What is FSULPHUR Technology? What are the desulfurization processes?

There are dozens of types of flue gas desulfurization technology, according to whether water is added in the desulfurization process and the dry and wet form of the desulfurization products, flue gas desulfurization is divided into: wet, semi-dry, dry three types of desulfurization processes. The wet desulfurization technology is relatively mature, with high efficiency and simple operation.

The traditional limestone-gypsum flue gas desulfurization process uses calcium-based desulfurizer to absorb sulfur dioxide to generate calcium sulfite and calcium sulfate, which are easy to form scaling and blockage in the desulfurization tower and pipeline due to their small solubility. The double alkali flue gas desulfurization technology is developed to overcome the shortcomings of the limestone-lime method.

Pre-combustion: coal preparation technology, microbial desulfurization.

Combustion: briquette sulfur fixation, circulating fluidized bed combustion.

Post-combustion: flue gas desulfurization technology (wet, dry, semi-dry) Coal conversion: coal gasification, liquefaction, coal-water slurry technology.

Wet after combustion.

--Limestone-gypsum method.

--Ammonia method. --Magnesium oxide method.

--Alkaline waste method (calcium carbide slag method, white mud method, waste alkali method) -- seawater desulfurization method.

--Double alkali method.

--Ammonium phosphate fertilizer method, zinc oxide method, basic aluminum sulfate method, etc.

Dry --- calcium injection in the furnace.

--Calcium spraying in the furnace and humidification and activation of flue gas at the tail.

--Electron beam irradiation, pulsed corona, charged dry absorbent injection semi-dry method--- circulating fluidized bed method.

--Spray drying method.

There are generally two types of desulfurization: wet desulfurization and dry desulfurization.

1. The coal desulfurization technology before combustion is mainly coal washing and desulfurization, that is, the coal is purified before combustion to remove part of the sulfur and ash in the raw coal. It is divided into physical method, chemical method and microbial method. 1. Physical Law:

It mainly refers to gravity beneficiation, which uses the density difference between organic matter and pyrite in coal to separate them. The influencing factors of this method mainly include the crushing particle size of coal and the state of sulfur. The main methods include jigging coal preparation, heavy medium coal preparation, wind coal preparation, etc.

2. Chemical method: it can be divided into physical chemical method and pure chemical method. The physicochemical method is flotation; Chemical methods include alkali desulfurization, gas desulfurization, pyrolysis and hydrogenation desulfurization, oxidation desulfurization, etc.

3. Microbial method: a new bioengineering technology applied to the coal industry on the basis of bacterial leaching of metals, which can remove organic sulfur and inorganic sulfur from coal. China's current coal washing rate is low, about 20, while the United States is 42, the United Kingdom is 94 9, France is 88 7, and Japan is 98 2.

Increasing the washing rate of coal is expected to significantly improve sulfur dioxide pollution from coal burning. However, physical separation can only remove 80 of the inorganic sulfur in the coal, accounting for 15 30 of the total sulfur content in the coal, which cannot meet the requirements of coal sulfur dioxide pollution control, so it can only be used as an auxiliary means of coal desulfurization. 2. Combustion of coal desulfurization technologyLimestone or dolomite is added as desulfurizer during coal combustion, calcium carbonate and magnesium carbonate are decomposed by heat to form calcium oxide and magnesium oxide, which react with sulfur dioxide in flue gas to form sulfate, which is discharged with ash.

There are two main types of desulfurization technologies used in the combustion process in China: briquette sulfur fixation and fluidized bed combustion desulfurization technology. 1. Briquette sulfur fixation technology:

After screening, different raw materials are mixed with coal in a certain proportion, mixed with pretreated binders and sulfur fixing agents after crushing, and extruded and dried by mechanical equipment to obtain finished industrial sulfur briquettes with certain strength and shape. Sulfur fixing agents mainly include limestone, marble, calcium carbide slag, etc., and the amount added depends on the sulfur content. Burning briquette can greatly reduce the concentration of sulfur dioxide, carbon monoxide and soot in flue gas, save coal, and the economic and environmental benefits are considerable, but the problems of ignition lag and improper operation caused by ignition lag and improper operation should be solved in industrial practical applications.

2. Fluidized bed combustion desulfurization technology: coal and adsorbent are added to the bed of the combustion chamber, and the bed is suspended for fluidized combustion by blasting air from the bottom of the furnace, which forms turbulent mixing conditions, prolongs the residence time, and improves the combustion efficiency. The reaction process is that sulfur in coal is burned to produce sulfur dioxide, and at the same time, limestone is calcined and decomposed into porous calcium oxide, and sulfur dioxide reaches the surface of the adsorbent and reacts, so as to achieve the desulfurization effect.

