Patent ID: 7449047

Claim:
A membrane separation process for the enrichment of oxygen in an air flow using a membrane separation system with a membrane separation unit having at least one membrane for separation of the air flow into a retentate, which is discharged on a retentate side of the at least one membrane, and a permeate, which is discharged on a permeate side of the at least one membrane, comprising the steps of: drawing the air flow into the membrane separation system directly from the atmosphere, compressing the air flow and then delivering the compressed air flow to the membrane separation unit at an absolute pressure of 1.35 to 1.5 bar, permeating oxygen through the at least one membrane using a solubility-diffusion mechanism so as to enrich the oxygen concentration of the permeate by 22 to 45 volume percent, and lowering the pressure on the permeate side of the at least one membrane and discharging the permeate from the membrane separation unit at an absolute pressure of 0.4 to 0.85 bar.