US4267027A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for the preparation of nitrogen oxides
Assignee: Electricite de France SA
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Filing: 1980-03-18
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Granted: 1981-05-12
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Expires: 2000-03-18
Abstract
Abstract The present invention relates to a process for the preparation of nitrogen oxides (NO and NO 2 ) by the reaction of nitrogen and oxygen in a plasma furnace. According to this process, a plasma of oxygen and nitrogen is introduced into the reaction chamber of the plasma furnace, whereof the internal surface of the walls is covered with a catalyst chosen from tungsten trioxide (WO 3 ) and molybdenum trioxide (MoO 3 ).
Inventors
- 👤 Jacques Amouroux
- 👤 Demetre Rapakoulias
- 👤 Simeon Cavadias
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:42
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/20; C01B21/24; C01B21/30; C01B21/32
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
98 words
Process for the preparation of nitrogen oxides (NO and NO 2 ) by the reaction of nitrogen and oxygen in a plasma furnace of the type comprising a plasma torch, a reaction chamber and a quenching device, wherein an oxygen and nitrogen plasma is introduced into said reaction chamber, whereof the inner surface of the walls is covered with a catalyst of tungsten trioxide (WO 3 ) and/or molybdenum trioxide (MoO 3 ), and a mixture of gaseous reaction products rich in nitrogen oxides (NO and NO 2 ) is recovered from the region of the quenching device.
Claim 2
Dependent Claim
98 words
Process for the preparation of nitrogen oxides (NO and NO 2 ) by the reaction of nitrogen and oxygen in a plasma furnace of the type comprising a plasma torch, a reaction chamber and a quenching device, wherein an oxygen and nitrogen plasma is introduced into said reaction chamber, whereof the inner surface of the walls is covered with a catalyst of tungsten trioxide (WO 3 ) and/or molybdenum trioxide (MoO 3 ), and a mixture of gaseous reaction products rich in nitrogen oxides (NO and NO 2 ) is recovered from the region of the quenching device.
Claim 3
Dependent Claim
22 words
Process according to claim 1 wherein said catalyst is at least partially deposited on a refractory support having a high surface area.
Claim 4
Dependent Claim
26 words
Process according to claim 2 wherein the refractory support is selected from the group consisting of Al 2 O 3 , MgO and ZrO 2 .
Claim 5
Dependent Claim
31 words
Process according to claim 1 wherein the deposition of said catalyst on the walls of the reaction chamber is effected by combustion of tungsten and/or molybdenum in a plasma of oxygen.
Claim 6
Dependent Claim
31 words
Process according to claim 2 wherein said at least partial deposition of said catalyst on the refractory support is effected by combustion of tungsten and/or molybdenum in a plasma of oxygen.
Claim 7
Dependent Claim
25 words
Process according to claim 1, wherein the electronic temperature of the plasma of oxygen and nitrogen is of the order of 1 to 5 eV.
Claim 8
Dependent Claim
23 words
Process according to claim 1, wherein the vibrational temperature of the plasma of oxygen and nitrogen is of the order of 5000-12000 K.
Claim 9
Dependent Claim
23 words
Process according to claim 1, wherein the rotation/translation temperature of the plasma of oxygen and nitrogen is of the order of 1000-8000 K.
Claim 10
Dependent Claim
22 words
Process according to claim 1, wherein the temperature of the walls of the reaction chamber is of the order of 400-1500 K.
Claim 11
Dependent Claim
18 words
Process according to claim 1, wherein the temperature of the quenching device is kept close to ambient temperature.
Claim 12
Dependent Claim
22 words
Process according to claim 1, wherein the pressure prevailing in the reaction chamber is of the order of 10-760 mm of Mercury.
Claim 13
Dependent Claim
29 words
Process according to claim 1, wherein oxygen and nitrogen are separated from the gaseous reaction product, the separated oxygen and nitrogen are dried and are recycled to the furnace.
References Cited (Backward Citations)
AT41946B
Cited
US1266717A
Cited
US1134583A
Cited
CH141011A
Cited
CH269501A
Cited
FR1250764A
Cited
GB1149858A
Cited
US3666408A
Cited
FR2213232B3
Cited
US4073866A
Cited
US4141715A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-11 | 1984-11-10 | 1985-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-11 | 1988-11-10 | 1989-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-11 | 1992-11-10 | 1993-05-12 | $7700.00 | Window Closed / Lapsed |