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Keywords:

  • rapid pressure swing adsorption;
  • medical oxygen concentrator;
  • LiLSX zeolite, process performance

A novel design of a compact rapid pressure swing adsorption system consisting of a single adsorber enclosed inside a product storage tank is proposed for application as a medical oxygen concentrator (MOC). A self-contained test unit for the process is constructed which is capable of directly and continuously producing 1–3 sl/m of 90% O2 from compressed air. Pelletized LiLSX zeolite is used as the air separation adsorbent. Steady state process performance data [bed size factor (BSF) and O2 recovery (R) as functions of total cycle time (tc)], as well as transient, cyclic, adsorber pressure, and temperature profiles are presented. A four-step Skarstrom-like pressure swing adsorption cycle was used. Two options for column pressurization, (a) using compressed feed air cocurrently or (b) using a part of the oxygen-enriched product gas counter-currently were evaluated. Option (b) exhibited superior performance. The optimum total cycle time for option (b) was 5–6 s where the BSF was lowest (∼45 kgs/TPD O2) and the corresponding R was ∼29.3%. These numbers indicate that the adsorbent inventory of a MOC can be potentially reduced by a factor of three while offering a ∼10–20% higher O2 recovery compared to a typical commercial unit. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3330–3335, 2014