JP2002274967A - Gamma alumina porous body, method for manufacturing the same and fluid separation filter by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a γ-alumina porous body having high water resistance and to provide a fluid separation filter having high water resistance by using the porous body. SOLUTION: The fluid separation filter 1 consists of a γ alumina porous body 3 essentially comprising γ-alumina and containing 0.1 to 30 mol yttrium to 100 mol of the γ alumina calculated as aluminum. The fluid separation filter 1 can separate a specified fluid by bringing a mixture of a plurality of fluids into contact with one surface of the above γ-alumina porous body 3 and selectively permeating only a specified fluid in the mixture fluid to the other surface of the γ-alumina porous body 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gamma-alumina porous material mainly composed of gamma-alumina, and is particularly suitable as a fluid separation filter capable of selectively permeating and separating only a specific fluid from a plurality of mixed fluids. The present invention relates to a γ-alumina porous body having a fine pore diameter and a method for producing the same.

[0002]

2. Description of the Related Art Hitherto, γ-alumina porous materials have been used for various applications such as adsorbents, catalyst carriers, and coating members for coating various member surfaces. The porous body is contacted with a mixed fluid composed of a plurality of types of fluids on one surface thereof, and a specific fluid in the mixed fluid is selectively transmitted to the other surface of the porous ceramic body by a specific fluid. It is suitably used as a fluid separation filter capable of separating a fluid.

[0003] As this type of fluid separation filter, for example, Japanese Patent Application Laid-Open No. Hei 5-192548 discloses that an aqueous sol of alumina is brought into contact with the surface of an α-alumina porous support, dried and calcined to obtain a γ-alumina. A fluid separation membrane in which an intermediate layer made of a porous material (a polymer thin film is formed on the surface of this layer) is described. In addition, Japanese Patent Application Laid-Open
In -876, γ-alumina is used as a carrier, lanthanum, praseodymium, neodymium and the like are prepared on the surface to produce a γ-alumina porous material modified with a basic oxide of a rare earth metal, and the affinity with carbon dioxide is increased. Describes that carbon dioxide can be separated.

[0004]

However, as disclosed in Japanese Patent Application Laid-Open No. 5-192548, a device using a gamma-alumina porous material, and as disclosed in Japanese Patent Application Laid-Open No. 9-876, a surface of a basic oxide of a rare-earth metal is used. In the fluid separation filter using the γ-alumina porous material modified with the substance, as is clear from the description in the example of the publication, the affinity for CO ₂ gas changes depending on the presence or absence of water vapor, and the gas separation characteristics Will change, and the γ-alumina itself will be altered by contact with water vapor, the pore diameter in the porous body will change, and the fluid separation characteristics will decrease.In some cases, cracks will occur in the layer, There is a problem that peeling occurs between the support and the thin film.

The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a γ having excellent water resistance capable of maintaining a stable structure even under severe conditions in which water or high-temperature steam contained in the atmosphere is present. An object of the present invention is to provide an alumina porous body, a method for producing the same, and a highly water-resistant and reliable fluid separation filter capable of maintaining high separation performance even in the presence of water.

[0006]

The inventors of the present invention have studied the above problem and found that a predetermined amount of yttrium is added to a γ-alumina porous body mainly composed of γ-alumina in an amount of 0.1 to 30 mo.
By preventing the deterioration of γ-alumina by water, it is possible to produce a γ-alumina porous body having excellent water resistance by using the γ-alumina porous body.
It has been found that a fluid separation filter having excellent water resistance can be manufactured.

That is, the gamma-alumina porous body of the present invention is mainly composed of gamma-alumina, and contains yttrium in an amount of 0.1 mol based on 100 mol of the aluminum equivalent of the gamma-alumina.
It is characterized in that it is contained at a ratio of 1 to 30 mol.

Here, the average pore diameter of the γ-alumina porous material is 0.5 to 50 nm, and the specific surface area of the γ-alumina porous material by a BET adsorption method is 50 to 500 m.
² / g is desirable.

