Flue Gas Desulfurization and Denitrification Equipment for Thermal Power Plants

     Flue gas desulfurization and denitrification equipment in thermal power plants are key technological installations for controlling atmospheric pollutant emissions from coal-fired power plants and reducing the formation of acid rain and photochemical smog. The selection of technical routes, system composition, and operational effectiveness directly impact environmental compliance and power generation costs. The following analysis is conducted from four aspects: technical principles, equipment types, core systems, and development trends:

    I. Principles of Desulfurization and Denitrification Technologies

• Desulfurization Technology: Converts sulfur dioxide (SO?) in flue gas into solid or liquid products through chemical absorption or catalytic conversion. Mainstream technologies include limestone-gypsum wet flue gas desulfurization (using limestone slurry to absorb SO? and generate gypsum), circulating fluidized bed dry desulfurization (using dry absorbents to react in a fluidized bed), and ammonia-based desulfurization (using ammonia water to absorb SO? and produce ammonium sulfate).
• Denitrification Technology: Uses reducing agents to convert nitrogen oxides (NOx) into nitrogen (N?) and water (H?O). Selective Catalytic Reduction (SCR) employs ammonia or urea as a reducing agent under the action of a catalyst to convert NOx into N? at 300-420°C; Selective Non-Catalytic Reduction (SNCR) directly injects the reducing agent into the high-temperature zone (850-1100°C) without a catalyst to facilitate the reaction.
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    II. Equipment Types and System Composition

• Desulfurization Equipment: Taking the limestone-gypsum wet flue gas desulfurization system as an example, core equipment includes the absorption tower (equipped with spray layers and mist eliminators), slurry circulation pumps (for transporting absorbents), oxidation fans (providing oxidation air), gypsum dewatering machines (separating gypsum and water), and process water tanks (for storing and supplying process water).
• Denitrification Equipment: The SCR system consists of a reactor (with built-in catalyst modules), an ammonia injection system (precisely controlling ammonia distribution), ammonia storage and supply devices (ensuring stable supply of the reducing agent), dilution fans (mixing ammonia with air), and soot blowers (removing ash deposits on catalysts). The SNCR system includes reducing agent storage tanks, metering and distribution modules, and injection lances (for injecting the reducing agent into high-temperature zones).
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