Patent US3789580A successfully refreshed from Google Patents.
US3789580A
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Removal of phosgene from an essentially anhydrous gas stream
Assignee: Dow Chemical Co
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Filing: 1972-08-17
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Granted: 1974-02-05
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Expires: 1992-08-17
Abstract
Abstract A method for removing phosgene from an essentially anhydrous gas stream which involves contacting such a stream with activated alumina at a temperature of from 110*C to 200*C under essentially anhydrous conditions. This method is particularly useful in removing phosgene from chlorinated hydrocarbon gas streams also containing acid gas impurities.
Inventors
- 👤 A Allemang
- 👤 H Bachtel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:50
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/38; B; B01; B01D; B01D53/00; B01D53/02; B01D53/34; B01D53/46; B01D53/68; B01D53/70; C01; C01B; C01B32/00; C01B32/70; C01B32/80; Y; Y02; Y02P; Y02P20/00; Y02P20/151
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
20 words
The method of claim 1 wherein the anhydrous gas stream is chlorinated hydrocarbon gas stream also containing an acid gas.
Claim 2
Dependent Claim
20 words
The method of claim 1 wherein the anhydrous gas stream is a methyl-chloride gas stream containing hydrogen chloride and phosgene.
Claim 3
Dependent Claim
39 words
The method of claim 1 wherein the activated alumina is made by heating Al2O3.H2O to at least about 300*C to remove at least a part of the water of crystallization to reorient the crystalline structure to produce gamma alumina.
References Cited (Backward Citations)
US3411867A
Cited
US3376113A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |