Process for producing very high purity helium or hydrogen
AssigneesAir Liquide Advanced Technologies U.S. LLC, L'Air Liquide, Societe Anonyme pour l'Etude et l’Exploitation des Procedes Georges Claude
InventorsPaul TERRIEN, Pierre-Philippe GUERIF
Life of this patent
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Abstract
A method of purifying a gas composed of a product gas and one or more impurity gases including combining a feed stream with a second stream thereby forming a combined feed stream, introducing the combined feed stream into a pressure swing adsorption device, thereby producing a high purity product gas stream and an off-gas stream, and introducing the off-gas stream into a membrane separation device, thereby producing a gas stream lean in product gas and a permeate stream.
Claims12
A method of purifying helium from natural gas (101), the method comprising:
- a) providing a first gas stream (103) having a first concentration of helium,
- b) performing a permeation separation by a membrane separation unit (104) on the first gas stream to form
- a retentate gas having a lower helium concentration than the first gas (105), and
- a permeate gas having a higher helium concentration than the first gas (106),
- c) providing the permeate gas (106) to a first pressure swing adsorption (PSA) unit (109) and performing a pressure swing adsorption separation of the permeate gas to form
- a first PSA product gas stream having a higher helium concentration than the permeate gas (113), and
- a first PSA tail gas stream having a lower helium concentration than the permeate gas (114),
- d) adding an externally sourced helium containing stream (115), having a higher concentration of helium than the first PSA product gas stream, to the first PSA product gas stream (113) to produce a mixed gas stream having a higher helium concentration than the first PSA product gas stream (116),
- e) providing the mixed gas stream (116) to a second PSA unit (117) and performing a pressure swing adsorption separation of the mixed gas stream to form
- a final helium product stream having a higher helium concentration than the mixed gas stream (121), and
- a second PSA tail gas stream having a lower helium concentration than the mixed gas stream (122),
- f) recycling the first PSA tail gas stream (114) into the natural gas stream (101) to form the first gas stream (103), and
- g) recycling the second PSA tail gas stream (122)
- into the natural gas stream (101) to form the first gas stream (103), or
- into the first PSA unit (109) for a pressure swing adsorption separation of the second PSA tail gas stream.
Dependencies are inferred from the claim text.