A catalyst for coal combustion and its preparation process

Abstract

The present invention relates to the field of catalyst technology, and in particular to a catalyst for coal combustion and a preparation process thereof, wherein the catalyst comprises the following materials by weight: 2%-8% of rare earth nitrate, 5%-18% of alkaline earth metal salt, 2%-5% of alkali metal salt, 0.5%-1% of copper-manganese composite oxide, 0.2%-1.5% of transition metal salt, 0.1%-0.3% of nonionic surfactant, 0.05%-0.15% of organosilicon compound and residual water. The coal-fired catalyst of the present invention is specially designed for power plants, has excellent permeability and adsorption properties, solves the problem of being difficult to evenly disperse in block coal, promotes the full combustion of coal in power plants, improves the combustion rate and burnout rate, and the preparation of raw materials excludes solid hazardous wastes, ensures safety and environmental protection, can not only help power plants save coal resources, but also reduce the emission of harmful pollutants at the source, and brings significant economic and environmental benefits to power plants.

Description

Technical Field

[0001] The invention relates to the technical field of catalysts, and in particular to a catalyst for coal combustion and a preparation process thereof. Background Art

[0002] As one of the world's major energy resources, coal is widely used in power generation, industrial heating, chemical production and other fields. The use of coal is also accompanied by a series of problems, especially in the combustion process, where low combustion efficiency and high pollutant emissions become its main technical bottlenecks.

[0003] In the power industry, the use of coal-fired catalysts is mainly concentrated in coal-fired power plants. As the main source of energy consumption and pollutant emissions, the combustion efficiency and pollutant emission levels of coal-fired power plants are directly related to the economy and environmental protection of power production. In the process of coal combustion, the main problems are reflected in the following aspects: (1) Low combustion efficiency: Due to outdated combustion equipment, backward combustion technology, and incomplete coal combustion, the thermal efficiency of the equipment is generally low, and energy waste is extremely serious. (2) The combustion problem of low-quality coal: Low-quality coal (such as inferior lignite and high-ash coal) usually has a low calorific value, high moisture and ash content, resulting in a large amount of ash produced during combustion, incomplete combustion, and difficulty in effectively controlling pollutant emissions. Especially when the combustion temperature is low, the combustion reaction rate of low-quality coal is slow and cannot be completely burned. For this low-quality coal, its combustion efficiency is usually 10%-15% lower than that of high-quality coal. (3) Pollutant emission problems: Coal combustion not only produces a large amount of greenhouse gases such as carbon dioxide (CO2), but also releases sulfur dioxide (SO2), nitrogen oxides (NO x ), carbon monoxide (CO), dust, etc. The emission of these pollutants not only has a serious impact on air quality, but also causes environmental problems such as acid rain and haze, which seriously threaten public health and the ecosystem.

[0004] In order to solve these problems, coal combustion promoters came into being. Coal combustion promoters refer to chemical additives that can improve the combustion characteristics of coal, promote the full combustion of coal and reduce the emission of harmful gases. This type of promoter reduces the ignition temperature of coal, increases the combustion reaction rate, promotes the release of volatile matter in coal and improves the characteristics of coal ash through physical and chemical methods, thereby improving the combustion efficiency of coal and reducing the emission of pollutants.

[0005] At present, various types of coal combustion promoters have been proposed, mainly including metal salts, inorganic compounds, and some organic chemical additives. These promoters react with coal through different physical and chemical effects to optimize the combustion characteristics of coal. However, the coal combustion promoters used in existing power plants still have certain limitations in improving combustion efficiency and reducing pollutant emissions, and some promoters may have adverse effects on the environment. Therefore, the development of new, more efficient and environmentally friendly coal combustion promoters used in power plants has become one of the hot spots in current coal combustion technology research. Based on this, the present invention proposes a catalyst for coal combustion and a preparation process thereof. Summary of the invention

[0006] The purpose of the present invention is to provide a catalyst for coal combustion and a preparation process thereof. The prepared catalyst has excellent permeability and adsorption properties, strong permeability and good dispersion effect in lump raw coal, can promote coal combustion to achieve the effect of saving coal, reduce the emission of harmful pollutants at the source, and bring significant economic and environmental benefits to power plants.

[0007] In a first aspect, the present invention provides a catalyst for coal combustion, comprising the following materials in parts by weight: 2%-8% rare earth nitrate, 5%-18% alkaline earth metal salt, 2%-5% alkali metal salt, 0.5%-1% copper-manganese composite oxide, 0.2%-1.5% transition metal salt, 0.1%-0.3% non-ionic surfactant, 0.05%-0.15% organosilicon compound and the remainder water.

