on the inlet side of the raw material, the hydrogen on the process gas side is sufficient. The partial pressure can be lowered to 0.15 MPa (absolute pressure) or less. When five reaction tubes are connected at 500 ° C., the hydrogen partial pressure at the outlet portion of the reaction tube using the first Pd-based alloy hydrogen separation membrane is 0.136 MPa (absolute pressure), and the group 5A metal is used in the second to fifth tubes. An alloy hydrogen separation membrane can be used.

  When a 5A metal alloy hydrogen separation membrane having the same dimensions as described above is used in place of the Pd alloy hydrogen separation membrane in the second to fifth, the raw material conversion rate at the fifth outlet is 89.7%, and the hydrogen production is 1529 NL. / H, an increase of 4.0% compared to 1471 NL / h when five Pd-based alloy hydrogen separation membrane reaction tubes are used at 550 ° C. The amount of Pd-based alloy hydrogen separation membrane can be greatly reduced, not only reducing raw material costs, but also reducing the input energy for reaction tube heating by reducing the operating temperature of the reactor, High efficiency can be achieved by keeping energy loss low.

Further, since hydrogen is extracted from the reformed gas, that is, the hydrogen-containing gas with a high recovery rate, the CO ₂ concentration in the off-gas from the reformer is relatively increased. At the time of 100% output of the applicant's 40 Nm ³ / h membrane reformer (improved type) that currently achieves the world's highest efficiency = 40 Nm ³ / h The CO ₂ concentration in the reformer off-gas during hydrogen production is 72.2 %, But depending on the conditions, higher CO ₂ concentrations can be obtained. From the off-gas of the two-stage hydrogen separation reformer, CO ₂ can be separated and recovered with higher efficiency only by compression liquefaction.

<Example of Configuration of the Present Invention (1)>
FIG. 5 is a diagram for explaining an example of the configuration of the present invention (1). As shown in FIG. 5, a hydrogen separator 1 in which a Pd alloy hydrogen separation membrane is installed and a hydrogen separator 2 in which a 5A group metal alloy hydrogen separation membrane is installed are arranged in a container 10. A burner 11 is disposed in the lower part of the container 10 containing the hydrogen separator 1 and the hydrogen separator 2. Reference numeral 12 denotes a burner gas dispersion plate in the burner. Reference numeral 13 denotes a flue gas exhaust pipe from the container 10.

  A hydrogen separator 1 provided with a Pd alloy hydrogen separation membrane is shown in FIG. 7A, and a hydrogen separator 2 provided with a 5A group metal alloy hydrogen separation membrane is shown in FIG. 7B. 7A to 7B show an example of a case where a reforming catalyst layer is arranged in the hydrogen separator.

  In the container 10, a row in which the hydrogen separator 1 and the hydrogen separator 2 are combined in series is arranged in a plurality of rows. The number of the columns can be set as appropriate. FIG. 5 shows a case where the number of columns is four. Moreover, the number of the hydrogen separators 1 and the number of the hydrogen separators 2 in the row | line | column which combined the hydrogen separator 1 and the hydrogen separator 2 in series can be set suitably. FIG. 5 shows a case where there are two hydrogen separators 1 and one hydrogen separator 2.

  A reforming catalyst layer is disposed in the hydrogen separator 1. FIG. 5 shows a case where a reforming catalyst layer is arranged in the lowermost hydrogen separator 1 in each row. The reforming catalyst generates hydrogen by steam reforming the raw fuel in the process gas (raw fuel + steam).

  The hydrogen separator 1 is configured by disposing a Pd-based alloy hydrogen separation membrane on a porous support made of an alloy or a support made of a porous plate. The support made of a porous support or a porous plate may be a cylindrical body or a casing. The hydrogen separator 2 is configured by arranging a group 5A metal alloy hydrogen separation membrane on a porous cylindrical body or casing made of an alloy. The term “porous” means that there are communication holes through which gas passes. As for the arrangement of the hydrogen separator 1 and the hydrogen separator 2, the hydrogen separator 1 is first arranged, and then the hydrogen separator 2 is arranged in the flow direction of the process gas (raw fuel + steam). Reference numeral 5 denotes a process gas introduction pipe, which opens at the lower end of the hydrogen separator 1.

  A process gas which is a mixed gas of raw fuel and water vapor is introduced through the introduction pipe 5. The raw fuel in the process gas introduced into the lower end of the lowermost hydrogen separator 1 is reformed by the reforming catalyst while rising in the reforming catalyst layer disposed in the hydrogen separator 1 together with the steam. Produce hydrogen. The process gas containing hydrogen generated by reforming by the reforming catalyst of the reforming catalyst layer is purified by passing through the Pd-based alloy hydrogen separation membrane while the hydrogen is passed through the hydrogen separator 1 and the permeated hydrogen. Is taken out through the hydrogen outlet pipe 8.

  The process gas that has passed through the lowermost hydrogen separator 1 (including product hydrogen that has not been separated in the lowermost hydrogen separator 1) passes through the connecting pipe 6 to the next hydrogen separator 1, that is, the second hydrogen. The hydrogen is introduced into the separator 1 and rises, and the hydrogen in the process gas is purified by permeating the Pd-based alloy hydrogen separation membrane, and the permeated hydrogen is taken out through the hydrogen outlet pipe 8.

