PSA, the best nitrogen source for DCA storage

Pressure Swing Adsorption, PSA, is a technique for producing pure nitrogen from environmental air. The system is made up of two beds/columns of CMS (Carbon Molecular Sieve) an air compressor, compressed air tank and appropriate necessary filtration.

• Pressure — Pre-treated compressed air enters the bed of CMS. Oxygen and other trace gases are preferentially adsorbed by the CMS.
• Swing — After a pre-set time the CMS is saturated with adsorbed gasses. The system automatically switches over to the other, regenerated, bed and takes over the separation process. The saturated bed will be regenerated by reducing the pressure inside the column allowing the adsorbed gasses escape to the atmosphere. This continuous swing between adsorption and regeneration gives the technology its name.
• Adsorption — The CMS has very narrow openings allowing small oxygen molecules to penetrate these openings at pressure. The smaller oxygen molecules are physically adsorbed and removed from the gas stream by the CMS. The larger nitrogen molecules by-pass the CMS and can be stored in a buffer tank or immediately used for flushing.

Besseling has been building PSA nitrogen generators for more than 25 years. We have always promoted this technology as being the best nitrogen source (capacity/purity/flexibility) for reducing the levels of oxygen in a controlled manner. In 2007 we took the initiative to have our generator tested by the University in Wageningen in comparison with the VSA and VPSA technology of our local competitors. The outcome was not surprising for us and we are happy that our competitors nowadays also choose for PSA technology; the best nitrogen source for (D)CA storage.