JP5264263B2 - Chemical heat storage material, chemical heat storage material molded body, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a chemical heat storage material having water repelling property and capable of suppressing a pulverization of the chemical heat storage material according to a hydration/dehydration reaction and of exercising fully an ability thereof as a chemical heat storage system; a chemical heat storage material molded article; and production methods thereof. <P>SOLUTION: This chemical heat storage material is produced by forming a carbide structure 3 produced by disposing a refractory organic substance 31 on at least a part of the surface of a powder chemical heat storage material 2 and by calcining the resultant laminate in an inactive atmosphere. The refractory organic substance 31 is preferably polysuccharides. The refractory organic substance 31 is preferably hydrophilic. The chemical heat storage material 2 is preferably a hydration reaction-type chemical heat storage material converted into an oxide according to a dehydration reaction and converted into a hydroxide according to a hydration reaction. The chemical heat storage material 2 preferably contains further a clay mineral. The clay mineral is preferably sepiolite and/or palygorskite. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a chemical heat storage material, a chemical heat storage material molded body, and a method for producing them.

  Conventionally, a chemical heat storage material has a large amount of heat storage per volume, does not require heat retention, and has a small heat storage loss, and thus can store heat for a long period of time. Therefore, research and development related to a chemical heat storage system that uses a chemical heat storage material has been promoted (Patent Documents 1 to 3).

The invention described in Patent Document 1 relates to a chemical heat storage material and a method for producing the same, and describes means for adjusting the specific surface area after calcining calcium carbonate and converting it to calcium oxide.
The invention described in Patent Document 2 relates to a heat storage device, and the invention described in Patent Document 3 relates to a chemical heat storage material capsule. These inventions are inventions that deal with the above-mentioned pulverization of the chemical heat storage material. There, there is described the suppression of exfoliation and reduction in reactivity due to pulverization by encapsulating a heat storage material in a porous capsule or porous cylinder having a pore size.

JP-A-1-225686 Japanese Patent Publication No. 6-80395 Japanese Patent Publication No. 8-80394

  However, the chemical heat storage material described in Patent Document 1 repeats a hydration reaction and a dehydration reaction during operation as a chemical heat storage system. At that time, the powdered chemical heat storage material repeatedly expands and contracts by a volume of several tens of percent, and as a result, the powder breaks down and the particles rub against each other, resulting in a pulverized reaction. There is a problem of lowering.

  In the heat storage system, it is also important to perform heat exchange that guides heat to the outside of the system in response to the reaction. However, the heat storage device and the chemical heat storage material capsule described in Patent Documents 2 and 3 generate heat regulation such as increase in heat conduction resistance due to encapsulation of the capsule or cylindrical body and complication of the contact path depending on the distance between particles. To do. Therefore, there exists a problem that sufficient capability cannot be exhibited as a chemical heat storage system.

  In addition, in the heat storage system, there is a problem that the chemical heat storage material melts when the droplets reach the chemical heat storage material due to a liquid jump phenomenon that occurs at the beginning of startup (at a low temperature) or the like.

  The present invention has been made in view of such conventional problems, has water repellency, suppresses pulverization of the chemical heat storage material associated with the hydration / dehydration reaction, and is sufficiently capable as a chemical heat storage system. It is intended to provide a chemical heat storage material, a chemical heat storage material molded body, and a method for producing them.

  A first aspect of the invention is characterized in that a carbide structure is formed by disposing a hardly volatile organic substance on a surface of at least a part of a powder chemical heat storage material and firing in an inert atmosphere. It exists in a heat storage material (Claim 1).

The chemical heat storage material of the present invention can obtain the following effects by forming the specific carbide structure on the surface of the powder chemical heat storage material.
First, the carbide structure is formed by firing a hardly volatile organic substance in an inert atmosphere, and is considered to be a cage-like structure made of fibrous carbide and having a large number of pores having a small pore diameter. It is done. Only water vapor can pass through pores with a small pore diameter, and droplets cannot pass through the pores. That is, the carbide structure can impart water repellency to the chemical heat storage material. Therefore, the chemical heat storage material is covered with the above-mentioned carbide structure, so that it does not come into contact with the liquid droplets. The problem that the chemical heat storage material melts when the material is reached can be suppressed.

