JP7334483B2 - Apparatus for treating outer peripheral surface of porous support, treatment method, and method for producing tubular separation membrane - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus and method for treating the outer peripheral surface of a porous support for tubular separation membranes, and more particularly, to an apparatus and method for rubbing the outer peripheral surface of a porous support having a zeolite membrane adhered to the outer peripheral surface. Regarding. The present invention also relates to a method for manufacturing tubular separation membranes.

A zeolite membrane composite, which is a zeolite membrane formed on a porous support, is used for the separation of liquid or gas mixtures. For example, by bringing a mixture of organic matter and water into contact with a zeolite membrane composite and selectively permeating water, the organic matter can be separated and concentrated.

In Patent Document 1, in order to form a homogeneous zeolite membrane by eliminating roughness unevenness on the surface of a porous support used for synthesizing a zeolite separation membrane, the porous support is rotated on a roller and brought into sliding contact with a grindstone. An apparatus is described for polishing the substrate surface with a .

The manufacturing process of a zeolite membrane composite includes a process of supporting seed crystals (seed crystals) on the outer peripheral surface of a porous support and a process of growing crystals. Paragraph 0148 of Patent Document 2 describes that after seed crystals are adhered onto a porous support, the surface is rubbed with a latex glove to push the seed crystals into the porous support or to remove excess seed crystals. It is

JP-A-2003-94304 JP 2018-130719 A

If the outer peripheral surface of the seed crystal-attached porous support is polished using the apparatus of Patent Document 1, the surface of the support is scraped off and almost all of the seed crystals are removed, which is inappropriate.

As in Patent Document 2, when the outer peripheral surface of the zeolite seed crystal-attached porous support is rubbed by hand, the work efficiency is low and it is not easy to evenly treat the outer peripheral surface.

The present invention provides an apparatus for treating the outer peripheral surface of a porous support for forming a zeolite membrane, which is capable of uniformly rubbing the outer peripheral surface of a porous support having zeolite seed crystals adhered to the outer peripheral surface thereof, and an apparatus for forming a zeolite membrane. An object of the present invention is to provide a method for treating the outer peripheral surface of a support. Another object of the present invention is to provide a method for producing a tubular separation membrane using a porous support having a treated outer peripheral surface.

The apparatus for treating the outer peripheral surface of a porous support for zeolite membrane formation of the present invention is an apparatus for rubbing the outer peripheral surface of a cylindrical porous support having zeolite seed crystals attached to the outer peripheral surface, wherein the porous support A rotation driving device for rotating the body around its axis, an elastic member in sliding contact with the outer peripheral surface of the porous support rotating around the axis, and a moving elastic member in the longitudinal direction of the porous support. and means.

One aspect of the present invention is characterized by comprising a cleaning means for ejecting a fluid toward the outer peripheral surface of the porous support to remove powder.

In one aspect of the present invention, the elastic material is made of rubber, synthetic resin, or microfiber.

The method for treating the outer peripheral surface of a support for zeolite membrane formation of the present invention comprises the step of rubbing the outer peripheral surface of a porous support to which zeolite seed crystals are adhered, wherein: A step of rubbing the outer peripheral surface of the porous support for forming a zeolite membrane by the apparatus for treating the outer peripheral surface of the porous support for forming a zeolite membrane according to any one of items 1 to 3.

The method for producing a tubular separation membrane of the present invention comprises the step of forming a zeolite membrane on the outer peripheral surface of the zeolite seed crystal-supporting porous support that has been treated by the method for treating the outer peripheral surface of a zeolite membrane-forming support according to claim 4. .

According to the apparatus and method for treating the outer peripheral surface of a zeolite membrane-forming porous support of the present invention, the elastic material is moved in the longitudinal direction of the porous support while rotating the zeolite seed crystal-attached porous support around its axis. By rubbing the outer peripheral surface with the elastic material, the entire outer peripheral surface of the porous support can be uniformly and efficiently rubbed. sure to get. In addition, since it is possible to adjust the leveling amount by reflecting the adhesion state of the seed crystals in the previous step, the formation of the zeolite membrane in the next step is also made more suitable.

1 is a plan view of an apparatus for treating the outer peripheral surface of a zeolite membrane-forming porous support according to an embodiment. FIG. FIG. 2 is a sectional view taken along line II-II of FIG. 1; FIG. 4 is an explanatory view of engagement between the end of the tubular separation membrane and the tip of the spindle;

Hereinafter, embodiments of a treatment apparatus and a treatment method for the outer peripheral surface of a porous support for zeolite membrane formation will be described with reference to FIGS. 1 to 3. FIG.

