This paper evaluates the possibility of using bioethanol blends
(mixtures of gasoline fuel and ethanol derived from biomass) of
varying strengths in an unmodified, small-displacement European
Euro 5 light-duty gasoline vehicle. The influence of different
proportions of bioethanol in the fuel blend (E5, E10, E25, E50 and
E85) on the emission of gaseous pollutants, such as: carbon
monoxide, hydrocarbons, oxides of nitrogen and carbon dioxide was
tested at normal (22°C) and low (-7°C) ambient temperatures for a
light-duty vehicle during the NEDC cycle on a chassis dynamometer.
Engine performance metrics were also tested. All test results are
presented in comparison to standard European gasoline (E5).
Tailpipe emission data presented here suggest that modest
improvements in air quality could result from usage of low-to-mid
ethanol blends in the vehicle tested. In general, blends up to and
including E50 were relatively unproblematic; emissions of regulated
compounds and CO₂ were in some cases substantially lower for
ethanol blends higher than E5 (standard European gasoline). This
finding has potentially significant implications for air quality
scenarios regarding potential greater usage of ethanol blends.
However, the usage of two ambient temperatures in this study
confirmed previous findings that such emissions reductions are in
some cases strongly temperature dependent, and further testing is
required in this area. Overall, no single blend emerged as a clear
best or worst performer at either test temperature.
Although maximum engine power and torque values for all blends
were very similar, it was observed that for the E5 blend, engine
power and torque were the highest, whereas for the blend E10 they
were the lowest. The maximum power for the blend E10 was some 2%
lower (significant at the 95% confidence level) in comparison to
results obtained for the E5 blend.
This paper represents a continuation of related research
previously described elsewhere.