Process for dehydration of a gas stream prior to cryogenic co2 fractionation

A process for recovery of carbon dioxide from a gas stream comprising:

• chilling the gas feed stream with a carbon dioxide product stream from a cryogenic fractionation system forming a chilled gas feed stream;
• removing water from the chilled gas feed stream in a dehydration unit comprising a liquid solvent-based absorbent to form a dried gas stream;
• chilling the dried gas stream with the carbon dioxide product stream from the cryogenic fractionation system forming a chilled gas feed stream;
• removing carbon dioxide from the chilled dried gas stream in a cryogenic carbon dioxide fractionation system comprising a cryogenic fractionation column to form a carbon dioxide product stream;
• optionally chilling the gas feed stream, or the dried gas feed stream, or the chilled dried gas feed stream, or combinations thereof with a cold stream from the cryogenic carbon dioxide fractionation system before removing the carbon dioxide from the chilled dried gas feed stream;
• passing an overhead stream comprising carbon dioxide and at least one of methane, hydrogen, nitrogen, carbon monoxide, argon, hydrogen sulfide, and helium from the cryogenic carbon dioxide fractionation column to an overhead pressure swing adsorption unit;
• separating the overhead stream into a residue gas stream comprising carbon dioxide and at least one of methane, nitrogen, hydrogen, carbon monoxide, argon, and helium, and a tail gas stream comprising carbon dioxide;
• compressing the tail gas stream and recycling the compressed tail gas stream to the carbon dioxide fractionation system;
• separating the residue gas stream in a CO2 thermal swing adsorption (TSA) unit into a CO2 lean stream comprising at least one of methane, nitrogen, hydrogen, carbon monoxide, argon, and helium, and a regeneration gas stream comprising carbon dioxide;
• passing the regeneration gas stream to the overhead PSA unit;
• passing the CO2 lean stream to a cryogenic nitrogen rejection unit (NRU) to form a nitrogen lean stream comprising methane and helium and a nitrogen rich stream;
• passing the nitrogen-lean stream to a helium recovery unit to form a residue gas stream comprising methane and a helium-enriched product stream comprising helium;
• and
• recovering the helium-enriched product stream.