US3873675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalyst and catalyst arrangement for the production of nitric acid
Assignee: Evonik Operations GmbH
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Filing: 1973-10-09
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Granted: 1975-03-25
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Expires: 1993-10-09
Abstract
Abstract A catalyst for the oxidation of ammonia, especially in the form of finely meshed wire gauze, is employed which contains 40 to 75% palladium, 1 to 8% rhodium and/or ruthenium and the balance being platinum.
Inventors
- 👤 Hans Roters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:43
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/20; C01B21/24; C01B21/26; C01B21/265; B; B01; B01J; B01J23/00; B01J23/02; B01J23/04; B01J23/38; B01J23/40; B01J23/46
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
65 words
IN A PROCESS OF FORMING OXIDES OF NITROGEN BY THE GAS PHASE OXIDATION OF AMMONIA WITH AIR IN THE PRESENCE OF A PLATINUM CONTAINING CATALYST THE IMPROVEMENT COMPRISING EMPLOYING AS THE CATALYST A CATALYST CONSISTING ESSENTIALLY OF 55 TO 70 PERCENT PALLADIUM, 1 TO 6 PERCENT OF A MEMBER OF THE GROUP CONSISTING OF RHODIU AND RUTHENIUM AND MIXTURES THEREOF AND THE BALANCE BEING PATINUM.
Claim 2
Dependent Claim
65 words
IN A PROCESS OF FORMING OXIDES OF NITROGEN BY THE GAS PHASE OXIDATION OF AMMONIA WITH AIR IN THE PRESENCE OF A PLATINUM CONTAINING CATALYST THE IMPROVEMENT COMPRISING EMPLOYING AS THE CATALYST A CATALYST CONSISTING ESSENTIALLY OF 55 TO 70 PERCENT PALLADIUM, 1 TO 6 PERCENT OF A MEMBER OF THE GROUP CONSISTING OF RHODIU AND RUTHENIUM AND MIXTURES THEREOF AND THE BALANCE BEING PATINUM.
Claim 3
Dependent Claim
37 words
A process according to claim 1, wherein the oxidation is carried out in a reaction zone having a gas inlet and a gas outlet and the exiting gas is passed through a gauze packet of said catalyst.
Claim 4
Dependent Claim
35 words
A process according to claim 2, wherein the entering gases are passed through a gauze packet of a platinum alloy containing catalyst having a lower palladium content than the gauze packet at the gas outlet.
Claim 5
Dependent Claim
11 words
A process according to claim 1 wherein Said member is rhodium.
Claim 6
Dependent Claim
11 words
A process according to claim 1 wherein said member is ruthenium.
Claim 7
Dependent Claim
19 words
A process according to claim 3 wherein the gauze packet at the gas outlet side has 70 percent Pd.
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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |