Pressurized oxyfuel combustion technology is a potential
solution
for reducing greenhouse gas emissions by carbon capture and storage
while burning hydrocarbon fuels. Numerous experiments on CH4 ignition delay times and laminar flame propagation velocities at
high pressures and CO2 atmosphere dilution have been reported,
contributing to the improvement of current CH4 combustion
kinetic models. However, existing mainstream models produce significantly
larger prediction errors for syngas ignition delay time data, especially
under oxyfuel combustion conditions. Motivated by the observation,
an optimized CH4 model was developed based on a comprehensive
set of experimental data, including 2205 ignition delay time, 3344
laminar flame speed, and 200 species profile measurements and balanced
the predicted performance of the syngas. A novel sampling strategy
was developed and embedded in the optimization algorithm to improve
the computational efficiency. The optimized rate constants fall reasonably
within the estimated uncertainty range. Prediction performance of
the optimized model was evaluated and compared to four well-established
models. The optimized model showed considerably improved results,
providing a better balance between the prediction of ignition delay
time and laminar flame speed data. The kinetic reasons for the improved
performance were examined and discussed.