The departure from an equilibrium gas phase behavior is described in order to obtain the rate of mass loss M of a pure carbon particle immersed in an oxidizing atmosphere over a wide range of the Damköhler number Dg (representing either the particle size or the ambient pressure). For equilibrium flow (Dg→∞) complete burning of CO occurs at a flame sheet standing either adjacent to or at a certain distance of the particle. In the former case oxygen is not totally consumed and the burning rate M depends on both, the direct oxidation C+o2and the indirect oxidation C + CO2. In the latter case oxygen does not reach the particle and M depends solely on the indirect oxidation. By lowering Dgand treating the flame as a thin but finite zone we establish the dependence of M on both heterogeneous reactions as well as on the homogeneous reaction CO + O2. The burning rate is reduced when Dg decreased and the flame moves towards the particle. This behavior persists until the critical Damkohler number Dg° is reached marking the extinction of the CO + O2flame.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology
- Physics and Astronomy(all)