JP5445398B2 - Method for producing porous support-zeolite membrane composite - Google Patents

Description

  The present invention relates to a method for producing a porous support-zeolite membrane composite, and more specifically, a zeolite membrane is formed on a porous support by hydrothermal synthesis in the presence of a seed crystal having a specific particle size distribution. The present invention relates to a method for producing a zeolite membrane composite, a porous support-zeolite membrane composite obtained by the method, and the like. The porous support-zeolite membrane composite obtained by the present invention can permeate and separate a highly permeable substance from a gas or liquid mixture containing an organic substance and concentrate the low permeable substance.

  Conventionally, separation or concentration of a gas or liquid mixture containing an organic substance is performed by a distillation method, an azeotropic distillation method, a solvent extraction / distillation method, an adsorbent, or the like depending on the properties of a target substance. However, these methods have drawbacks that they require a lot of energy or have a limited application range for separation and concentration.

  In recent years, membrane separation and concentration methods using membranes such as polymer membranes and zeolite membranes have been proposed as separation methods instead of these methods. Polymer membranes such as flat membranes and hollow fiber membranes are excellent in processability, but have the disadvantage of low heat resistance. In addition, polymer membranes have low chemical resistance, and many of them swell when contacted with organic substances such as organic solvents and organic acids. Therefore, the range of applications for separation and concentration is limited.

  Further, the zeolite membrane is usually used for separation and concentration as a zeolite membrane composite in which zeolite is formed into a membrane on a support. For example, the organic substance can be separated and concentrated by bringing a mixture of the organic substance and water into contact with the zeolite membrane composite and selectively permeating water. Separation and concentration using membranes of inorganic materials can reduce the amount of energy used compared to separation by distillation or adsorbent, and can be separated and concentrated in a wider temperature range than polymer membranes, and contain organic matter. It can also be applied to separation of mixtures.

  As a separation method using a zeolite membrane, for example, a method of selectively permeating water using an A-type zeolite membrane complex to concentrate alcohol (Patent Document 1), and a mordenite-type zeolite membrane complex using alcohol A method of selectively permeating water from a mixed system of water (Patent Document 2) or selectively permeating water from a mixed system of acetic acid and water using a ferrierite-type zeolite membrane composite. A method for separating and concentrating acetic acid (Patent Document 3) has been proposed.

JP-A-7-185275 JP 2003-144871 A JP 2000-237561 A

  However, a zeolite membrane that has both sufficient throughput and separation performance for practical use and has resistance to organic substances, particularly organic acids, has not yet been found. For example, the mordenite-type zeolite membrane composite of Patent Document 2 and the ferrierite-type zeolite membrane composite of Patent Document 3 have a small permeation flux and are insufficient for practical use. In addition, since the de-Al reaction proceeds under acidic conditions, the separation performance changes as the use time becomes longer, and use under conditions where an organic acid is present is not desirable. The A-type zeolite of Patent Document 1 cannot be used as a separation membrane in the presence of an organic acid because its structure is destroyed when it comes into contact with an acid.

  An object of the present invention is a porous support-zeolite membrane that solves the problems of the prior art, has no defects, and has both a practically sufficient throughput and separation performance in separation and concentration using an inorganic material separation membrane. An object of the present invention is to provide a method for producing a composite, a porous support-zeolite membrane composite obtained by the method, and a separation and concentration method using the zeolite membrane composite.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention can achieve both practically sufficient throughput and separation performance if a certain type of zeolite is formed into a film on an inorganic porous support. It has been found that a zeolite membrane composite can be obtained and proposed previously (Japanese Patent Application No. 2010-043366). As a result of further studies, the inventors of the present invention conducted a hydrothermal synthesis in the presence of a seed crystal having a specific particle size distribution when forming a zeolite membrane on a porous support. It was found that a simple zeolite membrane could be synthesized with good reproducibility. The present invention has been accomplished based on these findings.

That is, the gist of the present invention resides in the following (1) to (9).
(1) A method for producing a porous support-zeolite membrane composite by forming a zeolite membrane on a porous support by hydrothermal synthesis, wherein the zeolite membrane contains CHA-type zeolite, The following formula (1):
_{(D 90 -D 10) / D} 50 (1)
[In formula (1), D ₉₀ , D ₁₀ and D ₅₀ are cumulative distribution diagrams obtained by particle size distribution measurement (volume basis, integrated from the smallest particle diameter) and give a height of 90%. The diameter gives a 10% height and a 50% height (median diameter). ]
A method for producing a porous support-zeolite membrane composite, which is performed in the presence of a seed crystal having a particle size distribution of 0.3 to 1.8 .
(2) The method according to (1), wherein the seed crystal has a median diameter (D ₅₀ ) of 20 μm or less.
(3) The method according to (1) or (2), wherein a seed crystal is attached in advance to the porous support, and a zeolite membrane is formed on the porous support to which the seed crystal is attached.
(4) A porous support-zeolite membrane composite produced by the method according to any one of (1) to (3) .
(5) A porous support-zeolite membrane composite obtained by forming a zeolite membrane on a porous support by hydrothermal synthesis , wherein the zeolite membrane contains CHA-type zeolite, and the zeolite membrane composite is A porous support-zeolite membrane composite characterized by having an air permeation amount of 1400 L / (m ² · h) or less when connected to a vacuum line having an absolute pressure of 5 kPa.
(6) The porous support-zeolite membrane composite as described in (5), wherein the zeolite constituting the zeolite membrane is an aluminosilicate.
(7) The zeolite membrane has the following formula (1):
_{(D 90 -D 10) / D} 50 (1)
[In formula (1), D ₉₀ , D ₁₀ and D ₅₀ are cumulative distribution diagrams obtained by particle size distribution measurement (volume basis, integrated from the smallest particle diameter) and give a height of 90%. The diameter gives a 10% height and a 50% height (median diameter). ] Is formed by hydrothermal synthesis in the presence of a seed crystal having a particle size distribution with a particle size distribution of 0.3 to 1.8. (5) or (6) Porous support- zeolite membrane composite.
(8) The porous support-zeolite membrane composite as set forth in any one of (4) to (7), wherein the porous support is an inorganic porous support including a sintered ceramic.
(9) The porous support-zeolite membrane composite according to any one of (4) to (8) is contacted with a gas or liquid mixture containing an organic substance, and the mixture has high permeability. A separation method characterized by permeating and separating a substance.

  According to the present invention, when a specific compound is separated and concentrated from a gas or liquid mixture containing an organic substance, it has a sufficiently large processing amount for practical use and has a sufficient separation performance, and is a dense zeolite without defects. A porous support-zeolite membrane composite with a membrane is provided. By using this zeolite membrane composite as a separation means, it becomes possible to separate a highly permeable substance and concentrate the mixture from a gas or liquid mixture containing an organic substance that achieves both a sufficient throughput and separation performance.

It is the schematic of a pervaporation measuring apparatus.

  Hereinafter, embodiments of the present invention will be described in more detail. However, the description of the constituent elements described below is an example of embodiments of the present invention, and the present invention is not limited to these contents. Various modifications can be made within the scope of the gist.

The method for producing a porous support-zeolite membrane composite of the present invention is a method for producing a porous support-zeolite membrane composite by forming a zeolite membrane on a porous support by hydrothermal synthesis, Hydrothermal synthesis is represented by the following formula (1):
_{(D 90 -D 10) / D} 50 (1)
[In formula (1), D ₉₀ , D ₁₀ and D ₅₀ are cumulative distribution diagrams obtained by particle size distribution measurement (volume basis, integrated from the smallest particle diameter) and give a height of 90%. The diameter gives a 10% height and a 50% height (median diameter). ]
It is characterized by being performed in the presence of a seed crystal having a value represented by 2.2 or less.

  The porous support-zeolite membrane composite of the present invention is characterized by being produced by the above method.

The porous support-zeolite membrane composite of another aspect of the present invention is a porous support-zeolite membrane composite obtained by forming a zeolite membrane on a porous support by hydrothermal synthesis. The zeolite membrane composite is characterized in that the air permeation amount is 1400 L / (m ² · h) or less when connected to a vacuum line with an absolute pressure of 5 kPa.

  First, the constituent requirements of these inventions will be described in more detail. In the present specification, “porous support-zeolite membrane composite” is simply referred to as “zeolite membrane composite” or “membrane composite”, and “porous support” is simply referred to as “support”. Sometimes.

(Porous support)
The porous support used in the present invention has a chemical stability such that zeolite can be crystallized in the form of a film on the surface thereof, and is a support made of an inorganic porous material (inorganic porous support). Anything may be used. For example, sintered ceramics (ceramic support) such as silica, α-alumina, γ-alumina, mullite, zirconia, titania, yttria, silicon nitride, silicon carbide, sintered metals such as iron, bronze, stainless steel, glass And carbon moldings.

  Among these porous supports, there are inorganic porous supports (ceramic supports) including sintered ceramics, which are solid materials whose basic components or most of them are composed of inorganic nonmetallic substances. preferable. If this inorganic porous support is used, a part of the support is zeoliticized during the synthesis of the zeolite membrane, thereby improving the adhesion at the interface.

  Specific examples include a ceramic sintered body (ceramic support) containing silica, α-alumina, γ-alumina, mullite, zirconia, titania, yttria, silicon nitride, silicon carbide, and the like. Among them, an inorganic porous support containing at least one of alumina, silica, and mullite is preferable. When these supports are used, partial zeolitization is easy, so that the bond between the support and the zeolite becomes strong, and a dense membrane with high separation performance is easily formed.

  The shape of the porous support is not particularly limited as long as it can effectively separate a gas mixture or a liquid mixture, and specifically, for example, a flat plate shape, a tubular shape, a cylindrical shape, a cylindrical shape, a prismatic shape, or the like. Honeycomb-like ones having a large number of pores, monoliths and the like can be mentioned.

  In the present invention, zeolite is crystallized into a film on such a porous support, that is, on the surface of the support. The surface of the support may be any surface or a plurality of surfaces depending on the shape of the support. For example, in the case of a cylindrical tube support, it may be the outer surface or the inner surface, and in some cases both the outer and inner surfaces.

