Oxygen concentrator apparatus and method of use are described herein. The oxygen concentration may include at least one canister; gas separation adsorbent disposed in at least one canister, and a compression system. The compression system may include at least one compressor coupled to the at least one canister. The compressor may include a first rotor comprising at least two projections and a second rotor comprising at least two recesses. During rotation of the first and second rotors, gas moves through the compressor to at least one of the canisters. In the canisters, gas separation adsorbent may separate at least some nitrogen from air produce oxygen enriched gas.