分别在热重分析仪和0.5MW循环流化床燃烧系统上进行了煤和垃圾衍生燃料混烧实验。热重试验表明:混烧过程中,两者基本上保持各自的燃烧特性,同时垃圾衍生燃料的加入能显著提高煤粉的燃烧性能。循环流化床试验表明:相对于煤粉单独燃烧,混烧能使整个炉膛的温度分布更均匀;垃圾衍生燃料的加入降低了CO、NO、N2O、SO2的排放,但却大大增加了烟气中HCl的浓度;垃圾衍生燃料中的钙基物质能对SO2起到脱除作用,同时HCl的存在会促进钙基物质与SO2的反应;在混烧情况下,随着床层温度的升高,N、S、Cl等元素对气相污染物的转化率增加,同时,钙基物质对酸性气体SO2、HCl的脱除反应受到抑制,因此烟气中的NO、SO2、HCl等污染物浓度增加。
Co-firing of coal and refuse derived fuel(RDF) were investigated using a thermogravimetric analyzer(TGA) and a pilot-scale circulating fluidized bed combustor(CFB).Results obtained in TGA experiment show that,during co-firing process,coal and RDF can largely maintain their own combustion characteristics,while the addition of RDF significantly improve the combustion performance of coal.The CFB experiment shows that,compared to coal combustion,co-firing makes the axial temperature distribution more uniform;The addition of RDF reduce the CO,NO,N2O,SO2 emissions,but it greatly increase the HCl concentration in flue gas;The Ca-based materials contained in RDF can remove SO2 through sulfate reaction,while the presence of HCl promotes this kind of desulfurization reaction;During co-firing conditions,with the bed temperature increase,not only the conversion of fuel N/S/Cl to gas pollutants increase,but also the SO2 and HCl removal reactions by Ca-based substances are inhibited,therefore,the NO,SO2,HCl concentration in flue gas increase.