Aviation is one of the most challenging sectors to decarbonise. While efficiency improvements and electrification will contribute to emissions reductions in short-haul transport, long-haul aviation will remain dependent on liquid hydrocarbon fuels for decades. Sustainable Aviation Fuels (SAFs) are therefore essential to achieving the European Green Deal and the EU’s legally binding climate-neutrality target for 2050. Under the ReFuelEU Aviation regulation, SAF blending must increase from 2% in 2025 to 64% by 2050, implying a rapid scale-up to several million tonnes of SAF by 2030.
Current SAF supply chains rely largely on waste oils and fats processed via the HEFA route, which face constraints in feedstock availability, sustainability and cost. Advanced biofuels and e-fuels remain capital- and energy-intensive. Microalgae offer a highly attractive alternative because they deliver high productivity, do not compete with food or land, and can grow on waste nutrients and captured CO2. However, high cultivation costs, microbial instability and energy-intensive downstream processing have so far prevented their large-scale deployment.
SusAlgaeFuel addresses these barriers through an integrated, circular microalgae-to-SAF platform linking waste valorisation, advanced cultivation control, low-energy biorefinery processing and fuel upgrading. The project is fully aligned with EU priorities on climate neutrality, circular economy and clean-energy industrial leadership.
The overall objective is to demonstrate a scalable and cost-competitive microalgae-based SAF pathway based on four core innovations:
(i). Use of liquid digestate and biogenic CO2 from anaerobic digestion (AD) as nutrient and carbon sources.
(ii). In-line monitoring, machine-learning-assisted process control and selective UV irradiation for stable algal cultures.
(iii). A low-energy cascading biorefinery based on autolysis and solvent recovery; and
(iv). Algae-specific thermocatalytic routes to HEFA-SPK and additional kerosene streams.
These technologies are integrated with TEA, LCA and sustainability certification. The project targets a 49% reduction in HEFA-SPK cost (from 12.3 to 6.3 USD/kg) and >60% GHG savings relative to fossil jet fuel. The pathway culminates in a TRL-5 pilot facility at an AD site in Ireland producing ≥10 kg lipids/year and demonstrating the potential to supply up to 20% of EU SAF demand in 2030.
