JP6761999B2 - A water vapor adsorbent in which a hygroscopic salt is supported on an amorphous aluminum silicate granule. - Google Patents

Description

The present invention exhibits excellent adsorption ability and the like due to its unique shape in the technical field of nanotechnology, which is strongly expected to be put into practical use as an important basic technology supporting the next-generation industry. It relates to a substance that is expected to be applied as an innovative functional material, and in particular, a granulated body having macropores was prepared from amorphous aluminum silicate and supported on a hygroscopic salt. It relates to a water vapor adsorbent.

Porous inorganic materials having nano-sized pores have a property of being able to adsorb various substances based on their unique fine structure, and are therefore used in various applications. Further, since the porous inorganic material has excellent water vapor adsorption performance, it is expected to be applied to a heat pump heat exchange material, a dew condensation inhibitor, an autonomous humidity control material, and the like.
In particular, since the purpose of desiccant air conditioning is to remove the moisture in the air introduced from the outside air, it is not only necessary to efficiently remove the moisture from the high humidity air in the summer, but also. Since it is necessary to remove moisture in the air even in various air conditions, a substance capable of adsorbing water vapor in any humidity region is required.

On the other hand, in desiccant air conditioning, heated air is sent to regenerate the adsorbed water vapor, but if the temperature of the regenerated air sent is high, extra energy is required to warm the air. It ends up. Until now, the temperature of the regenerated air had been required to be 80 ° C or higher, but considering the use of unused heat sources, a material that can be regenerated with low-temperature air of about 60 ° C or even 40 ° C is required. There is.

Against the above background, in order to improve the performance of the desiccant air conditioning system, a high-performance water vapor adsorbent capable of low-temperature regeneration was developed. Under such circumstances, a substance composed of amorphous aluminum silicate (see Patent Document 1) or a substance composed of a composite of amorphous aluminum silicate and low crystalline layered clay mineral (Patent Document 2). (See) was developed, and the amount of adsorption and desorption at a temperature of 25 ° C and a relative humidity of 60% at the time of adsorption and a temperature of 60 ° C and a relative humidity of 10% at the time of desorption, which could not be achieved with conventional inorganic materials, was about 30 wt%. An inorganic material has been developed that has a linear relationship between relative humidity and the amount of water vapor adsorbed on the isotherm of water vapor adsorption.

On the other hand, for the purpose of improving the amount of water adsorbed, a porous water adsorbent such as silica gel, mesoporous silica, zeolite, or natural mineral is supported, and a hygroscopic salt such as lithium chloride, magnesium chloride, or calcium chloride is supported on the porous water adsorbent. Techniques have been proposed (see Patent Documents 3 to 6). However, there are problems that the structure of the water adsorbent is destroyed by the carried hygroscopic salt and that it cannot be regenerated at a low temperature (40 ° C. to less than 80 ° C.).

That is, in Cited Document 3, an amorphous and high-purity silica gel for a humidity control agent having a specific pore volume, specific surface area, and structure contains an alkali metal salt (hygroscopic salt) as a humidity control auxiliary agent. The technology is disclosed. However, according to the research by the present inventors, it has been found that silica gel having a small pore diameter has various problems as follows. That is, (1) silica gel having a pore diameter of 1 to 3 nm and a specific surface area of more than 900 m ² / g does not easily release the once adsorbed moisture, has a high regeneration temperature of 80 ° C. or higher, and contains a hygroscopic salt. Even if it is allowed to do so, the regeneration temperature cannot be lowered; (2) Silica gel having a pore diameter of 5 to 7 nm and a specific surface area of 700 m ² / g or more has a low regeneration temperature and a high moisture adsorption amount in a high humidity atmosphere. Although it is excellent, the amount of water adsorbed is small in a medium-low humidity atmosphere; (3) Even if it contains a hygroscopic salt, the amount of water adsorbed does not increase to the level required for use in a silica gel air conditioner; (4) Further , Silica gel has a problem of structural deterioration, and even when silica gel is used alone, it may fall off from the dehumidifying filter material, the dehumidifying performance may deteriorate, and if a hygroscopic salt is contained, the structural deterioration of silica gel may occur. More progress.

