城市生活垃圾与陈腐垃圾掺烧的燃烧特性与反应动力学分析

Combustion Characteristics and Kinetic Analysis of the Co-combustion of MSW and Excavated Waste

城市生活垃圾掺烧陈腐垃圾可以同时实现二者的资源化利用。使用热重分析法研究城市生活垃圾掺烧陈腐垃圾的燃烧过程,并根据获得的热特性曲线,计算陈腐垃圾掺混比为100%、75%、50%、25%以及0的样品的燃烧特性参数。运用Kissinger-Akahira-Sunose法(KAS法)、Coats-Redfern积分法(C-R法)探究掺烧的动力学特性,依据拟合校正系数(adjR2)来评价计算模型的拟合效果与适应性。结果表明,陈腐垃圾掺混比上升时,样品的着火特征指数下降,而燃尽特征指数和综合燃烧特征指数均呈现出先升后降的趋势。在实验条件下,燃尽特征指数和综合燃烧特征指数的优势掺混比例为0~50%,并且综合燃烧特征指数在掺混比为25%时达到峰值。随陈腐垃圾掺混比增大,KAS法计算出的全局活化能呈递减趋势,从244.49 kJ/mol降至79.40 kJ/mol,其adjR2从0.9366升为0.9889;而C-R法计算出的全局活化能呈递增趋势,从20.86 kJ/mol升至34.21 kJ/mol,其adjR2从0.9850升为0.9975。对两种动力学模型的拟合曲线与实验数据进行对比可知,KAS法的拟合曲线在高温燃烧段存在一定的失真现象,总体而言C-R法的拟合效果更为优秀。

The blending of MSW with aged waste could realize the resource utilization of both at the same time.Thermogravimetric analysis was used to study the combustion process of MSW blended with aged wastes.The combustion characteristics parameters of samples with 100%,75%,50%,25%and 0 blending ratios of aged waste were calculated based on the thermal characteristic curves obtained.Further,the Kissinger-Akahira-Sunose method(KAS method)and Coats-Redfern integral method(C-R method)were applied to investigate the kinetic properties of the blending,and the fitting effectiveness and adaptability of the computational model were evaluated based on the fitting correction factor(adjR2).The results showed that the ignition characteristic index of the samples decreased when the mixing ratio of aged waste increased,while the burnout characteristic index and the integrated combustion characteristic index both showed a tendency of first increased and then decreased.Under the experimental conditions,the dominant mixing ratios of the burnout characteristic index and the integrated combustion characteristic index were 0~50%,and the integrated combustion characteristic index reached the peak at the mixing ratio of 25%.With the increase of the blending ratio of aged waste,the global activation energy calculated by the KAS method showed a decreasing trend from 244.49 kJ/mol to 79.40 kJ/mol,and its adjR2 increased from 0.9366 to 0.9889;and the global activation energy calculated by the C-R method showed an increasing trend from 20.86 kJ/mol to 34.21 kJ/mol,while its adjR2 increased from 0.9850 to 0.9975.Comparing the fitting curves of the two kinetic models with the experimental data,it could be seen that the fitting curve of the KAS method had some distortion in the high temperature combustion section,and the fitting effect of the C-R method was better in general.