JP2007216106A - Manufacturing method of ceramic membrane for gas separation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a ceramic membrane for gas separation with superior quality, suppressing occurrence of pin holes caused by defect present in an intermediate layer, thus having a high permeation factor ratio even in an increased size of the membrane. <P>SOLUTION: In this manufacturing method of a ceramic membrane for gas separation, material gas containing vaporized organic silica compounds is supplied to a side forming the gas separation membrane of a base material, opposite gas is supplied to the opposite side of the material gas supply side of the base material, and the gas separation membrane consisting of silica oxide is formed on the surface of the base material supplied with the material gas. The material gas, while being heated and pressurized, is supplied to the surface of the base material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a ceramic membrane for gas separation used for purifying gas components, particularly hydrogen.

  Conventionally, when purifying or synthesizing chemicals in the field of chemical industry, or when using fuel cells in fields related to energy, etc., it has been required to obtain high purity hydrogen by a simple method. For this purpose, a hydrogen separation method using a gas separation membrane is known.

  Currently, metal membranes, alloy membranes or ceramic membranes are used as membranes for separating hydrogen. However, when purifying hydrogen from an air-fuel mixture containing methane or the like for use in fuel cells, etc. Alternatively, the alloy film has a problem that hydrogen embrittlement or oxidation / denaturation is caused. In this respect, the ceramic film which does not cause such a problem is superior.

  The ceramic membrane is mainly composed of a silicon oxide thin film, for example, a silicon oxide having a porous aluminum oxide or the like as a base material and having pores of 3 mm or less as a gas separation membrane on the surface of the base material. It is manufactured by forming a thin film.

  The gas separation membrane used for such a purpose has pores of 3 mm or less, and by passing only small molecules such as hydrogen and helium through such fine pores, Functions as a molecular sieve that can be separated from molecules larger than 3 cm.

  As a method for forming a silicon oxide thin film as a gas separation film on a substrate made of aluminum oxide or the like, a sol-gel method or a chemical vapor deposition method (CVD) method is most widely used.

  In the sol-gel method, a polymer sol or colloidal sol obtained by hydrolysis and polycondensation reaction of a predetermined alkoxide is applied on a substrate, and then dried to obtain a gel film, which is further baked to obtain a desired thin film. It is a method (nonpatent literature 1).

The CVD method is a method in which a reactive gas is allowed to flow on a high-temperature substrate to deposit a solid layer on the substrate surface. Since this method is not affected by dust or the like, it is known that a silicon oxide thin film having a transmission coefficient ratio α (H ₂ / N ₂ ) of 3310 can be formed (Non-patent Document 2).
Masae Asaeda and Michinari Kismoto, “Sol-Gel Delivered Silica Membrane for Separation of Hydrogen at High Temperature-Separation Performance and Stability Agenst Stem ( SOL-GEL DERIVED SIRICA MEMBRANES FOR SEPARATION OF HYDROGEN AT HIGH TEMPERATURE-SEPARATION PERFORMANCE AND STABILITY AGAINST STEM-), 5th International Conference on Inorganic Chemical Films, 1998, p172-175 Chemical Engineering Science, Vol. 44, No. 9, 1989, p1829-1835

  The substrate of the ceramic membrane has a multilayer structure, that is, a support layer and an intermediate layer that is positioned between the gas separation membrane and the support layer when the gas separation membrane is formed by a sol-gel method or a CVD method. Have at least. The support layer has pores with a large diameter of 0.1 to 10 μm compared to the gas separation membrane provided on the outermost surface, and when the gas separation membrane is directly formed on the support layer, the same is true. The silicon oxide constituting the separation membrane reaches the inside of the support layer, and the pores of the support layer are blocked. For this reason, the gas permeation rate of the obtained ceramic membrane is reduced. The intermediate layer is provided in order to prevent such adverse effects, and has 20 to 1 nm pores smaller than the support layer. However, this intermediate layer has uneven thickness and further has minute defects (holes).

  As described above, when a gas separation film is formed by a sol-gel method or a CVD method, a pinhole is generated in the gas separation film due to a defect in the intermediate layer due to the existence of a defect in the intermediate layer. There was a problem that the transmission coefficient ratio of the liquid crystal was reduced. Such a problem of pinholes tends to become more prominent by increasing the size (bundle shape), and accordingly, the problem of a decrease in the transmission coefficient ratio becomes more serious.

