Efficient fire coal catalyst applied to gasification furnace and preparation method of efficient fire coal catalyst

Abstract

The invention relates to the technical field of fire coal catalysts, and discloses an efficient fire coal catalyst applied to a gasification furnace and a preparation method of the efficient fire coal catalyst. Comprising the following materials in parts by weight: 5-15 parts of iodide, 15-25 parts of sodium salt, 20-25 parts of modified nano cerium oxide, 10-15 parts of supported transition metal oxide, 20-30 parts of ethanol, 40-50 parts of water, 5-10 parts of a surfactant and 3-6 parts of lignosulfonate. According to the efficient fire coal catalyst and the preparation method thereof, the utilization rate of coal is increased.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of coal combustion catalysts, in particular to a high-efficiency coal combustion catalyst applied to a vaporization furnace and a preparation method thereof. BACKGROUND

[0002] Coal is an important energy source in China, accounting for about 70% of the total energy consumption. However, coal is wasted during use, and therefore, a coal combustion catalyst is used to reduce the loss of coal combustion and improve the working efficiency of coal combustion. The coal combustion catalyst can reduce the apparent activation energy of coal combustion, reduce the ignition point of coal, accelerate the combustion rate of coke, accelerate the breaking of various bondings in the coal pyrolysis process, and improve the release speed of coal volatile matter, thereby improving the utilization rate of coal and saving energy. However, the coal combustion catalysts on the market have limited efficiency improvement for coal, and there is a gap between the market demand and the coal combustion catalysts. Therefore, a high-efficiency coal combustion catalyst is invented, which has a wide market prospect. SUMMARY

[0003] The application aims to provide a high-efficiency coal combustion catalyst applied to a vaporization furnace and a preparation method thereof, and improve the utilization rate of coal.

[0004] In one aspect, the application provides a high-efficiency coal combustion catalyst, which comprises the following materials in parts by weight: 5-15 parts of iodide, 15-25 parts of sodium salt, 20-25 parts of modified nano cerium oxide, 10-15 parts of supported transition metal oxide, 45-55 parts of ethanol, 20-30 parts of water, 5-10 parts of surfactant, and 3-6 parts of lignin sulfonate.

[0005] Further, the iodide is one or more of potassium iodide, sodium iodide and ammonium iodide.

[0006] Further, the sodium salt is one or more of sodium carbonate, sodium nitrate and sodium acetate.

[0007] Further, the surfactant comprises sodium dodecyl benzene sulfonate or sodium dodecyl sulfate.

[0008] Further, the preparation method of the modified nano cerium oxide comprises the following steps: dissolving cerium ammonium nitrate in deionized water to prepare a 1-1.5 mol / L solution; under stirring at a speed of 300-400 rpm, adding ammonia water dropwise until the pH value is 9-11, to generate light yellow precipitate; adding polyethylene glycol and continuously stirring for 30-60 min; water bath aging; and after filtration, washing and drying, calcining to obtain the modified nano cerium oxide.

[0009] Further, the amount of the polyethylene glycol is 5-15% of the mass of the precipitate.

[0010] Further, the water bath aging temperature is 80-95℃, and the time is 2-3h.

[0011] Further, the calcination temperature is 350-550℃, and the time is 3-4h.

[0012] Further, the preparation method of the supported transition metal oxide comprises dispersing kaolin in an aqueous ferric nitrate solution prepared by using ferric nitrate nine hydrate and water, drying after impregnation for 2-4h, and obtaining the supported transition metal oxide after calcination at 350-500℃ for 2-3h.

[0013] Further, the ratio of the amounts of kaolin, ferric nitrate nine hydrate and water is (65-75)g:(90-100)g:500mL.

[0014] In another aspect, the application provides a preparation method of the high-efficiency coal combustion catalyst, which comprises the following steps: mixing iodide, sodium salt, modified nanometer cerium oxide, supported transition metal oxide, ethanol, water, surfactant and lignosulfonate according to weight parts, and grinding uniformly to obtain a liquid catalyst; and mixing the liquid catalyst and coal according to a mass ratio of 1:14000-17000.

