Recovery of Pure Kr and Xe

Kr/Xe-fine-purification plants are available in numerous designs, combining the separation techniques cryogenic rectification, catalysis, adsorption, chemisorption or membrane separation. They may be operated continuously or, due to the small capacities, in batch mode. 

In the following, a continuous process will be described, the process steps of which are realized this way or similarly in a number of plants. 

The feed to the purification unit is liquid oxygen enriched with about 400 ppm of Xe and 4000 ppm of Kr. It contains numerous additional impurities (cf. Table 2.1), e.g. 

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