JPH02160046A - Production of gas adsorbing element - Google Patents

Abstract

PURPOSE:To improve the performance of the gas adsorbing element by integrally and securing fixing and binding active carbon and/or active alumina and metal silicate aerosol having gas adsorbing activity to a matrix. CONSTITUTION:Paper essentially consisting of inorg. fibers sheeted to a low density is laminated to form the matrix having the shape of the gas adsorbing element which has many small through-holes. A dispersion prepd. by dispersing the powdery or short fibrous active carbon and/or active alumina into an aq. water glass soln. is impregnated in this matrix. The matrix is immersed, after drying, into an aq. soln. of a metal salt, such as A1 salt or Mg salt, which is soluble in water and can generate an insoluble gel-like silicate by reacting with the water glass to form the hydrogel of the metal siliate by the reaction of the water and the above-mentioned metal salt. The gel is then rinsed and dried to integrally and securely fix and bind the active carbon and/or active alumina and the metal silicate aerosol having the gas adsorbing activity to the matrix. As a result, the performance of the gas adsorbing element is additionally improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a solid plate that reversibly adsorbs active gas using a block having a large number of small holes. An element for dehumidification and other gas adsorption which is molded with a T agent and passes a processing gas containing an active gas and a desorption gas alternately into the small through holes to obtain a gas from which the active gas is continuously adsorbed and removed. It concerns the manufacturing method.

Conventional Technology In Patent Application No. 206849 filed in 1981, the applicant of this patent applied corrugation processing to paper made with inorganic fibers as a main component to a low density, and laminated this paper alternately with flat paper to form a large number of small holes. Before or after the forming process, the paper is impregnated with water glass, dried and concentrated until it becomes a Japanese ice water glass-like or semi-solid state, and after forming, it is immersed in an acid to combine the water glass and the acid. 58! of a moisture exchange element in which silica hydrogel is produced in a matrix by the reaction of , and the silica hydrogel is integrally and firmly fixed and bonded to the matrix by washing with water and drying. The manufacturing method was disclosed.

In addition, in Patent Application No. 86969 filed in 1985, the applicant of this patent has formed a matrix having a large number of small pores by laminating paper made with inorganic fibers as a main component and having a low density, and the process is carried out either before or after the forming process. The paper is impregnated with water glass, and after shaping, it is immersed in an aqueous solution of aluminum salt, magnesium salt, or calcium salt to form a silicate hydrogel, which is then washed with water and dried to firmly fix and bond the silicate hydrogel to the matrix. A method for manufacturing a moisture exchange or total heat exchange element is disclosed.

Furthermore, the applicant for this patent is Patent Application No. 145873 filed in 1988.
In No. 1, a matrix having many small pores is formed by laminating low-density papers, and the matrix is impregnated with a dispersion of zeolite powder dispersed in a water glass solution. After drying, aluminum salt, magnesium salt, Production of an ultra-low concentration gas adsorption element that is immersed in an aqueous solution of calcium salts or other metal salts to produce a metal silicate hydrogel, washed with water and dried to integrally and firmly bond the zeolite and metal silicate hydrogel to the matrix. disclosed the law.

Problems to be Solved by the Invention In the above-mentioned prior application, silica gel, metal silicate gel, or zeolite acts as a moisture absorbent, and any of them is contained in an inert gas, such as air, by adsorption. It removes moisture.

On the other hand, in addition to the above-mentioned silica gel, metal silicate gel, and zeolite, examples of adsorbents capable of adsorbing and removing active gas such as moisture in an inert gas include activated carbon, alumina gel, activated clay,
There are inorganic adsorbents such as activated magnesia and various organic adsorbents.

The present invention aims to further improve the performance of the gas adsorption element of the above-mentioned prior application by adding an inorganic adsorbent with excellent heat resistance among such adsorbents to the components of the gas adsorption element of the prior application.

Means for Solving the Problems The present inventor has developed a method for producing an element for dehumidification and other gas adsorption using the reaction of water glass acid and water glass metal salt aqueous solution of the above-mentioned earlier application, in which the above activated carbon, the above activated carbon, and water glass are added to water glass. As a result of similar production and performance testing by mixing various inorganic adsorbents such as activated alumina, activated clay, and activated magnesia, we found that mixing powdered or short fiber activated carbon with water glass made it possible to process gases with particularly high humidity. A dehumidifying element and other gas adsorption element that exhibits outstanding dehumidifying performance against water glass can be obtained, and by mixing activated alumina with water glass, a gas with an ultra-low dew point can be produced like zeolite. They discovered that an element could be obtained and completed the present invention.

