To reduce the amounts of inerts in the synthesis gas stream, a Pressure Swing Adsorption (PSA) system can be used. The PSA technology has the potential to replace the Low Temperature Shift (LTS) conversion section, the CO₂ removal section, the methanation section and in some cases the secondary reformer section. PSA technology utilizes molecular sieves as adsorbents in a series of vessels (Ullmann’s, 2011 p.186). 

This measure can be applicable to all ammonia plants for which a recovered CO₂ stream is not of major importance. However, when a pure CO₂ stream is required, classical solvent scrubbing can be used to recover the CO₂ (IPTS/EC, 2007 p.41). 

Some examples of processes utilizing the PSA technology are the Jacobs Plus Ammonia Technology, the ICI LCA process, KTI PARC process and the Linde Ammonia Concept (LAC) process. In the Linde LAC process the PSA section is the only purification step of synthesis gas. The difference of the conventional ammonia manufacturing and the LAC process can be seen in Figure below.