초록 ▼

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 sing

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.

대표청구항 ▼

What is claimed is: 1. 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 f

What is claimed is: 1. 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. 2. The vacuum pressure swing adsorption process of claim 1, wherein the VPSA process contains four beds in a single train. 3. The vacuum pressure swing adsorption process of claim 2, wherein the cycles by steps comprise a twelve-step cycle. 4. The vacuum pressure swing adsorption process of claim 3, wherein the evacuation step is performed before and after a purge step. 5. The vacuum pressure swing adsorption process of claim 4, wherein void space gas obtained during cocurrent depressurization of a bed other than the bed undergoing the evacuation is suitable for use as a purge gas. 6. The vacuum pressure swing adsorption process of claim 1, wherein the at least one more strongly adsorbable component comprises nitrogen. 7. The vacuum pressure swing adsorption process of claim 1, wherein the at least one less strongly adsorbable product gas component comprises oxygen. 8. The vacuum pressure swing adsorption process of claim 7, wherein the oxygen has an average purity of about 85-95% oxygen. 9. The vacuum pressure swing adsorption process of claim 7, wherein the oxygen corresponds to an oxygen recovery of about 55-75%. 10. The vacuum pressure swing adsorption process of claim 7, wherein each adsorption bed contains an N2 selective adsorbent. 11. The vacuum pressure swing adsorption process of claim 10, wherein the adsorbent comprises at least one of: Li--X zeolite, 5A, 13X, CaX, and mixed cations zeolites. 12. The vacuum pressure swing adsorption process of claim 11, wherein the adsorbent comprises a LiX adsorbent. 13. The vacuum pressure swing adsorption process of claim 1, wherein the at least one less strongly adsorbable product gas component comprises hydrogen. 14. The vacuum pressure swing adsorption process of claim 1, wherein a highest adsorption pressure is in the range of about 100 kPa to about 2000 kPa, and the lowest desorption pressure is in the range of about 20 kPa to about 100 kPa. 15. The vacuum pressure swing adsorption process of claim 1, wherein the process can produce at least 200 tons/day O2. 16. The vacuum pressure swing adsorption process of claim 15, wherein the process can produce at least 350 tons/day O2. 17. 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. 18. The vacuum pressure swing adsorption process of claim 17, wherein the at least one more strongly adsorbable component comprises nitrogen. 19. The vacuum pressure swing adsorption process of claim 17, wherein the at least one less strongly adsorbable product gas component comprises oxygen. 20. The vacuum pressure swing adsorption process of claim 19, wherein the oxygen has an average purity of about 85-95% oxygen. 21. The vacuum pressure swing adsorption process of claim 19, wherein the oxygen corresponds to an oxygen recovery of about 55-75%. 22. The vacuum pressure swing adsorption process of claim 19, wherein each adsorption bed contains an N2 selective adsorbent. 23. The vacuum pressure swing adsorption process of claim 22, wherein the adsorbent comprises at least one of: Li--X zeolite, 5A, 13X, CaX, and mixed cations zeolites. 24. The vacuum pressure swing adsorption process of claim 23, wherein the adsorbent comprises a LiX adsorbent. 25. The vacuum pressure swing adsorption process of claim 17, wherein the at least one less strongly adsorbable product gas component comprises hydrogen. 26. The vacuum pressure swing adsorption process of claim 17, wherein a highest adsorption pressure is in the range of about 100 kPa to about 2000 kPa, and a lowest desorption pressure is in the range of about 20 kPa to about 100 kPa. 27. The vacuum pressure swing adsorption process of claim 17, wherein the process can produce at least 200 tons/day O2. 28. The vacuum pressure swing adsorption process of claim 27, wherein the process can produce at least 350 tons/day O2. 29. 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. 30. The vacuum pressure swing adsorption process of claim 29, wherein the at least one more strongly adsorbable component comprises nitrogen. 31. The vacuum pressure swing adsorption process of claim 29, wherein the at least one less strongly adsorbable product gas component comprises oxygen. 32. The vacuum pressure swing adsorption process of claim 31, wherein the oxygen has an average purity of about 85-95% oxygen. 33. The vacuum pressure swing adsorption process of claim 31, wherein the oxygen corresponds to an oxygen recovery of about 55-75%. 34. The vacuum pressure swing adsorption process of claim 31, wherein each adsorption bed contains an N2 selective adsorbent. 35. The vacuum pressure swing adsorption process of claim 34, wherein the adsorbent comprises at least one of: Li--X zeolite, 5A, 13X, CaX, and mixed cations zeolites. 36. The vacuum pressure swing adsorption process of claim 35, wherein the adsorbent comprises a LiX adsorbent. 37. The vacuum pressure swing adsorption process of claim 29, wherein the at least one less strongly adsorbable product gas component comprises hydrogen. 38. The vacuum pressure swing adsorption process of claim 29, wherein a highest adsorption pressure is in the range of about 100 kPa to about 2000 kPa, and a lowest desorption pressure is in the range of about 20 kPa to about 100 kPa. 39. The vacuum pressure swing adsorption process of claim 29, wherein the process can produce at least 200 tons/day O2. 40. The vacuum pressure swing adsorption process of claim 39, wherein the process can produce at least 350 tons/day O2.