In the method for producing a gamma-alumina porous material of the present invention, a yttrium compound is added to a gamma-alumina raw material solution in an amount of 0.1 to 30 mol in terms of yttrium with respect to 100 mol in terms of aluminum in the solution. It is characterized by mixing, drying and firing.

Here, it is desirable to add the yttrium compound after preparing a boehmite sol from the γ-alumina raw material solution.

Further, the fluid separation filter of the present invention comprises the above-mentioned γ-alumina porous material, and a mixed fluid comprising a plurality of kinds of fluids is brought into contact with one surface of the γ-alumina porous material, and The specific fluid is separated by selectively permeating only the specific fluid through the other surface of the γ-alumina porous material.

Here, the γ-alumina porous material is coated on the surface of a ceramic support having an average pore diameter larger than that of the γ-alumina porous material by 0.1 to 100 μm.
m, and further coated on the surface of the coating layer composed of the γ-alumina porous body, another porous body having an average pore diameter smaller than the average pore diameter of the γ-alumina porous body. It is desirable that it be formed by adhesion.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The gamma-alumina porous material of the present invention comprises:
With y-alumina as the main component, yttrium is added in an amount of 0.1 to
It is characterized in that it is contained at a ratio of 30 mol%. Here, yttrium is preferably present in the form of an oxide or a composite oxide, or preferably present as an amorphous glass.
It is uniformly dispersed and contained in the alumina particles or the gamma-alumina amorphous phase, or exists on the surface and the grain boundary of the gamma-alumina particles.

Further, according to the present invention, particularly in view of improvement of water resistance, in the X-ray diffraction pattern of the γ-alumina porous material, yttria (Y
₂ O _3), yttrium compounds such as (but it is desirable that the crystalline phase caused by excluding a composite oxide of yttrium with other metals) are contained in a state that does not substantially precipitated.

Further, the pore diameter of the γ-alumina porous material is set to 0.
In order to control within the range of 5 to 50 nm, the average particle diameter of the γ-alumina crystal phase determined from the half-width of the γ-alumina crystal phase in the X-ray diffraction pattern is 1 μm or less, particularly 0.5 μm or less.
It is desirable that it is not more than μm.

Further, according to the present invention, in order to improve the water resistance of the γ-alumina porous body and to improve the uniformity of the pore diameter, the γ-alumina is converted to an aluminum equivalent of 100 m.
It is important that yttrium be contained in a proportion of 0.1 to 30 mol, particularly 0.3 to 15 mol, and further 0.5 to 10 mol, based on ol. That is, the content of yttrium in the gamma alumina porous material is 0.1 mol.
If less than the water resistance of the γ-alumina porous body is reduced,
Conversely, if the amount of yttrium is more than 30 mol, γ
Alumina itself is transformed, and a porous body having a desired pore size cannot be produced.

Further, according to the present invention, a gas or a liquid is used as a fluid of a fluid separation filter described later, and a specific gas and / or a liquid can be permeated from a mixed fluid composed of a plurality of types of gases and / or liquids. In order to have a function as a fluid separation membrane or an intermediate layer for favorably forming the fluid separation membrane on the surface of the support, the average pore diameter is 0.5 to 100.
nm, especially 1 to 10 nm, nitrogen adsorption method (BE
T) specific surface area of 50 to 500 m ² / g, especially 10
Desirably, it is 0 to 350 m ² / g.

(Production Method) Next, a method for producing the above-mentioned gamma alumina porous body will be described. First, as a γ-alumina raw material, fine powder having an average particle size of 1 μm or less, a hydrosol solution of an alkoxide, an acylate, a xylate, a metal hydroxide, an alcohol solution of an alkoxide, or the like can be used. In order to enhance the dispersibility of the compound, an alkoxide such as aluminum trisecondary butoxide, which is suspended in water, hydrolyzed, and added with nitric acid, is preferably an aqueous solution of boehmite sol.
It is desirable that the amount of water added to 1 is 50 to 1000 mol.

According to the present invention, at least one yttrium salt selected from the group consisting of yttrium nitrate, yttrium sulfate, yttrium chloride, yttrium bromide and yttrium iodide, and trimethoxy yttrium, A powder or solution of an yttrium compound such as at least one yttrium alkoxide selected from the group consisting of triethoxy yttrium and tri-i-propoxy yttrium is used. And mix.

