US5116586A
Expired / Lapsed
US
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Method for the reduction of nitrogen oxides from waste gases using a zeolite
Assignee: Evonik Operations GmbH
•
Filing: 1989-12-14
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Granted: 1992-05-26
•
Expires: 2009-12-14
Abstract
Abstract A zeolite catalyst and a method for reduction of nitrogen oxides present in waste gas streams is described. The method includes mixing the waste gas containing nitrogen oxides with ammonia. At an elevated temperature, this mixture is passed over a zeolite catalyst. Preferably, the zeolite catalyst is in a monolithic or honeycomb form. The zeolite catalyst includes one or more of the following subgroup metals: copper, iron, molybdeum and cerium. The zeolite catalysts made in accordance with this invention show better conversion of nitrogen oxides and longer life than known catalysts.
Inventors
- 👤 Michael Baacke
- 👤 Reinhold Beand
- 👤 Bernd Engler
- 👤 Akos Kiss
- 👤 Peter Kleine-Mollhoff
- 👤 Peter Kleinschmit
- 👤 Edgar Koberstein
- 👤 Mustafa Siray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:38
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/54; B01D53/56; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/18; B01J29/26; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9413; B01D53/9418; B01J29/20; B01J29/24; B01D2251/00; B01D2251/20; B01D2251/206; B01D2251/2062; B01D2255/00; B01D2255/20; B01D2255/206; B01D2255/2065; B01D2255/207; B01D2255/20738; B01D2255/20761; B01D2255/20769; B01D2255/50
Claims Analysis
Total Claims: 60
Claim 1
Independent Claim
91 words
A method for the reduction of oxides of nitrogen present in waste gases containing oxygen, comprising mixing the waste gases containing nitrogen oxides with ammonia gas and passing said mixture at a temperature in the range of from 200°-600° C. with a space velocity of 1,000- 60,000 h -1 corresponding to a catalyst area velocity of 0.5-100 m 3 /h·m 2 at standard temperature and pressure over a mordenite type zeolite catalyst including 0.2-5.2% by weight copper, 0.1-4.5% by weight iron and 0.1-1.0% by weight cerium relative to the zeolite weight.
Claim 2
Independent Claim
91 words
A method for the reduction of oxides of nitrogen present in waste gases containing oxygen, comprising mixing the waste gases containing nitrogen oxides with ammonia gas and passing said mixture at a temperature in the range of from 200°-600° C. with a space velocity of 1,000- 60,000 h -1 corresponding to a catalyst area velocity of 0.5-100 m 3 /h·m 2 at standard temperature and pressure over a mordenite type zeolite catalyst including 0.2-5.2% by weight copper, 0.1-4.5% by weight iron and 0.1-1.0% by weight cerium relative to the zeolite weight.
Claim 3
Dependent Claim
25 words
The method according to claim 1, wherein the mordenite type zeolite exhibits a SiO 2 :Al 2 O 3 molar ratio of more than 8.
Claim 4
Dependent Claim
28 words
The method according to claim 1, wherein the catalyst is used as a surface coating on a chemically inert, formed carrier constructed from a ceramic or a metal.
Claim 5
Dependent Claim
21 words
The method according to claim 3, wherein said carrier is in a monolithic form, a honeycomb form, or a bulk form.
Claim 6
Dependent Claim
16 words
The method according to claim 1, wherein said temperature is in the range of 250°-550° C.
Claim 7
Dependent Claim
31 words
The method according to claim 1, wherein said space velocities are in the range of 2,000-40,000 h -1 , corresponding to a catalyst-area velocity of 1-70 m 3 /h·m 2 .
Claim 8
Dependent Claim
21 words
The method according to claim 1, wherein the molar ration between nitrogen oxide and ammonia is in the range of 0.6-1.6.
Claim 9
Dependent Claim
22 words
The method according to claim 1, wherein an oxygen component of at least 0.1% by volume is present in the waste gas.
Claim 10
Dependent Claim
26 words
The method according to claim 1, wherein the mordenite type zeolite exhibits a SiO 2 :Al 2 O 3 molar ratio in the range of 10-30.
Claim 11
Dependent Claim
26 words
The method according to claim 1, wherein the mordenite type zeolite exhibits a SiO 2 :Al 2 O 3 molar ratio in the range of 15-25.
Claim 12
Dependent Claim
32 words
The method according to claim 1, wherein the catalyst is formed with a binder, said catalyst is used as a form body in monolithic form, a honeycomb form, or a bulk form.
Claim 13
Dependent Claim
16 words
The method according to claim 1, wherein said temperature is in the range of 280°-500° C.
Claim 14
Dependent Claim
16 words
The method according to claim 1, wherein said temperature is in the range of 300°-480° C.
