JP3197096B2 - Hydrogen production equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing hydrogen from a hydrocarbon or a mixed gas of methanol and steam by a steam reforming reaction, and more particularly to an apparatus for use in a solid polymer fuel cell (polymer fuel cell). The present invention relates to an industrial-scale hydrogen production apparatus capable of obtaining such high-purity hydrogen at a low reaction temperature.

[0002]

2. Description of the Related Art Hydrogen used in fuel cells, particularly solid polymer fuel cells, preferably has a CO content of 10 ppm or less. Therefore, hydrogen obtained from naphtha, natural gas, city gas, etc. using a steam reforming reaction is unsuitable for a fuel cell because of its low hydrogen purity as it is. Was further purified by passing through a carbon monoxide converter and a hydrogen purifier to adjust the hydrogen purity to a desired value. However, the above-described process for producing high-purity hydrogen involves complicated production steps, requires high-temperature and high-pressure equipment, and consumes a large amount of high-temperature heat energy. It was not economical to put it to practical use as hydrogen for fuel cells.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 61-17401 and others, there has been a proposal to obtain high-purity hydrogen using a permeable membrane that selectively transmits hydrogen. It has been done. For example, the above publication is CH
A method for continuously separating product hydrogen from a reaction space at a temperature of 500 to 1,000 ° C. through a selective hydrogen permeable partition wall in a ₄ / H ₂ O reforming reaction or a water gas generation reaction; An apparatus is disclosed which states that high purity hydrogen can be separated. In addition, known documents including the above-mentioned publications disclose a laboratory-scale hydrogen production apparatus as shown in a principle diagram in FIG. 7, for example. In the conventional hydrogen production apparatus of FIG. 7, 90 is a reaction tube, 92 is a reforming catalyst layer,
Reference numeral 94 denotes a hydrogen permeation pipe. A mixed gas of hydrocarbon and water vapor is introduced from a lower arrow X and reformed by a reforming catalyst layer 92 to generate hydrogen gas.
, And flows out from the arrow Y above, and the reformed gas after hydrogen removal flows out from the arrow Z.

[0004]

However, the known literature hardly discloses a method or means for scaling up such a laboratory scale apparatus to an industrial scale apparatus. In other words, how to use the method of continuously separating the produced hydrogen through the hydrogen-permeable partition wall as an industrial-scale technique in practical terms, or use such a laboratory-scale apparatus as a large-scale industrial-scale hydrogen It is a technology that has not yet been established as to how to expand the manufacturing equipment.

By the way, in order to scale up a laboratory-scale technology to a large-scale industrial-scale hydrogen production apparatus, it is necessary to overcome various technical problems and to establish economical efficiency as a hydrogen production apparatus. For example, a multi-tube reactor may be constructed by arranging a large number of reaction tubes provided with hydrogen permeable tubes in a reforming catalyst layer as shown in FIG. 7 and connecting their respective inlets and outlets with headers. This is one method of increasing the size. But,
Since such a device has a large and complicated configuration, the device has poor operability, poor controllability and low thermal efficiency, and requires a large amount of material for construction and is poor in manufacturability.
It is a costly and uncompetitive device. Similarly, engineering issues such as the configuration of the separation means having a hydrogen permeable membrane or the configuration of the heating means for heating the reaction area are extremely important issues in scaling up the apparatus. However, no specific example is shown.

[0006] On the other hand, it is extremely important to provide high-purity hydrogen at low cost in order to put a fuel cell into practical use.
In response to such a demand, there has been a pending need to realize an industrial-scale hydrogen production apparatus capable of producing high-purity hydrogen at low cost. In view of the above-mentioned problems, an object of the present invention is to develop a laboratory-scale hydrogen production apparatus that is capable of separating and collecting hydrogen generated by a steam reforming reaction through a selective hydrogen-permeable partition wall. It is an object of the present invention to provide an industrial hydrogen production apparatus having a novel configuration.