[0008] Furthermore, the catalyst for coal combustion has a solid content of 16-32 wt% and a density of 1.05-1.35 g / cm 3 , pH is 1.2-5, and it is light yellow to yellow-brown; the amount of the catalyst used for coal combustion is 0.6-1.4‰ of the weight of the coal sample.

[0009] Furthermore, the rare earth nitrate includes one or more of yttrium nitrate, cerium nitrate, lanthanum nitrate and zirconium nitrate.

[0010] In the present invention, rare earth nitrates mainly improve the combustion process of coal, improve combustion efficiency, and reduce pollutant emissions through their redox reactions, catalytic oxygen release, and enhanced thermal stability. For example, cerium nitrate can play a catalytic role in the coal combustion process through redox reactions. Cerium ions can be used in Ce 3+ and Ce4 +The redox cycle can provide an additional oxygen source to promote the oxidation reaction of organic matter in coal. The presence of cerium can reduce the activation energy required for coal combustion, especially in the combustion of volatile matter and the oxidation of fixed carbon in coal. Cerium changes the oxidation mechanism of carbon in coal, making the combustion process easier. Its redox behavior helps to quickly break down the molecular structure of coal and enhances reactivity. The zirconium ion (Zr 4+ ) can react with oxides and organic matter in coal during combustion. Zirconium oxide (ZrO2) has a very stable crystal structure at high temperatures, which enables it to maintain a high catalytic activity during combustion. Zirconium can promote the release of oxygen and help convert carbon in coal into CO2. Its oxidizing property can effectively enhance the oxidation reaction during coal combustion and help decompose the non-combustible parts of coal. Zirconium ions interact with other oxides in coal (such as sulfides and nitrides), further promoting the redox reaction in coal combustion, promoting complete combustion, and reducing harmful substances in coal (such as SO2, NO x ) emissions.

[0011] Furthermore, the alkaline earth metal salt is a nitrate, sulfate or chloride of an alkaline earth metal, and the alkaline earth metal is one or more of magnesium, calcium, strontium and barium.

[0012] In the present invention, alkaline earth metal salt is an important component in coal combustion promoter, which plays a vital role in the coal combustion process by catalyzing coal combustion reaction, promoting oxidation of volatiles, improving combustion stability, controlling pollutant emissions, etc. Specifically, alkaline earth metal salt can reduce the combustion activation energy of coal and improve its reactivity by reacting with organic and inorganic substances in coal. They promote the combustion reaction by decomposing organic molecules in coal. Alkaline earth metal salt reduces the loss of volatile components by catalyzing the oxidation of organic matter, thereby improving the combustion efficiency of coal. Alkaline earth metal salt can promote the oxidation and combustion of volatile components in coal. For example, calcium salt and magnesium salt can promote the complete oxidation of volatile components such as hydrocarbons by providing an oxygen source, reducing the emission of soot and harmful gases. Alkaline earth metal salt can effectively react with impurities such as sulfur and nitrogen in coal to reduce the emission of sulfur dioxide, nitrogen oxides and smoke. For example, calcium salt can react with sulfur in coal to form calcium sulfate, reducing the emission of sulfur dioxide.

[0013] Furthermore, the alkali metal salt is one or more of alkali metal chloride, iodide, carbonate, nitrate, sulfate, and phosphate, and the alkali metal is one or more of lithium, sodium, potassium, rubidium, and cesium.

[0014] In the present invention, the alkali metal salt has a strong catalytic effect, which can reduce the combustion activation energy of coal, so that the coal can start to burn at a lower temperature. Sodium salt and potassium salt can accelerate the oxidation reaction of coal, especially the oxidation of volatile substances, thereby improving the combustion efficiency. In addition, the alkali metal salt reduces the generation of sulfur dioxide and nitrogen oxides by promoting the complete combustion of coal. For example, sodium salt and potassium salt can reduce the emission of sulfur dioxide and nitrogen oxides in incomplete combustion or local high temperature reaction by enhancing the combustion efficiency of coal.

[0015] Furthermore, the preparation method of the copper-manganese composite oxide includes: preparing copper nitrate and manganese nitrate into a mixed solution, adding ammonium carbonate solution until the pH value of the mixed solution is 8, continuing to stir for 40-50 minutes, drying the obtained precipitate and calcining it at a temperature of 560-570°C for 160-180 minutes to obtain the composite oxide.

[0016] Furthermore, the molar ratio of copper ions to manganese ions in the mixed solution is 2:1.