As shown in FIG. 1, this apparatus 1 for treating the outer peripheral surface of a porous support for forming a zeolite membrane includes a machine base 2, a drive-side spindle 3 that supports one end side of a porous support S, and a porous support S. A driven spindle 4 that supports the other end, bearing members 5 and 6 that support the spindles 3 and 4 on the machine base 2, a motor 7 that rotationally drives the drive spindle 3, and an outer peripheral surface of the porous support S. a slide base 10 movable in the longitudinal direction of the porous support S; a moving device 20 for moving the slide base 10;

As the elastic material 8, rubber, synthetic resin, microfiber, or the like is suitable. As the rubber, raw rubber having a Shore hardness of 0 to 90, particularly about 10 to 70, silicone rubber, etc. is suitable.

In this embodiment, the elastic members 8 are arranged so as to sandwich the porous support S from both sides. As shown in FIG. 2, one elastic member 8 is supported by the slide base 10 by means of brackets 12 . The other elastic member 8 is attached to the bracket 13 . The bracket 13 is movable in a direction perpendicular to the longitudinal direction of the porous support S along the support member 14, and is pressed against the outer peripheral surface of the porous support S by a pressing device 15 such as an air cylinder. It is configured to be pressed under pressure.

A pair of guide rails 16 , 16 extending parallel to the longitudinal direction of the porous support S are provided on the machine base 2 . A slider 17 provided on the bottom surface of the slide base 10 is slidably engaged with the guide rail 16 . The slide base 10 is provided with a screw block 18 that screws together with the ball screw 21 .

As shown in FIG. 1, the moving device 21 includes a ball screw 21 extending in a direction parallel to the longitudinal direction of the porous support S, a motor 22 for rotating the ball screw 21, and a tip end of the ball screw 21. A bearing member 23 supported by the base 2 is provided. The motor 22 and the motor 7 are attached to the machine base 2 .

In this embodiment, the spindles 3, 4 have the same outer diameter as the porous support S. The distal end of the spindle 3 is provided with a small diameter portion 3a to be inserted into the porous support S as shown in FIG. An O-ring 3b is interposed between the end surface of the porous support S and the falling surface to the small diameter portion 3a. An O-ring 3c is fitted in a ring groove provided around the outer peripheral surface of the small-diameter portion 3a, and the O-ring 3c contacts the inner peripheral surface of the porous support S. As shown in FIG.

Although illustration is omitted, the engaging portion between the tip portion of the spindle 4 and the porous support S is also the same as that shown in FIG. The spindles 3, 4 and the porous support S extend coaxially in a straight line.

In order to attach and detach the porous support S between the spindles 3 and 4, the support member 6 is supported on the machine base 2 so that its position can be changed in the axial direction.

Although illustration is omitted, a nozzle for injecting air toward the porous support S between the elastic members 8 is arranged, and powder particles generated when the outer peripheral surface of the porous support S is rubbed. It can be removed by blowing things away.

The processing apparatus 1 is also provided with a transparent cover (not shown) that covers the entire processing apparatus 1, and is configured to prevent dust from diffusing into the surroundings during operation.

In order to rub the outer peripheral surface of the porous support S using the apparatus 1 for treating the outer peripheral surface of the porous support for forming a zeolite membrane, as shown in FIGS. is held between the spindles 3 and 4, air is jetted from the nozzles, and the motors 7 and 22 are rotated. The elastic member 8 moves from one end of the porous support S to the other end while rubbing the outer peripheral surface of the rotating porous support S. As shown in FIG.

The pressure for pressing the elastic member 8 against the outer peripheral surface of the porous support is preferably about 1 to 700 kPa, more preferably about 1 to 75 kPa, but is not limited to this.

By moving the elastic member 8 from the spindle 3 to the spindle 4, the entire surface of the porous support S is evenly rubbed, and the zeolite seed crystals are rubbed into the porous support and excess zeolite seeds are removed. Crystals are removed.

The elastic member 8 may be reciprocated once from the spindle 3 side to the spindle 4 side (or in the opposite direction), may be reciprocated, or may be reciprocated multiple times.

After finishing the treatment of the outer peripheral surface of one porous support S, the motors 7 and 22 are stopped, the porous support S is exchanged, and the same treatment is performed.

