JP2017221945A - Porous support-zeolite membrane composite body and separation method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porous support-zeolite membrane composite body which permits both of practically adequate processing quantity and separation performance in separation and concentration by means of inorganic material separation membrane, and to provide a separation and concentration method using the zeolite membrane composite body.SOLUTION: A porous support-zeolite membrane composite body is prepared by forming a zeolite membrane on a porous support. Therein, an average thickness of the porous support is 0.1 to 7 mm and an index for representing pore distribution of the support is 40% or less, which is determined by a pore distribution measurement according to a mercury penetration method and is calculated by the following relation (1): (D-D)/D(1). (In the relation, D, D, and Deach are pore diameter when the sum of pore volume accumulated from large pore gets to 5% of the total pore volume, gets to 50% of the total pore volume, and gets to 95% of the total pore volume.)SELECTED DRAWING: None

Description

The present invention relates to a porous support-zeolite membrane composite, and more specifically, permeates and separates a highly permeable substance from a gas or liquid mixture containing an organic substance, and concentrates the low permeable substance. And a separation method using the zeolite membrane composite.

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.

The object of the present invention is to separate the inorganic material separation membrane by solving such problems of the prior art.
An object of the present invention is to provide a porous support-zeolite membrane composite that achieves both a practically sufficient throughput and separation performance, 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 investigations, the inventors of the present invention have found that if the distribution of the pore diameter of the porous support is within a specific range, the porosity, the average pore diameter and the thickness of the porous support are high without changing. It has been found that the permeation flux can be achieved. The present invention has been accomplished based on these findings.

That is, the gist of the present invention resides in the following [1] to [11].
[1] A porous support-zeolite membrane composite formed by forming a zeolite membrane on a porous support, the average thickness of the porous support being 0.1 mm or more and 7 mm or less, and mercury It is calculated | required by the pore distribution measurement by a press injection method, and following formula (1):
_{(D 5 -D 95) / D} 50 (1)
(In the formula, D ₅ , D ₅₀ and D ₉₅ are the pore diameter when the total amount of pore volume accumulated from large pores is 5% of the total pore volume, and 50 of the total pore volume, respectively. And the pore diameter when 95% of the total pore volume.)
The porous support-zeolite membrane composite characterized in that the index representing the pore distribution of the support calculated by the formula is 40 or less.
[2] The porous support-zeolite membrane composite as described in [1] above, wherein the porous support is subjected to surface polishing until the surface roughness (Ra) is 1.2 or less. body.
[3] The above [1] or [3], wherein the porous support is a ceramic support
[2] The porous support-zeolite membrane composite according to [2].
[4] The above-mentioned [1], wherein the zeolite membrane contains CHA-type zeolite.
] To [3], the porous support-zeolite membrane composite.
[5] A gas or liquid mixture containing an organic substance is brought into contact with the porous support-zeolite membrane composite according to any one of [1] to [4] above, and a highly permeable substance is obtained from the mixture. A separation method characterized in that the separation is carried out.
[6] A porous support-zeolite membrane composite formed by forming a zeolite membrane on a porous support, the average thickness of the porous support being 0.1 mm or more and 7 mm or less, and mercury It is calculated | required by the pore distribution measurement by a press injection method, and following formula (2):
(LogD ₅ -logD ₉₅ ) / logD ₅₀ (2)
(In the formula, D ₅ , D ₅₀ and D ₉₅ are the pore diameter when the total amount of pore volume accumulated from large pores is 5% of the total pore volume, and 50 of the total pore volume, respectively. And the pore diameter when the pore volume is 95% of the total pore volume, log represents a common logarithm.)
The porous support-zeolite membrane composite characterized in that the index representing the pore distribution of the support calculated by is 7 or less.
[7] A porous support-zeolite membrane composite formed by forming a zeolite membrane on a porous support, the average thickness of the porous support being 0.1 mm or more and 7 mm or less, and mercury It is calculated | required by the pore distribution measurement by a press injection method, and following formula (2):
(LogD ₅ -logD ₉₅ ) / logD ₅₀ (2)
(In the formula, D ₅ , D ₅₀ and D ₉₅ are the pore diameter when the total amount of pore volume accumulated from large pores is 5% of the total pore volume, and 50 of the total pore volume, respectively. The pore size of the porous support-zeolite membrane composite is calculated by the following equation: log represents the pore diameter at 95% and the pore diameter at 95% of the total pore volume. A porous support-zeolite membrane composite, wherein the index representing is 7 or less.
[8] The porous support according to [6] or [7], wherein the porous support is surface-polished until the surface roughness (Ra) becomes 1.2 or less. -Zeolite membrane composite.
[9] The above [6] to [8], wherein the porous support is a ceramic support.
] The porous support-zeolite membrane composite according to any one of the above.
[10] The zeolite membrane contains CHA-type zeolite [6]
Thru | or the porous support-zeolite membrane composite in any one of [9].
[11] A gas or liquid mixture containing an organic substance is brought into contact with the porous support-zeolite membrane composite according to any one of [6] to [10], and a highly permeable substance is formed from the mixture. Separation method characterized by permeating and separating.

According to the present invention, when a specific compound is separated and concentrated from a gas or liquid mixture containing an organic substance, the porous support-zeolite membrane has a sufficiently large throughput for practical use and sufficient separation performance. A complex is provided. By using this zeolite membrane composite as a separation means, it is 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. It is a mercury intrusion method indentation curve obtained by the pore distribution measurement by the mercury intrusion method of the porous support body (ceramics support body) used in Example 1 and Comparative Example 1. In the figure, the solid line is the curve of the porous support 1 used in Example 1, and the broken line is the curve of the porous support 2 used in Comparative Example 1.

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 porous support-zeolite membrane composite of the present invention is a porous support-zeolite membrane composite formed by forming a zeolite membrane on a porous support, and the average thickness of the porous support is 0.
It is 1 mm or more and 7 mm or less, and it is calculated | required by the pore distribution measurement by a mercury intrusion method, and following formula (1):
_{(D 5 -D 95) / D} 50 (1)
(In the formula, D ₅ , D ₅₀ and D ₉₅ are the pore diameter when the total amount of pore volume accumulated from large pores is 5% of the total pore volume, and 50 of the total pore volume, respectively. Is an index representing the pore distribution of the support (hereinafter, expressed by “Expression (1)”). "Indicator of pore distribution" or simply "Indicator (
1) ". ) Is 40 or less.