[0017] In the present invention, the catalytic active center of the copper-manganese composite oxide catalyst is a specific chemical composition and structure, and is the main contributor to surface adsorbed oxygen and lattice oxygen. The formation of this active center is closely related to the interaction between copper and manganese. The uniform distribution and close combination of copper and manganese at the atomic level can be achieved through doping technology, thereby forming an efficient catalytic active center. The crystal structure of the copper-manganese composite oxide catalyst has an important influence on its catalytic performance. Through doping technology, the crystal structure of the catalyst can be regulated to form a specific crystal phase and morphology. These specific crystal structures help the catalyst to maintain stable catalytic performance during the coal combustion process. In addition, the copper-manganese composite oxide catalyst also exhibits good thermal stability and chemical stability, and can maintain catalytic activity under high temperature and harsh environment. By optimizing the chemical reaction path during the coal combustion process, the catalyst can convert the chemical energy in the coal into thermal energy more efficiently. This helps to improve the utilization rate of the calorific value, making the energy output in the coal combustion process more stable and efficient.

[0018] Furthermore, the transition metal salt includes one or more of chlorides, nitrates, sulfates, oxalates, and manganates of transition metals, and the transition metal includes one or more of iron, cobalt, nickel, copper, zinc, and manganese.

[0019] In the present invention, the transition metal salt effectively improves the combustion process of coal, enhances combustion efficiency and reduces environmental impact by providing an oxygen source, reducing combustion activation energy and promoting redox reactions. During the coal combustion process, the transition metal salt can undergo a reversible redox reaction between its ionic states (e.g., Fe 2+ / Fe 3+ , Cu + / Cu 2+、Co 2+ / Co 3+ The catalytic effect helps to reduce the ignition temperature of coal, improve the reactivity of coal, and accelerate the combustion process of coal. Transition metal salts can improve the reactivity of coal, especially promote the oxidation reaction of non-combustible substances and organic substances in coal, thereby improving the combustion efficiency. In this way, the loss of volatile substances in coal during the combustion process can be reduced.

[0020] Furthermore, the nonionic surfactant includes one or more of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, and polyoxyethylene alkylamine.

[0021] In the present invention, the role of nonionic surfactant in coal combustion is mainly to improve the contact between coal and oxygen, and to increase the reactivity and dispersibility of coal. Nonionic surfactant has hydrophilic and lipophilic parts, which can reduce the surface tension of coal particles, improve the wettability of coal particles, and make coal better combined with water or other combustion media. And by changing the surface properties of coal, the contact area between coal and oxygen is increased, which promotes coal to react with oxygen more quickly and more completely, thereby improving the combustion rate and efficiency.

[0022] Furthermore, the organic silicon compound includes one or more of methyl silicone oil, dimethyl silicone oil, and diethyl silicone oil.

[0023] In the present invention, the role of the organosilicon compound in coal combustion is mainly reflected in improving the dispersibility and lubricity of coal powder, reducing coal powder aggregation, and improving combustion efficiency. Methyl silicone oil and dimethyl silicone oil have good lubricity and surface activity, and can reduce the adhesion and aggregation of coal powder. By improving the dispersibility of coal powder, the coal powder is promoted to be evenly distributed in the combustion chamber, reducing the local overheating problem caused by coal powder aggregation, thereby improving the combustion stability of coal. In addition, it helps to reduce the adhesive and non-reactive parts on the surface of coal powder, so that more coal powder can contact with oxygen and participate in combustion, promoting the complete reaction.

[0024] In a second aspect, the present invention provides a process for preparing a catalyst for coal combustion, the steps comprising: adding a formulated amount of rare earth nitrate, alkaline earth metal salt, alkali metal salt, copper-manganese composite oxide, transition metal salt, non-ionic surfactant and organosilicon compound to water in sequence; stirring and mixing thoroughly for 20-30 minutes to obtain the catalyst for coal combustion.

[0025] Furthermore, the time interval for adding each component in the adding step is 2-5 minutes, during which the raw materials are slowly added and fully stirred.

[0026] Furthermore, the time interval for adding each component in the adding step is 3 minutes.

[0027] In the present invention, various chemical components in the catalyst for coal combustion quickly penetrate through the coal gaps and are adsorbed into the interior of the coal. When the coal enters the combustion chamber, the various chemical components contained in the catalyst for coal combustion play a catalytic and promoting role, improving the combustion characteristics of the coal, reducing the ignition temperature of the coal, increasing the combustion reaction rate, promoting the release of volatiles in the coal, and improving the characteristics of the coal ash, thereby improving the combustion efficiency of the coal.

[0028] In the present invention, the effective chemical components in the catalyst used for coal combustion can effectively react with impurities such as sulfur and nitrogen in the coal. For example, calcium salt can react with sulfur in the coal to form calcium sulfate, thereby reducing the generation of harmful gases, promoting complete combustion of coal samples, reducing the emission of sulfur dioxide, nitrogen oxides and smoke, and reducing environmental pollution.

[0029] In the present invention, the effective chemical components in the catalyst used for coal combustion can improve the fluidity of coal ash, reduce the adhesion and sedimentation of ash, avoid slagging and sedimentation of coal ash at high temperature, reduce the accumulation of coal ash in boilers or combustion equipment, prevent furnace blockage and reduce corrosion problems, and improve the operating efficiency of equipment.