  The present invention has been made in view of the above circumstances, and suppresses the generation of pinholes due to defects present in the intermediate layer, and thereby, for excellent quality gas separation with a high permeability coefficient ratio even when the size is increased. An object of the present invention is to provide a method for producing a ceramic film.

  In order to solve the above problems, a method for producing a ceramic membrane for gas separation according to the present invention supplies a material gas, which is a vaporized organosilicon compound-containing gas, to the side of the base material on which the gas separation membrane is formed, A gas separation ceramic membrane for supplying a counter gas to a side opposite to a gas supply side and forming a gas separation membrane made of silicon oxide on the base material on the surface of the base material gas supplied In the manufacturing method, the material gas is supplied onto the surface of the base material while being heated and pressurized.

  If the material gas is less than 400 ° C., the reaction rate is slow, so that a gas separation membrane cannot be formed. If the material gas exceeds 700 ° C., the pores of the silicon compound that is the gas separation membrane cannot maintain 3%. Therefore, the heating conditions for the material gas are preferably 400 to 700 ° C., more preferably 450 to 600. Further, the pressure difference between the material gas and the counter gas is set to 0.01 to 0.5 MPa. If the pressure difference is less than 0.01 MPa, the pressure difference is too small, so that the silicon oxide cannot fill the defective portion on the surface of the substrate, and the effect of suppressing the generation of pinholes cannot be obtained. If the pressure difference is more than 0.5 MPa, the service strength of the support layer is exceeded, and there is a risk of damage. The pressure value of the material gas preferably exceeds atmospheric pressure and is 1 MPa or less, more preferably 0.11 to 0.6 MPa.

  In this way, by supplying the material gas onto the substrate surface while heating and pressurizing, even if defects are generated on the substrate surface, the silicon oxide generated by the reaction intensively fills the defective portions. Therefore, the generation of pinholes can be suppressed.

  In the method of the present invention described above, the pressure of the counter gas is equal to or higher than atmospheric pressure, but needs to be lower than that of the material gas.

  If the pressure on the counter gas supply side is less than the atmospheric pressure, the pressure of the material gas will be too high compared to the pressure of the counter gas, so the reaction between the counter gas and the material gas reaches the inner depth of the intermediate layer. As a result, the thickness of the gas separation membrane increases. If the number of gas separation membranes increases excessively, the permeation rate decreases as a result.

  In the method of the present invention, the material gas is a liquid obtained by bubbling at least one gas selected from the group consisting of nitrogen, helium, argon, neon, krypton, xenon and hydrogen into a liquid organosilicon compound. A vaporized organosilicon compound-containing gas obtained by vaporizing the organosilicon compound is preferred.

  In the method of the present invention, the liquid organosilicon compound is selected from the group consisting of methyl silicate, ethyl silicate, butyl silicate, hexamethyldisilane, hexamethyldisiloxane, hexamethyldisilazane, and tetramethylsilane. It is preferable that there is at least one.

  In the method of the present invention, the counter gas may be obtained by bubbling at least one gas selected from the group consisting of oxygen, nitrogen, helium, argon, neon, krypton, and xenon into liquid pure water. A water vapor-containing gas obtained by vaporizing pure water is preferred.

  When the counter gas is oxygen, oxygen assists the CVD reaction of the organosilicon compound and prevents silicon oxide from reaching the inside of the support layer.

  When the counter gas is another gas, the pressure on the side opposite to the material gas supply side is maintained to prevent the silicon oxide from reaching the inside of the support layer.

  In the method of the present invention, the substrate is preferably composed of porous ceramics.

