A New Concept for the Reduction of Pollutant Emissions in Industrial Gas Turbine Plants

This paper examines the possibility of reducing pollutant emissions from industrial and ground-based aero-derivative gas turbines by means of a new oxygen enriched combustion system. The emissions considered pollutants are carbon monoxide (CO), unburned hydrocarbons (UHC), nitrogen oxides (NOx) and smoke, whereas the presence of sulphur dioxide (SO2) and heavy metals is disregarded because sulphur and metallic compounds are supposed to be removed from or not contained in the fuel. Various thermodynamic parameters, such as specific heat, adiabatic coefficient and diffusion constant are compared when oxygen is used instead of air in a combustion chamber, and a simplified combustion model based on the computation of chemical equilibria of 14 given species is used for predicting the main pollutants. A comparison of the compression power requirements for both pure oxygen and air is also made. The results show that, with suitable oxygen enrichment in gas turbine combustion chambers, a reduction of the major pollutant emissions is theoretically feasible with a combined increase in power production.