市政污泥的热解与燃烧特性及动力学

Pyrolysis and Combustion Characteristics and Kinetics of Municipal Sludge

市政污泥的合理化处理可有效防治生态环境污染与水资源浪费,研究其热解处理技术对指导市政污泥的科学处治具有十分重要的意义。利用热重分析法分析了重庆5种典型市政污泥在不同升温速率下的热重法(thermogravimetric,TG)和微商热重法(derivative thermogravimetry,DTG)曲线演变规律,剖析了热解和燃烧条件下的挥发分析出特性指数D、综合燃烧特性指数、活化能、指前因子等参数的分布特征,揭示了其热解与燃烧特性及动力学规律。结果表明:5种市政污泥的挥发分和灰分的含量较高,而固定碳含量较低;随着升温速率的增加,不同污泥的综合热解性能和综合燃烧性能均越来越优异;综合所有升温速率下的热解和燃烧特性参数,土主和鱼洞污泥的综合热解性能最优,而唐家桥污泥的综合燃烧性能最佳。经过动力学分析,鱼洞污泥的热解过程平均活化能相比其他4种污泥更低,为112.34 kJ/mol,唐家桥污泥的燃烧过程平均活化能相比其他4种污泥更低,为67.46 kJ/mol,说明了鱼洞和唐家桥污泥分别具有优异的热解和燃烧特性。

In order to prevent ecological environment pollution and water resource waste effectively,the study of pyrolysis treatment technology is of great significance in guiding the scientific treatment of municipal sludge.Thermogravimetric analysis was used to investigate the TG(thermogravimetric analysis)and DTG(derivative thermogravimetry)curves of five typical municipal sludges in Chongqing under different heating rates.The distribution characteristics of volatile analysis parameters such as characteristic index D,comprehensive combustion characteristic index,activation energy,and pre-exponential factor under pyrolysis and combustion conditions were analyzed,revealing its pyrolysis and combustion characteristics and kinetic laws.The results show that the volatile and ash contents of the five municipal sludges is higher,while the fixed carbon content is lower.As the heating rate increases,the comprehensive pyrolysis and combustion performance of various sludges improve.Based on the pyrolysis and combustion characteristics parameters at all heating rates,the comprehensive pyrolysis performance of Tuzhu and Yudong sludge is the best,while Tangjiaqiao sludge exhibits the best comprehensive combustion performance.Kinetic analysis are used to toinvestigate regular pattern,the results show that the average activation energy of the pyrolysis process for Yudong sludge is lower than the other four types of sludge,at 112.34 kJ/mol.Similarly,the average activation energy of the combustion process of Tangjiaqiao sludge is lower than the other four types of sludge,at 67.46 kJ/mol.It is concluded that Yudong and Tangjiaqiao sludge exhibit excellent pyrolysis and combustion characteristics,respectively.