Kinetics and mechanisms of the reaction of air with nuclear grade graphites: IG-110

摘要: Abstract The work presented in this report is part of an ongoing effort the microgravimetric evaluation intrinsic reaction parameters for air reactions with graphite over temperature range 450 to 750°C. Earlier laboratory addressed oxidation/etching H-451 by oxygen and steam. This addresses oxidation Japanese formulated material, IG-110. Fractal analysis showed that each cylinder was remarkably smooth, average value, D , fractal dimension 0.895. activation energy, E a determined be 187.89 kJ/mol indicative occurring zone II kinetic regime as result porous nature cylinders. IG-110 microporous solid. low initial rate 9.8×10 −5 at 0% burn-off high value (764.9) Φ structural parameter confirm this. maximum rate, 1.35×10 −3 g/m 2 s, measured 34% burn-off. Reactions appeared proceed three stages transition between them smooth investigated. Both ln  A did not vary Δ S entropy activation, −41.4 eu, suggesting adsorption through immobile state complex. Additional recommended validate predictions will made relation accident scenarios reactors such modular gas-cooled reactor where fine grained graphites could used applications.