  The process gas that has passed through the second hydrogen separator 1 (including produced hydrogen that has not been separated by the second hydrogen separator 1) is introduced into the hydrogen separator 2 via the connecting pipe 6, and hydrogen separation is performed. While rising in the vessel 2, hydrogen in the process gas permeates and purifies the 5A metal alloy hydrogen separation membrane, and the permeated hydrogen is taken out through the hydrogen outlet tube 8.

  Thus, the process gas is sequentially supplied to the lowermost hydrogen separator 1, the second hydrogen separator 1 following the lowermost hydrogen separator 1, and the hydrogen separator 2 following the second hydrogen separator 1. Then, hydrogen is separated and purified by each of them and taken out through the hydrogen outlet pipe 8.

  On the other hand, the off gas of the process gas, that is, the remaining gas after separating the hydrogen therein is discharged through the off gas discharge pipe 7. More specifically, the process gas, which is a mixed gas of raw fuel and steam, is reformed by raw steam by steam by the catalytic action of the reforming catalyst while moving up in the reforming catalyst layer disposed in the hydrogen separator 1 (steam Reformed) to produce hydrogen. The produced hydrogen is separated and purified by the hydrogen separators 1 and 2, but the remaining gas that has not been separated is discharged through the off-gas discharge pipe 7.

  In the example shown in FIG. 5, the number of combinations of the hydrogen separator 1 and the hydrogen separator 2 is four, so there is a hydrogen outlet tube 8 for each column. Can be taken out together in a hydrogen outlet tube. Further, in FIG. 5, there are four rows of off-gas discharge pipes 7 for each row, but the off-gas can be discharged by collecting each off-gas discharge tube 7 into one off-gas discharge tube.

<Configuration Example of the Invention (2)>
In FIG. 5, the “porous support made of an alloy” constituting the lowermost hydrogen separator 1 is a cylindrical reforming catalyst / porous material that simultaneously serves as a reforming catalyst and supports a hydrogen separation membrane. It can be replaced with a quality support. This configuration is a configuration example of the present invention (2). Other configurations are the same as those in <Example of configuration of the present invention (1)>.

<Structural example of the present invention (3)>
FIG. 6 is a diagram for explaining an example of the configuration of the present invention (3). As shown in FIG. 6, a hydrogen separator 1 in which a Pd-based alloy hydrogen separation membrane is installed and a hydrogen separator 2 in which a 5A group metal alloy hydrogen separation membrane is installed are disposed in a container 10. A burner 11 is disposed in the lower part of the container 10 containing the hydrogen separator 1 and the hydrogen separator 2. Reference numeral 12 denotes a burner gas dispersion plate in the burner.

  FIG. 7C shows a hydrogen separator provided with a Pd-based alloy hydrogen separation membrane or a 5A group metal alloy hydrogen separation membrane. The hydrogen separator provided with the Pd alloy hydrogen separation membrane is the hydrogen separator 1, and the hydrogen separator provided with the 5A group metal alloy hydrogen separation membrane is the hydrogen separator 2.

  In the container 10, a row in which the hydrogen separator 1 and the hydrogen separator 2 are combined in series is arranged in a plurality of rows. The number of the columns can be set as appropriate. FIG. 6 shows a case where the number of columns is three. Moreover, the number of the hydrogen separators 1 and the number of the hydrogen separators 2 in the row | line | column which combined the hydrogen separator 1 and the hydrogen separator 2 in series can be set suitably. FIG. 6 shows a case where there is one hydrogen separator 1 and four hydrogen separators 2.

  A reforming catalyst layer is disposed in the hydrogen separator 1. FIG. 6 shows a case where a reforming catalyst layer is arranged in the lowermost hydrogen separator 1 in each row. The reforming catalyst reforms raw fuel in process gas (raw fuel + steam) with steam to generate hydrogen.

  The hydrogen separator 1 is configured by disposing a Pd-based alloy hydrogen separation membrane on a porous support made of an alloy or a support made of a porous plate. The support made of a porous support or a porous plate may be a cylindrical body or a casing. The hydrogen separator 2 is configured by arranging a group 5A metal alloy hydrogen separation membrane on a porous cylindrical body or casing made of an alloy. The term “porous” means that there are communication holes through which gas passes. As for the arrangement of the hydrogen separator 1 and the hydrogen separator 2, the hydrogen separator 1 is first arranged, and then the hydrogen separator 2 is arranged in the flow direction of the process gas (raw fuel + steam). Reference numeral 5 denotes a process gas introduction pipe, which opens at the lower end of the hydrogen separator 1.

  A process gas which is a mixed gas of raw fuel and water vapor is introduced through the introduction pipe 5. The raw fuel in the process gas introduced into the left end of the lowermost hydrogen separator 1 is reformed by the reforming catalyst while flowing through the reforming catalyst layer disposed in the hydrogen separator 1 to remove hydrogen. Generate. While the process gas containing the produced hydrogen flows through the hydrogen separator 1, the hydrogen in the process gas is purified by permeating the Pd alloy hydrogen separation membrane, and the permeated hydrogen is taken out through the hydrogen outlet pipe 8.

