为了解循环流化床（CFB）锅炉烟气中多环芳烃（PAHs）分布及排放情况，在某200 MW CFB锅炉机组上，对CFB锅炉排放烟气中气态和颗粒态PAHs采集分析，研究了PAHs在烟气中气相和固相的赋存和分布特征，并分析了燃煤、飞灰和炉渣3种固体样品中PAHs含量。结果显示，CFB锅炉机组最终PAHs排放质量浓度为4.03 μg/m3，其中气相、固相PAHs质量浓度分别为1.88和1.66 μg/m3。锅炉排放初始，烟气中气相PAHs中以2～5环为主，固相PAHs以4环和5环为主；经一系列超低排放控制设施处理后，最终排放烟气中PAHs以2环和3环为主。煤样中PAHs总质量分数为26.20 μg/g，其中以3～5环为主，炉渣和飞灰中PAHs总量分别为3.12和3.85 μg/g，均以3～4环为主。全部超低排放控制设施对PAHs整体协同脱除效率可达97.46%。研究结果表明现有超低排放控制设施对PAHs具有良好的协同处理效果。

In order to understand the distribution and emission of polycyclic aromatic hydrocarbons (PAHs) in flue gas of circulating fluidized bed (CFB) boiler, the gaseous and granular PAHs in flue gas of a 200 MW CFB boiler were collected and analyzed, and the occurrence and distribution characteristics of PAHs in gas and solid of flue gas were studied. The content of PAHs in three solid samples ofcoal, fly ash and slag was analyzed. The results show that the final PAHs emission concentration of CFB boiler unit is 4.03 μg/m3, with the gas phase and solid phase PAHs concentration of 1.88 μg/m3 and 1.66 μg/m3, respectively. The gas phase PAHs in the flue gas are dominated by 2-5 rings, while the solid PAHs are dominated by 4 and 5 rings at the beginning of boiler emission. After a series of ultra-low emission control facilities treatment, the final emission of PAHs are mainly 2 and 3 rings. The total amount of PAHs in coal sample is 26.20 μg/g, with the content of 3-5 rings. The total amount of PAHs in slag and fly ash is 3.12 μg/g and 3.85 μg/g, respectively, mainly consisting of 3-4 rings . The overall collaborative removal efficiency of PAHs by all ultra-low emission control facilities can reach 97.46%. The results show that the synergistic removal effect of existing flue gas treatment facilities can meet the corresponding emission requirements.

0 引言

1 试验

   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 CFB机组烟气中PAHs排放特征

   2.2 CFB机组烟气中PAHs赋存特征

   2.3 固体样品中CH4和NMHCs质量浓度

   2.4 环保设施对PAHs的脱除效果

3 结论