DEA is a common chemical used to extract H2S gas from refinery gas streams in the amine or girbotol unit.

The DEA abosrbs H2S when it comes into contact with an H2S rich stream, but leaves other hydrocarbons behind. The H2S rich DEA is heated to separate a pure H2S stream that can then be sent to the sulfur plant for conversion into elemental sulfur.

DEA is not consumed in the process, but it does degrade gradually with repeated use and must be periodically replaced with fresh DEA.

MEA (Monoethanolamine) is an alternative to DEA that performs essentially the same way.