Laminar flame speeds of methanol and ethanol at high pressure and temperature conditions: An experimental and modeling approach

• Laminar flame speeds are measured for methanol and ethanol in the OPTIPRIME setup. • A wide range of conditions is studied, including high pressures and temperatures. • Flame speed correlations are built based on the present measurements. • A new kinetic mechanism is developed to reproduce the experimental data. • The mechanism proves its ability to serve as a robust core for kinetic models. During the last few decades, the importance of bio-derived components as efficient alternatives for fossil fuels has significantly increased; however, their full characterization has not been completed yet. Laminar flame speed is one of the fundamental properties characterizing a fuel and is used to validate chemical kinetic mechanisms. In the present study, laminar flame speeds were measured for various methanol/O 2 and ethanol/O 2 diluted mixtures over a large range of conditions, including equivalence ratios (0.7 to 1.4) and initial fresh gas temperatures (331 and 358 K) and pressures (0.5–4 bar). The experimental apparatus used to perform the flame speed measurements is the perfectly spherical combustion chamber with full optical access (OPTIPRIME) developed at ICARE laboratory. The flame propagation compressed the fresh gas, resulting in high pressure and temperature conditions, under which the flame speed increased up to 150 cm.s −1 for the tested methanol mixtures and 80 cm.s −1 for those of ethanol. Experimental uncertainties on flame speed were estimated to be within ± 5%. The extensive database obtained in this work was used to build flame speed correlations as functions of pressure and temperature, generating comprehensive maps for various equivalence ratios that can be refined with additional data to improve accuracy and extend the range of validity. A kinetic mechanism was also developed in this work and showed good performance in representing the present experimental data, taking into account their uncertainties. The mechanism was further validated against previously reported data (including species mole fractions and ignition delay times) on methanol and ethanol oxidation.