Flue Gas Treatment: Technologies and Environmental Benefits Flue gas treatment is a critical process in industrial operations, particularly in power plants, waste incineration facilities, and manufacturing units, where combustion processes generate exhaust gases containing pollutants. These pollutants, including sulfur dioxide (SO₂), nitrogen oxides (NOₓ), particulate matter (PM), carbon monoxide (CO), heavy metals, and greenhouse gases like carbon dioxide (CO₂), pose significant risks to human health and the environment. Effective flue gas treatment systems are designed to minimize these emissions, ensuring compliance with environmental regulations and reducing ecological impact. Key Pollutants and Treatment Methods 1. Particulate Matter Removal - Electrostatic Precipitators (ESPs): Use electrical charges to remove fine particles from the gas stream. - Fabric Filters (Baghouses): Capture particles on porous fabric surfaces, achieving high removal efficiencies. 2. Sulfur Dioxide (SO₂) Control - Wet Scrubbers: Utilize alkaline slurries (e.g., limestone) to absorb SO₂, converting it into gypsum, a usable byproduct. - Dry Scrubbing: Involves injecting dry sorbents (e.g., lime) into the flue gas to neutralize SO₂. 3. Nitrogen Oxides (NOₓ) Reduction - Selective Catalytic Reduction (SCR): Uses ammonia or urea as a reducing agent over a catalyst to convert NOₓ into nitrogen (N₂) and water (H₂O). - Selective Non-Catalytic Reduction (SNCR): Injects reagents at high temperatures to break down NOₓ without a catalyst. 4. Carbon Dioxide (CO₂) Capture - Post-Combustion Capture: Absorbs CO₂ from flue gas using chemical solvents like amines. - Oxy-Fuel Combustion: Burns fuel in pure oxygen to produce a CO₂-rich stream for easier sequestration. 5. Heavy Metal and Dioxin Removal - Activated Carbon Injection (ACI): Adsorbs mercury and other toxic compounds, which are then filtered out. - Catalytic Filters: Combine particulate filtration with chemical reduction of hazardous substances. Environmental and Operational Benefits Flue gas treatment systems significantly reduce air pollution, mitigating acid rain, smog, and respiratory diseases. Advanced technologies also enable resource recovery, such as converting SO₂ into gypsum for construction or capturing CO₂ for industrial use. Compliance with stringent emission standards (e.g., EPA, EU directives) ensures sustainable operations while minimizing ecological footprints. Conclusion As environmental regulations tighten globally, flue gas treatment remains indispensable for balancing industrial growth with ecological preservation. Continuous advancements in scrubbing, filtration, and catalytic processes promise even cleaner emissions, supporting a transition toward greener industrial practices.