By Shandon Carroll
Sulfur dioxide (SO2) is one of a group of highly reactive gasses known as “oxides of sulfur.” The largest sources of SO2 emissions are from fossil fuel combustion at power plants (73%) and other industrial facilities (20%). Smaller sources of SO2 emissions include industrial processes such as extracting metal from ore, and the burning of high sulfur containing fuels by locomotives, large ships, and non-road equipment. SO2 is linked with a number of adverse effects on the respiratory system.
An SO2 scrubber system is the informal name for flue gas desulfurization (FGD) technology, which removes, or "scrubs," SO2 emissions from the exhaust of coal-fired power plants. A scrubber works by spraying a wet slurry of limestone into a large chamber where the calcium in the limestone reacts with the SO2 in the flue gas. There are some variations in design of scrubbers. For example, some scrubbers may use other chemicals such as magnesium oxide to react with the SO2 in the flue gas.