Gas separation pipe and gas separation apparatus

Abstract

This invention provides a technology to improve airtightness in gas separation pipes. [Solution] The gas separation pipe is a gas separation section for separating a target gas from a mixed gas containing the target gas, and comprises a cylindrical member formed of a cylindrical ceramic having pores, a gas separation membrane disposed on the outer circumference of the cylindrical member for separating the target gas from the mixed gas, a pair of metal members disposed at each end of the cylindrical member, a through hole formed in at least one of the metal members that connects the inside and outside of the cylindrical member, a joint that joins the gas separation section and the pair of metal members, and a biasing section connected to one of the pair of metal members that applies a force to the gas separation section in a direction from one of the pair of metal members toward the other.

Description

Technical Field

[0001] The present invention relates to a gas separation tube and a gas separation device.

Background Art

[0002] Conventionally, a gas separation tube provided with a gas separation membrane has been known (for example, Patent Documents 1 to 4).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, even with the prior art such as Patent Documents 1 to 4, there is still room for improvement in the technology for improving airtightness in the gas separation tube.

[0005] An object of the present invention is to provide a technology for improving airtightness in a gas separation tube.

Means for Solving the Problems

[0006] The present invention has been made to solve at least a part of the above problems and can be realized in the following forms.

[0007] (1) According to one embodiment of the present invention, a gas separation tube is provided. The gas separation tube is a gas separation section for separating a target gas from a mixed gas containing the target gas, and comprises: a cylindrical member formed of a cylindrical ceramic having pores; a gas separation membrane disposed on the outer circumference of the cylindrical member for separating the target gas from the mixed gas; a pair of metal members disposed at each end of the cylindrical member, with at least one of the metal members having a through hole that connects the inside and outside of the cylindrical member; a joint that joins the gas separation section and the pair of metal members, respectively; and a biasing section connected to one of the pair of metal members and applying a force to the gas separation section in a direction from one of the pair of metal members toward the other.

[0008] In this configuration, a cylindrical member made of ceramic and a pair of metal members are joined by a joint, and a biasing part is connected to one of the pair of metal members, which applies force from one metal member toward the other. As a result, for example, when the gas separation tube is used in a container made of a material with a higher coefficient of thermal expansion than ceramic, even if a difference in thermal expansion occurs between the cylindrical member supporting the gas separation membrane and the container due to high temperatures, the biasing part applies force in the direction from one metal member toward the other metal member, thereby relieving the tensile stress generated in the joint and cylindrical member. Therefore, the joined state between the cylindrical member and the metal members can be maintained, and the airtightness between the inside and outside of the gas separation section can be improved.

[0009] (2) In the gas separation pipe of the above form, the biasing part may have one of a bellows, a coil spring, or a leaf spring. With this configuration, the biasing part having one of a bellows, a coil spring, or a leaf spring can apply an appropriate force to the gas separation part having a cylindrical member made of ceramic. This makes it possible to maintain the joint state between the cylindrical member and the metal member while suppressing damage to the cylindrical member, thereby improving the airtightness between the inside and outside of the gas separation part.

[0010] (3) In the gas separation pipe of the above form, the joint may be made of inorganic glass. With this configuration, the cylindrical member and the pair of metal members are joined by inorganic glass which has relatively high heat resistance. As a result, the joint between the cylindrical member and the metal members can be maintained even under high temperature conditions, and the airtightness between the inside and outside of the gas separation section can be further improved.

[0011] (4) In the gas separation pipe of the above form, the joint may include at least one of an inorganic adhesive and silver solder. With this configuration, the cylindrical member and the pair of metal members are joined by a joint that is based on inorganic glass and includes at least one of an inorganic adhesive and silver solder. The inorganic adhesive has relatively high heat resistance, and the silver solder has relatively high bonding strength. This makes it possible to further improve the airtightness between the inside and outside of the gas separation section.

[0012] (5) In the gas separation pipe of the above form, the joint may include at least one of mica, expanded carbon, and talc compaction. In this configuration, the cylindrical member and the pair of metal members are joined by a joint that is based on inorganic glass and includes at least one of mica, expanded carbon, and talc compaction. Mica has relatively high heat resistance. Expanded carbon, which expands when the temperature rises, can improve airtightness, especially in high-temperature environments. Talc compaction has relatively high heat resistance and is chemically stable. This can further improve airtightness between the inside and outside of the gas separation section.

[0013] (6) According to another embodiment of the present invention, a gas separation device is provided. This gas separation device comprises the above-described gas separation pipe, a container housing the gas separation pipe, a catalyst disposed outside the gas separation pipe inside the container and generating the target gas from a raw material gas supplied to the inside of the container, and a support part that supports the other of the pair of metal members and is fixed inside the container, wherein the biasing part is fixed inside the container. In this configuration, the other of the pair of metal members of the gas separation pipe is supported by the support part fixed inside the container. As a result, when the temperature rises due to the use of the gas separation device, a difference in thermal expansion occurs between the cylindrical member made of ceramic and the container, and tensile stress is generated in the joint and the cylindrical member. In the gas separation pipe, a compressive force is applied to the gas separation part by the biasing part in the direction from one metal member to the other metal member, so that the tensile stress on the joint and the cylindrical member is relieved. As a result, the joint state between the cylindrical member and the metal member can be maintained, and airtightness between the inside and outside of the gas separation part can be maintained.

