Nitrogen generation by pressure swing adsorption based on carbon molecular sieves

Pressure swing adsorption (PSA) processes based on carbon molecular sieves have been known for more than twenty years. The most important industrial PSA process, the nitrogen PSA process, has been developed during the last ten years into a highly efficient technique for producing nitrogen on site. Nitrogen is currently produced by PSA with impurities down to the ppm level and at flow rates up to 1500 N m³ h⁻¹. The on-site supply of nitrogen using the PSA process is an alternative to cryogenic nitrogen. An overview of the theoretical background, of industrial units including purification by deoxo systems and of the economy of the nitrogen PSA system is presented.