The world is facing severe energy crisis attributed to global oil reserve depletion, increasingrnconsumption rate, incessant oil price hike and above all environmental concerns (air pollution andrnemission of Greenhouse Gases) dictate that the world community must hunt for alternative andrnsustainable energy sources. One of the mitigation efforts considered in response to the crisis isrnfinding substitute for petroleum oil. Biofuels are becoming the most reliable energy sources, amongrnwhich, biodiesel attracted attention to substitute for the ever-increasing petrodiesel demand andrnconsumptions for every activity of human beings. This research project assessed the potential ofrnbiodiesel production from oil seeds in Ethiopia and the qualities were compared to identify the mostrnsuitable species. Samples of oil seeds were collected from different locations. Suitable areas wererndelineated using ArcGIS software and the spatial analyst tool. Soxhlet extraction method was usedrnto extract oils from each species, using solvent, hexane. The biodiesel was synthesized byrntransesterification process and characterized by determining density, kinematic viscosity, iodinernvalue, saponification number, peroxide value, cetan number, heating value, cloud point, flashrnpoint, acid number and distillation test. GC analysis was conducted to determine the fatty acidrncompositions. The oil content results from the five collections of R. communis ranged from 36.45 torn45.76 %w. B. carinata rendered oil content of 47.62 %w and J. curcas, investigated at threerndifferent conditions resulted oil contents ranging from 29.55 to 41.04 %w. The gross heat contentsrnof the biodiesels from B. carinata, J. curcas, R. communis and E. guineensis were found to be 39.31,rn38.71, 36.86 and 38.95 MJ/kg respectively. J.curcas conforms with all the standard specificationsrnof ASTM D 6751 and EN 14214, except for its flash point result of 120rnC i.e., less than the ENrn14214 specification. R. communis fails to meet both the standards having density (0.9269 g/mL),rnkinematic viscosity (10.94 mmrn/s) and flashpoint (95 Ã‚Â°c) and that of EN standard due to its acidrnNo. (0.566 mgKOH/g). B. carinata meets both standards, except in acid number result of 0.885rnfile:///C|/Users/3020/Desktop/enviromental%20science/Thesis%20Mesfin%20Kinfu%202008.pdf.txt[6/1/2018 8:53:46 AM]rnmgKOH/g, which exceeded both limitations, and kinematec viscosity result of 5.09 mmrnexceeding the range set by EN 14214. E. guineensis fails to meet both the standards in densityrn(0.9121 g/mL), kinematic viscosity (13.91 mmrn2rn/s) and acid number (1.802 mgKOH/g). It can bernconcluded that, amongst the oil plants investigated, J. curcas surpassed in every aspect, thatrnrendered it the most suitable and potential candidate as a substitute for diesel, seconding B.rncarinata, while R. communis and E. guineensis can be used up to 20% blends with the other two.rnMoreover, the physicochemical characteristics were improved by blending the biodiesels fromrndifferent oils, and promisingly agreed with the standard specifications.rnKey words: Transesterification, Biodiesel, alternative feedstock, area suitability, physicochemical properties,rnblends.