JP5231077B2 - Chemical heat storage material composite and its manufacturing method - Google Patents

Description

  The present invention relates to a chemical heat storage material composite formed from a chemical heat storage material, and a method for producing the same.

After heating the crystalline limestone having a particle size of 0.3 mm to 4 mm within a range of 850 ° C. to 1100 ° C. for a predetermined time, the limestone is heated within a range of 500 ° C. to 600 ° C. for a predetermined time, so that There is known a technique for obtaining quicklime in which a large number of pores toward the surface are formed (for example, see Patent Document 1). Moreover, the technique which fills the reactor or reaction tower with the capsule which accommodated the powder chemical thermal storage material in the ratio of 10-60 volume% of internal space is known (for example, refer patent document 2, patent document 3). .
JP-A-1-225686 Japanese Patent Publication No. 6-80395 Japanese Patent Publication No. 6-80394

  However, as described in Patent Document 1, when quick lime having pores formed therein is used as a chemical heat storage material in a powder form, the hydration reaction and the dehydration reaction are repeated during operation. For this reason, the powder of the chemical heat storage material rubs against other powders by repeated volume expansion and contraction, and is pulverized, resulting in a problem that the reactivity as the heat storage system is lowered. Also. In the configurations of Patent Documents 2 and 3, due to the increase in heat conduction resistance due to the use of capsules and the complexity of the heat transfer path, the heat due to the exothermic reaction of the chemical heat storage material cannot be taken out efficiently, and the heat in the heat storage reaction is further reduced. There was a problem that could not be supplied efficiently.

  In view of the above facts, an object of the present invention is to obtain a chemical heat storage material composite in which a gap is formed between powder chemical heat storage materials, and a method for producing the chemical heat storage material composite.

  The chemical heat storage material composite according to the first aspect of the present invention is obtained by firing a powder chemical heat storage material mixed with a clay mineral at a predetermined ratio.

  In the chemical heat storage material composite according to claim 1, a powdery chemical heat storage material is formed and fired, and as a whole, a gap (flow path) is formed between the powders (chemical heat storage material). It is formed as a porous structure having a predetermined shape as a whole. That is, in the present chemical heat storage material composite, the powdery chemical heat storage material is structured while securing the introduction and discharge paths of the reactants and reaction products accompanying heat storage and heat dissipation.

  Here, in this chemical heat storage material composite, since the clay mineral is mixed with the chemical heat storage material at a predetermined ratio, in other words, the chemical heat storage material is dispersed and held in the skeleton of the porous clay mineral. The strength as the porous structure described above is high, and the structure as the porous structure is easily maintained stably.

  Thus, in the chemical heat storage material composite according to claim 1, a gap is formed between the powdered chemical heat storage materials. For this reason, the pulverization of the chemical heat storage material due to repeated heat storage and heat dissipation reaction is suppressed or prevented. Further, since the chemical heat storage material forms a molded body (exposed in the gap), the heat transfer performance is good.

  A chemical heat storage material composite according to a second aspect of the present invention is configured as a compact including a powder chemical heat storage material and a clay mineral, and the chemical heat storage material is exposed on the inner surfaces of the pores.

  The chemical heat storage material composite according to claim 2 is formed, for example, in a porous shape, and the chemical heat storage material that is powder is exposed on the inner surface of the pores. Thus, the chemical heat storage material composite is formed as a porous structure having a predetermined shape as a whole while a gap (flow path) is formed between the powders (chemical heat storage material). That is, the structure of the powdery chemical heat storage material is achieved while ensuring the introduction and discharge paths of the reactants and reaction products accompanying heat storage and heat dissipation.

  Here, in this chemical heat storage material composite, since the clay mineral is mixed with the chemical heat storage material, in other words, the chemical heat storage material is dispersed and held in the skeleton of the porous clay mineral. The strength as a body is high, and the structure as the porous body is easily maintained stably.

  Thus, in the chemical heat storage material composite according to claim 2, a gap is formed between the powdered chemical heat storage materials. For this reason, the pulverization of the chemical heat storage material due to repeated heat storage and heat dissipation reaction is suppressed or prevented. Moreover, since the chemical heat storage material forms a molded body, heat transfer performance is good.

  The chemical heat storage material composite according to claim 3 is the chemical heat storage material composite according to claim 1 or 2, wherein a clay mineral having a layer ribbon structure is used as the clay mineral.

  In the chemical heat storage material composite according to claim 3, since the clay mineral is porous and has a fibrous form of a layer ribbon structure having a large specific surface area, the structure of the chemical heat storage material in powder form is excellent due to its fiber and plasticity. And can be structured.

  The chemical heat storage material composite according to claim 4 is the chemical heat storage material composite according to claim 3, wherein sepiolite, palygorskite or kaolinite is used as the clay mineral having the layer ribbon structure.

  In the chemical heat storage material composite according to claim 4, since at least a part of the clay mineral is sepiolite, palygorskite (attapulgite) or kaolinite having a layer ribbon structure, the chemical heat storage material in powder form due to its fiber and plasticity. Can be well organized and structured.

  The chemical heat storage material composite according to claim 5 is the chemical heat storage material composite according to claim 1 or 2, wherein bentonite is used as the clay mineral.

  In the chemical heat storage material composite according to claim 5, bentonite, which is a clay mineral having a strong adhesive force, is used, so that the powder chemical heat storage material can be well organized and structured by this adhesive force.

  The chemical heat storage material composite according to claim 6 is the chemical heat storage material composite according to any one of claims 1 to 5, wherein the clay mineral is larger than the particle diameter of the chemical heat storage material. Made of fine fibers.

  In the chemical heat storage material composite according to claim 6, since the clay mineral forms a fiber having a fine fiber diameter, the organization and structure of the powder chemical heat storage material can be achieved using a small amount of clay mineral. Is possible. Thereby, the occupation amount of the chemical heat storage material per mass per volume in the chemical heat storage material composite can be increased.

  The chemical heat storage material composite according to claim 7 is the chemical heat storage material composite according to any one of claims 1 to 6, wherein at least a part of the clay mineral is the chemical heat storage material. It is a clay mineral fired before mixing.

