Four-stroke diesel engines operated on plant oil methylester mixtures : performance and environmental effects
Faculty of Applied Engineering Sciences
Engineering sciences. Technology
Fresenius environmental bulletin. - Basel
Past fuel energy crises and current high crude oil prices have forced the scientists to investigate the use of renewable fuels, thus succeeding in reducing the worlds dependence on fuels derived from petroleum products. Plant oils and their derivatives have been studied for their use as renewable fuels, but their impact upon the engine performance and upon the environment has not been adequately investigated. Preliminary results are presented from testing two cars with diesel engines on a chassis dynamometer. The fuel of these diesel engines was a mixture of diesel and biodiesel from cottonseed oil and used frying oil. The engine performance with mixtures of the methylesters as fuel is compared with the engine performance of the pure diesel as a fuel. Similar comparisons are made for the exhaust products. The cars ran smoothly even at 100% biodiesel. The fuel temperature did not affect the power, except that the soot and NOx values increased slightly with the fuel temperature. There was a decrease in soot and an increase in NOx values by advancing the ignition timing from its factory value. The soot values decreased considerably by increasing the biodiesel content, while the NOx values increased by a smaller amount.