As the paper used for the matrix, any paper can be used as long as it is resistant to the gas to be treated and the active gas contained therein and to be adsorbed and removed, and can be laminated into a honeycomb shape. However, in the case of heating in the regeneration process, for example, when the gas adsorption element of the present application is used for dehumidification and the heated regeneration air is used for desorption and regeneration, inorganic fiber paper such as ceramic fiber, glass fiber, carbon fiber, etc., which is not likely to catch fire due to heating, is used. , rock fibers, mineral slag fibers, etc., or a mixture of these as a main component.

As the water glass, any of No. 1, No. 2, and No. 3 water glass (sodium silicate) can be used, and potassium silicate may also be used. In addition, theoretically any acid stronger than silicic acid can be used as the acid, but due to the cost and
Sulfuric acid is most suitable from the viewpoint of working environment and other factors. Theoretically, any divalent or trivalent metal salt can be used as a water-soluble metal salt, but salts of aluminum, magnesium, and calcium can be used industrially, and among these, silicates have adsorption activity. As previously disclosed in Japanese Patent Application No. 60-86969, aluminum IIA acid and magnesium sulfate can be obtained in the form of an excellent gel.

After impregnating the matrix with the water glass solution, and prior to the process of immersing the matrix in the acid or metal salt aqueous solution, the matrix is heated and the water glass solution is concentrated until it becomes a Japanese ice water glass or semi-solid with a water content of 5 to 45%. When immersed in an aqueous acid or metal salt solution for a chemical reaction, loss due to elution of water glass can be prevented.

Embodiments will be described in detail below with reference to the drawings.

Embodiment 1 Figure 1 shows an example of an apparatus used in the molding process, which is the first step of the present invention. The forming gear 2 is in contact with the pressure roller 3, and the heavy speeds of both are approximately the same. 4.
Reference numeral 5 denotes an adhesive applicator, which includes adhesive containers 4a, 5a, adhesive applicator rollers 4b, 5b, and adhesive containers 4a, 5.
An adhesive 6.6 made of a water glass aqueous solution is put in a and a part of the adhesive application rollers 4b, 5b is immersed in the adhesive 6.6, and the adhesive application roller 4b is provided close to the forming gear 2.

Ceramic fiber If, 70-90%, valve 5-20%
, 5-10% binder, thickness 0, 1-0
A very porous paper 7.8, 5 mm in diameter and with an apparent specific gravity of O15 g/Crn' or more, was prepared by winding it up into a roll as shown in the figure, and one paper 7 was fitted with a forming gear 1°2 The adhesive 6 is applied to the corrugated paper 7a and then introduced to the contact area between the forming gear 2 and the adhesive application roller 4b to form the corrugated paper 7.
After applying the coating to the crest of the corrugated paper 7a, it is passed together with the other paper 8 between the forming gear 2 and the pressure roller 3 to bond them together, and an adhesive application device is applied to the crest of the corrugated paper 7a of the obtained single-wave molded body 9. After applying the adhesive 6 to the core 10 using the adhesive application roller 5b of 5, the core 10 is rolled up to obtain a cylindrical matrix 11 having a large number of small holes penetrating between both end faces as shown in FIG.

No. 1 water glass (silicon oxide to sodium oxide 2.1:1
) to an aqueous solution (solid content 25-30%) of 5-25
% of activated carbon in the form of fine powder or short fibers, this aqueous solution is impregnated into the above matrix and dried at 50 to 100°C for about 1 hour to transform water glass into hydrated water glass with a water content of about 5 to 20%. Or semi-solid water glass. The impregnating chamber affl of water glass and activated carbon to the matrix is preferably about 1 to 2.5 times the amount per 1 li.8 Next, it is immersed in a 21% aqueous solution of aluminum sulfate and stirred to form aluminum silicate by a chemical reaction between the water glass and aluminum sulfate. A hydrogel is produced, by-product sodium salts and excess aluminum sulfate are removed by washing with water, and then heated and dried to produce a strong aluminum silicate/erogel honeycomb-like body in which activated carbon is uniformly dispersed using the inorganic fiber paper matrix as a reinforcing material. A dehumidifying element is obtained.

