JP4890938B2 - Gas separation tube housing structure - Google Patents

Description

  The present invention relates to a gas separation tube housing structure that is suitably used mainly for a selectively permeable membrane reactor.

Conventionally, as a method for obtaining only a specific gas component from a multi-component mixed gas, a method of separating with an organic or inorganic gas separation membrane (membrane separation method) is known. As a related prior art, a tubular hydrogen gas separator (hydrogen gas separation tube) in which a gas separation membrane made of palladium, a palladium alloy, or silica is coated on one surface of a porous substrate is disclosed (for example, Patent Literatures 1 to 3). Further, a tubular carbon dioxide gas separator (carbon dioxide gas separation pipe) in which a gas separation membrane made of DDR (Deca-Dodecasil 3R) zeolite is formed on one surface of a porous substrate is disclosed (for example, (See Patent Documents 4 and 5). Moreover, a tubular oxygen gas separator (oxygen gas separation tube) in which a gas separation membrane made of carbon or LaGaO ₃ is coated on one surface of a porous substrate is disclosed (for example, Patent Documents 6 and 7, Patent Document 1). In such a gas separator, since the mechanical strength is insufficient only with the gas separation membrane, the gas separation membrane is coated on, for example, a tubular porous substrate.

  The gas separation pipe housing structure in which such a gas separation pipe is housed arranges the gas separation pipe in a metal container, introduces a gas to be treated (mixed gas) from one side of the gas separation pipe, Only a specific gas permeates through the gas separation pipe, and a purified permeated gas is taken out from the other side of the gas separation pipe. Therefore, it is necessary to hermetically separate the mixed gas side and the permeate gas side and connect the gas separation pipe to the permeate gas outlet of the metal container in an airtight manner. For this reason, it is important that the mixed gas does not leak to the permeate gas side from the joint between the gas separation pipe and the metal flange connected to the permeate gas outlet.

  As shown in FIG. 4, for example, as shown in FIG. 4, the cylindrical gas separation is performed by joining the gas separation tube and the container in a state where the permeate gas side (inside) and the mixed gas side (outside) of the gas separation tube are hermetically separated. There is a gas separation pipe housing structure 40 in which both ends of the pipe 12 are joined to the inner surface of the container 23 by an airtight joint 16 using a dense body such as glass. However, if there is a difference between the expansion rates of the container 23 and the gas separation pipe 12, stress is generated in the gas separation pipe 12 and the container 23 when they are used under heating and heating conditions, etc. There is also a possibility of causing a malfunction.

In order to avoid such a problem, one end of the gas separation pipe 12 is joined to the container 43 by the airtight joint 26 , and the other end is joined to a lid-like sealing member such as a lid-like flange (a lid-like member). The gas separation pipe housing structure 50 (FIG. 5) sealed by the joining member 4a) and one end of the gas separation pipe 12 are joined to the container 53 by the annular joining member 4b such as an annular flange, and the other end. A gas separation tube housing structure 60 (FIG. 6) and the like sealed with a lid-like sealing member (lid-like joining member 4a) such as a lid-like flange is disclosed (see, for example, Patent Documents 2, 8, and 9). ).

  Usually, the outer diameters of the joining members (the lid-like joining member 4a and the annular joining member 4b) of the gas separation pipe housing structures 50, 60 having the configuration shown in FIGS. 5 and 6 are the outer diameters of the gas separation pipe 12. Bigger than. Therefore, when the gas separation pipe 12 is accommodated in the containers 43 and 53, the inner diameters of the containers 43 and 53 must be made larger than the outer diameters of the joining members (the lid-like joining member 4a and the annular joining member 4b). Don't be.

On the other hand, becomes a problem when transmitting the desired gas from a gas mixture, in order to suppress the decrease flux by concentration polarization, it is effective to reduce the distance of the container inner peripheral surface and the gas separation pipe outer peripheral surface is there. Further, as shown in FIG. 7, the gas separation pipe housing structure 70 in which the catalyst 5 is disposed between the gas separation pipe 12 and the container 63 can be used as a permeable membrane reactor (membrane reactor). . Such membrane reactors also the distance D ₄ of the container inner peripheral surface and the gas separation tube outer peripheral surface is large, the amount of catalyst is increased more than necessary to use a suitable between the container 63 and the gas separation pipe 12 It is desirable to reduce the distance. However, an inner diameter of the flange (lid-like flange 4a, an annular flange 4b) of the container 63 Under large forced circumstances than the outer diameter of the smaller distance D ₄ of the container inner peripheral surface and the gas separation pipe outer peripheral surface There is a limit to doing it.
Japanese Patent No. 3213430 JP 2003-126662 A JP 2005-118767 A JP 2003-159518 A JP 2004-105942 A JP 2003-286018 A JP 2001-93325 A JP 2002-187706 A Japanese Patent Laid-Open No. 2004-1987 K. Okamoto et. al. , ACS Symp. Ser. , Vol. 744, p314 (2000).

  The present invention has been made in view of such problems of the prior art, and the problem is that the present invention is excellent in separability and can be designed in a compact manner in a limited narrow space. An object of the present invention is to provide a gas separation pipe housing structure that can be disposed even if it exists.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors used a bottomed cylindrical gas separation tube, and joined the gas separation tube and the container with a joining member, from the outer diameter of the joining member. However, it has been found that the above problem can be achieved by reducing the inner diameter of at least the portion of the container that accommodates the gas separation pipe, and the present invention has been completed.

  In addition, the present inventors use a bottomed cylindrical tube as the gas separation tube, and connect the gas separation tube and the container between the outer peripheral surface near the opening of the gas separation tube and the inner peripheral surface of the container. It has been found that the above-mentioned problems can be achieved by joining with the airtight joint portion provided, and the present invention has been completed.

  That is, according to the present invention, the following gas separation pipe housing structure is provided.

[1] A bottomed cylindrical gas separation pipe having a bottomed cylindrical base material, and a selectively permeable membrane formed on at least one surface of the base material, and having one opening, and the gas A container that accommodates the separation tube therein, and the gas separation tube and the container that are disposed in the opening of the gas separation tube and are hermetically separated from each other inside the gas separation tube A joining member having an outer diameter larger than the outer diameter of the gas separation pipe, and having an inner diameter of at least a portion of the container that accommodates the gas separation pipe as compared with the outer diameter of the joining member. it is rather small in the container, the portion in which the gas separation tube is arranged, the gap portion of the volume a between the inner peripheral surface of the outer peripheral surface and the container of the gas separation pipe (cm ^3), A gas component having a ratio X (= a / b) to an area b (cm ² ) of the permselective membrane of 0.1 to 10 A separation pipe housing structure, wherein the joining member is joined to the container in a state of coming out of the container, or has an inner diameter larger than an inner diameter of a portion of the container for housing the gas separation pipe. A gas separation tube housing structure (hereinafter, also referred to as “first gas separation tube housing structure”) characterized in that the gas separation tube housing structure is housed in a portion having the same .

  [2] The gas separation pipe housing structure according to [1], wherein the joining member is made of metal or ceramics.

[3] A bottomed cylindrical base material, and a bottomed cylindrical gas separation pipe having a single opening having a permselective membrane formed on at least one surface of the base material, and the gas A container that houses the separation tube therein, and is disposed between the outer peripheral surface in the vicinity of the opening of the gas separation tube and the inner peripheral surface of the container, so that the inside and the outside of the gas separation tube are hermetically isolated. An airtight joint that joins the gas separation pipe and the container in a state where the gas separation pipe is joined, and the airtight joint is disposed between the outer peripheral surface in the vicinity of the opening of the gas separation pipe and the inner peripheral surface of the container. It has been made gas separation tube receiving structure (hereinafter, also referred to as "second gas separation tube receiving structure").

  [4] The gas separation pipe housing structure according to any one of [1] to [3], further including a catalyst disposed between an outer peripheral surface of the gas separation pipe and an inner peripheral surface of the container.

  [5] The gas separation tube housing structure according to any one of [1] to [4], wherein the base material is made of ceramics.

[ 6 ] The [1] to [ 5 ], wherein the permselective membrane is a membrane that can selectively permeate at least one selected from the group consisting of hydrogen, oxygen, nitrogen, carbon monoxide, carbon dioxide, and water vapor. ] The gas separation pipe accommodation structure in any one of.

[ 7 ] The gas separation tube housing structure according to any one of [1] to [ 5 ], wherein the selectively permeable membrane is a membrane made of palladium or a palladium alloy.

[ 8 ] The gas separation tube housing structure according to any one of [1] to [ 5 ], wherein the selectively permeable membrane is a membrane made of zeolite.

[ 9 ] The gas separation tube housing structure according to any one of [1] to [ 5 ], wherein the selectively permeable membrane is a membrane made of carbon.

