污泥稻秆共热解特性及动力学分析

Kinetics and thermal behaviour of the co-pyrolysis between sewage sludge and rice straw

为研究不同配比下污泥和稻秆的混合热解协同作用,在氮气氛围下进行一系列配比的污泥稻秆混合热解实验,借助热重分析仪研究其热解特性。结果表明,污泥、稻秆以及二者混合热解均可分为两个主要阶段,在低温阶段,稻秆能提高挥发性特性指数,促进挥发分析出,并存在协同作用;高温阶段该作用并不明显。运用Friedman法和DAEM法对热解过程进行动力学分析,其结果显示,平均活化能并不是随稻秆比例增加而单调变化,当比例为50%时,平均活化能值最小,分别为179.6 k J/mol(Friedman)和178.5 k J/mol(DAEM),比较一致。

The pyrolysis experiments were performed in nitrogen atmosphere using thermogravimetric analyzer to study the thermal characteristics.The results showed that the pyrolysis of sewage sludge and rice straw can be divided into two main stages.The rice straw could increase the comprehensive index D and promote the volatilization process at low temperature,indicating a synergistic interaction.The dynamic analysis results obtained by Friedman method and DAEM method were similar.The average activtion energy did not change monotonously with the increase of the proportion of rice straw.When the proportion was 50%,the average activation was the smallest,which was 179.6 kJ/mol by Friedman and 178.5 kJ/mol by DAEM,respectively.