JP2006341205A - Method for manufacturing zeolite membrane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a zeolite membrane capable of manufacturing a uniform zeolite membrane having a sufficient penetration rate and separation property while improving a yield and work efficiency. <P>SOLUTION: The method for manufacturing the zeolite membrane comprises a membrane element formation process for reacting on a support and a reaction liquid containing the raw material of the zeolite membrane to form a zeolite membrane element on the surface of the support, a separation process for separating the zeolite membrane element and the reaction liquid, and a cleaning process for cleaning the zeolite membrane element to obtain the zeolite membrane. In the cleaning process, the zeolite membrane element is immersed in the liquid 3 in a vessel 5 and the zeolite membrane element is cleaned by applying an ultraviolet wave to the zeolite membrane element by a vibrator 2 fixed on the vessel 5 through the liquid 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a zeolite membrane.

  Zeolite, which is representative of a crystalline porous material, is a material that has solid acidity, ion exchange capacity, adsorption separation capacity, molecular level pores and the like due to its pore structure. In recent years, attention has been focused on the use of this zeolite as a membrane to separate water in an organic solvent.

  As the method for producing the zeolite membrane, the surface of the support is obtained by bringing the support into contact with a reaction solution containing a raw material of the zeolite membrane mainly composed of a silica source and an alumina source, and reacting the reaction solution with the support. A so-called “hydrothermal synthesis” method in which a zeolite membrane is formed is well known (see Patent Document 1).

  However, in the hydrothermal synthesis method, when a zeolite membrane body is formed on the surface of the support, deposits such as unreacted substances, zeolite particles, or amorphous components are observed on the surface of the zeolite membrane body. . In this case, when the zeolite membrane body is used as it is as a separation membrane, there arises a problem that the permeation rate Q of the permeation component that permeates the zeolite membrane decreases or the separation performance α of the zeolite membrane decreases.

In order to suppress such a situation, in the method for producing a zeolite membrane, the zeolite membrane element is washed after being lifted from the reaction solution. The washing of the zeolite membrane element at this time is performed, for example, by the operator rubbing each part with a brush for each zeolite membrane element (hereinafter referred to as “hand washing”).
Japanese Patent Laid-Open No. 2004-82008

  However, when the zeolite membrane body is cleaned by the above-described manual cleaning, it takes time to clean each zeolite membrane body, resulting in poor workability. Further, in the manual cleaning, there is a possibility that the degree of cleaning differs for each zeolite membrane element, and the deposits on the uncleaned portion may solidify during the cleaning. Moreover, this differs depending on the level of skill. For this reason, when producing a plurality of zeolite membranes, it is difficult to make the zeolite membrane homogeneous. Furthermore, some of the deposits cannot be visually confirmed, so that they cannot be sufficiently washed by hand washing, and a zeolite membrane having a sufficient permeation rate and separation performance may not be obtained.

  Further, the zeolite membrane has a thickness of, for example, about 10 μm and is extremely thin. Therefore, the worker may rub a certain area on the surface of the zeolite membrane body too much with a brush, and in that case, the zeolite membrane is easily damaged. Even if the zeolite membrane is not damaged, the separation performance of the zeolite membrane tends to be reduced by rubbing with a brush.

  The present invention has been made in view of the above circumstances, and is a zeolite membrane capable of producing a homogeneous zeolite membrane having sufficient permeation rate and separation performance regardless of skill level while improving working efficiency. An object is to provide a manufacturing method.

  In order to solve the above problems, the present invention provides a membrane element forming step of reacting a support and a reaction solution containing a raw material for a zeolite membrane to form a zeolite membrane element on the surface of the support, and a zeolite membrane element A method for producing a zeolite membrane, comprising: a separation step for separating the body and the reaction solution; and a washing step for washing the zeolite membrane body to obtain a zeolite membrane, wherein the zeolite membrane body is placed in a container in the washing step. The zeolite membrane body is washed by applying ultrasonic waves to the zeolite membrane body through the liquid by a vibrator fixed to the container. In the present invention, the term “support” refers to a support obtained by attaching a seed crystal of a zeolite membrane element on the surface of the support element, or a support element itself when no seed crystal is attached.

  In the method for producing a zeolite membrane of the present invention, in the cleaning step, the zeolite membrane is immersed in a liquid in a container, and ultrasonic waves are applied to the zeolite membrane through a liquid by a vibrator fixed to the container. Therefore, ultrasonic waves can be simultaneously applied to the entire zeolite membrane element. Therefore, the degree of washing for each zeolite membrane element can be made equal, and even when a plurality of zeolite membranes are manufactured without being influenced by the skill level, the zeolite membrane can be made homogeneous. Moreover, since the zeolite membrane is immersed in the liquid, solidification of the deposits during the cleaning can be sufficiently suppressed. Furthermore, since the removal of the deposits is performed by applying ultrasonic waves to the entire zeolite membrane element without visual observation, it is possible to prevent the occurrence of unwashed portions. Therefore, according to the method for producing a zeolite membrane of the present invention, it is possible to effectively remove deposits adhering to the surface of the zeolite membrane body and produce a homogeneous zeolite membrane having a sufficient permeation rate and separation performance. it can.

  Further, since ultrasonic waves are applied to the zeolite membrane body through the liquid in the cleaning step, it is possible to prevent the zeolite membrane from being damaged. Therefore, according to the production of the zeolite membrane of the present invention, the yield can be improved.

Here, the “permeation rate Q (kg / m ² h)” means the amount of liquid permeating the zeolite membrane per unit time. For example, when water is to be separated from a mixed solution of ethanol and water, when a zeolite membrane is used as the separation membrane, the amount of water passing through the zeolite membrane per unit time.

The “separation performance α” means, for example, in the case of a mixed solution of ethanol and water, when a zeolite membrane is used as a separation membrane, the concentration of water before separation is A1 mass%, and the concentration of ethanol is A2 mass. %, The concentration of water in the liquid or gas that has passed through the zeolite membrane is B1 mass%, and the ethanol concentration is B2 mass%, the following formula (2):
α = (B1 / B2) / (A1 / A2) (2)
It is represented by. In addition, it becomes possible to isolate | separate a specific liquid with higher concentration from a liquid mixture, so that this value is large.

  The method for producing a zeolite membrane preferably further includes a cooling step for cooling the zeolite membrane body after the separation step.

  After the separation step, since the zeolite membrane element is generally at a high temperature, the zeolite membrane element is easily dried. That is, when the zeolite membrane element is separated from the reaction solution, the moisture on the surface of the zeolite membrane element is evaporated and dried. In this case, the deposit on the surface of the zeolite membrane element is solidified, and it tends to be difficult to remove the deposit in the washing step. Therefore, by cooling the zeolite membrane body after the separation step, the zeolite membrane body becomes difficult to dry and the solidification of the deposits can be suppressed.

  In the above-described method for producing a zeolite membrane, the frequency of ultrasonic waves is preferably 50 kHz to 900 kHz. In this case, the deposits adhering to the zeolite membrane body can be more sufficiently removed.

  In the cleaning step, it is preferable to clean the zeolite membrane while changing the frequency of the ultrasonic wave. When the frequency of the ultrasonic wave is changed, the wavelength emitted from the vibrator fixed to the container can be changed. Therefore, in the cleaning process, the deposit having a size corresponding to the wavelength can be effectively removed. Therefore, the deposits of various sizes adhering to the zeolite membrane body are more effectively removed as a whole.

  According to the present invention, it is possible to provide a method for producing a zeolite membrane capable of producing a homogeneous zeolite membrane having sufficient permeation rate and separation performance regardless of skill level while improving yield and working efficiency. it can.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary. In addition, the dimensional ratio of drawing is not restricted to the ratio of illustration.

  The method for producing a zeolite membrane according to the present embodiment includes a seed attachment step in which a seed crystal is attached to a support element and reacting a reaction liquid containing a raw material of the support and the zeolite membrane on the surface of the support. A membrane element forming step for forming a zeolite membrane element, a separation step for separating the zeolite membrane element and the reaction solution, and a washing step for obtaining a zeolite membrane by washing the zeolite membrane element.