And / or the porous support-zeolite membrane composite of the present invention is a porous support-zeolite membrane composite formed by forming a zeolite membrane on the porous support, and is an average of the porous support. The thickness is 0.1 mm or more and 7 mm or less, and is obtained by pore distribution measurement by mercury porosimetry, and the following formula (2):

(LogD ₅ -logD ₉₅ ) / logD ₅₀ (2)
(In the formula, D ₅ , D ₅₀ and D ₉₅ are the pore diameter when the total amount of pore volume accumulated from large pores is 5% of the total pore volume, and 50 of the total pore volume, respectively. And the pore diameter when the pore volume is 95% of the total pore volume, log represents a common logarithm.)
The index representing the pore distribution of the support or the porous support-zeolite membrane composite (hereinafter referred to as “the index of pore distribution represented by the formula (2)”) or simply “index (2 ) ").) Is 7 or less.
In the present specification, the “porous support-zeolite membrane composite” of the present invention is simply referred to as “zeolite membrane composite” or “membrane composite”, and the “porous support” is simply referred to as “support”. May be abbreviated.

(Porous support)
The support used in the zeolite membrane composite of the present invention has a chemical stability that allows the zeolite to be crystallized in the form of a membrane on the surface thereof, and is a support made of an inorganic porous material (inorganic porous support). Any body). For example, silica, α-alumina, γ
-Ceramic sintered bodies (ceramic support) such as alumina, mullite, zirconia, titania, yttria, silicon nitride, and silicon carbide, sintered metals such as iron, bronze, and stainless steel, glass, and carbon molded bodies.

Among these porous supports, there are inorganic porous supports including those obtained by sintering ceramics (ceramic supports), 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 synthesis of the zeolite membrane, so that there is an effect of improving the adhesion at the interface.
Specifically, for example, silica, α-alumina, γ-alumina, mullite, zirconia,
Examples thereof include a ceramic sintered body (ceramic support) containing 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 in the form of a film on the surface of the porous 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 thickness (wall thickness) of the support is usually at least 0.1 mm, preferably at least 0.3 mm, more preferably at least 0.5 mm, usually at most 7 mm, preferably at most 5 mm, more preferably at most 3 mm. 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 May be weak. If the average thickness of the support is too thick, the permeation of the permeated substance may worsen and the permeation flux may be lowered.

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.

Furthermore, the support used in the present invention is determined by pore distribution measurement by mercury porosimetry,
Formula _{(1): (D 5 -D} 95) / D 50 (1)
(In the formula, D ₅ , D ₅₀ and D ₉₅ are the pore diameter when the total amount of pore volume accumulated from large pores is 5% of the total pore volume, and 50 of the total pore volume, respectively. The index representing the pore distribution of the support calculated by the formula (1) indicates the pore diameter when it becomes% and the pore diameter when it becomes 95% of the total pore volume. Details of the pore distribution measurement by the mercury intrusion method will be described in Examples.

The index representing the pore distribution of the support represented by the above formula (1) is usually 40 or less,
Preferably it is 30 or less, more preferably 20 or less, particularly preferably 10 or less. The lower limit is not particularly limited, but is usually 0.1 or more, preferably 0.5 or more, more preferably 1 or more.

The support used in the present invention is determined by pore distribution measurement by mercury porosimetry, and the following formula (2):
(LogD ₅ -logD ₉₅ ) / logD ₅₀ (2)
(In the formula, D ₅ , D ₅₀ and D ₉₅ are the pore diameter when the total amount of pore volume accumulated from large pores is 5% of the total pore volume, and 50 of the total pore volume, respectively. % Represents the pore diameter at 95% of the total pore volume and log represents the common logarithm), and the index representing the pore distribution of the support is 7 or less. It has a value.

The index representing the pore distribution of the support represented by the above formula (2) is usually 7 or less,
Preferably it is 6.5 or less, More preferably, it is 6 or less, Most preferably, it is 5.5 or less. The lower limit is not particularly limited, but is usually 0.1 or more, preferably 0.5 or more, more preferably 1
That's it.
The values of the formulas (1) and (2) are indices representing the pore distribution. The smaller this value, the more uniform the pore distribution of the support. If the pore distribution is uniform, the resistance decreases as the gas diffuses in the support, so the distribution of the diffusion rate in the support also decreases, increasing the diffusion rate and improving the permeation flux. To do. When the pore distribution of the support is large, there are various shapes of flow paths, which is disadvantageous for fluid diffusion and the permeation flux becomes small.

When a support having a more uniform pore distribution is used, the seed crystal is supported more uniformly when the support is loaded with a seed crystal to be described later to synthesize a zeolite membrane composite. Advantageously, a zeolite membrane with few defects tends to be formed on the support. In addition, it is advantageous in that the amount of necessary seed crystals tends to be small.
As described above, in the present invention, the pore distribution of the support is (D ₅ -D ₉₅ ) / D _5.
0 but is less than _{40, D 50} is usually 0.02μm or more, preferably 0.05μm or more, more preferably 0.1μm or more, usually 20μm or less, preferably 10μm or less,
More preferably, it is 5 μm or less. D ₅₀ tends to permeation amount decreases too small, the strength of the support itself too large may become insufficient, dense zeolite membrane is formed by increasing the proportion of the pores of the support surface It may be difficult.

Further, D ₅ is usually 0.05 μm or more, preferably 0.1 μm or more, more preferably 0.
. It is 2 μm or more, usually 300 μm or less, preferably 100 μm or less, more preferably 80 μm or less, further preferably 50 μm or less, particularly preferably 20 μm or less, and most preferably 10 μm or less. Tend D permeation amount and ₅ is too small decreases, the strength of the support itself too large may become insufficient, dense zeolite membrane is formed by increasing the proportion of the pores of the support surface It may be difficult.

_{Further, D 95} is usually 0.005μm or more, preferably 0.01μm or more, more preferably 0.05μm or more, more preferably 0.1μm or more, usually 10μm or less, preferably 5μm or less, more preferably 3μm It is as follows. If _D95 is too small, the amount of permeation tends to be small, and 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 increases to form a dense zeolite membrane. It may be difficult.

The pore distribution index represented by the formula (1) can be used as a simple index representing the pore distribution of the support. The index (1) is D ₅ , D ₉₅ , D representing the pore diameter in the calculation.
_The index representing the pore distribution is defined in a more easily understood form using ₅₀ as it is. However, since the pore diameter measured by pore distribution measurement by mercury porosimetry is very wide from 404 μm to 0.0036 μm as described in the following examples, the change in the value of the large pore diameter region is the pore diameter. Tends to be overestimated than small changes.

For example, when D ₉₅ = 1 μm and D ₅ = 100 μm, and each error is ± 50% of the value, when index (1) is used, D ₉₅ = 1 ± 0.5 μm and D ₅ = 100 ± 50 μm Become.
Thus, the error in the region having a large pore diameter value is a very large value even if the error ratio is the same as that in the region having a small pore diameter value. When the error range is expressed in logarithmic notation (common), logD ₉₅ = 0 (−0.3 to 0.18), log D ₅ = 2 (1.70 to 2.1).
8), and the error width is the same value for both the large and small pore sizes. (0.48 in this case)

Thus, when comparing the pore diameter regions in a very wide pore diameter distribution, it is more appropriate to use a numerical value expressed in logarithmic notation than an actual numerical value.
Therefore, it is desirable to take a common logarithm of the pore diameter in order to more accurately represent the actual state of the pore distribution. Therefore, it is desirable to use the index represented by the formula (2) represented by the common logarithm of the pore diameter.
Here, conventionally, a mixture of water and an organic compound using a porous support-zeolite membrane composite (
Hereinafter, this is sometimes referred to as “hydrous organic compound”. In the separation of), the factors affecting the permeation flux include the porosity ε, the average pore diameter d, and the thickness (thickness) 1 of the support, and the pressure loss expressed using these factors as well. The smaller the exit coefficient 1 / (ε · d), that is, the higher the porosity, the larger the average pore diameter, and the thinner the porous support, the greater the permeation flux (25th). Zeolite Research Presentation “Presentation Lectures”, page 56, November 2009)
.

However, when the porosity of the porous support is high, the average pore diameter is large, and the thickness is thin, there arises a problem that the strength of the porous support is reduced. Therefore, a method for realizing a high permeation flux without changing the porosity, average pore diameter, and thickness of the porous support has been desired.
By using a support whose index representing the pore distribution of the support is the above specific value,
A zeolite membrane composite having a high permeation flux can be provided without changing the porosity, average pore diameter, and thickness (wall thickness) of the support.

The porous support has a pore distribution index value of 40 expressed by the formula (1).
It is necessary that the value of the pore distribution index represented by the following formula (2) is 7 or less.
The means for obtaining a support having the index (1) or the index (2) satisfying the above values is not particularly limited. For example, a support having a narrow pore distribution can be obtained by adjusting the production conditions of the support. Examples thereof include a manufacturing method and a method of removing the surface layer of the support by a method such as polishing.

As a method for adjusting the production conditions of the support, conventionally known methods can be used as appropriate, for example, a method of reducing the variation in the size of the raw material particles constituting the support, a firing temperature, a temperature rise during firing. A method of optimizing firing conditions such as speed, and a method of optimizing the kind and amount of the sintering aid may be used when a sintering aid is used during the production of the support.
In the method of removing the surface layer of the support by a method such as polishing, the fine layer distribution on the surface of the ceramic support is removed by polishing or the like, thereby reducing the pore size distribution of the support. The porous support of the porous support-zeolite membrane composite used for the separation membrane or the like is usually a ceramic support. The ceramic support is manufactured by firing after extrusion molding. Therefore, the porosity of the surface is smaller than the inside, that is, the surface tends to be denser than the inside. Therefore, the pore size distribution of the support can be reduced by removing the dense layer on the surface of the inorganic ceramics by polishing or the like.

When removing the dense layer on the surface of the support by polishing the surface, the weight of the support to be removed is not particularly limited as long as the dense layer is removed, but the surface roughness is used as an index indicating the degree of removal. Usually, the surface roughness (Ra) may be 1.2 or less. The surface roughness (Ra) is preferably 1.1 or less, more preferably 1.0 or less. Although a minimum is not specifically limited, Usually, 0.3 or more, Preferably it is 0.4 or more, More preferably, it is 0.5 or more.

If the surface roughness (Ra) is too small, the zeolite seed crystals may be insufficiently adhered to the support in the step of forming a zeolite membrane on the support.
The method for polishing the surface of the support is not particularly limited, and examples thereof include a method of polishing using a sandpaper, a cloth file, a polishing paste, or the like. As a method of polishing with a sandpaper or a cloth file, the support or the pressed portion is moved while the files are pressed against the support by human power or a machine.
The material of the abrasive grains of sandpaper or cloth is not particularly limited, but silicon carbide (SiC) is preferable.

The roughness of sandpaper or cloth is usually # 200 or more and # 20000 or less, preferably # 500 or more and # 10000 or less. One kind of file with coarseness of the eyes may be used, and the coarseness of the eyes may be gradually made finer as the polishing progresses. If the roughness of the eyes is too rough, there is a risk that the surface of the support is damaged by the abrasive grains and the unevenness is increased. If the coarseness of the eyes is too fine, the abrasive grains are immediately peeled off from the sandpaper or cloth, and a large amount of sandpaper or cloth is required for polishing, which is not economical.

The polishing method using sandpaper or cloth may be wet polishing in which the file and the support are wetted with water, or dry polishing in which the polishing is performed in a dry state. As a polishing method other than using sandpaper or cloth, a method of cutting the surface of the support with a lathe can also be used.
Whichever polishing method is used, it is desirable to wash and dry the support polished before the production of the membrane composite. Cleaning methods include cleaning with running water and cleaning with an ultrasonic cleaner. Without washing, the fine powder generated by polishing will clog the pores of the porous support,
This may contribute to a decrease in the permeation flux.
Examples of the method other than the polishing in which the surface roughness (Ra) is 1.2 or less include a method of dissolving the surface of the support with an acid and a method of dissolving the surface of the support with an alkali.
The surface roughness (Ra) measurement method is not particularly limited, but a contact-type measurement method such as a measurement method using a surface roughness meter, or a measurement method using a laser microscope. There is such a non-contact type measuring method, and a measuring method using a surface roughness meter is usually used. Details of the method for measuring the surface roughness (Ra) using a surface roughness meter will be described in Examples.

(Zeolite membrane composite)
In the present invention, a zeolite membrane is formed on the porous support to form a porous support-zeolite membrane composite.
In the present invention, specific examples of zeolite constituting the membrane include silicates and phosphates. 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.

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 is preferably a zeolite membrane substantially composed only of zeolite.

The thickness of the zeolite membrane is not particularly limited, but is usually 0.1 μm or more, preferably 0.6 μm.
m or more, more preferably 1.0 μm or more, usually 100 μm or less, preferably 60 μm.
m or less, more preferably in the range of 20 μm or less. If the film thickness is too large, the amount of permeation tends to decrease. If it is too small, the selectivity tends to decrease or the film strength tends to decrease. If the film thickness is too large, the amount of transmission tends to decrease.

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, usually 30 nm or more, preferably 50 n
m or more, more preferably 100 nm or more, and the upper limit is less than the thickness of the film. Furthermore, it is particularly preferred that the zeolite particle size is the same as the membrane thickness. This is because when the particle diameter of the zeolite is the same as the thickness of the membrane, the grain boundary of the zeolite is the smallest.

The SiO ₂ / Al ₂ O ₃ molar ratio of the zeolite 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 1000 or less, Preferably 500 or less, particularly preferably 100
It is as follows. If the SiO ₂ / Al ₂ O ₃ molar ratio is less than the lower limit, the durability tends to decrease,
If the upper limit is exceeded, the permeation flux tends to be small 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 has the largest number of oxygen in the pores composed of oxygen forming the zeolite skeleton and T element (element other than oxygen constituting the skeleton). Show things. 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 6-10 membered ring structure include AEI, AEL, and AFG.
, ANA, BRE, CAS, CDO, CHA, DAC, DDR, DOH, EAB, EPI
, ESV, EUO, FAR, FRA, 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 and the like.

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, PAU, RHO, RTH, SOD, STI, TOL,
UFI etc. are mentioned.
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 deteriorate the separation performance, and the use may be limited.

When separating small molecules such as H ₂ O molecules from other molecules, if the pore size is large, it is difficult to separate molecules that are smaller than the pore size and larger than the H ₂ O molecule. Zeolite having a 6-8 membered ring structure is particularly desirable.
The framework density of the zeolite (T / 1000 ³ ) is not particularly limited, but is usually 1
It is 7 or less, preferably 16 or less, more preferably 15.5 or less, and particularly preferably 15 or less, and is usually 10 or more, preferably 11 or more, more preferably 12 or more.

The framework density means the number of elements (T elements) constituting a skeleton other than oxygen per 1000 ³ of the zeolite, and this value is determined by the structure of the zeolite. Therefore it means that space per 1000 Å ³ as the framework density is small is large, the framework as the density is less fast diffusion rate of a substance in the zeolite, the permeation flux is increased when the zeolite membrane. Therefore, it is desirable that the framework density is small.
On the other hand, if the framework density is too low, the framework structure of zeolite becomes brittle and the crystal structure is easily broken. The relationship between the framework density and the structure of zeolite is ATLAS OF ZEOLITE FRAMEWORK TYPES Fifth Revised Edition.
Shown in 2001 ELSEVIER.

In the present invention, preferred zeolite structures are AEI, AFG, CHA, EAB, E
RI, ESV, FAR, FRA, GIS, ITE, KFI, LEV, LIO, LOS, L
TN, MAR, PAU, RHO, RTH, SOD, STI, TOL, UFI, more preferably AEI, CH having an 8-membered ring structure and having a two-dimensional or three-dimensional structure
A, ERI, KFI, LEV, PAU, RHO, RTH, UFI. Further preferred structures are CHA and LEV, and the most preferred structure is the CHA type. The zeolite is preferable because it has high structural stability and a high diffusion rate of the substance in the zeolite, and can increase the permeation flux when combined with the support. .

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. It is a zeolite having a crystal structure equivalent to that of naturally occurring chabasite. CHA type zeolite is 3.8 ×
It has a structure characterized by having three-dimensional pores composed of an 8-membered oxygen ring having a diameter of 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.
The porous support-zeolite membrane composite of the present invention is determined by pore distribution measurement by mercury porosimetry, and the following formula (2):
(LogD ₅ -logD ₉₅ ) / logD ₅₀ (2)
(In the formula, D ₅ , D ₅₀ and D ₉₅ are the pore diameter when the total amount of pore volume accumulated from large pores is 5% of the total pore volume, and 50 of the total pore volume, respectively. The pore size of the porous support-zeolite membrane composite is calculated by the following equation: log represents the pore diameter at 95% and the pore diameter at 95% of the total pore volume. Is 7 or less.

The index representing the pore distribution of the zeolite membrane composite represented by the above formula (2) is usually 7 or less, preferably 6.5 or less, like the index representing the pore distribution of the support. Preferably 6
Hereinafter, it is particularly preferably 5.5 or less. The lower limit is not particularly limited, but is usually 0.1 or more, preferably 0.5 or more, more preferably 1 or more.
The value of formula (2) is the same as the index representing the pore distribution of the support, and the smaller the value, the more uniform the pore distribution of the zeolite membrane composite. The effect of uniform pore distribution is the same as the above effect on the support. If the pore distribution of the zeolite membrane composite is large,
Since there are various shapes of flow paths, it is disadvantageous for fluid diffusion and the permeation flux is reduced.

Incidentally, in the zeolite membrane composite of the present _invention, the value of D _{5, D 50} and _{D 95} are the same as the value of _{D 5, D 50} and _{D 95} in the support.
Further, as an index representing the pore distribution of the zeolite membrane composite of the present invention, the index obtained by the above formula (2) is used. As described above for the index representing the pore distribution of the support, the formula (
This is because the index obtained in 2) expresses the state of the pore distribution more accurately.

Specifically, most of the pores in the porous support-zeolite membrane composite of the present invention are pores derived from a commonly used porous support. Therefore, the pore distribution of the porous support-zeolite membrane composite is substantially the same as the pore distribution of the porous support used, and the formula of the porous support-zeolite membrane composite and the porous support used is The index representing the pore distribution represented by (2) is:
It is almost the same value. Since some of the pores of the support are filled with zeolite crystals during the preparation of the zeolite membrane, the pore size of the porous support-zeolite membrane composite of the present invention tends to be slightly smaller than the pore size of the support. There is also a case where the pore size is shifted to the smaller pore size while maintaining the distribution shape. The pore size shift that can be caused by making a zeolite membrane on a porous support may change due to lot variation during zeolite synthesis, so the pore distribution of the porous support-zeolite membrane composite Is used, the index represented by the formula (2) that represents the pore distribution more accurately is used. When actually using a zeolite membrane composite for various separation processes, it is suitable or unsuitable for application based on the pore distribution index represented by formula (2), which is an index that more accurately represents the state of the membrane composite. It is desirable to judge.

