JP2015174815A - Hydrogen purification device, and hydrogen purification system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide means for efficiently heating raw material hydrogen including impurities to be introduced to a primary side space of a cell, in a hydrogen purification device which is configured to take out pure hydrogen from a secondary side space after hydrogen including impurities is introduced from the primary side space and made transmit a palladium alloy tubule, the hydrogen purification device having a cell whose inside is partitioned into the primary side space and the secondary side space by: a palladium alloy tubule whose one end is sealed; and a tube plate for supporting an opening end of the tubule.SOLUTION: A length of a palladium alloy tubule is equal to or more than 15 times diameter of a tube plate, by making a shape of a cell slender, and an introduction tube of raw material hydrogen including impurities passes through a gap between a side wall of the cell and a heater for heating the cell.

Description

  The present invention relates to a hydrogen purification apparatus and a hydrogen purification system that utilize the hydrogen gas selective permeability of a palladium alloy thin film, and in particular, can efficiently heat raw material hydrogen containing impurities introduced into the primary space of a cell. The present invention relates to a possible hydrogen purification apparatus and a hydrogen purification system using the same.

Conventionally, high-purity hydrogen gas has been used in a large amount as an atmospheric gas in a semiconductor manufacturing process. Such a hydrogen gas is required to have an extremely low impurity concentration (ppb level or less) due to an improvement in semiconductor integration.
On the other hand, as a method for industrially producing a large amount of high-purity hydrogen, a reformed gas obtained by a steam reforming reaction from methanol, dimethyl ether, natural gas, liquefied petroleum gas, etc. is subjected to a cryogenic adsorption method or a pressure swing method. For example, a method of obtaining hydrogen by separating it into hydrogen and a gas other than hydrogen is known.

  The cryogenic adsorption method is a purification method in which a hydrogen-containing gas is circulated through an adsorption cylinder filled with an adsorbent that has been cryogenically cooled using liquefied nitrogen as a refrigerant to remove impurities other than hydrogen. This is a purification method in which a hydrogen-containing gas is sequentially circulated through the adsorption cylinder, and impurities other than hydrogen are removed by repeating the operations of pressure increase, impurity adsorption, impurity desorption, and adsorbent regeneration. The reformed gas as described above contains carbon monoxide, carbon dioxide, methane, nitrogen, water, etc. in addition to hydrogen. In the cryogenic adsorption method and the pressure swing method, these impurities are contained at a very low concentration ( It was difficult to remove until the ppb level or lower).

  On the other hand, as a method for obtaining a very high-purity hydrogen gas in a relatively small amount, raw hydrogen containing impurities is supplied to a hydrogen separation membrane made of a palladium alloy thin film, and the selective permeability of hydrogen gas is used. Thus, a method is known in which only hydrogen is taken out and taken out. Such an apparatus for purifying hydrogen is provided with a raw material hydrogen inlet containing impurities, a pure hydrogen outlet, and a palladium alloy thin film in a gas flow path between the inlet and the outlet. A hydrogen refining device, for example, as shown in Patent Documents 1 to 3, a plurality of palladium alloy capillaries (hydrogen separation membranes) sealed at one end are supported by a tube plate at the opening at the other end, and inside the cell. The inside of the cell is partitioned into two spaces, a primary space (impurity source hydrogen supply space) and a secondary space (pure hydrogen extraction space) by the palladium alloy thin tube and tube sheet. A hydrogen purification apparatus having a configuration.

JP-A-62-128903 JP-A-1-145302 JP-A-1-145303

  The hydrogen purification method using a palladium alloy hydrogen separation membrane has the disadvantage that the extraction amount of pure hydrogen per unit time is small compared to the cryogenic adsorption method and the pressure swing method. In addition to the hydrogen gas, the apparatus can be downsized and simplified. However, when the raw material hydrogen containing impurities is allowed to contact the palladium alloy thin tube and permeate the thin tube, it is necessary to sufficiently heat the thin tube and the raw material hydrogen, in addition to a heater for heating the inside of the cell, Equipment such as a heater for heating raw material hydrogen in advance is required.

