Airline aimed to send a double signal by crossing the Atlantic fuelled by cooking oil. Ian Taylor reports
Virgin Atlantic’s flight from Heathrow to New York using 100% sustainable aviation fuel (SAF) in late November marked “a step change” and showed “how far we’ve come”.
That is according to Virgin Atlantic head of sustainability Luke Irvine, who noted the airline first flew a biofuel test flight to Amsterdam in 2008, using a 20% blend of biofuels in a single engine.
Speaking on the flight, Irvine insisted: “Being able to fly on 100% SAF is a step change. We wanted to send a signal that 100% drop-in SAF is safe, but also send a demand signal.
“We’ve shown the technical capability to produce SAF. What we need now is a price-support mechanism and the SAF mandate [promised by the government] so investors can be confident there will be demand for SAF.”
He pointed out: “The government is committed to having five UK SAF plants in construction by 2025. But we’ll need more.
“The UK will need 1.25 million tonnes of SAF by 2030. It produced 16,000 tonnes last year.”
Alistair Blanshard, sustainable aviation lead at consultancy ICF which carried out the carbon lifecycle analysis on the Virgin Atlantic flight, agreed. He argued: “SAF requires a whole industry to be built.
“The fossil fuel industry is huge and has been developing for 100 years. At the end of 2021 we produced just 0.3 million tonnes of SAF globally. By the end of this year there is expected to be two million tonnes of SAF, mostly in western countries. It has increased sixfold.
“We expect an additional two million tonnes in 2024. That is the amount of aviation fuel used in Switzerland. Germany alone uses 10 million tonnes. But we’ve built the foundation to start using this fuel at scale.”
Not a 100% reduction in emissions
Most of the SAF on the flight was produced from used cooking oil, using a process for refining waste oils or fats to produce fuel termed HEFA (Hydrotreated Esters and Fatty Acids). The remaining 12% of fuel was made from corn waste in the US, producing Synthesised Aromatic Kerosene (SAK).
The two fuels had not been blended previously but combined to produce a fuel with identical properties to oil-derived kerosene or jet fuel.
Responding to criticism that the flight released the same CO2 emissions as a fossil-fuel flight, Blanshard pointed out the plants to produce the oil and corn “sucked carbon out of the atmosphere” when growing, so returning the carbon to the atmosphere created a carbon cycle.
He acknowledged: “It’s not a 100% reduction [in carbon added to the atmosphere] because of the emissions in the fuel production process.”
But he insisted: “It’s a case of doing the best we can with the resources we have. There is a trade-off between [being] perfect and [making] progress. No one thing, such as used cooking oil, is the solution. But this is not the end. Cooking oil is a stepping stone. It’s about developing technologies.
“There have been 300,000 flights using blended SAF already. The industry is moving from proving it is safe to commercial development.”
Blanshard added: “It has probably taken two decades to get here.
“The UK and EU don’t allow any crops to be used for SAF – that is important. We’re focussed on more-sustainable feedstocks in the UK [such as] developing solid biomass from municipal waste [when] most municipal waste is buried in the UK and decays to produce methane.”
He insisted: “We know where we want to get to. It’s true, SAF is just 0.1% of aviation fuel today and, globally, biofuel is 2%-3% [of total fuel supplies]. But in California over half the [road] fuel is biodiesel. It’s changing so quickly.”
‘We need 150 times what we have today’
It was the government, and then transport secretary Grant Shapps, which issued a challenge to operate the first transatlantic flight using 100% SAF in May 2022, offering up to £1 million in funding.
Virgin Atlantic led the consortium which took up the challenge. Corneel Koster, Virgin Atlantic chief customer and operating officer, said: “Kudos to the Department for Transport for setting this target. It triggered us to think about what’s possible.”
He hailed completion of the flight as fulfilling “a big ambitious goal” and said: “This was as safe as any Virgin Atlantic flight and the fuel can just be dropped in. That is a big message.
“It shows SAF can help to start decarbonising aviation. We want to fly it. But we need 150 times what we have today.”
Koster insisted: “Politicians fully understand what is needed. The message is getting through.”
The government is committed to a ‘SAF mandate’ requiring 10% of UK aviation fuel to be SAF by 2030. But airlines want the government to move quicker on introducing a price-support mechanism for UK SAF production, which is currently not expected until 2026.
Koster said: “The source of this fuel, the feedstocks, now are limited. But household waste could be a huge source of SAF. There are substantial feedstocks there.
“Another feedstock is waste biomass from agriculture and forestry. There is enough [of these] to supply 10% SAF.”
Irvine explained: “We worked on this project for 16 months, but in earnest since April.
“We knew we could solve it, but it has taken the whole value chain working in partnership to make sure it is not just possible from a technical perspective but that we build and share research [data]. We need industry collaboration.”
He noted: “Rolls Royce and Boeing have been involved in similar projects before, including an RAF SAF flight in November 2022. They brought that learning to the table.
“The biggest challenge was ensuring it all came together – the fuel, the approvals, the testing, the partner contributions, making sure the fuel was in the right place, bringing the fuels together in time as we had two fuel components which had never been blended.”
Irvine pointed out: “HEFA is only one form of SAF. The UK wants to develop a second-generation SAF industry, utilising different feedstocks – wood biomass, agricultural residues, municipal solid waste.
“We’re looking to get clean feedstocks. We have our own criteria. We’re very careful not to compete with food or agricultural land use.”
However, there is no international alignment on the feedstocks for aviation fuel, with the US – the world’s biggest producer of biofuel – most commonly using ethanol derived from corn grown for that purpose.
Irvine said: “We need more alignment between countries on feedstocks. It’s a challenge when you have different thresholds.
“If the US uses different feedstocks, it will limit our ability to use [US] SAF and there is not enough SAF already.”
Asked about alternative fuels, Koster acknowledged: “Hydrogen is exciting but very challenging. It needs an aircraft fuel tank three times bigger [than kerosene]. With electric batteries, the issue is the weight.”
He insisted: “SAF can be used now. We need aviation and this is the way to do it. It’s a matter of getting more serious about this.”