阅读说明：本技术 支撑体、沸石膜复合体、沸石膜复合体的制造方法以及分离方法 (Support, zeolite membrane composite, method for producing zeolite membrane composite, and separation method ) 是由 野田宪一 于 2019-08-02 设计创作，主要内容包括：用于支撑沸石膜(12)的多孔质的圆筒状的支撑体(11)具备：以在长度方向上延伸的中心轴(J1)为中心的大致圆筒面状的内侧面(113)、以及将内侧面(113)的周围包围的大致圆筒面状的外侧面(112)。在外侧面(112)形成有沸石膜(12)。作为内侧面(113)与外侧面(112)之间的径向上的距离的支撑体厚度在周向上的最大值A及最小值B在支撑体(11)的长度方向上的至少一部分满足“(A－B)/(A+B)≤0.3”。支撑体(11)中,通过抑制支撑体厚度的偏差,能够提高在支撑体(11)上所形成的沸石膜(12)的膜厚均匀性。(A porous cylindrical support (11) for supporting a zeolite membrane (12) is provided with: the device comprises a substantially cylindrical inner surface (113) having a center axis (J1) extending in the longitudinal direction as the center, and a substantially cylindrical outer surface (112) surrounding the inner surface (113). A zeolite membrane (12) is formed on the outer surface (112). At least a part of a maximum value A and a minimum value B of the thickness of the support body, which is a distance in the radial direction between the inner side surface (113) and the outer side surface (112), in the circumferential direction of the support body (11) satisfies "(A-B)/(A + B) ≦ 0.3". In the support (11), the uniformity of the thickness of the zeolite membrane (12) formed on the support (11) can be improved by suppressing variations in the thickness of the support.)

1. A porous cylindrical support for supporting a zeolite membrane,

the support is characterized by comprising:

an inner surface of a substantially cylindrical surface, the inner surface being centered on a central axis extending in a longitudinal direction; and

an outer surface of a substantially cylindrical surface surrounding the inner surface,

at least a part of the maximum value A and the minimum value B of the support body thickness in the circumferential direction, which is the distance in the radial direction between the inner side surface and the outer side surface, satisfies (A-B)/(A + B) of not more than 0.3 in the longitudinal direction.

2. The support body according to claim 1,

the total length in the length direction, the maximum value A and the minimum value B satisfy (A-B)/(A + B) ≦ 0.3.

3. The support body according to claim 1 or 2,

at least a part of the maximum value A and the minimum value B in the length direction satisfies (A-B)/(A + B) ≦ 0.2.

4. The support body according to any one of claims 1 to 3,

the average radius X and the roundness Y of the inner side surface at the at least one portion in the longitudinal direction satisfy Y/X ≦ 0.5.

5. The support body according to any one of claims 1 to 4,

the support body is formed of a ceramic sintered body.

6. A zeolite membrane composite comprising:

the support of any one of claims 1 to 5; and

a zeolite membrane formed on the support.

7. The zeolite membrane complex according to claim 6,

the maximum number of rings of the zeolite constituting the zeolite membrane is 8 or less.

8. The zeolite membrane complex according to claim 6 or 7,

the thickness of the zeolite membrane is 1 [ mu ] m or less.

9. A method for producing a zeolite membrane composite, comprising:

a) a step of preparing a seed crystal,

b) A step of attaching the seed crystal to the support according to any one of claims 1 to 5, and

c) and a step of forming a zeolite membrane on the support by growing zeolite from the seed crystal by hydrothermal synthesis.

10. A separation method, comprising:

d) a process for preparing the zeolite membrane composite according to any one of claims 6 to 8, and

e) and a step of supplying a mixed substance containing a plurality of gases or liquids to the zeolite membrane complex, and separating a substance having a high permeability out of the mixed substance from the mixed substance by allowing the substance to permeate the zeolite membrane complex.

11. The separation method according to claim 10,

the mixed substance contains 1 or more of hydrogen, helium, nitrogen, oxygen, water vapor, carbon monoxide, carbon dioxide, nitrogen oxide, ammonia, sulfur oxide, hydrogen sulfide, sulfur fluoride, mercury, arsine, hydrogen cyanide, carbonyl sulfide, C1-C8 hydrocarbon, organic acid, alcohol, thiol, ester, ether, ketone, and aldehyde.

Technical Field

The present invention relates to a support for supporting a zeolite membrane, a zeolite membrane complex provided with the support, a method for producing the zeolite membrane complex, and a method for separating a mixed substance using the zeolite membrane complex.

Background

Conventionally, various studies and developments have been made on the use of zeolite in molecular separation, molecular adsorption, and the like, which utilize the molecular sieving action of zeolite, by forming a zeolite membrane on a porous support to prepare a zeolite membrane composite.

For example, japanese patent application laid-open No. 9-71481 (document 1) discloses a ceramic support used as a support for a zeolite membrane. In addition, japanese patent laid-open publication No. 2012-66241 (document 2) and international publication No. 2007/105407 (document 3) disclose a zeolite membrane composite in which a zeolite membrane is formed on the outer surface of a cylindrical ceramic support by hydrothermal synthesis.

However, a cylindrical ceramic support (hereinafter, simply referred to as "support") is generally manufactured by extrusion molding and surface polishing. Specifically, first, a clay prepared by kneading predetermined raw materials is supplied to a die, and extruded from the die while being molded into a cylindrical shape. Next, the substantially cylindrical molded body extruded from the die is fired, and then the outer surface of the fired body is polished so that the cross-sectional shape of the outer surface becomes substantially perfect circle, thereby forming the support body.

In the production of the cylindrical support body, there is a possibility that the thickness of the support body in the radial direction may vary in the circumferential direction due to variations in the feed rate of the clay to the mold. Further, the thickness variation in the radial direction of the support may be caused by variation in the polishing amount during polishing of the outer surface. Specifically, when the material is extruded from the die, the cylindrical molded body spreads laterally due to gravity, and the cross-sectional shapes of the outer surface and the inner surface may be substantially elliptical in the lateral direction. In this case, the polishing amount on the side of the support is made larger than the polishing amounts on the upper and lower sides so that the cross-sectional shape of the outer side surface is close to a perfect circle. As a result, the thickness of the side of the support becomes thinner than the thickness of the upper and lower portions.

If a zeolite membrane is formed on the cylindrical support having the above-described variation in thickness, the variation in the amount of application per unit area becomes large when the seed crystal is applied to the surface of the support, and the uniformity of the membrane thickness of the zeolite membrane is reduced. Therefore, it is difficult to form a dense and thin zeolite membrane with good yield. However, no consideration has been made from the viewpoint of the extent to which variations in the thickness of the support must be suppressed in order to form a dense and thin zeolite membrane.

