Abstract: Taking Shaoxing municipal solid waste (MSW) and industrial solid waste (ISW) as the research objects, focused on the key and difficult problems of the large co-incineration proportion of ISW in MSW incineration system, the physical and chemical characteristics, the difference of combustion characteristics, the influence of the co-incineration ratio，and the influence of combustion on ash and slag characteristics of MSW and ISW were studied by combining the laboratory simulation and actual incineration system co-incineration test. It was found that the physical and chemical characteristics of MSW and ISW were significantly different, and ISW had more single composition, mainly textile waste (22.9%-72.0%), higher calorific value (9 121.2-14 975.8 kJ/kg) and volatile contents (44.9%-71.8%). And the pollution elements such as S and Cl introduced by ISW would bring certain challenges to the subsequent treatment of flue gas pollutants. The test results of combustion characteristics showed that the textile proportion of ISW was relatively large, resulted in higher ignition temperature, but a small temperature difference between the burnout temperature and the ignition temperature, that is, the combustion reaction after ignition was rapid and the time was short. The results of thermogravimetric (TG) analysis showed that the optimal co-incineration ratio of MSW and ISW was 1.00∶1.35, and the corresponding ignition temperature, combustion rate temperature and burnout temperature were lower than those of MSW, the flammability index C (2.73×10-5 %·min-1·℃-2) and combustion characteristic index S (4.34×10-8 %2·min-2·℃-3) also reached the highest level. In the operation process of MSW incinerator, a large co-incineration proportion of ISW (MSW∶ISW=1∶1) and increasing the ISW co-incineration ratio (MSW∶ISW=1.0∶1.5) would increase the slag thermal reduction rate, significantly expand the particle size of fly ash in the horizontal flue and bag, and reduce the characteristic melting temperature of fly ash. In addition, the increased contents of S/Cl also led to the increase of calcium absorbent dosage, resulting in more production of fly ash. The research results could provide a theoretical basis for the stable operation and technical optimization of the subsequent large-proportion co-disposal of ISW in MSW incineration system.

Key words: municipal solid waste incineration, industrial solid waste co-incineration, co-incineration ratio, combustion characteristics, ash and slag characteristics