Biodiesel–diesel–ethanol blends with ethanol concentrations of
3%, 5%, 15% and 25% with equal concentrations of biodiesel and
diesel equal were used to fuel a diesel engine. Effects of low and
high concentrations of alcohols, along with variation of engine
loads were investigated. Results indicate that emissions strongly
depended on not only engine operating conditions, but also fuel
blends concentrations. Cooling effects and oxygen contents of
alcohols were two of the most important factors in the outcomes.
Overall, alcohol blended fuels increased CO emissions as compared
to diesel fuel for all operating conditions. While ethanol blended
fuels reduced NO emissions for all concentrations, unburned HC
emissions depended not only on ethanol concentrations, but also
operating conditions. Overall, high concentrations of ethanol increased
HC emissions, and vice versa. But at over 50% load, ethanol
decreased HC emissions for all concentrations. Reduction of HC
emissions occurred for all concentrations at over 70% load
Investigation of CI engine emissions in biodiesel–ethanol–diesel blends as a function of ethanol concentration
Ethanol blended biodiesel–diesel fuels indicate a reduction of
UHC emissions at low concentrations and an increase at high
concentrations. But, at over 50% load, all of the ethanol blends
show a reduction of UHC emissions. These results strongly indicate
that emission characteristics depend on engine operating conditions
and/or concentrations.