Disclosure of Invention

The present invention relates to a porous cylindrical support for supporting a zeolite membrane. A support according to a preferred embodiment of the present invention includes: an inner surface of a substantially cylindrical surface shape having a central axis extending in a longitudinal direction as a center; and an outer surface of a substantially cylindrical surface surrounding the periphery of the inner surface. At least a part of the maximum value A and the minimum value B of the support body thickness in the circumferential direction, which is the distance in the radial direction between the inner side surface and the outer side surface, satisfies (A-B)/(A + B) of not more than 0.3 in the longitudinal direction. This can improve the uniformity of the zeolite membrane thickness.

Preferably, the maximum value A and the minimum value B satisfy (A-B)/(A + B) ≦ 0.3 for the entire length in the longitudinal direction.

Preferably, at least a part of the maximum value A and the minimum value B in the longitudinal direction satisfies (A-B)/(A + B) ≦ 0.2.

Preferably, the average radius X and the roundness Y of the inner side surface at the at least one portion in the longitudinal direction satisfy Y/X ≦ 0.5.

Preferably, the support is formed of a ceramic sintered body.

The invention also relates to zeolite membrane composites. A zeolite membrane composite according to a preferred embodiment of the present invention includes: the support and the zeolite membrane formed on the support.

Preferably, the maximum number of rings of the zeolite constituting the zeolite membrane is 8 or less.

Preferably, the thickness of the zeolite membrane is 1 μm or less.

The present invention also relates to a method for producing the zeolite membrane composite. A method for producing a zeolite membrane complex according to a preferred embodiment of the present invention includes: a) a step of preparing seed crystals, b) a step of attaching the seed crystals to the support according to any one of the first to fifth embodiments, and c) a step of forming a zeolite membrane on the support by starting zeolite growth from the seed crystals by hydrothermal synthesis.

The invention also relates to a separation method. A separation method according to a preferred embodiment of the present invention includes: d) a step of preparing the zeolite membrane composite according to any one of the sixth to eighth aspects, and e) a step of supplying a mixed substance containing a plurality of gases or liquids to the zeolite membrane composite, and separating a substance having a high permeability among the mixed substance from the mixed substance by allowing the substance to permeate the zeolite membrane composite.

Preferably, the mixed substance contains 1 or more species selected from the group consisting of hydrogen, helium, nitrogen, oxygen, water vapor, carbon monoxide, carbon dioxide, nitrogen oxide, ammonia, sulfur oxide, hydrogen sulfide, sulfur fluoride, mercury, arsine, hydrogen cyanide, carbonyl sulfide, hydrocarbons of C1 to C8, organic acids, alcohols, thiols, esters, ethers, ketones, and aldehydes.

The above and other objects, features, aspects and advantages will become apparent from the following detailed description of the present invention with reference to the accompanying drawings.

Drawings

Fig. 1 is a cross-sectional view of a zeolite membrane composite.

Fig. 2 is an enlarged cross-sectional view of the zeolite membrane composite.

Fig. 3 is a cross-sectional view of the support body.

Fig. 4 is a diagram showing a production flow of the zeolite membrane composite.

Fig. 5 is a diagram showing a zeolite membrane complex in the production process.

Fig. 6 is a diagram showing the separation device.

Fig. 7 is a diagram showing a flow of separation of mixed substances.

Detailed Description

Fig. 1 is a cross-sectional view of a zeolite membrane composite 1. Fig. 2 is an enlarged cross-sectional view of a part of the zeolite membrane composite 1. The zeolite membrane composite 1 includes: a porous support 11, and a zeolite membrane 12 formed on the support 11. In fig. 1, the zeolite membrane 12 is drawn with a thick line. In fig. 2, the zeolite membrane 12 is marked with parallel oblique lines. In fig. 2, the thickness of the zeolite membrane 12 is drawn to be thicker than the actual thickness.

The support 11 is a cylindrical member. The support 11 is a porous member that is permeable to gas and liquid. The support 11 includes: a substantially cylindrical inner surface 113 centered on a central axis J1 extending in the longitudinal direction (i.e., the left-right direction in fig. 1), and a substantially cylindrical outer surface 112 surrounding the periphery of the inner surface 113. The center axis J1 is: a central axis of an imaginary cylinder arranged to be circumscribed with the inner side surface 113. In a radial direction (hereinafter, also simply referred to as "radial direction") centered on the central axis J1, the outer side surface 112 is positioned outside the inner side surface 113 and surrounds the inner side surface 113. Zeolite membrane 12 is formed on outer side 112. The zeolite membrane 12 covers substantially the entire outer surface 112 of the support 11. In the following description, a substantially cylindrical space radially inside the inner surface 113 is referred to as an "inner flow path 111".

The length of the support 11 (i.e., the length in the left-right direction in fig. 1) is, for example, 10cm to 200 cm. The outer diameter of the support 11 is, for example, 0.5cm to 30 cm. The distance in the radial direction between the inner surface 113 and the outer surface 112 of the support 11 (hereinafter also referred to as "support thickness") is, for example, 0.1mm to 10 mm. The surface roughness (Ra) of the support 11 is, for example, 0.1 to 5.0. mu.m, preferably 0.2 to 2.0. mu.m.

The material of the support 11 may be chemically stable in the step of forming the zeolite membrane 12 on the surface, and various materials (for example, ceramics or metals) may be used. In the present embodiment, the support 11 is formed of a ceramic sintered body. Examples of the ceramic sintered body selected as the material of the support 11 include: alumina, silica, mullite, zirconia, titania, yttria, silicon nitride, silicon carbide, and the like. In the present embodiment, the support 11 contains at least 1 kind of alumina, silica, and mullite.

The support 11 may contain an inorganic binder material. As the inorganic binder, at least 1 kind of titania, mullite, easily sinterable alumina, silica, glass frit, clay mineral, and easily sinterable cordierite can be used.

The average pore diameter of the support 11 in the vicinity of the surface on which the zeolite membrane 12 is to be formed is preferably smaller than the average pore diameter of the other portions of the support 11. In order to realize such a structure, the support body 11 has a multilayer structure. When the support 11 has a multilayer structure, the materials of the respective layers may be the same as or different from each other. The average pore diameter of the support 11 can be measured by a mercury porosimeter, a pore diameter distribution measuring instrument, a nanometer-size pore diameter distribution measuring instrument, or the like.

The average pore diameter of the support 11 is, for example, 0.01 to 70 μm, preferably 0.05 to 25 μm. Regarding the pore diameter distribution of the support 11 in the vicinity of the surface of the zeolite membrane 12 to be formed, D5 is, for example, 0.01 to 50 μm, D50 is, for example, 0.05 to 70 μm, and D95 is, for example, 0.1 to 2000 μm. The porosity of the support 11 in the vicinity of the surface on which the zeolite membrane 12 is to be formed is, for example, 25% to 50%.

