Experimental Investigation on the Effects on Performance and Emissions of an Automotive Euro 5 Diesel Engine Fuelled with B30 from RME and HVO

The effects of using blended renewable diesel fuel (30% vol.), obtained from Rapeseed Methyl Ester (RME) and Hydrotreated Vegetable Oil (HVO), in a Euro 5 small displacement passenger car diesel engine have been evaluated in this paper. The hydraulic behaviour of the common rail injection system was verified in terms of injected volume and injection rate with both RME and HVO blends fuelling in comparison with commercial Diesel. Further, the spray obtained with RME B30 was analysed and compared with Diesel in terms of global shape and penetration, to investigate the potential differences in the air-fuel mixing process. Then, the impact of a biofuel blend usage on engine performance at full load was first analysed, adopting the same reference calibration for all the tested fuels. Afterwards, the effects of a biofuel blend usage on brake specific fuel consumption and on exhaust emissions were also evaluated at 7 different part load operating conditions, representative of the New European Driving Cycle. Finally, soot-NOx trade-off obtained by means of EGR sweeps were performed in the same operating points, in order to gather detailed information about further possible emissions benefits that could be achieved through a more extensive ECU recalibration.