STEAM GASIFICATION KINETICS AND BURN-OFF BEHAVIOR FOR A BITUMINOUS COAL-DERIVED CHAR IN THE PRESENCE OF H-2

Reaction rate data from gasification of a bituminous coal char in H2O and H(2)0/H-2, gas mixtures have been used to synthesize an overall re action rate model with contributions of the reaction kinetics, the por e development and the surface deactivation. The initial reaction rates could be described as a function ofpH(2)O, pH(2) and T by a Langmuir- Hinshelwood/Hougen-Watson (LHHW) type rate expression. The development of the reaction rate as a function of the carbon conversion (reactivi ty profiles) could be described by the Random Pore Model, for gasifica tion in H2O. The effect of H-2 on the profile could be described by a lumped deactivation model which is represented by the exponential equa tion exp(aX), where a includes contributions of T, pH(2) and pH(2)O. T he model was successfully used in predicting temperature programmed re activity profiles.