  In the method of the present invention, the substrate preferably has a multilayer structure having a support layer having a pore size of 0.1 to 10 μm and an intermediate layer having a pore size of 1 to 20 nm. Here, when the intermediate layer is only a support layer having a large diameter (0.1 to 10 μm), the generated silicon oxide particles reach the inside of the support layer when the gas separation membrane is formed. As a result, the support layer Since the permeation rate of the ceramic membrane is reduced by blocking the pores, the membrane is provided to prevent this, and has pores of 1 to 20 nm. When the pore diameter of the support layer exceeds 10 μm, the diameter is too large, and particles constituting the intermediate layer enter the support layer, resulting in a problem that the intermediate layer cannot be formed well. On the other hand, if the pore size of the support layer is less than 0.1 μm, the permeation of the separation gas will be hindered, and the gas permeation rate will decrease as described above. For this reason, it is preferable that the pore diameter of a support layer is 0.1-10 micrometers. On the other hand, when the pore diameter of the intermediate layer exceeds 20 nm, the silicon oxide particles generated by the reaction easily penetrate into the intermediate layer, and therefore the pores of the intermediate layer are blocked. Will be reduced. The pores of the intermediate layer need only be large enough to maintain the gas permeation rate of the gas separation membrane (silicon oxide thin film), and the lower limit is preferably about 1 nm, for example, those having pores of 1 to 20 nm. Used.

  In the method for producing a ceramic membrane for gas separation according to the present invention, since the material gas is supplied onto the substrate surface while being heated and pressurized, it is generated from the organosilicon compound even if a defect exists on the substrate surface. The silicon oxide that enters into the defect portion intensively fills it and suppresses the generation of pinholes. As a result, the obtained membrane has excellent permeation gas selectivity.

  Hereinafter, the manufacturing method of the ceramic membrane for gas separation of this invention is demonstrated in detail.

  In this embodiment, a case where a silicon oxide thin film that is a gas separation film is formed on a cylindrical base material will be described. Here, a cylindrical base material forms an intermediate | middle layer on the outer surface of the support layer of a cylindrical porous alumina.

  FIG. 1 is a block diagram showing an apparatus for carrying out the method for producing a ceramic membrane for gas separation according to the present invention.

  This apparatus generally includes a film formation chamber (1) for forming a gas separation membrane and a gas introduction system for supplying a counter gas and a material gas.

  The film forming chamber (1) is made of a material having heat resistance up to 1000 ° C., for example, stainless steel. A cylindrical base material (A) is arranged in the film forming chamber (1), and base material holding cylinders (2) connected to both ends of the base material (A) are provided at both ends of the film forming chamber (1). It penetrates the wall. The base material (A) is provided such that the support layer comes inside and the intermediate layer comes outside. The base material holding cylinder (2) is made of stainless steel or a dense ceramic tube, and at least the base material (A) exterior portion is gas permeable. The contact portion between the substrate holding cylinder (2) and the film forming chamber (1) can be fixed and sealed with an O-ring or Teflon (registered trademark) packing.

  A heater (3) for heating the inside of the film forming chamber (1) is provided around the film forming chamber (1). The heater (3) is controlled by a thermocouple (5) attached to the heater (3) and monitored by a thermocouple (4) attached in the film forming chamber (1).

  The gas introduction system includes a cylinder (6) filled with a gas used for material gas generation, a cylinder (7) filled with a gas used for counter gas generation, the concentration of the generated material gas or counter gas, and And a cylinder (8) for adjusting the pressure.

  The cylinder (6) is filled with at least one gas selected from the group consisting of oxygen, nitrogen, helium, argon, neon, krypton, xenon and hydrogen. The gas exiting the cylinder (6) first passes through a gas flow meter (9) for grasping the gas flow rate. The gas emitted from the gas flow meter (9) passes through either the path through the liquid organosilicon compound tank (10) in which the organosilicon compound as the material is charged or the path not through the tank. In the path passing through the liquid organosilicon compound tank (10), valves (11) and (12) for adjusting the opening and closing of the gas introduction and the amount of introduction are provided before and after the liquid organosilicon compound tank (10) on the path, respectively. Yes.

The liquid organosilicon compound tank (10) is charged with a liquid silicon oxide source. Examples of the liquid silicon oxide source include methyl silicate [Si (OCH ₃ ) ₄ ], ethyl silicate [Si (OC ₂ H ₅ ) ₄ ], butyl silicate [Si (OC ₃ H ₇ ) ₄ ], hexa Methyldisilane [(CH ₃ ) ₃ SiSi (CH ₃ ) ₃ ], hexamethyldisiloxane [(CH ₃ ) ₃ SiOSi (CH ₃ ) ₃ ], hexamethyldisilazane [(CH ₃ ) ₃ SiNHSi (CH ₃ ) ₃ ], Tetramethylsilane, etc. are mentioned. Or you may charge several things selected from these to a liquid silicon compound tank (10). As these liquid silicon oxide sources, methyl silicate and ethyl silicate are preferable.