  Moreover, since the said carbide | carbonized_material structure has a cage-like structure which has many holes, it can carry | support a chemical heat storage material. Further, as described above, a flow path through which water vapor or the like necessary for heat storage and heat dissipation of the chemical heat storage material passes is secured. Therefore, the chemical heat storage system configured using the chemical heat storage material can sufficiently exhibit the capability as the chemical heat storage system.

  The carbide structure is not involved in the dehydration / hydration reaction. Therefore, by forming a carbide structure on the surface of the chemical heat storage material, thermal discontinuity due to structural change accompanying volume change of dehydration and hydration inside is suppressed, and performance degradation is minimized even after repeated cycles. Can be suppressed. Therefore, the chemical heat storage material excellent in durability can be provided. Moreover, pulverization of the chemical heat storage material associated with the hydration / dehydration reaction can be suppressed.

  Thus, according to the present invention, it has water repellency, suppresses pulverization of the chemical heat storage material associated with the hydration / dehydration reaction, and exhibits sufficient ability when used in a chemical heat storage system. Possible chemical heat storage materials can be provided.

According to a second aspect of the present invention, there is provided a chemical heat storage material molded body, which is formed into a desired shape using the chemical heat storage material of the first invention (invention 8).
The chemical heat storage material molded body of the present invention is produced using the chemical heat storage material of the first invention described above. Therefore, the chemical heat storage material molded body of the present invention, like the chemical heat storage material of the first invention, has water repellency, suppresses pulverization of the chemical heat storage material associated with hydration / dehydration reaction, It is possible to obtain a chemical heat storage material molded body capable of exhibiting sufficient capability as a heat storage system.

A third invention is a chemical heat storage material molded body formed into a desired shape using a powder chemical heat storage material,
The chemical heat storage material has a carbide structure formed by firing a hardly volatile organic substance in an inert atmosphere on a surface thereof (Claim 10).

The chemical heat storage material molded body of the present invention has the above-mentioned specific carbide structure formed on the surface of the powder chemical heat storage material, so that the chemical heat storage material of the first invention described above and the second invention described above. The same effects as those of the chemical heat storage material molded product can be obtained.
That is, the chemical heat storage material molded body of the present invention also has a structure in which the powder chemical heat storage material is covered with a carbide structure having a cage structure having a large number of holes having a small hole diameter. Therefore, the chemical heat storage material molded body can have water repellency as described above, can sufficiently exhibit its ability as a chemical heat storage system, has excellent durability, and is also suitable for hydration and dehydration reactions. The accompanying pulverization of the chemical heat storage material can be suppressed.

A fourth invention is a method for producing the chemical heat storage material of the first invention,
A slurry production step of producing a slurry containing the chemical heat storage material;
Furthermore, a hardly volatile organic substance contacting step of bringing the hardly volatile organic substance into contact with the slurry,
A method for producing a chemical heat storage material comprising the firing step of forming a carbide structure on the surface of the chemical heat storage material by firing the slurry in an inert atmosphere (claim 20).

  The manufacturing method of the said chemical heat storage material performs the said non-volatile organic substance contact process and the said baking process with respect to a chemical heat storage material, and forms the carbide structure on the surface of the said chemical heat storage material. Thereby, the chemical heat storage material formed by forming a carbide structure on the surface of at least a part of the powder chemical heat storage material of the first invention described above can be manufactured.

  Therefore, according to the present invention, there is provided a chemical heat storage material that has water repellency, suppresses the pulverization of the chemical heat storage material associated with the hydration / dehydration reaction, and can sufficiently exhibit the ability as a chemical heat storage system. Can be manufactured.

5th invention is the method of manufacturing the chemical heat storage material molded object of 2nd invention, Comprising:
The present invention resides in a method for manufacturing a chemical heat storage material molded body, comprising a molding step of forming the chemical heat storage material produced by the chemical heat storage material manufacturing method according to the fourth invention into a desired shape. Item 27).

The present invention is a method for producing a chemical heat storage material molded body using a chemical heat storage material produced by the same method as the production method of the fourth invention, and obtains the chemical heat storage material molded body of the second invention described above. be able to.
Therefore, according to the present invention, the chemical heat storage material molding has water repellency, suppresses the pulverization of the chemical heat storage material associated with the hydration / dehydration reaction, and can sufficiently exhibit the ability as a chemical heat storage system. The body can be manufactured.

