Field Tests of Bunker Blends with Biodiesel

In July 2023, the International Maritime Organization (IMO) reviewed and intensified the decarbonization ambitions of the maritime segment, aiming to achieve net-zero greenhouse gases (GHG) emissions by 2050 and establishing an intermediate reduction target of 70% of GHG emissions by 2040. Among the set of measures that will contribute to meeting these goals, actions to improve the energy and operational efficiency of vessels and the introduction of marine fuels with a lower carbon footprint can be highlighted. Regarding the main options, mainly liquefied natural gas (LNG), hydrotreated vegetable oil (HVO), biodiesel (FAME – Fatty Acid Methyl Ester), methanol, hydrogen and ammonia are presented as the potential alternative that are being studied. However, due to the need for short-term measures, the use of renewable blends with bunker fuel and/or marine diesel has the advantage of requiring little or no adaptation in the engine or fuel supply system.

Petrobras' commitment to the transition towards a low-carbon future encompasses the maritime segment, exemplified by the development of renewable-content bunker fuel. In the first stage of the project, laboratory tests carried out at the Research and Development Center (Cenpes) facilities, using blends of marine fuel and biodiesel, did not result in any negative impacts on meeting the main properties specified for the bunker, according to the international standard ISO 8217. Complementary assessments of combustion quality and stability indicated the approval of the blend for field testing on maritime vessels. At this stage, the bunker, biodiesel, and the final mixture were evaluated prior to ship refueling to ensure compliance with the established test requirements.

This article presents the main results obtained from pioneering tests conducted in Brazil on coastal route ships, using blends of renewable-content bunker fuel, specifically biodiesel, in different contents and compositions. With the success of the tests, Petrobras is contributing to society's demand for fuels with lower greenhouse gas emissions, seeking short-term solutions aimed to reduce environmental impact and meeting decarbonization goals in the maritime sector.