Functional coal additive and preparation method thereof

Abstract

The invention relates to a functional coal additive. The present invention relates to a functional coal additive comprising: a first mixture and a second mixture surrounded by an outer membrane made of a heat resistant polymer to form a first mixture capsule and a second mixture capsule, the outer membrane of the first mixture and the outer membrane of the second mixture each containing nitrogen, the nitrogen content of the outer membrane of the second mixture is less than the nitrogen content of the outer membrane of the first mixture, and the rupture temperature of the outer membrane of the first mixture capsule is lower than the rupture temperature of the outer membrane of the second mixture capsule.

Description

Technical Field

[0001] The present invention relates to a functional coal additive and a method for preparing the coal additive, and more specifically, to a functional coal additive and a method for preparing the coal additive, wherein the function is improved as follows: the functional coal additive is a coal additive made of multiple mixtures, which is added together with coal during the operation of a coal-fired boiler to prevent clinker formation and improve combustion efficiency. It allows multiple mixtures with different functions to have a rupture (ignition and action) temperature difference so that they can play their role in sequence when the coal is burned. Background Art

[0002] Coal is a traditional fossil fuel. With the advent of the Industrial Revolution, it has been widely used as a safe and low-cost energy source due to its low cost, abundant reserves, and the fact that its reserves are not concentrated in any particular area.

[0003] Although usage has decreased due to adverse environmental impacts such as dust and smoke, coal-fired power plants and boilers continue to be used due to the weaponization of resources by oil-producing countries, the instability of nuclear power generation as a high-efficiency alternative energy source, and the low efficiency of environmentally friendly energy.

[0004] These coal-fired boilers suffer from the problem of clinker formation caused by the ash contained in the coal. This clinker accumulates on the heating surfaces of the boiler, hindering heat transfer and reducing thermal efficiency. It also obstructs ventilation, leading to unstable combustion and reducing boiler efficiency.

[0005] In addition, for example, the removal of clinker generated in the boiler increases management costs for boiler maintenance and the need to stop the boiler for maintenance, resulting in many economic losses.

[0006] As an example of the prior art for preventing clinker as described above, there are Korean Patent No. 10-1301400, "Fuel Additive Composition for Reducing Coal Usage and Harmful Gas," and Korean Patent No. 10-1569632, "Coal Additive Composition for Reducing Harmful Gas and Coal Usage and Removing Clinker."

[0007] The above-mentioned conventional technology has the advantages of being able to remove clinker and improve combustion efficiency. However, since each fuel additive is in a liquid phase, it has the problem of solidification caused by crystallization during long-term storage, making it difficult to function normally as a fuel additive.

[0008] Furthermore, in the case of the conventional technology, when the coal additive composition is added to the inside of the boiler, it is added in a liquid phase diluted with water, and thus there is a problem of lowering the boiler temperature.

[0009] Furthermore, under the existing technology, even if the coal additive is added in the form of fine powder, it is difficult to add the coal additive uniformly into the coal-fired boiler. Moreover, since multiple coal additives are added simultaneously, there is a problem in terms of efficiency that the functions of each coal additive cannot be effectively exerted.

[0010] Prior art literature

[0011] Patent Literature

[0012] (Patent Document 1) Korean Patent No. 10-1301400 (granted on August 22, 2013)

[0013] (Patent Document 2) Korean Patent No. 10-1569632 (granted on November 10, 2015) Summary of the Invention

[0014] Technical Problems to be Solved by the Invention

[0015] The problem to be solved by the present invention is to solve these existing problems and to provide a functional coal additive and a method for preparing a coal additive, wherein the functions are improved as follows: while being able to reduce the emission of harmful components and clinker generation, the performance is improved by maximizing the combustion efficiency of the boiler.

[0016] In addition, another object of the present invention is to provide a functional coal additive and a method for preparing a coal additive, wherein the function is improved as follows: a plurality of mixtures constituting coal additives having different functions from each other have a rupture (ignition and action) temperature difference, and act in sequence according to the functional expression period when the coal is burned.

[0017] In addition, another object of the present invention is to provide a functional coal additive and a method for preparing a coal additive, wherein the function is improved as follows: while the mixture constituting the coal additive is protected by a heat-resistant outer film to ensure safety, the disadvantage of weakened ignition performance is compensated by storing an ignition-promoting medium in the outer film.

[0018] Technical solution adopted by the present invention

[0019] The functional coal additive according to one feature of the present invention may comprise: a first mixture consisting of 15 to 25 wt% of potassium nitrate, 40 to 50 wt% of silicon oxide, 10 to 20 wt% of zinc oxide, 5 to 15 wt% of aluminum oxide and 5 to 15 wt% of copper (II) chloride; and a second mixture consisting of 15 to 25 wt% of aluminum oxide, 15 to 25 wt% of silicon oxide, 5 to 15 wt% of zinc oxide or chloride, 5 to 15 wt% of calcium oxide or chloride, 5 to 15 wt% of magnesium oxide or chloride, 1 to 1 The first mixture and the second mixture are composed of 0 weight% of barium oxide or chloride, 1 to 10 weight% of any one of manganese dioxide and cobalt oxide, and 1 to 5 weight% of amine salt, the first mixture and the second mixture are surrounded by an outer film made of a heat-resistant polymer to form a first mixture capsule and a second mixture capsule, the outer film of the first mixture and the outer film of the second mixture respectively contain nitrogen, the nitrogen content of the outer film of the second mixture is less than the nitrogen content of the outer film of the first mixture, and the rupture temperature of the outer film of the first mixture capsule is lower than the rupture temperature of the outer film of the second mixture capsule.

[0020] The heat-resistant polymer outer film of the first mixture and the second mixture of the present invention may be a polyimide film layer.

[0021] The nitrogen content of the outer film of the first mixture of the present invention may be 0.40 to 0.50 wt % of the total weight of the outer film, and the nitrogen content of the outer film of the second mixture may be 0.05 to 0.10 wt % of the total weight of the outer film.

[0022] At least one surface of the outer film of the first mixture and the second mixture of the present invention may contain titanium dioxide.

[0023] The outer film of the first mixture and the outer film of the second mixture of the present invention may both contain titanium dioxide.

[0024] The amount of titanium dioxide coated on the outer film of the second mixture of the present invention may be 50 to 60% less than the amount of titanium dioxide coated on the outer film of the first mixture.

[0025] The titanium dioxide of the present invention can be coated on the surface of the outer film.

[0026] The titanium dioxide of the present invention may be introduced into pores formed in the outer film.

[0027] The outer film of the present invention may further contain metal powder or glass fiber.

[0028] The mixture capsule of the present invention may further include an outer membrane located on the outer membrane and in contact with the first mixture or the mixture.

[0029] The outer film in contact with the first mixture or the second mixture of the present invention may contain a pH-sensitive polymer or a moisture-sensitive polymer.

[0030] The outer film of the present invention may contain silica or a metal material.

[0031] The second mixture of the present invention may further contain crushed crab shells.

[0032] The crushed crab shells of the present invention may be contained in a hydrogel.

[0033] The present invention may also contain a third mixture comprising magnesium carbonates and oxides, calcium carbonates and oxides, aluminum oxide, silicon oxide, zinc oxide, and copper (II) chloride.

[0034] The third mixture of the present invention may be surrounded by an outer film comprising a heat-resistant polymer.

[0035] According to another feature of the present invention, a method for preparing a functional coal additive may include: a step of forming a first mixture, mixing and pulverizing 15 to 25 weight percent of potassium nitrate, 40 to 50 weight percent of silicon oxide, 10 to 20 weight percent of zinc oxide, 5 to 15 weight percent of aluminum oxide, and 5 to 15 weight percent of copper (II) chloride to form a first mixture; and a step of forming a second mixture, mixing 15 to 25 weight percent of aluminum oxide, 15 to 25 weight percent of silicon oxide, 5 to 15 weight percent of zinc oxide or chloride, 5 to 15 weight percent of calcium oxide or chloride, 5 to 15 weight percent of magnesium oxide or chloride, and 1 to 10 weight percent of barium oxide or chloride. Chloride, 1 to 10 weight percent of any one of manganese dioxide and cobalt oxide, and 1 to 5 weight percent of amine salt are mixed and crushed to form a second mixture; and an encapsulation step of injecting the first mixture and the second mixture into the interior of an outer film formed using a heat-resistant polymer to form a capsule, the encapsulation step also comprising: a nitrogen adding step of adding nitrogen during the formation of the outer film of the first mixture and the outer film of the second mixture, respectively, and the nitrogen content of the outer film of the added second mixture is less than the nitrogen content of the outer film of the first mixture, and the rupture temperature of the outer film of the formed first mixture capsule is lower than the rupture temperature of the outer film of the second mixture capsule.

[0036] Beneficial effects

[0037] The present invention forms at least one of a first mixture having a function of hindering clinker generation and a second mixture having a function of improving combustion obstacles into a capsule, and makes the action time points of the first mixture and the second mixture different according to the surrounding environment, thereby effectively performing each function.

[0038] Therefore, inside the coal-fired boiler, the capsules of the first mixture and the capsules of the second mixture rupture to different degrees according to the surrounding environment, so that the first mixture and the second mixture take effect at different time points inside the coal-fired boiler, so that the first mixture and the second mixture can maximize their corresponding functions without interfering with each other.

[0039] As a result, the generation of clinker is prevented or significantly reduced, thereby improving the combustion efficiency of the coal-fired boiler.

[0040] In addition, it plays the role of adding oxygen to the coal to maximize the combustion efficiency of the carbon. Due to the improvement of this combustion efficiency, the heat energy extracted from the coal increases, thereby reducing the heat loss of the coal-fired boiler and improving the efficiency of the coal-fired boiler.

[0041] In addition, due to the increased efficiency of this option boiler, the amount of air required for coal combustion can be reduced and the generation of harmful substances can be significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic diagram of a functional coal additive according to an embodiment of the present invention.

[0043] Figure 2 Schematic diagram showing an example of applying titanium dioxide to an outer film in the present invention.

[0044] Figure 3 is a schematic diagram showing an example in which titanium dioxide is introduced into the pores of the outer film in the present invention.

[0045] Figure 4 4 is a flow chart of a method for preparing a coal additive according to an embodiment of the present invention.

[0046] Description of Reference Numerals

[0047] 100: First mixture capsule 101: First mixture

[0048] 200: Second mixture capsule 201: Second mixture

[0049] 102, 202: outer membrane DETAILED DESCRIPTION

[0050] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, when describing the present invention in detail, if the detailed description of a known configuration may make the technical concept of the present invention obscure or unclear, the description of the known configuration will be omitted.

[0051] Figure 1 is a schematic diagram of a functional coal additive according to an embodiment of the present invention.

[0052] The functional coal additive according to an embodiment of the present invention may contain a first mixture 101 and a second mixture 201 that are different from each other.

[0053] Clinker can be produced by melting the ash produced by burning coal at high temperatures.

[0054] In other words, ash melted at high temperatures moves in a molten state along the combustion airflow to the exhaust side. After cooling due to the low temperature (e.g., 400°C) near the exhaust chimney of the coal-fired boiler, the molten ash adheres to the chimney surface to form an initial layer. This initial layer can have a thickness of 1 to 2 mm, and the concentrated alkali metal salt and ash particles are mixed and remain highly cohesive.

[0055] This initial layer gradually grows, and as the temperature rises, a coherent sintering layer forms on top of the initial layer. Due to the coherent state of the sintering layer, particles moving from the sintering layer toward the exhaust continue to adhere to the sintering layer, allowing the sintering layer to grow.

[0056] When the boiler temperature further rises due to combustion in the boiler and the boiler surface temperature becomes higher, the surface of the firing layer melts to form a melting layer, thereby producing clinker.

[0057] Therefore, as this process is repeated, the size of the clinker surface inside the boiler gradually increases.

[0058] In such a coal-fired boiler, if the coal additive of this example is not added, the components in the ash will react to form compounds (for example, K2FeSO4 (melting point: 618 degrees)).

