Combustion rates of lignite char by TGA

Abstract The rate of combustion of size-graded (75–90 μm) Beulah (ND) lignite char was measured using TGA over a range of oxygen concentrations (5 to 20%), and at temperatures between 598 and 923 K. The activation energy in the chemical rate controlled zone was 120kJ mol −1 , and the transition to film diffusion control occurred at 700 K. No region of pore diffusion control was indicated by Arrhenius plots. Pyrolysis conditions were found to have a notable influence on the activation energy.