Abstract
The fast SCR reaction using equimolar amounts of NO and NO{sub 2} is a powerful means to enhance the NO{sub x} conversion over a given SCR catalyst. NO{sub 2} fractions in excess of 50% of total NO{sub x} should be avoided because the reaction with NO{sub 2} only is slower than the standard SCR reaction. At temperatures below 200C, due to its negative temperature coefficient, the ammonium nitrate reaction gets increasingly important. Half of each NH{sub 3} and NO{sub 2} react to form dinitrogen and water in analogy to a typical SCR reaction. The other half of NH{sub 3} and NO{sub 2} form ammonium nitrate in close analogy to a NO{sub x} storage-reduction catalyst. Ammonium nitrate tends to deposit in solid or liquid form in the pores of the catalyst and this will lead to its temporary deactivation.The various reactions have been studied experimentally in the temperature range 150-450C for various NO{sub 2}/NO{sub x} ratios. The fate of the deposited ammonium nitrate during a later reheating of the catalyst has also been investigated. In the absence of NO, the thermal decomposition yields mainly ammonia and nitric acid. If NO is present, its reaction with nitric acid on the catalyst will
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Koebel, Manfred;
Madia, Giuseppe;
Elsener, Martin
[1]
- Paul Scherrer Institute, CH-5232 PSI Villigen (Switzerland)
Citation Formats
Koebel, Manfred, Madia, Giuseppe, and Elsener, Martin.
Selective catalytic reduction of NO and NO{sub 2} at low temperatures.
Netherlands: N. p.,
2002.
Web.
doi:10.1016/S0920-5861(02)00006-8.
Koebel, Manfred, Madia, Giuseppe, & Elsener, Martin.
Selective catalytic reduction of NO and NO{sub 2} at low temperatures.
Netherlands.
https://doi.org/10.1016/S0920-5861(02)00006-8
Koebel, Manfred, Madia, Giuseppe, and Elsener, Martin.
2002.
"Selective catalytic reduction of NO and NO{sub 2} at low temperatures."
Netherlands.
https://doi.org/10.1016/S0920-5861(02)00006-8.
@misc{etde_20250439,
title = {Selective catalytic reduction of NO and NO{sub 2} at low temperatures}
author = {Koebel, Manfred, Madia, Giuseppe, and Elsener, Martin}
abstractNote = {The fast SCR reaction using equimolar amounts of NO and NO{sub 2} is a powerful means to enhance the NO{sub x} conversion over a given SCR catalyst. NO{sub 2} fractions in excess of 50% of total NO{sub x} should be avoided because the reaction with NO{sub 2} only is slower than the standard SCR reaction. At temperatures below 200C, due to its negative temperature coefficient, the ammonium nitrate reaction gets increasingly important. Half of each NH{sub 3} and NO{sub 2} react to form dinitrogen and water in analogy to a typical SCR reaction. The other half of NH{sub 3} and NO{sub 2} form ammonium nitrate in close analogy to a NO{sub x} storage-reduction catalyst. Ammonium nitrate tends to deposit in solid or liquid form in the pores of the catalyst and this will lead to its temporary deactivation.The various reactions have been studied experimentally in the temperature range 150-450C for various NO{sub 2}/NO{sub x} ratios. The fate of the deposited ammonium nitrate during a later reheating of the catalyst has also been investigated. In the absence of NO, the thermal decomposition yields mainly ammonia and nitric acid. If NO is present, its reaction with nitric acid on the catalyst will cause the formation of NO{sub 2}.}
doi = {10.1016/S0920-5861(02)00006-8}
journal = []
issue = {3-4}
volume = {73}
journal type = {AC}
place = {Netherlands}
year = {2002}
month = {Apr}
}
title = {Selective catalytic reduction of NO and NO{sub 2} at low temperatures}
author = {Koebel, Manfred, Madia, Giuseppe, and Elsener, Martin}
abstractNote = {The fast SCR reaction using equimolar amounts of NO and NO{sub 2} is a powerful means to enhance the NO{sub x} conversion over a given SCR catalyst. NO{sub 2} fractions in excess of 50% of total NO{sub x} should be avoided because the reaction with NO{sub 2} only is slower than the standard SCR reaction. At temperatures below 200C, due to its negative temperature coefficient, the ammonium nitrate reaction gets increasingly important. Half of each NH{sub 3} and NO{sub 2} react to form dinitrogen and water in analogy to a typical SCR reaction. The other half of NH{sub 3} and NO{sub 2} form ammonium nitrate in close analogy to a NO{sub x} storage-reduction catalyst. Ammonium nitrate tends to deposit in solid or liquid form in the pores of the catalyst and this will lead to its temporary deactivation.The various reactions have been studied experimentally in the temperature range 150-450C for various NO{sub 2}/NO{sub x} ratios. The fate of the deposited ammonium nitrate during a later reheating of the catalyst has also been investigated. In the absence of NO, the thermal decomposition yields mainly ammonia and nitric acid. If NO is present, its reaction with nitric acid on the catalyst will cause the formation of NO{sub 2}.}
doi = {10.1016/S0920-5861(02)00006-8}
journal = []
issue = {3-4}
volume = {73}
journal type = {AC}
place = {Netherlands}
year = {2002}
month = {Apr}
}