POLLUTANT EMISSIONS IN THE STRATOSPHERE

A survey is presented of pollutant emissions by turbojet engines. Chemical and physical processes resulting in the formation of polluting species in the combustor are described. Measurement techniques for determining species concentrations in the combustors and jet exhaust are considered. Pollutant formation mechanisms are dealt with from a constructor's point of view. Correlations of nitrogen oxide and carbon monoxide emissions are proposed for most existing engines, and in more detail for the Olympus turbojet mounted on the Concorde aircraft. Low pollution engines are discussed, and a two module combustor, allowing a reduction of nitrogen oxide production, is described.