Waste eggshell calcium oxide photocatalyst material and manufacturing method thereof

Abstract

A method for producing calcium oxide photocatalyst material from waste eggshells includes: providing at least one waste eggshell material; providing at least one microwave source; using the microwave source to perform a preliminary thermal decomposition process on the waste eggshell material to produce at least one pre-thermally decomposed waste eggshell material; and sintering the pre-thermally decomposed waste eggshell material to obtain at least one micron-sized photocatalyst material or at least one nano-sized photocatalyst material.

Description

Technical Field

[0001] This invention relates to a calcium oxide photocatalyst material (CaO) made from waste eggshells, a method thereof, and a manufacturing method thereof; particularly, it relates to a rapid method for producing micro-scaled or nano-scaled calcium oxide photocatalyst material from waste eggshells; and even more particularly, it relates to a method for producing nano-scale calcium oxide photocatalyst material from waste eggshells by microwave thermal-treating. Prior Technology

[0002] For example, conventional methods for processing calcium-containing biological waste into hydroxyapatite materials and methods thereof include the invention patent No. TW-I494270 of the Republic of China entitled "Method for synthesizing hydroxyapatite by adding plant extracts to calcium-containing biological waste", which discloses a method for synthesizing hydroxyapatite by adding plant extracts to calcium-containing biological waste.

[0003] As mentioned above, the method for synthesizing hydroxyapatite from calcium-containing biological waste with the addition of plant extracts, as described in Announcement No. TW-I494270, includes the following steps: a washing and drying process, a grinding process, a dissolving process, an adding process, a reaction synthesis process, and a drying process.

[0004] As mentioned above, the cleaning and drying process of the method for synthesizing hydroxyapatite by adding plant extracts to calcium-containing biological waste in the aforementioned announcement No. TW-I494270 is as follows: First, a calcium-containing biological waste is cleaned, and then the calcium-containing biological waste is dried to obtain a dried calcium-containing biological waste.

[0005] Continuing from the above, the grinding process of the aforementioned announcement No. TW-I494270 in the method of synthesizing hydroxyapatite by adding plant extracts to calcium-containing biological waste is as follows: the dried calcium-containing biological waste is then ground to form a calcium powder.

[0006] Continuing from the above, the dissolution process of the method for synthesizing hydroxyapatite by adding plant extracts to calcium-containing biological waste in the aforementioned announcement No. TW-I494270 is as follows: then, hydrochloric acid is added to the calcium powder, so that the calcium powder is fully dissolved in the hydrochloric acid to obtain a calcium solution, and phosphoric acid is added dropwise to the calcium solution to form a suspension.

[0007] Continuing from the above, the addition process of the method for synthesizing hydroxyapatite by adding plant extracts to calcium-containing biological waste in the aforementioned announcement No. TW-I494270 is as follows: Next, a plant extract is added to the suspension to form a mixture, and the particle size in the mixture is controlled. Then, the pH value of the mixture is adjusted with ammonia water, and the mixture is uniformly mixed to obtain a uniformly mixed solution.

[0008] Continuing from the above, the reaction synthesis process of the method for synthesizing hydroxyapatite by adding plant extracts to calcium-containing biological waste as described in the aforementioned announcement No. TW-I494270 is as follows: Next, the uniformly mixed solution with adjusted pH value is reacted for a reaction time to obtain a synthesized solution, and the synthesized solution is washed with deionized water to obtain a washed solution.

[0009] Continuing from the above, the drying process of the method for synthesizing hydroxyapatite by adding plant extracts to calcium-containing biological waste as described in the aforementioned announcement No. TW-I494270 is as follows: Finally, the cleaned mixture is dried to obtain hydroxyapatite powder.

[0010] However, although the aforementioned Republic of China Patent Publication No. TW-I494270 only discloses the synthesis of hydroxyapatite material and method by adding plant extracts to calcium-containing biological waste, it cannot be applied to the preparation of calcium oxide photocatalyst material. Therefore, there is a potential need to further improve its material, its operation method and its preparation system.

