Page "Acid rain" Paragraph 64

Many coal-burning power stations use flue-gas desulfurization ( FGD ) to remove sulfur-containing gases from their stack gases.

For a typical coal-fired power station, FGD will remove 95 percent or more of the SO2 in the flue gases.

An example of FGD is the wet scrubber which is commonly used.

A wet scrubber is basically a reaction tower equipped with a fan that extracts hot smoke stack gases from a power plant into the tower.

Lime or limestone in slurry form is also injected into the tower to mix with the stack gases and combine with the sulfur dioxide present.

The calcium carbonate of the limestone produces pH-neutral calcium sulfate that is physically removed from the scrubber.

That is, the scrubber turns sulfur pollution into industrial sulfates.