  When the gas from the cylinder (6) is introduced into the liquid organosilicon compound tank (10) by opening the valves (11) and (12), the vaporized organosilicon with the organosilicon compound vaporized in the gas by bubbling A compound-containing gas is produced. The vaporized organosilicon compound-containing gas generated in this way merges with the gas coming from the path not passing through the liquid organosilicon compound tank (10) via the valve (12). The ratio between the gas containing vaporized organosilicon obtained by passing through the liquid organosilicon compound tank (10) and the gas not passing through this tank (10) is adjusted by the opening degree of the valves (11) and (12). Is done. The gas containing the vaporized organosilicon obtained in this way passes through the valve (13), and the flow rate is adjusted by adjusting the opening of the valve (13). The gas flow rate is adjusted by the gas flow meter (9) so that the flow rate is 0.01 to 10 L / min.

  When the counter gas is a water vapor-containing gas, it is as follows.

  The cylinder (7) is filled with at least one gas selected from the group consisting of oxygen, nitrogen, helium, argon, neon, krypton and xenon. The gas exiting the cylinder (7) first passes through the flow meter (16) for grasping the gas flow rate. The gas emitted from the gas flow meter (16) passes through either a path through the pure tank (17) charged with pure water or a path not through the tank (17). In the path passing through the pure water tank (17), valves (18) and (19) for adjusting the opening and closing of the gas introduction and the amount of introduction are provided before and after the pure water tank (17) on the path, respectively.

  When a gas not containing water vapor is used as the counter gas, the valves (18) and (19) are closed, and the gas from the cylinder (7) is supplied as the counter gas as it is.

  When the valves (18) and (19) are open, the gas from the cylinder (7) is introduced into the pure water tank (17), and a water vapor-containing gas accompanied by water vapor is generated by bubbling. The pure water tank (17) may heat pure water charged by a heater (not shown) from room temperature to 100 ° C., so that high-concentration water vapor is contained. Can be. The water vapor-containing gas generated in this way merges with the gas coming from the path not passing through the pure water tank (17) by opening the valve (19). The ratio of the gas containing water vapor obtained by passing through the pure water tank (17) and the gas not passing through this tank (17) is adjusted by the opening degree of the valves (18) and (19).

  The gas directly sent from the cylinder (7) by closing the valves (18) and (19) or the water vapor-containing gas obtained through the pure water tank (17) passes through the valve (20), The flow rate is adjusted by adjusting the opening of the valve (20).

  In the cylinder (8) for adjusting the generated material gas or the counter gas, a gas common to the gas charged in the material gas cylinder and the gas charged in the counter gas cylinder, for example, oxygen, At least one gas selected from the group consisting of nitrogen, helium, argon, neon, krypton and xenon is filled. The gas filled in the cylinder (8) is merged with the material gas via the flow meter (23) and the valve (24), and is merged with the counter gas via the flow meter (25) and the valve (26). Thus, by adding gas from the cylinder (8) to the material gas and the counter gas, the concentration of the vaporized organosilicon compound or water vapor contained in each gas can be reduced, or the pressure of each gas is adjusted. be able to.

  The material gas generated as described above is introduced into the film forming chamber (1), and the counter gas is introduced into the substrate holding cylinder (2).

The flow rate of the material gas introduced into the film formation chamber (1) can be appropriately changed according to the film formation area. For example, when the film formation area is 20 cm ² , the flow rate is 100 to 400 ml / min. preferable. This is because if the flow rate is too high, the film formation is not good on the substrate, and if the flow rate is too slow, the film formation time becomes longer.

  The material gas introduced into the film forming chamber (1) is discharged from the gas discharge port (27). On the gas discharge side, a pressure gauge (28) for measuring the pressure in the film forming chamber (1) and an adjustment valve (29) for adjusting the pressure of the exhaust gas based on the pressure value measured by the pressure gauge (28). ) And are provided.

