工业废水污泥的热解及升温速率对热解的影响

利用热重分析法对印染、中药和废水处理厂3种典型工业废水污泥进行了热解动力学实验研究。结果表明,工业污泥是一种高挥发分、低固定碳和低热值的劣质燃料。经过消化处理的污泥灰分含量较高,挥发分含量变小。热解过程中有3个失重速率较高的阶段,以挥发分的析出为主。升温速率对热解的最终失重率有重要影响。升温速率增加,热解更剧烈,但最终失重率的变化趋势与污泥种类有关;为使热解效果更好,不同种类的污泥应选择不同的升温速率。不同种类的污泥具有不同的热解特性,印染污泥挥发分析出阶段有2次热解。中药污泥活化能最小,印染污泥挥发分第2次热解的活化能比第1次大幅增加。

Pyrolysis and influence of heating rate on industrial sewage sludge

The pyrolysis kinetics properties of three typical industrial sewage sludge(textile dyeing,medicine and wastewater) were investigated by simultaneous thermogravimetric analysis(TGA).The results indicate that industrial sludge is a kind of high volatile,low fixed carbon and low calorific value fuel.The digested sludge has a higher ash and lower volatile content.The pyrolysis process can be divided into three stages,and the second weight loss stage-volatile release process is dominant.Heating rate has a significant impact on the final weight loss rate.The thermal decomposition becomes more intense with increasing heating rate,but the change of final weight loss rate is related with the kinds of industrial sewage sludge.To improve the thermal decomposition performance,the different heating rate should be adopted for different kinds of industrial sewage sludge.Different kinds of sludge have the different pyrolysis characteristics.For textile dyeing sludge,there are two pyrolysises in the volatile release process.The activation energy of medicine sludge is minimal but the activation energy of textile dyeing sludge in the second volatile release process greatly increases than that in the first.