As an important means to control air pollution and achieve clean production, flue gas desulfurization and denitrification technology has been widely used in many industrial fields. Especially in countries and regions where coal is the main energy source, this technology is an important measure to control sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) emissions and reduce acid rain and haze. The following are the main application areas and characteristics of flue gas desulfurization and denitrification technology:
1. Thermal power generation industry
This is one of the earliest and most widely used areas for flue gas desulfurization and denitrification technology. Coal-fired power plants are the main sources of sulfur dioxide and nitrogen oxides, accounting for more than half of the total SO₂ and NOₓ emissions in the country. In order to meet environmental regulations, power plants widely use wet limestone-gypsum desulfurization technology and selective catalytic reduction (SCR) denitrification technology, which effectively increases the removal efficiency of SO₂ to more than 90%, and the removal rate of NOₓ can reach 70% to 90%. The technology in this field is mature, the equipment is large-scale, and the operation experience is rich. It is the core application place of desulfurization and denitrification technology.
2. Iron and Steel Industry
The iron and steel industry emits a large amount of flue gas during sintering, ironmaking and steelmaking, which contains SO₂, NOₓ and dust. In particular, the sintering process is the key link of pollution emission. In order to control pollution, many steel enterprises have installed dry or semi-dry desulfurization systems, and cooperated with low ammonia or ammonia-free denitrification technology (such as SNCR or low-temperature SCR) to adapt to high temperature, high dust content and large gas volume. In recent years, with the advancement of ultra-low emission standards, the steel industry has become more and more urgent in terms of desulfurization and denitrification technology.
3. Cement Industry
During the cement production process, the flue gas at the tail of the kiln also contains a large amount of SO₂ and NOₓ, especially when using high-sulfur fuel or alternative fuel. The cement industry often uses dry desulfurization processes, such as furnace calcium injection and tail gas dry spray absorption technology. SNCR technology is often used for denitrification. Some large production lines have also begun to introduce SCR systems to meet more stringent emission requirements. The introduction of desulfurization and denitrification technology has an important role in promoting the clean and green transformation of the cement industry.
4. Petrochemical and chemical industry
Industries such as petroleum refining, fertilizer manufacturing, and organic chemicals emit corrosive and toxic SO₂ and NOₓ during production. Due to the complex gas composition, these industries mostly use composite technologies such as wet desulfurization, redox absorption, and SCR. At the same time, in order to cope with high temperature, high pressure, corrosive gas and other working conditions, higher requirements are also placed on equipment materials and control systems.
5. Waste incineration and biomass power generation
A certain amount of SO₂ and NOₓ will also be released during waste incineration. In order to achieve standard emissions, incineration plants are usually equipped with semi-dry or dry desulfurization equipment and SNCR denitrification devices. Some new projects use high-efficiency SCR systems to meet more stringent local environmental protection standards. Biomass boilers also have similar needs. Although the sulfur content of their fuel is low, NOₓ emissions still need to be controlled.
In summary, flue gas desulfurization and denitrification technologies have been widely used in many pollution-intensive industries such as thermal power, steel, cement, chemicals, and waste incineration. With the continuous improvement of environmental protection standards and the acceleration of green transformation, the application scope of this technology will continue to expand, which will have far-reaching significance for promoting the clean development of industry.