Performance and estimation of regulated pollutant emissions of a touristic catamaran fueled with neat hydrotreated vegetable oil in the Atlantic Islands National Park (Spain)

The employment of sustainable liquid fuels in different power plants, including those which integrate Diesel engines into propulsive systems of land non-road or marine vehicles, results in a transient but interesting option to reach sustainability of tourist transportation. The goal was to compare the effect of a renewable Hydrotreated Vegetable Oil (HVO) and a fossil Diesel fuel on regulated pollutant emissions in the surroundings of the Atlantic Islands National Park. The experimental work was performed on a touristic catamaran travelling along the Vigo estuary (Galicia, Spain), transporting around 250 tourists each time during several trips a day. The catamaran tested is powered by two engines which comply with the International Maritime Organization Tier II emission standard. On the one hand, the exhaust pipe of one engine was connected to a HORIBA OBS-ONE analyzer for measuring regulated pollutant gaseous emissions and, on the other hand, its electronic control unit was connected to a manufacturer diagnosis tool. Higher fuel consumed was obtained with HVO, but also higher engine effective power during long- haul routes, results mainly justified by to the sea environmental conditions. CO 2 specific emissions were slightly lower with HVO, and mean reductions (all routes) of 40%, 38% and 32% were obtained for CO, THC and NOx emissions, respectively, with this renewable fuel. However, particle number emissions were higher with HVO, but differences depend on the engine operating mode. Results show great potential for using renewable fuel even in engines without aftertreatment devices in operations around a protected nature area.