Aircraft

European project says synthetic fuels could be vital

Members of a European project developing a strategy to reduce aeroengine emissions are seeking funding for research into advanced combustor technology, computational fluid dynamics and alternative hydrocarbon fuels.

The Technologies Enhancement for Clean Combustion in Aero-Engines (TECC-AE) project is proposed for funding under the European Union's Seven Framework programme. It would implement the strategy developed under the European Low-Emission Combustor Technology in Aero-engines (ELECT-AE) project.

Begun in January 2005, ELECT-AE is a four-year, €1.5 million ($2.1 million) European Commission-funded Sixth Framework project to develop a strategy to achieve the NOx emission reduction targets established by the Advisory Council for Aeronautics Research in Europe.

If approved, the TECC-AE research would focus on combustors and include work on flame stability, cooling methods and injection systems. Members of ELECT-AE met in early September to discuss alternative hydrocarbon fuels as part of its second ultra-low-NOx strategy workshop.

Synthetic fuels are expected to have lower NOx emissions, Rolls-Royce Deutschland combustor aerodynamics researcher and ELECT-AE co-ordinator Ralf Sebastian von der Bank said at the first Council of European Aeronautical Societies' European air and space conference.

"There is over 10 years of assessment of Fischer-Tropsch kerosene and Jet-A blends, and coal-to-liquid blends have already been approved," he says. The approved blend is 50:50 mix of Jet-A and CTL fuel produced by South African company Sasol, which has developed a 100% synthetic FT jet fuel now being assessed by engine manufacturers Pratt & Whitney, General Electric, Honeywell and Rolls-Royce.

Synthetic fuels are expected to have a high thermal stability that provides a low NOx output, but the industry has little knowledge about their emissions and compatibility with the lean-burn combustors planned for future engines.

Led by Rolls-Royce Deutschland, ELECT-AE's other members include French and German aerospace agencies ONERA and DLR as well as Alstom, Snecma, Avio, Turbomeca and MTU.