  In the cleaning step, the zeolite membrane element is immersed in the liquid in the container, and an ultrasonic wave is applied to the zeolite membrane element through the liquid by a vibrator fixed to the container. Wash.

  In the method for producing a zeolite membrane of the present invention, in the cleaning step, the zeolite membrane is immersed in a liquid in a container, and ultrasonic waves are applied to the zeolite membrane through a liquid by a vibrator fixed to the container. Therefore, ultrasonic waves can be simultaneously applied to the entire zeolite membrane element. Therefore, the degree of washing for each zeolite membrane element can be made equal, and even when a plurality of zeolite membranes are manufactured without being influenced by the skill level, the zeolite membrane can be made homogeneous. In addition, since the zeolite membrane is immersed in the liquid, solidification of the deposit during cleaning can be sufficiently suppressed, and furthermore, ultrasonic waves are applied to the entire zeolite membrane without removing the deposit. Therefore, it is possible to prevent an uncleaned portion from occurring. Therefore, according to the method for producing a zeolite membrane of the present invention, it is possible to effectively remove deposits adhering to the surface of the zeolite membrane body, and to produce a homogeneous zeolite membrane having a sufficient permeation rate and separation performance. it can.

  Further, since ultrasonic waves are applied to the zeolite membrane body through the liquid in the cleaning step, it is possible to prevent the zeolite membrane from being damaged. Therefore, according to the method for producing a zeolite membrane of the present invention, the yield can be improved.

  In the cleaning step, a plurality of zeolite membranes are immersed in a liquid in a container, and ultrasonic waves are applied to the plurality of zeolite membranes via a liquid by a vibrator fixed to the container. It is preferable to clean the membrane element.

  The method for producing a zeolite membrane of the present invention can simultaneously wash a zeolite membrane formed on a plurality of supports in a short time. Therefore, according to the production of the zeolite membrane of the present invention, the working efficiency can be further improved.

  Hereinafter, each step will be described in detail.

[Seed adhesion process]
The seed attachment step is a step of attaching a seed crystal to a support element to form a support.

  By performing the seed deposition step, it becomes possible to form a more uniform zeolite membrane body on the support in the membrane body forming step described later, and more uniform on the support also in the cleaning step described later. It becomes possible to form a zeolite membrane element.

  The seed crystal differs depending on the type of zeolite of the target zeolite membrane. For example, the same type of zeolite as the zeolite to be formed may be used, or the crystal structure may be similar.

  In the solution containing the seed crystal, the concentration of the seed crystal in the solution is preferably 0.01% by mass to 20% by mass, and more preferably 0.1% by mass to 10% by mass. When the concentration of the seed crystal is less than 0.01% by mass, the seed crystal does not sufficiently adhere to the support element and there are defects such as pinholes in the zeolite membrane as compared with the case where the concentration is in the above range. If the concentration of the seed crystal exceeds 20% by mass, the layer containing the seed crystal becomes too thick as compared with the case where the concentration is in the above range, and the seed crystal in the outer portion is crystallized. Since the inner seed crystal is retained without being sufficiently crystallized, the zeolite membrane tends to be peeled off or defective.

  The support element used in the present invention is not particularly limited, but is preferably porous, and is made of, for example, ceramics, organic polymer, or metal. Examples of ceramics include mullite, alumina, silica, titania, zirconia, and the like. Examples of metals include stainless steel, sintered nickel, and a mixture of sintered nickel and iron. Among these, it is preferable to use alumina as a support element. When alumina is used as the support element, elution of the material of the support element can be suppressed. Note that the support element may be made by sintering zeolite.

  When the support element is porous, the average pore diameter of the pores is preferably 0.1 μm to 20 μm, and more preferably 0.1 μm to 5 μm. In this case, a zeolite membrane with few pinholes can be formed, and a zeolite membrane with high separation performance can be obtained. Moreover, it is preferable that a porosity is 5 to 50%, and it is more preferable that it is 30 to 50%. In this case, since the gas permeation amount of the support element is high, a zeolite membrane having a high permeation rate can be obtained.

  When the average pore diameter is less than 0.1 μm, compared to the case where the average pore diameter is in the above range, the seed crystal does not sufficiently adhere in the support element pores, and therefore tends to be easily peeled off. When the average pore diameter exceeds 20, compared to the case where the average pore diameter is in the above range, the pores cannot be filled with zeolite crystals, pinholes are generated, and the separation performance tends to be lowered. Further, when the porosity is less than 5%, compared with the case where the porosity is in the above range, the gas permeation rate is low, and thus there is a tendency that a high permeation rate cannot be obtained, and the porosity is 50%. If the porosity exceeds the above range, the mechanical strength of the support is low compared to the case where the porosity is in the above range, so that the product tends to be unusable.

  The shape of the support element is not particularly limited, and examples thereof include a hollow shape such as a cylindrical shape, a hollow fiber shape, and a tube shape, a plate shape, a honeycomb shape (honeycomb shape), and a pellet shape. Such a shape can be changed according to the use for which the zeolite membrane is used. For example, when a zeolite membrane is used as a separation membrane for water and an organic solvent, it is preferably hollow. In this case, washing described later can be performed more uniformly, and a zeolite membrane having a sufficient permeation rate and separation performance can be produced.

  The seed attaching step is performed by bringing the support element into contact with a solution containing the seed crystal. Examples of the contacting method include an impregnation method, a dip coating method, a spray coating method, a coating method, and a filtration method.

  Note that the solution containing the seed crystal may contain an additive such as a surfactant.

  After passing through the seed attaching step, it is preferable to dry the seed crystal. In this case, the seed crystal can be sufficiently attached to the support element.

[Film body forming process]
The membrane element forming step is a step of forming a zeolite membrane element on the surface of the support by reacting the support and a reaction solution containing the raw material of the zeolite membrane. The membrane element forming step is performed by bringing the support to which the seed crystals are attached into contact with a reaction solution containing a raw material for the zeolite membrane.

  The synthesis of the zeolite membrane can be performed, for example, by a hydrothermal synthesis method, a dry gel conversion method, or the like. Of these, the zeolite membrane is preferably synthesized by a hydrothermal synthesis method.

  First, in the membrane element forming step, the raw material of the zeolite membrane is added to water and stirred to prepare a reaction solution used for the zeolite synthesis reaction. Then, a zeolite membrane is formed on the surface of the support by impregnating the support with the reaction solution.

  The raw material of the zeolite membrane is an alumina source and a silica source, and may contain an alkali metal source and / or an alkaline earth metal source as necessary. Examples of the alumina source include aluminum powder, aluminum aluminate, aluminum sulfate, aluminum nitrate, aluminum chloride, alumina powder, colloidal alumina, and the like. Silica sources include sodium silicate, water glass, alkali metal silicates such as potassium silicate, silica powder, silicic acid, colloidal silica, acid clay, kaolin, silicon alkoxide (aluminum isopropoxide, etc.), etc. Can be mentioned. Examples of the alkali (earth) metal source include sodium chloride, potassium chloride, calcium chloride, magnesium chloride and the like. In addition, alkali metal silicate can be used as a silica source and an alkali metal source.

The molar ratio (converted to SiO ₂ / Al ₂ O ₃ ) between the silica source and the alumina source in the reaction solution can be appropriately determined depending on the type of zeolite of the target zeolite membrane.

  Moreover, the density | concentration of the said silica source and an alumina source is not specifically limited. That is, in the film body forming step, the concentration of the silica source or the alumina source may be increased to make the reaction liquid gel, which may be brought into contact with the support, and the concentration of the silica source or the alumina source should be reduced. Thus, the low viscosity reaction liquid may be brought into contact (impregnated) with the support.

  That is, the composition of the reaction solution, the reaction temperature, the reaction time, and the like vary depending on the zeolite type of the target zeolite membrane.

  Note that the reaction solution may contain an additive such as a crystallization accelerator. Examples of the crystallization accelerator include tetrapropylammonium bromide, tetrabutylammonium bromide and the like.