[0007]

Means for Solving the Problems To achieve the above object, a hydrogen production apparatus according to the present invention comprises: (1) hydrogen produced by a steam reforming reaction through a selective hydrogen permeable partition wall; In a hydrogen production apparatus that is separated and collected, an upright outer cylinder with a closed bottom, an inner cylinder and an inner cylinder that are sequentially multiplexed and arranged inside the outer cylinder, and a ceiling wall of the inner cylinder are provided. A first annular space defined by the outer cylinder and the middle cylinder and the inner cylinder hollow inside the inner cylinder communicate with each other at the bottom thereof. A second annular space portion having a closed annular bottom portion is formed by connecting the lower edges to the cylinder, and a catalyst layer filled with a reforming catalyst is formed in the second annular space portion. Includes an outer wall having a hydrogen-permeable metal film on an inorganic porous layer, an inner wall, and an annular bottom wall. A double hydrogen permeable cylinder that defines the third annular space is disposed substantially concentrically and vertically with the second annular space, and a sweep gas pipe having an open lower end is arranged in the third annular space. The raw material gas is introduced from the upper part of the second annular space part, is converted to hydrogen under high temperature while flowing down the catalyst layer, and the generated hydrogen is selectively separated and collected by passing through the deuterium permeable cylinder, and is swept. A hydrogen production apparatus characterized in that a permeated hydrogen accompanies a sweep gas introduced from an upper part of a gas pipe and flows out of the upper part thereof along with the sweep gas through a third annular space. (2) In the hydrogen production apparatus according to the above (1), an annular pipe header having a large number of through holes in a header wall is replaced with an annular pipe header having a large number of through holes in place of the sweep gas pipe having an open lower end. A bottom end of the sweep gas pipe is connected to an annular pipe header, and the catalyst layer of the second annular space is connected to the inner cylinder and an inner wall of a deuterium permeable cylinder. And an outer catalyst layer between the middle cylinder and the outer wall of the deuterium permeable cylinder. A raw material gas is introduced from above the inner catalyst layer to flow down the inner catalyst layer. Further, while raising the outer catalyst layer, it is converted into hydrogen at a high temperature, and the generated hydrogen is selectively separated and collected by passing through a deuterium permeable cylinder, and is converted into a sweep gas introduced from the upper part of the third annular space. Via perforated hole in annular pipe header with permeated hydrogen To flow into the Ipugasu tube,
A hydrogen production apparatus characterized in that it is made to flow out along with a sweep gas from the upper part. (3) In the hydrogen production apparatus according to the above (2), a cylindrical partition is substantially concentrically provided in the third annular space portion of the double hydrogen permeable tube at the lower end instead of the sweep gas pipe having an open lower end. And further disposed apart from the annular bottom wall of the hydrogen permeable double cylinder, and furthermore, the catalyst layer of the second annular space is provided with an inner catalyst layer between the inner cylinder and the inner wall of the double hydrogen permeable cylinder. And an outer catalyst layer between the middle cylinder and the outer wall of the deuterium permeable cylinder. A raw material gas is introduced from above the inner catalyst layer to flow down the inner catalyst layer, and further, the outer catalyst layer is formed. While being raised, it was converted to hydrogen under high temperature, and the generated hydrogen was selectively separated and collected by passing through a deuterium permeable tube, and introduced from the upper part of the annular space between the outer wall and the partition wall of the deuterium permeable tube. The permeated hydrogen accompanies the sweep gas, and the perforated space above the annular space between the partition wall and the inner wall of the deuterium permeable cylinder. It made so as to flow out together with the sweep gas from the hydrogen production apparatus, characterized in that. (4) The hydrogen-permeable metal film is made of an alloy containing Pd, N
The hydrogen production apparatus according to any one of (1) to (3), wherein the hydrogen production apparatus is a nonporous thin film of any of an alloy containing i and an alloy containing V. (5) In the hydrogen production apparatus according to any one of (1) to (3), the permeated hydrogen is collected by purging the hydrogen permeation side with a pump instead of the permeated hydrogen collection method of the sweep gas entrainment method. A hydrogen production apparatus characterized in that: (6) The hydrogen production apparatus according to any one of (1) to (5) above, wherein the flow directions of the raw material gas and the sweep gas are set in opposite directions. It is.

