Airro Engineering Company

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PSA technique is a simple & reliable process of separation of nitrogen from compressed atmospheric air by adsorption of oxygen over a bed of Carbon Molecular Sieves (CMS). CMS is an adsorbent having infinite number of small pores. The diameter of the “Bottle Necks” is in the same range as those of the molecules. Thus when CMS is used in the PSA process, an Oxygen Molecule, having a smaller diameter than a Nitrogen molecule traps in to the pores. Therefore the nitrogen is recovered to a high degree while almost all the oxygen is adsorbed. 

Process:- The production of nitrogen gas from atmospheric air is based on pressure swing absorption (PSA) principle by adsorption of oxygen gas using a special grade of imported carbon molecular sieves (CMS). Atmospheric air is compressed by an air compressor to a pressure of 7.0 kg/cm2g and cooled to ambient temperature in a shell and tube type heat exchanger. The condensed moisture shall be drain out automatically from air receiver by automatic drain valve (ADT). The compressed air at ambient temperature is passed through PSA module packed with activated alumina and special grade of Carbon Molecular Sieves. The production of Nitrogen from air by PSA technology is largely based on the kinetic separation. Oxygen that is smaller in size (kinetic diameter 3.46 A0) diffuses much faster than Nitrogen (kinetic diameter 3.64 A0) and hence oxygen gets adsorbed in carbon molecular sieves and Nitrogen is collected as the high-pressure product. The entire operation is fully automatic and controlled by a combination of sequence programmer and quick change over valves. Nitrogen gas of desired purity at 5.0 kg/cm2g pressure and having a Dew Point of (-) 40 degree Celsius is produced by the PSA Unit, now flows to a surge vessel to balance the fluctuations in pressure and concentration. Now the gas can be stored in a storage tank at 5 Kg/cm2g pressure from where it can be made available for process application. The storage tank can selected of any desired capacity as per peak hours demand for Nitrogen gas or power interruptions. This system is fully automatic and need not any special operator for operation. Once it is started it generates Nitrogen at constant flow rate and at constant pressure. Further the produced nitrogen gas can be boosted to high pressures by providing any reliable booster compressors up to 40 kg/cm2g pressure. We offer three models of nitrogen gas plant and selection is based on the purity required.