Purification of inert gases to remove trace impurities

A method for purifying an argon stream comprising argon, nitrogen, hydrogen, carbon monoxide, carbon dioxide, water, and methane, the method comprising the steps of:

• cooling an argon waste stream with a cryogenic heat exchanger to create a cold feed stream;
• condensing the cold feed stream in a reboiler to create a liquid feed stream, wherein the cold feed stream is in a heat exchange relationship with bottoms liquid of a cryogenic distillation column, said distillation column comprising packing, the reboiler disposed in a lower portion of the cryogenic distillation column, and an overhead condenser in an upper portion of the cryogenic distillation column;
• withdrawing the liquid feed stream from the reboiler and introducing the liquid feed stream to the cryogenic distillation column;
• separating components of the liquid feed stream in the cryogenic distillation column into a bottoms argon product stream and a gas waste stream, the bottoms argon product stream having an increased purity of argon as compared to the cold feed stream;
• withdrawing the bottoms argon product stream from the cryogenic distillation column and expanding the bottoms argon product stream using an expansion device to provide a cooled bottoms argon product stream;
• feeding the cooled bottoms argon product stream to the overhead condenser and vaporizing the cooled bottoms argon product stream in the overhead condenser to create a purified vapor phase argon stream;
• feeding the purified vapor phase argon stream to the cryogenic heat exchanger, wherein the purified vapor phase argon stream is used to cool the pre-treated argon waste stream, thereby producing a warm product stream;
• and
• removing the gas waste stream from the cryogenic distillation column.