A coal-saving, desulfurizing and decoking catalyst for boilers and its application method

Abstract

The present invention provides a coal-saving, desulfurization, and decoking catalyst for boilers and an application method thereof. Through the synergistic effect of multiple components, the catalyst can simultaneously achieve coal-saving, desulfurization, decoking, corrosion protection, and ash cleaning functions during boiler operation, effectively solving the problems of single function, low desulfurization efficiency, poor decoking effect, and insufficient adaptability in the prior art. The desulfurization catalyst neutralizes sulfur oxides in flue gas, reducing low-temperature slagging. The temperature-sensitive expansion particles dynamically expand and peel off hard coke. The porous carrier particles adsorb ash and complex salts. The high-temperature retention loosening agent and the catalyst work together to prevent secondary accumulation, improve heat transfer conditions, and increase boiler thermal efficiency. The coal-saving agent reduces fuel consumption. The metal protective agent forms an anti-corrosion film on the heated surface, extending the life of the equipment and significantly improving the economic efficiency of boiler operation.

Description

Technical Field

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

[0002] Boilers, as an important thermal energy conversion device, are widely used in the fields of electricity, chemical industry, petrochemical industry, metallurgy, and civil heating. However, during boiler operation, the flue gas produced by fuel combustion contains sulfides (such as sulfur dioxide SO2 and sulfur trioxide SO3), 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 not only significantly reduces the thermal efficiency of the boiler and increases fuel consumption, but also causes corrosion and wear on the heating surfaces and other key components of the boiler, seriously affecting the operating performance, economy, and service life of the boiler equipment.

[0003] In low-temperature areas (such as economizers), sulfur oxides (SO2 and SO3) in flue gas react with water vapor to form sulfates, forming sticky wet slagging. Meanwhile, in high-temperature areas (such as the furnace heating surface), ash and sulfides in the fuel form low-melting-point salts, forming hard coke. These deposits significantly increase the thermal resistance of the heating surface, reducing boiler efficiency.

[0004] Currently, common solutions to boiler ash and coking problems include mechanical cleaning and chemical cleaning. Mechanical cleaning removes ash from the heating surface through soot blowers or manual knocking. It is suitable for loose ash, but its effect on removing high-temperature hard coke is limited. It is also labor-intensive and prone to damage to the equipment surface. Chemical cleaners decompose slag and coke through chemical reactions, but existing cleaner products usually have a single function and cannot meet multiple needs such as desulfurization, decoking, and corrosion protection at the same time. In addition, some chemical cleaners are corrosive to boiler materials. Long-term use will shorten the life of the equipment and reduce the overall economic efficiency of the boiler operation. At the same time, these cleaners have poor adaptability to different types of fuel boilers, making it difficult to cope with complex operating conditions, and their effectiveness is limited.

[0005] Existing technologies for addressing boiler slagging and coking suffer from limitations such as low desulfurization efficiency, poor decoking, high fuel consumption, insufficient corrosion resistance, and poor adaptability. Therefore, there is an urgent need in the field to develop a highly efficient, coal-saving, low-corrosion, and widely applicable coal-saving desulfurization and decoking catalyst for boilers that can effectively remove slagging and coking, improve boiler thermal efficiency, reduce fuel consumption, and extend equipment life. Summary of the Invention

[0006] This invention provides a coal-saving, desulfurization, and decoking catalyst for boilers and its application method. This catalyst effectively addresses issues such as low-temperature wet slagging, high-temperature hard coking, and complex salt adhesion caused by fuel combustion during boiler operation. By combining physical adsorption with dynamic stripping, this catalyst comprehensively achieves coal conservation, desulfurization, decoking, corrosion prevention, and ash cleaning. This significantly improves boiler thermal efficiency and reduces fuel consumption while extending the boiler's cleaning cycle and equipment life.

[0007] In order 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, desulfurization and decoking catalyst for a boiler, which comprises the following components by weight: 6-10% metal protective agent, 10-15% oxidant, 12-20% desulfurization catalyst, 8-12% porous carrier particles, 15-21% temperature-sensitive expansion particles, 12-18% high-temperature retention loosening agent, 6-11% promoter, 15-20% catalyst, 5-10% oxygenator, and 6-12% coal-saving agent.

[0009] Preferably, the metal protective agent 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, pore size range is 0.3–1.2 nm, and particle size range is 50–150 μm.

[0013] Preferably, 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.

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

[0015] Preferably, the accelerator 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 oxygenator 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 desulfurization and decoking catalyst for boilers, comprising: adding the coal-saving desulfurization and decoking catalyst for boilers at a rate of 0.02-0.06% of the amount of fuel and distributing the catalyst in the boiler.

