国内民用燃煤烟气中多环芳烃排放因子研究

模拟国内民用燃煤过程.确定燃煤排放烟气中PAHs的排放因子、PAHs在烟气气相与颗粒相之间的分配、特征排放谱以及不同燃烧方式的影响.结果表明:以15种母体PAHs加和计,燃煤排放因子的变化范围为71～882 mg·k8-1,排放因子和有毒PAHs组份排放量由高至低依次为烟煤、蜂窝煤和无烟煤,主要毒性成份存在于颗粒相中.PAH组份的气-固相分配比例与其饱和蒸汽压存在显著的正相关关系.燃煤类型和燃煤中挥发组份对烟气PAHs排放因子、气-固相分配以及排放谱分布具有决定性作用.另外,不同燃烧方式对燃煤排放因子也有一定影响,缺氧条件会导致排放系数升高.

Emission factors of PAHs in residential coal combustion in China

Emission characteristics of polycyclic aromatic hydrocarbons (PAHs) emitted from combustion of six types residential coal briquettes, including emission factors, partitioning between solid and gas phases, component profile and influence of burning methods, were investigated. The results indicate that, based on 15 parent PAH species, the average total PAH emission factors (EFs) ranged from 71 to 882 mg·kg-1. Both EF values and emission amounts for bituminous coal, honeycomb coal and anthracite showed a decreasing sequence. Particulate phases contributed most of the total carcinogenicity of the PAHs emitted. Positive correlations between ratios of gas to particulates and saturated steam pressures for the PAH compounds were generally significant at a statistical level of 0.05. EFs, partitioning between gas and particulate phases and profiles of PAH emissions were critically affected by residential coal types and the volatile contents of the coals. In addition, different combustion stoves and burning methods also influenced the corresponding EFs. Lack of oxygen supply may lead to an increase of PAH emissions of about 1 order of magnitude.