Obtaining high-purity krypton and/or xenon

摘要

The method comprises pre-cooling a krypton and/or xenon-containing raw mixture comprising oxygen and non-noble gas using oxygen, performing first cryogenic rectification of the pre-cooled mixture in a first rectifying column (1) to separate a portion of oxygen and to obtain a concentrated krypton and/or xenon-rich mixture, performing second cryogenic rectification of the krypton and/or xenon-rich mixture in a second rectifying column to remove krypton-rich fraction and/or a xenon-rich fraction using a heated sump tank. The method comprises pre-cooling a krypton and/or xenon-containing raw mixture comprising oxygen and non-noble gas using oxygen, performing first cryogenic rectification of the pre-cooled mixture in a first rectifying column (1) to separate a portion of oxygen and to obtain a concentrated krypton and/or xenon-rich mixture, performing second cryogenic rectification of the krypton and/or xenon-rich mixture in a second rectifying column to remove krypton-rich fraction and/or a xenon-rich fraction using a heated sump tank. The first cryogenic rectification is performed to remove the non-noble gas using a getter (5). The first cryogenic rectification step is performed at a first pressure of 1.5-5 bars, and the second cryogenic rectification step is performed at a second pressure of 0.5-4 bars. The first rectification column is operated with an integrated overhead condenser using a cryogenic heat transfer fluid and with a heatable sump tank (11), and the second rectification column is operated with a heatable sump tank in the xenon-rich fraction is temporarily stored. The krypton-rich fraction is remove at a top of the second rectification column, is transferred to a reservoir tank, from which a part of a condensate is returned to the second rectification column, and is temporarily stored in the condenser tank. The container tank is operated by a cryogenic cooling medium, and/or other non-inert gas in the condenser tank is removed by evaporation. An independent claim is included for a system for krypton and/or xenon from a krypton and/or xenon-containing raw mixture.