Search Results

Biodiesel, a fuel produced by transesterification of vegetable oils or animal fats, is receiving increasing attention as an alternative fuel for diesel engines. The properties of biodiesel can vary depending on its chemical composition. Biodiesel produced from vegetable oils is higher in esters of unsaturated fatty acids and biodiesel from animal fats is higher in esters of saturated fatty acids. This paper attempts to identify the mechanism for biodiesel's emissions reduction effect and discusses the effects of blending various pure esters with No. 2 diesel fuel on engine performance and emissions. This project concludes that biodiesel's particulate reducing effect can be attributed to two factors: its displacement of aromatic and shorter chain paraffin hydrocarbons and its oxygen content. The pure ester tests showed that while all esters demonstrated reductions in hydrocarbon and particulate emissions, methyl palmitate was the most effective ester in achieving these reductions.

This work presents the analytic and experimental results relating engine performance and operating schedule with fuel cost and tail-pipe emissions for the series hybrid electric vehicle (HEV) design. Results are based on vehicle data from the electric G-van produced by Conceptor Industries. A computer simulation developed using basic principles predicts the battery demand over a specified vehicle operation profile. Engine tests on the effects of engine power level and number of starts show that while fuel consumption did not vary, carbon monoxide (CO) emissions did show an increase. The engine used was a 2-cylinder, spark ignited, 4-stroke, carbureted engine and did not utilize exhaust after-treatment. The results of the engine tests and simulation data are combined to predict the CO emissions and fuel cost for the series HEV design. The estimated CO output was 18.7 g/km, and the fuel cost was estimated between 4.3 and 4.5 cents/km.