  Further, the counter gas introduced into the substrate holding cylinder (2) is discharged from the end of the substrate holding cylinder (2) opposite to the gas introduction end. At the gas discharge end, a pressure gauge (30) for measuring the pressure in the base material holding cylinder (2) and an adjustment for adjusting the pressure of the exhaust gas based on the pressure value measured by the pressure gauge (30) A valve (31) is provided.

  When forming a gas separation membrane of a ceramic membrane for gas separation using the apparatus configured as described above, a vaporized organosilicon compound-containing gas is generated by the material gas introduction system, and a water vapor-containing gas is generated by the counter gas introduction system. The former is introduced into the film forming chamber (1), and the latter is introduced into the substrate holding cylinder (2).

  The base material held by the base material holding cylinder (2) is a support layer having a pore diameter of 0.1 to 10 μm, most preferably 0.2 to 0.1 μm, and 1 to 20 nm, most preferably 6 to A multilayer structure including an intermediate layer having a pore diameter of 2 nm is preferable. By forming a silicon compound on the surface or pores of such a substrate, a gas separation membrane that can transmit only molecules of 3 cm or less can be obtained.

  The gas introduction was performed by monitoring the pressure gauge (30) for measuring the pressure in the substrate holding cylinder (2) while monitoring the pressure gauge (28) for measuring the pressure in the film forming chamber (1). The gas is introduced while adjusting the pressure of the gas.

  The pressure on the material gas side may vary depending on the gas flow rate, but is in the range of 0.11 to 0.6 MPa.

  The introduced material gas is heated by the heater (3). The deposition temperature of the gas separation membrane is preferably 400 to 700 ° C, more preferably 450 to 650 ° C. If the film formation temperature is too low, the reaction rate is slow, and if it is too high, a reaction occurs even on a substrate other than the substrate, resulting in poor efficiency and slow reaction time.

  The pressure of the counter gas is not less than the atmospheric pressure (provided that it does not exceed the pressurization value of the material gas). If the pressure of the counter gas is less than atmospheric pressure, the pressure of the counter gas is too low compared to the pressure of the material gas, so that the material gas does not stay on the surface of the intermediate layer but reaches the inside, thereby Since the reaction between the gas and the counter gas takes place inside the intermediate layer, the film thickness of the gas separation membrane is significantly increased. As a result, the gas permeation rate of the gas separation membrane is significantly reduced. It is not preferable.

  As described above, in the method for producing a ceramic membrane for gas separation according to the present invention, the base material is installed in the base material holding cylinder (2) in the film formation chamber (1), and the film formation chamber (1) is provided with the base material. A vaporized organosilicon compound-containing gas, that is, a material gas is introduced while being pressurized, a film forming portion in the film forming chamber (1) is heated by a heater (3), and a water vapor containing gas, By introducing the counter gas, it is possible to form a separation membrane having a function of molecular sieve capable of allowing only molecules of 3 cm or less made of a silicon compound to pass through on the intermediate layer.

  Next, a silicon oxide thin film was formed by actually supplying a material gas on the surface side of the base material and an opposing gas on the inner side of the base material by the CVD method using the apparatus having the above configuration according to the following examples.

Example 1
In the gas separation ceramic membrane manufacturing apparatus shown in FIG. 1, the material gas supply side is pressurized (0.2 MPa) and not pressurized (ie, at atmospheric pressure) at a temperature of 500 ° C. by the CVD method. ) (In either case, the pressure of the counter gas: atmospheric pressure), a gas separation membrane was formed. Next, with respect to the obtained gas separation membrane, the permeation rate of hydrogen and nitrogen was measured while changing the temperature. The material gas is formed by bubbling argon into methyl silicate, and the counter gas is oxygen. The result is shown in a graph in FIG.

  As shown in FIG. 2, about the hydrogen permeation rate, almost the same value was obtained in the case of atmospheric pressure (white circle) and in the case of pressurization (black circle). However, in the figure, a difference was observed in the low temperature region (portion surrounded by a chain line). This is considered due to the occurrence of pinholes due to defects. On the other hand, regarding the nitrogen permeation rate, when compared with the case of atmospheric pressure (white square) and the case of pressurization (black square), the permeation rate of the membrane obtained by pressurization over each temperature range is It was 1/10 of the permeation | transmission rate of the film | membrane obtained by.

