Comparative study of diesel engine performance and emission with soybean and waste oil biodiesel fuels

The study investigated the engine performance and emission using biodiesel from soybean oil and waste cooking oil. The fuel properties of these biodiesels were determined using ASTM D6751 and EN 14214 standards. The fuels were tested in a multi-cylinder diesel engine with an electromagnetic dynamometer and a 5-gas analyser was used for emission analysis. The result shows that the thermal performance of the engine slightly decreases with increase of the biodiesel blends ratio (i.e. B5, B10, B15, B20 and B50). On the other hand, emission decreases with the increase of biodiesel blends. The reduction in emissions was different for both biodiesels. Waste oil biodiesel showed better trends of emissions reduction with increase of the biodiesel percentage compared with soybean biodiesel. The brake specific fuel consumption (BSFC) of both biodiesels is (6.05%, 9.13%, 12.36% and 18.57% for soybean) and (8.17%, 11.40%, 17.71% and 14.96% for waste cooking oil) higher than diesel, respectively. However, soybean biodiesel consumed less fuel and produced more power and torque compared to waste oil biodiesel. The study concluded that B10 soybean biodiesel blend produced more consistent and expected results than waste oil biodiesel from the performance and emission point of view.