HVO: a sustainable alternative fuel for industrial and marine engines

The transportation sector is facing years of radical changes and technological evolution due to the increasing awareness of the regulatory bodies around the world towards the effects that this sector has on the environment. The main focus nowdays, is to reduce the emissions related to the human activities, of which the light and heavy duty vehicles represent a relevant percentage. For the light ones the hybridization and electrification paths seem to be already undertaken, but for the heavy duty ones there are some additional issues that prevent the manufacturers from going in the same way, mainly related to the range of the electric vehicles, that are currently strongly limited by the energy density of the battery packs. Therefore, the necessity of currently looking at different solutions, one of the main ones being the switch to the alternative fuels. These technologies will allow to contribute to the pollution’s reduction, while at the same time keeping the internal combustion engine alive and finding new ways to develop it in a more sustainable way. In this thesis, the application of a renewable biofuel, namely the Hydrotreated Vegetable Oil (or simply HVO), to an industrial diesel engine has been investigated. The fuel used for the scope has been provided by ENI and belongs to the second generation of biofuels. It is obtained entirely from agricultural waste, as the ethical guidelines impose. The experimental activity has been carried out in VM company, part of the Stellantis Group, with the aim to observe how the emissions and the performances of the engine were affected by the fuel. The different tests performed were of both functional and homologation type ones. It has been started with the Full Load performance analysis, Design Of Experiment (DOE) and Rapid Heat Up (RHU) procedures in order to examine the differences in emissions after varying certain combustion parameters, and successively with the three homologation tests WHTC (transient cycle), WHSC (steady state cycle) and KI (regeneration cycle), necessary for assessing the validity of the fuel for the normal road use. The results obtained, have showed that this fuel can be beneficial for the application, since it helped in reducing the emissions of both the greenhouse gasses and the criteria pollutants, while at the same time it guaranteed the required performances, while lowered the brake specific fuel consumption due to its lower density. It is important to underline that the tests have been performed with the same engine calibration used for the standard diesel in order to perform a fair comparison. In addition to the experimental section, the thesis presented a market overview for the HVO biofuel, where the current worldwide diffusion has been described, focusing on the current directives, the main companies that are producing and distributing it, the costs of the fuel and the possible future expansions.