When a hydrolyzed sol solution is used as the γ-alumina raw material solution, it is desirable that the yttrium salt of the yttrium compound be added after the hydrolysis, and that the yttrium alkoxide be added before the hydrolysis.

According to the present invention, as a method for adding yttrium, it is desirable to add a yttrium compound into a γ-alumina solution, whereby yttrium can be uniformly dispersed in γ-alumina, and the water resistance of γ-alumina can be reduced. Can be enhanced.

The amount of the yttrium compound to be added is 10% in terms of aluminum in the γ-alumina raw material solution.
0.1 to 30 mol, in particular, 0.3 to 15 mol of the yttrium compound in terms of yttrium with respect to 0 mol,
It is important that the amount is 0.5 to 10 mol. That is, when the addition amount of the yttrium compound is less than 0.1 mol, the water resistance of the γ-alumina porous body decreases, and when the addition amount of the yttrium compound is more than 30 mol, part of the yttrium compound precipitates. A uniform sol solution cannot be prepared, and coarse particles etc. are mixed in the γ-alumina porous body to generate pinholes, or γ-alumina is transformed to change the pore diameter of the porous body. is there.

Here, after adding the yttrium compound, boiling stirring may be performed in order to enhance the dispersibility of yttrium. Then, after drying this solution, for example, 350 to
By firing at 650 ° C., the γ-alumina porous body of the present invention can be produced.

(Fluid Separation Filter) Next, an example of the fluid separation filter of the present invention will be described with reference to FIG. According to FIG. 1, a fluid separation filter 1 has a γ-alumina porous body 3 having a large number of pores formed on at least one surface of a porous support 2.
Are formed.

According to the present invention, the gamma-alumina porous body 3 is characterized by being composed of the gamma-alumina porous body described above, whereby the fluid separation filter 1 is particularly suitable for gas and liquid permeation and separation. It is possible to control the pore diameter to be smaller than the average pore diameter of the porous support 2 and to control the pore diameter to be larger than the average pore diameter of the thin film 4 described later to function as an intermediate layer. While it is possible, even if water contacts the γ-alumina porous body, the pore diameter in the γ-alumina changes and the fluid separation characteristics do not deteriorate over time, for example, treatment of a fluid containing water, Even when exposed to a moisture-containing atmosphere such as air, the water resistance is excellent without deteriorating the separation characteristics.

The thickness of the γ-alumina porous body 3 should be 0.1 to 0.1 in order to form a uniform layer free of pinholes and cracks and to reduce fluid permeation resistance.
Preferably, it is 100 μm.

On the other hand, the porous support 2 may be in the shape of a pipe such as a pipe, a honeycomb, a monolith, or a plate such as a flat plate or a corrugated plate. ,
One end thereof may be sealed. Further, from the viewpoint of improving the mechanical strength and the membrane area per volume, the outer diameter is 1 to 15 mm and the inner diameter is 0.1 mm in the tubular shape.
2-3mm, thickness 0.2-10m in plate shape
It is desirable that the shape be m.

The material of the porous support 2 is preferably made of porous ceramics such as alumina, zirconia, silica, cordierite, silicon nitride, silicon carbide, or a composite thereof. In particular, gamma alumina porous body 3
Considering the high affinity with, heat resistance and cost, α-alumina porous material is preferable.

Further, from the viewpoint of gas or liquid separation performance and gas or liquid permeability, the porous support 2 has a porosity of 20 to 50%, an average pore diameter of 0.02 to 2 μm, and a surface roughness (Ra). ) Is preferably 2 μm or less, particularly preferably 1 μm or less.

On the other hand, according to the present invention, the γ-alumina porous body 3 itself can be used, for example, as a gas separation membrane or an ultrafiltration membrane for permeating and separating a specific gas or liquid. The thin film 4 having an average pore diameter smaller than the average pore diameter in the γ-alumina porous body 3 is formed on the surface of the γ-alumina porous body 3 opposite to the surface on which the porous support 2 is formed. In particular, even in this case, since the water resistance of the γ-alumina porous body 3 functioning as an intermediate layer is high, a small amount of the γ-alumina porous body 3 may be formed in the thin film 4 depending on the properties of the substrate (γ-alumina porous body). When cracks and pinholes occur, good water resistance can be obtained even in a gas separation filter that leads to significant deterioration of characteristics.

