An Emirates Boeing 777-300ER has performed a demonstration flight using 100% sustainable aviation fuel to power one of its two GE90 engines. The flight on 30 January was the latest initiative in an industry campaign to secure regulatory approval for flights fully powered by SAF. Currently, the maximum allowed is a 50% blend with conventional jet fuel. It was conducted in partnership with Boeing, GE Aerospace, Honeywell and renewable fuel companies Neste and Virent. The flight, which followed the Dubai coastline for more than one hour, was a key initiative of the ‘Year of Sustainability’ declared by the UAE to highlight what it describes as a commitment to and capability of delivering innovative responses to energy challenges, climate change and other sustainability issues. Emirate’s first flight with blended SAF was in 2017, on a Boeing 777 flying from Chicago, and in 2020 SAF was used to part-power the delivery flight of an A380.
“This is a milestone moment for Emirates and a positive step for our industry as we work collectively to address one of our biggest challenges – reducing our carbon footprint,” commented the airline’s COO, Adel Al Redha, who travelled on the test flight. “Emirates is the first passenger airline in the world to operate a Boeing 777 powering a GE engine with 100% SAF,” he said. “Such initiatives are critical contributors to industry knowledge on SAF and provide data to demonstrate the use of higher blends of SAF for future regulatory approvals. We hope that landmark demonstration flights like this one will help open the door to scale up the SAF supply chain and make it more available and accessible across geographies, and, most importantly, affordable for broader industry adoption in the future.”
The weight and lack of sufficient range for batteries and the immaturity of hydrogen as a near-term source of low emission propulsion, mean SAF is the only viable option to decarbonise large aircraft such as the Boeing 777 or the Airbus A380, both of which Emirates is the largest operator.
To perform the demo flight, the first in the Middle East and Africa to operate with 100% SAF, the airline worked with its partners to procure and develop a blend that closely replicated the properties of conventional fuel. Once a blend ratio was reached which reflected the characteristics of jet fuel, 18 tonnes of SAF were produced for use on the flight.
The SAF was comprised of hydro processed esters and fatty acids and synthetic paraffinic kerosene (HEFA-SPK), supplied by Finland-based Neste, and hydro deoxygenated synthetic aromatic kerosene (HDO-SAK) from US-based Virent. Neste’s ’drop-in’ SAF is mainly produced from waste fats, oils and greases, then blended with conventional fuel, while Virent converts widely-available plant-based sugars into compounds which enable the production of 100% SAF, without a requirement for blending. Virent used its BioForming process to produce the SAK, a critical component that made the 100% SAF possible, as today’s SAF – typically made from used cooking oil or other plant-based oil feedstocks – has to be blended with conventional jet fuel because they lack the aromatics required to meet jet fuel specifications. The Virent product was used to help other 100% SAF-powered demo flights conducted by United Airlines in December 2021 and Gulfstream in December 2022.
“SAF will play a critical role in the aviation industry’s commitment to be net zero by 2050, requiring strong industry collaboration,” said Omar Arekat, Boeing’s VP Commercial Sales and Marketing, Middle East.
Added Aziz Koleilat, VP Global Sales and Marketing for GE Aerospace in the Middle East, Eastern Europe and Turkey: “Collaborations like this to test 100% SAF globally will help bring us closer to this target.”
Honeywell Aerospace, which produces the auxiliary power unit for the Boeing 777, also participated in the Emirates SAF trial. “The APU provides main engine starting, environmental control and emergency back-up systems for the aircraft on the ground and in flight. It uses the same fuel as the main propulsion engines,” said Mosab Alkubaisy, Director of Airlines for Honeywell Aerospace, Middle East. “Currently the APU is certified to run only on 50% SAF, so this demonstration is a big first step in showing full APU functionality and capability when running on 100% SAF.”
Jonathan Wood, Neste’s VP Europe, Middle East and Africa, Renewable Aviation, said sustainable fuel played a key role in cutting aviation’s emissions, “but to fully leverage its decarbonisation potential we need to enable 100% SAF use.” He reported Neste was working closely with partners to speed up the supply and use of SAF as the company prepared to increase its production capacity to 1.5 million tonnes per year with the commissioning of new production facilities in Singapore and Rotterdam. “We look forward to growing the supply of SAF also to Dubai,” he said.
Virent’s President and General Counsel, Dave Kettner, welcomed the opportunity to demonstrate “that we can power sustainable aviation without modifying today’s modern airline engines or the infrastructure that serves the airline industry. Along with our parent company, Marathon Petroleum Corporation, we are committed to meeting today’s energy needs while investing in an energy-diverse future.”
Saif Humaid Al Falasi, Group CEO of the Dubai government-owned Emirates National Oil Company (ENOC), said: “We prioritise working closely with our strategic partners to implement a national roadmap for sustainable aviation fuel. This not only aims to accelerate the decarbonisation of the aviation sector, but also contributes to achieving the UAE’s goals in climate neutrality, enhances the efficiency and conservation of fuel, as well as positions the UAE as a regional hub for sustainable aviation fuel. Playing an active role in supplying Dubai Airports with aviation fuel, ENOC Group is participating in this achievement by securing and blending sustainable aviation fuel, which will help to secure this type of fuel in the UAE in the future.”
Emirates has 134 passenger and freight variants of Boeing 777 aircraft flying 119 routes, from the 349 km Dubai-Muscat sector to the 12,940 km journey between Dubai and Dallas Fort Worth. Aviation data group OAG has just ranked Dubai International Airport as the world’s second busiest global hub in 2022, after Atlanta Hartsfield-Jackson.