The rates of gasification by CO2have been determined for three laboratory produced chars derived from U.K. coals with varying ash contents. Data for the temperature range 900 to 1233K were obtained using an isothermal thermogravimetric technique. Reaction rates were determined in atmospheres of either CO2, O2or CO2/O2mixtures for which the CO2partial pressure varied between 10 to 101 kPa. Pre-exponential factors and activation energies for the elementary reaction steps were evaluated using the Langmuir-Hinshelwood expression. High temperature data for the range from 1400 to 1800K were obtained by projecting the char particles through a flat methane-air flame. Particle temperatures in the flame were measured using a two-colour pyrometer system and the rates of char gasification at various CO2partial pressures were calculated from energy balance equations and then used to provide limited information on the char/CO2reaction rate above 1400K.