Coal-saving desulfurization and decoking catalyst for boiler and application method of coal-saving desulfurization and decoking catalyst

Abstract

According to the coal-saving, desulfurization and decoking catalyst for the boiler and the application method of the coal-saving, desulfurization and decoking catalyst, through the synergistic effect of multiple components, the functions of coal saving, desulfurization, decoking, corrosion prevention and ash removal can be achieved at the same time in the operation process of the boiler, and the problems that in the prior art, the function is single, the desulfurization efficiency is low, the decoking effect is poor and adaptability is insufficient are effectively solved. The desulfurization catalyst neutralizes flue gas sulfur oxides, reduces low-temperature slag bonding, the temperature-sensitive expansion particles dynamically expand to peel hard cokes, the porous carrier particles adsorb ash and double salt, the high-temperature retention loosening agent and the catalyst cooperate to prevent secondary accumulation, improve heat transfer conditions and improve boiler heat efficiency, and the coal saving agent reduces fuel consumption. The metal protective agent forms an anti-corrosion film on the heating surface, the service life of equipment is prolonged, and the boiler operation economical efficiency is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the chemical industry field, and particularly relates to a coal-saving, desulfurizing and coke-removing catalyst for boilers and an application method thereof. Background Art

[0002] As an important heat energy conversion device, boilers are widely used in fields such as electric power, chemical industry, petrochemical industry, metallurgy, and civil heating. However, during the operation of boilers, since the flue gas generated after fuel combustion contains sulfides (such as sulfur dioxide SO 2 and sulfur trioxide SO 3 etc.), ash, and other impurities, these substances will form different types of ash slag and coke on the high-temperature and low-temperature heating surfaces of the boiler. The formation of ash slag and coke will not only significantly reduce the thermal efficiency of the boiler, increase fuel consumption, but also cause corrosion and wear to the heating surface and other key components of the boiler, seriously affecting the operation performance, economy, and service life of the boiler equipment.

[0003] In the low-temperature region (such as the economizer), sulfur oxides (SO 2 , SO 3 ) in the flue gas react with water vapor to form sulfates, forming adhesive wet slag; while in the high-temperature region (such as the furnace heating surface), the ash and sulfides in the fuel form low-melting salts, forming hard coke. These deposits significantly increase the heat resistance of the heating surface and reduce the boiler efficiency.

[0004] At present, the common solutions to the problems of boiler ash slag and coke include mechanical soot blowing and chemical soot blowing. Mechanical soot blowing removes the ash slag on the heating surface through soot blowers or manual knocking, which is suitable for loose ash slag, but has limited effect on removing high-temperature hard coke, and has a large labor intensity and is easy to damage the equipment surface. Chemical soot blowing agents decompose slag and coke through chemical reactions, but the existing soot blowing agent products usually have a single function and are difficult to meet multiple requirements such as desulfurization, coke removal, and anti-corrosion at the same time. In addition, some chemical soot blowing agents have a certain corrosive effect on boiler materials, and long-term use will shorten the equipment life and reduce the overall operation economy of the boiler. At the same time, these soot blowing agents have poor adaptability to different types of fuel boilers and are difficult to cope with complex operating conditions, and the use effect is limited.

[0005] The existing technologies have limitations such as low desulfurization efficiency, poor coke removal effect, large fuel consumption, insufficient anti-corrosion ability, and poor adaptability when dealing with the problems of boiler ash slag and coke. Therefore, developing a highly efficient, coal-saving, low-corrosion, and widely applicable coal-saving, desulfurizing and coke-removing catalyst for boilers, which can effectively remove slag and coke, improve the thermal efficiency of the boiler, reduce fuel consumption, and extend the service life of the equipment, has become an urgent need in this field. Summary of the Invention

[0006] The present invention provides a coal-saving, desulfurizing and coke-removing catalyst for boilers and an application method thereof. This catalyst can effectively solve problems such as low-temperature wet slagging, high-temperature hard coking, and double-salt adhesion caused by fuel combustion during boiler operation. Through the combination of physical adsorption and dynamic stripping, this catalyst comprehensively realizes functions of coal saving, desulfurization, coke removal, anti-corrosion, and ash cleaning. It can not only significantly improve the thermal efficiency of the boiler, reduce fuel consumption, but also extend the ash cleaning cycle and the service life of the equipment.

[0007] To solve the above technical problems, the embodiments of the present invention disclose the following technical solutions:

[0008] One aspect of the present invention provides a coal-saving, desulfurizing and coke-removing catalyst for boilers, which includes the following components by weight percentage: 6–10% of metal protectant, 10–15% of oxidant, 12–20% of desulfurization catalyst, 8–12% of porous carrier particles, 15–21% of temperature-sensitive expansion particles, 12–18% of high-temperature retention and loosening agent, 6-11% of promoter, 15–20% of catalyst, 5-10% of oxygen enhancer, and 6-12% of coal-saving agent.

