Journal of Mechanical Science and Technology

, Volume 25, Issue 11, pp 2943–2949 | Cite as

A numerical study on extinction and NOx formation in nonpremixed flames with syngas fuel

  • Kang Woo Chun
  • Hun-Jik Chung
  • Suk Ho Chung
  • Jae Hyuk Choi


The flame structure, extinction, and NOx emission characteristics of syngas/air nonpremixed flames, have been investigated numerically. The extinction stretch rate increased with the increase in the hydrogen proportion in the syngas and with lower fuel dilution and higher initial temperature. It also increased with pressure, except for the case of highly diluted fuel at high pressure. The maximum temperature and the emission index of nitric oxides (EINOx) also increased in aforementioned conditions. The EINOx decreased with stretch rate in general, while the decreasing rate was found to be somewhat different between the cases of N2 and CO2 dilutions. The reaction paths of NOx formation were analyzed and represented as NO reaction path diagram. The increase in N radical resulted in larger NOx production at high initial temperature and pressure. As the pressure increases, EINOx increases slower due to the third-body recombination. The thermal NO mechanism is weakened for high dilution cases and non-thermal mechanisms prevail. The combustion conditions achieving higher extinction stretch rate can be lead to more NOx emission, therefore that the selection of optimum operation range is needed in syngas combustion.


Syngas Extinction Stretch rate EINOx NO reaction path diagram 


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Copyright information

© The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Kang Woo Chun
    • 1
  • Hun-Jik Chung
    • 2
  • Suk Ho Chung
    • 3
  • Jae Hyuk Choi
    • 4
  1. 1.Energy Environment Industrial Business CenterKorea Register of ShippingDaejeonKorea
  2. 2.Energy Efficiency and Resources TeamKorea Institute of Energy Technology Evaluation and PlanningSeoulKorea
  3. 3.Clean Combustion Reseach CenterKing Abdullah University of Science and TechnologyThuwalSaudi Arabia
  4. 4.Korea Maritime UniversityBusanKorea

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