Emissions assessment of a vessel using a sustainable alcohol-based fuel produced by catalytic conversion of bioethanol

• Drop-in biofuel from aldol condensation contributes to decarbonize maritime sector. • A blend 80 % diesel fuel/20 % GrenOl+ (% by vol.) was selected as optimal. • Under real conditions, the blend reduced particle emissions by 21 % • CO and HCs were not greatly affected by GrenOl+, even lowering at medium–high load. • NO x was slightly higher at high load but could drop by minor changes in injection timing. The shipping sector faces significant challenges to meet decarbonization targets. This study investigates the use of GrenOl+, an advanced biofuel composed of short and long-chain alcohols, in a blend with marine diesel fuel as an alternative to reduce the atmospheric impact of this challenging sector. The experiments were carried out at the port of Valencia (Spain) in a vessel equipped with a 186 kW compression ignition engine operated at different loads. First, a blend consisting of 80 % marine diesel fuel and 20 % GrenOl+ (by vol.) was selected based on its physical and thermochemical properties. Although this blend resulted in a lower derived cetane number and heating value than the neat diesel fuel, thus increasing the specific fuel consumption, it allowed for a significant reduction in particles number (by 20 %) while keeping very similar CO 2 tailpipe emissions. Benefits in CO and HC emissions were also observed, which could be extended to NO x emissions throughout the whole engine map with minor changes in the engine settings. This study indicates that GrenOl+ can be a viable drop-in fuel to partially replace conventional fuels in the maritime sector, helping to meet the requirements of regulatory agencies in the future.