Rolls-Royce has signed an agreement with Air BP for a 10% SAF blend which is now being delivered to the company’s three sites at Derby and Bristol in the UK and Dahlewitz in Germany.
Environmental organisations and interest groups have been hammering aviation for placing its hopes on sustainable aviation fuels (SAF) that are not yet available in large enough quantities. However, one significant company is doing its part, namely aerospace and engine manufacturer Rolls-Royce, which is already using two – three million litres per year.
Rolls Royce has committed to delivering engines to Boeing and Airbus that are compatible with and can run on 100% SAF. Part of the problem is trying to convince investors and regulators of the need for unblended SAF. Presently, most users of SAF are blending the fuel with existing. No one is using 100% SAF.
Rolls Royce says that engine technology is already compatible and there are no engineering issues on the engine level, nor any impact on flight capability, but acknowledges that an engine is only one part of a wider aerospace chain.
“What we’ve been doing is trying to show that you can run engines on 100% SAF. And the reason for that is not some sort of egotistical thing. What we’re trying to do is to show to the investors and those who make very, very big plays in petrochemicals that there isn’t a barrier to adoption at higher rates, that there is a path to net-zero, which I would define that very simply as not using fossil fuels to power aircraft. It’s not that I expect people to fly 100% tomorrow – there isn’t the capacity to do that – but to give people confidence that engine technology is not a constraint to that investment,” said Rolls-Royce’s Director for Engineering and Technology, Simon Burr.
Burr went on to say that there are some issues regarding some of the sealing systems of older aircraft. Some SAF makes the seals swell, causing leakages, while some SAFs also have a different effect on measurement systems for fuel quantity, so the calibration of pumps may need to be changed. Another problem is fuel temperature, making some SAFs more viscous. However, these are in no way insurmountable problems, Burr believes.
Rolls-Royce has successfully tested engines on 100% SAF. This includes its latest business jet engine, currently going through certification, the Pearl 700, and its Trent 1000 using a Boeing 747 as a testbed aircraft. The path to certification for 100% SAF is not up to the company but the regulators.
“There is a difference between being compatible and being certified. To be certified, you have to have an agreed standard. And then you test against that, and you say yes, it is certified. What we’re showing is that the SAFs that are available today, that our engines could operate with them, so we’re not frightened of a standard being developed, and we could then show that we’re compatible and certified against that,” Burr continued.
“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,” said Dr Joerg Au, Chief Engineer – Business Aviation and Engineering Director Rolls-Royce Deutschland.
In June this year, Rolls Royce predicts the first 100% SAF Transatlantic flight by end of next year 2023. “Flights across the Atlantic could operate on neat biofuel within 18 months from now,” said
Warren East, the Chief Executive Officer of Rolls-Royce while speaking at the CogX conference in London. “There have been thousands, probably tens of thousands of flights powered by sustainable aviation fuel. What people do is use a small portion of sustainable fuels in a mix, although 100% is technically possible. We’re testing our engines right now.”
Rolls-Royce is also confident in bringing electrically powered aircraft to market within the near future, possibly even by the mid-2020s. The company has already produced the world’s fastest all-electric plane, and has its sights set on transferring the technology to commercial operations. Mr East commented,
“We expect by the middle of this decade to have Rolls-Royce-powered aircraft with paying passengers, relying on pure electric, to carry a relatively small number of people, who are going a relatively short distance, maybe 10 people for 250 miles or so.”