Experimental and numerical investigations of the laminar burning velocities of premixed fuel-rich methane oxy-fuel and oxygen-enhanced flames

•Measured laminar burning velocities for fuel-rich CH4/O2 flames under industrially relevant conditions.•Parametric variation of equivalence ratio, preheating temperature and oxidizer content.•Evaluation of 13 different reaction mechanism.•Comparison of species profiles obtained numerically with literature data. In the context of Oxy-fuel combustion, there is a strong industrial interest in highly fuel-rich flames, characterized by an equivalence ratio (Φ) exceeding 2.5, for the production of H2-CO-rich synthesis gas. The validation of existing chemical reaction mechanisms for this specific regime pose a significant challenge due to the scarcity of experimental data for this particular range of equivalence ratio. The scope of this study was therefore the determination of the laminar burning velocity sL of ultra-rich CH4-O2 flames under varying conditions, such as high equivalence ratios and preheating temperatures using the heat flux burner method. The laminar burning velocity was determined for equivalence ratio within the range of 2.3