Overview: Absorption is the process of using liquid absorbents to treat gas mixtures to remove one or more gases. During this process, there will be a physical effect of certain gases dissolving in the solution, which is physical absorption. Chemical reactions also occur between chemical substances in gas-liquid mixtures, which is known as chemical absorption. Absorption is often used for the treatment and recovery of gaseous pollutants, such as the absorption of sulfur dioxide in flue gas with lime lotion to generate gypsum; Absorb nitrogen oxides in the tail gas of nitric acid plants with alkaline solution or dilute nitric acid, and recover and reuse them; Also, alkaline solutions such as sodium carbonate can be used to absorb hydrogen sulfide. Absorption is also widely used in the pretreatment of organic waste gases, such as dust removal, oil mist removal, and removal of water-soluble components, in preparation for further purification. Absorption method is one of the most important methods for separating and purifying gas mixtures, and is widely used in the treatment of gaseous pollutants such as SO2 NOx、 Fluoride, hydrogen chloride and other waste gases