[0015] Further, the high-efficiency coal combustion catalyst is applied to a gasification furnace.

[0016] The application optimizes the proportioning of each component in the high-efficiency coal combustion catalyst and the mass ratio of the catalyst to coal, so as to maximize the performance of the catalyst.

[0017] The application has the following beneficial effects: The application adopts polyethylene glycol to modify nano cerium oxide and applies it to high-efficiency coal combustion catalyst, which significantly improves the catalytic activity and sulfur fixation effect in cooperation with surfactants. In the preparation process of the modified nano cerium oxide, polyethylene glycol is added to the precipitate system generated by the reaction of cerium ammonium nitrate and ammonia water as a dispersant and stabilizer. The long-chain structure in the polyethylene glycol molecule can be adsorbed on the surface of nano cerium oxide particles to form a steric hindrance layer, effectively preventing the agglomeration between particles, thereby increasing the specific surface area of nano cerium oxide. A larger specific surface area means more active sites exposed to the outside, which is conducive to catalytic reactions with substances generated during coal combustion. At the same time, the surfactant can further improve the dispersibility of nano cerium oxide in the catalyst system, making it uniformly distributed in the ethanol-water solution. In addition, the surfactant may also change the surface charge properties of nano cerium oxide through interaction with its surface, enhancing its adsorption capacity for sulfur oxides and other pollutants generated during coal combustion. During the combustion process, the active oxygen species on the surface of the modified nano cerium oxide can chemically react with sulfur oxides to fix them on the catalyst surface, reducing SO2 emissions and achieving efficient sulfur fixation.

[0018] The application loads iron nitrate nonahydrate on kaolin to prepare supported transition metal oxides, which are used as key components of high-efficiency coal combustion catalysts, achieving efficient promotion of coal combustion and effective inhibition of NOx emissions. x Kaolin has a large specific surface area and rich pore structure, which can provide a good carrier for the loading of iron nitrate nonahydrate. During the impregnation process, Fe 3+ ions in the iron nitrate nonahydrate solution adhere to the surface and inside of the pores of kaolin through physical adsorption or chemical bonding. After calcination, Fe 3+ ions are converted into iron-based oxides, which are uniformly distributed on the surface of kaolin. Iron-based oxides have unique redox activity and can catalyze the reaction between carbon in coal and oxygen during coal combustion, reducing the activation energy of the reaction and promoting combustion to improve combustion efficiency. At the same time, iron-based oxides can also participate in the reduction reaction of NOx. During the combustion process, NO x generated by coal combustion will react with the active sites on the surface of iron-based oxides, reducing it to harmless substances such as nitrogen, thereby effectively inhibiting the emission of NO x High kaolin as a carrier not only improves the dispersibility of iron-based oxides and increases their contact area with coal combustion products, but also adsorbs and fixes part of the pollutants generated during combustion to some extent, further enhancing the comprehensive performance of the catalyst.

[0019] The modified nano-cerium oxide and the iron-based supported transition metal oxide in the present invention have a synergistic effect. The sulfur fixation effect of the modified nano-cerium oxide can reduce the effect of SO2 on the catalytic activity of the iron-based supported transition metal oxide, while the iron-based supported transition metal oxide has a synergistic effect on NO. x The inhibitory effect also helps improve the combustion environment, enabling more stable and complete coal combustion. This provides better conditions for oxygen transfer and sulfur fixation in the modified nano-cerium oxide, thereby increasing its catalytic efficiency. Furthermore, the modified nano-cerium oxide has a large specific surface area and abundant oxygen vacancies, providing a large number of active sites. The iron-based transition metal oxide, supported on kaolin, exhibits good dispersibility and high activity. The two complement each other structurally, enabling more comprehensive coverage of the coal particle surface, increasing contact area with the coal, and improving catalytic efficiency. DETAILED DESCRIPTION

[0020] The following is a clear and complete description of the technical solution of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention. Example 1

