Lisbon, Portugal | December 17, 2025 – PRIO, Portugal’s leading energy company, has reached a key milestone in its partnership with Danish shipping company Uni-Tankers, marking a significant step toward scaling sustainable maritime operations. The vessel GTM DENMARK was recently bunkered with 210 tonnes of ECO Bunkers B30, a high-performance biodiesel blend delivering an immediate and measurable reduction in carbon intensity.
The operation, carried out from PRIO’s strategic energy hub at the Port of Aveiro, utilized a 30% advanced biodiesel blend, resulting in a 27.1% Tank-to-Wake (TtW) reduction in CO₂ emissions compared to conventional Low Sulphur Marine Gas Oil (LSMGO).
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A Circular Economy in Action
The collaboration between PRIO and Uni-Tankers represents a closed-loop approach to maritime sustainability. In a unique operational synergy, Uni-Tankers vessels transport residual waste feedstocks, such as used cooking oils, to PRIO’s refinery, where they are converted into advanced biodiesel. The fuel is then supplied back to the fleet as a drop-in solution, requiring no engine or infrastructure modifications.
“Our partnership with Uni-Tankers shows what happens when we combine technical expertise, innovation, and a shared commitment to sustainability,” said Telmo Ferreira, Head of Emerging Businesses and Shipping at PRIO. “By joining forces, we are able to make a concrete contribution to the decarbonization of the sector.”
Technical Profile: ECO Bunkers B30
| Feature | ECO Bunkers B30 | Conventional LSMGO |
|---|---|---|
| CO₂ Reduction (TtW) | 27.1% | 0% |
| Engine Modification | None | None |
| Compliance | FuelEU & EU ETS Optimized | Standard MARPOL |
| Sustainability | 100% Circular / Waste-based | Fossil-based |
- Emission Impact: Up to 90% lifecycle CO₂ reduction with 100% advanced biodiesel (B100).
- Compatibility: Drop-in fuel, zero modifications to engines or storage.
- Feedstock Integrity: Produced entirely from circular, waste-based feedstocks.
- Regulatory Alignment: Fully compliant with FuelEU Maritime and the EU ETS.
For Uni-Tankers, the project provides critical operational data supporting its long-term decarbonization strategy.
Lisa Clement Jensen, Head of Strategy at Uni-Tankers A/S, emphasized the dual value of the partnership: “By transporting residual feedstocks for production and the final advanced biodiesel product, while operating on a biofuel blend—we’re combining a commercial opportunity with valuable operational insight. Collaboration across the industry is essential to keep us moving forward.”
Driving Maritime Decarbonization
PRIO’s biodiesel facility at the Port of Aveiro has an annual production capacity of 113,880 tonnes, positioning it among Portugal’s largest biofuel producers. Through sustained investment in technology, partnerships, and supply-chain integration, PRIO is delivering scalable, low-carbon fuel solutions for the maritime sector.
“Today, our own advanced biofuel transports our own cargo. Together, we are reducing the carbon footprint and advancing the energy transition in maritime transport,” PRIO stated.
The operation demonstrates how collaboration, innovation, and circular economy principles can accelerate maritime decarbonization and provide a practical blueprint for shipping companies worldwide.
A Stronger Future Through Sustainable Partnerships
The PRIO-Uni-Tankers collaboration highlights the critical role of strategic partnerships in enabling the shipping industry’s transition toward lower-carbon operations. By integrating fuel production, logistics, and vessel deployment, the companies show how biofuels can be deployed at scale without compromising commercial performance. As adoption increases, initiatives like this help pave the way toward a more resilient and sustainable global shipping industry.
About Uni-Tankers A/S
Uni-Tankers, is a leading Danish tanker company specializing in the transport of chemicals and refined oil products. With a strong focus on sustainability, Uni-Tankers is a pioneer in testing and adopting alternative fuels and energy-saving technologies to achieve its goal of a climate-resilient maritime future.
PRIO: Leading the Way in Sustainable Energy Solutions
PRIO is a leading Portuguese energy company and the country’s largest biofuel producer, as well as one of Europe’s leading biodiesel producers using waste-based raw materials. Operating a state-of-the-art facility at the Port of Aveiro, PRIO controls the entire value chain, from feedstock collection and refining to storage and supply, ensuring high quality, traceability, and reliability for maritime customers.
Source: PRIO