Fig. 3 is a view showing a cross section perpendicular to the longitudinal direction of the support body 11 (i.e., a cross section perpendicular to the central axis J1). In fig. 3, a position where the distance in the radial direction between the inner surface 113 and the outer surface 112 of the support 11 is the largest in the circumferential direction is indicated by an arrow, and the support thickness at this position is set to the maximum value a of the support thickness. The position where the distance in the radial direction between the inner surface 113 and the outer surface 112 of the support 11 is smallest in the circumferential direction is indicated by an arrow, and the support thickness at this position is set to the minimum support thickness B.

In the support body 11, the maximum value A and the minimum value B of the thickness of the support body in a cross section perpendicular to the central axis J1 satisfy "(A-B)/(A + B) ≦ 0.3". In other words, at least a part of the support 11 in the longitudinal direction satisfies the relationship between the maximum value a and the minimum value B. Preferably, the entire length of the support 11 in the longitudinal direction (i.e., each cross section in the longitudinal direction) satisfies the relationship between the maximum value a and the minimum value B.

Preferably, the maximum value A and the minimum value B of the thickness of the support body satisfy "(A-B)/(A + B) ≦ 0.2" for at least a part of the longitudinal direction of the support body 11. More preferably, the relationship between the maximum value a and the minimum value B of the support thickness is satisfied over the entire length of the support 11 in the longitudinal direction (i.e., each cross section in the longitudinal direction).

In the support 11, the average radius X and the roundness Y of the inner surface 113 in the one cross section perpendicular to the central axis J1 satisfy "Y/X is 0.5 or less". In other words, at least a part of the support 11 in the longitudinal direction satisfies the relationship between the average radius X and the roundness Y. Preferably, the entire length of the support 11 in the longitudinal direction (i.e., each cross section in the longitudinal direction) satisfies the relationship between the average radius X and the roundness Y. The average radius X in a cross section of the support body 11 is the arithmetic mean of the maximum radius and the minimum radius in the cross section. The roundness Y was determined in accordance with JIS-B-0621. Specifically, in this cross section, a substantially circular shape (i.e., a circular shape) as the inner surface 113 is sandwiched by 2 concentric geometric circles, and the difference in the radii of the 2 geometric circles when the interval between the 2 geometric circles is the smallest is taken as the roundness Y.

The zeolite membrane 12 is a porous membrane having fine pores. The zeolite membrane 12 can be used as a separation membrane for separating a specific substance from a mixture substance in which a plurality of substances are mixed by the action of a molecular sieve. In the zeolite membrane 12, other substances are less permeable than the specific substance. In other words, the permeation rate of the other substance in the zeolite membrane 12 is lower than the permeation rate of the specific substance.

The thickness of the zeolite membrane 12 is, for example, 0.05 to 30 μm, preferably 0.1 to 20 μm, and more preferably 0.5 to 10 μm. The film thickness of the zeolite film 12 is: the minimum value of the distance from the surface of the support 11 to the surface of the zeolite membrane 12 (i.e., the minimum film thickness) in the entire zeolite membrane 12 excluding the defective portion. The same applies to the following description. In the present embodiment, the thickness of the zeolite membrane 12 is 1 μm or less. The average film thickness of the zeolite film 12 is preferably 5 μm or less, more preferably 3 μm or less, and still more preferably 2 μm or less. If the zeolite membrane 12 is made thicker, the separation performance is improved. If the zeolite membrane 12 is made thin, the transmission rate increases. The surface roughness (Ra) of the zeolite membrane 12 is, for example, 5 μm or less, preferably 2 μm or less, more preferably 1 μm or less, and still more preferably 0.5 μm or less.

As the zeolite constituting the zeolite membrane 12, an oxygen Tetrahedron (TO) located in the constituting zeolite can be used₄) Zeolite having only Si as the central atom (T atom) in (b), zeolite having Si and Al as the T atom, AlPO type zeolite having Al and P as the T atom, SAPO type zeolite having Si, Al and P as the T atom, MAPSO type zeolite having magnesium (Mg), Si, Al and P as the T atom, and ZnAPSO type zeolite having zinc (Zn), Si, Al and P as the T atom. Part of the T atoms may be replaced with other elements.

When the maximum number of rings of the zeolite constituting the separation membrane 12 is n, the average pore diameter is defined as the arithmetic mean of the minor axis and the major axis of the pores of the n-membered ring. The n-membered ring pores are: and n pores in which the number of oxygen atoms in the portion in which the oxygen atom is bonded to the T atom to form a ring structure is n. When the zeolite has a plurality of n-membered ring pores having the same number n, the average pore diameter of the zeolite is defined as the arithmetic average of the minor diameter and the major diameter of all the n-membered ring pores. As described above, the average pore diameter of the Zeolite membrane is uniquely determined by the framework structure of the Zeolite, and can be determined by the international Zeolite society, "Database of Zeolite Structures" [ online ], website address < URL: http: the average pore size was determined from the values disclosed in I/w w.iza-structure.org/databases/.

The average pore diameter of the zeolite membrane 12 is preferably 0.2nm or more and 0.8nm or less, more preferably 0.3nm or more and 0.6nm or less, and still more preferably 0.3nm or more and 0.5nm or less. The average pore diameter of the zeolite membrane 12 is smaller than the average pore diameter of the support 11 in the vicinity of the surface where the zeolite membrane 12 is to be formed.

The type of zeolite constituting the zeolite membrane 12 is not particularly limited, and the CO can be increased₂The maximum number of rings of the zeolite is preferably 8 or less (for example, 6 or 8) from the viewpoint of the permeability of (b) and the improvement of the separation performance. The zeolite membrane 12 is, for example, a DDR type zeolite. In other words, the zeolite membrane 12 is a zeolite membrane composed of a zeolite having a structure coded as "DDR" as specified by the international zeolite society. In this case, the inherent pore diameter of the zeolite constituting the zeolite membrane 12 is 0.36nm × 0.44nm, and the average pore diameter is 0.40 nm.

The zeolite membrane 12 may be, for example, a zeolite membrane of AEI type, AEN type, AFN type, AFV type, AFX type, BEA type, CHA type, ERI type, ETL type, FAU type (X type, Y type), GIS type, LEV type, LTA type, MEL type, MFI type, MOR type, PAU type, RHO type, SAT type, SOD type, or the like.

The zeolite membrane 12 contains, for example, silicon (Si). The zeolite membrane 12 may contain, for example, any 2 or more of Si, aluminum (Al), and phosphorus (P). The zeolite membrane 12 may comprise an alkali metal. The alkali metal is, for example, sodium (Na) or potassium (K). When the zeolite membrane 12 contains Si atoms, the Si/Al ratio in the zeolite membrane 12 is, for example, 1 to 10 ten thousand. The Si/Al ratio is preferably 5 or more, more preferably 20 or more, and further preferably 100 or more, and the higher the Si/Al ratio is, the more preferable the Si/Al ratio is. The Si/Al ratio in the zeolite membrane 12 can be adjusted by adjusting the mixing ratio of the Si source and the Al source in the raw material solution described later, and the like.