[0011] Another common method for processing waste eggshells into calcium fluoride materials is the invention patent No. TW-I734269 of the Republic of China, entitled "Method for reacting waste eggshells with hydrofluoric acid to generate calcium fluoride", which discloses a method for reacting waste eggshells with hydrofluoric acid to generate calcium fluoride.

[0012] As mentioned above, the method for reacting waste eggshells with hydrofluoric acid to produce calcium fluoride in the aforementioned announcement No. TW-I734269 includes step A: purifying a waste eggshell to obtain a purified waste eggshell and increasing the calcium carbonate content of the purified waste eggshell.

[0013] Continuing from the above, the method for reacting waste eggshells with hydrofluoric acid to produce calcium fluoride as described in the aforementioned announcement No. TW-I734269 includes step A: purification treatment, which involves washing the purified waste eggshells and then subjecting them to an alkali treatment, followed by crushing, grinding, and sieving to form a fine calcium carbonate powder. The alkali treatment involves placing the purified waste eggshells into a sodium hydroxide solution with a weight concentration between 20% and 50% for a reaction time of 2 to 4 hours, thereby dissolving one of the egg membranes of the waste eggshells in the sodium hydroxide solution. The solution is then filtered and dried at a temperature between 70°C and 105°C.

[0014] As mentioned above, the method for reacting waste eggshells with hydrofluoric acid to produce calcium fluoride in the aforementioned announcement No. TW-I734269 includes step B: reacting the purified waste eggshells with calcium carbonate to produce calcium chloride or calcium hydroxide.

[0015] Continuing from the above, in step B of the method for reacting waste eggshells with hydrofluoric acid to produce calcium fluoride as described in the aforementioned announcement No. TW-I734269: the reaction is carried out at a reaction temperature of 40°C for 20 minutes, and the ratio of calcium carbonate to hydrochloric acid is 1:2 (in moles), to produce calcium chloride. The calcium carbonate fine powder is then heated at a temperature of 900°C to 1100°C for 1 to 4 hours, thereby decomposing the calcium carbonate fine powder into calcium oxide. The calcium oxide is then dissolved in water to form calcium hydroxide.

[0016] As mentioned above, the method for reacting waste eggshells with hydrofluoric acid to produce calcium fluoride in the aforementioned announcement No. TW-I734269 includes step C: adding the calcium chloride or the calcium hydroxide to hydrofluoric acid so as to react and produce the final product of calcium fluoride.

[0017] However, although the aforementioned Republic of China Patent Publication No. TW-I734269 only discloses a method for reacting waste eggshells with hydrofluoric acid to generate calcium fluoride, it cannot be applied to the preparation of calcium oxide photocatalyst materials. Therefore, there is a potential need to further improve its materials, its operation method and its preparation system.

[0018] Obviously, the invention patents published by the Republic of China in TW-I494270 and TW-I734269 are only for reference and explanation of the current state of technological development of this invention, and are not intended to limit the scope of this invention.

[0019] In view of this, in order to meet the above-mentioned technical problems and needs, the present invention provides a method for producing calcium oxide photocatalyst material from waste eggshells. The method provides at least one waste eggshell material and at least one microwave source. The waste eggshell material is subjected to a preliminary thermal decomposition process using the microwave source to produce at least one pre-thermally decomposed waste eggshell material. This pre-thermally decomposed waste eggshell material is then sintered to obtain at least one micron-sized photocatalyst material (or micron-sized photocatalyst crystal material) or at least one nano-sized photocatalyst material (or nano-sized photocatalyst crystal material). Therefore, compared to conventional waste eggshell processing materials and preparation methods, this invention offers advantages such as increasing the economic value of waste eggshell materials, reducing the cost of calcium oxide photocatalyst materials, and rapidly forming nano-sized photocatalyst crystal materials. Summary of the Invention