[0008]

The raw material gas introduced into the hydrogen production apparatus according to the present invention is a mixture of light hydrocarbons such as natural gas, naphtha and city gas, and alcohols such as methanol mixed with water vapor. Further, as the reforming catalyst used in the present invention, any catalyst conventionally used in producing hydrogen from the above-mentioned raw material gas by a steam reforming method can be used.

[0009] The hydrogen production apparatus of the present invention is constituted by a multi-cylinder in which a vertical furnace is formed by an inner cylinder, and an upright middle cylinder and an outer cylinder are sequentially disposed outside the furnace. Furthermore, a reforming catalyst is filled in the second annular space to form a catalyst layer, and a double hydrogen permeable cylinder is disposed in the catalyst layer to form a reaction / separation region. Preferably, each tubular body is a cylindrical body. With this configuration, the concentric multi-cylindrical structure in which the furnace is disposed at the center makes it easy to make the heat flux distribution uniform in the radial direction, and prevents the generation of hot spots that exceed the heat resistant temperature of the deuterium permeable cylinder. Can be prevented.

The heat required to maintain the steam reforming reaction, which is an endothermic reaction, is supplied by a hanging combustion burner attached to the ceiling wall of the inner cylinder. The dripping combustion burner is a burner of a type in which the flame is directed downward, and a conventionally used burner can be used. By attaching the combustion burner to the top of the furnace in a hanging manner, the combustion burner is less contaminated than when an upright combustion burner with the flame facing upward is installed at the bottom of the furnace, and therefore, the availability required for cleaning the combustion burner is reduced. In addition, the inspection and maintenance of the combustion burner itself is facilitated. In addition, in the case of an upright combustion burner, it is not necessary to provide a space for maintenance and inspection of the combustion burner, which is required below the floor of the furnace, so that the height of the furnace can be reduced accordingly, thereby producing hydrogen. The cost of the device can be reduced accordingly.

A reactor comprising a hydrogen permeable wall provided with a hydrogen permeable metal film on an inorganic porous layer is a so-called membrane reactor which selectively permeates only hydrogen, and is used in the present invention. The deuterium permeable cylinder has a cylindrical inner wall and an outer wall, and is devised to be a more economical membrane reactor. Taking methane as an example of hydrocarbon, the operation of the hydrogen permeable cylinder will be described. The methane reforming reaction proceeds at a reaction temperature in the range of 500 ° C. to 1,000 ° C. according to the following equation and reaches chemical equilibrium.

[0012]

Embedded image

Here, hydrogen generated from the product is transferred to a hydrogen permeable cylinder.
To reduce the partial pressure of hydrogen in the product
Then, in the above equation, the reaction further proceeds to the right, and consequently
The conversion at the same reaction temperature increases. In other words,
In the next methane reforming method, the temperature of the reaction zone will be about 800 ° C
It was necessary to use a hydrogen permeable cylinder.
In the hydrogen production apparatus according to the present invention,
It can be achieved at a temperature of 500-600C. What
In addition, per unit area of the hydrogen permeable metal membrane of the hydrogen permeable wall
Of hydrogen permeation Q_HIs the square root of the partial pressure of hydrogen on the non-permeate side (P
h)^1/2And the square root of the hydrogen partial pressure on the permeate side (Pl) ^1/2With
It is proportional to the difference. That is, Q_H= K ((Ph)^1/2−
(Pl)^1/2).

As described above, since the hydrogen can be collected in the hydrogen permeable column and the chemical reaction can be shifted to the right side in the above equation, the reforming temperature is reduced by about 150 to 200 ° C. as compared with the conventional case. Thereby, the thermal efficiency is greatly improved. Also,
Since the reaction temperature is low, an inexpensive material that does not have high heat resistance can be used for the apparatus, and thus the cost of the apparatus can be reduced.

The sweep gas flows countercurrent to the reformed gas flowing through the catalyst layer. Therefore, in the vicinity of the outlet end of the catalyst layer, the generated hydrogen is swept almost completely to greatly reduce the hydrogen partial pressure. Therefore, the introduction of the sweep gas has the effect of increasing the conversion rate in the entire catalyst layer. Further, the recovery rate of generated hydrogen can be increased by countercurrent mass transfer of the sweep gas in the double hydrogen permeable cylinder and the reformed gas in the catalyst layer. Examples of the sweep gas used in the hydrogen production apparatus of the present invention include inert gas such as nitrogen and helium in addition to steam.

