Abstract: The laminar flame speeds of CH4/O2/CO2 mixtures in atmospheric conditions were measured using Bunsen method. The whole surface area methodology based on the images of flame was performed to obtain the laminar flame speeds of the Bunsen burner. The effect factors on laminar flame velocities of CH4/O2/CO2 mixtures were discussed， including equivalence ratios (08~12)， oxygen concentrations (25%~35%) and dilutions (N2， CO2). Results showed that the laminar flame speeds of the premixed oxymethane mixture reached a maximum at the stoichiometric ratio of 1 while gradually lowered on either side. The laminar flame speeds increased with the increase of the O2 concentration and there was a quadratic function relationship between the flame velocities and the concentration of the O2. Compared with N2， the high concentration of CO2 decreased the flame speeds and the measured flame speeds using CO2 as the oxidizer was about onefifth of that using N2 as the oxidizer.

Key words: oxycombustion, O2/CO2, laminar flame speed, Bensun burner, surface area methodology