[0020] The main objective of this invention is to provide a method for producing calcium oxide photocatalyst material from waste eggshells. The method involves providing at least one waste eggshell material and at least one microwave source. The waste eggshell material is subjected to a preliminary thermal decomposition process using the microwave source to produce at least one pre-thermally decomposed waste eggshell material. This pre-thermally decomposed waste eggshell material is then sintered to obtain at least one micron-sized photocatalyst material (or micron-sized photocatalyst crystal material) or at least one nano-sized photocatalyst material (or nano-sized photocatalyst crystal material). This achieves the objectives and effects of increasing the economic value of waste eggshell material, reducing the cost of calcium oxide photocatalyst material, and rapidly forming nano-sized photocatalyst crystal material.

[0021] To achieve the above objectives, a preferred embodiment of the present invention comprises a calcium oxide photocatalyst material made from waste eggshells, which includes:

[0022] At least one discarded eggshell material, which is formed from at least one eggshell material;

[0023] At least one microwave source is used to process the waste eggshell material;

[0024] At least one type of waste eggshell material that has undergone preliminary pyrolysis is generated by using the microwave source to perform a preliminary pyrolysis process on the waste eggshell material; and

[0025] At least one micrometer-scale photocatalytic material (or micrometer-scale photocatalytic crystal material) or at least one nanometer-scale photocatalytic material (or nanometer-scale photocatalytic crystal material) is obtained by sintering the waste eggshell material that has undergone preliminary thermal decomposition.

[0026] In a preferred embodiment of the present invention, a guiding element is used to perform an auxiliary thermal pyrolysis process on the waste eggshell material or the waste eggshell material that has been preliminarily thermally pyrolyzed, so as to produce at least one waste eggshell material that has been preliminarily thermally pyrolyzed.

[0027] In a preferred embodiment of the present invention, the guiding element is used to accommodate the waste eggshell material.

[0028] In a preferred embodiment of the present invention, the guiding element is used to guide the microwave source to the waste eggshell material.

[0029] In a preferred embodiment of the present invention, the micron-sized photocatalyst material (or micron-sized photocatalyst crystalline material) or nano-sized photocatalyst material (or nano-sized photocatalyst crystalline material) may be combined with at least one polyester plastic or at least one plastic.

[0030] To achieve the above objectives, a preferred embodiment of the present invention provides a method for producing calcium oxide photocatalyst material from waste eggshells, comprising:

[0031] Provide at least one piece of discarded eggshell material;

[0032] Provide at least one microwave source;

[0033] The waste eggshell material is subjected to a preliminary pyrolysis process using the microwave source to produce at least one partially pyrolyzed waste eggshell material; and

[0034] The waste eggshell material that has undergone preliminary thermal decomposition is sintered to obtain at least one micrometer-scale photocatalytic material (or micrometer-scale photocatalytic crystal material) or at least one nanometer-scale photocatalytic material (or nanometer-scale photocatalytic crystal material).

[0035] In a preferred embodiment of the present invention, a guiding element is used to perform an auxiliary thermal pyrolysis process on the waste eggshell material or the waste eggshell material that has been preliminarily thermally pyrolyzed, so as to produce at least one waste eggshell material that has been preliminarily thermally pyrolyzed.

[0036] In a preferred embodiment of the present invention, the guiding element is used to accommodate the waste eggshell material.

[0037] In a preferred embodiment of the present invention, the guiding element is used to guide the microwave source to the waste eggshell material.

[0038] In a preferred embodiment of the present invention, the micron-scale photocatalyst material (or micron-scale photocatalyst crystalline material) or nano-scale photocatalyst material (or nano-scale photocatalyst crystalline material) can be combined with at least one plastic material, at least one metal material, at least one ceramic material, at least one oxide material, at least one semiconductor material, at least one carbon material, or any combination thereof, to form a composite photocatalyst material. Simple Explanation of the Diagram

[0039]

[0040] Figure 1: A block diagram of a calcium oxide photocatalyst material made from waste eggshells according to a first preferred embodiment of the present invention.

