ExxonMobil Chemical Gas Treatment Plant aerial view

Gas treating

FLEXSORB™ technology and services are designed for the selective removal of H2S in the presence of CO2. Utilizing proprietary severely sterically hindered amines enables the FLEXSORB SE solvent to achieve high H2S cleanup selectively at low solvent circulation rates.

ExxonMobil’s FLEXSORB SE and SE PLUS solvents are used in a variety of gas treating applications including acid gas removal (AGR), acid gas enrichment (AGE) and tail gas cleanup units (TGCU). FLEXSORB technology easily fits into natural gas processing (including onshore and offshore), refining and petrochemical operations using standard gas treating equipment.

The technology and absorbents have been widely applied in petroleum refining, natural gas production and petrochemical operations. The FLEXSORB solvents have been applied successfully at offshore and onshore production sites around the world.

A simplified process flow diagram for a tail gas treating unit with FLEXSORB SE is shown in Figure 1. The feed gas is contacted countercurrently with lean FLEXSORB SE solution in the absorber tower. With low-pressure applications, it is recommended that the top of this tower include a water wash zone to minimize the loss of FLEXSORB SE amine with the treated gas. The water wash purge is combined with the rich amine to recover the FLEXSORB SE amine.


  • Shown to be the most selective and cost-effective amine solvent process
  • Reliable, robust and simple to operate
  • Operating experience has shown low corrosion and lower foaming than with conventional amines
  • Corrosion is low even at high rich loadings or high levels of heat-stable salts
  • Uses conventional equipment and is simple to operate
  • Cost-effective for grass roots and retrofits
  • Enables removal of H2S to less than 10 ppm
  • More than 120 commercial applications have repeatedly demonstrated the advantages of FLEXSORB SE and SE PLUS over competing solvents since the first commercial unit was started up in 1983

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