Methane/ammonia radical formation during high temperature reactions in swirl burners

Vigueras-Zuniga, Marco Osvaldo, Tejeda-del-Cueto, Maria Elena, Mashruk, Syed, Kovaleva, Marina, Ordonez-Romero, Cesar Leonardo and Valera Medina, Agustin ORCID: https://orcid.org/0000-0003-1580-7133 2021. Methane/ammonia radical formation during high temperature reactions in swirl burners. Energies 14 (20) , 6624. 10.3390/en14206624

Preview

PDF - Published Version Available under License Creative Commons Attribution. Download (4MB) | Preview

Abstract

Recent studies have demonstrated that ammonia is an emerging energy vector for the distribution of hydrogen from stranded sources. However, there are still many unknown parameters that need to be understood before ammonia can be a substantial substitute in fuelling current power generation systems. Therefore, current attempts have mainly utilised ammonia as a substitute for natural gas (mainly composed of methane) to mitigate the carbon footprint of the latter. Co-firing of ammonia/methane is likely to occur in the transition of replacing carbonaceous fuels with zero-carbo options. Hence, a better understanding of the combustion performance, flame features, and radical formation of ammonia/methane blends is required to address the challenges that these fuel combinations will bring. This study involves an experimental approach in combination with numerical modelling to elucidate the changes in radical formation across ammonia/methane flames at various concentrations. Radicals such as OH*, CH*, NH*, and NH2* are characterised via chemiluminescence whilst OH, CH, NH, and NH2 are described via RANS κ-ω SST complex chemistry modelling. The results show a clear progression of radicals across flames, with higher ammonia fraction blends showing flames with more retreated shape distribution of CH* and NH* radicals in combination with more spread distribution of OH*. Simultaneously, equivalence ratio is a key parameter in defining the flame features, especially for production of NH2*. Since NH2* distribution is dependent on the equivalence ratio, CFD modelling was conducted at a constant equivalence ratio to enable the comparison between different blends. The results denote the good qualitative resemblance between models and chemiluminescence experiments, whilst it was recognised that for ammonia/methane blends the combined use of OH, CH, and NH2 radicals is essential for defining the heat release rate of these flames.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Engineering
Additional Information:	This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).
Publisher:	MDPI
ISSN:	1996-1073
Funders:	EPSRC
Date of First Compliant Deposit:	12 October 2021
Date of Acceptance:	8 October 2021
Last Modified:	03 May 2023 00:56
URI:	https://orca.cardiff.ac.uk/id/eprint/144818

Citation Data

Cited 7 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item