The same result can be obtained by using a metal salt such as 41F aluminum in place of 15-30% aqueous solution such as aluminum phosphate, (Ii11 aluminum phosphate, or magnesium sulfate).

Example 2 Adding a small amount of valve and binder to silica/alumina ceramic fibers gives an apparent specific gravity of 0:3 to 0845
A paper made with a low density of about 17 mm and a width of about 0.15 to 0.25 mm is corrugated and molded in the same manner as in Example 1 using an adhesive made of a mixture of a synthetic resin such as polyvinyl acetate and an inorganic binder such as silica sol. The matrix 11 is formed and heated in air to about 400° C. to remove organic substances, that is, organic fibers and binder contained in the paper, as well as the organic adhesive used in the layer. Dilute No. 3 water glass (silicon oxide to sodium oxide 3.1:1) with water (solid content 30-45%), and add 10 to 10% of "Zeolum A-4" manufactured by Toyo Soda Co., Ltd. as a synthetic zeolite. After adding 20% by weight and 5 to 20% by weight of activated alumina powder and mixing uniformly, the matrix is impregnated and dried by heating.
Next, this is immersed in a 20% aqueous solution of magnesium sulfate for 3 to 4 hours to form and bond a hydrogel of magnesium silicate through a chemical reaction between water glass and magnesium sulfate.
After washing with water to remove the by-product sodium sulfate and excess magnesium sulfate, the product is dried to form a honeycomb-like structure of strong magnesium silicate aerogel, in which synthetic zeolite and activated alumina are uniformly dispersed, using a ceramic fiber paper matrix as a reinforcing material. A dehumidification element consisting of the following can be obtained.

The paper conveniently used for forming the matrix may be paper made by mixing ceramic mta, glass fiber, and bulb, or paper made mainly of carbon fiber or activated carbon fiber. Furthermore, the same effect can be achieved even if a metal salt such as aluminum sulfate, monobasic aluminum phosphate, or aluminum nitrate is used as an aqueous solution of about 15 to 30% in place of magnesium sulfate.

Example 3 Ceramics 1il 170-94%, bulb 2-22%
, 4-8% binder, thickness 0. 1~0.5m
m, apparent specific gravity 0.3-0.6g/ct+? Matrix 11 was prepared in the same manner as in Example 2 using paper made to a low density of
is molded and heated in air to around 400°C to remove organic substances contained in the paper and lamination adhesive. 5 by weight in an aqueous solution of No. 1 water glass (solid content 25-45%)
After adding ~25% of powdered activated carbon and mixing uniformly, it is impregnated into the above matrix and heated and dried at around 90°C to make water glass with 5~20% of hydrohydrated water glass or semi-solid water glass. do. The amount of water glass and activated carbon impregnated into the matrix is about 1.5 to 3 times [d] in Ichikawa. Next, by immersion in a 3N aqueous solution of sulfuric acid and stirring, the reaction between water glass and sulfuric acid causes silica hydrogel bonded to activated carbon to be integrally bonded to the matrix of ceramic fibers, and by-product sodium sulfate and excess sulfuric acid are removed by washing with water. Then, by heating and drying, a dehumidifying element is obtained, which is mainly composed of silica aerogel in which the matrix is used as a reinforcing material and activated carbon is uniformly dispersed, and the silica aerogel is firmly bonded to the matrix and integrated.

Other acids such as hydrochloric acid and phosphoric acid can be used instead of sulfuric acid as long as they do not act on ceramic fibers, activated carbon, etc. and cause undesirable deterioration, but sulfuric acid is the most preferred in terms of cost, working environment, etc.

Effect of the Invention The gas adsorption element of the present invention is assembled into, for example, a dehumidifier and used for dehumidifying gas. FIG. 3 shows an example of a rotary dehumidifier, in which a dehumidifying element 11a is rotatably held in a casing 12, separated into a processing zone 14 and a regeneration zone 15 by a separator 13, and a geared motor 16.
, the element 11 is rotated at a low speed of about 5 to 20 RPH by the drive belt 17, and the treated air 18 is fed into the treatment zone 14 and the high temperature and low humidity regeneration air 19 is fed into the regeneration zone 15, and the treatment air is dehumidified. Dry air 20 is obtained. In the figure, 21 is a pulley, 22 is a tension pulley, 23 is a rubber seal, and 24 is a regenerated air heater.

