Kinetics of the recovery of nickel from depleted catalysts used in the reforming of methane

In the current work the separation of nickel from alumina is proposed when it is present in the following mixtures: 10 wt% Ni+90 wt% Al2O3, 12 wt% NiO+88 wt% Al2O3, making use of a tubular reactor, with a flow of 2 l/h of gaseous chlorine and from 500 to 800 °C. nal products of the reaction, extracted from the hottest zones of the reactor where characterized as NiCl2 and NiCl2·6H2O, and the predominating phase of alumina condensed with NiCl2 up to 700 °C was γ-Al2O3. gravimetric (TG) measurements were carried out in a mixed flux of Cl2 and Ar in non-isothermal conditions up to 950 °C. The beginning of the reaction in the first mixture was detected at 384 °C and close to 653 °C the volatilization of NiCl2 started. Besides, NiO reacts at 473 °C and NiCl2 volatilizes at 577 °C. There is no reaction with Cl2 and no phase transition of γ-Al2O3. In order to find out the reaction rates, mass changes of the reactants were measured under the same gaseous flow and in isothermal conditions.