Argon recovery from partial oxidation based ammonia plant purge gases

Abstract

The present invention is directed to a method for recovering argon from a feed mixture comprising argon, carbon monoxide, methane, hydrogen, and nitrogen which comprises the steps of (a) passing the feed mixture through a pressure swing adsorption system to remove carbon monoxide, methane and part of the nitrogen thereby producing a fraction containing an increased amount of argon, and (b) passing the argon fraction to a cryogenic fractional distillation system to remove hydrogen and the remaining nitrogen in the fraction as a distillate product and to produce a pure argon product. In a second embodiment, the invention is directed to a method for recovering argon from a feed mixture comprising argon, carbon monoxide, methane, hydrogen, and nitrogen which comprises the steps of (a) passing the feed mixture through a first cryogenic fractional distillation system to remove carbon monoxide, hydrogen, and nitrogen as distillate products and to produce a fraction containing an increased amount of argon, and (b) passing the argon fraction to a second cryogenic fractional distillation system to remove methane and to produce pure argon as a distillate product.

Dependencies are inferred from the claim text.