[0041] Figure 2: Schematic diagram of the process for producing calcium oxide photocatalyst material from waste eggshells according to the first preferred embodiment of the present invention.

[0042] Figure 3: A block diagram of a calcium oxide photocatalyst material made from waste eggshells according to a second preferred embodiment of the present invention.

[0043] Figure 4: A schematic flowchart of a method for producing calcium oxide photocatalyst material from waste eggshells according to a second preferred embodiment of the present invention.

[0044] Figure 5: A side view schematic diagram of the method for producing calcium oxide photocatalyst material from waste eggshells according to the second preferred embodiment of the present invention.

[0045] Figure 6: A schematic diagram of the relationship between heating time and temperature in the method for producing calcium oxide photocatalyst material from waste eggshells according to a preferred embodiment of the present invention.

[0046] Figures 7(a) and 7(b): Schematic diagrams of scanning electron microscopy images of the calcium oxide photocatalyst material made from waste eggshells according to a preferred embodiment of the present invention.

[0047] Figures 8(a) to 8(c): Schematic diagrams of scanning electron microscopy images of calcium oxide photocatalyst material made from waste eggshells according to another preferred embodiment of the present invention. Implementation

[0048] To fully understand the present invention, preferred embodiments will be described in detail below with reference to the accompanying drawings, but these are not intended to limit the present invention.

[0049] The preferred embodiment of the present invention, which describes a calcium oxide photocatalyst material made from waste eggshells, its structure, method, and system, is applicable to various agricultural resource wastes (e.g., waste eggshell materials or materials containing waste eggshell components) or various agricultural resource recyclables (e.g., calcium oxide compound materials), as well as related photocatalyst technologies and products (e.g., powder materials, film materials, material coatings, or other products). However, it is not intended to limit the scope of the present invention.

[0050] Figure 1 is a block diagram illustrating a calcium oxide photocatalyst material made from waste eggshells according to a first preferred embodiment of the present invention. Referring to Figure 1, the calcium oxide photocatalyst material made from waste eggshells according to the first preferred embodiment of the present invention comprises at least one waste eggshell material 1.

[0051] Please refer to Figure 1 again. For example, the waste eggshell material 1 may include a waste chicken eggshell material, a waste duck eggshell material, a waste goose eggshell material, or a waste quail eggshell material or other waste eggshell materials (e.g., waste bird eggshell material).

[0052] Please refer to Figure 1 again. For example, the waste eggshell material 1 can be selected from a food waste eggshell material (e.g., kitchen waste eggshell material) or a processing waste eggshell material (e.g., preserved egg processing, salted egg processing, iron egg processing or other processing waste eggshell material).

[0053] Please refer to Figure 1 again. For example, the waste eggshell material 1 mainly contains at least one calcium carbonate (CaCO3) component, and the waste eggshell material 1 can be selected to undergo at least one or more pre-treatment operations, such as eggshell sorting, eggshell washing or other treatment operations.

[0054] Please refer to Figure 1 again. For example, the waste eggshell material 1 can be subjected to at least one or more pre-drying processes, such as natural wind circulation drying, hot air drying, heating drying, or other drying processes.

[0055] Figure 2 illustrates a flowchart of a method for manufacturing a gain-enhancing pyrolytic adhesive material according to a first preferred embodiment of the present invention. Referring to Figures 1 and 2, for example, the method for producing calcium oxide photocatalyst material from waste eggshells according to a first preferred embodiment of the present invention includes step S1A: First, at least one or more of the waste eggshell material 1 can be provided by appropriate technical means (e.g., automatic, semi-automatic, or manual methods), as shown in the upper half of Figure 1.

[0056] Please refer to Figures 1 and 2 again. For example, the waste eggshell material 1 can be selected in a predetermined amount and the predetermined amount of waste eggshell material 1 can be appropriately placed in a predetermined position of at least one carrying container (e.g., a cavity container or a heat-concentrating container, not shown) or a device with a similar carrying object function.

