Methyl diethanolamine is a clear, colorless or pale yellow liquid with an ammonia odor. It is miscible with water, alcohol and benzene. Methyl diethanolamine is also known as N-methyl diethanolamine and more commonly as MDEA. It has the formula CH3N(C2H4OH)2. MDEA is a tertiary amine and is widely used as a sweetening agent in chemical, oil refinery, syngas production and natural gas. This compound should not be confused with the recreational drug methylenedioxyethylamphetamine which is also abbreviated MDEA.
MDEA’s popularity as a solvent for gas treating stems from several advantages it has over other alkanolamines, especially its ability to preferentially remove H2S (and slip CO2) from sour gas streams.