Origin and monitoring of pollutants in fossil-fuel flames

A review is given of the origin of pollutants in fossil-fuel flames. Burning of fossil fuels is the major cause of air pollution and significant reductions in levels of environmental pollution can be achieved by more effective control of combustion systems. The chemical kinetics of formation of unburned hydrocarbons, oxides of nitrogen, carbon monoxide and particulate matter are described, as well as the reactions which can lead to oxidation and destruction of these pollutants within the flame. The important influence of mixing and aerodynamics is discussed, together with methods of mathematical modelling and prediction methods. Practical problems arising in gas turbine engines, spark ignition engines and diesel engines are investigated in order to minimize the emission of pollutants while preserving fuel economy. (author)