  The average pore diameter of the porous support surface is not particularly limited, but those having a controlled pore diameter are preferred. The average pore diameter is usually 0.02 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more, and usually 20 μm or less, preferably 10 μm or less, more preferably 5 μm or less. If the average pore diameter is too small, the amount of permeation tends to be small. If it is too large, the strength of the support itself may be insufficient, and the proportion of pores on the surface of the support will increase, forming a dense zeolite membrane. It may be difficult to be done.

  The average thickness (wall thickness) of the support is usually 0.1 mm or more, preferably 0.3 mm or more, more preferably 0.5 mm or more, and usually 7 mm or less, preferably 5 mm or less, more preferably 3 mm or less. is there. The support is used to give mechanical strength to the zeolite membrane, but if the average thickness of the support is too thin, the zeolite membrane composite will not have sufficient strength and It tends to weaken and cause problems in practice. If the average thickness of the support is too thick, the diffusion of the permeated material tends to be poor and the permeation flux tends to be low.

  The porosity of the support is usually 20% or more, preferably 25% or more, more preferably 30% or more, and usually 70% or less, preferably 60% or less, more preferably 50% or less. The porosity of the support influences the permeation flow rate when the gas or liquid is separated, and if it is less than the lower limit, it tends to inhibit the diffusion of the permeate, and if it exceeds the upper limit, the strength of the support tends to decrease.

  The surface of the porous support is preferably smooth, and the surface may be polished with a file or the like as necessary. The surface of the porous support means an inorganic porous support surface portion for crystallizing zeolite, and any surface of each shape may be used as long as it is a surface, good. For example, in the case of a cylindrical tube support, it may be the outer surface or the inner surface, and in some cases both the outer and inner surfaces.

(Zeolite membrane composite)
In the present invention, a zeolite membrane is formed on the porous support to obtain a zeolite membrane composite.

  As a component constituting the zeolite membrane, an inorganic binder such as silica or alumina, an organic substance such as a polymer, a silylating agent for modifying the zeolite surface, or the like may be included as necessary in addition to zeolite. In addition, the zeolite membrane in the present invention may partially contain an amorphous component or the like, but a zeolite membrane substantially composed only of zeolite is preferable.

  The thickness of the zeolite membrane is not particularly limited, but is usually 0.1 μm or more, preferably 0.6 μm or more, more preferably 1.0 μm or more, and usually 100 μm or less, preferably 60 μm or less, more preferably 20 μm or less. It is.

  The particle diameter of the zeolite is not particularly limited, but if it is too small, the grain boundary tends to increase, and the permeation selectivity tends to decrease. Therefore, it is usually 30 nm or more, preferably 50 nm or more, more preferably 100 nm or more, and the upper limit is the film thickness or less. Furthermore, it is particularly preferred that the zeolite particle size is the same as the membrane thickness. When the zeolite particle size is the same as the membrane thickness, the zeolite grain boundary is smallest.

  Examples of zeolite include silicate and phosphate. Examples of silicates include aluminosilicates, gallosilicates, ferrisilicates, titanosilicates, borosilicates, etc., and examples of phosphates include aluminophosphates composed of aluminum and phosphorus (such as ALPO-5). Called ALPO), silicoaluminophosphate composed of silicon, aluminum and phosphorus (called SAPO such as SAPO-34), MeAPO such as FAPO-5 containing elements such as Fe And metalloaluminophosphates. Of these, aluminosilicates and silicoaluminophosphates are preferred, and aluminosilicates are more preferred.

When the zeolite is an aluminosilicate, the SiO ₂ / Al ₂ O ₃ molar ratio is preferably 5 or more, more preferably 8 or more, further preferably 10 or more, particularly preferably 12 or more, preferably 2000 or less, More preferably, it is 1000 or less, More preferably, it is 500 or less, Most preferably, it is 100 or less. When the SiO ₂ / Al ₂ O ₃ molar ratio is less than the lower limit, the durability tends to decrease. When the SiO ₂ / Al ₂ O ₃ molar ratio exceeds the upper limit, the permeation flux tends to decrease because the hydrophobicity is too strong.

Incidentally, _SiO 2 / _Al 2 _{O 3} molar ratio in the present invention, a scanning electron microscope - is a value obtained by energy dispersive X-ray spectroscopy (SEM-EDX). In order to obtain information on only a film of several microns, the X-ray acceleration voltage is usually measured at 10 kV.

  The main zeolite constituting the zeolite membrane preferably contains a zeolite having an oxygen 6-10 membered ring structure, more preferably a zeolite having an oxygen 6-8 membered ring structure. Here, the value of n of the zeolite having an oxygen n-membered ring indicates the one having the largest number of oxygens among the pores composed of oxygen and T elements (elements other than oxygen) forming the zeolite skeleton. For example, when there are 12-membered and 8-membered pores of oxygen, such as MOR type zeolite, it is regarded as a 12-membered ring zeolite.

  Examples of the zeolite having an oxygen 6 to 10-membered ring structure include AEI, AEL, AFG, ANA, BRE, CAS, CDO, CHA, DAC, DDR, DOH, EAB, EPI, ESV, EUO, FAR, FRA, and FER. , GIS, GIU, GOO, HEU, IMF, ITE, ITH, KFI, LEV, LIO, LOS, LTN, MAR, MEP, MER, MEL, MFI, MFS, MON, MSO, MTF, MTN, MTT, MWW, NAT , NES, NON, PAU, PHI, RHO, RRO, RTE, RTH, RUT, SGT, SOD, STF, STI, STT, TER, TOL, TON, TSC, TUN, UFI, VNI, VSV, WEI, YUG, etc. Can be mentioned.

  Examples of the zeolite having an oxygen 6-8 membered ring structure include AEI, AFG, ANA, CHA, EAB, ERI, ESV, FAR, FRA, GIS, ITE, KFI, LEV, LIO, LOS, LTN, MAR, and PAU. , RHO, RTH, SOD, STI, TOL, UFI and the like.

The oxygen n-membered ring structure determines the pore size of the zeolite, and in the zeolite smaller than the 6-membered ring, the pore diameter is smaller than the kinetic radius of the H ₂ O molecule, so the permeation flux is reduced and is practical. It may not be. Moreover, when it is larger than the oxygen 10-membered ring structure, the pore diameter becomes large, and the organic substance having a small size may lower the separation performance, and the use may be limited.

The framework density (T / 1000 ³ ) of the zeolite is not particularly limited, but is usually 17 or less, preferably 16 or less, more preferably 15.5 or less, particularly preferably 15 or less, usually 10 or more, preferably 11 or more. More preferably, it is 12 or more.

The framework density means the number of elements (T elements) that form a skeleton other than oxygen per 1000 ³ of the zeolite, and this value is determined by the structure of the zeolite. The relationship between framework density and zeolite structure is shown in ATLAS OF ZEOLITE FRAMEWORK TYPES Fifth Revised Edition 2001 ELSEVIER.

  In the present invention, preferred zeolite structures are AEI, AFG, CHA, EAB, ERI, ESV, FAR, FRA, GIS, ITE, KFI, LEV, LIO, LOS, LTN, MAR, PAU, RHO, RTH, SOD, STI, TOL, UFI, more preferred structures are AEI, CHA, ERI, KFI, LEV, PAU, RHO, RTH, UFI, more preferred structures are CHA, LEV, and the most preferred structure is CHA. is there.

  Here, the CHA-type zeolite is a code that defines the structure of the zeolite defined by the International Zeolite Association (IZA) and indicates a CHA structure. This is a zeolite having a crystal structure equivalent to that of naturally occurring chabazite. The CHA-type zeolite has a structure characterized by having three-dimensional pores composed of 8-membered oxygen rings having a diameter of 3.8 × 3.8 mm, and the structure is characterized by X-ray diffraction data.

The framework density (T / 1000 ³ ) of the CHA-type zeolite is 14.5. The SiO ₂ / Al ₂ O ₃ molar ratio is the same as described above.

  In the present invention, when the zeolite membrane contains CHA-type zeolite, the intensity of the peak around 2θ = 17.9 ° is the intensity of the peak around 2θ = 20.8 ° in the X-ray diffraction pattern. It is preferable that the size is 0.5 times or more.

  Here, the peak intensity refers to a value obtained by subtracting the background value from the measured value. The peak intensity ratio represented by (the intensity of the peak around 2θ = 17.9 °) / (the intensity of the peak around 2θ = 20.8 °) (hereinafter this may be referred to as “peak intensity ratio A”). In other words, it is usually 0.5 or more, preferably 1 or more, more preferably 1.2 or more, and particularly preferably 1.5 or more. Although an upper limit is not specifically limited, Usually, it is 1000 or less.

  Further, in the zeolite membrane composite, when the zeolite membrane contains CHA-type zeolite, the peak intensity around 2θ = 9.6 ° is 4 of the peak intensity around 2θ = 20.8 ° in the X-ray diffraction pattern. The size is preferably twice or more.

  Peak intensity ratio represented by (Intensity of peak near 2θ = 9.6 °) / (Intensity of peak near 2θ = 20.8 °) (hereinafter this may be referred to as “peak intensity ratio B”) In other words, it is usually 4 or more, preferably 6 or more, more preferably 8 or more, and particularly preferably 10 or more. Although an upper limit is not specifically limited, Usually, it is 1000 or less.

  Here, the X-ray diffraction pattern is obtained by irradiating the surface on which zeolite is mainly attached with X-rays using CuKα as a radiation source to obtain a scanning axis of θ / 2θ. The shape of the sample to be measured may be any shape that can irradiate X-rays on the surface of the membrane composite on which the zeolite is mainly attached. The body itself or the one cut into an appropriate size restricted by the apparatus is preferable.

  Here, the X-ray diffraction pattern may be measured by fixing the irradiation width using an automatic variable slit when the surface of the zeolite membrane composite is a curved surface. An X-ray diffraction pattern using an automatic variable slit refers to a pattern subjected to variable → fixed slit correction.

  Here, the peak in the vicinity of 2θ = 17.9 ° refers to the maximum of the peaks present in the range of 17.9 ° ± 0.6 ° among the peaks not derived from the base material.

  The peak in the vicinity of 2θ = 20.8 ° refers to the maximum peak in the range of 20.8 ° ± 0.6 ° among the peaks not derived from the base material.

