CN1660977A

CN1660977A - High performance desulfurization and eliminating pollution of fly ash inside coal burning boiler in electric power plant

Info

Publication number: CN1660977A
Application number: CN 200410049920
Authority: CN
Inventors: 侯岛
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-06-18
Filing date: 2004-06-18
Publication date: 2005-08-31

Abstract

A process for effective desulfurizing in the boiler using coal as fuel in electric power plant and eliminating the pollution of powdered coal ash features that a multifunctional additive is jetted directly in the boiler or fed into the boiler in conjunction with coal for combining it with SiO2, Al2O3, Fe2O3 and GaO to become new minerals, so effective desulfurizing while modifying the powdered coal ash to become hydraulic cementing material.

Description

High-efficiency desulfurization and elimination of pollution of pulverized coal ash in coal-fired boiler of power plant

Firstly, the power plant boiler is used for efficiently desulfurizing and eliminating the pollution of fly ash, and relates to the technical field of environmental protection, electric power and building material subjects.

Secondly, the technical background is as follows:

since the innovation of China is open, the development of industry, agriculture, traffic and energy sources is rapid and vigorous. The development of industrial and agricultural electric power needs to be advanced, the development of electric power industry in China mainly depends on coal energy, the coal-fired boiler is used for generating electricity accounting for 80 percent of the total generated energy, the nuclear power generation is just started in China, the resource problem of water in water conservancy power generation is solved, the development of coal-fired thermal power generation, the flue gas pollution of the coal-fired boiler and the SO contained in main source coal cannot be kept up with₂According to the statistics of the national statistical office, the SO discharged by China currently₂More than 3000 million tons, more than the first in the United states, the loss caused by acid rain reaches 1300 million yuan per year, which is equivalent to ton of SO₂Loss of 5000 Yuan, foreign to SO₂The loss evaluation is $ 3000, which is a great problem affecting the coal-fired development, and national policy determines the atmospheric SO discharged by the coal-fired of industrial enterprises₂The concentration must be controlled in the state regulation SO₂The emission concentration is below the standard and does not reach the standard for a long time, and the country does not allow the energy-consuming households to survive.

The power industry is fast in thermal power development, and mainly uses coal for power generation and heating. The second difficulty of thermal power generation is that a great deal of methods are needed to solve the problem that a great deal of fly ash is removed after the coal is combusted in the boiler, most of the fly ash is not utilized, the ash is accumulated to occupy a great deal of farmland, and the environment is also influenced to cause great pollution.

Therefore, the coal-fired boiler of the power plant discharges a large amount of SO₂And the utilization of fly ash, which are two problems until the problem is solved.

Third, the main contents of the invention

The high-efficiency desulfurization and the elimination of the pollution of the pulverized coal ash in the boiler of the power plant mainly solve two major problems of the desulfurization of the coal-fired power plant and the pollution of the pulverized coal ash, namely two main contents of technical problems.

The multifunctional additive is directly injected into the furnace from the wall of the high-temperature furnace or is mixed with coal, and is injected into the furnace or fed into the furnace, the fuel is mixed and combusted, after the high-temperature combustion, the coal particles and the multifunctional additive fine particles move violently in the furnace, the contact points and the contact surfaces collide violently, reactants and the reacted reactants diffuse and migrate through a product layer, the reaction speed is accelerated, and the coal ash oxide SiO is enabled to be₂、Al₂O₃、Fe₂O₃CaO and multifunctional additive are oxidized to synthesize new mineral compositions, thereby achieving the purposes of high-efficiency desulfurization in the furnace and modification of ash slag into hydraulic cementing material, high value-added product, and elimination of SO of second pollution of power plant₂And fly ash contamination.

(1) The coal material is mixed and burnt at high temperature in the powder furnace, and a great amount of SO is released during the burning of the coal in the furnace₂The additive has various functions of catalysis, combustion supporting and desulfurization, and also has active metal oxide, so that the original insufficient combustion condition is changed, the coal can be fully combusted in the furnace, not only a large amount of heat energy is released, but also the carbon content of the fly ash residue is greatly reduced, and moreimportantly, the carbon content is combined under the action of a strong oxidant

The formed calcium sulfate and the modified ash are integrated into a whole, and the calcium sulfate plays an important role in physical strength and activity in the modified ash. At the same time overcome SO₂The corrosion of the entering flue gas to the boiler and the pipeline can effectively improve the operation efficiency of the boiler. Owing to the new effect of the multifunctional additive, the desulfurizing rate of the circulating fluidized bed furnace can reach over 99 percent, the desulfurizing rate of the pulverized coal furnace can reach over 80 percent, and the desulfurizing rate of the cyclone furnace can reach over 80 percent.

(2) The coal material is mixed and burnt at high temperature in the furnace to lead the fly ash oxide SiO to be burnt₂、Al₂O₃、Fe₂O₃CaO and a multifunctional additive strong oxide are combined into a plurality of new minerals, the modified ash becomes a hydraulic cementing material and becomes a high value-added product, and the modified fly ash can be fully utilized by 100 percent. As the ash residue field is not used, a large amount of farmlands can be saved, the surrounding environment is improved, and the strategic policy of national sustainable development is met.

(3) Before and after the modified ash is produced, an excitant is added, the excitant breaks Si-O bonds and Ai-O bonds, so that the activity of the modified ash can be obviously improved, and the excitant is added to promote fly ash-Ca (OH)₂The reaction rate is improved, and the excitant is used for modifying fly ash residue-Ca (OH)₂The effect of (3) promotes the disintegration of the vitreous body ofthe modified fly ash. The reaction speed of various substances is improved, and the substances react with the substances of the system to form a new mineral composition. Accelerating the firm formation of the modified fly ash residue gel material.

(4) The technology realizes a short evaluation project with low investment, short construction period and quick response, improves the environmental protection benefit and the economic benefit of enterprises and society, and has wide development prospect.

Claims

1. A technology for high-efficiency desulfurizing and eliminating the pollution of powdered coal ash in coal-fired boiler of electric power plant features that the multifunctional additive and coal are burnt at high temp in furnace to combine the oxide of coal ash and the oxide of multifunctional additive into a new mineral composition, resulting in high-efficiency desulfurizing and modifying powdered coal ash to become high-value-added hydraulic cementing material.

2. The method of claim 1: the multifunctional additive is directly injected into the furnace from four positions of the high-temperature furnace wall or is mixed with coal and injected into the furnace or fed into the furnace.

3. The method of claim 2: the multifunctional additive is characterized by comprising minerals, limestone, quicklime, wollastonite, pumice, waste slag discharged by smelting rare metals, iron-manganese-silicon slag, zinc slag, silicon slag, magnesium slag, nickel slag, manganese slag, chemical by-product sodium sulfate, calcium chloride and potassium oxide, and has the main functions of: catalysis, desulfurization and combustion supporting.

4. The method of claim 3: ratio range of multifunctional additive to coal

Additive coal

(5～55)∶(95～45)。

5. The method of claim 4: the technology for high-efficiency desulfurization and eliminating pollution of fly ash in coal-fired boiler of power plant is applicable to three types of circulating fluidized bed boiler, pulverized coal furnace and cyclone furnace.