Flue Gas Desulfurization (FGD) Technology Overview Flue Gas Desulfurization (FGD) is a critical environmental technology designed to remove sulfur dioxide (SO₂) from exhaust flue gases generated by industrial processes, particularly fossil fuel combustion in power plants and refineries. SO₂ is a major contributor to acid rain and air pollution, posing risks to human health, ecosystems, and infrastructure. FGD systems mitigate these impacts by capturing SO₂ before it is released into the atmosphere. There are two primary types of FGD systems: wet scrubbing and dry scrubbing. Wet scrubbing, the most widely used method, involves passing flue gas through an alkaline slurry—typically limestone (calcium carbonate) or lime (calcium oxide). The slurry reacts with SO₂ to form calcium sulfite, which can be further oxidized to gypsum (calcium sulfate), a reusable byproduct in construction materials. Wet scrubbers achieve over 90% SO₂ removal efficiency but require significant water and energy inputs. Dry scrubbing, alternatively, injects a dry sorbent (e.g., hydrated lime or sodium bicarbonate) into the flue gas stream, where it reacts with SO₂ to form solid particles collected via filters. While less efficient than wet systems (70–90% removal), dry FGD consumes less water and is更适合 for plants with limited water resources or smaller SO₂ emissions. Advanced FGD technologies, such as seawater scrubbing (using natural alkalinity of seawater) and regenerative processes (recycling the sorbent), offer niche solutions. Seawater FGD is ideal for coastal facilities, while regenerative systems reduce waste but involve higher operational complexity. FGD systems also address secondary pollutants like particulate matter and heavy metals. However, challenges include high capital/operational costs, sludge disposal, and energy penalties (3–5% of plant output). Innovations like hybrid systems and AI-driven optimization aim to improve efficiency and cost-effectiveness. In summary, FGD is indispensable for compliance with global emission standards (e.g., IMO 2020, EPA regulations) and sustainable industrial growth. Its evolution continues to balance environmental protection with economic feasibility, supporting cleaner air and circular economy goals. (Word count: 500)