As described above, in order to increase the amount of hydrogen permeating the hydrogen permeable tube, it is necessary to increase the difference between the hydrogen partial pressure on the non-permeate side and the hydrogen partial pressure on the permeate side. It is effective to flow the sweep gas to the permeate side in order to reduce the hydrogen partial pressure, but it is also effective to adopt a means to suck the permeate side by a pump as a means to reduce the hydrogen partial pressure on the permeate side. It is.

Since the hydrogen-permeable metal membrane of the double hydrogen permeable cylinder selectively allows only hydrogen to permeate, the purity of the hydrogen separated by the double hydrogen permeable cylinder is extremely high. Most suitable as hydrogen.

The hydrogen-permeable metal film has a thickness of 5 to 50.
μm, formed on the inorganic porous layer and capable of selectively transmitting hydrogen. The underlying inorganic porous layer is a carrier for holding a hydrogen-permeable metal film, and is formed of a porous stainless steel nonwoven fabric, ceramics, glass, or the like in a thickness range of 0.1 mm to 1 mm. Further, a wire mesh composed of a single layer or a plurality of layers is disposed as a structural strength member on the inner side.

In a preferred embodiment of the present invention, the hydrogen-permeable metal film is preferably a non-porous layer made of an alloy containing Pd or an alloy containing V or Ni. Pd-containing alloys include Pd-Ag alloy, Pd-Y alloy, Pd-Ag-
Au alloys and the like can be given.
· Ni, and the like LaNi ₅ is a like V · Ni · Co, also an alloy containing Ni. Further, a method for producing a non-porous Pd layer is described in, for example, US Pat. No. 3,155,467.
And No. 277361.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the accompanying drawings. (Embodiment 1) FIG. 1 is a perspective sectional view of Embodiment 1 of a hydrogen production apparatus according to the present invention, FIG. 2 is a schematic cross-sectional view of the hydrogen production apparatus of FIG. 1, and FIG. It is a fragmentary sectional view of the deuterium permeable cylinder in X. As shown in FIGS. 1 and 2, the hydrogen production apparatus 10 includes an outer cylinder 14 having a bottom portion 12, and a middle cylinder 16 and an inner cylinder 18 sequentially and concentrically arranged inside the outer cylinder 14. In this embodiment, the outer cylinder 14, the middle cylinder 16 and the inner cylinder 18 also have an upright cylindrical shape.

The outer cylinder 14 and the middle cylinder 16 are located between the cylinder walls.
An annular space 20 is defined, and the first annular space 20 and the inner cylinder 1 are defined.
The inner cylindrical hollow portion 22 inside the inner portion 8 communicates with each other at the bottom. The lower ends of the middle cylinder 16 and the inner cylinder 18 are connected to form a closed annular bottom 24 and a second annular space 26 is formed between the cylinder walls. Inner cylinder hollow part 22, outer cylinder 14
The space between the bottom portion 12 and the annular bottom portion 24, and the continuous space portion composed of the first annular space portion 20 form a flow path of the combustion gas, and the outer cylinder wall 14 and the bottom wall 12 of the outer cylinder 14 Each is built with firebricks.

A catalyst layer 26 filled with the reforming catalyst A (for convenience, the same reference numeral as that of the second annular space portion) is formed in the second annular space portion 26. Further, the catalyst layer has an outer wall 28 and a inner wall 3 provided with a hydrogen-permeable metal film on an inorganic porous layer.
A double hydrogen permeable cylinder 34, which is comprised of a zero and an annular bottom wall 32, thereby defining a third annular space 33, is disposed concentrically within the second annular space 26. As shown in FIG. 2, in the deuterium permeable cylinder 34, a number of cylindrical sweep gas pipes 36 made of stainless steel are arranged at substantially equal intervals in the inner circumferential direction of the third annular space 33 of the deuterium permeable cylinder 34. It is arranged in.