Claim 15
Dependent Claim
31 words
The method according to claim 1, wherein said space velocities are in the range of 3,000-20,000 h -1 , corresponding to a catalyst-area velocity of 3-45 m 3 /h·m 2 .
Claim 16
Dependent Claim
31 words
The method according to claim 1, wherein said space velocities are in the range of 5,000-10,000 h -1 , corresponding to a catalyst-area velocity of 5-15 m 3 /h·m 2 .
Claim 17
Dependent Claim
21 words
The method according to claim 1, wherein the molar ratio between nitrogen oxide and ammonia is in the range of 0.7-1.1.
Claim 18
Dependent Claim
21 words
The method according to claim 1, wherein the molar ratio between nitrogen oxide and ammonia is in the range of 0.8-1.0.
Claim 19
Dependent Claim
22 words
The method according to claim 1, wherein an oxygen component of at least 0.5% by volume is present in the waste gas.
Claim 20
Dependent Claim
22 words
The method according to claim 1, wherein an oxygen component of at least 1.0% by volume is present in the waste gas.
Claim 21
Independent Claim
90 words
A method for the reduction of oxides of nitrogen present in waste gases containing oxygen, comprising mixing the waste gases containing nitrogen oxides with ammonia gas and passing said mixture at a temperature in the range of from 200°-600° C. with a space velocity of 1,000-60,000 h -1 corresponding to a catalyst area velocity of 0.5-100 m 3 /h·m 2 at standard temperature and pressure over a mordenite type zeolite catalyst including 0.2-5.2% by weight copper, 0.1-4.5% by weight iron and 0.2-2.5% by weight molybdenum, relative to the zeolite weight.
Claim 22
Independent Claim
90 words
A method for the reduction of oxides of nitrogen present in waste gases containing oxygen, comprising mixing the waste gases containing nitrogen oxides with ammonia gas and passing said mixture at a temperature in the range of from 200°-600° C. with a space velocity of 1,000-60,000 h -1 corresponding to a catalyst area velocity of 0.5-100 m 3 /h·m 2 at standard temperature and pressure over a mordenite type zeolite catalyst including 0.2-5.2% by weight copper, 0.1-4.5% by weight iron and 0.2-2.5% by weight molybdenum, relative to the zeolite weight.
Claim 23
Dependent Claim
25 words
The method according to claim 20, wherein the mordenite type zeolite exhibits a SiO 2 :Al 2 O 3 molar ratio of more than 8.
Claim 24
Dependent Claim
28 words
The method according to claim 20, wherein the catalyst is used as a surface coating on a chemically inert, formed carrier constructed from a ceramic or a metal.
Claim 25
Dependent Claim
16 words
The method according to claim 20, wherein the temperature is in the range of 250°-550° C.
Claim 26
Dependent Claim
31 words
The method according to claim 20, wherein the space velocities are in the range of 2,000-40,000 h -1 , corresponding to a catalyst-area velocity of 1-70 m 3 /h·m 2 .
Claim 27
Dependent Claim
21 words
The method according to claim 20, wherein the molar ratio between nitrogen oxide and ammonia is in the range of 0.6-1.6.
Claim 28
Dependent Claim
20 words
The method according to claim 20, wherein the oxygen component of at least 0.1% by volume is presently waste gas.
Claim 29
Dependent Claim
26 words
The method according to claim 20, wherein the mordenite type zeolite exhibits a SiO 2 :Al 2 O 3 molar ration in the range of 10-30.
Claim 30
Dependent Claim
26 words
The method according to claim 20, wherein the mordenite type zeolite exhibits a SiO 2 :Al 2 O 3 molar ration in the range of 15-25.
Claim 31
Dependent Claim
21 words
The method according to claim 22, wherein said carrier is in a monolithic form, a honeycomb form, or a bulk form.
Claim 32
Dependent Claim
32 words
The method according to claim 20, wherein the catalyst is formed with a binder, said catalyst is used as a form body in monolithic form, a honeycomb form, or a bulk form.
Claim 33
Dependent Claim
16 words
The method according to claim 20, wherein said temperature is in the range of 280°-500° C.
Claim 34
Dependent Claim
16 words
The method according to claim 20, wherein said temperature is in the range of 300°-480° C.
Claim 35
Dependent Claim
31 words
The method according to claim 20, wherein said space velocities are in the range of 3,000-20,000 h -1 , corresponding to a catalyst-area velocity of 3-45 m 3 /h·m 2 .
Claim 36
Dependent Claim
32 words
The method according to claim 20, wherein said space velocities are in the range of 5,000-10,000 h -1 , corresponding to a catalyst surface load of 5-15 m 3 /h·m 2 .
Claim 37
Dependent Claim
21 words
The method according to claim 20, wherein the molar ratio between nitrogen oxide and ammonia is in the range of 0.7-1.1.
