US3739583A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control of nitrogen oxides emission from engines
Assignee: Chemical Construction Corp
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Filing: 1972-02-25
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Granted: 1973-06-19
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Expires: 1992-02-25
Abstract
Abstract The emission of nitrogen oxides in engine exhaust gas is curtailed, by passing the engine exhaust gas through a catalyst bed for selective reduction of nitrogen oxides to nitrogen, and recycling a minor portion of the treated exhaust gas to the engine intake, so that the recycled exhaust gas is present during fuel combustion in the engine and nitrogen oxides formation is reduced.
Inventors
- 👤 J Tourtellotte
- 👤 Fisher J Villiers
- 👤 J Negra
- 👤 A Warshaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:48
CPC Classifications
F; F01; F01N; F01N13/00; F01N13/009; F01N3/00; F01N3/08; F01N3/10; F01N3/24; F01N3/30; F02; F02B; F02B47/00; F02B47/04; F02B47/08; F02M; F02M26/00; F02M26/13; F02M26/14; F02M26/15; F02M26/52; F02M26/53; F02M2026/001; F02M2026/004; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
14 words
The method of claim 1, in which said engine is an internal combustion engine.
Claim 2
Dependent Claim
33 words
The method of claim 2, in which said internal combustion engine is mounted on a vehicle selected from the group consisting of an automobile, a truck, a bus, a tractor and a motorcycle.
Claim 3
Dependent Claim
43 words
The method of claim 1, in which the temperature of said catalyst bed is at least 350* C during recycle of treated exhaust gas to said engine, and the initial temperature of the exhaust gas discharged from said engine is below 900* C.
Claim 4
Dependent Claim
26 words
The method of claim 1, in which in the range of about 7 to 13 percent of the treated exhaust gas is recycled to said engine.
Claim 5
Dependent Claim
47 words
The method of claim 1, in which a small but effective proportion of air is added to the exhaust gas discharged from said engine, prior to passing the exhaust gas through said catalyst bed, whereby a portion of the oxidizable components in said exhaust gas are oxidized.
Claim 6
Dependent Claim
33 words
The method of claim 1, in which said catalyst bed contains an active catalytic agent selected from the group consisting of copper, cobalt, nickel and manganese, and mixtures thereof, deposited on a carrier.
Claim 7
Independent Claim
181 words
A method of reducing nitrogen oxides concentration in the exhaust gas from an engine which comprises passing the exhaust gas from an engine through a first catalyst bed for the selective reduction of nitrogen oxides to nitrogen, whereby a portion of the nitrogen oxides originally present in the exhaust gas discharged from said engine is catalytically reduced to nitrogen, adding air to the exhaust gas discharged from said first catalyst bed, passing the resulting air-exhaust gas mixture through a second catalyst bed for the selective oxidation of oxidizable components in said exhaust gas, dividing the treated exhaust gas discharged from said second catalyst bed into a major portion and a minor portion, said minor portion being in the range of about 3 to 20 percent of the total treated exhaust gas, discharging said major portion of treated exhaust gas and recycling said minor portion of treated exhaust gas to the intAke of said engine, whereby treated exhaust gas passes into said engine and is present during combustion of fuel in said engine and thereby reduces nitrogen oxides formation in said engine.
Claim 8
Dependent Claim
14 words
The method of claim 8, in which said engine is an internal combustion engine.
Claim 9
Dependent Claim
33 words
The method of claim 9, in which said internal combustion engine is mounted on a vehicle selected from the group consisting of an automobile, a truck, a bus, a tractor and a motorcycle.
Claim 10
Dependent Claim
29 words
The method of claim 8, in which the temperature of said first catalyst bed is at least about 200* C during recycle of treated exhaust gas to said engine.
Claim 11
Dependent Claim
30 words
The method of claim 8, in which said minor portion of treated exhaust gas is in the range of about 7 to 13 percent of the total treated exhaust gas.
Claim 12
Dependent Claim
48 words
The method of claim 8, in which a small but effective proportion of air is added to the exhaust gas discharged from said engine, prior to passing the exhaust gas through said first catalyst bed, whereby a portion of the oxidizable components in said exhaust gas are oxidized.
Claim 13
Dependent Claim
36 words
The method of claim 8, in which said first and second catalyst beds contain an active catalytic agent selected from the group consisting of copper, cobalt, nickel and manganese, and mixtures thereof, deposited on a carrier.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |