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NOx Emissions from Coal Combustion

AUTHOR: Lesley L. Sloss
DATE: March 1991

This report evaluates the extent to which coal combustion contributes to the emissions of nitrogen oxides to the atmosphere, the resulting concentrations and environmental effects.

The report addresses:

  • nitrogen chemistry;
  • effects of nitrogen oxides;
  • emission sources and concentrations;
  • transport and deposition of NOx;
  • regional emissions, concentrations and legislation;
  • impacts of legislation and future NOx emissions.

Although NOx arises from natural sources, the majority of emissions are due to the combustion of biomass and fossil fuels. Combustion of coal, oil, gas and related fuels in both stationary and mobile sources accounts for around 42% of total global NOx emissions. By far the largest source of NOx in most IEA countries is oil, and in particular the transport sector which alone accounts for at least 50% of the emissions arising from human activities. Power stations are likely to account for 25% of emissions due to human activities, of which only part is due to coal.

Several countries including the FRG, Japan and the USA introduced restrictions on NOx emissions a number of years ago and are already reporting a reduction in emissions in some areas. Other countries have been slow to follow.