초록 ▼

Novel polybed VPSA process and system to achieve enhanced O2 recovery are disclosed. The VPSA process comprises using three or more adsorber beds; providing a continuous feed supply gas using a single feed blower to one bed, wherein at any instant during the process, two beds are in an evacuation st

Novel polybed VPSA process and system to achieve enhanced O2 recovery are disclosed. The VPSA process comprises using three or more adsorber beds; providing a continuous feed supply gas using a single feed blower to one bed, wherein at any instant during the process, two beds are in an evacuation step and only one bed is in a feed mode; and purging the adsorber beds using two purge gases of different purity. The VPSA cycle may further comprise utilizing a storage device (e.g., a packed or empty equalization tank) to capture void gases during co-current depressurization step of the VPSA cycle, which is used at a later stage for purging and repressurization of the bed. In addition, the VPSA process employs a single feed compressor and two vacuum pumps at 100% utilization. Furthermore, the use of the storage device minimizes the use of product quality gas for purging. About 10-20% improvement in O2 productivity is realized in the new VPSA process.

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: (a) using a system comprising three or more a

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: (a) using a system comprising three or more adsorber beds, (b) continuously feeding a feed supply gas into a feed input end of one adsorber bed, said 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, (c) providing continuous feeding of the feed supply gas using a single feed blower, (d) purging the adsorber beds using two purge gases of different purity, and (e) producing the product gas component in cycles by steps wherein at any instant during the process, two beds are in an evacuation step and only one bed is in a feed mode. 2. The VPSA process of claim 1, wherein the process further comprises using an equalization tank (ET) to collect co-current depressurization gas. 3. The VPSA process of claim 2, wherein the VPSA process comprises four adsorber beds in a single train. 4. The VPSA process of claim 3, wherein the cycles by steps comprise a sixteen-step cycle. 5. The VPSA process of claim 4, wherein the VPSA process comprises partially pressurizing the adsorber beds using the co-current depressurization gas collected in the equalization tank via bed-to-tank equalization. 6. The VPSA process of claim 5, wherein the first purge gas is a purge gas that goes directly from one adsorber bed to another adsorber bed and the second purge gas is generated from another adsorber bed undergoing a co-current depressurization step following the bed-to-tank depressurization step. 7. The VPSA process of claim 6, wherein the VPSA process comprises a first purge step using the first purge gas followed by a second purge step using the second purge gas. 8. The VPSA process of claim 7, wherein the VPSA process comprises a separate counter-current blowdown step such that any waste generated during said blowdown step bypasses the vacuum pump. 9. The VPSA process of claim 8, wherein the VPSA process comprises intermediate pressurization steps. 10. The VPSA process of claim 9, wherein the intermediate pressurization steps comprise a bed-to-tank equalization step and an overlap feed and product pressurization step. 11. The VPSA process of claim 1, wherein the process comprises bed-to-bed equalization and a pressurization step in which the feed supply gas is provided at the bottom of an adsorber bed. 12. The VPSA process of claim 1, wherein the highest adsorption pressure is in the range of about 100 kPa to about 2000 kPa and the lowest adsorption pressure is in the range of about 20 kPa to about 100 kPa. 13. A vacuum pressure swing adsorption (VPSA) system for separating a feed supply gas containing at least one more strongly adsorbable component and at least one less strongly adsorbable product gas component, wherein the system comprises: a single feed supply line; three or more adsorber beds operated in series in a single train; an equalization tank (ET) to collect void gas that is co-currently discharged from the adsorber beds; at least one vacuum pump to evacuate two adsorber beds simultaneously; and a feed compressor. 14. The VPSA system of claim 13, wherein the at least one vacuum pump comprises two vacuum pumps. 15. The VPSA system of claim 14, wherein one vacuum pump is a centrifugal vacuum pump and one vacuum pump is a Roots-type vacuum pump. 16. The VPSA system of claim 13, wherein the equalization tank is packed with inert or adsorbent materials. 17. The VPSA system of claim 16, wherein the inert or adsorbent materials are in the form of bead, pellets or structured supports. 18. The VPSA system of claim 17, wherein the structured supports are monoliths, stainless steel wire mesh or alumina foams. 19. The VPSA system of claim 13, wherein the equalization tank contains baffles. 20. The VPSA system of claim 13, wherein each adsorbent bed comprises a prepurifier section located at the upstream end of the adsorbent bed. 21. The VPSA system of claim 20, wherein the prepurifier section comprises a layer of alumina. 22. The VPSA system of claim 13, wherein the at least one vacuum pump and the feed compressor can be utilized 100% of the time of operation of the system. 23. The VPSA system of claim 13, wherein the system is configured to produce at least 175 tons per day of oxygen. 24. The VPSA system of claim 13, wherein each adsorber bed contains an N2 selective adsorbent. 25. The VPSA system of claim 13, wherein the adsorbent comprises at least one of: Li—X zeolite, 5A, 13X, CaX, and mixed cations zeolites. 26. The VPSA system of claim 13, wherein the system comprises four adsorber beds in a single train. 27. 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: (a) using a system comprising four adsorption beds, (b) continuously feeding a feed supply gas into a feed input end of at least one adsorption bed, said 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 adsorption bed, (c) providing continuous feeding of the feed supply gas using a single feed blower, (d) purging the adsorption beds using a first purge gas having the lower concentration of the less strongly adsorbable product gas component followed by a second purge gas having a higher concentration of the less strongly adsorbable product gas component then the first purge gas, and (e) producing the product gas component. 28. The VPSA process of claim 27 wherein the first purge gas is a co-current depressurization gas and the second purge gas is product gas. 29. The VPSA process of claim 28 wherein the first purge gas also goes directly to another adsorption bed that has just completed the last counter-current evacuation step in the cycle. 30. The VPSA process of claim 27 wherein only one compressor and two vacuum pumps are employed. 31. The VPSA process of claim 27 wherein one vacuum pump evacuates two adsorption beds simultaneously.