为了解循环流化床（CFB）锅炉烟气中挥发性有机物（VOCs）的分布和排放情况，明晰烟气处理装置对VOCs的处理效果，在某台200 MW CFB锅炉机组上，开展了烟气中CH4、非甲烷总烃（NMHCs）和多种典型VOCs组分的全流程浓度监测，并分析了燃煤、飞灰和炉渣3种固体样品中CH4、NMHCs含量。结果表明，CFB锅炉机组在100%和50%负荷下SCR入口处烟气中CH4和NMHCs质量浓度分别为0.65和6.63 mg/m3，经过一系列烟气处理装置后CH4质量浓度为0.14～0.18 mg/m3，NMHCs质量浓度为1.05～1.43 mg/m3。煤样中VOCs质量分数为49 979.65 mg/kg，而飞灰和炉渣内只残余少量VOCs。CFB锅炉机组排放烟气中主要以苯、甲苯、乙苯、对/间二甲苯、苯乙烯、邻二甲苯等碳原子数≥6的苯系物和以正己烷为代表的烃类化合物为主。SCR脱硝系统和袋式除尘器对烟气中VOCs处理效率较好，经过全部污染物治理设备后，通过烟囱排放的总VOCs质量浓度为1.19～1.61 mg/m3，总VOCs协同脱除效率为77.88%～78.64%，现有烟气处理设施整体脱除效果可以满足相应排放要求。

In order to understand the distribution and emission of volatile organic compounds (VOCs) in flue gas of circulating fluidized bed (CFB) boiler,as well as the treatment effect of flue gas treatment device,the whole process concentration monitoring of CH4,non-methane total hydrocarbon (NMHCs) and a variety of typical VOCs components in flue gas of a 200 MW CFB boiler unit was carried out. The contents of CH4 and NMHCs in three solid samples of coal burning,fly ash and slag were analyzed. The results show that the mass concentrations of CH4 and NMHCs in the flue gas at the entrance of SCR are 0.65 and 6.63 mg/m3 respectively under 100% and 50% load of CFB boiler units,and the mass concentrations of CH4 emission and NMHCs after a series of flue gas treatment devices are 0.14-0.18 and 1.05-1.43 mg/m3,respectively. The total VOCs content in coal sample is 49 979.65 mg/kg,while only a small amount of VOCs remains in fly ash and slag. The flue gas of CFB boiler unit is mainly benzene series with carbon atomic number ≥6,such as benzene,toluene,ethylbenzene,p/m-xylene,styrene,o-xylene and hydrocarbons represented by n-hexane. SCR denitration system and bag filter have better treatment efficiency for VOCs in flue gas. After all pollutant treatment equipment,the total VOCs mass concentration discharged through the chimney is 1.19-1.61 mg/m3,and the total VOCs synergistic removal efficiency is 77.88%-78.64%. The overall removal effect of existing flue gas treatment facilities can meet the corresponding discharge requirements.

0 引言

1 试验方法

   1.1 电厂概况

   1.2 样品采集

   1.3 样品分析

2 结果与讨论

   2.1 烟气中CH4和NMHCs分布

   2.2 不同烟气处理设施的烟气总VOCs处理效率

   2.3 固体样品中CH4和NMHCs质量分数

   2.4 典型VOCs在电厂的分布

3 结论