In the present invention, when the zeolite membrane contains CHA-type zeolite, the intensity of the peak in the vicinity of 2θ = 17.9 ° is 2θ = 20.
The size is preferably 0.5 times or more the peak intensity around 8 °.
Here, the peak intensity refers to a value obtained by subtracting the background value from the measured value. (
The peak intensity ratio represented by 2θ = 17.9 ° peak intensity / (2θ = 20.8 ° peak intensity) (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”) Speaking of
Usually, it is 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.

The X-ray diffraction pattern referred to here is Cu on the surface where zeolite is mainly attached.
X-rays with Kα as the radiation source are irradiated to obtain a scanning axis of θ / 2θ. The shape of the sample to be measured may be any shape that can irradiate the surface of the membrane composite to which the zeolite is mainly attached, with X-ray irradiation. 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 in which variable → fixed slit correction is performed.
Here, the peak near 2θ = 17.9 ° is 17.9 ° out of the peaks not derived from the base material.
This refers to the largest peak in the range of ± 0.6 °.

The peak near 2θ = 20.8 ° is 20.8 ° ± 0.6 of the peaks not derived from the substrate.
The maximum peak in the range of °.
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 substrate.
The peak near 2θ = 9.6 ° in the X-ray diffraction pattern is COLLECTION OF SIMULATED XRD PO
Rhombohedra according to WDER PATTERNS FOR ZEOLITE Third Revised Edition 1996 ELSEVIER
l Set the space group

(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 is COLLECTION OF SIMULATE.
According to D XRD POWDER PATTERNS FOR ZEOLITE Third Revised Edition 1996 ELSEVIER
Space group with mbohedral setting

(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 COLLECTION OF SIMULATED XRD.
According to POWDER PATTERNS FOR ZEOLITE Third Revised Edition 1996 ELSEVIER, rhombohed
Space group with ral setting

(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 ZE
According to OLITE Third Revised Edition 1996 ELSEVIER, it is 2.5.

Therefore, when this ratio is 4 or more, for example, the CHA structure is converted into rhombohedral s.
It is considered that this means that the zeolite crystals are oriented and grown so that the (1,0,0) plane in the case of etting is oriented almost parallel to the surface of the membrane composite. 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 ZE
According to OLITE Third Revised Edition 1996 ELSEVIER, it is 0.3.
Therefore, if this ratio is 0.5 or more, for example, the CHA structure is converted to rhombohedr.
This is considered to mean that the zeolite crystals are oriented and grown so that the (1, 1, 1) plane in the al setting is oriented almost parallel to the surface of the membrane composite. 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 oriented and grown is formed by using, for example, a specific organic template and K in an aqueous reaction mixture when an oleite membrane is formed by hydrothermal synthesis. It can be achieved by coexisting ⁺ ions.

(Method for producing zeolite membrane composite)
In the present invention, the method for producing a zeolite membrane is not particularly limited as long as it can form a membrane containing zeolite. For example, (1) a method of crystallizing zeolite into a membrane on a porous support, (2 ) Method of fixing zeolite to the porous support with an inorganic binder or organic binder, (3) Method of fixing the polymer in which the zeolite is dispersed, (4) Impregnation of the porous support with the zeolite slurry Depending on the method, any method such as a method of fixing the zeolite to the porous support by suction may be used.

Among these, a method of crystallizing zeolite on a porous support in a film form is particularly preferable.
There is no particular limitation on the crystallization method, but the porous support is placed in a reaction mixture for hydrothermal synthesis used for zeolite production (hereinafter sometimes referred to as “aqueous reaction mixture”), and water is directly added. A method of crystallizing zeolite on the surface of the support by thermal synthesis is preferred.
Specifically, for example, an aqueous reaction mixture whose composition is adjusted and homogenized is sealed in a heat and pressure resistant container such as an autoclave, in which a porous support is gently fixed, and heated for a certain period of time. Good.

As an aqueous reaction mixture, an Si element source, an Al element source, an organic template as necessary,
And water, and further containing an alkali source as required.
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 such as Ga, Fe, B, Ti,
An element source such as Zr, Sn, or 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, N, N, N-trialkyl-1
More preferred is an adamantane ammonium cation. N, N, N-trialkyl-1-
The three alkyl groups of the adamantane ammonium 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. Also,
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 usually Na, K, Li, Rb, Cs, Ca, Mg,
Sr, Ba, etc. are 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 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 ratio is in this range, the zeolite membrane is densely formed, and the produced zeolite exhibits strong hydrophilicity, and a hydrophilic compound, particularly water, is selectively selected from the mixture containing organic matter. Can penetrate. Further, 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 ratio is in this range, CHA-type zeolite capable of forming 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
Below, more preferably 0.2 or less.
When this molar ratio is in the above range, in addition to being able to produce a dense zeolite membrane, the produced zeolite is strong in 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). So usually 0
. 02 or more, preferably 0.04 or more, more preferably 0.05 or more, usually 0.5
Hereinafter, it is 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 that 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 and 1 It is as follows.

  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), or (1,1,1)
The peak intensity in the vicinity of 2θ = 17.9 ° which is a peak derived from the surface of 1) and (2, 0, −1)
Of peak intensity around 2θ = 20.8 ° which is a peak derived from the surface of the surface (peak intensity ratio A)
Tends to increase.

The ratio of Si element source to water is the molar ratio of water to SiO ₂ (H ₂ O / SiO ₂ molar ratio),
Usually 10 or more, preferably 30 or more, more preferably 40 or more, particularly preferably 50 or more, and usually 1000 or less, preferably 500 or less, more preferably 200 or less, 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. H ₂ O / SiO ₂ molar ratio is high (50 or more and 1000 or less)
That is, by making the conditions rich in water, it is possible to obtain a zeolite membrane composite with high separation performance in which CHA-type zeolite is crystallized into a dense membrane on the support.
Further, in the hydrothermal synthesis, it is not always necessary to have a seed crystal in the reaction system, but the crystallization of zeolite can be promoted on the support by adding the seed crystal. The method of adding the seed crystal is not particularly limited, and a method of adding the seed crystal to the aqueous reaction mixture or the method of attaching the seed crystal on the support as in the synthesis of the powdered zeolite is used. Can do.
When producing a zeolite membrane composite, it is preferable to attach a seed crystal on the support. 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.
It is desirable that the seed crystal has a small particle size, and it may be used after pulverization if necessary. The particle size is usually 0.5 nm or more, preferably 1 nm or more, more preferably 2 nm or more, and is usually 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less.

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 to the surface, For example, a method of applying a slurry obtained by mixing crystals with a solvent such as water onto 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.
There may be a portion where zeolite is not partially formed on the surface of the support during hydrothermal synthesis, resulting in a defective membrane. If the amount of seed crystals in the dispersion is too large, the amount of seed crystals adhering to the support by the dipping method becomes almost constant when the amount of seed crystals in the dispersion is above a certain level. If the amount of crystals is too large, the seed crystals are wasted, which is 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 be difficult to crystallize. If the reaction temperature is too high, a zeolite of a type different from the zeolite in the present invention may be easily generated.

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 crystallize and become difficult.
If the reaction time is too long, a zeolite of a type different from the zeolite in the present invention may be easily generated.

The pressure at the time of forming the zeolite membrane is not particularly limited, and the aqueous reaction mixture placed in a sealed container is
The self-generated pressure that occurs when 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 when drying is intended.
More preferably, it is 100 ° C. or higher, usually 200 ° C. or lower, preferably 150 ° C. or lower. The temperature of the heat treatment is usually 350 ° C. or higher, preferably 400 when firing the template.
Or higher, more preferably 430 ° C. or higher, still more preferably 480 ° C. or higher, usually 900
° C or lower, preferably 850 ° C or lower, more preferably 800 ° C or lower, particularly preferably 75
0 ° 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, more preferably 10 hours.
Within 0 hours.
When hydrothermal synthesis is performed in the presence of an organic template, the resulting zeolite membrane composite is
After washing with water, it is appropriate to remove the organic template, for example, by heat treatment or extraction, preferably by heat treatment, that is, baking.

The firing temperature is usually 350 ° C. or higher, preferably 400 ° C. or higher, more preferably 430 ° C. or higher, further preferably 480 ° C. or higher, and usually 900 ° C. or lower, preferably 850 ° C. or lower.
More preferably, it is 800 degrees C or less, Most 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 cooling rate is usually 5 ° C
/ Min or less, preferably 2 ° C./min or less, more preferably 1 ° C./min or less, 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 alkali metal ions such as protons, Na ⁺ , K ⁺ , and Li ⁺ , Ca ²⁺ , Mg
^Examples thereof include alkaline earth metal ions such as ²⁺ , Sr ²⁺ and Ba ^2+, and transition metal ions such as Fe, Cu and Zn. Among these, alkali metal ions such as proton, Na ⁺ , K ⁺ , and Li ⁺ are preferable.

For ion exchange, the zeolite membrane after calcination (such as when using a template) is replaced with NH ₄
An aqueous solution containing an ammonium salt such as NO ₃ or NaNO ₃ or an ion to be exchanged, or an acid such as hydrochloric acid in some cases, is usually treated at a temperature of room temperature to 100 ° C. and then washed with water. 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.
The lower limit of the amount of permeation is not particularly limited, but is usually 0.01 L / (m ² · h) or more, preferably 0.
1 L / (m ² · h) or more, more preferably 1 L / (m ² · h) or more.

Here, as described in detail in the examples, the air permeation amount refers to the zeolite membrane composite having an absolute pressure of 5 k.
The air permeation amount [L / (m ² · h)] when connected to the Pa vacuum line.
The zeolite membrane composite 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 is what has. In the present invention, the same porous support-zeolite membrane composite as described above is used. The preferred 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). ,
1 kg / (m ² · h) or more, preferably 3 kg / (m ² · h) or more, more preferably 5
It means that it is 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, a mixture of 2-propanol and water having a water content of 30% by mass is 7
The permeance of water when permeated at 0 ° C. with a pressure difference of 1 atm (1.01 × 10 ⁵ Pa) 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 · P)
a) or more, particularly preferably 2 × 10 ⁻⁶ mol / (m ² · s · Pa). 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, a mixture of 2-propanol and water having a water content of 30% by mass.
When it permeates at 0 ° C. with a pressure difference of 1 atmosphere (1.01 × 10 ⁵ Pa), it is usually 100
0 or more, preferably 4000 or more, more preferably 10,000 or more, particularly preferably 20
000 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.

The object to be separated is a mixture of water and an organic substance (hereinafter sometimes referred to as “water-containing organic compound”).
), The water content in the mixture is usually 20% by mass or more, preferably 30% by mass or more, more preferably 45% by mass or more, and usually 95% by mass or less, preferably 80% by mass or less, more preferably 70% by 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, the effect of the porous support-zeolite membrane composite of the present invention can be used to separate an organic acid from a mixture of an organic acid and water, which can take advantage of both molecular sieve and hydrophilic characteristics. Is prominently expressed. A preferred example is a mixture of carboxylic acids and water, particularly preferably separation of acetic acid and water.
In addition, the organic substance in the case of separating the organic substance and water from the mixture of the organic substance other than the organic acid and water preferably has 2 or more carbon atoms, and more preferably 3 or more carbon atoms.
Among these organic acids, organic compounds containing at least one selected from alcohols, ethers, ketones, aldehydes, and amides are 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.
The water-containing mixture may be a mixture that forms an azeotrope such as a mixture of water and phenol. In the separation of a mixture that forms an azeotrope, water can be selectively and efficiently separated. Is preferable.

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. As a polymer used in the polymer emulsion, for example,
Thermoplastic resins such as polyvinyl acetate, polyvinyl alcohol, acrylic resin, polyolefin, olefin-polar monomer copolymer such as ethylene-vinyl alcohol copolymer, polystyrene, polyvinyl ether, polyamide, polyester, cellulose derivative; urea resin, phenol Examples thereof include thermosetting resins such as resins, epoxy resins, and polyurethane; rubbers such as natural rubber, polyisoprene, polychloroprene, and butadiene copolymers such as styrene-butadiene copolymers. 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 surface roughness The surface roughness (Ra) of the porous support was measured by a surface roughness meter SURFCOM 14 manufactured by Tokyo Seimitsu Co., Ltd.
Measurement was performed under the following conditions using 00D.
Calculation standard: JIS '94 standard Measurement length: 4 mm
Cut-off wavelength: 0.8mm
Measurement magnification: x5000

(2) Pore distribution measurement by mercury porosimetry The pore distribution of the porous support and the zeolite membrane composite is 10 minutes under reduced pressure (50 μmHg or less) using an Autopore IV 9520 model manufactured by Micromeritex. After the pressure reduction treatment, the pressure was determined by measuring a mercury intrusion method intrusion curve from 0.53 psia (corresponding to a pore diameter of 404 μm) to 60000 psia (corresponding to a pore diameter of 0.0036 μm).

From this mercury intrusion method intrusion curve, D ₅ (total pore volume accumulated from large pores (
Hereinafter, the pore diameter when the “integrated pore volume (ml / g)” is 5% of the total pore volume), D ₅₀ (pores accumulated from the larger pores) Pore diameter when the total volume is 50% of the total pore volume), D ₉₅ (when the total pore volume accumulated from the large pores is 95% of the total pore volume) Index (1) (D ₅ ) for determining pore diameter and representing pore distribution
It was calculated -D _{95) / D 50.}
In addition, the common logarithm of D ₅ , D ₅₀ , and D ₉₅ obtained is obtained, and index (2) (l
was calculated _{ogD 5 -logD 95) / logD 50} .

(3) X-ray diffraction (XRD) measurement 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)
Horizontal 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.
In addition, the irradiation width is fixed to 1 mm with an automatic variable slit, and measured.
s Data, Inc. XRD analysis software JADE 7.5.2 (Japanese version) was used to perform variable slit → fixed slit conversion to obtain an XRD pattern.

(4) SEM measurement SEM measurement was performed based on the following conditions.
Device name: SEM: FE-SEM Hitachi: S-4100
・ Acceleration voltage: 10 kV
(5) Air permeation amount One end of the zeolite membrane composite is sealed, the other end is sealed and connected to a 5 kPa vacuum line, and the 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. KOF as a mass flow meter
LOC 8300, for N ₂ gas, maximum flow rate 500ml / min (20 ° C, 1atm conversion)
Was used. The mass flow meter display is 10 ml / m in 8300 manufactured by KOFLOC.
If it is less than in (20 ° C, 1 atm), Lintec MM-2100M, Ai
For r gas, the maximum flow rate was 20 ml / min (0 ° C., converted to 1 atm).

(6) SEM-EDX measurement SEM-EDX measurement of the zeolite membrane was performed under 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.

(7) Pervaporation method The schematic of the apparatus used for the pervaporation method is shown in FIG. 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.

Mass measurement and composition analysis of the permeate collected in the trap 7 at regular intervals, liquid to be separated 4
The composition analysis was performed, and using these values, the separation factor, permeation flux, water permeance, etc. for each time were calculated as described above. The composition analysis was performed by gas chromatography. Since the permeation flux and the separation factor become stable about 5 hours after the start of permeation, the results are values after 5 hours unless otherwise specified.

[Example 1]
A porous support-zeolite membrane composite was prepared by forming a zeolite membrane on a porous support by a hydrothermal synthesis method, and the separation performance was measured.
(Preparation of porous support)
After cutting a Nikkato mullite tube PM (outer diameter 12 mm, inner diameter 9 mm) to a length of 80 mm, the outer surface is cleaned with # 1000 sandpaper until the surface roughness (Ra) reaches 1.0. Polished. The thickness of the support after polishing was 1.4 mm.

The polished porous support was washed with an ultrasonic cleaner and dried at 120 ° C. for 2 hours to obtain a porous support 1.
The mercury intrusion method intrusion curve of the porous support 1 obtained by the pore distribution measurement by the mercury intrusion method is shown in FIG. Total pore volume of the porous support 1 0.252ml / _{g, D 50} is 1.63μm
, _{D 5} is 8.41Myuemu, D95 is _{0.68μm, (D 5 -D 95)} / D 50 4.75,
_{(LogD 5 -logD 95) / logD} 50 was 5.16.

(Reaction mixture for hydrothermal synthesis)
The following was prepared as a reaction mixture for hydrothermal synthesis.
A mixture of 10.5 g of 1 mol / L-NaOH aqueous solution, 7.0 g of 1 mol / L-KOH aqueous solution and 100.4 g of water was added to aluminum hydroxide (containing 53.5% by mass of Al ₂ O ₃ ,
0.88 g (Aldrich) was added and dissolved by stirring to obtain a transparent solution. As an organic template, N, N, N-trimethyl-1-adamantanammonium hydroxide (hereinafter referred to as “TMADAOH”) aqueous solution (containing 25% by mass of TMADAOH,
2.36 g of Sechem Co., Ltd.) and 10.5 g of colloidal silica (Snowtech-40, Nissan Chemical Co., Ltd.) were added and stirred for 2 hours to obtain a reaction mixture for hydrothermal synthesis.
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
/ Al ₂ O ₃ = 15.

(Preparation of seed crystal and adhesion to porous support)
Prior to formation of the zeolite membrane on the porous support, seed crystals were attached to the porous support 1 as follows.
As a seed crystal, a TMADAOH aqueous solution (containing 25% by mass of TMADAOH, manufactured by Sechem Co.) was used, and SiO ₂ / Al ₂ O ₃ / NaOH / KOH / H ₂ O / TMADAOH = 1 /
A gel composition of 0.066 / 0.15 / 0.1 / 100 / 0.1, which was crystallized by hydrothermal synthesis at 160 ° C. for 2 days, was obtained by filtration, washing with water and drying. CHA type zeolite was used.
The seed crystal grain size was about 2 μm.
The porous support 1 was immersed in 3% by mass of this seed crystal in water for a predetermined time, and then dried at 100 ° C. for 5 hours or more to attach the seed crystal. Mass of attached seed crystal is 1g
/ M ² .

(Formation of zeolite membrane on porous support 1)
A porous support 1 to which a seed crystal is attached is made of Teflon (registered trademark) containing the above reaction mixture.
Immerse the inner cylinder (200 ml) in the vertical direction and seal the autoclave.
Heated at 0 ° C. for 48 hours under autogenous pressure. Porous support after cooling for a predetermined time
The zeolite membrane composite was removed from the reaction mixture, washed, and dried at 100 ° C. for 5 hours or more.

The dried porous support-zeolite membrane composite was calcined in an electric furnace at 500 ° C. for 5 hours to obtain a porous support-zeolite membrane composite 1. The mass of the zeolite membrane formed on the porous support determined from the difference between the mass of the porous support-zeolite membrane composite 1 after firing and the mass of the porous support was 130 g / m ² . The air permeation amount of the calcined porous support-zeolite membrane composite 1 was 240 L / (m ² · h).
Index (2) logD ₅ -logD ₉₅ representing pore distribution obtained from mercury intrusion method indentation curve of porous support-zeolite membrane composite 1 obtained by measurement of pore distribution by mercury intrusion method
) / LogD ₅₀ was 4.01.

(Physical properties of zeolite membrane)
When XRD of the produced zeolite membrane was measured, it was found that CHA-type zeolite was produced.
From the XRD pattern, (the intensity of the peak around 2θ = 17.9 °) / (2θ = 20.8 °
The intensity of the peak in the vicinity) is 1.4, and the XR of the powdered CHA zeolite used for the seed crystal
Compared to D, the intensity of the peak near 2θ = 17.9 ° was significantly larger, and the orientation to the (1,1,1) plane in the rhombohedral setting was estimated.
As a result of observing the zeolite membrane composite 1 cut into strips by SEM, it was found that crystals were densely formed on the surface.
The SiO ₂ / Al ₂ O ₃ molar ratio of the zeolite membrane measured by SEM-EDX was 17.

(Separation test of water / acetic acid mixed solution)
Using the porous support-zeolite membrane composite 1 produced above, separation was performed by selectively permeating water from a 70 ° C. water / acetic acid mixed solution (50/50 mass%) by a pervaporation method. .
As a result, the permeation flux was 5.8 kg / (m ² · h), the separation factor was 700, and the concentration of water in the permeate was 99.86% by mass. The water permeance is 3.6 × 10 ⁻⁶ mol / (m ²
· S · Pa).

[Comparative Example 1]
The porous support 2 is made of the same material and method as in Example 1 except that the sandpaper used is # 800, and is polished by a wet process and smoothed until the surface roughness (Ra) becomes 1.3. Got ready.
The thickness of the porous support 2 after polishing was 1.4 mm.
FIG. 2 shows a mercury intrusion method intrusion curve of the porous support 2 obtained by measurement of pore distribution by the mercury intrusion method. Total pore volume of the porous support 2 is 0.263ml / _{g, D 50} is 1.72μm
, D ₅ is 72.39 μm, D ₉₅ is 0.70 μm, (D ₅ -D ₉₅ ) / D ₅₀ is 41.5.
_{7, (logD 5 -logD 95)} / logD 50 was 8.50.

Example 1 except that the porous support 2 was used as the porous support-zeolite membrane composite 2.
It produced similarly. The mass of the zeolite membrane formed on the porous support 2 obtained from the difference between the mass of the porous support-zeolite membrane composite 2 after firing and the mass of the porous support was 120 g / m.
² . The air permeation amount of the porous support-zeolite membrane composite 2 after calcination is 270 L / (
m ² · h). Index (2) representing the pore distribution obtained from the mercury intrusion method intrusion curve of the porous support-zeolite membrane composite 2 obtained by the pore intrusion measurement by the mercury intrusion method (1)
ogD ₅ -logD ₉₅₎ / logD ₅₀ was 12.97.

When XRD of the produced zeolite membrane was measured, it was found that CHA-type zeolite was produced.
From the XRD pattern, (the intensity of the peak around 2θ = 17.9 °) / (2θ = 20.8 °
The intensity of the peak in the vicinity) is 2.1, and the XR of the powdered CHA zeolite used for the seed crystal
Compared to D, the intensity of the peak near 2θ = 17.9 ° was significantly larger, and the orientation to the (1,1,1) plane in the rhombohedral setting was estimated.

The obtained porous support-zeolite membrane composite 2 was subjected to separation by selectively permeating water from a water / acetic acid mixed solution (50/50% by mass) at 70 ° C. by a pervaporation method.
As a result, the permeation flux was 4.0 kg / (m ² · h), the separation factor was 600, and the concentration of water in the permeate was 99.83% by mass. The water permeance is 2.6 × 10 ⁻⁶ mol / (m
² · s · Pa).

Porous support 2 used in Comparative Example 1, the thickness of the support, the total pore volume is substantially the same as the porous support 1 of D ₅₀ both Example _{1, (D 5 -D 95)} / D ₅₀ (an index representing the pore distribution) of 40 or _{more, (logD 5 -logD 95) /} logD 50 is not less than 7, but pore distribution is wider than in example 1. Although the mass of the zeolite membrane of the porous-zeolite membrane composite 2 used in Comparative Example 1 is almost the same as that of the porous support 1 of Example 1 and the thickness of the zeolite membrane is considered to be almost the same, (logD ₅ -logD ₉₅₎ / logD ₅₀ is not less than 7, but pore distribution is wider than in example 1. In Comparative Example 1, since a support having a wide pore distribution is used, the permeation flux is considered to be low even if the thickness of the support and the thickness of the zeolite membrane are the same.

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.

DESCRIPTION OF SYMBOLS 1 Stirrer 2 Hot water bath 3 Stirrer 4 Liquid to be separated 5 Porous support-zeolite membrane composite 6 Pirani gauge 7 Permeate trap 8 Cold trap 9 Vacuum pump

Claims (5)

A porous support-zeolite membrane composite formed by forming a zeolite membrane on a porous support, wherein the average thickness of the porous support is 0.1 mm or more and 7 mm or less, and the surface roughness (Ra) Is 1
. A porous support-zeolite membrane composite characterized by being 2 or less. The porous support-zeolite membrane composite according to claim 1, wherein the permeation flux is 1 kg / (m ² · h) or more. A method for producing a porous support-zeolite membrane composite formed by forming a zeolite membrane on a porous support, wherein the average thickness is 0.1 mm or more and 7 mm or less, and the surface roughness (Ra) is 1. .2
A method for producing a porous support-zeolite membrane composite, characterized in that zeolite is crystallized into a membrane by hydrothermal synthesis on a porous support as described below. The method for producing a porous support-zeolite membrane composite according to claim 3, wherein the SiO ₂ / Al ₂ O ₃ molar ratio in the aqueous reaction mixture used for hydrothermal synthesis is 5 or more. The method for producing a porous support-zeolite membrane composite according to claim 3 or 4, wherein the zeolite constituting the zeolite membrane comprises a zeolite having an oxygen 8-membered ring structure.

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