  In hydrogen refining using a hydrogen separation membrane of palladium alloy, in order to increase the extraction amount of pure hydrogen per unit time, for example, when the hydrogen refining apparatus is enlarged, a heater or the like for heating raw material hydrogen in advance is used. When the equipment becomes larger and the number of hydrogen purifiers is increased, the number of equipment such as heaters and piping is increased and complicated, and the advantages of downsizing and simplification are reduced. Therefore, the problem to be solved by the present invention is that a hydrogen purifier capable of efficiently heating raw hydrogen containing impurities introduced into the primary space of the cell, and a hydrogen using a plurality of the hydrogen purifiers It is to provide a purification system.

  As a result of diligent studies to solve these problems, the present inventors set the shape of the primary space of the cell to a slender shape in the hydrogen purifier as described above, and introduced raw material hydrogen containing impurities. If the piping is provided so as to pass through the gap between the elongated side wall of the cell and the heater for heating the inside of the cell, the raw material hydrogen flowing through the inside of the introduction piping is sufficiently heated by the heat from the heater, Even when the hydrogen purifier is large or when a large number of hydrogen purifiers are used, it has been found that the apparatus can be maintained in a small and simple form, and the hydrogen purifier of the present invention has been reached.

That is, the present invention provides a plurality of palladium alloy thin tubes sealed at one end and a tube plate that supports the thin tube at the open end of the thin tube, so that the interior of the cell having the heater on the outer periphery is the primary side space and the secondary side. A hydrogen refining device having a structure partitioned into a space, introducing raw material hydrogen containing impurities from a primary side space, permeating the palladium alloy thin tube and taking out pure hydrogen from the secondary side space, The hydrogen purifier is characterized in that its length is 15 times or more of the diameter of the tube plate, and an introduction pipe for raw hydrogen containing impurities is provided so as to pass through the gap between the side wall of the cell and the heater.
In the present invention, a plurality of the hydrogen purifiers described above are installed in parallel, and the raw hydrogen introduction pipes of the hydrogen purifiers are connected to one external raw hydrogen supply pipe. The hydrogen purification system is characterized in that each pure hydrogen extraction pipe of the hydrogen purification apparatus is connected to one external pure hydrogen recovery pipe.

  In the hydrogen purification apparatus of the present invention, the primary space of the cell is set to be an elongated shape, and the introduction pipe for the source hydrogen containing impurities is between the elongated sidewall of the cell and the heater for heating the inside of the cell. It is configured to pass. That is, in the present invention, since the raw hydrogen introduction pipe is sufficiently heated by the heater for heating the inside of the cell, facilities such as a heater for preheating the raw hydrogen are reduced or unnecessary. Is possible. In particular, when the hydrogen purifier is large, when there are a plurality of hydrogen purifiers, it is effective in that the apparatus can be reduced in size and simplified.

  In the present invention, the inside of the cell is partitioned into a primary side space and a secondary side space by a palladium alloy thin tube sealed at one end and a tube plate supporting the open end of the thin tube, and hydrogen containing impurities is introduced from the primary side space. In addition, the present invention is applied to a hydrogen purifier of a type in which pure hydrogen is taken out from the secondary space through a palladium alloy capillary. In addition, as raw material hydrogen applied to the present invention, a reformed gas obtained by a steam reforming reaction from methanol, dimethyl ether, natural gas, liquefied petroleum gas, or the like, or relatively filled in a cylinder etc. for industrial use. Examples include high-purity hydrogen. The extremely high purity purified hydrogen obtained by the present invention is used as, for example, an atmospheric gas (carrier gas) in a semiconductor manufacturing process.

  Hereinafter, although the hydrogen purification apparatus of this invention and the hydrogen purification system using the same are demonstrated in detail based on FIGS. 1-4, this invention is not limited by these. 1 and 2 are block diagrams showing an example of the hydrogen purifier of the present invention, and FIG. 3 (1) is a block diagram showing an example of a cross section at the position of the tube plate of the hydrogen purifier of FIG. 3 (2) is a block diagram showing an example of a cross section at the position of the palladium alloy thin tube in FIG. 1, and FIG. 4 is a block diagram showing an example of the hydrogen purification system of the present invention.

