SAF competing for fuel feedstocks will have negative impacts on many other sectors

The aviation industry, and its enthusiastic backers like the UK government, are keen to claim the problem of the sector’s vast carbon emissions can be solved, fairly soon, by SAF (“sustainable aviation fuels”). They agree these should not come directly from agricultural crops, competing with human food and animal fodder for land. They will instead come (as well as fuels produced using electricity) from agricultural, forestry and domestic wastes. These would be the feedstocks.  But there are significant problems, so far apparently overlooked by governments etc, about competing uses for those feedstocks. There are already markets for used cooking oil, and it can all be used for animal food, or in other industries. Taking crop wastes off the land not only means lower organic matter returned to the soil, reducing its structure and fertility, but also its removal for other uses – such as for animal bedding. There are competing uses for forestry waste, such as the paper and pulp industry.  Feedstocks could be used to make diesel for road vehicles, or burned to produce electricity. So if aviation wants these feedstocks, there will be competition and higher prices for other sectors. These problems should not be ignored in the mindlessly optimistic rush for the illusion of “jet zero”.



Authors: Jane O’Malley, Nikita Pavlenko, Stephanie Searle   (ICCT_

March 2021



If the European Union aviation industry is to meet its long-term goal of decarbonization
without curbing traffic growth or relying on out-of-sector carbon offsets, switching
to sustainable aviation fuels (SAFs) is one of the few methods of achieving in-sector
greenhouse gas (GHG) reductions.

Though previous, transport-wide EU fuel policies have done little to stimulate the development of the SAF industry, the recently proposed ReFuel EU initiative could set a clear policy signal for the introduction and expansion of an advanced-only SAF industry producing ultra-low carbon fuels.

However, it is critical that policymakers set realistic SAF deployment goals that match the amount of fuel that could be made from available feedstock.

This study evaluates the EU resource base to support SAF production from 2025 to 2035, focusing only on the potential volumes available from sustainably available feedstocks.

Without taking into account the political or economic barriers to SAF production, we
estimate that there is a sufficient resource base to support approximately 3.4 million
tonnes (Mt) of advanced SAF production annually, or 5.5% of projected EU jet fuel
demand in 2030.

The estimated production potential takes into account feedstock availability, sustainable harvesting limits, existing other uses of those materials, and SAF conversion yields.

This assessment does not factor in the economic incentives necessary
to drive that level of market demand or to mobilize investment in new biorefineries.-
The commercialization of SAF depends on many factors beyond the resource base for
SAF production. Currently, even with some incentives and targeted support in place,
SAF production covers less than 0.05% of global jet fuel demand.

While producing SAF from waste oils is the most technically mature SAF conversion pathway, waste oils are highly resource-constrained and are already largely consumed by the road sector.

High near-term targets for SAF blending may only incentivize the diversion of waste oils from
existing uses in the road sector, approaching approximately 2% of 2030 jet fuel demand
from waste oil alone.

Moving beyond 2% of SAF deployment will require targeted support for more conversion pathways with more challenging economics and uncertain production timelines.

To achieve long-term success for the advanced SAF industry, the ReFuel EU initiative must first lay the groundwork for these pathways through targeted incentives for individual projects before laying out a sector-wide blending target.

Acknowledgements: Thanks to Dan Rutherford of the ICCT, Karlijn Arts of SkyNRG, and Laura Buffet of Transport & Environment for helpful reviews.

twitter @theicct


This also says:

As with food-based biofuels, interactions with existing markets for some SAF feedstocks may lead to indirect emissions that change our understanding of their GHG savings. Feedstocks are rarely pure wastes that are disposed of in the absence of biofuel demand. In most cases, they contain market and ecological value. For example, residues from crops such as wheat are already productively used for livestock fodder and bedding, as well as in other uses such as mushroom production and horticulture (Searle & Malins, 2016). If all wheat straw were instead diverted to biofuels production, the other uses would lack raw materials and require an increase in production of substitutable materials. Understanding a feedstock’s displacement effects is critical for ensuring GHG savings as well as determining quantities that can be diverted to biofuels production without reducing its availability for use in other applications.


