In this study, preheated crude sunflower oil (PCSO) was tested for combustion and emission
properties against petroleum based diesel fuel (PBDF) in a naturally aspirated, indirect
injection (IDI) engine. The cylinder gas pressure and heat release curves for PCSO at 75 C
were similar to those of PBDF. The ignition delays for the PCSO were longer and the start of
injection timing was earlier than for PBDF. The difference in the average brake torque was
a decrease of 1.36% for PCSO though this was statistically insignificant. The brake specific
fuel consumption increased by almost 5% more or less in proportion to the difference in
calorific value, so that the 1.06% increase in thermal efficiency was again statistically
insignificant.
The emission test results showed that the decreases in CO2 emissions and smoke opacity
2.05% and 4.66%, respectively; however, this was not statistically significant, though in line
with the apparent increase in thermal efficiency. There was a significant 34% improvement
in the emissions of unburnt hydrocarbons. Carbon monoxide increased by 1.77% again the
result was not statistically significant given the small number of repeat tests.
The use of PCSO does not have any negative effects on the engine performance and
emissions in short duration engine testing.