The master thesis fits with the abatement of pollutants coming from gas exhausts of diesel engines. Two catalysts, the first fresh and the second which has been subjected to a process of thermal aging, have been tested in order to study the reactivity of unburned hydrocarbons, as propane and propylene, of carbon monoxide and of the reduction of nitrogen oxides. The analysis and the conclusions performed have been possible through the simultaneous use of a mass and infrared spectrometer and the chemiluminescence. The experiments have been carried out in the laboratory of ENSICAEN, university of Caen, France. Three experiments have been performed: "DOC test", "LO conditions test" e "LO severe conditions test". The first has been devoted to the isothermal (70°C and 150°C) adsorption of the reacting mixture, the closing of nitrogen oxides feeding and the successive decomposition through a ramp of a temperature controlled. The effect of aging and the use of only NO or of an equimolar mixture of NO and NO2 have been object of studies. The second and the third have been performed through the same operating procedure: isothermal (70°C) adsorption of the reacting mixture and the successive decomposition through a ramp of a temperature controlled. The severe conditions have been obtained through the use of a higher carbon monoxide concentration and the presence of toluene and decane. The effect of aging and the comparison between the "LO conditions" and the "LO severe conditions" have been object of studies.
Il presente lavoro di tesi si inserisce nell'ambito dell'abbattimento di sostanze inquinanti provenienti dai gas esausti dei motori diesel. Due catalizzatori, il primo fresco e il secondo che ha subito un trattamento di invecchiamento, sono stati testati per verificare la reattività di ossidazione di idrocarburi incombusti, quali propano e propilene, del monossido di carbonio e in maniera minore degli ossidi di azoto. Le analisi e le conclusioni effettuate sono state possibili grazie all'utilizzo simultaneo dello spettrometro di massa, dello spettrometro a infrarossi e la chemiluminescenza nei laboratori dell'università ENSICAEN a Caen, Francia. Tre esperimenti sono stati condotti "DOC test", "LO conditions test" e "LO severe conditions test". Il primo prevedeva l'adsorbimento in isoterma (70°C o 150°C) della miscela reagente, la chiusura dell'alimentazione degli ossidi di azoto e la successiva decomposizione data da una scalata di temperatura controllata. L'effetto dell'invecchiamento e l'uso di solo NO o di una miscela equi molare di NO e NO2 sono stati oggetto di studio e di approfondimento. Il secondo e il terzo consistevano della medesima procedura operativa: l'adsorbimento in isoterma (70°C) della miscela reagente e la successiva decomposizione data da una scalata di temperatura controllata. Le condizioni severe sono state ottenute attraverso l'utilizzo di una concentrazione di alimentazione maggiore di monossido di carbonio e della presenza di toluene e decano. L'effetto dell'invecchiamento e il confronto tra le "LO conditions" e le "LO severe conditions", sono stati oggetto di analisi.
Spectroscopic analysis of the reactivity of Diesel oxidation catalysts under operando conditions
MANFRA, EUGENIO
2014/2015
Abstract
The master thesis fits with the abatement of pollutants coming from gas exhausts of diesel engines. Two catalysts, the first fresh and the second which has been subjected to a process of thermal aging, have been tested in order to study the reactivity of unburned hydrocarbons, as propane and propylene, of carbon monoxide and of the reduction of nitrogen oxides. The analysis and the conclusions performed have been possible through the simultaneous use of a mass and infrared spectrometer and the chemiluminescence. The experiments have been carried out in the laboratory of ENSICAEN, university of Caen, France. Three experiments have been performed: "DOC test", "LO conditions test" e "LO severe conditions test". The first has been devoted to the isothermal (70°C and 150°C) adsorption of the reacting mixture, the closing of nitrogen oxides feeding and the successive decomposition through a ramp of a temperature controlled. The effect of aging and the use of only NO or of an equimolar mixture of NO and NO2 have been object of studies. The second and the third have been performed through the same operating procedure: isothermal (70°C) adsorption of the reacting mixture and the successive decomposition through a ramp of a temperature controlled. The severe conditions have been obtained through the use of a higher carbon monoxide concentration and the presence of toluene and decane. The effect of aging and the comparison between the "LO conditions" and the "LO severe conditions" have been object of studies.| File | Dimensione | Formato | |
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2015_15_Manfra.pdf
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Descrizione: Testo della tesi
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https://hdl.handle.net/10589/115422