| 摘要 |
A pressure swing adsorption (PSA) process for the separation of a component from a gas mixture also containing water vapour, eg the separation of nitrogen from air, employs adsorbers 1 and 2 each having a first stage 3, 3' containing a desiccant adsorbent and a second stage 4, 4' containing an adsorbent which preferentially adsorbs another component of the mixture eg a carbon molecular sieve which adsorbs oxygen more rapidly than nitrogen. Each adsorber is put through a cycle comprising an adsorption step during which the mixture is passed through the adsorber by a compressor 5 and unadsorbed product is withdrawn through a delivery line 11, and a desorption step during which the adsorber is vented to atmosphere through a waste gas line 9. The pressure reached in the adsorber during such venting is the lowest reached during the entire cycle, no vacuum pump being employed. A valved line 12 allows pressure equalisation between the adsorbers. <IMAGE> |
