Performance and Exhaust Emissions of a Diesel Engine Running on Jojoba Biofuel and Blends with Diesel

An experimental investigation was carried out to examine the combustion, engine performance and exhaust emissions of a direct-injection diesel engine running on biofuel derived from Jojoba raw oil and its blends with diesel fuel. The biofuel was prepared by a transesterification method using a volume ratio of 1:1 for raw Jojoba oil: Methanol to produce different grades of biodiesel fuels. Transesterification of raw jojoba oil, mixed with methanol and with a catalyst of NaOH, resulted in Jojoba Methyl Ester as the biofuel used in the present work. The physiochemical properties of biofuel were analysed including density, viscosity and distillation date. The engine used is a single cylinder diesel engine equipped for measuring all performance parameters and exhaust emissions including different exhaust gas analysis and exhaust gas opacity. The test parameters included the engine speed in the range of 1000 to 1950 rpm, the Jojoba/diesel blend ratio and varied as 0 (pure diesel), 25%, 50%, 75% and 100% (pure Jojoba biofuel). Using more Jojoba biofuel in the blend (up to 100% biofuel) increased the brake power output of the engine, decreased the brake specific fuel consumption, increased the exhaust gas temperature, increased oxides of nitrogen in the exhaust, decreased the hydrocarbons and smoke opacity was almost similar to diesel fuel case. Maximum combustion pressure has slightly increased in the cases with more Jojoba biofuel in the blend. The engine could run successfully at 100% Jojoba biofuel without any modifications.