[0014] Furthermore, the present invention can be realized in various forms, for example, as an apparatus equipped with a gas separation pipe, a method for manufacturing a gas separation pipe, a method for controlling an apparatus equipped with a gas separation pipe, or a computer program that causes the apparatus equipped with a gas separation pipe to perform the separation of a specific gas. [Brief explanation of the drawing]

[0015] [Figure 1] This is a cross-sectional view of the gas separation pipe according to the first embodiment. [Figure 2] This is a cross-sectional view of the gas separation apparatus according to the first embodiment. [Figure 3] This is a cross-sectional view of the gas separation pipe according to the second embodiment. [Figure 4] This is a cross-sectional view of the gas separation apparatus according to the second embodiment. [Figure 5] This is a cross-sectional view of the gas separation pipe according to the third embodiment. [Modes for carrying out the invention]

[0016] <First Embodiment> FIG. 1 is a cross-sectional view of the gas separation tube 1 of the first embodiment. The gas separation tube 1 is a member capable of separating a target gas from a mixed gas containing the target gas. The gas separation tube 1 of the present embodiment separates, for example, methanol and water as target gases and other gases from a mixed gas containing methanol and water. The gas separation tube 1 includes a gas separation section 10, a pair of metal members 21 and 22, joining sections 31 and 32, and a biasing section 40. Note that in FIG. 1, the size relationships of the gas separation section 10, the pair of metal members 21 and 22, the joining sections 31 and 32, and the biasing section 40 are illustrated to be different from the actual size relationships for convenience of explanation.

[0017] The gas separation section 10 is a member having a cylindrical shape. The gas separation section 10 has a cylindrical member 11 and a gas separation membrane 12. In the present embodiment, the size of the gas separation section 10 is, for example, an outer diameter of 12 mm, an inner diameter of 9 mm, and an overall length of 1200 mm.

[0018] The cylindrical member 11 is formed of a cylindrical ceramic having pores. The cylindrical member 11 of the present embodiment is formed of alumina (Al2O3) and is a ceramic porous substrate having a porosity of 40%. The cylindrical member 11 has through holes 11a inside.

[0019] The gas separation membrane 12 is disposed on the outer periphery of the cylindrical member 11. The gas separation membrane 12 of the present embodiment is disposed on the side surface 11b of the cylindrical member 11 and has a cylindrical shape. The gas separation membrane 12 of the present embodiment is a zeolite membrane having the property of permeating methanol molecules and water molecules while not permeating hydrogen molecules, carbon monoxide molecules, and carbon dioxide molecules. Thereby, the gas separation membrane 12 can separate methanol and water from a mixed gas containing methanol, water, hydrogen, carbon monoxide, and carbon dioxide.

[0020] A pair of metal members 21 and 22 are positioned at each of the pair of ends 101 and 102 of the gas separation section 10. Each of the pair of metal members 21 and 22 has a cylindrical shape. In this embodiment, the dimensions of each of the pair of metal members 21 and 22 are, for example, an outer diameter of 12 mm, an inner diameter of 10 mm, and a total length of 30 mm. Each of the pair of metal members 21 and 22 is made of SUS316. In this embodiment, each of the pair of metal members 21 and 22 has through holes 21a and 21b inside.

[0021] The joint 31 is positioned between the gas separation unit 10 and the metal member 21, and joins the gas separation unit 10 and the metal member 21. Specifically, the joint 31 joins one end 101 of the gas separation unit 10 to the other end 212 of the metal member 21. The joint 31 is based on inorganic glass and includes at least one of an inorganic adhesive and silver solder. The joint 31 in this embodiment includes inorganic glass and an inorganic adhesive. The glass transition points of the inorganic glass included in the joint 31 are 357°C and 529°C. The joint 31 may also be based on inorganic glass and include at least one of mica, expanded carbon, and talc powder.

[0022] An inner guide portion 33 and an outer guide portion 34 are positioned on the inside and outside of the joint portion 31, respectively. The inner guide portion 33 is a substantially cylindrical member positioned on the inside of the joint portion 31. One end of the inner guide portion 33 is located inside the cylindrical member 11 of the gas separation section 10 (through hole 11a), and the other end of the inner guide portion 33 is located inside the metal member 21 (through hole 21a). The inner guide portion 33 has a through hole 33a that connects the through hole 11a and the through hole 21a. The outer guide portion 34 is a substantially cylindrical member positioned on the outside of the joint portion 31. One end of the outer guide portion 34 is located outside the gas separation membrane 12 of the gas separation section 10, and the other end of the outer guide portion 34 is located outside the metal member 21. In the gas separation pipe 1 of this embodiment, the misalignment between the central axis of the gas separation section 10 and the central axis of the metal member 21 is suppressed by using the inner guide section 33 and the outer guide section 34 in combination.

[0023] The joint 32 is positioned between the gas separation unit 10 and the metal member 22, and joins the gas separation unit 10 and the metal member 22. Specifically, the joint 32 joins the other end 102 of the gas separation unit 10 to one end 221 of the metal member 22. The joint 32 is based on inorganic glass and includes at least one of mica, expanded carbon, and talc powder. The joint 32 in this embodiment includes inorganic glass and mica. The glass transition points of the inorganic glass included in the joint 32 are 357°C and 529°C. The joint 32 may also be based on inorganic glass and include at least one of an inorganic adhesive and silver solder.

[0024] An inner guide portion 35 and an outer guide portion 36 are positioned on the inside and outside of the joint portion 32, respectively. The inner guide portion 35 is a substantially cylindrical member positioned on the inside of the joint portion 32. One end of the inner guide portion 35 is located inside the cylindrical member 11 of the gas separation section 10 (through hole 11a), and the other end of the inner guide portion 35 is located inside the metal member 22 (through hole 22a). The inner guide portion 35 has a through hole 35a that connects the through hole 11a and the through hole 22a. The outer guide portion 36 is a substantially cylindrical member positioned on the outside of the joint portion 32. One end of the outer guide portion 36 is located outside the gas separation membrane 12 of the gas separation section 10, and the other end of the outer guide portion 36 is located outside the metal member 22. In the gas separation pipe 1 of this embodiment, the misalignment between the central axis of the gas separation section 10 and the central axis of the metal member 22 is suppressed by using the inner guide section 35 and the outer guide section 36 in combination.

[0025] The biasing section 40 includes a biasing member 41 and a support member 42. In this embodiment, the biasing member 41 is a bellows, with one end 411 connected to the support member 42 and the other end 412 connected to one end 211 of the metal member 21. The biasing member 41 is positioned between the metal member 21 and the support member 42 such that its length is shorter than the length in the natural state when no external force is acting. As a result, the biasing member 41 applies force to the metal member 21 in the direction from the metal member 21 to the metal member 22.

[0026] Next, the manufacturing method of the gas separation tube 1 will be described. In the manufacturing method of the gas separation tube 1, a gas separation section 10 is fabricated by generating zeolite, which will become a gas separation membrane 12, on a cylindrical member 11, and then the gas separation section 10 is joined to a pair of metal members 21 and 22 by joints 31 and 32.

[0027] In the fabrication of the gas separation unit 10, first, a clay mold for extrusion molding is prepared by mixing and kneading 100 parts by weight of alumina powder with an average particle size of 3 μm with 10 parts by mass of methylcellulose, 30 parts by mass of water, and 5 parts by mass of lubricant in a mixer. Next, a tubular molded body is produced by extruding the prepared clay molded body into a tubular shape using an extrusion molding machine. Next, the prepared tubular molded body is dried using a roller dryer in a temperature range of room temperature to 80°C to produce a dried molded body. Next, a cylindrical member 11, which is a ceramic porous substrate with a porosity of 40%, is produced by firing the dried molded body in an air atmosphere at a temperature of 1400°C to 1500°C for 3 hours.

[0028] Next, the prepared cylindrical member 11 is immersed vertically in a slurry of Na-ZSM-5 type crystals (Si / Al=11.9) (concentration 2.40 g / L) for 1 minute, then pulled out at 30 mm / s and dried (temperature: 180°C, time: 30 minutes). This immersion in the slurry and drying of the cylindrical member 11 is repeated twice to support seed crystals on the cylindrical member 11. Next, crystallization is performed using a hydrothermal synthesis method (temperature: 180°C, time: 6 hours) with raw materials (10Na2O:0.15Al2O3:36SiO2:960H2O) that have been aged at 50°C for 4 hours, and a zeolite film is formed on the cylindrical member 11. After the zeolite film is formed on the cylindrical member 11, it is washed with distilled water, air-dried, and then dried at 150°C to produce the gas separation unit 10. The dimensions of the gas separation membrane 12 in this embodiment are, for example, an outer diameter of 12 mm, an inner diameter of 9 mm, and a total length of 1200 mm.

[0029] A component comprising a joint 31 and a metal member 21 is joined to one end 101 of the fabricated gas separation unit 10, and a component comprising a joint 32 and a metal member 22 is joined to the other end 102. The joining of the gas separation unit 10 and the pair of metal members 21 and 22 by the joints 31 and 32 is performed in air at a temperature of 600°C for a heat treatment time of 30 minutes. In this embodiment, the dimensions of the joints 31 and 32 are, for example, an outer diameter of 14 mm, an inner diameter of 12 mm, and a total length of 5 mm.

[0030] After joining the gas separation section 10 to the pair of metal members 21 and 22 by the joints 31 and 32, a vacuum pump is connected to the gas separation section 10 so that the inside becomes a vacuum. The change in vacuum level is observed by measuring the vacuum level inside the gas separation section 10 after 1 hour using a vacuum pressure gauge to confirm that the airtightness inside the gas separation section 10 is maintained. After that, the biasing section 40 is attached to the metal member 21, and the biasing section 41 is compressed to a predetermined length and placed in a forced-air constant-temperature oven. A thermal cycle test is performed in which the temperature is maintained at room temperature and maintained at 365°C 20 times. After the thermal cycle test, a vacuum pump is connected to the gas separation section 10 so that the inside becomes a vacuum. The change in vacuum level is observed by measuring the vacuum level inside the gas separation section 10 after 1 hour using a vacuum pressure gauge to confirm that the airtightness inside the gas separation section 10 is maintained. This completes the gas separation pipe 1 of this embodiment.

