基于热重红外联用技术的不同煤种燃烧特性研究

Combustion characteristics of different coals based on TG-DSC-FTIR coupled technology

采用热重红外(TG-DSC-FTIR)联用技术对锡盟褐煤、大同烟煤和阳泉无烟煤进行了煤粉燃烧特性试验,分析了煤化程度对燃烧特性、反应动力学特性以及气体产物释放过程的影响。结果表明:随着煤化程度的降低,煤粉的着火点和燃尽点降低,着火特性增强,燃尽时间缩短,TG-DTG-DSC曲线向低温区移动;随着煤化程度的降低,煤种的燃烧特性指数S、Sw、Rw和Cb增大,煤粉燃烧表观活化能降低,各项指标均表明锡盟褐煤的着火燃烧特性最好;随着煤化程度的降低,燃烧气体产物CO和CO2析出峰向低温区移动,析出峰的宽度变窄,燃烧气体产物释放时间缩短,CO与CO2的释放量之比下降,燃尽特性增强;煤中硫的赋存形态对SO2的析出特性具有重要的作用。

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 TG- DTG-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.