Methods and systems for helium recovery
AssigneePraxair Technology, Inc.
InventorMohamed Safdar Allie
Life of this patent
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Abstract
The present invention relates generally to processes and systems for recovering helium from low helium-containing feed gases (i.e., containing less than about 10 volume % helium and more typically, less than about 5% helium by volume). The present invention more particularly relates to processes and systems for recovering helium from low helium-containing feed gases using temperature swing adsorption (TSA) systems and multiple (e.g. two) stage vacuum pressure swing adsorption (VPSA) systems. In preferred embodiments of the invention, the first stage VPSA system is configured to provide regeneration gas for the TSA system, and/or the VPSA second stage tail gas is recycled to the first stage VPSA system.
Claims22
A process for the recovery of helium, the process comprising:
- introducing a helium-containing feed gas into a temperature swing adsorption system;
- pretreating the helium-containing feed gas in the temperature swing adsorption system to produce a helium-containing pretreated feed gas;
- treating the helium-containing pretreated feed gas in a stage one pressure swing adsorption system to produce a stage one helium-containing purified gas and a stage one tail gas;
- and
- treating the helium-containing purified gas in a stage two pressure swing adsorption system to produce a helium-containing product stream and a stage two tail gas,
- wherein at least a portion of the stage one tail gas is introduced into the temperature swing adsorption system.
A process for the recovery of helium, the process comprising:
- treating a helium-containing feed gas in a stage one pressure swing adsorption system comprising four adsorption beds (Bed 1 (BD1), Bed 2 (BD2), Bed 3 (BD3), Bed 4 (BD4)) to produce a stage one helium-containing purified feed gas and a stage one tail gas;
- and
- treating the helium-containing purified feed gas in a stage two pressure swing adsorption system comprising four adsorption beds (Bed 5 (BD5), Bed 6 (BD6), Bed 7 (BD7), Bed 8 (BD8)) to produce a helium-containing product stream and a stage two tail gas,
- wherein the stage one pressure swing adsorption system to produce the helium-containing purified feed gas comprises a twelve-step cycle in which:
- Step
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- Bed 1
- AD1
- AD2/
- AD3/
- EQ1DN
- PPG
- EQ2DN
- BD
- PG
- EQ1UP
- EQ2UP
- PP1
- PP2
- (BD1)
- PP1
- PP2
- Bed 2
- BD
- PG
- EQ1UP
- EQ2UP
- PP1
- PP2
- AD1
- AD2/
- AD3/
- EQ1DN
- PPG
- EQ2DN
- (BD2)
- PP1
- PP2
- Bed 3
- EQ1DN
- PPG
- EQ2DN
- BD
- PG
- EQ1UP
- EQ2UP
- PP1
- PP2
- AD1
- AD2/
- AD3/
- (BD3)
- PP1
- PP2
- Bed 4
- EQ2UP
- PP1
- PP2
- AD1
- AD2/
- AD3/
- EQ1DN
- PPG
- EQ2DN
- BD
- PG
- EQ1UP
- (BD4)
- PP1
- PP2
- wherein
- AD1 = First Adsorption Step
- AD2/PP1 = Second Adsorption Step/First product pressurization
- AD3/PP2 = Third Adsorption Step/Second product pressurization
- EQ1DN = First Equalization Down or top-to-top bed equalization
- PPG = Provide Purge Gas
- EQ2DN = Second Equalization Down or bottom-to-bottom bed equalization
- BD = Blowdown
- PG = Purge
- EQ1UP = First Equalization Up or bottom-to-bottom bed equalization
- EQ2UP = Second Equalization Up or top-to-top bed equalization
- PP1 = First Product Pressurization
- PP2 = Second Product Pressurization,
- and wherein the helium-containing purified gas is processed in the stage two pressure swing adsorption system to produce the helium-containing product feed gas comprises a twelve-step cycle in which:
- Step
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- Bed 5
- AD1
- AD2/
- AD3/
- EQ1DN
- PPG
- EQ2DN
- BD
- PG
- EQ1UP
- EQ2UP
- PP1
- PP2
- (BD5)
- PP1
- PP2
- Bed 6
- BD
- PG
- EQ1UP
- EQ2UP
- PP1
- PP2
- AD1
- AD2/
- AD3/
- EQ1DN
- PPG
- EQ2DN
- (BD6)
- PP1
- PP2
- Bed 7
- EQ1DN
- PPG
- EQ2DN
- BD
- PG
- EQ1UP
- EQ2UP
- PP1
- PP2
- AD1
- AD2/
- AD3/
- (BD7)
- PP1
- PP2
- Bed 8
- EQ2UP
- PP1
- PP2
- AD1
- AD2/
- AD3/
- EQ1DN
- PPG
- EQ2DN
- BD
- PG
- EQ1UP
- (BD8)
- PP1
- PP2
- wherein
- AD1 = First Adsorption Step
- AD2/PP1 = Second Adsorption Step/First product pressurization
- AD3/PP2 = Third Adsorption Step/Second product pressurization
- EQ1DN = First Equalization Down or top-to-top bed equalization
- PPG = Provide Purge Gas
- EQ2DN = Second Equalization Down or top-to-bottom bed equalization
- BD = Blowdown
- PG = Purge
- EQ1UP = First Equalization Up or top-to-bottom bed equalization
- EQ2UP = Second Equalization Up or top-to-top bed equalization
- PP1 = First Product Pressurization
- PP2 = Second Product Pressurization.
Dependencies are inferred from the claim text.