  The peak in the vicinity of 2θ = 9.6 ° refers to the maximum of the peaks present in the range of 9.6 ° ± 0.6 ° among the peaks not derived from the base material.

  According to COLLECTION OF SIMULATED XRD POWDER PATTERNS FOR ZEOLITE Third Revised Edition 1996 ELSEVIER, the peak near 2θ = 9.6 ° in the X-ray diffraction pattern is a rhombohedral setting.

(No. 166), it is a peak derived from the plane having an index of (1, 0, 0) in the CHA structure.

  In addition, the peak near 2θ = 17.9 ° in the X-ray diffraction pattern shows the space group in the rhombohedral setting according to COLLECTION OF SIMULATED XRD POWDER PATTERNS FOR ZEOLITE Third Revised Edition 1996 ELSEVIER.

(No. 166) is a peak derived from the (1,1,1) index in the CHA structure.

  The peak near 2θ = 20.8 ° in the X-ray diffraction pattern is a collection of SIMULATED XRD POWDER PATTERNS FOR ZEOLITE Third Revised Edition 1996 ELSEVIER.

(No. 166) is a peak derived from the (2, 0, -1) index in the CHA structure.

  The typical ratio (peak intensity ratio B) of the peak intensity derived from the (1, 0, 0) plane and the peak intensity derived from the (2, 0, -1) plane (peak intensity ratio B) is COLLECTION OF SIMULATED XRD POWDER PATTERNS FOR ZEOLITE According to Third Revised Edition 1996 ELSEVIER, it is 2.5.

  Therefore, when this ratio is 4 or more, for example, the zeolite crystal is oriented so that the (1, 0, 0) plane is almost parallel to the surface of the membrane composite when the CHA structure is a rhombohedral setting. Is considered to mean that the crystals are oriented and growing. Orientation and growth of zeolite crystals in the zeolite membrane composite is advantageous in that a dense membrane with high separation performance can be formed.

  The typical ratio (peak intensity ratio A) of the peak intensity derived from the (1, 1, 1) plane and the peak intensity derived from the (2, 0, -1) plane (peak intensity ratio A) is COLLECTION OF SIMULATED XRD POWDER PATTERNS FOR ZEOLITE According to Third Revised Edition 1996 ELSEVIER, it is 0.3.

  Therefore, this ratio of 0.5 or more means, for example, that the (1, 1, 1) plane when the CHA structure is a rhombohedral setting is oriented so that the orientation is almost parallel to the surface of the membrane composite. It is thought to mean that the crystals are oriented and growing. Orientation and growth of zeolite crystals in the zeolite membrane composite is advantageous in that a dense membrane with high separation performance can be formed.

  As described above, the fact that any one of the peak intensity ratios A and B is a value in the above-mentioned specific range means that the zeolite crystals are oriented and grow, and a dense membrane with high separation performance is formed. Is shown.

As described below, a dense zeolite membrane in which CHA-type zeolite crystals are grown in an orientated state is formed by using, for example, a specific organic template and K in the aqueous reaction mixture when the zeolite membrane is formed by hydrothermal synthesis. It can be achieved by coexisting ⁺ ions.

(Method for producing zeolite membrane composite)
As long as the method for producing a zeolite membrane is a method for forming a zeolite membrane by hydrothermal synthesis on a support in the presence of seed crystals having a specific particle size distribution as described above, other conditions are not particularly limited.

  Specifically, for example, a reaction mixture for hydrothermal synthesis (hereinafter sometimes referred to as an “aqueous reaction mixture”) having a uniform composition is adjusted, and the porous support is gently fixed inside. What is necessary is just to heat in a heat-resistant pressure-resistant container, such as an autoclave, and to seal for a fixed time.

  The aqueous reaction mixture preferably contains an Si element source, an Al element source, an organic template and water as necessary, and an alkali source as necessary.

  Examples of the Si element source used in the aqueous reaction mixture include amorphous silica, colloidal silica, silica gel, sodium silicate, amorphous aluminum silicate gel, tetraethoxysilane (TEOS), trimethylethoxysilane, and the like.

  As the Al element source, for example, sodium aluminate, aluminum hydroxide, aluminum sulfate, aluminum nitrate, aluminum oxide, amorphous aluminosilicate gel, or the like can be used. In addition to the Al element source, other element sources, for example, element sources such as Ga, Fe, B, Ti, Zr, Sn, and Zn may be included.

  In crystallization of zeolite, an organic template (structure directing agent) can be used as necessary, but those synthesized using an organic template are preferred. By synthesizing using the organic template, the ratio of silicon atoms to aluminum atoms in the crystallized zeolite is increased, and the acid resistance is improved.

  The organic template may be any type as long as it can form a desired zeolite membrane. Further, one type of template or a combination of two or more types may be used.

  When the zeolite is of the CHA type, amines and quaternary ammonium salts are usually used as the organic template. For example, organic templates described in U.S. Pat. No. 4,544,538 and U.S. Patent Publication No. 2008/0075656 are preferred.

  Specific examples include cations derived from alicyclic amines such as cations derived from 1-adamantanamine, cations derived from 3-quinacridinal, and cations derived from 3-exo-aminonorbornene. It is done. Among these, a cation derived from 1-adamantanamine is more preferable.

  When a cation derived from 1-adamantanamine is used as an organic template, CHA-type zeolite capable of forming a dense film is crystallized. In addition, a CHA-type zeolite having hydrophilicity sufficient for the membrane to selectively permeate water can be generated, and a CHA-type zeolite excellent in acid resistance can be obtained.

  Of the cations derived from 1-adamantanamine, the N, N, N-trialkyl-1-adamantanammonium cation is more preferred. The three alkyl groups of the N, N, N-trialkyl-1-adamantanammonium cation are usually independent alkyl groups, preferably a lower alkyl group, more preferably a methyl group. The most preferred compound among them is the N, N, N-trimethyl-1-adamantanammonium cation.

Such cations are accompanied by anions that do not harm the formation of CHA-type zeolite. Representative examples of such anions include halogen ions such as Cl ⁻ , Br ⁻ and I ⁻ , hydroxide ions, acetates, sulfates, and carboxylates. Of these, hydroxide ions are particularly preferably used.

  As another organic template, N, N, N-trialkylbenzylammonium cation can also be used. Also in this case, the alkyl group is an independent alkyl group, preferably a lower alkyl group, more preferably a methyl group. Among them, the most preferred compound is N, N, N-trimethylbenzylammonium cation. The anion accompanied by this cation is the same as described above.

As an alkali source used in the aqueous reaction mixture, a hydroxide ion of a counter anion of an organic template, an alkali metal hydroxide such as NaOH or KOH, or an alkaline earth metal hydroxide such as Ca (OH) ₂ is used. Can do.

  The type of alkali is not particularly limited, and Na, K, Li, Rb, Cs, Ca, Mg, Sr, Ba and the like are usually used. Among these, Na and K are preferable, and K is more preferable. Further, two or more alkalis may be used in combination, and specifically, Na and K are preferably used in combination.

The ratio of Si element source to Al element source in the aqueous reaction mixture is usually expressed as the molar ratio of the oxides of the respective elements, that is, the SiO ₂ / Al ₂ O ₃ molar ratio.

The SiO ₂ / Al ₂ O ₃ molar ratio is not particularly limited, but is usually 5 or more, preferably 8 or more, more preferably 10 or more, and further preferably 15 or more. Further, it is usually 10,000 or less, preferably 1000 or less, more preferably 300 or less, and still more preferably 100 or less.

When the SiO ₂ / Al ₂ O ₃ molar ratio is within this range, the zeolite membrane is densely formed, and the produced zeolite exhibits strong hydrophilicity, and a hydrophilic compound, particularly water, is added from the mixture containing organic matter. It can be selectively transmitted. In addition, a zeolite membrane that is strong in acid resistance and difficult to remove from Al can be obtained.

In particular, when the SiO ₂ / Al ₂ O ₃ molar ratio is within this range, CHA-type zeolite that can form a dense film can be crystallized. In addition, a CHA-type zeolite having hydrophilicity sufficient for the membrane to selectively permeate water can be produced, and a CHA-type zeolite excellent in acid resistance can be obtained.

The ratio of the silica source and an organic template in the aqueous reaction mixture, the molar ratio of the organic template for SiO ₂ (organic template / SiO ₂ molar ratio), usually 0.005 or higher, preferably at least 0.01, more preferably 0 0.02 or more, usually 1 or less, preferably 0.4 or less, more preferably 0.2 or less.

When the organic template / SiO ₂ molar ratio is in the above range, in addition to being able to produce a dense zeolite membrane, the produced zeolite has strong acid resistance and Al is not easily desorbed. Moreover, a particularly dense and acid-resistant CHA-type zeolite can be formed under these conditions.

The ratio of the Si element source to the alkali source is M _{(2 / n) 2} O / SiO ₂ (where M represents an alkali metal or alkaline earth metal, and n represents the valence 1 or 2). In general, it is 0.02 or more, preferably 0.04 or more, more preferably 0.05 or more, and usually 0.5 or less, preferably 0.4 or less, more preferably 0.3 or less.

  In the case of forming a CHA-type zeolite membrane, it is preferable that K is contained in the alkali metal because a denser and highly crystalline membrane is formed. In this case, the molar ratio of K to all alkali metals and / or alkaline earth metals containing K is usually 0.01 or more and 1 or less, preferably 0.1 or more and 1 or less, more preferably 0.3 or more. 1 or less.

  As described above, the addition of K to the aqueous reaction mixture is performed by changing the space group in the rhombohedral setting.

(No. 166), the peak intensity in the vicinity of 2θ = 9.6 °, which is a peak derived from the (1, 0, 0) index surface in the CHA structure, and the (2, 0, −1) surface The peak intensity ratio in the vicinity of 2θ = 20.8 ° (peak intensity ratio B), which is a peak derived from the above, or the peak derived from the plane of (1,1,1), in the vicinity of 2θ = 17.9 ° There is a tendency to increase the ratio between the peak intensity and the peak intensity in the vicinity of 2θ = 20.8 ° (peak intensity ratio A), which is a peak derived from the (2, 0, −1) plane.

