Lower carbon flights in big commercial jets moved a step closer to reality today, as Shell and Rolls Royce inked a memo, committing both to co-developing SAFs, or sustainable aviation fuels.
Two months ago, engine builder Rolls-Royce launched SAFinity, its service enabling substitution of conventional carbon-laden avgas with new low-carbon fuel. The scheme supports only small business jets. Shell is SAFinity’s sole supplier.
Burned either neat or in blends alongside conventional avgas, SAFs are viewed as the key to greening mass aviation. They are made from a variety of sources, including refined animal fats, re-purposed cooking oil or even waste wood.
The liquids’ high power density fits them as a replacement for conventional fuel, both immediately and over decades to come. Electric planes, particularly big passenger carriers, struggle to overcome the disproportionate weight of batteries.
The Derby-headquartered engineer ranks alongside Pratt & Whitney and GE in the world’s top three producers of turbofan jets.
Built in Britain and Dahlewitz, Germany, its Trent XWB is the workhorse of over 700 planes now flying. It powers the Airbus, whose 350-plus seat variant can load up to 156,000 litres of fuel.
Rolls-Royce’s experience in achieving certification of clean fuels is the partnership’s attraction to Shell. The engine-maker already has a programme focused on 100%-pure SAF combustion. The parties see worldwide approval by aviation regulators for unmixed SAF in big jets as a key goal.
Paul Stein, the engine-maker’s chief technology officer, said the agreement would assist wider efforts to decarbonise the aviation sector.
“SAFs will not only power large aircraft and business aviation”, Stein predicted, “but also hybrid electric Urban Air Mobility (‘Flying taxis’) and the forthcoming generation of hybrid, fixed wing city hoppers.
“That’s why we place such importance on the ramp-up of SAFs across the industry.”