[0030] In a third aspect, the catalyst for coal combustion in the present invention is used in cement production or thermal power fields.

[0031] Furthermore, the application method comprises: adding the catalyst for coal combustion or a diluted solution of the catalyst for coal combustion into a coal sample for combustion.

[0032] Furthermore, the amount of the catalyst used for coal combustion is 0.6-1.4‰ of the weight of the coal sample.

[0033] The catalyst for coal combustion of the present invention has strong penetration ability and good dispersion effect in lump raw coal, can promote coal combustion to achieve the effect of saving coal, and at the same time reduce the emission of sulfur dioxide and nitrogen oxides in exhaust gas.

[0034] The beneficial effects of the present invention are:

[0035] The coal-fired catalyst of the present invention is specially designed for power plants, exhibits excellent permeability and adsorption properties, and effectively solves the problem that the catalytic promoter is difficult to disperse evenly in lump coal.

[0036] The various components in the catalyst of the present invention can act together in the combustion process of coal, by reducing the combustion activation energy, and at the same time, these active components can also fully contact with the combustible components in the coal, accelerate its oxidation process, and produce more low-molecular or small-molecule hydrocarbons when cracking the macromolecular carbon chains in the coal molecules. These small-molecule hydrocarbons are easier to burn, thereby improving combustion efficiency. The catalyst used for coal combustion achieves optimization and improvement of the coal combustion process through the interaction and synergy between different components. This composite synergistic mechanism enables the catalyst to play a more significant effect in the coal combustion process, providing strong support for the sustainable development of the coal-fired industry.

[0037] The catalyst for coal combustion of the present invention promotes the full combustion of coal in power plants, improves the combustion characteristics of coal, reduces the ignition temperature of coal, increases the combustion reaction rate, promotes the release of volatile matter in coal, and improves the characteristics of coal ash, significantly improves the combustion efficiency and burnout rate of coal, and ensures efficient energy utilization. Through extensive comparative test verification, the catalyst shows a wide adaptability to different types of coal, including coking coal, gas coal, lean coal, anthracite, lignite and even biofuels, and can achieve excellent catalytic effects. More importantly, the raw materials for the preparation of the catalyst completely exclude solid hazardous wastes, ensuring the safety and environmental protection of use.

[0038] Therefore, the implementation of the present invention can not only help power plants save coal resources and reduce operating costs, but also effectively react with impurities such as sulfur and nitrogen in coal, reduce the generation of harmful gases, promote the complete combustion of coal samples, reduce the emission of sulfur dioxide, nitrogen oxides and smoke, and reduce environmental pollution. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Example 1

[0041] The present embodiment provides a catalyst for coal combustion, comprising the following materials in parts by weight: 2% sodium nitrate, 2% cerium nitrate, 6% calcium chloride, 0.75% copper-manganese composite oxide, 0.5% nickel nitrate, 1.5% cobalt chloride, 0.2% glycerol, 0.1% methyl silicone oil, and the remainder water;

[0042] The preparation method of the copper-manganese composite oxide comprises: preparing 100 mL of a mixed solution of copper nitrate and manganese nitrate with a molar ratio of copper ions to manganese ions of 2:1 and a concentration of 0.5 mol / L, adding an ammonium carbonate solution until the pH value of the mixed solution reaches 8, continuing to stir for 45 minutes, drying the obtained precipitate, and calcining it at a temperature of 565° C. for 170 minutes to obtain the obtained product;

[0043] The preparation method of the catalyst for coal combustion is as follows:

[0044] (1) Sodium nitrate, cerium nitrate, calcium chloride, copper-manganese composite oxide, nickel nitrate, cobalt chloride, glycerol, and methyl silicone oil were added to water in sequence while stirring; the time interval between adding each raw material component was 3 minutes;

[0045] (2) After all the raw materials are added, stir and mix thoroughly for 30 minutes to obtain the catalyst for coal combustion. The obtained mixture is light yellow to yellow-brown in color.

[0046] The amount of the catalyst used for coal combustion in the present invention is 0.6-1.4‰ of the weight of the coal sample. The optimal value is 1‰ in this embodiment, and the following embodiments and comparative examples all take this optimal value.

[0047] Example 2

[0048] Adjustments were made based on Example 1, except that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% zirconium nitrate, 0.8% zinc chloride, 1.2% ferric nitrate, 5% potassium iodide, 8% calcium chloride, 0.75% copper-manganese composite oxide, 0.2% sorbitol, 0.1% dimethyl silicone oil, and the remainder was water.