  As schematically shown in FIGS. 3 (a) and 3 (b), these results show that the reaction between the material gas and the counter gas in the case of the pressurized type of (b) even if the intermediate layer has a defect. In the case of the atmospheric pressure type (a), such an effect is obtained. In this way, in the film obtained by the pressurization method, it is considered that the permeation of nitrogen was lowered because the intermediate layer was filled.

  Such pressure adjustment is easy to respond to such an increase in size even if the apparatus is increased in size. Therefore, the method for producing a ceramic membrane for gas separation by the pressurization method is as described above. This is a very effective method when manufacturing a ceramic membrane for gas separation having a permeability coefficient ratio on a large scale.

(Example 2)
In the ceramic membrane manufacturing apparatus for gas separation having the configuration shown in FIG. 1, a base material is composed of a cylindrical α-alumina porous tube as a support layer and γ-alumina as an intermediate layer formed on the outside thereof. And this was hold | maintained at the base-material holding | maintenance cylinder (2) in the film-forming chamber (1). Argon gas containing ethyl silicate was used as a material gas, which was introduced into the film forming chamber (1), and oxygen was introduced into the substrate holding cylinder (2) as the counter gas. The film formation temperature was set to 600 ° C., the material gas pressure was set to 0.12 MPa, and film formation was performed for 10 hours to obtain a ceramic film for hydrogen separation.

(Example 3)
In the ceramic membrane manufacturing apparatus for gas separation having the configuration shown in FIG. 1, a base material is composed of a cylindrical α-alumina porous tube as a support layer and γ-alumina as an intermediate layer formed on the outside thereof. And this was hold | maintained at the base-material holding | maintenance cylinder (2) in the film-forming chamber (1). Nitrogen containing methyl silicate was used as a material gas, which was introduced into the deposition chamber (1), and oxygen (obtained by bubbling oxygen into pure water heated to 60 ° C.) as a counter gas. It introduce | transduced in the base-material holding cylinder (2). The film formation temperature was set to 600 ° C., the pressure of the material gas was set to 0.30 MPa, and film formation was performed for 10 hours to obtain a ceramic film for hydrogen separation.

Example 4
In the ceramic membrane manufacturing apparatus for gas separation having the configuration shown in FIG. 1, a base material is composed of a cylindrical α-alumina porous tube as a support layer and γ-alumina as an intermediate layer formed on the outside thereof. And this was hold | maintained at the base-material holding | maintenance cylinder (2) in the film-forming chamber (1). Nitrogen containing methyl silicate is used as a material gas, which is introduced into the film forming chamber (1), and oxygen containing water vapor as a counter gas (by bubbling oxygen into pure water heated to 60 ° C. Obtained) was introduced into the substrate holding cylinder (2). The film forming temperature was set to 600 ° C., the material gas pressure was set to 0.15 MPa, and the film forming process was performed for 10 hours to obtain a ceramic film for hydrogen separation.

(Comparative Example 1)
Except that the source gas was not pressurized, the same operation as in Example 2 was performed to obtain a ceramic membrane for hydrogen separation.

  The films obtained in Examples 2 to 4 and Comparative Example 1 were evaluated. Specifically, each ceramic membrane for hydrogen separation was set in the film forming chamber (1) shown in FIG. 1, and the gas permeation count was measured while heating to 500 ° C. with the heater (3). The hydrogen permeation was measured by supplying 0.2 MPa of hydrogen into the film formation chamber (1), passing through the ceramic membrane for hydrogen separation installed in the film formation chamber (1), and The hydrogen coming out from the outlet of 2) was measured with a soap film flow meter (not shown). Nitrogen permeation was measured by depressurizing the inside of the base material holding cylinder (2) while supplying nitrogen into the film forming chamber (1), and using a Pirani vacuum gauge (not shown). The nitrogen permeability coefficient was calculated from the increasing rate.