When the apparatus is used for processing, the motors 7 and 22 are rotated at set rotation speeds, respectively, and the pressing device 15 presses the elastic material 8 against the outer peripheral surface of the porous support S with a constant pressing force, A large number of porous supports S can be efficiently treated under the same treatment conditions.

In the above description, the elastic member 8 is pressed against the outer peripheral surface of the porous support S by the pressing device 15. You may make it press against the support body S. FIG. Instead of the pressing device, an urging member such as a spring may be used to press the elastic member 8 against the porous support S.

In the above embodiment, one pair of elastic members 8 are arranged facing each other with the porous support S interposed therebetween, but two or more pairs of elastic members 8 may be arranged.

The porous support to which the treatment apparatus and method of the present invention are applied is a tubular (cylindrical) porous support on which zeolite seed crystals are adhered. The porous support is preferably made of an inorganic porous ceramic tube such as porous alumina and has a porosity of about 10% to 90%.

As seed crystals attached to the outer peripheral surface of the porous support S, any kind of zeolite can be used as long as it promotes crystallization.

If seed crystals with a large average particle size are used, the seed crystals may detach from the support during hydrothermal synthesis and may not play their role. Desirably, it may be pulverized and used as necessary. The particle size is usually 1 nm or more, preferably 10 nm or more, more preferably 50 nm or more, still more preferably 0.1 μm or more, particularly preferably 0.5 μm or more, most preferably 1 μm or more, and usually 5 μm or less, preferably It is 3 µm or less, more preferably 2 µm or less, and particularly preferably 1.5 µm or less.

The method for depositing seed crystals on the support is not particularly limited. A suction method in which crystals are dispersed in a solvent such as water, a support sealed at one end is immersed in the dispersion, and then the support is sucked from the other end to firmly adhere seed crystals to the surface of the support. A method of mixing seed crystals with a solvent such as water to form a slurry and applying the slurry onto a support can be used.

A tubular separation membrane is produced by forming a zeolite membrane by a hydrothermal synthesis method or the like on the outer peripheral surface of the porous support having the outer peripheral surface treated as described above.

In the hydrothermal synthesis, the support supporting the seed crystal as described above and the prepared raw material mixture for hydrothermal synthesis or the aqueous gel obtained by maturing this are placed in a pressure vessel, and under self-generating pressure, Alternatively, it is carried out by maintaining a predetermined temperature under a gas pressurization that does not hinder crystallization, under stirring, while rotating or rocking the container, or in a stationary state.

[Reference Example 1] (conventional method of rubbing by hand)
<Production of seed crystal-attached porous support>
A porous alumina tube (outer diameter: 12 mm, inner diameter: 9 mm, length: 120 cm, porosity: 34%) was used as the inorganic porous support.

The support was immersed in a dispersion of FAU-type zeolite seed crystals (average particle size: 1.2 μm) in water, and then dried to attach the seed crystals. The adhesion amount was 14.8 mg/cm ² . The surface of this support was rubbed (rubbed) with a hand wearing a rubber glove, and the seed crystals were rubbed in and excess seed crystals were removed to homogenize the surface.

The following were prepared as aqueous reaction mixtures for hydrothermal synthesis.

An aqueous potassium hydroxide solution and water were added to aluminum hydroxide (manufactured by Aldrich, containing 53.5% by weight of Al ₂ O ₃ ), and the mixture was stirred and dissolved to form a solution. Colloidal silica (Snowtech-40 manufactured by Nissan Chemical Industries, Ltd.) was added thereto and stirred for 2 hours to obtain an aqueous reaction mixture for hydrothermal synthesis (Al ₂ O ₃ /SiO ₂ mass ratio=10/24).

<Production of Tubular Separation Membrane>
The rubbed seed crystal-attached support was immersed in the above aqueous reaction mixture for hydrothermal synthesis in an autoclave, then the autoclave was sealed and the temperature was raised from room temperature to 180° C. over 5 hours. After completion of the temperature rise, it was heated at 180° C. for 24 hours while standing still under autogenous pressure. Then, it was allowed to cool, and the zeolite membrane composite was taken out from the aqueous reaction mixture, washed, and dried at 100° C. for 4 hours.

The dried support was immersed in demineralized water in an autoclave, then the autoclave was sealed and heated to 120°C. After completion of heating, the mixture was heated at 120° C. for 20 hours under autogenous pressure while standing still. Then, it was allowed to cool, and the tubular separation membrane (porous support-zeolite membrane composite) was taken out.