[0049] Example 3

[0050] Adjustments were made based on Example 1, except that: the catalyst used for coal combustion in this example includes the following materials in parts by weight: 5% cerium nitrate, 0.8% zinc chloride, 1.2% ferric nitrate, 5% potassium iodide, 8% calcium chloride, 0.75% copper-manganese composite oxide, 0.2% sorbitol, 0.1% dimethyl silicone oil, and the rest is water.

[0051] Example 4

[0052] Adjustments were made based on Example 1, except that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% lanthanum nitrate, 0.8% zinc chloride, 1.2% ferric nitrate, 5% potassium iodide, 8% calcium chloride, 0.75% copper-manganese composite oxide, 0.2% sorbitol, 0.1% dimethyl silicone oil, and the remainder was water.

[0053] Example 5

[0054] Adjustments were made based on Example 1, except that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% yttrium nitrate, 0.8% zinc chloride, 1.2% ferric nitrate, 5% potassium iodide, 8% calcium chloride, 0.75% copper-manganese composite oxide, 0.2% sorbitol, 0.1% dimethyl silicone oil, and the remainder was water.

[0055] Example 6

[0056] Adjustments were made based on Example 1, with the difference being that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% lanthanum nitrate, 5% magnesium chloride, 1.2% copper nitrate, 6% potassium nitrate, 0.75% copper-manganese composite oxide, 0.2% polyoxyethylene ether, 0.1% dimethyl silicone oil, and the remainder being water.

[0057] Example 7

[0058] Adjustments were made based on Example 1, with the difference being that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% lanthanum nitrate, 5% calcium chloride, 1.2% copper nitrate, 6% potassium nitrate, 0.75% copper-manganese composite oxide, 0.2% polyoxyethylene ether, 0.1% dimethyl silicone oil, and the remainder being water.

[0059] Example 8

[0060] Adjustments were made based on Example 1, with the difference being that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% lanthanum nitrate, 5% strontium chloride, 1.2% copper nitrate, 6% potassium nitrate, 0.75% copper-manganese composite oxide, 0.2% polyoxyethylene ether, 0.1% dimethyl silicone oil, and the remainder being water.

[0061] Example 9

[0062] Adjustments were made based on Example 1, with the difference being that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% lanthanum nitrate, 5% barium chloride, 1.2% copper nitrate, 6% potassium nitrate, 0.75% copper-manganese composite oxide, 0.2% polyoxyethylene ether, 0.1% dimethyl silicone oil, and the remainder being water.

[0063] Example 10

[0064] Adjustments were made based on Example 1, except that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% yttrium nitrate, 6% calcium chloride, 4% sodium carbonate, 1.2% nickel nitrate, 0.75% copper-manganese composite oxide, 0.8% iron nitrate, 0.2% lauryl amine oxide, 0.1% diethyl silicone oil, and the remainder was water.

[0065] Embodiment 11

[0066] Adjustments were made based on Example 1, with the difference being that the catalyst used for coal combustion in this example comprises the following materials in parts by weight: 5% yttrium nitrate, 6% calcium chloride, 4% sodium chloride, 1.2% nickel nitrate, 0.75% copper-manganese composite oxide, 0.8% ferric nitrate, 0.2% lauryl amine oxide, 0.1% diethyl silicone oil, and the remainder being water.

[0067] Example 12

[0068] Adjustments were made based on Example 1, except that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% yttrium nitrate, 6% calcium chloride, 4% sodium sulfate, 1.2% nickel nitrate, 0.75% copper-manganese composite oxide, 0.8% ferric nitrate, 0.2% lauryl amine oxide, 0.1% diethyl silicone oil, and the remainder was water.

[0069] Embodiment 13

[0070] Adjustments were made based on Example 1, except that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% yttrium nitrate, 6% calcium chloride, 4% sodium nitrate, 1.2% nickel nitrate, 0.75% copper-manganese composite oxide, 0.8% iron nitrate, 0.2% lauryl amine oxide, 0.1% diethyl silicone oil, and the remainder was water.

[0071] Embodiment 14

[0072] Adjustments were made based on Example 1, except that: the catalyst for coal combustion in this example included the following materials in parts by weight: 5% cerium nitrate, 6% calcium chloride, 3% magnesium chloride, 4% potassium chloride, 0.75% copper-manganese composite oxide, 1.2% copper nitrate, 0.8% cobalt nitrate, 0.2% cocoamide, 0.1% diethyl silicone oil, and the remainder was water.

[0073] Embodiment 15

[0074] Adjustments were made based on Example 1, except that: the catalyst for coal combustion in this example included the following materials in parts by weight: 5% cerium nitrate, 6% calcium chloride, 3% magnesium chloride, 4% potassium carbonate, 0.75% copper-manganese composite oxide, 1.2% copper nitrate, 0.8% cobalt nitrate, 0.2% cocoamide, 0.1% diethyl silicone oil, and the remainder was water.

