低活性无烟煤二氧化碳催化气化动力学--热天平等温热重法

以碳酸钠为催化剂，用热天平的等温热重法研究了4种低活性无烟煤（挥发分含量V_ad=2.69%～4.35%）常压下二氧化碳催化气化反应动力学.考察了消除内外扩散影响的化学反应控制实验条件.测定了温度为750～950℃低活性无烟煤的转化率与时间的关系.并对这一关系用缩芯模型、均相模型以及修正模型进行了拟合关联，得出4种低活性无烟煤二氧化碳催化气化反应的活化能、指前因子和反应速率常数，其活性大小顺序为：上京煤>永安加筛>永安丰筛>永定煤，活化能区间范围：122.27～214.72 kJ•mol^-1，与文献给出的高活性煤种催化气化活化能范围相一致.

Catalytic gasification kinetics of low activity anthracites with carbon dioxide--Isothermal thermo-gravimetric analysis

Using sodium carbonate as catalyst, carbon dioxide gasification kinetics for four kinds of low activity anthracites（V_ad=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 kJ•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.