Second Generation Coconut Biodiesel: the Best Biodiesel Alternative to Diesel as a Fuel in a Compression Ignition Engine

The numerous experimental works carried out in the past on biodiesels have not come up with any conclusion on the best biodiesel that can replace diesel. Hence, the present work focuses on understanding the technical feasibility of coconut methyl esters (CME), palm methyl esters (PME) and sunflower methyl esters (SME) derived from used oil in a diesel engine. As physiochemical properties of the fuels influence their combustion and performance characteristics, an attempt to relate the properties to the performance is made. It can be concluded that not one property influences the efficiency, but the cumulative effect of all the properties does. Apparently, thermal efficiency can be slightly improved by using SME and CME than diesel, while PME yields least thermal efficiency among all, at all the loads. Though, it shows higher specific fuel consumption, its higher thermal efficiency and lesser NOx emissions justify the technical feasibility of CME as the best biodiesel that can replace diesel among PME, SME and CME at the given injection pressure and timing.