The coal char reactivity is usually evaluated in TG at a low heating rate under ex-situ conditions, which is far from the real condition in boiler and gasifier. In this work, the isothermal CO2 gasification reactivity of in-situ chars which were pyrolyzed under different heating rates and terminal temperatures was measured by a rapid TG apparatus. Furthermore, the char structural parameters were correlated with the reactivity index. Results showed that heating rate had little effect on the gasification reactivity of the in-situ char when it exceeded 50oC /min. The carbon crystalline structure related closely to the reactivity index. Simultaneously, the HTSM experiments demonstrated that the reaction rates were slightly higher compared with TG.
Keywords Heating Rate, In-Situ Char, Rapid TG Apparatus, Structural Parameters, Heating Stage Microscope