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The “4th Generation DLE” (4G-DLE) gas turbine burner has been developed at Siemens Industrial Turbomachinery AB in Finspong, Sweden (SIT). The present document describes the design concepts of the 4G-DLE burner; emission performance and fuel flexibility capacity. These features were explored at atmospheric conditions at SIT. High concentrations of H2 and N2 mixed with natural gas were used in the experiments. Emissions (NOx, Unburned hydrocarbons, CO), combustion dynamics and temperature operation range were evaluated. Moreover, operation characteristics of the burner were investigated through forced flashback, flameouts and unfavorable ignition situations. The fuel flexibility concerning H2 stretched up to 90% vol. in a mixture with natural gas. In the case of N2 it was possible to use over 50% vol. mixed with natural gas. The operation was stable in all cases. The 4G-DLE burner showed good NOx emission performance that was linearly dependent on the flame temperature, while CO levels were also low. This fact reveals the high mixing level achieved in the burner. Finally; the burner operated over in a wide flame temperature range (approximately 200 K), showing both good stability and good emission levels.

Associated gases at oil wells are often rich in heavy hydrocarbons (HHC, here denoting hydrocarbons heavier than propane). HHC cause handling difficulties and the combustion properties are quite different from standard natural gas. For this and other reasons HHC rich associated gases are often flared or vented. This is an enormous waste of useable energy and a significant contribution to emissions of pollutants, global CO2 and other greenhouse gases. Siemens Industrial Turbomachinery AB in Finspong (SIT AB) recently tested a standard DLE 25 MW SGT-600 gas turbine and a standard 31 MW SGT-700 gas turbine with HHC rich natural gas. Pentane was chosen as a model substance for HHC. The tested gases had up to 30% of the fuel heating value from pentane. The unmodified standard DLE gas turbines proved to be very tolerant to the tested pentane rich gases. CO emissions were reduced with increasing pentane content in the fuel for the same power output. NOx was observed to increase linearly with the pentane content. Combustion dynamics was affected mildly, but noticeably by the pentane rich fuel. This result, together with earlier presented results for the same DLE engines on nitrogen rich natural gases, gives an accepted and tested total LHV range of 25–50 MJ/kg and Wobbe index range of 25–55 MJ/Nm3. No special adaptation of the gas turbines was necessary for allowing this wide fuel range. The benefit of increased and proven fuel flexibility is obvious as it allows the gas turbine owner to make full use of opportunity fuels and to supply power at low fuel cost.

Catalytic systems for methane combustion, with Rh and Pt in a BaZrO3-based perovskite, were synthesized at the University of L’Aquila and tested at close to industrial conditions at the KTH Energy Centre in Stockholm. Because of the resistance to high temperature of BaZrO3 (up to ∼2600 °C), such systems are suitable for resolving stability problems frequently encountered with high-temperature operations. Furthermore, these perovskites contain the noble metal in a high oxidation state, giving rise to very active compounds. They also result in ultra-low emissions, compatible with legislation in such places as southern California and Japan.