针对采用不同方法计算混合物共热解的动力学参数易出现发散、范围较宽等问题。采用热分析(TGA)方法对两种不同性质的煤样(ZC和XL)、秸秆(ST)和煤焦油(T)混合压球进行共热解实验研究,在此基础上采用等转化率方法(Ozawa-Flynn-Wall(OFW)和Kissinger-Akahira-Sunose(KAS))计算单独和混合共热解的动力学参数并进行对比,分析了产生差别的深层原因。实验结果表明:在较高升温速率下,单独组分热解达到所需热解温度的时间缩短,而在低的升温速率下单独组分的加热发生在颗粒内部的热传递更加有效率。单独热解采用KAS和OFW法计算得到反应过程平均活化能平均值由大到小依次为ZC>XL>T>ST。无论是采用等转化率方法还是采用等温方法对不同性质的物料进行热解反应动力学参数计算受选择计算方法的影响。在热解过程中,随热解温度升高,失重率呈现先增大后降低的变化趋势,E1,E2,E3,E4失重率的实验值和计算值的差值在800℃时达到最大。通过混合压球热解失重的实验值与计算值对比,ZC,XL与ST共热解的协同作用不明显。

According to different models,the kinetic parameters of co-pyrolysis of a mixture are easy to diverge and have a wide range. Co-pyrolysis of briquettes consisting of coal samples (ZC and XL),straw ( ST) and coal tar ( T) was studied by thermal analysis (TGA). On this basis,the kinetic parameters of single pyrolysis and mixed co-pyroly- sis were calculated and compared using isoconversional models ( Ozawa-Flynn-Wall ( OFW) and Kissinger-Akahira- Sunose (KAS)),and the underlying reasons for the difference are analyzed. The experimental results show that the py- rolysis time of the individual components can be reduced at a higher rising temperature rate,while the heating of indi- vidual components occurs more efficiently in the interior of the particles at lower heating rates. The average value of activation energy in the individual pyrolysis is calculated by KAS and OFW method is as follows:ZC >XL >T >ST. Whether the method of isoconversional or isothermal is used for pyrolysis reaction of different materials,the calculation of kinetic parameters is influenced by the selected calculation method. With the increase of pyrolysis temperature,the weight loss firstly increases and then decreases,and the difference of weight loss between the experimental value and the calculated value of E1,E2,E3 and E4 reaches the maximum at 800 ℃ . By comparing the experimental value and calculated value of co-pyrolysis weightlessness of briquettes,the synergistic effect in co-pyrolysis is not obvious.