Supply Chain

The start of each SAF batch is the feedstock. As the feedstock largely determines the overall sustainability performance of our fuels, it must meet very strict criteria. Currently, SkyNRG uses Used Cooking Oil (UCO) as its main feedstock. Of course, there is a limited supply of UCO, and so SkyNRG is also actively involved in projects developing alternative feedstocks (for HEFA) and different feedstock/technology combinations.

The current SkyNRG supply chain

Today, SkyNRG has a focus on the downstream part of the supply chain. We have pioneered the SAF downstream supply chain in many different locations around the world. Since 2018 we have a partnership with Shell Aviation, to further increase the efficiency of our current and future supply chains to be able to serve all our customers in the best way possible.

Feedstocks and SAF production

In a bio-refinery renewable feedstock is aggregated and converted into sustainable aviation fuel. All SAF delivered by SkyNRG to date has been produced using the HEFA technology, with Used Cooking Oil as main feedstock. UCO is a waste stream from the food processing industry and has limited, high value end-uses. As it does not compete with the food or feed chain and offers significant CO2 reduction, it qualifies as a very sustainable feedstock. Next to HEFA, there are five other SAF production pathways approved for use in commercial aviation by the aviation OEMs (through the ASTM certification process). Please visit Technology to learn more about these different pathways.

Blending and certification

After the neat SAF is produced, it is certified to the ASTM D7566 specifications for neat alternative jet fuel. Once certified, it needs to be blended with conventional Jet A/A-1 fuel, before it can be used in aviation. The final step is to certify the blended SAF to ASTM D7566 specifications for blended alternative jet fuel. Once certified, it automatically receives the Jet A/A-1 certificate and can then be handled and used as conventional fossil jet fuel.

Downstream logistics

Once the SAF is blended, it needs to be distributed to the airport where it will be used. Early SAF supply chains were completely segregated from existing jet fuel supply chains, so that specific aircrafts could be fuelled with the SAF. This resulted in complex and expensive operations. Today, SkyNRG integrates the SAF into existing jet fuel supply chains as much as possible to minimize the additional operations and cost. A growing number of airports have already received our SAF into their commingled fuel system, including Los Angeles (LAX), San Francisco (SFO) and Oslo (OSL).

Fuelling operations

In case of an integrated downstream supply chain, SAF is delivered straight into the airport’s commingled fuel tank. The fuel is than distributed per standard operations, either via the hydrant system or per refueler trucks. This means that all aircrafts refuelling at the airport physically receive part of the SAF. The SAF volume will however be allocated to the entity holding the SAF supply contract, and that entity may claim the benefits. This is done on a mass balance basis and is called the book-and-claim system. 

For segregated supply chains, the SAF arrives per dedicated fuel truck or other transport mode and is transferred into dedicated airport refueler trucks. This way, the SAF can be physically delivered to a specific aircraft. Although SkyNRG tries to push for integrated supply chains to optimize economics and impact, we can organize both types of supply chains.

If you want to learn more about the supply of SAF or supply chains we have developed and managed to date, please contact me at


Renco Beunis

Operations Manager