  As shown in FIGS. 1 and 2, the hydrogen purifier of the present invention comprises a plurality of palladium alloy thin tubes 1 sealed at one end, and a tube plate 2 that supports the thin tubes at the open ends of the thin tubes. The inside of the cell 4 having the heater 3 is partitioned into a primary side space 4 ′ and a secondary side space 4 ″, and source hydrogen containing impurities is introduced from the source hydrogen supply port 9 of the primary side space 4 ′. And a hydrogen purifier for extracting pure hydrogen from the pure hydrogen outlet 11 of the secondary space 4 ″ through the palladium alloy thin tube, wherein the length of the palladium alloy thin tube 1 is at least 15 times the diameter of the tube plate 2. As shown in FIGS. 1 to 3, the hydrogen purification apparatus is characterized in that an introduction pipe 5 for source hydrogen containing impurities is provided so as to pass through the gap between the side wall 6 of the cell 4 and the heater 3. It is.

Hereinafter, each component of the hydrogen purifier according to the present invention will be described in detail.
As shown in FIGS. 1 and 2, the cell of the hydrogen purification apparatus of the present invention has a U-shaped outer shape, a U-shaped shape, or a similar shape, and a circular cross section. In this embodiment, a lid provided with a pure hydrogen outlet is provided at the opening of a container. In the hydrogen purifier of the present invention, the cell 4 (particularly, the raw hydrogen flowing through the raw hydrogen introduction pipe 5 is sufficiently heated by the heater 3 before reaching the raw hydrogen supply port 9. 4 ′ side) is set in an elongated shape (so that the diameter of the tube sheet is reduced). Moreover, the heater 3 is provided over the whole outer periphery of the side wall of the part in which the palladium alloy thin tube is installed among the side walls of the cell. Therefore, in the present invention, the length of the palladium alloy thin tube 1 is preferably set so as to be significantly longer than the diameter of the tube plate 2, and is usually 15 times or more, preferably 20 times or more, the diameter of the tube plate. It is said. Since the secondary space 4 ″ side of the cell 4 is preferably small in terms of downsizing of the apparatus, the volume of the space upstream of the cell tube plate is relatively downstream of the cell tube plate. It is usually set to be 10 times or more, preferably 15 times or more, more preferably 20 times or more of the volume of the space downstream of the cell tube plate.

  In the hydrogen purification apparatus of the present invention, the raw material hydrogen introduction pipe 5 containing impurities is set so as to pass through the gap between the side wall 6 of the cell 4 and the heater 3 as described above, but as shown in FIG. The gap between the raw hydrogen introduction pipe 5 and the side wall 6 of the cell and the heater 3 is filled with a solid heat transfer medium 12 such as heat transfer cement so that the heat from the heater 3 is efficiently transferred to the raw hydrogen introduction pipe 5. It is preferable to make it. The length of the raw hydrogen introduction pipe (the raw hydrogen introduction pipe having the structure shown in FIG. 3) set so as to pass through the gap between the side wall of the cell and the heater via the heat transfer medium is normally The length of the side wall 6 is 50% or more, preferably 80% or more, and more preferably 90% or more. The length of the side wall 6 of the cell 4 refers to the straight portion of the side wall 6 of the cell 4 in FIGS.

  In the hydrogen purification apparatus of the present invention, the raw material hydrogen introduction pipe 5 is usually provided in parallel with the palladium alloy thin pipe, but may be provided in a spiral shape. Even when it is provided in parallel with the palladium alloy thin tube, the length of the raw hydrogen introduction pipe configured to pass through the gap between the side wall of the cell and the heater is usually 30 cm or more, preferably 40 cm or more. The inner diameter of the raw hydrogen introduction pipe 5 is usually 6 mm or less. If the inner diameter of the introduction pipe 5 exceeds 6 mm, the raw hydrogen flowing through the introduction pipe 5 may not be heated sufficiently.

  As shown in FIG. 1, a palladium alloy thin tube 1 used in the hydrogen purification apparatus of the present invention has an open end 7 at one end on the tube plate 2 side and a closed end 8 at one end on the opposite side. Consists of. As described above, the palladium alloy thin tube 1 has a length that is at least 15 times the diameter of the tube plate, specifically 20 to 200 cm. Moreover, an outer diameter is 1.0-5.0 mm normally, and thickness is 30-100 micrometers normally. Further, 3 to 100 palladium alloy capillaries 1 are used for one palladium alloy membrane unit. Although there is no restriction | limiting in particular about these arrangement | positioning, The space | interval of adjacent palladium alloy thin tubes is set so that it may become 1.0-2.5 mm normally.

