Numerical Analysis of the Natural Gas Combustion Products


The combustion products of fuels containing the elements C, H, O, N and S are calculated. The methodology is based on the equations obtained in the stoichiometric balance of atoms. The adiabatic flame temperature is determined considering that the pressure of the boiler furnace remains constant. The scope of this work is limited to the analysis of natural gas (methane) with molecular formula CH4. The methodology can, however, be employed for the calculation of combustion products of a great variety of hydrocarbons under the established restrictions.In the development of the methodology two cases are contemplated: Φ ≤ 1 (lean and stoichiometric mixture) and Φ > 1 (rich mixture). In the first case it is considered that when the combustion is complete, the combustion products are O2, H2O, CO2, N2, SO2, and the solution follows directly. When the combustion is incomplete, however, the products H, O, N, H2, OH, CO, NO, O2, H2O, CO2, N2 and SO2 can be generated, according to Stephen R. Turns, (2000). When bal-ances of atoms are performed, four conservation equations are obtained, one for each of the C, O, H and N elements. An additional restriction requires that the sum of the molar fractions of the products equals one mol. Finally, seven equilibrium constants, corresponding to the seven chemical reactions of combustion, are introduced. All this provides a system of four nonlinear equations which is solved with the Newton-Raphson method.

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F. Martínez, M. Velázquez, G. Polupan, J. Francis, G. López, C. Rosas and J. Herrera, "Numerical Analysis of the Natural Gas Combustion Products," Energy and Power Engineering, Vol. 4 No. 5, 2012, pp. 353-357. doi: 10.4236/epe.2012.45046.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] M. J. Moran and H. N. Shapiro, “Fundamentals of Engineering Thermodynamics,” John Wiley and Sons, New York, 2000.
[2] J. H. Mathews, “Numerical Methods for Mathematics, Science and Engineering,” 2nd Edition, Prentice Hall, Englewood Cliffs, 1992.
[3] G. Zirkel and E. Berlinger, “Understanding Fortran 77 and 90,” PWS Publishing Company, Boston, 1994.
[4] J. Warnatz, U. Maas and R. W. Dibble, “Combustion Physical and Chemical Fundamentals, Modeling and Simulation, Experiments, Pollutant Formation,” 3rd Edition, Springer-Verlang, Berlín Heidelberg, 2001.
[5] D. R. Lide, “CRC Handbook of Chemistry and Physics,” 71st Edition, 1990-1991.
[6] S. R. Turns, “An Introduction to Combustión. Concepts and Applications,” 2nd Edition, McGraw Hill, New York, 2000.

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