PRESSURE-SWING ADSORPTION-TYPE NITROGEN PRODUCTION PROCESS

摘要

PURPOSE:To enable effective utilization of exhaust gas of a nitrogen-production apparatus and an oxygen-production apparatus while keeping the purity of the produced nitrogen, by producing nitrogen with a nitrogen-production apparatus from air, using the exhaust gas of the nitrogen-production apparatus as a raw material of an oxygen-production apparatus, dehumidifying a part of the exhaust gas of the oxygen-production apparatus and using the gas as a raw material of the nitrogen-production apparatus. CONSTITUTION:Feed air is treated in a pretreatment column 21a, etc., to remove H2O and CO2 and the treated air is repeatedly subjected to the steps of adsorption-desorption- compression with an adsorption column 41a, etc., to increase the N2 purity and obtain the objective N2 gas product. The oxygen-rich exhaust gas of the above pressure-swing adsorption- type nitrogen-production apparatus (a) is used as a part of feed air for a pressure-swing adsorption-type oxygen-production apparatus (b) for the production of O2 gas product with an adsorption column 41b in the same manner as above. Since the N2-rich exhaust gas of the oxygen-production apparatus (b) sucked with a vacuum pump 13b contains a large amount of H2O, it is dehumidified with a dehumidifying means 6 and utilized as a part of feed air for the nitrogen-production apparatus (a). The exhaust gases of both apparatuses (a) and (b) can be effectively utilized by this process and, in addition to the above, the overload of the pretreatment column 21a, etc., is prevented and the purity of the N2 gas product can be maintained.