| 摘要 |
<p>An oxygen-rich gas product of at least about 95% O2 purity is obtained from ambient air in a single-stage pressure swing adsorption operation carried out in four steps, comprised of: (a) selective adsorption of nitrogen from the air feed at superatmospheric pressure, (b) followed, without intermediate purge or rinse, by pressure let down through countercurrent gas withdrawal to about atmospheric level, (c) desorption by evacuation of the adsorbent bed to subatmospheric pressure level of 1/20 (5%) or less than 1/20<th> of the pressure prevailing during the adsorption step; and (d) repressuring the evacuated bed with part of the oxygen-rich effluent obtained during the adsorption step. Optionally, the operating cycle may include pressure equalization between two columns performed intermediate steps (a) and (b), whereby O2 recovery is increased. Under the prescribed conditions the oxygen production capacity at high purity level ( SIMILAR 95%) is substantially increased.</p> |