[0057] Please refer again to Figures 1 and 2. For example, the method of making calcium oxide photocatalyst material from waste eggshells according to the first preferred embodiment of the present invention includes step S1B: then, at least one or more microwave generating sources 2 (e.g., microwave oven equipment) can be provided by appropriate technical means (e.g., automatic, semi-automatic or manual), as shown on the right side of Figure 1.

[0058] Please refer to Figures 1 and 2 again. For example, the microwave source 2 can be selected from a microwave source unit or a device with similar microwave generation function, and the microwave source 2 is appropriately matched with the carrying container (not shown) and the waste eggshell material 1 contained therein.

[0059] Please refer to Figures 1 and 2 again. For example, the microwave source 2 can be selected from a microwave oven, and the microwave oven can be selected to generate a predetermined microwave frequency, which can be selected to be between approximately 2450MHz (microwave oven heating food) and 22GHz (microwave oven heating free water molecules).

[0060] Please refer again to Figures 1 and 2. For example, the method for making calcium oxide photocatalyst material from waste eggshells in the first preferred embodiment of the present invention includes step S2: Then, by means of appropriate technology (e.g., automatic, semi-automatic or manual), the waste eggshell material 1 can be subjected to a preliminary thermal decomposition process (e.g., microwave heating process or microwave oven heating process) using the microwave source 2, and the preliminary thermal decomposition process is executed for a predetermined time in order to produce at least one preliminary thermally decomposed waste eggshell material 10.

[0061] Please refer to Figures 1 and 2 again. For example, the preparation of the preliminarily pyrolyzed waste eggshell material 10 can partially (or completely) replace the operation of the traditional high-temperature furnace by using microwave oven heating, so as to achieve appropriate energy saving and improved processing efficiency.

[0062] Please refer again to Figures 1 and 2. For example, the method for making calcium oxide photocatalyst material from waste eggshells in the first preferred embodiment of the present invention includes step S3: Then, the waste eggshell material 10 that has been preliminarily thermally decomposed can be subjected to appropriate sintering treatment by appropriate technical means (e.g., automatic, semi-automatic or manual), such as microwave heating treatment or microwave oven heating treatment, in order to obtain at least one micron-sized photocatalyst crystal material 100 (or micron-sized photocatalyst material, i.e., material that has not yet formed crystals) or at least one nano-sized photocatalyst crystal material 101 (or nano-sized photocatalyst material, i.e., material that has not yet formed crystals).

[0063] Please refer to Figures 1 and 2 again. For example, the sintering process (e.g., microwave heating process or microwave oven heating process) can be performed for a predetermined time, which can be selected as about 20 minutes or other processing time, compared to the traditional sintering process which requires heating for about 8 hours or more.

[0064] Please refer to Figures 1 and 2 again. For example, the micron-scale photocatalytic crystal material 100 (or micron-scale photocatalytic material, i.e., material that has not yet formed crystals) or the nano-scale photocatalytic crystal material 101 (or nano-scale photocatalytic material, i.e., material that has not yet formed crystals) can be selectively combined with at least one predetermined material to form at least one composite micron-scale or nano-scale photocatalytic material.

[0065] Please refer again to Figures 1 and 2. For example, in another preferred embodiment of the present invention, the predetermined material combined with the composite micron- or nano-scale photocatalyst material can be selected from various materials, and the micron-scale photocatalyst crystal material 100 (or micron-scale photocatalyst material, i.e., material that has not yet formed crystals) or the nano-scale photocatalyst crystal material 101 (or nano-scale photocatalyst material, i.e., material that has not yet formed crystals) can be selected to be combined with at least one plastic material, at least one metal material, at least one ceramic material, at least one oxide material, at least one semiconductor material, at least one carbon material, or any combination thereof to form a composite photocatalyst material.