The ratio of Si element source to water is the molar ratio of water to SiO ₂ (H ₂ O / SiO ₂ molar ratio), which is usually 10 or more, preferably 30 or more, more preferably 40 or more, and particularly preferably 50 or more. Usually, it is 1000 or less, preferably 500 or less, more preferably 200 or less, and particularly preferably 150 or less.

  When the molar ratio of materials in the aqueous reaction mixture is in these ranges, a dense zeolite membrane can be formed. The amount of water is particularly important in the formation of a dense zeolite membrane, and finer crystals are more likely to form and form a dense membrane when the amount of water is greater than that of the general powder synthesis method. is there.

In general, the amount of water in the synthesis of powdered CHA-type zeolite is about 15 to 50 in terms of H ₂ O / SiO ₂ molar ratio. Zeolite membrane composite with high separation performance in which CHA-type zeolite is crystallized into a dense membrane on the support by using a high H ₂ O / SiO ₂ molar ratio (50 to 1000), that is, water-rich conditions. You can get a body.

Furthermore, in the production method of the present invention, the following formula (1):
_{(D 90 -D 10) / D} 50 (1)
[In formula (1), D ₉₀ , D ₁₀ and D ₅₀ are cumulative distribution diagrams obtained by particle size distribution measurement (volume basis, integrated from the smallest particle diameter) and give a height of 90%. The diameter gives a 10% height and a 50% height (median diameter). ]
A zeolite membrane is formed by performing hydrothermal synthesis in the presence of a seed crystal having a particle size distribution of 2.2 or less.

The value of (D ₉₀ -D ₁₀ ) / D ₅₀ in formula (1) is 2.2 or less, preferably 2.0 or less, more preferably 1.9 or less, and even more preferably 1.8 or less. Usually, it is 0.1 or more, preferably 0.2 or more, more preferably 0.3 or more.

  The value of equation (1) indicates the width of the particle size distribution, and the smaller the value, the narrower the particle size distribution. When a seed crystal having a narrow particle size distribution is used, a dense film with few defects can be synthesized with good reproducibility. Until now, attempts have been made to make the zeolite membrane dense by adjusting the grain size of the seed crystal, the method of attaching the seed crystal, and the concentration of the seed crystal slurry to be used. However, the control of these conditions is limited, and in order to synthesize a dense film without defects with good reproducibility, it is particularly important that the width of the seed crystal grain size distribution is within a specific range in the present invention.

The particle size distribution of the seed crystal is as described above, but D ₅₀ (median diameter) is usually 0.5 nm or more, preferably 1 nm or more, more preferably 2 nm or more, and usually 20 μm or less, preferably 15 μm or less, more Preferably it is 10 micrometers or less, More preferably, it is 5 micrometers or less.

_{Further, D 90} is usually 0.5nm or more, preferably 1nm or more, more preferably 2nm or more, usually 100μm or less, preferably 50μm or less, more preferably 30μm or less, more preferably 20μm or less.

_{Further, D 10} is usually 0.1nm or more, preferably 0.5nm or more, more preferably 1nm or more, usually 20μm or less, preferably 15μm or less, more preferably 10μm or less, more preferably 5μm or less.

  As a method for adding a seed crystal, a method of adding it to an aqueous reaction mixture as in the synthesis of a powdered zeolite, a method of attaching a seed crystal on a support, and the like can be used. It is preferable to attach a seed crystal. By attaching a seed crystal in advance to the support, a dense zeolite membrane with good separation performance can be easily formed.

  The seed crystal to be used is not limited as long as it is a zeolite that promotes crystallization, but it is preferably the same crystal type as the zeolite membrane to be formed for efficient crystallization. When forming a CHA type zeolite membrane, it is preferable to use seed crystals of CHA type zeolite.

  The method for attaching the seed crystal on the support is not particularly limited. For example, a dip method in which the seed crystal is dispersed in a solvent such as water and the support is immersed in the dispersion to attach the seed crystal, or a seed crystal is attached. For example, a method in which a slurry mixed with a solvent such as water is coated on a support can be used. The dip method is desirable for controlling the amount of seed crystals attached and producing a membrane composite with good reproducibility.

The solvent for dispersing the seed crystal is not particularly limited, but water is particularly preferable.
The amount of the seed crystal to be dispersed is not particularly limited, and is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.5% by mass or more with respect to the total mass of the dispersion. Moreover, it is 20 mass% or less normally, Preferably it is 10 mass% or less, More preferably, it is 5 mass% or less, More preferably, it is 4 mass% or less, Most preferably, it is 3 mass% or less.

  If the amount of seed crystals to be dispersed is too small, the amount of seed crystals adhering to the support is small, so that a portion where no zeolite is generated on the support during hydrothermal synthesis is created, resulting in a defective film. there is a possibility. The amount of seed crystals adhering to the support by the dip method becomes almost constant when the amount of seed crystals in the dispersion is higher than a certain level, so if the amount of seed crystals in the dispersion is too large, the seed crystals are wasted. It is more disadvantageous in terms of cost.

  It is desirable to deposit the seed crystal on the support by dipping or slurry coating, and after drying, form a zeolite membrane.

The amount of the seed crystal to be preliminarily deposited on the support is not particularly limited, and is usually 0.01 g or more, preferably 0.05 g or more, more preferably 0.1 g or more, by mass per 1 m ^{2 of} the base material. Usually, it is 100 g or less, preferably 50 g or less, more preferably 10 g or less, still more preferably 8 g or less.

  When the amount of the seed crystal is less than the lower limit, it becomes difficult to form a crystal, and there is a tendency that the film growth becomes insufficient or the film growth becomes uneven. In addition, when the amount of the seed crystal exceeds the upper limit, surface irregularities are increased by the seed crystal, or spontaneous nuclei are likely to grow due to the seed crystal falling from the support, thereby inhibiting film growth on the support. Sometimes. In either case, it tends to be difficult to form a dense zeolite membrane.

  When a zeolite membrane is formed on a support by hydrothermal synthesis, there are no particular limitations on the method for immobilizing the support, and it can take any form such as vertical or horizontal placement. In this case, the zeolite membrane may be formed by a stationary method, or the aqueous reaction mixture may be stirred to form a zeolite membrane.

  The temperature at which the zeolite membrane is formed is not particularly limited, but is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 150 ° C. or higher, usually 200 ° C. or lower, preferably 190 ° C. or lower, more preferably 180 ° C. It is as follows. If the reaction temperature is too low, the zeolite may not crystallize. Further, if the reaction temperature is too high, a type of zeolite different from the zeolite in the present invention may be produced.

  The heating time is not particularly limited, but is usually 1 hour or more, preferably 5 hours or more, more preferably 10 hours or more, and usually 10 days or less, preferably 5 days or less, more preferably 3 days or less, and even more preferably 2 Less than a day. If the reaction time is too short, the zeolite may not crystallize. If the reaction time is too long, a type of zeolite different from the zeolite in the present invention may be produced.

  The pressure at the time of forming the zeolite membrane is not particularly limited, and the self-generated pressure generated when the aqueous reaction mixture placed in the closed vessel is heated to this temperature range is sufficient. If necessary, an inert gas such as nitrogen may be added.

  The zeolite membrane composite obtained by hydrothermal synthesis is washed with water, then heated and dried. Here, the heat treatment means that the template is fired when heat is applied to dry the zeolite membrane composite or the template is used.

  The temperature of the heat treatment is usually 50 ° C or higher, preferably 80 ° C or higher, more preferably 100 ° C or higher, usually 200 ° C or lower, preferably 150 ° C or lower when drying is intended. The temperature of the heat treatment is usually 350 ° C. or higher, preferably 400 ° C. or higher, more preferably 430 ° C. or higher, more preferably 480 ° C. or higher, and usually 900 ° C. or lower, preferably 850 ° C., for the purpose of firing the template. Hereinafter, it is more preferably 800 ° C or lower, particularly preferably 750 ° C or lower.

  The heating time is not particularly limited as long as the zeolite membrane is sufficiently dried or the template is calcined, and is preferably 0.5 hours or more, more preferably 1 hour or more. The upper limit is not particularly limited, and is usually within 200 hours, preferably within 150 hours, and more preferably within 100 hours.

  When hydrothermal synthesis is performed in the presence of an organic template, the obtained zeolite membrane composite can be washed with water, and then the organic template can be removed by, for example, heat treatment or extraction, preferably by heat treatment, that is, baking. Is appropriate.

  The firing temperature is usually 350 ° C. or higher, preferably 400 ° C. or higher, more preferably 430 ° C. or higher, more preferably 480 ° C. or higher, usually 900 ° C. or lower, preferably 850 ° C. or lower, more preferably 800 ° C. or lower, particularly Preferably it is 750 degrees C or less. If the calcination temperature is too low, the proportion of the remaining organic template tends to increase, and the zeolite has fewer pores, which may reduce the permeation flux during separation and concentration. If the calcination temperature is too high, the difference in the coefficient of thermal expansion between the support and the zeolite becomes large, so that the zeolite membrane may be easily cracked, and the denseness of the zeolite membrane may be lost and the separation performance may be lowered.

  The firing time varies depending on the temperature rising rate or the temperature falling rate, but is not particularly limited as long as the organic template is sufficiently removed, and is preferably 1 hour or longer, more preferably 5 hours or longer. The upper limit is not particularly limited, and is, for example, usually within 200 hours, preferably within 150 hours, more preferably within 100 hours, and most preferably within 24 hours. Firing may be performed in an air atmosphere, but may be performed in an atmosphere to which oxygen is added.

  It is desirable that the rate of temperature increase during firing be as slow as possible in order to reduce the difference in the thermal expansion coefficient between the support and the zeolite from causing cracks in the zeolite membrane. The temperature rising rate is usually 5 ° C./min or less, preferably 2 ° C./min or less, more preferably 1 ° C./min or less, and particularly preferably 0.5 ° C./min or less. Usually, it is 0.1 ° C./min or more in consideration of workability.

  Moreover, it is necessary to control the temperature drop rate after firing in order to avoid cracks in the zeolite membrane. Similar to the rate of temperature increase, the slower the better. The temperature lowering rate is usually 5 ° C./min or less, preferably 2 ° C./min or less, more preferably 1 ° C./min or less, and particularly preferably 0.5 ° C./min or less. Usually, it is 0.1 ° C./min or more in consideration of workability.

