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Modeling species inhibition of NO oxidation in urea-SCR catalysts for diesel engine NOx control / Maruthi Devarakonda in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 9 (Septembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 9 (Septembre 2011) . - 06 p. Titre : Modeling species inhibition of NO oxidation in urea-SCR catalysts for diesel engine NOx control Type de document : texte imprimé Auteurs : Maruthi Devarakonda, Auteur ; Russell Tonkyn, Auteur ; Diana Tran, Auteur Année de publication : 2012 Article en page(s) : 06 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Catalysts  Diesel  engines  Nitrogen  compounds  Pyrolysis Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Urea-selective catalytic reduction (SCR) catalysts are regarded as the leading NOx aftertreatment technology to meet the 2010 NOx emission standards for on-highway vehicles running on heavy duty diesel engines. However, issues such as low NOx conversion at low temperature conditions still exist due to various factors, including incomplete urea thermolysis, inhibition of SCR reactions by hydrocarbons, and H2O. We have observed a noticeable reduction in the standard SCR reaction efficiency at low temperature with increasing water content. We observed a similar effect when hydrocarbons are present in the stream. This effect is absent under fast SCR conditions where NO~NO2 in the feed gas. As a first step in understanding the effects of such inhibition on SCR reaction steps, kinetic models that predict the inhibition behavior of H2O and hydrocarbons on NO oxidation are presented in the paper. A one-dimensional SCR model was developed based on the conservation of species equations and was coded as a C-language S-function and implemented in MATLAB/SIMULINK environment. NO oxidation and NO2 dissociation kinetics were defined as a function of the respective adsorbate's storage in the Fe–zeolite SCR catalyst. The corresponding kinetic models were then validated on temperature ramp tests that showed good match with the test data. Such inhibition models will improve the accuracy of the model based control design for integrated diesel particulate filter-SCR aftertreatment systems. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Modeling species inhibition of NO oxidation in urea-SCR catalysts for diesel engine NOx control [texte imprimé] / Maruthi Devarakonda, Auteur ; Russell Tonkyn, Auteur ; Diana Tran, Auteur . - 2012 . - 06 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 9 (Septembre 2011) . - 06 p. Mots-clés : Catalysts  Diesel  engines  Nitrogen  compounds  Pyrolysis Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Urea-selective catalytic reduction (SCR) catalysts are regarded as the leading NOx aftertreatment technology to meet the 2010 NOx emission standards for on-highway vehicles running on heavy duty diesel engines. However, issues such as low NOx conversion at low temperature conditions still exist due to various factors, including incomplete urea thermolysis, inhibition of SCR reactions by hydrocarbons, and H2O. We have observed a noticeable reduction in the standard SCR reaction efficiency at low temperature with increasing water content. We observed a similar effect when hydrocarbons are present in the stream. This effect is absent under fast SCR conditions where NO~NO2 in the feed gas. As a first step in understanding the effects of such inhibition on SCR reaction steps, kinetic models that predict the inhibition behavior of H2O and hydrocarbons on NO oxidation are presented in the paper. A one-dimensional SCR model was developed based on the conservation of species equations and was coded as a C-language S-function and implemented in MATLAB/SIMULINK environment. NO oxidation and NO2 dissociation kinetics were defined as a function of the respective adsorbate's storage in the Fe–zeolite SCR catalyst. The corresponding kinetic models were then validated on temperature ramp tests that showed good match with the test data. Such inhibition models will improve the accuracy of the model based control design for integrated diesel particulate filter-SCR aftertreatment systems. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]