[0075] Example 16

[0076] Adjustments were made based on Example 1, except that: the catalyst for coal combustion in this example includes the following materials in parts by weight: 5% cerium nitrate, 6% calcium chloride, 3% magnesium chloride, 4% potassium sulfate, 0.75% copper-manganese composite oxide, 1.2% copper nitrate, 0.8% cobalt nitrate, 0.2% cocoamide, 0.1% diethyl silicone oil, and the rest is water.

[0077] Embodiment 17

[0078] Adjustments were made based on Example 1, except that: the catalyst for coal combustion in this example included the following materials in parts by weight: 5% cerium nitrate, 6% calcium chloride, 3% magnesium chloride, 4% potassium nitrate, 0.75% copper-manganese composite oxide, 1.2% copper nitrate, 0.8% cobalt nitrate, 0.2% cocoamide, 0.1% diethyl silicone oil, and the remainder was water.

[0079] Embodiment 18

[0080] Adjustments were made based on Example 1, with the difference being that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% lanthanum nitrate, 5% calcium chloride, 1.2% ferric nitrate, 6% potassium nitrate, 0.75% copper-manganese composite oxide, 0.2% polyoxyethylene ether, 0.1% dimethyl silicone oil, and the remainder being water.

[0081] Embodiment 19

[0082] Adjustments were made based on Example 1, with the difference being that the catalyst used for coal combustion in this example comprises the following materials in parts by weight: 5% lanthanum nitrate, 5% calcium chloride, 1.2% cobalt nitrate, 6% potassium nitrate, 0.75% copper-manganese composite oxide, 0.2% polyoxyethylene ether, 0.1% dimethyl silicone oil, and the remainder being water.

[0083] Embodiment 20

[0084] Adjustments were made based on Example 1, with the difference being that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% lanthanum nitrate, 5% calcium chloride, 1.2% nickel nitrate, 6% potassium nitrate, 0.75% copper-manganese composite oxide, 0.2% polyoxyethylene ether, 0.1% dimethyl silicone oil, and the remainder being water.

[0085] Embodiment 21

[0086] Adjustments were made based on Example 1, with the difference being that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% lanthanum nitrate, 5% calcium chloride, 1.2% copper nitrate, 6% potassium nitrate, 0.75% copper-manganese composite oxide, 0.2% polyoxyethylene ether, 0.1% dimethyl silicone oil, and the remainder being water.

[0087] Embodiment 22

[0088] Adjustments were made based on Example 1, with the difference being that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% lanthanum nitrate, 5% calcium chloride, 1.2% zinc nitrate, 6% potassium nitrate, 0.75% copper-manganese composite oxide, 0.2% polyoxyethylene ether, 0.1% dimethyl silicone oil, and the remainder being water.

[0089] Embodiment 23

[0090] Adjustments were made based on Example 7, except that the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% lanthanum nitrate, 5% calcium chloride, 1.2% copper nitrate, 6% potassium nitrate, 0.2% polyoxyethylene ether, 0.1% dimethyl silicone oil, and the remainder was water.

[0091] Embodiment 24

[0092] Adjustments were made based on Example 13, with the difference being that the catalyst used for burning coal in this example included the following materials in parts by weight: 5% yttrium nitrate, 6% calcium chloride, 4% sodium nitrate, 1.2% nickel nitrate, 0.25% copper-manganese composite oxide, 0.8% iron nitrate, 0.2% lauryl amine oxide, 0.1% diethyl silicone oil, and the remainder being water.

[0093] Embodiment 25

[0094] Adjustments were made based on Example 17, except that: the catalyst used for coal combustion in this example included the following materials in parts by weight: 5% cerium nitrate, 6% calcium chloride, 3% magnesium chloride, 4% potassium nitrate, 0.5% copper-manganese composite oxide, 1.2% copper nitrate, 0.8% cobalt nitrate, 0.2% cocoamide, 0.1% diethyl silicone oil, and the remainder was water.

[0095] Embodiment 26

[0096] Adjustments were made based on Example 18, with the difference being that the catalyst used for burning coal in this example included the following materials in parts by weight: 5% lanthanum nitrate, 5% calcium chloride, 1.2% ferric nitrate, 6% potassium nitrate, 1.2% copper-manganese composite oxide, 0.2% polyoxyethylene ether, 0.1% dimethyl silicone oil, and the remainder being water.

[0097] The catalyst for coal combustion prepared in the embodiment was tested:

[0098] 1. Calorific value: Usually, an oxygen bomb instrument is used to test the heat released during coal combustion. The method is to take a certain mass of coal sample and put it into the oxygen bomb instrument, fill the bomb cylinder with excess oxygen (oxygen pressure is 2.5-3.0MPa), place the bomb cylinder in an inner cylinder filled with a certain amount of water, and ignite the coal sample to burn. The heat released is absorbed by the calorimetric system, thereby calculating the heat released by the coal.

