Pressure Swing Adsorption or just PSA is a technique used to separate a specific gas out of mixture of different gases; it works on the principle of adsorption. The process of PSA consists of few steps which on completion gives high purity of the desired gas to be separated from others at an effectively low cost.

The most common application of this technique is in the nitrogen generator plants. Nitrogen Generator usually uses two different techniques for nitrogen separation, PSA and the other one is Membrane system. Membrane system is used in case of requirement of low purity of Nitrogen gas but when it comes to achieve maximum purity then PSA do the job pretty well.


The approach that the PSA system takes is based on the different adsorption rates and temperature factor of the gases in the separation process. In the PSA process, compressed air is first passed through number of filters to clean it from all impurities like water and oil then this filtered air is passed into one of the two adsorption vessels which contains adsorbent i.e. carbon molecular sieves (CMS) which adsorbs remaining impurities like carbon monoxide and residual water at the entrance of the adsorbent bed.

The CMS in the vessel let the flow of the nitrogen gas be continuous as much as possible through the adsorber-adsorbent vessels, after a while the vessel reaches the saturation level of wastes gases after which the regeneration process of nitrogen gets activated through depressurization of the vessel to atmospheric pressure which is fairly lower than the pressure which was at the beginning of the process. Other waste gases are vented out in the atmosphere and the automatic process of adsorption and desorption among the two vessels enables the continuous production of nitrogen.

A large magnitude of flow and purity combination can be achieved by altering the size of the air compressor and adsorption vessels containing CMS, whereas range of purity is from 95% to 99.9995%.


  1. Low operating cost- The cost of nitrogen produced via the PSA technique is comparatively lower than the cost of liquid or bottled nitrogen.
  2. Minor impact on the environment- Nitrogen is a environment friendly gas and the process of its generation is a sustainable and energy efficient approach to provide clean, pure and dry nitrogen gas. PSA process needs less energy and produces fewer green house gases than the other processes like cryogenic air separation.
  3. High Purity range- PSA technique assures high purity level of the nitrogen gas produced ranges from 95% to 99.9995% which membrane system doesn’t allow. Cryogenic air separation process does produce high purity but is very complex system and you need to generate large consumption value to justify the purity.


  1. Air driven tools/Machinery
  2. Automobile tire
  3. Aircraft fuel tank inerting
  4. Brazing
  5. Beverage mixing/dispensing
  6. Food packaging
  7. Fire prevention
  8. Cold storage
  9. Laser cutting/welding and much more


The benefits from the nitrogen gas are numerous and can be used in most of the industry for different purposes out of nitrogen’s unique properties to optimize performance, improve yields, protect product quality and make operations safer. Technique like PSA continues to advance as a highly efficient process to produce highly purified nitrogen gas as an much more economical and convenient alternative and is used by a large number of industries as a on-site Nitrogen Generator.

Author's Bio: 

I am Gaurav Gautam, live in New Delhi, India. I am 28 years old. I am pursuing Mass. Comm. I love blogging, writing on health, fitness, lifestyle and Consumer Goods. I am available on Facebook, Twitter, Google+. Above article is about PSA Technique for Nitrogen Generator.