Commonly used desulfurizers are generally divided into primary amines, secondary amines and tertiary amines according to the number of C atoms connected to N atoms. Monoethanolamine (MEA) and diglycolamine (DGA) belong to primary amines, -L alcohol amine (DEA) and diisopropanolamine (DIPA) belong to secondary amines, triethanolamine (TEA), methyldiethanolamine ( MDEA) is a tertiary amine.
Alcohol amine desulfurization is a typical method of coking desulfurization. It is a typical absorption reaction process. At present, most desulfurization systems choose compound methyldiethanolamine as the absorbent, which has a strong absorption capacity for hydrogen sulfide and a fast chemical reaction. In the desulfurization tower, the absorbent is in countercurrent contact with dry gas and liquefied gas. The amine liquid absorbs the acid gas H2S (CO2) and other sulfur-containing impurities in the dry gas and liquefied gas to generate acid sulfide amine salt (or acid amine carbonate salt). When the temperature rises, the generated amine salt decomposes again. Release H2S (CO2) gas. The released H2S is sent to the sulfur recovery unit to be converted into sulfur, and the amine solution can be recycled.
