Amine (AMN) Unit

Alkanolamines have been used for acid gas removal in the last 60 years and are still a competitive technology.

Their action is based on a chemical absorption of the acid gas, followed by a regeneration of the enriched solution obtained. This regeneration is achieved through stripping.

This chemical absorption is based on an acid-base reaction: H2S dissolved in water (weak acids) react  with alkanolamines (weak bases) yielding salts that can be decomposed at high temperatures, and thus removed.

During absorption, acid gas molecules pass from vapor phase to liquid phase, through the gas-liquid interface.

All the reactions involved are equilibrium reactions. Absorption, being an exothermic reaction, takes place almost at ambient temperature, while regeneration occurs at the boiling point of the solution in the stripping column.

In the Amine Treatment Unit (AMN) the gaseous feed streams, Sour Off Gas from the process units, are being processed in order to remove H2S, using chemical absorption with DEA solution (25 % wt), in order to route a Sweet Off Gas to refinery fuel gas system.

Furthermore, this unit has the purpose to receive rich DEA streams from LPG Treatment unit in order to perform amine regeneration and deliver to LPT unit a lean DEA solution with required acid load (mol H2S / mol DEA).

AMN Unit consists of the following sections:

• Feed Section
• Regeneration Section
• Absorbing Section
• Amine drain Section
• Facilities (Utilities & Antifoam)