Investigation and reduction of two methane combustion mechanisms

Analyses of two methane oxidation mechanisms, the GRI mechanism (version 3.0) and the Leeds Methane Oxidation Mechanism (version 1.4), are reported here. Laminar premixed flames were simulated using program PREMIX, and redundant species and the redundant reactions were identified by program KINALC. Two series of reductions were carried out, where the aims were (i) the reproduction of flame speed, flame temperature and major species concentrations and (ii) the reproduction of also the concentration of radicals that play an important role in NOx production. The two mechanisms were investigated at fuel lean, stoichiometric and rich conditions. More than one hundred reactions could be eliminated in each case. Simulation results obtained by the reduced mechanisms differ by a few percent only from that calculated by the original mechanism.