Weight-optimized portable oxygen concentrator

A system for producing an oxygen-rich gas comprising

• (a) a primary gas mover including a first compressor adapted to compress atmospheric air to provide pressurized feed air and a second compressor adapted to compress a waste gas from subatmospheric pressure to atmospheric pressure, wherein the primary gas mover is characterized by a weight Wp;
• (b) a drive motor adapted to drive the first and second compressors;
• (c) a rechargeable power supply adapted to supply power to the drive motor, wherein the rechargeable power supply is characterized by a weight, Wb, and an operating run time, tr, between maximum and minimum working charge;
• and
• (d) a pressure/vacuum swing adsorption unit adapted to separate the pressurized feed air into an oxygen-rich product at a product flow rate Fp and an oxygen-depleted waste gas, wherein the adsorption unit comprises a plurality of adsorber beds containing adsorbent, wherein the total amount of the adsorbent contained in the adsorber beds is characterized by a total adsorbent weight Wa;
• wherein the system is characterized by any of the expressions
• 0.21 Fp<Wa<0.61 Fp,
• 0.36 Fp<Wp<0.70 Fp,
• 0.18 Fp<Wb<0.71 Fp, and
• 0.10 Fp tr<Wb<0.40 Fp tr,
• where Fp is in liters per min (at 23° C. and 1 atma pressure), tr is in hours, and Wa, Wp and Wb, are in pounds.