JPH059126B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ceramic membrane structure for condensing and separating condensable gas components and a method for manufacturing the same.

[Prior art]

Condensation separation of condensable gas components involves capillary condensation of condensable gas components within the micropores of a porous membrane to separate them from non-condensable gas components, and has been studied in a variety of ways in recent years. There is. As an example, as shown in the publication Chemistry Apparatus, pages 61 to 65 (November 1985 issue: Kogyo Kenkyukai), silica gel with micropores on the outer surface of a porous ceramic tube. There are examples of separating and removing moisture in the air and separating and concentrating alcohol using a structure supporting a thin film or alumina gel thin film.

[Problem that the invention seeks to solve]

By the way, the above-mentioned publications do not provide any concrete means for utilizing such structures on an industrial scale, and proposals for such concrete means are desired. The present invention focuses on a conventionally known ceramic honeycomb structure,
The present invention aims to provide an industrially advantageous ceramic membrane structure for condensation separation by imparting the same separation function to the structure shown in the above-mentioned publication.

[Means for solving problems]

A first aspect of the present invention is to arrange a plurality of first pores that are open at one end and a plurality of second pores that are closed at the same end, which are partitioned by a porous partition wall having a large number of continuous pores, in parallel with each other. The structure is a ceramic honeycomb structure having a fluid inlet/outlet hole in the closed portion of any of the holes, and a plurality of holes for condensing condensable gas components on the inner periphery of any of the holes of each of the partition walls. Equipped with a ceramic thin film with continuous micropores,
The ceramic membrane structure for condensing and separating condensable gas components is characterized in that the first hole and the second hole are at least partially separated by a common partition wall.

Further, the second invention of the present invention is a method for manufacturing such a ceramic membrane structure, in which a large number of through holes partitioned by porous partition walls having a large number of continuous pores are formed in parallel with each other. A ceramic honeycomb structure provided with the structure is used as a basic structure, and at least one end side of each predetermined through hole of the structure is closed and one end side is at least partially partitioned by a common partition wall. A slurry for forming a ceramic thin film having a large number of continuous fine pores that form a large number of open pores and a large number of second pores that are closed at the same end and condense condensable gas components is applied to any of the pores. The ceramic thin film is formed on the inner wall of the hole by entering the ceramic thin film from the open end of the hole.

In the present invention, the basic structure is a ceramic honeycomb structure made by extruding a mixture made by adding an organic binder and a plasticizer to fine powder of ceramic raw materials and kneading them through a die equipped with many slits, and then firing the mixture. Alumina, silica, mullite, cordierite, etc. are used as ceramic raw materials. Such a ceramic honeycomb structure has a large number of through-holes separated by porous partition walls having a large number of continuous pores in parallel with each other, and the cross-sectional shape of the through-holes may be triangular, quadrilateral, other polygonal, It has an appropriate shape such as a circle or an ellipse. In addition, the average pore diameter of the pores of the porous partition wall is preferably
It is 0.2 μm to 5 μm.

The ceramic membrane structure according to the present invention is formed by dividing each through hole in the ceramic honeycomb structure into two types, first hole and second hole, and the first hole is open at least on one end side. The other end is open or closed. Further, at least one end of the second hole is closed, and the other end is closed or opened. The first hole and the second hole are at least partially separated by a common partition wall. Further, such a ceramic membrane structure has a fluid inlet/outlet hole in the closed portion of any of the holes, and also includes a ceramic thin film having a large number of continuous micropores on the inner periphery of each partition wall on the side of any of the holes. A ceramic thin film has a large number of continuous micropores that condense condensable gas components, and is preferably formed from an alumina sol obtained by hydrolyzing aluminum alcoholate or aluminum chelate, and the average diameter of the micropores is 100 Å or less. Yes, and the film thickness is 5μ
It is preferable that it is m - 100 micrometers. The ceramic thin film forming material is introduced into the ceramic honeycomb structure through the opening of any of the pores and attached to the inner wall of the ceramic honeycomb structure.
It is then subjected to steam treatment in high temperature steam to form a thin film. The ceramic thin film is made of PVD,
It may also be formed by CVD or the like.

[Action/effect of the invention]

In a ceramic membrane structure having such a configuration,
If a gas to be treated in which a condensable gas and a non-condensable gas are mixed is supplied from the open end of the first or second hole and sucked from the closed part of either hole or the opening of either hole, At least a portion of the gas to be treated attempts to pass through the ceramic thin film and the partition wall. At this time, the condensable gas in the gas to be treated condenses in the fine pores of the ceramic thin film and vaporizes at one end of the fine pore, and the condensable gas repeats this state one after another and passes through the ceramic thin film and the partition wall. . The non-condensable gas in the gas to be treated is suppressed from passing through the micropores by the condensate of the condensable gas, and the first
Two types of processing gases having greatly different concentrations flow out from the hole and the second hole.

