Analysis of Performance and Emissions of an Automotive Euro 5 Diesel Engine Fuelled with B30 from RME and JME

The effects of using a B30 blend of ultra low sulphur diesel and two different Fatty Acid Methyl Esters (FAME) obtained from both Rapeseed Methyl Ester (RME) and Jatropha Methyl Ester (JME) in a Euro 5 small displacement passenger car diesel engine on both full load performance and part load emissions have been evaluated in this paper. In particular the effects on engine torque were firstly analyzed, for both a standard ECU calibration (i.e. without any special tuning for the different fuel characteristics) and for a specifically adjusted ECU calibration obtained by properly increasing the injected fuel quantities to compensate for the lower LHV of the B30: with the latter, the same torque levels measured under diesel operation could be observed with the B30 blend too, with lower smoke levels, thus highlighting the potential for maintaining the same level of performance while achieving substantial emissions benefits. Moreover, the effects of the two different 30% vol. blends on brake specific fuel consumption and on engine-out exhaust emissions (CO2, CO, HC, NOx and smoke) were also evaluated at 6 different part load operating conditions, representative of the New European Driving Cycle. Both standard engine calibration (change of the accelerator pedal position) and specifically adjusted engine calibration (adjustment of the energizing time of main injection) were evaluated for part load operating conditions, highlighting a 4% average rise of fuel consumption, on a mass basis, at same fuel conversion efficiency and CO2 emissions. A noticeable increase of CO and HC emissions at low load could also be noticed, along with a significant NOx emissions decrease when using a specifically adjusted engine calibration, and a considerable smoke emission reduction.