生物质锅炉羰基化合物排放特征分析

为了探讨生物质锅炉羰基化合物的排放特征，采用气袋采样-PFPH衍生-GC/MS分析的方法测量了6台生物质锅炉排放烟气中的21种羰基化合物.结果表明，这些生物质锅炉的烟气中羰基化合物排放特征存在明显差异，总体而言，己醛和丙醛浓度在测定的21种目标化合物中比重最高，分别占总量的29%~47%和19%~31%，其次为甲醛和丙酮，乙醛和壬醛.通过羰基化合物排放量与消耗的燃料质量比值估算了排放因子，6台锅炉羰基化合物排放因子介于3.06~18.29mg/kg之间，平均为9.45±6.05mg/kg.采用最大增量反应活性法（MIR）评价了羰基化合物的化学反应活性及臭氧生成潜势（OFP），平均总的臭氧生成潜势（以O₃计）为5.97gO₃/gVOCs；己醛、丙醛、甲醛对OFP的贡献尤为明显，丙酮虽然占有较高的质量浓度，但对OFP的贡献较低.

Emission characteristics of carbonyl compounds emitted from biomass-fired-boilers

To characterize the carbonyl emission from biomass-fired boilers, air samples collected from six typical biomass-fired boilers were analyzed by a PFPH-GC/MS method to determine 21carbonyl species. The results showed that distinctive emission characteristics of carbonyl compounds for each boiler. In general, hexanaldehyde and propionaldehyde were the most abundant carbonyl compounds with a percentage of 29%~47% and 19%~31% in the total carbonyls, respectively, followed by formaldehyde and acetone; otherwise, acetaldehyde and nonanal. The emission factors of carbonyl compounds were calculated with the total amount of emission and the mass ration of consumed fuels. It found that the emission factors of carbonyl compounds ranged from 3.06 to 18.29mg/kg (with an average of 9.45±6.05mg/kg). The calculated Maximum Increment Reactivity (MIR) was utilized to assess the atmospheric chemical reactivity and the Ozone Formation Potential (OFP) of emissions from the biomass-fired boilers. The average of OFP (in O₃) was 5.97gO₃/gVOCs, and the three largest contributors among the measured carbonyl compounds were hexanaldehyde, propionaldehyde and formaldehyde. Although acetone had a high mass concentration, it only gave a relatively low contribution to ozone formation.