By the way, in the ceramic membrane structure having such a configuration, the ceramic honeycomb structure is used as the basic structure and the many partition walls of the same structure have a condensable gas separation function. The effective area per unit volume is extremely high. Furthermore, since all of the partition walls are integrally connected, there is no need for means for integrating a large number of members constituting each partition wall, and the structure is extremely strong. Therefore,
Such a ceramic membrane structure is industrially extremely advantageous as a structure for condensing and separating condensable gases.

On the other hand, such a ceramic membrane structure is manufactured by creating a ceramic honeycomb structure, closing a predetermined opening end of a through hole of the structure, and forming a ceramic thin film on the inner periphery of a predetermined partition wall. It can be easily manufactured without using any particularly difficult means.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a dehumidifying device employing a ceramic membrane structure according to a first embodiment of the present invention. The dehumidifier includes a ceramic membrane structure 20 housed within a main body case 11, and is supported within the case 11 via a pair of upper and lower support members 12 and 13. The case 11 has an inlet 11a and two outlets 11b, 11c, untreated air is supplied through the inlet 11a, and a first
Water vapor, which is a condensable gas component, is selectively sucked from the outlet 11b side by a suction means (not shown).
At the same time, so-called dehumidified air with reduced water vapor content flows out from the second outlet 11c.

As shown in FIGS. 2 and 3, the ceramic membrane structure 20 is a ceramic honeycomb structure having a ceramic honeycomb structure in parallel with each other, which is partitioned by porous partition walls. The through holes of the basic structure 21 (hereinafter simply referred to as the structure) have a rectangular cross section and extend in parallel to each other in the longitudinal direction of the structure 21. Such structure 2
1 is obtained by extruding and firing a mixture obtained by kneading fine powder of ceramic raw materials such as alumina, silica, mullite, cordierite, etc. with an organic binder and a plasticizer under the same conditions as those used to form ordinary porous ceramics. The large number of partition walls 21a that partition each through hole are porous partition walls having a large number of continuous pores. FIG. 4 shows a highly enlarged local cross section of the partition wall 21a and a ceramic thin film 24, which will be described later.
The average pore diameter of 1b is preferably 0.2 μm to 5 μm. If the average pore diameter is 0.2 μm or more, it will not interfere with the gas diffusion of the gas to be treated, and if the average pore diameter is 5 μm or more, it will not interfere with the gas diffusion of the gas to be treated.
If the thickness is less than m, cracks, pinholes, etc. can be prevented from occurring in the ceramic thin film during formation, and a uniform film thickness can be formed. In addition, partition wall 2
The thickness of 1a is arbitrary, but from the viewpoint of strength and processing, it is preferably about 1 mm.

In the ceramic membrane structure 20 of this embodiment, both ends of each through hole in the structure 21 are closed in a staggered manner, and each through hole is divided into a large number of open holes 21c at both ends and closed holes 21d at both ends. are doing. These holes 21c and 21d respectively correspond to the first and second holes in the present invention, and the closing member 22a, which closes both ends of the closing hole 21d,
The partition wall 22b is made of the same material as the partition wall 21a and has a glaze applied to the outside thereof, and is airtightly sealed. A fluid inlet/output pipe 23 made of the same material is implanted in the closing member 22a. The open hole 21c and the closed hole 21d that are adjacent to each other are partitioned on one side by a common partition wall 21a. Further, a ceramic thin film 24 is supported on the inner periphery of the partition wall 21a constituting each opening hole 21c.

The ceramic thin film 24 has a large number of continuous fine pores 24a for condensing condensable gas components, and the average diameter of the fine pores 24a is 100 Å or less, and the film thickness is 5 μm to 100 μm. In this example, the average pore diameter of the micropores was 10 Å and the film thickness was 10 μm, taking into account the condensation effect of water vapor in the air, the permeation rate, etc.
It is prepared in The ceramic thin film 24 is made of aluminum isopropoxide, aluminum-
aluminum alcoholates such as 2-butyrate;
aluminum tris (ethyl acetoacetate),
It is formed using alumina sol obtained by hydrolyzing aluminum chelate such as ethyl acetoacetate aluminum diisopropylate.
The structure 21 is immersed in the alumina sol, introduced into each opening 21c, and supported on the inner periphery of the partition wall 21a on the side of the opening 21c. Thereafter, a ceramic thin film 24 is formed by treatment with an aqueous sodium silicate solution and further treatment with high temperature steam. In this example, 5 g of aluminum isopropoxide was added to water maintained at 80 to 90° C. per 100 g of water, and the aluminum isopropoxide was hydrolyzed. Add 0.6ml of concentrated nitric acid to this,
The mixture was kept at 80 to 90°C for 24 hours and peptized to obtain an alumina sol. After immersing the structure 21 in this alumina sol for 5 minutes, it was immersed in a 0.1 mol/sodium silicate aqueous solution for 1 hour, kept in steam at 100°C for 1 hour, and then immersed in hot water at 90°C for 1 minute to form an alkali. was washed and removed.

