DESORPTION OF ETHYLENE-GLYCOL FROM ACTIVATED BENTONITES

A theoretical approach to the high-temperature oxidation kinetics of a metal system oxidized through the formation of surface nodules has been developed. The overall oxidation rate is given by the convolution between the nodulation rate and the single-nodule growth rate functions. Impingement effects between growing grains have also been considered in the general theoretical formulation. The theory has been developed in the specific case of hemispherical, cylindrical and screw nodule growth geometries by assuming, as the rate-limiting step of the oxidation reaction, ionic transport into the oxide. This approach gives rise to an 'anomalous' shape of the overall reaction rate, with respect to the formation kinetics of a compact oxide scale, as is experimentally observed.