KR102228863B1 - Fabrication method of honeycomb structure and honeycomb structured thermochemical heat storage materials - Google Patents

Abstract

The present invention comprises the steps of obtaining a mixture by mixing an inorganic hydroxide and an aqueous binder; Preparing a composition for producing a honeycomb structure by adding water to the mixture; And manufacturing a honeycomb structure according to the method of manufacturing a honeycomb structure and the method of manufacturing the honeycomb structure, including the step of extruding the composition for producing the honeycomb structure into a honeycomb structure. And heat-treating the honeycomb structure to produce a heat storage material having a honeycomb structure.

Description

Manufacturing method of honeycomb structure and method of manufacturing heat storage material of honeycomb structure {FABRICATION METHOD OF HONEYCOMB STRUCTURE AND HONEYCOMB STRUCTURED THERMOCHEMICAL HEAT STORAGE MATERIALS}

The present invention relates to a method of manufacturing a honeycomb structure by adding water to a mixture of an inorganic hydroxide and an aqueous binder, and a method of manufacturing a heat storage material having a honeycomb structure by heat-treating the honeycomb structure.

As the importance of the supply of new and renewable energy and energy efficiency increases, the importance of energy storage technology is gradually increasing, and not only electricity storage but also heat storage technology is becoming increasingly important.

Thermochemical heat storage technology is the technology that can store heat for the longest time among heat storage technologies. Thermochemical heat storage technology is a technology that stores heat by causing an endothermic reaction to a material in which a chemical reaction occurs reversibly, and obtains heat by causing an exothermic reaction. The following reactions are typical thermochemical heat storage reactions.

(Endothermic reaction) Mg(OH) ₂ → MgO + H ₂ O

(Exothermic reaction) MgO + H ₂ O → Mg(OH) ₂

Latent heat storage or sensible heat storage does not cause a molding problem because a liquid phase is generated during the axial heat storage process, but the thermochemical heat storage technology produces axial heat while maintaining a solid state, so the molded form is important. MgO described above reacts with moisture to generate heat and absorbs heat by contacting with high-temperature air. Therefore, it is advantageous to form a honeycomb shape so that gas and solid can easily contact the axial heat dissipation rate.

In general, ceramic powder does not have plasticity, so a binder and water are added to the ceramic powder, kneaded and kneaded to obtain suitable plasticity, and then a honeycomb is obtained through extrusion. MgO is known as a material that is difficult to extrude because when water is mixed, it generates heat _{and causes a chemical reaction with Mg(OH) 2} , and the material produced as a result of the chemical reaction becomes hard and plasticity cannot be obtained.

_{Specifically, in the process of obtaining Mg(OH) 2} by reacting MgO and water, water having a stoichiometry or higher must be added, and _{the strength of the obtained Mg(OH) 2} is large, requiring a pulverization process, and noise and dust are generated when pulverizing. There was a problem.

US published patent US2015-0344763, 2015.12.03 published

The present invention was conceived to solve the above problems of the prior art, and a honeycomb that can be molded into a honeycomb shape without a process of reacting a thermochemical heat storage material such as inorganic hydroxide with water and without a phenomenon of heat generation or hardening of dough. An object of the present invention is to provide a method for manufacturing a structure and a method for manufacturing a heat storage material having a honeycomb structure.

In addition, it is an object of the present invention to provide a method of manufacturing a heat storage material capable of compensating for a phenomenon in which strength is weakened during a heat treatment step when manufacturing a heat storage material having a honeycomb structure.

The present invention comprises the steps of obtaining a mixture by mixing an inorganic hydroxide and an aqueous binder; Preparing a composition for producing a honeycomb structure by adding water to the mixture; And extruding the composition for producing a honeycomb structure to form a honeycomb structure.

In the present invention, the inorganic hydroxide may be one or more selected from the group consisting of magnesium hydroxide, calcium hydroxide, iron hydroxide and zinc hydroxide.

In the present invention, the step of obtaining the mixture includes: obtaining a preliminary mixture by mixing an inorganic hydroxide and aluminum oxide; And mixing the preliminary mixture with an aqueous binder to obtain a mixture.

In the present invention, the aqueous binder may be mixed in an amount of 5 to 30% by weight based on the inorganic hydroxide.

In the present invention, the aqueous binder may be mixed in an amount of 5 to 30% by weight compared to the preliminary mixture.

In the present invention, the water may be added in an amount of 3 to 80% by weight of the mixture.

The present invention comprises the steps of manufacturing a honeycomb structure according to the method of manufacturing the honeycomb structure; And heat-treating the honeycomb structure to produce a heat storage material having a honeycomb structure.

The present invention can be molded into a honeycomb shape without a process of reacting a thermochemical heat storage material such as an inorganic hydroxide with water and without a heat generation phenomenon or a hardening phenomenon, and strength is weakened in the heat treatment step when manufacturing a heat storage material having a honeycomb structure. The phenomenon can be compensated.

1 is an XRD analysis result of magnesium hydroxide.
2 is an XRD analysis result of heat-treated magnesium hydroxide.
3 is a result of DSC analysis of magnesium hydroxide.
4 is an extrusion photograph of a honeycomb structure according to Example 1. FIG.
5 is an extrusion photograph of a honeycomb structure according to Example 2.
6 is an extrusion photograph of a honeycomb structure according to Example 3.
7 is an extrusion photograph of a honeycomb structure according to Example 4.
8 is an extrusion photograph of a honeycomb structure according to Example 5.
9 is a DSC analysis result of a heat storage material having a honeycomb structure according to Experimental Example 1.
10 is a DSC analysis result of a heat storage material having a honeycomb structure according to Experimental Example 2.
11 is a DSC analysis result of a heat storage material having a honeycomb structure according to Experimental Example 3.
12 is a DSC analysis result of the heat storage material having a honeycomb structure according to Experimental Example 4.

The following examples are intended to illustrate the present invention, and the present invention is not limited by the following examples and may be variously modified and changed. Prior to describing the present invention, when it is determined that a detailed description of related known functions and configurations may unnecessarily obscure the subject matter of the present invention, a description thereof will be omitted.

Specific structural or functional descriptions of the embodiments according to the concept of the present invention disclosed in the present specification are exemplified only for the purpose of describing the embodiments according to the concept of the present invention, and the embodiments according to the concept of the present invention are It may be implemented in various forms and is not limited to the embodiments described herein, and includes all changes, equivalents, or substitutes included in the spirit and scope of the present invention.

Hereinafter, the present invention will be described in detail.

The method of manufacturing a honeycomb structure includes obtaining a mixture by mixing an inorganic hydroxide and an aqueous binder, preparing a composition for manufacturing a honeycomb structure by adding water to the mixture, and extruding the composition for producing a honeycomb structure to produce a honeycomb structure. Includes steps.

The inorganic hydroxide may be one or more selected from the group consisting of magnesium hydroxide, calcium hydroxide, iron hydroxide, and zinc hydroxide. Preferably, the inorganic hydroxide may be magnesium hydroxide.

The aqueous binder may be at least one selected from the group consisting of polyvinyl alcohol (PVA), polyethylene glycol (PEG), methylene cellulose (MC), polyethylene oxide (PEO), acrylic compounds, and waxes.

The aqueous binder may be mixed in an amount of 5 to 30% by weight relative to the inorganic hydroxide, and preferably, it may be mixed in an amount of 8 to 15% by weight. When the aqueous binder is mixed in less than 5% by weight, the composition for manufacturing the honeycomb structure cannot be extruded because it does not have sufficient plasticity, and when it is mixed in more than 30% by weight, the honeycomb structure after the heat treatment process for removing the aqueous binder, which will be described later The compressive strength of the heat storage material may be significantly reduced.

The water may be mixed in an amount of 3 to 80% by weight relative to the mixture, and preferably, it may be mixed in an amount of 8 to 65% by weight. If the water is mixed in less than 3% by weight, the fluidity of the composition for producing the honeycomb structure is lowered and it cannot be extruded, and if it is mixed in more than 80% by weight, the fluidity becomes too good, and the shape of the honeycomb structure after passing through the extrusion mold is changed. It becomes impossible to maintain.

