Process for recovery of krypton and/or xenon comprises removing oxygen-enriched fraction from the pressure column at an intermediate point

摘要

The oxygen-enriched fraction (13) of the pressure column is removed from an intermediate point and has a theoretical or practical base (15) arranged above the point at which compressed pre-purified air (5) is injected into the column. The krypton- and xenon-containing fraction (116) is removed from the column below the intermediate point. Process for recovery of krypton and/or xenon comprises: introducing compressed prepurified air into the rectification system for nitrogen-oxygen, the system having a pressure column (6) and a low pressure column (7) or a pressure column with head condenser; introducing a part of the compressed pre-purified air into the pressure column; removing an oxygen-enriched fraction from the column and feeding into the low pressure column and/or head condenser of the single column; removing a krypton- and xenon-containing fraction from the rectification system for nitrogen-oxygen separation and feeding into the above or middle region of an exchange column (102); feeding an inert gas to the lower or middle region of the exchange column; and removing a krypton- and/or xenon-enriched mixture (117) from the lower region of the exchange column. The oxygen-enriched fraction (13) of the pressure column is removed from an intermediate point and has a theoretical or practical base (15) arranged above the point at which compressed pre-purified air (5) is injected into the column. The krypton- and xenon-containing fraction (116) is removed from the column below the intermediate point. An Independent claim is also included for an apparatus for carrying out the low temperature decomposition of air.