30 Years Ago

DECARBONISING AVIATION – SAF TAKING OFF

In this article, Stopford advises on recent government initiatives and its involvement in the development and manufacture of Sustainable Aviation Fuels (SAF) promoting these areas via innovation and collaboration.

Deb Pal, Consultancy Director, Stopford

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orldwide, the aviation sector generates 3% of all greenhouse gases (GHG). A myriad of future technologies are being explored in the aviation sector to reduce GHG’s, such as hydrogen, fuel cells and, electrification. However, they all present challenges, especially for long haul flights that requires fuel to have a high energy density. In the short and medium term, SAF has been identified as a pathway to reducing greenhouse gas (GHG) emissions.

The combination of bio and synthetic SAF has the greatest potential to reduce the carbon footprint in the aviation sector in the medium term. Governments are introducing tax incentives for the manufacture of SAF. In August, US Congress passed the Inflation Reduction Act of 2022. Among the incentives in the act is a SAF fuel tax credit of $1.25 to $1.75 per gallon, depending on usage and production.

In the UK, the government announced in July the following measures following a consultation1 to: • SAF mandate equivalent to at least 10% (c1.5bn litres) of fuel to be made from sustainable sources by 2030. The mandate will operate as a greenhouse gas emission reduction scheme with tradeable certificates. • The mandate will apply to jet fuel suppliers and will begin in 2025, outside of the Renewable

Transport Fuel Obligation (RTFO). • Eligible fuels will be wastederived biofuels, recycled carbon fuels (making use of unrecyclable plastic and waste industrial gases) and power to liquid (PtL) fuels. • SAF must meet strict sustainability criteria including delivering at least 50% GHG savings relative to fossil jet fuel. • SAF derived from hydroprocessed esters and fatty acids (HEFA) will be capped and a PtL subtarget will be introduced to encourage the development of strategically important SAF pathways. Stopford are working with partners to produce SAF from a variety of waste products; one such feedstock is nonrecyclable waste plastic. There are several challenges, from availability of sufficient quantities of feedstock to certifying the fuel as a SAF. SAF must have the same characteristics as conventional jet fuel, i.e. it must be fully fungible. No modifications are required to the aircraft engine or any of the fuel delivery infrastructure to use SAF, so the same tanks, pipes and hydrant