Syngas production from burner-stabilized methane/air flames: The effect of preheated reactants

The effect of preheated reactants on syngas production from a methane/air flame was investigated over a range of inlet temperatures up to 630 K. In addition to experimental measurements, the results from a burner-stabilized flame and freely-propagating flame models are presented. A comparison of the modeling and experimental results in terms of flame standoff distance, stability limit conditions and species yields show excellent agreement across a broad range of equivalence ratios and preheat temperatures. Preheating of reactants increased the rich limit for stable operation from 1.26 to 1.75 for a given inlet velocity, and syngas yields were shown to increase with equivalence ratio. The preheat temperature of the reactants was shown to have little impact on syngas yields beyond extending the limits of stable operation. The results of this study are useful for the design and analysis of heat recirculating reactors and other reactors that are designed for producing syngas through the combustion of rich mixtures.