Emissions of volatile organic compounds by coal-fired power stations

This study concerns the emissions of volatile organic compounds (VOC) by coal-fired power stations. The most abundant compounds are aldehydes (formaldehyde and acetaldehyde), aliphatic and aromatic hydrocarbons (toluene, xylenes, ethylbenzene and benzene) and chlorinated hydrocarbons (tetrachloroethene). The relative importance of combustion parameters determining the level and the nature of emissions is described. The most important of these is the load of the station. A method is proposed to evaluate the combustion efficiency and to show the relationship between the compounds emitted, the compounds formed during the combustion and those already present in the fuel. Mechanisms are proposed to explain the formation of chlorocompounds. Finally, a comparative study of the two sources of VOC—power stations and motor vehicle—indicates that the impact of the second on the environment is, by far, the most important.