Sulfur Dioxide Scrubbers
Flue gas desulfurization (FGD) technology, commonly referred to as a scrubber, is a proven and effective method for removing sulfur dioxide (SO2) emissions from the exhaust of coal-fired power plants.How does a scrubber work?
During the combustion process the sulfur in the coal combines with the oxygen in the combustion air to form SO2. To remove the SO2, the exhaust from a coal-fired power plant is bubbled through a mixture of lime or limestone and water which reacts with the SO2 to remove it before the exhaust gas is released to the atmosphere. Duke Energy’s scrubbers are typically designed to remove 95 percent or more of the SO2 in the exhaust gas.
What happens to the SO2 that is captured in a scrubber?
The SO2 that is captured in a scrubber combines with the lime or limestone to form a number of byproducts. A primary byproduct is calcium sulfate, commonly known as gypsum. It is a recyclable product and has many beneficial uses like the chalky middle of wallboard. It is also used as a soil amendment in agricultural and construction applications, and in the manufacturing of cement. Much of the gypsum that is produced from Duke Energy’s scrubbers is reused in these and other applications. The gypsum that is not reused is disposed of in permitted landfills along with the scrubber byproducts that are not reusable.
