A model of particulate and species formation applied to laminar, nonpremixed flames for three aliphatic-hydrocarbon fuels

Journal Article · Sat Mar 15 00:00:00 EDT 2008 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2007.08.003· OSTI ID:21030270

D'Anna, A ^[1]; Kent, J H ^[2]

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1. Dipartimento di Ingegneria Chimica, Universita ''Federico II,'' Naples (Italy)
2. School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney (Australia)

A detailed kinetic mechanism is developed that includes aromatic growth and particulate formation. The model includes reaction pathways leading to the formation of nanosized particles and their coagulation and growth to larger soot particles using a sectional approach for the particle phase. It is tested against literature data of species concentrations and particulate measurements in nonpremixed laminar flames of methane, ethylene, and butene. Reasonably good predictions of gas and particle-phase concentrations and particle sizes are obtained without any change to the kinetic scheme for the different fuels. The model predicts the low concentration of particulates in the methane flame (about 0.5 ppm) and the higher concentration of soot in the ethylene and butene flames (near 10 ppm). Model predictions show that in the methane flame small precursor particles dominate the particulate loading, whereas soot is the major component in ethylene and butene flames, in accordance with the experimental data. The driving factors in the model responsible for the quite different soot predictions in the ethylene and butene flames compared with the methane flame are benzene and acetylene concentrations, which are higher in the ethylene and butene flames. Soot loadings in the ethylene flame are sensitive to the acetylene soot growth reaction, whereas particle inception rates are linked to benzene in the model. A coagulation model is used to obtain collision efficiencies for some of the particle reactions, and tests show that the modeled results are not particularly sensitive to coagulation at the rates used in our model. Soot oxidation rates are not high enough to correctly predict burnout, and this aspect of the model needs further attention. (author)

• OSTI ID: 21030270
• Journal Information: Combustion and Flame, Vol. 152, Issue 4; Other Information: Elsevier Ltd. All rights reserved; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
03 NATURAL GAS
ETHYLENE
BUTENES
ACETYLENE
METHANE
LAMINAR FLAMES
PARTICULATES
SOOT
BENZENE
EXPERIMENTAL DATA
FORECASTING
PARTICLE SIZE
ABUNDANCE
NANOSTRUCTURES
OXIDATION
BURNOUT
DIFFUSION
SYNTHESIS
PRECURSOR
SIMULATION
COMBUSTION KINETICS
MATHEMATICAL MODELS
Nanoparticles modeling
Diffusion flames