6th invention is the method of manufacturing the chemical heat storage material molded object of 3rd invention, Comprising:
A slurry production step of producing a slurry containing the chemical heat storage material;
A molding step of molding the slurry into a desired shape to form a molded body,
Furthermore, a hardly volatile organic substance contact step of bringing the hardly volatile organic substance into contact with the slurry or the molded body,
The method for producing a chemical heat storage material molded body has a firing step of forming a carbide structure on the surface of the chemical heat storage material by firing the molded body in an inert atmosphere (Claim 28).

  The manufacturing method of the said chemical heat storage material molded object is the carbide | carbonized_material on the surface of the said chemical heat storage material by giving the said baking process with respect to a molded object after giving the said non-volatile organic substance contact process with respect to a slurry or a molded object. A structure is formed. Thereby, the chemical heat storage material molded body of the above-mentioned third invention can be manufactured.

  Therefore, according to the present invention, the chemical heat storage material molding has water repellency, suppresses the pulverization of the chemical heat storage material associated with the hydration / dehydration reaction, and can sufficiently exhibit the ability as a chemical heat storage system. The body can be manufactured.

As described above, the first invention forms a carbide structure by disposing a hardly volatile organic substance on at least a part of the surface of the powdered chemical heat storage material and firing it in an inert atmosphere.
As described above, the hardly volatile organic substance is fired in an inert atmosphere to form a cage structure having a small pore diameter.
The pore size of the carbide structure is preferably 0.2 μm or less.
In addition, the pore size and the like of the formed carbide structure can be adjusted according to the type of the hardly volatile organic material to be used.
Moreover, it is preferable that the said carbide structure occupies at least 10 area% or more of the surface area of a chemical heat storage material.
The inert atmosphere refers to, for example, a rare gas element such as helium, neon, or argon, or a gas that hardly causes a chemical reaction such as nitrogen.

In the first invention, the third invention, the fourth invention, and the sixth invention, examples of the hardly volatile organic substance include polysaccharides, glycols, acrylic fibers, pitches, and the like.
Among these, it is preferable that the said hardly volatile organic substance is a polysaccharide (Claims 2, 13, 21, and 31). In this case, when the carbide structure is formed, a cage-like structure having a particularly small pore diameter can be obtained.
Examples of the polysaccharide include sucrose, cellulose, glycogen, carrageenan, starch and the like.

Further, the hardly volatile organic substance may be a polymer having a molecular weight of 100,000 or less (claims 3, 14, 22, and 32).
In this case, it is possible to form a carbide structure that easily forms a fiber and that holds the chemical heat storage material satisfactorily in firing in an inert atmosphere.
Examples of the polymer having a molecular weight of 100,000 or less include polyvinyl alcohol, polyethylene glycol, and lignin.

As described later, the hardly volatile organic substance is supplied to a slurry in which a chemical heat storage material and water are kneaded, or by applying a solution dissolved in water or a solvent to a molded body. Arranged on the surface of the material. And it is preferable that the said non-volatile organic substance has affinity with water and the solvent used so that the said non-volatile organic substance can be arrange | positioned uniformly on the surface of the said chemical heat storage material. From the viewpoint of environmental measures, it is preferable to dissolve the hardly volatile organic substance in water. Therefore, it is preferable that the hardly volatile organic substance is hydrophilic (claims 4, 15, 23, 33).
In addition, even if it is hydrophilic at the time of the hardly volatile organic substance, the carbide structure after firing is not necessary for water and can impart water repellency to the chemical heat storage material.

In addition, the chemical heat storage material is preferably a hydration reaction type chemical heat storage material that absorbs heat with a dehydration reaction and dissipates heat with a hydration reaction, and the chemical heat storage material is an oxide with a dehydration reaction. It is more preferable that the material is a hydration reaction type chemical heat storage material that becomes a hydroxide along with the hydration reaction (claims 5, 16, 24, 34).
The said chemical heat storage material can perform heat dissipation and heat storage favorably by a hydration reaction and dehydration (reverse hydration) reaction, and can improve the performance as a heat storage system. Although the volume of the chemical heat storage material repeatedly expands and contracts with the hydration reaction and dehydration reaction, the chemical heat storage material is well supported by the carbide structure. It can be sufficiently suppressed.

Moreover, it is preferable that the said chemical heat storage material consists of hydroxides.
In this case, when forming the chemical heat storage material, it becomes possible to use water that could not be used when the carbonate compound was used as the chemical heat storage material as a binder for mixing and thickening. . Thereby, the moldability in the case of shape | molding using the said chemical heat storage material can also be improved. Moreover, high-temperature baking at around 1000 ° C. during the decarbonation step, which was necessary when a carbonic acid compound was used as the chemical heat storage material, becomes unnecessary. Thereby, a calcination temperature can be made low and the freedom degree of a use material and a process can be raised.

