Powder composition for 3D printing based on alumina cement capable of fixing carbon dioxide and method for manufacturing the same

Abstract

The present invention relates to an alumina cement-based powder composition for 3D printing capable of carbon dioxide fixation, a molded body, and a method for manufacturing the same. The powder composition and molded body of the present invention are manufactured by including inorganic powder, calcium aluminate cement, and wollastonite. A catalyst support using the molded body can fix carbon dioxide to possess suitable strength and shape while contributing to carbon neutrality, and thus can be used as a high-performance environmental catalyst. Furthermore, the problems associated with conventional extrusion processes, which require long manufacturing times and additional organic additives, can be overcome through simple and fast 3D printing.

Description

Technology Field

[0001] The present invention relates to an alumina cement-based powder composition for 3D printing capable of carbon dioxide fixation and a method for manufacturing the same. Background Technology

[0002] Cement emits approximately 0.8 tons of carbon dioxide per ton, a major culprit of greenhouse gases, and accounted for 7% (about 2.3 billion tons) of global carbon dioxide emissions as of 2019. Therefore, the utilization of Carbon Capture, Storage, and Utilization (CCUS) technology is essential for the cement industry to achieve carbon neutrality by 2050. A representative technology is mineral carbonation, which fixes CO2 in inorganic materials and is a technology with high potential as it can store CO2 semi-permanently.

[0003] By contacting exhaust gas containing CO2 with an aggregate of solid particles containing CaO or Ca(OH)2, and fixing the CO2 in the exhaust gas as CaCO3 on the solid particles, the concentration of CO2 in the exhaust gas can be reduced, thereby reducing the emission of carbon dioxide. According to this method, CO2 in exhaust gas generated from industrial processes can be efficiently absorbed and removed, thereby reducing the amount of CO2 emitted into the atmosphere.

[0004] Therefore, research on cement powder compositions capable of reducing carbon dioxide is necessary. Prior art literature

[0005] Japanese Patent No. 3248514 (2001.11.09) The problem to be solved

[0006] The object of the present invention is to provide an alumina cement-based powder composition for 3D printing capable of carbon dioxide fixation, comprising an inorganic powder, calcium aluminate cement, and wollastonite.

[0007] In addition, the objective of the present invention is to provide a molded article comprising an alumina cement-based powder composition for 3D printing capable of carbon dioxide fixation.

[0008] In addition, the objective of the present invention is to provide a method for manufacturing a molded body using an alumina cement-based powder composition for 3D printing capable of carbon dioxide fixation.

[0009] In addition, the objective of the present invention is to provide a molded body having strength and shape suitable for an environmental catalyst, which contributes to carbon neutrality by fixing carbon dioxide. means of solving the problem

[0010] According to one aspect of the present invention, a powder composition comprising inorganic powder; calcium aluminate cement; and wollastonite (CaSiO3) is provided.

[0011] In addition, the powder composition may be intended for use in 3D printing.

[0012] In addition, the above powder composition may fix carbon dioxide.

[0013] In addition, the calcium aluminate cement and the wollastonite may each fix carbon dioxide.

[0014] In addition, the above inorganic powder may include one or more selected from the group consisting of silica (SiO2), alumina (Al2O3), zirconia (ZrO2), zirconium silicate (ZrSiO4), chromium oxide (Cr2O3), magnesium oxide (MgO), calcium oxide (CaO), phosphorus oxide (P2O5), sodium oxide (Na2O), iron oxide (Fe2O3), potassium oxide (K2O), and titanium dioxide (TiO2).

[0015] In addition, the cement may include one or more selected from the group consisting of CaOAl2O3(CA), 3CaOAl2O3(C3A), CaO2Al2O3(CA2), and CaO6Al2O3(CA6).

[0016] In addition, the powder composition may further include 12CaO-7Al2O3 (C12A7).

[0017] In addition, the powder composition may further include a fluidizing agent.

[0018] In addition, the fluidizing agent may include one or more selected from the group consisting of fumed silica, fly ash, naphthalene sulfonate formaldehyde, sulfonated melamine formaldehyde, calcium lignosulfonate, titanium dioxide, and aluminum oxide.

[0019] In addition, the powder composition may further include a binder.

[0020] In addition, the binder may include one or more selected from the group consisting of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), dextrin, methyl cellulose (MC), hydroxypropyl methyl cellulose (HPMC), polyethylene oxide (PEO), polyvinyl butyral (PB), colloidal silica, and polyethylene glycol.