  The chemical heat storage material composite according to claim 7, wherein the clay mineral is adjusted in size (for example, particle diameter if granular, wire diameter and length if fibrous) and pore size by firing. It is comprised by mixing and baking with a chemical heat storage material. For this reason, the present chemical heat storage material composite can form a clay mineral skeleton having a large porosity with a reduced bulk density in the skeleton of the clay mineral that disperses and holds the chemical heat storage material. Improvement is achieved.

  The chemical heat storage material composite according to claim 8 is the chemical heat storage material composite according to claim 7, wherein the clay mineral is a clay mineral baked before mixing with the chemical heat storage material and the chemical heat storage material. Contains unfired clay minerals when mixed with wood.

  In the chemical heat storage material composite according to claim 8, since the calcined clay mineral and the unfired clay mineral are mixed with the chemical heat storage material, the clay mixed with the chemical heat storage material is controlled by controlling the blending ratio thereof. It is possible to achieve both the adjustment of the mineral size and void size, the adjustment of the void size, and the retention strength of the chemical heat storage material by the skeleton structure of the clay mineral. For this reason, this chemical heat storage material composite is easy to form a clay mineral skeleton with a large porosity with reduced bulk density while ensuring the strength as a structure, and the packing density of the chemical heat storage material is improved.

  The chemical heat storage material composite according to claim 9 is the chemical heat storage material composite according to any one of claims 1 to 8, wherein the chemical heat storage material has fine cracks.

  In the chemical heat storage material composite according to claim 9, since the specific surface area of the chemical heat storage material having fine cracks is large, the reaction rate improvement in the heat storage and heat dissipation reaction is shown. Thereby, the efficiency of heat storage and heat dissipation can be improved.

  The chemical heat storage material composite according to claim 10 is the chemical heat storage material composite according to any one of claims 1 to 9, wherein the chemical heat storage material composite absorbs heat in accordance with a dehydration reaction as water. Hydration reaction type chemical heat storage materials that dissipate heat during the sum reaction are used.

  The chemical heat storage material composite according to claim 10, wherein the hydration reaction type chemical heat storage material repeats volume expansion and contraction with a hydration reaction and a dehydration (reverse hydration) reaction, but the chemical heat storage material has a structure using clay minerals. As a result of the organization and the formation of gaps, the pulverization of the chemical heat storage material is effectively suppressed or prevented.

  A chemical heat storage material composite according to an eleventh aspect of the present invention is the chemical heat storage material composite according to any one of the first to tenth aspects, wherein the chemical heat storage material composite is oxidized along with a dehydration reaction and hydroxylated along with a hydration reaction. Hydration reaction type chemical heat storage material is used.

  In the chemical heat storage material composite according to claim 11, the hydration reaction type chemical heat storage material repeats volume expansion and contraction with a hydration reaction and a dehydration (reverse hydration) reaction, but a chemical heat storage material in a structure using clay minerals. As a result of the organization and the formation of gaps, the pulverization of the chemical heat storage material is effectively suppressed or prevented.

  The chemical heat storage material composite according to claim 12 is the chemical heat storage material composite according to claim 11, wherein the hydration reaction type chemical heat storage material is an inorganic compound.

  In the chemical heat storage material composite according to claim 12, since an inorganic compound is used as the chemical heat storage material, the material stability against heat storage and heat radiation reaction (hydration, dehydration) is high. For this reason, a stable heat storage effect can be obtained over a long period of time.

  The chemical heat storage material composite according to claim 13 is the chemical heat storage material composite according to claim 12, in which the inorganic compound is an alkaline earth metal compound.

  In the chemical heat storage material composite according to claim 13, since an alkaline earth metal compound (hydroxide) is used, in other words, since a material with a small environmental load is used, safety including manufacturing, use, and recycling is ensured. Securement becomes easy. Further, in the configuration using sepiolite as the clay mineral, the alkalinity of the hydroxide helps vitrification by reaction with the clay mineral (especially described above), which contributes to improving the strength of the porous structure.

  The chemical heat storage material composite according to claim 14 is the chemical heat storage material composite according to any one of claims 11 to 13, wherein the powder hydration reaction system chemical heat storage material, A mixture of sepiolite as a clay mineral and molded into a predetermined shape is fired at a temperature of 350 ° C to 500 ° C.

  The chemical heat storage material composite according to claim 14 is configured as a porous structure in which sepiolite is sintered by firing a molded body in which a hydration reaction type chemical heat storage material and sepiolite are mixed. Yes. The hydration reaction type chemical heat storage material, which is an inorganic compound, is fired at a temperature of 350 ° C. to 500 ° C., thereby generating microcracks and increasing the specific surface area. Since this large specific surface area contributes to the improvement of the reaction speed in heat storage and heat dissipation reaction, in this chemical heat storage material composite, the efficiency of heat storage and heat dissipation can be improved.

  Moreover, since the sintering temperature of sepiolite is 350 ° C. to 400 ° C., the sintering of sepiolite and the generation of microcracks in the chemical heat storage material proceed simultaneously. In other words, the sintering of sepiolite and the generation of microcracks in the chemical heat storage material do not adversely affect each other. The chemical heat storage material dispersed and held in sepiolite is suppressed from being pulverized by microcracks.

  The method for producing a chemical heat storage material composite according to the invention of claim 15 includes a kneading step of kneading clay mineral in a predetermined ratio with a powder chemical heat storage material, and the chemical heat storage material kneaded in the kneading step; A molding step of molding the kneaded product with the clay mineral into a predetermined shape, and a firing step of firing the kneaded product of the chemical heat storage material and the clay mineral molded in the molding step.

  In the method for producing a chemical heat storage material composite according to claim 15, the clay mineral is kneaded at a predetermined ratio in the powder chemical heat storage material in the kneading step, and then the process proceeds to the molding step. In the molding process, the kneaded product of the chemical heat storage material and the clay mineral is molded into a predetermined shape, and then the process proceeds to the firing process. In the firing step, the kneaded product of the chemical heat storage material and the clay mineral molded in the molding step is fired by heating. Thereby, a gap (flow path) is formed between the powders (chemical heat storage materials), and a chemical heat storage material composite having a predetermined shape as a whole is formed.

  In the method for producing a chemical heat storage material composite according to the present invention, since the clay mineral is kneaded in a predetermined ratio with the powder chemical heat storage material, the chemical heat storage material can be dispersed and held in the skeleton of the porous clay mineral. . For this reason, the chemical heat storage material composite manufactured by the method for manufacturing the chemical heat storage material composite has high strength as the porous body described above, and the structure as the porous body is easily maintained stably.

  Thus, in the manufacturing method of the chemical heat storage material composite of Claim 15, the chemical heat storage material composite in which the clearance gap was formed between the powder chemical heat storage materials can be obtained. For this reason, the pulverization of the chemical heat storage material due to repeated heat storage and heat dissipation reaction is suppressed or prevented. Moreover, since the chemical heat storage material forms a molded body, heat transfer performance is good.

  A chemical heat storage material composite manufacturing method according to a sixteenth aspect of the present invention is the chemical heat storage material composite manufacturing method according to the fifteenth aspect, wherein a clay mineral having a layer ribbon structure is used as the clay mineral.

  In the method for producing a chemical heat storage material composite according to claim 16, since the clay mineral forms a fibrous form having a large porous surface area and a large specific surface area, the fiber and plasticity are used to improve the chemical heat storage material in powder form. Can be organized and structured.

  The method for producing a chemical heat storage material composite according to claim 17 is the chemical heat storage material composite production method according to claim 16, wherein sepiolite, palygorskite or kaolinite is used as the clay mineral having the layer ribbon structure. Use.

  In the method for producing a chemical heat storage material composite according to claim 17, since sepiolite, palygorskite (attapulgite) or kaolinite having a layered ribbon structure is used as at least part of the clay mineral, the fiber and plasticity thereof are used. The powder chemical heat storage material can be well organized and structured.

  The method for producing a chemical heat storage material composite according to the invention described in claim 18 uses bentonite as the clay mineral in the method for producing a chemical heat storage material composite according to claim 15.

  In the method for producing a chemical heat storage material composite according to claim 18, since bentonite which is a clay mineral having a strong adhesive force is used, the chemical heat storage material in powder form can be well organized and structured by this adhesive force. it can.

  The method for producing a chemical heat storage material composite according to the invention described in claim 19 is the chemical heat storage material composite production method according to any one of claims 15 to 18, wherein the chemical heat storage material is used in the kneading step. The clay mineral having a fiber shape smaller than the particle diameter of the material is used.

  In the manufacturing method of the chemical heat storage material composite according to claim 19, since the clay mineral forms a fiber having a fine fiber diameter, a small amount of the clay mineral is kneaded in the kneading step, whereby the structure of the powder chemical heat storage material And can be structured. Thereby, it becomes possible to obtain a chemical heat storage material composite having a large occupation amount of the chemical heat storage material per mass and per volume.

  The method for producing a chemical heat storage material composite according to claim 20 is the chemical heat storage material composite production method according to any one of claims 15 to 19, wherein the chemical heat storage material is a dehydration reaction. In this kneading step, the hydrated chemical heat storage material is kneaded with the clay mineral.

  In the method for producing a chemical heat storage material composite according to claim 20, since the hydrated chemical heat storage material is kneaded with the clay mineral in the kneading step, the water is a concern when a dehydrated chemical heat storage material is used. There is no reaction. For this reason, water can be used as a binder during kneading in the kneading step.

  The method for producing a chemical heat storage material composite according to claim 21 is the method for producing a chemical heat storage material composite according to any one of claims 15 to 20, wherein the chemical heat storage material is a dehydration reaction. A hydration reaction type chemical heat storage material that is oxidized along with hydration reaction is used, and in the kneading step, the chemical heat storage material in a hydroxide state is kneaded with the clay mineral. .

  In the method for producing a chemical heat storage material composite according to claim 21, water that is a concern when a dehydrated chemical heat storage material is used to knead a chemical heat storage material in a hydroxide state with clay mineral in the kneading step. Reaction with does not occur. For this reason, water can be used as a binder during kneading in the kneading step.

  The method for producing a chemical heat storage material composite according to the invention described in claim 22 is the method for producing a chemical heat storage material composite according to claim 21, wherein the hydration reaction type chemical heat storage material is an inorganic compound.

  In the method for producing a chemical heat storage material composite according to claim 22, since an inorganic compound is used as the chemical heat storage material, the manufactured chemical heat storage material composite has material stability against heat storage and heat release reaction (hydration, dehydration). high. For this reason, a stable heat storage effect can be obtained over a long period of time.

  The method for producing a chemical heat storage material composite according to the invention described in claim 23 is the method for producing a chemical heat storage material composite according to claim 22, wherein the inorganic compound is an alkaline earth metal compound.

  In the method for producing a chemical heat storage material composite according to claim 23, since an alkaline earth metal compound (hydroxide) is used, it is easy to ensure safety during production. In addition, it is easy to ensure safety including when using the product (chemical heat storage material composite) and recycling. Further, in the configuration using sepiolite as the clay mineral, the alkalinity of the hydroxide helps vitrification by reaction with the clay mineral (especially described above), which contributes to improving the strength of the porous structure.

  The method for producing a chemical heat storage material composite according to the invention described in claim 24 is the chemical heat storage material composite production method according to any one of claims 21 to 23, wherein the hydration is performed in the firing step. The kneaded product is fired at a temperature at which the system chemical heat storage material is dehydrated.

  In the method for producing a chemical heat storage material composite according to claim 24, since the hydrated chemical heat storage material is dehydrated during firing in the firing step, the specific surface area of the chemical heat storage material can be easily adjusted.

  The method for manufacturing a chemical heat storage material composite according to the invention described in claim 25 is the chemical heat storage material composite manufacturing method according to claim 24, wherein, in the firing step, fine cracks are formed in the chemical heat storage material. Bake at temperature.

  26. In the method for producing a chemical heat storage material composite according to claim 25, as the clay mineral is structured together with the chemical heat storage material by the baking in the baking step (a sintered state is ensured), the dehydrated chemistry Fine cracks are formed in the heat storage material. Thereby, the specific surface area of the chemical heat storage material in the chemical heat storage material composite formed as a porous structure can be increased, which contributes to improvement of heat storage and heat dissipation reaction rate. In addition, it is preferable that the firing temperature of the clay mineral is close to the dehydration temperature of the hydration reaction type chemical heat storage material. As such a combination, for example, an alkaline earth metal compound (dehydration temperature of 400 ° C. to 450 ° C.) and sepiolite ( And a combination with a firing temperature of 350 ° C. or higher.

  The method for manufacturing a chemical heat storage material composite according to the invention described in claim 26 is the chemical heat storage material composite manufacturing method according to any one of claims 15 to 25, wherein the kneading step is pre-fired. The clay mineral containing the clay mineral is kneaded at a predetermined ratio with the powdered chemical heat storage material.

  In the method for producing a chemical heat storage material composite according to claim 26, since the clay mineral partially or wholly calcined in advance is kneaded with the chemical heat storage material in the kneading step, the size (for example, granular) In some cases, the particle diameter, in the case of a fiber, the wire diameter and length, etc.), and the clay mineral whose pore size is adjusted can be mixed and fired with a chemical heat storage material. Thereby, in the manufacturing method of the present chemical heat storage material composite, a clay mineral skeleton having a large porosity with reduced bulk density in the skeleton of the clay mineral that disperses and holds the chemical heat storage material can be formed. A chemical heat storage material composite with an improved packing density can be obtained.

  The method for producing a chemical heat storage material composite according to the invention described in claim 27 is the chemical heat storage material composite production method according to any one of claims 15 to 25, wherein the firing is performed before the kneading step. A premixing step of mixing the clay mineral and the unfired clay mineral is performed, and in the kneading step, the clay mineral mixed in the mixing step is kneaded to a powder chemical heat storage material at a predetermined ratio. .

  In the method for producing a chemical heat storage material composite according to claim 27, since the calcined clay mineral and the unfired clay mineral are mixed in the premixing step, the chemical heat storage material is controlled by controlling the blending ratio thereof. It is possible to adjust both the dimensions of the clay mineral to be mixed, the void size to an arbitrary size, the adjustment of the void size, and the retention strength of the chemical heat storage material by the skeleton structure of the clay mineral. For this reason, in the manufacturing method of the present chemical heat storage material composite, it is possible to form a clay mineral skeleton having a large porosity with reduced bulk density while ensuring strength as a structure, and the packing density of the chemical heat storage material It is possible to obtain a chemical heat storage material composite with improved resistance.

  As described above, the chemical heat storage material composite according to the present invention has an excellent effect that a gap is formed between the powdered chemical heat storage materials.

  A chemical heat storage material composite molded body 10 as a chemical heat storage material composite according to a first embodiment of the present invention and a manufacturing method thereof will be described with reference to FIGS.

  FIG. 1 shows a schematic cross-sectional view of a chemical heat storage material composite molded body 10. As shown in this figure, the chemical heat storage material composite molded body 10 is a structure in which a large number of powder chemical heat storage materials 12 are organized and structured. A pore 14 is formed. Therefore, the chemical heat storage material composite molded body 10 according to this embodiment is configured as a porous structure (porous body) and the powder chemical heat storage material 12 is exposed on the inner surfaces of the pores 14. It is grasped as a thing.

  In this chemical heat storage material composite formed body 10, sepiolite 16, which is a clay mineral, is interposed between a large number of powder chemical heat storage materials 12 so as to be entangled with a large number of powder chemical heat storage materials 12. In other words, the chemical heat storage material composite molded body 10 is grasped as a structure in which a large number of powder chemical heat storage materials 12 are dispersed and held in the skeleton of the sepiolite 16 that is porous. Thereby, in the chemical heat storage material composite molded body 10, the structure as a porous structure in which pores 14 are formed between a large number of powder chemical heat storage materials 12 is held (reinforced) by the sepiolite 16. ing.

In this embodiment, the powder chemical heat storage material 12 is calcium hydroxide (Ca (OH) ₂ ), stores heat (endothermic) with dehydration, and accompanies hydration (restoration to calcium hydroxide). Heat dissipation (heat generation). That is, many powder chemical heat storage materials 12 are set as the structure which can reversibly repeat heat storage and heat dissipation by reaction shown below.

Ca (OH) ₂ Ｃａ CaO + H ₂ O
When the heat storage amount and the heat generation amount Q are shown together in this equation,
Ca (OH) ₂ + Q → CaO + H ₂ O
CaO + H ₂ O → Ca (OH) ₂ + Q
It becomes.

Sepiolite 16 is grasped as a clay mineral having a layered ribbon structure, more specifically, one of clay minerals in which a plurality of single chains resembling pyroxene are combined to form a tetrahedral ribbon. Sepiolite 16 is a 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, for example, and is itself porous and has a specific surface area. Made of large fibers. In this embodiment, variants of those represented by the above chemical formula are also included in the sepiolite 16.

  Hereinafter, the chemical heat storage material composite molded body 10 will be described together with its manufacturing method.

  FIG. 2 schematically shows a method for manufacturing the chemical heat storage material composite molded body 10. In producing the chemical heat storage material composite formed body 10, first, as shown in FIG. 2A, a powder chemical heat storage material 12 and a sepiolite 16 as raw materials are prepared.

  As the powder chemical heat storage material 12, for example, a material having an average particle diameter D = 10 μm (laser diffraction measurement method, by SALD-2000A manufactured by Shimadzu Corporation) is used, and sepiolite 16 is used when suspended in water. A fiber having a fiber diameter smaller than the average particle diameter D of the powder chemical heat storage material 12 is used. Specifically, it is desirable to use the sepiolite 16 having a wire diameter (fiber diameter) of 1 μm or less and a length (fiber length) of 200 μm or less. In this embodiment, Turkish sepiolite having a wire diameter of about 0.01 μm and a length of about several tens of μm is used. Instead of Turkish sepiolite, for example, Spanish sepiolite having a wire diameter of approximately 0.1 μm and a length of approximately 100 μm can be used. Moreover, in this embodiment, the mixing ratio of the sepiolite 16 with respect to the powder chemical heat storage material 12 is about 5-10 mass%, for example.

  Next, the process proceeds to the mixing step. In the mixing step, as shown in FIG. 2B, the powder chemical heat storage material 12 and sepiolite 16 in a dry powder state are respectively mixed in the mixing container 18 and uniformly mixed. Next, the process proceeds to the kneading step. In the kneading step, as shown in FIG. 2 (C), the mixture of the powder chemical heat storage material 12 and sepiolite 16 is put into a kneading machine 19, and kneading (kneading) thickening while gradually adding water as a binder. Make it. Thereby, the kneaded material M of the powder chemical heat storage material 12 and the sepiolite 16 is produced | generated. This kneaded material M shows a clay state as a whole. In this embodiment, an organic binder (for example, CMC (carboxyl methylcellulose)) is mixed and kneaded as a lubricant and a binder. This organic binder disappears in a baking step at 400 ° C. or higher, which will be described later, and does not remain in the molded product. This organic binder exhibits a glue function and is effective in improving accuracy and density at the time of forming a structure.

  Next, the process proceeds to the molding step shown in FIG. In the molding step, the kneaded product M of the powder chemical heat storage material 12 and sepiolite 16 thickened in the kneading step as described above is transferred to the extrusion die 20 and extrusion molded. Thereby, the kneaded material M is formed in a predetermined shape corresponding to the shape of the extrusion die 20. In the example of FIG. 2D, it is formed as a pellet P having a size of several mm. The pellet P can be formed into, for example, a substantially cylindrical shape with a diameter of about 3 mm and a length of about 3 to 5 mm, a prismatic shape with an equivalent size, or the like. Moreover, you may make it form the pellet P by cut | disconnecting the said kneaded material M extruded from the extrusion type | mold 20 as needed.

  Next, as shown in FIG. 2E, the process proceeds to the firing step. In the firing step, the pellet P is placed in the firing furnace 22, and the pellet P is fired at a predetermined temperature for a predetermined time. Thereby, the chemical heat storage material composite molded body 10 having the predetermined shape described above is formed. That is, the production of the chemical heat storage material composite formed body 10 is completed. The firing temperature in this firing step is in the range of 350 ° C to 500 ° C.

  Since this firing temperature is equal to or higher than the dehydration temperature of the powder chemical heat storage material 12, that is, calcium hydroxide (the dehydration temperature varies depending on the atmospheric water vapor pressure, approximately 400 ° C. to 450 ° C.), Immediately after production, the chemical heat storage material composite molded body 10 is formed in the state of calcium oxide. That is, the chemical heat storage material composite molded body 10 is in a heat storage state in which heat can be radiated by supplying moisture (water vapor) at the time of manufacture.

  Moreover, the firing temperature in the range of 400 ° C. to 500 ° C. in the firing step is a temperature at which microcracks are formed in the powder chemical heat storage material 12, and thereby, a large number of the chemical heat storage material composite molded body 10 is formed. The powder chemical heat storage material 12 has microcracks as shown in FIG. Thereby, the specific surface area of the powder chemical heat storage material 12 is increased by passing through a baking process.

  The chemical heat storage material composite formed body 10 manufactured as described above may be directly applied to a heat storage system as a chemical heat storage material composite formed body, and as a raw material (intermediate body) for manufacturing a larger heat storage material. It may be used, and may be formed in the molding process into a shape corresponding to the application to be applied. When forming as a raw material (intermediate) for producing a large heat storage material, the firing temperature is set to be lower than the dehydration temperature of calcium hydroxide (for example, 350 ° C. or less), and the calcium hydroxide is dehydrated during secondary molding. It is desirable to bake at a temperature higher than the temperature.

  Here, in the method for producing the chemical heat storage material composite molded body 10, the sepiolite 16 having a large porous surface area and a specific surface area is kneaded into the powder chemical heat storage material 12 at a predetermined ratio in the kneading step. A thickening effect is exhibited by stirring the sepiolite 16 together with the powder chemical heat storage material 12 and water by modification (thixotropic). Thereby, the pellet P based on the powder chemical heat storage material 12 can be molded with higher accuracy and higher density.

  Then, organization of the powder chemical heat storage material 12 using the fiber of the sepiolite 16 (porous after crystallization) and structuring of the many powder chemical heat storage materials 12 using the plasticity of the sepiolite 16 are achieved. That is, by mixing the sepiolite 16 with the powder chemical heat storage material 12 at a predetermined ratio, pores 14 for releasing or introducing water vapor accompanying heat storage and heat dissipation are formed between the many powder chemical heat storage materials 12. On the other hand, it was realized that a large number of powder chemical heat storage materials 12 were made into the chemical heat storage material composite formed body 10 as one structure and maintained as the chemical heat storage material composite formed body 10.

  Moreover, since the chemical heat storage material composite molded body 10 manufactured as described above is organized and structured such that a large number of powder chemical heat storage materials 12 are formed with pores 14 therebetween. Further, the hydration of the powder chemical heat storage material 12 and the volume expansion and contraction accompanying the dehydration reaction are prevented or significantly suppressed from interfering with the other powder chemical heat storage material 12. For this reason, pulverization resulting from the volume expansion and contraction of the powder chemical heat storage material 12 is prevented. In other words, the release and introduction of water vapor into the powder chemical heat storage material 12 is not delayed, and the reaction of heat storage and heat dissipation. Deterioration is prevented or markedly suppressed.

  Furthermore, in the chemical heat storage material composite molded body 10, surplus water vapor is adsorbed to the sepiolite 16 (micropores) by the adsorptivity of the sepiolite 16 having a large specific surface area and being porous. Thereby, for example, when the heat storage system to which the chemical heat storage material composite molded body 10 is applied is in a low temperature state (when the powder chemical heat storage material 12 is calcium oxide), the powder chemical heat storage material 12 Is absorbed or liquefied in the chemical heat storage material composite molded body 10 and prevented from being sintered by deliquescence.

  Here, in the method for producing the chemical heat storage material composite formed body 10, sepiolite 16 having a fiber shape with a fiber diameter finer than the average particle diameter D of the powder chemical heat storage material 12 in a state suspended in water is used. Therefore, it is possible to obtain the chemical heat storage material composite molded body 10 in which the porous structure in which the pores 14 are formed between the powder chemical heat storage material 12 with a small amount of sepiolite 16 is reinforced. Therefore, the chemical heat storage material composite molded body 10 can increase the amount of the powder chemical heat storage material 12 occupying per unit mass and unit volume. That is, the chemical heat storage material composite molded body 10 having a large heat storage capacity can be obtained. Moreover, in the chemical heat storage material composite molded body 10, since the powder chemical heat storage material 12 itself forms the main structure of the chemical heat storage material composite molded body 10, the heat transfer path is simple, the heat storage efficiency, and the heat stored. Use efficiency is high.

