EP0099211A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for nitrogen enrichment
Assignee: BOC Group Ltd
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Filing: 1983-07-01
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Granted: —
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Expires: 2003-07-01
Abstract
Abstract In a pressure swing adsorption process for the production of nitrogen enriched product gas from air, when the process is halted during a pressure equalisation step, that is, with valves 5 and 6 open to permit the flow of gas from one vessel 16 to a second vessel 16', then the gas remaining in the vessels 16, 16' is exhausted to atmosphere by opening valve 14. This results in rapid return to the required purity of nitrogen enriched product gas on start-up of the process. Preferably, subsequent to opening valve 14, valve 15 is opened, thereby permitting nitrogen-rich product gas from reservoir 11 to flow through the vessels 16, 16', thereby purging said vessels with nitrogen enriched product gas.
Inventors
- 👤 Umeki Mazakazu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 12:18
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/02; B01D53/04; B01D53/047; B01D53/0476; B01D53/0473; B01D2253/00; B01D2253/10; B01D2253/116; B01D2253/25; B01D2256/00; B01D2256/10; B01D2257/00; B01D2257/10; B01D2257/104; B01D2259/00; B01D2259/40; B01D2259/40011; B01D2259/40028; B01D2259/4003; B01D2259/40035; B01D2259/40037; B01D2259/40043; B01D2259/4005; B01D2259/40052; B01D2259/40058; B01D2259/40062; B01D2259/40064; B01D2259/40066; B01D2259/402
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
244 words
A process for the separation of a gas mixture comprising the steps of :- a) repeatedly performing a cycle of operations in employing a first vessel 16 containing adsorbent which absorbs one component of a gas mixture more readily than another or the other component of the gas mixture, the cycle of operations comprising : (i) passing the gaseous mixture under pressure through the vessel 16 whereby said one component is adsorbed and a gas stream reletively lean in the adsorbed component flows out of the bed as product gas; (ii) regenerating the adsorbent by desorbing gas therefrom and causing a gas stream relatively rich in the desorbed gas to flow out of the vessel 16; b) repeatedly performing such a cycle of operations employing a second vessel 16' containing said adsorbent, the cycles being phase relative to one another such that at no time is step (i) or step (ii) in one cycle performed simultaneously with the corresponding step in the other cycle; c) passing the product gas stream into a reservoir 11; and d) at intervals between successive adsorption steps the two beds are placed in flow communication with each other; characterised in that when the process is halted during the intervals between successive adsorption steps when the two beds are placed in flow communication, then any gas remaining in the vessels 16, 16' is exhausted from the said vessels countercurrently to the flow of product gas thereby to depressurise the vessels.
Claim 2
Dependent Claim
244 words
A process for the separation of a gas mixture comprising the steps of :- a) repeatedly performing a cycle of operations in employing a first vessel 16 containing adsorbent which absorbs one component of a gas mixture more readily than another or the other component of the gas mixture, the cycle of operations comprising : (i) passing the gaseous mixture under pressure through the vessel 16 whereby said one component is adsorbed and a gas stream reletively lean in the adsorbed component flows out of the bed as product gas; (ii) regenerating the adsorbent by desorbing gas therefrom and causing a gas stream relatively rich in the desorbed gas to flow out of the vessel 16; b) repeatedly performing such a cycle of operations employing a second vessel 16' containing said adsorbent, the cycles being phase relative to one another such that at no time is step (i) or step (ii) in one cycle performed simultaneously with the corresponding step in the other cycle; c) passing the product gas stream into a reservoir 11; and d) at intervals between successive adsorption steps the two beds are placed in flow communication with each other; characterised in that when the process is halted during the intervals between successive adsorption steps when the two beds are placed in flow communication, then any gas remaining in the vessels 16, 16' is exhausted from the said vessels countercurrently to the flow of product gas thereby to depressurise the vessels.
Claim 3
Dependent Claim
25 words
A process as claimed in claim 1, characterised in that subsequent to depressurisation of the vessels 16, 16', the vessels are purged with product gas.
Claim 4
Dependent Claim
25 words
A process as claimed in claim 1 or 2, characterised in that the gas mixture is air and the product gas is nitrogen enriched gas.
Claim 5
Dependent Claim
39 words
A process as claimed in claim 3, characterised in that the nitrogen enriched product gas used for purging the vessels is in the range of 3 to 10% on the basis of nitrogen enriched product by the adsorption step.
Claim 6
Dependent Claim
35 words
A process as claimed in any one of claims 1 to 4, characterised in that the pressure within the vessels during adsorption is in the range of 1 to 10 k g/ cm 2 g.
Claim 7
Dependent Claim
31 words
A process as claimed in claim 5, characterised in that the pressure within the vessels during adsorption is in the range of 2 to 9 k g /cm 2 g .
Claim 8
Dependent Claim
37 words
A process as claimed in any one of claims 1 to 6, characterised in that during the desorption step each vessel is subject to a vacuum to reduce the pressure within the vessel to below atmospheric pressure.
References Cited (Backward Citations)
No citation records indexed.
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