Smart revamp options for amine regenerators Case study on retrofitting an existing amine regenerator column, originally equipped with tray internals, to include random packing
Ayan Dasgupta, Debopam Chaudhuri, and Vaneet Garg Fluor Corp.
I n the complex world of modern refinery operations, the circulating amine system is a cornerstone of gas purification technology. Its primary mission is to strip hydrogen sulphide (H₂S) from sour gas streams, ensuring environmental compliance and protecting downstream equipment from corrosion. The system runs in a continuous cycle, including two fundamental components: the absorber and the regenerator. Each unit fulfils a distinct function while staying intrinsically linked in their operational interdependence. Figure 1 shows a simplified sketch of a typical amine circulation system in a refinery. The absorber is often a packed column, engineered to maximise
reduces the partial pressure of H₂S in the vapour phase. This helps the transfer of H₂S from the liquid phase to the vapour phase. The desorbed H₂S is then directed to the sulphur recovery unit (SRU), where it is converted into elemental sulphur. The regenerated amine, now ‘lean’ and practically free of H₂S, is recirculated to the absorber(s) to carry on with the acid gas removal process. Historically, regenerators have been equipped with tray internals, which are preferred due to their robustness and ability to withstand the demanding conditions associated with rich amine service. These trays show strong resistance to fouling and offer ease of inspection and maintenance, making them a dependable solution
contact between the rising sour gas and descending aqueous amine solution. This counter-current flow fosters efficient mass transfer, allowing the amine to capture H₂S from the gas. The result is a ‘rich amine’ solution, laden with acid gases, which is then sent to the regenerator for rejuvenation. Within the regenerator, the rich amine solution is subjected to thermal energy under controlled pressure conditions. The steam produced in the reboiler not only elevates the temperature but also
Lean amine to other absorbers
Lean amine cooler
Lean amine circulation pump
Sweet process gas
Acid gas to SRU
Absorber
Condenser
Sour process gas
Re ux drum
Flash tank
Lean/rich exchanger
Rich amine
Re ux pump
Rich amine pump
Rich amine from other absorbers
Regenerator
Reboiler
Steam
Lean amine
Condensate
Figure 1 Typical amine circulation system in a refinery
Refining India
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