Molecular sieve air separation nitrogen production is also called PSA nitrogen production, using air as the raw material, carbon molecular sieve as the absorbant, applying the pressure conversion adsorption principle, the method of separating nitrogen and oxygen by using the selective adsorption of carbon molecular sieve on oxygen and nitrogen.
Brief introduction of technological process
After removing dust and mechanical impurities through the air filter, the air extracted by the nitrogen generator enters the air compressor, compresses to the required pressure, and outputs clean compressed air through strict oil removal, water removal, dust removal and purification treatment, the purpose is to ensure the service life of the molecular sieve in the absorption tower. There are two absorption towers equipped with carbon molecular sieve. When one tower is working, the other tower is decompressed and desolated. Clean air enters the working absorption tower. When passing through the molecular sieve, oxygen, carbon dioxide and water are adsorbed by it, and the gas flowing to the outlet is nitrogen and trace of argon and oxygen. Another tower (release Tower) makes the adsorbed oxygen, carbon dioxide and water separate from the micropores of the molecular sieve and discharge into the atmosphere. In this way, the two towers take turns to complete the separation of nitrogen and oxygen and output nitrogen continuously. The purity of nitrogen produced by pressure swing adsorption is 95%-99.999%. If higher purity of nitrogen is needed, nitrogen purification equipment should be added. 95%-99.9% nitrogen output by the pressure conversion absorption nitrogen generator enters into the nitrogen purification equipment, and at the same time, add a proper amount of hydrogen through a flow meter to conduct catalytic reaction between hydrogen in the oxygen removal tower of the purification equipment and the micro oxygen in nitrogen, in order to remove oxygen, then cool it through water condenser, remove water from steam-water separator, and then deeply dry it through dryer (two adsorption drying towers are used alternately: one is adsorption drying to remove water, and the other is heating, degassing and draining water), to obtain high purity nitrogen, at this time, the purity of nitrogen can reach 99.9995%. At present, the largest production capacity of domestic pressure conversion adsorption nitrogen production is 3000 m.3n/h