[0021] In addition, the powder composition may further include a curing accelerator.

[0022] In addition, the hardening accelerator may include one or more selected from the group consisting of lithium carbonate, lithium bromide, lithium hydroxide, lithium chloride, lithium carbonate, lithium nitrate, lithium sulfate, lithium sulfide, lithium phosphate, lithium oxalate, and quicklime.

[0023] In addition, the powder composition may include 1 to 50 parts by weight of calcium aluminate cement and 10 to 50 parts by weight of wollastonite based on 100 parts by weight of inorganic powder.

[0024] In addition, the above powder composition may further include 3 to 10 parts by weight of 12CaO-7Al2O3 (C12A7) based on 100 parts by weight of inorganic powder.

[0025] In addition, the powder composition may further include a fluidizing agent.

[0026] In addition, the powder composition may include 0.1 to 10 parts by weight of the fluidizing agent based on 100 parts by weight of the inorganic powder.

[0027] In addition, the size of the inorganic particles may be 10 to 100 μm.

[0028] According to another aspect of the present invention, a molded body is provided by fixing carbon dioxide in the powder composition and curing it.

[0029] According to another aspect of the present invention, a method for manufacturing a molded body is provided, comprising: (a) a step of preparing a powder composition comprising an inorganic powder, calcium aluminate cement, and wollastonite (CaSiO3); (b) a step of manufacturing a first molded body by 3D printing the powder composition; (c) a step of impregnating the first molded body with a silica sol; (d) a step of manufacturing a second molded body by reacting the first molded body impregnated with the silica sol with carbon dioxide (CO2) to immobilize CO2 in the first molded body; and (e) a step of manufacturing a third molded body by calcining the second molded body by heat treatment to remove impurities.

[0030] Additionally, the above step (b) may include: (b-1) a step of forming a powder composition layer comprising the above powder composition; (b-2) a step of preparing a pattern layer by irradiating a binder mixed solution comprising a binder onto the powder composition layer in a predetermined pattern; and (b-3) a step of preparing a first molded body by repeating the above steps (b-1) and (b-2) n times each (n is an integer greater than or equal to 0) onto the pattern layer.

[0031] In addition, the method for manufacturing the molded body may further include a step (a') of sieving the powder composition after step (a).

[0032] In addition, the binder mixture solution may include one or more selected from the group consisting of polyethylene glycol (PEG) and glycerol, and water.

[0033] In addition, the 3D printing of step (c) above can be performed using binder jet 3D printing.

[0034] In addition, the conditions for CO2 fixation in step (d) above may be such that the carbon dioxide concentration is 99.9% or higher, the carbon dioxide pressure is 0.1 to 1 MPa, the fixation temperature is 5 to 100 ℃, and the fixation reaction time is 1 to 48 hours. Effects of the invention

[0035] The present invention can provide an alumina cement-based powder composition for 3D printing capable of carbon dioxide fixation, comprising inorganic powder, calcium aluminate cement, and wollastonite.

[0036] In addition, the present invention can provide a molded body comprising an alumina cement-based powder composition for 3D printing capable of carbon dioxide fixation.

[0037] In addition, the present invention can provide a method for manufacturing a molded body using an alumina cement-based powder composition for 3D printing capable of carbon dioxide fixation.

[0038] In addition, the present invention can provide a molded body having strength and shape suitable for environmental catalysts, which contributes to carbon neutrality by fixing carbon dioxide. Brief explanation of the drawing

[0039] These drawings are for reference to explain exemplary embodiments of the present invention, and therefore, the technical concept of the present invention should not be interpreted as being limited to the attached drawings. Figure 1 is a schematic diagram illustrating a process of manufacturing a molded body by 3D printing a powder composition and curing the molded body with carbon dioxide. Figure 2 is a schematic diagram of the carbon dioxide hardening reaction in a carbon dioxide reactor. Figure 3 is a diagram showing the post-processing process of a molded body manufactured by 3D printing. Figure 4 shows photographs of a catalyst support manufactured by 3D printing before and after calcination heat treatment. Figure 5 is a graph showing the flow characteristics of the powder composition. Figure 6 is a scanning electron microscope (SEM) image of a powder composition according to the additive. Figure 7 is a photograph showing the surface condition of a powder bed according to the additive. Figure 8 is a graph showing the compressive strength (Mpa) and carbon dioxide fixation rate (%) of the molded body according to the post-treatment step and the carbon dioxide fixation reaction time. Specific details for implementing the invention

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention.