Next, an example of the production flow of the zeolite membrane composite 1 will be described with reference to fig. 4. In order to produce the zeolite membrane composite 1, first, the support 11 is formed (step S11). Specifically, first, ceramic particles, an inorganic binder, water, a dispersant, and a thickener are kneaded to prepare a clay as a raw material of the support 11. Next, the clay is extrusion-molded to form a substantially cylindrical molded body. Next, the molded article is fired to obtain a substantially cylindrical fired body. Then, the outer surface of the fired body is polished to form a support member. Then, an intermediate layer, which is a ceramic porous membrane having a smaller pore diameter than the support member, is formed on the outer surface of the support member, and a surface layer, which is a ceramic porous membrane having a smaller pore diameter, is further formed on the intermediate layer, thereby forming the support 11 having a multilayer structure.

In the above-described clay preparation, for example, 0.1 to 50 parts by mass (20 parts by mass in the present embodiment) of an inorganic binder is added to 100 parts by mass of ceramic particles (alumina particles in the present embodiment). The average particle diameter of the alumina particles is, for example, 1 to 200 μm, and in the present embodiment, 50 μm. The firing temperature of the above-mentioned molded article is, for example, 1000 ℃ to 1800 ℃ and 1250 ℃ in the present embodiment. The firing time of the above-mentioned molded article is, for example, 0.1 to 100 hours, and in the present embodiment, 1 hour.

The polishing of the outer surface of the sintered body is performed by a belt centerless method using a fixed grindstone abrasive grain including diamond fixed abrasive grains, for example, using a belt grinder. The polishing method in the polishing process and the type of the polishing machine used in the polishing process may be variously changed. The intermediate layer and the surface layer are, for example, porous alumina membranes having a thickness of several micrometers to several hundred micrometers. The intermediate layer and the surface layer are formed by, for example, a filtration film formation method. The intermediate layer and the surface layer may be formed by other methods. The average pore diameter of the intermediate layer is, for example, 0.1 to 10 μm, and in the present embodiment, 0.5. mu.m. The average pore diameter of the surface layer is, for example, 0.01 to 5 μm, and in the present embodiment, 0.1. mu.m.

Next, seed crystals for producing the zeolite membrane 12 are prepared (step S12). For example, a powder of DDR type zeolite is produced by hydrothermal synthesis, and seed crystals are obtained from the zeolite powder. The zeolite powder may be used as a seed crystal as it is, or the powder may be processed by grinding or the like to obtain a seed crystal. Step S12 may be performed simultaneously with step S11, or may be performed before step S11.

Next, the seed crystal is attached to the outer surface 112 of the support 11 (step S13). In step S13, for example, the seed crystal is attached to the support 11 by filtration. Specifically, first, the lower end opening of the support body 11 standing with the central axis J1 parallel to the vertical direction is liquid-tightly sealed, and the substantially cylindrical opening member 83 made of a liquid-tight material is attached to the upper end opening in a liquid-tight manner. Next, as shown in fig. 5, the support 11 is inserted from the lower end side (i.e., the side to which the sealing member 82 is attached) into the storage tank 80 in which the seed crystal dispersed solution 81 is stored, and immersed in the solution 81. The upper end opening of the opening member 83 attached to the upper end of the support 11 is positioned above the liquid surface of the solution 81, and the outer surface 112 of the support 11 is positioned in the solution 81. Thus, the solvent of the solution 81 passes through the support 11 from the outer surface 112 of the support 11 and moves to the inner flow path 111 as indicated by the arrows facing the left and right directions in fig. 5. On the other hand, the seed crystal in the solution 81 does not penetrate the support 11 but remains on the outer surface 112 of the support 11, and adheres to the outer surface 112. Thus, a support having the seed crystal attached thereto was produced.

After step S13 is completed, the support 11 with the seed crystal attached is pulled up from the solution 81 and dried. The dried support 11 to which the seed crystal is attached is immersed in the raw material solution. The raw material solution is prepared by dissolving and dispersing, for example, an Si source and a Structure-Directing Agent (hereinafter also referred to as "SDA") in a solvent. As the solvent of the raw material solution, water or alcohol such as ethanol can be used. The SDA contained in the raw material solution is, for example, an organic substance. As the SDA, for example, 1-adamantanamine can be used.

Then, the DDR type zeolite is grown around the seed crystal by hydrothermal synthesis, thereby forming the DDR type zeolite membrane 12 on the support 11 (step S14). The temperature during hydrothermal synthesis is preferably 120 to 200 ℃, for example 160 ℃. The hydrothermal synthesis time is preferably 10 to 100 hours, for example, 30 hours.

After completion of the hydrothermal synthesis, the support 11 and the zeolite membrane 12 were washed with pure water. The cleaned support 11 and zeolite membrane 12 are dried at, for example, 80 ℃. After the support 11 and the zeolite membrane 12 are dried, the zeolite membrane 12 is subjected to a heat treatment, whereby the SDA in the zeolite membrane 12 is substantially completely burned and removed, and the micropores in the zeolite membrane 12 are penetrated (step S15). Thereby, the zeolite membrane composite 1 was obtained.

In the production of the zeolite membrane composite 1 described above, if there is a large variation in the support thickness of the support 11, the amount of seed crystal attached in step S13 varies. Specifically, in the portion of the support 11 having a small support thickness, the resistance of the solution to the solvent passing through the support 11 is small, and therefore the amount of the solvent passing therethrough increases, and the amount of the seed crystal adhering to the outer surface 112 also increases. On the other hand, in the portion where the thickness of the support is large, the resistance when the solvent penetrates through the support 11 is large, and therefore, the amount of the solvent penetration is reduced, and the amount of the seed crystal attached to the outer surface 112 is also reduced. As a result, in the zeolite membrane composite 1, the zeolite membrane 12 becomes thick in the portion where the support thickness is small, and the zeolite membrane 12 becomes thin in the portion where the support thickness is large, so that variation in the membrane thickness of the zeolite membrane 12 occurs.

Table 1 shows the relationship between the variation in the support thickness of the support 11 and the variation in the film thickness of the zeolite membrane 12 in the zeolite membrane composite 1. The substantially cylindrical support 11 of examples 1 to 7 had an outer diameter of 20mm and a length of 15cm in the longitudinal direction. The same applies to the support of comparative example 1. The zeolite membranes 12 of examples 1 to 3 and the zeolite membrane of comparative example 1 were DDR type zeolite membranes. The zeolite membranes 12 of examples 4 to 5 were CHA-type zeolite membranes. The zeolite membranes 12 of examples 6 to 7 were AEI type zeolite membranes.

