Experimental Study On The Flue Gases Pollution And Control In Municipal Solid Waste Incineration

The issue of proceeding Municipal Solid Waste (MSW) has attracted generally attention all over the society. The non-disposal or improper disposal of MSW caused serious problems,such as Environmental pollution, even endangering people’ properties. The rational and effective treatment, to avoid contamination are environmental requirements. At present,there were three main mature methods in the disposal MSW:landfill,compost and incineration. Incineration was considered the most suitable for the principle of minimization harmlessness and utilization, it has gradually become the mainstream way of MSW disposal technology in China. Reduce the secondary pollution during incineration is the key to promote the use of MSW Incineration Technology. In this thesis, the controlling of emissions of SO2, NOx and CO during incineration were studied.The method of chemical thermodynamics analysis was used to discuss the characters of CaCO3 sulfation. Decomposition of CaCO3 in high temperature, direct sulfation and indirect sulfation.The decomposition of CaCO3 at a temperature of 1120K which was analyzed by means of calculationg the changes of the Gibbs free energy(△G). providing the basis for experimental design behind.The MSW combustion and the comparison of characteristics of sulfation between CaCO3 and nano-CaCO3 were studied in tube furnace.The effects of reaction temperature and Ca/S molar ratio on the sulfation characters of CaCO3 and nano-CaCO3 were studied in the experiments. The conversion ratio of S increased with the temperature,but the conversion rate of less than 35% during the burning.The sulfur capture efficiency of nano-CaCO3 is much larger than the sulfur capture efficiency of CaCO3 at the same temperature.The sulfur capture efficiency of CaCO3 reached a maximum of 71.97% in 950℃,the sulfur capture efficiency of nano-CaCO3 can reach above 80% when the temperature is higher than 850 ℃.Both the desulfurization efficiency increased with Ca/S molar ratio, Ca/S=3.6 better than others based on the desulfurization efficiency and the use of factor of CaCO3 while Ca/S molar ratio is preferably about 1.8:1 when nano-CaCO3 was uesed.The effects of temperature and air flow rate on the CO and NOx emission characteristics during MSW combustion were investigated based on a self-made combustion experiment platform. the CO emission curves expressed single peak, with the temperature increasing, the average concentration and peak values of CO decreased first and then increased, the peak moved forward, the burning time decreased. With the air flow rate increasing, the average concentration and peak values of CO decreased, and the peak backwards, the burning time increased. The NOx emission curves had two peaks, with the temperature increasing, the average concentration and peak values of NOx increased. With the air flow rate increasing, the average concentration and peak values of NOx increased.