The thin film 4 is made of, for example, Si, Ti, Zr, A
1 or at least one oxide selected from the above, or a crystalline or amorphous phase of a composite oxide, and when functioning as a gas separation membrane, has an average pore diameter of 0.1 to 10 n.
m, in particular, 0.1 to 1 nm, and a film thickness of 0.01 to 5 μm, particularly 0.1 to 1 μm.

The pore diameter of the thin film 4 is, for example,
By controlling to 0.3-0.4 nm, for example,
Water vapor having a molecular diameter of 0.26 to 0.28 nm and 0.5
From a mixed gas with IPA having a molecular diameter of ~ 0.6 nm,
Very high separation performance can be obtained by selectively permeating only water vapor. Further, it is desirable that the thin film 4 be made of a material having high water resistance.

In the filter 1 shown in FIG. 1, the γ-alumina porous body 3 and the thin film 4 may be formed on the inner surface of the tubular support 2. The alumina porous body 3 and the thin film 4 may be sequentially formed. When the shape of the support 2 is flat (layered), the γ-alumina porous body 3 and the thin film 4 may be sequentially laminated on one surface of the porous support 2.

(Manufacturing Method) An example of a method for manufacturing the above fluid separation filter will be described. First, an average particle size of 0.
A desired organic binder is added to a predetermined ceramic powder having a mean particle size of from 0.05 to 10 μm, particularly from 0.1 to 2 μm, and a desired shape is formed by known molding means such as press molding, extrusion molding, injection molding, casting molding, and tape molding. After forming into a porous support, the porous support is produced by firing. The support is preferably fired in an oxidizing atmosphere in order to prevent residual carbon from remaining.

Next, the above-mentioned γ-alumina raw material solution is applied to the surface of the support. In addition, as a method of applying and forming the γ-alumina raw material solution, when the support is formed of a tubular body, the solution is filled into the inner surface of the tubular body using a liquid sending pump or a syringe (syringe), and the remaining portion is filled. A method of discharging and forming a coating on a tube, a method of immersing in a solution with one end of a tubular body sealed, and pulling up to form a coating on an outer surface of the tube. The method of application to the substrate can be applied. When the support is a flat plate, a method of applying the support to the surface of the support by a spin coater method, a spray method, or the like can be employed. In addition, the said coating method can also be performed in the state which heated the porous support body.

Then, the structure on which the above-mentioned γ-alumina raw material solution is formed is heated in an oxidizing atmosphere, for example, at a temperature of 400 ° C. or more, particularly 450 to 600 ° C., to sinter the ceramic in the γ-alumina raw material solution. By evaporating and evaporating the organic components in the γ-alumina raw material solution, a γ-alumina porous material having an average pore diameter of 1 to 10 nm is formed. In addition, film formation of the γ-alumina porous body,
The desired thickness can also be adjusted by repeating firing.

Next, a thin film is formed on the surface of the porous γ-alumina material. As the method for forming the thin film, the above-described method for applying the γ-alumina porous body can be suitably used.In particular, when the γ-alumina porous body and the thin film are formed on the outer surface of the tubular porous support, the operation is difficult. From the viewpoint of simplicity and ease of handling, a method of dipping and pulling up a support on which a γ-alumina porous body is formed in a solution is desirable.

After the thin film raw material solution is dried, the thin film raw material solution is dried at a predetermined temperature, for example, 30 ° C. in an oxidizing or non-oxidizing atmosphere.
By baking at 0 to 700 ° C., a thin film can be formed on the outer peripheral surface of the tubular porous support. Further, the thickness can be adjusted to a desired thickness by repeating the formation and firing of the thin film.