And it is preferable that the said hydroxide is an inorganic compound.
From the viewpoint of heat storage density, long-term heat storage stability, release rate, and safety, an inorganic system is preferable.
In this case, the material stability with respect to the heat storage / heat radiation reaction (dehydration / hydration reaction) of the chemical heat storage material is increased. Therefore, the chemical heat storage material can obtain a stable heat storage effect over a long period of time.

The inorganic compound is preferably an alkaline earth metal hydroxide.
In this case, the material stability with respect to the heat storage / heat radiation reaction (dehydration / hydration reaction) of the chemical heat storage material is increased. Therefore, the chemical heat storage material can obtain a stable heat storage effect over a long period of time. Further, by using a safe material with a small environmental load as the chemical heat storage material, it becomes easy to ensure safety including manufacturing, use, recycling, and the like.

The alkaline earth metal hydroxide is preferably one or more of calcium hydroxide, magnesium hydroxide, and barium hydroxide.
In this case, it is possible to further improve the material stability of the chemical heat storage material with respect to heat storage / radiation reaction (dehydration / hydration reaction), and stably maintain the heat storage effect of the chemical heat storage material over a long period of time. can do.
A mixture of magnesium hydroxide and calcium hydroxide can also be used.

  In addition to the alkaline earth metal hydroxide, the inorganic compound may be one or more of nickel hydroxide, aluminum hydroxide, cobalt hydroxide, and copper hydroxide.

Moreover, it is preferable that the said chemical heat storage material contains a clay mineral further (Claims 6, 17, 25, and 35).
In this case, due to the properties of the clay mineral, such as fiber, porosity and plasticity, the composite has a structure in which a chemical heat storage material in pairs of powder is dispersed and supported in the skeleton of the clay mineral. The chemical heat storage material molded body is further structurally stable.

The clay mineral is preferably a clay mineral having a layer ribbon structure.
The clay mineral having the above layer ribbon structure has a fibrous form having a large porous surface area and a large specific surface area. Therefore, the chemical heat storage material can be well organized and structured by the properties of the clay mineral such as fiber, porosity, and plasticity.
And it is preferable that the clay mineral which shows the said layer ribbon structure is a sepiolite and / or a palygorskite (Claim 7, 18, 26, 36).

Here, the sepiolite is a clay mineral having a layered ribbon structure. Specifically, the sepiolite is one of clay minerals in which a plurality of single chains resembling pyroxene are combined to form a tetrahedral ribbon. Sepiolite includes, for example, hydrous magnesium silicate that can be represented by the chemical formula Mg ₈ Si ₁₂ O ₃₀ (OH) ₄ (OH ₂ ) ₄ · 8H ₂ O. Sepiolite itself is porous and has a fibrous shape with a large specific surface area. Sepiolite also includes variants of those represented by the above chemical formula.

The clay mineral may be bentonite.
Since the bentonite is a clay mineral with strong adhesive strength, the chemical heat storage material can be well organized and structured by this adhesive strength.

As described above, the chemical heat storage material molded body of the second invention is formed into a desired shape using the chemical heat storage material of the first invention.
It is preferable that the said chemical heat storage material molded object has the hollow part formed by penetration (Claim 9).
In this case, since the said hollow part becomes a flow path into and out of water vapor | steam, the reactivity of a chemical heat storage material can be ensured, and heat storage and heat dissipation can be performed favorably.

Further, as described above, the chemical heat storage material molded body of the third invention is a chemical heat storage material molded body formed into a desired shape using a powdered chemical heat storage material, The surface has a carbide structure formed by firing a hardly volatile organic substance in an inert atmosphere.
And it is preferable that the said carbide | carbonized_material structure of the said chemical heat storage material molded object is formed by making the said chemical heat storage material molded object contact the said non-volatile organic substance after the said shaping | molding, and baking in inert atmosphere. (Claim 11).
When the hardly volatile organic substance is brought into contact with the molded body, it is preferable to bring the molded body into contact with a solution obtained by melting the hardly volatile organic substance in water or a solvent by showering or dipping.