[0066] Please refer again to Figures 1 and 2. For example, in another preferred embodiment of the present invention, the plastic material may be selected from polyester plastic materials, which may be selected from polycaprolactone (PCL), polylactic acid (PLA) or other plastic materials.

[0067] Figure 3 is a block diagram illustrating a calcium oxide photocatalyst material made from waste eggshells according to a second preferred embodiment of the present invention, corresponding to the calcium oxide photocatalyst material made from waste eggshells shown in Figure 1. Figure 4 is a flowchart illustrating a method for making calcium oxide photocatalyst material from waste eggshells according to a second preferred embodiment of the present invention, corresponding to the method for making calcium oxide photocatalyst material from waste eggshells shown in Figure 2.

[0068] Please refer to Figures 3 and 4. For example, the method of making calcium oxide photocatalyst material from waste eggshells according to the second preferred embodiment of the present invention includes step S1A: First, at least one or more of the waste eggshell material 1 can be provided by appropriate technical means (e.g., automatic, semi-automatic or manual method), as shown in the upper half of Figure 3.

[0069] Please refer to Figures 3 and 4 again. For example, the method of making calcium oxide photocatalyst material from waste eggshells according to the second preferred embodiment of the present invention includes step S1B: then, at least one or more microwave generating sources 2 (e.g., microwave oven equipment) can be provided by appropriate technical means (e.g., automatic, semi-automatic or manual mode), as shown on the right side of Figure 3.

[0070] Please refer again to Figures 3 and 4. For example, the method for making calcium oxide photocatalyst material from waste eggshells according to the second preferred embodiment of the present invention includes step S2: Then, the waste eggshell material 1 is subjected to a preliminary thermal decomposition process (e.g., microwave heating process or microwave oven heating process) by means of appropriate technical means (e.g., automatic, semi-automatic or manual method) using the microwave source 2, and the preliminary thermal decomposition process is executed for a predetermined time to produce at least one piece of waste eggshell material that has been preliminarily thermally decomposed (as shown in Figure 1, 10).

[0071] Figure 5 is a side view schematic diagram illustrating the execution of a method for producing calcium oxide photocatalyst material from waste eggshells according to a second preferred embodiment of the present invention. Referring to Figure 5, for example, a guiding element 20 or an element with similar guiding function is applied to the preliminary pyrolysis process or other subsequent processing procedures (e.g., auxiliary sintering process).

[0072] Please refer to Figure 5. For example, the guide element 20 is used to properly accommodate the waste eggshell material 1, and the guide element 20 is used to properly guide the microwave source 2 to the waste eggshell material 1 to assist in subsequent processing procedures.

[0073] Please refer again to Figures 3, 4, and 5. For example, the method for producing calcium oxide photocatalyst material from waste eggshells in a preferred embodiment of the present invention includes step S20: Then, using appropriate technical means (e.g., automatic, semi-automatic, or manual), the waste eggshell material 1 or the waste eggshell material that has undergone preliminary pyrolysis (as shown in Figure 1, 10) can be selected to undergo an auxiliary pyrolysis process using the guide element 20, and the auxiliary pyrolysis process is executed for a predetermined time to produce at least one waste eggshell material 10a that has undergone preliminary pyrolysis.

[0074] Please refer to Figures 3, 4 and 5. For example, the guide element 20 may have at least one heat insulation element 21, which may be selected from a wrapping element or a heat-resistant container (e.g., ceramic material). The guide element 20 may have at least one heat-retaining material (not shown), which may be selected from a heat-retaining coating, a heat-retaining powder material or any combination thereof.

[0075] Please refer again to Figures 3, 4, and 5. For example, the method for making calcium oxide photocatalyst material from waste eggshells in the second preferred embodiment of the present invention includes step S30: Then, the waste eggshell material 10a that has undergone preliminary thermal decomposition can be appropriately sintered using appropriate technical means (e.g., automatic, semi-automatic, or manual methods), such as microwave heating, microwave oven heating, electric heating, or other heating processes, in order to obtain at least one micrometer-scale photocatalyst crystal material 100 (or micrometer-scale photocatalyst material, i.e., material that has not yet formed crystals) or at least one nanometer-scale photocatalyst crystal material 101 (or nanometer-scale photocatalyst material, i.e., material that has not yet formed crystals).

