In-situ light scattering measurements are combined with chemical analysis of sampled soot particles to elucidate the mechanisms through which iron addition affects soot formation and growth processes in fuel-rich premixed propane/oxygen flames. Soot particle optical inhomogeneity resulting from the addition of iron is accounted for in the light scattering analysis using an effective refractive index model. The influence of iron addition on soot particle diameters, number densities, volume fractions, surface area, and specific growth rates is investigated. In addition, X-ray photoelectron spectroscopy was used to determine the chemical state of iron species throughout the flame. The analysis revealed that the iron oxide Fe2O3 is the dominant species within the soot particles, corresponding to residence times from 10 to 32 milliseconds. The role of iron additives as soot suppressants is discussed, and mechanims are proposed to explain the soot suppressing behavior associated with iron in practical combustors.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology
- Mechanical Engineering
- Physical and Theoretical Chemistry
- Fluid Flow and Transfer Processes