  Examples of the constituent components of the palladium alloy thin tube 1 include an alloy mainly composed of palladium and copper, an alloy mainly composed of palladium and silver, and an alloy mainly composed of palladium, silver and gold. When these alloys are used, an alloy of palladium 50 to 70 wt% and copper 30 to 50 wt%, an alloy of palladium 60 to 90 wt% and silver 10 to 40 wt%, palladium 60 to 80 wt%, silver 10 to 37 wt% and gold A 3-10 wt% alloy is preferred. The palladium alloy may contain other metals, but the metal is usually contained in an amount of 95 wt% or more, preferably 99 wt% or more.

  The tube sheet 2 used in the present invention is usually a disk having a thickness of 3 to 30 mm. Further, the diameter of the tube plate 2 is 1/15 or less, preferably 1/20 or less of the length of the palladium alloy tubule, and is usually 10 to 40 mm, although it varies depending on the diameter and number of the palladium alloy tubule 1. . As shown in FIG. 3 (1), the tube plate 2 is provided with a through-hole for inserting the palladium alloy thin tube 1 in advance at a position where the tube plate 2 is attached. The palladium alloy thin tube 1 is supported on the tube plate 2 by welding or the like. At that time, a coil-shaped spring can be inserted into the inside of the palladium alloy thin tube 1 as necessary in order to secure a flow path space of pure hydrogen that has passed through the hydrogen separation membrane. The tube sheet 2 is preferably made of nickel.

  The heater 3 used in the present invention can efficiently heat the raw material hydrogen flowing through the palladium alloy thin tube 1 and the raw hydrogen inside the cell 4 and the raw hydrogen introduction pipe 5 at a predetermined temperature. Although not particularly limited, for example, as shown in FIG. 1 and FIG. 2, the heat generating wire 13 is spirally wound around the outer periphery of the side wall 6 of the cell 4 to heat transfer such as heat transfer cement having excellent heat conductivity. The heating wire 13 can be covered with the medium 12 and the medium 12 can be fixed to the side wall 6 of the cell 4. It is preferable to set the heater 3 so as to cover and heat at least the entire side wall upstream of the tube plate of the cell.

  In the hydrogen purifier of the present invention, an impurity-containing gas outlet 10 is provided in the primary space of the cell in order to recover the gas that does not permeate the palladium alloy thin tube 1. The positions of the source hydrogen supply port 9 and the impurity-containing gas extraction port 10 are not particularly limited as long as they are upstream of the position of the tube plate 2, but they are preferably set at positions separated from each other. For example, as shown in FIG. 1, when the raw material hydrogen supply port 9 is provided at a position away from the tube plate 2, the impurity-containing gas outlet 10 is provided at a position close to the tube plate 2, as shown in FIG. When the raw material hydrogen supply port 9 is provided at a position close to the tube plate 2, the impurity-containing gas outlet 10 is provided at a position away from the tube plate 2. Further, in order to recover the hydrogen that has permeated through the palladium alloy thin tube 1, a pure hydrogen outlet 11 is provided in the secondary space of the cell, and a pure hydrogen outlet for recovering the pure hydrogen that has reached the pure hydrogen outlet 11 is also provided. A pipe 16 is provided.

Next, the hydrogen purification system of the present invention will be described.
In the hydrogen system of the present invention, a plurality of the hydrogen purifiers of the present invention as described above are installed in parallel as shown in FIG. 4, and the raw hydrogen introduction pipes 5 of the plurality of hydrogen purifiers are connected to the outside. The hydrogen purification system is connected to one raw hydrogen supply pipe 14 and each of the plurality of hydrogen purifiers is connected to one pure hydrogen recovery pipe 17. In the hydrogen system of the present invention, the pipe is connected so that hydrogen containing impurities recovered from the impurity-containing gas outlets 10 of the plurality of hydrogen purifiers is recovered to the external impurity-containing gas recovery pipe 15. The

  When performing hydrogen purification according to the present invention, after connecting one hydrogen purification apparatus of the present invention or a plurality of hydrogen purification apparatuses of the present invention arranged as shown in FIG. The inside of the hydrogen introduction pipe 5 and the inside of the cell 4 are heated by the heater 3, and hydrogen is purified by supplying the raw hydrogen from the raw hydrogen supply pipe. The temperature of the palladium alloy thin tube 1 during the hydrogen purification is usually 250 to 500 ° C, preferably 300 to 450 ° C. The raw material hydrogen contacts with the heated palladium alloy capillary tube 1, and only hydrogen passes through the palladium alloy capillary tube 1 and is recovered via the pure hydrogen outlet 11, the pure hydrogen outlet pipe 16, and the pure hydrogen recovery pipe 17. .