[0031] Figure 2 is a cross-sectional view of a gas separation apparatus 100 equipped with a gas separation tube 1 according to the first embodiment. The gas separation apparatus 100 produces methanol from a raw material gas containing hydrogen, carbon monoxide, and carbon dioxide, and separates and recovers the produced methanol and the by-product water. The gas separation apparatus 100 comprises a plurality of gas separation tubes 1, a container 51 that houses the plurality of gas separation tubes 1, a catalyst 52 that produces methanol and water from the raw material gas, and a support part 53 that supports the gas separation tubes 1. For the convenience of explaining the positional relationship of each part of the gas separation apparatus 100, in the cross-sectional view of the gas separation apparatus 100 shown in Figure 2, the longitudinal direction of the gas separation apparatus 100 is defined as the x-axis, the direction in which the plurality of gas separation tubes 1 are arranged side by side and perpendicular to the x-axis is defined as the y-axis, and the direction perpendicular to the x-axis and y-axis is defined as the z-axis.

[0032] The container 51 is a container having a roughly rectangular parallelepiped shape, and houses a plurality of gas separation pipes 1, a plurality of catalysts 52, etc. The container 51 in this embodiment is made of SUS316. The container 51 has a raw material gas inlet 51a, a used gas outlet 51b, a sweep gas inlet 51c, and a generated gas outlet 51d.

[0033] As shown in Figure 2, the raw material gas inlet 51a is located on the positive side in the y-axis direction of the gas separation device 100. The raw material gas inlet 51a supplies raw material gas containing hydrogen, carbon monoxide, and carbon dioxide into the container 51 (white arrow F1 shown in Figure 2). In this embodiment, the raw material gas supplied via the raw material gas inlet 51a has a temperature of approximately 250°C and a pressure of 2 MPa to 3 MPa. The maximum temperature of the raw material gas is 400°C, and the maximum pressure of the raw material gas is 5 MPa. As shown in Figure 2, the spent gas outlet 51b is located on the negative side in the y-axis direction of the gas separation device 100. The spent gas outlet 51b discharges the spent gas from inside the container 51 after methanol and water, which are produced by the catalyst 52 (described later), have been separated by the gas separation pipe 1 (white arrow F2 shown in Figure 2). The spent gas contains unreacted hydrogen, carbon monoxide, and carbon dioxide that were not used in the production of methanol and water by the catalyst 52.

[0034] The sweep gas inlet 51c is located on the negative side in the x-axis direction of the gas separation device 100, as shown in Figure 2. The sweep gas inlet 51c supplies an inert gas such as nitrogen into the container 51 (white arrow F3 shown in Figure 2). The generated gas outlet 51d is located on the positive side in the x-axis direction of the gas separation device 100, as shown in Figure 2. The generated gas outlet 51d removes the gas (generated gas) containing methanol and water that is generated inside the container 51 from inside the container 51 (white arrow F4 shown in Figure 2).

[0035] The catalyst 52 is positioned outside each of the multiple gas separation tubes 1 inside the containment 51. In this embodiment, the catalyst 52 is formed to have a cylindrical shape and is positioned outside the gas separation membrane 12 provided by the gas separation tube 1. The catalyst 52 is, for example, a Cu / ZnO-based catalyst that generates methanol from the raw material gas supplied into the containment 51 via the raw material gas inlet 51a. The methanol generated in the catalyst 52 passes through the gas separation membrane 12 of the gas separation tube 1 and flows into the through-hole 11a of the cylindrical member 11.

[0036] The support portion 53 supports the metal member 22 of the pair of metal members 21, 22 that each of the multiple gas separation pipes 1 has. The support portion 53 has a flat plate shape, and its outer circumference is fixed to the walls 511, 512 of the container 51 around its entire circumference. As a result, the position of the metal member 22 of each of the multiple gas separation pipes 1 relative to the container 51 does not change.

[0037] In the gas separation device 100, the metal members 21 of each of the multiple gas separation pipes 1 are fixed to a flange 54 located inside the containment container 51. The outer circumference of the flange 54 is connected to the inner wall of the containment container 51 via a curved joint 55 that deforms according to the position of the flange 54. The other end 412 of a biasing member 41, which is a bellows, is connected to the positive x-axis side of the flange 54. One end 411 of the biasing member 41 is connected to the wall portion 513 of the containment container 51. The wall portion 513 is a member corresponding to the support member 42 of the gas separation pipe 1 shown in Figure 1. When the gas separation device 100 is not operating and at room temperature, the biasing member 41 is installed so as to compress, for example, 3.5 mm or more between the flange 54 and the wall portion 513 of the containment container 51. This allows the biasing member 41 to apply a force to the metal members 21 in the negative x-axis direction.

[0038] In the gas separation apparatus 100 of this embodiment, the inside of the container 51 is divided into three spaces by the support portion 53, the flange 54 and the curved joint portion 55. Specifically, as shown in Figure 2, the inside of the container 51 is divided into a space 50a that connects the raw material gas inlet 51a and the spent gas outlet 51b, a space 50b that connects to the sweep gas inlet 51c and a space 50c that connects to the generated gas outlet 51d.