[0059] However, when the coal additive of this example is added to the boiler, the melting point of the compounds formed from the ash components is significantly higher than in the absence of the coal additive (for example, MgSO4 (melting point: 1910°C)), which can reduce or prevent the melting of the ash. This can suppress the formation of clinker inside the boiler (for example, MgO (the additive of this example) + SO3 = MgSO4 (melting point: 1910°C)).

[0060] To this end, the first mixture 101 in this example may contain potassium nitrate (KNO 3 ), silicon oxide (SiO 2 ), zinc oxide (ZnO), aluminum oxide (Al 2 O 3 ) and copper (II) chloride (CuCl 2 ).

[0061] In addition, the second mixture 201 of this example may contain at least any one of aluminum oxide (Al2O3), silicon oxide (SiO2), zinc (Zn) oxide or chloride, calcium (Ca) oxide or chloride, magnesium (Mg) oxide or chloride, barium (Ba) oxide or chloride, manganese dioxide (MnO2) and cobalt oxide (CoO) and an amine salt.

[0062] An example of the first mixture 101 is to prevent the formation of clinker, and as an example, it can contain 15 to 25 weight % potassium nitrate, 40 to 50 weight % silicon oxide, 10 to 20 weight % zinc oxide, 5 to 15 weight % aluminum oxide and 5 to 15 weight % copper (II) chloride.

[0063] The first mixture 101, more specifically potassium nitrate, can prevent slag formation by increasing the melting point of coal waste and making molten slag porous. Furthermore, potassium nitrate can help deoxidize slag, allowing slag residue discharged from the exhaust port of the coal-fired boiler to be quickly removed.

[0064] The silicon oxide in the first mixture 101 can increase the oxidation degree of the waste powder when the coal is burned in a high-temperature boiler. Due to the increase in the oxidation degree of the waste powder, the melting point of the waste powder increases, which may indirectly hinder the generation of alkaline substances.

[0065] Furthermore, the zinc oxide in the first mixture can directly react with (Na+K)2O in the waste powder, which is the cause of the melting point drop, to convert the waste powder into a substance with a high melting point.

[0066] The aluminum oxide in the first mixture acts as a melting point enhancer for the waste powder, and the copper (II) chloride acts as a desulfurizer in the high-temperature coal-fired boiler and simultaneously decomposes into copper oxide and chlorine to enable complete combustion of unburned carbon in the waste coal powder.

[0067] In addition, chlorine can play a combustion-supporting role by converting iron oxide (Fe2O3) in the molten slag into chloride for volatilization while making it porous.

[0068] Example 1

[0069] The first mixture 101 of the present invention is prepared, as an example, by mixing and pulverizing 20 wt% of potassium nitrate, 45 wt% of silicon oxide, 15 wt% of zinc oxide, 10 wt% of aluminum oxide, and 10 wt% of copper (II) chloride, and the first mixture 101 is added to the boiler in an amount equivalent to 1 / 3000 to 1 / 5000 of the coal added to the boiler.

[0070] As a result, the melting point of the waste powder is increased, and the generation of clinker is drastically reduced.

[0071] The second mixture 201 of the present invention is prepared, as an example, by mixing and pulverizing 15 to 25 weight % of aluminum oxide, 15 to 25 weight % of silicon oxide, 5 to 15 weight % of zinc oxide or chloride, 5 to 15 weight % of calcium oxide or chloride, 5 to 15 weight % of magnesium oxide or chloride, 1 to 10 weight % of barium oxide or chloride, 1 to 10 weight % of at least one of manganese dioxide and cobalt oxide, and 1 to 5 weight % of an amine salt.

[0072] For reference, coal burns slowly and has a low melting point, so it tends to burn incompletely.

[0073] The second mixture 201 of this example can be used to increase the combustion speed of the coal and prevent the generation of a large amount of sulfur dioxide gas that may cause internal corrosion of the coal-fired boiler.

[0074] In other words, during the combustion process of coal, the surface of the coal can be oxidized, and ash covers the surface of the coal to form an oxide film. Due to this phenomenon, the combustion rate of the coal can be reduced.

[0075] In this case, at least one of zinc chloride, calcium chloride, magnesium chloride, barium chloride and amine salt can remove the oxide film that gradually decomposes and forms at high temperatures, thereby allowing the coal to continuously be exposed to air, thereby not only increasing the combustion rate of the coal, but also removing the ash fused (fusion splice) on the water pipes or walls of the coal-fired boiler.

[0076] Furthermore, calcium sulfate, magnesium sulfate, barium sulfate, etc. generated by burning aluminum oxide and silicon oxide with sulfur combine with ash to form high-melting-point substances, thereby preventing fusion splices.

[0077] At least one of the manganese dioxide and cobalt oxide acts as a catalyst during the combustion process, and is particularly helpful in rapidly burning refractory fuels such as coal.

[0078] Example 2

[0079] The present invention includes: a first mixture 101, consisting of 15 to 25 weight% of potassium nitrate, 40 to 50 weight% of silicon oxide, 10 to 20 weight% of zinc oxide, 5 to 15 weight% of aluminum oxide and 5 to 15 weight% of copper (II) chloride; and a second mixture 201, consisting of 15 to 25 weight% of aluminum oxide, 15 to 25 weight% of silicon oxide, 5 to 15 weight% of zinc oxide or chloride, 5 to 15 weight% of calcium oxide or chloride, 5 to 15 weight% of magnesium oxide or chloride, 1 to 10 weight% of barium oxide or chloride, 1 to 10 weight% of any one of manganese dioxide and cobalt oxide, and 1 to 5 weight% of amine salt, the first mixture 101 and the second mixture 201 are respectively surrounded by outer films 102 and 202 made of a heat-resistant polymer to form a first mixture capsule 100 and a second mixture capsule 200, and the heat-resistant polymer outer film is a polyimide film layer.

[0080] The polyimide film layer as the heat-resistant polymer film includes: polyimide, polyamide-imide, polyether-imide and fluorinated polyimide (e.g., aromatic polyimide resin, aliphatic polyimide resin); polyethylene, polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene-2,6-naphthalate copolyester (e.g., fully aromatic polyester, semi-aromatic polyester); polymethyl methacrylate (PMMA) Examples of the present invention include copolymerized (meth)acrylates represented by polymethacrylates; polycarbonate; polyamide; polysulfon; polyethersulfone; polyetherketone; cellulose acetate cellulose nitrate; aromatic polyamide; polyvinyl chloride; and examples of thin films include polyphenol; polyarylate; polyphenylene sulfide; polyphenyleneoxyde; and polystyrene.

