Etude de la combustion de gaz de synthèse issus d'un processus de ...

Chapter 4
4.1.1.6 Comparison with other fuels
The experimental values of the syngas are compared in Fig. 4.23 with those for other
fuels obtained by other workers. The laminar burning velocity of typical syngas
compositions besides its lower heat of reaction is not dissimilar to that of methane
especially the downdraft syngas case, although somewhat slower than propane.
For lean mixtures (φ=0.6) the burning velocity of methane is the same as the updraft
syngas while the burning of propane is equal to the downdraft syngas. For
stoichiometric mixtures S of downdraft and updraft typical syngas–air mixtures is
0 u
respectively 15% and 42% slower than those of methane–air mixtures, being lower for
other equivalence ratio.
tel-00623090, version 1 - 13 Sep 2011
In the case of propane, it is observed an increasing difference of the laminar burning
velocity of the typical syngas mixtures from lean to rich mixtures. For φ=1.2.
0
S
u
is 25%
and 75% slower for downdraft and updraft cases, respectively. For these results
contributes the fact that the syngas stoichiometric air–fuel ratio ranges between 1.0
(downdraft) to 1.2 (fluidized bed) compared with the value of 9.52 for the methane and
23.8 for the propane. Thus, the energy content per unit quantity of mixture (air + fuel)
inducted to the chamber is only marginally lower when using syngas, compared with
the corresponding common gas fuels.
S 0 u (m/s)
0.5
0.4
0.3
0.2
Updraft
Downdraft
Methane
Propane
0.1
0
0.6 0.8 1.0 1.2
Equivalence ratio
Figure 4.23 – Comparison of laminar burning velocity for different fuels: syngas (this work).
Methane (Gu et al., 2000) and Propane (Bosschaart and Goey, 2004)
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