[ 10 ] The gas separation tube housing structure according to any one of [1] to [ 5 ], wherein the selectively permeable membrane is a membrane made of silica.

[ 11 ] The gas separation tube housing structure according to any one of [1] to [ 10 ], wherein the selectively permeable membrane has a thickness of 0.05 to 10 μm.

  The first and second gas separation pipe housing structures of the present invention are excellent in separation performance, can be designed compactly, and can be arranged even in a limited narrow space. It is what you play.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention. Hereinafter, the term “gas separation pipe housing structure of the present invention (this embodiment)” means both the first gas separation pipe housing structure and the second gas separation pipe housing structure.

  FIG. 1 is a cross-sectional view schematically showing an embodiment of the first gas separation pipe housing structure of the present invention. As shown in FIG. 1, the first gas separation pipe housing structure 10 of the present embodiment includes a gas separation pipe 2, a container 3, and a joining member (annular joining member 4).

The gas separation tube 2 includes a bottomed cylindrical base material and a permselective membrane formed on at least one surface of the base material, and has a bottomed cylindrical shape having one opening 1. It is a structural member. The cross-sectional shape perpendicular to the longitudinal direction (bottom to opening direction) of the gas separation tube is preferably circular, but may be other shapes such as an ellipse. Examples of the shape of the bottom of the gas separation tube include a hemispherical shape, a conical shape, a disc shape, and similar shapes thereof. Although not limited outer diameter _{D 3} is particularly gas separation tube, usually, 1～50Mmfai, preferably 2～30Mmfai. Moreover, although it does not specifically limit about the full length L of a gas separation pipe, Usually, 0.05-1m, Preferably it is 0.1-0.5m.

  The base material constituting the gas separation pipe 2 is a bottomed tubular (bag tubular) member having one end closed. This substrate alone supports a permselective membrane that has low mechanical strength and is difficult to stand by itself. The substrate is preferably of a porous structure that does not prevent gas permeation. When the substrate has a porous structure, the average pore diameter of the surface of the substrate on which the permselective membrane is formed is preferably 0.01 to 1 μm, and more preferably 0.05 to 0.6 μm. preferable. When the average pore diameter is less than 0.01 μm, the resistance when the gas passes increases and the adhesion of the selectively permeable membrane may decrease. On the other hand, if the average pore diameter exceeds 1 μm, pinholes are likely to occur in the selectively permeable membrane, and the film thickness necessary for filling the pores increases.

  The material of the base material is preferably ceramics because it hardly reacts with the gas to be treated (mixed gas) and can be used under high temperature conditions. In particular, when the permselective membrane is made of a metal, it is difficult for the permselective membrane and the base material to react at a high temperature. In the present specification, even if the base material body is made of metal, if the surface portion of the base material that comes into contact with the permselective membrane is mainly made of ceramics, the base material is “a base material made of ceramics”. To be included in the concept. Examples of the ceramic that is the material of the substrate include alumina, zirconia, silica, mullite, spinel, silicon carbide, silicon nitride, or a composite or mixture containing at least one of these. The ceramic substrate can be produced by, for example, the method described in JP-A-62-273030.

  The permselective membrane is disposed in a film shape on at least one surface of the substrate. The permselective membrane may be formed on the outer side of the substrate, on the inner side, or on both the inner and outer surfaces, but is more preferably formed on at least the outer side of the substrate. . Further, a part of the permselective membrane may enter a part of the pores of the base material. In order to coat the permselective membrane on the surface of the substrate, a known method may be used. For example, a plating method, a vacuum evaporation method, a CVD method, a sputtering method, a hydrothermal method, a sol-gel method, or the like can be used.

  Specific examples of the selectively permeable membrane include a membrane that can selectively permeate at least one selected from the group consisting of hydrogen, oxygen, nitrogen, carbon monoxide, carbon dioxide, and water vapor. The thickness of the permselective membrane is not particularly limited because it is appropriately set depending on the purpose of use, but it is generally preferably 10 μm or less in order to obtain a high flux. Further, if the permselective membrane is too thin, defects such as pinholes are liable to occur in the membrane, so the thickness is preferably 0.05 μm or more.

