What are the compressed air requirements for a nitrogen generator? 

Whether the system is a PSA or a Membrane, each requires clean, dry air. The compressor should have particulate and coalescing filtration to remove oil and dirt. The compressor is also required to have some form of air dryer. This can be either refrigerated or desiccant, depending on the final dewpoint requirement for the nitrogen produced. You will typically see temperature and dewpoint requirements of air supplied between 100 Deg F / 38 Deg F, with a water dew point of 40 Deg F or lower. It is also not uncommon to see an ISO quality sited as ISO Class 1.4.1 compressed air quality. This refers to the amount of particulate, dirt, and oil in the air stream. The above specifications are easily achieved using standard compressor filters and dryers. Contrary to rumors, Oil Free compressors are not a typical requirement for a nitrogen generator.

If you are interested in learning how a PSA nitrogen generator works, click this link. 

To learn how a membrane nitrogen generator works, click this link.