The process of removing a component such as an impurity from a mixed gas stream or extract phase, by means of contacting it with a selective liquid solvent. The absorption process takes place within an absorption tower or scrubber. Scrubbing is used to remove sulphur dioxide from the flue gases from power stations, hydrocarbons from air, NOx from combustion gases, and hydrogen sulphide from natural gas. It is also known as gas scrubbing. Compare stripping.