Investigation of carbonization kinetic of Tunçbilek lignite used for the preparation of activated carbon

The main objective of this study was to investigate the carbonization of Tunçbilek lignite by TG. Thermogravimetric analyses were performed at different conditions such as heating rates of 10 and 30 °C/min, temperatures of 500, 650 and 800 °C, particle sizes of 1700-700 and 150-100 um, heating mediums of nitrogen and carbon dioxide and gas flow rates of 15 and 40 cm ³/min. Based on TG curves, the kinetic parameters of the process were calculated using the methods of Coats-Redfern, Horowitz-Metzger and Dharwadkar-Karkhanavala in order to illuminate the mechanism of carbonization of Tunçbilek lignite. The carbonization kinetic models of Tunçbilek lignite were set up. The main carbonization stage could be described by the second order global models for Tunçbilek lignite and activation energies varied in the range of 31.7-69.0 kJ/mol.