  Furthermore, since the chemical heat storage material composite molded body 10 uses calcium hydroxide, which is an inorganic compound, as the powder chemical heat storage material 12, the material stability against heat storage and heat dissipation reactions (hydration and dehydration) is high. In particular, since calcium hydroxide is highly reversible with respect to magnesium hydroxide and the like (having almost 100% hydration and dehydration rate), a stable heat storage effect can be obtained over a long period of time. Further, since calcium hydroxide has low sensitivity to impurities with respect to magnesium hydroxide and the like, this point also contributes to long-term stable operation. In particular, since calcium hydroxide, which is an alkaline earth metal compound, is used as the powder chemical heat storage material 12, in other words, by using a material with a small environmental load, the chemical heat storage material composite molded body 10 can be manufactured. It is easy to ensure safety including use and recycling.

  Furthermore, in the manufacturing method of the chemical heat storage material composite molded body 10, since powder of calcium hydroxide that is a hydroxide is used, the powder chemical heat storage material 12 and sepiolite 16 are kneaded and thickened in the kneading step. Water can be used as a binder for the purpose. Thereby, the chemical heat storage material composite molded body 10 can be obtained by a simple and inexpensive method. For example, when calcium oxide is used as a starting material, water (a liquid containing water) cannot be used as a binder because the calcium oxide reacts with water. For example, when obtaining the powder chemical heat storage material 12 (calcium hydroxide) using calcium carbonate as a starting material, high-temperature firing at about 950 ° C. to 1000 ° C. is required in the decarbonation step.

  On the other hand, in the manufacturing method of the chemical heat storage material composite molded body 10, since calcium hydroxide is used as a starting material as described above, a thickening effect can be obtained by kneading with sepiolite 16 using water as a binder. Will improve. In addition, since the firing temperature can be lowered, the degree of freedom of materials used and processes (including materials for manufacturing equipment) is increased. Furthermore, in the chemical heat storage material composite molded article 10, since alkaline calcium hydroxide is kneaded into sepiolite, sepiolite reacts slightly with alkali and changes to glassy. For this reason, the strength of the chemical heat storage material composite formed body 10 which is a sintered structure formed by sintering the kneaded material M of the vitrified sepiolite 16 and the powder chemical heat storage material 12 is improved.

  On the other hand, in the manufacturing method of the chemical heat storage material composite molded body 10, since 400 ° C. to 500 ° C. is adopted as the firing temperature, while structuring (immobilizing) the powder chemical heat storage material 12 and sepiolite 16, The dehydration reaction of the powder chemical heat storage material 12 can proceed. And since the micro crack is formed in the powder chemical heat storage material 12 by the calcination temperature of 400 degreeC-500 degreeC, in the manufacturing method of the chemical heat storage material composite molded object 10, the organization of the powder chemical heat storage material 12, It is possible to simultaneously achieve structuring and increase in specific surface area.

  In addition, as a baking temperature which produces the micro crack in the powder chemical thermal storage material 12 used as calcium oxide, about 450 degreeC is the most preferable. When the firing temperature is 400 ° C. or less, the generation of microcracks is small, and when the firing temperature is 500 ° C. or more, the probability of cracking of the powder chemical heat storage material 12 increases and the specific surface area of the powder chemical heat storage material 12 decreases due to sintering. It has been confirmed. Although this temperature range is slightly lower than that of calcium oxide, for example, magnesium oxide (dehydrated magnesium hydroxide) can also be used as a firing temperature for generating microcracks. In addition, although the dehydration temperature of magnesium hydroxide changes with atmospheric water vapor pressures, it is a little lower than the dehydration temperature of calcium hydroxide (about 350 to 400 degreeC).

  Next, the chemical heat storage material composite molded body 30 and the manufacturing method thereof according to the second embodiment of the present invention will be described with reference to FIG.

  FIG. 3 schematically shows a part of the method for manufacturing the chemical heat storage material composite molded body 30 which is mainly different from the method for manufacturing the chemical heat storage material composite molded body 10. As shown in this figure, when manufacturing the chemical heat storage material composite molded body 30, first, as shown in FIG. 3A, a part of the sepiolite 16 is fired in the firing furnace 22 in the preliminary firing step. . In this embodiment, approximately 50% of the sepiolite 16 mixed with the powder chemical heat storage material 12 is fired in the preliminary firing step. The fired sepiolite 16A fired in this way has a lower density and a higher porosity than the unfired sepiolite 16B. The fired sepiolite 16A has a larger wire diameter and a shorter length than the unfired sepiolite 16B.

  Next, the process proceeds to a preliminary mixing step. In the preliminary mixing step, as shown in FIG. 3B, the pre-fired sepiolite 16A preliminarily fired in the pre-baking step and the unfired sepiolite 16B are mixed (illustration of the pre-mixing step itself is omitted). By mixing the fired sepiolite 16A and the unfired sepiolite 16B, the average wire diameter, average length, average porosity (average void size), and the like of the sepiolite 16 are adjusted.

  Next, the process proceeds to the mixing step. In the mixing step, as shown in FIG. 3 (C), the powder chemical heat storage material 12 in a dry powder state, a premix of sepiolite 16 and unfired sepiolite 16B) are placed in a mixing vessel 18 and mixed uniformly. . Thereafter, the chemical heat storage material composite formed body 30 is manufactured through the kneading step, the forming step, and the firing step (all refer to FIG. 2) as in the manufacturing process of the chemical heat storage material composite formed body 10.

  The chemical heat storage material composite molded body 30 manufactured as described above may be directly applied to a heat storage system as a chemical heat storage material composite molded body, and as a raw material (intermediate) for manufacturing a larger heat storage material. It may be used, and may be formed in the molding process into a shape corresponding to the application to be applied. When forming as a raw material (intermediate) for producing a large heat storage material, the firing temperature is set to be lower than the dehydration temperature of calcium hydroxide (for example, 350 ° C. or less), and the calcium hydroxide is dehydrated during secondary molding. It is desirable to bake at a temperature higher than the temperature.

  Here, the chemical heat storage material composite molded body 30 manufactured as described above is configured in the same manner as the chemical heat storage material composite molded body 10 in terms of composition. Further, the basic structure of the chemical heat storage material composite molded body 30 is the same as the structure of the chemical heat storage material composite molded body 10 (see FIG. 1).

