Improving the performance and emission characteristics of a diesel engine fueled by jojoba methyl ester-diesel-ethanol ternary blends

This paper describes an experimental effort for fueling a single cylinder air-cooled direct injection diesel engine with jojoba methyl ester-diesel-ethanol ternary blends to evaluate their effects on engine performance and exhaust emissions. Jojoba methyl ester-diesel-ethanol ternary blends were prepared, developed, and tested. The tests were made in three stages. Firstly optimum preparations conditions for the transesterification process of jojoba oil with methanol have been determined for the production of jojoba methyl ester (JME) with improved properties. The JME-diesel blends were evaluated and their properties were compared with fuel specifications provided by the latest biodiesel standards. Secondly, the measured performance and exhaust emissions of the diesel engine operating with the selected JME-diesel blends compared to pure diesel fuel case. B10 blend (10% JME + 90% diesel fuel) was the best one of the blends substitution of the diesel fuel under variable load operating conditions and at a constant speed of 1500 rpm. Thirdly, tests were performed for B10 blend at two loads to improve the engine performance and exhaust emissions by adopting various proportions of ethanol. With the same brake mean effective pressure for different blended fuels and pure diesel fuel, the engine performance parameters such as brake thermal efficiency, brake specific fuel consumption, and exhaust gas temperatures are measured. Exhaust emission parameters such as levels of carbon monoxide, unburnt hydrocarbon, smoke and nitrogen oxides are also evaluated. The results showed that, the ternary blend of 90B10-E10 (10% of ethanol and 90% of B10 blend) by volume showed the best engine performance and improved exhaust emissions of the diesel engine as compared with pure diesel fuel.