Comparative studies on fly ash coated low heat rejection diesel engine on performance and emission characteristics fueled by rice bran and pongamia methyl ester and their blend with diesel

In this study, for the first time, fly ash was used as a thermal barrier coating material in a diesel engine. The study consists of three phases. In first phase, biodiesel was prepared in a laboratory scale setup by single step base catalyzed transesterification method. In the second phase, engine combustion chamber elements such as cylinder head, cylinder liner, valves and piston crown face were coated with fly ash, which is a thermal power plant waste, to a thickness of 200 μm by using plasma spray coating method. In third phase, experiments were carried out on fly ash coated single cylinder diesel engine fueled by methyl ester of rice bran, pongamia oil and its blend (20% by volume) with diesel. The test run was repeated on uncoated engine under the same running conditions and the results were compared. An increase in engine power and decrease in specific fuel consumption, as well as significant improvements in exhaust gas emissions (except NOx) were observed for all test fuels used in the fly ash coated engine compared with that of the uncoated engine.

► Methyl ester of pongamia and rice bran oil was prepared by single step base catalyzed transesterification method.
► The yield of prepared biodiesel of pongamia and rice bran oil was 92% and 94% respectively.
► Cylinder head, liner, valves and piston crown face were coated with fly ash using plasma spray coating method.
► Fly ash coating may be applied successfully without requiring any significant modifications of the internal combustion engine.
► Diesel, neat biodiesel, and their blends may be used successfully as an alternative fuels in fly ash coated engine.