Further, Patent Document 4 discloses a vapor absorption / release material made of a mesoporous material in which an antihypertensive agent (hygroscopic salt) is impregnated inside pores having a specific pore diameter. The mesoporous material has mesopores with a sharp pore size distribution, and water is spontaneously absorbed into the mesopores by surface tension, so that the amount of water adsorbed is large. However, according to the research by the present inventors, the pore diameter of the mesopores of the mesoporous material is 1 to 10 nm, and the amount of water adsorbed in a medium-low humidity atmosphere is large, but the amount of water adsorption in a high-humidity atmosphere is small. There was a problem. Further, when a hygroscopic salt is impregnated in this mesoporous material, there is a big problem that the structure of the mesoporous material is destroyed and the amount of water adsorbed is further reduced.

Further, Patent Document 5 discloses a deliquescent inorganic compound carried by a carrying member in which porous inorganic fine particles are bound with polytetrafluoroethylene. Examples of the porous inorganic fine particles include fine particles such as silica gel and zeolite. According to the research by the present inventors, zeolite has a sharp pore distribution and a very small pore diameter of about 1 nm on average. Although the amount of water adsorbed in a medium-low humidity atmosphere is large, there is a problem that the amount of water adsorbed in a high-humidity atmosphere is small. Further, since the pore diameter is small, there is a problem that water is difficult to be desorbed, and the regeneration temperature is as high as 100 ° C. or higher. Even if a hygroscopic salt such as an alkali metal salt is supported on this zeolite, there is a problem that the amount of water adsorbed does not increase and the hygroscopic salt in the pores inhibits the desorption of water.

Patent Document 6 discloses a hygroscopic agent in which cristobalite, which is a natural mineral, is supported by hygroscopic salts of calcium chloride and lithium chloride. However, according to the research by the present inventors, cristobalite also has a problem that the regeneration temperature for desorbing the adsorbed water is high, and the structure of cristobalite is destroyed by the hygroscopic salt.

Among them, in the amorphous aluminum silicate described in Patent Document 1, a nonflammable moisture absorbing / releasing sheet has been developed because structural deterioration does not occur even if a hygroscopic salt is supported. A method for producing a moisture absorbing / releasing structure has been developed by forming this nonflammable moisture absorbing / releasing sheet into a honeycomb structure (see Patent Document 7).

Further, in the composite of the amorphous aluminum silicate and the crystalline layered clay mineral described in Patent Document 2, a powder having a hygroscopic salt supported on the composite and improved adsorption performance has been developed. (See Patent Document 8).

JP-A-2008-179533 International Publication No. 2009/084632 Japanese Unexamined Patent Publication No. 2003-201113 Japanese Unexamined Patent Publication No. 11-114410 Special Fair 7-49091 Gazette Japanese Unexamined Patent Publication No. 60-241930 JP-A-2010-240554 Japanese Unexamined Patent Publication No. 2011-255331

In a desiccant air conditioning system, when the adsorbent is packed in a dehumidifying tower and the wind flows, the adsorbent is granulated because the wind does not flow and stops or the wind resistance increases if the adsorbent remains in powder form. There is a way to reduce the resistance.
Therefore, as a result of studies by the present inventors, a powder obtained by supporting a hygroscopic salt on an amorphous aluminum silicate, or a composite of an amorphous aluminum silicate and a crystalline layered clay mineral. When a powder obtained by supporting a hygroscopic salt on a body (Patent Document 8 above) is granulated, it expands and collapses during drying or adsorption of water vapor, and a granulated body capable of repeated adsorption and desorption is produced. It turned out to be impossible to do.

The present invention has been made in view of the above circumstances, and not only has high-performance adsorption performance in the medium humidity region, but also has excellent adsorption performance capable of being regenerated at a low temperature of 40 to 60 ° C. It is an object of the present invention to provide a granulated body which does not cause structural deterioration even if a hygroscopic salt is supported, and a method for producing the same.

As a result of repeated studies to achieve the above object, the present inventors prepared a granulated material having macroscopic pores using a powder made of amorphous aluminum silicate, and obtained granulated material. It has been found that the above-mentioned problems can be solved by carrying a hygroscopic salt such as calcium chloride on the body.

