Domenico Cipriano* The 33rd International Technical Conference on Coal Utilization & Fuel Systems Clearwater, Florida, USA, 1-5 Giugno 2008 * CESI RICERCA The Author has developed and tested an improved measurement protocol in order to characterize the hitherto poorly documented level of fine (PM10 and PM2.5) particles emitted by gas turbines burning natural gas. The method, that is a refinement of the state of art monitoring techniques, addresses the predictably low emission level and has been validated within an inter-laboratory measurement campaign on a 40 MWe gas turbine. The metrological improvements adopted included: computer assisted isokinetic sampling; high precision weighing and long lasting sampling. In a preliminary step, a horizontal section of the flue gas stack has been qualified for the uniformity of flow and particle concentration. This section was used as a common platform for parallel sampling by the two laboratories. This methodology enabled the collection of statistically homogeneous samples, a necessary condition for unbiased estimation of measurement reproducibility. In addition, these emission data were correlated with the ambient air quality measurements; samples of ambient air dust that were submitted to microscopic examination and chemical speciation along with some of the emission samples. As major outcomes: – Detection limit of the method around 50
g/m03 – Level of particle emitted by the gas fired CCGT is, as expected, well below the 1mg/ m03 range : no value higher than 80
g/ m03 has been actually measured. – The scattering of the inter-laboratory results is rather high which shows the high degree of attention to be paid to protocol details in the measurement of very low emissions – there is no evidence of any contribution of the combustion process to the dust content. the emitted particles are not different from the ambient dust except disappearance of carbon matter that has been burned in the combustion.