JP2017186538A - Chemical heat storage granulated body and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a dehydration endothermal reaction at a low temperature range of 100 to 350°C and to provide a chemical heat storage granulated body with high strength.SOLUTION: There is provided a chemical heat storage granulated body constituted mainly by at least one kind of compound selected from oxide of magnesium, hydroxide of magnesium, composite oxide of magnesium or composite oxide of magnesium, at least one kind of compound selected a lithium compound, a potassium compound and a sodium compound and a carbon compound, and exhibiting excellent durability to a dehydration endothermal reaction at a low temperature range of 100 to 350°C with Li, K and/or Na in a range of 0.1 to 50 mol% to Mg in the chemical heat storage granulated body and further at least one kind of element selected from Ni, Co, Cu and Al in a range of 1 to 40 mol% to the composite oxide of magnesium and the composite hydroxide when the carbon content in the chemical heat storage granulated body is 12 to 35 mass%.SELECTED DRAWING: None

Description

  TECHNICAL FIELD The present invention relates to a chemical heat storage granule that undergoes a dehydration endothermic reaction in a low temperature range of 100 to 350 ° C. and is excellent in repeated resistance.

  In recent years, the use of fossil fuels has been demanded by carbon dioxide emission regulations, and it is necessary to promote the use of exhaust heat in addition to energy saving in each process. As means for using exhaust heat, warm water storage at 100 ° C. or less using water is known. However, in hot water heat storage, (1) long-term heat storage is impossible due to heat dissipation loss, and (2) a large amount of water is required because the amount of sensible heat is small, making it difficult to make the heat storage equipment compact. (3) There is a problem that the output temperature is unsteady according to the usage amount and gradually drops. Therefore, it is necessary to develop a more efficient heat storage technology in order to promote consumer use of such waste heat.

  A chemical heat storage method is an example of a highly efficient heat storage technology. Since the chemical heat storage method involves chemical changes such as adsorption and hydration of substances, the amount of heat stored per unit mass is higher than the heat storage method using latent heat or sensible heat of the material itself (water, molten salt, etc.). As the chemical heat storage method, a water vapor adsorption / desorption method by adsorption / desorption of water vapor in the atmosphere, ammonia absorption to a metal salt (ammine complex formation reaction), a reaction by adsorption / desorption of an organic substance such as alcohol, and the like have been proposed. The water vapor adsorption / desorption method is most advantageous in view of environmental load and simplicity of the apparatus. Magnesium oxide is known as a chemical heat storage material used in the water vapor adsorption / desorption method.

  Magnesium oxide does not function as a practical heat storage material in a low temperature range of 100 to 300 ° C. This is because magnesium hydroxide does not cause an effective dehydration reaction in the low temperature range. In order to solve these problems, a chemical heat storage material that can store heat at about 100 to 300 ° C. by combining Mg and at least one metal component selected from the group consisting of Ni, Co, Cu, and Al is proposed. (Patent Document 1). In addition, a chemical heat storage material that has a high heat storage amount per unit mass or unit volume and can store heat at about 100 to 350 ° C. by adding a hygroscopic metal salt made of lithium chloride to magnesium hydroxide has been proposed. (Patent Document 2). Furthermore, in the chemical heat storage material by calcium hydroxide, by forming a skeletal structure such as sepiolite, aggregation of the chemical heat storage material layer during the dehydration reaction can be suppressed, and when the hydration reaction is transferred after the dehydration reaction, It is disclosed that a hydration reaction can be allowed to proceed and that the reversibility of the dehydration reaction and the hydration reaction is maintained (Patent Document 3).

JP 2007-309561 A JP 2009-186119 A JP 2009-256517 A

  However, in the techniques described in Patent Documents 1 and 2, when used as a chemical heat storage material in the form of powder, it is agglomerated after pulverization due to repetition of hydration reaction and dehydration reaction during operation, and the reaction area There is a problem that the reactivity as the heat storage system is reduced due to the decrease in the temperature. Further, the chemical heat storage material described in Patent Document 3 suppresses aggregation of the chemical heat storage material layer during the dehydration reaction by forming a skeleton structure such as sepiolite, but the strength of the skeleton structure is weak, Aggregation suppression of the chemical heat storage material layer was not sufficient.

