Research On Pyrolysis & Gasification Characteristics Of Typical MSW Components In Fluidized Beds

Municipal solid waste (MSW) has become a serious environmental problem besetting each country. The traditional technologies to disposal MSW have been proven that they have many shortcomings. If they have not in proper disposal and utilization, the second-step pollution of environment will occur, especially the problem of the release of toxic substances, such as heavy metals and dioxins by incinerator technology. MSW gasification & melting is a new technology for waste treatment. It combines the advantages of MSW gasification and fly ash melting, works at high efficiency and does not cause atmospheric pollution, and absolutely resolve the problem of heavy metals and dioxins. So in the past few years, the MSW gasification & melting technology has been widely used in Japan, America and other western developed countries, it has attracted attention as "next generation" MSW processing method and been considered the replacer of the incineration. But in China, there is quite limit successful practical gasification & melting applying on MSW and deficient of relative fundamental research on them. Because the physical and chemical character of MSW in China is very different from developed countries, the fundamental research about MSW gasification & melting must base on the situation of China.After analyzing the physical and chemical character of MSW in China, Two novel and improved MSW gasification & melting schemes are brought forward preferably:1. The gasification and melting system based on integrated disposal of MSW;2. The gasification and melting system of original MSW+ assistant fuel.Typical biomass (wood & bamboo) components' characteristics of gasification were studied in a fluidized bed, which was designed and developed at the laboratory scale. It is analyzed that different reaction conditions (excessive air coefficient and temperature) impact on such parameters as the composition of gasification gas, the heat value of the gas and the gasification efficiency etc, and put forward the mechanism of biomass components' gasification reaction. The pyrolysis experiments of biomass components were carried out on the fluidized bed. Different characteristics of distributing of pyrolysis outcomes, pyrolysis oil, pyrolysis carbon,and property of synthesis gas producing were analyzed. With the rising of final pyrolysis temperature factor, the production rate of pyrolysis carbon decreases; the production rate of pyrolysis oil increases first and then decreases (max value at 500°C); the production rate of pyrolysis gas increases. Finally, the reacting mechanism of wood and bamboo was made detailed description.The gasification mechanism and characteristics of polymer component (PVC & PE) in MSW were studied. The main factors were analyzed respectively, such as the heat value of the gas, the gasification efficiency, the transform rate of Cl to HC1 and the producing rate of smog. In the end, the pyrolysis trial of PE was carried out on a fluidized bed.In this paper, the experimental studies on kitchen residual component of MSW gasification have also been carried out. Investigating its response characteristic under gasification & melting technology, the result has reached the anticipated goal basically, all of these give the fluidized bed gasification in large scale a good suggestion.In the last part of this paper, the Neural Network Model is built up to anticipate the gasification products of MSW, it has carried on beneficial exploration for seting up gasification & melting model.