The zeolite membrane may be ion exchanged as necessary. In the case of synthesizing using a template, ion exchange is usually performed after removing the template. Examples of ions to be ion-exchanged include protons, alkali metal ions such as Na ⁺ , K ⁺ and Li ⁺ , alkaline earth metal ions such as Ca ²⁺ , Mg ²⁺ , Sr ²⁺ and Ba ^2+, and transitions such as Fe, Cu and Zn. Examples include metal ions. Among these, alkali metal ions such as proton, Na ⁺ , K ⁺ , and Li ⁺ are preferable.

In ion exchange, the zeolite membrane after calcination (such as when a template is used) is replaced with an ammonium salt such as NH ₄ NO ₃ or NaNO ₃ or an aqueous solution containing ions to be exchanged, and in some cases an acid such as hydrochloric acid. What is necessary is just to perform by the method of washing with water etc. after processing at the temperature of 100 degreeC. Furthermore, you may bake at 200 to 500 degreeC as needed.

The air permeation [L / (m ² · h)] of the porous support-zeolite membrane composite (zeolite membrane composite after heat treatment) thus obtained is usually 1400 L / (m ² · h) or less, preferably Is 1000 L / (m ² · h) or less, more preferably 700 L / (m ² · h) or less, more preferably 600 L / (m ² · h) or less, more preferably 500 L / (m ² · h) or less, Particularly preferred is 300 L / (m ² · h) or less, and most preferred is 200 L / (m ² · h) or less. In lower limit of the transmission amount is not particularly limited, it is generally 0.01L / ^{(m 2} · h) or more, preferably 0.1L / ^{(m 2} · h) or more, more preferably 1L / ^{(m 2} · h) or higher is there.

Here, the air permeation amount is the air permeation amount [L / (m ² · h)] when the zeolite membrane composite is connected to a vacuum line with an absolute pressure of 5 kPa, as described in detail in the examples.

  The zeolite membrane composite obtained by the method of the present invention has excellent characteristics as described above, and can be suitably used as a membrane separation means in the separation method of the present invention.

(Separation method)
The separation method of the present invention is characterized in that a gas or liquid mixture containing an organic substance is brought into contact with the porous support-zeolite membrane complex to separate a highly permeable substance from the mixture. It has something. In the present invention, the same porous support-zeolite membrane composite as described above is used. The preferable ones are also the same as described above.

  In the separation method of the present invention, a gas or liquid mixture containing an organic substance is brought into contact with one side of the support side or the zeolite membrane side through an inorganic porous support provided with a zeolite membrane, and the mixture is brought into contact with the opposite side. By setting the pressure lower than that on the side, the substance having a high permeability to the zeolite membrane (a substance in the mixture having a relatively high permeability) is selectively permeated from the mixture, that is, as a main component of the permeable substance. Thereby, a highly permeable substance can be separated from the mixture. As a result, the specific organic substance can be separated and recovered or concentrated by increasing the concentration of the specific organic substance (substance in the mixture having relatively low permeability) in the mixture.

  For example, in the case of a mixture of water and organic matter, water is usually highly permeable to the zeolite membrane, so water is separated from the mixture and the organic matter is concentrated in the original mixture. A separation / concentration method called a pervaporation method (pervaporation method) or a vapor permeation method (vapor permeation method) is one embodiment of the separation method of the present invention.

  By using the porous support-zeolite membrane composite as a separation membrane, it is possible to carry out membrane separation with a sufficient amount of treatment and sufficient separation performance.

Here, the sufficient amount of treatment means that the permeation flux of the substance that permeates the membrane is 1 kg / (m ² · h) or more. The sufficient separation performance means that the separation coefficient represented by the following formula is 100 or more, or the concentration of the main component in the permeate is 95% by mass or more.

Separation factor = (Pα / Pβ) / (Fα / Fβ)
[Wherein Pα represents the mass percentage concentration of the main component in the permeate, Pβ represents the mass percent concentration of the subcomponent in the permeate, and Fα represents the mass of the component that is the main component in the permeate in the separated mixture. The percentage concentration is indicated, and Fβ is the weight percentage concentration in the separated mixture of the components that are subcomponents in the permeate. ]

More specifically, the permeation flux is, for example, when a mixture of 2-propanol and water having a water content of 30% by mass is permeated at 70 ° C. with a pressure difference of 1 atm (1.01 × 10 ⁵ Pa). In general, it means 1 kg / (m ² · h) or more, preferably 3 kg / (m ² · h) or more, more preferably 5 kg / (m ² · h) or more. The upper limit of the permeation flux is not particularly limited, and is usually 20 kg / (m ² · h) or less, preferably 15 kg / (m ² · h) or less.

In addition, high transmission performance can be expressed by permeance. Permeance is obtained by dividing the amount of substance permeated by the product of the membrane area, time and the partial pressure difference of the permeating substance. When expressed in units of permeance, for example, water in a case where a mixture of 2-propanol having a water content of 30% by mass and water is permeated at 70 ° C. with a pressure difference of 1 atm (1.01 × 10 ⁵ Pa). The permeance is usually 3 × 10 ⁻⁷ mol / (m ² · s · Pa) or more, preferably 5 × 10 ⁻⁷ mol / (m ² · s · Pa) or more, more preferably 1 × 10 ⁻⁶ mol / (M ² · s · Pa) or more, particularly preferably 2 × 10 ⁻⁶ mol / (m ² · s · Pa) or more. The upper limit of the water permeance is not particularly limited, and is usually 1 × 10 ⁻⁴ mol / (m ² · s · Pa) or less, preferably 5 × 10 ⁻⁵ mol / (m ² · s · Pa) or less.

Furthermore, the separation factor is, for example, usually 1000 or more when a mixture of 2-propanol and water having a water content of 30% by mass is permeated at 70 ° C. with a pressure difference of 1 atm (1.01 × 10 ⁵ Pa). Preferably it is 4000 or more, More preferably, it is 10,000 or more, Most preferably, it is 20000 or more. The upper limit of the separation factor is the case where only water is completely transmitted. In this case, the separation factor is infinite, but is preferably 10000000 or less, more preferably 1000000 or less.

  When the object to be separated is a mixture of water and an organic substance (hereinafter sometimes referred to as “hydrous organic compound”), the water content in the mixture is usually 20% by mass or more, preferably 30% by mass or more, more preferably It is 45 mass% or more, and is 95 mass% or less normally, Preferably it is 80 mass% or less, More preferably, it is 70 mass% or less.

  In the separation method of the present invention, since the substance that permeates the zeolite membrane is usually water, if the water content decreases, the amount of treatment decreases, which is not efficient. On the other hand, if the water content is too high, the membrane required for concentration becomes a large area (in the case where the membrane is formed in a tubular shape, the number is increased), and the economic effect is reduced.

  As a water-containing organic compound, the water content may be adjusted in advance by an appropriate water adjustment method. In this case, the preferred water content is the same as described above. Examples of the moisture adjustment method include methods known per se, such as distillation, pressure swing adsorption (PSA), temperature swing adsorption (TSA), and desiccant system.

  Further, water may be further separated from the water-containing organic compound from which water has been separated by the zeolite membrane composite. Thereby, water can be separated to a higher degree and the water-containing organic compound can be further concentrated.

  Examples of organic compounds include carboxylic acids such as acetic acid, acrylic acid, propionic acid, formic acid, lactic acid, oxalic acid, tartaric acid, benzoic acid, sulfonic acid, sulfinic acid, habituric acid, uric acid, phenol, enol, and diketone type compounds. Organic acids such as thiophenol, imide, oxime, aromatic sulfonamide, primary and secondary nitro compounds; alcohols such as methanol, ethanol and isopropanol (2-propanol); ketones such as acetone and methyl isobutyl ketone Aldehydes such as acetaldehyde, ethers such as dioxane and tetrahydrofuran; organic compounds containing nitrogen such as amides such as dimethylformamide and N-methylpyrrolidone (N-containing organic compounds), esters such as acetates and acrylates Na And the like.

  Among these, an organic compound containing at least one selected from alcohol, ether, ketone, aldehyde, and amide is particularly desirable. Among these organic compounds, those having 2 to 10 carbon atoms are preferable, and those having 3 to 8 carbon atoms are more preferable.

  Moreover, as an organic compound, the high molecular compound which can form a mixture (mixed solution) with water may be sufficient. Examples of such a polymer compound include those having a polar group in the molecule, for example, polyols such as polyethylene glycol and polyvinyl alcohol; polyamines; polysulfonic acids; polycarboxylic acids such as polyacrylic acid; Carboxylic acid esters; modified polymer compounds obtained by modifying polymers by graft polymerization, etc .; copolymerized polymer compounds obtained by copolymerization of nonpolar monomers such as olefins and polar monomers having polar groups such as carboxyl groups And the like.

  Further, the water-containing organic compound may be a mixture of water and a polymer emulsion. Here, the polymer emulsion is a mixture of a surfactant and a polymer, which is usually used for adhesives, paints, and the like. Examples of the polymer used in the polymer emulsion include polyvinyl acetate, polyvinyl alcohol, acrylic resin, polyolefin, olefin-polar monomer copolymer such as ethylene-vinyl alcohol copolymer, polystyrene, polyvinyl ether, polyamide, polyester, and cellulose. Thermoplastic resins such as derivatives; thermosetting resins such as urea resins, phenol resins, epoxy resins, polyurethanes; rubbers such as natural rubber, polyisoprene, polychloroprene, butadiene copolymers such as styrene-butadiene copolymers, etc. Can be mentioned. As the surfactant, a known one may be used.

  Since the zeolite membrane composite of the present invention has acid resistance, it can be effectively used for water separation from a mixture of water and an organic acid such as acetic acid and water separation for promoting esterification reaction.

  The separation method of the present invention may be carried out by preparing a suitable separation device using the zeolite membrane composite and introducing a gas or liquid mixture containing an organic compound into the separation device. These separation devices can be made of a member known per se.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited to a following example, unless the summary is exceeded.
In the following examples and comparative examples, measurements of physical properties and separation performance were performed as follows.