We estimate feedstock availability in 2030 based on previous ICCT analyses assessing physical production of feedstocks and taking into account limits on maximum collection rates including harvesting capability, in situ ecological value, and usage as raw materials in other markets. We also note that diverting available feedstock toward fuel for the aviation sector would reduce its availability for competing uses in other transportation applications such as on-road diesel fuel. While waste fats are easier to process into “drop-in” fuels — or direct substitutes — lignocellulosic feedstocks are more abundant and could theoretically provide greater quantities of SAF. Previous research on lignocellulosic waste and residue availability in the European Union by Searle and Malins (2016) groups sustainable feedstocks into three categories: agricultural residues, forestry residues, and municipal and industrial waste. We supplement those findings by evaluating the potential from three additional potential SAF feedstocks including cover crops, industrial flue gases, and electrofuels produced using renewable electricity, CO2, and water.

And much more. See the whole paper at


March 2021





Is growth of sustainable aviation fuel in the market set to soar?

Fast Markets


A focus on biofuels
Governments are acknowledging the increasingly obvious gap around aviation in the response to transportation decarbonization. They have stepped up plans to promote the use of biofuels across the sector. Many consider increasingly stringent mandates and are poised to demand sustainable fuels play a greater part in the landscape.

But a lot is asked of any aviation fuel. Average engines on the newest fleets of airlines will deliver up to 90,000 lbs of thrust per engine. They must operate reliably in the harsh, cold environment at 40,000 feet.

The sector has had some successes, with sustainable fuels used in a limited number of passenger and freight routes recently. But, to drive economies of scale, the hunt is now on to unlock production on an industrial scale.

And that’s the key to allowing advanced biofuels to play in this space.

The path ahead
Clear mandates set out a flight path for the fuel’s adoption and use. Increasingly, the sector is leading the decarbonization debate. This is while innovators turn to new technologies or reliable older chemical processes to boost production and scale up promising demonstration concepts.

That is pulling in an ever-wider slate of feedstock, from algae to household waste, from corn through to forestry. Aviation’s thirst is set to bring fresh disruption to existing commodities. It will challenge the use of used cooking oils in biodiesel production, adding another dimension to the pulp and paper industry or even disrupting the role of corn within ethanol and animal feed use.

The ambition is large, and it needs to be. Even against the backdrop of pandemic, the United States alone burned nearly 10.3 billion gallons (350 million tonnes) of jet fuel in 2020. It is already showing signs of powering back toward pre-pandemic levels of up to 18 billion gallons in 2021.

At a basic 5% flat blend mandate, that will generate demand for 17.5 million tonnes of jet fuel on Covid-based data versus current production levels that amount to around 100,000 tonnes equating to around 0.05% of total European Union jet fuel consumption.

The EU is looking to deliver a mandate of 63% sustainable fuel by 2050.


See earlier:

Jet Zero consultation – what it says on “sustainable aviation fuels” (spoiler…crazy over-optimism)

The DfT’s consultation on reducing aviation carbon emissions, “Jet Zero” places a lot of faith in finding novel, low carbon fuels, so people can continue to fly as much as they want. These are called “Sustainable Aviation Fuels” (SAF). The consultation says SAF “could play a key role in decarbonising aviation, whilst also representing an industrial leadership opportunity for the UK.” The economic opportunity aspect, and producing jobs, is key for the DfT.  They say “Many experts view SAF as the only alternative for long-haul flights up to 2050, which are the flights with the biggest climate impact.” The DfT is hoping SAF could “result in over 70% CO2 emissions saving on a lifecycle basis and could deliver net zero emissions with the addition of greenhouse gas removal technologies.” SAF would either be biogenic, non-biogenic (from wastes) or made using zero-carbon electricity.  There are huge problems, glossed over by the consultation. A key problem is that “there is currently no comprehensive global regulatory standard for SAF sustainability. The UK is therefore active at ICAO in negotiating for a full set of sustainability criteria for SAF.” The DfT “will shortly consult on a UK SAF mandate setting out our level of ambition for future SAF uptake.”

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