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these.

[Example 1]
(Production of hydrogen purification equipment)
Palladium alloy thin tube 1 (outer diameter 1.8 mm, thickness 70 μm, length 600 mm) made of an alloy containing palladium, silver, and gold as main components on a disk-shaped nickel tube plate 2 having a diameter of 20 mm and a thickness of 5 mm Nineteen were welded onto a plurality of concentric circles. Next, the SUS316L cell 4 having an inner diameter of 20 mm and a length of 700 mm having the raw material hydrogen supply port 9, the impurity-containing gas extraction port 10, and the pure hydrogen extraction port 11 at the position shown in FIG. The plate 2 and the palladium alloy thin tube 1 were accommodated. Note that the volume of the space upstream of the cell tube plate 2 was about 35 times the volume of the space downstream of the cell tube plate 2.

  A raw material hydrogen introduction pipe 5 made of SUS316L having a straight pipe section with an inner diameter of 4.3 mm and a length of 800 mm is provided so that the straight pipe section is in contact with the side wall 6 of the cell, and the raw hydrogen supply port 9 of the cell 4 is provided. Connected to. Further, the heating wire 13 is spirally wound around the outer periphery of the side wall 6 of the cell and the outer periphery of the straight piping portion of the introduction piping 5, and these gaps are filled with heat transfer cement so as to have a configuration as shown in FIG. A hydrogen purifier having a configuration as shown in FIG. 1 was produced. The length of the raw hydrogen introduction pipe 5 set so as to pass through the gap between the side wall 6 of the cell and the heater 3 through the heat transfer cement was 95% of the length of the side wall 6 of the cell. Further, a pure hydrogen extraction pipe 16 and the like were connected.

(Hydrogen purification test)
The temperature inside the space 4 ′ on the primary side of the cell of the hydrogen purifier was raised to 600 ° C., hydrogen was introduced, and heat treatment was performed for 10 hours. Subsequently, the temperature inside the primary space 4 ′ of the cell of the hydrogen purifier is lowered to 420 ° C., and the differential pressure between the primary space 4 ′ of the cell and the secondary space 4 ″ of the cell is 1.0 MPa. The raw material hydrogen containing about 400 ppm of impurities (nitrogen, oxygen, carbon dioxide, etc.) in total was introduced from the raw hydrogen introduction pipe 5 to purify the hydrogen, while supplying the raw hydrogen. The temperature of the raw material hydrogen at the port 9 was about 400 ° C. As a result of performing the treatment for 1 hour, 900 L of pure hydrogen was obtained from the pure hydrogen extraction pipe.

[Example 2]
In the production of the hydrogen purification apparatus in Example 1, the configuration as shown in FIG. A hydrogen refining device was manufactured. The length of the raw hydrogen introduction pipe 5 set so as to pass through the gap between the side wall 6 of the cell 4 and the heater 3 through the heat transfer cement was 85% of the length of the side wall 6 of the cell 4.
A hydrogen purification test was conducted in the same manner as in Example 1 except that the hydrogen purification apparatus was used. As a result, the temperature of the source hydrogen at the source hydrogen supply port 9 was about 390 ° C. In addition, 900 L of pure hydrogen was obtained from the pure hydrogen take-out piping after 1 hour of treatment.

[Example 3]
(Production of hydrogen purification system)
Three hydrogen purifiers similar to those in Example 1 were prepared, and a plurality of hydrogen purifiers were installed in parallel. The raw hydrogen introduction pipes 5 of each of these hydrogen purifiers are connected to one external raw hydrogen supply pipe 14, and each of the pure hydrogen extraction pipes 16 of these hydrogen purifiers is connected to one external hydrogen supply pipe 14. A hydrogen purification system as shown in FIG. 4 is manufactured by connecting to the pure hydrogen recovery pipe 17 and further connecting the impurity-containing gas outlet 10 and one external impurity-containing gas recovery pipe 15 through an intermediate pipe. did.

