Arezoo Emrani - Rasad Technology Management, Bonian Daneshpajouhan Ins.
Zahra Kiaei - Rasad Technology Management, Bonian Daneshpajouhan Ins.
Mohammad Mahdyarfar - Research Institute of Petroleum Industry

A comparative method has been developed for reliable selection of possible technologies in nitrogen separation from compressed air. In this method, using the data gathered from various references, process qualified and economic regions for using each of three technologies including cryogenic, pressure swing adsorption and membrane were plotted. Then, a comparative study was carried out in using these processes at the same conditions of nitrogen production. The graphs drawn for nitrogen purity of 94 to 100 % and flow rates between 0 to 15000 nm3/hr. Based on presented graphs, the best operating conditions zone for each technology has been proposed. The results show that the scale of production has an important role in the process selection. For small scale production membrane technology is the most economic option. In medium scale it is better to choose PSA and the cryogenic process should be applied in large nitrogen plants.

Nitrogen, air, Cryogenic, PSA, Membrane, comparative study