Author(s)

S. W. K. Cheng & D. Y. C. Leung

Abstract

Dynamometer testing of in-service vehicles using biodiesel and ultra low sulphur diesel S. W. K. Cheng & D. Y.C. Leung Department of Mechanical Engineering, The University of Hong Kong, Hong Kong Abstract A study was conducted to compare the performance of diesel-powered vehicles using biodiesel with ultra low sulphur diesel fuel. The study aimed to provide more information about the tailpipe emissions and engine Performance of in- service vehicles using biodiesel with different percentages. Three types of biodiesel fuels were tested with blending ratios of 0, 20 and 100% biodiesel/ULSD fuel. The whole study comprised of two parts, namely, a chassis dynamometer exhaust emission test and a diesel lug down test (adopted by the Environmental Protection Department of the Hong Kong Special Administrative Region Government) for each of the vehicle tested. Totally ten vehicles were tested in this study, covering a wide range of makes, types and models. This paper describes the results of the dynamometer testing focusing on the road power and concentration of the exhaust emissions. The result revealed that whilst there was a slight drop in the maximum road power, a significant reduction in smoke emission was found with the use of biodiesel, even for the 20% blend. Since engine exhaust emissions greatly depend on engine conditions and settings, the effectiveness of biodiesel on reduction of gaseous pollutant varies for different type of vehicles. In average biodiesel blends could reduce the carbon monoxide and unburned hydrocarbon but with small increase in the oxides of nitrogen. The effect of biodiesel on the performance and emissions of

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