The zeolite membrane composites 1 of examples 1 to 7 and the zeolite membrane composites of comparative examples were produced by a production method substantially similar to the production method shown in steps S11 to S15 described above. The detailed production conditions and the like are shown below.

In the production of the DDR type zeolite membranes 12 of examples 1 to 3, in step S13, a seed crystal introduction slurry liquid prepared so that the concentration of the seed crystals of the DDR type zeolite dispersed in water is 0.1 mass% was used as the solution 81 described above. Then, the support 11 having the seed crystal adhered thereto was air-dried under predetermined conditions (room temperature, air speed 5 m/sec, 10 minutes). In step S14, 88.0g of 30 wt% silica sol (trade name: SNOWTEX S, manufactured by Nissan chemical Co., Ltd.), 6.59g of ethylenediamine (manufactured by Fuji film and Wako pure chemical industries, Ltd.), 1.04g of 1-amantadine (manufactured by Sigmaaldrich Japan contract Co., Ltd.), and 104.4g of pure water were mixed to prepare the above-mentioned raw material solution. Further, hydrothermal synthesis was performed in a hot air dryer at 130 ℃ for 10 hours to form the zeolite membrane 12. The support 11 on which the zeolite membrane 12 was formed was heated at 450 ℃ for 50 hours in an electric furnace, whereby SDA was removed. The same applies to the production of the DDR type zeolite membrane of comparative example 1.

In the production of the CHA-type zeolite membranes 12 of examples 4 to 5, seed crystals of the CHA-type zeolite are produced in step S12 by using a structure conversion method of Y-type zeolite, hydrothermal synthesis of an aluminosilicate aqueous solution, or the like. In step S13, a seed crystal-introducing slurry liquid prepared in such a manner that the concentration of the seed crystals of the CHA-type zeolite dispersed in water is 0.1 mass% is used as the above-described solution 81. Then, the support 11 having the seed crystal adhered thereto was air-dried under predetermined conditions (room temperature, air speed 5 m/sec, 10 minutes). In step S14, 21.3g of 30 wt% silica sol (trade name: SNOWTEX S, manufactured by Nissan chemical Co., Ltd.), 0.90g of potassium hydroxide (Fuji film and Wako pure chemical industries, Ltd.), 1.18g of sodium aluminate (Fuji film and Wako pure chemical industries, Ltd.), 3.58g of 25 mass% N, N, N-trimethyl-1-adamantyl ammonium hydroxide aqueous solution (manufactured by SACHEM Co., Ltd.), and 173.1g of pure water were mixed to prepare the above-mentioned raw material solution. Further, hydrothermal synthesis was performed in a hot air dryer at 160 ℃ for 30 hours, thereby forming the zeolite membrane 12. The support 11 on which the zeolite membrane 12 is formed is heated at 550 ℃ for 10 hours, whereby the SDA is removed.

In the production of the AEI type zeolite membranes 12 of examples 6 to 7, seed crystals of AEI type zeolite were produced by hydrothermal synthesis or the like using an aluminum phosphate salt aqueous solution in step S12. In step S13, a seed crystal-introducing slurry liquid prepared in such a manner that the concentration of the seed crystals of the AEI type zeolite dispersed in water is 0.1 mass% is used as the above-described solution 81. Then, the support 11 having the seed crystal adhered thereto was air-dried under predetermined conditions (room temperature, wind speed 2 m/sec to 7 m/sec, 30 minutes). In step S13, the seed crystal introducing slurry liquid was applied and air-dried 2 times. In step S14, 4.72g of aluminum triisopropoxide (manufactured by kanto chemical corporation), 30.71g of a 35 mass% tetraethylammonium hydroxide aqueous solution (manufactured by sigmaldrich japan contract corporation), 8.41g of 85% phosphoric acid (manufactured by sigmaldrich japan contract corporation), and 156.17g of pure water were mixed to prepare the above-described raw material solution. Further, hydrothermal synthesis was performed at 150 ℃ for 30 hours, thereby forming the zeolite membrane 12. The support 11 on which the zeolite membrane 12 is formed is heated at 400 ℃ for 10 hours, whereby the SDA is removed.

[ Table 1]

The variation in the thickness of the support in Table 1 is the above "(A-B)/(A + B)" in one cross section of the support 11. That is, the variation in the thickness of the support is: the difference between the maximum value a and the minimum value B of the support thickness in one cross section of the support 11 is divided by the sum of the maximum value a and the minimum value B. The larger the value, the larger the deviation of the support thickness.

The deviations in film thickness in table 1 are: in this cross section of the support 11, the film thickness of the zeolite membrane 12 at the portion where the support thickness is the maximum value a is represented by a, the film thickness of the zeolite membrane 12 at the portion where the support thickness is the minimum value B is represented by B, and the absolute value of the difference between the film thickness a and the film thickness B is divided by the arithmetic mean of the film thickness a and the film thickness B (i.e., "| a-B |/((a + B)/2)"). In Table 1, the values are expressed in percentage. The larger this value, the larger the variation in the film thickness of the zeolite film 12.

The maximum value a and the minimum value B of the support thickness, and the film thickness a and the film thickness B are obtained by cutting the support 11 on a plane perpendicular to the central axis J1, and observing a cross section formed by the cutting with a Scanning Electron Microscope (SEM).

As shown in comparative example 1, when the variation in the thickness of the support "(a-B)/(a + B)" is greater than 0.3, the variation in the thickness of the DDR type zeolite membrane 12 "| a-B |/((a + B)/2)" is greater than 10%. On the other hand, as shown in examples 1 to 3, when the variation in the support thickness "(a-B)/(a + B)" is 0.3 or less, the variation in the film thickness "| a-B |/((a + B)/2)" of the DDR type zeolite membrane 12 is 10% or less.

Similarly, in the CHA-type zeolite membrane 12, when the variation in the thickness of the support "(a-B)/(a + B)" is 0.3 or less, the variation in the thickness of the zeolite membrane 12 "| a-B |/((a + B)/2)" is 10% or less (examples 4 to 5). Similarly, in the AEI zeolite membrane 12, when the variation in the thickness of the support "(a-B)/(a + B)" is 0.3 or less, the variation in the thickness of the zeolite membrane 12 "| a-B |/((a + B)/2)" is 10% or less (examples 6 to 7).

Next, the separation of the mixed substance by the zeolite membrane composite 1 will be described with reference to fig. 6 and 7. Fig. 6 is a diagram showing the separation apparatus 2. Fig. 7 is a diagram showing a separation flow for separating the mixed substances by the separation apparatus 2.

