Systematic study of the role played by ZnCl2 during the carbonization of a chemically activated carbon by TG-MS and DSC

In this study, thermal and calorimetric techniques are used in order to get a better insight into the progress of the carbonization process of a lignocellulosic material for activated carbon preparation. Therefore, the pyrolysis process of the precursor (olive waste) alone and in the presence of the activating agent (ZnCl2) at different temperatures is followed via thermogravimetry-mass spectroscopy analysis. The mass loss and the temperature programmed desorption profiles of the signals m/e=16, 18, 28, 30, and 44 allow the determination of the role of the activating agent during the synthesis of the activated carbons at different temperatures. In order to follow the changes in energy during the pyrolysis process, differential scanning calorimetry is used. The obtained results are linked to the properties of the activated carbons obtained at the different temperatures and characterized in a previous paper. In this manner, it is possible not only to determine the thermal events taking place during the pyrolysis process but also to unravel their impact on the textural, structural, and surface properties of the final materials.