[0039] Space 50a is the space located between the support portion 53, the flange 54, and the curved joint portion 55. The catalyst 52 is located in space 50a. Space 50b connects the sweep gas inlet 51c and the through-hole 22a of the metal member 22. Space 50c connects the through-hole 21a of the metal member 21 and the generated gas outlet 51d. Thus, the sweep gas inlet 51c and the generated gas outlet 51d are in communication via space 50b, the through-hole 22a of the metal member 22, the through-hole 11a of the cylindrical member 11, the through-hole 21a of the metal member 21, and space 50c. In other words, the gas separation device 100 has a cross-flow structure in which the gas flowing from the raw material gas inlet 51a to the spent gas outlet 51b via space 50a intersects with the gas flowing from the sweep gas inlet 51c to the generated gas outlet 51d via spaces 50b and 50c.

[0040] In the gas separation apparatus 100 of this embodiment, when raw material gas is supplied from the raw material gas inlet 51a, nitrogen is supplied from the sweep gas inlet 51c. When the raw material gas supplied from the raw material gas inlet 51a comes into contact with the catalyst 52, methanol and water are generated in the raw material gas. The generated methanol and water pass through the gas separation membrane 12 and the cylindrical member 11 and flow into the through hole 11a of the cylindrical member 11. The remaining raw material gas (spent gas) from which the generated methanol and water have been separated is discharged to the outside of the gas separation apparatus 100 from the spent gas outlet 51b. The methanol and water flowing into the through hole 11a of the cylindrical member 11 are pushed out into the space 50c by the nitrogen supplied from the sweep gas inlet 51c, and then removed from the gas separation apparatus 100 via the generated gas outlet 51d.

[0041] In the gas separation apparatus 100 of this embodiment, the container 51 has a thermal expansion coefficient of 16 × 10 -6 It is formed from SUS316 of type / K. On the other hand, the cylindrical member 11 that supports the gas separation membrane 12 has a thermal expansion coefficient of 7.2 × 10 -6It is formed from alumina of / K. If the length of the gas separation membrane 12 in the longitudinal direction (x-axis direction) is 1000 mm, when the gas separation device 100 is used at 400°C, the difference between the thermal expansion of the containment 51 and the thermal expansion of the cylindrical member 11 will be 3.5 mm. In the gas separation device 100, this difference in thermal expansion causes tensile stress to act on the joints 31, 32, the cylindrical member 11, and the gas separation membrane 12 supported by the cylindrical member 11, which may cause them to break. Therefore, in the gas separation device 100 of this embodiment, the biasing member 41 is compressed in advance by 3.5 mm or more so that it can absorb the difference in thermal expansion, thereby suppressing damage to the joints 31, 32, the cylindrical member 11, and the gas separation membrane 12 supported by the cylindrical member 11. This makes it possible to maintain airtightness between the inside and outside of the gas separation section 10.

[0042] The gas separation device 100 of this embodiment includes a plurality of gas separation pipes 1. When the design value for the longitudinal length of the gas separation section 10 is 1000 mm, there is a manufacturing variation of ±1 mm in the length of the gas separation section 10 provided by each of the plurality of gas separation pipes 1. Therefore, there is a maximum dimensional variation of 2 mm in the amount of shrinkage of the biasing member 41. Such dimensional variation in the biasing member 41 also causes variation in the magnitude of stress in the biasing member 41. Therefore, in the manufacturing method of the gas separation device 100 of this embodiment, the gas separation membrane 12 to be manufactured is ranked according to its actual total length. For example, the total length of the manufactured gas separation section 10 is ranked in combinations of -1.0 mm to -0.5 mm, -0.5 mm to 0 mm, 0 mm to +0.5 mm, and +0.5 mm to +1.0 mm. The metal member 21 to which the biasing section 40 connects is prepared in four types, for example, -0.75 mm, -0.25 mm, +0.25 mm, and +0.75 mm for a design dimension of 100 mm, and is joined in combination with the ranked gas separation membrane 12. This reduces variations in compressive stress applied to the joints 31 and 32.

[0043] As described above, in the gas separation pipe 1 of this embodiment, a cylindrical member 11 made of ceramic and a pair of metal members 21 and 22 are joined by joints 31 and 32, and a biasing part 40 is connected to one of the pair of metal members 21, 22, which applies force from one metal member 21 toward the other metal member 22. As a result, when the gas separation pipe 1 is used while housed in a container 51 made of SUS316, which has a higher coefficient of thermal expansion than ceramic, even if a difference in thermal expansion occurs between the cylindrical member 11 supporting the gas separation membrane 12 and the container 51 due to high temperatures, the biasing part 40 applies force in the direction from one metal member 21 toward the other metal member 22, thereby relieving the tensile stress generated in the joints 31 and 32, the cylindrical member 11, the gas separation membrane 12, etc. Therefore, the joined state between the cylindrical member 11 and the metal members 21 and 22 can be maintained, and the airtightness between the inside and outside of the gas separation section 10 can be improved.

[0044] Furthermore, according to the gas separation pipe 1 of this embodiment, since the biasing section 40 has a bellows, it can apply an appropriate force to the gas separation section 10 which has a cylindrical member 11 made of ceramic. This suppresses damage to the cylindrical member 11 while maintaining the joint state between the cylindrical member 11 and the metal members 21 and 22, thereby improving the airtightness between the inside and outside of the gas separation section 10.

