Distribution and emission of speciated volatile organic compounds from a coal-fired power plant with ultra-low emission technologies

To reduce the volatile organic compounds (VOCs) emission and to achieve an ultra-low emission in coal-fired power plant, it is essential to understand the effect of air pollution control device system (APCD) on the emission of VOCs. In this study, the mass concentration of speciated VOCs in the flue gas on the nine sampling locations from the coal-fired power plant was obtained at different boiler loads. The samples were collected by the portable gas chromatograph equipped with a flame ionization detector sampling system and a sorbent trap sampling system. The results showed that the collaborative removal efficiency of VOCs could reach over 80% using the APCD system with ultra-low emission technologies. Boiler load would affect not only the concentration and distribution of VOCs but also the removal efficiency of the APCD system. The major products for 100% and 50% loads were aromatic and halogenated organic compounds, respectively. Besides, higher load also received more VOCs reduction benefits. The reduction of aromatics and alkane/alkene compounds could reach 93% and 94%, respectively. However, the reduction of polycyclic aromatic hydrocarbons in fly ash was 57%, and the reduction of halogenated organic compounds and oxygen-containing VOCs could only reach less than 45%. The major mechanisms for the removal of VOCs are oxidation and condensation through a selective catalytic reduction system (SCR) and the air preheater system. The types and reaction conditions of catalysts in the SCR system play an important role in promoting the removal of organic pollutants. The information generated from this study can help the power plant to select the correct control technologies for the VOCs emission. (C) 2020 Elsevier Ltd. All rights reserved.