以三种不同升温速率下准东原煤样品的热解失重数据为研究对象,应用分布活化能模型(DAEM)法进行动力学计算,分析了此种方法在煤热解整体动力学研究中的适用性.结果表明,由于升温速率对热解过程的影响以及反应机理的转变,DAEM法对煤热解二次脱气阶段失重数据的适用性较差;失水脱气及二次脱气阶段失重的取舍对各转化率所对应的活化能值具有不同的影响,而对活化能分布函数则影响不大;在几乎整个热解过程中,频率因子和活化能之间均呈现明显的动力学补偿效应,且其具体表现形式仅取决于煤种,而与所选取的温度计算范围关系不大.
The weight loss data of temperature programmed pyrolysis of Zhundong raw coal at three heating rates were investigated and the kinetic parameters were calculated by using distributed activation energy model (DAEM) method. The applicability of this method in global kinetics research of coal pyrolysis was analyzed. The main conclusions are as follows: due to the effect of heating rate on pyrolysis process as well as the change of reaction mechanism, the appli- cability of DAEM method to the weight loss data of secondary degassing stage of coal pyrolysis is weak; inclusion or exclusion of the weight loss in the dehydration and degassing stage or the secondary degassing stage, has different effects on the activation energy values corresponding to various degrees of conversion, but little effect on the activation energy distribution function; the relationship between frequency factor and activation energy presents obvious kinetic compensation effect in the almost entire pyrolysis process, and the expression form of this effect only depends on coal type and is not associated with the selected range of temperature for calculation.