[0041] However, the following description is not intended to limit the present invention to specific embodiments, and detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions could obscure the essence of the present invention.

[0042] The terms used herein are merely for describing specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to indicate the presence of the features, numbers, steps, actions, components, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, or combinations thereof.

[0043] Hereinafter, the powder composition and molded body of the present invention will be described.

[0044] According to one aspect of the present invention, a powder composition comprising inorganic powder; calcium aluminate cement; and wollastonite (CaSiO3) is provided.

[0045] In addition, the powder composition may be intended for use in 3D printing.

[0046] In addition, the above powder composition may fix carbon dioxide.

[0047] In addition, the calcium aluminate cement and the wollastonite may each fix carbon dioxide.

[0048] In addition, the above inorganic powder may include one or more selected from the group consisting of silica (SiO2), alumina (Al2O3), zirconia (ZrO2), zirconium silicate (ZrSiO4), chromium oxide (Cr2O3), magnesium oxide (MgO), calcium oxide (CaO), phosphorus oxide (P2O5), sodium oxide (Na2O), iron oxide (Fe2O3), potassium oxide (K2O), and titanium dioxide (TiO2).

[0049] In addition, the cement may include one or more selected from the group consisting of CaOAl2O3(CA), 3CaOAl2O3(C3A), CaO2Al2O3(CA2), and CaO6Al2O3(CA6).

[0050] In addition, the powder composition may further include 12CaO-7Al2O3 (C12A7).

[0051] In addition, the powder composition may further include a fluidizing agent.

[0052] In addition, the fluidizing agent may include one or more selected from the group consisting of fumed silica, fly ash, naphthalene sulfonate formaldehyde, sulfonated melamine formaldehyde, calcium lignosulfonate, titanium dioxide, and aluminum oxide.

[0053] In addition, the powder composition may further include a binder.

[0054] In addition, the binder may include one or more selected from the group consisting of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), dextrin, methyl cellulose (MC), hydroxypropyl methyl cellulose (HPMC), polyethylene oxide (PEO), polyvinyl butyral (PB), colloidal silica, and polyethylene glycol.

[0055] In addition, the powder composition may further include a curing accelerator.

[0056] In addition, the hardening accelerator may include one or more selected from the group consisting of lithium carbonate, lithium bromide, lithium hydroxide, lithium chloride, lithium carbonate, lithium nitrate, lithium sulfate, lithium sulfide, lithium phosphate, lithium oxalate, and quicklime.

[0057] In addition, the powder composition may comprise 1 to 50 parts by weight of calcium aluminate cement and 10 to 50 parts by weight of wollastonite based on 100 parts by weight of inorganic powder. Here, if the powder composition contains less than 1 part by weight of calcium aluminate cement based on 100 parts by weight of inorganic powder, it is undesirable because strength cannot be developed through a hydration reaction in the entire material, and if it exceeds 50 parts by weight, it is undesirable because it significantly reduces powder fluidity. In addition, if it contains less than 10 parts by weight of wollastonite based on 100 parts by weight of inorganic powder, it is undesirable because the carbon dioxide fixation rate is reduced, and if it exceeds 50 parts by weight, it is undesirable because it significantly reduces powder fluidity.

[0058] In addition, the powder composition may further include a fluidizing agent.

[0059] In addition, the powder composition may include 0.1 to 10 parts by weight of the fluidizing agent based on 100 parts by weight of the inorganic powder. Here, if the powder composition includes less than 0.1 parts by weight of the fluidizing agent based on 100 parts by weight of the inorganic powder, it is not sufficient to improve the fluidity of the powder, and if it includes more than 10 parts by weight, the density of the entire powder decreases, which is undesirable as it lowers the strength.

[0060] In addition, the size of the inorganic particles may be 10 to 100 μm. Here, if the size of the inorganic particles is less than 10 μm, it is undesirable because it exhibits low strength, and if it exceeds 100 μm, it is undesirable because the surface resolution and dimensional accuracy are reduced.

[0061] According to another aspect of the present invention, a molded body is provided by fixing carbon dioxide in the powder composition and curing it.

[0062] According to another aspect of the present invention, a method for manufacturing a molded body is provided, comprising: (a) a step of preparing a powder composition comprising an inorganic powder, calcium aluminate cement, and wollastonite (CaSiO3); (b) a step of manufacturing a first molded body by 3D printing the powder composition; (c) a step of impregnating the first molded body with a silica sol; (d) a step of manufacturing a second molded body by reacting the first molded body impregnated with the silica sol with carbon dioxide (CO2) to immobilize CO2 in the first molded body; and (e) a step of manufacturing a third molded body by calcining the second molded body by heat treatment to remove impurities.

[0063] Additionally, the above step (b) may include: (b-1) a step of forming a powder composition layer comprising the above powder composition; (b-2) a step of preparing a pattern layer by irradiating a binder mixed solution comprising a binder onto the powder composition layer in a predetermined pattern; and (b-3) a step of preparing a first molded body by repeating the above steps (b-1) and (b-2) n times each (n is an integer greater than or equal to 0) onto the pattern layer.

[0064] In addition, the method for manufacturing the molded body may further include a step (a') of sieving the powder composition after step (a).

[0065] In addition, the binder mixture solution may include one or more selected from the group consisting of polyethylene glycol (PEG) and glycerol, and water.

[0066] In addition, the 3D printing of step (c) above can be performed using binder jet 3D printing.

[0067] In addition, the conditions for CO2 fixation in step (d) above may be a carbon dioxide concentration of 99.9% or higher, a carbon dioxide pressure of 0.1 to 1 MPa, a fixation temperature of 5 to 100 ℃, and a fixation reaction time of 1 to 48 hours. Here, if the carbon dioxide pressure is less than 0.1 MPa, it is undesirable because the reaction time becomes too long, and if it exceeds 1 MPa, it is undesirable because the molded body may be damaged by the high pressure. Also, if the fixation temperature is less than 5 ℃ or exceeds 100 ℃, it is undesirable because ionization is difficult to occur.

[0068] [Example]

[0069] Hereinafter, preferred embodiments of the present invention will be described. However, this is for illustrative purposes only and does not limit the scope of the present invention.

[0070] Example 1: Preparation of Powder Composition

[0071] Example 1-0: Fumed silica not used

[0072] Referring to Table 1 below, a mixture comprising silica powder, calcium aluminate cement (CAC) powder, C12A7 (12CaO-7Al2O3), wolastonite (CS), polyvinyl alcohol (PVA) as a binder, and lithium carbonate (Li2CO3) as a curing accelerator was mixed dry for 24 hours under the conditions of Table 1. The mixed powder was sieved through a 200 mesh sieve to produce a powder composition having a uniform particle size distribution.

[0073] Example 1-1: 0.1 wt% fumed silica used

[0074] Examples 1-1-1 to 1-1-7: Use of K150, K200, K300, A200, A300, R972, R974

[0075] Referring to Table 1 below, a mixture comprising silica powder, calcium aluminate cement (CAC) powder, C12A7 (12CaO-7Al2O3), wollastonite (CS), polyvinyl alcohol (PVA) as a binder, lithium carbonate (Li2CO3) as a curing accelerator, and fumed silica as a fluidizing agent was mixed dry for 24 hours under the conditions of Table 1. The mixed powder was sieved through a 200 mesh sieve to prepare the powder compositions of Examples 1-1-1 to 1-1-7, each having a uniform particle size distribution. Here, the fumed silica was Konasil K150, Konasil K200, Konasil K300, Aerosil A200, Aerosil A300, Aerosil R972, and Aerosil R974, respectively.

[0076] Examples 1-2: Fumed silica 0.5 wt%

[0077] Examples 1-2-1 to 1-2-7: Use of K150, K200, K300, A200, A300, R972, R974

[0078] Referring to Table 1 below, a mixture comprising silica powder, calcium aluminate cement (CAC) powder, C12A7 (12CaO-7Al2O3), wollastonite (CS), polyvinyl alcohol (PVA) as a binder, lithium carbonate (Li2CO3) as a curing accelerator, and fumed silica as a fluidizing agent was mixed dry for 24 hours under the conditions of Table 1. The mixed powder was sieved through a 200 mesh sieve to prepare the powder compositions of Examples 1-2-1 to 1-2-7, each having a uniform particle size distribution. Here, the fumed silica was Konasil K150, Konasil K200, Konasil K300, Aerosil A200, Aerosil A300, Aerosil R972, and Aerosil R974, respectively.