Further, the carbide structure may be formed by bringing the powder chemical heat storage material into contact with the hardly volatile organic substance, molding, and then firing in an inert atmosphere (claim 12).
In the case where a hardly volatile organic substance is brought into contact with the powdered chemical heat storage material, it is preferable to supply the chemical heat storage material before molding by mixing the hardly volatile organic substance.

  Moreover, it is preferable that the said chemical heat storage material molded object has the hollow part formed by penetration similarly to the said 2nd invention (Claim 19).

Moreover, the manufacturing method of the chemical heat storage material of 4th invention has a slurry preparation process, a non-volatile organic substance contact process, and a baking process as mentioned above.
In the slurry preparation step, for example, a slurry in which a chemical heat storage material and water are kneaded is prepared. And since the optimal values, such as the compounding quantity and viscosity of the said slurry, fluctuate | varies with manufacturing environments etc., it is preferable to derive | lead-out suitably by experiment.

Moreover, it is preferable that the said non-volatile organic substance contact process makes a non-volatile organic substance contact a chemical heat storage material by supplying a non-volatile organic substance in a slurry in the said slurry preparation process.
Moreover, the said non-volatile organic substance contact process needs to make the amount of non-volatile organic substance made to contact the minimum quantity which exhibits water repellency. Specifically, when the total solid content is 100% by mass, the content of the hardly volatile organic substance is preferably 5 to 10% by mass.

  The firing step is performed under conditions of a holding temperature of 500 to 2000 ° C. and a holding time of 0.5 to 100 hours in a rare gas element such as helium, neon, or argon, or a gas that hardly causes a chemical reaction such as nitrogen. It is preferable to carry out with.

Moreover, the manufacturing method of the chemical heat storage material molded object of 5th invention adds a shaping | molding process to the manufacturing process of the chemical heat storage material of said 4th invention as mentioned above.
The molding step can be performed by extrusion molding, compression molding, or the like.

Moreover, the manufacturing method of the chemical heat storage material molded body of 6th invention has a slurry preparation process, a shaping | molding process, a hardly volatile organic substance contact process, and a baking process as mentioned above.
The optimum blending amount of the slurry and the clay and the like in the slurry preparation step vary depending on the manufacturing environment and the like, and therefore it is preferable to derive it appropriately through experiments and the like.
Moreover, the said shaping | molding process can be performed by extrusion molding, compression molding, etc.

  Moreover, it is preferable to perform the said hardly volatile organic substance contact process by apply | coating a hardly volatile organic substance to the surface of the said molded object after the said shaping | molding process (Claim 29). In this case, the hardly volatile organic substance is applied to the surface of the molded article by bringing the molded article obtained in the molding step into contact with a solution in which the hardly volatile organic substance is dissolved by showering or dipping. be able to.

Further, the hardly volatile organic matter contact step may be performed by mixing the hardly volatile organic matter with the slurry in the slurry preparation step (claim 30). In this case, in the slurry preparation step, the chemical heat storage material and the hardly volatile organic substance can be brought into contact with each other by supplying the hardly volatile organic substance into the mixed material.
Moreover, you may perform further with respect to a molded object after a formation process, after performing the said non-volatile organic substance contact process with respect to a slurry during a slurry preparation process.

  And the said non-volatile organic substance contact process needs to make the amount of non-volatile organic substance made to contact the minimum quantity which exhibits water repellency. Specifically, when the total solid content is 100% by mass, the content of the hardly volatile organic substance is preferably 5 to 10% by mass.

  The firing step is performed under conditions of a holding temperature of 500 to 2000 ° C. and a holding time of 0.5 to 100 hours in a rare gas element such as helium, neon, or argon, or a gas that hardly causes a chemical reaction such as nitrogen. It is preferable to carry out with.

Example 1
This example explains a chemical heat storage material according to an embodiment of the present invention.
As shown in FIG.1 (c), the chemical thermal storage material 1 of this example arrange | positions the non-volatile organic substance 31 on the surface of at least one part of the powdered chemical thermal storage material 2, and bakes it by inert atmosphere. Thus, the carbide structure 3 is formed. The carbide structure 3 has a cage structure with a small hole diameter. Therefore, the chemical heat storage material 1 of this example has a granular shape in which a plurality of powdered chemical heat storage materials 2 are gathered and surrounded between and around the carbide structure 3.

First, as shown in FIG. 1A, a chemical heat storage material 2 and a hardly volatile organic substance 31 were prepared.
As the chemical heat storage material 2, an alkaline earth metal Ca hydroxide Ca (OH) ₂ was prepared. The average particle diameter D of this chemical heat storage material is 7 μm (laser diffraction measurement method, according to SALD-2000A manufactured by Shimadzu Corporation).
In addition, the chemical heat storage material 2 reversibly repeats heat storage and heat release by the following reactions.
Ca (OH) ₂ Ｃａ CaO + H ₂ O
Further, when the heat storage amount and the heat generation amount Q are shown together in the above formula, the following is obtained.
Ca (OH) ₂ + Q → CaO + H ₂ O
CaO + H ₂ O → Ca (OH) ₂ + Q
In addition, sucrose was prepared as the hardly volatile organic substance 31.

Next, the manufacturing method of a chemical heat storage material is demonstrated.
First, as shown in FIG.1 (b), the said chemical heat storage material 2, the said non-volatile organic substance 31, and water were mixed in the slurry preparation process.
The total content of Ca (OH) ₂ and sucrose was 100% by mass, the content of Ca (OH) ₂ was 90% by mass, and the content of sucrose was 10% by mass. The mixing ratio of the total content of Ca (OH) ₂ and sucrose and water was 1: 2.
Thereafter, in the firing step, firing was performed in nitrogen (inert atmosphere) at a holding temperature of 1000 ° C. and a holding time of 2 hours. Thereby, the chemical heat storage material 1 was obtained.

Next, after the obtained granular chemical heat storage material 1 is loaded into a chemical heat storage reactor, a dehydration (at 400 ° C.) and hydration (at 200 ° C.) cycle is repeated, and the reaction rate of Ca (OH) ₂ is determined by thermogravimetry. It was evaluated by the law.
As a result, the reaction rate of Ca (OH) _{2 in} the first cycle was 87%, and the reaction rate in the 10th cycle was 84%. Thus, it was confirmed that the chemical heat storage material 1 of the present example was excellent in cycle characteristics without much deterioration in characteristics even after repeated cycles.

  Thus, according to the present invention, chemical heat storage that has water repellency, suppresses pulverization of the chemical heat storage material associated with hydration and dehydration reactions, and can fully exhibit its ability as a chemical heat storage system. It can be seen that the material can be obtained.

  In this example, calcium hydroxide is used as the chemical heat storage material. However, magnesium hydroxide or a mixture of magnesium hydroxide and calcium hydroxide can be used instead.

(Example 2)
In this example, as shown in FIGS. 2 (a) to 2 (c), water is introduced while kneading the chemical heat storage material 2, the hardly volatile organic substance 31, and the clay mineral 4 in the slurry preparation process of Example 1 above. In this example, the chemical heat storage material 12 is produced by further kneading. Others were performed in the same manner as in Example 1.
The chemical heat storage material 2 and the hardly volatile organic substance 31 were the same as those in Example 1.
As the clay compound 4, sepiolite (Mg ₈ Si ₁₂ O ₃₀ (OH) ₄ (OH ₂ ) ₄ · 8H ₂ O) was prepared.

The sepiolite is a clay mineral having a layer ribbon structure.
The sepiolite exhibits a fiber shape having a fiber diameter smaller than the average particle diameter of the chemical heat storage material when suspended in water.
Specifically, the sepiolite preferably has a wire diameter (fiber diameter) of 1 μm or less and a length (fiber length) of 200 μm or less. In this example, Turkish sepiolite having a wire diameter of approximately 0.01 μm and a length of approximately several tens of μm is prepared.
Instead of Turkish sepiolite, for example, Spanish sepiolite having a wire diameter of 0.1 μm and a length of approximately 100 μm can be used.

The total content of the Ca (OH) ₂ , the sucrose, and sepiolite is 100% by mass, the content of the Ca (OH) ₂ is 84% by mass, the content of the sucrose is 10% by mass, and the sepiolite. The content of was 6% by mass. The mixing ratio of the total content of the Ca (OH) ₂ , the sucrose, and the sepiolite and water was 1: 2.

Moreover, the reaction rate of Ca (OH) ₂ was also evaluated for the chemical heat storage material 12 of this example in the same manner as in Example 1. As a result, the reaction rate of Ca (OH) _{2 in} the first cycle was 88%, and the reaction rate in the 10th cycle was 86%. Thus, it was confirmed that the chemical heat storage material 1 of the present example was excellent in cycle characteristics without much deterioration in characteristics even after repeated cycles.

The chemical heat storage material 12 of this example is a composite including the chemical heat storage material 2, the carbide structure 3, and the clay mineral 4. Therefore, due to the properties of clay mineral 4 such as fiber, porosity, and plasticity, the above composite has a structure in which powder chemical heat storage material 2 is dispersed and supported in the skeleton of carbide structure 3 and clay mineral 4. It is considered that the chemical heat storage material 12 is further structurally stable, and as a result, more excellent cycle characteristics are obtained as described above.
In this example, sepiolite is used as the clay mineral 4, but palygorskite, bentonite, or the like can be used instead of sepiolite.

(Example 3)
This example is an example in which a chemical heat storage material molded body 5 was manufactured using the chemical heat storage material 1 manufactured in Example 1.
After mixing the chemical heat storage material 1 and water, as shown in FIG. 3, it is molded into a shape having a hollow portion 51 formed through (outer diameter: 100 mm × 40 mmφ, diameter of the hollow portion: 10 mmφ). The chemical heat storage material molded body 5 was obtained by drying at 80 ° C. for 96 hours.

About the obtained chemical heat storage material molded object 5, when the reaction rate of Ca (OH) ₂ was evaluated similarly to Example 1, the reaction rate of Ca (OH) _{2 in} the first cycle was 86%, and 10 cycles. The eye reaction rate was 84%. Thus, even if it repeated the cycle, the characteristic fall was not seen so much, and it has confirmed that it was excellent in cycling characteristics.

(Comparative Example 1)
In this example, for comparison, only the Ca (OH) ₂ used as the chemical heat storage material in Examples 1 to 3 was evaluated for the reaction rate and water repellency of Ca (OH) _2. is there.
After loading Ca (OH) ₂ into the chemical heat storage reactor, the reaction rate of Ca (OH) ₂ was evaluated by the thermogravimetric method in the same manner as in Example 1. As a result, the reaction rate of Ca (OH) _{2 in} the first cycle was 80%, the reaction rate in the 10th cycle was 32%, and when the cycle was repeated, a specific decrease was observed.

Explanatory drawing which shows the manufacture process of the chemical thermal storage material in Example 1. FIG. Explanatory drawing which shows the manufacture process of the chemical thermal storage material in Example 2. FIG. Explanatory drawing which shows the chemical heat storage material molded object in Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chemical heat storage material 2 Chemical heat storage material 3 Carbide structure 31 Hardly volatile organic substance

Claims (36)

  A chemical heat storage material, wherein a carbide structure is formed by disposing a hardly volatile organic substance on a surface of at least a part of a powder chemical heat storage material and firing in an inert atmosphere.   The chemical heat storage material according to claim 1, wherein the hardly volatile organic substance is a polysaccharide.   2. The chemical heat storage material according to claim 1, wherein the hardly volatile organic substance is a polymer having a molecular weight of 100,000 or less.   The chemical heat storage material according to claim 1, wherein the hardly volatile organic substance is hydrophilic.   5. The chemical heat storage material according to claim 1, wherein the chemical heat storage material is an hydration reaction type chemical heat storage material that becomes an oxide along with a dehydration reaction and becomes a hydroxide along with a hydration reaction. Characteristic chemical heat storage material.   The chemical heat storage material according to any one of claims 1 to 5, wherein the chemical heat storage material further contains a clay mineral.   7. The chemical heat storage material according to claim 6, wherein the clay mineral is sepiolite and / or palygorskite.   A chemical heat storage material molded body, which is formed into a desired shape using the chemical heat storage material according to any one of claims 1 to 7.   9. The chemical heat storage material molded body according to claim 8, wherein the chemical heat storage material molded body has a hollow portion formed through. In a chemical heat storage material molded body formed into a desired shape using a powder chemical heat storage material,
The said chemical heat storage material has the carbide structure formed by baking a non-volatile organic substance in an inert atmosphere on the surface, The chemical heat storage material molded object characterized by the above-mentioned.   11. The chemical heat storage according to claim 10, wherein the carbide structure is formed by bringing the chemical heat storage material formed body into contact with the hardly volatile organic substance after the forming and firing in an inert atmosphere. Material molded body.   The chemical structure according to claim 10, wherein the carbide structure is formed by bringing the powder chemical heat storage material into contact with the hardly volatile organic substance, molding the resultant, and then firing in an inert atmosphere. Thermal storage material molded body.   The chemical heat storage material molded body according to any one of claims 10 to 12, wherein the hardly volatile organic substance is a polysaccharide.   The chemical heat storage material molded body according to any one of claims 10 to 12, wherein the hardly volatile organic substance is a polymer having a molecular weight of 100,000 or less.   The chemical heat storage material molded body according to any one of claims 10 to 14, wherein the hardly volatile organic substance is hydrophilic.   The chemical heat storage material according to any one of claims 10 to 15, wherein the chemical heat storage material is an hydration reaction type chemical heat storage material that becomes an oxide along with a dehydration reaction and becomes a hydroxide along with a hydration reaction. Characteristic chemical heat storage material molded body.   The chemical heat storage material molded body according to any one of claims 10 to 16, wherein the chemical heat storage material molded body further contains a clay mineral.   The chemical heat storage material molded body according to claim 17, wherein the clay mineral is sepiolite and / or palygorskite.   The chemical heat storage material molded body according to any one of claims 10 to 18, wherein the chemical heat storage material molded body has a hollow portion formed through. A method for producing the chemical heat storage material according to claim 1,
A slurry production step of producing a slurry containing the chemical heat storage material;
Furthermore, a hardly volatile organic substance contacting step of bringing the hardly volatile organic substance into contact with the slurry,
A method for producing a chemical heat storage material, comprising a firing step of forming a carbide structure on the surface of the chemical heat storage material by firing the slurry in an inert atmosphere.   The method for producing a chemical heat storage material according to claim 20, wherein the hardly volatile organic substance is a polysaccharide.   The method for producing a chemical heat storage material according to claim 20, wherein the hardly volatile organic substance is a polymer having a molecular weight of 100,000 or less.   The method for producing a chemical heat storage material according to any one of claims 20 to 22, wherein the hardly volatile organic substance is hydrophilic.   The chemical heat storage material according to any one of claims 20 to 23, wherein the chemical heat storage material is a hydration reaction type chemical heat storage material that becomes an oxide along with a dehydration reaction and becomes a hydroxide along with a hydration reaction. A method for producing a chemical heat storage material.   25. The method for producing a chemical heat storage material according to any one of claims 20 to 24, wherein the slurry further contains a clay mineral.   26. The method for producing a chemical heat storage material according to claim 25, wherein the clay mineral is sepiolite and / or palygorskite. A method for producing the chemical heat storage material molded body according to claim 8, comprising:
A chemical heat storage material molding comprising a forming step of forming a chemical heat storage material produced by the chemical heat storage material manufacturing method according to any one of claims 20 to 26 into a desired shape. Body manufacturing method. A method for producing the chemical heat storage material molded body according to claim 10,
A slurry production step of producing a slurry containing the chemical heat storage material;
A molding step of molding the slurry into a desired shape to form a molded body,
Furthermore, a hardly volatile organic substance contact step of bringing the hardly volatile organic substance into contact with the slurry or the molded body,
A method for producing a chemical heat storage material molded body, comprising a firing step of forming a carbide structure on the surface of the chemical heat storage material by firing the molded body in an inert atmosphere.   The method for producing a chemical heat storage material molded body according to claim 28, wherein the hardly volatile organic matter contact step is performed by applying a hardly volatile organic matter to the surface of the shaped body after the molding step. .   29. The method for producing a chemical heat storage material molded body according to claim 28, wherein the hardly volatile organic matter contact step is performed by mixing the hardly volatile organic matter into the slurry in the slurry preparation step.   The method for producing a chemical heat storage material molded body according to any one of claims 28 to 30, wherein the hardly volatile organic substance is a polysaccharide.   The method for producing a chemical heat storage material molded body according to any one of claims 28 to 30, wherein the hardly volatile organic substance is a polymer having a molecular weight of 100,000 or less.   33. The method for producing a chemical heat storage material molded body according to any one of claims 28 to 32, wherein the hardly volatile organic substance is hydrophilic.   34. The chemical heat storage material according to any one of claims 28 to 33, wherein the chemical heat storage material is an hydration reaction type chemical heat storage material that becomes an oxide along with a dehydration reaction and becomes a hydroxide along with a hydration reaction. The manufacturing method of the chemical heat storage material molded object characterized.   35. The method for producing a chemical heat storage material molded body according to any one of claims 28 to 34, wherein the slurry further contains a clay mineral.   36. The method for producing a chemical heat storage material molded body according to claim 35, wherein the clay mineral is sepiolite and / or palygorskite.

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