Among these permselective membranes, for example, as a hydrogen permselective membrane, a palladium membrane, a palladium alloy membrane, and a silica membrane can be cited as preferred examples. Moreover, as a carbon dioxide permeation | transmission film | membrane, a DDR type | mold zeolite film can be mentioned as a suitable example. Moreover, as a selective oxygen permeable film, a carbon film or a LaGaO ₃ film can be cited as a suitable example. Details of the DDR type zeolite membrane and the production method thereof are described in, for example, Patent Documents 4 and 5. In addition, it is known that there are very many types of zeolite. For this reason, in addition to the above-mentioned DDR type zeolite, other zeolites such as MFI type zeolite, FAU type zeolite, MOR type zeolite, and A type zeolite can be suitably used as the zeolite constituting the permselective membrane. .

  In particular, a hydrogen separation membrane usually contains a specific metal. The metal contained in the permselective membrane may be any metal that selectively permeates hydrogen, but palladium (Pd), palladium alloy, or palladium (Pd) and silver (Ag) or copper (Cu) as main components. The metal is preferable because of its high hydrogen permeation rate. Palladium alloys are described, for example, in Journal of Membrane Science, 56 (1991) 315-325: “Hydrogen Permeable Palladium-Silver Alloy Membrane Supported on Porous Ceramics”, Jpn. Thus, it is preferable that the content of metals other than palladium is 10 to 50 mass% of the whole. The main purpose of alloying palladium is to prevent hydrogen embrittlement of palladium and improve the separation efficiency at high temperatures. Moreover, containing silver or copper as a metal other than palladium is preferable for preventing hydrogen embrittlement of palladium.

  Since the joining member needs to have joining strength, it is preferable that the main part is made of metal, ceramics, a composite of metal and ceramics, or the like. In addition, as a joining member, it is preferable to use the member (flange) of the structure based on a disk or a cylindrical shape from the ease of handling etc. The annular joining member 4 and the gas separation pipe 2 can be joined by welding, metal brazing, glass, resin, rubber, gland packing, or the like. When corrosion resistance or heat resistance is required for the joint, it is preferable to join by welding, metal brazing, glass, gland packing, or the like. In particular, when the selectively permeable membrane is thin, in order to avoid damage to the gas separation tube 2 due to thermal stress, a gland packing and a flange as described in a publicly known document such as JP-A-2003-126662 are disclosed. It is preferable to employ a joining method using In addition, the outer diameter of a joining member means the longest dimension among the diagonal lines of a joining member cross section when a joining member is cut | disconnected in the substantially perpendicular direction of a gas separation pipe.

  The materials of the containers 3, 13, and 23 are not particularly limited as long as they can accommodate the gas separation pipe 2, but are usually made of metal or the like. Normally, an inflow hole through which the mixed gas can flow from the outside and an outflow hole through which the permeated gas can flow out are formed.

  The annular joint member 4 is a member disposed in the opening 1 of the gas separation pipe 2 and is usually a member having an annular structure in which a hole portion through which gas can flow in and out is formed. The annular joining member 4 joins the gas separation pipe 2 and the container in a state where the inside and the outside of the gas separation pipe 2 are hermetically separated. The annular joining member 4 and the container are joined together by screwing or welding via an appropriate sealing material such as a gasket or ferrule.

  When using the gas separation tube housing structure under high temperature conditions, the difference in the thermal expansion coefficient between the annular bonding member 4 and the base material within the operating temperature range is within 30% from the viewpoint of preventing damage to the base material. Preferably there is. By setting the difference in the thermal expansion coefficient between the annular bonding member 4 and the base material to be within 30%, it is possible to more effectively prevent the occurrence of permeated gas leakage and the base material damage under high temperature conditions.

The volume a of the space between the outer peripheral surface of the gas separation tube 2 and the inner peripheral surface of the container 3 at the portion where the gas separation tube 2 is disposed (within the range of the total length L of the gas separation tube) in the container 3. The ratio X (= a / b) between (cm ³ ) and the area b (cm ² ) of the selectively permeable membrane is preferably 0.1 to 10. When the value of X exceeds 10, the distance D ₄ of the container inner peripheral surface and the gas separation tube outer circumference is increased, the concentration polarization increases, there is a case where the flux of the selectively permeable membrane is reduced. Moreover, when heating and using the container 3, a container becomes uselessly large (thick), and thermal efficiency may fall. On the other hand, when the value of X is less than 0.1, the catalyst 5 is disposed between the outer peripheral surface of the gas separation pipe 2 and the inner peripheral surface of the container 3 to form a permeable membrane reactor (membrane reactor). Since there is too little quantity, reaction may become difficult to advance. Further, since the distance D ₄ of the container inner peripheral surface and the gas separation tube outer peripheral surface is reduced, in some cases the handling of the attachment, such as a gas separation tube 2 to the container 3 becomes difficult.

