论文部分内容阅读
为实现城市污水污泥与锯末共热解的工业应用,利用热重分析仪对污泥耦合锯末共热解过程进行了实验与理论研究,揭示了锯末添加比例、升温速率对污泥热解特性的影响,并基于Coats-Redfern法,结合20种常见固体热解机理函数确定了污泥耦合锯末共热解过程最优热解动力学模型.结果表明:锯末相比污泥具有更低的表观活化能,最大失重速率是污泥的4倍;锯末的添加使得热重分析(TG)曲线向下偏移,最大失重速率明显增大,挥发份析出特性变强;随着升温速率的增大,固态残渣增加,最大失重速率减小,不利于热解反应的进行;按7:3比例混合的污泥锯末耦合热解微分热重分析(DTG)曲线峰前(230 ~ 350℃)表观活化能为38.81 kJ/mol,最优动力学模型为D5-3D扩散模型;峰后(350 ~ 500℃)表观活化能为29.93 kJ/mol,最优动力学模型为C2-化学反应模型.“,”To realize the industrial application of co-pyrolysis of municipal sewage sludge coupled with sawdust,the Thermogravimetric Analyzer(DTA-60AH) was used to study the pyrolysis characteristics and kinetics of sewage sludge,sawdust and their blends.The influence of sawdust ratio,heating rate on the pyrolysis characteristics were investigated.The optimal kinetic model of blends was achieved based on CoatsRedfern method and 20 common pyrolysis mechanism functions.Results showed that sawdust has a lower apparent activation energy compared with sewage sludge.The addition of sawdust leads to a downward TG (thermogravimetric analysis) curve,and the maximum weight loss rate increases significantly,and volatile properties become much stronger.With the increase in heating rate,the solid residue increases,but the maximum weight loss rate decreases,which is not conducive to the pyrolysis reaction.The optimal kinetic models for the blend with a sawdust ratio of 30% before and after the DTG peak (230-350 ℃ and 350-500 ℃) are the D5-3D diffusion model and C2 Chemical-Reaction model,respectively.