[0045] Furthermore, according to the gas separation pipe 1 of this embodiment, the joints 31 and 32 are made of inorganic glass with relatively high heat resistance. As a result, the joint state between the cylindrical member 11 and the metal members 21 and 22 can be maintained even under high temperature conditions such as 400°C, thereby further improving the airtightness between the inside and outside of the gas separation section 10.

[0046] Furthermore, in the gas separation pipe 1 of this embodiment, the cylindrical member 11 and the metal member 21 are joined by a joint 31 that is based on inorganic glass and contains an inorganic adhesive. Since the inorganic adhesive has relatively high heat resistance, airtightness can be maintained between the cylindrical member 11 and the metal member 21. This further improves the airtightness between the inside and outside of the gas separation section 10.

[0047] Furthermore, in the gas separation pipe 1 of this embodiment, the cylindrical member 11 and the metal member 22 are joined by a joint 32 that includes mica, based on inorganic glass. Since mica has relatively high heat resistance, it is possible to maintain airtightness between the cylindrical member 11 and the metal member 22. This further improves the airtightness between the inside and outside of the gas separation section 10.

[0048] Furthermore, in the gas separation device 100 of this embodiment, the gas separation pipe 1 is supported by a support portion 53 fixed inside the container 51, which is the other metal member 22 of the pair of metal members 21, 22. As a result, when the temperature rises due to the use of the gas separation device 100, a difference in thermal expansion occurs between the cylindrical member 11 made of ceramic and the container 51 made of SUS316, causing tensile stress to occur in the joints 31, 32 and the cylindrical member 11. In the gas separation pipe 1, a compressive force is applied to the gas separation section 10 by the biasing portion 40 in the direction from one metal member 21 to the other metal member 22, thereby relieving the tensile stress. As a result, damage to the joints 31, 32 and the cylindrical member 11 is suppressed, and the joint state between the cylindrical member 11 and the metal members 21, 22 can be maintained, thus maintaining airtightness between the inside and outside of the gas separation section 10.

[0049] Furthermore, according to the gas separation device 100 of this embodiment, for each of the multiple gas separation pipes 1, the length of the gas separation section 10 and the length of the metal member 21 to which the biasing section 40 is connected are ranked according to the difference between the design dimensions and the actual lengths, and the gas separation section 10 and the metal member 21 are combined according to the rank. This reduces variations in compressive stress applied to the joints 31 and 32.

[0050] <Second Embodiment> Figure 3 is a cross-sectional view of the gas separation pipe 2 of the second embodiment. The gas separation pipe 2 of the second embodiment differs from the gas separation pipe 1 of the first embodiment (Figure 1) in that the through hole of the cylindrical member is sealed by one of a pair of metal members.

[0051] The gas separation pipe 2 of the second embodiment comprises a gas separation section 10, a pair of metal members 21 and 23, joint sections 31 and 32, and a biasing section 40. Note that, for the sake of explanation, the size relationships of the gas separation section 10, the pair of metal members 21 and 23, the joint sections 31 and 32, and the biasing section 40 in Figure 3 are illustrated differently from the actual size relationships.

[0052] The metal member 23 is positioned at the other end 102 of the pair of ends 101, 102 of the gas separation section 10. The metal member 23 is cylindrical and made of SUS316. The metal member 23 in this embodiment does not have a through hole. As a result, the other end 102 side of the gas separation section 10 is sealed by the metal member 23 which is joined by the joint 32.

[0053] Figure 4 is a cross-sectional view of a gas separation apparatus 200 equipped with gas separation pipes 2 according to the second embodiment. The gas separation apparatus 200 produces methanol and water from a raw material gas containing hydrogen, carbon monoxide, and carbon dioxide, and separates and recovers the produced methanol and water. The gas separation apparatus 200 comprises a plurality of gas separation pipes 2, a container 61 that houses the plurality of gas separation pipes 2, and a catalyst 52 that produces methanol and water from the raw material gas. That is, unlike the gas separation apparatus 100 of the first embodiment, the gas separation apparatus 200 of the second embodiment does not have a support part that supports the gas separation pipes. Note that, for the convenience of explaining the positional relationship of each part of the gas separation apparatus 200, in the cross-sectional view of the gas separation apparatus 200 shown in Figure 4, the longitudinal direction of the gas separation apparatus 200 is defined as the x-axis direction, the direction in which the plurality of gas separation pipes 2 are arranged side by side and perpendicular to the x-axis is defined as the y-axis direction, and the direction perpendicular to the x-axis and y-axis is defined as the z-axis.

[0054] The container 61 is a container having a roughly rectangular parallelepiped shape, and houses a plurality of gas separation pipes 2, a plurality of catalysts 52, etc. The container 61 in this embodiment is made of SUS316. The container 61 has a raw material gas inlet 51a, a used gas outlet 51b, and a generated gas outlet 51d.

[0055] In the gas separation apparatus 200 of the second embodiment, the metal members 23 provided on the multiple gas separation pipes 2 are fixed to the wall portion 611 connected to the containment 61, as shown in Figure 4. As a result, the position of the metal members 23 of each of the multiple gas separation pipes 2 relative to the containment 61 does not change. The wall portion 611 corresponds to the "support portion" in the claims.

