Question

how is N2 commercially produced?

Answer 1

N2 in commercially produced by the process of fractional distillation of liquid air.

Answer 2

Nitrogen or N2 is produced commercially almost exclusively from air, most commonly the fractional distillation of liquid air. In this process, air is first cooled to a temperature below that of the boiling points of major components, a temperature somewhat less than -328°F. The liquid air is then allowed to warm up allowing the lower boiling point Nitrogen to evaporate from the mixture first. Nitrogen gas  escaping from the liquid air is then captured, cooled and then liquefied once more.