US4246255A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disposal of PCB
Assignee: Boeing North American Inc
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Filing: 1979-04-02
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Granted: 1981-01-20
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Expires: 1999-04-02
Abstract
Abstract A process for the decomposition of polychlorinated biphenyls (PCB's) with negligible environmental pollution. The process comprises feeding the PCB and a source of oxygen to a molten salt comprising an alkali metal carbonate and preferably also an alkali metal sulfate to decompose the PCB by pyrolysis and oxidation. Some of the resulting decomposition products react with and are retained in the molten salt; the remaining gaseous products pass through the melt and are safely exhaustable to the atmosphere or, alternatively, the PCB is introduced into a first zone for partial pyrolysis and oxidation and then into a second reaction zone for further oxidation of any remaining combustible gases.
Inventors
- 👤 LeRoy F. Grantham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:26
CPC Classifications
A; A62; A62D; A62D3/00; A62D3/30; A62D3/32; B; B01; B01J; B01J10/00; B01J10/005; C; C01; C01B; C01B7/00; C01B7/01; C01D; C01D3/00; C01D3/04; C01D3/08; C10; C10B; C10B53/00; A62D2101/00; A62D2101/20; A62D2101/22; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/908; Y10S210/909; Y10S423/00; Y10S423/09; Y10S423/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
109 words
A process for the decomposition of a polychlorinated biphenyl resulting in negligible environmental pollution comprising feeding the polychlorinated biphenyl and a source of oxygen into a pool of a molten salt maintained at a temperature between 700° and 1000° C., and salt comprising an alkali metal carbonate or a mixture of alkali metal carbonates to thermally decompose and at least partially oxidize said polychlorinated biphenyl to form decomposition products including a gaseous effluent and venting said gaseous effluent product consisting essentially only of gases selected from carbon dioxide, water vapor, oxygen and nitrogen to the atmosphere while retaining the remaining decomposition products of the polychlorinated biphenyl in the melt.
Claim 2
Dependent Claim
109 words
A process for the decomposition of a polychlorinated biphenyl resulting in negligible environmental pollution comprising feeding the polychlorinated biphenyl and a source of oxygen into a pool of a molten salt maintained at a temperature between 700° and 1000° C., and salt comprising an alkali metal carbonate or a mixture of alkali metal carbonates to thermally decompose and at least partially oxidize said polychlorinated biphenyl to form decomposition products including a gaseous effluent and venting said gaseous effluent product consisting essentially only of gases selected from carbon dioxide, water vapor, oxygen and nitrogen to the atmosphere while retaining the remaining decomposition products of the polychlorinated biphenyl in the melt.
Claim 3
Dependent Claim
37 words
The process of claim 1 wherein the molten salt mixture is maintained at a temperature of between about 850° and 950° C. and consists essentially of sodium carbonate containing from about one to 25 wt.% sodium sulfate.
Claim 4
Dependent Claim
16 words
The process of claim 1 wherein the molten salt mixture initially consists essentially of sodium carbonate.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein the source of oxygen comprises air.
Claim 6
Dependent Claim
13 words
The process of claim 4 wherein the air is enriched with gaseous oxygen.
Claim 7
Dependent Claim
21 words
The process of claim 4 wherein the molten salt mixture is maintained at a temperature of between 850° and 950° C.
Claim 8
Dependent Claim
37 words
The process of claim 1 wherein said polychlorinated biphenyl is partially oxidized in a first reaction zone and subsequently passed into a second reaction zone for complete oxidation prior to venting said gaseous effluent to the atmosphere.
References Cited (Backward Citations)
US3845190A
Cited
US4140066A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-20 | 1984-07-21 | 1985-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-20 | 1988-07-21 | 1989-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-20 | 1992-07-21 | 1993-01-20 | $7700.00 | Window Closed / Lapsed |