Membrane nitrogen generators employ semi-permeable hollow fiber to selectively separate nitrogen (N₂) from compressed air. By leveraging the differential permeation rates of gas molecules through polymer membranes, these systems efficiently extract N₂ (78% in ambient air) while venting faster-permeating gases like O₂, H₂O, CO₂, and hydrocarbons. This purely physical separation process operates at ambient temperatures, eliminating the energy-intensive cooling required by cryogenic distillation.