Nitrogen Dioxide Formation in Gas Turbine Engines: Measurements and Measurement Methods

Abstract

Abstract The possibility of significant nitrogen dioxide (NO2 ) formation within a gas turbine engine is a topic of much current discussion. Theoretical studies generally predict the NO2 emissions to be negligible while some experimental studies suggest a large percentage of the total oxides of nitrogen (NO2) is emitted as NO2 at certain engine operating modes. Evidence in the literature supporting both points of view is reviewed and discussed. Methods of NO2 detection are discussed with particular emphasis upon the converter— chemiluminescent and non-dispersive ultraviolet instruments. Sources of substantial measurement error associated with each analyzer are also noted. In addition, errors induced during sample transfer from probe to analyzer are discussed. Results suggest significant NO2 losses should be expected during the sample transport process, and that at the present time it remains unclear as to whether gas turbine engines do or do not emit NO2.