Assuming that the base material constituting the gas separation tube 2 is made of porous ceramics, the thermal expansion coefficient of this base material is 0.5 × 10 ^{−6 to} 11 × 10 ⁻⁶ / ° C. Therefore, specific examples of the metal material constituting the annular joining member include permalloy, kovar, invar, super invar, molybdenum, tungsten, iron / nickel alloy, and the like, and particularly, permalloy is preferable. Further, specific examples of the ceramic material constituting the annular joint member include alumina, zirconia, silica, mullite, spinel, silicon carbide, silicon nitride, or a composite or mixture containing at least one of these. be able to. Further, as the annular joining member, a combination of metal and ceramic, or a composite of metal and ceramic may be used.

The first gas separator tube receiving structure 10 of the present embodiment, the outer diameter than the D _1, the container having an inner diameter (gas separation tube housing portion that houses at least a gas separation tube 2 of the container 3 of the joining members The inner diameter D ₂ ) is smaller (D ₁ > D ₂ ), and the gas separation pipe 2 and the container 3 are joined with the annular flange 4 protruding to the outside of the container 3. Therefore, it is possible to reduce the distance D ₄ of the container inner peripheral surface and the gas separation pipe outer peripheral surface. Therefore, it is possible to effectively suppress a flux decrease due to concentration polarization, which has been a problem in gas separation until now. Incidentally, that the first gas separation tube receiving structure 10 of the present embodiment, the distance _{D 4} of the container inner peripheral surface and the gas separation pipe outer peripheral surface, usually, 0.5 to 20 mm, and preferably 1~10mm Can do.

  In the first gas separation pipe housing structure 10 of the present embodiment, only one end of the gas separation pipe 2 is fixed to the container 3, and the other end needs to be fixed to the container 3. Absent. Therefore, the gas separation pipe 2 is hardly damaged due to expansion / contraction due to the load of the thermal cycle, and it is possible to use it for a long time.

  Furthermore, as shown in FIG. 1, by disposing the catalyst 5 between the outer peripheral surface of the gas separation pipe 2 and the inner peripheral surface of the container 3, the reaction amount is excellent while making the amount of the catalyst 5 used an appropriate amount. It can be a membrane reactor. In addition, what is necessary is just to use the kind of catalyst 5 to arrange | position, and the optimal thing can be selected by reaction. Specifically, nickel, ruthenium, etc. can be mentioned, for example, in the case of steam reforming of methane.

FIG. 2 is a cross-sectional view schematically showing another embodiment of the first gas separation pipe housing structure of the present invention. The container 13 of the first gas separation tube housing structure 20 shown in FIG. 2 is divided into a gas separation tube housing portion 13a and a joining member housing portion 13b. For this reason, the gas separation pipe 2 is mainly accommodated in the gas separation pipe accommodating portion 13a. Further, the annular joining member 4 is accommodated in the joining member accommodating portion 13b. By adopting such a configuration, the first gas separation tube receiving structure 20 of the present embodiment is different from the outer diameter D ₁ of the joint member, towards the container inside diameter D ₂ of the gas separation tube housing Is getting smaller. Therefore, it is possible to reduce the distance D ₄ of the container inner peripheral surface and the gas separation pipe outer peripheral surface, heretofore can be effectively suppressed decrease flux by concentration polarization which has been a problem in gas separation is there.

  Next, an embodiment of the second gas separation pipe housing structure of the present invention will be described. FIG. 3 is a cross-sectional view schematically showing an embodiment of the second gas separation pipe housing structure of the present invention. As shown in FIG. 3, the second gas separation pipe housing structure 30 of the present embodiment includes the gas separation pipe 2, the container 23, and the airtight joint 6. About the gas separation pipe 2 and the container 23, the thing similar to a 1st gas separation pipe accommodation structure can be used.

  The airtight joint 6 is disposed between the outer peripheral surface near the opening 1 of the gas separation pipe 2 and the inner peripheral surface of the container 23. The hermetic joint 6 is a portion formed by a dense body, for example. Specific examples of the dense body include glass, cement, and resin. The airtight joint 6 joins the gas separation pipe 2 and the container 23 in a state where the inside and the outside of the gas separation pipe 2 are hermetically separated.

