民用燃煤源中多环芳烃排放因子实测及其影响因素研究

民用燃煤是我国目前关注较多的多环芳烃(polycyclic aromatic hydrocarbons,PAHs)排放源.根据我国民用燃煤所涉及的煤种、燃烧方式和炉灶类型,利用全流稀释采样系统对5种不同成熟度的煤种,分别以散块煤和蜂窝煤形式在3种炉灶类型中燃烧产生的烟气进行了采样和分析,初步获取了我国民用燃煤烟气中PAHs排放因子(EFPAHs)的实测数据.结果表明,烟煤的EFPAHs在块煤燃烧方式下的变化范围为1.1～3.9 mg.kg-1,在蜂窝煤燃烧方式下的变化范围为2.5～21.1 mg.kg-1,无烟煤的EFPAHs在块煤与蜂窝煤燃烧方式下分别为0.2 mg.kg-1与0.6 mg.kg-1.在民用燃煤的EFPAHs的各种影响因素中,煤的地质成熟度起主导作用,不同成熟度煤种的EFPAHs差异幅度高达1～2个数量级.其次是燃烧形态(块煤/蜂窝煤),主要表现为同一种地质成熟度的煤在蜂窝煤燃烧方式下排放的PAHs比块煤高2～6倍.炉灶类型的影响最小.

Emission Factors of Polycyclic Aromatic Hydrocarbons (PAHs) in Residential Coal Combustion and Its Influence Factors

As the emission source of polycyclic aromatic hydrocarbons (PAHs), domestic coal combustion has attracted increasing attention in China. According to the coal maturity, combustion form and stove type associated with domestic coal combustion, a large-size, full-flow dilution tunnel and fractional sampling system was employed to collect the emissions from five coals with various maturities, which were burned in the form of raw-coal-chunk (RCC)/honeycomb-coal-briquettes (HCB) in different residential stoves, and then the emission factors of PAHs (EF_PAHs) were achieved. The results indicate that the EF_PAHs of bituminous coal ranged from 1.1 mg·kg^-1 to 3.9 mg·kg^-1 for RCC and 2.5 mg·kg^-1 to 21.1 mg·kg^-1 for HCB, and the anthracite EF_PAHs were 0.2 mg·kg^-1 for RCC and 0.6 mg·kg^-1 for HCB, respectively. Among all the influence factors of emission factors of PAHs from domestic coal combustion, the maturity of coal played a major role,the range of variance reaching 1 to 2 orders of magnitude in coals with different maturity. Followed by the form of combustion (RCC/HCB), the EF_PAHs of HCB was 2-6 times higher than that of RCC for the same geological maturity of the coal. The type of stove had little influence on EF_PAHs.