Core Technology of Desulfurization

Spray Tower Desulfurization Technology

Main Features of Spray Tower Desulfurization Technology:
■ Simple process
■ Small area
■ Large capacity of single unit
■ High flow rate in tower
■ Small liquid ratio
■ Large-amount investment
■ Steady and reliable operation
■ Many materials that can be applied, including the coal that has high content of aluminum, fluoride and chloride.

Bubble Tower Desulfurization Technology

Main Features of Bubble Tower Desulfurization Technology:
■ High rate of removal of sulfur dioxide
■ High reliability and simple operation
■ Free of scaling
■ High usage of limestone
■ Operation of closed system
■ Flexible in operating with ability to adopt the immersion depth to sulfur-containing conditions so as to adjust the booster fan and minimize energy consumption
■ Many materials that can be applied, including coals that have high contents of aluminum, fluoride and chloride

Semi-Dry Desulfurization Technology

Main Features of Semi-Dry Desulfurization Technology:
■ The desulfurization efficiency is up to 90% or more and the system can effectively remove other harmful gases, heavy metals and other pollutants.
■ The bag-type dust collector or electrostatic dust collector is adopted and can effectively control the dust emission below 50mg/Nm³.
■ The process is advanced with high level of automatic control. The equipment is of high corrosion resistance and the complete set of equipment has high availability.
■ The system covers a small area and is easy to operate. The operation is reliable and the investment and operation costs are low.
■ The system can realize “Zero Emission” and will not cause secondary pollution. The products from desulfurization are dry and easy to transport, and they can be recycled and have certain economic interests.
■ The complete set is power-saving and water-saving, and conforms to national policies on energy conservation and emission reduction.

Technology of Ammonia Process of Desulfurization

Technology of Ammonia Process of Desulfurization takes advantage of the ammonium hydroxide’s alkalinity to absorb acidic SO₂ gas in the flue gas and produce byproduct such as thiamine or thiamine fertilizer. Such technology applies to the flue gas desulfurization of any types of coal with a desulfurization degree of more than 95 %.Such process is composed of flue gad washing (desulfuration) section, oxidation section and evaporative crystallization and prilling section, etc.

The ammonia process technology of Jiangsu Fengye Technology & Environment Group has the following main characteristics: high technology readiness level; high desulfurization degree; high utilization efficiency of absorbent; no wastewater and waste residue discharge; no secondary pollution; realizable recycling resources; advanced control system with reliable and stable operation; high load tracking performance. The enterprises with byproduct of ammonium hydroxide may adopt the process of fire coal (oil) boiler flue gas desulfuration according to the industrial dispersion features of various regions to realize the control of wastes with process of wastes against one another and achieve circular economy.

Magnesium Desulfurization Technology

Magnesium oxide desulfurization technology uses the magnesium oxide as absorbent and has a byproduct of magnesium sulfate solution which can be directly charged into the sea. Such technology has certain characteristics such as simple technological process, small floor space, high desulphurization efficiency and low equipment investment, etc. Small and medium size boilers as well as the high-capacity utility boiler may adopt such desulfurization technology.

Seawater Desulfurization Technology

Seawater desulfurization technology takes advantage of the alkalinity of natural seawater to treat the flue gas. This technology is mainly composed of flue gas system, absorption tower system, seawater feed system and seawater recovery system.
The main characteristics of this technology are as follows:
■ Desulphurization efficiency of more than 95%;
■ Simple process having no need of reactant, only seawater and air participate in the desulphurization process with on scale formation and abrasion;
■ Stable system operation and simple operating maintenance with small number of operating maintenance personnel;
■ The reaction product is the intrinsic element in the seawater and no solid byproduct is produced. There is no need to treat the product;

Sintering Machine Desulfurization Technology

The SO₂ pollutant discharge management has been carried out since 2003 in China, and the SO₂ discharge management at iron and steel industry has begun as the key emphasis of China’s next SO₂ discharge control. Sintering machine flue gas desulfurization is the main implementation direction at present.

Characteristics of sintering machine flue gas
■ Large flue gas amount and high oxygen content;
■ High flue gas temperature (normally 90-120℃);
■ High dust concentration in the flue gas with a general concentration of 10g/Nm³;
■ Large moisture content; Moisture content is about 10% calculated by volume ratio;
■ A large number of corrosive gas;
■ Low SO₂ concentration (normally 1000-3000mg/Nm³);
■ Heavy metal pollutant included mainly from the iron ore;
■ Large amplitude and high frequency of SO₂ variant in the flue gas during the sintering with low concentration of SO₂ at the head and tail of the sintering machine and high concentration of SO₂ at the middle part of the sintering machine.

Control method of sintering flue gas
■ Allocate low-sulfur raw materials, but it is difficult to popularize such method because of the high costs of iron ore and fuel with low sulphur content.
■ Generally, the height of main drawring chimney is 80m-120m (230m for Japan and 360m for the U.S) for chimney stack diffusion and attenuation. Limited by the emission concentration and the emission total amount, this method is not suitable for the actual requirement.
■ Flue gas desulfurization is the effective method to control SO₂ up-to-standard discharge at present. Limestone-wet desulphurization process applies and works well. Some projects with low requirement for the desulphurization effect and limited site may adopt semidry dry desulfurization process.

Flow Chart of Sintering Process