Study On The Performance Of Combustion & Pollutants Release Of Municipal Sludge

In recent years, with the acceleration of urbanization process in China and the rapid development of industrial production, the quantity of sewage sludge is being generated sharply. As the output of the sludge is such huge and the components are so complicated. How to deal with this issue properly and scientifically has become one of the most important studies for China and the world.This paper introduced the main components, hazards and disposal methods of the sludge. And the domestic and foreign sludge incineration technology was probed. And then the following aspects of experimental studies were carried out:First of all, according to the STA- MS method, the sludge incineration process were studied. Using the principle of a single variable, the heating rate, the sludge particle size and combustion atmosphere（O₂ / N₂, O₂ / CO₂） were studied on the sludge combustion process. By studying the combustion TG and DTG curves to understand the combustion characteristics under conditions of different factors and the kinetic parameters were calculated. Also by mass spectrometry analysis, to understand these factors working on the precipitation of SO₂ and NO_x in the process of sludge combustion.Secondly, two kinds of sludge and two types of pulverized coal mixed at ratio of 0: 1, 3: 7, 5: 5, 7: 3 and 1: 0. As well as the burning characteristics of mixed combustion and kinetic parameters, liberation of SO₂ and NO_x in the process of combustion was studied. The results showed that each component displayed its own burning characteristics. With the increase of sludge mixing amount, ignition point will be gradually reduced. Due to combustion intensity reduced, the comprehensive combustion performance became wores.Finally, blending experiments in the field of coal-fired power plants with 3%, 5%, 7% of the proportion of mixed sludge were made. And then study the situation of the gas emissions, dioxin formation and heavy metals content after blending a small amount of sludge on the power plant. Results show that the power plant of blending in small amounts（less than 7%） of the sludge will not have much impact on the desulfurization denitration work of power plant and it won’t promote the generation of dioxin. But the blending experiments affected the content of heavy metals in fly ash and slag to some extent.In this paper, through a number of studies on the sewage sludge 、 mixed combustion characteristics and pollutant emissions, as well as analysis of actual datas in coal-fired power plants, they are desirable to provide some experimental datas for the development of sludge incineration technology.