As shown in FIG. 3, the double hydrogen permeable cylinder 34
The outer wall 28, the inner wall 30, and the annular bottom wall 32 each have a mesh 38 made of stainless steel as a support member on the inner side, and an inorganic porous layer 40 made of stainless steel nonwoven fabric thereon as a hydrogen-permeable metal film carrier, Further, a non-porous Pd film 42 is coated thereon as a hydrogen-permeable metal film.

The ceiling wall 4 for closing the top of the hollow portion 22
4, a hanging combustion burner 46 is attached downward. A fuel gas pipe 48 and an air intake pipe 50 are connected to the combustion burner 46.

Next, the process of the hydrogen production apparatus 10 will be described with reference to FIGS. The hanging combustion burner 46 burns fuel gas introduced through a fuel gas pipe 48 by air introduced through an air intake pipe 50,
The thermal energy required for the steam reforming reaction is supplied to the catalyst layer 26 and maintained at a predetermined temperature. The combustion gas is the hollow part 2 of the inner cylinder.
2, the space between the bottom 12 of the outer cylinder 14 and the annular bottom 24,
Next, the fuel gas exits from the combustion gas outlet 52 through the first annular space 20. Meanwhile, the catalyst layer 26 is heated.

A source gas comprising a mixture of light hydrocarbon or methanol gas and water vapor is introduced from a source gas inlet 54 provided at the upper part of the second annular space 26, flows into the catalyst layer 26, and is heated under a high temperature. Converts to hydrogen. The generated hydrogen is selectively separated and collected by the deuterium permeable cylinder 34,
The gas flows out along with the sweep gas from a hydrogen outlet 56 provided at an upper portion thereof via the third annular space portion 33.

The sweep gas is fed from the sweep gas inlet 58 at the top of the apparatus, flows down the sweep gas pipe 36, flows into the third annular space 33 from the lower end opening, and entrains generated hydrogen while sweeping hydrogen. Rise to hydrogen outlet 5
Outflow from 6. By causing the sweep gas to flow along with the hydrogen so as to flush out the hydrogen, the hydrogen partial pressure on the permeation side of the hydrogen permeation tube 32 is kept low. For example, steam or inert gas is used as the sweep gas. On the other hand, unreacted raw material gas that has passed through the catalyst layer 26, generated CO and C
The O ₂ gas flows out of the system from an off gas outlet 62 via an off gas pipe 60 having an opening below the catalyst layer 26.

(Embodiment 2) FIG. 4 shows Embodiment 2 according to the present invention.
5 is a cross-sectional view of the hydrogen production apparatus 110 shown in FIG. The differences from the first embodiment are as follows. First, there is a structure of a sweep gas pipe. In this embodiment, a relatively small number of sweep gas pipes 36, in this case four sweep gas pipes 36, are charged into the third annular space 33 of the double hydrogen permeable cylinder 34, and the double hydrogen It is connected to an annular pipe header 39 disposed along the annular bottom wall 32 of the transmission cylinder 34. The annular pipe header 39 is provided with a large number of through holes (not shown) penetrating the header wall.

Second, an inner catalyst layer 27 in which the catalyst layer 26 is filled in an annular space defined by the inner cylinder 18 and the inner wall 30 of the deuterium permeable cylinder 34, And an outer catalyst layer 29 filled in an annular space defined by the outer wall 28 of the cylinder 34.

Third, a raw material gas (process feed gas) is introduced from a raw material gas inlet 54 provided on the upper part of the inner catalyst layer 27, flows down to the inner catalyst layer 27, and further rises in the outer catalyst layer 29. Converts to hydrogen at elevated temperatures. The generated hydrogen is swept into a sweep gas while being selectively separated and collected by a deuterium permeable cylinder 34, is entrained therethrough, passes through a through hole of an annular pipe header 39, a sweep gas pipe 36, and a hydrogen outlet provided at an upper portion thereof It flows out from 56 together with the sweep gas.

Fourth, the sweep gas is fed from the sweep gas inlet 58 at the upper part of the apparatus, flows down the annular space 33 and entrains while sweeping hydrogen, and the annular pipe header 39.
Through the through-hole and the sweep gas pipe 36, and flows out from the hydrogen outlet 56 provided on the upper part thereof.

