Kinetic Parameter Estimation of Lignite by Thermo-gravimetric Analysis

摘要

TGA studies of lignite have been carried out. Lignite sample from Gujarat, India have been non-isothermally pyrolyzed using thermogravimetric analyzer and kinetics of decomposition of lignite was studied by non-isothermal method. The sample was heated over a range of temperature from room temperature to 1000 °C with seven different heating rates of 5, 7, 10, 15, 20, 30, 50 °C min~(-1) and non-isothermal weight loss was recorded for all heating rates. The weight loss curve showed that pyrolysis of lignite took place mainly in the range of 200-500 °C. Two non-isothermal methods, namely the direct Arrhenius plot method and the integral method were applied for determination of kinetic parameters-activation energy (E_a) and frequency factor (A). The activation energy obtained by the direct Arrhenius plot method ranged between 60 kJ/mol to 92 kJ/mol. While the result obtained by integral method shows lesser value of activation energy (28 kJ/mol to 50 kJ/mol).