Modeling of NO{sub x} release from a single coal particle. 2: Formation of NO from char-nitrogen
- Univ. of Queensland, Brisbane, Queensland (Australia)
Computational modeling has been carried out to study the formation of nitric oxide during the combustion of a single spherical char particle. Combustion conditions are representative of pulverized coal in the temperature range 1,250 to 1,750 K. The model is a generalized mechanistic model with nitric oxide or HCN being released directly from the char N. Homogeneous gas-phase reactions of NO occur within the particle, as well as heterogeneous NO reduction on the char`s surface. Intrinsic rate kinetics are used to model the char combustion, while the NO reduction kinetics are chosen from the literature. The model was tested against experimental results for coal chars found in the literature and the authors` own work with petroleum coke. Modeling suggests that two mechanisms are possible for the conversion of char N to NO at high temperatures: char N goes completely to NO and is subsequently reduced on the char`s surface; or char N goes completely to HCN and is oxidized and reduced in the atmosphere external to the particle. Both approaches produce realistic results when applied to a laminar flow computational fluid flow/heat transfer model of a drop tube furnace. The model describes NO formation at high temperatures and does not consider N{sub 2}O reactions which are important at fluidized bed temperatures.
- OSTI ID:
- 367840
- Journal Information:
- Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 3 Vol. 106; ISSN CBFMAO; ISSN 0010-2180
- Country of Publication:
- United States
- Language:
- English
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