| Municipal sludge incineration has been widely recognized as a volume reduction, harmlessness and resource-oriented approach, but the utilization in China is significantly less than those developed countries. Combining with our national condition, in order to look for a best equilibrium point in sludge treatment among environment, energy and economic, research in this area is very significant.Firstly, this paper obtained constant volume net calorific value and energy loss of Jinan municipal sludge under different moisture contents. We found that the proportion of energy loss of Jinan municipal sludge is 100% when the moisture content achieved 81%. Through ash fusion analyzer, a series of ash melting point of sludge including deformation temperature (DT), softening temperature (ST), hemisphere temperature (HT) and fusing temperature (FT) were obtained that equal to 1138℃,1159℃,1205℃and 1281℃respectively.Secondly, the influence of operation condition and mixing coal on sludge combustion characteristics were studied by thermal analyzer. Research showed that, except for the water evaporation, sludge combustion process could be divided into three stages, which were the first and second volatile combustion satge as well as char combustion satge respectively. With the increase of heating rate, the maximum combustion rate of each stage, ignition temperature, burnout temperature and combustion characteristics index of sluge increased. The maximum weight loss per unit of temperature decreased slightly during the first volatile combustion stage while it's almost unchanged during the second volatile combustion stage and char combustion stage. As the increase of sludge particle size, ignition temperature increased slightly, the maximum combustion rate and combustion characteristics index decreased slightly during the first volatile combustion stage while it's increased slightly during the second volatile combustion stage, but the sludge combustion characteristics was influenced little on the whole.The combustion characteristics of sludge mixing with lean coal were also studied. The ignition temperature of samples changed little around 475℃when sludge percentage less than 40%, but it decreased rapidly as the percentage changed from 40% to 60%, and finally reached 315℃. With the decrease of sludge proportion, the maximum volatile combustion rate of the first peak and its corresponding temperature decreased, the second peak gradually disappeared, and the third peak of char combustion increased rapidly and its corresponding temperature decreased slightly. The mass fraction of solid residues declined on the whole.Thirdly, this paper obtained best mechanism function of the first volatile combustion satge, the second volatile combustion satge and the char combustion stage through Coats-Redfern method. As some parts of the first volatile and the second stage DTG curves overlapped, the traditional data processing may lead to big errors. By adopting the rising edge of the first volatile peak and the falling edge of the second peak, this paper made some improvements on the traditional method. As a result, the first stage of sludge volatile meet the second order reaction model, in which the activation energy equaled 94.1kJ/mol and the frequency factor equals 1.2x107 min-1, and the second stage meet the three-dimensional diffusion model, in which the activation energy equaled 134.2kJ/mol and the frequency factor equals 1.36x1011min-1. The model was fairly agreed with experimental results.Fourthly, the effect of operating parameters such as combustion temperature, particle size and air flow on nitrogen oxides (NO) emissions of the sludge were studied using a double tube-type furnace. The results showed that NO release presented double peak at low air flow, and it presented three peaks with the air flow increasing. When the air flow increased, the time of NO precipitation can be shorten, the first release peak of NO came to broaden and the beginning release time of NO retarded, however the second precipitation peak of NO became broaden obviously, the total release of NO increased simultaneously. Under the high air flow, the three release peaks of NO emission came to broaden and the time to peak moved up with combustion temperature increasing. At the same time, the time differential among three NO release peaks shortened and NO release became more focused when the combustion temperature increases. With particle size becoming large the three release peaks of NO emission firstly decreased and then increased, and the total release of NO obviously increases.At last, a new thermal calculate method of sludge drying-incineration integration was proposed to ensure sludge zero inventory. Energy coupling between drying and incineration were taken into in the method. It had certain reference value in sludge drying-incineration integration system design.
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