In a dehumidifying device employing the ceramic membrane structure 20 having such a configuration, the inlet 11 of the case 11 is
Untreated air is supplied from the a side at a predetermined flow rate, and is sucked from the first outlet 11b side by a vacuum pump. As a result, the supplied air flows into the opening holes 21c from the lower end of each opening hole 21c in the ceramic membrane structure 20, and a part of the air flows into the opening hole 21c.
The second outlet 11c of the case 11 through the upper end of the
Water vapor, which is a condensed gas component, selectively passes through each ceramic thin film 24 and partition wall 21a and passes through each fluid inlet/output pipe 23 to the first outlet 11.
It flows out from b. FIG. 4 shows a model diagram when air passes through the ceramic thin film 24 and the partition wall 21a. When air tries to pass through the ceramic thin film 24 as indicated by the arrow in the figure, water vapor in the air It condenses in the micropore 24a and the same pore 24
a to the partition wall 21a and reach the pore 21b of the partition wall 21a. Condensed water H that has reached the pores 21b
is vaporized into the pore 21b, passes through the partition wall 21a, and flows into the closed hole 21d. At this time, the condensed water blocks many parts of the micropores 24a, so that almost no air passes through the micropores 24a. As a result, water vapor (humidity) in the air is separated, and dehumidified air flows out from the second outflow port 11c, and water vapor flows out from the first outflow port 11b.

By the way, the ceramic membrane structure 20 of this example
This structure uses a conventionally known ceramic honeycomb structure 21 as a basic structure, and a large number of partition walls 21a of the structure 21 have a function of condensing and separating moisture in the air. Therefore, the partition wall 2 having a separation function
The effective area per unit volume of the structure 21 of 1a is large, and there is no need for a means to integrate a large number of members constituting each partition wall 21a, and the strength is extremely high, making it suitable for industrial use as a structure for condensation and separation. Extremely advantageous.

In addition, the ceramic membrane structure 20 of this embodiment is extrusion molded under the usual manufacturing conditions of ceramic honeycomb structures, and, for example, the same base material as the clay for extrusion is used at the predetermined both ends of each through hole in the structure 21. Either the opening is closed, a fluid inlet/output pipe 23 is planted, and then the structure 21 is produced by firing.
Or fabricate the structure 21 by extrusion molding and firing,
Next, predetermined openings at both ends of each through hole in the structure 21 may be closed. Further, the obtained structure 21 is formed by applying alumina sol from the open end of each opening 21c to support a ceramic thin film 24 on the inner periphery of the opening 21c. Therefore, according to this manufacturing method, there is no need to use particularly difficult or complicated means, so that the ceramic membrane structure 2
0 can be easily manufactured.

5 and 6 show a portion of a ceramic membrane structure 30 according to a second embodiment of the present invention. In the ceramic membrane structure 30, the basic structure 31 is a ceramic honeycomb structure similar to the basic structure 21 of the first embodiment, and the differences from the ceramic membrane structure 20 of the first embodiment are as follows. The following points apply. That is, in the ceramic membrane structure 30, the second hole 3 corresponding to the blocked hole 21d of the ceramic membrane structure 20 of the first embodiment is
1d has only one end closed with a closing member 32a, and correspondingly, in the first hole 31c corresponding to the opening hole 21c, one end is open and the other end is closed with a closing member 32b. There is. In addition,
In such a ceramic film structure 30, the first
A ceramic thin film 34 is supported on the inner periphery of the partition wall 31a that constitutes the second hole 31c, and a fluid inlet/output pipe 3 is attached to a closing member 32a that closes one end of the second hole 31d.
3 is planted, air is supplied from the other end side of the second hole 31d, and the second outlet 11c
The first hole 31c is kept under vacuum. As a result, water vapor in the air selectively permeates through the partition wall 31a and the ceramic thin film 34, and passes through the first hole 31c to the second outlet 11.
The so-called dehumidified air that flows out from the first outlet 11b and has a reduced water vapor content flows out from the first outlet 11b. Note that even if air is supplied from the fluid inlet/output pipe 33, dehumidified air with a reduced water vapor content can be obtained from the other end of the second hole 31d. Further, the same effect can be expected even if the ceramic thin film 34 located inside the first hole 31c is located inside the second hole 31d.

In the ceramic membrane structure 20 of the first embodiment described above, the fluid inlet/output pipe 23 is implanted only in the closing member 22a at one end of the closing hole 21d, but at the other end of the closing hole 21d. Closing member 22
A similar fluid inlet/output pipe may also be installed in b, so that the air flowing through the opening hole 21c is sucked from both ends of the blocking hole 21d.

