Pressure Swing Adsorption for Purification

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. 

Development Status Products

Pressure Swing Adsorption for PurificationCosts & Benefits

Parent Process: Gas Refining
Energy Savings Potential
CO2 Emission Reduction Potential

Not available. 

Pressure Swing Adsorption for PurificationSchematic

Pressure Swing Adsorption for Purification Reference Documents

Reference Document on Best Available Techniques for the Manufacture of Large Volume Inorganic Chemicals - Ammonia, Acids and Fertilisers

Prepared by the Institute for Prospective Technical Studies of European Commision, this document provides detalied information on Best Available Technologies applicable to Ammonia production – as well as on the production of Acids and Fertilizers.  

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