Pollutant Emissions From Gas Fired Turbine Engines in Offshore Practice: Measurements and Scaling

Abstract

Field measurements of CO, NOx, N2O and UHC from natural gas fired gas turbines have been performed at oil production platforms in the North Sea and at an oil and gas processing plant on-shore. The measuring objects comprised a total of 17 engines. The emissions were measured at different loads, ranging from idle to 100% power output. The emissions vary considerably as a function of load. NOx and UHC agree reasonably well with manufacturers’ data. The NO2/NOx ratio is inversely proportional to the load. The CO emissions are somewhat lower than specified. N2O emissions are typically less than 2 ppmv @15% O2, dry. From the collected data, a scaling law for NOx emissions is developed. The scaling law is based on machine specific parameters governing NOx production and will apply to gas-fired turbine engines at various loads in the power range and makes indicated. Good agreement between measured and predicted NOx emissions from the proposed correlation is achieved.