[Separation process]
The separation step is a step of separating the zeolite membrane body and the reaction liquid. Separation methods include, for example, a method in which the support on which the zeolite membrane element is formed is pulled out from the reaction solution, and the support in which the zeolite membrane element is formed is immersed in the reaction solution. For example, a method of removing from a discharge port or the like provided at the bottom of the container, a method of moving the container together with the reaction liquid from a state in which the support on which the zeolite membrane element is formed is immersed in the reaction liquid, Etc.

  In addition, it is preferable to perform a isolation | separation process immediately from the state which the support body in which the zeolite membrane element was formed is immersed in the reaction liquid. In this case, it can suppress that a zeolite membrane body dries and a deposit | attachment solidifies.

[Washing process]
The washing step is a step of obtaining a zeolite membrane by washing the zeolite membrane. Specifically, in the membrane element forming step, it is a step of removing deposits such as unreacted substances, zeolite particles, or amorphous components formed on the zeolite membrane element.

  Immediately after the separation step, the zeolite membrane element is at a high temperature, so that the zeolite membrane element is easily dried. That is, when the zeolite membrane element is separated from the reaction solution, the moisture on the surface of the zeolite membrane element is evaporated and dried. In this case, when the surface of the zeolite membrane element is dried, the deposit on the surface of the zeolite membrane element is solidified, and it tends to be difficult to remove the deposit in the washing step.

  Therefore, the zeolite membrane is washed after the separation step. The washing step is preferably performed immediately after the separation step. Here, the reason why the washing step is performed immediately after the separation step is to perform washing before the zeolite membrane is dried, and specifically, it is preferably within 30 minutes.

  Here, the zeolite membrane is cleaned by ultrasonic cleaning. FIG. 1 is a schematic cross-sectional view showing an ultrasonic cleaning apparatus used for ultrasonic cleaning in the cleaning process of the present embodiment. As shown in FIG. 1, the ultrasonic cleaning apparatus 10 includes a container 5, and the container 5 includes a bottom portion 5 a and a cylindrical side wall portion extending from the peripheral edge of the bottom portion 5 a. The vibrator 2 is provided in the lower part of the container 5, and the liquid 3 is stored inside the container 5. Furthermore, the support body 1 that has undergone the film body forming step is immersed in the liquid 3 so as not to contact the wall surface of the container 5.

  In this ultrasonic cleaning apparatus 10, first, the support 1 on which the zeolite membrane was formed is immersed in the liquid in the container. Then, ultrasonic waves are applied to the zeolite membrane element of the support 1 through the liquid 3 by the vibrator 2 fixed to the container 5. Thereby, the zeolite membrane is washed. That is, the deposits formed on the surface of the zeolite membrane body are sufficiently removed. Although the shape of the said container 5 is not specifically limited, For example, square pillar shape, a column shape, etc. are mentioned.

  Further, the type of the vibrator 2 is not particularly limited. In the ultrasonic cleaning apparatus 10, the vibrator 2 is provided on the bottom 5 a of the container 5, but may be provided on the side wall 5 b of the container 5 instead of the bottom 5 a of the container 5. The bottom 5a and the side wall 5b may be provided.

  Examples of the liquid 3 include water and organic solvents, and water is generally used. Among these, it is preferable to use pure water. When tap water or the like containing a large amount of alkali ions in the liquid is used, the characteristics of the membrane tend to be changed as compared with the case of using pure water. Moreover, it is preferable that the pH of the said liquid 3 is 4-9 in an initial state. When the pH of the liquid is less than 4, the zeolite crystals tend to be decomposed compared to the case where the pH of the liquid is in the above range, and when the pH of the liquid exceeds 9, the pH of the liquid is in the above range. As compared with the case of the above, there is a tendency that the ultrasonic wave is attenuated and sufficient cleaning ability cannot be obtained.

  Examples of the organic solvent include lower alcohols such as acetone and ethanol.

  In the cleaning step, the ultrasonic frequency is preferably 50 kHz to 900 kHz. In this case, the deposits adhered to the zeolite membrane element can be more effectively removed.

