US3832443A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exhaust gas conversion process
Assignee: Union Oil Company of California
•
Filing: 1971-08-26
•
Granted: 1974-08-27
•
Expires: 1991-08-26
Abstract
Abstract A process is disclosed for the catalytic conversion of nitrogen oxides, unburned hydrocarbons and carbon monoxide in exhaust gases initially containing less than a stoichiometric ratio of oxygen to carbon monoxide. The basic novel feature of the process involves gradually increasing the oxygen concentration of the gases downstreamwardly in the conversion zone, in such manner as to maintain a generally increasing O2/CO mole-ratio in that section of the conversion zone (the initial section) in which the ratio of O2/CO is less than stoichiometric. In the latter part of the conversion zone, the ratio of O2/CO is greater than stoichiometric.
Inventors
- 👤 R Hass
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:05
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/945; B01J; B01J23/00; B01J23/70; B01J23/72; B01J23/76; B01J23/84; B01J23/85; B01J23/86; B01J23/868; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
16 words
A process as defined in claim 1 wherein said gas stream consists of automotive exhaust gases.
Claim 2
Dependent Claim
45 words
A process as defined in claim 1 wherein said oxidation-reduction catalyst comprises an oxide of at least one metal selected from the class consisting of the metals of Groups IB, VB, VIB, VIIB and VIII of the Periodic Table, supported upon a refractory oxide carrier.
Claim 3
Dependent Claim
42 words
A process as defined in claim 1 wherein said oxidation-reduction catalyst comprises an oxide of at least one metal selected from the class consisting of copper, silver, vanadium, chromium, manganese, iron, cobalt, nickel, palladium and platinum supported upon a refractory oxide carrier.
Claim 4
Dependent Claim
24 words
A process as defined in claim 1 wherein said oxidation-reduction catalyst comprises an oxide of copper or chromium supported on a refractory oxide carrier.
Claim 5
Dependent Claim
53 words
A process as defined in claim 1 wherein said oxidation-reduction catalyst comprises an oxide of copper supported on a refractory oxide carrier, and wherein said addition of air is controlled so as to provide a mole-ratio of O2/CO of between about 1/4 and 1/2 in at least a portion of said upstream zone.
Claim 6
Dependent Claim
170 words
In a process for the conversion of automotive exhaust gases containing substantially varying proportions of carbon monoxide and nitrogen oxides, and in which the O2/CO mole ratio is below about 1/4, wherein said exhaust gases are passed at temperatures above about 700* F through a contacting zone in contact with an oxidation-reduction catalyst comprising at least one easily reducible oxide of a multivalent metal selected from the class consisting of the Group IB, VB, VIB, VIIB and VIII metals, and wherein air is injected into the flow path of said gases at a plurality of points in said contacting zone thereby establishing a downstream zone in which net oxidizing conditions prevail and an upstream zone in which net reducing conditions prevail, the improvement which comprises injecting air into said upstream zone at a plurality of points along its length in incremental amounts insufficient to provide at any point therein an O2/CO ratio greater than 1/2, but sufficient to provide a generally ascending profile of O2/CO ratios along the length thereof.
Claim 7
Dependent Claim
42 words
A process as defined in claim 7 wherein said oxidation-reduction catalyst comprises an oxide of at least one metal selected from the class consisting of copper, silver, vanadium, chromium, manganese, iron, cobalt, nickel, palladium and platinum supported upon a refractory oxide carrier.
Claim 8
Dependent Claim
24 words
A process as defined in claim 7 wherein said oxidation-reduction catalyst comprises an oxide of copper or chromium supported on a refractory oxide carrier.
Claim 9
Dependent Claim
55 words
A process as defined in claim 7 wherein said oxidation-reduction catalyst comprises an oxide of copper supported on a refractory oxide carrier, and wherein said addition of air or oxygen is controlled so as to provide a mole-ratio of O2/CO of between about 1/4 and 1/2 in at least a portion of said reducing zone.
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) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |