Detailed Modeling and Analysis of Aromatic Additive Effects in Ethylene-Air Flames.
Detailed Modeling and Analysis of Aromatic Additive
Effects in Ethylene-Air Flames.
(257 K)
Stroud, C. B.; Tsang, W.; Manzello, S. L.
Paper F06;
Combustion Institute/Western States. Fifth (5th) Joint
Meeting of the U.S. Sections. Meeting Theme:
Fundamentals of Combustion, Air Pollution and Global
Warming, Alternative Fuels. Hosted by The University of
California. March 25-28, 2007, San Diego, CA, 1-9 pp,
2007.
Keywords:
combustion; soot; ethylene-air flames; aromatic
intermidiates; combustion chemistry; aromatics; vapor
phases; gas chromatography; additives; benzene;
ethylbenzene; residence time; molecular weight;
polycyclic aromatic hydrocarbons; fuel additives;
experiments; argon; injection; probes
Abstract:
Ethylene-air flames are being studied to determine the
etTects of small amounts of stable aromatic
intermediates on the combustion chemistry as it relates
to the formation of soot. We show that the introduction
of aromatics into the transition regime between a
well-stirred and plug tlow reactor can trigger the
formation of larger aromatics at various concentrations,
providing information concerning the gas phase chemistry
during soot inception. Gas chromatography is performed
on combustion samples extracted from the plug tlow
reactor at known residence times for a given flame
equivalence ratio and additive concentration. The
additives studied include benzene and ethylbenzene. For
these additives, the results show that the smaller ring
compounds achieve steady state between ring tormation
and expansion. As residence times increase, higher
molecular weight molecules are formed at higher
concentrations in comparison to baseline data were no
additive is introduced. This body of work provides
experimental data which will be useful in the expansion
of the range of conditions used to validate and "fine
tune" existing PAH/Soot models.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899