(1) Measurement of particle size distribution The particle size distribution of the seed crystal was measured under the following conditions.
-Device name: Laser diffraction particle size distribution measuring device LA-500 (manufactured by Horiba Ltd.)
・ Measurement method: Combined use of Franhofer diffraction theory and Mie scattering theory ・ Measurement range: 0.1 to 200 μm
-Light source: He-Ne laser (632.8 nm)
・ Detector: Ring-shaped silicon photodiode ・ Dispersed solvent: Water

  The dispersion for measuring the particle size distribution of the seed crystal is obtained by circulating the dispersion through the flow cell while stirring with a stirrer in the ultrasonic dispersion bath of the measuring device, and the intensity of the light transmitted through the dispersion is high. It was prepared by adding a seed crystal to water in an ultrasonic dispersion bath so as to fall within the appropriate light intensity range displayed on the apparatus. The amount of water as a dispersion solvent at this time is usually 250 ml, and the seed crystal to be dispersed is usually 0.01 g. After putting the seed crystal, ultrasonic waves were taken for 10 minutes to aggregate the seed crystal in the dispersion, and measurement was performed by a flow method.

In the obtained cumulative distribution chart (volume basis, integration from the smallest particle diameter), the diameter (median diameter) giving a height of 50% is D ₅₀ , and the diameter giving a height of 10% is D ₁₀ , 90% the diameter or give height and D _90.

(2) Measurement of X-ray diffraction (XRD) XRD measurement of the zeolite membrane was performed under the following conditions.
-Device name: X'PertPro MPD manufactured by PANalytical, the Netherlands
Optical system specifications Incident side: Enclosed X-ray tube (CuKα)
Soller Slit (0.04 rad)
Divergence Slit (Variable Slit)
Sample stage: XYZ stage
Light receiving side: Semiconductor array detector (X 'Celerator)
Ni-filter
Soller Slit (0.04 rad)
Goniometer radius: 240mm
Measurement conditions X-ray output (CuKα): 45 kV, 40 mA
Scanning axis: θ / 2θ
Scanning range (2θ): 5.0-70.0 °
Measurement mode: Continuous
Reading width: 0.05 °
Counting time: 99.7 sec
Automatic variable slit (Automatic-DS): 1 mm (irradiation width)
Lateral divergence mask: 10 mm (irradiation width)

  X-rays were irradiated in a direction perpendicular to the axial direction of the cylindrical tube. Also, the X-ray is not the sample table surface, but the sample table surface, out of the two lines where the cylindrical tubular membrane complex placed on the sample table and the plane parallel to the sample table surface are in contact with each other so that noise and the like are not introduced as much as possible. It was made to hit mainly on the other line above the surface.

(3) Air permeation amount One end of the zeolite membrane composite was sealed, the other end was sealed and connected to a 5 kPa vacuum line, and the air flow was measured with a mass flow meter installed between the vacuum line and the zeolite membrane composite. The flow rate was measured and the air permeation amount [L / (m ² · h)] was obtained. As the mass flow meter, 8300 manufactured by KOFLOC, for N ₂ gas, maximum flow rate 500 ml / min (20 ° C., converted to 1 atm) was used. When the mass flow meter display on KOFLOC 8300 is 10 ml / min (20 ° C, converted to 1 atm) or less, Lintec MM-2100M, for Air gas, maximum flow rate 20 ml / min (converted to 0 ° C, 1 atm) It measured using.

(4) SEM-EDX measurement SEM-EDX measurement was performed based on the following conditions.
-Device name: SEM: FE-SEM Hitachi: S-4800
EDX: EDAX Genesis
・ Acceleration voltage: 10 kV
The entire field of view (25 μm × 18 μm) at a magnification of 5000 was scanned, and X-ray quantitative analysis was performed.

(5) Pervaporation method FIG. 1 shows a schematic diagram of an apparatus used for the pervaporation method. In FIG. 1, the inside of the zeolite membrane composite 5 is depressurized by a vacuum pump 9, and the pressure difference from the outside in contact with the liquid to be separated 4 is about 1 atm. Due to this pressure difference, the permeated water in the liquid to be separated 4 permeates and permeates into the zeolite membrane composite 5. The permeated material is collected by the trap 7. On the other hand, the organic compound in the liquid to be separated 4 stays outside the zeolite membrane composite 5.

  At regular intervals, mass measurement and composition analysis of the permeate collected in the trap 7 and composition analysis of the liquid 4 to be separated are performed, and using these values, the separation factor, permeation flux, water permeance, etc. Was calculated as described above. The composition analysis was performed by gas chromatography.

[Example 1]
(Synthesis of seed crystal 1)
For hydrothermal synthesis having a composition (molar ratio) of SiO ₂ / Al ₂ O ₃ / NaOH / KOH / H ₂ O / TMADAOH = 1 / 0.033 / 0.1 / 0.06 / 40 / 0.07 The reaction mixture was prepared as follows. TMADAOH in the above composition is N, N, N-trimethyl-1-adamantanammonium hydroxide used as an organic template (the same applies hereinafter).

To a mixture of 15 g of 1 mol / L-NaOH aqueous solution, 9 g of 1 mol / L-KOH aqueous solution and 64 g of water, 0.94 g of aluminum hydroxide (containing 53.5% by mass of Al ₂ O ₃ , manufactured by Aldrich) was added and stirred. Dissolved to give a clear solution. To this was added 8.9 g of TMADAOH aqueous solution (containing 25% by mass of TMADAOH, manufactured by Seychem), and further 22.5 g of colloidal silica (Snowtech-40 manufactured by Nissan Chemical Co., Ltd.) was added and stirred for 2 hours to obtain a reaction mixture.

  A Teflon (registered trademark) inner cylinder (200 ml) containing the reaction mixture was sealed in an autoclave and heated at 160 ° C. for 5 days under autogenous pressure. The autoclave was allowed to cool after stirring at 15 rpm for a predetermined time. The reaction mixture was taken out, filtered and washed, and dried at 100 ° C. for 5 hours or more. The obtained zeolite crystal was 10 g.

  A reaction mixture for hydrothermal synthesis was prepared in the same manner as above except that 0.2 g of the zeolite crystals obtained above was added as a seed crystal to the transparent solution.

A Teflon (registered trademark) inner cylinder (200 ml) containing the reaction mixture was sealed in an autoclave and heated at 160 ° C. for 48 hours under an autogenous pressure. The autoclave was allowed to cool after being stirred at 15 rpm for a predetermined time. The reaction mixture was taken out, filtered, washed, and dried at 100 ° C. for 5 hours or more to obtain 10 g of zeolite crystals. This zeolite crystal was pulverized using an agate mortar to obtain seed crystal 1. D _{90 of} seed crystal 1 was 5.0 μm, D ₁₀ was 1.5 μm, D ₅₀ (median diameter) was 2.6 μm, and (D ₉₀ -D ₁₀ ) / D ₅₀ was 1.4.

(Preparation of porous support-CHA type zeolite membrane composite 1 and measurement of physical properties)
A reaction mixture for hydrothermal synthesis was prepared as follows.
Aluminum hydroxide (containing 53.5% by mass of Al ₂ O ₃ , manufactured by Aldrich) mixed with 13.2 g of 1 mol / L-NaOH aqueous solution, 13.2 g of 1 mol / L-KOH aqueous solution and 90.2 g of water 39 g was added, stirred and dissolved to obtain a transparent solution. To this was added 2.98 g of TMADAOH aqueous solution (containing 25% by mass of TMADAOH, manufactured by Seychem), and further 13.2 g of colloidal silica (Snowtech-40 manufactured by Nissan Chemical Co., Ltd.) was added and stirred for 2 hours to obtain a reaction mixture.

The composition (molar ratio) of this reaction mixture was SiO ₂ / Al ₂ O ₃ / NaOH / KOH / H ₂ O / TMADAOH = 1 / 0.083 / 0.15 / 0.15 / 80 / 0.04, SiO 2 ₂ / Al ₂ O ₃ = 12.

  As an inorganic porous support, a mullite tube PM (outer diameter 12 mm, inner diameter 9 mm) manufactured by Nikkato Co., Ltd. was cut into a length of 80 mm, washed with an ultrasonic cleaner, and dried.

The support was immersed in a slurry in which the seed crystal 1 synthesized above was dispersed in water at 0.6% by mass, and then dried at 100 ° C. for 5 hours or more to attach the seed crystal. The mass of the attached seed crystal was 0.7 g / m ² .

  The support to which the seed crystal was attached was immersed in a Teflon (registered trademark) inner cylinder (200 ml) containing the reaction mixture in the vertical direction to seal the autoclave, and left standing at 160 ° C. for 48 hours. Heated under autogenous pressure. After the elapse of a predetermined time, the mixture was allowed to cool, the support-zeolite membrane complex was taken out of the reaction mixture, washed, and dried at 100 ° C. for 5 hours or more.

The zeolite membrane composite before template firing was placed in an electric furnace and fired at 500 ° C. for 5 hours. The mass of the CHA-type zeolite crystallized on the support, which was determined from the difference between the mass of the zeolite membrane composite 1 after calcination and the mass of the support, was 180 g / m ² .

The air permeation amount of the zeolite membrane composite 1 was 460 L / (m ² · h).

  When XRD of the produced membrane was measured, it was found that CHA-type zeolite was produced.

[Example 2]
(Synthesis of seed crystal 2)
For hydrothermal synthesis having a composition (molar ratio) of SiO ₂ / Al ₂ O ₃ / NaOH / KOH / H ₂ O / TMADAOH = 1 / 0.033 / 0.1 / 0.06 / 60 / 0.07 The reaction mixture was prepared as follows.

To a mixture of 40 g of 1 mol / L-NaOH aqueous solution, 24 g of 1 mol / L-KOH aqueous solution, and 314 g of water, 2.5 g of aluminum hydroxide (containing 53.5 mass% of Al ₂ O ₃ , manufactured by Aldrich) was added and stirred. Dissolved to give a clear solution. To this was added 23.7 g of TMADAOH aqueous solution (containing 25% by mass of TMADAOH, manufactured by Sechem Co.), 60 g of colloidal silica (Snowtech-40 manufactured by Nissan Chemical Co., Ltd.) was added, and the mixture was stirred for 2 hours to obtain a reaction mixture.