[0081] However, since the polymer film is assumed to be used in a process accompanied by a heat treatment at 450° C. or higher, among the exemplified polymer films, polymer films applicable to actual situations are also limited.

[0082] As an example, among polymer films, so-called super engineering plastics films are most preferably used, more specifically, including aromatic polyimide films, aromatic amide films, aromatic amide imide films, and aromatic benzoxazole films. Examples thereof include Al films, aromatic benzothiazole films, and aromatic benzimidazole films.

[0083] Hereinafter, the polyimide resin film as an example of a polymer film will be described in detail. Typically, the polyimide resin film is prepared by applying a polyamide (polyamide) acid (polyimide precursor (polyimide precursor)) solution to a support for the preparation of a polyimide film, drying, grease-forming, and imidizing with diamine and tetracarboxylic acid (tetracarboxylic acid) in a solvent A. The film further comprises a filler (hereinafter referred to as "polyamic acid film"), and is further in a state of being peeled off from the support or being positioned on a support for the preparation of a polyimide film. The film is subjected to high temperature treatment, and a dehydration cyclization reaction is performed to obtain the film.

[0084] In the application of the polyamic acid (polyimide precursor) solution, for example, spin coating, reading, application, etc. are performed.

[0085] The diamine constituting the polyamic acid is not particularly limited, and aromatic diamines, aliphatic diamines, alicyclic diamines, and the like generally used for polyimide synthesis can be used.

[0086] However, from the perspective of heat resistance, aromatic diamines are preferred, and among aromatic diamines, aromatic diamines having a benzoxazole structure are more preferred. When an aromatic diamine having a benzoxazole structure is used, it has high elastic modulus, low thermal conductivity, low linear expansion coupling, and high heat resistance.

[0087] As described above, in the present invention, when the first mixture 101 and the second mixture 201 are respectively surrounded by outer films 102 and 202 made of a heat-resistant polymer (e.g., polyimide) to form a first mixture capsule 100 and a second mixture capsule 200, heat resistance is improved to ensure thermal safety even in dangerous environments such as external high temperatures or around fire, thereby enabling safe storage.

[0088] In the present invention, the outer films 102 and 202 of the first and second mixtures 101 and 201 are made of heat-resistant polyimide. The outer film 202 of the second mixture 201 is thicker than the outer film 102 of the first mixture 101 .

[0089] Only in this way, when added to a coal-fired boiler, the outer membrane 102 of the first mixture 101 is broken first so that the first mixture 101 can work when the coal is burned, and then the outer membrane 202 of the second mixture 201 is broken so that the second mixture 201 can work, that is, they work in sequence according to the functional expression period to exert the function of the mixture.

[0090] Example 3

[0091] The present invention comprises: a first mixture 101 consisting of 15 to 25 wt% potassium nitrate, 40 to 50 wt% silicon oxide, 10 to 20 wt% zinc oxide, 5 to 15 wt% aluminum oxide, and 5 to 15 wt% copper (II) chloride; and a second mixture 201 consisting of 15 to 25 wt% aluminum oxide, 15 to 25 wt% silicon oxide, 5 to 15 wt% zinc oxide or chloride, 5 to 15 wt% calcium oxide or chloride, 5 to 15 wt% magnesium oxide or chloride, 1 to 10 wt% barium oxide or chloride. The first mixture 101 and the second mixture 201 are respectively surrounded by outer films 102 and 202 made of a heat-resistant polymer to form a first mixture capsule 100 and a second mixture capsule 200, wherein the outer film 102 of the first mixture 101 and the outer film 202 of the second mixture 201 respectively contain nitrogen, and the nitrogen content of the outer film 202 of the second mixture 201 is less than the nitrogen content of the outer film 102 of the first mixture 101.

[0092] At this time, the nitrogen content of the outer film 102 of the first mixture 101 is 0.40 to 0.50 weight % of the total weight of the outer film, and the nitrogen content of the outer film 202 of the second mixture 201 is 0.05 to 0.10 weight % of the total weight of the outer film.

[0093] The nitrogen is in the form of particles that permeate or coat the outer film to promote ignition above a certain temperature, and since the nitrogen is in a very small amount relative to the total weight of the outer film, very little nitrogen monoxide or nitrogen dioxide is generated after combustion.

[0094] As described above, in the present invention, when added to a coal-fired boiler, the nitrogen contained in the outer film 102 of the first mixture 101 first promotes ignition, causing the outer film 102 to rupture, allowing the first mixture 101 to function first. Then, the nitrogen contained in the outer film 202 of the second mixture 201 functions, promoting rupture. As described above, when the outer film 202 ruptures, the second mixture 201 functions. In other words, the first mixture 101 and the second mixture 201 function sequentially, each fulfilling its respective function.

[0095] At this time, in the present invention, the first mixture 101 and the second mixture 201 constituting the coal additive are protected by the heat-resistant outer films 102 and 202, respectively, and therefore have the advantage of ensuring safety. However, during the combustion of coal, the ignition effect is delayed, and there is a risk of producing clinker and reducing the combustion efficiency. Therefore, by containing nitrogen as an ignition-promoting medium in the outer films 102 and 202, the disadvantage of the weakened ignitability mentioned above is compensated, thereby preventing the generation of clinker and the reduction of combustion efficiency.

[0096] The present invention can control the time point of rupture of the outer films 102 and 202 by selectively adjusting the nitrogen content within a certain range.

[0097] Example 4

[0098] As an example of the present invention, the present invention comprises: a first mixture 101 consisting of 15 to 25 wt% of potassium nitrate, 40 to 50 wt% of silicon oxide, 10 to 20 wt% of zinc oxide, 5 to 15 wt% of aluminum oxide, and 5 to 15 wt% of copper (II) chloride; and a second mixture 201 consisting of 15 to 25 wt% of aluminum oxide, 15 to 25 wt% of silicon oxide, 5 to 15 wt% of zinc oxide or chloride, 5 to 15 wt% of calcium oxide or chloride, 5 to 15 wt% of magnesium oxide, and 15 to 25 wt% of aluminum oxide. The first mixture 101 and the second mixture 201 are respectively surrounded by outer films 102 and 202 made of a heat-resistant polymer to form a first mixture capsule 100 and a second mixture capsule 200, and at least one surface of the outer films 102 and 202 of the first mixture 101 and the second mixture 201 contains titanium dioxide 103 and 203.