[0079] Examples 1-3: Fumed silica 1.0 wt%

[0080] Examples 1-3-1 to 1-3-7: Use of K150, K200, K300, A200, A300, R972, R974

[0081] Referring to Table 1 below, a mixture comprising silica powder, calcium aluminate cement (CAC) powder, C12A7 (12CaO-7Al2O3), wollastonite (CS), polyvinyl alcohol (PVA) as a binder, lithium carbonate (Li2CO3) as a curing accelerator, and fumed silica as a fluidizing agent was mixed dry for 24 hours under the conditions of Table 1. The mixed powder was sieved through a 200 mesh sieve to prepare the powder compositions of Examples 1-3-1 to 1-3-7, each having a uniform particle size distribution. Here, the fumed silica was Konasil K150, Konasil K200, Konasil K300, Aerosil A200, Aerosil A300, Aerosil R972, and Aerosil R974, respectively.

[0082] Examples Silica (parts by weight) CAC (weight part) C12A7 (weight part) Wollastonite (parts by weight) PVA (parts by weight) Li2CO3 (parts by weight) fumed silica weight part type 1-0 59.78 16 4 20 0.02 0.2 0 - 1-1-1 59.68 16 4 20 0.02 0.2 0.1 K150 1-1-2 59.68 16 4 20 0.02 0.2 0.1 K200 1-1-3 59.68 16 4 20 0.02 0.2 0.1 K300 1-1-4 59.68 16 4 20 0.02 0.2 0.1 A200 1-1-5 59.68 16 4 20 0.02 0.2 0.1 A300 1-1-6 59.68 16 4 20 0.02 0.2 0.1 R972 1-1-7 59.68 16 4 20 0.02 0.2 0.1 R974 1-2-1 59.28 16 4 20 0.02 0.2 0.5 K150 1-2-2 59.28 16 4 20 0.02 0.2 0.5 K200 1-2-3 59.28 16 4 20 0.02 0.2 0.5 K300 1-2-4 59.28 16 4 20 0.02 0.2 0.5 A200 1-2-5 59.28 16 4 20 0.02 0.2 0.5 A300 1-2-6 59.28 16 4 20 0.02 0.2 0.5 R972 1-2-7 59.28 16 4 20 0.02 0.2 0.5 R974 1-3-1 58.78 16 4 20 0.02 0.2 1.0 K150 1-3-2 58.78 16 4 20 0.02 0.2 1.0 K200 1-3-3 58.78 16 4 20 0.02 0.2 1.0 K300 1-3-4 58.78 16 4 20 0.02 0.2 1.0 A200 1-3-5 58.78 16 4 20 0.02 0.2 1.0 A300 1-3-6 58.78 16 4 20 0.02 0.2 1.0 R972 1-3-7 58.78 16 4 20 0.02 0.2 1.0 R974

[0083] Example 2: Preparation of molded body (catalyst support)

[0084] FIG. 1 is a schematic diagram illustrating a process of manufacturing a molded body by 3D printing a powder composition and performing a carbon dioxide curing reaction, FIG. 2 is a schematic diagram of a carbon dioxide curing reaction in a carbon dioxide reactor, and FIG. 3 is a diagram showing a post-processing process of a molded body manufactured by 3D printing.

[0085] Example 2-1: Molded body immediately after 3D printing, CO 2 2 hours of curing

[0086] A molded body was obtained by printing the powder composition of Example 1-1-1 using a binder jet 3D printer with a water-soluble binder composition comprising 97 to 99.8 wt% deionized water, 0.1 to 2 wt% polyethylene glycol (PEG), and 0.1 to 1 wt% glycerol.

[0087] Afterward, the molded body was subjected to a CO2 curing reaction in a carbon dioxide reactor for 2 hours. At this time, the carbon dioxide density in the reactor was set to 99.9% or higher, the pressure to 0.45 MPa, and the temperature to room temperature.

[0088] Finally, to remove impurities from the carbon dioxide-cured molded body, a catalyst support was prepared by calcining heat treatment at 1000°C for 0.5 hours.

[0089] Example 2-2: Molded body immediately after 3D printing, CO 2 12 hours of curing

[0090] A catalyst support was prepared in the same manner as in Example 2-1, except that the CO2 curing reaction was carried out for 12 hours instead of 2 hours.

[0091] Examples 2-3: Molded body immediately after 3D printing, CO 2 24 hours of curing

[0092] A catalyst support was prepared in the same manner as in Example 2-1, except that the CO2 curing reaction was carried out for 24 hours instead of 2 hours.

