Patent US3907975A successfully refreshed from Google Patents.
US3907975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalytic oxidation of ammonia
Assignee: Azote et Produits Chimiques SA
•
Filing: 1973-04-11
•
Granted: 1975-09-23
•
Expires: 1993-04-11
Abstract
Abstract This invention relates to the catalytic oxidation of ammonia. The catalytic compounds are complex catalysts with limited porosities, with specific surface areas between 0.02 and 2 m2/g, containing an active material bonded by ceramic-type bonds to the elements of a refractory carrier made of refractory oxides such as magnesia, zirconia, silica. Such compounds are suitable for the oxidation of ammonia over fixed beds or fluidized beds.
Inventors
- 👤 Michel Senes
- 👤 Pierre Lhonore
- 👤 Michel Pottier
- 👤 Jacques Quibel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:36
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/38; B01J23/40; B01J23/42; B01J23/70; B01J23/76; B01J23/84; B01J23/847; B01J23/8472; B01J23/89; C; C01; C01B; C01B21/00; C01B21/20; C01B21/24; C01B21/26; C01B21/265; B01J31/00; B01J31/16
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
113 words
IN A METHOD FOR THE CATALYTIC OXIDATION OF AMMONIA COMPRISING PASSING A MIXTURE OF AMMONIA AND AIR OVER A CATALYST UNDER AMMONIA OXIDATION CONDITIONS, THE IMPROVEMENT WHEREIN SAID CATALYST COMPRISES: A COMPOSITION, CONTAINING NO MEMBERS OF THE PLATINUM GROUP, WITH LIMITED POROSITY, WITH SPECIFIC SURFACE AREA BETWEEN 0.02 AND 2M2/G, WHEREIN SAID COMPOSITION CONSISTS ESSENTIALLY OF METALLIC OXIDES CONSISTING OF IRON OXIDE, VANADIUM OXIDE AND AT LEAST ONE FURTHER METALLIC OXIDE, SELECTED FROM THE GROUP CONSISTING OF OXIDES OF NICKEL, COBALT, AND BISMUTH, AND A REFRACTORY MATERIAL CONSISTING OF MAGNESIA, SILICA, ZIRCONIA OR A MIXTURE THEREOF, ALL COMBINED BY MIXING THE POWDERED CONSTITUENTS, COMPRESSING AT 1,000-10,000 BARS AND SINTERING AT 1300*C OR HIGHER.
Claim 2
Dependent Claim
113 words
IN A METHOD FOR THE CATALYTIC OXIDATION OF AMMONIA COMPRISING PASSING A MIXTURE OF AMMONIA AND AIR OVER A CATALYST UNDER AMMONIA OXIDATION CONDITIONS, THE IMPROVEMENT WHEREIN SAID CATALYST COMPRISES: A COMPOSITION, CONTAINING NO MEMBERS OF THE PLATINUM GROUP, WITH LIMITED POROSITY, WITH SPECIFIC SURFACE AREA BETWEEN 0.02 AND 2M2/G, WHEREIN SAID COMPOSITION CONSISTS ESSENTIALLY OF METALLIC OXIDES CONSISTING OF IRON OXIDE, VANADIUM OXIDE AND AT LEAST ONE FURTHER METALLIC OXIDE, SELECTED FROM THE GROUP CONSISTING OF OXIDES OF NICKEL, COBALT, AND BISMUTH, AND A REFRACTORY MATERIAL CONSISTING OF MAGNESIA, SILICA, ZIRCONIA OR A MIXTURE THEREOF, ALL COMBINED BY MIXING THE POWDERED CONSTITUENTS, COMPRESSING AT 1,000-10,000 BARS AND SINTERING AT 1300*C OR HIGHER.
Claim 3
Dependent Claim
42 words
A method in accordance with claim 1 wherein said conditions comprise a flow rate of ammonia and air between 10,000 and 500, 000 Nl/h. per liter catalyst under pressures lying between 1 bar and 60 bars, with an inlet temperature around 150*C.
Claim 4
Dependent Claim
22 words
A method in accordance with claim 1 in which the mixture of ammonia and air contains 5 to 14% ammonia by volume.
Claim 5
Dependent Claim
18 words
A method in accordance with claim 1 in which the mixture is ammonia and air enriched with oxygen.
Claim 6
Dependent Claim
60 words
A method in accordance with claim 1, wherein the contents by weight of said metallic oxides, when present in said composition, are from 0.5 to 20% for Fe3O4, from 9 to 80% for Fe2O3, from 4 to 20% for NiO, from 4 to 20% for CoO, from 0.5 to 10% for V2O5 and from 4 to 20% for bismuth oxide.
Claim 7
Dependent Claim
27 words
A method in accordance with claim 1 wherein the contents by weight of said refractory material in said compound are 10-60% MgO, 0.2-10% SiO2 and 5-50% ZrO2.
Claim 8
Dependent Claim
120 words
In a method for the catalytic oxidation of ammonia in a fluidized bed comprising introducing a mixture of ammonia and air into a fluidized bed of catalyst under ammonia oxidation conditions, the improvement wherein said catalyst comprises: a composition, containing no members of the platinum group, with limited porosity, with specific surface area between 0.02 and 2m2/g, wherein said composition consists essentially of metallic oxides consisting of iron oxide, vanadium oxide and at least one further metallic oxide selected from the group consisting of oxides of nickel, cobalt, and bismuth, and a refractory material consisting of magnesia, silica, zirconia or a mixture thereof, all combined by Mixing the powdered constituents, compressing at 1,000-10,000 bars and sintering at 1300*C or higher.
Claim 9
Dependent Claim
120 words
In a method for the catalytic oxidation of ammonia in a fluidized bed comprising introducing a mixture of ammonia and air into a fluidized bed of catalyst under ammonia oxidation conditions, the improvement wherein said catalyst comprises: a composition, containing no members of the platinum group, with limited porosity, with specific surface area between 0.02 and 2m2/g, wherein said composition consists essentially of metallic oxides consisting of iron oxide, vanadium oxide and at least one further metallic oxide selected from the group consisting of oxides of nickel, cobalt, and bismuth, and a refractory material consisting of magnesia, silica, zirconia or a mixture thereof, all combined by Mixing the powdered constituents, compressing at 1,000-10,000 bars and sintering at 1300*C or higher.
Claim 10
Dependent Claim
42 words
A method in accordance with claim 7, wherein said conditions comprise a flow rate of ammonia and air between 3, 500 and 20,000 Nl/h per liter catalyst, under pressure lying between 1 and 60 bars and at temperatures between 500* and 800*C.
Claim 11
Dependent Claim
22 words
A method in accordance with claim 7 in which the mixture of ammonia and air contains 5 to 14% ammonia by volume.
Claim 12
Dependent Claim
18 words
A method in accordance with claim 7 in which the mixture is ammonia and air enriched with oxygen.
Claim 13
Dependent Claim
60 words
A method in accordance with claim 7 wherein the contents by weight of said metallic oxides, when present in said composition, are from 0.5 to 20% for Fe3O4, from 9 to 80% for Fe2O3, from 4 to 20% from NiO, from 4 to 20% for CoO, from 0.5 to 10% for V2O5, and from 4 to 20% for bismuth oxide.
Claim 14
Dependent Claim
27 words
A method in accordance with claim 7 wherein the contents by weight of said refractory material in said compound are 10-60% MgO, 0.2-10% SiO2 and 5-50% ZrO2.
References Cited (Backward Citations)
US1322291A
Cited
US1558598A
Cited
US1345323A
Cited
US1765352A
Cited
US1919216A
Cited
US3533963A
Cited
US3666412A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |