REACTION-MECHANISM AND KINETIC-ANALYSIS OF COKE GASIFICATION BY H2O

Kinetic analysis of coke gasification by H2O was studied. The reaction mechanism was considered according to the restricting the adsorption site as the carbon having dangling bond at periphery of carbon net plane. The kinds of reactions estimated from reaction mechanism were consistent with the results of gas analysis in gasification experiment. From the reaction mechanism, rate equation which expressed the rate of three kinds of reactions (Water gas reaction I, water gas reaction II and Boudouard reaction) was proposed. That is, K = S(T)(k1-w1 P(H2O) + k1-B P(CO2))(1 + k1-w2)/1 + k3P(H2) + k5P(H2O) + k2P(CO) + k2P(CO2) where S(T) is the dimensionless concentration of adsorption site (or the number of carbon having dangling bond per a carbon atom). k1-w1, k1-B, k1-w2 are rate contant as promotion term of gasification, corresponding to Water gas reaction I, Boudouard reaction and Water gas reaction II, respectively. k2 approximately k5 are rate constant as restriction term by each gases. The results of calculation using the rate constants obtained by kinetic analysis have good agreement with the reaction rate but also the produced gas composition.