The feedstock frontier: how SAF's next decade will be won or lost

The sustainable aviation fuel (SAF) industry has achieved something remarkable: it has built a commercially viable, growing sector in under a decade. But could the conditions that enabled that success now be working against the industry's long-term ambitions? Three structural challenges - feedstock scarcity, technology readiness and the gap between innovation and deployment - are converging in ways that will define which producers, pathways and technology providers shape the next generation of SAF. Understanding them clearly will be essential, write Mikala Grubb and Milica Folić.

The feedstock transition is already underway – whether the industry is ready or not

The commercial success of HEFA-based SAF has been built on a foundation of used cooking oil and fats. It is a logical, pragmatic foundation: these are waste streams, available in meaningful volumes and processable with existing hydroprocessing infrastructure. That foundation is now under strain given the growing demand for SAF.

Feedstock costs routinely account for well over half of total SAF production costs. When feedstock markets tighten - and they are tightening, with road transport, aviation and maritime sectors now competing simultaneously for the same lipid and waste oil streams - the economics of SAF production shift in ways that no process optimization can fully offset. The EU's Renewable Energy Directive III will compound this pressure, raising the bar on sustainability and traceability at precisely the moment when the most accessible certified streams are becoming hardest to secure.

The second generational shift

The transition toward solid biomass, advanced crops, recycled carbon sources and manufactured feedstocks is more technically demanding. It will require deliberate, parallel investment in process development, supply chain partnerships and regulatory certification well before the post-2030 feedstock crunch arrives.

Candidates attracting serious attention

Several streams are drawing genuine commercial interest now. Intermediate and rotational crops - planted on otherwise fallow agricultural land between main harvests – could reach 28 million tonnes of SAF-relevant supply by 2050, according to SkyNRG and ICF market analysis. They sidestep the food-versus-fuel controversy that damaged first-generation biofuels and require no significant land use change. 

Biogas and renewable natural gas are gaining traction because they are pipeline-compatible and suited to proven gas-to-liquids infrastructure, dramatically reducing the technology risk premium. Municipal solid waste via gasification pathways offer waste management benefits alongside meaningful renewable fuel volumes. More niche but genuinely viable streams – cashew nutshell liquid, crude tall oil, rubber seed oil and synthetic fatty acids - are already in early commercial use or active certification processes.

The manufactured feedstock advantage

Perhaps the most structurally interesting category is manufactured feedstocks: synthetic fatty acids and ketones produced from waste CO₂, biogas or agricultural residues. These are chemically similar to conventional HEFA inputs, enabling integration into existing process chains with limited adaptation while fundamentally decoupling supply from agricultural cycles and their associated price volatility. That decoupling represents a qualitatively different kind of supply security – one that could prove increasingly valuable as the feedstock landscape grows more contested.

Producers who begin developing technical knowledge and supply chain relationships around these next-generation streams now will be materially better positioned when those feedstocks scale and gain regulatory recognition. First-mover advantage in feedstock capability, once established, is durable.

*****

Process technology is a strategic lever, not just an engineering decision

The choice of production pathway and process configuration carries direct implications for project economics, financing probability and long-term resilience. Designing for optionality from the outset is a meaningful determinant of project economics – and a capability gap that is not always well understood at the project development stage.

Feedstock flexibility as a hedge

Feedstock flexibility, properly designed for, is a solid hedge. The conventional approach involves establishing a base case feedstock and defining sensitivity windows around it – directly analogous to how conventional refiners manage crude variability. A plant designed for used cooking oil can typically accommodate tallow or soybean oil without process failure; the variables are yield and operating parameters, not feasibility. Extending that flexibility systematically to emerging feedstocks is the natural next step, provided process chemistry, catalyst selection and pretreatment design are approached rigorously.

Catalyst performance as a core economic driver

Catalyst performance sits at the center of this. Renewable feedstocks require hydrodeoxygenation catalysts to remove oxygen and contaminants, and dewaxing catalysts to meet freezing point specifications. Contaminant levels in more complex feedstocks can shorten catalyst life, making feedstock characterization and pretreatment core determinants of plant economics over its operational life. Continuous catalyst development in parallel with process licensing is what translates feedstock diversification from a theoretical ambition into an operational reality.