The Teflon (registered trademark) inner cylinder (1 L) containing the reaction mixture was sealed in a 1 L induction stirring autoclave, stirred at 150 rpm using an anchor blade, and heated at 160 ° C. for 48 hours under autogenous pressure. And heated. The mixture was allowed to cool after a predetermined time, and the reaction mixture was taken out, filtered, washed, and dried at 100 ° C. for 5 hours or more to obtain 28 g of zeolite crystals. This zeolite crystal was pulverized using an agate mortar to obtain seed crystal 2. D _{90 of} seed crystal 2 was 12.1 μm, D ₁₀ was 3.5 μm, D ₅₀ (median diameter) was 7.2 μm, and (D ₉₀ -D ₁₀ ) / D ₅₀ was 1.2.

(Preparation of porous support-CHA type zeolite membrane composite 2 and measurement of physical properties)
A reaction mixture for hydrothermal synthesis having the same composition as in Example 1 was prepared. A porous mullite tube PM (outer diameter 12 mm, inner diameter 9 mm) manufactured by Nikkato Co., Ltd. as an inorganic porous support was cut to a length of 80 mm, and the outer surface was polished with a # 800 sandpaper. The support was washed with an ultrasonic cleaner and dried at 120 ° C. for 2 hours.

The support was immersed in a slurry in which the seed crystal 2 synthesized above was dispersed in water at 3% by mass, and then dried under the same conditions as in Example 1 to adhere the seed crystal. The mass of the attached seed crystal was 1.8 g / m ² .

A zeolite membrane was formed on the support to which the seed crystal 2 was adhered under the same conditions as in Example 1 and then baked to obtain a zeolite membrane composite 2. The mass of the CHA-type zeolite crystallized on the support, which was determined from the difference between the mass of the membrane composite after firing and the mass of the support, was 160 g / m ² .

The air permeation amount of the zeolite membrane composite 2 was 430 L / (m ² · h).

  When XRD of the produced membrane was measured, it was found that CHA-type zeolite was produced.

[Example 3]
The zeolite membrane composite 2 obtained in Example 2 was subjected to separation by selectively permeating water from a 70 ° C. water / acetic acid mixed solution (50/50 mass%) by a pervaporation method.

The permeation performance 5 hours after the start of permeation was permeation flux: 3.4 kg / (m ² · h), separation factor: 300, and water concentration in the permeate: 99.62% by mass. The water permeance was 2.1 × 10 ⁻⁶ mol / (m ² · s · Pa).

[Example 4]
(Synthesis of seed crystal 3)
For hydrothermal synthesis having a composition (molar ratio) of SiO ₂ / Al ₂ O ₃ / NaOH / KOH / H ₂ O / TMADAOH = 1 / 0.066 / 0.15 / 0.1 / 100 / 0.1 The reaction mixture was prepared as follows.

To a mixture of 48 g of 1 mol / L-NaOH aqueous solution, 32 g of 1 mol / L-KOH aqueous solution and 447 g of water, 4.0 g of aluminum hydroxide (containing 53.5 mass% of Al ₂ O ₃ , manufactured by Aldrich) was added and stirred. Dissolved to give a clear solution. To this, 27 g of TMADAOH) aqueous solution (containing 25% by mass of TMADAOH, manufactured by Sechem Co.) was added, and 48 g of colloidal silica (Snowtech-40 manufactured by Nissan Chemical Co., Ltd.) was further added, and further used to synthesize seed crystal 1 in Example 1. 0.007 g of the obtained seed crystal was added and stirred for 2 hours to obtain a reaction mixture.

A Teflon (registered trademark) inner cylinder containing the reaction mixture was sealed in a 1 L induction stirring autoclave, stirred at 200 rpm using an anchor blade, and heated at 160 ° C. for 48 hours under an autogenous pressure. . The mixture was allowed to cool after a predetermined time, and the reaction mixture was taken out, filtered, washed and dried at 100 ° C. for 5 hours or more to obtain 22 g of zeolite crystals. This zeolite crystal was pulverized using an agate mortar to obtain seed crystal 3. D _{90 of} seed crystal 3 was 6.1 μm, D ₁₀ was 1.8 μm, D ₅₀ (median diameter) was 3.5 μm, and (D ₉₀ -D ₁₀ ) / D ₅₀ was 1.3.

(Preparation of porous support-CHA-type zeolite membrane composite 3 and measurement of physical properties)
A reaction mixture for hydrothermal synthesis was prepared as follows.
To a mixture of 10.5 g of 1 mol / L-NaOH aqueous solution, 7.0 g of 1 mol / L-KOH aqueous solution and 100 g of water, 0.88 g of aluminum hydroxide (containing 53.5% by mass of Al ₂ O ₃ , manufactured by Aldrich) In addition, the mixture was stirred and dissolved to obtain a transparent solution. To this was added 2.38 g of a TMADAOH aqueous solution (containing 25% by mass of TMADAOH, manufactured by Seychem), and further 10.5 g of colloidal silica (Snowtech-40 manufactured by Nissan Chemical Co., Ltd.) was added and stirred for 2 hours to obtain a reaction mixture.

The composition (molar ratio) of this reaction mixture was SiO ₂ / Al ₂ O ₃ / NaOH / KOH / H ₂ O / TMADAOH = 1 / 0.066 / 0.15 / 0.1 / 100 / 0.04, SiO 2 ₂ / Al ₂ O ₃ = 15.

The same support as in Example 2 was used after being treated in the same manner.
The support was immersed in a slurry in which the seed crystal 3 synthesized above was dispersed in water at 4% by mass, and then dried under the same conditions as in Example 1 to attach the seed crystal. The mass of the attached seed crystal was 5.2 g / m ² .

A zeolite membrane composite 3 was obtained by forming a zeolite membrane on the support to which the seed crystal 3 was adhered under the same conditions as in Example 1 and then firing. The mass of the CHA-type zeolite crystallized on the support, which was determined from the difference between the mass of the membrane composite after firing and the mass of the support, was 130 g / m ² .

The air permeation amount of the zeolite membrane composite 3 was 50 L / (m ² · h).

  When XRD of the produced membrane was measured, it was found that CHA-type zeolite was produced.

The SiO ₂ / Al ₂ O ₃ molar ratio of the zeolite membrane measured by SEM-EDX was 17.

[Example 5]
The zeolite membrane composite 3 obtained in Example 4 was subjected to separation by selectively permeating water from a 70 ° C. water / 2-propanol mixed solution (30/70 mass%) by a pervaporation method.

The permeation results 4 hours after the start of permeation were permeation flux: 5.3 kg / (m ² · h), separation factor: 31000, and water concentration in the permeate: 99.99% by mass. The water permeance was 3.1 × 10 ⁻⁶ mol / (m ² · s · Pa).

[Example 6]
Separation in which water is selectively permeated from a water / N-methyl-2-pyrrolidone mixed solution (30/70% by mass) at 70 ° C. by the pervaporation method using the zeolite membrane composite 3 obtained in Example 4. Went.

The permeation results 4 hours after the start of permeation were permeation flux: 4.3 kg / (m ² · h), separation factor: 23100, and water concentration in the permeate: 99.99% by mass. The water permeance was 3.1 × 10 ⁻⁶ mol / (m ² · s · Pa).

[Example 7]
(Synthesis of seed crystal 4)
For hydrothermal synthesis having a composition (molar ratio) of SiO ₂ / Al ₂ O ₃ / NaOH / KOH / H ₂ O / TMADAOH = 1 / 0.033 / 0.1 / 0.06 / 40 / 0.07 The reaction mixture was prepared as follows.

To a mixture of 50 g of 1 mol / L-NaOH aqueous solution, 30 g of 1 mol / L-KOH aqueous solution and 213 g of water, 3.15 g of aluminum hydroxide (containing 53.5% by mass of Al ₂ O ₃ , manufactured by Aldrich) was added and stirred. Dissolved to give a clear solution. 29.6 g of TMADAOH aqueous solution (containing 25% by mass of TMADAOH, manufactured by Seychem) was added thereto, and 75 g of colloidal silica (Snowtech-40 manufactured by Nissan Chemical Co., Ltd.) was further added and stirred for 2 hours to obtain a reaction mixture.

The Teflon (registered trademark) inner cylinder (1 L) containing the reaction mixture was sealed in a 1 L induction stirring autoclave, stirred at 150 rpm using an anchor blade, and heated at 160 ° C. for 48 hours under autogenous pressure. And heated. The mixture was allowed to cool after a predetermined time, and the reaction mixture was taken out, filtered, washed and dried at 100 ° C. for 5 hours or more to obtain 35 g of zeolite crystals. This zeolite crystal was pulverized using an agate mortar to obtain seed crystal 4. D _{90 of} seed crystal 4 was 12.6 μm, D ₁₀ was 4.2 μm, D ₅₀ (median diameter) was 7.4 μm, and (D ₉₀ -D ₁₀ ) / D ₅₀ was 1.1.

(Preparation of inorganic porous support CHA-type zeolite membrane composite 4)
A reaction mixture for hydrothermal synthesis was prepared in the same manner as in Example 4. The same porous support as in Example 2 was treated and used.

The support was immersed in a slurry in which the seed crystal 4 synthesized above was dispersed in water at 3 mass%, and then dried under the same conditions as in Example 1 to attach the seed crystal. The mass of the attached seed crystal was 3.4 g / m ² .

A zeolite membrane composite 4 was obtained by forming a zeolite membrane on the support to which the seed crystal 4 was adhered under the same conditions as in Example 1 and then firing. The mass of the CHA-type zeolite crystallized on the support, which was determined from the difference between the mass of the membrane composite after firing and the mass of the support, was 140 g / m ² .

The air permeability of the zeolite membrane composite 4 was 290 L / (m ² · h).

  When XRD of the produced membrane was measured, it was found that CHA-type zeolite was produced.

[Example 8]
The zeolite membrane composite 4 obtained in Example 7 was subjected to separation by selectively permeating water from a 70 ° C. water / acetic acid mixed solution (50/50 mass%) by a pervaporation method.