(Module) A method for separating a specific fluid from a fluid to be treated using the fluid separation filter of the present invention obtained by the above method will be described with reference to a fluid separation apparatus having the fluid separation filter of the present invention shown in FIG. An example will be described based on a schematic cross-sectional view. According to FIG. 2, a fluid separation module (hereinafter simply abbreviated as a module) 5 has a plurality of cylindrical fluid separation filters 1 converged, and a converging body 7 having both ends adhered and fixed to a support member 6. It is housed in a housing 8.

The housing 8 is formed of a member that does not transmit gas or liquid, such as heat-resistant glass, metal such as stainless steel, ceramics such as alumina and zirconia, and is hermetically sealed from the outside. When the inside of the housing 8 is pressurized or depressurized, a metal such as stainless steel having high mechanical strength is preferable, and it is preferable that the housing 8 is formed of a substantially tubular body.

The supporting member 6 is made of dense ceramics such as alumina, silica, cordierite, forsterite, steatite, zirconia, silicon carbide and silicon nitride, stainless steel, titanium,
It consists of at least one selected from metals such as aluminum and glass, and has a coefficient of thermal expansion with the porous support 2 of ± 1 ×
It is desirable that the values be approximated within 10 ^-6 / ° C.

Further, according to FIG. 2, the support member 6 for supporting the converging body 7 is a fixed member 1 provided in a housing 8.
0 is fixed and sealed with a gasket 11 made of ground packing, metal, resin, or rubber.
As a result, the gas or liquid separation performance can be improved by increasing the airtightness of the area partitioned by the support member 6 of the module 5, the filter can be attached and detached, and mechanical vibration and impact from the outside of the module 5 can be achieved. And the like can be reduced.

The housing 8 has a fluid supply port 12 for introducing a fluid or a liquid to be treated, and a specific fluid which has passed through the tubular filter 1 by bringing the mixed fluid into contact with the surface of the tubular filter 1. Permeate fluid outlet 13 for collecting or discharging gas or liquid, and remaining fluid outlet 14 for discharging or recovering the remainder of the mixed fluid
Are formed.

Specifically, according to FIG. 2, one permeated fluid outlet 13 is provided on the side wall between the support members 6 housed in the housing 8, but it is necessary to improve the fluid separation efficiency. In such a case, it is desirable to be provided at a position close to the side close to the fluid supply port 12 to be processed, and a plurality of them may be provided.

The fluid to be treated introduced between the fluid supply port 12 and the support member 6 in the housing 8 is
A part of the permeate passes through the separation membrane 3 through the inside of the tubular filter 1 and moves to a region between the support members 6 housed in the housing 8 outside the converging body 7 and further out of the module 5 through the permeated fluid outlet 13. Is discharged. On the other hand, the remaining portion of the fluid to be processed is discharged out of the module 5 through the remaining fluid outlet 14. Further, it is also possible to increase the gas or liquid separation performance by increasing the pressure of the fluid supply port 12 to be processed or reducing the pressure of the permeated fluid discharge port 13 to provide a pressure difference therebetween.

Although the module 5 in FIG. 2 is a cylindrical filter tube, the present invention is not limited to this. For another fluid separation module having the fluid separation filter of the present invention in FIG. As shown in the schematic cross-sectional view, a flat filter may be used.

As shown in FIG. 3, the module 20 is a plate-like fluid separation filter layer (hereinafter referred to as a “lambda”) in which a γ-alumina porous body 22 and a separation membrane 23 are formed on one surface of a rectangular plate-like support 21. The laminated body is formed by laminating a plurality of layers 24 at predetermined intervals, and supporting members 26 are provided at different positions between the filter layers 24 of the laminated body. In particular, it is sealed and fixed so as to cover the side surface of the support 21. Also,
A support member 26 is similarly disposed on the remaining fluid discharge port side 28, which is a side surface opposite to the fluid supply port side 27 to be processed.

That is, the permeated fluid discharge port 3 formed on one of the side faces adjacent to the surface 27 to be processed fluid supply port.
0, the support member 29 is sealed and fixed between the filter layers 24 on which the support member 26 on the processing fluid supply port side 27 is not disposed. And a space 32 having a thickness of the support member 26 is formed on the permeated fluid outlet side 30. In addition, the side surface facing the permeated fluid discharge port side 30 is entirely sealed from the outside by support members 26 and 29 or a wall.