[0093] Examples 2-4: Molded body impregnated in silica sol, CO 2 2 hours of curing

[0094] A molded body was obtained by printing the powder composition of Example 1-1-1 using a binder jet 3D printer with a water-soluble binder composition comprising 97 to 99.8 wt% deionized water, 0.1 to 2 wt% polyethylene glycol (PEG), and 0.1 to 1 wt% glycerol.

[0095] The above molded body was air-dried in a powder bed for 24 hours, recovered, and impregnated in silica sol for 0.1 hours.

[0096] Afterward, the molded body was subjected to a CO2 curing reaction in a carbon dioxide reactor for 2 hours. At this time, the carbon dioxide density in the reactor was set to 99.9% or higher, the pressure to 0.45 MPa, and the temperature to room temperature.

[0097] Finally, to remove impurities from the carbon dioxide-cured molded body, a catalyst support was prepared by calcining heat treatment at 1000°C for 0.5 hours.

[0098] Examples 2-5: Molded body impregnated in silica sol, CO 2 12 hours of curing

[0099] A catalyst support was prepared in the same manner as in Examples 2-4, except that the CO2 curing reaction was carried out for 12 hours instead of 2 hours.

[0100] Examples 2-6: Molded body impregnated in silica sol, CO 2 24 hours of curing

[0101] A catalyst support was prepared in the same manner as in Examples 2-4, except that the CO2 curing reaction was carried out for 24 hours instead of 2 hours.

[0102] Examples 2-7: Molded body heat-treated after impregnation in silica sol, CO 2 2 hours of curing

[0103] A molded body was obtained by printing the powder composition of Example 1-1-1 using a binder jet 3D printer with a water-soluble binder composition comprising 97 to 99.8 wt% deionized water, 0.1 to 2 wt% polyethylene glycol (PEG), and 0.1 to 1 wt% glycerol. The molded body was air-dried on a powder bed for 24 hours, recovered, and impregnated in silica sol for 0.1 hours.

[0104] In addition, the impregnated molded body was heat-treated at 1000°C for 30 minutes. Afterward, the molded body was subjected to a CO2 curing reaction in a carbon dioxide reactor for 2 hours. At this time, the carbon dioxide density in the reactor was set to 99.9% or higher, the pressure to 0.45 MPa, and the temperature to room temperature.

[0105] Finally, to remove impurities from the carbon dioxide-cured molded body, a catalyst support was prepared by calcining heat treatment at 1000°C for 0.5 hours.

[0106] Examples 2-8: Molded body heat-treated after impregnation in silica sol, CO 2 12 hours of curing

[0107] A catalyst support was prepared in the same manner as in Examples 2-7, except that the CO2 curing reaction was carried out for 12 hours instead of 2 hours.

[0108] Examples 2-9: Molded body heat-treated after impregnation in silica sol, CO 2 24 hours of curing

[0109] A catalyst support was prepared in the same manner as in Examples 2-7, except that the CO2 curing reaction was carried out for 24 hours instead of 2 hours.

[0110] Table 2 below shows the manufacturing methods of Examples 2-1 to 2-9.

[0111] 3D printing Silica sol impregnation heat treatment Curing reaction time (hr) Example 2-1 ○ ⅹ ⅹ 2 Example 2-2 ○ ⅹ ⅹ 12 Examples 2-3 ○ ⅹ ⅹ 24 Examples 2-4 ○ ○ ⅹ 2 Examples 2-5 ○ ○ ⅹ 12 Examples 2-6 ○ ○ ⅹ 24 Examples 2-7 ○ ○ ○ 2 Examples 2-8 ○ ○ ○ 12 Examples 2-9 ○ ○ ○ 24

[0112] ○: Perform, ⅹ: Not perform

[0113] [Test Example]

[0114] Test Example 1: Shape Analysis of Molded Body

[0115] Figure 4 shows photographs of a catalyst support manufactured by 3D printing before and after calcination heat treatment.

[0116] Referring to Fig. 4, the shape of the catalyst support before and after calcination heat treatment, which is the final step in the manufacturing process of Example 2-9, can be observed.

[0117] Test Example 2: Analysis of Powder Flow Characteristics

[0118] Figure 5 is a graph showing the flow characteristics of the powder composition. The powder flow characteristics were measured using a dynamic powder flowability analysis method.

