Analysis of the combustion and pyrolysis of dried sewage sludge by TGA and MS

In this study, the combustion and pyrolysis processes of three sewage sludge were investigated. The sewage sludge came from three wastewater treatment plants.Proximate and ultimate analyses were performed. The thermal behaviour of studied sewage sludge was investigated by thermogravimetric analysis with mass spectrometry (TGA-MS). The samples were heated from ambient temperature to 800 °C at a constant rate 10 °C/min in air (combustion process) and argon flows (pyrolysis process). The thermal profiles presented in form of TG/DTG curves were comparable for studied sludges. All TG/DTG curves were divided into three stages. The main decomposition of sewage sludge during the combustion process took place in the range 180–580 °C with c.a. 70% mass loss. The pyrolysis process occurred in lower temperature but with less mass loss. The evolved gaseous products (H₂, CH₄, CO₂, H₂O) from the decomposition of sewage sludge were identified on-line.     

厌氧消化污泥和未消化污泥在TG-MS上的热化学特性比较

利用热重-质谱联用仪对厌氧消化污泥和未消化污泥的燃烧和热解过程分别进行了研究.结果表明,2种污泥燃烧和热解过程中的热失重行为都可分为失水、有机物分解、无机物分解3个阶段.在300～350℃温度范围内,无论燃烧还是热解过程,未消化污泥有机物分解造成的热失重现象均比厌氧消化污泥明显.无机物分解阶段,厌氧消化污泥主要是碳酸盐的分解,未消化污泥主要是硫酸盐的分解.采用同步质谱仪对热解和燃烧的气态产物进行了分析,结果表明,污泥燃烧和热解过程除了产生大量的H2O和CO2外,热解过程还产生CH4、C2H6、C4H10、C7H8等有机气体以及H2.厌氧消化污泥热解时有机气体产生量小于未消化污泥.     

热重-质谱联用研究城市生活垃圾热解特性

采用热重-质谱(TG-MS)联用技术研究城市生活垃圾的热解特性以及Ca O的添加对垃圾热解过程和挥发分析出特性的影响。结果表明,城市生活垃圾在热解过程于低温区(240~385℃)的失重主要是由于垃圾样品中纤维素和半纤维素的分解以及部分塑料的低温分解,而发生在385~500℃间的第二失重峰主要是由于塑料和木质素组分的分解。添加Ca O有利于城市生活垃圾在低温区域的热解,并且能减少焦油组分的逸出,减弱CO2气体的逸出强度,促进CH4和CO气体的释放,但对C2H6气体的释放影响较小。     

热重质谱联用研究废旧汽车高聚物热解特性

采用热重-质谱（TG-MS）联用技术研究了N2气氛下废旧汽车塑料和橡胶高聚物混合物料热解气体的种类和产生机理.结果表明,废旧汽车高聚物热解过程在240～350℃和420～500℃有两个明显失重阶段,分别有20.9%和28.3%的挥发分析出.650～730℃范围失重峰是由无机填料热分解造成的,产生的挥发性气体产物为CO2...