Catalytical decarboxylation of lignites

The catalytic effect of the transition metal ions Cr2+, Mn2+, Fe2+, Co2+, Cu2+ and Zn2+ on the decarboxylation of Beypazari lignite was investigated, in terms of the change in calorific values of the decarboxylated lignite samples obtained after the decarboxylation process and activation energies of the decarboxylation processes. The optimum temperature to run the decarboxylation experiments and the optimum concentrations of the metal ion loadings to obtain the highest calorific value coal after decarboxylation reactions were determined. Catalytic activity of Fe2+, Cu2+ and Zn2+ was relatively higher than those of Cr2+, Mn2+ and Co2+ ions in decarboxylation reactions. Activation energies of the decarboxylation reactions using different metal ions were calculated and correlated with increases in the calorific values. Catalytic effect of different metal ions were also related to their d-electron configurations of the ions.