Patent ID: 7875101

Claim:
A method of generating high-purity oxygen gas from air with the aid of a hybrid membrane/PSA system, comprising: a) feeding an input stream of air to a compressor; b) compressing the input air stream to a high pressure with a compressor; c) feeding the compressed air to a membrane separation unit, thereby generating an oxygen-rich permeate stream of enriched oxygen with most of the argon removed, and generating a nitrogen-rich retentate stream of enriched nitrogen and argon; d) feeding the permeate stream to a turbine; e) re-compressing the permeate stream to a medium pressure with the turbine; f) feeding the re-compressed permeate stream to a PSA unit, thereby generating an output oxygen stream with high purity; g) generating a purge and vent stream from the PSA unit; and h) using the nitrogen-rich retentate stream to power the turbine, thereby reducing total system power use; whereby the purity of the output oxygen stream is greater than about 98%.