Pressure swing adsorption process for large capacity oxygen production
AssigneePraxair Technology, Inc.
InventorsMohamed Safdar Allie Baksh, Andrew Rosinski
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Abstract
The present invention generally relates to large capacity (e.g., greater than 350 tons/day O2) vacuum pressure adsorption (VPSA) systems and processes that employ a single train including four beds, at least one feed compressor feeding two beds simultaneously at any given instant in time, and a single vacuum pump. The compressor(s) and the vacuum pump can be utilized 100% of the time. Use of product quality gas for purging is avoided, with about 10-20% improvement in O2 productivity and 5-10% reduction in capital cost expected.
Claims40
A vacuum pressure swing adsorption (VPSA) process for separating a feed supply gas containing at least one more strongly adsorbable component and at least one less strongly adsorbable product gas component, the process comprising:
- continuously feeding a feed supply gas into feed input ends of each of two adsorber beds, each bed containing at least one adsorbent which preferentially adsorbs the more strongly adsorbable component and withdrawing the at least one less strongly adsorbable product gas component from exit ends of the adsorber beds, producing in cycles by steps in which two beds are simultaneously in a feed mode and two other beds are in a regeneration/refluxing mode, wherein at any instant during the process, only one bed is in an evacuation step using a pump.
A vacuum pressure swing adsorption process for separating a feed supply gas containing at least one more strongly adsorbable component and at least one less strongly adsorbable product gas component in a four bed system which comprises continuously feeding the supply gas into a feed input end of an adsorber bed containing at least one adsorbent which preferentially adsorbs the more strongly adsorbable component and withdrawing the at least one less strongly adsorbable product gas component from an exit end of the adsorber bed in a twelve-step cycle following the cycle chart:
- Step
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- Bed 1
- AD1
- AD2
- AD3/PPP
- AD4
- ED
- PPG
- BD
- EV1
- PG/EV2
- EV3
- EU/FP
- PP/FP
- Bed 2
- EV3
- EU/FP
- PP/FP
- AD1
- AD2
- AD3/PPP
- AD4
- ED
- PPG
- BD
- EV1
- PG/EV2
- Bed 3
- BD
- EV1
- PG/EV2
- EV3
- EU/FP
- PP/FP
- AD1
- AD2
- AD3/PPP
- AD4
- ED
- PPG
- Bed 4
- AD4
- ED
- PPG
- BD
- EV1
- PG/EV2
- EV3
- EU/FP
- PP/FP
- AD1
- AD2
- AD3/PPP
- wherein AD:
- Adsorption/Product Production, ED:
- Equalization Down, PPG:
- Provide Purge Gas, PPP:
- Provide Product Pressurization Gas, BD:
- Blowdown, PG:
- Receive Purge, EU:
- equalization Up, PP:
- product Pressurization, FP:
- Feed Pressurization, EV:
- Evacuation.
A vacuum pressure swing adsorption process for separating a feed supply gas containing at least one more strongly adsorbable component and at least one less strongly adsorbable product gas component in a four bed system which comprises continuously feeding the supply gas into a feed input end of an adsorber bed containing at least one adsorbent which preferentially adsorbs the more strongly adsorbable component and withdrawing the at least one less strongly adsorbable product gas component from an exit end of the adsorber bed in a twelve-step cycle following the cycle chart:
- Step
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- Bed 1
- AD1
- AD2
- AD3
- AD4
- ED/EV1
- PPG/EV2
- EV3
- EV4
- PG1/EV5
- PG2/EV6
- EU/FP
- PP/FP
- (RC)
- (CC)
- (CC)/PPP
- (CC)/PPG
- (RV)
- (RV)
- (RV)
- (CV)
- (CV)
- (CV)
- (RC)
- (RC)
- Bed 2
- PG2/EV6
- EU/FP
- PP/FP
- AD1
- AD2
- AD3
- AD4
- ED/EV1
- PPG/EV2
- EV3
- EV4
- PG1/EV5
- (CV)
- (RC)
- (RC)
- (RC)
- (CC)
- (CC)/PPP
- (CC)/PPG
- (RV)
- (RV)
- (RV)
- (CV)
- (CV)
- Bed 3
- EV3
- EV4
- PG1/EV5
- PG2/EV6
- EU/FP
- PP/FP
- AD1
- AD2
- AD3
- AD4
- ED/EV1
- PPG/EV2
- (RV)
- (CV)
- (CV)
- (CV)
- (RC)
- (RC)
- (RC)
- (CC)
- (CC)/PPP
- (CC)/PPG
- (RV)
- (RV)
- Bed 4
- AD4
- ED/EV1
- PPG/EV2
- EV3
- EV4
- PG1/EV5
- PG2/EV6
- EU/FP
- PP/FP
- AD1
- AD2
- AD3
- (CC)/PPG
- (RV)
- (RV)
- (RV)
- (CV)
- (CV)
- (CV)
- (RC)
- (RC)
- (RC)
- (CC)
- (CC)/PPP
- wherein AD:
- Adsorption/Product Production, ED:
- Equalization Down, PPG:
- Provide Purge Gas, PPP:
- Provide Product Pressurization Gas, BD:
- Blowdown, PG:
- Receive Purge, EU:
- equalization Up, PP:
- product Pressurization, FP:
- Feed Pressurization, RC:
- Roots Compressor, CC:
- Centrifugal Compressor, RV:
- Roots Vacuum, CV:
- Centrifugal Vacuum, EV:
- evacuation.
Dependencies are inferred from the claim text.