Abstract: 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 0.936 6 to 0.988 9; 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 0.985 0 to 0.997 5. 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.

Key words: thermogravimetric analysis, excavated waste, municipal solid waste, combustion characteristics, kinetic analysis