[0056] In the gas separation apparatus 200 of this embodiment, the interior of the container 61 is partitioned by a flange 54 and a curved joint 55. Specifically, as shown in Figure 4, the interior of the container 61 is partitioned into a space 60a that connects the raw material gas inlet 51a and the spent gas outlet 51b, and a space 60b that connects to the generated gas outlet 51d. The catalyst 52 is arranged in space 60a. Space 60b is connected to the through hole 11a of the cylindrical member 11 via a through hole 21a of the metal member 21.

[0057] In the gas separation apparatus 200 of this embodiment, when the raw material gas supplied from the raw material gas inlet 51a comes into contact with the catalyst 52, methanol and water are generated in the raw material gas. The generated methanol and water pass through the gas separation membrane 12 and the cylindrical member 11 and flow into the through-hole 11a of the cylindrical member 11. The remaining raw material gas (spent gas) from which the generated methanol and water have been separated is discharged to the outside of the gas separation apparatus 200 from the spent gas outlet 51b. The methanol flowing into the through-hole 11a of the cylindrical member 11 is removed from the gas separation apparatus 200 via the through-hole 21a of the metal member 21, the space 60b, and the generated gas outlet 51d.

[0058] As described above, in the gas separation pipe 2 of this embodiment, a cylindrical member 11 made of ceramic and a pair of metal members 21 and 23 are joined by joints 31 and 32, and a biasing part 40 that applies force from one metal member 21 toward the other metal member 22 is connected to one metal member 21. As a result, even if a difference in thermal expansion occurs between the cylindrical member 11 supporting the gas separation membrane 12 and the container 61, the biasing part 40 applies force in the direction from one metal member 21 toward the other metal member 23, thereby maintaining the joined state between the cylindrical member 11 and the metal members 21 and 23. Therefore, the airtightness between the inside and outside of the gas separation section 10 can be improved.

[0059] <Third Embodiment> Figure 5 is a cross-sectional view of the gas separation pipe 3 of the third embodiment. Compared to the gas separation pipe 1 of the first embodiment (Figure 1), the gas separation pipe 3 of the third embodiment differs in the type of biasing member and the shape of the metal member to which the biasing member is connected.

[0060] The gas separation pipe 3 of the third embodiment comprises a gas separation section 10, a pair of metal members 22 and 24, joint sections 31 and 32, and a biasing section 70. Note that, for the sake of explanation, the size relationships of the gas separation section 10, the pair of metal members 22 and 24, the joint sections 31 and 32, and the biasing section 70 in Figure 5 are illustrated differently from the actual size relationships.

[0061] The metal member 24 is positioned at one of the pair of ends 101 and 102 of the gas separation section 10, specifically at end 102. The metal member 24 is cylindrical and made of SUS316 stainless steel. The metal member 24 in this embodiment does not have a through hole. As a result, one end 101 of the gas separation section 10 is sealed by the metal member 24, which is joined by the joint 31.

[0062] The biasing section 70 includes a biasing member 71 and a support member 42. In this embodiment, the biasing member 71 is a coil spring, with one end 711 connected to the support member 42 and the other end 712 connected to one end 241 of the metal member 24. The biasing member 71 is positioned between the metal member 24 and the support member 42 such that its length is shorter than the length in its natural state when no external force is acting on it. As a result, the biasing member 71 applies force to the metal member 24 in the direction from the metal member 24 towards the metal member 22.

[0063] As described above, in the gas separation pipe 3 of this embodiment, a cylindrical member 11 made of ceramic and a pair of metal members 22 and 24 are joined by joints 32 and 31, and a biasing part 70 that applies force from one metal member 24 toward the other metal member 22 is connected to one metal member 24. As a result, even if a difference in thermal expansion occurs between the cylindrical member 11 that supports the gas separation membrane 12 and the container that houses the gas separation pipe 3, the biasing part 70 applies force in the direction from one metal member 24 toward the other metal member 22, thereby maintaining the joined state between the cylindrical member 11 and the metal members 22 and 24. Therefore, the airtightness between the inside and outside of the gas separation section 10 can be improved.

[0064] Furthermore, according to the gas separation pipe 3 of this embodiment, since the biasing part 70 has a coil spring, it can apply an appropriate force to the gas separation part 10 which has a cylindrical member 11 made of ceramic. This prevents the cylindrical member 11 from being damaged by the force applied to the biasing part 70.

[0065] <Modified form of this embodiment> The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit, for example, the following modifications are also possible.

[0066] [Example 1] In the above-described embodiment, the gas separation membrane 12 was assumed to be a zeolite membrane that allows methanol molecules and water molecules to pass through, but does not allow hydrogen molecules, carbon monoxide molecules, and carbon dioxide molecules to pass through. The properties of the gas separation membrane are not limited to this.

[0067] [Differentiation 2] In the embodiments described above, the biasing member that applies force from one of a pair of metal members toward the other is a bellows or a coil spring. For example, in the third embodiment, the biasing member 71 of the biasing member 70 may be a leaf spring instead of a coil spring. The biasing member can be any member that can apply a force to a cylindrical member made of cylindrical ceramic that does not damage the cylindrical member.

