On the basis of thermogravimetric-differential scanning calorimetry-fourier transform infrared spectroscopy(TG-DSC-FTIR)coupled technology

the combustion characteristics of pulverized Ximeng lignite

Datong bitumite and Yangquan anthracite were investigated.The influence of coal rank on the combustion characteristics

reaction kinetics and gaseous products release process was discussed.The results show that

with the decreasing coal rank

the ignition temperature and burnout temperature of the coals decreased

thus their ignition characteristics got stronger.Therefore

the burnout time decreased and the TGDTG-DSC curves shifted to lower temperatures.In addition

the combustion parameters of the coals

including the combustion characteristic index S

Sw

Rw and Cb

increased and the activation energy decreased.The changes of each index indicated the ignition and combustion characteristics of Ximeng lignite are the best.With a decrease in the coal rank

the precipitation peaks of CO and CO2 shifted to lower temperatures

the width of the precipitation peaks became narrower

and the release time of gaseous products shortened.Meanwhile

the ratio of release amount of CO to CO2 decreased

indicating the burnout characteristics improved.The existence pattern of sulfur in coals plays an important role in its release characterstics.