Claim 38
Dependent Claim
21 words
The method according to claim 20, wherein the molar ration between nitrogen oxide and ammonia is in the range of 0.8-1.0.
Claim 39
Dependent Claim
22 words
The method according to claim 20, wherein an oxygen component of at least 0.5% by volume is present in the waste gas.
Claim 40
Dependent Claim
22 words
The method according to claim 20, wherein an oxygen component of at least 1.0% by volume is present in the waste gas.
Claim 41
Independent Claim
88 words
A method for the reduction of oxides of nitrogen present in waste gases containing oxygen, comprising mixing the waste gases containing nitrogen oxides with ammonia gas and passing said mixture at a temperature in the range of from 200° -600° C. with a space velocity of 1,000-60,000 h -1 corresponding to a catalyst area velocity of 0.5-100 m 3 /h·m 2 at standard temperature and pressure over a mordenite type zeolite catalyst including b 0.2-5.2% by weight copper and 0.2-2.5% by weight molybdenum, relative to the zeolite weight.
Claim 42
Independent Claim
88 words
A method for the reduction of oxides of nitrogen present in waste gases containing oxygen, comprising mixing the waste gases containing nitrogen oxides with ammonia gas and passing said mixture at a temperature in the range of from 200° -600° C. with a space velocity of 1,000-60,000 h -1 corresponding to a catalyst area velocity of 0.5-100 m 3 /h·m 2 at standard temperature and pressure over a mordenite type zeolite catalyst including b 0.2-5.2% by weight copper and 0.2-2.5% by weight molybdenum, relative to the zeolite weight.
Claim 43
Dependent Claim
25 words
The method according to claim 39, wherein the mordenite type zeolite exhibits a SiO 2 :Al 2 O 3 molar ration of more than 8.
Claim 44
Dependent Claim
28 words
The method according to claim 39, wherein the catalyst is used as a surface coating on a chemically inert, formed carrier constructed from a ceramic or a metal.
Claim 45
Dependent Claim
16 words
The method according to claim 39, wherein said temperature is in the range of 250°-550° C.
Claim 46
Dependent Claim
31 words
The method according to claim 39, wherein said space velocities are in the range of 2,000-40,000 h -1 , corresponding to a catalyst-area velocity of 1-70 m 3 /h·m 2 .
Claim 47
Dependent Claim
21 words
The method according to claim 39, wherein the molar ratio between nitrogen oxide and ammonia is in the range of 0.6-1.6.
Claim 48
Dependent Claim
22 words
The method according to claim 39, wherein an oxygen component of at least 0.1% by volume is present in the waste gas.
Claim 49
Dependent Claim
26 words
The method according to claim 39, wherein the mordenite type zeolite exhibits a SiO 2 :Al 2 O 3 molar ration in the range of 10-30.
Claim 50
Dependent Claim
26 words
The method according to claim 39, wherein the mordenite type zeolite exhibits a SiO 2 :Al 2 O 3 molar ration in the range of 15-25.
Claim 51
Dependent Claim
21 words
The method according to claim 41, wherein said carrier is in a monolithic form, a honeycomb form, or a bulk form.
Claim 52
Dependent Claim
32 words
The method according to claim 39, wherein the catalyst is formed with a binder, said catalyst is used as a form body in monolithic form, a honeycomb form, or a bulk form.
Claim 53
Dependent Claim
16 words
The method according to claim 39, wherein said temperature is in the range of 280°-500° C.
Claim 54
Dependent Claim
16 words
The method according to claim 39, wherein said temperature is in the range of 300°-480° C.
Claim 55
Dependent Claim
31 words
The method according to claim 39, wherein said space velocities are in the range of 3,000-20,000 h -1 , corresponding to a catalyst-area velocity of 3-45 m 3 /·m 2 .
Claim 56
Dependent Claim
32 words
The method according to claim 39, wherein said space velocities are in the range of 5,000-10,000 h -1 , corresponding to a catalyst surface load of 5-15 m 3 /h·m 2 .
Claim 57
Dependent Claim
21 words
The method according to claim 39, wherein the molar ration between nitrogen oxide and ammonia is in the range of 0.7-1.1.
Claim 58
Dependent Claim
21 words
The method according to claim 39, wherein the molar ratio between nitrogen oxide and ammonia is in the range of 0.8-1.0.
Claim 59
Dependent Claim
22 words
The method according to claim 39, wherein an oxygen component of at least 0.5% by volume is present in the waste gas.
Claim 60
Dependent Claim
22 words
The method according to claim 39, wherein an oxygen component of at least 1.0% by volume is present in the waste gas.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-05-26 | 1995-11-25 | 1996-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-26 | 1999-11-25 | 2000-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-26 | 2003-11-25 | 2004-05-26 | $7700.00 | Window Closed / Lapsed |