Study On Thermal Gravimetric Analysis And Pollutant Emission Of Sludge Under Controlled Oxygen Atmosphere

With the development of the society, the amount of sludge is increasing year by year, and the treatment of sludge is more and more important for the society. Incineration is a good way to dispose sludge. However, because of the low heat value, it always needs to add coal or other fuels to make sludge combust well.To sludge incineration, increasing the oxygen concentration can reduce the ignition temperature effectively, accelerate the burning rate, reduce the amount of flue gas, and also compensate for the problem of insufficient heat value in the sludge treatment process. So it has the worth of energy conservation.As background of the research, this paper choices Yiwu and Jiaxing sewage sludge as the object of the study. The paper researches the combustion and emission characteristics of sludge under different concentrations of O2/N2/CO2and analysis the influence of the temperature through theoretical calculation and analysis, TGA experiments, the horizontal tube furnace test.Through theoretical calculation this paper gets the conclusion that the increase of the oxygen concentration can significantly reduce the supply of the air and the volume of flue gas, and then it can save energy.TGA experiments show that with the increase of oxygen concentration the reaction order n, activation energy E, and the pre-exponential factor A and the kinetic parameters are changed, and the reaction order n and activation energy E tend to become larger.Based on these, through the tube furnace experiments this paper study the pollutant emission characteristics under different oxygen concentrations and heavy metal migration characteristics, and gets the changes of CO, NOx, SO2and other gases with the oxygen concentration and enrichment migration of the heavy metals in the sludge in the different atmosphere. And this paper analyzes the cause to provide a basis for follow-up of sludge burning under control oxygen atmosphere.From the results of the study, controlled oxygen atmosphere used in the incineration of sludge disposal in the reduction of pollutant emissions, especially nitrogen oxide emissions has a good effect; different oxygen concentration has influence of the enrichment of heavy metals in the residue and leaching toxicity, so controlled oxygen atmosphere also has a good effect on the heavy metal pollution control.