The gasification reactivity of high-heating-rate chars in single and mixed atmospheres of H2O and CO2

► Reliable kinetic data for HHR-char gasification reactions with H2O and CO2. ► Introducing CO2 alongside H2O results in a higher char gasification reaction rate. ► Gasifying a char under CO2 does not affect its reactivity toward H2O. ► Char reactivity in a H2O + CO2 atmosphere is the sum of the individual reactivities.