When the Langmuir-Hinshelwood (L-H) kinetic model based on the theory of adsorption and desorption is used to describe the gasification reaction of coal char in the mixtures of H2O and CO2

there exist two controversial assumptions of separate active sites and common active sites. The gasification reaction characteristics of the Inner Mongolia coal char (NMJ) in the mixtures of H2O and CO2 were investigated using a tubular furnace experimental system at various reactant gas partial pressures and temperatures. The gasification reaction mechanisms of NMJ in the mixtures of H2O and CO2 were also investigated. The activation energies of NMJ-H2O and NMJ-CO2 were 214.78 kJ·mol-1 and 145.96 kJ·mol-1

respectively. H2 and CO had obvious inhibition effects on the reaction of NMJ-H2O and NMJ-CO2

and the inhibition effects of CO increased with the decrease of reaction temperature. The reaction rate curves calculated by the L-H kinetic model fitted the experimental results very well. For the gasification reaction of NMJ in the mixtures of H2O and CO2

the L-H model based on the common active sites assumption fitted the experimental results very well under atmospheric pressure

indicating that common active sites assumption was more applicable to the gasification mechanisms of NMJ in the mixtures of H2O and CO2.