The fuel used as energy source for aluminum melting is of extreme importance for a better performance of the process. However, the type of oxidant can also lead to better performance, leading to a greater preservation of the equipments. Air is more abundant and cheaper, however due to the presence of nitrogen, there is undesirable NOx formation. An alternative is to employ pure oxygen. Although it is more expensive, it can lead to a cleaner and much more efficient combustion process, by significantly altering the combustion aspects inside the furnace, such as the shape of the flame and the distribution of temperature and heat flux. In the present work, numerical simulations were carried out using the commercial package FLUENT, analyzing different cases with pure oxygen and air as the oxidant for the combustion of natural gas. The results showed the possible damages caused by the process if long or too intense and concentrated flames are present.

1.
Hill
SC
, and
Smoot
LD
,
2000
, “
Modeling of nitrogen oxides formation and destruction in combustion systems
”,
Progress in Energy and Combustion Science
, v
26
, pp
417
558
2.
Frassoldati
A
,
Frigerio
S
,
Colombo
E
,
Inzoli
F
, and
Faravelli
T
,
2005
, “
Determination of NOx emissions from strong swirling confined flames with an integrated CFDbased procedure
”,
Chemical Engineering Science
, v
60
, pp
2851
2869
.
3.
Nieckele
A. O.
,
Naccache
M. F.
,
Gomes
M. S. P.
,
2004
, “
Numerical Simulation of a Three Dimensional Aluminum Melting Furnace
”,
Journal of Energy Resources Technology, ASME
, vol.
126
, pp.
72
81
.
4.
Nieckele
A. O.
;
Naccache
M. F.
;
Gomes
M. S. P.
and
Kobayashi
W.
,
1999
, “
The influence of oxygen injection configuration in the performance of an aluminum melting furnace
,”
Proceedings of 1999 ASME-IMECE, USA, Heat Transfer Division
,
2
, pp.
405
412
.
5.
Nieckele, A.O.; Naccache, M. F.; Gomes, M. S. P., Carneiro, J. N. E., and Silva, B. G., 2005, “Performance Of The Combustion Process Inside An Aluminum Melting Furnace With Natural Gas And Liquid Fuel,” Proceedings of 2005 ASME-IMECE, USA, IMECE2005-79042.
6.
Brewster
B. S.
;
Webb
B. W.
;
McQuay;
M. Q.
,
D’Agostini
M.
and
Baukal
C. E.
,
2001
, “
Combustion measurements and modelling in an oxygen-enriched aluminium-recycling furnace
,”
Journal of the Institute of Energy
,
74
, pp.
11
17
.
7.
Mukhopadhyay, A.; Puri, I.K.; Zelepouga, S. and Rue, D.M., 2001, “Numerical simulation of methane-air nozzle burners for aluminum remelt furnaces,” Proceedings of 2001 ASME-IMECE, USA, CD-ROM, HTD-24234.
8.
Nieckele, A.O.; Naccache, M.F.; Gomes, M. S. P.; Carneiro, J.N.E.; Serfaty, R., 2002, “Numerical simulation of natural gas combustion using a one step and a two step reaction”, Proceedings of 2002 ASME-IMECE, November 11–16, New Orleans, LO, USA.
9.
Fluent User’s Guide, v. 6.2, 2006, Fluent Inc., New Hampshire.
10.
Kuo, K.K., 1986. Principles of Combustion, John Wiley & Sons, New York.
11.
Launder
B. E.
and
Spalding
D. B.
,
1974
. “
The Numerical Computation of Turbulent Flows
”,
Computer Methods in App. Mech. and Engineering
,
3
, p.
269
289
.
12.
Patankar, S.V. and Spalding, D.B., 1967. Heat and Mass transfer in Boundary Layers, Morgan-Grampian, London.
13.
Smith
T. F.
,
Shen
Z. F.
, and
Friedman
J. N.
,
1982
. “
Evaluation of Coefficients for the Weighted Sum of Gray Gases Model
”,
Transactions of the ASME - Journal of Heat Transfer
, v.
104
, p.
602
608
.
14.
Magnussen, B. F. and Hjertager, B.H., 1976, On mathematical models of turbulent combustion with special emphasis on soot formation and combustion. In 16th Symp. (Int’l.) on Combustion. The Combustion Institute.
15.
Tomeczek, J. and Grado´n, B, 1997. “The Rate of Nitric Oxide Formation in Hydrocarbon Flames”, Fourth International Conference on Technologies and Combustion for a Clean Environment, Lisbon, Portugal.
16.
Hanson, R. K. and Salimian, S. 1984, “Survey of Rate Constants in H/N/O Systems”. In W. C. Gardiner, editor, Combustion Chemistry, page 361.
17.
Fenimore, C.P., 1971, “Formation of nitric oxide in premixed hydrocarbon flames”, in 13th Int. Symp. on Combustion, p. 373, The Combustion Institute.
18.
Soete, G.G., 1975, “Overall reaction rates of NO and N2 formation from fuel nitrogen”, 15th Symp. on Combustion, p. 1093–1102, The Combustion Institute.
19.
Nieckele, A.O.; Naccache, M.F., Gomes, M.S.P.; Carneiro, J.N.E.; Serfaty, R., 2001, “Models evaluations of combustion processes in a cylindrical furnace”, Procedings of 2001 ASME IMECE, 2001, New York, NY, CD-ROM
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