Steady-state NH3-SCR global model and kinetic parameter estimation for NOx removal in diesel engine exhaust aftertreatment with Cu over chabazite-type zeolite
A steady-state global kinetic model for the NOx NH3-SCR reaction system, including NH3 oxidation, NO oxidation, standard SCR reaction, fast SCR reaction, NO2 SCR reaction, and N2O formation and decomposition is proposed, based on the Eley-Rideal formalism in which only ammonia is adsorbed and NO rea...
| Autores: | , , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2017 |
| País: | España |
| Recursos: | Universidad del País Vasco |
| Repositorio: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:addi.ehu.eus:10810/72022 |
| Acesso em linha: | http://hdl.handle.net/10810/72022 |
| Access Level: | acceso abierto |
| Palavra-chave: | NH3-SCR NOx removal kinetic model parameter estimation Cu/CHA chabazite zeolite |
| Resumo: | A steady-state global kinetic model for the NOx NH3-SCR reaction system, including NH3 oxidation, NO oxidation, standard SCR reaction, fast SCR reaction, NO2 SCR reaction, and N2O formation and decomposition is proposed, based on the Eley-Rideal formalism in which only ammonia is adsorbed and NO reacts directly from the gas phase. The experimental runs were designed under operational conditions simulating NO, NH3, NO2 feed stream composition near to the real application for NOx removal from diesel engine automobile exhaust aftertreatment. An initial set of 62 experiments, with only NO2 and NH3 in the feed stream allows a preliminary estimation of some kinetic parameters. Additional extensive experimentation up to 176 runs under a wide range of feed stream composition, temperature and space time was carried out. The experimental outlet NO, NH3, NO2 and N2O concentrations are analyzed for kinetic parameter estimation of seven reactions included in the proposed global NOx NH3-SCR system, resulting in activation energy values for standard SCR reaction, fast SCR reaction and NO2 SCR reaction of 91.5, 42.0, and 118 kJ mol−1, respectively. The proposed model resulted of high statistical significance deduced from the analysis of variance, with a determination coefficient of 0.952, and excellent F-test for a probability superior to 99%. |
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