Flue Gas Desulfurization (FGD) is a critical process employed in power plants and other industrial facilities to mitigate the harmful effects of sulfur dioxide (SO2) emissions on the environment. It is a technology designed to remove sulfur dioxide from the exhaust flue gases produced by burning fossil fuels, primarily coal, oil, or gas. FGD technology emerged as a response to the increasing concern over acid rain, which is caused by the release of SO2 into the atmosphere. The SO2 reacts with water vapor to form sulfuric acid, leading to environmental degradation and health issues. FGD systems have become an essential tool in global efforts to meet stringent air quality regulations and combat climate change. There are several methods used in FGD, but the most common are wet FGD, dry FGD, and semi-dry FGD. Wet FGD, the most widely used method, involves spraying the flue gas with a limestone-based slurry, where the sulfur dioxide reacts to form calcium sulfate. This process can remove up to 95% of the sulfur dioxide present in the gas. Dry FGD systems, on the other hand, use a solid sorbent, like limestone or lime, to react with the SO2. The resulting compound is then removed from the gas stream through a filtration process. Although less efficient than wet FGD, it is more suitable for smaller installations due to its lower capital cost Although less efficient than wet FGD, it is more suitable for smaller installations due to its lower capital cost Although less efficient than wet FGD, it is more suitable for smaller installations due to its lower capital cost Although less efficient than wet FGD, it is more suitable for smaller installations due to its lower capital costflue gas desulfurization. Semi-dry FGD combines aspects of both wet and dry methods. A spray dryer or a fabric filter is used to inject a slurry or sorbent powder into the flue gas, creating a semi-dry product that can be easily collected. The byproducts of FGD, such as gypsum, can often be recycled and used in products like wallboard or concrete, promoting a more sustainable approach. However, the disposal of these byproducts also requires careful management to prevent environmental impacts. In conclusion, Flue Gas Desulfurization plays a vital role in mitigating the environmental impact of industrial activities. It not only reduces sulfur dioxide emissions but also contributes to the circular economy by recycling byproducts. As the world continues to grapple with the challenges of climate change, FGD technology will remain an essential part of our arsenal to protect the environment and public health. Continuous research and development in this field promise to enhance efficiency and reduce costs, making FGD even more effective in the fight against atmospheric pollution.