Modeling CO[subscript 2] Chemical Effects on CO Formation in Oxy-Fuel Diffusion Flames Using Detailed, Quasi-Global, and Global Reaction Mechanisms
Interest in oxy-fuel combustion as one of the leading carbon capture technologies has grown significantly in the past two decades. Experimental studies have shown higher CO concentration in oxy-fuel diffusion flames than in traditional air-fuel flames of both gaseous and solid fuels. The higher CO c...
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| Format: | Article |
| Language: | en_US |
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Taylor & Francis
2015
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| Online Access: | http://hdl.handle.net/1721.1/98227 https://orcid.org/0000-0001-8730-272X |
| _version_ | 1811073794995912704 |
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| author | Chen, Lei Ghoniem, Ahmed F. |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Chen, Lei Ghoniem, Ahmed F. |
| author_sort | Chen, Lei |
| collection | MIT |
| description | Interest in oxy-fuel combustion as one of the leading carbon capture technologies has grown significantly in the past two decades. Experimental studies have shown higher CO concentration in oxy-fuel diffusion flames than in traditional air-fuel flames of both gaseous and solid fuels. The higher CO concentration changes the flame profiles, and it may have impacts on pollutants formation. This article presents a numerical study regarding the chemical effects of CO[subscript 2] on CO formation in the flame region, and their modeling approaches in CFD simulations. Equilibrium calculation confirms higher CO concentration associated with fuel-rich stoichiometry in CO[subscript 2] diluted combustion environment. One-dimensional counter-flow diffusion flame simulation using detailed reaction mechanisms reveals that the reaction H + CO[subscript 2] OH + CO enhances CO formation in the presence of high CO[subscript 2] concentration, leading to a significantly higher CO concentration under oxy-fuel combustion conditions. High CO[subscript 2] concentration also impacts the reaction OH + H[subscript 2] H + H[subscript 2]O via OH radical and results in lower H[subscript 2] and higher H[subscript 2]O concentrations in the flame profile. Computational fluid dynamics (CFD) simulations of a swirling diffusion flame under air-fired and oxy-fuel conditions were conducted using the eddy dissipation model and the eddy dissipation concept model with quasi-global and global kinetic mechanisms. Results show that reasonable CO predictions can only be obtained using finite-rate approach with appropriate mechanisms considering the CO[subscript 2] chemical effects. The Westbrook–Dryer two-step mechanism consistently underestimates the CO concentrations. In contrast, the Westbrook–Dryer multiple-step mechanism captures the chemical effects of CO[subscript 2], and improves the predictions. |
| first_indexed | 2024-09-23T09:38:54Z |
| format | Article |
| id | mit-1721.1/98227 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T09:38:54Z |
| publishDate | 2015 |
| publisher | Taylor & Francis |
| record_format | dspace |
| spelling | mit-1721.1/982272022-09-26T12:48:51Z Modeling CO[subscript 2] Chemical Effects on CO Formation in Oxy-Fuel Diffusion Flames Using Detailed, Quasi-Global, and Global Reaction Mechanisms Chen, Lei Ghoniem, Ahmed F. Massachusetts Institute of Technology. Department of Mechanical Engineering Ghoniem, Ahmed F. Chen, Lei Interest in oxy-fuel combustion as one of the leading carbon capture technologies has grown significantly in the past two decades. Experimental studies have shown higher CO concentration in oxy-fuel diffusion flames than in traditional air-fuel flames of both gaseous and solid fuels. The higher CO concentration changes the flame profiles, and it may have impacts on pollutants formation. This article presents a numerical study regarding the chemical effects of CO[subscript 2] on CO formation in the flame region, and their modeling approaches in CFD simulations. Equilibrium calculation confirms higher CO concentration associated with fuel-rich stoichiometry in CO[subscript 2] diluted combustion environment. One-dimensional counter-flow diffusion flame simulation using detailed reaction mechanisms reveals that the reaction H + CO[subscript 2] OH + CO enhances CO formation in the presence of high CO[subscript 2] concentration, leading to a significantly higher CO concentration under oxy-fuel combustion conditions. High CO[subscript 2] concentration also impacts the reaction OH + H[subscript 2] H + H[subscript 2]O via OH radical and results in lower H[subscript 2] and higher H[subscript 2]O concentrations in the flame profile. Computational fluid dynamics (CFD) simulations of a swirling diffusion flame under air-fired and oxy-fuel conditions were conducted using the eddy dissipation model and the eddy dissipation concept model with quasi-global and global kinetic mechanisms. Results show that reasonable CO predictions can only be obtained using finite-rate approach with appropriate mechanisms considering the CO[subscript 2] chemical effects. The Westbrook–Dryer two-step mechanism consistently underestimates the CO concentrations. In contrast, the Westbrook–Dryer multiple-step mechanism captures the chemical effects of CO[subscript 2], and improves the predictions. Clean Energy Research Program at MIT and ENEL 2015-08-25T19:17:07Z 2015-08-25T19:17:07Z 2014-01 2013-10 Article http://purl.org/eprint/type/JournalArticle 0010-2202 1563-521X http://hdl.handle.net/1721.1/98227 Chen, Lei, and Ahmed F. Ghoniem. “Modeling CO[subscript 2] Chemical Effects on CO Formation in Oxy-Fuel Diffusion Flames Using Detailed, Quasi-Global, and Global Reaction Mechanisms.” Combustion Science and Technology 186, no. 7 (May 28, 2014): 829–848. https://orcid.org/0000-0001-8730-272X en_US http://dx.doi.org/10.1080/00102202.2014.883384 Combustion Science and Technology Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Taylor & Francis Prof. Ghoniem via Angie Locknar |
| spellingShingle | Chen, Lei Ghoniem, Ahmed F. Modeling CO[subscript 2] Chemical Effects on CO Formation in Oxy-Fuel Diffusion Flames Using Detailed, Quasi-Global, and Global Reaction Mechanisms |
| title | Modeling CO[subscript 2] Chemical Effects on CO Formation in Oxy-Fuel Diffusion Flames Using Detailed, Quasi-Global, and Global Reaction Mechanisms |
| title_full | Modeling CO[subscript 2] Chemical Effects on CO Formation in Oxy-Fuel Diffusion Flames Using Detailed, Quasi-Global, and Global Reaction Mechanisms |
| title_fullStr | Modeling CO[subscript 2] Chemical Effects on CO Formation in Oxy-Fuel Diffusion Flames Using Detailed, Quasi-Global, and Global Reaction Mechanisms |
| title_full_unstemmed | Modeling CO[subscript 2] Chemical Effects on CO Formation in Oxy-Fuel Diffusion Flames Using Detailed, Quasi-Global, and Global Reaction Mechanisms |
| title_short | Modeling CO[subscript 2] Chemical Effects on CO Formation in Oxy-Fuel Diffusion Flames Using Detailed, Quasi-Global, and Global Reaction Mechanisms |
| title_sort | modeling co subscript 2 chemical effects on co formation in oxy fuel diffusion flames using detailed quasi global and global reaction mechanisms |
| url | http://hdl.handle.net/1721.1/98227 https://orcid.org/0000-0001-8730-272X |
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