[0021] This embodiment provides a high-efficiency coal-burning catalyst, comprising the following materials in parts by weight: 10 parts iodide, 20 parts sodium salt, 22 parts modified nano-cerium oxide, 12 parts supported transition metal oxide, 50 parts ethanol, 25 parts water, 8 parts surfactant sodium dodecylbenzene sulfonate, and 5 parts sodium lignin sulfonate; Wherein, the iodide is potassium iodide, sodium iodide, and ammonium iodide in a weight ratio of 1:1:1; the sodium salt is sodium carbonate; Among them, the preparation method of modified nano-cerium oxide includes: dissolving ammonium cerium nitrate in deionized water to prepare a 1.2 mol / L solution; adding 3 mol / L ammonia water dropwise to pH=10 under stirring at 350 rpm to generate a light yellow precipitate; adding polyethylene glycol PEG-400 (10% by mass of the precipitate) and continuously stirring for 45 minutes; aging in a 90°C water bath for 2.5 hours; filtering, washing with deionized water and ethanol three times, and drying at 95°C; and calcining in a muffle furnace at 450°C for 3.5 hours to obtain modified nano-cerium oxide.

[0022] The preparation method of the supported transition metal oxide includes: dispersing 70g of kaolin in an aqueous solution of ferric nitrate prepared by using 95g of ferric nitrate nonahydrate and 500mL of water, soaking for 3h, drying, and calcining at 450°C for 2.5h to obtain the supported transition metal oxide.

[0023] In another aspect, the present application provides a preparation method of the high-efficiency coal combustion catalyst, which comprises the following steps: mixing iodide, sodium salt, modified nano cerium oxide, supported transition metal oxide, ethanol, water, surfactant and lignin sulfonate according to weight parts, grinding uniformly to prepare a liquid catalyst; and mixing the liquid catalyst and coal according to a mass ratio of 1:15000. Example 2

[0024] In this embodiment, the high-efficiency coal combustion catalyst comprises the following materials according to weight parts: 10 parts of iodide, 20 parts of sodium salt, 22 parts of modified nano cerium oxide, 12 parts of supported transition metal oxide, 50 parts of ethanol, 25 parts of water, 8 parts of surfactant sodium dodecyl benzene sulfonate and 5 parts of sodium lignin sulfonate. The iodide is potassium iodide, sodium iodide and ammonium iodide with a weight ratio of 1:1:1. The preparation method of the modified nano cerium oxide comprises the following steps: dissolving cerium ammonium nitrate in deionized water to prepare a 1.2 mol / L solution; adding 3 mol / L ammonia water dropwise to the solution under stirring at a speed of 350 rpm until the pH value is 10, to generate a light yellow precipitate; adding 10% polyethylene glycol PEG-400 based on the mass of the precipitate and continuously stirring for 45 min; aging in a 90℃ water bath for 2.5 h; filtering and washing with deionized water and ethanol for 3 times, and drying at 95℃; and calcining in a muffle furnace at 450℃ for 3.5 h to obtain the modified nano cerium oxide.

[0025] The preparation method of the supported transition metal oxide comprises the following steps: dispersing 70 g of kaolin in a ferric nitrate aqueous solution prepared by using 95 g of ferric nitrate nonahydrate and 500 mL of water, drying after immersion for 3 h, and calcining at 450℃ for 2.5 h to obtain the supported transition metal oxide.

[0026] In another aspect, the present application provides a preparation method of the high-efficiency coal combustion catalyst, which comprises the following steps: mixing iodide, sodium salt, modified nano cerium oxide, supported transition metal oxide, ethanol, water, surfactant and lignin sulfonate according to weight parts, grinding uniformly to prepare a liquid catalyst; and mixing the liquid catalyst and coal according to a mass ratio of 1:14000. Example 3