  Therefore, an object of the present invention is to provide a chemical heat storage body that causes a dehydration endothermic reaction in a low temperature range of 100 to 350 ° C. and is excellent in repeated resistance.

  In order to solve the above problems, the present inventor has made various studies, and as a result, at least selected from a magnesium oxide, a magnesium hydroxide, a magnesium composite oxide, and a magnesium composite hydroxide. A chemical heat storage granulation comprising, as a main component, at least one alkali metal compound selected from one kind of magnesium compound, lithium compound, potassium compound, and sodium compound, and a carbon compound, the chemical heat storage granulation A chemical heat storage granule characterized in that the carbon content in the body is 12 to 35% by mass, causes a dehydration endothermic reaction in a low temperature range of 100 to 350 ° C., has sufficient strength and is resistant to repetition. The present invention has been found to be excellent, and the present invention has been completed.

The present invention has excellent strength with excellent repeatability in the following aspects.
At least one compound selected from magnesium oxide, magnesium hydroxide, magnesium composite oxide, and magnesium composite hydroxide, at least one selected from lithium compounds, potassium compounds, and sodium compounds It is a chemical heat storage granule mainly composed of the above compound and a carbon compound, and the gist is that the carbon content in the chemical heat storage granulation is 12 to 35% by mass.

  The chemical heat storage granule of the present invention causes a dehydration endothermic reaction in a low temperature range of 100 to 350 ° C., and has sufficient strength and excellent repeat resistance. This is because the strength of the chemical heat storage granulation is higher than that of the prior art as a result of controlling to ˜35% by mass, which is apparent from the cycle test measurement result (pass rate). Therefore, even if the heat storage dehydration / hydration cycle is repeated, a chemical heat storage material is provided in which aggregation due to pulverization is suppressed and the heat storage performance does not deteriorate. In the present invention, the magnesium composite oxide and the magnesium composite hydroxide contain 100 to 40 mol% of at least one element selected from Ni, Co, Cu, and Al with respect to Mg. It has a dehydration endothermic reaction in a low temperature range of 350 ° C., has sufficient strength, and is excellent in repeated resistance. In addition, dehydration endothermic reaction is caused in a low temperature range of 100 to 350 ° C. in a wide range containing 0.1 to 50 mol% of Li, K, and / or Na with respect to Mg in the chemical heat storage granule, and It has sufficient strength and excellent repeatability.

[Chemical thermal storage granulation]
The chemical heat storage granule includes at least one compound selected from magnesium oxide, magnesium hydroxide, magnesium composite oxide, and magnesium composite hydroxide, a lithium compound, a potassium compound, and a sodium compound. At least one compound selected from the above, and a carbon compound as a main component, containing Li, K and / or Na with respect to Mg in the chemical heat storage granule, and chemical heat storage granulation The carbon content in the body is 12 to 35% by mass.

  Here, as the at least one compound selected from magnesium oxide, magnesium hydroxide, magnesium composite oxide, and magnesium composite hydroxide, magnesium oxide, magnesium hydroxide, or a mixture thereof, Alternatively, a magnesium composite oxide, a composite hydroxide, or a mixture thereof containing 1 to 40 mol% of at least one element selected from the group consisting of Ni, Co, Cu, and Al with respect to Mg can be given.

  As the lithium compound, potassium compound, and sodium compound, any compound may be used as long as it has hygroscopicity and adsorbs moisture in the atmosphere or generates a corresponding hydrate. The lithium compound, potassium compound, and sodium compound are preferably chlorides, hydroxides, oxides, bromides, nitrates, or sulfates that satisfy the above requirements and are easy to handle. The lithium compound is more preferably lithium halide or lithium hydroxide, and further preferably lithium chloride, lithium bromide, or lithium hydroxide. The potassium compound is more preferably potassium halide or potassium hydroxide, and further preferably potassium chloride, potassium bromide, or potassium hydroxide. The sodium compound is preferably sodium halide or sodium hydroxide, more preferably sodium chloride, sodium bromide, or sodium hydroxide. At least one compound selected from a magnesium oxide, a magnesium hydroxide, a magnesium composite oxide, and a magnesium composite hydroxide, and at least one selected from a lithium compound, a potassium compound, and a sodium compound By adding a seed compound, a dehydration endothermic temperature of less than 350 ° C. is exhibited, and the temperature varies depending on the addition ratio.