That is, the supporting member 26 and the supporting member are formed such that a fluid supply port to be processed is formed on one side of the laminate, a permeated fluid outlet is formed on the other side, and a remaining outlet is formed on the other side. 29 are provided.

In the module 20, a gas or liquid material to be treated is introduced into the space 31 in the module 20 from the fluid supply port side 27 of the module 20, and the filter layer 2 is removed.
In the separation membrane 23 of FIG.
2 and is discharged to the permeated fluid discharge port side 30.
The specific gas or liquid can be separated by discharging the remaining fluid or liquid that does not pass through the filter layer 24 to the remaining fluid discharge port side 28 which is the side face facing the fluid supply port side 27 to be processed.

The gas permeation path in the above-described filter includes a support 21 and a γ-alumina porous material 2.
2. The gas may permeate in the order of the separation membrane 23, or conversely, may permeate through the separation membrane 23 and then permeate in the order of the γ-alumina porous body 22 and the support 21. Further, when the support 21 has a tubular shape, the fluid to be treated is allowed to flow through the inner surface of the tubular body, and gas is allowed to permeate the outer surface of the tubular body, and separation and collection can be performed. It is also possible to allow the gas to permeate the inner surface of the tubular body while flowing the fluid to be treated on the outer surface.

As a method for lowering the gas partial pressure on the permeation side, a gas other than the specific gas can be supplied to the specific gas discharge surface side (permeate fluid discharge port side 30). The specific gas can be separated more efficiently by lowering the pressure on the gas discharge surface side from the pressure on the fluid supply surface side 27 to be processed.

The method of providing the above-mentioned pressure difference is as follows.
Any of a method of depressurizing the gas discharge surface, a method of pressurizing the mixed gas supply surface containing the specific gas, and a method of using the above two methods in combination may be used. It is preferable that the pressure difference is 10 kPa or more.

The fluid separation filter of the present invention having the above structure can produce a thin and uniform separation membrane.
In particular, even in an atmosphere where water coexists, the temperature can be reduced from room temperature to 50 ° C.
High fluid separation performance can be maintained over a wide temperature range up to 0 ° C.

[0055]

EXAMPLE 1 First, a predetermined organic binder, a lubricant, a plasticizer and water were added to alumina powder having a purity of 99.9% and an average particle diameter of 0.1 μm, mixed, and extruded. After producing a tubular molded body at, baked at 1200 ℃, outer diameter 2.0mm, inner diameter 1.1mm, length 10cm
Thus, an α-alumina porous support tube having an average particle size of 0.2 μm and a porosity of 39% was produced.

Then, the melted wax is filled in both ends thereof by dipping (immersion and pulling up), and the wax adhered to the outer peripheral portion of the support tube is removed by wiping, and the support is cooled to a temperature at which the wax hardens. Was prepared.

Next, aluminum trisecondary butoxide (ATS) was added to 1 liter of water heated to 85 ° C.
B) was added and mixed in an amount of 0.5 mol, and nitric acid was added as a catalyst to the alkoxide in an amount of 0.07 mol per 1 mol of the alkoxide. The mixture was stirred at 95 ° C. for 16 hours to give a boehmite sol as a precursor through a hydrolysis-condensation polymerization reaction. Produced.

1 mol of boehmite sol as this precursor
Then, an aqueous solution of the compound shown in Table 1 was added at a ratio shown in Table 1 and mixed to prepare a sol solution of a γ-alumina porous material. The sample No. 7 alone, triethoxy yttrium (T) was added to the aluminum trisecondary butoxide (ATSB) solution before sol formation (before hydrolysis).
EY) was added followed by hydrolysis.

Then, one end of the support tube is plugged and dipped into the sol solution to form a sol solution on the outer surface of the support. After drying, the support is baked at 500 ° C. for 1 hour. A thin film made of a gamma alumina porous body was formed on the outer surface of the tube.