Furthermore, in the ceramic membrane structures 20 and 30 of the first and second embodiments described above, each of the closing members 22
a, 22b, 32a, and 32b are treated with glaze or the like to have a function of airtightly closing them, but each of the partition walls 21a, 31a, or the partition wall 21 serves as a closing member.
A, 31a and the ceramic thin films 24, 34 may be made of an integral material to provide air permeability. In these cases, the air inside the hole can be directly sucked through each closing member, and the fluid inlet/output pipes 23, 3
3 can be omitted, and the function of selectively permeating condensable gas components in the closing member and the fluid inlet/outlet pipe (fluid inlet/outlet hole) can also be expected.

Furthermore, in the ceramic membrane structure 30 of the second embodiment described above, the first hole 31 of each partition 31a
A ceramic thin film 34 is supported on the inner periphery of the c side, and the same thin film 34 is inserted into the second hole 31d of each partition wall 31a.
It may also be supported on the inner circumference of the side.

Furthermore, in the above embodiment, a ceramic membrane structure 2 for condensing and separating moisture in the air is used.
0 and 30, by appropriately setting the average pore diameter of the ceramic thin films 24 and 34 in each of these structures 20 and 30,
Inorganic gases such as hydrogen sulfide and ammonia, and organic gases such as alcohols, aldehydes, and carboxylic acids can be condensed and separated from non-condensable gases.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a dehumidifying device employing a ceramic membrane structure according to the first embodiment of the present invention, and FIG.
The figure is an enlarged partial perspective view of the membrane structure, and Figure 3 is the second
FIG. 4 is a super-enlarged sectional view of the partition wall portion of the same structure, and FIG. 5 is a perspective view corresponding to FIG. 2 of a ceramic membrane structure according to a second embodiment of the present invention. FIG. 6 is a longitudinal sectional view of the membrane structure corresponding to FIG. 3. Explanation of symbols: 20, 30... Ceramic membrane structure, 21, 31... Basic structure, 21a, 31a...
Partition wall, 21b...pore, 21c, 31c...first hole, 21d, 31d...second hole, 24, 34...ceramic thin film, 24a...micropore.

Claims (1)

[Scope of Claims] 1 A device comprising a large number of first pores which are partitioned by a porous partition having a large number of continuous pores and which are open at one end and a large number of second pores which are closed at the same end and are arranged in parallel with each other. The structure is a ceramic honeycomb structure having fluid inlet/outlet holes in the closed portions of any of the pores, and a large number of continuous fine particles that condense condensable gas components on the inner periphery of any of the pores of each of the partition walls. A ceramic for condensing and separating condensable gas components, comprising a ceramic thin film having holes, and the first hole and the second hole are at least partially separated by a common partition wall. Membrane structure. 2. The ceramic membrane structure for condensation separation according to claim 1, wherein the other end of the first hole is open and the other end of the second hole is closed. 3. The ceramic membrane structure for condensation separation according to claim 1, wherein the other end of the first hole is closed and the other end of the second hole is open. 4 The average pore diameter of the micropores of the ceramic thin film is
A ceramic membrane structure for condensation separation according to claim 1, 2 or 3, which has a thickness of 100 Å or less. 5 The thickness of the ceramic thin film is 5 μm to 100 μm.
A ceramic membrane structure for condensation separation according to claim 1, 2, 3, or 4. 6. The ceramic membrane structure for condensation separation according to claim 1, 2, 3, 4, or 5, wherein the average pore diameter of the pores of the partition wall is 0.2 μm to 5 μm. 7. Claims 1, 2, 3, 4, 5, or 6, wherein the blocking portion is made of the same porous material as the partition wall or the ceramic thin film. The ceramic membrane structure for condensation separation described above. 8. Claims 1, 2, 3, and 4, wherein the closing portion is formed of a non-porous airtight material, and a fluid inlet/output pipe is implanted in the closing portion. The ceramic membrane structure for condensation separation according to item 5 or 6. 9 A ceramic honeycomb structure having a large number of through holes in parallel with each other separated by porous partition walls having a large number of continuous pores is used as a basic structure, and each of the above-mentioned through holes of the structure has a predetermined At least one end of the through hole is closed to form a number of first holes that are at least partially partitioned by a common partition wall and that are open at one end and a number of second holes that are closed at the same end. , characterized in that a slurry for forming a ceramic thin film having a large number of continuous micropores for condensing condensable gas components is introduced into the interior from the open end of one of the holes, and the ceramic thin film is formed on the inner wall of the hole. A method for manufacturing a ceramic membrane structure for condensation separation of condensable gas components. 10. The method for producing a ceramic membrane structure for condensation separation according to claim 9, wherein the slurry is an alumina sol obtained by hydrolyzing aluminum alcoholate or aluminum chelate.