Pressure Effect in Droplet Combustion of Blended Fuel on Ethanol and Kemiri Sunan (Reutealis Trisperma (Blanco) Airy Shaw) Biodiesel

Bio oil from seeds of Kemiri Sunan (reutealis trisperma (Blanco) airy shaw) plant is particularly attractive to be studied since its high potential as alternative of biodiesel. This paper describes the results of a fundamental study of the combustion characteristics of a single droplet of blended fuel of Kemiri Sunan (reutealis trisperma (Blanco) airy shaw) biodiesel and ethanol in various levels of ambient pressure. The ambient pressures of the burning chamber were varied at 1, 3, and 5 bars. The fuels were prepared by mixing the biodiesel with the ethanol at concentrations of 0%, 10%, 20%, and 30% vol/vol. The single droplets of blended fuels were suspended using micro-syringe on a tip of the thermocouple. It was ignited and combusted using an electrical heater. The ignition and combustion processes of the single droplets were recorded using a high-speed camera. It was found that the ignition delay of the droplet decrease with the increase of ambient pressure and the concentration of ethanol in blended fuels. Also, the burning rate of blended droplets increased with increasing biodiesel concentration and pressure. The maximum droplet temperature slightly increased during the combustion with the increasing ethanol concentration, but not with increasing ambient pressure. (paper)