[0119] Referring to FIG. 5 and Table 3 below, the avalanche angles of Examples 1-1-1 to 1-1-6, Examples 1-2-1 to 1-2-6, Examples 1-3-1 to 1-3-6 and Example 1-0 can be confirmed.

[0120] Based on the fact that fluidity decreases as the avalanche angle increases, it can be seen that the fluidity of Example 1-0, which does not contain fumed silica, will be the lowest because its avalanche angle is the largest at 63.2˚. Furthermore, it can be seen that when the same fumed silica product is used, fluidity will improve as the weight percentage of fumed silica increases, as the avalanche angle decreases. In particular, in the case of Example 1-3-5, a powder composition containing 1 weight% of Aerosil A300 fumed silica, it can be expected to have the best fluidity as the avalanche angle is the smallest at 31.8˚.

[0121] Examples Avalanche angle (degree) Example 1-1-1 48.2 Example 1-1-2 47.2 Example 1-1-3 48.8 Example 1-1-4 48.8 Example 1-1-5 37.3 Example 1-1-6 52.5 Example 1-2-1 38.1 Example 1-2-2 35.9 Example 1-2-3 37.3 Example 1-2-4 37.3 Example 1-2-5 35.1 Example 1-2-6 45.8 Example 1-3-1 34.7 Example 1-3-2 32.3 Example 1-3-3 36.2 Example 1-3-4 36.0 Example 1-3-5 31.8 Example 1-3-6 42.5 Example 1-0 63.2

[0122] Test Example 3: SEM Analysis

[0123] Figure 6 is a scanning electron microscope (SEM) image of a powder composition according to an additive. Referring to Figure 6, one can see scanning electron microscope (SEM) images of fumed silica, wollastonite, and the powder compositions of Examples 1-1-2, 1-2-2, 1-3-2, 1-1-5, 1-2-5, 1-3-5, 1-1-7, 1-2-7, and 1-3-7. According to the SEM images of each powder composition, it can be confirmed that the fumed silica used as a fluidizing agent is uniformly and stably coated on the surface of the raw powder particles. It can be seen that this effect effectively reduces the frictional force between powder particles, thereby improving powder flowability.

[0124] Test Example 4: Analysis of the surface condition of the powder bed

[0125] Figure 7 is a diagram comparing the surface condition of a powder bed according to additives. Referring to Figure 7, Example 1-0, which does not contain fumed silica as a fluidizing agent, has a non-uniform powder bed surface and is unsuitable, whereas the powder bed surface of Example 1-3-5, which contains 1 wt% of fumed silica Aerosil A300, is uniform and is suitable. It can be seen that a powder composition with improved fluidity using fumed silica can form a suitable powder bed.

[0126] Test Example 5: Measurement of Compressive Strength and Carbon Dioxide Immobilization Rate

[0127] Figure 8 is a graph showing the compressive strength (Mpa) and carbon dioxide fixation rate (%) of the molded body according to the post-treatment step and the carbon dioxide fixation reaction time.

[0128] Compressive strength

[0129] Compressive strength was measured using the uniaxial load compressive strength measurement method. Compressive strength measurement samples were prepared as 10*10*10 mm cubes, and each was measured at least 5 times; the average value was presented excluding the minimum and maximum values.

[0130] Referring to Figure 8 and Table 4 below, it can be seen that the compressive strength improves with carbon dioxide curing time. Comparing Examples 2-1 and 2-3, it can be confirmed that the compressive strength improves by approximately 35% with curing for up to 24 hours, which indicates that the compressive strength can be improved through carbon dioxide fixation.

[0131] Examples Compressive strength (Mpa) Example 2-1 1.31 Example 2-2 1.78 Examples 2-3 1.78 Examples 2-4 2.68 Examples 2-5 3.23 Examples 2-6 3.45 Examples 2-7 4.25 Examples 2-8 4.52 Examples 2-9 4.56

[0132] Measurement of carbon dioxide fixation rate

[0133] The carbon dioxide fixation rate was measured by thermogravimetric analysis (DT-TGA). Since carbonates produced by the carbon dioxide reaction decompose at temperatures above approximately 650°C, the weight loss at 650 to 1000°C was expressed as the carbon dioxide fixation rate as the total weight ratio.

[0134] Referring to Figure 8 and Table 5 below, it can be seen that the immobilization rate improves with carbon dioxide curing time. Additionally, it can be seen that Examples 2-6 can immobilize 14.37 wt% of carbon dioxide in the molded body by carbon dioxide curing for up to 24 hours.