The e-SAF efficiency advantage

For e-SAF, the G2L™ eFuels pathway achieves greater than 95% carbon efficiency and up to 100% e-SAF selectivity through its naphtha and light ends recycle loop. This requires approximately 10-15% less CO₂ feed than methanol-to-jet approaches to deliver the same output. At the volumes the industry needs to reach, differences of this magnitude translate into significant structural advantages in both cost and carbon intensity.

The SAF-HVO optionality case

The ability to switch between SAF and HVO output is underappreciated as a project design feature. Plants capable of producing renewable diesel before SAF certification is achieved – or when HVO markets offer better short-term returns – can begin generating revenue earlier, build operational confidence with challenging feedstocks and reduce financing risk associated with a long pre-revenue development phase. The path to 100% SAF production becomes more accessible when a pragmatic intermediate step is built in from the start.

******

The deployment gap is where ambition goes to... well, stall....

The SAF industry faces a structural gap between what is technically possible, what is commercially certifiable and what can attract a final investment decision in the current environment. Very few FIDs are materializing relative to the volume of announced projects. Given that projects typically require several years from FID to first production, delays accumulating today are mathematically incompatible with 2030 mandate targets in multiple jurisdictions. The barrier is a compounding set of structural friction points that each individually appear manageable but together prove formidable.

The certification lag

Regulatory certification timelines create a durable lag between technical readiness and commercial deployment. A feedstock or pathway that is technically proven today may not be certifiable for SAF compliance for several years, regardless of the quality of the underlying science. The consequences of premature certification of aviation fuel components are severe, and caution is warranted. 

Technology developers and producers need to engage with ASTM approval processes well in advance of anticipated commercial need. Co-processing offers a practical pathway through this constraint: it builds regulatory track records, generates operational data and establishes process confidence without requiring full capital commitment to a dedicated new plant.

Policy fragmentation and the scale challenge

Differing certification schemes, carbon accounting methodologies and incentive structures across regions force projects to optimize for multiple regulatory environments simultaneously, slowing standardization, limiting the scale benefits and suppressing the cost reductions that greater volume would otherwise deliver. This matters enormously given what demand projections suggest: the Asia-Pacific region alone could require up to 70 million tonnes of SAF annually by 2050, roughly twice Europe’s current total jet fuel consumption. The global supply chain, feedstock base and financing ecosystem are not currently configured to meet differing scale up, or indeed demand, at anything close to that scale.

The green hydrogen question

The green hydrogen constraint on e-SAF and power-to-liquids pathways deserves particular attention. Clean hydrogen investments have passed USD 110 billion across past-FID projects, under-construction projects and operational projects globally. The ramp-up required to supply e-fuel production at meaningful scale remains an open question. The economics of green hydrogen are improving, but the timeline to cost-competitive availability at scale will be a primary determinant of how quickly the e-SAF pathway can contribute at volume.

What successful projects have in common

Project success correlates strongly with preparation quality. Projects that reach FID consistently share a common profile: secure feedstock partnerships established in parallel with process development, offtake agreements in place, thoughtful location selection and a coalition of partners with complementary technical, commercial and financial capabilities. SAF production is genuinely a team endeavor - and the teams that assemble the right combination of expertise early are the ones converting announcements into operating plants.

The next frontier is being defined now

The SAF industry is at an inflection point that is only starting to really look like one. Current feedstock supplies are broadly adequate for announced projects. The most commercially mature pathways are well understood and de-risked. Investment is flowing. The mandates are in place and tightening.

The decisions being made today, such as which feedstocks to develop projects around, which process configurations to build for, which demonstration projects to fund and how to engage with certification processes, will determine whether the industry can bridge the structural gap between 2025 ambitions and 2035 realities.

Producers and technology partners who treat their current HEFA operations as a platform for capability extension, rather than a standalone endpoint, are building the foundations for durable competitive advantage. The next generation of SAF will be won on the strength of the mandate but most importantly on the depth of the preparation.