[0027] In this embodiment, the high-efficiency coal combustion catalyst comprises the following materials according to weight parts: 10 parts of iodide, 20 parts of sodium salt, 22 parts of modified nano cerium oxide, 12 parts of supported transition metal oxide, 50 parts of ethanol, 25 parts of water, 8 parts of surfactant sodium dodecyl benzene sulfonate and 5 parts of sodium lignin sulfonate. The iodide is potassium iodide, sodium iodide and ammonium iodide with a weight ratio of 1:1:1. The preparation method of the modified nanometer cerium oxide comprises the following steps: dissolving cerium ammonium nitrate in deionized water to prepare a 1.2 mol / L solution; under stirring at a speed of 350 rpm, 3 mol / L ammonia water is added dropwise until the pH value is 10, and a light yellow precipitate is generated; 10% of the mass of the precipitate is added with polyethylene glycol PEG-400, and the stirring is continued for 45 min; the water bath is aged at 90℃ for 2.5 h; the filter is extracted, washed with deionized water and ethanol for three times, and dried at 95℃; and the modified nanometer cerium oxide is obtained by calcining in a muffle furnace at 450℃ for 3.5 h.

[0028] The preparation method of the supported transition metal oxide comprises the following steps: 70 g of kaolin is dispersed in an aqueous ferric nitrate solution prepared by using 95 g of ferric nitrate nonahydrate and 500 mL of water, dried after being immersed for 3 h, and calcined at 450℃ for 2.5 h to obtain the supported transition metal oxide.

[0029] In another aspect, the present application provides a preparation method of the high-efficiency coal combustion catalyst, which comprises the following steps: mixing iodide, sodium salt, modified nanometer cerium oxide, supported transition metal oxide, ethanol, water, surfactant and lignin sulfonate according to the weight parts, grinding uniformly to prepare a liquid catalyst; and mixing the liquid catalyst and coal according to a mass ratio of 1:17000. Example 4

[0030] The high-efficiency coal combustion catalyst provided in the present embodiment comprises the following materials according to the weight parts: 5 parts of iodide, 15 parts of sodium salt, 20 parts of modified nanometer cerium oxide, 10 parts of supported transition metal oxide, 45 parts of ethanol, 20 parts of water, 5 parts of surfactant sodium dodecyl benzene sulfonate, and 3 parts of sodium lignin sulfonate. The iodide is potassium iodide, sodium iodide and ammonium iodide with a weight ratio of 1:1:1; and the sodium salt is sodium carbonate. The preparation method of the modified nanometer cerium oxide comprises the following steps: dissolving cerium ammonium nitrate in deionized water to prepare a 1 mol / L solution; under stirring at a speed of 300 rpm, 2 mol / L ammonia water is added dropwise until the pH value is 9, and a light yellow precipitate is generated; 5% of the mass of the precipitate is added with polyethylene glycol PEG-400, and the stirring is continued for 30 min; the water bath is aged at 80℃ for 2 h; the filter is extracted, washed with deionized water and ethanol for three times, and dried at 80℃; and the modified nanometer cerium oxide is obtained by calcining in a muffle furnace at 350℃ for 3 h.

[0031] The preparation method of the supported transition metal oxide comprises the following steps: 65 g of kaolin is dispersed in an aqueous ferric nitrate solution prepared by using 90 g of ferric nitrate nonahydrate and 500 mL of water, dried after being immersed for 2 h, and calcined at 350℃ for 2 h to obtain the supported transition metal oxide.

[0032] In another aspect, the present application provides a preparation method of the high-efficiency coal combustion catalyst, which comprises the following steps: mixing iodide, sodium salt, modified nano cerium oxide, supported transition metal oxide, ethanol, water, surfactant and lignin sulfonate according to weight parts, grinding uniformly to prepare a liquid catalyst; and mixing the liquid catalyst and coal according to a mass ratio of 1:15000. Example 5

