Thermogravimetric analysis of Thai lignite—II. Char combustion kinetics

Abstract

In this paper, nonisothermal thermogravimetric (TG) data have been used with the integral method to estimate the combustion kinetics of Thai lignite char obtained by pyrolysing the parent lignite at about 1173 K in LPG flame. The results show that the reaction is affected by pore diffusion when a high heating rate is used. The derived activation energy is about 21.31 kcal/gmol and 12.60 kcal/gmol for chemical kinetics and pore diffusion control, respectively. A small discrepancy is observed when these results are compared with those obtained from the literature. The difference may be due to the parent lignite and pyrolysis method used when preparing the sample.