Gas sweetening absorbents — ethanolamine service Ethanolamine solutions (e.g., MEA) are commonly employed to remove which contaminant(s) from process gas or air streams?

Introduction / Context:
Amine treating (gas sweetening) is a standard process for purifying natural gas, refinery gases, and synthesis gas. Ethanolamine (MEA) is a primary amine absorbent used to capture acid gases through reversible chemical reactions.

Given Data / Assumptions:

• The absorbent is ethanolamine (MEA) in aqueous solution.
• Common acid gas contaminants include H2S and CO2.
• We select among HF, SO2, H2S, or a combination.

Concept / Approach:
MEA reacts readily with hydrogen sulfide (H2S) and carbon dioxide (CO2), forming protonated amine salts or carbamates that are later regenerated by heating and pressure reduction. Industrially, MEA is not the standard reagent for flue-gas SO2 scrubbing (limestone, lime, or ammonia solutions are typical). HF handling requires specialized sorbents or aqueous neutralization, not MEA.

Step-by-Step Solution:

Verification / Alternative check:
Standard process design texts list MEA units as H2S/CO2 removal (sweetening) steps ahead of sulfur recovery units (Claus) in refineries and gas plants.

Why Other Options Are Wrong:

Common Pitfalls:
Assuming all acid gases behave similarly in all absorbents; process selection depends on kinetics, corrosion, and regeneration practicality.

Final Answer:
H2S