As in the prior art, when a composition is prepared by adding water to an inorganic oxide (eg, magnesium oxide), the composition formed by the exothermic reaction is very hard and moldability may be deteriorated.

On the other hand, when the composition for producing the honeycomb structure is prepared by adding water to the mixture containing the inorganic hydroxide as in the present invention, the composition for producing the honeycomb structure may be prepared in a kneaded state, thereby having excellent moldability. Accordingly, when manufacturing the honeycomb structure by extrusion molding the composition for producing the honeycomb structure, a separate grinding process may not be required.

The step of obtaining the mixture may include obtaining a preliminary mixture by mixing an inorganic hydroxide and aluminum oxide, and mixing the preliminary mixture with an aqueous binder to obtain a mixture.

The aluminum oxide may be mixed in an amount of 1 to 10% by weight, and preferably, in an amount of 5% by weight, relative to the composition for manufacturing the honeycomb structure.

As the composition for manufacturing the honeycomb structure includes the aluminum oxide, the compressive strength of the honeycomb structure may be improved.

When the mixture includes the aluminum oxide, the aqueous binder may be mixed in an amount of 5 to 30% by weight, preferably 8 to 15% by weight, based on the weight of the preliminary mixture.

The method of manufacturing a heat storage material having a honeycomb structure may include manufacturing a honeycomb structure according to the manufacturing method of the honeycomb structure, and preparing a heat storage material having a honeycomb structure by heat-treating the honeycomb structure.

Specifically, heating of the honeycomb structure is a configuration for removing the aqueous binder, and is performed at a temperature lower than the melting point of each of the inorganic oxide and the aluminum oxide, which is oxidized by heat treatment of the inorganic hydroxide. (For example, it is understood as a different composition from sintering, in which an inorganic hydroxide is heat-treated and oxidized, or the inorganic oxide and aluminum oxide) are heated near the melting point and bonded at the adjacent surfaces of the constituent particles. Can be.

Hereinafter, the present invention will be described in detail with reference to test examples and examples.

Test Example: XRD and DSC analysis of magnesium hydroxide.

MagShield S (Martin Marietta Magnesia Specialties' MagShield S) powder was analyzed by XRD (X-ray Diffraction) to show an XRD pattern in FIG. 2, the magnesium hydroxide powder was analyzed by DSC (Differential scanning calorimetry), and the analysis results are shown in FIG. 3.

Referring to FIG. 1, the XRD pattern of magnesium hydroxide can be confirmed. Referring to FIG. 2, an XRD pattern of magnesium hydroxide and magnesium oxide can be confirmed. Accordingly, it can be seen that when magnesium hydroxide is heat-treated, it is converted into magnesium oxide.

Referring to FIG. 3, it can be seen that magnesium hydroxide exhibits an endothermic property of 888 J/g at 313°C. Accordingly, it can be seen that magnesium hydroxide has excellent axial heat dissipation properties and is suitable for use as a starting material for a chemical heat storage material.

Preparation of honeycomb structures according to Examples 1 to 5.

A mixture was prepared by mixing 800 g of Martin Marietta Magnesia Specialties' MagShield S as magnesium hydroxide and 80 g of Yuken's YB-132A as a binder, and 308 g of water was added to the mixture to prepare a composition, and then 40 cells/in ^{2 with a diameter of 40 mm.} The composition was extrusion-molded with a vacuum extruder (V-20) of Sanko Shoji using a circular extrusion mold to prepare a honeycomb structure according to Example 1 having a length of 30 cm.

4 is an extrusion photograph of a honeycomb structure according to Example 1. FIG.

MagShield S 733g of Martin Marietta Magnesia Specialties as magnesium hydroxide, 67g of 99.0% aluminum oxide of Samjeon Pure Chemicals, and 80g of YB-132A of Yuken as a binder are mixed, so that the mixed molar ratio of magnesium hydroxide and aluminum oxide is 95:5. A mixture was prepared, and 277 g of water was added to the mixture to prepare a composition, and then a honeycomb structure according to Example 2 was manufactured through the same extrusion process as in the method of manufacturing a honeycomb structure according to Example 1.

