Study of the fuel oxygen effect on soot formation in counterflow diffusion flames

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6370417

Hura, H S

The effect of addition of small quantities of oxygen to the fuel on soot formation in diffusion flames has been studied by making optical diagnostic measurements in laminar counterflow diffusion flames (CFDF) established around a porous cylindrical burner. The fuel oxygen effect was studied in flames of five fuels: ethene, propene, propane, n-butane and isobutane. Chemical kinetic computations using the HCT code were performed to understand the effect of oxygen on the fuel pyrolysis chemistry and relate it to the soot formation trends in the counterflow diffusion flames. HCT is a computer program for calculating time dependent phenomena involving one dimensional hydrodynamics, transport, and detailed kinetics. The soot particle diameter, number density, and volume fraction profiles were obtained by making laser light scattering and extinction (LLS) measurements in the CFDF's. The fuel oxygen effect was found to be the strongest in ethene flames, less so in propene, and negligible in the alkanes. In ethene, addition of 10% of oxygen by volume to the fuel resulted in a 100% increase in the soot loadings. For alkanes, a critical value of the oxygen/fuel molar flow rate ratio was discovered. Below the critical oxygen/fuel ratio, the fuel oxygen had little effect on the soot formation in the alkane flames, but incremental oxygen additions beyond the critical value increased the soot loadings substantially. The soot production is expected to eventually decrease as the fuel oxygen content is increased, but flames with much greater oxygen concentrations than the critical oxygen/fuel ratio could not be studied due to experimental constraints.

• Research Organization: Princeton Univ., NJ (USA)
• OSTI ID: 6370417
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
025000* -- Petroleum-- Combustion
2-METHYLPROPANE
ALKANES
ALKENES
BURNERS
BUTANE
CATALYTIC EFFECTS
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMBUSTION KINETICS
COMPARATIVE EVALUATIONS
COMPUTER CALCULATIONS
COMPUTER CODES
COUNTERFLOW SYSTEMS
DECOMPOSITION
ELEMENTS
ETHYLENE
FLAMES
H CODES
HYDROCARBONS
KINETICS
LASERS
LIGHT SCATTERING
MEASURING INSTRUMENTS
NONMETALS
ORGANIC COMPOUNDS
OXYGEN
PARTICLE SIZE
PROPANE
PROPYLENE
PYROLYSIS
QUANTITY RATIO
REACTION KINETICS
SCATTERING
SIZE
SOOT
SYNTHESIS
THERMOCHEMICAL PROCESSES