燃煤耦合垃圾焚烧灰渣的二噁英再合成实验研究  

Experimental Study on Dioxin Re-synthesis of Coal-firedCoupled with Waste Incineration

作　　者：马瀚程 詹明秀 蔡鹏涛 徐旭 陆胜勇[2] MA Hancheng;ZHAN Mingxiu;CAI Pengtao;XU Xu;LU Shengyong(College of Measurement and Test Engineering,China University of Metrology,310018 Hangzhou,China;State Key Laboratory of Clean Energy Utilization,Zhejiang University,310027 Hangzhou,China)

机构地区：[1]中国计量大学计量测试工程学院,杭州310018 [2]浙江大学能源清洁利用国家重点实验室,杭州310027

出　　处：《煤炭转化》2020年第6期84-94,共11页Coal Conversion

基　　金：国家自然科学基金资助项目(51806205);宁波市“科技创新2025”重大专项科技项目(2018B10027).

摘　　要：利用燃煤耦合垃圾焚烧实验台和二噁英再合成实验台,研究了燃煤耦合垃圾焚烧烟气时二噁英浓度变化情况,重点探明了耦合焚烧后粉煤灰和灰渣再合成二噁英的质量浓度和同分异构体的分布情况。结果表明:与燃煤未耦合垃圾焚烧烟气产生的粉煤灰相比,燃煤耦合垃圾焚烧烟气后,煤粉炉烟气和灰渣中二噁英毒性当量降低;燃煤未耦合垃圾焚烧烟气产生的粉煤灰在350℃加热时,二噁英的质量分数由2.93 ng/g增加为3.86 ng/g,二噁英毒性当量由0.24 ng I-TEQ/g(International Toxic Equivalence Quantity)增加为0.49 ng I-TEQ/g,燃煤耦合垃圾焚烧烟气产生的灰渣在350℃加热时,二噁英的质量分数由1.64 ng/g增加为4.30 ng/g,而二噁英毒性当量却由0.63 ng I-TEQ/g降低为0.12 ng I-TEQ/g,这表明粉煤灰和灰渣加热后二噁英同分异构体分布变化趋势差异较大;在灰渣加热过程中通入41.2 mg/m 3的HCl时,二噁英毒性当量变化较小,这表明灰渣和二噁英再合成过程中可能还缺少CuCl 2等金属催化剂;灰渣再合成的二噁英主要以PCDFs(polychlorinated dibenzofurans)为主,表明从头合成反应可能是二噁英生成的主要途径,同时低氯代PCDDs(polychlorinated dibenzo-p-dioxins)更容易被氯化生成高氯代PCDDs,因此二噁英毒性当量有所降低。The change in the dioxin mass concentration in the flue gas of the coal-fired coupled waste incineration was studied by using the experimental platforms of the coal-fired coupled waste incineration and the dioxin re-synthesis.The experiments were focused on the investigation of the mass concentration and isomer distribution of the fly ash and the ash re-synthesis after the coupled incineration.The results show that the toxic equivalent of the dioxin in the flue gas and ash of coal-fired boiler decrease after the coal-fired coupling waste incineration.The mass concentration of dioxin increase from 2.93 to 3.86 ng/g and the toxic equivalent of the dioxin increased from 0.24 ng I-TEQ/g(International Toxic Equivalence Quantity)to 0.49 ng I-TEQ/g when the coal-fired uncoupled waste incineration flue gas is heated at 350℃.When the ash generated from the flue gas of coal-fired coupled waste incineration is heated at 350℃,the mass concentration of dioxin increase from 1.64 ng/g to 4.3 ng/g,while the toxic equivalent of dioxin decrease from 0.63 ng I-TEQ/g to 0.12 ng I-TEQ/g,indicating that the distribution of dioxin isomers varied greatly after the thermal treatment of the fly ash and ash;In case that 41.2 mg/m 3 HCl is introduced to the thermal treatment of the ash,the toxicity equivalent of the dioxin barely vary,indicating a lack of metal catalysts such as CuCl 2 during the process of the ash dioxin re-synthesis.The PCDFs(polychlorinated dibenzofurans)is the main mechanism of the dioxin re-synthesis,indicating that the ab initio synthesis may be the driving mechanism for the dioxin formation,and low-chlorinated PCDDs(polychlorinated dibenzo-p-dioxin)is more likely to be chlorinated to produce high-chlorinated PCDDs.To this end,the toxic equivalent of the dioxin is reduced.

关 键 词：燃煤 垃圾焚烧 灰渣 再合成 二噁英 

分 类 号：X705[环境科学与工程—环境工程]