不同煤燃烧方式多环芳烃生成特性的研究

Study of PAHs Formation From Different Kinds of Coal Combustion Process

研究比较了不同煤燃烧方式多环芳烃生成特性。固定床煤燃烧多环芳烃生成随温度升高出现了先增加后减少的趋势,流化床煤燃烧多环芳烃生成随温度升高而增加。流化床煤燃烧多环芳烃生成量要少于固定床燃烧方式,总量上低1～2个数量级。固定床燃烧(管式炉等)PAHs低温由热解生成,高温由前驱物生成。流化床燃烧PAHs低温由高环芳香性物质的热分解和缩聚反应生成,高温由小分子烃类的聚合。

PAHs formation from two kinds of coal combustion process (fixed bed and fluidized bed) was studied. With increasing temperature during fixed bed coal combustion, PAHs concentrations increase up to a maximum value and then decrease. The amount of PAHs formation from fluidized bed coal combustion increases with temperature and total amount of PAHs concentration from fluidized bed coal combustion is one or two magnitude level less than that from fixed bed. During fixed bed combustion, pyrolysis is the main PAHs formation pathway at low temperature and precursor formation at high temperature. During fluidized bed combustion, decomposition and condensation reactions are the main PAHs formation pathway at low temperature and polymerization of small hydrocarbons at high temperature. Figs 12, table 1 and refs 13.