US4375949A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of at least partially burning a hydrocarbon and/or carbonaceous fuel
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1980-12-29
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Granted: 1983-03-08
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Expires: 2000-12-29
Abstract
Abstract A method of at least partially burning a hydrocarbon and/or carbonaceous fuel in order to yield hot gaseous products of relatively low pollutant content, in which the fuel is partially burned in a first stage flame under such conditions that the partially combusted fuel has a temperature in the range 800 DEG to 1600 DEG C., (e.g., about 1150 DEG C.) and is substantially free of smoke and/or carbon, bringing the partially combusted fuel at 800 DEG to 1600 DEG C. into contact with a substantially non-volatile catalyst (19) which is active for reducing the amount of NOx in the partially combusted fuel, and then at least partially burning the partially combusted fuel, after contact with the catalyst (19) in a second stage flame to yield the desired low pollutant hot gaseous products. Preferably one or both of the said flames burns in contact with a substantially non-volatile catalyst (25, 23) to reduce still further the NOx content of the final gaseous products. The preferred non-volatile catalysts (19, 25, 23) comprise either a mixture of iron and chromium oxides or cobalt oxide.
Inventors
- 👤 Kailash C. Salooja
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:51
CPC Classifications
F; F23; F23C; F23C13/00; F23C6/00; F23C6/04; F23C6/045; F23M; F23M9/00; F23M9/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
113 words
A method of at least partially burning a hydrocarbon and/or carbonaceous fuel comprising the following steps in sequence: (a) partially burning the fuel in a first stage flame and producing a substantially carbon-free or smoke-free partially combusted gaseous phase fuel at a temperature of at least 800° C.; (b) contacting the said partially combusted fuel with a solid, substantially non-volatile catalyst which is active for reducing the amount of nitrogen oxide(s) in the partially combusted fuel, the contacting being effected at a temperature of at least 800° C.; and (c) at least partially burning the partially combusted fuel in a second stage flame to yield hot gaseous products of relatively low pollutant content.
Claim 2
Independent Claim
113 words
A method of at least partially burning a hydrocarbon and/or carbonaceous fuel comprising the following steps in sequence: (a) partially burning the fuel in a first stage flame and producing a substantially carbon-free or smoke-free partially combusted gaseous phase fuel at a temperature of at least 800° C.; (b) contacting the said partially combusted fuel with a solid, substantially non-volatile catalyst which is active for reducing the amount of nitrogen oxide(s) in the partially combusted fuel, the contacting being effected at a temperature of at least 800° C.; and (c) at least partially burning the partially combusted fuel in a second stage flame to yield hot gaseous products of relatively low pollutant content.
Claim 3
Dependent Claim
40 words
A method according to claim 1 comprising contacting at least one of the first and second stage flames with a respective solid, substantially non-volatile catalyst which is active for reducing or inhibiting the formation of nitrogen oxide(s) in the flame(s).
Claim 4
Dependent Claim
18 words
A method according to claim 2 in which the hottest region(s) of the flame(s) contacts the said catalyst.
Claim 5
Dependent Claim
33 words
A method according to claim 2 in which the or each catalyst contacts the respective flame at a region from 30% to 45% of the length of the flame from its upstream end.
Claim 6
Dependent Claim
30 words
A method according to claim 1 in which the or each catalyst comprises a metal selected from iron, chromium, cobalt and a mixture of at least two of the foregoing.
Claim 7
Dependent Claim
66 words
A method according to claim 1 in which at least one of the first stage flame and the second stage flame is laterally confined for at least part of its length by a surrounding combustion chamber which reduces the cross-sectional dimensions of at least a portion of the laterally confined part of the flames relative to the cross-sectional dimensions of the flame(s) when not laterally confined.
Claim 8
Dependent Claim
42 words
A method according to claim 6 in which the cross-sectional dimensions of the said portion of the laterally confined part of the flame(s) are reduced by not more than 20% relative to the cross-sectional dimensions of the flame(s) when not laterally confined.
Claim 9
Dependent Claim
37 words
A method according to claim 6 in which the cross-sectional dimensions of the said portion of the laterally confined part of the flame(s) are reduced by an amount in the range of from 1.00 to 6.50 cms.
Claim 10
Dependent Claim
40 words
A method according to claim 1 in which at least one of the first stage flame and the second stage flame contacts at least one baffle disposed for promoting recirculation of reactive species in the flame(s) contacting the said baffle(s).
Claim 11
Dependent Claim
33 words
A method according to claim 9 in which the or each respective flame contacts a baffle at a distance less than half way down the length of the flame from its upstream end.
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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) | 1986-03-07 | 1986-09-06 | 1987-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-07 | 1990-09-06 | 1991-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-07 | 1994-09-06 | 1995-03-08 | $7700.00 | Window Closed / Lapsed |