采用热重法对不同加热速率、氮气气氛条件下的麦秆失重行为进行了研究.研究发现,麦秆失重主要由水分析出、有机物热解和无机物分解等3个阶段组成,其中在无机物分解阶段还伴随有轻微的炭化；此外,随着加热速率增加,有机物分解的初始温度、终了温度、峰值失重速率对应温度等相应增加,利用双外推法推断了麦秆中有机物热解的最概然机理函数,发现麦秆热解可以用二级反应机理进行模化,同时,确定了麦秆热解的活化能、指前因子等反应动力学参数.对利用双外推法得到的模型计算结果与实验结果进行了对比.结果表明,两者之间符合较好,但仍存在一定偏差.对引起偏差的原因进行了分析.%A thermogravimetric experiment was performed to investigate the mass loss of wheat straw in inertial ambience of nitrogen. The results show that, in the process of mass loss, there exist three stages: preheat drying, pyrolysis and thermal decomposition of inorganic components, accompanying mild carbonization in the third stage. At the same time, the characteristic parameters, such as onset temperature, final temperature and peak temperature, increase along with the increase of heating rate. Furthermore, the dual extrapolation method was utilized to obtain appropriate kinetic mechanisms to model the pyrolysis of wheat straw. It was concluded that the mechanisms of pyrolysis for wheat straw follow second-order reaction. In addition, the parameters of chemical kinetics, such as activation energy and frequency factor, were obtained as well. The preliminary comparisons between the model and the experimental data validate the reliability of the kinetic mechanisms as a whole. Finally, the causes of the discrepancy were analyzed.
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