Fifth, the unreacted raw material gas and the generated CO and CO ₂ gases that have passed through the outer catalyst layer 29
Flows out of the system from an off-gas outlet 62 provided at the upper part of the system. Except for the above differences, the hydrogen production apparatus 110 of the second embodiment has the same configuration as the hydrogen production apparatus 10 of the first embodiment. The height of the catalyst layer of Example 2 is twice that of Example 1, which is advantageous for the reforming reaction.

(Embodiment 3) FIG. 6 shows Embodiment 3 according to the present invention.
FIG. 2 is a perspective sectional view of the hydrogen production apparatus 120 of FIG. Example 2
6 is different from that shown in FIG. 6 in that a cylindrical partition wall 41 is replaced with a double hydrogen permeable cylinder 34 instead of inserting a sweep gas pipe.
Is arranged concentrically in the third annular space portion 33. The sweep gas is supplied to the sweep gas inlet 58 at the top of the apparatus.
And flows down the annular space between the partition wall 41 and the outer wall 28 of the double hydrogen permeable cylinder 34 to accompany the hydrogen while sweeping the hydrogen. The gas flows into the annular space between the inner wall 34 and the inner wall 30 and rises, and then flows out from the hydrogen outlet 56 provided at the upper portion thereof. Except for the above differences, the hydrogen production apparatus 120 of the third embodiment has the same configuration as the hydrogen production apparatus 110 of the second embodiment. In the third embodiment, since the cylindrical partition wall 41 is provided instead of the sweep gas pipes of the first and second embodiments, the configuration of the apparatus is further simplified.

Hereinafter, specific examples of the embodiment of the present invention will be described. (1) Apparatus Configuration As the hydrogen production apparatus 10 shown in FIG.
0 mm) 20, middle cylinder (inner diameter 173 mm) 18, outer cylinder (inner diameter 188 mm) 14, double hydrogen permeable cylinder (inner diameter 125 m)
m, outer diameter 165mm) 34, sweep gas pipe (outer diameter 6m)
m) A reactor having an effective length of 600 mm consisting of 36 is constructed as shown in FIG. 1, and the above-mentioned double hydrogen permeable cylinders 34 are arranged upright at equal intervals in the circumferential direction in the catalyst layer of the second annular space 26. did. As the reforming catalyst A, a nickel-based catalyst (average particle size 2
mmφ). The configuration of the furnace was such that only the hanging type burner 46 as shown in FIG. 1 was arranged, and the outside of the outer cylinder 14 was kept warm with rock wool having a thickness of 200 mm in order to reduce heat radiation to the outside air.

(2) Operating conditions Supply amount of reforming side raw material gas (city gas 13A): 42.8
Mol / h {Steam supply in the reforming-side raw material gas: 1.54 kg /
h {Steam for reforming / reforming raw material gas (molar ratio): 2.0} Reforming reaction temperature: 560 ° C. {Reforming reaction pressure: 6.05 kgf / cm ² -abs.供給 Sweep gas (steam) supply amount: 1.88 kg / h 〇Sweep gas pressure: 1.25 kgf / cm ² -ab
s.

(3) Results of hydrogen generation test As a result of the reaction under the above-mentioned conditions, the amount of hydrogen obtained with the sweep gas was 164.0 mol / h, and CO as an impurity in hydrogen contained 1 ppm. It was below. The conversion of hydrocarbons in the raw material gas was about 86%. On the other hand, in the conventional reformer that does not employ the amount of hydrogen permeation, there is a chemical equilibrium wall due to the relationship between the operating temperature and the pressure.
It was only%.

In the first embodiment described above, the raw material gas flows downward from the upper part of the second annular space through the catalyst layer, while the sweep gas is introduced from the upper part of the sweep gas pipe and the third annular space flows upward. It is taken out from the upper part together with the accompanying hydrogen. In Example 2, the raw material gas was introduced from above the inner catalyst layer, and flowed downward through the inner catalyst layer.
Further, the sweep gas is raised in the outer catalyst layer, while the sweep gas is introduced from the upper portion of the third annular space, flows downward, and is taken out together with the entrained hydrogen from the upper portion of the sweep gas pipe. Furthermore,
In the third embodiment, the raw material gas is introduced from the upper part of the inner catalyst layer, while the sweep gas is introduced from the upper part of the annular space between the outer wall of the deuterium permeable tube and the partition wall and flows downward. The hydrogen was taken out together with the entrained hydrogen from the upper part of the annular space with the inner wall. In Examples 1 and 3, the flow directions of the raw material gas and the sweep gas were reversed. It is obvious that the same effect can be expected by reversing the flow direction of each and / or one of the gas and the sweep gas.

