UK’s SAF Policy: Caught between ready HEFA and a hard place


The British have been obsessed with fish and chips for decades. Charles Dickens even wrote about a “fried fish warehouse” in Oliver Twist in 1839. So you would expect that there is enough used cooking oil supplies to make Sustainable Aviation Fuel (SAF) using the HEFA pathway. But the UK government is not convinced. 

The biofuel and aviation sectors in the UK have repeatedly criticised the government for its lack of clarity on SAF. They have long pushed for policy adjustment to support HEFA-pathway production of SAF; arguing that the technology is ready for adoption and has the potential to account for a major share of demand set by UK’s 2030 SAF mandate.

The UK wants to focus on Second Generation (2G) and Third Generation (3G) SAF made from biomass feedstocks, rubbish, industrial waste gas, CO2, waste, hydrogen (on-site) or fossil hydrogen. Among these, the power-to-liquid pathway has attracted most interest from the UK government. 

The UK government has also set a cap on how much fats-oil derived SAF can support decarbonisation of the aviation sector. With a tentative target of 10% SAF for jet fuel by 2030, the UK government’s HEFA cap in effect aims to create a separate market for non-HEFA 2G/3G SAF.

The HEFA cap has put existing fossil fuel refineries into a quandary. Petroineos, which operates one of the only six remaining fossil fuel refineries in the UK, had planned to convert its Grangemouth site into a biorefinery (to produce sustainable fuels using HEFA pathway) following the planned shutdown of its existing operations in 2025. However, these plans came to halt as they require a removal of caps on HEFA SAF and Graham Stuart, the UK’s Minister for Energy Security and Net Zero, said the government will not reshape its policy.

The government says that its HEFA policy is simple. It feels that the UK does not have adequate local feedstocks (and unlike US it does not have a local ethanol industry). The UK’s biofuel industry, supported by the Road Transport Fuel Obligation (RTFO), already consumes a significant volume of potential feedstocks for SAF for land transport.

Phillips 66, the only refinery producing HEFA SAF in the UK, also imports its feedstock. “We process waste biogenic oil, including used cooking oil, from multiple sources predominantly in the UK, Asia and Europe to produce SAF,” said a Phillips 66 spokesperson speaking to SAF Investor. The refinery also expresses concerns on industries competing for the same feedstock.

“We believe that HEFA gives us a pathway today and the other pathways will follow. However, issues such as competing demand for some of these feedstocks may need to be addressed along the way.” Phillips 66 began co-processing waste oils in 2021 at the Humber Refinery to produce SAF at scale in the UK.

Power-to-liquid may be the right option in UK’s context, however, it is not without its own set of challenges and will require support.

“The UK government has been supporting power-to-liquid pathway. The government’s opposition towards HEFA is primarily due to lack of local feedstock availability and also due to general concerns amongst the public about the sustainability of feedstocks used in HEFA process,” says Dr Maria Fernanda Rojas, research associate at the Translational Research Centre, of the University of Sheffield.

The Department of Transport recently announced £53m in grant funding for nine first-of-a-kind (FOAK) commercial and demonstration-scale SAF projects in the UK. Of these, five were developing the power-to-liquid technology. However, despite this support, these projects are years away from achieving the scale required to meet production targets. They face multiple challenges including the need for large quantities of energy which can result in higher price premiums.

“Based on my mathematical models, power-to-liquid SAF production requires a lot of electricity. Depending on renewable sources for electricity will also be more challenging, because they cannot be relied upon to produce constant electricity subsequently leading to use of grid to high energy requirements,” says Rojas. She recently published a paper on technoeconomic and lifecycle assessment of SAF produced via through power-to-liquid in the UK.

So, in the face of these challenges, what is the best option for UK government to achieve its targets? “The best way for the UK to achieve its 2030 targets could be the use of HEFA but taking into account that they need to support research and development of other pathways,” says Rojas. “One way to go to about this is that in the first years, they can rely on processes that are already mature such as HEFA and reduce the production from these processes in the following years once other technologies are more developed.”

Regardless of which direction the UK chooses to ensure enough SAF is available for airlines, it will require a tough balancing act.

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