SAF fuels

SAF fuel is a sustainable aviation fuel produced from renewable sources (used oils, biomass, waste) that significantly reduces CO₂ emissions. In 2008, Virgin Atlantic operated the world's first commercial flight partially powered by biofuel. A Boeing 747 linked London with Amsterdam using a blend made from coconut and babassu oils.

What was relevant about that milestone was not just the flight itself. It was the fact that it was done without any technical modification to conventional engines, demonstrating that the existing infrastructure was already capable of accommodating the transition.

But in order for the industry to adopt this solution massively, a global safety framework was needed. This was consolidated in 2009, when the international organization ASTM International published ASTM D7566. A regulation that defines the specifications that an aviation fuel containing synthesized hydrocarbons must meet. Thanks to this standard, SAF fuel earned the “drop-in” fuel label. In other words, a liquid that can be mixed with traditional kerosene in current infrastructures without risk to aviation safety.

SAF fuel can be produced from different raw materials, such as used cooking oils, agricultural waste, or forest biomass, through processes that transform those materials into a fuel with properties similar to conventional kerosene. Examples include the hydrogenation of oils or the combination of renewable hydrogen with captured CO₂.

Currently, there are several certified production methods that guarantee its safe use in commercial aviation. In addition, new ways are being developed to incorporate more types of waste and technologies, with the aim of expanding production capacity and advancing the decarbonization of the sector.

The European Union, under the Fit for 55 package, has designed the ReFuelEU Aviation regulation to decisively boost the supply and demand of sustainable fuels for the aviation sector. This framework seeks to reduce aviation’s carbon footprint while contributing to the continent's energy sovereignty. Thus, it establishes mandatory SAF incorporation quotas that all EU airports must comply with:

A progression that recognizes the viability of SAF fuel as a valid technology to reduce carbon emissions. Indeed, according to IATA data, the SAF used in commercial aviation can reduce CO₂ emissions by up to 80%.

At Repsol, we have become a key enabler, anticipating EU measures through a strategy based on industrial capacity and technical innovation. We are not just a supplier. We are an engine that allows the emission reduction plans of our partners in the aeronautical sector to become tangible milestones.

An ambitious response that is perfectly visible in our Cartagena Industrial Complex, where in 2024 the first plant in the iberian peninsula dedicated exclusively to the production of 100% renewable fuels on a large scale was launched.

With an investment of 250 million euros, this facility has a production capacity of 250,000 tonnes per year. We apply advanced hydrogenation processes to transform 300,000 tonnes of organic waste, such as used cooking oils and agri-food waste, into renewable diesel and SAF. 

This plant is an example of circular economy that prevents the emission of 900,000 tonnes of CO₂ per year. But Cartagena is just the beginning of a vision that expands to 2.7 million tonnes of capacity by 2030. A present and future project that, in reality, is the result of many previous works in the field of industrial investment and innovation.

As we said, the consolidation of the Cartagena plant is based on a series of previous milestones.

In 2021, we operated the first domestic flight with Iberia using biofuel produced from waste at the Petronor refinery. That journey between Madrid and Bilbao, carried out with an Airbus A320neo, resulted in a reduction of 1.4 tonnes of CO₂ and demonstrated the technical feasibility of circularizing waste to power commercial aircraft.

Just a few months later, in November of that same year, the partnership was extended to Vueling, which operated its first flight with SAF between Barcelona and Seville, coinciding with the Tourism Innovation Summit. On that occasion, we used renewable fuel produced from biomass at the Tarragona industrial complex, managing to prevent the emission of 2.5 tonnes of CO₂.

The validation of this technology went beyond the civil sphere in 2022. During Spain’s National Day airshow, the Spanish Air and Space Force’s Patrulla Águila used our renewable fuel for the first time. That the elite acrobatic unit relied on this biojet for its precision maneuvers was the definitive proof that the technical performance of the product meets the most demanding standards of military aviation.

With the technology more than validated, 2023 was the year of the leap to large commercial scale. We signed with Ryanair, the leading airline by number of passengers in Europe, a strategic agreement to promote the use of renewable fuels in Spain and Portugal. This pact guarantees Ryanair access to 155,000 tonnes of SAF between 2025 and 2030, a volume equivalent to more than 28,000 flights between Dublin and Madrid that will prevent the emission of about 490,000 tonnes of CO₂. This partnership is a fundamental piece for the Irish airline to achieve its ambitious goal of operating with 12.5% of SAF by the end of the decade.

In 2024 there were new agreements ranging from specific routes to the largest operation in the history of the sector in Spain.

First, we agreed with Volotea to use 50% of SAF on the Madrid-Murcia route, to subsequently expand their collaboration in August with a supply contract of more than 6 million liters until 2029. This commitment will allow Volotea to comply with the 2% quota required by the European ReFuelEU Aviation regulations.

Simultaneously, innovation was extended to logistics through the "Círculo SAF", an initiative with Iberia, Amadeus, BBVA, and Telefónica to reduce emissions in corporate travel and air cargo. Within this framework, Inditex signed an agreement to use 5% of SAF to transport its merchandise.

Finally, in July 2024, we closed the circle with the largest voluntary purchase of SAF made to date in Spain: the IAG group acquired more than 28,000 tonnes to supply Aer Lingus, British Airways, Iberia, Iberia Express, and Vueling, confirming that sustainable aviation has ceased to be a pilot project to become a reality.

Our commitment to SAF continues and is consolidated. Thus, we designed the Ecoplanta in Tarragona, with an investment of more than 800 million euros, to transform waste into renewable methanol, which in turn can be a raw material to manufacture SAF.

The strategic position of SAF fuel in aviation places us before a necessary reflection on the future of land mobility. If the European Union has validated this technology as a solution to decarbonize aviation, precisely because long-range electrification is currently unfeasible, it is incoherent not to apply the same pragmatism to heavy-duty road transport.

In addition, when we process waste in Cartagena to obtain SAF, we simultaneously produce fuels for road transport (HVO or diesel of 100% renewable origin). The production of both is indivisible. It is not feasible to produce SAF massively if renewable fuels are not also validated as another decarbonization option for transport.

A position defended in the Manifesto of the Global Initiative for Sustainable Fuels, signed by Repsol together with leaders such as Airbus, BMW, Iveco, or Ryanair, which argues that decarbonization requires technological neutrality.

Renewable fuels are an immediate solution, making the most of the refueling infrastructures and fleets that already exist today.

If SAF is the key to reducing emissions in air transport, diesel of 100% renewable origin is the key to reducing the land carbon footprint, without waiting years to renew critical infrastructure and without impacting the competitiveness of companies.

It's time for the pragmatism that allows us to reduce CO₂ when we fly to land on our roads, ensuring all technologies contribute towards the path to carbon neutrality.