SAF was first introduced on a commercial aircraft back in 2008. Today it is key to achieving the industry’s low carbon goals. Although innovations in hybrid and electric as well as hydrogen-powered aircraft are advancing all the time SAF is available today and is recognised as key to achieving the aviation industry’s lower-carbon goals both now and in the future. According to the Air Transport Action Group (ATAG), more than 400,000 commercial flights have already taken place using SAF, since it was approved for use in aircraft operations in 2011.
The main challenge with it currently is that limited production capacity and cost premiums over conventional fossil fuels mean that SAF today comprises less than 0.1% of total aviation fuel consumption.
The spotlight is now on achieving the same optimisation and a wider roll-out for SAF as a drop-in fuel, as has been achieved for conventional jet volumes over the decades.
SAF production and feedstocks
Produced from sustainable feedstocks SAF is very similar in its chemistry to traditional fossil jet fuel. Some typical feedstocks used are used cooking oil and other waste oils from animals or plants; solid waste from homes and businesses, such as packaging, paper, textiles, and food scraps that would otherwise go to landfill or incineration. Other potential sources include forestry waste, such as waste wood, and energy crops, including fast growing plants and algae. Air bp supplied SAF is made from waste-based sustainable feedstocks such as used cooking oils, and in future household wastes.
Approved SAF production pathways are defined according to a combination of accepted feedstocks and specific conversion processes, ensuring that the products of the pathway are known and understood.
Pathways currently approved are:
| Pathway description | Max blending ratio |
| Fischer-Tropsch synthetic paraffinic kerosene (SPK) | 50% |
| Hydrotreated esters and fatty acids | 50% |
| Synthesised iso-paraffins produced from fermented sugars | 10% |
| Fischer-Tropsch SPK plus synthesised aromatic components | 50% |
| Alcohol to Jet produced from either ethanol or butanol | 50% |
| Catalytic Hydothermolysis Jet produced from esters and fatty acids | 50% |
| Hydroprocessed hydrocarbons produced from algal oils | 10% |
Before being delivered to an airport, SAF is blended at up to 50% with traditional jet fuel before being re-certified as Jet A or Jet A-1. It can be handled in the same way as a traditional jet fuel, so no changes are required in the fuelling infrastructure or for an aircraft wanting to use SAF. In 2016, Air bp was the first operator to commence commercial supply of SAF through an existing hydrant fuelling system, at Norway’s Oslo Airport.
Scaling up SAF supply with existing facilities
SAF can be certified under a range of certification schemes. The International Sustainability & Carbon Certification System (ISCC) is one such scheme offering independent third-party certification. It ensures compliance with high sustainability requirements, carbon emission savings and traceability throughout the supply chain. Air bp’s Castellon refinery in Spain is ISCC PLUS certified.
The limited availability of production plants available today is one of the primary factors restricting SAF supply. To help boost production bp believes that co-processing SAF at existing refineries will help the sector as it transitions to a low-carbon industry, while building dedicated and more efficient standalone units for SAF production.
Co-processing is a method where vegetable oils, waste oils and fats, or similar sustainable feedstocks are processed along with crude oil feedstocks in existing refineries. This can offer benefits in terms of cost savings and carbon reduction as it removes the need to build dedicated processing units. The fuel can also enter the standard distribution infrastructure to airports, again reducing transport and complexity.
In 2018, Air bp, working with Chevron and Phillips 66, gained approval for a co-processing pathway featuring vegetable oils or waste oils and fats for SAF production. This was a ground-breaking move as it opened the door for traditional refineries across the globe to enter SAF supply. Thoughts then turned to potential approval for co-processing Fischer-Tropsch syn-crude, an intermediate product featured in a municipal waste to SAF route. This would benefit bp’s investment in 2016 in California-based Fulcrum BioEnergy, a company commercialising such a process. In July 2020 ASTM approval was gained, a significant success for Air bp and Fulcrum.
More recently, in 2022 Air bp marked another milestone when bp’s refinery in Lingen, Germany used co-processing to produce SAF from used cooking oil. Speaking at the time, Martin Thomsen, CEO, Air bp, said: “Co-processing is an important step in replacing fossil fuel with renewable feedstocks within refineries. This production of SAF at Lingen will open up new supply opportunities in the region.”
Using mass balancing to meet blending mandates
To scale up production and increase supply, blending mandates alongside other regulatory measures, including incentives to bridge the gap with conventional jet fuel, are currently being introduced in countries around the world.
A central component of the European Union’s (EU’s) strategy to reduce emissions 55% by 2030, compared to 1990 levels is a blending mandate for SAF via the ReFuel EU Aviation Initiative. The proposal includes a blending obligation for fuel suppliers. From 2030, the aviation fuel made available to EU airports should contain 5% SAF, increasing to 63% by 2050.
The EU’s SAF blending mandate will require multiple supporting policies including preferential feedstock access for the aviation sector and a long-term framework to support SAF production. In addition, and rather than mandating that SAF should be segregated and available at all airports, Air bp believes in the implementation of mass balancing centres within a country from which SAF can be delivered into select air transport hubs, to decrease the regulatory cost burden and simplify logistics. This approach would allow fuel suppliers to meet SAF targets within a country or region by delivering the necessary SAF quota to a particular airport or several larger locations, rather than physically moving small volumes to every single airport.
Increasing SAF supply shouldn’t be about how much of the fuel is being delivered into one particular airport or aircraft. Ultimately it should come down to how much SAF is replacing conventional fossil fuel overall and ensuring SAF is delivered as efficiently as possible and with minimal carbon emissions.
In line with this mass balancing approach, initiatives such as Air bp’s book and claim system also help broaden SAF’s reach. The programme enables Air bp to deliver the SAF into the supply chain at one airport location and ‘book’ the carbon reduction associated with it into a registry. Then a customer at another location can ‘claim’ those carbon reductions by purchasing their traditional jet fuel along with the benefit of the lifecycle carbon reductions that have been logged in the registry.
Currently available with jet fuel purchases in France, Germany, Spain, Switzerland, the UK and the US, Air bp would like to open its book and claim system to wider market adoption. This will provide customers with ongoing and greater access to SAF while waiting for it to be physically available across a global supply chain.
Fuelling up to and beyond 2050
With most of the current supply of SAF derived from HEFA, which includes waste oils and fat, quantities of these feedstocks are limited. As such, Andreea Moyes, Air bp’s global sustainability director underlines that, “achieving the industry’s low-carbon goals will require a mix of different pathways to produce SAF, including the growth of eSAF – a synthetic fuel derived from renewable energy (such as solar, hydro or wind).”
She adds, “there is already legislation in Europe that places the development of eSAF at the forefront of aviation’s sustainability agenda. Germany for example has agreed a roadmap which will come into effect in 2026 for the development and use of eSAF for the aviation sector. In addition, the EU’s ‘Fit for 55’ proposal includes ambitious goals for eSAF starting in 2030 with 0.7% of jet fuel and reaching 28% in 2050.”
In 2021, the air transport sector committed to achieving net-zero carbon emissions by 2050, by which date the Air Transport Action Group (ATAG) anticipates that aviation will need around 330-445 million tonnes of SAF per annum. Producing SAF in every country and making it available at every airport is neither viable nor a cost-effective solution. To achieve the industry goals of decarbonising aviation, Air bp believes that mass balancing alongside the advancement of alternative production pathways and incentives to bridge the gap with conventional jet fuel will be key to ensuring SAF can be supplied at scale not just in the short term, but up to and beyond 2050.