Transmission count is
P = M / A / t / (P1-P2)
It is. In the formula, P is a transmission coefficient (unit: mol · m ⁻² · s ⁻¹ · Pa ⁻¹ ), A is a membrane area (m ² ), t is a time (s), and (P1−P2). Is the partial pressure difference (Pa) between the permeate on the gas supply side and the permeate side.

The permeability coefficient ratio of hydrogen and nitrogen can be calculated from the ratio of permeability coefficients measured under the same conditions, that is, α = P _H2 / P _N2 .

  The results obtained for Examples 2 to 4 and Comparative Example 1 are shown in the following table.

  As is apparent from Table 1, in Examples 2 to 4 in which the material gas was pressurized, it was shown that the hydrogen / nitrogen permeability coefficient ratio was remarkably superior to that of Comparative Example 1. In particular, in Example 2, although the pressurization of the material gas is about 0.12 MPa, it can be seen that a significant transmission coefficient ratio effect is obtained.

It is a block diagram which shows the apparatus for enforcing the method of manufacturing the ceramic membrane for gas separation of this invention. It is a graph which shows the result of having measured the permeation | transmission rate of hydrogen and nitrogen of the gas separation membrane formed by supplying material gas while being pressurized and the gas separation membrane formed by supplying material gas without being pressurized . It is the schematic explaining the case where the silicon oxide produced | generated by reaction of material gas and counter gas is laminated | stacked on an intermediate | middle layer, (a) when not pressurizing material gas, (b) is pressurizing material gas Shows the case.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Deposition chamber 2 Base material holding cylinder 3 Heater 4 Thermocouple 5 Thermocouple 6 Cylinder 7 Cylinder 8 Cylinder 9 Gas flow meter 10 Liquid organosilicon compound tank 11 Valve 12 Valve 13 Valve 16 Flow meter 17 Pure water tank 18 Valve 19 Valve 20 valve 23 flow meter 24 valve 25 flow meter 26 valve 27 gas outlet 28 pressure gauge 29 adjustment valve 30 pressure gauge 31 adjustment valve

Claims (8)

A material gas that is a vaporized organosilicon compound-containing gas is supplied to the side of the base material on which the gas separation membrane is formed, and a counter gas is supplied to the side of the base material opposite to the side of supplying the material gas. In the method for producing a ceramic membrane for gas separation, wherein a gas separation membrane made of silicon oxide is formed on a substrate on a surface supplied with a material gas,
A method for producing a ceramic membrane for gas separation, wherein the material gas is supplied onto the surface of the substrate while being heated and pressurized.   The method for producing a ceramic membrane for gas separation according to claim 1, wherein the pressure of the counter gas is equal to or higher than atmospheric pressure but lower than the pressure of the material gas.   The manufacturing method of the gas separation melt | dissolution ceramic membrane of Claim 2 whose heating temperature of the said material gas is 400-700 degreeC, and the pressure difference of the said material gas and counter gas is 0.01-0.5 MPa.   As the material gas, at least one gas selected from the group consisting of nitrogen, helium, argon, neon, krypton, xenon and hydrogen is bubbled into the liquid organosilicon compound to vaporize the liquid organosilicon compound. The manufacturing method of the ceramic membrane for gas separation as described in any one of Claims 1-3 obtained by these.   The liquid organosilicon compound is at least one selected from the group consisting of methyl silicate, ethyl silicate, butyl silicate, hexamethyldisilane, hexamethyldisiloxane, hexamethyldisilazane, and tetramethylsilane. Item 5. A method for producing a ceramic membrane for gas separation as described in any one of Items 1 to 4.   The counter gas is obtained by bubbling at least one gas selected from the group consisting of oxygen, nitrogen, helium, argon, neon, krypton and xenon, or the gas into pure water to vaporize the pure water. The method for producing a ceramic membrane for gas separation according to any one of claims 1 to 5, which is a steam-containing gas to be produced.   The said base material is a manufacturing method of the ceramic membrane for gas separation as described in any one of Claims 1-6 comprised from porous ceramics.   The ceramic for gas separation according to any one of claims 1 to 7, wherein the base material has a multilayer structure having a support layer having pores of 0.1 to 10 µm and an intermediate layer having pores of 1 to 20 nm. A method for producing a membrane.

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