[0076] Figure 6 illustrates a schematic diagram of the relationship between heating time and temperature in the method for producing calcium oxide photocatalyst material from waste eggshells according to a preferred embodiment of the present invention. Referring to Figure 6, for example, in the present invention, the heating temperature reaches 700°C approximately 5 minutes after heating, 1100°C approximately after 10 minutes, and 1300°C approximately after 20 minutes.

[0077] Figures 7(a) and 7(b) illustrate schematic diagrams of scanning electron micrographs of the calcium oxide photocatalyst material made from waste eggshells according to a preferred embodiment of the present invention. Referring to Figures 7(a) and 7(b), for example, the scanning electron micrographs of the calcium oxide photocatalyst material made from waste eggshells according to a preferred embodiment of the present invention include longitudinal section micrographs (as shown in Figure 7(a)) and top-view micrographs (as shown in Figure 7(b)).

[0078] Please refer again to Figures 7(a) and 7(b). For example, in a preferred embodiment of the present invention, longitudinal section micrographs (as shown in Figure 7(a)) and top view micrographs (as shown in Figure 7(b)) of waste eggshell material are used to show that the surface of the eggshell material in the longitudinal section and top view has several microporous structures (as shown by the dashed lines A1 and A2 in Figure 7(a)), several loose microstructures, or both.

[0079] Please refer again to Figures 7(a) and 7(b). For example, compared to using a common source of calcium carbonate, the preferred embodiment of the present invention uses calcium oxide photocatalyst material made from waste eggshells. Using waste eggshell material is particularly suitable for rapidly forming photocatalyst materials with a relatively large surface area ratio (or a relatively large surface area ratio) (as shown by the dashed lines A1 and A2 in Figure 7(a)).

[0080] Figures 8(a) to 8(c) illustrate scanning electron microscopy (SEM) images of a calcium oxide photocatalyst material made from waste eggshells according to another preferred embodiment of the present invention. Referring to Figure 8(a), for example, in another preferred embodiment of the present invention, when the heating time reaches about 15 minutes, it shows that the CaO particles are large in size and have a high degree of interparticle density, while the CaCO3 particles have a low specific surface area and insufficient crystallinity, that is, the carbon dioxide in the calcium carbonate has not been completely removed.

[0081] Please refer to Figure 8(b). For example, in another preferred embodiment of the present invention, when the heating time reaches about 20 minutes, it is shown that the particle size of CaO has gradually decreased, and the micro-nano-level unevenness of its surface has become more obvious, and the gaps between its particles have gradually increased. Compared with the crystallinity shown in Figure 8(a), its crystallinity is relatively high, that is, the carbon dioxide in its calcium carbonate has been almost removed.

[0082] Please refer to Figure 8(c). For example, in another preferred embodiment of the present invention, when the heating time reaches about 25 minutes, the particle size of the CaO is shown to gradually decrease, and the micro-nano-level unevenness of its surface becomes more obvious, and the gaps between its particles gradually increase. Compared with the crystallinity shown in Figure 8(b), its crystallinity is relatively higher, that is, the carbon dioxide in its calcium carbonate has been completely removed.

[0083] Furthermore, given that the calcium carbonate in eggshells is formed through biomineralization on the egg membrane, its source differs from other sources of calcium carbonate. Generally speaking, eggshells belong to the fastest biomineralization system on Earth. That is, due to its rapid growth, the surface of the eggshell's calcium carbonate is not a dense calcium carbonate crystal. Its thickness is 10 to 30 μm, and its surface has approximately 7,000 to 17,000 pores. In addition to allowing oxygen or water vapor to pass through, it also allows chicks to peck open the eggshell after hatching and thus hatch.