[0038]

According to the present invention, it is possible to provide an industrial-scale hydrogen production apparatus having the following advantages and economically producing high-purity hydrogen. (A) Since the apparatus including the deuterium permeable cylinder is composed of multiple cylinders, the structure is simple and compact. Therefore, the hydrogen production apparatus of the present invention can be constructed economically with a small number of materials. (B) The heat capacity is small because it is much lighter than a multi-tube apparatus in which many reaction tubes are arranged in parallel. Therefore, the apparatus can be started and stopped quickly, and the responsiveness at the time of changing the apparatus load is good. (C) Since the contact layer is heated from both sides, the catalyst layer can be more uniformly heated. Further, the heat flux distribution in the radial direction tends to be uniform due to the configuration of the multi-cylindrical body in which the furnace is arranged at the center. Therefore, it is possible to prevent the generation of a hot spot exceeding the heat resistant temperature of the double hydrogen permeable cylinder. (D) Countercurrent mass transfer between the sweep gas in the double hydrogen permeable cylinder and the reformed gas in the catalyst layer can increase the recovery rate of generated hydrogen. (E) Hydrogen can be separated and collected in a deuterium permeation cylinder to shift the chemical equilibrium to the production of the product in an advantageous manner.
The reforming temperature can be lowered by about 150 to 200 ° C. as compared with the related art. Thus, the amount of heat for heating the source gas can be reduced, and the thermal efficiency can be greatly improved. (F) Since the reaction temperature is low, an inexpensive material having high heat resistance can be used for the apparatus. Therefore, the cost of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective sectional view of a first embodiment of a hydrogen production apparatus according to the present invention.

FIG. 2 is a schematic cross-sectional view of the hydrogen production apparatus of FIG.

FIG. 3 is a partial cross-sectional view of the double hydrogen permeable cylinder taken along line XX in FIG. 2;

FIG. 4 is a perspective sectional view of Embodiment 2 of the hydrogen production apparatus according to the present invention.

FIG. 5 is a schematic cross-sectional view of the hydrogen production apparatus shown in FIG.

FIG. 6 is a perspective sectional view of a third embodiment of the hydrogen production apparatus according to the present invention.

FIG. 7 is a schematic structural view of a laboratory-scale apparatus of a conventional hydrogen production apparatus.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI C01B 3/56 C01B 3/56 Z H01M 8/06 H01M 8/06 R (72) Inventor Kennosuke Kuroda 2-chome Marunouchi, Chiyoda-ku, Tokyo No.5-1 Mitsubishi Heavy Industries, Ltd. Main Office (72) Inventor Hiroshi Makihara 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd., Hiroshima Research Laboratory (72) Inventor Shinsuke Ota Kannon, Nishi-ku, Hiroshima City, Hiroshima Prefecture 4-22 Shinmachi, Mitsubishi Heavy Industries, Ltd. Hiroshima Works (56) References JP-A-61-17401 (JP, A) JP-A-2-311301 (JP, A) JP-A-4-321502 (JP, A A) JP-A-4-325402 (JP, A) JP-A-63-23733 (JP, A) JP-A-2-83208 (JP, A) JP-A-2-141403 (JP, A) JP-A-6 −263402 (J P, A) JP-A-6-263403 (JP, A) JP-A-6-263405 (JP, A) JP-B-44-13363 (JP, B1) US Patent 4,981,676 (US, A) (58) Field (Int.Cl. ⁷ , DB name) C01B 3/32-3/48 B01D 53/22 B01J 8/02 B01J 8/06 301 C01B 3/56 H01M 8/06

Claims (6)