5 is an extrusion photograph of a honeycomb structure according to Example 2.

In the method of manufacturing the honeycomb structure according to Example 2, the honeycomb structure according to Example 3 was changed to 670 g of magnesium hydroxide, 130 g of aluminum oxide, and 290 g of water, and the mixing molar ratio of magnesium hydroxide and aluminum oxide was 90:10. Was prepared.

6 is an extrusion photograph of a honeycomb structure according to Example 3.

In the method of manufacturing the honeycomb structure according to Example 2, the honeycomb structure according to Example 4 was changed to 611 g of magnesium hydroxide, 189 g of aluminum oxide, and 290 g of water, and the mixing molar ratio of magnesium hydroxide and aluminum oxide was 85:15. Was prepared.

7 is an extrusion photograph of a honeycomb structure according to Example 4.

In the method of manufacturing a honeycomb structure according to Example 2, the honeycomb structure according to Example 5 was changed to 557 g of magnesium hydroxide, 243 g of aluminum oxide, and 286 g of water, and the mixing molar ratio of magnesium hydroxide and aluminum oxide was 80:20. Was prepared.

8 is an extrusion photograph of a honeycomb structure according to Example 5.

The components and composition ratios of the honeycomb structures according to Examples 1 to 5 were compared and summarized in the following [Table 1].

Magnesium hydroxide (g) Aluminum oxide (g) Binder (g) Water(g) Example 1 800 - 80 308 Example 2 733 67 277 Example 3 670 130 290 Example 4 611 189 290 Example 5 557 243 286

Test Example: Analysis of compressive strength of honeycomb structures according to Examples 1 to 5.

After processing the honeycomb structure according to Examples 1 to 5 into a cylindrical specimen having a diameter of 35 mm and a height of 40 mm, using the Instron Series IX Automated Material Testing System with a crosshead speed of 1 mm/min, the binder was not removed. The compressive strength of the honeycomb structures according to Examples 1 to 5 was analyzed.

In addition, after processing the honeycomb structure according to Examples 1 to 4 into a cylindrical specimen having a diameter of 35 mm and a height of 40 mm, heat treatment at 500°C for 500 minutes, Instron Series IX Automated Material Testing with a crosshead speed of 1 mm/min. Using the system, the compressive strength of the honeycomb structures according to Examples 1 to 4 in which the binder was removed was analyzed.

The compressive strength of the honeycomb structures according to Examples 1 to 5 before and after removal of the binder are shown in Table 2 below.

Example 1 Example 2 Example 3 Example 4 Example 5 Compressive strength before removing binder 6.54±0.43MPa 5.21±0.51MPa 5.17±0.72MPa 4.91±0.20MPa 3.99±0.14MPa Compressive strength after removing the binder 178±76kPa 187±52kPa 94±14kPa 56±8kPa -

Referring to [Table 1], the compressive strength of the honeycomb structures according to Examples 1 to 5 before removing the binder is about 4 to 7 MPa, the compressive strength after removing the binder is about 50 to 250 kPa, and the content of aluminum oxide is 5 mol%. In this case, it can be seen that the compressive strength is the best.

Manufacturing of a honeycomb-structured heat storage material according to Examples 6 and 7.

The honeycomb structure according to Example 1 was heat-treated at 500° C. for 500 minutes to prepare a heat storage material having a honeycomb structure according to Example 6 from which the binder was removed.

The honeycomb structure according to Example 2 was heat-treated at 500° C. for 500 minutes to prepare a heat storage material having a honeycomb structure according to Example 7 in which the binder was removed.

DSC analysis of the heat storage material having a honeycomb structure according to Experimental Examples 1 to 4.