[0009] Preferably, the metal protectant is one or more of copper carbonate, barium sulfate, and zinc phosphate.

[0010] Preferably, the oxidant is one or more of potassium permanganate and sodium nitrate.

[0011] Preferably, the desulfurization catalyst is one or more of magnesium oxide and sodium carbonate.

[0012] Preferably, the porous carrier particles are one or more of zeolite and activated carbon, with a specific surface area of 50–150m 2 / g, a pore diameter range of 0.3–1.2nm, and a particle size range of 50–150μm.

[0013] Preferably, the temperature-sensitive expansion particles are calcium carbonate coated with alumina, with a coating thickness of 2–8μm and a particle size range of 50–150μm.

[0014] Preferably, the high-temperature retention and loosening agent is one or more of borax, sodium carbonate, and sodium bicarbonate.

[0015] Preferably, the promoter is one or more of ammonium sulfate and potassium chloride.

[0016] Preferably, the catalyst is one or more of sodium metasilicate, aluminum silicate, and silicon dioxide.

[0017] Preferably, the oxygen enhancer is one or more of calcium oxide and potassium nitrate.

[0018] Preferably, the coal-saving agent is one or more of sodium sulfate and lithium carbonate.

[0019] Another aspect of the present invention provides an application method of the above-mentioned coal-saving, desulfurizing and coke-removing catalyst for boilers, including: adding the coal-saving, desulfurizing and coke-removing catalyst for boilers at 0.02–0.06% of the fuel amount and distributing it in the boiler.

[0020] Preferably, adding the coal-saving, desulfurizing and coke-removing catalyst for boilers at 0.02–0.06% of the fuel amount and distributing it in the boiler includes: adding the coal-saving, desulfurizing and coke-removing catalyst for boilers to the coal conveyor belt and mixing it with fuel coal, grinding it into powder by a coal mill, and then sending it into the furnace together with the fuel coal powder for combustion.

[0021] The present invention provides a coal-saving, desulfurizing and coke-removing catalyst for boilers and its application method, which has the following beneficial effects: through the synergistic effect of multiple components, it can simultaneously achieve the functions of coal saving, desulfurization, coke removal, anti-corrosion and ash cleaning during the operation of the boiler, effectively solving the problems of single function, low desulfurization efficiency, poor coke removal effect and insufficient adaptability in the prior art. Neutralize sulfur oxides in flue gas through the desulfurization catalyst to reduce low-temperature slagging; the thermosensitive expansion particles trigger the core decomposition at high temperature to release gas, generate dynamic expansion force to peel off hard coke, and delay heat conduction and stabilize the particle structure through the coating layer, regulating the core decomposition rate to ensure the stability and high efficiency of the expansion reaction; through the high specific surface area and appropriate pore size, the porous carrier particles adsorb sulfur oxides and ash particles in the flue gas, reduce the adhesion of double salts and slagging, and at the same time enhance the ash desorption effect, significantly improving the heat transfer performance of the boiler heating surface; the high-temperature retention loosening agent and the catalyst cooperate to prevent secondary accumulation, improve the heat transfer conditions, increase the boiler thermal efficiency, and the coal-saving agent reduces fuel consumption; the metal protective agent forms an anti-corrosion film on the heating surface, extends the equipment life, and significantly improves the economic efficiency of boiler operation.

[0022] The invention content part is provided to introduce the selection of concepts in a simplified form, which will be further described in the specific implementation manners below. The invention content part is not intended to identify the important features or essential features of the present disclosure, nor is it intended to limit the scope of the present disclosure. Brief Description of the Drawings

[0023] By describing the exemplary embodiments of the present disclosure in more detail in conjunction with the drawings, the above and other objects, features and advantages of the present disclosure will become more obvious, wherein, in the exemplary embodiments of the present disclosure, the same reference numerals generally represent the same components.

[0024] Figure 1 It is a schematic diagram of the thermosensitive expansion particles provided by the embodiment of the present invention. Detailed Description of the Invention

[0025] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be more thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0026] As used herein, the term "comprising" and its variations mean open inclusion, i.e., "including but not limited to". Unless otherwise specified, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0027] Embodiment:

[0028] Metal protectant: copper carbonate, 6%;

[0029] Oxidant: potassium permanganate, 10%;

[0030] Desulfurization catalyst: magnesium oxide, 12%;

[0031] Porous carrier particles: zeolite, 8%, specific surface area 100 m 2 / g, pore diameter 0.8 nm, particle size range 80–120 μm;

[0032] Thermosensitive swelling particles: calcium carbonate coated with alumina, 18%, coating thickness 4 μm, particle size range 80–120 μm (see Figure 1 );

[0033] High-temperature retention loosening agent: borax, 12%;

[0034] Promoter: ammonium sulfate, 8%;

[0035] Catalyst: sodium metasilicate, 15%;

[0036] Oxygen enhancer: calcium oxide, 5%;

[0037] Coal saver: sodium sulfate, 6%.

