CARAVEL

CARAVEL will deliver the first integrated, TRL8 hydrothermal liquefaction (HTL) value chain that converts diverse wet biogenic residues into ready-to-deploy marine fuels with low greenhouse-gas intensity, while ensuring circular, compliant management of process water and hydrochar. The project integrates full-scale conversion, upgrading, end-user validation, sustainability verification, permitting and regulatory readiness in one demonstration designed for replication.

A TRL 8, modular HTL plant will be operated under real feedstock variability for ≥30 days, generating evidence on operability, separation, fouling and corrosion, and producing >100 t of biocrude. A harmonised cross-TRL dataset and predictive model will link feedstock composition to yields and fuel quality and define allowable mixtures of biocrudes produced from multiple HTL units for centralised upgrading in a hub-and-spoke concept.

A central innovation in CARAVEL is fuel upgrading and market deployment: First, it will formulate ISO 8217-compliant blending recipes using biocrudes from multiple residues, validate miscibility and stability, and prove performance through accredited fuel testing, long-duration injector trials, and a vessel trial at TRL8.

Second, CARAVEL will demonstrate two complementary TRL7 routes to 100% renewable marine fuels from individual and mixed biocrudes: (i) esterification scale-up using an industrial loop reactor concept to deliver deep acidity reduction and fuel-grade stability, and (ii) refinery-environment hydrotreating. In parallel, CARAVEL generates TRL 7 operational and catalyst stability evidence for sustainable aviation fuel production from mixed biocrudes, targeting high jet yields and carbon efficiency.

Validated performance will be translated into audit-ready life-cycle assessment, techno-economic analysis and bankable business cases, enabling an investor-grade replication roadmap for ≥10 EU locations aligned with RED III, FuelEU Maritime and ReFuel.