In the separation apparatus 2, a mixed substance containing a plurality of fluids (i.e., gas or liquid) is supplied to the zeolite membrane composite 1, and a substance having a high permeability among the mixed substance is separated from the mixed substance by allowing the substance to permeate the zeolite membrane composite 1. The purpose of the separation in the separation device 2 may be, for example, to extract a substance having high permeability from a mixed substance or to concentrate a substance having low permeability.

The mixed substance (i.e., the mixed fluid) may be a mixed gas containing a plurality of gases, a mixed liquid containing a plurality of liquids, or a gas-liquid two-phase fluid containing both gases and liquids.

CO of the zeolite membrane complex 1 at 20 to 400 ℃ in the separation device 2₂The amount of permeation (permeation amount) of (B) is, for example, 100nmol/m²s.Pa or more. CO in the zeolite membrane composite 1 at 20 to 400 ℃₂Permeability of/CH₄The leakage amount ratio (permeation ratio) is, for example, 100 or more. The permeation amount and permeation ratio are the amount of CO between the supply side and the permeation side of the zeolite membrane composite 1₂The partial pressure difference of (A) is 1.5 MPa.

The mixed substance contains, for example, hydrogen (H)₂) Helium (He), nitrogen (N)₂) Oxygen (O)₂) Water (H)₂O), water vapor (H)₂O), carbon monoxide (CO), carbon dioxide (CO)₂) Nitrogen oxides and nitrogen oxidesAmmonia (NH)₃) Sulfur oxide, hydrogen sulfide (H)₂S), sulfur fluoride, mercury (Hg), arsine (AsH)₃) Hydrogen Cyanide (HCN), carbonyl sulfide (COS), C1-C8 hydrocarbon, organic acid, alcohol, thiol, ester, ether, ketone, and aldehyde.

Nitrogen oxides are compounds of nitrogen and oxygen. The nitrogen oxides are, for example, nitrogen monoxide (NO) and nitrogen dioxide (NO)₂) Nitrous oxide (also known as nitrous oxide). ) (N)₂O), dinitrogen trioxide (N)₂O₃) Dinitrogen tetroxide (N)₂O₄) Dinitrogen pentoxide (N)₂O₅) Is referred to as NO_X(Nitrogen oxides).

Sulfur oxides are compounds of sulfur and oxygen. The sulfur oxide is, for example, sulfur dioxide (SO)₂) Sulfur trioxide (SO)₃) Is referred to as SO_X(Sulfur oxide) gas.

Sulfur fluoride is a compound of fluorine and sulfur. The sulfur fluoride is, for example, disulfide difluoride (F-S-S-F, S ═ SF)₂) Sulfur difluoride (SF)₂) Sulfur tetrafluoride (SF)₄) Sulfur hexafluoride (SF)₆) Or dithiodecafluoride (S)₂F₁₀) And the like.

The hydrocarbon of C1 to C8 has 1 to 8 carbon atoms. The hydrocarbon of C3 to C8 may be any of a linear compound, a side chain compound, and a cyclic compound. The hydrocarbon of C2 to C8 may be either a saturated hydrocarbon (i.e., a hydrocarbon having no double bond or triple bond in the molecule) or an unsaturated hydrocarbon (i.e., a hydrocarbon having a double bond and/or triple bond in the molecule). The hydrocarbon of C1 to C4 is, for example, methane (CH)₄) Ethane (C)₂H₆) Ethylene (C)₂H₄) Propane (C)₃H₈) Propylene (C)₃H₆) N-butane (CH)₃(CH₂)₂CH₃) Isobutane (CH)₃)₃) 1-butene (CH)₂＝CHCH₂CH₃) 2-butene (CH)₃CH＝CHCH₃) Or isobutene (CH)₂＝C(CH₃)₂)。

The organic acid is a carboxylic acidOr sulfonic acids, and the like. Carboxylic acids are, for example, formic acid (CH)₂O₂) Acetic acid (C)₂H₄O₂) Oxalic acid (C)₂H₂O₄) Acrylic acid (C)₃H₄O₂) Or benzoic acid (C)₆H₅COOH), and the like. Sulfonic acids are, for example, ethanesulfonic acid (C)₂H₆O₃S), and the like. The organic acid may be a chain compound or a cyclic compound.

The above-mentioned alcohol is, for example, methanol (CH)₃OH), ethanol (C)₂H₅OH), isopropyl alcohol (2-propanol) (CH)₃CH(OH)CH₃) Ethylene glycol (CH)₂(OH)CH₂(OH)) or butanol (C)₄H₉OH), and the like.

Thiols are organic compounds having hydrogenated Sulfur (SH) at the end, and are also known as Thiol or thioalcohol. The above-mentioned thiols are, for example, methanethiol (CH)₃SH), ethanethiol (C)₂H₅SH) or 1-propanethiol (C)₃H₇SH), and the like.

The above ester is, for example, formate, acetate, or the like.

The above-mentioned ether is, for example, dimethyl ether ((CH)₃)₂O), methyl ethyl ether (C)₂H₅OCH₃) Or diethyl ether ((C)₂H₅)₂O), and the like.

The above ketone is, for example, acetone ((CH)₃)₂CO), methyl ethyl ketone (C)₂H₅COCH₃) Or diethyl ketone ((C)₂H₅)₂CO), and the like.

The above aldehyde is, for example, acetaldehyde (CH)₃CHO), propionaldehyde (C)₂H₅CHO) or Butyraldehyde (Butyraldehyde) (C)₃H₇CHO), and the like.

In the following description, a mixed substance separated by the separation device 2 is described as an example of a mixed gas including a plurality of gases.

The separation device 2 includes: the zeolite membrane composite 1, the sealing section 21, the outer cylinder 22, the sealing member 23, the supply section 26, the first recovery section 27, and the second recovery section 28. The zeolite membrane composite 1, the sealing portion 21, and the sealing member 23 are housed in the outer tube 22. The supply unit 26, the first recovery unit 27, and the second recovery unit 28 are disposed outside the outer cylinder 22 and connected to the outer cylinder 22.

The seal portion 21 is: the members are attached to both end portions of the support body 11 in the longitudinal direction (i.e., the left-right direction in fig. 6), and cover and seal both end surfaces of the support body 11 in the longitudinal direction and outer side surfaces in the vicinity of the both end surfaces. The sealing portion 21 prevents gas from flowing in and out from the substantially annular both end surfaces of the support body 11. The seal portion 21 is, for example: a plate-like member formed of glass or resin. The material and shape of the sealing portion 21 may be changed as appropriate. Since the right sealing portion 21 in fig. 6 has an opening overlapping the inner flow channel 111 of the support 11, the right end opening of the inner flow channel 111 is not covered by the sealing portion 21. Therefore, the gas in the inner flow path 111 can flow out of the zeolite membrane composite 1 through the end opening. On the other hand, since the left seal portion 21 in fig. 6 is not provided with an opening, gas cannot flow in or out from the left end opening of the inner passage 111.