[0135] Examples Carbon dioxide fixation rate (weight%) Example 2-1 3.05 Example 2-2 9.82 Examples 2-3 12.28 Examples 2-4 4.67 Examples 2-5 13.47 Examples 2-6 14.37 Examples 2-7 2.43 Examples 2-8 5.58 Examples 2-9 7.62

[0136] The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention.

Claims

Claim 1 A powder composition comprising inorganic powder; calcium aluminate cement; and wollastonite (CaSiO3); wherein the powder composition further comprises a fluidizing agent, and the fluidizing agent comprises fumed silica. Claim 2 A powder composition according to claim 1, characterized in that the powder composition is intended for use in 3D printing. Claim 3 A powder composition according to claim 1, characterized in that the powder composition fixes carbon dioxide. Claim 4 A powder composition according to claim 1, characterized in that the calcium aluminate cement and the wollastonite each fix carbon dioxide. Claim 5 A powder composition according to claim 1, characterized in that the inorganic powder comprises one or more selected from the group consisting of silica (SiO2), alumina (Al2O3), zirconia (ZrO2), zirconium silicate (ZrSiO4), chromium oxide (Cr2O3), magnesium oxide (MgO), calcium oxide (CaO), phosphorus oxide (P2O5), sodium oxide (Na2O), iron oxide (Fe2O3), potassium oxide (K2O), and titanium dioxide (TiO2). Claim 6 A powder composition according to claim 1, characterized in that the cement comprises one or more selected from the group consisting of CaOAl2O3(CA), 3CaOAl2O3(C3A), CaO2Al2O3(CA2), and CaO6Al2O3(CA6). Claim 7 A powder composition according to claim 1, characterized in that the powder composition further comprises 12CaO-7Al2O3 (C12A7). Claim 8 delete Claim 9 delete Claim 10 A powder composition according to claim 1, characterized in that the powder composition further comprises a binder. Claim 11 A powder composition according to claim 10, characterized in that the binder comprises one or more selected from the group consisting of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), dextrin, methyl cellulose (MC), hydroxypropyl methyl cellulose (HPMC), polyethylene oxide (PEO), polyvinyl butyral (PB), colloidal silica, and polyethylene glycol. Claim 12 A powder composition according to claim 1, characterized in that the powder composition further comprises a curing accelerator. Claim 13 A powder composition according to claim 12, characterized in that the hardening accelerator comprises one or more selected from the group consisting of lithium carbonate, lithium bromide hydroxide, lithium chloride, lithium carbonate hydroxide, lithium nitrate, lithium sulfate, lithium sulfide, lithium phosphate, lithium oxalate, and quicklime. Claim 14 A powder composition according to claim 1, characterized in that the powder composition comprises 100 parts by weight of inorganic powder; 1 to 50 parts by weight of calcium aluminate cement; and 10 to 50 parts by weight of wollastonite. Claim 15 A powder composition according to claim 14, characterized in that the powder composition further comprises 0.1 to 10 parts by weight of a fluidizing agent. Claim 16 A powder composition according to claim 1, characterized in that the size of the inorganic particles is 10 to 100 μm. Claim 17 A molded body hardened by fixing carbon dioxide in the powder composition according to claim 1. Claim 18 (a) a step of preparing a powder composition comprising inorganic powder, calcium aluminate cement, and wollastonite (CaSiO3); (b) a step of preparing a first molded body by 3D printing the powder composition; (c) a step of impregnating the first molded body with a silica sol; (d) a step of preparing a second molded body by reacting the first molded body impregnated with the silica sol with carbon dioxide (CO2) to immobilize the CO2 in the first molded body; and (e) a step of preparing a third molded body by calcining the second molded body by heat treatment to remove impurities; a method for preparing a molded body comprising. Claim 19 A method for manufacturing a molded body according to claim 18, wherein the above step (b) comprises: (b-1) a step of forming a powder composition layer comprising the above powder composition; (b-2) a step of manufacturing a pattern layer by irradiating a binder mixed solution comprising a binder onto the powder composition layer in a predetermined pattern; and (b-3) a step of manufacturing a first molded body by repeating the above steps (b-1) and (b-2) each n times (n is an integer greater than or equal to 0) onto the pattern layer. Claim 20 A method for manufacturing a molded body according to claim 19, characterized in that the binder mixture solution comprises one or more selected from the group consisting of polyethylene glycol (PEG) and glycerol and water.

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