Gumpon Prateepchaikul and Teerawat Apichato

pp. 317 - 326

Abstract

Due to unstable oil price situation in the world market, many countries have been looking for alternative energy sources to substitute for petroleum. Vegetable oil is one of the alternatives which can be used as
fuel in automotive engines either in the form of straight vegetable oil, or in the form of ethyl or methyl ester.
This paper presents a comparative performance testing of diesel engine using diesel oil and refined palm oil
over 2,000 hours of continuous running time. Short-term performance testing was conducted for each fuel on
the dynamometer engine test bed. Specific fuel consumption, exhaust temperature and black smoke density
were determined and measured. Long-term performance testing (or endurance test) was also done by running the engines coupled with a generator in order to supply load (electricity) to a lightbulb board. For each
500 hours of engine run time, the engines were dissembled for engine wear inspection. It was found that the
fuel pump and fuel valve weight losses from both engines showed insignificant differences either at the first
500 hours of running time or at the second 500 hours of running time but the inlet valve from the engine
fueled by diesel oil had a higher weight loss than the engine fueled by refined palm oil at the first 500 hours
and at the second 500 hours of running time. The compression rings from the engine fueled by refined
palm oil showed a significant weight loss compared to the engine fueled by diesel oil both after 500 hours
and after 1000 hours of running time.