[0020] Preferably, the step of adding the boiler coal-saving desulfurization and decoking catalyst at 0.02-0.06% of the amount of fuel and distributing it in the boiler comprises: adding the boiler coal-saving desulfurization and decoking catalyst to a coal conveyor belt and mixing it with the fuel coal, grinding it into powder through a coal mill, and then feeding it into the furnace together with the fuel coal powder for combustion.

[0021] The present invention provides a coal-saving, desulfurization, and decoking catalyst for boilers and its application method, which have the following beneficial effects: through the synergistic effect of multiple components, it can simultaneously achieve coal saving, desulfurization, decoking, corrosion protection, and ash cleaning functions during boiler operation, effectively solving the problems of single function, low desulfurization efficiency, poor decoking effect, and insufficient adaptability in the existing technology. The desulfurization catalyst neutralizes sulfur oxides in flue gas, reducing low-temperature slagging; the temperature-sensitive expansion particles release gas by triggering core decomposition at high temperature, generating 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, and ensuring the stability and efficiency of the expansion reaction; through high specific surface area and appropriate pore size, the porous carrier particles adsorb sulfur oxides and ash particles in the flue gas, reducing the adhesion of complex salts and slagging, while enhancing the ash desorption effect, and significantly improving the heat transfer performance of the boiler heating surface; the high-temperature retention loosening agent and the catalyst synergistically prevent secondary accumulation, improve heat transfer conditions, and increase the thermal efficiency of the boiler, and the coal-saving agent reduces fuel consumption; the metal protective agent forms an anti-corrosion film on the heating surface, extending the equipment life and significantly improving the economic efficiency of boiler operation.

[0022] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the disclosure, nor is it intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present disclosure.

[0024] Figure 1 Schematic diagram of temperature-sensitive expansion particles provided by an embodiment of the present invention. DETAILED DESCRIPTION

[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 accompanying 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. Rather, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0026] As used herein, the term "including" and its variations represent open inclusion, i.e., "including but not limited to." Unless otherwise stated, the term "or" means "and / or." The term "based on" means "based at least in part 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] Example:

[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 100m 2 / g, pore size 0.8nm, particle size range 80–120μm;

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

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

[0034] Accelerator: ammonium sulfate, 8%;

[0035] Catalyst: sodium metasilicate, 15%;

[0036] Oxygenator: calcium oxide, 5%;

[0037] Coal saving agent: sodium sulfate, 6%.

[0038] After weighing the above components in proportion, the components were placed in a mixing device and mixed at high speed for 15 minutes at 25° C. to obtain a uniform granular coal-saving, desulfurization and decoking catalyst for boilers.

[0039] The boiler-use coal-saving desulfurization and decoking catalyst is added to the coal conveyor belt at a rate of 0.02-0.06% of the fuel volume. After being thoroughly mixed with the fuel coal, it is ground into powder in a coal mill and fed into the furnace along with the pulverized fuel coal for combustion. This dynamic expansion and removal of hard coke occurs in the high-temperature region, while reducing wet slagging in the low-temperature region. The catalyst is evenly distributed on the surface of the heat pipe heat exchanger through flue gas flow, further adsorbing complex salts and ash, reducing adhesion. Simultaneously, the desulfurization reaction within the tail gas channel completes the flue gas purification process, ensuring the efficient operation of the boiler-use coal-saving desulfurization and decoking catalyst throughout the boiler system. This improves boiler thermal efficiency by approximately 5%, fully realizing coal saving, desulfurization, decoking, corrosion prevention, and ash cleaning functions.

[0040] While various embodiments of the present disclosure have been described above, the foregoing description is intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technical improvements to existing technologies, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A coal-saving, desulfurization and decoking catalyst for boilers, characterized in that: The invention comprises the following components by weight percentage: 6-10% metal protective agent, 10-15% oxidant, 12-20% desulfurization catalyst, 8-12% porous carrier particles, 15-21% temperature-sensitive expansion particles, 12-18% high-temperature retention loosening agent, 6-11% promoter, 10-15% catalyst, 5-10% oxygenator, and 6-12% coal-saving agent. The metal protective agent is one or more of copper carbonate, barium sulfate, and zinc phosphate. The porous carrier particles are one or more of zeolite and activated carbon, with a specific surface area of ​​50-150 m² / g, a pore size range of 0.3-1.2 nm, and a particle size range of 50-150 μm. The temperature-sensitive expansion particles are calcium carbonate with a surface coated with alumina, with a coating thickness of 2-8 μm and a particle size range of 50-150 μm.

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

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

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

5. 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.

6. 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.

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

8. 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.

9. A method for using the coal-saving, desulfurization and decoking catalyst for boilers according to any one of claims 1 to 8, characterized in that: include: The coal-saving desulfurization and decoking catalyst for the boiler is added at 0.02-0.06% of the amount of fuel and distributed in the boiler.

10. The application method according to claim 9, 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 the fuel coal, grinding it into powder through a coal mill, and then feeding it into the furnace for combustion together with the fuel coal powder.

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