  Therefore, the chemical heat storage material composite molded body 30 according to the second embodiment and the manufacturing method thereof basically have the same effects as the chemical heat storage material composite molded body 10 according to the first embodiment and the manufacturing method thereof. Can be obtained.

  Moreover, in the manufacturing method of the chemical heat storage material composite molded body 30, since the burned sepiolite 16A and the unburned sepiolite 16B are mixed in the pre-mixing step, the sepiolite 16 of the same production area is used to average the sepiolite 16 Dimensions and porosity can be adjusted. For this reason, in the chemical heat storage material composite formed body 30 having a structure in which a large number of powder chemical heat storage materials 12 are dispersed and held in the porous skeleton of sepiolite 16, the skeleton of the sepiolite 16 has a large porosity. A configuration with a low density can be obtained. That is, in the chemical heat storage material composite molded body 30, both the structuring of the chemical heat storage material composite molded body 30 and the securing of the water vapor movement path are achieved. More specifically, in the chemical heat storage material composite molded body 30, the specific surface area of the skeleton structure formed by the sepiolite 16 is increased to secure a movement path of water vapor, and the chemistry of the powder structure is achieved by the skeleton structure formed by the sepiolite 16. The heat storage material 12 can be dispersedly held.

  And compared with the chemical heat storage material composite molded body 10, the chemical heat storage material composite molded body 30 according to this embodiment secures a movement path with low resistance to water vapor due to the porous structure of the sepiolite 16, and has a powder chemistry. The dispersion retention strength of the powder chemical heat storage material 12 is ensured by the structure of the packing density of the heat storage material 12 and the skeleton structure of the sepiolite 16. By improving the packing density of the powder chemical heat storage material 12 and securing the water vapor movement path (avoidance of water vapor movement regulation), the chemical heat storage material composite molded body 30 is improved in heat storage density (heat storage capacity per volume). . For example, the chemical heat storage material composite molded body 10 includes approximately 10% by mass of sepiolite 16, whereas the chemical heat storage material composite molded body 30 includes 7 to 8% by mass of sepiolite 16. The chemical heat storage material composite molded body 10 has the same strength and the reaction rate of the powder chemical heat storage material 12.

  As described above, in the chemical heat storage material composite molded body 30 and the manufacturing method thereof according to the second embodiment, at least a part of the sepiolite 16 is baked before mixing with the powder chemical heat storage material 12, thereby generating powder. The dimension and porosity of the sepiolite 16 mixed with the body chemical heat storage material 12 can be controlled, and the heat storage density can be improved. In addition, the blending ratio of the fired sepiolite 16A and the unfired sepiolite 16B can be arbitrarily set, and the fired sepiolite 16A may be 100%.

In the second embodiment, a small amount of calcium hydroxide (Ca (OH) ₂ ), that is, the powder chemical heat storage material 12 may be mixed when the sepiolite 16 is pre-fired. In this configuration and method, the self-structuring of sepiolite 16 can be promoted by utilizing the solubility of sepiolite 16 in alkali. For this reason, in the chemical heat storage material composite molded body 30 of this configuration and the manufacturing method thereof, the size and porosity of the sepiolite 16 mixed with the powder chemical heat storage material 12 can be controlled more easily (good). it can.

  In each of the above-described embodiments, an example is shown in which sepiolite is used as a clay mineral having a layer ribbon structure as the clay mineral. However, the present invention is not limited to this, and for example, a clay mineral having a layer ribbon structure is used. A certain palygorskite (attapulgite) or kaolinite (a wire diameter of 5 μm or less, or 1 μm or less) may be used, or a bentonite that does not belong to a clay mineral having a layered ribbon structure may be used. Note that when bentonite is supplemented, bentonite is a clay mineral that has a stronger adhesive strength than a clay mineral having a layered ribbon structure, and can obtain a strong porous structure, for example, bonding to a metal wall. Contributes to improving strength. The chemical heat storage material composite molded body 10 using bentonite also forms a porous structure in which pores 14 are formed between a large number of powder chemical heat storage materials 12. On the other hand, clay minerals having a layered ribbon structure have the advantage of less sintering (densification) compared to bentonite. In particular, sepiolite is sintered at a temperature close to the dehydration temperature (the temperature at which microcracks are generated) of the powder chemical heat storage material 12 as described above, and the specific surface area is less reduced by sintering at that temperature (due to microcracks). The increase in specific surface area is advantageous). What is necessary is just to determine the clay mineral used for manufacture of the chemical heat storage material composite molded object 10 according to a use etc. in consideration of these merit. Moreover, also in the structure using clay minerals other than sepiolite 16, as in the second embodiment, an arbitrary blending ratio of the fired one and the unfired one (including one of which is 100%) is included. The clay mineral mixed in step) can be mixed with the powder chemical heat storage material 12.

  Further, in each of the above-described embodiments, an example is shown in which Turkish or Spanish sepiolite is used for molding the chemical heat storage material composite molded body 10, but the present invention is not limited to this, and for example, Chinese sepiolite. It is also possible to use. However, the sepiolite used for molding the chemical heat storage material composite molded body 10 is most preferably from Turkey, secondly from Spain, and then from China. This is because Turkish sepiolite has few impurities, is fine (the wire diameter is thin, and the length is short), is easy to form a shell structure by kneading and baking with the powder chemical heat storage material 12, and is advantageous in terms of dispersibility. In addition, it is preferable that the amount of impurities is small because the shell structure is easily made brittle and causes firing to be hindered.

Moreover, in each above-mentioned embodiment, although the example using the calcium hydroxide (Ca (OH) ₂ ) which is a hydration type chemical heat storage material was shown as the powder chemical heat storage material 12, this invention is limited to this. For example, magnesium hydroxide (Mg (OH) ₂ ), which is an inorganic compound of an alkaline earth metal, may be used as the powder chemical heat storage material 12. Similarly, Ba (OH) ₂ and Ba (OH) ₂ .H ₂ O, which are inorganic compounds of alkaline earth metals, may be used as the powder chemical heat storage material 12 and are inorganic compounds other than alkaline earth metals. LiOH.H ₂ O, Al ₂ O ₃ .3H ₂ O, or the like may be used as the powder chemical heat storage material 12. Furthermore, instead of the hydrated powder chemical heat storage material 12 that generates and stores heat by hydration and dehydration reactions, a powder chemical heat storage material 12 using other reactions may be used.