By the structure as shown in FIG. 3, the second gas separation tube receiving structure 30 of the present embodiment, it is possible to reduce the distance D ₄ of the container inner peripheral surface and the gas separation pipe outer peripheral surface. Therefore, it is possible to effectively suppress a flux decrease due to concentration polarization, which has been a problem in gas separation until now. Further, by further disposing the catalyst 5 between the outer peripheral surface of the gas separation pipe 2 and the inner peripheral surface of the container 3, a membrane reactor having excellent reaction efficiency can be obtained while making the amount of the catalyst 5 used appropriate. it can. In addition, about the catalyst 5 to arrange | position, the thing similar to a 1st gas separation pipe accommodation structure can be used.

  In the second gas separation pipe housing structure 30 of this embodiment, only one end of the gas separation pipe 2 is fixed to the container 23 and the other end needs to be fixed to the container 23. Absent. Therefore, the gas separation pipe 2 is hardly damaged due to expansion / contraction due to the load of the thermal cycle, and it is possible to use it for a long time.

  In the case where importance is attached to the point that the gas separation pipe can be easily detached and replaced from the container, the first gas separation pipe housing structure is more preferable than the second gas separation pipe housing structure. . On the other hand, when importance is attached to the point that it is possible to design more compactly, the second gas separation pipe housing structure is more preferable than the first gas separation pipe housing structure.

  1 to 3 show one gas separation pipe disposed in the container, but even when a plurality of gas separation pipes are disposed in the container, By using a gas separation tube, according to the same concept as in the case of a single gas separation tube, it has excellent separation performance, can be designed compactly, and should be installed even in a limited space. It is possible to design a gas separation pipe housing structure capable of

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples.

Example 1
A palladium (Pd) film was formed on a bottomed cylindrical alumina substrate having an inner diameter of 10 mm and a total length of 100 mm so as to have a thickness of 2 μm, thereby preparing a bottomed cylindrical hydrogen separation tube. A metal flange (joining member) was attached to the opening of the hydrogen separation tube to obtain a hydrogen separation tube module. The flange of the obtained hydrogen separation tube module is connected to a container having an inner diameter of 20 mm so that the hydrogen separation tube is accommodated in the inside thereof, so that the configuration shown in FIG. 1 (however, no catalyst is provided) ) Hydrogen separation tube housing structure (Example 1).

(Example 2)
A palladium (Pd) film was formed on a bottomed cylindrical alumina substrate having an inner diameter of 30 mm and a total length of 300 mm so as to have a thickness of 2 μm, thereby preparing a bottomed cylindrical hydrogen separation tube. A metal flange (joining member) was attached to the opening of the hydrogen separation tube to obtain a hydrogen separation tube module. The flange of the obtained hydrogen separation tube module is connected to a container having an inner diameter of 40 mm so that the hydrogen separation tube is accommodated in the inside thereof, so that the configuration shown in FIG. 1 (however, no catalyst is provided) ) Was prepared (Example 2).

(Example 3)
A palladium (Pd) film was formed on a bottomed cylindrical alumina substrate having an inner diameter of 30 mm and a total length of 300 mm so as to have a thickness of 2 μm, thereby preparing a bottomed cylindrical hydrogen separation tube. A metal flange (joining member) having an outer diameter of 60 mm was attached to the opening of the hydrogen separation tube to obtain a hydrogen separation tube module. The flange of the obtained hydrogen separation tube module is connected to a container having an inner diameter of 40 mm for accommodating the hydrogen separation tube and an inner diameter of 70 mm for accommodating the flange so that the hydrogen separation tube is accommodated therein. As a result, a hydrogen separation tube housing structure (Example 3) having a configuration as shown in FIG. 2 (where no catalyst was disposed) was produced.

(Comparative Example 1)
Palladium (Pd) was deposited on a cylindrical alumina substrate having an inner diameter of 10 mm and a total length of 100 mm so that the thickness was 2 μm, thereby producing a cylindrical hydrogen separation tube. A hydrogen lid flange (joining member) with an outer diameter of 35 mm is attached to one opening of the hydrogen separation tube, and a metal annular flange (joining member) with an outer diameter of 35 mm is attached to the other opening to separate hydrogen. A tube module was obtained. By connecting the annular flange of the obtained hydrogen separation tube module to a container having an inner diameter of 70 mm so that the hydrogen separation tube is accommodated therein, a hydrogen separation tube accommodating structure (comparison) shown in FIG. Example 1) was prepared.

