ATTAINING SIMULTANEOUS REDUCTION IN NOX AND SMOKE BY USING WATER-IN-BIODIESEL EMULSION FUELS FOR DIESEL ENGINE

This paper presents the study of water-in-biodiesel emulsions (WiBE) stabilized by surfactants with different hydrophiliclipophilic balance (HLB) on a single-cylinder diesel engine. The engine performance and exhaust emissions were compared against the base fuel biodiesel (B5 diesel) which contained 5% palm oil methyl ester (POME) in the diesel fuel, at a constant engine speed of 2000 rpm with different engine loads. 36 emulsion blends of B5 diesel mixed with 9%, 12% and 15% volume of water, HLB values of 6, 7, 8 and 9, and surfactant dosage of 5%, 10% or 15% by percentage volume of water added. The results exhibited 11.7% lower engine power with WiBE as compared to B5 diesel. It was also observed that WiBE produced higher in-cylinder pressure and heat release rate. WiBE with higher water content at high load condition produced up to 15.2% higher peak pressure with a significant reduction in both NOx and smoke opacity, while a moderate decrease in the exhaust temperature was recorded for WiBE. The research work proved that WiBE with 15% water content with optimum HLB value is capable of reducing up to 79% NOx and 23% smoke opacity simultaneously, due to the heat sink effect during combustion

Solar Energy Resource Assessment of the Geba Catchment, Northern Ethiopia

AbstractThe global shift towards renewable energy is manifested in developing countries such as Ethiopia primarily because of continuous economic growth in the last two decades and secondly due to the vast untapped potential resources. In addition to other factors, the lack of accurate data of the resources has, however, hampered the development of solar energy technologies. The aim of this paper is to investigate the resource estimation by undertaking direct measurements at selected sites in the Northern part of Ethiopia.This paper presents an assessment of the solar energy resource based on the primary data collected between January 2011 and December 2012. The daily and monthly average global solar radiation is analyzed based on the 10minute interval measurement retrieved from the data loggers.From the analysis it is seen that the measured values give a better accuracy and distribution of the global solar radiation than earlier Fig.s that were based on satellite images and model calculations. Furthermore, these results can be used to determine the solar resource potential of Northern Ethiopia for further energy development