CPC C01B 23/0042 (2013.01) [B01D 53/229 (2013.01); C01B 23/0078 (2013.01); B01D 2256/18 (2013.01)] | 15 Claims |
1. A process for purifying a pressurized feed stream containing at least 30 mol % CO2 and at most 10 mol % helium, comprising the steps of: partially condensing the pressurized feed stream in a heat exchanger to obtain a helium-rich gas stream and a CO2-rich liquid stream; separating the helium-rich gas stream in a gas separation membrane-based separation unit to obtain a first permeate stream and a first residue stream; compressing the first permeate stream, or a fraction thereof, to obtain a compressed permeate stream; introducing at least a fraction of the compressed permeate stream into the heat exchanger at which the introduced at least one fraction of the compressed stream is partially condensed to produce a gaseous permeate stream and a liquid permeate stream; and purifying at least a fraction of the gaseous permeate stream to obtain a purified helium stream containing at least 70 mol % helium.
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