燃煤耦合污泥发电过程二噁英生成与排放研究  

Formation and emission of polychlorinated dibenzo-p-dioxins and dibenzofurans during the co-firing of coal and sludge in power plant

作　　者：周虹光[1,2] 李帅英 王超 丹慧杰 卢琦 房凡 赵亮[5] 张宁[5] 高媛[5] 张海军[5] ZHOU Hongguang;LI Shuaiying;WANG Chao;DAN Huijie;LU Qi;FANG Fan;ZHAO Liang;ZHANG Ning;GAO Yuan;ZHANG Haijun(Xi’an Thermal Power Research Institute Co.,Ltd.,Xi’an 710054,China;Xi’an Boiler&Environmental Protection Engineering Co.,Ltd.,Xi’an 710054,China;Hebei Hanfeng Power Generation Co.,Ltd.,Handan 056200,China;Huaneng Changjiang Environmental Protection Technology Co.,Ltd.,Beijing 100031,China;Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China)

机构地区：[1]西安热工研究院有限公司,陕西西安710054 [2]西安西热锅炉环保工程有限公司,陕西西安710054 [3]河北邯峰发电有限责任公司,河北邯郸056200 [4]华能长江环保科技有限公司,北京100031 [5]中国科学院大连化学物理研究所,辽宁大连116023

出　　处：《热力发电》2023年第5期160-166,共7页Thermal Power Generation

基　　金：中国华能集团有限公司总部科技项目(HNKJ20-H19)。

摘　　要：为了解耦合污泥对燃煤系统中二噁英的生成和排放的影响,在某600 MW机组锅炉上进行实炉掺烧造纸污泥试验。在未掺烧污泥和掺烧污泥2个工况下,分别采集干燥炭化机进出口烟气、选择性催化还原(SCR)脱硝装置进口烟气、空气预热器出口烟气、烟囱烟气、原料污泥、干燥炭化污泥、炉渣和飞灰样品,采用高分辨气质联用仪分析了其中二噁英含量。结果表明:掺烧污泥(质量分数约为燃煤量的1%)没有导致二噁英的高温气相均相生成,以及中低温催化生成和大气排放水平的增加;掺烧污泥工况下采集的6个烟囱烟气样品中二噁英毒性当量(I-TEQ)质量浓度为0.008~0.013 ng/m^(3)(均值为0.010 ng/m^(3))和未掺烧污泥工况下采集的6个烟囱烟气样品中二噁英I-TEQ质量浓度(范围为0.008~0.015 ng/m^(3),均值为0.012 ng/m^(3))无显著差别;污泥干燥炭化过程中有少量二噁英生成,在煤粉燃烧室的污泥中二噁英可被高温彻底销毁;SCR催化剂发挥了催化二噁英降解的作用,高氯取代二噁英更易于被SCR催化剂降解;飞灰中二噁英I-TEQ质量浓度均低于0.2 ng/m^(3),其资源化利用过程不会引起环境二噁英污染。A field test of paper mill sludge and coal co-firing was conducted on a 600 MW unit boiler to explore the effect of mix-firing sludge on the formation and emission of dioxins(PCDD/Fs).Under the conditions with and without sludge co-firing,flue gas samples at the inlet and outlet of drying-charring machine,the inlet of selective catalytic reduction(SCR)equipment,the outlet of air preheater and chimney as well as solid samples including raw sludge,dried and partly charred sludge,slag and fly ash were collected,and the PCDD/Fs were analyzed by a highresolution gas chromatograph combined with high-resolution mass spectrometer.The obtained results indicated that,co-firing sludge(accounted for about 1%(weight percent)of pulverized coal)did not result in the formation of PCDD/Fs via high-temperature gas-phase homogeneous formation mechanism and medium-and low-temperature catalytic formation mechanism,and did not increase the emission of PCDD/Fs to atmosphere.The international toxic equivalence quantity(I-TEQ)concentrations of 6 chimney gas samples collected under the condition with sludge co-firing were in the range of 0.008~0.013 ng/m^(3)(average value:0.010 ng/m^(3)),which did not significantly differ from that(0.008~0.015 ng/m^(3),average value:0.012 ng/m^(3))of the 6 chimney gas samples collected under the condition without sludge co-firing.It was found that,a small quantity of PCDD/Fs was formed during sludge dryingcharring process.The newly-formed and original PCDD/Fs in sludge could be completely destroyed by high temperature in coal combustor.The SCR catalyst induced the catalytic degradation of PCDD/Fs,especially the highly-chlorinated dioxins.The concentration of the PCDD/Fs in fly ash samples were lower than 0.2 ng/m^(3),indicating its resource utilization could not pose dioxin pollution risk to ambient environment.

关 键 词：污泥掺烧 燃煤 二噁英 生成 排放 

分 类 号：X793[环境科学与工程—环境工程] X773