Effect of heating rate on pyrolysis kinetics of Tuncbilek lignite

Pyrolysis kinetics of the Tuncbilek lignite was investigated by thermogravi metric analysis in the present study. All experiments were conducted at non isothermal conditions with a heating rate range of 10-80 K/min in the pyrol ysis temperature interval 298-1173 K under argon atmosphere. Although some differences were obtained in TG/DTG curves of the lignite samples at differ ent heating rates, the same volatile matter yield of 40.7% of the total wei ght of the sample was calculated in the same temperature range of 673-873 K of the TG curves. Kinetic parameters were determined with the use of the p roposed model. A comparison of the experimental and model values of the wei ght of lignite at arty time was presented. Lower activation energies were c alculated at higher heating rates for Tuncbilek lignite. Minimum activation energy was obtained as 24.8 kJ/mol at the heating rate value of 60 K/min. It appears to be the lowest one when compared to those obtained from the li terature.