Experimental Example 1 by repeating the axial heat dissipation cycle 20 times in which the heat storage material of the honeycomb structure according to Example 6 was heat-treated at 500°C for 60 minutes to convert magnesium hydroxide into magnesium oxide, and heat radiated by adding water. DSC analysis of the heat storage material having a honeycomb structure according to

In the DSC analysis of the honeycomb structured heat storage material according to Experimental Example 1, the number of repetitions of the axial heat dissipation cycle was changed to 30, and DSC analysis of the honeycomb structured heat storage material according to Experimental Example 2 was performed.

The heat storage material of the honeycomb structure according to Example 7 was heat-treated at 500°C for 60 minutes to convert magnesium hydroxide into magnesium oxide, and dried in a dryer at 120°C for 24 hours to radiate heat, and an axial heat dissipation cycle was performed once. DSC analysis of the heat storage material having a honeycomb structure according to Example 3 was performed.

Experimental Example 4 by heat-treating the heat storage material having a honeycomb structure according to Example 7 at 500°C for 30 minutes to convert magnesium hydroxide into magnesium oxide, and repeating the axial heat dissipation cycle 50 times in which heat is radiated for 30 minutes using 100 steam. DSC analysis of the heat storage material having a honeycomb structure according to

DSC analysis results of the honeycomb-structured heat storage materials according to Experimental Examples 1 to 4 are shown in FIGS. 9 to 12, respectively.

9 and 10, DSC analysis results of the honeycomb-structured thermal storage material according to Experimental Examples 1 and 2, the honeycomb-structured thermal storage material according to Example 6, excellent heat storage and heat dissipation characteristics even when the heat storage cycle is repeatedly performed. Can be seen to keep.

Specifically, when performing DSC analysis of the honeycomb structured heat storage material according to Experimental Example 1, the heat absorbing property of the honeycomb structured heat storage material according to Example 6 was measured at 303.66°C to 1029 J/g, and the honeycomb structure according to Experimental Example 2 When performing the DSC analysis of the heat storage material of, it can be seen that the heat absorbing property of the heat storage material of the honeycomb structure according to Example 6 was measured as 1047 J/g at 300.86°C.

11 and 12, DSC analysis results of the honeycomb-structured thermal storage material according to Experimental Examples 3 and 4 can be confirmed.

When performing DSC analysis of the honeycomb structured heat storage material according to Experimental Example 3, the heat absorbing property of the honeycomb structured heat storage material according to Example 7 was measured as 734.7 J/g at 304.73°C, and the heat of the honeycomb structure according to Experimental Example 4 When performing the DSC analysis of the storage material, it can be seen that the heat absorbing property of the heat storage material having a honeycomb structure according to Example 7 was measured as 547.1 J/g at 287.86°C.

Claims (7)

Mixing magnesium hydroxide and an aqueous binder to obtain a mixture;
Preparing a composition for producing a honeycomb structure by adding water to the mixture;
Extruding the composition for producing a honeycomb structure to produce a honeycomb structure; And
Heat-treating the honeycomb structure to remove the aqueous binder, and manufacturing a thermochemical heat storage storage material having a honeycomb structure,
The aqueous binder includes one or more selected from the group consisting of PVA (polyvinyl alcohol), PEG (polyethylene glycol), MC (methylene cellulose), PEO (polyethylene oxide), acrylic compound, and wax,
The composition for producing a honeycomb structure does not contain pyrophyllite, a method for producing a thermochemical heat storage storage material having a honeycomb structure.
delete The method according to claim 1,
The step of obtaining the mixture
Mixing magnesium hydroxide and aluminum oxide to obtain a preliminary mixture; And
A method for producing a thermochemical heat storage storage material having a honeycomb structure, comprising the step of obtaining a mixture by mixing an aqueous binder with the preliminary mixture.
The method of claim 3,
The aqueous binder is mixed in an amount of 5 to 30 parts by weight based on 100 parts by weight of the preliminary mixture.
The method according to claim 1,
The aqueous binder is mixed in an amount of 5 to 30 parts by weight based on 100 parts by weight of the magnesium hydroxide, a method for producing a thermochemical heat storage storage material having a honeycomb structure.
The method according to claim 1,
The water is added in an amount of 3 to 80 parts by weight based on 100 parts by weight of the mixture. delete

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