不同升温速率下城市污水污泥热解特性及动力学研究

利用差热-热重分析法和Coats-Redfern积分法,对杭州某污水处理厂污泥在不同升温速率下的热解特性及反应动力学特征进行研究。实验结果表明,热解温度从室温升至900℃时,污泥热解过程可分为4个失重阶段;升温速率对污泥热解转化率、挥发分析出温度以及最大失重率等热解特性参数都有显著影响。升温速率越高污泥最大失重率越大;而较低的升温速率延迟了污泥热解反应时间,导致污泥失重量相对较大。根据Coats-Redfern积分法计算结果,污泥在氮气氛围下的热解反应为二级反应模式。提高升温速率可显著增加污泥热解的表观活化能和频率因子。

Pyrolysis characteristics of municipal wastewater sewage sludge under different heating rate

The differential scanning calorimetry,simultaneous thermal analysis and theoretical analysis method of Coats-Redfern were employed to study the pyrolysis process and kinetics characteristics of Hangzhou municipal wastewater sewage sludge under various heating rates.It was found that the pyrolysis process of sludge from indoor temperature to 900 ℃ could devided into 4 the weight loss stages.Heating rate had obvious effects on pyrolysis process of the sludge.Higher heating rate resulted in higher maximun weight loss rate,while lower heating rate could extend the pyrolysis time and finally incresed the sludge weight loss.Base on the results of Coats-Redfern integration method,the pyrolysis process of sludge under N2 atmosphere was belongs to two-class reaction.The knetic characteristics of the sludge pyrolysis under different heating rates was caluculted.Results showed that the apparent activation energy and the frequency factor of were greatly increased after increasing heating rate.