  The carbon compound is not particularly limited as long as it does not change in the hydration / dehydration temperature range, and calcined carbides and inorganic carbon compounds obtained by firing a polymer compound in an inert atmosphere can be used.

  If the carbon content in the chemical heat storage granule is 12 to 35% by mass, the chemical heat storage granule has a Li, K, and / or Na content of 0.1 with respect to Mg in the chemical heat storage granulation. Although a predetermined effect is exhibited in the range of 1 to 50 mol%, the content range of Li, K, and / or Na is preferably 2 to 45 mol%, and more preferably 3 to 30 mol%. When the content of Li, K and / or Na is less than 0.1 mol%, the effect of lowering the dehydration temperature is obtained even if the carbon content in the chemical heat storage granulation is 12 to 35 mass%. However, when it exceeds 50 mol%, the dehydration / hydration reaction of magnesium hydroxide itself is inhibited, the heat storage amount per unit mass or unit volume is reduced, and the heat storage performance is lowered. The range of the carbon content is preferably 13 to 33% by mass, and more preferably 14 to 30% by mass. When the carbon content is less than 12% by mass, a skeletal structure having sufficient strength cannot be obtained. When the carbon content exceeds 35% by mass, the heat storage amount per unit mass or unit volume decreases and the heat storage performance decreases. .

The chemical heat storage granulated material is obtained by processing a powder raw material composed of a single component or multiple components into a particle larger than the raw material using a binder containing a carbon component and then carbonizing in an inert atmosphere. The chemical heat storage granule of the present invention is obtained by using a polymer compound constituting a carbon compound as a binder, granulating, and then carbonizing. The chemical heat storage granule may have a pellet shape with a bulk density of about 0.2 to 1.0 g / cm ³ . In the chemical heat storage granule of the present invention, the strength of the heat storage material is improved, and even when the heat storage dehydration / hydration cycle is repeated, aggregation due to pulverization is suppressed and the heat storage performance does not deteriorate.

  The chemical heat storage granule can be produced by granulating a mixture containing a chemical heat storage material using a granulator and carbonizing the mixture. There is no limitation in the granulation method, It can carry out using dry granulation or wet granulation. When wet granulation is performed, the chemical heat storage granule can be obtained by drying after granulation, passing through a sieve, and then carbonizing. The chemical heat storage granule may have a particle size that can be used as a chemical heat storage material, and is preferably 1 to 20 mm. When the particle diameter is less than 1 mm, the steam introduction pipe or the like may be clogged in the chemical heat pump system. When the particle diameter exceeds 20 mm, large pores are required for passing water vapor, but in this case, the strength of the chemical heat storage granule is reduced and the chemical heat storage granule is easily broken.

  The carbon compound in the chemical heat storage granule preferably has a porous structure. The porous structure is a solid structure having a very large number of pores and functions as a flow path for passing water vapor. The porous body may have a porosity of about 10 to 80%, and the structure in which the pores are randomly dispersed in the chemical heat storage granule is preferable from the viewpoint of reaction efficiency.

