Diagnostic for the characterization of nanometric structures in high temperature reactive systems

Commodo, Mario (2008) Diagnostic for the characterization of nanometric structures in high temperature reactive systems. [Tesi di dottorato] (Inedito)

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Abstract

It is now well know that the fraction of particulate mater in the ambient air defined as ultrafine particles can be considered the most critical for adverse human health effects because of their chemical composition and the ability of these particles to penetrate deeply into the respiratory tract. Moreover combustion has been recognised as the major source of harmful fine and ultrafine particles. The aim of the present thesis work is to investigate carbonaceous nanoparticles formation by combustion processes. An experimental procedure based on the use of the fifth harmonic of a Nd:YAG laser at 213 nm as exiting source and on an accurate signals acquisition has been realized. In-situ spectral optical measurements based on a combination of: Laser Induced Fluorescence (LIF), Laser Induced Incandescence (LII), Light Extinction (Kext) and Laser Light Scattering (Qvv) techniques have allowed to follow particles formation and their evolution directly in combustion environments with high spatial and temporal resolution. Laminar premixed and laminar and turbulent diffusion flames have been investigated burning ethylene, methane and benzene as fuels. Optical results are then compared with Particle Size Distribution Function (PSDF) obtained by Scanning Mobility Particles Sizer (SMPS) measurements in same flame conditions. An experimental investigation of the particulate emissions from commercial burners for home appliances fueled with natural gas has been also included. The experimental evidences, in according to literature in laminar premixed conditions, allow to conclude that two classes of nanoparticles are formed in flame:Nanoparticles of Organic Carbon (NOC) with sizes smaller than three nanometers and “primary” soot particles with sizes larger than ten nanometers that lead to the formation of soot aggregates. Moreover, the thesis work shows that these combustion-generated nanoparticles strongly depend on the type of fuel, type of combustion system and eventual exhaust treatment systems.

Tipologia di documento:Tesi di dottorato
Parole chiave:Nanoparticolato; Diagnostiche ottiche
Settori scientifico-disciplinari MIUR:Area 09 Ingegneria industriale e dell'informazione > ING-IND/25 IMPIANTI CHIMICI
Coordinatori della Scuola di dottorato:
Coordinatore del Corso di dottoratoe-mail (se nota)
Maffettone, Pier Luca
Tutor della Scuola di dottorato:
Tutor del Corso di dottoratoe-mail (se nota)
D'Alessio, Antonio
Stato del full text:Accessibile
Data:2008
Numero di pagine:122
Istituzione:Università degli Studi di Napoli Federico II
Dipartimento o Struttura:Ingegneria Chimica
Tipo di tesi:Dottorato
Stato dell'Eprint:Inedito
Denominazione del dottorato:Ingegneria Chimica
Ciclo di dottorato:XX
Numero di sistema:1850
Depositato il:21 Maggio 2008
Ultima modifica:04 Febbraio 2009 09:46

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