[0033] In this embodiment, the high-efficiency coal combustion catalyst comprises the following materials according to weight parts: 15 parts of iodide, 25 parts of sodium salt, 25 parts of modified nano cerium oxide, 15 parts of supported transition metal oxide, 55 parts of ethanol, 30 parts of water, 10 parts of surfactant sodium dodecyl benzene sulfonate and 6 parts of sodium lignin sulfonate. In the formula, the iodide is potassium iodide, sodium iodide and ammonium iodide with a weight ratio of 1:1:1; the sodium salt is sodium carbonate. In the formula, the preparation method of the modified nano cerium oxide comprises the following steps: dissolving cerium ammonium nitrate in deionized water to prepare a 1.5 mol / L solution; adding 4 mol / L ammonia water dropwise to the solution under stirring at a speed of 400 rpm until the pH value is 11, to generate a light yellow precipitate; adding 15% of polyethylene glycol PEG-400 based on the mass of the precipitate and continuously stirring for 60 min; aging in a 95℃ water bath for 3 h; filtering and washing with deionized water and ethanol for 3 times, and drying at 110℃; and calcining in a muffle furnace at 550℃ for 4 h to obtain the modified nano cerium oxide.

[0034] In the formula, the preparation method of the supported transition metal oxide comprises the following steps: dispersing 75 g of kaolin in a ferric nitrate aqueous solution prepared by using 100 g of ferric nitrate nonahydrate and 500 mL of water, drying after immersion for 4 h, and calcining at 500℃ for 3 h to obtain the supported transition metal oxide.

[0035] In another aspect, the present application provides a preparation method of the high-efficiency coal combustion catalyst, which comprises the following steps: mixing iodide, sodium salt, modified nano cerium oxide, supported transition metal oxide, ethanol, water, surfactant and lignin sulfonate according to weight parts, grinding uniformly to prepare a liquid catalyst; and mixing the liquid catalyst and coal according to a mass ratio of 1:15000.

[0036] Comparative Example 1 Different from Example 1, the modified nano cerium oxide in this comparative example is replaced by nano cerium oxide with the same mass.

[0037] Comparative Example 2 Different from Example 1, the raw materials in this comparative example do not contain modified nano cerium oxide.

[0038] Comparative Example 3 Different from Example 1, the ferric nitrate nonahydrate in this comparative example is replaced by nickel nitrate hexahydrate with the same molar amount.

[0039] Comparative Example 4 Different from Example 1, the supported transition metal oxide in this comparative example was replaced by kaolin calcined at 50℃ for 2.5h.

[0040] Comparative Example 5 Different from Example 1, the raw material in this comparative example did not contain supported transition metal oxide.

[0041] Blank control group: ordinary coal, no addition.

[0042] Take 150 g of coal sample and add high-efficiency coal combustion catalyst according to the ratio in Example and Comparative Example 1 for combustion test.

[0043] Combustion efficiency test: mix coal powder (particle size ≤200 mesh) with catalyst in proportion and mix uniformly; pass air at a flow rate of 2 L / min in a tube furnace, heat to 800℃ at 10℃ / min, and keep constant temperature for 30 min; collect the combustion residue and calculate the combustion rate: combustion rate (%) = (1-residue mass / initial coal mass) x 100%; Pollutant emission test: flue gas analyzer (Testo 350), constant temperature section (800℃) continuous sampling for 15 min, take the average value, test SO2 emission concentration (mg / m 3 ) and NO x emission concentration (mg / m 3 ); Coal saving rate calculation: (experimental group combustion rate-blank group combustion rate) / blank group combustion rate x 100%; Table 1 test results Group Combustion efficiency (%) SO2 emission reduction rate (%) NO x Reduction rate (%)]] Coal saving rate (relative to blank group) (%) Example 1 96.7 71.5 48.2 13.2 Example 2 96.2 70.1 46.8 12.6 Example 3 95.8 69.3 45.5 12.2 Example 4 95.1 68.7 44.2 11.4 Example 5 96.5 70.9 47.6 13 Comparative Example 1 92.3 65.2 40.1 8.1 Comparative Example 2 89.7 58.4 35.3 5 Comparative Example 3 93.1 63.8 -42.6 9 Comparative Example 4 88.5 55.1 33.7 3.6 Comparative Example 5 90.2 60.3 37.9 5.6 Blank group 85.4 0 0 0 According to the foregoing, all examples significantly improve combustion efficiency, reduce SO2 / NO x emission, and the coal saving rate is 11.4%~13.2%. Comparative Example 1 lacks the modification step, leading to particle agglomeration, reduced specific surface area, and decreased catalytic activity, resulting in decreased combustion efficiency, SO2 emission reduction rate, and coal saving rate; Comparative Example 2 lacks the oxygen transfer and sulfur fixation ability of cerium-based catalyst, weakening combustion promotion and SO2 adsorption, resulting in decreased combustion efficiency, SO2 emission reduction rate, and coal saving rate; in Comparative Example 3, Ni lacks the redox activity of Fe, which may promote the NO x generation path, resulting in increased NO x emission and decreased NO xReduction rate -42.6% (dramatic increase), SO2 reduction rate decreased; Comparative Example 4, no Fe loading, only calcined kaolin, no transition metal active sites, unable to catalyze carbon oxidation and pollutant conversion, combustion efficiency, SO2 reduction rate and coal saving rate all decreased; Comparative Example 5, remove the entire loaded transition metal, lack of Fe-based catalyst combustion promotion and NOx reduction capacity, weaker than cerium deficiency but still significantly decreased.