  A chemical heat storage granule can be produced by carbonizing at 400 to 800 ° C. in an inert atmosphere, and forms a porous structure by carbonization. When the calcination temperature is less than 400 ° C., the polymer compound constituting the carbon compound is not carbonized, and when it exceeds 800 ° C., the activity of magnesium oxide is lowered and the hydration reactivity is lowered. The polymer compound constituting the carbon compound may be a polymer compound such as a resin that has a high residual carbon ratio and / or is likely to have a three-dimensional structure during carbonization. As the polymer compound constituting the carbon compound, thermosetting resins such as phenol resin, melamine resin, urea resin, epoxy resin, furan resin, polyamide resin, polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, acrylic resin, It is preferable to use a thermoplastic resin such as a vinyl chloride resin, a fluororesin, a polyacetal resin, a polycarbonate resin, and a polyurethane resin, or a mixture of one or two or more of cellulose, from phenol resin, melamine resin, and cellulose. More preferably, there is at least one polymer compound selected from the group consisting of:

  In order to make it easier to form a porous structure, a polymer compound that easily volatilizes at 400 to 800 ° C. in an inert atmosphere may be further added. As the polymer compound which is easily volatilized, potato starch, corn starch, sweet potato starch, tapioca starch, sago starch, rice starch, amaranth starch and the like are preferable.

Magnesium composite oxide containing at least one element selected from the group consisting of Ni, Co, Cu, and Al with respect to Mg, and at least one compound selected from composite hydroxides The chemical heat storage granule made of the above-mentioned material utilizes the following reversible reaction of the magnesium oxide / water chemical heat storage material described in Patent Documents 1 and 2.
MgO + H ₂ O⇔Mg (OH) ₂ ΔH = −81.2 kJ / mol

  Co and Ni have ΔH of 50 to 60 kJ / mol, which is lower than that of Mg, and Cu and Al also show the same value. The composite magnesium compound containing at least one element selected from the group consisting of Ni, Co, Cu, and Al exhibits a dehydration endothermic temperature of less than 350 ° C., and the temperature changes according to the composite composition ratio. As the element, Ni, Co, or Al is preferable, and Ni or Co is more preferable. As element content, 3-30 mol% is preferable and 10-25 mol% is more preferable. When the element content is less than 1 mol%, the effect of lowering the dehydration temperature cannot be obtained, and when it exceeds 40 mol%, the heat storage amount per unit mass or unit volume is lowered.

  The at least one element source selected from the group consisting of Ni, Co, Cu, and Al may be any material that can be mixed with water and easily handled, such as chloride, hydroxide, oxide, carbonic acid. Chloride, nitrate, and / or sulfate can be used, preferably chloride, nitrate, and / or sulfate, and more preferably chloride. When chloride is used, it has high solubility in water, is easy to handle, and can be easily dispersed uniformly.

  After removing the chemical heat storage granule having a small particle diameter from the chemical heat storage granule using a mesh-size sieve in which 80 to 99% by mass of the chemical heat storage granule remains, a nylon ball having a diameter of 15 mm Is used to remove the above-mentioned chemical heat storage granule having a small particle diameter after putting the chemical heat storage granule up to 250 mL in a 500 mL plastic container containing 5 and rotating at 148 rpm for 2 hours on a turntable. The amount that has passed through the sieve is preferably 40% by mass or less. When the passing amount exceeds 40% by mass, the strength of the chemical heat storage granule is insufficient, and when the heat storage dehydration / hydration cycle is repeated, the heat storage performance decreases due to aggregation due to pulverization.

(Method for producing chemical heat storage granulation)
The chemical heat storage granule manufacturing method is
(A): A step of preparing magnesium hydroxide or magnesium composite hydroxide containing 1 to 40 mol% of at least one element selected from the group consisting of Ni, Co, Cu, and Al with respect to Mg ;
(B): selected from 0.1 to 50 mol% lithium compound, potassium compound, and sodium compound with respect to magnesium hydroxide or magnesium composite hydroxide prepared in step (A) and Mg Mixing at least one compound and a polymer compound constituting 15 to 60 parts by weight of a carbon compound with respect to 100 parts by weight of magnesium hydroxide or magnesium composite hydroxide;
(C): a step of granulating the mixture containing magnesium hydroxide or magnesium composite hydroxide obtained in step (B);
(D): a step of classifying the granulated product containing magnesium hydroxide or magnesium composite hydroxide obtained in step (C); and (E): magnesium water prepared in step (D). Baking the mixture containing oxide or magnesium composite hydroxide in an inert atmosphere at 400 to 800 ° C. for 1 to 24 hours;
including.