That is, the present invention for solving the above problems is as follows.
(1) amorphous aluminum silicate, the extrusion granulation having macropores, water vapor adsorbent, characterized in that by supporting a hygroscopic salt.
(2) The water vapor adsorbent according to (1), wherein the hygroscopic salt is magnesium chloride and / or calcium chloride.
(3) It is characterized in that a granulated body having macropores is produced by extrusion granulation using an amorphous aluminum silicate, and then the granulated body is supported with a hygroscopic salt. A method for producing a water vapor adsorbent.
(4) The method for producing a water vapor adsorbent according to (3), wherein the hygroscopic salt is magnesium chloride and / or calcium chloride.
(5) Water glass and an aqueous solution of aluminum sulfate are mixed so that the Si / Al molar ratio is larger than 0.8 and 1.2 or less, and an acid or alkali is added thereto to adjust the pH to 6 to 9. The method for producing a water vapor adsorbent according to (3) or (4), which comprises heating to produce the amorphous aluminum silicate.
(6) The water vapor adsorbent according to (1) or (2), which is a desiccant air-conditioning adsorbent.
(7) A desiccant air-conditioning system using the water vapor adsorbent according to (1) or (2).
(8) The water vapor adsorbent according to (1) or (2), which is a heat storage adsorbent.
(9) A heat storage system characterized in that the water vapor adsorbent according to (1) or (2) is used as the adsorbent.

The water vapor adsorbent obtained by impregnating a granulated body of amorphous aluminum silicate having macropores with a calcium chloride solution obtained by the present invention is regenerated at 40 ° C. at 25 ° C. and a relative humidity of 60%. Excellent water vapor adsorption amount of about 30 wt%, water vapor adsorption amount of about 40 wt% at 25 ° C relative humidity 60% at 60 ° C regeneration, and water vapor adsorption amount of about 50 wt% at 25 ° C relative humidity 60% at 100 ° C regeneration. Since it has a water vapor adsorption performance and a stable structure in which structural deterioration does not occur even if hygroscopic salts are carried, a special effect is exhibited as a water vapor adsorbent, particularly as an adsorbent for desiccant air conditioning.

The figure which shows the steam adsorption result of the granule impregnated with calcium chloride in Example 1. FIG. The figure which shows the water vapor adsorption result of the granule impregnated with magnesium chloride in Example 1. FIG. An observation photograph of a flaky sample of the granulated body obtained in Example 1 with an optical microscope. The figure which shows the steam adsorption result of the granulated body in Example 2. FIG. The figure which shows the water vapor adsorption result in the structural stability evaluation after impregnation.

Next, the present invention will be described in more detail.
The amorphous substance as the base material in the present invention contains silicon (Si), aluminum (Al), oxygen (O) and hydrogen (H) as constituent elements, and water assembled by a large number of Si—O—Al bonds. Japanese aluminum silicate.
This amorphous aluminum silicate is prepared by mixing an inorganic silicon compound solution and an inorganic aluminum compound solution so that the Si / Al ratio is 0.8 to 1.2, and adding an acid or alkali to adjust the pH to 6 to 6 . It can be artificially obtained by adjusting the pH to 9 and then heating the desalted compound at about 95 ° C.

In the present invention, methyl cellulose, which is one of the organic binders, and water are added to the amorphous aluminum silicate powder and kneaded, and then extruded granulation is performed to prepare a granulated material having macropores. By supporting calcium chloride, which is one of the hygroscopic salts, in this granulated product, 30.3 wt% at 60% relative humidity at 40 ° C. and 40.7 wt% at 60% relative humidity at 60 ° C. It has become possible to produce a substance having an excellent water vapor adsorption performance of 51.3 wt% at a relative humidity of 60% by regeneration at 100 ° C.
That is, by creating a granulated body having macropores using amorphous aluminum silicate and supporting a hygroscopic salt, granulated granules having excellent water vapor moisture absorption behavior which could not be obtained in the past. It is possible to provide the body.

In the present invention, an inorganic silicon compound and an inorganic aluminum compound are usually used as raw materials for the preparation of the precursor before heating.
The reagent used as a silicon source may be an aqueous solution of silicic acid, and specifically, sodium orthosilate, sodium metasilicate, water glass, amorphous colloidal silicon dioxide (aerosil, etc.), etc. are suitable. Can be mentioned.
The aluminum source to be bonded to the silicate molecule may be aluminum ions, and specific examples thereof include aluminum compounds such as aluminum chloride, aluminum nitrate, aluminum sulfate and sodium aluminate. These silicon sources and aluminum sources are not limited to the above compounds, and can be used in the same manner as long as they have the same effect.

