Cryogenic air separation nitrogen is a traditional Nitrogen has been the history of recent decades. It is based on the air as raw material, compression, purification, recycling heat exchange air liquefaction Air Liquide. Air Liquide is a mixture of liquid oxygen and liquid nitrogen, liquid oxygen and liquid nitrogen boiling point (1 atm, the the former boiling point of -183 ° C, the latter to -196 ° C) by distillation of liquid air so that they are separated to obtain nitrogen. Cryogenic air separation nitrogen plant complex, large area, high infrastructure costs, equipment more one-time investment, high operating costs, slow gas production (12 to 24 hours), installation requirements, a longer period. Integrated equipment, installation and infrastructure of various factors the following equipment 3500Nm3 / h, the same specifications of the PSA unit investment scale than the cryogenic air separation unit by 20% to 50%. Appropriate for large-scale industrial nitrogen cryogenic nitrogen air separation unit, and in small-scale nitrogen uneconomical.