  Process gas that has passed through the lowermost hydrogen separator 1 (including produced hydrogen that has not been separated by the lowermost hydrogen separator 1) is introduced into the hydrogen separator 2 via the connecting pipe 6, and the hydrogen separator The hydrogen in the process gas permeates and purifies the 5A metal alloy hydrogen separation membrane while flowing in the gas 2, and the permeated hydrogen is taken out through the hydrogen outlet pipe 8.

  In this way, the process gas is separated and purified through the hydrogen separator 1 at the bottom and the hydrogen separator 2 following the hydrogen separator 1 in this order, and is taken out via the hydrogen outlet pipe 8. The hydrogen is separated and purified through the subsequent hydrogen separator 2 and taken out through the hydrogen outlet pipe 8.

  On the other hand, the off gas of the process gas, that is, the remaining gas after separating the hydrogen therein is discharged through the off gas discharge pipe 7. More specifically, the process gas, which is a mixed gas of raw fuel and steam, is reformed by raw steam by steam by the catalytic action of the reforming catalyst while moving up in the reforming catalyst layer disposed in the hydrogen separator 1 (steam Reformed) to produce hydrogen. The produced hydrogen is separated and purified by the hydrogen separators 1 and 2, but the remaining gas that has not been separated is discharged through the off-gas discharge pipe 7.

  In the example shown in FIG. 6, since there are three rows of combinations of the hydrogen separator 1 and the hydrogen separator 2, there are hydrogen lead-out tubes 8 for each row. Derived hydrogen has one hydrogen lead-out tube 8. Can be taken out together in a hydrogen outlet tube. Further, in FIG. 6, there are three off-gas discharge pipes 7 for each row, but the off-gas can be discharged by collecting each off-gas discharge pipe 7 into one off-gas discharge pipe.

<Structural example of the present invention (4)>
In FIG. 6, the “porous support made of an alloy” constituting the lowermost hydrogen separator 1 is a cylindrical reforming catalyst / porous material that simultaneously serves as a reforming catalyst and supports a hydrogen separation membrane. It can be replaced with a quality support. This configuration is a configuration example of the present invention (4). Other configurations are the same as those of the <configuration mode example of the present invention (3)>.

DESCRIPTION OF SYMBOLS 1, 2 Hydrogen separator 2 Porous support body 3 Vessel-like container 5 Process gas introduction pipe 6 Connection pipe 7 Off-gas discharge pipe 8 Hydrogen outlet pipe 10 Container 11 Burner 12 Dispersion plate 13 Combustion exhaust gas outlet pipe

Claims (5)

A hydrogen separation membrane is arranged on the outer peripheral surface of a cylindrical porous support or a porous plate supporting the hydrogen separation membrane, and a reforming catalyst layer is arranged on the outer periphery of the hydrogen separation membrane. A hydrogen separation system comprising a plurality of hydrogen separation reformers arranged in series,
The hydrogen separation membrane is characterized in that a Pd alloy hydrogen separation membrane is used on the upstream side of the gas to be processed, and a 5A group metal alloy hydrogen separation membrane is used on the downstream side of the gas to be processed. . Multiple hydrogen separation reformers with a hydrogen separation membrane arranged in series on the outer peripheral surface of a cylindrical reforming catalyst / porous support that simultaneously serves as a reforming catalyst and supports the hydrogen separation membrane A hydrogen separation system comprising:
The hydrogen separation membrane is characterized in that a Pd alloy hydrogen separation membrane is used on the upstream side of the gas to be processed, and a 5A group metal alloy hydrogen separation membrane is used on the downstream side of the gas to be processed. . A hydrogen separation membrane is disposed on the outer peripheral surface of a cage-like porous support or a porous plate supporting the hydrogen separation membrane, and a reforming catalyst layer is disposed on the outer periphery of the hydrogen separation membrane. A hydrogen separation system comprising a plurality of hydrogen separation reformers arranged in series,
The hydrogen separation membrane is characterized in that a Pd alloy hydrogen separation membrane is used on the upstream side of the gas to be processed, and a 5A group metal alloy hydrogen separation membrane is used on the downstream side of the gas to be processed. . A plurality of hydrogen separation type reformers, in which a hydrogen separation membrane is arranged on the outer peripheral surface of a bowl-shaped reforming catalyst / support that simultaneously serves as a reforming catalyst and supports a hydrogen separation membrane, are arranged in series. A hydrogen separation system comprising:
The hydrogen separation membrane is characterized in that a Pd alloy hydrogen separation membrane is used on the upstream side of the gas to be processed, and a 5A group metal alloy hydrogen separation membrane is used on the downstream side of the gas to be processed. . 5. The hydrogen separation system according to claim 1, wherein the 5A group metal alloy hydrogen separation membrane used downstream of the gas to be treated is a VW alloy hydrogen separation membrane or a Ta—W alloy hydrogen. A hydrogen separation system characterized by being a separation membrane.

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