System and method for cryogenic purification of a feed stream comprising hydrogen, methane, nitrogen and argon
AssigneePraxair Technology, Inc.
InventorHenry E. Howard
Life of this patent
Estimating the term…
Abstract
A system and method for cryogenic purification of a hydrogen, nitrogen, methane and argon containing feed stream to produce a methane free, hydrogen and nitrogen containing synthesis gas and a methane rich fuel gas, as well as to recover an argon product stream, excess hydrogen, and excess nitrogen is provided. The disclosed system and method are particularly useful as an integrated cryogenic purifier in an ammonia synthesis process in an ammonia plant. The excess nitrogen is a nitrogen stream substantially free of methane and hydrogen that can be used in other parts of the plant, recovered as a gaseous nitrogen product and/or liquefied to produce a liquid nitrogen product.
Claims31
A cryogenic purification system configured for purifying a hydrogen, nitrogen, methane and argon containing feed stream, the system comprising:
- a synthesis gas rectification column configured to receive the feed stream and produce a hydrogen and nitrogen enriched overhead vapor stream and a methane-rich condensed phase stream at the bottom of the synthesis gas rectification column;
- a hydrogen stripping column configured to receive the methane-rich condensed phase stream from the synthesis gas rectification column, strip hydrogen from the methane-rich condensed phase stream and produce a hydrogen free methane bottom stream and a hydrogen enriched gaseous overhead;
- a condenser configured to receive the hydrogen free methane bottom stream and a working fluid and to vaporize the hydrogen free methane stream to produce a vaporized hydrogen free methane-rich stream or a partially vaporized hydrogen free methane-rich stream;
- and
- a heat exchanger configured to (a) warm the hydrogen and nitrogen enriched overhead vapor stream via indirect heat exchange with the feed stream to produce a hydrogen and nitrogen containing synthesis gas;
- and (b) to warm the vaporized hydrogen free methane-rich stream or the partially vaporized hydrogen free methane-rich stream via indirect heat exchange with the feed stream to produce a methane fuel gas.
A cryogenic purification system configured for purifying a hydrogen, nitrogen, methane and argon containing feed stream, the system comprising:
- a synthesis gas rectification column configured to receive the feed stream and produce a hydrogen and nitrogen enriched overhead vapor stream and a methane-rich condensed phase stream at the bottom of the synthesis gas rectification column;
- a hydrogen stripping column configured to receive the methane-rich condensed phase stream from the synthesis gas rectification column, strip hydrogen from the methane-rich condensed phase stream and produce a hydrogen free methane bottom stream and a hydrogen enriched gaseous overhead;
- a condenser configured to receive the hydrogen free methane bottom stream and a working fluid and to vaporize the hydrogen free methane stream to produce a vaporized hydrogen free methane-rich stream or a partially vaporized hydrogen free methane-rich stream;
- a nitrogen rectification column configured to receive the vaporized hydrogen free methane-rich stream or the partially vaporized hydrogen free methane-rich stream and a nitrogen reflux stream and produce a nitrogen containing overhead vapor stream substantially free of methane and hydrogen, and a methane enriched liquid bottom stream;
- a heat exchanger configured to (a) warm the nitrogen containing overhead vapor stream substantially free of methane and hydrogen via indirect heat exchange with the feed stream to produce a warm nitrogen stream, and (b) warm the methane enriched liquid bottom stream via indirect heat exchange with the feed stream to produce a methane fuel gas.
A cryogenic purification system configured for purifying a hydrogen, nitrogen, methane and argon containing feed stream, the system comprising:
- a synthesis gas rectification column configured to receive the hydrogen, nitrogen, methane and argon containing feed stream and produce a hydrogen and nitrogen enriched overhead vapor stream and a methane-rich condensed phase stream at the bottom of the synthesis gas rectification column;
- a condenser-reboiler disposed within the synthesis gas rectification column configured to vaporize the hydrogen free methane bottom stream against a working fluid to produce a vaporized hydrogen free methane-rich stream or a partially vaporized hydrogen free methane-rich stream;
- a nitrogen rectification column configured to receive the vaporized hydrogen free methane-rich stream or the partially vaporized hydrogen free methane-rich stream and a nitrogen reflux stream and produce a nitrogen containing overhead vapor stream substantially free of methane, and a methane enriched liquid bottom stream;
- a heat exchanger configured to (a) warm the hydrogen and nitrogen enriched overhead vapor stream via indirect heat exchange with the hydrogen, nitrogen, methane and argon containing feed stream to produce a hydrogen and nitrogen containing synthesis gas;
- (b) warm the nitrogen containing overhead vapor stream substantially free of methane to produce a warm gaseous nitrogen stream, and (c) warm the methane enriched liquid bottom stream to produce a methane fuel gas;
- and
- a nitrogen recovery system configured to receive the warm nitrogen containing stream and produce at least one nitrogen product.
Dependencies are inferred from the claim text.