The step of obtaining the magnesium hydroxide in the step (A)
A magnesium chloride aqueous solution having a concentration of 1 to 10 mol / L and a sodium hydroxide solution or calcium hydroxide dispersion of 1 to 18 mol / L are prepared, and the magnesium chloride aqueous solution and a sodium hydroxide solution having a reaction rate of 80 to 150% or A step of simultaneously adding and reacting a calcium hydroxide dispersion to obtain a magnesium hydroxide slurry, filtering, washing and drying the obtained magnesium hydroxide slurry to obtain a magnesium hydroxide;
Is preferably included.

Step (A) The step of obtaining a composite hydroxide of magnesium includes:
Magnesium chloride aqueous solution having a concentration of 1 to 10 mol / L, an aqueous solution containing at least one element selected from the group consisting of Ni, Co, Cu, and Al having a concentration of 0.1 to 10 mol / L, and 1 to 18 mol / L A sodium hydroxide solution or a calcium hydroxide dispersion is prepared, a magnesium chloride aqueous solution and a solution containing at least one element selected from the group consisting of Ni, Co, Cu, and Al are mixed, and the reaction rate is further increased. 80-150% sodium hydroxide solution or calcium hydroxide dispersion was added and reacted to obtain a composite magnesium hydroxide slurry, and the resulting composite magnesium hydroxide slurry was filtered, washed with water and dried to obtain magnesium. Obtaining a composite hydroxide of:
Is preferably included.

  The step (B) is selected from a magnesium hydroxide or a magnesium composite hydroxide prepared in the step (A) and 0.1 to 50 mol% of a lithium compound, a potassium compound, and a sodium compound with respect to Mg. And mixing at least one kind of compound and a polymer compound constituting 15 to 60 parts by weight of a carbon compound with respect to 100 parts by weight of magnesium hydroxide or magnesium composite hydroxide. A universal mixing stirrer, ribbon mixer, spartan luzer, etc. can be used.

  Step (C) is a step of granulating the mixture of magnesium hydroxide or magnesium composite hydroxide obtained in step (B). For granulation, wet extrusion granulator dome gran, A disk pelleter, a round machine, etc. can be used.

  In the present invention, Ni and Co are used as metal elements, and Li is used as an alkali metal, and the strength and repetitive resistance of the granule will be specifically described by examples. The hydroxide has sufficient strength in a wide range including 1 to 40 mol% of at least one element selected from Ni, Co, Cu, and Al with respect to Mg, and is excellent in repeated resistance. Moreover, it has sufficient intensity | strength in the wide range which contains Li, K, and / or Na 0.1-50 mol% with respect to Mg in the said chemical heat storage granulation body, and is excellent in repetition tolerance. Therefore, it is not limited to the following examples.

[Evaluation]
(1) Mass measurement method for Mg, Li, K, Na, Ni, Co, Cu, Al The measurement sample is added to 12N hydrochloric acid (reagent special grade) and perchloric acid (reagent special grade) and heated to completely dissolve. After that, the measurement was performed using an ICP emission spectroscopic analyzer (PS3520 VDD, manufactured by Hitachi High-Tech Science Co., Ltd.).

(2) Measuring method of carbon content In addition to Mg, Li, K, Na, Ni, Co, Cu, Al measured in (1), contents of Fe, Ba, Ti, Zn, P, Si, B And Li, K, and Na are calculated in terms of the compounds used, other elements are calculated in terms of oxides, and it is assumed that these chemical components and C are not present in the chemical heat storage granule. The carbon content (%) was calculated by subtracting these chemical component values from 100%.

