Nitric oxide pollutant formation in high hydrogen content (HHC) syngas flames

Dinesh, K. K. J. Ranga and van Oijen, J.A. and Luo, Kai H and Jiang, Xi (2015) Nitric oxide pollutant formation in high hydrogen content (HHC) syngas flames. International Journal of Hydrogen Energy, 40 (39). pp. 13621-13634. ISSN 0360-3199

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Abstract

Three-dimensional direct numerical simulations (DNS) of high hydrogen content (HHC) syngas nonpremixed jet flames with a Reynolds number of Re = 6000 have been carried out to study the nitric oxide (NO) pollutant formation. The detailed chemistry employed is the GRI 3.0 updated with the influence of the NCN radical chemistry using flamelet generated manifolds (FGM). Preferential diffusion effects have been considered via FGM tabulation and the reaction progress variable transport equation. The DNS based quantitative results indicate a strong correlation between the flame temperature and NO concentration for the pure hydrogen flame, in which NO formation is mainly characterised by the Zeldovich mechanism. The results also indicate a rapid decrease of maximum NO values in H2/CO syngas mixtures due to lower temperatures associated with the CO-dilution into H2. Results on NO formation routes in H2/CO syngas flames show that while the Zeldovich mechanism dominates the NO formation at low strain rates, the high NO formation rate at high strain rates is entirely caused by the NNH mechanism. We also found that the Fenimore mechanism has a least contribution on NO formation in H2/CO syngas flames due to absence of CH radicals in the oxidation of CO. It is found that, due to preferential diffusion, NO concentration exhibits higher values near the flame base depending on the hydrogen content in H2/CO syngas fuel mixture.

Item Type:
Journal Article
Journal or Publication Title:
International Journal of Hydrogen Energy
Additional Information:
This is the author’s version of a work that was accepted for publication in International Journal of Hydrogen Energy. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in International Journal of Hydrogen Energy, 40, (39), 13621-13624, 2015 DOI: 10.1016/j.ijhydene.2015.08.068
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/2100/2105
Subjects:
ID Code:
77923
Deposited By:
Deposited On:
26 Jan 2016 09:46
Refereed?:
Yes
Published?:
Published
Last Modified:
25 Sep 2020 02:19