Purification of argon through liquid phase cryogenic adsorption

An adsorption process for removing oxygen from liquid argon, employing an adsorbent exhibiting a faster rate of adsorption of oxygen and a slower rate of argon under the liquid argon feed conditions, comprising the following steps:

• a) supplying from the inlet of an adsorbent bed liquid argon feed that contains oxygen in the concentration range of about 10 to 10,000 parts per million, adsorbing at least part of the oxygen on the adsorbent thereby producing a purified liquid argon product leaving said adsorbent bed from the outlet with less than or equal to 1 parts per million of oxygen;
• b) supplying a nitrogen purge at the outlet of said adsorbent bed and draining from the inlet of said adsorbent bed purified residual liquid argon and;
• c) continuing said nitrogen purge at the outlet of the adsorbent bed and allowing said adsorbent bed containing said adsorbent to warm to a predetermined temperature of at least 200 degrees Kelvin, desorbing at least part of the adsorbed oxygen and removing this from the inlet of said adsorbent bed;
• d) supplying a gaseous argon purge of at least 200 degrees Kelvin at the outlet of the adsorbent bed, so that the gaseous effluent at the inlet side of said adsorbent bed is predominantly argon;
• e) indirectly cooling said adsorbent bed containing adsorbent and having an inlet and an outlet, as well as direct and indirect cooling means, to a temperature of less than about 150 degrees Kelvin using liquid nitrogen;
• f) directly cooling said adsorbent bed with purified liquid argon to a temperature such that said adsorbent bed sustains an argon feed in a liquid phase;
• and
• g) wherein said process steps (a)-(f) are repeated in a cyclical manner.