The outer cylinder 22 is a substantially cylindrical tubular member. The outer cylinder 22 is formed of, for example, stainless steel or carbon steel. The longitudinal direction of the outer cylinder 22 is substantially parallel to the longitudinal direction of the zeolite membrane composite 1 (i.e., the direction in which the central axis J1 faces). A supply port 221 and a first discharge port 222 are provided on the outer surface of the outer cylinder 22. The supply port 221 and the first discharge port 222 are disposed on opposite sides in the radial direction (i.e., at positions 180 ° apart in the circumferential direction) so as to sandwich the zeolite membrane composite 1, for example. A second discharge port 223 is provided at one end portion in the longitudinal direction of the outer cylinder 22 (i.e., the end portion on the right side in fig. 6). The supply section 26 is connected to the supply port 221. The first recovery portion 27 is connected to the first discharge port 222. The second recovery portion 28 is connected to the second discharge port 223. The inner space of the outer cylinder 22 is a sealed space isolated from the space around the outer cylinder 22.

The sealing members 23 are disposed between the outer surface of the zeolite membrane composite 1 and the inner surface of the outer tube 22 over the entire circumference in the vicinity of both ends in the longitudinal direction of the zeolite membrane composite 1. Each seal member 23 is a substantially annular member formed of a material impermeable to gas. The sealing member 23 is, for example, an O-ring formed of a flexible resin. The sealing member 23 is tightly attached to the outer surface of the zeolite membrane composite 1 and the inner surface of the outer tube 22 over the entire circumference. In the example shown in fig. 6, the sealing member 23 is in close contact with the outer surface of the sealing portion 21 on the right side in the figure, and is in indirect contact with the outer surface of the zeolite membrane composite 1 across the sealing portion 21. The space between the sealing member 23 and the outer surface of the zeolite membrane composite 1 and the space between the sealing member 23 and the inner surface of the outer tube 22 are sealed, and gas hardly passes through or does not pass through at all. The sealing member 23 may be provided between the end face of the zeolite membrane composite 1 in the longitudinal direction and the outer tube 22.

The supply section 26 supplies the mixed gas to the internal space of the outer tube 22 through the supply port 221. The supply unit 26 is, for example, a blower or a pump that pressure-feeds the mixed gas toward the outer cylinder 22. The blower or the pump is provided with: a pressure adjusting part for adjusting the pressure of the mixed gas supplied to the outer cylinder 22. The first recovery unit 27 and the second recovery unit 28 are: such as a storage container for storing the gas discharged from the outer cylinder 22, or a blower or a pump for transferring the gas.

When the mixed gas is separated, the above-described separation apparatus 2 is prepared, whereby the zeolite membrane composite 1 is prepared (step S21). Then, a mixed gas containing a plurality of gases having different permeabilities to the zeolite membrane 12 is supplied to the internal space of the outer tube 22 by the supply unit 26. For example, the main component of the mixed gas is CO₂And CH₄. The mixed gas may contain CO₂And CH₄Other than the gas. The pressure of the mixed gas supplied from the supply portion 26 to the internal space of the outer tube 22 (i.e., the introduction pressure) is, for example, 0.1 to 20.0 MPa. The separation temperature of the mixed gas is, for example, 10 to 150 ℃.

The mixed gas supplied from the supply unit 26 to the outer tube 22 moves toward the outer surface of the zeolite membrane composite 1 as indicated by an arrow 251. Gas (e.g., CO) having high permeability in mixed gas₂Hereinafter, referred to as "high permeability substance". ) The zeolite membrane 12 and the support 11 provided on the outer surface 112 of the support 11 are led out from the inner surface 113 of the support 11 to the inner flow path 111. Thereby the device is provided withGas (e.g. CH) having low permeability of high permeability substance from mixed gas₄Hereinafter, referred to as "low permeability substance". ) Is separated (step S22). The gas (hereinafter referred to as "permeated substance") led out to the inner flow path 111 from the inner surface 113 of the support 11 is collected by the second collection unit 28 through the second discharge port 223 as indicated by an arrow 253. The pressure (i.e., the permeation pressure) of the gas recovered by the second recovery unit 28 through the second discharge port 223 is, for example, about 1 atmosphere (0.101 MPa). The permeable substance may contain a substance other than the high-permeability substance described above.

The gas other than the gas that has permeated through the zeolite membrane 12 and the support 11 (hereinafter referred to as "impermeable substance") in the mixed gas passes from the upper side to the lower side in the drawing between the outer surface of the zeolite membrane composite 1 and the inner surface of the outer tube 22, and is recovered by the first recovery unit 27 through the first discharge port 222 as indicated by an arrow 252. The pressure of the gas recovered by the first recovery unit 27 through the first discharge port 222 is, for example, substantially the same as the introduction pressure. The impermeable substance may contain a high-permeability substance that does not permeate the zeolite membrane 12 in addition to the low-permeability substance described above.

As described above, the porous cylindrical support 11 for supporting the zeolite membrane 12 includes: a substantially cylindrical inner surface 113 centered on a central axis J1 extending in the longitudinal direction, and a substantially cylindrical outer surface 112 surrounding the inner surface 113. The zeolite membrane 12 is formed on the outer surface 112. At least a part of the maximum value A and the minimum value B of the support thickness in the circumferential direction, which is the distance in the radial direction between the inner side surface 113 and the outer side surface 112, satisfies "(A-B)/(A + B) ≦ 0.3" in the longitudinal direction of the support 11.

In this support 11, by suppressing variations in the support thickness in this manner, the uniformity of the film thickness of the zeolite film 12 formed on the support 11 can be improved as described above. Therefore, even when the zeolite membrane 12 having a small average membrane thickness is formed, it is possible to prevent a part of the zeolite membrane 12 from being damaged due to being excessively thin. As a result, a dense and thin zeolite membrane 12 can be formed on the support 11.

In the support body 11, as described above, it is preferable that the maximum value A and the minimum value B of the thickness of the support body in the circumferential direction satisfy "(A-B)/(A + B) ≦ 0.3" for the entire length of the support body 11 in the longitudinal direction. This can further improve the uniformity of the thickness of the zeolite membrane 12 formed on the support 11.

In the support body 11, as described above, it is preferable that the maximum value A and the minimum value B of the thickness of the support body in the circumferential direction satisfy "(A-B)/(A + B) ≦ 0.2", more preferably "(A-B)/(A + B) ≦ 0.1", at least in part in the longitudinal direction of the support body 11. This can further improve the uniformity of the thickness of the zeolite membrane 12 formed on the support 11.

