Definition - What does Lean Amine mean?
Lean Amine is an organic compound that is used in amine gas treating process to absorb hydrogen sulfide (H2S) and carbon dioxide (CO2) constituents from sour natural gas. Once the lean amine absorbs all the sour gas constituents, it becomes rich amine which can be collected at the bottom of an absorber unit in amine gas treating process.
In general, Amine is a compound that contains a lone pair nitrogen atom. It is derived from ammonia by substituting of one or more hydrogen atoms by an organic group like an alkyl or aryl group.
Petropedia explains Lean Amine
In amine gas treatment process, sour natural gas enters the absorber unit/column from the bottom and being light in weight, the gas rises upward. Inside the column, the lean amine solution is flown in the opposite direction of the flow of gas, i.e., downward. While moving down, the amine solution absorbs hydrogen sulfide (H2S) and carbon dioxide (CO2) from the sour gas stream, converting it into sweet gas stream. During the process, this amine solution keep absorbing H2S and CO2 and settles down in the bottom of the column as a rich amine liquid.
In order to use it again as a lean amine solution inside the absorber unit, this rich amine solution is fed into the regenerator unit where hydrogen sulfide (H2S) and carbon dioxide (CO2) are removed from the rich amine. The regenerator unit acts as a recycler in converting rich amine solution into a lean amine solution and the process carries on thereby turning sour natural gas into sweet natural gas.