  Furthermore, in each of the above-described embodiments, an example in which the chemical heat storage material composite formed body 10 is formed in the pellet P has been shown, but the present invention is not limited to this, and for example, in various shapes such as a thin plate shape and an elongated shape. It goes without saying that it can be formed.

It is sectional drawing which shows typically the internal structure of the chemical heat storage material composite molded object which concerns on the 1st Embodiment of this invention. It is a figure which shows typically the manufacturing method of the chemical heat storage material composite molded object which concerns on the 1st Embodiment of this invention, Comprising: (A) is a figure which shows a raw material, (B) is the mixed state of each raw material and a binder. (C) is a figure which shows a kneading | mixing process, (D) is a figure which shows a shaping | molding process, (E) is a figure which shows a baking process. It is a figure which shows typically a part of manufacturing method of the chemical heat storage material composite molded object which concerns on the 2nd Embodiment of this invention, Comprising: (A) is a figure which shows a pre-baking process, (B) is preliminary mixing The figure which shows a state, (C) is a figure which shows a mixing process.

Explanation of symbols

10 Chemical heat storage material composite molded body (chemical heat storage material composite)
12 Powder chemical heat storage material (chemical heat storage material)
14 pores 16 sepiolite (clay mineral)
30 Chemical heat storage material composite molded body (chemical heat storage material composite)
M Kneaded product

Claims (27)

  A chemical heat storage material composite made by firing a powder chemical heat storage material mixed with a clay mineral at a predetermined ratio.   A chemical heat storage material composite comprising a powder chemical heat storage material and a clay mineral, wherein the chemical heat storage material is exposed on the inner surfaces of the pores.   The chemical heat storage material composite according to claim 1 or 2, wherein a clay mineral having a layer ribbon structure is used as the clay mineral.   The chemical heat storage material composite according to claim 3, wherein sepiolite, palygorskite, or kaolinite is used as the clay mineral having the layer ribbon structure.   The chemical heat storage material composite according to claim 1 or 2, wherein bentonite is used as the clay mineral.   The chemical heat storage material composite according to any one of claims 1 to 5, wherein the clay mineral has a fiber shape smaller than a particle diameter of the chemical heat storage material.   The chemical heat storage material composite according to any one of claims 1 to 6, wherein at least a part of the clay mineral is a clay mineral fired before mixing with the chemical heat storage material.   The chemical heat storage material composite according to claim 7, wherein the clay mineral includes a clay mineral fired before mixing with the chemical heat storage material and an unfired clay mineral upon mixing with the chemical heat storage material.   The chemical heat storage material composite according to any one of claims 1 to 8, wherein the chemical heat storage material has fine cracks.   The chemical heat storage material composite according to any one of claims 1 to 9, wherein the chemical heat storage material is a hydration reaction type chemical heat storage material that absorbs heat with a dehydration reaction and dissipates heat with a hydration reaction. body.   The chemical heat storage material according to any one of claims 1 to 10, wherein a hydration reaction type chemical heat storage material that is oxidized with a dehydration reaction and hydroxylated with a hydration reaction is used as the chemical heat storage material. Material composite.   The chemical heat storage material composite according to claim 11, wherein the hydration reaction type chemical heat storage material is an inorganic compound.   The chemical heat storage material composite according to claim 12, wherein the inorganic compound is an alkaline earth metal compound.   The powder hydration reaction type chemical heat storage material and the sepiolite as the clay mineral mixed into a predetermined shape and fired at a temperature of 350 ° C to 500 ° C. 14. The chemical heat storage material composite according to any one of items 13. A kneading step of kneading the clay mineral in a predetermined ratio to the powder chemical heat storage material;
A molding step of molding the kneaded product of the chemical heat storage material and the clay mineral kneaded in the kneading step into a predetermined shape;
A firing step of firing the kneaded product of the chemical heat storage material and the clay mineral molded in the molding step;
A method for producing a chemical heat storage material composite comprising:   The method for producing a chemical heat storage material composite according to claim 15, wherein a clay mineral having a layer ribbon structure is used as the clay mineral.   The method for producing a chemical heat storage material composite according to claim 16, wherein sepiolite, palygorskite, or kaolinite is used as the clay mineral having the layer ribbon structure.   The method for producing a chemical heat storage material composite according to claim 15, wherein bentonite is used as the clay mineral.   The method for producing a chemical heat storage material composite according to any one of claims 15 to 18, wherein in the kneading step, the clay mineral having a fiber shape smaller than a particle diameter of the chemical heat storage material is used. As the chemical heat storage material, a hydration reaction type chemical heat storage material that absorbs heat with a dehydration reaction and dissipates heat with a hydration reaction is used,
The method for producing a chemical heat storage material composite according to any one of claims 15 to 19, wherein in the kneading step, the chemical heat storage material in a hydrated state is kneaded with the clay mineral. As the chemical heat storage material, a hydration reaction type chemical heat storage material that is oxidized with a dehydration reaction and hydroxylated with a hydration reaction is used,
21. The method for producing a chemical heat storage material composite according to any one of claims 15 to 20, wherein, in the kneading step, the chemical heat storage material in a hydroxide state is kneaded with the clay mineral.   The method for producing a chemical heat storage material composite according to claim 21, wherein the hydration reaction type chemical heat storage material is an inorganic compound.   The method for producing a chemical heat storage material composite according to claim 22, wherein the inorganic compound is an alkaline earth metal compound.   The method for producing a chemical heat storage material composite according to any one of claims 21 to 23, wherein, in the baking step, the kneaded product is fired at a temperature at which the hydrated chemical heat storage material is dehydrated.   25. The method for producing a chemical heat storage material composite according to claim 24, wherein the chemical heat storage material is fired at a temperature at which fine cracks are formed in the chemical heat storage material.   26. The chemical heat storage material composite according to any one of claims 15 to 25, wherein in the kneading step, the clay mineral containing a pre-fired clay mineral is kneaded with a powder chemical heat storage material at a predetermined ratio. Manufacturing method. Prior to the kneading step, a premixing step of mixing the calcined clay mineral and the unfired clay mineral is performed,
The production of the chemical heat storage material composite according to any one of claims 15 to 25, wherein in the kneading step, the clay mineral mixed in the mixing step is kneaded with a powder chemical heat storage material at a predetermined ratio. Method.