Process and apparatus for the cryogenic separation of air

A process for the production of liquid oxygen (“LOX”) product and a krypton- and xenon-enriched liquid product from the cryogenic separation of air using a cryogenic distillation system comprising at least an HP column and an LP column, said columns being thermally integrated via a reboiler/condenser, and at least a first additional distillation column, said process comprising:

• separating feed air in the HP column into nitrogen-enriched overhead vapor and crude liquid oxygen (“CLOX”) bottoms liquid;
• feeding at least a portion of said CLOX bottoms liquid to said LP column after pressure adjustment;
• separating said CLOX bottoms liquid in said LP column into nitrogen-rich overhead vapor and said krypton- and xenon-enriched liquid product;
• condensing at least a portion of said nitrogen-enriched overhead vapor in said reboiler/condenser by indirect heat exchange against krypton- and xenon-enriched liquid product to produce condensed nitrogen-enriched overhead vapor;
• feeding at least a portion of said condensed nitrogen-enriched overhead vapor to the HP column as reflux;
• and
• feeding liquid from or derived from the HP column to the LP column as reflux after pressure adjustment;
• removing at least a portion of said krypton- and xenon-enriched liquid product from said LP column for further processing to produce at least one krypton- and/or xenon-rich product;
• removing xenon-lean liquid from said LP column and feeding said liquid to said first additional distillation column;
• and
• separating said portion of xenon-lean liquid in said first additional distillation column into oxygen-rich overhead vapor and said LOX product having a concentration of xenon less than that in said feed air.

A process for the production of liquid oxygen (“LOX”) product and a krypton- and xenon-enriched liquid product from the cryogenic separation of air using a cryogenic distillation system comprising at least an HP column and an LP column, said columns being thermally integrated via a reboiler/condenser, and at least a first additional distillation column, said process comprising:

• separating feed air in the HP column into nitrogen-enriched overhead vapor and crude liquid oxygen (“CLOX”) bottoms liquid;
• feeding at least a portion of said CLOX bottoms liquid to said LP column after pressure adjustment;
• separating said CLOX bottoms liquid in the LP column into nitrogen-rich overhead vapor and said krypton- and xenon-enriched liquid product;
• condensing at least a portion of said nitrogen-enriched overhead vapor in said reboiler/condenser by indirect heat exchange against krypton- and xenon-enriched liquid product to produce condensed nitrogen-enriched overhead vapor;
• feeding at least a portion of said condensed nitrogen-enriched overhead vapor to the HP column as reflux;
• and
• feeding liquid from or derived from the HP column to the LP column as reflux after pressure adjustment;
• removing at least a portion of said krypton- and xenon-enriched liquid product from said LP column for further processing to produce at least one krypton- and/or xenon-rich product;
• feeding xenon-lean liquid removed from or derived from liquid removed from said HP column to said first additional distillation column;
• and
• separating said portion of xenon-lean liquid in said first additional distillation column into oxygen-rich overhead vapor and said LOX product having a concentration of xenon less than that in said feed air.