[0099] The catalyst for coal combustion prepared in the embodiment is added to coal, and the calorific value is tested by an oxygen bomb instrument to obtain Q1, and the calorific value Q2 of the coal without adding the catalyst for coal combustion is tested, and the difference in calorific value is calculated as Q1-Q2, and an evaluation is performed, wherein level 1 means that the difference in calorific value is less than 50 kcal / kg; level 2 means that the difference in calorific value is greater than or equal to 50 kcal / kg and less than 100 kcal / kg; level 3 means that the difference in calorific value is greater than or equal to 100 kcal / kg and less than 150 kcal / kg; level 4 means that the difference in calorific value is greater than or equal to 150 kcal / kg and less than 200 kcal / kg; level 5 means that the difference in calorific value is greater than or equal to 200 kcal / kg and less than 250 kcal / kg; level 6 means that the difference in calorific value is greater than or equal to 250 kcal / kg;

[0100] 2. Combustion rate: The catalyst for coal combustion provided in the embodiment is added to the coal for combustion, and the flame is observed to measure the combustion rate. The brighter and more concentrated the flame is, the faster the combustion rate is. The rate is rated, where level 1 means the flame is dim and dispersed; level 2 means the flame is bright and concentrated; and level 3 means the flame is obviously bright and concentrated.

[0101] The test results are shown in Table 1.

[0102] Table 1 Test results

[0103] Calorific value Burning rate Example 1 Level 2 Level 1 Example 2 Level 5 Level 3 Example 3 Level 6 Level 3 Example 4 Level 3 Level 2 Example 5 Level 4 Level 2 Example 6 Level 4 Level 2 Example 7 Level 6 Level 3 Example 8 Level 2 Level 1 Example 9 Level 3 Level 2 Example 10 Level 1 Level 1 Embodiment 11 Level 4 Level 2 Example 12 Level 2 Level 1 Embodiment 13 Level 6 Level 3 Embodiment 14 Level 4 Level 2 Embodiment 15 Level 3 Level 2 Example 16 Level 2 Level 1 Embodiment 17 Level 6 Level 3 Embodiment 18 Level 6 Level 3 Embodiment 19 Level 5 Level 3 Embodiment 20 Level 2 Level 1 Embodiment 21 Level 5 Level 3 Embodiment 22 Level 1 Level 1 Embodiment 23 Level 1 Level 1 Embodiment 24 Level 3 Level 2 Embodiment 25 Level 5 Level 3 Embodiment 26 Level 6 Level 3

[0104] It can be seen from the test results in Table 1 that using the catalyst for coal combustion provided by the present invention to catalyze the combustion of coal can increase the calorific value generated by the combustion of coal and improve the combustion efficiency.

[0105] Comparative Examples 2-5, without changing other raw materials, compare the effects of yttrium nitrate, cerium nitrate, lanthanum nitrate, and zirconium nitrate in the catalyst for coal combustion. The coal powder with the addition of cerium nitrate component has better combustion effect than the other three rare earth nitrates. This is because during the combustion process, the oxidation state of cerium can be Ce 3+ With Ce 4+ Transform between each other. 3+ It is a reducing agent that can react with organic matter in coal to release more oxygen; Ce 4+ It is a strong oxidant that can enhance the release of oxygen and combustion efficiency during coal combustion. It can circulate continuously during the combustion process, playing an oxidizing role and being reactivated through its own reduction behavior, thereby continuously participating in the coal combustion reaction.

[0106] Comparing Examples 6-9, without changing other raw materials, comparing the effects of magnesium chloride, calcium chloride, strontium chloride, and barium chloride in the catalyst for coal combustion, the coal powder with calcium chloride added has a better combustion effect than the other three alkaline earth metal salts. This is because calcium chloride can be used as a catalyst promoter to promote the combustion of volatile matter and fixed carbon in coal during the combustion process. It can reduce the excitation temperature of volatile substances during the combustion process, accelerate the release of volatile matter in coal, and help control the reaction rate during the coal combustion process, thereby improving the completeness and efficiency of combustion.

[0107] Comparative Examples 10-13, without changing other raw materials, compare the effects of sodium carbonate, sodium chloride, sodium sulfate, and sodium nitrate in the catalyst for coal combustion. The coal powder combustion effect with the addition of sodium nitrate component is better than the other three alkali metal salts. This is because sodium nitrate is a strong oxidant that can provide oxygen under high temperature conditions to promote the combustion of carbon and volatiles in coal. In the process of coal combustion, sodium nitrate can release oxygen and promote the occurrence of combustion reactions, especially under conditions of insufficient oxygen or low combustion temperature. This effect is particularly important. Its reaction formula can be expressed as: NaNO3→NaNO2+1 / 2O2. In addition, at high temperatures, sodium nitrate can form molten salts with some metal components in coal (such as calcium, magnesium, etc.), promoting heat conduction and reaction between coal particles. This helps to reduce the accumulation and aggregation of coal particles, increase the reaction rate of coal, and promote the transfer of heat, thereby accelerating the complete combustion of coal.

