Evolution of soot size distribution in premixed ethylene/air and ethylene/benzene/air flames: Experimental and modeling study

Journal Article · Sat Jan 15 00:00:00 EST 2011 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2010.07.021· OSTI ID:21396162

Echavarria, Carlos A; Sarofim, Adel F; Lighty, JoAnn S ^[1]; D'Anna, Andrea ^[2]

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1. Department of Chemical Engineering, University of Utah, Salt Lake City, UT (United States)
2. Dipartimento di Ingegneria Chimica, Universita ''Federico II'' di Napoli, Naples (Italy)

The effect of benzene concentration in the initial fuel on the evolution of soot size distribution in ethylene/air and ethylene/benzene/air flat flames was characterized by experimental measurements and model predictions of size and number concentration within the flames. Experimentally, a scanning mobility particle sizer was used to allow spatially resolved and online measurements of particle concentration and sizes in the nanometer-size range. The model couples a detailed kinetic scheme with a discrete-sectional approach to follow the transition from gas-phase to nascent particles and their coagulation to larger soot particles. The evolution of soot size distribution (experimental and modeled) in pure ethylene and ethylene flames doped with benzene showed a typical nucleation-sized (since particles do not actually nucleate in the classical sense particle inception is often used in place of nucleation) mode close to the burner surface, and a bimodal behavior at greater height above burner (HAB). However, major features were distinguished between the data sets. The growth of nucleation and agglomeration-sized particles was faster for ethylene/benzene/air flames, evidenced by the earlier presence of bimodality in these flames. The most significant changes in size distribution were attributed to an increase in benzene concentration in the initial fuel. However, these changes were more evident for high temperature flames. In agreement with the experimental data, the model also predicted the decrease of nucleation-sized particles in the postflame region for ethylene flames doped with benzene. This behavior was associated with the decrease of soot precursors after the main oxidation zone of the flames. (author)

• OSTI ID: 21396162
• Journal Information: Combustion and Flame, Vol. 158, Issue 1; 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
ETHYLENE
BENZENE
AIR
SOOT
FLAMES
DISTRIBUTION
ABUNDANCE
EXPERIMENTAL DATA
NUCLEATION
TIME DEPENDENCE
TEMPERATURE RANGE 1000-4000 K
SIMULATION
PARTICLE SIZE
AGGLOMERATION
FUELS
OXIDATION
PRECURSOR
ZONES
Soot size distribution
Particle nucleation
Agglomeration modeling