Investigation On Incineration Characteristics And Process Of Municipal Solid Waste Oxygen-enriched Incineration

With the social development and the improvement of living standards, the yield of municipal solid waste(MSW) has increased significantly in recent years. The growing accumulation of MSW has caused serious environmental and social problems. Incineration is one of the most efficient technologies for MSW disposal as it operates to reduce waste while realizing a resource in an environmentally sound manner through MSW incineration power generation.MSW has high moisture content, high ash content and low heating value, hence, it encounterts many problems during utilization, such as combustion instability, complex pollutants, and unsuitability for plateau areas. Oxy-enriched incineration technology is an effective method for overcoming these difficulties as a result of its high combustion efficiency and low pollutant emissions. Therefore, the incineration properties and the process development of the oxy-enriched incineration technology were explored in this study.Firstly, the oxygen-enriched incineration characteristic of typical MSW combustible components and mixed components were investigated through a thermogravimetri analyzer(TGA). The experimental results show that high oxygen concentration can improve incineration effectively, while moisture can delay ignition and TG curve. According to TG/DTG data, general combustion parameters(SN), kinetic parameters and ignition temperatures were analyzed, and the results also indicated that high oxygen concentration can promote incineration greatly.Secondly, the occurrence form of C, N, S and Cl in MSW combustible components were analyzed qualitatively through X-ray photoelectron spectroscopy(XPS). The oxygen-enriched incineration experiments were carried out in a tube furnace in order to investigate pollutant emission characteristics and the effect of moisture content on pollutant emission. The results show that CO, CH4 emission decreased with the increase of oxygen concentration, HCN also decreased because CH radicals were oxidized by oxygen. However, NO emission increased with the increase of oxygen concentration because more fuel-N was oxidized to NO. With the increase of oxygen concentration, SO2 emission increased while HCl decreased because high oxidizing atmosphere can promote the reaction between HCl and sulfate. Moisture can oxidize CO, CH4 and fixed carbon, as a result, CO, CH4 and HCN all decreased. But excessive moisture can promote the gas water reaction with fixed carbon. In this case, CO, CH4 and HCN emission all appear a small rise. Fuel-N can be oxidized as NO by OH radical, therefore, NO emission will increase with a raise of moisture. In the meanwhile, moisture can promote pyrohydrolysis which can make chlorine salt release HCl. In addition, moisture has no influence on SO2 emission. Therefore, drying pretreatment, desulfurization and denitrification are also necessary for MSW oxygen-enriched incineration.Finally, the key parameters and process of MSW oxygen-enriched incineration have been investigated in comparison with conventional incineration in different aspects. The research presents several oxygen supply models, technical processes and different structures of oxygen injection device.In summary, MSW oxygen-enriched incineration presents a promising application potential. Much more experiments, analysies, industrial experiments are needed to promote the development of MSW oxygen-enriched incineration technology.