What is the term used for an amine containing very little H2S?

The term used for an amine solution that contains very little hydrogen sulfide (H2S) is referred to as "lean." In the context of amine gas treating, a lean amine solution has passed through the contactor or absorber where it has removed sulfur compounds from the gas stream, resulting in a lower concentration of H2S. This indicates that the amine has effectively absorbed H2S from the gas it treated.

"Lean" amine solutions are desirable in processes because they have a greater capacity to absorb H2S when they contact sour gas. The term signifies that the amine has a low loading of acid gases, making it more efficient for subsequent cycles of gas treatment. A lean solution is typically ready to receive more sour gas for processing, while a rich amine solution would be one that has absorbed a significant amount of H2S and is ready for regeneration.

In contrast, the term "sour" typically describes gas that contains a significant amount of H2S, while "stripped" might refer to an amine solution that has undergone a regeneration process to remove H2S, which may not specifically indicate the amount of H2S present post-regeneration.