The permeation results after 5 hours from the start of permeation were permeation flux: 5.6 kg / (m ² · h), separation factor: 960, and water concentration in the permeate: 99.89% by mass. The water permeance was 3.6 × 10 ⁻⁶ mol / (m ² · s · Pa).

[Example 9]
(Synthesis of seed crystal 5)
For hydrothermal synthesis having a composition (molar ratio) of SiO ₂ / Al ₂ O ₃ / NaOH / KOH / H ₂ O / TMADAOH = 1 / 0.033 / 0.1 / 0.06 / 40 / 0.07 The reaction mixture was prepared as follows.

A mixture of 50 g of 1 mol / L-NaOH aqueous solution, 30 g of 1 mol / L-KOH aqueous solution and 213 g of water was added with 3.2 g of aluminum hydroxide (containing 53.5% by mass of Al ₂ O ₃ , manufactured by Aldrich) and stirred. Dissolved to give a clear solution. To this was added 29.6 g of TMADAOH aqueous solution (containing 25% by weight of TMADAOH, manufactured by Sechem Co.), and 75 g of colloidal silica (Snowtech-40 manufactured by Nissan Chemical Co., Ltd.) was further added to be used for synthesizing seed crystal 1 in Example 1. 0.6 g of the seed crystal was added and stirred for 2 hours to obtain a reaction mixture.

The Teflon (registered trademark) inner cylinder (1 L) containing the above reaction mixture was sealed in a 1 L induction stirring autoclave, stirred at 100 rpm using an anchor blade, and heated at 160 ° C. for 48 hours under autogenous pressure. And heated. The mixture was allowed to cool after a predetermined time, and the reaction mixture was taken out, filtered, washed, and dried at 100 ° C. for 5 hours or more to obtain 35 g of zeolite crystals. The zeolite crystals were pulverized using an agate mortar to obtain seed crystals 5. D _{90 of} seed crystal 5 was 7.2 μm, D ₁₀ was 1.2 μm, D ₅₀ (median diameter) was 3.3 μm, and (D ₉₀ -D ₁₀ ) / D ₅₀ was 1.8.

(Preparation of inorganic porous support CHA-type zeolite membrane composite 5)
A reaction mixture for hydrothermal synthesis was prepared in the same manner as in Example 4. The same porous support as in Example 1 was treated and used.

The support was immersed in a slurry in which the seed crystal 5 synthesized above was dispersed in water at 1% by mass, and then dried under the same conditions as in Example 1 to attach the seed crystal. The mass of the attached seed crystal was 0.9 g / m ² .

A zeolite membrane composite 5 was obtained by forming a zeolite membrane on the support to which the seed crystal 5 was adhered under the same conditions as in Example 1 and then firing. The mass of the CHA-type zeolite crystallized on the support, which was determined from the difference between the mass of the membrane composite after firing and the mass of the support, was 130 g / m ² .

The air permeation amount of the zeolite membrane composite 5 was 50 L / (m ² · h).

  When XRD of the produced membrane was measured, it was found that CHA-type zeolite was produced.

[Example 10]
The zeolite membrane composite 5 obtained in Example 9 was subjected to separation by selectively permeating water from a 70 ° C. water / acetic acid mixed solution (50/50 mass%) by a pervaporation method.

The permeation results after 5 hours from the start of permeation were permeation flux: 5.5 kg / (m ² · h), separation factor: 2100, and water concentration in the permeate: 99.95% by mass. The water permeance was 3.5 × 10 ⁻⁶ mol / (m ² · s · Pa).

[Comparative Example 1]
(Synthesis of seed crystal 6)
A reaction mixture for hydrothermal synthesis having a composition (molar ratio) of SiO ₂ / Al ₂ O ₃ / NaOH / H ₂ O / TMADAOH = 1 / 0.066 / 0.2 / 40 / 0.1 is as follows: Prepared.

182.5 g of water was added to 80 g of a 1 mol / L-NaOH aqueous solution, and 5.0 g of aluminum hydroxide (containing 53.5% by mass of Al ₂ O ₃ , manufactured by Aldrich) was added and dissolved by stirring to obtain a transparent solution. . 34 g of TMADAOH aqueous solution (containing 25% by mass of TMADAOH, manufactured by Sechem Co.) was added to this, 24 g of fumed silica (Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.) was further added, and 0.5 g of the seed crystal described in Example 1 was further added. Stir for hours to give a reaction mixture.

The Teflon (registered trademark) inner cylinder (1 L) containing the above reaction mixture was sealed in a 1 L induction stirring autoclave, stirred at 150 rpm using an anchor blade, and heated at 160 ° C. for 48 hours under an autogenous pressure. And heated. The mixture was allowed to cool after a predetermined time, and the reaction mixture was taken out, filtered and washed, and then dried at 100 ° C. for 5 hours or more to obtain 30 g of zeolite crystals. This zeolite crystal was pulverized using an agate mortar to obtain seed crystal 6. D _{90 of} seed crystal 6 was 8.2 μm, D ₁₀ was 0.9 μm, D ₅₀ (median diameter) was 3.0 μm, and (D ₉₀ -D ₁₀ ) / D ₅₀ was 2.4.

(Preparation of inorganic porous support CHA-type zeolite membrane composite 6)
A reaction mixture for hydrothermal synthesis having the same composition as in Example 1 was prepared. The same porous support as in Example 2 was treated and used.

The support was immersed in a slurry in which the seed crystal 6 synthesized above was dispersed in water at 4% by mass, and then dried under the same conditions as in Example 1 to attach the seed crystal. The mass of the attached seed crystal was 3.6 g / m ² .

A zeolite membrane composite 6 was obtained by forming a zeolite membrane on the support on which the seed crystal 6 was adhered under the same conditions as in Example 1 and then firing. The mass of the CHA zeolite crystallized on the support, which was determined from the difference between the mass of the membrane composite after firing and the mass of the support, was 120 g / m ² .

  When XRD of the produced membrane was measured, it was found that CHA-type zeolite was produced.

The air permeation amount of the zeolite membrane composite 6 was 2500 L / (m ² · h). This zeolite membrane was presumed to have defects due to a large amount of air permeation.

[Comparative Example 2]
(Preparation of inorganic porous support CHA-type zeolite membrane composite 7)
A reaction mixture for hydrothermal synthesis (for forming a zeolite membrane) having the same composition as in Example 4 was prepared. The same porous support as in Example 2 was treated and used.

The support was immersed in a slurry in which seed crystal 6 synthesized in Comparative Example 1 was dispersed in water at 4% by mass, and then dried under the same conditions as in Example 1 to attach the seed crystal. The mass of the attached seed crystal was 4.0 g / m ² .

A zeolite membrane composite 7 was obtained by forming a zeolite membrane on the support to which the seed crystal 6 was adhered under the same conditions as in Example 1 and then firing. The mass of the CHA zeolite crystallized on the support, which was determined from the difference between the mass of the membrane composite after firing and the mass of the support, was 110 g / m ² .

The air permeation amount of the zeolite membrane composite 7 was 1500 L / (m ² · h). This zeolite membrane was presumed to have defects due to a large amount of air permeation.

  When XRD of the produced membrane was measured, it was found that CHA-type zeolite was produced.

As in Comparative Examples 1 and 2, when a seed crystal having a particle size distribution [(D ₉₀ -D ₁₀ ) / D ₅₀ ] exceeding 2.2 is used, a zeolite membrane having a large air permeation amount after firing, that is, a defect exists. Is assumed to generate.

  The present invention can be used in any industrial field. For example, water is separated from a water-containing organic compound such as a chemical plant, a fermentation plant, a precision electronic component factory, a battery manufacturing factory, etc. It can be particularly suitably used in a required field.

1 Stirrer 2 Hot water bath 3 Stirrer 4 Liquid to be separated 5 Zeolite membrane composite 6 Pirani gauge 7 Trap for permeate collection 8 Cold trap 9 Vacuum pump

Claims (9)

A method for producing a porous support-zeolite membrane composite by forming a zeolite membrane on a porous support by hydrothermal synthesis, wherein the zeolite membrane contains CHA-type zeolite, (1):
_{(D 90 -D 10) / D} 50 (1)
[In formula (1), D ₉₀ , D ₁₀ and D ₅₀ are cumulative distribution diagrams obtained by particle size distribution measurement (volume basis, integrated from the smallest particle diameter) and give a height of 90%. The diameter gives a 10% height and a 50% height (median diameter). ]
A method for producing a porous support-zeolite membrane composite, which is performed in the presence of a seed crystal having a particle size distribution of 0.3 to 1.8 . The method according to claim 1, wherein the seed crystal has a median diameter (D ₅₀ ) of 20 μm or less.   The method according to claim 1 or 2, wherein a seed crystal is previously attached to the porous support, and a zeolite membrane is formed on the porous support to which the seed crystal is attached. A porous support-zeolite membrane composite produced by the method according to any one of claims 1 to 3 . A porous support-zeolite membrane composite obtained by forming a zeolite membrane by hydrothermal synthesis on a porous support , wherein the zeolite membrane contains CHA-type zeolite, and the zeolite membrane composite is Air permeation when connected to a 5 kPa vacuum line is 1400 L / (m ²
H) A porous support-zeolite membrane composite characterized by: The porous support-zeolite membrane composite according to claim 5, wherein the zeolite constituting the zeolite membrane is an aluminosilicate. The zeolite membrane has the following formula (1):
_{(D 90 -D 10) / D} 50 (1)
[In formula (1), D ₉₀ , D ₁₀ and D ₅₀ are cumulative distribution diagrams obtained by particle size distribution measurement (volume basis, integrated from the smallest particle diameter) and give a height of 90%. The diameter gives a 10% height and a 50% height (median diameter). The porous material according to claim 5 or 6 , which is formed by hydrothermal synthesis in the presence of a seed crystal having a particle size distribution of 0.3 to 1.8. Support- zeolite membrane composite. The porous support-zeolite membrane composite according to any one of claims 4 to 7, wherein the porous support is an inorganic porous support including a sintered ceramic. The porous support-zeolite membrane composite according to any one of claims 4 to 8 is brought into contact with a gas or liquid mixture containing an organic substance, and a highly permeable substance is permeated from the mixture. Separation method characterized by separating.

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