These raw materials are dissolved in an appropriate aqueous solution to prepare a solution having a predetermined concentration. In order to synthesize an amorphous aluminum silicate showing excellent adsorption behavior satisfying this purpose, it is necessary to mix the silicon / aluminum molar ratio so as to be 0.8 to 1.2. The concentration of the silicon compound in the solution is 1 to 2000 mmol / L, and the concentration of the solution of the aluminum compound is 1 to 2000 mmol / L. Suitable concentrations are 1 to 700 mmol / L of the silicon compound solution and 1 to 1000 mmol. It is preferable to mix a / L aluminum compound solution. Based on these ratios and concentrations, the silicon compound solution is mixed with the aluminum compound solution, acid or alkali is added to adjust the pH to 6-9 to form a precursor, and then this precursor substance is contained. The suspension is heated at about 95 ° C. for a predetermined time, washed and dried to obtain an amorphous aluminum silicate as a target base material.

A binder and water are added to the obtained amorphous aluminum silicate to prepare a granule having macropores, that is, pores having a diameter of 50 nm or more. In order to produce a granulated product satisfying the purpose, it is necessary to add 0 to 50 wt% of the binder to the weight of the amorphous aluminum silicate, preferably 0 to 5 wt%, which is completely It is possible without addition. The amount of water to be added needs to be 50 to 200 wt% with respect to the amorphous aluminum silicate, but is preferably 100 to 150 wt%.
The type of binder added to the amorphous aluminum silicate is not particularly limited, but methyl cellulose, which is an organic binder, is preferably used. The method for producing a granulated product from this amorphous aluminum silicate is not particularly limited, but extrusion granulation is preferably used.

As the binder in the present invention, both an inorganic binder and an organic binder can be used.
Examples of the inorganic binder include an inorganic sol and a clay-based binder. Examples of the inorganic sol include alumina sol, silica sol, titania sol, sepiolite sol, attapulsite sol, water glass and the like. Examples of the clay-based binder include white clay, kaolinite, montmorillonite, frog-eye clay, sepiolite, and attapulsite.
Examples of the organic binder include cellulose-based binders such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, and carmellose (carboxysimyl cellulose), alginic acid-based binders such as sodium alginate, starch, wheat flour, British gum, xanthan gum, and dextrin. , Polysaccharide binders such as dextran and pullulan, animal binders such as gelatin, vinyl binders such as polyvinyl alcohol and polyvinylpyrrolidone, acrylic binders such as polyacrylic acid and polyacrylic acid ester, polyethylene oxide, polypropylene oxide, polyethylene. Other resin-based binders such as glycol can be mentioned.
One or a mixture of two or more of these binders may be used.

Further, as a method for producing a granulated material in the present invention, compression granulation, extrusion granulation, crushing granulation, rolling granulation, fluidized bed granulation, stirring granulation, spray granulation and the like can be mentioned. Of these, compression granulation, extrusion granulation, and rolling granulation are preferable.

As described above, methyl cellulose, which is one of the organic binders, and water are added to the amorphous aluminum silicate powder and kneaded, and then extruded granulation is performed to prepare a granulated material having macropores. By supporting calcium chloride, which is one of the hygroscopic salts, in the granulated material, an adsorbent having excellent water vapor adsorption characteristics can be obtained.
The method for supporting the hygroscopic salt on the above-mentioned granulated body is not particularly limited, but a method of impregnating the granulated body made of amorphous aluminum silicate with a solution of the hygroscopic salt is preferably used. ..
Specifically, a granulated product made of amorphous aluminum silicate is immersed in a solution of a hygroscopic salt such as calcium chloride, stirred, and then dried at 100 ° C. for 1 day to achieve the desired water vapor adsorption characteristics. An excellent adsorbent can be obtained in.

The hygroscopic salts in the present invention include metal halide salts such as lithium chloride, sodium chloride and magnesium chloride, metal sulfates such as sodium sulfate, calcium sulfate, magnesium sulfate and zinc sulfate, and metal acetates such as potassium acetate. Amin salts such as dimethylamine hydrochloride, phosphoric acid compounds such as orthophosphoric acid, guanidine salts such as guanidine hydrochloride, guanidine phosphate, guanidine sulfamate, metal hydroxides such as ammonium hydroxide, sodium hydroxide, magnesium hydroxide, etc. Of these, metal halide salts and guanidine salts are preferable.

Next, the present invention will be specifically described based on examples, but the present invention is not limited to the following examples.

