Investigation of performance and emissions of diesel engine run on biodiesel produced from karanja oil in a single-step transesterification process using heterogeneous catalyst (lithium-impregnated calcium oxide)

Biodiesel (karanja oil methyl ester, KOME) was produced from karanja oil using heterogeneous catalyst (lithium impregnated calcium oxide, Li-CaO) in a single-step process. A performance and emission analysis of a diesel engine was carried out by blending 10, 20, 30 and 50% KOME with diesel, as well as with pure KOME, and comparing the results with diesel fuel. Calcium oxide was produced from calcium carbonate and used to prepare Li-CaO. Reaction parameters such as molar ratio of methanol to oil, concentration of Li-CaO and reaction temperature were varied to obtain the optimized reaction condition. For the entire process, reaction time was kept constant (2 h). A 100% yield was obtained using 5 wt.% of Li-CaO with a 12:1 molar ratio of methanol to oil at 65 degrees C. The ester content of KOME was 98.37% as measured by the gas chromatography method (GCM) technique. Important properties of KOME were measured which meet the biodiesel standard. At higher loads, BD10 showed an improvement in brake thermal efficiency as compared to diesel. The emissions of CO and smoke were reduced for blended fuels while emissions of NOx were increased for almost all loading conditions, as compared with diesel. A blend of up to 20% KOME with diesel shows satisfactory engine performance.