The main influencing factors of fluidized bed combustion desulfurization include calcium-sulfur ratio, calcination temperature, particle size, pore structure and type of desulfurizer. In order to improve the desulfurization efficiency, the following methods can be adopted: (1) improve the design and operating conditions of the combustion system (2) pre-calcination of desulfurizer (3) use additives, such as sodium carbonate, potassium carbonate, etc. (4) develop new desulfurizers.

Hello, glad to answer for you. "Desulfurization generally refers to the removal of sulfur from fuel before combustion and the desulfurization process before flue gas discharge. It is one of the important technical measures for the prevention and control of air pollution. There are generally three desulfurization methods: pre-combustion, combustion and post-combustion desulfurization. ”

Desulfurization is the reaction of two molecules containing active sulfur to acid-base enzymes.

The chemical change process that occurs when a sulfur atom or sulfur group is lost under the action of force energy or other catalysts.

Sulfur is harmful in petrochemical production and can poison expensive catalysts. However, natural gas and oil also contain sulfur, which must be desulphised before these raw materials can be used.

The desulfurization of ** is different from the desulfurization of natural gas. ** desulfurization also requires catalysts, and it is a popular research direction (industry gives a lot of money). The desulphurization of natural gas is relatively simple.

Through the solution of natural gas to a certain compound, the chemical reaction forms a sulfur-containing precipitate to remove sulfur.

Desulfurization methods for coal:

1. Physical method: Iron sulfide (pyrite) in coal is usually removed by gravity separation or magnetic separation method, and the sulfur in this form accounts for about 2 3 of the sulfur in coal.

2. Chemical method: the coal is mixed with the aqueous solution of iron sulfate after crushing, heated to 100 130 in the reactor, and the iron sulfate reacts with pyrite to convert into ferrous sulfate and monomer sulfur, the former is recycled after oxidizing Yunchang, and the latter is used as a by-product.

3. Gasification method: coal is subjected to incomplete oxidation through a gasifier at a high temperature of 1000 to 1300 to become gas. Most of the sulfur in coal becomes hydrogen sulfide when it is gasified, and then it is removed by liquid absorption or solid adsorption.

4. Liquefaction method: The liquefaction of coal includes synthesis method, direct cracking hydrogenation method and hot melt hydrogenation method. In the liquefaction process, sulfur reacts with hydrogen to form hydrogen sulfide and escapes, thus obtaining a fuel with high calorific value, low sulfur and low ash content.

Flue gas desulfurization is divided into dry and wet process. The former uses solid powder or granules as adsorbents, such as lime powder blowing method, activated carbon method and activated manganese oxide method. The latter uses liquid as an absorbent, such as ammonia absorption, limestone or lime milk absorption, magnesium oxide absorption, sodium (potassium) absorption, and oxidation bypass absorption.

Fuel desulfurization can improve sulfur content, reduce sulfur oxide pollution, and improve the calorific value of fuel.

Flue gas desulfurization refers to the removal of sulfides from flue gas.

Flue gas desulfurization is generally divided into wet and dry desulfurization, semi-dry desulfurization, and now the more commonly used flue gas desulfurization method is SDS dry desulfurization, the main process is to send the activated calcium desulfurizer into the silo for temporary storage, and then in the lower part of the storage silo variable control feeder, combined with the change of flue gas volume to output an appropriate amount of active calcium desulfurizer, through the powder fan to the desulfurization reactor, so that the flue gas energy speed mixed with its entering, reaction to remove the sulfide and other components in the flue gas.

1. SDS dry desulfurization.

The main purpose of SDS dry desulfurization is to decompose the exhaust gas into sodium carbonate through reaction, and after the sodium carbonate is highly mixed with the flue gas, sodium sulfate and other sodium salts are generated, so as to achieve the flue gas emission standard and reduce environmental pollution.

Advantages of SDS dry desulfurization:

1.SDS dry desulfurization efficiency reaches more than 95% and can maintain continuous discharge;

2.SDS dry desulfurization equipment occupies a small area, has small site restrictions, low power consumption, low fault, and prolongs the life of the equipment;

3.SDS dry desulfurization systems have low temperatures, which are more energy-efficient and convenient than those processes that require high temperatures.

4.SDS dry desulfurization system operates in full dry mode, without wastewater treatment and discharge problems, no chimney tailing, and no flue gas whitening treatment.

2. Limestone - Shichang patting paste wet flue gas desulfurization process:

Limestone - gypsum wet flue gas desulfurization process principle This method is to grind limestone (lime) into fine powder, prepare into slurry, flue gas and limestone slurry flow down in the absorption tower, the SO2 in the smoke and limestone chemical reaction to generate calcium sulfite and calcium sulfate, in the bottom tank of the absorption tower into a large amount of air, calcium sulfite oxidation into calcium sulfate, crystallization separation of the by-product gypsum.

Limestone-gypsum wet desulfurization technology is mature, high desulfurization efficiency, large unit capacity, low operating cost and easy by-product desulfurization process.