Experimental study of kinetics of coal char combustion characteristics under mixed O_2/CO_2 atmosphere

Coal char combustion under the O2/CO2 atmosphere is considered as a clean coal technology with promising prospect,and the research on its combustion characteristics and dynamics constitutes the foundation of project application.In this paper,the thermo-gravimetric analysis(TGA) method was used to conduct experimental study of the combustion characteristics of three coal chars(Liupanshui lignite,Zhungeer bituminous,and Qinhuangdao anthracite) under different oxygen volume contents(21%,25%,30%,and 35%),and the effect of oxygen volume fraction on coal-char combustion was analyzed.Meanwhile,the classical dynamics and the time effect fractal dynamics were adopted respectively to analyze the coal char combustion.The results showed that the higher oxygen content leads to lower ignition and burnout temperature,shorter combustion time,and increased char burnout index.What′s more,the activation energy indices obtained through classical dynamics and time effect dynamics analysis respectively were both reduced,however,the former is smaller than the latter.