Effects of the Invention Figure 4 shows the equilibrium moisture absorption 1ij per volume weight of the adsorbent contained in the three types of dehumidifying element T- at various relative humidity (RH).
(Irrlij%). In the figure, C is the element obtained in Example 1, and S is the earlier patent application filed in 1983.
86969, a device mainly composed of aluminum silicate aerogel obtained in Example 1 except for activated carbon, A is a device obtained in Example 2, and y is a device based on the earlier patent application 1986-
145873, except for the activated alumina of Example 2, and whose main components are magnesium silicate and synthetic zeolite. 206849, excluding the activated carbon of Example 3. As is clear from the figure, when particulate or short fibrous activated carbon is mixed, the processing gas is particularly humid. It was also found that when activated alumina was mixed in, it had a remarkable dehumidifying performance especially against low-humidity process gases, similar to when synthetic zeolite was mixed in.

Since the present invention is configured as described above, water glass has a high affinity with inorganic fiber paper, and not only wets the surface of the inorganic fiber paper well, but also penetrates well into the fiber gaps inside the inorganic Mt paper, and then the water glass or react with aqueous solutions of metal salts to produce silica or metal silicate hydrogels, so that fibrous or powdered activated carbon and/or activated alumina powders and/or zeolite powders are uniformly distributed throughout the interior of the low-density paper matrix. The hydrogel of silica or metal silicate dispersed in the water is strongly integrated and bonded, and this is dried to form the Erogel, so there is almost no shrinkage during drying, and the Erogel maintains its strength without cracking or breaking into fine pieces. A highly aerogel is obtained, and the hygroscopicity of this aerogel and activated carbon and/or activated alumina and/or zeolite together significantly improves the dehumidifying ability i).

The above has only described the case where the gas adsorption element obtained by the present invention is used exclusively as a dehumidifying element, but of course it can be used for active gases other than moisture, such as nitrogen oxide, Akatsuki oxide, -carbon oxide, ammonia, and various other types. It can also be used to adsorb and remove organic malodorous substances, and in particular, elements with activated carbon added can be used to adsorb and remove organic malodors with relatively low polarity or dissolved M vapor, and elements with activated alumina added. can have a remarkable effect on the adsorption and removal of relatively highly polar inorganic gases.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, Fig. 1 is a partially cross-sectional explanatory diagram showing the first step of the invention, Fig. 2 is a perspective view of a matrix, and Fig. 3 is an example of a rotary dehumidifier. FIG. 4 is a partially cutaway perspective view and is a graph showing the performance of the dehumidifying element obtained by the present invention. In the figure, 1.2 is a forming gear, 3 is a pressure roller, 4°5 is an adhesive coating device, 7.8 is paper made with low density, 18 is processing air, 19 is recycled air, and 2o is dry air. .

Claims (1)

[Claims] 1) A matrix having the shape of a gas adsorption element having a large number of small pores is formed by laminating papers mainly composed of inorganic fibers made into low-density paper, and A dispersion of activated carbon and/or activated alumina in an aqueous water glass solution is impregnated into the matrix, and after drying, an aluminum salt or a magnesium salt or other water-soluble metal salt that can react with water glass to form an insoluble gelled silicate is impregnated into the matrix. A hydrogel of metal silicate is generated by the reaction between water glass and the metal salt by immersion in an aqueous solution, and then washed with water and dried to integrate activated carbon and/or activated alumina and a metal silicate hydrogel having gas adsorption activity into the matrix. A method for manufacturing a gas adsorption element characterized by firmly fixing and bonding it to a gas adsorption element. 2) The method for manufacturing a gas adsorption element according to claim 1, wherein the gas adsorption element is a dehumidification element. 3) The method for producing a gas adsorption element according to claim 1 or 2, wherein the dispersion is a dispersion of activated carbon and/or activated alumina and zeolite dispersed in an aqueous water glass solution. 4) A matrix having the shape of a gas adsorption element having a large number of small pores is formed by laminating papers mainly composed of inorganic fibers made into low-density paper, and powdered or short fiber activated carbon and/or activated alumina are added to the matrix. The matrix is impregnated with a dispersion dispersed in an aqueous solution of water glass, dried and immersed in sulfuric acid or other acids to form a silica hydrogel through the reaction of water glass and acid. 1. A method for producing a gas adsorption element, which comprises integrally and firmly fixing and bonding a silica aerogel having adsorption activity to the matrix. 5) The method for manufacturing a gas adsorption element according to claim 4, wherein the gas adsorption element is a dehumidification element.