| 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.Based on the advantage of oxygen-enriched combustion and the low heat of sludge, oxygen-enriched combustion of sludge is a novel technology of energy-saving and environmental protection.This paper chooses sludge from Sibao Sewage Plant of Hangzhou and makes oxygen-enriched combustion tests in the TG apparatus, tube furnace, fluidized bed and Bunsen-Burner to research the combustion and emission characteristics of sludge under different oxygen concentrations.Theoretical calculation results show that the supply gas volume, the flue gas volume and the waste heat loss decreases, the adiabatic flame temperature increases, and the combustion performance is improved when the oxygen concentration increases.The thermogravimetric (TG) analysis shows that the ignition temperature decreases, the reaction rate increases and the overall combustion performance is improved with the increase of oxygen concentration. The computing results from the comprehensive combustion kinetic model are suitable for various oxygen concentrations and agreed well with experimental results. It is also found that the reaction order n, activation energy E and pre-exponential factor A were independent of oxygen concentration.This paper also analyses the effect of oxygen concentration on the release of NOx and SO2, the bottom ash form and heavy metals migration. And then, this paper studies the effect of oxygen concentration on gas combustion characteristics.Based on theoretical analysis and experimental research, the oxygen concentration from 25% to 35% is the ideal region for oxygen-enriched combustion of sludge samples.
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