To understand the environmental impact of a marine fuel, it is no longer enough to consider only the emissions from a vessel’s stack. Where the fuel’s feedstock comes from, how it is produced and transported, and how it is delivered to the vessel are also part of its carbon footprint calculation. This is why the International Maritime Organization’s life-cycle approach presents the industry with a new question: How low-carbon is a fuel, really?
Efforts to reduce emissions in shipping have long focused on more efficient engines, alternative fuels, and operational improvements. However, the climate impact of a fuel extends beyond its combustion on board a vessel. Greenhouse gas emissions are also generated during the extraction of raw materials, processing, fuel production, transportation, and storage. Therefore, two fuels that deliver similar performance on board may have different overall carbon footprints depending on their production processes.
IMO’s life-cycle assessment highlights this difference. In this approach, Well-to-Tank covers emissions generated from raw material extraction through to the delivery of the fuel to the vessel’s tank. Tank-to-Wake refers to emissions generated by the use of the fuel on board. Well-to-Wake, the combination of these two stages, reflects the fuel’s total greenhouse gas impact from its source to its use on board the vessel.
In this way, emissions generated during the production process of a fuel that delivers low emissions on board are also taken into account. The environmental performance of a fuel is determined not only by its type, but also by its feedstock, production method, the source of the energy used, and its supply chain.
A New Measure of Fuel Value: Traceability
With the life-cycle approach, traceability is also becoming increasingly important. Beyond stating that a fuel is low-carbon, it is necessary to demonstrate with data the entire process, from the source of the feedstock and the production method to the final product.
This is particularly important in the case of biofuels. While the reuse of waste and residue feedstocks contributes to the circular economy, it also requires the source of the feedstock and the production process to be documented. At this point, certification systems serve as mechanisms for verifying the fuel’s origin, production chain, and sustainability characteristics.
This transformation is also changing the role of fuel suppliers. In addition to delivering the right quantity of fuel to the vessel at the right time, information on its feedstock, production process, sustainability criteria, and supply chain traceability is also becoming an integral part of fuel supply.
From Waste to Fuel: A Traceable Chain at Arkas Bunker
Arkas Bunker, the first marine fuel supply company in Türkiye to receive ISCC EU certification, implements a biofuel supply model that ensures traceability from feedstock through to the final product. Developed by Arkas Bunker and DB Tarımsal Enerji, the model was also presented at the Maritime Biofuels Technical Seminar held at IMO Headquarters in February 2026.
Within the framework of the model, used vegetable oils collected in Türkiye are transformed into marine fuel through an ISCC EU-certified process. By integrating the stages of waste collection, production, certification, and fuel supply, the model provides traceability throughout the fuel’s journey from its source to the final product.