EP0107923A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process and apparatus for removing NOx and NH3 from gas streams
Assignee: BASF Catalysts LLC
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Filing: 1983-09-29
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Granted: —
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Expires: 2003-09-29
Abstract
Abstract Selective reduction of NOx with NH3 as well as decomposition of excess NH3 is provided over a wide temperature range by a platinum-gold catalyst.
Inventors
- 👤 Joseph C. Dettling
- 👤 William F. Carr
- 👤 Ronald M. Heck
- 👤 James M. Chen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 00:16
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9413; B01D53/9418; B01D2251/00; B01D2251/20; B01D2251/206; B01D2251/2062; B01D2255/00; B01D2255/10; B01D2255/102; B01D2255/1021; B01D2255/106; B01D2255/20; B01D2255/207; B01D2255/20723
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
122 words
A process for reducing oxides of nitrogen while maintaining an effluent free of ammonia in a gas stream containing at least about 0.8 moles of ammonia for each mole of NO present, at least 2 mole % of oxygen, comprising the step of passing the gas stream over a catalyst containing an amount of noble metal which is effective to catalyze the reduction of nitrogen oxides to nitrogen, wherein the noble metal consists essentially of from about .001 to about 5.0 percent platinum and from about .0005 to about 2.5 percent gold by weight of support and noble metal and the temperature of the gas stream is maintained within a range in which the noble metal catalyst is effective to decompose ammonia.
Claim 2
Dependent Claim
122 words
A process for reducing oxides of nitrogen while maintaining an effluent free of ammonia in a gas stream containing at least about 0.8 moles of ammonia for each mole of NO present, at least 2 mole % of oxygen, comprising the step of passing the gas stream over a catalyst containing an amount of noble metal which is effective to catalyze the reduction of nitrogen oxides to nitrogen, wherein the noble metal consists essentially of from about .001 to about 5.0 percent platinum and from about .0005 to about 2.5 percent gold by weight of support and noble metal and the temperature of the gas stream is maintained within a range in which the noble metal catalyst is effective to decompose ammonia.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein the weight ratio of platinum to gold is from about 20:1 to about 1:20.
Claim 4
Dependent Claim
26 words
The process of claim 1 wherein prior to passing the gas stream over the platinum-gold catalyst, the stream is passed over a vanadium oxide containing catalyst.
Claim 5
Dependent Claim
22 words
The process of claim 1 wherein the temperature of the stream is maintained within the range of from about 250°C to 500°C.
Claim 6
Independent Claim
75 words
An apparatus for reducing NO comprising a first catalyst region, including an effective amount of vanadium pentoxide for reducing NO x and a second catalyst region including gold and platinum, the gold being present in an amount of from about 80 to about 10 weight percent, the platinum being present in an amount of from about 20 to about 90 weight percent, both weight percents being based on the total weight of precious metal present.
Claim 7
Independent Claim
75 words
An apparatus for reducing NO comprising a first catalyst region, including an effective amount of vanadium pentoxide for reducing NO x and a second catalyst region including gold and platinum, the gold being present in an amount of from about 80 to about 10 weight percent, the platinum being present in an amount of from about 20 to about 90 weight percent, both weight percents being based on the total weight of precious metal present.
Claim 8
Dependent Claim
83 words
A process for decomposing ammonia in a gas stream comprising the step of passing the gas over a catalyst containing an amount of a noble metal which is effective to catalyze the decomposition of ammonia to nitrogen and hydrogen, wherein the noble metal consists essentially of from about .001 to about 5.0 percent platinum and from about .0015 to about 2.5 percent gold by weight of support and noble metal and the temperature of the gas stream is effective to preferentially decompose ammonia.
Claim 9
Dependent Claim
83 words
A process for decomposing ammonia in a gas stream comprising the step of passing the gas over a catalyst containing an amount of a noble metal which is effective to catalyze the decomposition of ammonia to nitrogen and hydrogen, wherein the noble metal consists essentially of from about .001 to about 5.0 percent platinum and from about .0015 to about 2.5 percent gold by weight of support and noble metal and the temperature of the gas stream is effective to preferentially decompose ammonia.
Claim 10
Dependent Claim
21 words
The process of claim 6 wherein the gas stream also contains at least 10 ppm of oxides of nitrogen by volume.
Claim 11
Dependent Claim
27 words
The process of claim 6 wherein the gas stream contains at least 10 ppm of oxides of nitrogen and is passed over a vanadium pentoxide- containing catalyst.
References Cited (Backward Citations)
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