  If the frequency is less than 50 kHz, the zeolite membrane may be damaged as compared with the case where the frequency is in the above range. If the frequency exceeds 900 kHz, the output of the ultrasonic wave is too weak, so that it is sufficiently applied. There is a tendency that the kimono cannot be removed.

  In the cleaning step, it is preferable to clean the zeolite membrane while changing the frequency of the ultrasonic waves. When the frequency of the ultrasonic wave is changed, the wavelength emitted from the vibrator fixed to the container can be changed. Therefore, in the cleaning process, the deposit having a size corresponding to the wavelength can be effectively removed. Therefore, the deposits of various sizes adhering to the zeolite membrane body are more effectively removed as a whole.

  Zeolite membranes having various compositions and structures such as MFI type, X type, Y type, A type, and T type can be produced by the above-described method for producing a zeolite membrane of the present invention. These zeolite membranes can be used as separation membranes.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  For example, the production method of the present invention preferably further includes a cooling step for cooling the zeolite membrane element after the separation step in the above embodiment. By performing the cooling step in this way, it is difficult to dry the zeolite membrane body and the deposits can be prevented from solidifying. Then, in the ultrasonic cleaning, deposits on the zeolite membrane body can be easily removed, and a homogeneous zeolite membrane having a sufficient permeation rate and separation performance can be obtained.

  In addition, if it is after a separation process, the said cooling process may be performed simultaneously with a washing | cleaning process, and may be performed between a separation process and a washing | cleaning process. In the case where the cooling step and the washing step are performed simultaneously, the liquid 3 is water having a low temperature (for example, 10 ° C. to 40 ° C.), and the zeolite membrane is washed while being cooled by the liquid 3. In this case, since the number of steps can be reduced, the working time can be shortened. Further, when the cooling step is performed between the separation step and the washing step, for example, in a container storing the reaction solution, the reaction solution is extracted from the state in which the zeolite membrane element is immersed in the reaction solution, and cooled. Pure water is introduced. Thereby, the reaction liquid adhering to the zeolite membrane element is diluted, and the ratio of the reaction liquid mixed into the liquid 3 can be reduced in the washing step.

  In the cooling step, the method for cooling the zeolite membrane is not particularly limited. Examples of the cooling method include a method of immersing the zeolite membrane element in water, a method of spraying water onto the zeolite membrane element, and a method of dropping water onto the zeolite membrane element.

  Moreover, the seed attachment process in the said embodiment is arbitrary, and is not necessarily an essential process for this invention. In addition, when not performing a seed adhesion process, a support element | base_body becomes a support body.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to the Example given below.

(Example 1)
[Seed adhesion process]
A type A zeolite fine particles (seed crystals, particle size 100 nm) were placed in water and stirred to prepare a solution having a concentration of 0.5 mass%. A tubular porous support body (average pore diameter 1.3 μm, outer diameter 10 mm, inner diameter 6 mm, length 13 cm) made of α-alumina is immersed in this solution for 3 minutes and then pulled up at a rate of about 0.2 cm / s. It was. This was dried in a thermostatic bath at 25 ° C. for 2 hours and then dried in a thermostatic bath at 70 ° C. for 16 hours to obtain a support.

[Film body forming process]
Next, 1 mol part of alumina (Al ₂ O ₃ ), 2 mol parts of silicon dioxide (SiO ₂ ), and 2 mol parts of sodium oxide (Na ₂ O) were added to 150 mol parts of water to obtain a reaction solution. The support was immersed in this reaction solution and held at 100 ° C. for 4 hours to form a zeolite membrane element on the surface of the support.

[Washing process]
On the other hand, as shown in FIG. 1, pure water was put into a container of an ultrasonic cleaning apparatus (vibrator, trade name: MID SONIC600, manufactured by Kaijo Corporation). And the support body in which the said zeolite membrane element was formed was immersed in the pure water, and the pure membrane was impregnated with the pure water. Then, ultrasonic cleaning was performed by applying electric power to the ultrasonic vibrator and applying ultrasonic waves having a frequency of 100 Hz to the support for 5 minutes. A separation membrane having a zeolite membrane formed on the surface of the support was thus obtained.

