This study evaluates the potential of hydrotreated vegetable oil (HVO) produced from used cooking oil (UCO) as a renewable marine fuel for decarbonizing Brazilian maritime cabotage. Using the 2024 IMO MEPC.391(81) Well-to-Wake (WtW) methodology, the analysis quantifies emissions from Marine Diesel Oil (MDO) and Very Low Sulphur Fuel Oil (VLSFO) across all container cabotage services and assesses the reductions achievable through progressive substitution with UCO-based HVO. Operational data from the four cabotage operators are integrated into a stepwise fuel-replacement roadmap that incorporates realistic circular-economy constraints, including UCO availability, conversion efficiency, and national recycling capacity. Results indicate that full fuel substitution can reduce WtW emissions by up to 85%, while requiring only 17% of Brazil’s theoretical UCO generation, suggesting that deep decarbonization is achievable without exceeding national feedstock potential. The early phases of the roadmap demand modest UCO volumes, enabling gradual scaling of collection networks, whereas the largest emission reductions occur once VLSFO substitution begins. The study also situates the findings within Brazil’s evolving policy environment, including the Fuel of the Future Act, the new National Circular Economy Strategy, and emerging regional initiatives such as the Mercosur Green Corridor. Overall, the results demonstrate that UCO-derived HVO offers an immediate, drop-in, and policy-aligned pathway for substantially reducing emissions from Brazilian cabotage, reinforcing its strategic role in the country’s broader transition to circular, low-carbon fuels.
Costa et al. (Sun,) studied this question.