US4971606A
Expired / Lapsed
US
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Closed-loop thermal regeneration of adsorbents containing reactive adsorbates
Assignee: Air Products and Chemicals Inc
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Filing: 1989-11-06
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Granted: 1990-11-20
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Expires: 2009-11-06
Abstract
Abstract A method is disclosed for the thermal regeneration of an adsorbent which contains adsorbed components which can react with and damage the adsorbent at regeneration temperatures. The method comprises passing a hot regeneration gas through a bed of the adsorbent at a sufficiently high flow rate such that the residence time and reaction of the desorbed components in the adsorbent bed are minimized. For removing water from CaX or SrX zeolites, the flow of nitrogen regeneration gas is controlled so that the nitrogen gas residence time in the bed is less than one second.
Inventors
- 👤 Shivaji Sircar
- 👤 Roger R. Conrad
- 👤 William R. Koch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:31
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/02; B01D53/04; B01D53/047; B01D53/0462; B01D2253/00; B01D2253/10; B01D2253/102; B01D2253/104; B01D2253/106; B01D2253/108; B01D2257/00; B01D2257/80; B01D2259/00; B01D2259/40; B01D2259/40083; B01D2259/40088; B01D2259/4009; B01D53/0407; B01D53/0446; Y; Y10; Y10S; Y10S95/00; Y10S95/90; Y10S95/902
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
131 words
A method for the thermal regeneration of an adsorbent containing one or more adsorbed reactive components which can react with and damage said adsorbent during regeneration comprising passing at a regeneration temperature a regeneration gas which is essentially free of said reactive components through a bed of said adsorbent which initially contains said adsorbed reactive components at a temperature less than said regeneration temperature whereby said adsorbed reactive components are desorbed, and withdrawing therefrom a purge effluent stream comprising desorbed reactive components and said inert regeneration gas, wherein the flow rate of said regeneration gas is controlled such that the gas residence time in said bed of adsorbent is less than about one second, whereby damage to said adsorbent by reaction with said reactive components at said regeneration temperature is minimized.
Claim 2
Independent Claim
131 words
A method for the thermal regeneration of an adsorbent containing one or more adsorbed reactive components which can react with and damage said adsorbent during regeneration comprising passing at a regeneration temperature a regeneration gas which is essentially free of said reactive components through a bed of said adsorbent which initially contains said adsorbed reactive components at a temperature less than said regeneration temperature whereby said adsorbed reactive components are desorbed, and withdrawing therefrom a purge effluent stream comprising desorbed reactive components and said inert regeneration gas, wherein the flow rate of said regeneration gas is controlled such that the gas residence time in said bed of adsorbent is less than about one second, whereby damage to said adsorbent by reaction with said reactive components at said regeneration temperature is minimized.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein said adsorbent is a bivalent ion-exchanged type A or type X zeolite.
Claim 4
Dependent Claim
14 words
The method of claim 2 wherein said adsorbent is a calcium-exchanged type X zeolite.
Claim 5
Dependent Claim
14 words
The method of claim 2 wherein said adsorbent is a strontium-exchanged type X zeolite.
Claim 6
Dependent Claim
22 words
The method of claim 1 wherein said regeneration temperature is between about 200° and 800° F. and said regeneration gas is nitrogen.
Claim 7
Dependent Claim
11 words
The method of claim 1 wherein said regeneration gas is air.
Claim 8
Dependent Claim
26 words
The method of claim 1 wherein less than about 10% of the adsorption capacity at ambient temperatures of a selected reversibly-adsorbed component is lost during regeneration.
Claim 9
Dependent Claim
12 words
The method of claim 1 wherein said desorbed reactive components comprise water.
Claim 10
Dependent Claim
39 words
The method of claim 8 wherein at least a portion of said water is removed from said purge effluent stream and the resulting stream is heated and recycled to said bed of adsorbent for use as said regeneration gas.
Claim 11
Dependent Claim
31 words
The method for claim 9 wherein said regeneration gas is passed through said bed of adsorbent until said purge effluent stream reaches a dew point of less than about -4° F.
Claim 12
Dependent Claim
42 words
The method of claim 9 wherein said water is removed by cooling said purge effluent stream and removing condensed water therefrom, and removing essentially all of the non-condensed water from said cooled purge effluent stream by adsorption in a cyclic adsorption system.
Claim 13
Dependent Claim
31 words
The method of claim 11 wherein said regeneration gas is passed through said bed of adsorbent until said purge effluent stream reaches a dew point of less than about -4° F.
Claim 14
Dependent Claim
16 words
The method of claim 11 wherein said cyclic adsorption system is a pressure swing adsorption system.
Claim 15
Dependent Claim
16 words
The method of claim 11 wherein said cyclic adsorption system is a temperature swing adsorption system.
Claim 16
Dependent Claim
42 words
The method of claim 14 wherein said temperature swing adsorption system contains an adsorbent selected from the group consisting of type 3A zeolite, type 4A zeolite, type 5A zeolite. NaX zeolite, high silica sodium mordenite, silica gel, activated alumina, and activated carbon.
Claim 17
Dependent Claim
25 words
The method of claim 14 wherein the product stream from said temperature swing adsorption system has a dew point of as low as -80° F.
Claim 18
Dependent Claim
74 words
The method of claim 9 wherein said water is removed from said purge effluent stream by cooling said stream and removing condensed water therefrom, compressing and cooling the resulting stream and removing additional condensed water therefrom, removing essentially all of the non-condensed water from the resulting cooled and compressed stream by a first cyclic adsorption system and reducing the pressure of the resulting stream prior to heating and recycling to said bed of adsorbent.
Claim 19
Dependent Claim
29 words
The method of claim 17 wherein the effluent stream from said first cyclic adsorption system is passed to a second cyclic adsorption system for the removal of additional water.
Claim 20
Dependent Claim
18 words
The method of claim 18 wherein said first and second cyclic adsorption systems are temperature swing adsorption systems.
Claim 21
Dependent Claim
45 words
The method of claim 19 wherein the adsorbents in said first and second cyclic adsorption systems are selected from the group consisting of type 3A zeolite, type 4A zeolite, type 5A zeolite, NaX zeolite, high silica sodium mordenite, silica gel, activated alumina, and activated carbon.
Claim 22
Dependent Claim
43 words
The method of claim 19 wherein the effluent stream from said first cyclic adsorption system has a dew point as low as -40° F. and the product stream from the second cyclic adsorption system has a dew point as low as -80° F.
Claim 23
Dependent Claim
17 words
The method of claim 17 wherein said second cyclic adsorption system is a pressure swing adsorption system.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-19 | 1994-05-21 | 1994-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-19 | 1998-05-21 | 1998-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-19 | 2002-05-21 | 2002-11-20 | $7700.00 | Window Closed / Lapsed |