<Separation performance test>
This tubular separation membrane was used to selectively permeate water from water/ethanol aqueous solution (15/85% by weight) at 130° C. by the pervaporation method.

The compositions of the permeated liquid collected in the trap and the liquid to be separated were analyzed by a gas chromatograph. Water concentration in permeate and permeation flux (total permeation flux, Qw: permeation flux of water, Qa: permeation flux of ethanol) at the point where the composition of the liquid to be separated is water / ethanol = 15/85% by weight asked for

The total permeation flux was 10.8 kg/m ² h, Qw was 9.5 kg/m ² h, Qa was 1.3 kg/m ² h, and the water concentration in the permeate was 87.7 wt%.

<Alkaline durability test>
After that, NaHCO ₃ and Na ₂ CO ₃ were added to water/ethanol=50/50% by weight to adjust the pH to 12 to prepare an alkaline hydrous organic compound.

A U-shaped pipe was connected to one end of the tubular separation membrane after the separation performance test, and an end piece was connected to the other end. It was placed in the autoclave with the end piece facing up. The above alkaline hydrous organic compound was placed in an autoclave. The side of the U-shaped pipe that was not connected to the membrane was positioned above the liquid surface to prevent the liquid from entering the membrane.

The autoclave was heated to 130° C. and soaked for 2 days.

After that, the tubular separation membrane is taken out, washed with water, and again subjected to separation by selectively permeating water from water/ethanol aqueous solution (15/85% by weight) at 130° C. by pervaporation. The concentration and permeation flux (total permeation flux, Qw: water permeation flux, Qa: ethanol permeation flux) were determined.

The total permeation flux was 13.1 kg/m ² h, Qw was 12.3 kg/m ² h, Qa was 0.8 kg/m ² h, and the water concentration in the permeate was 93.5 wt%.

Table 1 shows the results.

[Example 1]
A tubular separation membrane was prepared and evaluated in the same manner as in Reference Example 1, except that the apparatus shown in FIGS. 1 to 3 was used instead of rubbing the seed crystal-attached porous support by hand. The concentration of water in the permeate and the permeation flux (total permeation flux, Qw: permeation flux of water, Qa: permeation flux of ethanol) were obtained. Table 1 shows the results.

The total permeation flux before the durability test was 10.4 kg/m ² h, Qw was 9.6 kg/m ² h, Qa was 0.8 kg/m ² h, and the water concentration in the permeate was 92.5 wt%. . After the endurance test, the total permeation flux was 12.0 kg/m ² h, Qw was 11.5 kg/m ² h, Qa was 0.5 kg/m ² h, and the water concentration in the permeate was 95.5 wt%. .

As a result, it was confirmed that by performing rubbing using the apparatus of the present invention, a tubular separation membrane having excellent separation performance similar to that obtained by performing rubbing by hand can be obtained. In addition, the use of the apparatus has made it possible to reduce variation among porous supports, improve work efficiency, and increase productivity.

REFERENCE SIGNS LIST 1 device for treating the outer peripheral surface of a porous support 2 machine base 3 drive-side spindle 4 driven-side spindle 8 elastic member 10 slide base 20 moving device 21 ball screw

Claims (5)

A device for rubbing the outer peripheral surface of a cylindrical porous support having zeolite seed crystals attached to the outer peripheral surface,
a rotary driving device for rotating the porous support around its axis;
an elastic member in sliding contact with the outer peripheral surface of the porous support that rotates about its axis;
and means for moving the elastic material in the longitudinal direction of the porous support. 2. The apparatus for treating the outer peripheral surface of a porous support for forming a zeolite membrane according to claim 1, further comprising cleaning means for ejecting a fluid toward the outer peripheral surface of the porous support to remove powder. . 3. The apparatus for treating the outer peripheral surface of a porous support for forming a zeolite membrane according to claim 1, wherein said elastic material is made of rubber, synthetic resin or microfiber. In the method for treating the outer peripheral surface of the porous support, which comprises rubbing the outer peripheral surface of the porous support to which the zeolite seed crystals are attached,
The outer peripheral surface of a support for zeolite membrane formation, characterized in that a step of rubbing the outer peripheral surface with the apparatus for treating the outer peripheral surface of the porous support for zeolite membrane formation according to any one of claims 1 to 3. Processing method. A method for producing a tubular separation membrane, comprising the step of forming a zeolite membrane on the outer peripheral surface of the zeolite seed crystal-supporting porous support treated by the method for treating the outer peripheral surface of a support for forming a zeolite membrane according to claim 4.

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