[0099] In the present invention, as described above, when at least one surface of the outer films 102 and 202 of the first mixture 101 and the second mixture 201 contains titanium dioxide 103 and 203 , titanium dioxide is preferably contained in the outer film 102 of the first mixture 101 .

[0100] In this case, due to the flame and heat generated when coal is burned in the coal-fired boiler, the outer film 102 of the first mixture 101 ignites and ruptures first, so that the first mixture 101 works before the second mixture 201 .

[0101] As another example, the titanium dioxide 103 and 203 of the present invention is contained in both the outer film 102 of the first mixture 101 and the outer film 202 of the second mixture 102 .

[0102] At this time, it is preferable that the amount of titanium dioxide 203 coated on the outer film 202 of the second mixture 201 is 50 to 60% less than the amount of titanium dioxide 103 coated on the outer film 102 of the first mixture 101 .

[0103] As described above, in the present invention, when added to a coal-fired boiler, titanium dioxide 103 contained in outer film 102 of first mixture 101 first promotes ignition, causing outer film 102 to rupture, allowing first mixture 101 to function first. Then, titanium dioxide 203 contained in outer film 202 of second mixture 201 functions to facilitate rupture. As described above, when outer film 202 ruptures, second mixture 201 functions. In other words, first mixture 101 and second mixture 201 function sequentially, each fulfilling its respective function.

[0104] The present invention can control the rupture time point of the outer membranes 102 and 202 by selectively adjusting the amount of the titanium dioxide 103 and 203 within a certain range.

[0105] At this time, in the present invention, the first mixture 101 and the second mixture 201 constituting the coal additive are protected by the heat-resistant outer films 102 and 202, respectively, and therefore have the advantage of ensuring safety. However, during the combustion of coal, the ignition effect is delayed, and there is a risk of producing clinker and reducing the combustion efficiency. Therefore, by containing titanium dioxide 103 and 203 as an ignition-promoting medium in the outer films 102 and 202, the above-mentioned disadvantage of weakened ignition performance is compensated, thereby preventing the generation of clinker and the reduction of combustion efficiency.

[0106] At this time, as an example, the titanium dioxide 103 and 203 are as shown in the accompanying drawings. Figure 2 As shown, it is coated on the surface of the outer films 102 and 202.

[0107] In addition, as another example, the titanium dioxide 103 and 203 are as shown in the accompanying drawings. Figure 3 As shown, it is introduced into the pores formed in the outer films 102 and 202 and combined.

[0108] As another example, in the case of coal containing a large amount of sulfur powder (sulfur component), in Examples 2 to 4, it is preferable to increase the amounts of calcium oxide, magnesium oxide, calcium chloride, and magnesium chloride.

[0109] Therefore, it is preferred that the first mixture 101 and the second mixture 201 are added separately at appropriate periods during the combustion process inside the coal-fired boiler.

[0110] However, for process convenience, in this example, at least one of the first mixture 101 and the second mixture 201 can be encapsulated, and the capsules of the first mixture 101 and the capsules of the second mixture 201 can be broken under different environments so that the action periods of the first mixture 101 and the second mixture 201 are different from each other.

[0111] Thus, as an example, in the functional coal additive of this example, at least one of the first mixture 101 and the second mixture 201 is formed by encapsulation.

[0112] Due to the encapsulation process of the first mixture 101 and the second mixture 201, as Figure 1 As shown, a first mixture capsule 100 in which a first mixture 101 is surrounded by an outer film 102 and a second mixture capsule 200 in which a second mixture 201 is surrounded by an outer film 202 are formed, and can be included in the functional coal additive.

[0113] For example, in the first mixture capsule 100 and the second mixture capsule 200, based on the preset environmental conditions of any one of the environmental factors of use temperature, humidity and pH, the outer membranes 102 and 202 are ruptured, i.e., broken, so that the first mixture 101 and the second mixture 102 inside the outer membranes 102 and 202 can be exposed to the outside.

[0114] Therefore, the encapsulation of the first mixture and the second mixture is to achieve the following effect: in the process of the temperature of the coal-fired boiler rising and the combustion of coal starting, the first mixture that performs the clinker removal function and the second mixture that performs the combustion efficiency increase function are sequentially added to the inside of the boiler according to at least one environmental change among temperature, humidity and pH.

[0115] As described above, through this encapsulation process, the first mixture 101 and the second mixture 201 can be respectively disposed inside the outer films 102 and 202 formed using the heat-resistant polymer.

[0116] The heat-resistant polymer used for the outer films 102 and 202 is different from general polymers that are easily deformed at low temperatures, and can contain at least one of acrylonitrile butadiene styrene (ABS), polyamide, polystyrene, acetal copolymer, acrylic, nylon, polycarbonate (PC), polyethylene terephthalate (PET) and polypropylene, which have a high heat deflection temperature (HDT).

[0117] The heat-resistant polymer may be a super heat-resistant polymer such as silicone, or a high heat-resistant resin composite such as epoxy resin, silicone resin, amine filler, or polyurethane resin.

[0118] In another example, the outer membrane 102 of the first mixture capsule 100 and the outer membrane 202 of the second mixture capsule 200 using a heat-resistant polymer are respectively formed using polymers having heat resistance up to different temperatures. The first mixture 101 and the second mixture 201 of this example are respectively injected into the polymer outer membranes 102 and 202, thereby forming the first mixture capsule 100 and the second mixture capsule 200.

[0119] Therefore, the outer film 102 of the first mixture capsule 100 and the outer film 202 of the second mixture capsule 200 may be made of materials having different heat resistance temperatures from each other, for example, the heat resistance temperature of the outer film 102 of the first mixture capsule 100 may be lower than the heat resistance temperature of the outer film 202 of the second mixture capsule 200.

[0120] Thus, the first mixture 101 can be injected into the outer film 102 made of a polymer with a relatively low heat resistance temperature (e.g., polypropylene) to form a first mixture capsule 100, and the second mixture is injected into the outer film 202 made of a polymer with a relatively high heat resistance temperature (e.g., nylon) to form a second mixture capsule 200.

[0121] As another example, the first mixture capsule 100 and the second mixture capsule 200 may be configured in a form of coating the first mixture 101 and the second mixture 201 from the outside, respectively, to surround the corresponding mixtures 101 and 201 .

[0122] Each of the outer films 102 and 202 formed by such coating can be formed by coating the first mixture 101 and the second mixture 201 with a heat-resistant resin in the form of an organic solvent and hardening the resin.

[0123] Compared with the case where the outer films 102 and 102 are formed into capsule form in advance and then the first mixture 101 and the second mixture 201 are respectively injected into the interior of the outer films 102 and 202, this coating method has the advantage that, since there is no size restriction or form restriction, mixture capsules 100 and 200 with various sizes and forms can be formed.

[0124] The outer films 102 and 202 formed by external coating of such a heat-resistant resin also break according to temperature, so that the first mixture 101 and the second mixture 201 provided inside act inside the coal-fired boiler, respectively, thereby playing the role of removing clinker and improving combustion efficiency.

[0125] In this case, when coal is burned, the outer membrane 102 of the first mixture capsule 100 made of a polymer with a low heat-resistant temperature ruptures before the outer membrane 202 of the second mixture capsule 200, so that the first mixture 101 diffuses into the interior of the coal-fired boiler before the second mixture 201, thereby being able to be used as an additive to prevent the formation of clinker when coal is burned.

[0126] Subsequently, as the internal temperature of the coal-fired boiler rises, the polymer outer membrane 202 of the second mixture capsule 200 with a higher heat resistance temperature ruptures relative to the first mixture capsule 100, allowing the second mixture 201 to diffuse into the interior of the coal-fired boiler, thereby serving as a combustion obstacle during coal combustion, that is, an additive that promotes better combustion of coal.

[0127] The purpose of adding the first mixture 101 and the second mixture 201 in sequence is to, depending on the temperature, firstly prevent the formation of clinker to eliminate ventilation obstacles, heat transfer hindrance, efficiency reduction, unstable operation and other factors, and reduce unburned materials; secondly, further promote the combustion of coal, thereby achieving the function of efficient combustion of coal.

[0128] Unlike this example, when the non-encapsulated first mixture 101 and / or second mixture 201 are added in the early steps of coal combustion, each mixture 101 and 201 acts simultaneously during the coal combustion process, which may hinder the expression of mutual effects.

[0129] However, in the case of this example, the outer membrane 102 of the first mixture capsule 100 and the outer membrane 202 of the first mixture capsule 100 are ruptured in sequence according to the temperature, so that the action time point of the first mixture 101 and the action time point of the second mixture 201 are different from each other and do not interfere with each other, so the functions of the first mixture 101 and the first mixture 201 are effectively exerted, thereby achieving more effective removal of clinker and improving combustion efficiency.

[0130] If the first mixture 101 and / or the second mixture 201 are added directly to the interior of the coal-fired boiler during the intermediate stage of coal combustion, rather than in capsule form (first mixture capsules 100 and second mixture capsules 200), the first mixture 101 and the second mixture 201 may flow into the coal-fired boiler and oxidize, making it difficult to evenly distribute the mixture across the coal and the inner surface of the boiler. Consequently, the amount of the first mixture 101 and the second mixture 201 added to the coal-fired boiler must be significantly increased, and in some cases, a large amount of an anti-oxidation additive may need to be added.

[0131] However, in the coal additive according to this example, since at least one of the first mixture capsule 100 and the second mixture capsule 200 that protect the first mixture 101 and the second mixture 202 are added to the inside of the boiler by the outer membranes 102 and 202, at least one of the first mixture capsule 100 and the second mixture capsule 200 can be added to the inside of the boiler in advance before combustion, and exert an effect that acts evenly on the entire interior of the boiler during combustion, thereby increasing the convenience of use.

[0132] As another example, the outer films 102 and 202 formed of a heat-resistant polymer may additionally contain metal (e.g., aluminum) powder or glass fiber. In this case, the metal powder or glass fiber can further increase the rupture temperature of the heat-resistant polymer, causing the outer films 102 and 202 to rupture at a slightly higher temperature, thereby allowing the first mixture 101 and the second mixture 201 contained therein to diffuse into the interior of the coal-fired boiler.

[0133] As another example, the outer films 102 and 202 may contain silica or a metal material. In this case, the heat resistance of the outer films 102 and 202 is further improved, so that the coal additive can sequentially perform its functions according to various temperature changes.

[0134] As another example, at least one of the first mixture 101 and the second mixture 201 may be encapsulated within an outer film containing a moisture-sensitive polymer or a pH-sensitive polymer. In this case, when the outer films 102 and 202 reach a predetermined moisture content or pH, they rupture, allowing the enclosed first mixture 101 and the second mixture 201 to be sprayed into the coal-fired boiler.

[0135] For example, a pH-sensitive polymer can be formed by combining a hydrophilic polyaspartate-based compound with a hydrophobic functional group and a pH-sensitive amine group, and the outer film formed using the pH-sensitive polymer is preferably formed on the inside of the outer films 102 and 202 made of a heat-resistant polymer to prevent premature rupture when heated for burning coal.

[0136] In this case, the mixture 101 and 201 can be surrounded and the outer film has a double-layer membrane structure, and therefore, there can be a first outer film and a second outer film, wherein the first outer film is in direct contact with the outside and contains a heat-resistant polymer, and the second outer film is located on the first outer film (i.e., the inside) and contains a pH-sensitive polymer or a humidity-sensitive polymer, and is in direct contact with the mixture 101 and 201.

[0137] Therefore, when the first outer film made of a heat-resistant polymer ruptures during coal combustion, the second outer film containing a pH-sensitive polymer or a humidity-sensitive polymer ruptures at a certain pH (established pH) or at a certain humidity, and the first mixture 101 or the second mixture 201 as the corresponding mixture located inside is discharged to the outside, i.e., the inside of the coal-fired boiler.

[0138] In another example, the second mixture 201 may further include crushed crab shells.

[0139] The crushed crab shells can further enhance the effect of improving the combustion efficiency by the second mixture 201 of this example.

[0140] The crushed crab shells contain a large amount of chitosan, and this chitosan component can make the second mixture 201 adhere to the coal during the combustion process to increase the combustion efficiency. In other words, the crushed crab shells can enhance the adhesion of the second mixture 201.

[0141] In yet another example, crushed crab shells may be included in the form of being contained within the hydrogel.

[0142] Hydrogels, also known as water-based gels, are three-dimensional crosslinked structures formed by water-soluble polymers bonded together physically or chemically. Hydrogel structures do not dissolve even in aqueous environments and can contain large amounts of water.

[0143] According to another example, the crushed crab shells of the second mixture 201 are contained inside the hydrogel so that the hydrogel protects the chitosan component before the coal is burned, and transfers the chitosan component to the outside during the coal combustion process so that the second mixture 201 adheres to the coal, thereby improving the combustion efficiency.

[0144] According to another embodiment, the coal additive may further include a third mixture containing 45 to 55 weight percent of magnesium carbonates and oxides, 22 to 32 weight percent of calcium carbonates and oxides, 3 to 13 weight percent of aluminum oxide, 1 to 10 weight percent of silicon oxide, 2 to 12 weight percent of zinc oxide, and 1 to 10 weight percent of copper (II) chloride (CuCl2).

[0145] The third mixture is used to prevent sulfuric acid and vanadium contained in the ash from contacting the heated surfaces during combustion in coal-fired boilers and potentially corroding the metal. Similar to the first and second mixtures, this third mixture can be formed into capsules surrounded by and located within an outer membrane. The outer membrane of the third mixture capsule can also be formed using a heat-resistant polymer. The third mixture capsules are formed by injecting the third mixture into the outer membrane formed as described above.

[0146] At this time, for encapsulation of the third mixture, the heat-resistant polymer contained in the outer film may be a polymer that breaks at a lower temperature than the heat-resistant polymer constituting the outer films 102 and 202 of the first and second mixture capsules.

[0147] Thus, the rupture order of the outer membrane according to the temperature increase is the outer membrane of the third mixture capsule -> the outer membrane of the first mixture capsule -> the outer membrane of the second mixture capsule. Among the first to second mixture capsules, the rupture temperature of the outer membrane of the third mixture capsule is the lowest, and the rupture temperature of the outer membrane of the second mixture capsule is the highest.

[0148] Therefore, the outer membrane of the third mixture capsule is first broken during the combustion of coal, thereby protecting the inner surface of the boiler.

[0149] In the third mixture, the oxides and carbonates of magnesium and calcium, aluminum oxide, and silicon oxide all have high melting points. When combined with vanadium and sodium compounds, they form a high-melting-point metal salt compound. Therefore, the temperature is higher than the heat transfer temperature to the heating surface of the coal-fired boiler, preventing the ash from fusing together while also separating the attached matter that has already been fused together.

[0150] During combustion, copper (II) chloride combines with oxygen and decomposes to form copper oxide and chlorine. Chlorine acts as an oxidizing agent, oxidizing unburned carbon in the combustion ash to reduce the generation of unburned components, thereby improving thermal efficiency. Chlorine also reacts with deposits to form metal chloride, making them porous and easily detachable.

[0151] Example 5

[0152] 30 wt% of magnesium carbonate, 20 wt% of magnesium oxide, 15 wt% of calcium carbonate, 12 wt% of calcium oxide, 5 wt% of silicon oxide, 8 wt% of aluminum oxide, 7 wt% of zinc oxide, and 3 wt% of copper (II) chloride were mixed and pulverized to a size of 300 mesh or larger to prepare a third mixture, which was then added to a boiler. As a result, the amount of ash adhering to the inside of the boiler was reduced, and the amount of corrosion was reduced.

[0153] Figure 4 4 is a flow chart of a method for preparing a coal additive according to an embodiment of the present invention.

[0154] The method for preparing a functional coal additive according to an embodiment of the present invention includes: a first mixture forming step (S10), a second mixture forming step (S20), and an encapsulation step (S30) of at least one of the first mixture and the second mixture.

[0155] In the first mixture forming step (S10), 15 to 25 wt% of potassium nitrate, 40 to 50 wt% of silicon oxide, 10 to 20 wt% of zinc oxide, 5 to 15 wt% of aluminum oxide, and 5 to 15 wt% of copper (II) chloride are mixed and pulverized to form a first mixture.

[0156] In the second mixture forming step (S20), 15 to 25 weight % of aluminum oxide, 15 to 25 weight % of silicon oxide, 5 to 15 weight % of zinc oxide or chloride, 5 to 15 weight % of calcium oxide or chloride, 5 to 15 weight % of magnesium oxide or chloride, 1 to 10 weight % of barium oxide or chloride, 1 to 10 weight % of at least one of manganese dioxide and cobalt oxide, and 1 to 5 weight % of an amine salt are mixed and pulverized to form a second mixture.

[0157] In the encapsulation step ( S30 ), at least any one of the first mixture and the second mixture is injected into the interior of the outer film formed using the heat-resistant polymer to form at least one of the first mixture capsule and the second mixture capsule.

[0158] As for encapsulation, as described above, in another example, at least one of the first mixture and the second mixture capsules can be formed by coating the exterior of at least one of the first mixture and the second mixture with a heat-resistant polymer in the form of an aqueous solution and performing a coating process to form an outer film.

[0159] Through such encapsulation, the first mixture and the second mixture can act sequentially according to environmental changes such as temperature to realize the function of the coal additive.

[0160] According to the present invention, the combustion of coal can be promoted by causing a chemical reaction through solid-solid contact, thereby improving the combustion efficiency of power generation equipment.

[0161] By reducing excess air, exhaust gas is reduced, thereby improving heat recovery, allowing the coal-fired boiler to burn at a constant rate and maximizing the maximum combustion capacity of the coal-fired boiler.

