Absorption and Control of Acid Gases with Wet Scrubber Systems
Wet scrubbers control sulfur dioxide (SO2), hydrogen chloride (HCl, hydrogen fluoride (HF) acid gas emissions from various industrial processes. Wet scrubbers are often required with other air pollution control technologies such as thermal oxidizers and wet electrostatic precipitators (wet ESPs). Wet ESPs are sometimes required for the control of acid mists that may pass through a wet scrubber.
Wet scrubber systems use a scrubber vessel with specialized random or structured type packing (packed tower type scrubber) or a series of spray nozzles (open spray tower type scrubber) to remove acid gases. A recycled liquid scrubbing solution is introduced to absorb the pollutants from the gas stream and a reagent such as sodium hydroxide (caustic) is used to control the pH of the recycled scrubber water.