[0084] The preferred embodiment of the present invention uses calcium oxide photocatalyst material made from waste eggshells, which has a porous surface to achieve a large contact area. Therefore, compared with other photocatalyst materials and technologies, it is more suitable for development as a composite photocatalyst.

[0085] The above experimental data are preliminary results obtained under specific conditions and are only used to facilitate understanding or reference of the technical content of this invention. Further related experiments are required. This experimental data and its results are not intended to limit the scope of this invention.

[0086] The foregoing preferred embodiments are merely illustrative of the present invention and its technical features. The technology of these embodiments can still be implemented with various substantially equivalent modifications and / or substitutions; therefore, the scope of the present invention must be determined by the scope defined in the appended claims. This copyright application is limited to the uses specified in the Republic of China patent application.

[0087]

[0088] 1: Waste eggshell material

[0089] 10: Waste eggshell materials that have undergone preliminary pyrolysis

[0090] 10a: Waste eggshell material has been preliminarily pyrolyzed with assistance.

[0091] 100: Micron-scale photocatalytic crystal material

[0092] 101: Nanoscale photocatalytic crystallizing material

[0093] 2: Microwave source

[0094] 20: Guiding element

[0095] 21: Thermal insulation element

[0096] A1: Micropores

[0097] A2: Micropores

Claims

1. A calcium oxide photocatalyst material made from waste eggshells, comprising: at least one micron-sized photocatalyst material or at least one nano-sized photocatalyst material, wherein at least one waste eggshell material is formed from at least one eggshell material, and at least one microwave source is used to process the waste eggshell material, and the waste eggshell material is subjected to a preliminary thermal decomposition process using the microwave source to produce at least one pre-thermally thermally decomposed waste eggshell material, wherein the preliminary thermal decomposition process is a microwave heating process or a microwave oven heating process, and the pre-thermally thermally decomposed waste eggshell material is subjected to sintering treatment to obtain the final product.

2. The calcium oxide photocatalyst material made from waste eggshells as described in claim 1, wherein a guiding element is used to perform an auxiliary pyrolysis process on the waste eggshell material or the pre-pyrolyzed waste eggshell material to produce at least one pre-pyrolyzed waste eggshell material.

3. The calcium oxide photocatalyst material made from waste eggshells as described in claim 2, wherein the guiding element is used to contain the waste eggshell material.

4. The calcium oxide photocatalyst material made from waste eggshells as described in claim 2, wherein the guiding element is used to guide the microwave source to the waste eggshell material.

5. The calcium oxide photocatalyst material made from waste eggshells as described in claim 1, wherein the micron-sized or nano-sized photocatalyst material may be bonded to at least one plastic.

6. A method for producing calcium oxide photocatalyst material from waste eggshells, comprising: providing at least one waste eggshell material; providing at least one microwave source; using the microwave source to perform a preliminary thermal decomposition process on the waste eggshell material to produce at least one preliminarily thermally decomposed waste eggshell material, wherein the preliminary thermal decomposition process is a microwave heating process or a microwave oven heating process; and sintering the preliminarily thermally decomposed waste eggshell material to obtain at least one micron-sized photocatalyst material or at least one nano-sized photocatalyst material.

7. The method for producing calcium oxide photocatalyst material from waste eggshells as described in claim 6, wherein a guiding element is used to perform an auxiliary pyrolysis process on the waste eggshell material or the pre-pyrolyzed waste eggshell material to produce at least one pre-pyrolyzed waste eggshell material.

8. The method for producing calcium oxide photocatalyst material from waste eggshells as described in claim 7, wherein the guiding element is used to contain the waste eggshell material.

9. The method for producing calcium oxide photocatalyst material from waste eggshells as described in claim 7, wherein the guiding element is used to correspondingly guide the microwave source to the waste eggshell material.

10. The method for producing calcium oxide photocatalyst material from waste eggshells as described in claim 6, wherein the micron-sized or nano-sized photocatalyst material may be bonded to at least one plastic.