UK-based global major industrial technology group Rolls-Royce has carried out the first trials using 100% sustainable aviation fuel (SAF) in an engine developed for business jets. The tests were carried out at the group’s facility at Dahlewitz, in Germany, and came just weeks after it had successfully used unblended SAF in ground tests using a Trent 1000 engine (designed for widebody airliners) at Derby in the UK.

The SAF used in these tests was produced by a US specialist low-carbon fuel company, World Energy, based in Paramount in the state of California. It was sourced by global major energy company Shell and delivered by SkyNRG. This SAF, used unblended, could cut net lifecycle carbon dioxide emissions by more than 75%, with the potential for yet greater reductions in the future, in comparison to conventional jet fuels.

This test has reaffirmed that Rolls-Royce’s engines for both business jets and large civil airliners can operate on 100% SAF, without needing any modifications. This helps open the way to the certification of 100% SAF. Currently, SAF is certified only for use in blends of up to 50% with conventional jet fuel. 

The engine used in the Dahlewitz tests was Rolls-Royce’s latest in the business aviation category, the Pearl 700. “Sustainable aviation fuels have the potential to significantly reduce the carbon emissions of our engines and combining this potential with the extraordinary performance of our Pearl engine family brings us another important step closer to enabling our customers to achieve net zero carbon emissions,” highlighted Rolls-Royce Business Aviation chief engineer and engineering director Rolls-Royce Deutschland Dr Joerg Au.

The Pearl 700 has been developed using two sets of inputs. One of these was the company’s experience with its BR700 engine family, which is the leading business aviation jet engine family, while the other was its Advance2 engine technology demonstrator programme. 

“The highly efficient Pearl 700 combines the Advance2 engine core, the most efficient core available across the business aviation sector, with a brand-new low-pressure system, resulting in an 8% increase in take-off thrust at 18 250 lb compared to the BR725 engine,” stated Rolls-Royce. “The engine offers a 12% better thrust-to-weight ratio and 5% higher efficiency, while maintaining its class-leading low noise and emissions performance.”