[0068] [Difference 3] In the embodiments described above, joint 31 is said to include inorganic glass and an inorganic adhesive, and joint 32 is said to include inorganic glass and mica. The materials forming the joint are not limited to these. Based on inorganic glass, it may include at least one of an inorganic adhesive and silver solder, or at least one of mica, expanded carbon, and talc powder. The joint does not necessarily have to contain inorganic glass, but it is desirable that it be made of a heat-resistant material. Furthermore, based on inorganic glass, the joint may contain only an inorganic adhesive, only silver solder, or both an inorganic adhesive and silver solder. Also, based on inorganic glass, the joint may contain at least one of mica, expanded carbon, and talc powder, or it may contain all of mica, expanded carbon, and talc powder. Furthermore, joint 31 and joint 32 may be formed from the same material, for example, inorganic glass.

[0069] [Differentiation Example 4] In the above-described embodiment, the gas separation device is provided with a catalyst. However, the catalyst may not be necessary, and the gas separation device may simply separate the target gas from the mixed gas supplied to the container.

[0070] The embodiments of this specification have been described above based on the embodiments and modifications described above. The embodiments described above are for the purpose of facilitating understanding of this specification and do not limit it. This specification may be modified and improved without departing from its spirit and the scope of the claims, and equivalents thereof are included in this specification. Furthermore, any technical features that are not described as essential in this specification may be deleted as appropriate.

[0071] <Application Example 1> It is a gas separation pipe, A gas separation unit for separating a target gas from a mixed gas containing the target gas, comprising: a cylindrical member formed of a tubular ceramic having pores; and a gas separation membrane disposed on the outer circumference of the cylindrical member for separating the target gas from the mixed gas; A pair of metal members arranged at each end of the cylindrical member, the pair of metal members having a through hole formed in at least one of them that connects the inside and outside of the cylindrical member, A joint that connects the gas separation section and the pair of metal members, The device is characterized by comprising a biasing unit connected to one of the pair of metal members, which applies a force to the gas separation unit in a direction from one of the pair of metal members toward the other, Gas separation pipe. <Application Example 2> The gas separation pipe described in Application Example 1, The biasing portion is characterized by having one of the following: a bellows, a coil spring, or a leaf spring. Gas separation pipe. <Application Example 3> A gas separation pipe as described in Application Example 1 or Application Example 2, The aforementioned joint is characterized by being made of inorganic glass. Gas separation pipe. <Application Example 4> A gas separation pipe described in any one of the examples from Application Example 1 to Application Example 3, The joint is characterized by comprising at least one of an inorganic adhesive and silver solder. Gas separation pipe. <Application Example 5> A gas separation pipe described in any one of the examples from Application Example 1 to Application Example 4, The joint is characterized by containing at least one of mica, expanded carbon, and talc powder. Gas separation pipe. <Application Example 6> A gas separation device, A gas separation pipe described in any one of Application Examples 1 to 5, A container for housing the aforementioned gas separation pipe, A catalyst is located inside the containment and outside the gas separation pipe, and generates the target gas from the raw material gas supplied inside the containment. The container comprises a support portion that supports the other of the pair of metal members and is fixed inside the container, The biasing portion is characterized by being fixed inside the housing. Gas separation device. [Explanation of symbols]

[0072] 1, 2, 3... Gas separation pipes 10...Gas separation section 11…Cylindrical member 12…Gas separation membrane 21, 22, 23, 24… Metal components 21a, 22a...Through hole 31,32...Joint part 40, 70… biased part 51, 61… containment containers 52…Catalyst 53...Support part 513,611…Wall part 100,200... Gas separation equipment

Claims

1. It is a gas separation pipe, A gas separation unit for separating a target gas from a mixed gas containing the target gas, comprising: a cylindrical member formed of a tubular ceramic having pores; and a gas separation membrane disposed on the outer circumference of the cylindrical member for separating the target gas from the mixed gas; A pair of metal members arranged at each end of the cylindrical member, the pair of metal members having a through hole formed in at least one of them that connects the inside and outside of the cylindrical member, A joint that connects the gas separation section and the pair of metal members, The device is characterized by comprising a biasing unit connected to one of the pair of metal members, which applies a force to the gas separation unit in a direction from one of the pair of metal members toward the other, Gas separation pipe.

2. A gas separation pipe according to claim 1, The biasing portion is characterized by having one of the following: a bellows, a coil spring, or a leaf spring. Gas separation pipe.

3. A gas separation pipe according to claim 1 or claim 2, The aforementioned joint is characterized by being made of inorganic glass. Gas separation pipe.

4. A gas separation pipe according to claim 3, The joint is characterized by comprising at least one of an inorganic adhesive and silver solder. Gas separation pipe.

5. A gas separation pipe according to claim 3, The joint is characterized by containing at least one of mica, expanded carbon, and talc powder. Gas separation pipe.

6. A gas separation device, A gas separation pipe according to claim 1 or claim 2, A container for housing the aforementioned gas separation pipe, A catalyst is located inside the containment and outside the gas separation pipe, and generates the target gas from the raw material gas supplied inside the containment. The container comprises a support portion that supports the other of the pair of metal members and is fixed inside the container, The biasing portion is characterized by being fixed inside the housing. Gas separation device.

Images