(Hydrogen purification test)
The temperature inside the space 4 ′ on the primary side of each hydrogen purifier cell was raised to 600 ° C. and hydrogen was introduced, followed by heat treatment for 10 hours. Subsequently, the temperature inside the primary space 4 ′ of each cell of the hydrogen purifier is lowered to 420 ° C., and the differential pressure between the primary space 4 ′ of the cell and the secondary space 4 ″ of the cell is 1 While controlling to 0.0 MPa, raw hydrogen containing impurities (nitrogen, oxygen, carbon dioxide, etc.) in total of about 400 ppm was introduced from the raw hydrogen supply pipe 14 to purify the hydrogen. As a result, a total of 2600 L of pure hydrogen was obtained from the pure hydrogen recovery pipe 17.

  As described above, the hydrogen purification apparatus and the hydrogen purification system of the present invention can eliminate the need for a heater for preheating raw material hydrogen, as shown in the examples. Therefore, the apparatus and system can be reduced in size and simplified.

The block diagram which shows an example of the hydrogen purification apparatus of this invention The block diagram which shows an example of hydrogen purification apparatuses other than FIG. 1 of this invention (1) Configuration diagram showing an example of a cross section at the position of the tube plate of the hydrogen purification apparatus of FIG. 1 (2) Configuration diagram showing an example of a cross section at the position of the palladium alloy thin tube of the hydrogen purification apparatus of FIG. Configuration diagram showing an example of the hydrogen purification system of the present invention

DESCRIPTION OF SYMBOLS 1 Palladium alloy thin tube 2 Tube plate 3 Heater 4 Cell 4 'cell primary side space 4 "cell secondary side space 5 Raw material hydrogen introduction piping 6 Cell side wall 7 Open end 8 Closed end 9 Raw material hydrogen supply port 10 Impurity-containing gas outlet 11 Pure hydrogen outlet 12 Heat transfer medium 13 Heating wire 14 Raw material hydrogen supply piping 15 Impurity-containing gas recovery piping 16 Pure hydrogen extraction piping 17 Pure hydrogen recovery piping

Claims (8)

  The inside of the cell having the heater on the outer periphery is partitioned into a primary space and a secondary space by a plurality of palladium alloy thin tubes sealed at one end and a tube plate that supports the thin tube at the open end of the thin tube. A hydrogen refining apparatus having a configuration, introducing raw material hydrogen containing impurities from a primary side space, permeating through a palladium alloy thin tube and taking out pure hydrogen from the secondary side space, the length of the palladium alloy thin tube being a tube plate A hydrogen refining apparatus characterized in that an introduction pipe for raw material hydrogen containing impurities is provided so as to pass through the gap between the side wall of the cell and the heater.   The hydrogen purifier according to claim 1, wherein the raw hydrogen introduction pipe and the palladium alloy thin pipe are parallel to each other.   2. The hydrogen purifier according to claim 1, wherein a solid heat transfer medium is filled in a gap between the raw hydrogen introduction pipe, the cell side wall, and the heater.   2. The hydrogen purifier according to claim 1, wherein the volume of the space upstream of the cell tube plate is 10 times or more the volume of the space downstream of the cell tube plate.   The hydrogen purifier according to claim 1, wherein the length of the raw hydrogen introduction pipe passing through the gap between the side wall of the cell and the heater is 30 cm or more.   2. The hydrogen purifier according to claim 1, wherein an inner diameter of the raw hydrogen introduction pipe passing through a gap between the side wall of the cell and the heater is 6 mm or less.   The hydrogen purifier according to claim 1, wherein the heater is a heating wire spirally wound around the outer periphery of the side wall of the cell.   A plurality of hydrogen purifiers according to claim 1 are installed in parallel, and the raw hydrogen introduction pipes of each of the plurality of hydrogen purifiers are connected to one external raw hydrogen supply pipe. A hydrogen purification system, wherein each pure hydrogen take-out pipe of the purifier is connected to one external pure hydrogen recovery pipe.

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