(3) Durability evaluation method of chemical heat storage granulation After drying the chemical heat storage granulation at 120 ° C. for 12 hours, 200 g is weighed and 80 g on the sieve to remove the chemical heat storage granulation having a small particle diameter. A chemical heat storage granule having a small particle diameter was removed using a sieve in which ˜99% by mass remained. Thereafter, the measurement sample from which the chemical heat storage granule having a small particle diameter has been removed is put into a 500 mL plastic container up to 250 mL, and further, five nylon balls having a diameter of 15 mm are put into the container, and the pot mill rotary table is 148 rpm for 2 hours. Turned. In order to investigate the pulverization of the granulated material, the weight of the passed measurement sample was measured using the sieve used when removing the above-mentioned chemical heat storage granulated material having a small particle diameter, and the pass rate was calculated. .

(4) Particle diameter measurement method The particle diameter of the chemical heat storage granule was measured with 20 calipers, and the average value was calculated except for the minimum and maximum values. The diameter of the cylindrical granule was taken as the particle size.

(5) Durability evaluation method after cycle test After weighing 30 g of the chemical heat storage granule, (i) held at 350 ° C. for 80 minutes to form an oxide, (ii) allowed to cool at 140 ° C. for 40 minutes, (iii It was kept at 140 ° C. for 80 minutes under steam and converted to a hydroxide, and (iv) dried at 140 ° C. for 40 minutes. After carrying out 10 cycles of the steps (i) to (iv), a sieve having a sieve opening of 1 mm was used, the weight of the passed measurement sample was measured, and the pass rate was calculated.

(Manufacture of chemical heat storage granules)
[Example 1]
To a magnesium chloride aqueous solution prepared by dissolving anhydrous magnesium chloride with a purity of 98% by mass with pure water and adjusting the Mg ion concentration to 2.0 mol / L, pure water is added to a nickel chloride solution with a purity of 97% by mass, A solution prepared so that the Ni ion concentration was 0.8 mol / L was added so that the Ni ions might be 20 mol% with respect to the Mg ions to prepare a mixed solution.

  To the prepared mixed solution, pure water is added to a reagent-grade sodium hydroxide solution to adjust the concentration to 2.0 mol / L, and the reaction rate of sodium hydroxide to magnesium chloride is 90% using a roller pump. The solution was dropped at 5 mL / min, stirred at 300 rpm, and reacted at 30 ° C. for 1 hour. After the reaction, the composite magnesium hydroxide dispersion was filtered, washed with water, and dried at 120 ° C. for 12 hours to obtain composite magnesium hydroxide.

  In the obtained composite magnesium hydroxide, 10 mol% of lithium chloride with respect to Mg, 100 parts by weight of composite magnesium hydroxide, 20 parts by weight of powdered phenol resin, and 7.3 parts by weight of melamine resin were purified. Melamine resin solution adjusted to a 77% solution with water and 240 parts by weight of pure water are put into a container of a universal mixing stirrer (5DM-r type manufactured by Dalton), under the conditions of a revolution number of 62 rpm and a rotation number of 141 rpm. The mixture was stirred for 10 minutes to obtain a mixture mainly composed of composite magnesium hydroxide.

  After that, the mixture in the form of clay is put into a hopper of a wet extrusion granulator dome gran (DG-L1 type manufactured by Fuji Powder Co., Ltd.) little by little, screw rotation speed 40rpm, dome die hole diameter 3.0mm, plate thickness Granulation was performed under conditions of 1.0 mm and an opening ratio of 22.7%. After granulation, it was dried at 100 ° C. for 24 hours, and a granulated body mainly composed of composite magnesium hydroxide having a particle diameter of about 2 to 5 mm was obtained through a sieve.

  Thereafter, the obtained granulated material is carbonized under conditions of 600 ° C. for 1 hour while flowing nitrogen gas at a flow rate of 0.25 L / min in an atmosphere substitution type electric furnace (SPX1518-17V manufactured by Marusho Denki). And a chemical heat storage granule having a carbon content of 14.4% by mass was obtained.

[Example 2]
A chemical heat storage granule having a carbon content of 19.6% by mass was obtained in the same manner as in Example 1 except that the nickel chloride aqueous solution was changed to a cobalt chloride aqueous solution.

[Example 3]
Except not adding Ni, it manufactured by the method similar to Example 1, and obtained the chemical heat storage granule whose carbon content is 28.3 mass%.