(Example 1)
The amorphous aluminum silicate used as the base material of the water vapor adsorbent in the present invention was synthesized as follows.
As a Si source, 1000 mL of a water glass aqueous solution having a Si concentration of 0.41 mol / L and 1000 mL of an aluminum sulfate aqueous solution having an Al concentration of 0.45 mol / L were used as an Al source. A water glass aqueous solution was added to the aluminum sulfate aqueous solution, and the mixture was stirred for about 15 minutes. The Si / Al ratio at this time is 0.91. After stirring, a 5N aqueous sodium hydroxide solution was added, and the mixture was added until the pH reached about 7. The dropping amount of the sodium hydroxide aqueous solution was 18 mL. The suspension thus produced was stirred for 1 hour to prepare a precursor suspension.
The prepared 1 L precursor suspension was placed in a heat-resistant container for 2000 mL and heated at 98 ° C. for 18 hours. After the reaction, the cells were washed by centrifugation three times and dried at 60 ° C. for 1 day.

The obtained product was subjected to powder X-ray diffraction measurement. The powder X-ray diffraction pattern of the product showed a broad peak near 2θ = 26 and 40 °, confirming that amorphous aluminum silicate was formed.

To 20 g of the amorphous aluminum silicate obtained as described above, 0.8 g of methyl cellulose and 30 g of water were added, kneaded by hand, and then extruded and granulated with a clay gun. The resulting string-shaped molded body was cut and dried at 60 ° C. for 1 day to obtain the desired granulated body. The bulk density of the granules obtained at this time was 0.38 g / mL.

The granulated product obtained as described above is immersed in a 5 mol / L calcium chloride aqueous solution or a 5 mol / L magnesium chloride aqueous solution for 1 hour, and then immersed in pure water for 5 seconds to wash the surface of the granulated product, and then at 100 ° C. By drying in 1 day, a granulated product having excellent water vapor adsorption performance was obtained.

(Evaluation of water vapor adsorption)
The granulated product obtained by impregnating the amorphous aluminum silicate obtained in Example 1 with calcium chloride or magnesium chloride was dried in a dryer at each temperature of 40 to 100 ° C. for 18 hours, and then the temperature was 25 ° C. Water vapor was adsorbed in a constant temperature and humidity chamber under the condition of humidity of 60% for 6 hours, and the amount of water vapor adsorbed was determined from each weight change, and the water vapor adsorption performance was evaluated. At this time, a granule, silica gel, and zeolite 13X on which no salt was supported were used as comparative samples.
The result of the water vapor adsorption rate immersed in the 5 mol / L calcium chloride aqueous solution is shown in FIG. 1, and the result of the immersion in the 5 mol / L calcium chloride aqueous solution is shown in FIG. Table 1 shows the results combined with the comparative sample.

As shown in FIGS. 1 and 1, the water vapor adsorption rate of the granulated product immersed in a 5 mol / L calcium chloride aqueous solution was 30.3 wt% when dried at 40 ° C., 40.7 wt% when dried at 60 ° C., and dried at 100 ° C. It was 51.3 wt%.
Further, as shown in FIGS. 2 and 1, the water vapor adsorption rate of the granules immersed in the 5 mol / L magnesium chloride aqueous solution was 26.9 wt% when dried at 40 ° C., 37.4 wt% when dried at 60 ° C., 100. It was 48.3 wt% when dried at ° C.

On the other hand, as shown in Table 1, the steam adsorption rates of the untreated granulated product, silica gel, and zeolite 13X used for comparison were 14.3 wt% and dried at 60 ° C. for the untreated granulated product. 18.5 wt% and 22.1 wt% when dried at 100 ° C. Silica gel is 14.8 wt% when dried at 40 ° C., 18.8 wt% when dried at 60 ° C., 22.5 wt% when dried at 100 ° C., and 13X zeolite. It was 2.6 wt% when dried at 40 ° C., 4.9 wt% when dried at 60 ° C., and 11.1 wt% when dried at 100 ° C.

From the above adsorption evaluation, the water vapor adsorption performance of the substance obtained in the example cannot be obtained only by the granulated body made of amorphous aluminum silicate, and the granulated product made of amorphous aluminum silicate. It was clarified that it is the property obtained only by impregnating the body with an aqueous solution of calcium chloride.

(Macro pore observation)
FIG. 3 shows a photograph of a flaky sample observed with an optical microscope in the granulated body obtained by extrusion granulation of Example 1. As shown in FIG. 3, it was confirmed that macropores on the order of submicrons to micrometers were present.

