Scrubbing, sometimes referred to as flue gas desulfurization is the most effective sulfur-removal technique that is in widespread use. Removing the sulfur oxides is fairly simple, the flue gases pass through a spray of water in a wet scrubber that contains a variety of chemicals. Generally speaking, the main chemical is calcium carbonate. If a dry scrubber is used, the flue gas comes into contact with pulverized limestone - which is mainly calcium carbonate. The chemical reaction between the calcium carbonate and the sulfur dioxide yields calcium sulfite. This calcium sulfite either falls out of the gas stream or is removed with other particulates.

Scrubbers are very effective, removing about 98% of sulfur from flue gases, but they are very expensive to maintain and install. Additionally, it is energy-intensive as the flue gas must be reheated after coming into contact with water vapor in the wet scrubber for the gas to be buoyant enough to exit through the smokestacks.