[Example 4]
A chemical heat storage granule having a carbon content of 20.6% by mass was obtained in the same manner as in Example 1 except that the Co ion was changed to 5 mol% with respect to Mg ions.

[Example 5]
Chemical heat storage granulation produced in the same manner as in Example 4 except that 50 parts by weight of powdered phenol resin was used with respect to 100 parts by weight of composite magnesium hydroxide, and the carbon content was 32.2% by mass. Got the body.

[Example 6]
Chemical heat storage granulation produced in the same manner as in Example 4 except that 10 parts by weight of the powdery phenol resin was used per 100 parts by weight of the composite magnesium hydroxide, and the carbon content was 14.5% by mass. Got the body.

[Example 7]
Manufactured in the same manner as in Example 4 except that cellulose was used in place of the melamine resin, and a chemical heat storage granule having a carbon content of 20.6% by mass was obtained.

[Example 8]
A chemical heat storage granule having a carbon content of 26.4% by mass was obtained in the same manner as in Example 1 except that lithium bromide was used instead of lithium chloride.

[Comparative Example 1]
A chemical heat storage granule was obtained in the same manner as in Example 3 except that 27.3 parts by weight of sepiolite was used instead of phenol resin and melamine resin with respect to 100 parts by weight of composite magnesium hydroxide.

[Comparative Example 2]
Although the polymer compound which comprises a carbon compound was not used and it manufactured by the method similar to Example 3, the granulated body was not able to be formed.

[Comparative Example 3]
A chemical heat storage granule produced in the same manner as in Example 4 except that 5 parts by weight of the powdery phenol resin was used with respect to 100 parts by weight of the composite magnesium hydroxide and having a carbon content of 10.9% by mass. Got.

[Comparative Example 4]
A chemical heat storage granule produced in the same manner as in Example 4 except that 70 parts by weight of the powdery phenol resin was used with respect to 100 parts by weight of the composite magnesium hydroxide and having a carbon content of 38.9% by mass. Got.

  The results are summarized in Table 1.

* 1 Judgment made the part which can be stored heat except a carbon among chemical heat storage granulations as a heat storage body, and made the case where the content is 65% or more into (circle) and less than 65% x. When it is less than 65%, the heat storage capacity decreases.
* 2 The heat storage body content of Comparative Example 1 was calculated by subtracting the sepiolite used during mixing.

  As is clear from the results of Table 1, the chemical heat storage granule of the present invention used sepiolite instead of the carbon compound (Comparative Example 1) and did not use the polymer compound constituting the carbon compound. Compared with a thing (comparative example 2), intensity | strength became high clearly and the high intensity | strength chemical thermal storage granulation body was obtained.

  The heat storage granule of the present invention causes a dehydration endothermic reaction in a low temperature range of 100 to 350 ° C. and has high strength. Therefore, it is suitable for effectively using the heat of exhaust gas discharged from an engine, a fuel cell, or the like. For example, the heat of exhaust gas can be used for shortening the warm-up operation of an automobile, improving passenger amenity, improving fuel efficiency, and reducing exhaust gas damage by improving the activity of an exhaust gas catalyst. In particular, in the case of an engine, since the load due to operation is not constant and the exhaust output is also unstable, the direct use of exhaust heat is necessarily inefficient and inconvenient. According to the chemical heat storage system of the present invention, exhaust heat is temporarily stored temporarily, and heat output according to the heat demand enables more ideal exhaust heat utilization.