[0162] The additives in this example can introduce oxygen into the coal, thereby maximizing the coal combustion efficiency.

[0163] In addition, it reduces the levels of flue gas and solid combustibles and induces complete combustion to reduce the amount of unburned carbon emitted from the stack, thereby significantly reducing atmospheric pollutants (SO X 、NO X , dust) emissions, and lower the ignition temperature to extend the combustion time and increase the combustion speed, thereby promoting the combustion process.

[0164] Coal additives made of inorganic materials (SiO2, Al2O3, ZnO3, MgO, etc.) are introduced into coal-fired boilers, so they do not change the internal temperature or pressure of the coal and can inhibit slagging and clinker formation.

[0165] When coal is burned, it reacts with substances that cause pipeline corrosion (sulfuric acid gas or acid gas, etc.) to form high-melting-point compounds, thereby inhibiting the formation of clinker and rendering harmful gases harmless.

[0166] Due to the generation of high melting point compounds, clinker generation is suppressed due to the effect of unmelted pores inside the slag phase such as clinker, and the generated clinker can be easily removed from the heating surface, and foreign matter can also be easily removed using a soot blower. Above, the present invention is described in detail with reference to specific embodiments, but the embodiments are only examples to help understand the present invention. Therefore, within the scope of the technical spirit of the present invention, replacements, additions and modifications should be deemed to fall within the scope of protection of the present invention as defined by the appended claims.

Claims

1. A functional coal additive, characterized in that: Include: a first mixture consisting of 15 to 25 weight percent potassium nitrate, 40 to 50 weight percent silicon oxide, 10 to 20 weight percent zinc oxide, 5 to 15 weight percent aluminum oxide, and 5 to 15 weight percent copper (II) chloride; and a second mixture consisting of 15 to 25 weight percent aluminum oxide, 15 to 25 weight percent silicon oxide, 5 to 15 weight percent zinc oxide or chloride, 5 to 15 weight percent calcium oxide or chloride, 5 to 15 weight percent magnesium oxide or chloride, 1 to 10 weight percent barium oxide or chloride, 1 to 10 weight percent of any one of manganese dioxide and cobalt oxide, and 1 to 5 weight percent of an amine salt; The first mixture and the second mixture are surrounded by an outer film made of a heat-resistant polymer to form a first mixture capsule and a second mixture capsule, The outer film of the first mixture and the outer film of the second mixture respectively contain nitrogen, The nitrogen content of the outer film of the second mixture is less than the nitrogen content of the outer film of the first mixture, The rupture temperature of the outer membrane of the first mixture capsule is lower than the rupture temperature of the outer membrane of the second mixture capsule.

2. The functional coal additive according to claim 1, characterized in that The heat-resistant polymer outer films of the first mixture and the second mixture are polyimide film layers.

3. The functional coal additive according to claim 1, characterized in that The nitrogen content of the outer film of the first mixture is 0.40 to 0.50 weight % of the total weight of the outer film, and the nitrogen content of the outer film of the second mixture is 0.05 to 0.10 weight % of the total weight of the outer film.

4. The functional coal additive according to claim 1, characterized in that At least one surface of the outer films of the first mixture and the second mixture contains titanium dioxide.

5. The functional coal additive according to claim 4, characterized in that The outer film of the first mixture and the outer film of the second mixture both contain titanium dioxide.

6. The functional coal additive according to claim 5, characterized in that The amount of titanium dioxide coated on the outer film of the second mixture is 50 to 60% less than the amount of titanium dioxide coated on the outer film of the first mixture.

7. The functional coal additive according to claim 4, characterized in that The titanium dioxide is coated on the surface of the outer film.

8. The functional coal additive according to claim 4, characterized in that The titanium dioxide is introduced into the pores formed in the outer film.

9. The functional coal additive according to claim 1, characterized in that The outer film further contains metal powder or glass fiber.

10. The functional coal additive according to claim 1, characterized in that: The mixture capsule further includes an outer membrane located on the outer membrane and in contact with the first mixture or mixture.

11. The functional coal additive according to claim 1, characterized in that: The outer film in contact with the first mixture or the second mixture contains a pH-sensitive polymer or a moisture-sensitive polymer.

12. The functional coal additive according to claim 1, characterized in that The outer film contains silicon dioxide or a metal material.

13. The functional coal additive according to claim 1, characterized in that The second mixture also contains crushed crab shells.

14. The functional coal additive according to claim 13, characterized in that The crushed crab shells are contained within the hydrogel.

15. The functional coal additive according to claim 1, characterized in that The functional coal additive further comprises a third mixture containing magnesium carbonates and oxides, calcium carbonates and oxides, aluminum oxide, silicon oxide, zinc oxide, and copper (II) chloride.

16. The functional coal additive according to claim 15, characterized in that The third mixture is surrounded by an outer film comprising a heat-resistant polymer.

17. A method for preparing a functional coal additive, characterized in that: include: a step of forming a first mixture, mixing and pulverizing 15 to 25 weight percent potassium nitrate, 40 to 50 weight percent silicon oxide, 10 to 20 weight percent zinc oxide, 5 to 15 weight percent aluminum oxide, and 5 to 15 weight percent copper (II) chloride to form a first mixture; a step of forming a second mixture by mixing and pulverizing 15 to 25 weight % of aluminum oxide, 15 to 25 weight % of silicon oxide, 5 to 15 weight % of zinc oxide or chloride, 5 to 15 weight % of calcium oxide or chloride, 5 to 15 weight % of magnesium oxide or chloride, 1 to 10 weight % of barium oxide or chloride, 1 to 10 weight % of any one of manganese dioxide and cobalt oxide, and 1 to 5 weight % of an amine salt to form a second mixture; as well as an encapsulation step of injecting the first mixture and the second mixture into an outer membrane formed of a heat-resistant polymer to form a capsule, The encapsulation step further comprises: a nitrogen adding step of adding nitrogen during the formation of the outer film of the first mixture and the outer film of the second mixture, wherein the nitrogen content of the outer film of the second mixture is less than the nitrogen content of the outer film of the first mixture; And the rupture temperature of the outer membrane of the formed first mixture capsule is lower than the rupture temperature of the outer membrane of the second mixture capsule.

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