麻豆传媒

For aviation to progress towards net-zero emissions and support the world in achieving the goals of the Paris Agreement, new sustainable modes of flight are needed.

Despite significant investment in electric and hydrogen propulsion, these technologies are unlikely to have a scale impact on aviation emissions until 2050 or beyond.

This leaves sustainable fuel, made from waste and renewable biomass sources as the most viable option for aviation to start cutting emissions in the short to medium term. Most importantly, this fuel can be used in the current generation of aircraft, with delivery via the current fuelling infrastructure.

A significant step in the development of sustainable fuels was made on 12 October 2009, when a Qatar Airways Airbus A340-600 undertook the world鈥檚 first revenue passenger service with a certified synthetic fuel made from natural gas.

The fuel was developed by Shell Aviation, which produced a 50:50 blend of synthetic gas to liquid kerosene (GTL) and conventional oil-based kerosene, at its GTL plant in Bintulu, Malaysia. The blend was used in one of the A340鈥檚 Rolls-Royce Trent engines for the six-hour flight from London to Doha.

The demonstration followed a two-year intensive study into synthetic fuel technology, which was announced at the Dubai air show in November 2007 by a team comprising Qatar Airways, Qatar Petroleum, Shell, Airbus, Rolls-Royce, Qatar Science & Technology Park and Woqod (Qatar Fuel Company).

Shell began developing GTL technology in the 1970s and opened the world鈥檚 first commercial GTL plant in Bintulu in 1993 and the world鈥檚 largest GTL plant, Pearl GTL, in Qatar in 2011.

GTL burns with lower sulphur oxide and particulate emissions compared to conventional kerosene, which make it attractive for improving local air quality at busy airports. Although that first flight still relied on fuel from fossil sources, natural gas rather than oil, the technology is now being developed to produce fuel from renewable and waste feedstock sources, providing the aviation industry with the options of continuing to fly, while emitting less over the lifecycle of the fuel, as it works to meet its sustainability targets.

In 2021, Shell helped advance this concept further, producing 500 litres of a synthetic Power-to-liquid kerosene in The Netherlands. On 8 February 2021, this fuel was mixed with regular jet fuel and used to power a KLM flight from Amsterdam to Madrid, the world鈥檚 first scheduled passenger service using certified synthetic kerosene from a non-fossil fuel source.

This Power-to-liquid kerosene, or e-fuel, was produced by combining captured carbon with green hydrogen made from water and renewable power. As the availability of the carbon feedstock is potentially abundant, synthetic kerosene made in this way is viewed as one of the more promising long-term options for production of SAF at the volumes required to help aviation progress towards net-zero emissions.

Sources:

_{R. van Egmond and A. Westra, Shell and aviation. The story of more than a century of collaboration. Shell International B.V., 2019, p. 87.
Gas-to-Liquids Jet Fuel development ICAO Workshop Montreal 10-12 jan 09, see:}