Patent ID: 6694775
Filing Date: 2004-02-24
Classification: F25J,Y02P,Y10S

Abstract:
A process for the recovery of at least one rare gas selected from the group consisting of krypton and xenon from a mixture comprising oxygen and at least one rare gas selected from the group consisting of krypton and xenon, said process comprising:separating feed air in a cryogenic air separation unit (â€œASUâ€ ) into nitrogen-rich overhead vapor and liquid oxygen (â€œLOXâ€ ); pressurising at least a portion of said LOX to provide pressurized LOX; at least partially vaporizing at least a portion of said pressurized LOX to provide said mixture such that at least about 50 mol % of said mixture is in the gaseous phase; feeding said mixture or a mixture derived therefrom at a pressure greater than the pressure of the part of the ASU producing said LOX to a rare gas recovery system; and separating said mixture feed in said rare gas recovery system into rare gas-lean gaseous oxygen (â€œGOXâ€ ) and rare gas-enriched product, provided that, when said mixture feed is separated by selective adsorption, the concentration of xenon in the mixture feed is no greater than 50 times the concentration of xenon in air.