[0044] Finally, it should be noted that: the above examples are only used to illustrate the present application and not limit the technical solutions described in the present application; those skilled in the art should understand that the present application can still be modified or replaced by the equivalent; and all technical solutions and improvements that do not deviate from the spirit and scope of the present application should be covered in the scope of the claims of the present application.

Claims

1. A high-efficiency coal-fired catalyst, characterized in that: The invention comprises the following materials in parts by weight: 5-15 parts of iodide, 15-25 parts of sodium salt, 20-25 parts of modified nano-cerium oxide, 10-15 parts of supported transition metal oxide, 45-55 parts of ethanol, 20-30 parts of water, 5-10 parts of surfactant and 3-6 parts of lignin sulfonate.

2. A high-efficiency coal-fired catalyst according to claim 1, characterized in that: The iodide is one or more of potassium iodide, sodium iodide, and ammonium iodide.

3. A high-efficiency coal-fired catalyst according to claim 1, characterized in that: The sodium salt is one or more of sodium carbonate, sodium nitrate and sodium acetate.

4. A high-efficiency coal-fired catalyst according to claim 1, characterized in that: The preparation method of the modified nano-cerium oxide comprises: dissolving ammonium cerium nitrate in deionized water to prepare a 1-1.5 mol / L solution; adding ammonia water dropwise while stirring at 300-400 rpm until the pH reaches 9-11 to generate a light yellow precipitate; adding polyethylene glycol and continuously stirring for 30-60 minutes; aging in a water bath; and filtering, washing, drying, and then calcining to obtain the modified nano-cerium oxide.

5. A high-efficiency coal-fired catalyst according to claim 4, characterized in that: The amount of polyethylene glycol used is 5-15% of the precipitate mass.

6. A high-efficiency coal-fired catalyst according to claim 4, characterized in that: The water bath aging temperature is 80-95° C., and the time is 2-3 hours; the calcination temperature is 350-550° C., and the time is 3-4 hours.

7. A high-efficiency coal-fired catalyst according to claim 1, characterized in that: The preparation method of the supported transition metal oxide comprises: dispersing kaolin in an aqueous solution of ferric nitrate prepared by using ferric nitrate nonahydrate and water, soaking for 2-4 hours, drying, and calcining at 350-500° C. for 2-3 hours to obtain the supported transition metal oxide.

8. A high-efficiency coal-fired catalyst according to claim 7, characterized in that: The usage ratio of the kaolin, ferric nitrate nonahydrate and water is (65-75) g: (90-100) g: 500 mL.

9. A method for preparing a high-efficiency coal-fired catalyst according to any one of claims 1 to 8, characterized in that the steps include: Iodide, sodium salt, modified nano-cerium oxide, supported transition metal oxide, ethanol, water, surfactant and lignin sulfonate are mixed by weight and ground evenly to prepare a liquid catalyst; the liquid catalyst and coal are mixed at a mass ratio of 1:14000-17000.

10. Use of a high-efficiency coal-fired catalyst obtained by the preparation method according to any one of claims 1 to 9 in a gasification furnace.