Current gas processing plant designs originate from an era with low cost energy and little concern over the level of CO2 emissions. Process selection for acid gas removal and drying has been based on in-situ regeneration of adsorbents by heat derived by burning part of the hydrocarbon feed.
This approach has had the advantage of standardization to the extent that processing plants tend to use the same units and have similar operating procedures. However, a combination of environmental and cost pressures are requiring a rethink of the basis of design for gas processing plants to see if they can be made more energy efficient and release less CO2.
One option worth considering is the use of fixed bed absorbents. Whilst it is true that CO2 is evolved in their production none is released during operation and they allow a greater degree of flexibility than adsorbents when in service.