A process used to remove hydrogen sulfide (H₂S) and carbon dioxide (CO₂) from a gas stream. These components are removed because they can form acidic solutions when they contact water, which will cause corrosion problems in gas pipelines.

In a sweetening process, different types of ethanolamine can be used, including monoethanolamine (MEA), diethanolamine (DEA), diglycolamine (DGA) and methyldiethanolamine (MDEA). Hydrogen sulfide and carbon dioxide are absorbed by the ethanolamine and sweet gas leaves at the top of the absorber.

The ethanolamine is heated and acid gas (hydrogen sulfide and carbon dioxide gases) and water vapor are obtained. The water is removed while the acid gas can be flared or further treated in a sulfur recovery unit to separate out elemental sulfur. Finally, the lean ethanolamine is returned to the absorber.