(Example 2)
In the washing step, the zeolite membrane was ultrasonically washed in the same manner as in Example 1 except that the frequency was 200 Hz, and a separation membrane having a zeolite membrane formed on the surface of the support was obtained.

(Comparative Example 1)
A separation membrane having a zeolite membrane formed on the surface of the support was obtained in the same manner as in Example 1 except that the washing step was not performed.

(Evaluation methods)
[Separation performance and permeation speed]
In order to evaluate the separation performance of the zeolite membranes obtained in Examples 1 and 2 and Comparative Example 1,
1118299985997_0
The pervaporation (PV) test apparatus shown in FIG. This PV test apparatus has a supply tank 11 to which a supply liquid A is supplied. A pipe 21 for supplying the supply liquid A to the supply tank 11 is connected to the supply tank 11, and a separator 12 is installed in the supply tank 11 and a stirring device 22 for stirring the supply liquid A is provided. ing. As the separator 12, the separation membranes of Examples 1 and 2 and Comparative Example 1 were used. A tube 16 is connected to the open end of the separator 12, and a vacuum pump 14 is connected to the end of the tube 16 via a liquid nitrogen trap 13. A vacuum gauge 15 is attached in the middle of the tube 16.

A 75 ° C. supply liquid A (mass ratio of ethanol / water = 90/10) was supplied to the supply liquid container 11 of the PV test apparatus through a tube 21 and the inside of the separator 12 was sucked by a vacuum pump 14 (vacuum gauge) 15 degree of vacuum: 10 to 1000 Pa). The liquid B that passed through the separator 12 was collected by a liquid nitrogen trap 13. The composition of the feed liquid A and the permeate B was measured using a gas chromatograph (trade name: GC-14B, manufactured by Shimadzu Corporation) to determine the separation performance α. Further, the weight of the collected liquid was measured, and the permeation rate Q was determined based on the weight, membrane area, and collection time. The obtained results are shown in Table 1. In Table 1, “No separation performance” means a case where the separation factor is 1000 or less under the above measurement conditions.

  From the results of Examples 1 and 2 and Comparative Example 1 described above, it was found that the permeation rate and the separation performance were greatly improved according to the method for producing a zeolite membrane according to the present invention. From this, it is considered that according to the method for producing a zeolite membrane of the present invention, a homogeneous zeolite membrane can be produced with a high yield, and a zeolite membrane having a sufficient permeation rate and separation performance can be provided. It is done.

FIG. 1 is a schematic cross-sectional view showing an ultrasonic cleaning apparatus used in a cleaning process which is one process of the present invention. FIG. 2 is a schematic diagram showing the pervaporation (PV) test apparatus used in Examples 1 to 3 and Comparative Example 1.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Support body, 2 ... Vibrator, 3 ... Solution, 5 ... Container, 10 ... Ultrasonic cleaning apparatus, 11 ... Supply tank device, 12 ... Separator, 13 ... Liquid nitrogen trap, 14 ... Vacuum pump, 15 ... Vacuum Gauge, 16, 21 ... tube, 22 ... stirring device.

Claims (4)

A membrane element forming step of reacting a support and a reaction solution containing a raw material of the zeolite membrane to form a zeolite membrane element on the surface of the support;
A separation step of separating the zeolite membrane and the reaction solution;
A washing step of washing the zeolite membrane to obtain a zeolite membrane;
A method for producing a zeolite membrane comprising:
In the cleaning step, the zeolite membrane is immersed in a liquid in a container, and an ultrasonic wave is applied to the zeolite membrane through the liquid by a vibrator fixed to the container. A method for producing a zeolite membrane, wherein the element body is washed.   The method for producing a zeolite membrane according to claim 1, further comprising a cooling step of cooling the zeolite membrane body after the separation step.   The method for cleaning a zeolite membrane according to claim 1 or 2, wherein the ultrasonic frequency is 50 kHz to 900 kHz.   The method for producing a zeolite membrane according to any one of claims 1 to 3, wherein in the washing step, the zeolite membrane body is washed while changing a frequency of the ultrasonic wave.

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