(Example 2)
Using the same amorphous aluminum silicate powder as in Example 1, 0.2 kg of methyl cellulose and 6.5 kg of water were added to 5 kg of amorphous aluminum silicate, kneaded by a machine, and then extruded granulated. Extrusion granulation was performed by a machine. The resulting string-shaped molded body was cut and dried at 80 ° C. for 1 day to obtain the desired granulated body. The bulk density of the granules obtained at this time was 0.44 g / mL.

The granules obtained as described above are immersed in a 5 mol / L calcium chloride aqueous solution for 1 hour, then immersed in pure water for 5 seconds to wash the surface of the granules, and then dried at 100 ° C. for 1 day. , A granulated material having excellent water vapor adsorption performance was obtained.

(Evaluation of water vapor adsorption)
The granulated product obtained by impregnating the amorphous aluminum silicate obtained in Example 2 with calcium chloride was dried in a dryer at each temperature of 40 to 100 ° C. for 18 hours, and then the temperature was 25 ° C. and the humidity was 60%. Water vapor was adsorbed in a constant temperature and humidity chamber for 6 hours under the above conditions, and the amount of water vapor adsorbed was determined from each weight change, and the water vapor adsorption performance was evaluated.
The result of the water vapor adsorption rate immersed in a 5 mol / L calcium chloride aqueous solution is shown in FIG.
As shown in FIG. 4, the water vapor adsorption rate of the granules immersed in a 5 mol / L calcium chloride aqueous solution was 29.4 wt% when dried at 40 ° C., 40.7 wt% when dried at 60 ° C., and 50. It was 6 wt%.

From the above adsorption evaluation, the water vapor adsorption performance of the substance obtained in the example cannot be obtained only by the granulated body made of amorphous aluminum silicate, and the granulated product made of amorphous aluminum silicate. It was clarified that it is the property obtained only by impregnating the body with an aqueous solution of calcium chloride.

(Evaluation of structural stability after impregnation)
In order to evaluate the structural stability of the granulated product immersed in the 5 mol / L calcium chloride aqueous solution prepared in Example 1, a durability test was conducted in which drying and adsorption were repeated 120 times. The result of water vapor adsorption performance at that time is shown in FIG.
Since the adsorption performance of water vapor does not change even if the drying and adsorption are repeated 120 times in this way, it is clear that the structural deterioration does not occur even in the granulated body immersed in the calcium chloride aqueous solution.

(Comparison example)
To 5 kg of the powder obtained by immersing the amorphous aluminum silicate powder used in Examples 1 and 2 in a 5 mol / L calcium chloride aqueous solution and drying it, 0.2 kg of methyl cellulose and 2 kg of water were added to the machine. After kneading with the above, extrusion granulation was performed by an extrusion granulator. When the produced string-shaped molded body was cut and dried at 80 ° C. for 1 day, the molded body collapsed and a granulated body could not be produced.

The water vapor adsorbent of the present invention in which a hygroscopic salt is supported on a granulated body having macropores of amorphous aluminum silicate not only has high-performance adsorption performance in a medium humidity region, but also 40. It is an adsorbent having excellent adsorptivity that can be regenerated at a low temperature of about 60 ° C., and is useful as an adsorbent for heat storage, batch-type desiccant air conditioning, and the like.

Claims (9)

Amorphous aluminum silicate, the extrusion granulation having macropores, water vapor adsorbent, characterized in that by supporting a hygroscopic salt. The water vapor adsorbent according to claim 1, wherein the hygroscopic salt is magnesium chloride and / or calcium chloride. A water vapor adsorbent characterized by producing a granulated product having macropores by extrusion granulation using an amorphous aluminum silicate, and then supporting a hygroscopic salt on the granulated product. Manufacturing method. The method for producing a water vapor adsorbent according to claim 3 , wherein the hygroscopic salt is magnesium chloride and / or calcium chloride. Water glass and an aqueous solution of aluminum sulfate are mixed so that the Si / Al molar ratio is larger than 0.8 and 1.2 or less, and acid or alkali is added to adjust the pH to 6 to 9 , and then the mixture is heated. The method for producing a water vapor adsorbent according to claim 3 or 4 , wherein the amorphous aluminum silicate is produced. The water vapor adsorbent according to claim 1 or 2, wherein the adsorbent is a desiccant air conditioner. A desiccant air conditioning system characterized in that the water vapor adsorbent according to claim 1 or 2 is used as the adsorbent. The water vapor adsorbent according to claim 1 or 2, wherein the adsorbent is a heat storage adsorbent. A heat storage system characterized in that the water vapor adsorbent according to claim 1 or 2 is used as the adsorbent.

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