Type-approval procedure of a conversion system for the use of biofuel in a CI engine

With the aim of contributing to the reduction of the environmental impact of the existing vehicle fleet, ReFuel Solutions S.p.A. Benefit has developed a biofuel conversion system for compression-ignition engines, named BiodieselKit. The system enables the use of FAME biodiesel at high blending ratios by addressing the main technical issues that limit its direct application in conventional diesel engines. This thesis focuses on the technical and regulatory analysis of the type-approval process for a biofuel retrofit system. The work began with an in-depth study of the applicable regulatory framework and the relevant Ministerial Decree, to understand the requirements, procedures, and documentation structure necessary for the submission of the type-approval application. On this basis, the technical dossier for the BiodieselKit system was prepared, including the regulatory framework, the engineering description of the system, the criteria adopted for the selection of the base vehicle, and the organisation of the required documentation. Alongside the regulatory activity, and constituting the core part of this dissertation, a series of experimental tests were carried out in the company’s engine test facility. The tests were conducted with the objective of evaluating the behaviour of a compression-ignition engine fuelled with different biofuels, analysing variations in performance in terms of torque and power, as well as differences in the emission profile directly detected by the sensors installed along the exhaust line. The processing of the experimental results made it possible to identify the biofuel considered most suitable, based on the balance between engine performance and emission behaviour, in view of the subsequent tests required for type approval. The work highlights how the integration of regulatory analysis and experimental validation represents a fundamental element for the market introduction of biofuel conversion systems, thereby contributing to the reduction of the environmental impact of the existing vehicle fleet.