Siemens Industrial Turbomachinery AB in Finspang, Sweden, manufactures gas turbines in the load range from 19 to 50.5 MW. The SGT-700 (33 MW) gas turbine has experience from more than one million hours of field operation using the 3rd generation DLE (dry low emissions) system. The same DLE burner is also used as standard in the SGT-800 (50.5 MW) engine and is an available option for the SGT-600 (25 MW) engine. Highly reactive gaseous fuels containing components such as hydrogen, ethane, propane or heavier hydrocarbons have traditionally been used in gas turbines with non-DLE combustion systems, resulting in high NOx emissions. The DLE systems have commonly only operated on natural gas fuels. Stricter environmental legislation pushes for the use of DLE engines also for the more reactive fuel types, thus potentially introducing combustion related problems such as flashback or instability. The stability and fuel flexibility of the 3rd generation DLE system has been systematically verified on both unreactive fuels containing nitrogen and reactive fuels containing hydrogen, ethane and pentane. Some recent data from continued tests with hydrogen is presented in this work. Propane was successfully used in the SGT-600 with DLE combustion system already in the 90′s, where an engine accumulated around 10 000 hours of operation. NOx emissions below 20 ppm were achievable at full load. Recently, ethane and propane has gained an increased interest as turbine fuels. An important example is the shale gas industry which has created an oversupply of low priced ethane and propane to the market. Other chemical industries, such as PDH (propane dehydrogenation) plants could also produce off-gases rich in ethane and or/propane. Propane or ethane could also be suitable as backup fuels to natural gas as they have many advantages compared to distillate fuels, which is commonly used as backup fuel for gas turbine installations. Commercial operation on propane has been verified in a SGT-700 in mechanical drive application for a PDH (propane dehydrogenation) plant in China. The gas turbine also uses another fuel source of variable composition predominantly consisting of ethane. The SGT-700 with DLE combustion system shows stable operation on both fuels in any combination. The current work describes the operation on ethane and propane rich fuels in the SGT-700.
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