On the other hand, tetraethoxysilane (TEOS)
And vinyltriethoxysilane and zirconium tetra-n
-After dissolving butoxide in ethanol, nitric acid and water are added and mixed to prepare a silica-zirconia sol, and by the same method as the sol solution and dipping of the γ-alumina porous material, A silica-zirconia sol was dipped on the outer surface, dried, and baked at 500 ° C. for 1 hour to produce a thin film made of another porous body.

For the obtained fluid separation filter, 60
Nitrogen gas is circulated (bubbled) in water at a temperature of 0 ° C., and nitrogen gas in a saturated vapor state (mixed gas of nitrogen gas and water vapor) is supplied into the housing at a flow rate of 500 ml / min from the processing fluid supply port. 1 inside the system from the fluid supply port
After a lapse of 30 minutes (B) in a state where the pressure is increased to 00 kPa, a membrane flow meter and a gas chromatograph (G2800 manufactured by Yanaco) are used as initial characteristics of the amount of water vapor (water) and nitrogen permeated from the permeated fluid discharge port. was determined and calculated nitrogen and water each transmission coefficient (p _N, p _H), and permeability coefficient ratio of water (p _H / p _N). Similarly, a change with time and a change rate (A / B) of each gas permeation characteristic after 60 hours (A) were measured. The results are shown in Table 1.

(Measurement of Specific Surface Area) Further, the specific surface area before and after exposing the sintered body produced by the same method as the γ-alumina porous body of the filter of the above sample to a powder and exposing it to a saturated steam atmosphere at 150 ° C. for 48 hours. Was measured by the BET adsorption method.
The results are shown in Table 1.

[0063]

[Table 1]

As is clear from the results in Table 1, the amount of γ-alumina in terms of alumina was 1 without adding the yttrium compound.
The content of yttrium with respect to 00 mol is 0.1 mol.
l of sample no. In the case of No. 1, it was suggested that the separation characteristics changed greatly with time and the water resistance was low. Further, the addition amount of the yttrium compound is 3 in terms of yttrium with respect to 100 mol in terms of aluminum of the γ-alumina raw material solution.
Sample No. exceeding 0 mol. In No. 7, a precipitate was seen in the boehmite sol, and the filter using this had a low transmission coefficient ratio, and the occurrence of pinholes was confirmed from the result of SEM observation. Further, lanthanum nitrate (La (NO) is used instead of yttrium (yttrium nitrate (Y (NO ₃ ) ₃ )).
₃ ) Sample No. ₃ using ₃ ) or strontium nitrate (Sr (NO ₃ ) ₂ ). In Nos. 9 and 10, it was suggested that the separation characteristics greatly changed with time and the water resistance was low.

On the other hand, according to the present invention, based on 100 mol of aluminum in the γ-alumina raw material solution,
The yttrium compound is converted to yttrium in an amount of 0.1 to 3 in terms of yttrium.
The sample N was added at a rate of 0 mol, and 0.1 to 30 mol of yttrium was contained in the γ-alumina porous body with respect to 100 mol of aluminum as γ-alumina.
o. In 2～6,8, permeability coefficient ratio of both water (p _B /
p _A ) was 18 or more, and the time-dependent change (A / B) of the separation characteristics was 0.7 or more.

From the results of the exposure test of the sintered body prepared by the same method as the γ-alumina porous body of each sample, the change rate of the specific surface area of the γ-alumina porous body containing yttrium was smaller, It turned out to be high.

(Example 2) The fluid separation filter of Example 1 was the same as Example 1 except that a silica-zirconia porous body (other porous body) was not formed on the outer surface of the γ-alumina porous body. A fluid separation filter was made.

As a result of evaluating the permeability coefficients of water vapor and nitrogen in the same manner as in Example 1, the permeability coefficient of nitrogen (p _N ) at the initial stage was 8.42 × 10 ^-7 mol / m ² · Pa · se.
c, water permeability coefficient (p _H ) is 19.1 × 10 ⁻⁷ mol /
m ² · Pa · sec, Permeability coefficient ratio of water vapor (p _H / p _N )
Was 2.27.

