Flue gas treatment refers to the process of removing or reducing harmful pollutants from the exhaust gases produced by industrial processes, power plants, and other combustion activities before they are released into the atmosphere. The primary goal is to minimize the environmental impact of these emissions, particularly concerning air pollution and greenhouse gases.

Key Components of Flue Gas Treatment:

1. Particulate Removal:

• Electrostatic Precipitators (ESPs): Use electric charges to capture and remove fine particles (e.g., dust, ash) from the gas stream.

• Baghouse Filters: Utilize fabric filters to trap particulate matter as the gas passes through.

3. Gas Cleaning:

• Scrubbers: These devices use liquid (usually water or a chemical solution) to wash out pollutants like sulfur dioxide (SO₂) from the flue gas. Types include wet scrubbers and dry scrubbers.

• Selective Catalytic Reduction (SCR): A process where nitrogen oxides (NOₓ) are converted into nitrogen (N₂) and water (H₂O) using a catalyst and ammonia.

5. Desulfurization:

• Flue Gas Desulfurization (FGD): This process specifically targets the removal of sulfur dioxide (SO₂), a major contributor to acid rain. It often involves the use of lime or limestone to form calcium sulfate or gypsum.

7. DeNOx Systems:

• Selective Non-Catalytic Reduction (SNCR): A method for reducing nitrogen oxides (NOₓ) without a catalyst, using reagents like ammonia or urea at high temperatures.

9. Mercury and Heavy Metal Removal:

• Activated carbon injection and other technologies are used to capture and remove mercury and other heavy metals from flue gas.

11. Carbon Capture:

• Technologies that capture carbon dioxide (CO₂) from flue gas to reduce greenhouse gas emissions. This can involve chemical absorption, adsorption, or membrane separation.

Importance:

Flue gas treatment is essential for complying with environmental regulations, protecting public health, and reducing the environmental impact of industrial activities. By treating flue gases, industries can significantly lower their emissions of harmful substances, contributing to cleaner air and a healthier environment.