污泥在CO2气氛下热解CO与CH4的生成特性

利用热重-红外(TG-FTIR)联用技术研究了典型市政污水污泥在CO2和N2气氛下的热解特性。基于TG-FTIR分析结果,采用等温模式配合法研究了CO2气氛下污泥固定床热解过程中CO和CH4的生成特性,建立了CO和CH4的生成动力学机理模型,并同传统N2气氛下污泥热解情况进行了对比,理论模型利用实际实验数据进行了验证分析。结果表明,在实验温度范围内2种气氛下CO与CH4的生成情况有着比较明显的差异,CO2气氛下CH4释放浓度在峰值和总量上都要低于N2气氛,CH4释放峰值来得更早,释放时间更为集中,释放过程也结束得更快。相反,CO的释放浓度峰值,总量以及持续时间在CO2气氛下都要远远高于N2气氛,随着温度的升高,差距越来越大,CO2的存在大大促进了CO的生成。经实验验证,理论推导所得的模型公式对于热解产物生成有着良好的预测结果。

CO and CH4 emission characteristics during sewage sludge pyrolysis in CO2 atmosphere

Pyrolysis characteristics of sewage sludge in a CO2 and N2 atmosphere were studied using a thermogravimetric analyzer(TG) coupled with a Fourier transform infrared analyzer(FTIR).The TG-FTIR results were fitted with a model to investigate CO and CH4 emission during sludge pyrolysis in CO2 and N2.Kinetic models were developed to estimate the production of CO and CH4,and the results indicated significantly different generation models of CO and CH4 in a CO2 and N2 atmosphere,respectively.The peak concentration and yield of CH4 emission were lower in CO2 than that in N2.The CH4 emission in CO2 reached the maximum earlier and was also released more quickly.On the contrary,the peak concentration and yield of CO in CO2 were much higher than those in N2,and this difference increased with increasing temperature;the presence of CO2 was a significant contributor to CO generation.After tests and verifications,the experimental emission data was fitted to theoretical predictions using the kinetic models developed in this report.