Formation and emission characteristics of VOCs from a coal-fired power plant

Abstract On-site measurements of volatile organic compounds (VOCs) in different streams of flue gas were carried out on a real coal-fired power plant using sampling bags and SUMMA canisters to collect gas samples, filters to collect particle samples. Gas chromatography-flame ionization detector/mass spectrometry and gas chromatography-mass spectrometry was the offline analysis method. We found that the total mass concentration of the tested 102 VOC species at the outlet of wet flue gas desulfuration device was (13456 ± 47) µg·m–3, which contained aliphatic hydrocarbons (57.9%), aromatic hydrocarbons (26.8%), halogen-containing species (14.5%), and a small amount of oxygen-containing and nitrogen-containing species. The most abundant species were 1-hexene, n-hexane and 2-methylpentane. The top ten species in terms of mass fraction (with a total mass fraction of 75.3%) were mainly hydrocarbons with a carbon number of 6 or higher and halogenated hydrocarbons with a lower carbon number. The mass concentration of VOC species in the particle phase was significantly lower than that in the gas phase. The change of VOC mass concentrations along the air pollution control devices indicates that conventional pollutant control equipment had a limited effect on VOC reduction. Ozone formation potential calculations showed that aromatic hydrocarbons contributed the highest ozone formation (46.4%) due to their relatively high mass concentrations and MIR (maximum increment reactivity) values.