[0038] After weighing the above components in proportion, place them in a mixing device and mix at high speed at 25 °C for 15 minutes to obtain a uniform granular coal-saving, desulfurizing and coke-removing catalyst for boilers.

[0039] The boiler coal-saving desulfurization and decoking catalyst is added to the coal conveyor belt at 0.02-0.06% of the fuel amount, and after being fully mixed with the fuel coal, it is ground into powder by a coal mill and sent into the furnace for combustion together with the fuel coal powder, so as to dynamically expand and peel off the hard coke in the high-temperature area, reduce the formation of wet slagging in the low-temperature area, and evenly distribute on the surface of the heat pipe heat exchanger through the flue gas flow, further adsorb the complex salt and ash, and reduce adhesion. At the same time, through the desulfurization reaction in the tail gas channel, the flue gas purification treatment is completed, ensuring the efficient role of the boiler coal-saving desulfurization and decoking catalyst in the boiler system throughout the process, the boiler thermal efficiency is increased by about 5%, and the coal-saving, desulfurization, decoking, anti-corrosion and ash cleaning functions are fully realized.

[0040] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A coal-saving desulfurization and decoking catalyst for boilers, characterized in that: In terms of weight percentage, it includes the following components: metal protective agent 6-10%, oxidant 10-15%, desulfurization catalyst 12-20%, porous carrier particles 8-12%, temperature-sensitive expansion particles 15-21%, high-temperature retention loosening agent 12-18%, promoter 6-11%, catalyst 10-15%, oxygenator 5-10%, and coal-saving agent 6-12%.

2. The coal-saving desulfurization and decoking catalyst for boiler according to claim 1, characterized in that: The metal protective agent is one or more of copper carbonate, barium sulfate and zinc phosphate.

3. The coal-saving desulfurization and decoking catalyst for boiler according to claim 1, characterized in that: The oxidant is one or more of potassium permanganate and sodium nitrate.

4. The coal-saving desulfurization and decoking catalyst for boiler according to claim 1, characterized in that: The desulfurization catalyst is one or more of magnesium oxide and sodium carbonate.

5. The coal-saving desulfurization and decoking catalyst for boiler according to claim 1, characterized in that: The porous carrier particles are one or more of zeolite and activated carbon, and have a specific surface area of ​​50-150m 2 / g, pore size range is 0.3–1.2nm, and particle size range is 50–150μm.

6. The coal-saving desulfurization and decoking catalyst for boiler according to claim 1, characterized in that: The temperature-sensitive expansion particles are calcium carbonate with aluminum oxide coated on the surface, the coating thickness is 2-8 μm, and the particle size range is 50-150 μm.

7. The coal-saving desulfurization and decoking catalyst for boiler according to claim 1, characterized in that: The high temperature retention loosening agent is one or more of borax, sodium carbonate and sodium bicarbonate.

8. The coal-saving, desulfurization and decoking catalyst for boilers according to claim 1, characterized in that: The accelerator is one or more of ammonium sulfate and potassium chloride.

9. The coal-saving, desulfurization and decoking catalyst for boilers according to claim 1, characterized in that: The catalyst is one or more of sodium metasilicate, aluminum silicate and silicon dioxide.

10. The coal-saving desulfurization and decoking catalyst for boiler according to claim 1, characterized in that: The oxygenator is one or more of calcium oxide and potassium nitrate.

11. The coal-saving, desulfurization and decoking catalyst for boilers according to claim 1, characterized in that: The coal saving agent is one or more of sodium sulfate and lithium carbonate.

12. A method for using the coal-saving, desulfurization and decoking catalyst for boilers according to any one of claims 1 to 11, characterized in that: include: The boiler coal-saving desulfurization and decoking catalyst is added at 0.02-0.06% of the amount of fuel and distributed in the boiler.

13. The application method according to claim 12, characterized in that: The method of adding the boiler coal-saving desulfurization and decoking catalyst at 0.02-0.06% of the fuel amount and distributing it in the boiler includes: adding the boiler coal-saving desulfurization and decoking catalyst to a coal conveyor belt and mixing it with fuel coal, grinding it into powder through a coal mill, and then sending it into the furnace together with the fuel coal powder for combustion.

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