(Comparative Example 2)
Palladium (Pd) was formed on a cylindrical alumina substrate having an inner diameter of 30 mm and a total length of 300 mm so as to have a thickness of 2 μm to produce a cylindrical hydrogen separation tube. The hydrogen separation pipe is attached with a metal lid flange (joining member) with an outer diameter of 90 mm at one opening and a metal annular flange (joining member) with an outer diameter of 90 mm at the other opening. Got a module. By connecting the annular flange of the obtained hydrogen separation tube module to a container having an inner diameter of 120 mm so that the hydrogen separation tube is accommodated therein, a hydrogen separation tube accommodation structure having a configuration as shown in FIG. Example 2) was prepared.

  [Hydrogen separation and recovery test (1)]: Hydrogen: nitrogen = 1: 1 (volume ratio) in each of the hydrogen separation tube housing structures of Examples 1 to 3 and Comparative Examples 1 and 2 heated to 500 ° C. The mixed gas was introduced and hydrogen was separated and recovered, and the hydrogen recovery rate of each hydrogen separation tube housing structure was measured. The results are shown in Table 1. As shown in Table 1, when Example 1 and Comparative Example 1 and Examples 2 and 3 and Comparative Example 2 are compared, the hydrogen recovery rate may increase by 5 to 7% in the Example as compared to the Comparative Example. I understood.

(Examples 4 to 6, Comparative Examples 3 and 4)
By filling a pellet-shaped ruthenium-alumina catalyst between the container and the hydrogen separation pipe of each of the hydrogen separation pipe housing structures of Examples 1 to 3 and Comparative Examples 1 and 2, the catalyst filled Hydrogen separation tube housing structures (Examples 4 to 6, Comparative Examples 3 and 4) were produced.

  [Hydrogen separation / recovery test (2)]: The hydrogen separation tube housing structures of Examples 4 to 6 and Comparative Examples 3 and 4 were heated to 550 ° C. and mixed with methane: water vapor = 1: 3 (volume ratio). A reforming reaction was caused by injecting gas, and the produced hydrogen was separated and recovered. Table 2 shows the result of measuring the hydrogen recovery rate of each hydrogen separation tube housing structure. As shown in Table 2, when Example 4 and Comparative Example 3 and Examples 5 and 6 and Comparative Example 4 are compared, the methane conversion rate in the Examples may increase by 8 to 14% compared to the Comparative Example. I understood.

(Example 7)
A DDR type zeolite film was formed on a bottomed cylindrical alumina substrate having an inner diameter of 10 mm and a total length of 100 mm so as to have a thickness of 1 μm to produce a bottomed cylindrical carbon dioxide separation tube. By connecting the opening of the carbon dioxide separation tube to a container having an inner diameter of 20 mm using low-melting glass so that the carbon dioxide separation tube is accommodated therein, a configuration as shown in FIG. A carbon dioxide separation tube housing structure (Example 7) was prepared.

(Comparative Example 5)
A DDR type zeolite film was formed on a cylindrical alumina substrate having an inner diameter of 10 mm and a total length of 100 mm so as to have a thickness of 1 μm to produce a cylindrical carbon dioxide separation tube. A lid flange (joining member) made of an alumina dense body having an outer diameter of 35 mm is attached to one opening of the carbon dioxide separator, and an annular flange (joining member) made of an alumina dense body having an outer diameter of 35 mm is attached to the other opening. To obtain a carbon dioxide separation tube module. The annular flange of the obtained carbon dioxide separation tube module is connected to a container having an inner diameter of 70 mm so that the carbon dioxide separation tube is accommodated therein, whereby a carbon dioxide separation tube accommodation structure configured as shown in FIG. A body (Comparative Example 5) was prepared.

  [Carbon dioxide separation and recovery test]: A mixed gas of carbon dioxide: methane = 1: 1 (volume ratio) was introduced into each of the carbon dioxide separation tube housing structures of Example 7 and Comparative Example 5 at room temperature. The carbon dioxide was separated and recovered, and the carbon dioxide recovery rate of each carbon dioxide separation tube housing structure was measured. The results are shown in Table 3. As shown in Table 3, when Example 7 and Comparative Example 5 were compared, it was found that the carbon dioxide recovery rate increased by 3% in the Example as compared with the Comparative Example.

  The gas separation pipe housing structure of the present invention includes, for example, a fuel cell hydrogen purifier, a hydrogen production device by hydrocarbon reforming, a methane purification device by carbon dioxide separation, an oxygen enrichment device by oxygen separation, a membrane reactor, etc. It is suitable as.