After 60 hours, the separation characteristics were such that the nitrogen permeability coefficient (p _N ) was 7.91 × 10 ⁻⁷ mol / m ² · P
a · sec), and the water permeability coefficient (p _H ) is 18.2 × 10
^{-7 mol / m 2 · Pa ·} sec, permeability coefficient ratio of water (p _H /
p _N ) was 2.30.

(Comparative Example) In the fluid separation filter of Example 2, except that the γ-alumina porous material was prepared only from boehmite sol without adding an yttrium compound.
A fluid separation filter was prepared in the same manner as described above, and evaluated similarly.

As a result of evaluating the permeability coefficients of water (steam) and nitrogen in the same manner as in Example 1, the nitrogen permeability coefficient (p _N ) at the initial stage was 7.72 × 10 ⁻⁷ mol / m ² · Pa ·
sec, water permeability coefficient (p _H ) is 15.9 × 10 ⁻⁷ mo
1 / m ² · Pa · s and the water permeability coefficient ratio (p _H / p _N ) were 2.06.

After 60 hours, the separation characteristics were such that the nitrogen permeability coefficient (p _N ) was 10.9 × 10 ⁻⁷ mol / m ² · P
a · sec, water vapor transmission coefficient (p _H ) is 11.9 × 1
0 ^-7 mol / m ² · Pa · sec, and the water vapor transmission coefficient ratio (p _H / p _N ) was 1.09.

[0073]

As described above in detail, according to the γ-alumina porous body of the present invention, the γ-alumina porous body mainly composed of γ-alumina contains yttrium, whereby the γ-alumina is deteriorated by water. Thus, a γ-alumina porous body excellent in water resistance can be produced, and by using this, a fluid separation filter excellent in water resistance can be produced.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a fluid separation filter using a gamma-alumina porous body of the present invention as a gamma-alumina porous body.

FIG. 2 is a schematic sectional view showing an example of a fluid separation module including the fluid separation filter of FIG.

FIG. 3 is a schematic sectional view showing another example of the fluid separation module including the fluid separation filter of FIG. 1;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fluid separation filter 2 porous support (support) 3 γ-alumina porous material 4 thin film 6, 26, 29 support member 7 converging body 8 housing 10 fixing member 11 gasket 12 fluid supply port 13 permeate fluid discharge port 14 Remaining fluid discharge outlet 24 Fluid separation filter layer (filter layer) 31, 32 Space 27 Fluid supply port side to be treated 28 Remaining fluid discharge port side 30 Permeate fluid discharge port side

Claims (8)

[Claims] 1. A γ-alumina porous material comprising γ-alumina as a main component and 0.1 to 30 mol of yttrium with respect to 100 mol of aluminum in γ-alumina. 2. The γ-alumina porous body according to claim 1, wherein the γ-alumina porous body has an average pore diameter of 0.5 to 50 nm. 3. The γ-alumina porous body according to claim 1, wherein a specific surface area of the γ-alumina porous body by a BET adsorption method is 50 to 500 m ² / g. 4. A y-alumina raw material solution is characterized by adding 0.1 to 30 mol of an yttrium compound in terms of yttrium with respect to 100 mol of aluminum in the solution, mixing, drying and firing. A method for producing a gamma alumina porous body. 5. The method for producing a γ-alumina porous material according to claim 4, wherein said yttrium compound is added after preparing a boehmite sol from said γ-alumina raw material solution. 6. A mixed fluid comprising the gamma-alumina porous material according to claim 1 and a mixed fluid comprising a plurality of types of fluids in contact with one surface of the gamma-alumina porous material. A fluid separation filter for separating a specific fluid by selectively permeating only a specific fluid therein to the other surface of the γ-alumina porous body. 7. A ceramic support having an average pore diameter larger than the average pore diameter of the γ-alumina porous body is formed by coating the surface of the γ-alumina porous body with a thickness of 0.1 to 100 μm. 7. The fluid separation filter according to claim 6, wherein: 8. A method in which another porous body having an average pore diameter smaller than the average pore diameter of the γ-alumina porous body is formed on the surface of the coating layer comprising the γ-alumina porous body. The fluid separation filter according to claim 6 or 7, wherein