carbon dioxide gasification kinetics for four kinds of low activity anthracites(Vad=2.69%—4.35%) was investigated with isothermal thermo-gravimetric analysis under ambient pressure.The reaction control conditions
eliminating both inner and outer diffusion effects
were examined.The relationships of coal conversion versus reaction time for these low activity anthracites were measured from 750 ℃ to 950 ℃.The shrinkingcore model (SCM)
homogeneous model (HM) and modification volumetric model (MVM) were used to correlate the relationships between conversion and time and to obtain the reaction rate constants at different temperatures.Then the reaction activation energy and the pre-exponential factor of four anthracites were predicted respectively by using the Arrhenius equation.According to the order of reaction rate constant determined by the above three models(SCM
HM
MVM)
the activity order of the four anthracites was Shangjing coal>Yong’an Jiashai coal>Yong’an Fengshai coal>Yongding coal.The activation energy
ranging from 122.27—214.72 kJ8226;mol-1 estimated by this study
agreed well with the literature reported for the case of potassium chloride catalytic gasification by carbon dioxide for higher activity coals.