Interfacial Rate of CO2-CO Reaction with the Solid Iron and Iron Oxide by Isotope Exchange Technique at 1 273 K

The interfacial rate constant of CO2-CO reaction with the solid iron and iron oxide has been measured by means of the isotope exchange reaction at 1 273 K. Changing the total flowrate, the composition of CO2/CO of gas mixture and the reaction area, the effects of experimental conditions on rate constant were investigated. Varying the CO2/CO ratio in the range of 0.1 to 10, the dependence of rate constant on CO2/CO ratio was studied. It is found that the relationship of the rate constant and CO2/CO ratio can be divided to three regions represented iron, wustite and magnetite phase field, respectively. In three phase regions, the slopes of the linear relationship of logk(c) and log(CO2/CO) were about -0.48, -1.14 and -1.71, respectively. The microstructure of reaction surface of sample was also observed by SEM, with the CO2/CO ratio, the reacted surface became less smooth and showed the crystal morphology.