城市固体废弃物混合热解特性及动力学

Pyrolysis characteristics and kinetic study of mixed pyrolysis of municipal solid waste

在研究城市固体废弃物(MSW)典型成分单组分失重规律的基础上,对两两组分混合热解相互影响进行了实验研究.结果表明:白菜、纸板和棉布热解主要分为3个阶段,而聚氯乙烯(PVC)和废轮胎的热解规律较复杂,但其热解过程可等效地看作2个和3个阶段,二者在前2个阶段失重率已经分别达到了100%和88%;两两组分混合后,对应阶段热解温度范围与单组分相比变化不大,而混合后热解速率则受到较大影响,说明所选组分两两混合对各单组分热解温度影响不明显,而热解产物或残留物可能会促进或抑制混合物的分解.根据单组分和混合组分原料的失重规律采用Coats-Redfern法分阶段进行动力学计算,结果表明:拟合曲线线性度很好,说明各单组分和混合组分热解过程分阶段处理是合理的;对于PVC和废轮胎单独热解和两两混合热解,将失重曲线上一些联系紧密的失重峰看作同一个失重阶段进行处理可获得更好的拟合线性度.

The interactions of pyrolysis in every two components were investigated by experiments based on the study of weight loss of single typical component of municipal solid waste （MSW）. The results show that the pyrolysis of celery cabbage, cardboard and cotton cloth consist of three main stages. The pyrolysis characteristic of polyvinyl chloride （PVC） and waste tyre are relatively sophis- ticated, however they can be equiralently regarded as two and three stages, respectively. Their weight losses in the first two stages reach 100% and 88%, respectively. The corresponding pyrolysis temperature is slightly influenced by the blend of different components, while the rates are affected apparently. It can be concluded that the interactions of mixtures have little impact on the pyrolysis temperature. Moreover, the products or residues may promote or suppress the decomposition. The kinetic parameters of both single and mixed components were calculated in stages by the Coats-Red- fern method according to weight loss. The results show that the fitting curves show good linearity, indicating that it is reasonable to deal with the pyrolysis of single and mixed components in stages. In addition, with regard to the single and mixed pyrolysis of PVC and waste tyre, better linearity can be obtained by treating weight loss peaks with tight relations as one stage.