The purpose of an amine contactor is to absorb carbon dioxide (CO2) and/or hydrogen sulfide (H2S) contaminants from natural gas streams. In a general operation for an amine contactor, a “sour” natural gas (vapor) is fed into the bottom of the vessel and “lean” amine (liquid) is fed into the top. The contact between the natural gas vapor and the amine liquid drives the absorption of CO2 and/or H2S from the vapor stream. Thus, clean (sweet) gas exits from the top of the vessel and “rich” amine is sent to the amine regenerator for removal of contaminants.
If the contaminants are not removed from the vapor stream, they can cause pipeline corrosion and degradation in product quality. In cryogenic services, CO2 may freeze during operation and limit tower capacity. Below are a few common amines; although, there are many variations including amine mixtures.
- Monoethanolamine (MEA) / Methyldiethanolamine (MDEA) / Diethanolamine (DEA)
There are many tower arrangements for amine contactors depending on capacity requirements, contaminant level, etc. Amine contactors can utilize either trays or packing to achieve a desired separation. DEMISTER® mist eliminators are typically used to minimize the loss of valuable amine solvent from the top of the vessel.