Enriched Air by a Membrane Process

This Review briefly examines the economics of a membrane process for producing 30%m oxygen, 70%m nitrogen from air. A typical commercial polymeric membrane, in the form of modules of spiral-wound film, was selected for evaluation. At plant capacities of 263 and 789 short tons/day of contained oxygen, we estimate that the product value of the stream is no lower than that of a 30%m oxygen stream produced by simply mixing pure oxygen with air.

Membranes that are able to make a sharper separation are under development. For such membranes the product value is estimated to be slightly lower than that of a 30%m oxygen stream produced by mixing pure oxygen with air at some scales.

If a 30%m oxygen stream is available at $19/ton of contained oxygen, it may be an attractive alternative feed in commercial oxidation processes that use air as an oxidant.