Influence of hydrocarbon fuel structural constitution and flame temperature on soot formation in laminar diffusion flames

Journal Article · Wed Nov 01 04:00:00 EST 1989 · Combustion and Flame; (USA)

DOI:https://doi.org/10.1016/0010-2180(89)90124-7· OSTI ID:5297355

Gulder, O L ^[1]

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1. National Research Council of Canada, Ottawa, ON (Canada). Div. of Mechanical Engineering

A systematic study of soot formation along the centerlines of axisymmetric laminar diffusion flames of a large number of liquid hydrocarbons, hydrocarbon blends, and transportation fuels were made. Measurements of the attenuation of a laser beam across the flame diameter were used to obtain the soot volume fraction, assuming Rayleigh extinction. Two sets of hydrocarbon blends were designed such that the molecular fuel composition varied considerably but the temperature fields in the flames were kept practically constant. Thus it was possible to separate the effects of molecular structure and the flame temperature on soot formation. It was quantitatively shown that the smoke height is a lumped measure of fuel molecular constitution and hydrogen-to-carbon ratio. Hydrocarbon fuel molecular composition was characterized by six carbon atom types that can be obtained, for complex hydrocarbon mixtures like transportation fuels, from proton nuclear magnetic resonance (/sup 1/H NMR) measurements. Strong attenuation of the laser beam was observed at heights very close to the burner rim. Visible flame profiles along the flame length were shown to have good self-similarity. Kent's model for diffusion flames was modified to include the effects of differences in flame temperatures and molecular diffusivities between fuels. An analysis based on the present data provides an assessment of the degree of contribution of different carbon atom types to the maximum soot volume fractions.

• OSTI ID: 5297355
• Journal Information: Combustion and Flame; (USA), Journal Name: Combustion and Flame; (USA) Vol. 78:2; ISSN 0010-2180; ISSN CBFMA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
025000 -- Petroleum-- Combustion
09 BIOMASS FUELS
091000 -- Biomass Fuels-- Properties & Composition-- (1990-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
ALKENES
ATOMS
CARBON
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
DIFFUSION
ELEMENTS
FLAMES
FLUID FLOW
HYDROCARBONS
KINETICS
LAMINAR FLOW
LASERS
MAGNETIC RESONANCE
MOLECULAR STRUCTURE
NONMETALS
NUCLEAR MAGNETIC RESONANCE
ORGANIC COMPOUNDS
POLLUTION
REACTION KINETICS
RESONANCE
SOOT
TEMPERATURE EFFECTS