Kinetic study of nickel oxide reduction by methane

The reduction of the nickel oxide, NiO, by methane was investigated in this work. The thermogravimetric technique was used for the determination of kinetic parameters for the reaction. The reaction was carried out in the temperature range of 600-725 degrees C, at atmospheric pressure with porous pellets prepared from nickel oxide powder with a mean particle size of 0.026 mu m. The conversion-time data have been interpreted by using the grain model. Complete conversion can be achieved in 11 min at 72 5 degrees C, which is shorter than the time required by carbon, i.e., ca. 120 min at 1000 degrees C. This faster reduction in comparison with carbon-thermal reduction is attributed to the high carbon activity in methane. For the first order reaction with respect to methane concentration, the activation energy is found to be 63.9 kcal/g mol.