Method for separating hydrogen and nitrogen from cracked ammonia

A method for separating hydrogen and nitrogen from a gas mixture, comprising:

• a) removing heat from a gas mixture comprising hydrogen and nitrogen, thereby partially condensing the gas mixture and producing a two-phase stream,
• b) phase separating the two-phase stream, thereby producing a nitrogen-enriched liquid fraction and a hydrogen-enriched gaseous fraction,
• c) expanding the nitrogen-enriched liquid fraction, thereby producing a lower-pressure nitrogen-enriched liquid or two-phase stream,
• d) adding heat to the lower-pressure nitrogen-enriched liquid stream, thereby producing a warm nitrogen enriched gaseous stream, and
• e) adding heat to the hydrogen-enriched gaseous fraction, thereby producing a hydrogen-rich product stream,
• wherein,
• at least a portion of the heat added in step d) is removed in step a),
• at least a portion of the heat added in step e) is removed in step a), or
• at least a portion of the heat added in step d) and at least a portion of the heat added in step e) is removed in step a)
• said lower-pressure nitrogen-enriched liquid stream is a two-phase stream and is at a pressure sufficient to allow a nitrogen-enriched vapor fraction to mix with a lower-pressure hydrogen-rich stream after phase separation.