The effects of using a B30 blend of ultra-low sulfur 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.