Comparative Assessment of Performance, Emission and Combustion Characteristics of Blends of Methyl and Ethyl Ester of Jatropha Oil and Diesel in Compression Ignition Engine 2013-01-2664

India possesses only 0.3% of world petroleum reserves and hence heavily dependent upon petroleum derived fuels to feed its rapidly growing economy. Diesel Engines due to their superior performance have wide application in India, however, they also pollute environment significantly. Research is underway in India and elsewhere to explore the potential of variety of alternative fuels which could substitute diesel in a holistic manner. And in this context, non-edible vegetable oils are very promising as India has a large area of degraded land where such crops could be raised without compromising food security. Large number of studies have suggested that vegetable oils are not suitable in neat form as a fuel in diesel engine and should be trans-esterified using either methanol or ethanol to form esters to bring their properties similar to diesel fuel. Jatropha curcas is a very promising plant for developing country like India and non-edible oil extracted from Jatropha seed has the potential to lease a new life to millions of diesel engines. Methanolysis of Jatropha oil has been studied to a great extent; however, transesterification of Jatropha oil using ethanol has not been adequately investigated.

In the present study, Jatropha oil methyl and ethyl ester (JOME & JOEE) were prepared through transestrification and evaluation of important physico-chemical properties was carried and the properties were found within acceptable limits. A compression ignition engine was fuelled with four blends of JOME & JOEE with diesel (5, 10, 15, 20% v/v) and various performance, emission and combustion characteristics were evaluated and results compared with baseline data of diesel.

The results suggest that BTE was higher for both JOME and JOEE blends and CO, HC and smoke opacity were lower as compared to diesel fuel. This may be attributed to improved combustion as both JOME and JOEE are oxygenated fuels and have higher cetane number. NO_x was found to be increasing for both JOME and JOEE. The combustion characteristics revel that in cylinder pressure for JOME and JOEE blends are lower as compared to diesel fuel and heat release analysis suggest smaller ignition delay for JOME and JOEE diesel blends in comparison to diesel fuel.