It is sectional drawing which shows typically one Embodiment of the 1st gas separation pipe accommodation structure of this invention. It is sectional drawing which shows typically other embodiment of the 1st gas separation pipe accommodation structure of this invention. It is sectional drawing which shows typically one Embodiment of the 2nd gas separation pipe accommodation structure of this invention. It is sectional drawing which shows typically one Embodiment of the conventional gas separation pipe accommodation structure. It is sectional drawing which shows typically other embodiment of the conventional gas separation pipe accommodation structure. It is sectional drawing which shows typically other embodiment of the conventional gas separation pipe accommodation structure. It is sectional drawing which shows typically other embodiment of the conventional gas separation pipe accommodation structure.

Explanation of symbols

1: opening, 2, 12: gas separation pipe, 3, 13, 23: container, 4: joining member, 4a: lid-like joining member, 4b: annular joining member, 5: catalyst, 6, 16, 26: airtight Joint part, 10, 20: first gas separation pipe housing structure, 30: second gas separation pipe housing structure, 40, 50, 60, 70: gas separation pipe housing structure, 13a: gas separation pipe housing Part, 13b: joining member accommodating part, D ₁ : outer diameter of joining member, D ₂ : container inner diameter of gas separation pipe accommodating part, D ₃ : outer diameter of gas separation pipe, D ₄ : container inner peripheral surface and gas separation Distance of pipe outer peripheral surface, L: total length of gas separation pipe

Claims (11)

A bottomed cylindrical base material, and a bottomed cylindrical gas separation tube having a single opening, having a permselective membrane formed on at least one surface of the base material;
A container for accommodating the gas separation pipe therein;
The gas separation pipe is disposed at the opening of the gas separation pipe, and the gas separation pipe and the container are joined in an airtightly separated state from the inside and outside of the gas separation pipe. A joining member larger than the diameter,
Than the outer diameter of the joint member, towards the inside diameter of the portion accommodating at least said gas separation tube of the container is rather small,
In the container, the volume a (cm ³ ) of the gap between the outer peripheral surface of the gas separation pipe and the inner peripheral surface of the container at the portion where the gas separation pipe is disposed ,
A gas separation tube housing structure in which a ratio X (= a / b) to an area b (cm ² ) of the permselective membrane is 0.1 to 10, and the joining member is exposed to the outside of the container. A gas separation pipe housing structure, wherein the gas separation pipe housing structure is joined to the container in a closed state or is housed in a portion having an inner diameter larger than the inner diameter of the portion of the container housing the gas separation tube.   The gas separation pipe housing structure according to claim 1, wherein the joining member is made of metal or ceramics. A bottomed cylindrical base material, and a bottomed cylindrical gas separation tube having a single opening, having a permselective membrane formed on at least one surface of the base material;
A container for accommodating the gas separation pipe therein;
The gas separation pipe and the container are disposed between an outer peripheral surface near the opening of the gas separation pipe and an inner peripheral surface of the container, and the inside and the outside of the gas separation pipe are hermetically separated. An airtight joint to be joined ,
The airtight junction, the gas separation pipe inner peripheral surface disposed has been made gas separation tube receiving structure during the outer peripheral surface and the container near the opening of the.   The gas separation pipe accommodation structure according to any one of claims 1 to 3, further comprising a catalyst disposed between an outer peripheral surface of the gas separation pipe and an inner peripheral surface of the container.   The gas separation pipe accommodation structure according to any one of claims 1 to 4, wherein the base material is made of ceramics. The permselective membrane, hydrogen, oxygen, nitrogen, carbon monoxide, carbon dioxide, and any one of claims 1 to 5 which is a selectively permeable membrane at least one selected from the group consisting of steam 2. A gas separation tube housing structure according to 1. The gas separation tube housing structure according to any one of claims 1 to 5 , wherein the permselective membrane is a membrane made of palladium or a palladium alloy. The gas permeation tube housing structure according to any one of claims 1 to 5 , wherein the permselective membrane is a membrane made of zeolite. The gas permeation tube housing structure according to any one of claims 1 to 5 , wherein the permselective membrane is a membrane made of carbon. The gas permeation tube housing structure according to any one of claims 1 to 5 , wherein the permselective membrane is a membrane made of silica. The gas separation tube housing structure according to any one of claims 1 to 10 , wherein the selectively permeable membrane has a thickness of 0.05 to 10 µm.

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