In the support body 11, as described above, it is more preferable that the maximum value A and the minimum value B in the circumferential direction of the thickness of the support body over the entire length of the support body 11 in the longitudinal direction satisfy "(A-B)/(A + B) ≦ 0.2", and particularly preferably satisfy "(A-B)/(A + B) ≦ 0.1". This can further improve the uniformity of the thickness of the zeolite membrane 12 formed on the support 11.

In the support body 11, as described above, the average radius X and the roundness Y of the inner side surface 113 at least a part of the support body 11 in the longitudinal direction preferably satisfy "Y/X.ltoreq.0.5", more preferably satisfy "Y/X.ltoreq.0.3", and still more preferably satisfy "Y/X.ltoreq.0.1". As described above, if the cross-sectional shape of the inner surface 113 perpendicular to the central axis J1 is a shape relatively close to a perfect circle, the uniformity of the support thickness in the circumferential direction can be improved when the outer surface 112 is brought close to a perfect circle by polishing or the like at the time of forming the support 11. Therefore, the support 11 satisfying "(A-B)/(A + B) ≦ 0.3" for at least a part in the longitudinal direction can be formed with high yield.

In the support 11, as described above, the average radius X and the roundness Y of the inner surface 113 over the entire length of the support 11 in the longitudinal direction satisfy "Y/X. ltoreq.0.5", more preferably "Y/X. ltoreq.0.3", and particularly preferably "Y/X. ltoreq.0.1". Thus, the support 11 having the total length in the longitudinal direction of ≦ 0.3 "(A-B)/(A + B) can be formed with a higher yield.

As described above, the support body 11 is preferably formed of a ceramic sintered body. This can increase the bonding strength between the zeolite membrane 12 and the support 11, as compared with the case where the support is formed of a material other than the ceramic sintered body, and therefore, the zeolite membrane 12 can be stably supported.

The zeolite membrane composite 1 includes: the support 11 described above, and the zeolite membrane 12 formed on the outer surface 112 of the support 11. This makes it possible to provide the zeolite membrane composite 1 having the zeolite membrane 12 with high membrane thickness uniformity. Therefore, the zeolite membrane composite 1 including the dense and thin zeolite membrane 12 can also be provided. In other words, in the zeolite membrane composite 1, the zeolite membrane 12 can be made thin.

As described above, in the zeolite membrane composite 1, since the zeolite membrane 12 can be made thin, the structure of the zeolite membrane composite 1 is particularly suitable for a zeolite membrane composite in which the thickness (minimum film thickness) of the zeolite membrane 12 is 1 μm or less.

As described above, the maximum number of rings of the zeolite constituting the zeolite membrane 12 is preferably 8 or less. Thus, when the zeolite membrane 12 is used for separating a mixed substance, CO having a relatively small molecular diameter can be favorably realized₂The permeation target substance selectively permeates and is efficiently separated from the mixture substance.

The method for producing the zeolite membrane composite 1 includes: a step of preparing seed crystals (step S12), a step of attaching the seed crystals to the support 11 (step S13), and a step of forming the zeolite membrane 12 on the support 11 by starting the growth of zeolite from the seed crystals by hydrothermal synthesis (step S14). This makes it possible to provide the zeolite membrane composite 1 having the zeolite membrane 12 with high membrane thickness uniformity. Therefore, it is also possible to provide the zeolite membrane composite 1 including the dense and thin zeolite membrane 12.

The separation method includes: a step of preparing the zeolite membrane composite 1 (step S21), and a step of supplying a mixed substance containing a plurality of gases or liquids to the zeolite membrane 12, and allowing a highly permeable substance among the mixed substance to permeate the zeolite membrane composite 1 to separate the substance from the mixed substance (step S22). This makes it possible to separate a substance having a high permeability (i.e., a highly permeable substance) from the mixed substance.

The separation method is particularly suitable for separation of a mixed substance containing 1 or more substances selected from hydrogen, helium, nitrogen, oxygen, water vapor, carbon monoxide, carbon dioxide, nitrogen oxides, ammonia, sulfur oxides, hydrogen sulfide, sulfur fluoride, mercury, arsine, hydrogen cyanide, carbonyl sulfide, C1-C8 hydrocarbons, organic acids, alcohols, thiols, esters, ethers, ketones, and aldehydes.

The support 11, the zeolite membrane composite 1, the method for producing the same, and the method for separating the mixed substance may be variously modified.

For example, the support 11 is not necessarily formed of a ceramic sintered body, and may be formed of another material such as a metal. In the support 11, the average radius X and the roundness Y of the inner surface 113 do not necessarily satisfy "Y/X is not more than 0.5". The central axis of the outer surface 112 of the support 11 does not necessarily have to be coincident with the central axis J1 of the inner surface 113, and may be different.

In the zeolite membrane composite 1, the thickness of the zeolite membrane 12 is not limited to 1 μm or less, and various modifications can be made. The maximum number of rings of the zeolite constituting the zeolite membrane 12 may be greater than 8 or less than 8.

The support 11 can be manufactured by a manufacturing method different from the above-described example. For example, the outer side surface may not be polished.

The zeolite membrane composite 1 can be produced by a production method different from that of the above example. For example, the seed crystal may be attached to the support 11 by a method different from the above-described example. The zeolite membrane 12 may be formed on the inner surface 113 of the support 11, or may be formed on both the outer surface 112 and the inner surface 113 of the support 11.

The structure of the separation apparatus 2 shown in fig. 6 can be variously modified. For example, the left sealing portion 21 in fig. 6 may be provided with an opening overlapping the inner flow path 111, a sealing member 23 for sealing, and a second discharge port 223 connected to the second recovery portion 28 on the left end surface of the outer tube 22, as in the case of the right sealing portion 21 in fig. 6.

The separation apparatus 2 and the separation method described above can separate substances other than the substances exemplified in the above description from the mixture substance.

The zeolite membrane 12 of the zeolite membrane composite 1 is not necessarily used for separating a highly permeable substance from a mixed substance, and may be used for other applications such as an adsorption membrane and a pervaporation membrane.

The configurations in the above embodiments and the modifications may be appropriately combined as long as they are not contradictory to each other.

While the invention has been described and illustrated in detail, the foregoing description is illustrative and not restrictive. Thus, it can be said that: numerous variations or modifications may be employed without departing from the scope of the invention.

Industrial applicability

The support of the present invention can be used to support, for example, a zeolite membrane that can be used as a gas separation membrane. The zeolite membrane composite of the present invention can be used in various fields where zeolite is used, such as a gas separation membrane, a separation membrane other than a gas, and an adsorption membrane for various substances.

Description of the symbols

1 Zeolite Membrane Complex

11 support body

12 Zeolite Membrane

112 (of the support body) outer side surface

113 (of the support body)

Maximum value of A (thickness of support body in circumferential direction)

B (of the support thickness in the circumferential direction) minimum value

J1 center shaft

S11-S15 and S21-S22.