Ansaldo Energia has been working on the use of low caloric value gas in heavy duty gas turbines since 1997. The special AE94.2K version, specifically designed for low BTU fuels (syngas, steel mill, blast furnace gases, biomass, etc.), can burn fuels with LHV in the range 8-13 MJ/kg and lower. The combustion system, including the modification to allow it to burn a wide range of fuels, has been patented.