[0108] Comparative Examples 14-17, without changing other raw materials, compare the effects of potassium chloride, potassium carbonate, potassium sulfate, and potassium nitrate in the catalyst for coal combustion. The coal powder combustion effect with the addition of potassium nitrate component is better than the other three alkali metal salts. This is because potassium nitrate is a strong oxidant that can decompose and release oxygen at high temperatures to promote the combustion of carbon and volatiles in coal. It enhances the oxidation reaction of coal by releasing oxygen, especially when the oxygen supply is insufficient, it can provide additional oxygen to support the complete combustion of coal. In addition, the main components of volatiles in coal include moisture and some light organic matter. The oxidizability of potassium nitrate helps these substances to be ignited more easily, thereby improving the combustion efficiency of coal.

[0109] Comparative Examples 18-22, without changing other raw materials for production, compare the effects of ferric nitrate, cobalt nitrate, nickel nitrate, copper nitrate, and zinc nitrate in the catalyst for coal combustion, and the coal powder combustion effect of adding ferric nitrate component is better than that of other four transition metal salts, because ferric nitrate, as an oxidant, can provide oxygen to promote the combustion reaction of coal. Iron ion has strong oxidizability and can effectively promote the complete combustion of coal during combustion. In addition, iron ion can carry out redox reaction during combustion, release oxygen and participate in combustion reaction, and promote the combustion of volatile matter and fixed carbon in coal through its redox property.

[0110] In comparative examples 23-26, the amount of copper-manganese composite oxide used as a raw material is adjusted. In the copper-manganese composite oxide catalyst, there is a strong mutual synergistic effect between the copper species and the manganese species. This synergistic effect can optimize the catalytic performance of the catalyst, so that it exhibits higher activity and stability during the coal combustion process. Specifically, the synergistic effect of copper and manganese can promote the adsorption and conversion of reactant molecules, accelerate the rate of chemical reactions, and thus improve coal combustion efficiency.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. All technical solutions and improvements that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A catalyst for coal combustion, characterized in that: The invention comprises the following materials in parts by weight: 2%-8% rare earth nitrate, 5%-18% alkaline earth metal chloride, 2%-5% alkali metal salt, 0.5%-1% copper-manganese composite oxide, 0.2%-1.5% transition metal nitrate, 0.1%-0.3% nonionic surfactant, 0.05%-0.15% organosilicon compound and the balance water; The rare earth nitrate is cerium nitrate; The chloride of alkaline earth metals is calcium chloride; The alkali metal of the alkali metal salt is a combination of sodium salt and potassium salt, wherein the sodium salt is sodium nitrate and the potassium salt is potassium nitrate; The nitrate of transition metal is iron nitrate; The preparation method of the copper-manganese composite oxide comprises: preparing copper nitrate and manganese nitrate into a mixed solution, adding ammonium carbonate solution until the pH value of the mixed solution reaches 8, continuing stirring for 40-50 minutes, drying the obtained precipitate and calcining it at a temperature of 560-570° C. for 160-180 minutes to obtain the composite oxide.

2. A catalyst for coal combustion according to claim 1, characterized in that: The solid content of the catalyst for coal combustion is 16-32wt% and the density is 1.05-1.35g / cm 3 , pH is 1.2-5, and it is light yellow to yellow-brown; the amount of the catalyst used for coal combustion is 0.6-1.4‰ of the weight of the coal sample.

3. A catalyst for coal combustion according to claim 1, characterized in that: The nonionic surfactant includes one or more of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, and polyoxyethylene alkylamine; the organosilicon compound includes one or more of methyl silicone oil, dimethyl silicone oil, and diethyl silicone oil.

4. A process for preparing a catalyst for coal combustion as claimed in any one of claims 1 to 3, characterized in that the steps include: Add the formulated amount of rare earth nitrate, alkaline earth metal salt, alkali metal salt, copper-manganese composite oxide, transition metal salt, nonionic surfactant and organosilicon compound to water in sequence; fully stir and mix for 20-30 minutes to obtain the catalyst for coal combustion; the addition time interval of each component in the adding step is 2-5 minutes, during which the raw materials are slowly added and fully stirred.

5. Use of the catalyst for coal combustion as claimed in any one of claims 1 to 3 in cement production or thermal power fields.