Abstract
The transformation of chromium was studied numerically and experimentally in a simple laminar pre-mixed hydrogen-air flame. Chromium was added to the flame as a vapor of chromium hexacarbonyl that provided a source of zero-oxidation-state pure elemental chromium through its rapid pyrolysis. The flame was operated over a range of equivalence ratios. The metal aerosol and vapors that were created in the flame were sampled at different heights with a dilution sampling probe. Aerosol was collected on a filter and vapors in a liquid nitrogen trap. Analysis of the samples showed an initial increase in the amount of hexavalent chromium with increasing distance from the burner, followed by a drop to about 5% far from the burner. The modeling of detailed chromium kinetics showed a similar behavior. The observations highlighted the importance of finite-rate kinetics in controlling the ultimate state of the metal oxide. Aerosol samples were analyzed with an electrical mobility analyzer and condensation nuclei counter. Mean diameters were of the order of 40 nm. The numerical model of the chromium aerosol showed qualitatively good agreement between measured and predicted aerosol size distributions.
Original language | English (US) |
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Pages (from-to) | 1639-1645 |
Number of pages | 7 |
Journal | Symposium (International) on Combustion |
Volume | 2 |
State | Published - 1998 |
ASJC Scopus subject areas
- Chemical Engineering(all)
- Fluid Flow and Transfer Processes
- Physical and Theoretical Chemistry
- Energy Engineering and Power Technology
- Fuel Technology
- Mechanical Engineering