Claims (9)

  At least one selected from at least one magnesium compound selected from magnesium oxide, magnesium hydroxide, magnesium composite oxide, and magnesium composite hydroxide, lithium compound, potassium compound, and sodium compound A chemical heat storage granule composed mainly of a seed alkali metal compound and a carbon compound, wherein the chemical heat storage granule has a carbon content of 12 to 35% by mass. Granulated body.   The chemical heat storage granule according to claim 1, wherein the carbon compound in the chemical heat storage granule has a porous structure.   The chemical heat storage structure according to claim 1 or 2, wherein the porous carbon compound is a fired product in an inert atmosphere of at least one resin selected from the group consisting of a phenol resin, a melamine resin, and cellulose. Granules.   The alkali metal compound is in the form of chloride, hydroxide, oxide, bromide, nitrate, and / or sulfate of lithium, potassium, and sodium, and with respect to Mg in the chemical heat storage granulation The chemical heat storage granule according to claim 1, comprising 0.1 to 50 mol% of Li, K, and / or Na.   The magnesium composite oxide or the magnesium composite hydroxide is at least one element source selected from the group consisting of Ni, Co, Cu, and Al, chloride, hydroxide, oxide, carbonate, nitrate, and It is in the form of / or sulfate and contains 1 to 40 mol% of Ni, Co, Cu and / or Al with respect to Mg in the chemical heat storage granule. Chemical heat storage granulation.   After removing the chemical heat storage granule having a small particle diameter from the chemical heat storage granule using a mesh-size sieve in which 80 to 99% by mass of the chemical heat storage granule remains, a nylon ball having a diameter of 15 mm Was put into a 500 mL plastic container containing 5 to 250 mL of chemical heat storage granules, and after rotating for 2 hours at 148 rpm on a rotating table, it was used to remove the above-mentioned chemical heat storage granules with a small particle diameter. The chemical heat storage granule according to any one of claims 1 to 5, wherein an amount of the sieve passing is 40 mass% or less. (A): Prepare a magnesium hydroxide or a magnesium composite hydroxide containing 1 to 40 mol% of at least one element selected from the group consisting of Ni, Co, Cu, and Al with respect to Mg. Process;
(B): selected from 0.1 to 50 mol% lithium compound, potassium compound, and sodium compound with respect to magnesium hydroxide or magnesium composite hydroxide prepared in step (A) and Mg Mixing at least one compound and a polymer compound constituting 15 to 60 parts by weight of a carbon compound with respect to 100 parts by weight of magnesium hydroxide or magnesium composite hydroxide;
(C): a step of granulating the mixture containing magnesium hydroxide or magnesium composite hydroxide obtained in step (B);
(D): a step of classifying the granulated product containing magnesium hydroxide or magnesium composite hydroxide obtained in step (C); and (E): magnesium water prepared in step (D). Baking the mixture containing oxide or magnesium composite hydroxide in an inert atmosphere at 400 to 800 ° C. for 1 to 24 hours;
The manufacturing method of a chemical thermal storage granulation body containing. The step of obtaining the magnesium hydroxide in the step (A)
A magnesium chloride aqueous solution having a concentration of 1 to 10 mol / L and a sodium hydroxide solution or calcium hydroxide dispersion of 1 to 18 mol / L are prepared, and the magnesium chloride aqueous solution and a sodium hydroxide solution having a reaction rate of 80 to 150% or A step of simultaneously adding and reacting a calcium hydroxide dispersion to obtain a magnesium hydroxide slurry, filtering, washing and drying the obtained magnesium hydroxide slurry to obtain a magnesium hydroxide;
The manufacturing method of the chemical heat storage body of Claim 7 containing this. The step of obtaining the magnesium composite hydroxide in step (A)
Magnesium chloride aqueous solution having a concentration of 1 to 10 mol / L, an aqueous solution containing at least one element selected from the group consisting of Ni, Co, Cu, and Al having a concentration of 0.1 to 10 mol / L, and 1 to 18 mol / L A sodium hydroxide solution or a calcium hydroxide dispersion is prepared, a magnesium chloride aqueous solution and a solution containing at least one element selected from the group consisting of Ni, Co, Cu, and Al are mixed, and the reaction rate is further increased. 80-150% sodium hydroxide solution or calcium hydroxide dispersion was added and reacted to obtain a composite magnesium hydroxide slurry, and the resulting composite magnesium hydroxide slurry was filtered, washed with water and dried to obtain magnesium. Obtaining a composite hydroxide of:
The manufacturing method of the chemical heat storage body of Claim 7 containing this.