(57) [Claims] 1. A hydrogen production apparatus for separating and collecting hydrogen generated by a steam reforming reaction through a selective hydrogen permeable partition wall, comprising: an upright outer cylinder having a closed bottom; A first cylinder in which an outer cylinder and a middle cylinder are defined, comprising a middle cylinder and an inner cylinder, which are sequentially multiplexed and arranged vertically, and a hanging combustion burner arranged on a ceiling wall of the inner cylinder. The annular space portion and the inner cylinder hollow portion inside the inner cylinder communicate with each other at their respective bottoms, and the middle cylinder and the inner cylinder further include a second annular space portion having a closed annular bottom portion in which lower edges are connected to each other and closed. A catalyst layer filled with a reforming catalyst is formed in the second annular space. The catalyst layer has an outer wall having a hydrogen-permeable metal film on an inorganic porous layer, an inner wall, and an annular bottom wall. A deuterium permeable cylinder defining a third annular space portion is disposed substantially concentrically with the second annular space portion and substantially vertically. And a sweep gas pipe having a lower end opened is disposed in the third annular space, and a raw material gas is introduced from the upper part of the second annular space to flow down the catalyst layer and convert it to hydrogen at a high temperature. Then, the generated hydrogen is selectively separated and collected by passing through the deuterium permeable tube, and the permeated hydrogen is accompanied by the permeated hydrogen to the sweep gas introduced from the upper part of the sweep gas pipe, and the hydrogen is passed through the third annular space. An apparatus for producing hydrogen, wherein the apparatus is caused to flow out along with a sweep gas from an upper portion. 2. The hydrogen production apparatus according to claim 1, wherein an annular pipe header having a plurality of through holes in a header wall is provided in place of the sweep gas pipe having an open lower end. It is arranged along the annular bottom wall, and the lower end of the sweep gas pipe is connected to the annular pipe header. Further, the catalyst layer of the second annular space is connected to the inner cylinder and the inner wall of the double hydrogen permeable cylinder. And an outer catalyst layer between the middle cylinder and the outer wall of the deuterium permeable cylinder. A raw material gas is introduced from above the inner catalyst layer to flow down the inner catalyst layer. Then, while raising the outer catalyst layer, it is converted to hydrogen under high temperature, and the generated hydrogen is selectively separated and collected by passing through a deuterium permeable cylinder, and the sweep gas introduced from the upper part of the third annular space portion Through the through hole of the annular pipe header with permeated hydrogen And let it flow into the sweep gas pipe,
A hydrogen production apparatus characterized in that it is made to flow out along with a sweep gas from the upper part. 3. The hydrogen production apparatus according to claim 1, wherein a cylindrical partition wall is disposed substantially concentrically in the third annular space of the double hydrogen permeable cylinder in place of the sweep gas pipe whose lower end is open. The lower end is disposed apart from the annular bottom wall of the hydrogen permeable double cylinder, and the catalyst layer of the second annular space is further provided with an inner catalyst layer between the inner cylinder and the inner wall of the double hydrogen permeable cylinder. And an outer catalyst layer between the middle cylinder and the outer wall of the deuterium permeable cylinder. A raw material gas is introduced from above the inner catalyst layer to flow down the inner catalyst layer. Is converted to hydrogen under high temperature while the hydrogen is raised, and the generated hydrogen is selectively separated and collected by passing through the deuterium permeable tube, and introduced from the upper part of the annular space between the outer wall and the partition wall of the deuterium permeable tube. The permeated hydrogen is entrained in the swept gas and the annular space between the partition and the inner wall of the deuterium permeable cylinder Characterized in that it is caused to flow out together with a sweep gas from an upper portion of the hydrogen production device. 4. The hydrogen-permeable metal film is a non-porous thin film of any one of an alloy containing Pd, an alloy containing Ni and an alloy containing V. A hydrogen production apparatus according to any one of the above. 5. The hydrogen producing apparatus according to claim 1, wherein the permeated hydrogen is collected by purging the hydrogen permeable side with a pump instead of the permeated hydrogen collecting method of the sweep gas entrainment method. A hydrogen production apparatus, comprising: 6. The hydrogen production apparatus according to claim 1, wherein the flow directions of the raw material gas and the sweep gas are set in opposite directions.