LAS VEGAS—As business jet engine-makers continue to push toward more environmentally friendly performance, Rolls-Royce has successfully completed ground tests with 100% sustainable aviation fuel (SAF) on its Pearl 15 and the Pearl 10X turbofans.
The Pearl 15 powers Bombardier’s Global 5500 and 6500 aircraft, while the Pearl 10X–the third in the company’s Pearl engine series—will power Dassault’s ultra-long-range Falcon 10X. The tests took place at Rolls-Royce’s Business Aviation headquarters in Dahlewitz, Germany, and in the case of the 10X included back-to-back emissions tests with both conventional Jet A1 and SAF fuels.
Completed under standard certification conditions, the work was a “very cool exercise to do,” says Rolls-Royce Business Aviation Director Dirk Geisinger. “As you’d expect with the SAF we got significantly better emissions, most obviously on the nonvolatile particulate matter (nvPM) and with a big improvement in NOx (nitrogen oxides) emissions.”
The reductions in NOx improvement were “double-digit” compared with the BR700 engine family, says Geisinger, who adds that much of the improved emissions profile is attributable to the Pearl 10X’s combustor design. Developed and tested as part of Rolls-Royce’s Advance2 core demonstrator program, the combustor incorporates 3D-printed tiles, manufactured by an advanced Additive Layer Manufacturing process, which reduces the formation of emissions-generating hot spots.
Testing was done with HEFA (hydroprocessed esters and fatty acids) SAF that was produced from waste-based sustainable feedstocks such as used cooking oils and waste fat. Rolls-Royce says this fuel has the potential to significantly reduce net CO2 life-cycle emissions by about 80% compared with conventional jet fuel.
Rolls plans to complete testing all its current civil production engines with 100% SAF by year-end, and as part of that effort will evaluate the BR710 with the alternative fuel in the fourth quarter, says Geisinger. “We did those tests on a BR725 on a Gulfstream G650 in 2022 and so we are planning to do the same thing with the BR710, which will undergo ground tests at Rolls-Royce’s facility in Canada. The engine is already prepared and ready to go,” he adds.
